Fix the six tests the merge gate refused: assignments beside pulled-in modules, migration tests on the tables, the event compared as JSON, the restarted move settled to the table (issues 1090, 1092, 1093, 1095)

Review round 2. The writer's leave to write is the lease's and AssignmentsMirrorMayWrite, a flag set before the settle of the assignments' switch, kept after the commit and cleared only if the switch fails, so a pass that read its source before the switch lays and purges nothing after it.

.gitignore

@@ -3,3 +3,8 @@
 # A built binary. The lab writes one here when pointed at the repository root by mistake;
 # built artifacts belong in build/, which is already ignored.
 /mesh-builder
+/mesh-controller
+/postgres-provisioner
+/redis-provisioner
+# And where `go build` in cmd/mesh-controller leaves it (novox/hq issue 233).
+/cmd/mesh-controller/mesh-controller

Dockerfile

@@ -1,4 +1,11 @@
-# The control plane's image.
+# The Go it builds with, pinned here because genesis builds this file with no arguments (novox/hq
+# issue 223) — the Makefile passes the same digest. A tag older than go.mod asks for is how
+# `make image` broke once before (issue 146).
+ARG GO_BASE=golang@sha256:8ac98ca534ac3f51e1f420a1dd2c15e74c75cfa0f23f3ad27eb5d7236c349a0c
+# The control plane's image — for genesis and the lab only. The mesh runs the controller as a Go
+# bundle the host starts as a process (module.json; novox/hq issue 213), and builds no image of it.
+# Genesis builds this file and raises it as the container the process replaces on the first push
+# (mesh-host internal/bootstrap, novox/hq issue 223).
 #
 # novox/hq ADR 0006: this image is pinned by digest in the bundle the host carries, fetched on a
 # machine where no mesh exists yet, and run before there is anything to check it against. So it
@@ -11,16 +18,20 @@
 # (novox/hq ADR 0004). Adding them "just in case" would put a trust store in the one image whose
 # whole argument is that it contains nothing to reason about.
 
-FROM golang:1.25-alpine AS build
+FROM ${GO_BASE} AS build
 WORKDIR /src
 
-# Dependencies first, so a change to the source does not refetch them.
+# **Nothing is fetched** (novox/hq to-be 45 Phase 1): every dependency is in vendor/, committed, so
+# the image builds from this repository alone — the host's validator among them, whose module no
+# public proxy is asked for. Dependencies first, so a change to the source does not re-copy them.
 COPY go.mod go.sum ./
-RUN go mod download
+COPY vendor/ vendor/
 
+# `COPY . .` brings `.git` along, so Go is told not to stamp the commit: the version is said by -X, and a
+# rebuild of an unchanged program is the same bytes (novox/hq ADR 0267 rule 6, issue 363).
 COPY . .
 ARG VERSION=development
-RUN CGO_ENABLED=0 go build -trimpath \
+RUN CGO_ENABLED=0 GOFLAGS=-mod=vendor GOPROXY=off go build -trimpath -buildvcs=false \
         -ldflags "-s -w -X main.version=${VERSION}" \
         -o /mesh-controller ./cmd/mesh-controller
 

Makefile

@@ -27,8 +27,22 @@ build:
 IMAGE ?= mesh-controller:$(VERSION)
 DEV_TAG ?= mesh-controller:development
 
+# The Go base the image is built on.
+#
+# **`make image` was broken and stayed broken**, because the Dockerfile's fallback base was a Go
+# older than go.mod asks for: every build died at `go mod download` with "go.mod requires go >=
+# 1.26.0", and the pipeline never saw it because the pipeline passes the declared base in. Anybody
+# building the image by hand hit it and had to find the digest themselves (novox/hq 04-ISSUES/146,
+# what it cost).
+#
+# **Pinned here since the manifest stopped building an image** (novox/hq issue 213): the mesh builds
+# the controller as a Go bundle with its own toolchain, and only `make image` — genesis and the lab —
+# still needs a Go base. The digest is the one the manifest declared until then.
+GO_BASE ?= golang@sha256:8ac98ca534ac3f51e1f420a1dd2c15e74c75cfa0f23f3ad27eb5d7236c349a0c
+
 image:
-	docker build --build-arg VERSION=$(VERSION) -t $(IMAGE) -t $(DEV_TAG) .
+	@test -n "$(GO_BASE)" || { echo "no GO_BASE; pass GO_BASE=<image>"; exit 1; }
+	docker build --build-arg GO_BASE=$(GO_BASE) --build-arg VERSION=$(VERSION) -t $(IMAGE) -t $(DEV_TAG) .
 	@echo
 	@docker image inspect $(IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
 
@@ -38,7 +52,8 @@ BUILDER_IMAGE ?= mesh-builder:$(VERSION)
 BUILDER_DEV_TAG ?= mesh-builder:development
 
 builder-image:
-	docker build -f cmd/mesh-builder/Dockerfile -t $(BUILDER_IMAGE) -t $(BUILDER_DEV_TAG) .
+	@test -n "$(GO_BASE)" || { echo "no GO_BASE; pass GO_BASE=<image>"; exit 1; }
+	docker build --build-arg GO_BASE=$(GO_BASE) -f cmd/mesh-builder/Dockerfile -t $(BUILDER_IMAGE) -t $(BUILDER_DEV_TAG) .
 	@echo
 	@docker image inspect $(BUILDER_IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
 
@@ -48,7 +63,7 @@ PROVISIONER_IMAGE ?= mesh-provision-postgres:$(VERSION)
 PROVISIONER_DEV_TAG ?= mesh-provision-postgres:development
 
 provisioner-image:
-	docker build -f examples/postgres-provisioner/Dockerfile \
+	docker build --build-arg GO_BASE=$(GO_BASE) -f examples/postgres-provisioner/Dockerfile \
 		-t $(PROVISIONER_IMAGE) -t $(PROVISIONER_DEV_TAG) .
 	@echo
 	@docker image inspect $(PROVISIONER_IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
@@ -59,7 +74,7 @@ OBJECTSTORE_IMAGE ?= mesh-provision-objectstore:$(VERSION)
 OBJECTSTORE_DEV_TAG ?= mesh-provision-objectstore:development
 
 objectstore-image:
-	docker build -f examples/objectstore-provisioner/Dockerfile \
+	docker build --build-arg GO_BASE=$(GO_BASE) -f examples/objectstore-provisioner/Dockerfile \
 		-t $(OBJECTSTORE_IMAGE) -t $(OBJECTSTORE_DEV_TAG) .
 	@echo
 	@docker image inspect $(OBJECTSTORE_IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
@@ -70,7 +85,7 @@ REDIS_PROVISIONER_IMAGE ?= mesh-provision-redis:$(VERSION)
 REDIS_PROVISIONER_DEV_TAG ?= mesh-provision-redis:development
 
 redis-provisioner-image:
-	docker build -f examples/redis-provisioner/Dockerfile \
+	docker build --build-arg GO_BASE=$(GO_BASE) -f examples/redis-provisioner/Dockerfile \
 		-t $(REDIS_PROVISIONER_IMAGE) -t $(REDIS_PROVISIONER_DEV_TAG) .
 	@echo
 	@docker image inspect $(REDIS_PROVISIONER_IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
@@ -80,25 +95,43 @@ PROXY_IMAGE ?= mesh-route-proxy:$(VERSION)
 PROXY_DEV_TAG ?= mesh-route-proxy:development
 
 proxy-image:
-	docker build -f examples/route-proxy/Dockerfile -t $(PROXY_IMAGE) -t $(PROXY_DEV_TAG) .
+	docker build --build-arg GO_BASE=$(GO_BASE) -f modules/route-proxy/Dockerfile -t $(PROXY_IMAGE) -t $(PROXY_DEV_TAG) .
 	@echo
 	@docker image inspect $(PROXY_IMAGE) --format 'built {{.RepoTags}}  {{.Size}} bytes'
 
-# The whole gate. Raises a database, runs everything against it, and takes it down again --
-# including when the tests fail, which is why the teardown is not conditional.
-check: fmt vet postgres
-	@go test ./... ; status=$$? ; $(MAKE) postgres-stop ; exit $$status
+# The whole check. Raises a database, runs the repository's own check against it -- merge-check.sh,
+# the very script `mesh/repo-check` runs -- and takes the database down again, including when the
+# check fails, which is why the teardown is not conditional and the script's exit status is the
+# target's.
+#
+# **It calls the script rather than restating it** (novox/hq issue 431): this target used to list its
+# own steps, its formatting step walked vendor/ where the script's does not, and it failed on
+# third-party code no change could fix -- so a developer's check and the gate disagreed, and the steps
+# after formatting never ran through it. The script is the one list of steps; this target only gives it
+# a database (MESH_TEST_POSTGRES, exported above).
+#
+# **Two levels** (issue 895): the unit level, `go test ./...` untagged, timed and held to a bound; and the integration
+# level, `-tags integration`, the tests that start a bus, a store or another process. Each is said with its time.
+#
+# **Packages in parallel, under the race detector, each test on a bus of its own** (internal/testbus),
+# as the script runs them: a bus per test, of the release the mesh runs, makes the suite the same in any
+# order, and the timeout bounds a hang to a failure with a stack, never a stalled gate.
+check: postgres
+	@sh merge-check.sh ; status=$$? ; docker rm -f $(PG_CONTAINER) >/dev/null 2>&1 || true ; exit $$status
 
-# Without a database the live tests skip rather than fail, so this is the honest subset and not
-# the gate.
+# The unit level alone (untagged: no bus, no store, no other process), which a developer runs continuously. The tests
+# that need a bus or the store carry `//go:build integration` and run in `check`, not here; without a database the
+# store's tests would skip rather than fail anyway.
 test:
-	go test ./...
+	go test -timeout 15m ./...
 
 vet:
 	go vet ./...
 
+# Quick steps for a developer, not part of `check`. The directories gofmt reads must be the ones
+# merge-check.sh lists, never `.`, which walks vendor/ (novox/hq issue 431).
 fmt:
-	@unformatted=$$(gofmt -l . 2>/dev/null) ; \
+	@unformatted=$$(gofmt -l cmd internal examples) ; \
 	if [ -n "$$unformatted" ] ; then echo "not gofmt'd:" ; echo "$$unformatted" ; exit 1 ; fi
 
 postgres:

README.md

@@ -193,6 +193,13 @@ passes every check that only looks at the message.
 
 ## The image
 
+**The mesh no longer runs the controller from it** (novox/hq issue 213). The module declares a Go
+bundle, `controller`, which the host on the controller's machine unpacks and runs as the process
+`mesh-controller` under the account of the same name (ADR 0188 §1, §3). The image stays for what
+still runs a container of the controller: genesis, which raises the first controller from it and
+installs the module from its manifest (mesh-host `internal/bootstrap`), and the lab. Neither is the
+mesh's own build any more — `make image` builds it.
+
 `FROM scratch`, holding one statically linked binary and nothing else — no shell, no package
 manager, no libc, no CA certificates.
 

RELEASE-57.md

@@ -0,0 +1,6 @@
+# Release 57: config and provisioning
+
+This branch carries the work of hq design 57 (ADR 0348, ADR 0349) in this repository. Each package
+merges here through its own reviewed pull request; the branch reaches main as one pull request, in one
+delivery group with the branch of the same name in mesh-controller, mesh-host, mesh-sdk, mesh-catalog
+and hq, after a rehearsal in the lab. This file is deleted by the last commit before that pull request.

check-nested-modules.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+# The unit tests of every Go module of its own below this repository's root, run from the root, for merge-check.sh
+# and for the test that tries it on a tree (merge_check_nested_test.go). Its own file so that the test needs no
+# particular merge-check.sh: the check that judges a change to merge-check.sh is main's.
+set -eu
+cgo="${cgo:-0}"
+race="${race:-}"
+
+# nested_modules vets and tests every Go module of its own below the root, `modules/<name>/go.mod` (novox/hq ADR 0420
+# §5, issue 1025): `./...` stops at a nested go.mod, so a module that lives whole in this repository would have its
+# unit tests run by nobody. None is a pass. Each runs in its own directory, outside the vendor directory this
+# repository's own packages are built from; a nested module vendors what the forge holds (its own `vendor/`, so the
+# check runs offline), as this repository's root module does (issue 1019). A failing module fails the check; the others are still run.
+nested_modules() {
+	nested=0
+	for gomod in modules/*/go.mod; do
+		[ -e "$gomod" ] || continue
+		dir=$(dirname "$gomod")
+		echo "nested module $dir:"
+		if ! (cd "$dir" && GOFLAGS= CGO_ENABLED=0 go vet ./... &&
+			GOFLAGS= CGO_ENABLED="${cgo:-0}" go test ${race:-} -count=1 -timeout 30m ./...); then
+			echo "nested module $dir FAILED"
+			nested=1
+		fi
+	done
+	return $nested
+}
+
+nested_modules

cmd/mesh-builder/Dockerfile

@@ -1,17 +1,19 @@
+ARG ALPINE_BASE=alpine:3
+ARG GO_BASE=golang:1.25-alpine
 # The builder, as a module ships one.
 #
 # Not FROM scratch, unlike the control plane: this one runs git and a container client, so it
 # needs a filesystem with them on it. That is the honest cost of a machine whose job is to build —
 # and it is why building is a MODULE on a machine that has a runtime rather than something the
 # control plane does (novox/hq ADR 0005).
-FROM golang:1.25-alpine AS build
+FROM ${GO_BASE} AS build
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN CGO_ENABLED=0 go build -trimpath -ldflags '-s -w' -o /mesh-builder ./cmd/mesh-builder
+RUN CGO_ENABLED=0 go build -trimpath -buildvcs=false -ldflags '-s -w' -o /mesh-builder ./cmd/mesh-builder
 
-FROM alpine:3
+FROM ${ALPINE_BASE}
 # git to clone what it is asked to build, and the docker client to build and push it. The daemon
 # is the machine's, reached through its socket — a build machine shares the runtime it was given
 # rather than running one inside itself.

cmd/mesh-builder/busy.go

@@ -0,0 +1,146 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+// **The build agent says whether it is busy, and being asked drains it** (novox/hq ADR 0335 §1, §5). Its
+// container declares `busy` as `mesh-builder busy`: the node-engine runs it inside the container before it
+// replaces it. It exits 0 while a build is in hand and 1 when none is; and from the first ask the agent takes
+// no new build request, so its answer ends once the build in hand ends — a replaced builder finishes the check
+// it runs, instead of the build queue handing it out again from the start (issue 594).
+//
+// Two marks in the container's own temporary directory, as the ready mark (ready.go): a new container starts
+// without them, and a restarted one removes them before it takes work again.
+//
+//   - in hand: written by the agent when it claims a request, before it reads whether it is drained; removed
+//     when the build ends.
+//   - drained: written by the ask, before it reads whether a build is in hand.
+//
+// Each side writes its own mark before it reads the other's, so an ask racing a fetch sees the build in hand,
+// or the agent sees the drain and hands the request back; never neither.
+
+func inHandMark() string { return filepath.Join(os.TempDir(), "mesh-builder.in-hand") }
+func drainMark() string  { return filepath.Join(os.TempDir(), "mesh-builder.drained") }
+
+// The drain lapses when no ask has come for drainLapse: the node-engine asks every 20 seconds for as long as it
+// really waits, so an agent whose replacement was withdrawn — the declaration put back, the walk stopped —
+// takes work again rather than staying drained for ever (review of ADR 0335). And an agent drained for longer
+// than the node-engine's bound and the slack says it is not ready: the replacement it was drained for never
+// came, which is a fault to see.
+const (
+	drainLapse   = 2 * time.Minute
+	drainTooLong = 15*time.Minute + 5*time.Minute
+)
+
+// drainedAt is when the drain began and when it was last asked, from its mark; false when there is no mark.
+func drainedAt() (began, asked time.Time, ok bool) {
+	info, err := os.Stat(drainMark())
+	if err != nil {
+		return time.Time{}, time.Time{}, false
+	}
+	asked = info.ModTime()
+	began = asked
+	if raw, err := os.ReadFile(drainMark()); err == nil {
+		if t, err := time.Parse(time.RFC3339, strings.TrimSpace(string(raw))); err == nil && !t.After(asked) {
+			began = t
+		}
+	}
+	return began, asked, true
+}
+
+// drained says the agent was asked whether it is busy within drainLapse: it takes no new build request.
+func drained() bool { return drainedSince(time.Now()) }
+
+func drainedSince(now time.Time) bool {
+	_, asked, ok := drainedAt()
+	return ok && now.Sub(asked) < drainLapse
+}
+
+// drainedTooLong is the health check's second half: nil unless the agent has been drained, asked all along, for
+// longer than its node-engine's bound and the slack.
+func drainedTooLong(now time.Time) error {
+	began, asked, ok := drainedAt()
+	if !ok || now.Sub(asked) >= drainLapse || now.Sub(began) <= drainTooLong {
+		return nil
+	}
+	return fmt.Errorf("drained since %s and still asked: the replacement its node-engine waits for has not come "+
+		"within %s (novox/hq ADR 0335)", began.UTC().Format(time.RFC3339), drainTooLong)
+}
+
+// claim marks a request in hand, unless the agent is drained: then nothing is in hand, and the request goes
+// back to the queue.
+func claim() bool {
+	// Made, never written over: one build at a time, and a mark already there is a build in hand.
+	f, err := os.OpenFile(inHandMark(), os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o644)
+	if err != nil {
+		// Unmarked, an ask would say idle while this build runs: the build is not taken.
+		fmt.Fprintf(os.Stderr, "cannot mark a build in hand (%s), so it is handed back: %v\n", inHandMark(), err)
+		return false
+	}
+	_, err = f.WriteString(time.Now().UTC().Format(time.RFC3339) + "\n")
+	if closeErr := f.Close(); err == nil {
+		err = closeErr
+	}
+	if err != nil {
+		_ = os.Remove(inHandMark())
+		fmt.Fprintf(os.Stderr, "cannot mark a build in hand (%s), so it is handed back: %v\n", inHandMark(), err)
+		return false
+	}
+	if drained() {
+		_ = os.Remove(inHandMark())
+		fmt.Fprintln(os.Stderr, "asked whether busy, so this agent takes no new build: handed back")
+		return false
+	}
+	return true
+}
+
+// holding says what is in hand, for the ask to print: written once the request is read.
+func holding(what string) {
+	_ = os.WriteFile(inHandMark(), []byte(time.Now().UTC().Format(time.RFC3339)+" "+what+"\n"), 0o644)
+}
+
+// released ends the build in hand.
+func released() {
+	if err := os.Remove(inHandMark()); err != nil && !errors.Is(err, os.ErrNotExist) {
+		fmt.Fprintf(os.Stderr, "cannot remove the mark of the build in hand (%s): %v\n", inHandMark(), err)
+	}
+}
+
+// undrained clears both marks at the start of a holder: a container started again is asked afresh.
+func undrained() error {
+	for _, mark := range []string{drainMark(), inHandMark()} {
+		if err := os.Remove(mark); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return fmt.Errorf("cannot remove %s: %w", mark, err)
+		}
+	}
+	return nil
+}
+
+// busy is the ask: it drains the agent, then says whether a build is in hand. Nil — exit 0 — while one is.
+func busy() (string, error) {
+	// The mark keeps when the drain began while it is asked within drainLapse, and is written again on every
+	// ask: its time is the last ask.
+	began := time.Now().UTC()
+	if was, _, ok := drainedAt(); ok && drained() {
+		began = was.UTC()
+	}
+	if err := os.WriteFile(drainMark(), []byte(began.Format(time.RFC3339)+"\n"), 0o644); err != nil {
+		// Not drained, it could take the next build: said, and answered busy only for what is in hand now.
+		fmt.Fprintf(os.Stderr, "cannot mark this agent drained (%s): %v\n", drainMark(), err)
+	}
+	held, err := os.ReadFile(inHandMark())
+	if err != nil {
+		return "", errors.New("idle: no build in hand, and this agent takes no new one")
+	}
+	since, what, _ := strings.Cut(strings.TrimSpace(string(held)), " ")
+	if what == "" {
+		what = "a build"
+	}
+	return fmt.Sprintf("busy: %s, in hand since %s; taking no new build", what, since), nil
+}

cmd/mesh-builder/busy_test.go

@@ -0,0 +1,162 @@
+package main
+
+import (
+	"os"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+// `mesh-builder busy` answers 0 while a build is in hand and non-zero when idle, and after its first ask the
+// agent takes no new build request (novox/hq ADR 0335 §5).
+func TestBusyAnswersWhileABuildIsInHandAndDrainsTheAgent(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	if err := undrained(); err != nil {
+		t.Fatal(err)
+	}
+	if drained() {
+		t.Fatal("an agent never asked is drained")
+	}
+	// A build is claimed and runs.
+	if !claim() {
+		t.Fatal("an agent never asked refused a build")
+	}
+	holding("novox/mesh-controller (check-280)")
+	said, err := busy()
+	if err != nil || !strings.Contains(said, "novox/mesh-controller (check-280)") {
+		t.Fatalf("an agent with a build in hand did not answer busy with what it holds: %q %v", said, err)
+	}
+	// From that ask on it takes nothing new: the fetch is not made, and one fetched is handed back.
+	if !drained() {
+		t.Fatal("the ask did not drain the agent")
+	}
+	if claim() {
+		t.Fatal("a drained agent took a new build")
+	}
+	// The build in hand is still in hand after the refused claim, and busy goes on saying so.
+	if _, err := busy(); err != nil {
+		t.Fatalf("a refused claim ended the build in hand: %v", err)
+	}
+	// It ends: idle, and still drained.
+	released()
+	if _, err := busy(); err == nil {
+		t.Fatal("an agent with nothing in hand answered busy")
+	}
+	if claim() {
+		t.Fatal("a drained agent took a build after its last one ended")
+	}
+	// Started again, it is asked afresh.
+	if err := undrained(); err != nil {
+		t.Fatal(err)
+	}
+	if drained() || !claim() {
+		t.Fatal("a holder started again is still drained")
+	}
+	released()
+}
+
+// An ask racing a fetch sees the build in hand, or the agent sees the drain and hands the request back: never
+// neither, which would replace the container under a build just taken.
+func TestAnAskRacingAFetchNeverMissesTheBuild(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	for i := 0; i < 200; i++ {
+		if err := undrained(); err != nil {
+			t.Fatal(err)
+		}
+		var claimed bool
+		var askErr error
+		var wg sync.WaitGroup
+		wg.Add(2)
+		go func() { defer wg.Done(); claimed = claim() }()
+		go func() { defer wg.Done(); _, askErr = busy() }()
+		wg.Wait()
+		if claimed && askErr != nil {
+			t.Fatalf("round %d: the agent took a build and the ask said idle", i)
+		}
+		released()
+	}
+}
+
+// A drain no longer asked lapses: an agent whose replacement was withdrawn after the first ask (a put-back, a
+// revert, a stopped walk) takes work again after drainLapse, rather than staying drained with its health green.
+func TestADrainNoLongerAskedLapses(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	if err := undrained(); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := busy(); err == nil {
+		t.Fatal("an idle agent answered busy")
+	}
+	if !drained() || claim() {
+		t.Fatal("an agent just asked takes work")
+	}
+	// The last ask was three minutes ago.
+	old := time.Now().Add(-3 * time.Minute)
+	if err := os.Chtimes(drainMark(), old, old); err != nil {
+		t.Fatal(err)
+	}
+	if drained() {
+		t.Fatal("a drain no longer asked for three minutes still holds")
+	}
+	if !claim() {
+		t.Fatal("an agent whose drain lapsed takes no work")
+	}
+	released()
+}
+
+// An agent drained, and asked all along, for longer than its node-engine's bound and the slack is not ready: the
+// replacement it was drained for never came. One asked again after a lapse starts a new drain.
+func TestAnAgentDrainedTooLongIsNotReady(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	if err := undrained(); err != nil {
+		t.Fatal(err)
+	}
+	taking("mesh-build-machine")
+	if _, err := busy(); err == nil {
+		t.Fatal("an idle agent answered busy")
+	}
+	now := time.Now()
+	if err := drainedTooLong(now); err != nil {
+		t.Fatalf("an agent drained a moment ago is not ready: %v", err)
+	}
+	// The drain began 25 minutes ago, and the node-engine asked a moment ago.
+	began := now.Add(-25 * time.Minute).UTC().Format(time.RFC3339)
+	if err := os.WriteFile(drainMark(), []byte(began+"\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	err := drainedTooLong(time.Now())
+	if err == nil || !strings.Contains(err.Error(), "has not come") {
+		t.Fatalf("an agent drained for 25 minutes reads ready: %v", err)
+	}
+	// Each ask keeps when the drain began.
+	if _, err := busy(); err == nil {
+		t.Fatal("an idle agent answered busy")
+	}
+	if err := drainedTooLong(time.Now()); err == nil {
+		t.Fatal("an ask started the drain again")
+	}
+	// The asks stopped: the drain lapsed, and so did the fault.
+	old := time.Now().Add(-3 * time.Minute)
+	if err := os.Chtimes(drainMark(), old, old); err != nil {
+		t.Fatal(err)
+	}
+	if err := drainedTooLong(time.Now()); err != nil {
+		t.Fatalf("a lapsed drain still reads not ready: %v", err)
+	}
+}
+
+// An ask this build does not know exits non-zero: an older image asked `busy` reads idle, not busy for the
+// node-engine's whole bound.
+func TestAnUnknownCommandFails(t *testing.T) {
+	was := os.Args
+	t.Cleanup(func() { os.Args = was })
+	os.Args = []string{"mesh-builder", "some-later-word"}
+	if err := run(); err == nil {
+		t.Fatal("an unknown command exited 0")
+	}
+	os.Args = []string{"mesh-builder", "help"}
+	if err := run(); err != nil {
+		t.Fatalf("help failed: %v", err)
+	}
+}

cmd/mesh-builder/check_spec_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/builder"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The build seat hands the check the judge cache the build agent declares (MESH_JUDGE_CACHE), never a path of its own.
+func TestTheBuildSeatHandsTheCheckTheJudgeCacheItDeclares(t *testing.T) {
+	t.Setenv("MESH_JUDGE_CACHE", "/var/lib/mesh/build-agent/judge-cache")
+	if got := judgeCache(); got != "/var/lib/mesh/build-agent/judge-cache" {
+		t.Fatalf("the judge cache the manifest declares is read as %q", got)
+	}
+	t.Setenv("MESH_JUDGE_CACHE", "")
+	if got := judgeCache(); got != "" {
+		t.Fatalf("with no judge cache declared, %q is used", got)
+	}
+}
+
+// The siblings a check is asked to read reach the build seat's spec and, as read, the outcome (novox/hq ADR 0382).
+func TestTheSiblingsAnAskNamesReachTheSpecAndTheOutcome(t *testing.T) {
+	spec := checkSpecOf(link.BuildRequest{Check: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Base: "main",
+		Siblings:        []link.CheckSibling{{Repository: "novox/mesh-controller", Number: 346, Head: "a", Base: "main", Dir: "mesh-controller"}},
+		SiblingsUnknown: "why"}})
+	if len(spec.Siblings) != 1 || spec.Siblings[0] != (builder.Sibling{Repository: "novox/mesh-controller", Number: 346,
+		Head: "a", Base: "main", Dir: "mesh-controller"}) || spec.SiblingsUnknown != "why" {
+		t.Fatalf("the spec reads %+v", spec)
+	}
+	out := siblingsOut([]builder.JudgedSibling{{Repository: "novox/mesh-controller", Number: 346, Head: "a", Base: "main", BaseCommit: "b"}})
+	if len(out) != 1 || out[0].BaseCommit != "b" || out[0].Number != 346 {
+		t.Fatalf("the outcome reads %+v", out)
+	}
+	if plain := checkSpecOf(link.BuildRequest{Check: &link.CheckRequest{Owner: "o", Repo: "r"}}); plain.Siblings != nil {
+		t.Fatalf("a request that names none has siblings %+v", plain.Siblings)
+	}
+}

cmd/mesh-builder/holder.go

@@ -0,0 +1,433 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go/micro"
+
+	"github.com/novox/mesh-controller/internal/builder"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// What a holder of the build seat answers for, on its own machine (novox/hq ADR 0219).
+//
+// **The queue is the controller's; the build running here is this machine's.** The controller can
+// see and change what waits in the seat's queue, but an ask a holder already took is a process tree
+// on this machine and containers in this machine's runtime, and only this machine can end them. So
+// the holder serves four verbs on the seat's subjects for this machine: what it is building, kill
+// it, pause, resume.
+//
+// **One build at a time** (ADR 0190), which is also what builder.Said assumes — a package global
+// set per build — so "the build running here" is one or none, and kill names it by id so a call
+// that arrives as one build ends and the next begins cannot end the wrong one.
+
+// holder is this machine's state as a holder of the build seat.
+type holder struct {
+	on, seat string
+	// workspace is where the paused flag is kept, so a holder restarted while paused stays paused
+	// rather than silently taking work again.
+	workspace string
+	// say publishes this machine's state: whether it takes work (link.HolderState).
+	say func(link.HolderState) error
+	// remove runs what a kill needs outside the build: the containers left behind.
+	remove builder.Runner
+	// scratch is where check builds are kept (novox/hq ADR 0350 §5): what the week's sweep lets go of. Nil where
+	// this machine publishes to no artifact store.
+	scratch builder.Scratch
+
+	mu      sync.Mutex
+	paused  bool
+	running *running
+}
+
+// running is the build this machine is doing.
+type running struct {
+	request link.BuildRequest
+	step    string
+	started time.Time
+	cancel  context.CancelFunc
+	killed  bool
+	// returned is the build's own work having ended, before a kill or not; outcome is what was then
+	// announced, and announced whether it went out.
+	returned  bool
+	outcome   string
+	announced bool
+	done      chan struct{}
+}
+
+// pausedFile is where the flag lives in the workspace.
+func pausedFile(workspace string) string { return filepath.Join(workspace, ".mesh-builder-paused") }
+
+// newHolder reads the paused flag the workspace keeps.
+func newHolder(on, seat, workspace string, say func(link.HolderState) error) *holder {
+	h := &holder{on: on, seat: seat, workspace: workspace, say: say, remove: plainRun}
+	if _, err := os.Stat(pausedFile(workspace)); err == nil {
+		h.paused = true
+	}
+	return h
+}
+
+// Paused is asked by the taking loop before every fetch.
+func (h *holder) Paused() bool {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	return h.paused
+}
+
+// setPaused records the flag in the workspace first and then in memory, so what this holder says
+// it is and what it would be after a restart never differ.
+func (h *holder) setPaused(paused bool) error {
+	path := pausedFile(h.workspace)
+	if paused {
+		if err := os.MkdirAll(h.workspace, 0o755); err != nil {
+			return err
+		}
+		if err := os.WriteFile(path, []byte(time.Now().UTC().Format(time.RFC3339)+"\n"), 0o644); err != nil {
+			return fmt.Errorf("cannot keep the paused flag in %s: %w", path, err)
+		}
+	} else if err := os.Remove(path); err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("cannot remove the paused flag %s: %w", path, err)
+	}
+	h.mu.Lock()
+	h.paused = paused
+	h.mu.Unlock()
+	h.announce()
+	return nil
+}
+
+// announce says whether this machine takes work. Never fatal: the flag is kept either way, and the
+// controller reading an older state is a plan read as late rather than a build lost.
+func (h *holder) announce() {
+	if h.say == nil {
+		return
+	}
+	if err := h.say(link.HolderState{On: h.on, Paused: h.Paused(), At: time.Now().UTC().Format(time.RFC3339Nano)}); err != nil {
+		fmt.Fprintf(os.Stderr, "cannot say whether this machine takes builds: %v\n", err)
+	}
+}
+
+// stateWhilePaused says this machine's state at start, and again every while it stays paused, so
+// a pause outlives the events stream's retention.
+func (h *holder) stateWhilePaused(ctx context.Context, every time.Duration) {
+	h.announce()
+	tick := time.NewTicker(every)
+	defer tick.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+			if h.Paused() {
+				h.announce()
+			}
+		}
+	}
+}
+
+// expireChecks lets go of every check build older than a week (novox/hq ADR 0350 §5), at start and every while
+// after. Every holder sweeps the one store; what one let go of, another finds gone.
+func (h *holder) expireChecks(ctx context.Context, every time.Duration, now func() time.Time) {
+	sweep := func() {
+		if h.scratch == nil {
+			return
+		}
+		n, err := h.scratch.Expire(ctx, builder.CheckBuildsKept, now())
+		switch {
+		case err != nil:
+			fmt.Fprintf(os.Stderr, "check builds older than %s: %d let go of, and not all: %v\n", builder.CheckBuildsKept, n, err)
+		case n > 0:
+			fmt.Fprintf(os.Stderr, "check builds older than %s: %d check(s)' builds let go of\n", builder.CheckBuildsKept, n)
+		}
+	}
+	sweep()
+	tick := time.NewTicker(every)
+	defer tick.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+			sweep()
+		}
+	}
+}
+
+// begin records the build this machine took, with the cancel that ends it.
+func (h *holder) begin(request link.BuildRequest, cancel context.CancelFunc) *running {
+	r := &running{request: request, started: time.Now(), cancel: cancel, done: make(chan struct{})}
+	h.mu.Lock()
+	h.running = r
+	h.mu.Unlock()
+	return r
+}
+
+// end clears it, and lets a kill waiting on it know it is over.
+func (h *holder) end(r *running) {
+	h.mu.Lock()
+	if h.running == r {
+		h.running = nil
+	}
+	h.mu.Unlock()
+	close(r.done)
+}
+
+// stepped records the step a build is at, for `current`.
+func (h *holder) stepped(r *running, step string) {
+	h.mu.Lock()
+	r.step = step
+	h.mu.Unlock()
+}
+
+// currentBuild is what `current` answers.
+type currentBuild struct {
+	On      string `json:"on"`
+	Paused  bool   `json:"paused"`
+	Running *struct {
+		ID         string `json:"id"`
+		Repository string `json:"repository"`
+		Path       string `json:"path,omitempty"`
+		Ref        string `json:"ref,omitempty"`
+		Step       string `json:"step,omitempty"`
+		Started    string `json:"started"`
+		Elapsed    string `json:"elapsed"`
+	} `json:"running,omitempty"`
+	Said string `json:"said"`
+}
+
+func (h *holder) current() currentBuild {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	out := currentBuild{On: h.on, Paused: h.paused}
+	taking := "taking builds"
+	if h.paused {
+		taking = "paused, taking no new build"
+	}
+	if h.running == nil {
+		out.Said = fmt.Sprintf("%s is building nothing; %s", h.on, taking)
+		return out
+	}
+	r := h.running
+	elapsed := time.Since(r.started).Round(time.Second)
+	out.Running = &struct {
+		ID         string `json:"id"`
+		Repository string `json:"repository"`
+		Path       string `json:"path,omitempty"`
+		Ref        string `json:"ref,omitempty"`
+		Step       string `json:"step,omitempty"`
+		Started    string `json:"started"`
+		Elapsed    string `json:"elapsed"`
+	}{r.request.ID, r.request.Repository, r.request.Path, r.request.Ref, r.step,
+		r.started.UTC().Format(time.RFC3339), elapsed.String()}
+	out.Said = fmt.Sprintf("%s is building %s (%s) at %s for %s; %s",
+		h.on, r.request.Repository, r.request.ID, orNothing(r.step), elapsed, taking)
+	return out
+}
+
+// The bounds a kill keeps: each pass removing containers, and the wait for the build to end between
+// them. The worst case — 15s, 20s, 15s — is inside what the controller waits for the answer
+// (killAnswer in the controller's queue.go, 75s).
+var (
+	killRemoves = 15 * time.Second
+	killWaits   = 20 * time.Second
+)
+
+// kill ends the build with this id, if it is the one running here and still working: its context
+// cancelled — which kills each command's process group — and the containers it started removed by
+// their label, once at once and again after the build has ended, so one created while it was being
+// killed is not left. The build's own goroutine announces it failed, killed by hand, and settles the
+// ask so it is not redelivered; the answer says whether that happened.
+func (h *holder) kill(id string) (string, error) {
+	h.mu.Lock()
+	r := h.running
+	if r == nil || r.request.ID != id {
+		doing := "nothing"
+		if r != nil {
+			doing = r.request.ID
+		}
+		h.mu.Unlock()
+		return "", fmt.Errorf("%s is not building %s; it is building %s. `queue` says where an ask is", h.on, id, doing)
+	}
+	if r.returned {
+		h.mu.Unlock()
+		return "", fmt.Errorf("%s on %s has already ended on its own and is saying how; `builds` shows it", id, h.on)
+	}
+	r.killed = true
+	cancel, done := r.cancel, r.done
+	h.mu.Unlock()
+
+	cancel()
+	removed, removeErr := h.removeContainers(id)
+	ended := false
+	select {
+	case <-done:
+		ended = true
+	case <-time.After(killWaits):
+	}
+	again, againErr := h.removeContainers(id)
+	removed += again
+	if removeErr == nil {
+		removeErr = againErr
+	}
+	containers := fmt.Sprintf("%d container(s) it started removed", removed)
+	if removeErr != nil {
+		containers = "its containers could not all be listed or removed: " + removeErr.Error()
+	}
+	if !ended {
+		return fmt.Sprintf("killed %s on %s: %s; the build has not finished ending yet — `builds` says when "+
+			"its outcome is in", id, h.on, containers), nil
+	}
+	h.mu.Lock()
+	outcome, announced := r.outcome, r.announced
+	h.mu.Unlock()
+	if !announced {
+		return fmt.Sprintf("killed %s (%s) on %s: its commands ended and %s, and its outcome could not be "+
+			"announced — the ask is not settled and will be handed out again", id, r.request.Repository, h.on,
+			containers), nil
+	}
+	return fmt.Sprintf("killed %s (%s) on %s: its commands ended, %s, and its outcome announced as failed, %s — "+
+		"settled, so it is not handed to another machine", id, r.request.Repository, h.on, containers, outcome), nil
+}
+
+// removeContainers is one pass of removing what the build left, bounded.
+func (h *holder) removeContainers(id string) (int, error) {
+	cleanup, stop := context.WithTimeout(context.Background(), killRemoves)
+	defer stop()
+	return builder.RemoveContainersOf(cleanup, h.remove, id)
+}
+
+// removeLeftBehind removes, once, what earlier holders on this machine left — called before anything is
+// taken, so none of it is this holder's — and says what it did. A runtime that cannot be asked is said
+// and the holder takes work all the same: what is left is waste, not a reason to stop building.
+func (h *holder) removeLeftBehind() int {
+	cleanup, stop := context.WithTimeout(context.Background(), killRemoves)
+	defer stop()
+	n, err := builder.RemoveLeftBehind(cleanup, h.remove)
+	switch {
+	case err != nil:
+		fmt.Fprintf(os.Stderr, "could not look for containers earlier builds left on %s: %v\n", h.on, err)
+	case n > 0:
+		fmt.Fprintf(os.Stderr, "removed %d container(s) earlier builds left on %s\n", n, h.on)
+	}
+	return n
+}
+
+// returned records that the build's work ended, and says whether a kill came first — only then is
+// the build killed; an error it ended with on its own is its own outcome.
+func (h *holder) returned(r *running) bool {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	r.returned = true
+	return r.killed
+}
+
+// said records the outcome announced, and whether it went out, for a kill to answer with.
+func (h *holder) said(r *running, outcome string, announced bool) {
+	h.mu.Lock()
+	r.outcome, r.announced = outcome, announced
+	h.mu.Unlock()
+}
+
+// handlers are the seat's verbs, as this machine answers them.
+func (h *holder) handlers() map[string]link.ToolHandler {
+	return map[string]link.ToolHandler{
+		"current": func(context.Context, json.RawMessage) (any, error) { return h.current(), nil },
+		"kill": func(_ context.Context, raw json.RawMessage) (any, error) {
+			var args struct {
+				ID string `json:"id"`
+			}
+			if err := json.Unmarshal(raw, &args); err != nil || strings.TrimSpace(args.ID) == "" {
+				return nil, errors.New("kill needs the build's id")
+			}
+			said, err := h.kill(strings.TrimSpace(args.ID))
+			if err != nil {
+				return nil, err
+			}
+			return map[string]any{"said": said}, nil
+		},
+		"pause": func(context.Context, json.RawMessage) (any, error) {
+			if err := h.setPaused(true); err != nil {
+				return nil, err
+			}
+			said := h.on + " is paused: it takes no new build until resumed"
+			if c := h.current(); c.Running != nil {
+				said += "; " + c.Running.ID + " runs on and finishes"
+			}
+			return map[string]any{"said": said, "paused": true}, nil
+		},
+		"resume": func(context.Context, json.RawMessage) (any, error) {
+			if err := h.setPaused(false); err != nil {
+				return nil, err
+			}
+			return map[string]any{"said": h.on + " takes builds again", "paused": false}, nil
+		},
+	}
+}
+
+func orNothing(s string) string {
+	if s == "" {
+		return "its start"
+	}
+	return s
+}
+
+// plainRun runs a command outside any build: no line reaches a build's log, because the build whose
+// log it would be is the one being ended.
+func plainRun(ctx context.Context, dir, name string, args ...string) (string, error) {
+	cmd := exec.CommandContext(ctx, name, args...)
+	cmd.Dir = dir
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return string(out), fmt.Errorf("%s %s: %w: %s", name, strings.Join(args, " "), err, strings.TrimSpace(string(out)))
+	}
+	return string(out), nil
+}
+
+// announcement is what this holder answers discovery with (novox/hq ADR 0195, ADR 0197): this
+// machine's verbs of the seat, in the shape every tool runtime announces a seat's verb — kind seat,
+// the module answering, the seat, scope node, the machine, its description and argument schema — so
+// the console finds `<node>/node-build-agent.kill` by searching, as it finds any seat's verb.
+//
+// One service per machine, named for the seat and identified by the machine, so the answer is this
+// machine's four verbs and nothing more. The verbs are the compiled seat row's: a build machine has no
+// store, and what it serves is what this binary was built to serve.
+func announcement(seat, module, node string) micro.Info {
+	s, _ := catalogue.SeatNamed(seat)
+	var endpoints []micro.EndpointInfo
+	for _, v := range s.Serves {
+		schema, _ := json.Marshal(v.Input)
+		endpoints = append(endpoints, micro.EndpointInfo{
+			Name:    seat + "__" + v.Name,
+			Subject: link.NodeSeatToolSubject(seat, v.Name, node),
+			// The queue group the verbs are served in, as every runtime announces its own.
+			QueueGroup: "seat." + seat,
+			Metadata: map[string]string{
+				"kind": "seat", "module": module, "tool": v.Name, "seat": seat, "scope": "node",
+				"node": node, "interchangeable": "false", "description": v.Description, "schema": string(schema),
+			},
+		})
+	}
+	return micro.Info{
+		ServiceIdentity: micro.ServiceIdentity{Name: seat, ID: node, Version: "0.1.0",
+			Metadata: map[string]string{"seat": seat, "scope": "node", "node": node, "module": module}},
+		Description: "what the build running on " + node + " is, and ending, pausing and resuming it (novox/hq ADR 0219)",
+		Endpoints:   endpoints,
+	}
+}
+
+// moduleOf is the module a credential was issued for: its user is `<node>.<module>`.
+func moduleOf(user string) string {
+	if _, module, ok := strings.Cut(user, "."); ok && module != "" {
+		return module
+	}
+	return "build-agent"
+}

cmd/mesh-builder/holder_test.go

@@ -0,0 +1,172 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// A holder paused stays paused across its restart: the flag is kept in its workspace (novox/hq ADR
+// 0219), and what it says about itself follows.
+func TestAPausedHolderStaysPausedAcrossARestart(t *testing.T) {
+	workspace := t.TempDir()
+	var said []link.HolderState
+	h := newHolder("ace", link.TheBuildMachine, workspace, func(s link.HolderState) error {
+		said = append(said, s)
+		return nil
+	})
+	if h.Paused() {
+		t.Fatal("a new holder starts paused")
+	}
+	if _, err := h.handlers()["pause"](context.Background(), json.RawMessage(`{}`)); err != nil {
+		t.Fatal(err)
+	}
+	if !h.Paused() || len(said) != 1 || !said[0].Paused || said[0].On != "ace" {
+		t.Fatalf("paused: %v, said %+v", h.Paused(), said)
+	}
+	again := newHolder("ace", link.TheBuildMachine, workspace, nil)
+	if !again.Paused() {
+		t.Fatal("restarted, the holder forgot it was paused")
+	}
+	if _, err := again.handlers()["resume"](context.Background(), json.RawMessage(`{}`)); err != nil {
+		t.Fatal(err)
+	}
+	if newHolder("ace", link.TheBuildMachine, workspace, nil).Paused() {
+		t.Fatal("resumed, the holder came back paused")
+	}
+}
+
+// kill ends the build with that id — its context, which ends its commands — removes what it left by
+// label, and refuses an id it is not building.
+func TestKillEndsTheBuildRunningHereAndNoOther(t *testing.T) {
+	h := newHolder("ace", link.TheBuildMachine, t.TempDir(), nil)
+	var removed []string
+	h.remove = func(_ context.Context, _ string, name string, args ...string) (string, error) {
+		removed = append(removed, name+" "+strings.Join(args, " "))
+		if args[0] == "ps" {
+			return "c1\n", nil
+		}
+		return "", nil
+	}
+	kill := h.handlers()["kill"]
+	if _, err := kill(context.Background(), json.RawMessage(`{"id":"build-1"}`)); err == nil {
+		t.Fatal("killed a build while none ran")
+	}
+
+	building, cancel := context.WithCancel(context.Background())
+	r := h.begin(link.BuildRequest{ID: "build-1", Repository: "novox/a"}, cancel)
+	h.stepped(r, "image")
+	if c := h.current(); c.Running == nil || c.Running.ID != "build-1" || c.Running.Step != "image" {
+		t.Fatalf("current says %+v", c)
+	}
+	if _, err := kill(context.Background(), json.RawMessage(`{"id":"build-2"}`)); err == nil ||
+		!strings.Contains(err.Error(), "build-1") {
+		t.Fatalf("killed another id: %v", err)
+	}
+	// The build's own goroutine: it ends when its context does, as a build's commands do, and
+	// announces what came of it.
+	go func() {
+		<-building.Done()
+		if h.returned(r) {
+			h.said(r, link.KilledByHand, true)
+		}
+		h.end(r)
+	}()
+	answer, err := kill(context.Background(), json.RawMessage(`{"id":"build-1"}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if building.Err() == nil {
+		t.Fatal("the build's context was not cancelled")
+	}
+	if !r.killed {
+		t.Error("the build is not marked killed, so it would be announced as an ordinary failure")
+	}
+	said := answer.(map[string]any)["said"].(string)
+	if !strings.Contains(said, "2 container(s)") || !strings.Contains(said, "announced as failed") || !strings.Contains(said, link.KilledByHand) {
+		t.Errorf("kill said %q", said)
+	}
+	// Removed at the kill and again once the build had ended: a container made in between is caught.
+	if len(removed) != 4 || !strings.Contains(removed[0], "label=mesh.build=build-1") || !strings.Contains(removed[2], "label=mesh.build=build-1") {
+		t.Errorf("removed %v", removed)
+	}
+	if c := h.current(); c.Running != nil {
+		t.Errorf("after the kill current says %+v", c)
+	}
+}
+
+// A holder announces this machine's verbs of the seat as the console reads a seat's verb, and no more.
+func TestAHolderAnnouncesItsMachinesVerbsForTheConsole(t *testing.T) {
+	info := announcement(link.TheBuildMachine, moduleOf("ace.build-agent"), "ace")
+	if info.Name != "node-build-agent" || info.ID != "ace" || len(info.Endpoints) != 4 {
+		t.Fatalf("announced %s/%s with %d endpoints", info.Name, info.ID, len(info.Endpoints))
+	}
+	kill := info.Endpoints[1]
+	md := kill.Metadata
+	if kill.Subject != "mesh.seat.node-build-agent.tool.kill.ace" || kill.QueueGroup != "seat.node-build-agent" || md["kind"] != "seat" || md["seat"] != "node-build-agent" ||
+		md["scope"] != "node" || md["node"] != "ace" || md["tool"] != "kill" || md["module"] != "build-agent" ||
+		!strings.Contains(md["description"], "killed by hand") || !strings.Contains(md["schema"], `"id"`) {
+		t.Fatalf("kill is announced as %+v", kill)
+	}
+	body, err := json.Marshal(info)
+	if err != nil || len(body) > 8*1024 {
+		t.Fatalf("the answer is %d bytes (%v)", len(body), err)
+	}
+}
+
+// A build that ended on its own as the kill arrived says what it did: the kill is refused, and its
+// own error is its outcome. One whose outcome could not be announced is not said to be settled.
+func TestAKillArrivingAfterTheBuildEndedIsRefusedAndAnUnannouncedKillSaysSo(t *testing.T) {
+	h := newHolder("ace", link.TheBuildMachine, t.TempDir(), nil)
+	h.remove = func(context.Context, string, string, ...string) (string, error) { return "", nil }
+	_, cancel := context.WithCancel(context.Background())
+	r := h.begin(link.BuildRequest{ID: "build-1"}, cancel)
+	if killed := h.returned(r); killed {
+		t.Fatal("a build nobody killed reads as killed")
+	}
+	if _, err := h.kill("build-1"); err == nil || !strings.Contains(err.Error(), "ended on its own") {
+		t.Fatalf("killed a build that had ended: %v", err)
+	}
+	h.end(r)
+
+	building, cancel := context.WithCancel(context.Background())
+	r = h.begin(link.BuildRequest{ID: "build-2"}, cancel)
+	go func() {
+		<-building.Done()
+		if h.returned(r) {
+			h.said(r, link.KilledByHand, false)
+		}
+		h.end(r)
+	}()
+	said, err := h.kill("build-2")
+	if err != nil || strings.Contains(said, "announced as failed") || !strings.Contains(said, "could not be announced") {
+		t.Fatalf("kill said %q (%v)", said, err)
+	}
+}
+
+// **Issue 306**: a holder starting removes the containers earlier builds left on its machine, through
+// the runner a kill uses, and a runtime that cannot be asked does not stop it.
+func TestAHolderStartingRemovesWhatEarlierBuildsLeftHere(t *testing.T) {
+	h := newHolder("novox", link.TheBuildMachine, t.TempDir(), nil)
+	var removed []string
+	h.remove = func(_ context.Context, _ string, name string, args ...string) (string, error) {
+		removed = append(removed, name+" "+strings.Join(args, " "))
+		if args[0] == "ps" {
+			return "c1 build-1\nc2 build-1\nc3 check-here-2\n", nil
+		}
+		return "", nil
+	}
+	if n := h.removeLeftBehind(); n != 2 || len(removed) != 2 || removed[1] != "docker rm -f c1 c2" {
+		t.Fatalf("removed %d: %v", n, removed)
+	}
+	h.remove = func(context.Context, string, string, ...string) (string, error) {
+		return "", errors.New("no runtime")
+	}
+	if n := h.removeLeftBehind(); n != 0 {
+		t.Errorf("a runtime that cannot be asked removed %d", n)
+	}
+}

cmd/mesh-builder/once.go

@@ -84,11 +84,17 @@ func buildOnce(ctx context.Context, args []string) error {
 	}
 	fmt.Fprintln(os.Stderr)
 
-	npmrc, err := packagesFrom()
+	machine := os.Getenv("MESH_NODE")
+	if machine == "" {
+		machine, _ = os.Hostname()
+	}
+	npmrc, err := packagesFrom(machine)
 	if err != nil {
 		return err
 	}
+	fmt.Fprintf(os.Stderr, "  [packages] %s\n", saysRegistry(npmrc))
 	built, buildErr := builder.Build(ctx, builder.Command, publisher, repository, *path, *ref, where, bases, npmrc,
+		forgeFrom(),
 		func(step, message string) { fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message) })
 	if buildErr != nil {
 		return buildErr
@@ -104,6 +110,10 @@ func buildOnce(ctx context.Context, args []string) error {
 		Ref:        *ref,
 		Manifest:   built.Manifest,
 		Against:    built.Against,
+		Source:     built.Source,
+	}
+	for _, r := range built.Read {
+		out.Read = append(out.Read, readRepository{Repository: r.Repository, Ref: r.Ref})
 	}
 	for _, made := range built.Built {
 		out.Made = append(out.Made, madeArtifact{Name: made.Name, Kind: made.Kind, Reference: made.Reference})
@@ -122,14 +132,22 @@ func buildOnce(ctx context.Context, args []string) error {
 // The same fields the mesh records for a build, so a reader comparing a genesis build against an
 // ordinary one is comparing the same thing said the same way.
 type onceResult struct {
-	Module     string         `json:"module"`
-	Commit     string         `json:"commit"`
-	Repository string         `json:"repository"`
-	Path       string         `json:"path,omitempty"`
-	Ref        string         `json:"ref,omitempty"`
-	Manifest   any            `json:"manifest"`
-	Made       []madeArtifact `json:"made"`
-	Against    []string       `json:"against,omitempty"`
+	Module     string           `json:"module"`
+	Commit     string           `json:"commit"`
+	Repository string           `json:"repository"`
+	Path       string           `json:"path,omitempty"`
+	Ref        string           `json:"ref,omitempty"`
+	Manifest   any              `json:"manifest"`
+	Made       []madeArtifact   `json:"made"`
+	Against    []string         `json:"against,omitempty"`
+	Read       []readRepository `json:"read,omitempty"`
+	Source     string           `json:"source-fingerprint,omitempty"`
+}
+
+// readRepository is a repository this build read source from besides the module's own.
+type readRepository struct {
+	Repository string `json:"repository"`
+	Ref        string `json:"ref,omitempty"`
 }
 
 type madeArtifact struct {

cmd/mesh-builder/packages_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/builder"
+)
+
+// The build agent's package registry (novox/hq ADR 0336, issue 121): its npm-package-registry
+// requirement is optional, so the binding may be absent, and on genesis's node the installer seals
+// the forge it raised as one genesis document instead.
+
+// registryFiles names the three paths the build agent's environment always names, writing only those
+// given.
+func registryFiles(t *testing.T, binding, token, genesis string) {
+	t.Helper()
+	dir := t.TempDir()
+	for env, content := range map[string]string{
+		"MESH_PACKAGE_BINDING":          binding,
+		"MESH_NPM_TOKEN_FILE":           token,
+		"MESH_GENESIS_PACKAGE_REGISTRY": genesis,
+	} {
+		path := filepath.Join(dir, env)
+		t.Setenv(env, path)
+		if content != "" {
+			if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
+				t.Fatal(err)
+			}
+		}
+	}
+	for _, env := range []string{"MESH_NPM_REGISTRY", "MESH_NPM_TOKEN", "MESH_NPM_USER", "MESH_NPM_SCOPE"} {
+		t.Setenv(env, "")
+	}
+}
+
+const (
+	aBinding = `{"from":"gitea","at":"anchor.mesh","as":"anchor-agent",
+	  "serves":{"scheme":"http","port":3000,"npm-path":"/api/packages/novox/npm/"}}`
+	aGenesisDocument = `{"scheme":"http","at":"127.0.0.1","port":3100,"npm-path":"/api/packages/novox/npm/",
+	  "as":"mesh-builder","password":"genesis-secret"}`
+)
+
+func TestUntilTheRequirementBindsTheGenesisDocumentIsRead(t *testing.T) {
+	registryFiles(t, "", "", aGenesisDocument)
+	n, err := packagesFrom("anchor")
+	if err != nil {
+		t.Fatalf("an absent binding beside a genesis document was refused: %v", err)
+	}
+	if n.From != builder.FromGenesis || n.Registry != "http://127.0.0.1:3100/api/packages/novox/npm/" ||
+		n.Username != "mesh-builder" || n.Password != "genesis-secret" || n.Scope != "@novox" {
+		t.Fatalf("the genesis document was not what the registry came from: %+v", n)
+	}
+	file, err := n.File()
+	if err != nil || !strings.Contains(file, "//127.0.0.1:3100/api/packages/novox/npm/:username=mesh-builder") {
+		t.Fatalf("the .npmrc is not written from the genesis document: %v\n%s", err, file)
+	}
+	if got := saysRegistry(n); !strings.Contains(got, "genesis document") {
+		t.Errorf("the log does not say the genesis document: %s", got)
+	}
+}
+
+func TestARealBindingWinsOverTheGenesisDocument(t *testing.T) {
+	registryFiles(t, aBinding, "bound-secret\n", aGenesisDocument)
+	n, err := packagesFrom("anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n.From != builder.FromBinding || n.Registry != "http://anchor.mesh:3000/api/packages/novox/npm/" ||
+		n.Username != "anchor-agent" || n.Password != "bound-secret" {
+		t.Fatalf("the binding did not win over the genesis document: %+v", n)
+	}
+	if got := saysRegistry(n); !strings.Contains(got, "binding") {
+		t.Errorf("the log does not say the binding: %s", got)
+	}
+}
+
+func TestWithNeitherTheAgentHasNoRegistryAndSaysWhere(t *testing.T) {
+	registryFiles(t, "", "", "")
+	n, err := packagesFrom("workstation")
+	if err != nil {
+		t.Fatalf("an unbound optional requirement was a fault: %v", err)
+	}
+	if n.Enabled() || n.Machine != "workstation" {
+		t.Fatalf("a registry came from nowhere: %+v", n)
+	}
+	got := saysRegistry(n)
+	for _, want := range []string{"npm-package-registry", "unbound", "workstation"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("the log does not say %q: %s", want, got)
+		}
+	}
+}
+
+func TestAGenesisDocumentMissingAFieldIsRefusedByName(t *testing.T) {
+	registryFiles(t, "", "", `{"at":"127.0.0.1","port":3000,"npm-path":"/api/packages/novox/npm/","as":"mesh-builder"}`)
+	if _, err := packagesFrom("anchor"); err == nil || !strings.Contains(err.Error(), "password") {
+		t.Fatalf("a genesis document with no password was taken: %v", err)
+	}
+}

cmd/mesh-builder/ready.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// **The build agent says it is ready** (novox/hq issue 544). It listens on nothing, so no http or tcp
+// check can see it work; it writes a mark once it is bound to its worker and pulls build work, and its
+// container's health check runs `mesh-builder ready`, which passes only while the mark is there. Without
+// it the node-engine could judge the agent only alive, and every walk that moved it waited out the whole
+// grace on each machine.
+//
+// The mark lives in the container's own temporary directory, never in the workspace the machine keeps:
+// a new container starts without it, and a restarted one removes it before it binds again.
+func readyMark() string { return filepath.Join(os.TempDir(), "mesh-builder.ready") }
+
+// notReady removes the mark: a holder starting is not taking work until it says so again.
+func notReady() error {
+	if err := os.Remove(readyMark()); err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("cannot remove the mark that this agent takes build work (%s): %w", readyMark(), err)
+	}
+	return nil
+}
+
+// taking writes the mark. A mark that cannot be written is said, and the agent goes on building: its
+// check then says it is not ready, which is the truth the gate should hear.
+func taking(seat string) {
+	if err := os.WriteFile(readyMark(), []byte(seat+"\n"), 0o644); err != nil {
+		fmt.Fprintf(os.Stderr, "cannot mark that this agent takes build work (%s): %v\n", readyMark(), err)
+		return
+	}
+	fmt.Fprintf(os.Stderr, "taking build work from %s\n", seat)
+}
+
+// ready is the health check: nil when this container's agent is bound and pulling build work.
+func ready() error {
+	if _, err := os.Stat(readyMark()); err != nil {
+		return fmt.Errorf("not taking build work yet: %s is not there", readyMark())
+	}
+	return nil
+}

cmd/mesh-builder/ready_test.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+// The health check passes only between the agent saying it takes work and its next start (novox/hq
+// issue 544).
+func TestTheAgentIsReadyOnlyOnceItTakesWork(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	if err := ready(); err == nil {
+		t.Fatal("an agent that never took work is ready")
+	}
+	taking("mesh-build-machine")
+	if err := ready(); err != nil {
+		t.Fatalf("an agent taking work is not ready: %v", err)
+	}
+	// Started again, it is not ready until it binds again.
+	if err := notReady(); err != nil {
+		t.Fatal(err)
+	}
+	if err := ready(); err == nil {
+		t.Fatal("an agent starting again is ready before it takes work")
+	}
+	if err := notReady(); err != nil {
+		t.Fatalf("removing a mark that is not there failed: %v", err)
+	}
+	if _, err := os.Stat(readyMark()); err == nil {
+		t.Fatal("the mark is still there")
+	}
+}

cmd/mesh-builder/seat_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The seat a build machine serves comes from its credential (novox/hq ADR 0190 handover).
+func TestTheCredentialSaysWhichBuildRoleThisMachineServes(t *testing.T) {
+	var held Credential
+	if err := json.Unmarshal([]byte(`{"url":"nats://bus:4222","user":"anchor.builder","password":"x",
+		"claims":[{"seat":"mesh-build-machine","scope":"mesh","serves":[]}]}`), &held); err != nil {
+		t.Fatal(err)
+	}
+	if got := link.BuildSeatClaimed(held.seatsClaimed()); got != "mesh-build-machine" {
+		t.Errorf("the old builder's credential serves %q", got)
+	}
+	var bare Credential
+	if err := json.Unmarshal([]byte(`{"url":"nats://bus:4222","user":"anchor.build-agent","password":"x"}`), &bare); err != nil {
+		t.Fatal(err)
+	}
+	if got := link.BuildSeatClaimed(bare.seatsClaimed()); got != link.TheBuildMachine {
+		t.Errorf("a credential without claims serves %q, want %s", got, link.TheBuildMachine)
+	}
+}

cmd/mesh-builder/stdout_test.go

@@ -14,8 +14,9 @@ func TestBuilderDiagnosticsStayOffStdout(t *testing.T) {
 	allowed := map[string]bool{
 		"string(body)": true, // once.go: the result JSON, which IS stdout
 		"version)":     true, // --version
-		`"stopping")`: true,  // the loop.s shutdown line
-		"usage)":       true,  // --help text, for a human
+		`"stopping")`:  true, // the loop.s shutdown line
+		"usage)":       true, // --help text, for a human
+		"said)":        true, // busy: the answer its node-engine reads (novox/hq ADR 0335)
 	}
 	for _, file := range []string{"once.go", "main.go"} {
 		src, err := os.ReadFile(file)

cmd/mesh-builder/tried_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/builder"
+)
+
+// A try's outcome, as the build seat says it in the build's log (novox/hq issue 686): the repository's own
+// check's verdict, how long it took, and each line naming what failed.
+func TestATrysOutcomeNamesWhatFailed(t *testing.T) {
+	tried := triedOf(builder.CheckVerdict{Verdict: "pass", Summary: "the change touches no module", Took: 303 * time.Second,
+		Head: "c0ffee", Trunk: "ca3f43c", Gate: &builder.Layer{Verdict: "pass"},
+		Repo: &builder.Layer{Verdict: "fail", Summary: "its merge-check.sh failed: TestX",
+			Failed: "--- FAIL: TestX (0.01s)\n    x_test.go:12: got 1, want 2"}})
+	if tried.Verdict != "fail" || tried.Took != "5m3s" || len(tried.Failed) != 2 || tried.Trunk != "ca3f43c" ||
+		tried.Summary != "its merge-check.sh failed: TestX" {
+		t.Fatalf("a failed try: %+v", tried)
+	}
+	// A head that does not merge fails both layers: the check's own word.
+	conflict := triedOf(builder.CheckVerdict{Verdict: "fail", Summary: "does not merge", Gate: &builder.Layer{Verdict: "fail"},
+		Repo: &builder.Layer{Verdict: "fail", Summary: "does not merge"}})
+	if conflict.Verdict != "fail" || conflict.Summary != "does not merge" {
+		t.Fatalf("a try that does not merge: %+v", conflict)
+	}
+	// No verdict is an error, never a pass.
+	if none := triedOf(builder.CheckVerdict{}); none.Verdict != "error" {
+		t.Fatalf("a try with no verdict: %+v", none)
+	}
+}

cmd/mesh-builder/where_test.go

@@ -15,6 +15,8 @@ import (
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/novox/mesh-controller/internal/broker"
 )
 
 // Where a builder publishes.
@@ -193,9 +195,9 @@ func TestThePinIsComparedInTheSpellingTheMeshWritesIt(t *testing.T) {
 	}
 }
 
-// handshakeWith runs the builder's own pin check against an address.
+// handshakeWith runs the pin check the builder dials with against an address.
 func handshakeWith(address, pin string) error {
-	conn, err := tls.Dial("tcp", address, pinning(pin))
+	conn, err := tls.Dial("tcp", address, broker.PinnedToFingerprint(pin))
 	if err != nil {
 		return err
 	}

cmd/mesh-controller/accept_outside.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A provision whose credential only a person outside the mesh can give (novox/hq ADR 0337, issue 164, issue 165):
+// given once for its provider, at the controller's terminal, and sealed in one act to every consumer that binds the
+// provision from that provider now. The value is never read back, printed or kept.
+
+// outsideOffer is the provider module's own name when `secret accept <node> <module> <name>` names a provision that
+// module offers with a credential issued outside the mesh, and "" when it names anything else (an own secret, or a
+// pair with --provider).
+func outsideOffer(ctx context.Context, module, name, provider string) (string, error) {
+	if provider != "" {
+		return "", nil
+	}
+	open, err := openStores(ctx)
+	if err != nil {
+		return "", err
+	}
+	defer open.Close()
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		return "", err
+	}
+	if m, known := shelf[module]; known && m.IssuedOutsideOf(name) {
+		return module, nil
+	}
+	return "", nil
+}
+
+// offeredOutsideBy is a module that offers the provision with a credential issued outside the mesh, or "".
+func offeredOutsideBy(ctx context.Context, provision string) (string, error) {
+	open, err := openStores(ctx)
+	if err != nil {
+		return "", err
+	}
+	defer open.Close()
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		return "", err
+	}
+	module, _ := catalogue.OffersIssuedOutside(shelf, provision)
+	return module, nil
+}
+
+// consumersFrom is every consumer that binds a provision from one provider now, found by resolving every machine as
+// its next send would, and the machines that could not be resolved, with why.
+func consumersFrom(ctx context.Context, open *stores, provider, providerModule, provision string) (
+	[]inventory.PairEnd, []string, error) {
+	nodes, err := open.inventory.Nodes(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	var out []inventory.PairEnd
+	var unresolved []string
+	for _, n := range nodes {
+		plan, _, err := planFor(ctx, open, n.Name)
+		if err != nil {
+			unresolved = append(unresolved, fmt.Sprintf("%s: %s", n.Name, oneLine(err.Error())))
+			continue
+		}
+		out = append(out, bindsFrom(plan, n.Name, provider, providerModule, provision)...)
+	}
+	return out, unresolved, nil
+}
+
+// bindsFrom is every consumer on one machine whose resolution answers the provision from that provider. Pure.
+func bindsFrom(plan catalogue.Resolution, machine, provider, providerModule, provision string) []inventory.PairEnd {
+	var out []inventory.PairEnd
+	for _, need := range plan.Needs {
+		if need.ByRecord || need.Name != provision || need.From != provider {
+			continue
+		}
+		if need.Module != "" && need.Module != providerModule {
+			continue
+		}
+		out = append(out, inventory.PairEnd{Consumer: machine, ConsumerModule: need.For, Local: need.Local})
+	}
+	sort.Slice(out, func(i, j int) bool {
+		return out[i].ConsumerModule+"\x00"+out[i].Local < out[j].ConsumerModule+"\x00"+out[j].Local
+	})
+	return out
+}
+
+// acceptForProvision gives a provision's credential issued outside the mesh, once for its provider (ADR 0337 §3).
+func acceptForProvision(ctx context.Context, provider, providerModule, provision, value string) error {
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	consumers, unresolved, err := consumersFrom(ctx, open, provider, providerModule, provision)
+	if err != nil {
+		return err
+	}
+	accepted, err := open.inventory.AcceptSecretForProvision(ctx, provision, provider, providerModule, value, consumers)
+	value = ""
+	if err != nil {
+		return err
+	}
+	fmt.Print(acceptedSaid(provider, providerModule, provision, accepted, unresolved))
+	if len(accepted.Sealed) == 0 {
+		return nil
+	}
+	if err := sendTo(ctx, open, accepted.Machines); err != nil {
+		return fmt.Errorf("%s is sealed and could not be sent: %w; `push %s` sends it", provision, err,
+			strings.Join(accepted.Machines, "`, `push "))
+	}
+	fmt.Printf("  sent %s; each consumer starts again on it\n", strings.Join(accepted.Machines, ", "))
+	return nil
+}
+
+// acceptedSaid is what one accept for a provider did, in words that never carry the value. Pure.
+func acceptedSaid(provider, providerModule, provision string, a inventory.ProvisionAccepted, unresolved []string) string {
+	var b strings.Builder
+	if len(a.Sealed) == 0 {
+		fmt.Fprintf(&b, "%s from %s on %s: no consumer binds it now, so nothing was sealed; a consumer that binds "+
+			"later waits for it, and this line given again seals it to every consumer then\n", provision,
+			providerModule, provider)
+	} else {
+		var names []string
+		for _, c := range a.Sealed {
+			names = append(names, fmt.Sprintf("%s on %s%s", c.ConsumerModule, c.Consumer, asLocal(c.Local)))
+		}
+		fmt.Fprintf(&b, "%s from %s on %s is given, sealed to %s and to %s\n", provision, providerModule, provider,
+			strings.Join(names, ", "), provider)
+		fmt.Fprintf(&b, "  the mesh cannot read it back, never makes one of its own for it, and will not rotate it\n")
+	}
+	for _, c := range a.Unsealable {
+		fmt.Fprintf(&b, "  not sealed to %s on %s: no sealing key on that machine; give it again once it has one\n",
+			c.ConsumerModule, c.Consumer)
+	}
+	for _, u := range unresolved {
+		fmt.Fprintf(&b, "  not known whether a consumer on %s binds it, which did not resolve; give it again once it does\n", u)
+	}
+	return b.String()
+}

cmd/mesh-controller/acting.go

@@ -0,0 +1,378 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/lease"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// Acting under the lease (novox/hq to-be 45 §6, ADR 0227 rule 1).
+//
+// **Only the instance holding the lease acts**: sends a declaration, writes a plan, a condition or a
+// call. Every one of those passes theLease.epoch, which answers the epoch the act carries or why it may
+// not happen. Three ways a process stands to the lease:
+//
+//   - **The serving controller** takes it before it does anything else — before it asserts the bus's
+//     objects, which are the controller's to write — waiting while another holds it, and renews it.
+//     Another holder seen, or the key's age passed with no renewal made, is the lease lost: the gate
+//     closes at once and the process exits, so its service manager restarts it as a candidate (serve,
+//     in push.go). A renewal the bus does not answer in time is not a loss (novox/hq issue 477): the
+//     lease is kept, no new act starts once half the key's age passed unrenewed, and the next renewal
+//     made opens the gate again.
+//   - **A command run at a shell** — `push` in the installer, the lab, a person repairing a mesh whose
+//     controller is down (issue 201) — acts **under the holder's epoch** when a controller holds the
+//     lease: it is the same mesh's word, composed and sent under the store's hold of each machine like
+//     the serving controller's, and the epoch it carries is read at the moment it acts, so a handover
+//     between makes it stale and refused like any other. **When nobody holds the lease, the command
+//     takes it** for as long as it runs and gives it back; a controller starting meanwhile waits for
+//     it, as it would for another controller.
+//   - **A process with no bus** — a test, a command that only reads — acts with no epoch and is
+//     refused nothing: there is nothing to order against, and nothing it does reaches a machine.
+//
+// **Unleased, said and temporary.** A serving controller whose bus refuses it the lease's key — the bus's
+// user list is older than this build and does not grant the bucket yet — and that sees no other holder
+// serves without one, as every controller did before the lease: declarations carry no epoch, which no
+// node-engine refuses. Said once, kept as a condition (S12), and tried again every renewal interval; the
+// first push that sends the bus its new user list grants it, and the next try takes it. Refusing to act
+// instead would be a controller that can never send the user list that lets it act.
+
+// actor is this process's standing to the lease.
+type actor struct {
+	mu sync.Mutex
+	// held is the lease this process holds: the serving controller's, or a command's own.
+	held *lease.Lease
+	// unleased is why a serving controller acts without the lease; empty while it holds it or is not
+	// serving.
+	unleased string
+	// serving is a serving controller, which never borrows another's epoch.
+	serving bool
+	// kv is the lease bucket, for a command to read the holder's epoch from.
+	kv    jetstream.KeyValue
+	close func()
+	// noBus is a process with no bus configured.
+	noBus bool
+	// reset is when the lease bucket was found raised again from nothing and its revisions moved past
+	// the highest epoch issued, and what was said of it; zero when it was not (S12).
+	reset     time.Time
+	resetSaid string
+	// renewEvery and poll, when set, are how often the serving controller renews the lease it holds and
+	// looks again at one another holds, in place of the lease's own: a test's, so two controllers hand the
+	// lease over in a second rather than in a renewal of five (novox/hq issue 591). A renewal is given
+	// the lease's own RenewEvery to answer however often it is made, so a slow bus does not lose it.
+	renewEvery, poll time.Duration
+}
+
+// theLease is this process's standing to the lease.
+var theLease = &actor{}
+
+// instance names this process among controller instances: its machine, its process and when it
+// started. The lease's holder and every call this process keeps carry it.
+var instance = func() string {
+	host, _ := os.Hostname()
+	return fmt.Sprintf("controller@%s pid %d since %s", host, os.Getpid(), time.Now().UTC().Format(time.RFC3339))
+}()
+
+// epoch is the gate: the epoch an act carries — zero for none — or why it may not happen.
+func (a *actor) epoch(ctx context.Context) (uint64, error) {
+	a.mu.Lock()
+	held, serving, unleased, noBus := a.held, a.serving, a.unleased, a.noBus
+	a.mu.Unlock()
+	switch {
+	case held != nil:
+		return held.Epoch()
+	case serving && unleased != "":
+		return 0, nil
+	case serving:
+		return 0, lease.ErrNotHeld
+	case noBus:
+		return 0, nil
+	}
+	return a.forACommand(ctx)
+}
+
+// forACommand is a command's epoch: the holder's, or a lease of its own when nobody holds one.
+func (a *actor) forACommand(ctx context.Context) (uint64, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if a.held != nil {
+		return a.held.Epoch()
+	}
+	if a.kv == nil {
+		address, err := broker.BusAddress()
+		if err != nil {
+			// No bus: this process reaches no machine, and has nothing to order against.
+			a.noBus = true
+			return 0, nil
+		}
+		js, err := broker.Dial(address)
+		if err != nil {
+			return 0, fmt.Errorf("the bus cannot be reached, so whether a controller holds the lease cannot be "+
+				"read and nothing is done: %w", err)
+		}
+		api, err := jetstream.New(js.Conn())
+		if err != nil {
+			js.Close()
+			return 0, err
+		}
+		reading, cancel := context.WithTimeout(ctx, 10*time.Second)
+		defer cancel()
+		if err := broker.EnsureLeaseBucket(reading, api); err != nil {
+			js.Close()
+			return 0, err
+		}
+		kv, err := api.KeyValue(reading, broker.LeaseBucket)
+		if err != nil {
+			js.Close()
+			return 0, err
+		}
+		a.kv, a.close = kv, js.Close
+		if _, found, err := lease.Current(reading, kv); err == nil && !found {
+			// Nobody: this command takes it for as long as it runs.
+			l, err := lease.Open(reading, api, broker.LeaseBucket, lease.Options{Holder: holderOf(instance),
+				Say: func(format string, args ...any) { fmt.Printf(format+"\n", args...) }})
+			if err != nil {
+				return 0, err
+			}
+			epoch, err := l.TryTake(reading)
+			if err != nil {
+				return 0, fmt.Errorf("no controller holds the lease and this command could not take it: %w", err)
+			}
+			keeping, stop := context.WithCancel(context.Background())
+			go l.Keep(keeping)
+			a.held = l
+			closeBus := a.close
+			a.close = func() {
+				stop()
+				l.Release(context.Background())
+				closeBus()
+			}
+			return epoch, nil
+		}
+	}
+	reading, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	holder, found, err := lease.Current(reading, a.kv)
+	if err != nil {
+		return 0, fmt.Errorf("who holds the controller lease cannot be read, so nothing is done: %w", err)
+	}
+	if !found {
+		return 0, errors.New("the controller that held the lease while this command ran let go of it; nothing " +
+			"more is done under an epoch nobody holds — run the command again")
+	}
+	return holder.Epoch, nil
+}
+
+// release gives back what this process holds, at its end.
+func (a *actor) release() {
+	a.mu.Lock()
+	closing := a.close
+	a.close = nil
+	a.mu.Unlock()
+	if closing != nil {
+		closing()
+	}
+}
+
+// holderOf is this process as the lease's holder.
+func holderOf(instance string) lease.Holder {
+	host, _ := os.Hostname()
+	build := runningBuild()
+	if build == "" {
+		build = version
+	}
+	return lease.Holder{Instance: instance, Host: host, Build: build}
+}
+
+// RunningBuildVar is where the declaration tells this process which build it is (module.json, the
+// controller process's env): the version its bundle is delivered as, `${version}` composed by the
+// catalogue from the bundle's digest. Empty for a process placed by hand.
+const RunningBuildVar = "MESH_CONTROLLER_VERSION"
+
+// runningBuild is the version of the build this process is, or empty when the declaration did not say.
+func runningBuild() string {
+	return strings.TrimSpace(os.Getenv(RunningBuildVar))
+}
+
+// serveUnderTheLease takes the lease for the serving controller, waiting while another holds it, and
+// keeps it until ctx ends. Lost is closed when it is lost; the caller exits on it.
+func (a *actor) serveUnderTheLease(ctx context.Context, inv *inventory.Inventory, address string) (lost <-chan struct{}, err error) {
+	a.mu.Lock()
+	a.serving = true
+	a.mu.Unlock()
+	// Its own connection, held as long as the lease, and named so (novox/hq issue 327).
+	js, err := broker.Dial(address, nats.Name(broker.ConnectionName+" lease"))
+	if err != nil {
+		return nil, fmt.Errorf("the mesh is on the bus at %s and this control plane cannot reach it to take the "+
+			"lease: %w", broker.BareAddress(address), err)
+	}
+	api, err := jetstream.New(js.Conn())
+	if err != nil {
+		js.Close()
+		return nil, err
+	}
+	asserting, cancel := context.WithTimeout(ctx, 10*time.Second)
+	err = broker.EnsureLeaseBucket(asserting, api)
+	cancel()
+	if err != nil {
+		js.Close()
+		return nil, err
+	}
+	say := func(format string, args ...any) { fmt.Printf(format+"\n", args...) }
+	l, err := lease.Open(ctx, api, broker.LeaseBucket, lease.Options{Holder: holderOf(instance),
+		RenewEvery: a.renewEvery, RenewWithin: lease.RenewEvery, Poll: a.poll, Floor: inv.HighestEpoch, Say: say, Health: controllerHealth, Moved: func(was, floor uint64) {
+			a.mu.Lock()
+			defer a.mu.Unlock()
+			a.reset = time.Now()
+			a.resetSaid = fmt.Sprintf("the lease bucket was at revision %d with epoch %d already issued: it was "+
+				"raised again from nothing (a bus whose data was replaced), and its revisions were moved past %d so "+
+				"no machine refuses the next epoch", was, floor, floor)
+		}})
+	if err != nil {
+		js.Close()
+		return nil, err
+	}
+	gone := make(chan struct{})
+	epoch, err := l.Take(ctx)
+	switch {
+	case ctx.Err() != nil:
+		js.Close()
+		return nil, ctx.Err()
+	case err != nil && !errors.Is(err, lease.ErrUnwritable):
+		// Whether another controller acts cannot be told: this one does not act, and exits to try again.
+		js.Close()
+		return nil, err
+	case err != nil:
+		// Nobody holds it and the bus will not let it be written: unleased, said, tried again (see above).
+		a.mu.Lock()
+		a.unleased = err.Error()
+		a.mu.Unlock()
+		say("this controller serves WITHOUT the lease: %v. Its declarations carry no epoch; it tries again "+
+			"every %s, and the first push that sends the bus its user list grants it", err, lease.RenewEvery)
+		go a.takeWhenGranted(ctx, l, inv, gone)
+	default:
+		a.took(ctx, l, inv, epoch, gone)
+	}
+	a.mu.Lock()
+	a.close = func() {
+		if held, err := l.Epoch(); err == nil {
+			ending, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			if err := inv.EndEpoch(ending, held, inventory.EpochReleased); err != nil {
+				say("how epoch %d ended could not be recorded: %v", held, err)
+			}
+			cancel()
+		}
+		l.Release(context.Background())
+		js.Close()
+	}
+	a.mu.Unlock()
+	return gone, nil
+}
+
+// took is the lease taken: recorded, earlier epochs nobody gave back ended as expired, kept.
+func (a *actor) took(ctx context.Context, l *lease.Lease, inv *inventory.Inventory, epoch uint64, gone chan struct{}) {
+	a.mu.Lock()
+	a.held, a.unleased = l, ""
+	a.mu.Unlock()
+	h := holderOf(instance)
+	recording, cancel := context.WithTimeout(ctx, 10*time.Second)
+	expired, err := inv.TookEpoch(recording, inventory.Epoch{Epoch: epoch, Instance: h.Instance, Host: h.Host,
+		Build: h.Build, Taken: time.Now()})
+	cancel()
+	if err != nil {
+		fmt.Printf("epoch %d could not be recorded as taken, so a stale refusal from it will not name it: %v\n", epoch, err)
+	}
+	for _, e := range expired {
+		fmt.Printf("the controller of epoch %d (%s) stopped renewing the lease without giving it back: it is "+
+			"taken over at epoch %d\n", e.Epoch, e.Instance, epoch)
+	}
+	go l.Keep(ctx)
+	go func() {
+		<-l.Lost()
+		if ctx.Err() == nil {
+			why := l.LostWhy()
+			ending, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			_ = inv.EndEpoch(ending, epoch, inventory.EpochLost)
+			cancel()
+			fmt.Printf("the controller lease was lost (epoch %d): %v — this controller stops and exits, to "+
+				"be started again as a candidate\n", epoch, why)
+		}
+		close(gone)
+	}()
+}
+
+// takeWhenGranted tries the lease again every renewal interval while serving unleased, and stops this
+// controller if another took it meanwhile: two serving at once is what the lease is for.
+func (a *actor) takeWhenGranted(ctx context.Context, l *lease.Lease, inv *inventory.Inventory, gone chan struct{}) {
+	tick := time.NewTicker(lease.RenewEvery)
+	defer tick.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+		}
+		epoch, err := l.TryTake(ctx)
+		if errors.Is(err, lease.ErrTaken) {
+			fmt.Printf("another controller took the lease while this one served without it: %v — this one "+
+				"stops and exits\n", err)
+			close(gone)
+			return
+		}
+		if err != nil {
+			// Still not written, or not readable this time: unleased, said by S12, tried again.
+			a.mu.Lock()
+			a.unleased = err.Error()
+			a.mu.Unlock()
+			continue
+		}
+		a.took(ctx, l, inv, epoch, gone)
+		return
+	}
+}
+
+// standing is what `status` and the self-check say of this process and the lease.
+type standing struct {
+	Epoch    uint64
+	Held     bool
+	Renewed  time.Time
+	Unleased string
+	// Reset is when the lease bucket was found raised again from nothing, and ResetSaid what of it.
+	Reset     time.Time
+	ResetSaid string
+}
+
+func (a *actor) standing() standing {
+	a.mu.Lock()
+	held, unleased, reset, resetSaid := a.held, a.unleased, a.reset, a.resetSaid
+	a.mu.Unlock()
+	st := standing{Unleased: unleased, Reset: reset, ResetSaid: resetSaid}
+	if held == nil {
+		return st
+	}
+	epoch, err := held.Epoch()
+	st.Epoch, st.Held, st.Renewed = epoch, err == nil, held.Renewed()
+	return st
+}
+
+// The gates, given to what acts: a declaration's send (link) and a plan's write (the inventory).
+func init() {
+	link.ActingGate = func(ctx context.Context) error {
+		_, err := theLease.epoch(ctx)
+		if err != nil {
+			return fmt.Errorf("this controller may not send: %w", err)
+		}
+		return nil
+	}
+}

cmd/mesh-controller/acts.go

@@ -3,10 +3,15 @@ package main
 import (
 	"context"
 	"fmt"
+	"github.com/novox/mesh-controller/internal/broker"
+	"io"
+	"slices"
 	"sort"
 	"strings"
+	"time"
 
 	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
 )
 
 // The things the mesh can be asked to do, separated from how it was asked.
@@ -38,44 +43,305 @@ import (
 //
 // It costs a resolution per machine. Assignment is a person typing a command, and being told which
 // machines this just blocked is worth more than the milliseconds.
-func assign(ctx context.Context, open *stores, node, module string) (string, error) {
-	if err := open.inventory.Assign(ctx, node, module); err != nil {
+func assign(ctx context.Context, open *stores, node string, modules ...string) (string, error) {
+	return assignWith(ctx, open, node, assignOptions{}, modules...)
+}
+
+// assignWith is assign asked with its options: build, for a module known and not built (novox/hq issue 325).
+func assignWith(ctx context.Context, open *stores, node string, opts assignOptions, modules ...string) (string, error) {
+	if len(modules) == 0 {
+		return "", fmt.Errorf("assign %s names no module", node)
+	}
+	if err := refusedMovingTheController(modules); err != nil {
 		return "", err
 	}
-	said := fmt.Sprintf("%s is assigned %s", node, module)
-	plan, _, err := planFor(ctx, open, node)
+	// Every line of the answer comes from the one resolution after the write (novox/hq issue 237):
+	// what the reads before it would say about a machine left out is not the answer's.
+	ctx = leftOutSaidBy(ctx, io.Discard)
+	// Held while it is recorded, so it cannot land between a converge's preview and its flip and
+	// be taken without ever having been previewed (novox/hq ADR 0100).
+	ctx, release, err := holdNodes(ctx, open, []string{node})
+	if err != nil {
+		return "", err
+	}
+	defer release()
+	// **A module the catalogue does not hold is looked for further before it is refused** (novox/hq issue
+	// 325): a build in flight keeps the assignment pending, a module known and not built is said with how to
+	// build it, and only a name the mesh never heard of is refused as unknown. Several modules in one act
+	// are judged together (ADR 0207), so an act naming one not registered is not made in part.
+	if missing, err := notInCatalogue(ctx, open, modules); err != nil {
+		return "", err
+	} else if len(missing) > 0 {
+		if len(modules) == 1 {
+			return notRegistered(ctx, open, node, modules[0], opts)
+		}
+		var lines []string
+		for _, m := range missing {
+			where, err := whereIs(ctx, open.inventory, m, time.Now())
+			if err != nil {
+				return "", err
+			}
+			lines = append(lines, where.said)
+		}
+		return "", fmt.Errorf("%w: nothing was assigned, since modules assigned together are judged together "+
+			"(ADR 0207) and %s not registered:\n  %s\n  assign them together once each is registered, or each "+
+			"alone to keep it pending on its build", inventory.ErrNoSuchModule, strings.Join(missing, ", "),
+			strings.Join(lines, "\n  "))
+	}
+	// **The one assignment refused for what the node lacks** (novox/hq ADR 0207). Everything else
+	// an assignment leaves unresolved is kept, because assignment is not an ordering; a module whose
+	// resources are applied through a seat nothing on the node holds is refused, because that order
+	// — the service manager, the package manager and the runtime before anything that installs,
+	// runs or contains — is the mesh's to keep. Several modules in one act are judged together, so
+	// holders that depend on each other go on in one command.
+	shelf, before, err := seatDependenciesOnAssign(ctx, open, node, modules)
+	if err != nil {
+		return "", err
+	}
+	// **Before the new assignment can unsettle a seat somebody holds only by being alone**
+	// (novox/hq 04-ISSUES/170): what the mesh derived so far is written down, and then the
+	// assignment resolves against a record rather than against a coincidence.
+	settled, err := recordDerivedHolders(ctx, open)
+	if err != nil {
+		return "", err
+	}
+	var lines []string
+	var added []string
+	for _, module := range modules {
+		fresh, err := open.inventory.Assign(ctx, node, module)
+		if err != nil {
+			return strings.Join(lines, "\n"), err
+		}
+		if !fresh {
+			// Nothing changed, and saying "is assigned" would read as an action. One node runs one
+			// of each — the module's name is the assignment's identity (novox/hq ADR 0115).
+			lines = append(lines, fmt.Sprintf(
+				"%s already runs %s — one node runs one of each (ADR 0115); nothing changed", node, module))
+			continue
+		}
+		added = append(added, module)
+		lines = append(lines, fmt.Sprintf("%s is assigned %s", node, module))
+	}
+	if len(added) == 0 {
+		return strings.Join(lines, "\n"), nil
+	}
+	answer := strings.Join(lines, "\n")
+	for _, line := range settled {
+		answer += "\n  " + line
+	}
+	// Its bus credential, in the same act (novox/hq issue 203): an assignment pushed before its
+	// credential exists delivers a process that cannot authenticate and crash-loops until somebody
+	// runs a second verb and a second push. Issued here when the module speaks on the bus and has
+	// no credential yet; kept when it has one, so re-assigning rotates nothing.
+	var issued []string
+	for _, module := range added {
+		if line := issueOnAssign(ctx, open, node, module); line != "" {
+			issued = append(issued, line)
+		}
+	}
+	// **The one resolution the rest of the answer is said from** (novox/hq issue 237), taken after
+	// the write: what this act changed about this node's unmet seat dependencies, and nothing else
+	// (novox/hq ADR 0207) — a dependency of a module just assigned, or one this assignment met; the
+	// rest of the node's list, and every other node's, is `status`'s — and whether the node resolves.
+	after := resolvedAfter(ctx, open, shelf, node)
+	for _, line := range unheldChangeTo(shelf, node, before, after.modules, after.unheld) {
+		answer += "\n  " + line
+	}
+	for _, line := range issued {
+		answer += "\n  " + line
+	}
+	plan, err := after.plan, after.err
 	if err != nil {
 		// Kept, and still refused. Both halves are the answer, and the rest of the mesh is still
 		// worth reporting: this machine's refusal is rarely the only consequence.
-		return said + blockedElsewhere(ctx, open, node), err
+		return answer + blockedElsewhere(ctx, open, node), err
 	}
 	// Kept, and cannot be hosted here. Said at once rather than discovered at push: a module whose
 	// capability the machine lacks is on the wrong machine, and the assignment records what a person
 	// meant while this line says it will not run until it moves. The rest of the node still pushes.
+	isAdded := map[string]bool{}
+	for _, m := range added {
+		isAdded[m] = true
+	}
 	for _, u := range plan.Unhostable {
-		if u.Module != module {
+		if !isAdded[u.Module] {
 			continue
 		}
 		for _, c := range u.Missing {
-			said += "\n  but " + catalogue.WrongMachine(u.Module, c, node)
+			answer += "\n  but " + catalogue.WrongMachine(u.Module, c, node)
 		}
 	}
-	return said + fmt.Sprintf("\n  run `push %s` to send it", node) +
+	return answer + fmt.Sprintf("\n  run `push %s` to send it", node) +
 		blockedElsewhere(ctx, open, node), nil
 }
 
-// unassign takes a module off a node. What it leaves behind is the host's business: a directory
+// seatDependenciesOnAssign is the refusal ADR 0207 makes at assignment, or nothing, with the
+// catalogue and the node's assignments it was judged against. Modules already assigned are not new
+// and are not judged again.
+func seatDependenciesOnAssign(ctx context.Context, open *stores, node string, modules []string) (
+	map[string]catalogue.Manifest, []string, error) {
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	assigned, err := open.inventory.Assigned(ctx, node)
+	if err != nil {
+		return nil, nil, err
+	}
+	already := map[string]bool{}
+	for _, a := range assigned {
+		already[a] = true
+	}
+	var adding []string
+	for _, m := range modules {
+		if !already[m] {
+			adding = append(adding, m)
+		}
+	}
+	// The lines AssignRefusal says beside an assignment it lets through are said by unheldChange
+	// with everything else this act changed, so they are not said twice.
+	if _, err := catalogue.AssignRefusal(shelf, node, assigned, adding); err != nil {
+		return nil, nil, err
+	}
+	// Two modules declaring one path or unit, or one package present and absent, is refused before anything
+	// is recorded (novox/hq ADR 0210, ADR 0303, 04-ISSUES/235): kept, the node would not resolve until one came
+	// off again. Two modules declaring one package present is not a collision (ADR 0303, issue 628).
+	if err := catalogue.CollisionRefusal(shelf, node, assigned, adding); err != nil {
+		return nil, nil, err
+	}
+	return shelf, assigned, nil
+}
+
+// unassign takes modules off a node. What they leave behind is the host's business: a directory
 // holding anything the mesh did not put there is kept (novox/hq ADR 0030).
 //
 // It reports the rest of the mesh for the same reason assign does, and more sharply: taking a
 // module off one machine is the ordinary way to stop providing something to another, and nothing
 // about the command's own output would ever have said so.
-func unassign(ctx context.Context, open *stores, node, module string) (string, error) {
-	if err := open.inventory.Unassign(ctx, node, module); err != nil {
+//
+// **Refused when it takes away the last holder of a seat a module left on the node depends on**
+// (novox/hq ADR 0207) — the other side of refusing that module's assignment without one. Several
+// modules in one act are judged together, so a holder and its dependents come off in one command.
+func unassign(ctx context.Context, open *stores, node string, modules ...string) (string, error) {
+	if err := refusedMovingTheController(modules); err != nil {
 		return "", err
 	}
-	return fmt.Sprintf("%s no longer runs %s — run `push %s` to make it so",
-		node, module, node) + blockedElsewhere(ctx, open, node), nil
+	if len(modules) == 0 {
+		return "", fmt.Errorf("unassign %s names no module", node)
+	}
+	// One resolution after the write, as assign's answer (novox/hq issue 237).
+	ctx = leftOutSaidBy(ctx, io.Discard)
+	ctx, release, err := holdNodes(ctx, open, []string{node})
+	if err != nil {
+		return "", err
+	}
+	defer release()
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		return "", err
+	}
+	assigned, err := open.inventory.Assigned(ctx, node)
+	if err != nil {
+		return "", err
+	}
+	// Every one checked before any is taken off, so a refusal leaves the node as it was.
+	runs := map[string]bool{}
+	for _, a := range assigned {
+		runs[a] = true
+	}
+	// A module only pending on the node (novox/hq issue 325) is withdrawn, when it is the act's one module:
+	// that is the undo of an assignment kept while its build runs.
+	if len(modules) == 1 && !runs[modules[0]] {
+		said, withdrawn, err := withdrawPending(ctx, open.inventory, node, modules[0])
+		if err != nil {
+			return "", err
+		}
+		if withdrawn {
+			return said, nil
+		}
+	}
+	for _, module := range modules {
+		if !runs[module] {
+			return "", fmt.Errorf("%s is not assigned to %s", module, node)
+		}
+	}
+	if err := catalogue.UnassignRefusal(shelf, node, assigned, modules); err != nil {
+		return "", err
+	}
+	for _, module := range modules {
+		if err := open.inventory.Unassign(ctx, node, module); err != nil {
+			return "", err
+		}
+	}
+	answer := fmt.Sprintf("%s no longer runs %s — run `push %s` to make it so",
+		node, strings.Join(modules, ", "), node)
+	after := resolvedAfter(ctx, open, shelf, node)
+	for _, line := range unheldChangeTo(shelf, node, assigned, after.modules, after.unheld) {
+		answer += "\n  " + line
+	}
+	// Whether the node itself still resolves, from the same resolution: before, only the rest of the
+	// mesh's reads said it, on standard error and once per other machine.
+	if after.err != nil {
+		if unresolvable(after.err) {
+			answer += fmt.Sprintf("\n  but %s does not resolve now, so nothing will be sent to it:", node)
+		} else {
+			answer += fmt.Sprintf("\n  but whether %s still resolves could not be read:", node)
+		}
+		for _, line := range strings.Split(strings.TrimRight(after.err.Error(), "\n"), "\n") {
+			answer += "\n    " + strings.TrimSpace(line)
+		}
+	}
+	// What it leaves behind that is irreplaceable is kept and retired, never removed (novox/hq ADR 0233).
+	for _, line := range keptOnUnassign(ctx, open.inventory, node, modules) {
+		answer += "\n  " + line
+	}
+	return answer + blockedElsewhere(ctx, open, node), nil
+}
+
+// afterAct is the one resolution of a node an act's answer is said from, taken after its write
+// (novox/hq issue 237): the plan or why there is none, the modules it has on the node, and its unmet
+// seat dependencies.
+type afterAct struct {
+	plan    catalogue.Resolution
+	err     error
+	modules []string
+	unheld  []catalogue.Unheld
+}
+
+// resolvedAfter resolves the node as `plan` does, once, after the act's write. When the node resolves,
+// its modules and unmet seat dependencies are the resolution's — the closure, so a holder pulled in by
+// a requirement counts as `plan` counts it. When it does not, they are judged over the assignments read
+// after the write, which can only find more unmet than the closure would: a seat said held there is
+// held in the closure too.
+func resolvedAfter(ctx context.Context, open *stores, shelf map[string]catalogue.Manifest, node string) afterAct {
+	plan, _, err := planFor(ctx, open, node)
+	if err == nil {
+		out := afterAct{plan: plan, unheld: plan.Unheld}
+		for _, m := range plan.Modules {
+			out.modules = append(out.modules, m.Module)
+		}
+		return out
+	}
+	out := afterAct{err: err}
+	assigned, readErr := open.inventory.Assigned(ctx, node)
+	if readErr != nil {
+		return out
+	}
+	out.modules, out.unheld = assigned, unheldOver(shelf, node, assigned)
+	return out
+}
+
+// splitModules is a surface's one `module` field as the modules it names: several, comma-separated,
+// are one act (novox/hq ADR 0207), so the holders that depend on each other go on together from the
+// command API and the controller seat's verbs as they do from the command line.
+func splitModules(field string) []string {
+	var out []string
+	for _, m := range strings.Split(field, ",") {
+		if m = strings.TrimSpace(m); m != "" {
+			out = append(out, m)
+		}
+	}
+	return out
 }
 
 // blockedElsewhere is every OTHER machine that cannot be worked out as things now stand.
@@ -123,3 +389,51 @@ func blockedElsewhere(ctx context.Context, open *stores, except string) string {
 	out.WriteString("\nThis may or may not be what just changed — it is what is true now.")
 	return out.String()
 }
+
+// issueOnAssign gives a newly assigned module its bus credential, the way `module issue` does, and
+// says what it did in one line. Nothing for a module that declares no broker secret and runs no
+// provisioner client; nothing for one whose user is already minted (a credential is rotated on
+// purpose, never by re-assigning); and when the bus cannot be reached from here, the line names the
+// verb and the push that would refuse the module until it is run — never a silent placeholder (novox/hq issue 203).
+func issueOnAssign(ctx context.Context, open *stores, node, module string) string {
+	inv := open.inventory
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return ""
+	}
+	m, known := shelf[module]
+	if !known || mayIssue(m) != nil {
+		return ""
+	}
+	user := broker.Principal{Kind: broker.KindModule, Node: node, Module: module}.Username()
+	if _, reads := m.OwnSecrets["broker"]; !reads {
+		// A module running the provisioner client alone is minted the client's account (issue 917).
+		user = broker.Principal{Kind: broker.KindProvisioner, Node: node, Module: module}.Username()
+	}
+	if _, minted, err := inv.BusUserHash(ctx, user); err != nil || minted {
+		return ""
+	}
+	busAddress, err := broker.BusAddress()
+	if err == nil {
+		err = issueOnTheNewBus(ctx, inv, m, node, busAddress)
+	}
+	if err != nil {
+		return fmt.Sprintf("its bus credential is not issued (%v): `module issue %s --node %s` first — "+
+			"`push %s` refuses to send %s until it is", err, module, node, node, module)
+	}
+	return fmt.Sprintf("its bus credential is issued and sealed to %s, and arrives with the push", node)
+}
+
+// refusedMovingTheController refuses assigning or unassigning the controller's module through a verb (review of
+// novox/hq ADR 0272): the node it is assigned to is the control-node, and the control-node's operator account is
+// the controller's terminal, so whoever moves the module chooses the terminal. At the terminal alone, as every
+// change that says who may change what.
+func refusedMovingTheController(modules []string) error {
+	verb, through := throughAVerb()
+	if !through || !slices.Contains(modules, controllerModule) {
+		return nil
+	}
+	return fmt.Errorf("%s is assigned and unassigned at the controller's terminal only (mesh-cli on the control-node), "+
+		"never through a verb (this came through %q): the node it runs on is the control-node, whose operator is the "+
+		"terminal (novox/hq ADR 0272). Nothing was assigned", controllerModule, verb)
+}

cmd/mesh-controller/acts_test.go

@@ -1,3 +1,5 @@
+//go:build integration
+
 package main
 
 import (

cmd/mesh-controller/addresses_integration_test.go

@@ -0,0 +1,228 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/licences"
+)
+
+func TestTheRegistryTrustAndEveryImageFollowThePortTheNodeGaveTheStore(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aStore())
+	if _, err := assign(ctx, open, "anchor", "distribution"); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.SetSettings(ctx, "anchor", "distribution",
+		map[string]any{catalogue.PortsSetting: map[string]any{"5000": 5101}}); err != nil {
+		t.Fatal(err)
+	}
+	// A module the mesh built, recorded by digest and path, running on the other machine.
+	if err := open.inventory.RecordBuild(ctx, inventory.Build{
+		ID: "b1", Repository: "r", Module: "app", Commit: "abc",
+		Made: []inventory.Artifact{{Name: "server", Kind: "image",
+			Reference: catalogue.ArtifactStoreScheme + "app/server@" + aDigest}},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	register(t, open, catalogue.Manifest{Module: "app", Version: "1",
+		Resources: []map[string]any{{"id": "server", "type": "container", "name": "mesh-app",
+			"image": catalogue.ArtifactStoreScheme + "app/server@" + aDigest}}})
+	if _, err := assign(ctx, open, "laptop", "app"); err != nil {
+		t.Fatal(err)
+	}
+	// The runtime's trust is the runtime's module's to write (novox/hq ADR 0222): a stand-in for it
+	// asks where this machine reaches the store, as the docker module does.
+	register(t, open, catalogue.Manifest{Module: "runtime", Version: "1",
+		Resources: []map[string]any{{"id": "daemon", "type": "file", "path": "/etc/docker/daemon.json",
+			"into": "json", "content": `{"insecure-registries": ["${seat:mesh-artifact-store:reach}"]}` + "\n"}}})
+	if _, err := assign(ctx, open, "laptop", "runtime"); err != nil {
+		t.Fatal(err)
+	}
+
+	on := map[string]bool{"anchor": true, "laptop": true}
+	node, port, found, err := artifactStoreOnNetwork(ctx, open.inventory, on)
+	if err != nil || !found || node != "anchor" || port != "5101" {
+		t.Fatalf("the store is found on %q:%q (%v, %v); the node put it on 5101", node, port, found, err)
+	}
+
+	var trust string
+	for _, r := range composed(t, open, "laptop").Resources {
+		if r["path"] == "/etc/docker/daemon.json" {
+			trust, _ = r["content"].(string)
+		}
+		if r["id"] == "app.server" && r["image"] != "anchor.internal:5101/app/server@"+aDigest {
+			t.Errorf("the image the mesh built is fetched as %v", r["image"])
+		}
+	}
+	if !strings.Contains(trust, "anchor.internal:5101") || strings.Contains(trust, ":5000") {
+		t.Fatalf("the runtime is told to trust %q; the node put the store on 5101", trust)
+	}
+
+	// And a replay to the catalogue says where the store is now.
+	announced, err := following{open: open}.Announceable(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(announced) != 1 || announced[0].Made[0].Reference != "anchor.internal:5101/app/server@"+aDigest {
+		t.Fatalf("the replay announces %+v", announced)
+	}
+}
+
+func TestTheControlPlaneIsToldWhereTheNodePutTheStoreAndTheBroker(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	raw, err := os.ReadFile("../../module.json")
+	if err != nil {
+		t.Fatal(err)
+	}
+	m, err := catalogue.ParseManifest(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	control, err := withSeatPorts(m).Resolve([]catalogue.Built{{Name: "controller", Kind: catalogue.ArtifactBundle,
+		Reference: "https://registry.example/mesh-controller/controller.tar.gz", Digest: aDigest}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	register(t, open, control)
+	register(t, open, catalogue.Manifest{Module: "postgres", Version: "1",
+		Claims:  []catalogue.Claim{{Name: "mesh-store", Scope: catalogue.ScopeMesh}},
+		Listens: []catalogue.Listening{{Port: 5432, From: catalogue.FromMesh}},
+		Resources: []map[string]any{{"id": "server", "type": "container", "name": "mesh-store",
+			"ports": []any{"5432:5432"}, "image": "pg@" + aDigest}}})
+	register(t, open, catalogue.Manifest{Module: "lavinmq", Version: "1",
+		Claims: []catalogue.Claim{{Name: "mesh-broker", Scope: catalogue.ScopeMesh}},
+		Listens: []catalogue.Listening{{Port: 5671, From: catalogue.FromMesh},
+			{Port: 5672, From: catalogue.FromMesh}},
+		Guards: []int{15672},
+		Resources: []map[string]any{{"id": "server", "type": "container", "name": "mesh-broker",
+			"ports": []any{"5671:5671", "5672:5672", "127.0.0.1:15672:15672"}, "image": "mq@" + aDigest}}})
+	// The control plane's own bus user is the installer's, seeded at genesis before the controller
+	// runs (SeedBusUser); without it a push now refuses the credential nobody issued (issue 203).
+	if err := open.inventory.SeedBusUser(ctx, inventory.BusUser{Username: "anchor.mesh-controller",
+		Kind: inventory.BusController, Node: "anchor", Module: "mesh-controller"}, "bootstrap"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := assign(ctx, open, "anchor", "mesh-controller"); err != nil {
+		t.Fatal(err)
+	}
+	// The store's module is registered and given its port, and NOT assigned: the state genesis
+	// leaves a given-port node in before the foundation is adopted as modules (04-ISSUES/085).
+	if err := open.inventory.SetSettings(ctx, "anchor", "postgres",
+		map[string]any{catalogue.PortsSetting: map[string]any{"5432": 6852}}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := assign(ctx, open, "anchor", "lavinmq"); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.SetSettings(ctx, "anchor", "lavinmq",
+		map[string]any{catalogue.PortsSetting: map[string]any{"5672": 5679}}); err != nil {
+		t.Fatal(err)
+	}
+
+	var env map[string]any
+	for _, r := range composed(t, open, "anchor").Resources {
+		if r["id"] == "mesh-controller.controller" {
+			env, _ = r["env"].(map[string]any)
+		}
+	}
+	if env == nil {
+		t.Fatal("the control plane's process is not in its own node's declaration")
+	}
+	for key, want := range map[string]string{
+		"MESH_STORE_INVENTORY_PORT": "6852",
+		"MESH_STORE_IDENTITY_PORT":  "6852",
+		"MESH_STORE_LICENCES_PORT":  "6852",
+		"MESH_BROKER_AMQP_PORT":     "5679",
+		// Neither given nor assigned by the mesh: the manifest's own number is NOT the answer,
+		// because the sealed value beside it carries the port genesis wrote (finding F3).
+		"MESH_BROKER_ADDRESS_PORT":    "",
+		"MESH_BROKER_MANAGEMENT_PORT": "",
+	} {
+		if env[key] != want {
+			t.Errorf("the control plane is told %s=%v; the node says %q", key, env[key], want)
+		}
+	}
+}
+
+func aLoneNode(t *testing.T) *stores {
+	t.Helper()
+	inventory.ForTest(t)
+	licences.ForTest(t)
+	open, err := openStores(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(open.Close)
+	for _, m := range provided {
+		if err := open.inventory.Provide(t.Context(), m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	record, err := open.inventory.AddNode(t.Context(), "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	reported, _ := json.Marshal(map[string]any{"capabilities": []map[string]any{
+		{"name": "container-runtime", "present": true}}})
+	var profile map[string]any
+	_ = json.Unmarshal(reported, &profile)
+	if err := open.inventory.RecordProfile(t.Context(), record.ID, profile); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.RecordSealingKey(t.Context(), record.ID, aPublicKey(t)); err != nil {
+		t.Fatal(err)
+	}
+	return open
+}
+
+func TestOnANodeWithNoNetworkTheStoreIsReachedByLoopback(t *testing.T) {
+	open := aLoneNode(t)
+	ctx := t.Context()
+	register(t, open, aStore())
+	register(t, open, catalogue.Manifest{Module: "builder", Version: "1",
+		Requires: []string{catalogue.ArtifactStoreProvision},
+		Resources: []map[string]any{{"id": "server", "type": "container", "name": "mesh-builder",
+			"image": "registry.example/mesh-builder@" + aDigest}}})
+	if err := open.inventory.RecordBuild(ctx, inventory.Build{
+		ID: "b1", Repository: "r", Module: "postgres", Commit: "abc",
+		Made: []inventory.Artifact{{Name: "runtime", Kind: "image",
+			Reference: catalogue.ArtifactStoreScheme + "postgres/runtime@" + aDigest}},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	register(t, open, catalogue.Manifest{Module: "postgres", Version: "1",
+		Resources: []map[string]any{{"id": "runtime", "type": "container", "name": "mesh-postgres",
+			"image": catalogue.ArtifactStoreScheme + "postgres/runtime@" + aDigest}}})
+	for _, module := range []string{"distribution", "builder", "postgres"} {
+		if _, err := assign(ctx, open, "anchor", module); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := open.inventory.SetSettings(ctx, "anchor", "distribution",
+		map[string]any{catalogue.PortsSetting: map[string]any{"5000": 5100}}); err != nil {
+		t.Fatal(err)
+	}
+
+	var image any
+	for _, r := range composed(t, open, "anchor").Resources {
+		if r["id"] == "postgres.runtime" {
+			image = r["image"]
+		}
+	}
+	if image != "127.0.0.1:5100/postgres/runtime@"+aDigest {
+		t.Fatalf("on the store's own node, off any network, the image is fetched as %v", image)
+	}
+	held := heldBy(ctx)
+	if got := held["postgres/runtime"]; got != "127.0.0.1:5100/postgres/runtime@"+aDigest {
+		t.Fatalf("a builder beside the store is handed the base %q", got)
+	}
+}

cmd/mesh-controller/addresses_test.go

@@ -0,0 +1,139 @@
+package main
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// An address is read from the node's settings where it is used, never recorded with a port
+// (novox/hq 04-ISSUES/102). Three readers did not follow the setting; each is held to it here.
+
+var aDigest = "sha256:" + strings.Repeat("e", 64)
+
+// **A build is recorded by digest and path**, whatever address the builder pushed to — what it
+// made and what it stood on both; an image the module runs from elsewhere is left where it says.
+func TestABuildIsRecordedWithoutTheStoresAddress(t *testing.T) {
+	manifest, _ := json.Marshal(map[string]any{
+		"module": "gitea", "version": "1",
+		"resources": []map[string]any{
+			{"id": "server", "type": "container", "name": "mesh-gitea",
+				"image": "anchor.internal:5100/gitea/server@" + aDigest},
+			{"id": "config", "type": "archive", "path": "/etc/gitea", "digest": aDigest,
+				"source": "http://anchor.internal:5100/v2/gitea/config/blobs/" + aDigest},
+			{"id": "cache", "type": "container", "name": "mesh-gitea-cache",
+				"image": "valkey/valkey@" + aDigest},
+		},
+	})
+	kept := buildFrom(link.BuildResult{
+		ID: "b1", Repository: "https://forge.example/gitea.git", Commit: "abc", On: "laptop",
+		Manifest: manifest,
+		Made: []link.MadeArtifact{
+			{Name: "server", Kind: "image", Reference: "anchor.internal:5100/gitea/server@" + aDigest},
+			{Name: "config", Kind: "archive", Reference: "http://anchor.internal:5100/v2/gitea/config/blobs/" + aDigest},
+		},
+		Against: []string{"anchor.internal:5100/mesh-tools/runtime@" + aDigest},
+	})
+	if kept.Module != "gitea" {
+		t.Fatalf("the module was not read from the recorded manifest: %q", kept.Module)
+	}
+	if kept.Made[0].Reference != catalogue.ArtifactStoreScheme+"gitea/server@"+aDigest {
+		t.Errorf("the image is recorded as %q, address and all", kept.Made[0].Reference)
+	}
+	if kept.Made[1].Reference != catalogue.ArtifactStoreScheme+"gitea/config/blobs/"+aDigest {
+		t.Errorf("the archive is recorded as %q, address and all", kept.Made[1].Reference)
+	}
+	recorded, err := catalogue.ParseManifest(kept.Manifest)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := recorded.Resources[0]["image"]; got != catalogue.ArtifactStoreScheme+"gitea/server@"+aDigest {
+		t.Errorf("the recorded manifest's image is %v", got)
+	}
+	if got := recorded.Resources[1]["source"]; got != catalogue.ArtifactStoreScheme+"gitea/config/blobs/"+aDigest {
+		t.Errorf("the recorded manifest's archive is %v", got)
+	}
+	if got := recorded.Resources[2]["image"]; got != "valkey/valkey@"+aDigest {
+		t.Errorf("an image the build did not make was rewritten: %v", got)
+	}
+	if strings.Contains(string(kept.Manifest), "anchor.internal:5100") {
+		t.Errorf("the recorded manifest still carries the store's address:\n%s", kept.Manifest)
+	}
+	// What the build stood on is an edge to another module's artifact, and it is recorded the way
+	// that artifact is: by path in the store, so the edge still names the same thing when the
+	// store answers at another address.
+	if kept.Against[0] != catalogue.ArtifactStoreScheme+"mesh-tools/runtime@"+aDigest {
+		t.Errorf("what the build stood on was recorded by address: %v", kept.Against)
+	}
+}
+
+// aStore is a module offering the artifact store on 5000, published the long way as the
+// distribution module does, so a node may be given another number for it.
+func aStore() catalogue.Manifest {
+	return catalogue.Manifest{Module: "distribution", Version: "1",
+		Provides: []catalogue.Offer{{Name: catalogue.ArtifactStoreProvision, Scope: catalogue.ScopeMesh}},
+		Serves:   map[string]map[string]any{catalogue.ArtifactStoreProvision: {"port": float64(5000)}},
+		Listens:  []catalogue.Listening{{Port: 5000, From: catalogue.FromMesh}},
+		Resources: []map[string]any{{"id": "store", "type": "container", "name": "mesh-registry",
+			"ports": []any{"5000:5000"}, "image": "registry@" + aDigest}}}
+}
+
+// **The trust a machine writes for the store, and the address every built image is fetched
+// through, say the port the node gave the store** — not the catalogue's number.
+
+// **The control plane's own connections say the port the node gave the store and the broker.**
+//
+// Composed from the control plane's own manifest against a real inventory: the store's module is
+// given 6852 on this node the way genesis or an operator gives it, and the control plane's
+// process is told so beside the sealed connection genesis wrote.
+
+// withSeatPorts is the control plane's manifest with the seat placeholders in its environment —
+// added here until module.json carries them (the manifest lands one commit after the code that
+// fills it, so a control plane one build behind never sees a placeholder it cannot fill).
+func withSeatPorts(m catalogue.Manifest) catalogue.Manifest {
+	seatPorts := map[string]string{
+		"MESH_STORE_INVENTORY_PORT":   "${seat:mesh-store:5432}",
+		"MESH_STORE_IDENTITY_PORT":    "${seat:mesh-store:5432}",
+		"MESH_STORE_LICENCES_PORT":    "${seat:mesh-store:5432}",
+		"MESH_BROKER_AMQP_PORT":       "${seat:mesh-broker:5672}",
+		"MESH_BROKER_MANAGEMENT_PORT": "${seat:mesh-broker:15672}",
+		"MESH_BROKER_ADDRESS_PORT":    "${seat:mesh-broker:5671}",
+	}
+	out := m
+	out.Resources = nil
+	for _, r := range m.Resources {
+		if r["type"] != "container" && r["type"] != "process" {
+			out.Resources = append(out.Resources, r)
+			continue
+		}
+		copied := map[string]any{}
+		for k, v := range r {
+			copied[k] = v
+		}
+		env := map[string]any{}
+		if had, ok := r["env"].(map[string]any); ok {
+			for k, v := range had {
+				env[k] = v
+			}
+		}
+		for k, v := range seatPorts {
+			if _, said := env[k]; !said {
+				env[k] = v
+			}
+		}
+		copied["env"] = env
+		out.Resources = append(out.Resources, copied)
+	}
+	return out
+}
+
+// aLoneNode is one capable machine with nothing placed on any network — the control-node during
+// genesis, before the "network" step, which is after the store, the broker, the vault and the
+// catalogue have each been built and pushed (finding F2).
+
+// **Before the network exists, the store's own node reaches it by loopback** — never refused,
+// never handed the scheme: a genesis pushes the store, the broker, the vault and the catalogue to
+// a node on no network, and builds the catalogue on a base it must be able to pull.

cmd/mesh-controller/adopting_test.go

@@ -0,0 +1,643 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/overlay"
+)
+
+// novox/hq ADR 0100: taking a module is its cutover; converging a node is one act, previewed, and
+// refused while a found container is held; returning to adopted keeps what was taken.
+
+// anAdoptedAnchor is aMesh with the anchor adopted, running a served module the predecessor also
+// runs and a module with only a file, and a filter module in the catalogue.
+func anAdoptedAnchor(t *testing.T) (*stores, *[]string) {
+	t.Helper()
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, catalogue.Manifest{Module: "hello-web", Version: "1",
+		Listens: []catalogue.Listening{{Port: 8080, From: catalogue.FromEverywhere}},
+		Resources: []map[string]any{
+			{"id": "page", "type": "file", "path": "/var/lib/hello-web/index.html", "content": "hi"},
+			{"id": "server", "type": "container", "name": "hello-web", "ports": []any{"8080:80"},
+				"image": "registry.example/hello@sha256:" + strings.Repeat("a", 64)},
+		}})
+	register(t, open, catalogue.Manifest{Module: "notes", Version: "1",
+		Resources: []map[string]any{
+			{"id": "conf", "type": "file", "path": "/etc/notes.conf", "content": "x"},
+		}})
+	register(t, open, catalogue.Manifest{Module: "nftables", Version: "1",
+		Filtering: &catalogue.Filtering{Into: "/etc/nftables.conf"},
+		Resources: []map[string]any{{"id": "load", "type": "service", "unit": "mesh-filter.service",
+			"state": "running", "restart-on": []any{"filtering"}}}})
+	if err := open.inventory.SetAdopted(ctx, "anchor", true); err != nil {
+		t.Fatal(err)
+	}
+	for _, m := range []string{"hello-web", "notes"} {
+		if _, err := assign(ctx, open, "anchor", m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	sent := &[]string{}
+	saved := sendNodes
+	sendNodes = func(_ context.Context, _ *stores, names []string) error {
+		*sent = append(*sent, names...)
+		return nil
+	}
+	t.Cleanup(func() { sendNodes = saved })
+	return open, sent
+}
+
+// reportsHolding has the anchor report, on what it was last sent, holding what is given.
+func reportsHolding(t *testing.T, open *stores, held ...link.Held) {
+	t.Helper()
+	reportsReaching(t, open, []link.Reach{
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 22, By: "sshd"},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 8080, By: "hello-web", Published: true,
+			ContainerPort: 80},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 5000, By: "predecessor-registry",
+			Published: true, ContainerPort: 5000},
+		{Protocol: "tcp", Address: "127.0.0.1", Port: 15672, By: "mesh-broker",
+			Published: true, ContainerPort: 15672},
+	}, held...)
+}
+
+// reportsReaching has the anchor report, on what it was last sent, what is reachable on it and
+// holding what is given.
+func reportsReaching(t *testing.T, open *stores, reachable []link.Reach, held ...link.Held) {
+	t.Helper()
+	ctx := t.Context()
+	body, err := composed(t, open, "anchor").Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	record, err := open.inventory.NodeByName(ctx, "anchor")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.RecordSent(ctx, record.ID, digestOf(body), nil); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := (link.Enrolment{Inventory: open.inventory}).Heard(ctx, link.Report{
+		Node: "anchor", Applied: []string{"hello-web.x"}, Declared: digestOf(body),
+		Firewall: "ufw", Held: held, Reachable: reachable,
+		// A machine says which of its links face outside on every apply (novox/hq ADR 0140), and a
+		// filter is not sent to one that has not. The anchor reports one, as a real host does; this
+		// fixture lacked it from 2026-09-28 and nothing ran the test (issue 177).
+		Outward: []string{"eth0"},
+		// And what filters it (ADR 0168): its front end, the runtime's own, and a chain a
+		// predecessor left in the runtime's user chain.
+		Filters: anchorFilters,
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// anchorFilters is what the adopted anchor says filters it: ufw's chains, the runtime's, and a
+// predecessor's chain the mesh did not write.
+var anchorFilters = []link.Filter{
+	{Where: "table ip filter, chain ufw-reject-input", Owner: "found-firewall", Refuses: "reject"},
+	{Where: "table ip filter, chain DOCKER", Owner: "runtime", Refuses: `iifname != "docker0" oifname "docker0" drop`},
+	{Where: "table ip filter, chain DOCKER-USER", Owner: "other", Refuses: `iifname "eth0" tcp dport 6000 drop`},
+}
+
+var (
+	heldContainer = link.Held{ID: "hello-web.server", Module: "hello-web", Kind: "container",
+		Target: "hello-web", Since: time.Now()}
+	heldFile = link.Held{ID: "notes.conf", Module: "notes", Kind: "file",
+		Target: "/etc/notes.conf", Since: time.Now(), Kept: "/var/lib/mesh-host/kept/abc-notes.conf"}
+)
+
+func TestTakingAModuleNotOnTheNodeIsRefused(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	if _, err := take(t.Context(), open, "anchor", "nftables", takeOptions{Yes: true}); !errors.Is(err, inventory.ErrNotAssigned) {
+		t.Fatalf("taking an unassigned module gave %v", err)
+	}
+	if _, err := take(t.Context(), open, "laptop", "network", takeOptions{Yes: true}); !errors.Is(err, inventory.ErrNotAdopted) {
+		t.Fatalf("taking on a converged node gave %v", err)
+	}
+}
+
+func TestConvergingIsRefusedOnAPreviewThatWouldBeStale(t *testing.T) {
+	open, sent := anAdoptedAnchor(t)
+	_, err := converge(t.Context(), open, "anchor", false, "", "")
+	if err == nil || !strings.Contains(err.Error(), "has not reported") {
+		t.Fatalf("a node that never reported was previewed: %v", err)
+	}
+	if len(*sent) != 0 {
+		t.Fatal("a refused converge sent something")
+	}
+}
+
+func TestTheFlipIsRefusedWhileAFoundContainerIsHeld(t *testing.T) {
+	open, sent := anAdoptedAnchor(t)
+	reportsHolding(t, open, heldContainer, heldFile)
+	_, err := converge(t.Context(), open, "anchor", true, "", "")
+	if err == nil || !strings.Contains(err.Error(), "take anchor hello-web once its data has moved") {
+		t.Fatalf("the flip was not refused while hello-web holds its found container: %v", err)
+	}
+	if n, _ := open.inventory.NodeByName(t.Context(), "anchor"); !n.Adopted || len(*sent) != 0 {
+		t.Fatal("a refused flip changed something")
+	}
+}
+
+func TestTakingNamesWhatItReplaces(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	reportsHolding(t, open, heldContainer, heldFile)
+	ctx := t.Context()
+	// The machine holds something for the module, so the take acts on the preview the operator
+	// saw and names its digest (novox/hq ADR 0163).
+	preview, err := take(ctx, open, "anchor", "hello-web", takeOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	saw := takeDigestIn(t, preview)
+	if !strings.Contains(preview, "nothing taken; `take anchor hello-web --yes "+saw+"`") {
+		t.Fatalf("the preview does not say how to act on it:\n%s", preview)
+	}
+	if taken, _ := open.inventory.Taken(ctx, "anchor"); len(taken) != 0 {
+		t.Fatal("the preview took something")
+	}
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err == nil || !strings.Contains(err.Error(), "name its digest") {
+		t.Fatalf("--yes without the digest was not refused: %v", err)
+	}
+	said, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true, Digest: saw})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(said, "container hello-web (hello-web.server)") ||
+		!strings.Contains(said, "push anchor") {
+		t.Fatalf("taking did not say what it replaces and what to run:\n%s", said)
+	}
+}
+
+// takeDigestIn is the digest a take's preview printed.
+func takeDigestIn(t *testing.T, preview string) string {
+	t.Helper()
+	for _, line := range strings.Split(preview, "\n") {
+		if fields := strings.Fields(line); len(fields) == 2 && fields[0] == "preview" {
+			return fields[1]
+		}
+	}
+	t.Fatalf("the preview printed no digest:\n%s", preview)
+	return ""
+}
+
+// A take acts on the preview the operator saw, and on an account of the machine that is still the
+// machine: a changed preview and a stale account refuse (novox/hq ADR 0163, rule 1).
+func TestATakeIsRefusedOnAChangedPreviewOrAStaleAccount(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	reportsHolding(t, open, heldContainer, heldFile)
+	preview, err := take(ctx, open, "anchor", "hello-web", takeOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	saw := takeDigestIn(t, preview)
+
+	// The machine reports again, and what it holds has changed: the found container now carries
+	// facts the preview never showed.
+	changed := heldContainer
+	changed.Facts = map[string]any{"image": "hello:2", "declared_image": "registry.example/hello"}
+	reportsHolding(t, open, changed, heldFile)
+	_, err = take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true, Digest: saw})
+	if err == nil || !strings.Contains(err.Error(), "has changed since preview "+saw) {
+		t.Fatalf("a changed preview was acted on: %v", err)
+	}
+	if taken, _ := open.inventory.Taken(ctx, "anchor"); len(taken) != 0 {
+		t.Fatal("a refused take took something")
+	}
+
+	// And an account older than the flip allows.
+	preview, err = take(ctx, open, "anchor", "hello-web", takeOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	saw = takeDigestIn(t, preview)
+	saved := reportFreshFor
+	reportFreshFor = -time.Second
+	defer func() { reportFreshFor = saved }()
+	_, err = take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true, Digest: saw})
+	if err == nil || !strings.Contains(err.Error(), "a take acts only on an account newer than") {
+		t.Fatalf("a stale account was acted on: %v", err)
+	}
+	reportFreshFor = saved
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true, Digest: saw}); err != nil {
+		t.Fatal(err)
+	}
+	// A module the machine holds nothing for has nothing to compare: --yes alone suffices.
+	if _, err := take(ctx, open, "anchor", "notes", takeOptions{Yes: true}); err == nil {
+		// notes holds a file, so this one needs the digest too.
+		t.Fatal("notes holds a found file and was taken without a digest")
+	}
+}
+
+func TestConvergingPreviewsThenChangesAndAdoptingKeepsWhatWasTaken(t *testing.T) {
+	open, sent := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	reportsHolding(t, open, heldFile)
+
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, want := range []string{
+		"tcp/8080 hello-web (published, container port 80)",
+		"declared by hello-web (from anywhere)",
+		"WILL CLOSE — no module assigned here declares it",
+		// The anchor faces inward and is on the private network: the derived filter admits ssh
+		// from the mesh only.
+		"WILL CLOSE to everything outside the private network — ssh stays open from the mesh",
+		"notes\n      replacing the found file /etc/notes.conf (notes.conf), original kept at",
+		"assigns nftables",
+		"the found firewall (ufw) is disabled, never flushed",
+		// What it routes is not a listener: said not to be previewed, and to be dropped.
+		"not previewed: traffic the machine routes that is not a published port",
+		"the derived filter drops it unless a module declares it",
+	} {
+		if !strings.Contains(preview, want) {
+			t.Errorf("the preview does not say %q:\n%s", want, preview)
+		}
+	}
+	if strings.Contains(preview, "15672") {
+		t.Errorf("a loopback listener is in the preview:\n%s", preview)
+	}
+	// What filters the machine now, and the fate of each (novox/hq ADR 0168): the predecessor's
+	// chain is named as not the mesh's and left, so the reader knows before the flip.
+	for _, want := range []string{
+		"table ip filter, chain DOCKER-USER",
+		"NOT THE MESH'S; left in force",
+		`iifname "eth0" tcp dport 6000 drop`,
+		"table ip filter, chain ufw-reject-input",
+		"the found firewall's; retired with it",
+		"the container runtime's own; left",
+	} {
+		if !strings.Contains(preview, want) {
+			t.Errorf("the preview does not say %q:\n%s", want, preview)
+		}
+	}
+	for _, line := range strings.Split(preview, "\n") {
+		if strings.Contains(line, "5000") && !strings.Contains(line, "WILL CLOSE") {
+			t.Errorf("an undeclared published port is not said to close: %s", line)
+		}
+	}
+	if n, _ := open.inventory.NodeByName(ctx, "anchor"); !n.Adopted || len(*sent) != 0 {
+		t.Fatal("the preview changed something")
+	}
+
+	if _, err := converge(ctx, open, "anchor", true, digestIn(t, preview), ""); err != nil {
+		t.Fatal(err)
+	}
+	n, _ := open.inventory.NodeByName(ctx, "anchor")
+	if n.Adopted {
+		t.Fatal("converge --yes left the node adopted")
+	}
+	taken, _ := open.inventory.Taken(ctx, "anchor")
+	if !reflect.DeepEqual(taken, []string{"hello-web", overlay.Name, "nftables", "notes"}) {
+		t.Fatalf("the flip took %v", taken)
+	}
+	if !reflect.DeepEqual(*sent, []string{"anchor"}) {
+		t.Fatalf("the flip sent %v", *sent)
+	}
+	declared := composed(t, open, "anchor")
+	if declared.Adoption != nil {
+		t.Fatal("a converged node is still sent an adoption envelope")
+	}
+	if !hasID(declared.Resources, "nftables.filtering") {
+		t.Fatal("the converged node is not declared the mesh's filter")
+	}
+
+	if _, err := adopt(ctx, open, "anchor"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := adopt(ctx, open, "anchor"); err == nil {
+		t.Fatal("adopting an adopted node was not refused")
+	}
+	again, _ := open.inventory.Taken(ctx, "anchor")
+	if !reflect.DeepEqual(again, taken) {
+		t.Fatalf("returning to adopted lost what was taken: %v", again)
+	}
+	declared = composed(t, open, "anchor")
+	if declared.Adoption == nil || len(declared.Adoption.Untaken) != 0 {
+		t.Fatalf("returned to adopted, the envelope is %+v", declared.Adoption)
+	}
+	if hasID(declared.Resources, "nftables.filtering") || hasID(declared.Resources, "nftables.load") {
+		t.Fatal("returned to adopted, the mesh's filter is still declared")
+	}
+}
+
+func hasID(resources []map[string]any, id string) bool {
+	for _, r := range resources {
+		if r["id"] == id {
+			return true
+		}
+	}
+	return false
+}
+
+// The command API refuses a flip exactly as the command line does, in the same words.
+func TestTheApiRefusesTheFlipInTheCommandLinesWords(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	reportsHolding(t, open, heldContainer)
+	_, direct := converge(t.Context(), open, "anchor", true, "", "")
+	if direct == nil {
+		t.Fatal("the flip was not refused")
+	}
+	got := asking(t, letIn{}, "POST", "/converge", `{"node":"anchor","yes":true}`)
+	if got.Code != http.StatusConflict {
+		t.Fatalf("got %d: %s", got.Code, got.Body.String())
+	}
+	var said map[string]any
+	if err := json.Unmarshal(got.Body.Bytes(), &said); err != nil {
+		t.Fatal(err)
+	}
+	if said["refused"] != direct.Error() {
+		t.Fatalf("the API said %q and the command line %q", said["refused"], direct.Error())
+	}
+	if got := asking(t, letIn{}, "POST", "/take", `{"node":"anchor"}`); got.Code != http.StatusBadRequest {
+		t.Fatalf("a take naming no module got %d", got.Code)
+	}
+}
+
+// novox/hq ADR 0100: the preview says what the derived filter does, rendered as it is rendered. On
+// a machine that faces inward, ssh is admitted from the private network only, and a port a module
+// admits from the mesh only closes to everything outside it: both are said to close.
+func TestThePreviewSaysWhatNarrowsToTheMeshCloses(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	register(t, open, catalogue.Manifest{Module: "store", Version: "1",
+		Listens: []catalogue.Listening{{Port: 5432, From: catalogue.FromMesh}}})
+	if _, err := assign(ctx, open, "anchor", "store"); err != nil {
+		t.Fatal(err)
+	}
+	reportsReaching(t, open, []link.Reach{
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 22, By: "sshd"},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 5432, By: "postgres"},
+		{Protocol: "tcp", Address: "10.77.0.1", Port: 5432, By: "postgres"},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 8080, By: "hello-web", Published: true,
+			ContainerPort: 80},
+	})
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	lines := map[string]string{}
+	for _, line := range strings.Split(preview, "\n") {
+		fields := strings.Fields(line)
+		if len(fields) > 1 && strings.HasPrefix(fields[0], "tcp/") {
+			lines[fields[0]+" "+fields[1]] += line + "\n"
+		}
+	}
+	if got := lines["tcp/22 sshd"]; !strings.Contains(got, "WILL CLOSE to everything outside "+
+		"the private network") {
+		t.Errorf("ssh on an inward machine is not said to close outside the mesh:\n%s", preview)
+	}
+	store := lines["tcp/5432 postgres"]
+	if strings.Count(store, "WILL CLOSE to everything outside the private network") != 1 ||
+		!strings.Contains(store, "declared by store (from mesh)") {
+		t.Errorf("the store's narrowing is not said to close, or its mesh address is:\n%s", preview)
+	}
+	if got := lines["tcp/8080 hello-web"]; !strings.Contains(got, "declared by hello-web (from anywhere)") {
+		t.Errorf("a port open to everywhere is not said to stay:\n%s", preview)
+	}
+}
+
+// digestIn is the digest a converge preview printed.
+func digestIn(t *testing.T, preview string) string {
+	t.Helper()
+	for _, line := range strings.Split(preview, "\n") {
+		if fields := strings.Fields(line); len(fields) == 2 && fields[0] == "preview" {
+			return fields[1]
+		}
+	}
+	t.Fatalf("the preview printed no digest:\n%s", preview)
+	return ""
+}
+
+// The flip acts on the preview the operator saw: it names that preview's digest, and it is refused
+// when the digest is missing, when anything the preview says has changed since, or when the node's
+// account of itself is too old to be the machine as it is.
+func TestTheFlipActsOnlyOnThePreviewTheOperatorSaw(t *testing.T) {
+	open, sent := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	reportsHolding(t, open, heldFile)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	saw := digestIn(t, preview)
+	if !strings.Contains(preview, "converge anchor --yes "+saw) {
+		t.Fatalf("the preview does not say how to act on it:\n%s", preview)
+	}
+	unchanged := func() {
+		t.Helper()
+		if n, _ := open.inventory.NodeByName(ctx, "anchor"); !n.Adopted || len(*sent) != 0 {
+			t.Fatal("a refused flip changed something")
+		}
+	}
+
+	if _, err := converge(ctx, open, "anchor", true, "", ""); err == nil ||
+		!strings.Contains(err.Error(), "--yes "+saw) {
+		t.Fatalf("a flip naming no preview was not refused: %v", err)
+	}
+	unchanged()
+
+	// Something new is reachable: the preview the operator saw is not what would happen.
+	reportsReaching(t, open, []link.Reach{
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 22, By: "sshd"},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 8080, By: "hello-web", Published: true,
+			ContainerPort: 80},
+		{Protocol: "tcp", Address: "0.0.0.0", Port: 6000, By: "something-new"},
+	}, heldFile)
+	_, err = converge(ctx, open, "anchor", true, saw, "")
+	if err == nil || !strings.Contains(err.Error(), "has changed since preview "+saw) {
+		t.Fatalf("a flip on a changed preview was not refused: %v", err)
+	}
+	unchanged()
+
+	// An account older than the flip trusts is refused, whatever digest is named.
+	again, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	saved := reportFreshFor
+	reportFreshFor = time.Nanosecond
+	_, err = converge(ctx, open, "anchor", true, digestIn(t, again), "")
+	reportFreshFor = saved
+	if err == nil || !strings.Contains(err.Error(), "wait for its next report") {
+		t.Fatalf("a flip on an old account was not refused: %v", err)
+	}
+	unchanged()
+
+	if _, err := converge(ctx, open, "anchor", true, digestIn(t, again), ""); err != nil {
+		t.Fatalf("the flip on the preview just seen was refused: %v", err)
+	}
+	if n, _ := open.inventory.NodeByName(ctx, "anchor"); n.Adopted {
+		t.Fatal("the flip did not converge the node")
+	}
+}
+
+// The flip holds the node from its checks to its send, so a push composed meanwhile waits and is
+// composed after it — never sent after it with the node still adopted. And the send inside the
+// flip is not made to wait on the flip's own hold.
+func TestTheFlipHoldsTheNodeWhileItSends(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	reportsHolding(t, open, heldFile)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var heldElsewhere, heldHere error
+	sendNodes = func(inner context.Context, open *stores, names []string) error {
+		// Another caller cannot hold the node while the flip sends it.
+		waiting, cancel := context.WithTimeout(ctx, 300*time.Millisecond)
+		defer cancel()
+		if release, err := open.inventory.HoldNodes(waiting, names); err == nil {
+			release()
+			heldElsewhere = errors.New("another caller held the node while the flip sent it")
+		}
+		// The flip's own send holds it without waiting on itself.
+		_, release, err := holdNodes(inner, open, names)
+		if err != nil {
+			heldHere = err
+			return err
+		}
+		release()
+		return nil
+	}
+	if _, err := converge(ctx, open, "anchor", true, digestIn(t, preview), ""); err != nil {
+		t.Fatal(err)
+	}
+	if heldElsewhere != nil || heldHere != nil {
+		t.Fatalf("%v %v", heldElsewhere, heldHere)
+	}
+	// And given back once it is done.
+	release, err := open.inventory.HoldNodes(ctx, []string{"anchor"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	release()
+}
+
+// novox/hq ADR 0103: the preview names every kind of thing a module the flip takes holds as found,
+// not only its files, and the digest changes when any of them does.
+func TestThePreviewNamesEveryHeldKind(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	since := time.Now()
+	held := []link.Held{heldFile,
+		{ID: "notes.data", Module: "notes", Kind: "directory", Target: "/var/lib/notes", Since: since},
+		{ID: "notes.daemon", Module: "notes", Kind: "service", Target: "notes.service", Since: since},
+		{ID: "notes.seed", Module: "notes", Kind: "archive", Target: "/srv/notes", Since: since},
+		{ID: "notes.worker", Module: "notes", Kind: "process", Target: "notes-worker", Since: since},
+		{ID: "notes.account", Module: "notes", Kind: "user", Target: "notes", Since: since},
+	}
+	reportsHolding(t, open, held...)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, want := range []string{
+		"replacing the found directory /var/lib/notes (notes.data)",
+		"replacing the found service notes.service (notes.daemon)",
+		"replacing the found archive /srv/notes (notes.seed)",
+		"replacing the found process notes-worker (notes.worker)",
+		"replacing the found user notes (notes.account)",
+	} {
+		if !strings.Contains(preview, want) {
+			t.Errorf("the preview does not say %q:\n%s", want, preview)
+		}
+	}
+	reportsHolding(t, open, held[:len(held)-1]...)
+	fewer, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if digestIn(t, fewer) == digestIn(t, preview) {
+		t.Fatal("the digest does not change with what is held")
+	}
+}
+
+// novox/hq ADR 0100: the flip acts on what the node said is reachable, so an account naming nothing
+// is refused. Every machine that is up answers on ssh; nothing reported means the host's collectors
+// did not, and flipping would close ports the preview never named.
+func TestTheFlipIsRefusedOnAnAccountNamingNothingReachable(t *testing.T) {
+	open, sent := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	// Only a loopback listener: nothing off the machine, which is the same silence.
+	reportsReaching(t, open, []link.Reach{
+		{Protocol: "tcp", Address: "127.0.0.1", Port: 15672, By: "mesh-broker"},
+	}, heldFile)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(preview, "this account looks partial") {
+		t.Errorf("the preview does not mark a partial account:\n%s", preview)
+	}
+	_, err = converge(ctx, open, "anchor", true, digestIn(t, preview), "")
+	if err == nil || !strings.Contains(err.Error(), "says nothing is reachable on it") {
+		t.Fatalf("the flip was not refused on an account naming nothing: %v", err)
+	}
+	if n, _ := open.inventory.NodeByName(ctx, "anchor"); !n.Adopted || len(*sent) != 0 {
+		t.Fatal("a refused flip changed something")
+	}
+}
+
+// An assignment cannot land between a preview and the flip that takes every module: assigning
+// holds the node, so it waits for whatever is converging it.
+func TestAssigningWaitsForWhateverIsConvergingTheNode(t *testing.T) {
+	open, _ := anAdoptedAnchor(t)
+	ctx := t.Context()
+	if _, err := take(ctx, open, "anchor", "hello-web", takeOptions{Yes: true}); err != nil {
+		t.Fatal(err)
+	}
+	reportsHolding(t, open, heldFile)
+	preview, err := converge(ctx, open, "anchor", false, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	saved, savedPoll := inventory.HoldWaitFor, inventory.HoldPoll
+	inventory.HoldWaitFor, inventory.HoldPoll = time.Second, 50*time.Millisecond
+	defer func() { inventory.HoldWaitFor, inventory.HoldPoll = saved, savedPoll }()
+
+	var whileFlipping error
+	sendNodes = func(context.Context, *stores, []string) error {
+		_, whileFlipping = assign(ctx, open, "anchor", "notes")
+		return nil
+	}
+	if _, err := converge(ctx, open, "anchor", true, digestIn(t, preview), ""); err != nil {
+		t.Fatal(err)
+	}
+	if !errors.Is(whileFlipping, inventory.ErrNodeBusy) {
+		t.Fatalf("an assignment landed while the node was being converged: %v", whileFlipping)
+	}
+}

cmd/mesh-controller/advisories_counted_test.go

@@ -0,0 +1,180 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **A refusal the bus said once is counted once** (novox/hq issue 402). The bus refused the controller
+// one publish at 18:52:59 UTC on 2026-10-10 and never again, yet S9 looked at the one remembered
+// advisory every half minute for the hour it is kept, and the condition said "observed 15 time(s), last
+// 13s ago" with a refusal in its evidence every 30 seconds: two of us read it as a refusal going on and
+// went looking for a missing grant. The condition counts what the bus said, with when it last said it,
+// never how often the controller looked.
+func TestARefusalSaidOnceIsCountedOnceHoweverOftenItIsLookedAt(t *testing.T) {
+	refused := time.Date(2026, 10, 10, 18, 52, 59, 0, time.UTC)
+	now := refused.Add(10 * time.Second)
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return now }})
+	t.Cleanup(func() { k.Close(t.Context()) })
+
+	// The words the live condition bus.controller.refused carried on 2026-10-10.
+	said := "the bus refused the controller: nats: permissions violation: Permissions Violation for " +
+		`Publish to "mesh.seat.mesh-delivery.tool.times"`
+	advisory := link.Advisory{Kind: link.AdvisoryRefused, ID: "controller", Said: said,
+		First: refused, Last: refused, Count: 1}
+	look := func() conditions.Condition {
+		t.Helper()
+		f := &signalFacts{now: now, host: "novox", advisories: []link.Advisory{advisory}}
+		if err := k.Reconcile(t.Context(), "S9", watchAdvisories(f)); err != nil {
+			t.Fatal(err)
+		}
+		c, found, err := conditions.ReadOne(t.Context(), store, "bus.controller.refused")
+		if err != nil || !found {
+			t.Fatalf("bus.controller.refused: found %v, %v", found, err)
+		}
+		return c
+	}
+
+	var c conditions.Condition
+	for range 15 {
+		c = look()
+		now = now.Add(30 * time.Second)
+	}
+	if c.Observations != 1 || len(c.Evidence) != 1 {
+		t.Fatalf("one refusal, looked at 15 times, reads as observed %d time(s) with %d evidence lines: %+v",
+			c.Observations, len(c.Evidence), c.Evidence)
+	}
+	if !c.LastObserved.Equal(refused) || !c.Evidence[0].At.Equal(refused) {
+		t.Fatalf("last observed %s, evidence at %s: the refusal was at %s", c.LastObserved, c.Evidence[0].At, refused)
+	}
+
+	// The bus refuses it three times more between two looks: the condition counts four refusals, says
+	// the newest, and adds one line of evidence for the look that saw them.
+	again := now.Add(-5 * time.Second)
+	advisory.Last, advisory.Count = again, 4
+	c = look()
+	if c.Observations != 4 || len(c.Evidence) != 2 || !c.LastObserved.Equal(again) || !c.Evidence[0].At.Equal(again) {
+		t.Fatalf("four refusals read as observed %d time(s), last %s, evidence %+v", c.Observations, c.LastObserved, c.Evidence)
+	}
+	if !strings.Contains(c.Summary, "(4 times since 18:52 UTC)") {
+		t.Fatalf("summary %q", c.Summary)
+	}
+	now = now.Add(30 * time.Second)
+	if c = look(); c.Observations != 4 || len(c.Evidence) != 2 {
+		t.Fatalf("a look with nothing new counted: observed %d time(s), evidence %+v", c.Observations, c.Evidence)
+	}
+}
+
+// **A condition that looks at the present still counts its looks** (novox/hq issue 402 changes only
+// what reads a record): a machine silent for three looks was observed three times, and says so.
+func TestAConditionOfThePresentCountsItsLooks(t *testing.T) {
+	now := time.Date(2026, 10, 10, 19, 0, 0, 0, time.UTC)
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return now }})
+	t.Cleanup(func() { k.Close(t.Context()) })
+	var c conditions.Condition
+	for range 3 {
+		var err error
+		if c, err = k.Observe(t.Context(), conditions.Observation{Scope: conditions.ScopeMachine, ID: "ace",
+			Kind: "silent", Machine: "ace", Severity: conditions.Warning, Summary: "ace has not been heard from",
+			Source: "S1"}); err != nil {
+			t.Fatal(err)
+		}
+		now = now.Add(30 * time.Second)
+	}
+	if c.Observations != 3 || len(c.Evidence) != 3 || !c.LastObserved.Equal(now.Add(-30*time.Second)) {
+		t.Fatalf("observed %d time(s), %d evidence lines, last %s", c.Observations, len(c.Evidence), c.LastObserved)
+	}
+}
+
+// **One key, one watcher** (novox/hq issue 440). A consumer's max-deliveries condition is said from
+// DEAD_LETTERS while it holds a message the consumer gave up on (issue 330). A max-deliveries advisory
+// without a token names the same key; read beside it, each look added an observation and a line of
+// evidence through the dead-letter half, and the two summaries overwrote each other on every look. The
+// dead-letter row alone says that key, and counts the messages given up on, never the looks.
+func TestAHeldDeadLetterIsCountedByWhatWasGivenUpNotByTheLooks(t *testing.T) {
+	gaveUp := time.Date(2026, 10, 10, 21, 4, 0, 0, time.UTC)
+	now := gaveUp.Add(20 * time.Second)
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return now }})
+	t.Cleanup(func() { k.Close(t.Context()) })
+
+	const key = "bus.EVENTS.media_sonarr.max-deliveries"
+	held := map[string]int{"EVENTS.media_sonarr": 1}
+	newest := map[string]time.Time{"EVENTS.media_sonarr": gaveUp}
+	advisory := link.Advisory{Kind: link.AdvisoryMaxDeliveries, ID: "EVENTS.media_sonarr", Stream: "EVENTS",
+		Consumer: "media_sonarr", Said: "sonarr on media handed message 7 over 5 times and gave up on it",
+		First: gaveUp, Last: gaveUp, Count: 1}
+	look := func() conditions.Condition {
+		t.Helper()
+		f := &signalFacts{now: now, host: "novox", advisories: []link.Advisory{advisory},
+			deadLetters: held, deadLettersNewest: newest}
+		if err := k.Reconcile(t.Context(), "S9", watchAdvisories(f)); err != nil {
+			t.Fatal(err)
+		}
+		c, found, err := conditions.ReadOne(t.Context(), store, key)
+		if err != nil || !found {
+			t.Fatalf("%s: found %v, %v", key, found, err)
+		}
+		if !strings.Contains(c.Summary, "dead-letters verb") {
+			t.Fatalf("the summary is not the dead-letter row's: %q", c.Summary)
+		}
+		return c
+	}
+
+	var c conditions.Condition
+	for range 5 {
+		c = look()
+		now = now.Add(30 * time.Second)
+	}
+	if c.Observations != 1 || len(c.Evidence) != 1 || !c.LastObserved.Equal(gaveUp) {
+		t.Fatalf("one message given up on, looked at five times, reads as observed %d time(s), last %s, "+
+			"with %d evidence lines: %+v", c.Observations, c.LastObserved, len(c.Evidence), c.Evidence)
+	}
+
+	// The consumer gives up on a second message between two looks: two given up on, one more line.
+	again := now.Add(-10 * time.Second)
+	held["EVENTS.media_sonarr"], newest["EVENTS.media_sonarr"] = 2, again
+	c = look()
+	if c.Observations != 2 || len(c.Evidence) != 2 || !c.LastObserved.Equal(again) {
+		t.Fatalf("two given up on read as observed %d time(s), last %s, evidence %+v", c.Observations,
+			c.LastObserved, c.Evidence)
+	}
+	now = now.Add(30 * time.Second)
+	if c = look(); c.Observations != 2 || len(c.Evidence) != 2 {
+		t.Fatalf("a look with nothing new counted: observed %d time(s), evidence %+v", c.Observations, c.Evidence)
+	}
+}
+
+// The advisory still says the max-deliveries it alone knows: a message given up on that could not be
+// kept, under a key of its own (issue 330), which issue 440's change leaves as it was.
+func TestAMessageThatCouldNotBeKeptIsStillSaidFromTheAdvisory(t *testing.T) {
+	at := time.Date(2026, 10, 10, 21, 4, 0, 0, time.UTC)
+	f := &signalFacts{now: at, host: "novox", advisories: []link.Advisory{{Kind: link.AdvisoryMaxDeliveries,
+		ID: "EVENTS.media_sonarr", Stream: "EVENTS", Consumer: "media_sonarr", Token: link.AdvisoryNotKept,
+		Said: "sonarr on media gave up on message 7, and it could not be kept", First: at, Last: at, Count: 1}}}
+	said := watchAdvisories(f)
+	if len(said) != 1 || said[0].Key() != "bus.EVENTS.media_sonarr.not-kept" {
+		t.Fatalf("%+v", said)
+	}
+}
+
+// A max-deliveries advisory without a token names a consumer's dead-letter key, which only DEAD_LETTERS
+// says (novox/hq issues 330 and 440): with nothing held, the advisory alone raises nothing.
+func TestAMaxDeliveriesAdvisoryAloneRaisesNothing(t *testing.T) {
+	at := time.Date(2026, 10, 10, 21, 4, 0, 0, time.UTC)
+	f := &signalFacts{now: at, host: "novox", advisories: []link.Advisory{{Kind: link.AdvisoryMaxDeliveries,
+		ID: "EVENTS.media_sonarr", Stream: "EVENTS", Consumer: "media_sonarr",
+		Said: "sonarr on media handed message 7 over 5 times and gave up on it", First: at, Last: at, Count: 1}}}
+	if said := watchAdvisories(f); len(said) != 0 {
+		t.Fatalf("said %+v", said)
+	}
+}

cmd/mesh-controller/agent_account.go

@@ -0,0 +1,253 @@
+package main
+
+// The account agents run as (novox/hq ADR 0266).
+//
+// On the control node every agent session ran as the operator's account, which may become root without a
+// password — so any agent there could become root without a person, and ADR 0259 §8 (an answer from the
+// operator's phone authorises an act) rests on that being false where the router and its channels run. The
+// decision: a node may name an account its agents run as, of their own and without sudo; the operator's
+// account keeps its sudo.
+//
+//   - **Named at the controller's terminal only** (`node agent-account`): not a verb, not a setting, so no
+//     agent can name itself another account. Empty is a real state: agents run as the operator there.
+//   - **Composed** as `${machine:agent-account}`, `${machine:agent-home}` and `${machine:agent-root}` for the
+//     agent's module, which declares the account with `root: never`, and as MESH_AGENT_ACCOUNT and
+//     MESH_AGENT_HOME for its tools (catalogue/machine_into_files.go, runtime.go).
+//   - **Judged by the machine itself.** The node-engine reads, on every look, whether an account declared
+//     `root: never` can become root without a person — uid 0, a group that grants root, a sudo rule, a
+//     secret of the mesh it may read — and says it as the declaring module's account verdict, marked
+//     Root "never". agentConfined reads that verdict; the self-check (probe DA) raises
+//     `agent-can-become-root` while it does not hold, and `node show` says it.
+//
+// A verdict not given is never a pass: an engine older than the judging, an account not yet declared, a
+// statement that says nothing of it — each is "not judged", and fails.
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// kindAgentCanBecomeRoot is the condition raised while a machine's agent account can become root without
+// a person, or is not judged (ADR 0266).
+const kindAgentCanBecomeRoot = "agent-can-become-root"
+
+// agentAccountProbe is the self-check's probe of it.
+const agentAccountProbe = "DA"
+
+// agentConfined says whether the agents of a machine that names an agent account are confined: the
+// machine's newest statement holds a healthy account verdict, judged for root, on that account. named is
+// false for a machine that names none — agents run as the operator account there, which this does not
+// judge. why is said either way, in the mesh's words; err is a store that could not be read.
+//
+// The one judgement: `node show`, the self-check, and ADR 0259's router honouring a verified sender read
+// it here.
+// now is the judging clock, threaded so a caller judging several things at one instant judges them all at it.
+func agentConfined(ctx context.Context, inv *inventory.Inventory, node string, now time.Time) (named, confined bool, why string, err error) {
+	n, err := inv.NodeByName(ctx, node)
+	if err != nil {
+		return false, false, "", err
+	}
+	if n.AgentAccount == "" {
+		return false, false, fmt.Sprintf("%s names no agent account: agents run as the operator account (%s)",
+			node, orNoneKnown(n.Account)), nil
+	}
+	h, had, err := inv.HealthOf(ctx, node)
+	if err != nil {
+		return true, false, "", err
+	}
+	confined, why = judgedConfined(n.AgentAccount, h, had, now)
+	return true, confined, why, nil
+}
+
+// verdictFreshFor is how old the statement holding the verdict may be, by this controller's clock. A
+// node-engine states its health on every change and at least every five minutes (mesh-host's sayAnyway), so
+// three statements missed is a node-engine stopped, or a machine away. **A stale verdict is not a pass**: an
+// agent that stopped the node-engine must not leave "cannot become root" standing from before.
+const verdictFreshFor = 15 * time.Minute
+
+// judgedConfined is the judgement over one statement, without the store, at now.
+func judgedConfined(agent string, h inventory.NodeHealth, had bool, now time.Time) (bool, string) {
+	if !had {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's node-engine has stated "+
+			"nothing of what it runs", agent)
+	}
+	if age := now.Sub(h.HeardAt); age > verdictFreshFor {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's newest statement was heard at "+
+			"%s, more than %d minutes ago, and a verdict that old is not a verdict on now", agent,
+			h.HeardAt.Local().Format("2006-01-02 15:04"), int(verdictFreshFor.Minutes()))
+	}
+	if h.Contract < link.RootContract {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's node-engine is older than "+
+			"the judging of an account's root (its statement's contract is %d, the judging is %d)",
+			agent, h.Contract, link.RootContract)
+	}
+	var verdicts []inventory.ResourceHealth
+	for _, r := range h.Resources {
+		if r.Kind == link.KindAccount && r.Target == agent && r.Root == link.RootNever {
+			verdicts = append(verdicts, r)
+		}
+	}
+	if len(verdicts) == 0 {
+		return false, fmt.Sprintf("the agent account %s is not judged: the machine's newest statement holds no "+
+			"verdict on it — no module there declares it never to become root, or the declaration naming it "+
+			"has not been applied", agent)
+	}
+	sort.Slice(verdicts, func(i, j int) bool {
+		return verdicts[i].Module+verdicts[i].Resource < verdicts[j].Module+verdicts[j].Resource
+	})
+	for _, v := range verdicts {
+		switch v.State {
+		case link.StateHealthy:
+		case link.StateUnhealthy:
+			// The engine's own words, which start with link.ReasonRoot when it found a way to root.
+			return false, fmt.Sprintf("the agent account %s %s (said by %s's %s)", agent,
+				orNoneKnown(v.Reason), v.Module, v.Resource)
+		default:
+			return false, fmt.Sprintf("the agent account %s is not judged: %s (%s's %s, %s)", agent,
+				orNoneKnown(v.Reason), v.Module, v.Resource, v.State)
+		}
+	}
+	return true, fmt.Sprintf("the agent account %s cannot become root without a person (judged %s)", agent,
+		h.SaidAt.Local().Format("2006-01-02 15:04"))
+}
+
+// searchQuietFor is how long the controller lets an agent account's verdict wait for the node-engine's setuid
+// search before that is itself the urgent condition: the longest a search is expected to take (link.RootSearchQuiet,
+// the engine's own value; novox/hq issue 361 — the search runs to completion, with no bound of its own), counted
+// from when this controller first saw it waiting, never from the engine's start. Quiet raises nothing; it never
+// makes the agent account confined, which only a healthy verdict from a complete, fresh search does.
+const searchQuietFor = link.RootSearchQuiet
+
+// The kinds of an agent account's verdict, for the quiet a search earns.
+const (
+	verdictOther    = iota // anything else: a stale statement, an older engine, no verdict, another unknown
+	verdictPending         // waiting for the search, and otherwise healthy
+	verdictComplete        // judged: healthy, or a way to root found
+)
+
+// rootVerdictKind reads a statement for the agent account (novox/hq ADR 0266): pending when every verdict on it
+// is healthy or not judged yet because the engine's setuid search runs, at least one of them that; complete when
+// every verdict is healthy or one found a way to root. The engine's own "since" is not read: it starts again at
+// every restart of the engine.
+func rootVerdictKind(agent string, h inventory.NodeHealth, had bool, now time.Time) int {
+	if !had || now.Sub(h.HeardAt) > verdictFreshFor || h.Contract < link.RootContract {
+		return verdictOther
+	}
+	pending, any := false, false
+	for _, r := range h.Resources {
+		if r.Kind != link.KindAccount || r.Target != agent || r.Root != link.RootNever {
+			continue
+		}
+		any = true
+		switch {
+		case r.State == link.StateHealthy:
+		case r.State == link.StateUnhealthy:
+			return verdictComplete
+		case r.State == link.StateUnknown && strings.HasPrefix(r.Reason, link.ReasonRootPending):
+			pending = true
+		default:
+			return verdictOther
+		}
+	}
+	switch {
+	case !any:
+		return verdictOther
+	case pending:
+		return verdictPending
+	}
+	return verdictComplete
+}
+
+// searchStillRunning says the one thing keeping an agent account from being judged is the node-engine's setuid
+// search, and that this controller first saw it waiting less than searchQuietFor ago — kept in the store, so a
+// node-engine restarted in a loop does not keep it quiet. A complete verdict forgets when it began.
+func searchStillRunning(ctx context.Context, inv *inventory.Inventory, node, agent string, h inventory.NodeHealth,
+	had bool, now time.Time) (bool, error) {
+	switch rootVerdictKind(agent, h, had, now) {
+	case verdictComplete:
+		return false, inv.RootSearchJudged(ctx, node)
+	case verdictPending:
+		since, err := inv.RootSearchPending(ctx, node, now)
+		if err != nil {
+			return false, err
+		}
+		return now.Sub(since) <= searchQuietFor, nil
+	}
+	return false, nil
+}
+
+// probeAgentAccounts is DA: every machine that names an agent account has it judged, on its node-engine's
+// newest statement, unable to become root without a person (ADR 0266).
+func probeAgentAccounts(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	inv := d.open.inventory
+	nodes, err := inv.Nodes(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var out []conditions.Observation
+	for _, n := range nodes {
+		if n.AgentAccount == "" {
+			continue
+		}
+		h, had, err := inv.HealthOf(ctx, n.Name)
+		if err != nil {
+			return nil, err
+		}
+		now := time.Now()
+		quiet, err := searchStillRunning(ctx, inv, n.Name, n.AgentAccount, h, had, now)
+		if err != nil {
+			return nil, err
+		}
+		confined, why := judgedConfined(n.AgentAccount, h, had, now)
+		if confined {
+			continue
+		}
+		// Not judged yet only because the node-engine's search runs and no complete, fresh one judges: not the
+		// urgent condition after every restart. The agent is still not confined — ADR 0259's router reads
+		// agentConfined, not this — and `node show` still says not judged. Loud again once the search fails,
+		// waits past searchQuietFor, or the statement goes stale.
+		if quiet {
+			continue
+		}
+		out = append(out, conditions.Observation{Scope: conditions.ScopeMachine, ID: n.Name, Token: "agent-root",
+			Machine: n.Name, Severity: conditions.Urgent,
+			Summary: fmt.Sprintf("on %s, %s (ADR 0266): an agent there may become root without a person, and "+
+				"no answer from a channel authorises an act there (ADR 0259 §8)", n.Name, why),
+			Said: why})
+	}
+	return sortedFound(out), nil
+}
+
+// agentAccountLines is what `node show` says of the account agents run as.
+func agentAccountLines(ctx context.Context, inv *inventory.Inventory, n inventory.Node) []string {
+	if n.AgentAccount == "" {
+		return []string{fmt.Sprintf("  agents run as      the operator account (%s); no agent account is named",
+			orNoneKnown(n.Account))}
+	}
+	_, confined, why, err := agentConfined(ctx, inv, n.Name, time.Now())
+	if err != nil {
+		return []string{fmt.Sprintf("  agents run as      %s (home %s); whether it can become root could NOT be read: %v",
+			n.AgentAccount, n.AgentHome(), err)}
+	}
+	verdict := "CAN become root, or is not judged: " + why
+	if confined {
+		verdict = why
+	}
+	return []string{fmt.Sprintf("  agents run as      %s (home %s)", n.AgentAccount, n.AgentHome()),
+		"                     " + verdict}
+}
+
+// orNoneKnown is a value, or that none is known.
+func orNoneKnown(s string) string {
+	if strings.TrimSpace(s) == "" {
+		return "none known"
+	}
+	return s
+}

cmd/mesh-controller/agent_account_integration_test.go

@@ -0,0 +1,161 @@
+//go:build integration
+
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	snapshot "github.com/novox/mesh-controller/internal/facts"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-host/rootsearch"
+)
+
+func TestTheSelfCheckSaysAnAgentAccountThatCanBecomeRoot(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	for _, n := range []string{"anchor", "laptop"} {
+		if _, err := inv.NodeByName(ctx, n); err != nil {
+			if _, err := inv.AddNode(ctx, n); err != nil {
+				t.Fatal(err)
+			}
+		}
+		if err := inv.SetAccount(ctx, n, "ops", ""); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := inv.SetAgentAccount(ctx, "anchor", "agent", ""); err != nil {
+		t.Fatal(err)
+	}
+	d := &doctor{open: open}
+	found, err := probeAgentAccounts(ctx, d)
+	if err != nil {
+		t.Fatal(err)
+	}
+	found = onlyMachine(found, "anchor")
+	if len(found) != 1 || found[0].Machine != "anchor" || found[0].Severity != conditions.Urgent ||
+		!strings.Contains(found[0].Said, "not judged") {
+		t.Fatalf("a named agent account with no verdict: %+v", found)
+	}
+	w := plainWordings[kindAgentCanBecomeRoot](conditions.Observation{Kind: kindAgentCanBecomeRoot, Machine: "anchor"})
+	if w.Headline == "" || w.Needs == "" || w.Resolved == "" {
+		t.Errorf("the condition has no plain words: %+v", w)
+	}
+
+	healthy := inventory.ResourceHealth{Module: "claude-code", Resource: "claude-code.agent-account",
+		Kind: link.KindAccount, Target: "agent", State: link.StateHealthy, Root: link.RootNever, Account: "agent"}
+	if _, err := inv.RecordHealth(ctx, inventory.NodeHealth{Node: "anchor", Contract: link.RootContract,
+		SaidAt: time.Now(), HeardAt: time.Now(), Resources: []inventory.ResourceHealth{healthy}}); err != nil {
+		t.Fatal(err)
+	}
+	if found, err = probeAgentAccounts(ctx, d); err != nil || len(onlyMachine(found, "anchor")) != 0 {
+		t.Fatalf("a judged agent account still fails: %+v %v", found, err)
+	}
+	if named, confined, why, err := agentConfined(ctx, inv, "anchor", time.Now()); err != nil || !named || !confined {
+		t.Fatalf("agentConfined on anchor: %v %v %q %v", named, confined, why, err)
+	}
+	if named, _, why, err := agentConfined(ctx, inv, "laptop", time.Now()); err != nil || named ||
+		!strings.Contains(why, "operator account") {
+		t.Fatalf("agentConfined on a machine naming none: %v %q %v", named, why, err)
+	}
+}
+
+func TestTheFactsCarryTheAgentAccountAsAPseudonym(t *testing.T) {
+	open, _ := aMeshWithSecrets(t)
+	ctx := t.Context()
+	if err := open.inventory.SetAccount(ctx, "anchor", "keeper", ""); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.SetAgentAccount(ctx, "anchor", "warden", ""); err != nil {
+		t.Fatal(err)
+	}
+	f, err := gatherFacts(ctx, open, "2.11.17")
+	if err != nil {
+		t.Fatal(err)
+	}
+	body, _ := f.Encode()
+	if strings.Contains(string(body), "warden") {
+		t.Error("the agent account's name is in the snapshot")
+	}
+	m, ok := f.Machine(snapshot.Pseudonym("machine", "anchor"))
+	if !ok || m.AgentAccount != snapshot.Pseudonym("account", "warden") || m.Account == m.AgentAccount {
+		t.Fatalf("the anchor's agent account reads as %q (operator %q)", m.AgentAccount, m.Account)
+	}
+}
+
+func TestASearchStillRunningAfterARestartIsNotUrgent(t *testing.T) {
+	if searchQuietFor != rootsearch.Quiet {
+		t.Fatalf("the quiet is %s and the node-engine's %s: they are one value", searchQuietFor, rootsearch.Quiet)
+	}
+	// A daily search that finishes within the quiet never leaves the account unjudged between two of them.
+	if rootsearch.FreshFor < rootsearch.Every+rootsearch.Quiet {
+		t.Fatalf("a complete search judges for %s, less than a day's search (%s) and the quiet (%s)",
+			rootsearch.FreshFor, rootsearch.Every, rootsearch.Quiet)
+	}
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	if _, err := inv.NodeByName(ctx, "anchor"); err != nil {
+		if _, err := inv.AddNode(ctx, "anchor"); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := inv.SetAgentAccount(ctx, "anchor", "agent", ""); err != nil {
+		t.Fatal(err)
+	}
+	d := &doctor{open: open}
+	say := func(state, reason string) []conditions.Observation {
+		t.Helper()
+		// The engine's since is always now: it was just restarted.
+		v := inventory.ResourceHealth{Module: "claude-code", Resource: "claude-code.agent-account",
+			Kind: link.KindAccount, Target: "agent", State: state, Reason: reason, Root: link.RootNever,
+			Account: "agent", Since: time.Now()}
+		if _, err := inv.RecordHealth(ctx, inventory.NodeHealth{Node: "anchor", Contract: link.RootContract,
+			SaidAt: time.Now(), HeardAt: time.Now(), Resources: []inventory.ResourceHealth{v}}); err != nil {
+			t.Fatal(err)
+		}
+		found, err := probeAgentAccounts(ctx, d)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return onlyMachine(found, "anchor")
+	}
+	running := link.ReasonRootPending + ": the search for setuid programs, started at 19:21, has not finished yet"
+	healthy := func() {
+		t.Helper()
+		if found := say(link.StateHealthy, ""); len(found) != 0 {
+			t.Fatalf("a healthy verdict raised: %+v", found)
+		}
+	}
+	if found := say(link.StateUnknown, running); len(found) != 0 {
+		t.Fatalf("a search first seen now was raised: %+v", found)
+	}
+	if _, confined, why, _ := agentConfined(ctx, inv, "anchor", time.Now()); confined || !strings.Contains(why, "not judged") {
+		t.Fatalf("an account whose search runs was read as confined: %q", why)
+	}
+	// The engine restarted again and again, each statement's own since fresh: the controller's clock runs on.
+	if _, err := inv.RootSearchPending(ctx, "anchor", time.Now().Add(-searchQuietFor-time.Minute)); err != nil {
+		t.Fatal(err)
+	}
+	healthy() // a complete verdict forgets when the waiting began …
+	if _, err := inv.RootSearchPending(ctx, "anchor", time.Now().Add(-searchQuietFor-time.Minute)); err != nil {
+		t.Fatal(err) // … and this restart loop began past the bound
+	}
+	if found := say(link.StateUnknown, running); len(found) != 1 || found[0].Severity != conditions.Urgent {
+		t.Fatalf("a search pending past the bound, by the controller's clock, was not urgent: %+v", found)
+	}
+	healthy()
+	incomplete := rootsearch.ReasonIncomplete + ": the search for setuid programs did not finish (last tried at " +
+		"19:23: timeout); it is tried again later"
+	if found := say(link.StateUnknown, incomplete); len(found) != 1 || found[0].Severity != conditions.Urgent {
+		t.Fatalf("a search that did not finish was not urgent: %+v", found)
+	}
+	if found := say(link.StateUnhealthy, link.ReasonRoot+": in the group docker; "+running); len(found) != 1 ||
+		found[0].Severity != conditions.Urgent {
+		t.Fatalf("a way to root found while the search runs was not urgent: %+v", found)
+	}
+}

cmd/mesh-controller/agent_account_test.go

@@ -0,0 +1,134 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The agent account's judgement (novox/hq ADR 0266): confined only on a healthy account verdict judged for
+// root, on the very account; every verdict not given — no statement, an older engine, no verdict on it, a
+// verdict of unknown — is "not judged" and fails, never a pass.
+func TestAnAgentAccountIsConfinedOnlyOnAHealthyVerdictJudgedForRoot(t *testing.T) {
+	at := time.Date(2026, 10, 8, 19, 21, 0, 0, time.UTC)
+	verdict := func(target, root, state, reason string) inventory.ResourceHealth {
+		return inventory.ResourceHealth{Module: "claude-code", Resource: "claude-code.agent-account",
+			Kind: link.KindAccount, Target: target, State: state, Reason: reason, Root: root, Account: target}
+	}
+	statement := func(contract int, rs ...inventory.ResourceHealth) inventory.NodeHealth {
+		return inventory.NodeHealth{Node: "anchor", Contract: contract, SaidAt: at, HeardAt: at, Resources: rs}
+	}
+	for _, c := range []struct {
+		name     string
+		h        inventory.NodeHealth
+		had      bool
+		confined bool
+		says     string
+	}{
+		{"judged and unable", statement(link.RootContract, verdict("agent", link.RootNever, link.StateHealthy, "")),
+			true, true, "cannot become root without a person"},
+		{"judged and able", statement(link.RootContract, verdict("agent", link.RootNever, link.StateUnhealthy,
+			link.ReasonRoot+": in the group docker, which grants root")), true, false, "in the group docker"},
+		{"a verdict of unknown", statement(link.RootContract, verdict("agent", link.RootNever, link.StateUnknown,
+			"sudo could not be read")), true, false, "not judged"},
+		{"no statement", inventory.NodeHealth{}, false, false, "not judged"},
+		{"an older engine", statement(link.ReadinessContract, verdict("agent", "", link.StateHealthy, "")),
+			true, false, "older than the judging"},
+		{"a verdict on groups only", statement(link.RootContract, verdict("agent", "", link.StateHealthy, "")),
+			true, false, "no verdict on it"},
+		{"a verdict on another account", statement(link.RootContract, verdict("ops", link.RootNever, link.StateHealthy, "")),
+			true, false, "no verdict on it"},
+	} {
+		confined, why := judgedConfined("agent", c.h, c.had, at.Add(time.Minute))
+		if confined != c.confined || !strings.Contains(why, c.says) {
+			t.Errorf("%s: confined %v, %q; want %v saying %q", c.name, confined, why, c.confined, c.says)
+		}
+	}
+	// A verdict heard longer ago than the bound is no verdict: an agent that stopped the node-engine must not
+	// leave "healthy" standing.
+	fresh := statement(link.RootContract, verdict("agent", link.RootNever, link.StateHealthy, ""))
+	if ok, _ := judgedConfined("agent", fresh, true, at.Add(verdictFreshFor)); !ok {
+		t.Error("a verdict exactly at the bound is still one")
+	}
+	if ok, why := judgedConfined("agent", fresh, true, at.Add(verdictFreshFor+time.Second)); ok ||
+		!strings.Contains(why, "not judged") {
+		t.Errorf("a stale healthy verdict passed: %q", why)
+	}
+}
+
+// DA raises an urgent condition, with plain words, on a machine whose agent account is not judged unable to
+// become root; a machine that names none is not its to judge.
+
+func TestTheAgentRootWordsArePlain(t *testing.T) {
+	w := plainWordings[kindAgentCanBecomeRoot](conditions.Observation{Kind: kindAgentCanBecomeRoot, Machine: "anchor"})
+	if why, ok := conditions.PlainWords(w, "anchor"); !ok {
+		t.Fatalf("not plain: %s: %+v", why, w)
+	}
+}
+
+func onlyMachine(obs []conditions.Observation, machine string) []conditions.Observation {
+	var out []conditions.Observation
+	for _, o := range obs {
+		if o.Machine == machine {
+			out = append(out, o)
+		}
+	}
+	return out
+}
+
+// The snapshot a merge check composes from carries the agent account as a pseudonym (novox/hq ADR 0266),
+// so a change is judged against machines that name one, and the name never leaves.
+
+// No verb runs a `node` command that sets something: through the generic `command` verb, `node account`,
+// `node agent-account` and every other `node` subcommand but list and show are refused, naming the terminal.
+func TestNoVerbSetsANodesAccounts(t *testing.T) {
+	for _, line := range []string{
+		"node agent-account novox --clear",
+		"node agent-account novox ops",
+		"node account novox agent",
+		"node account novox",
+		"node add intruder",
+		"node public-domain novox --clear",
+		"node",
+		"node frobnicate",
+	} {
+		argv, err := argvFor("command", map[string]any{"command": line})
+		if err == nil || !strings.Contains(err.Error(), "controller's terminal") ||
+			!strings.Contains(err.Error(), "ADR 0266") {
+			t.Errorf("%q ran as %v (%v); want a refusal naming the terminal", line, argv, err)
+		}
+	}
+	for _, line := range []string{"node show novox", "node list --json", "status --json"} {
+		if _, err := argvFor("command", map[string]any{"command": line}); err != nil {
+			t.Errorf("%q, a read, was refused: %v", line, err)
+		}
+	}
+	if err := terminalOnly([]string{"node", "account", "a", "b"}); err == nil {
+		t.Error("the refusal is not only the command verb's")
+	}
+}
+
+// Naming the agent account is the controller's terminal's alone: the `node` verb only shows.
+func TestTheNodeVerbOnlyShows(t *testing.T) {
+	argv, err := argvFor("node", map[string]any{"node": "anchor"})
+	if err != nil || strings.Join(argv, " ") != "node show anchor" {
+		t.Fatalf("the node verb runs %v (%v)", argv, err)
+	}
+	for _, v := range catalogue.ControllerVerbs {
+		if strings.Contains(v.Name, "agent") {
+			t.Errorf("a verb %q may name the agent account", v.Name)
+		}
+	}
+}
+
+// Until a complete search for setuid programs judges — none since the node-engine's state was kept, or the last
+// older than the engine lets one judge — the agent account is not judged, and the search runs to its end with no
+// bound (novox/hq issue 361). DA does not raise that as urgent within searchQuietFor, counted from when this
+// controller first saw it waiting — never from the engine's own "since", which a restart resets, so an engine
+// restarted in a loop does not keep it quiet. The account is still not confined, and `node show` still says not
+// judged; a search that failed, or a way to root found, is urgent at once.

cmd/mesh-controller/api.go

@@ -94,19 +94,29 @@ func (n notYet) Who(*http.Request) (string, error) {
 func commands(who Authenticator) http.Handler {
 	mux := http.NewServeMux()
 
-	mux.HandleFunc("POST /assign", acting(who, func(ctx context.Context, open *stores, in request) (string, error) {
-		return assign(ctx, open, in.Node, in.Module)
+	mux.HandleFunc("POST /assign", acting(who, true, func(ctx context.Context, open *stores, in request) (string, error) {
+		return assign(ctx, open, in.Node, splitModules(in.Module)...)
 	}))
-	mux.HandleFunc("POST /unassign", acting(who, func(ctx context.Context, open *stores, in request) (string, error) {
-		return unassign(ctx, open, in.Node, in.Module)
+	mux.HandleFunc("POST /unassign", acting(who, true, func(ctx context.Context, open *stores, in request) (string, error) {
+		return unassign(ctx, open, in.Node, splitModules(in.Module)...)
+	}))
+	// Adoption (novox/hq ADR 0100): the same acts as `take`, `converge` and `adopt`.
+	mux.HandleFunc("POST /take", acting(who, true, func(ctx context.Context, open *stores, in request) (string, error) {
+		return take(ctx, open, in.Node, in.Module, takeOptions{Yes: in.Yes, Digest: in.Digest})
+	}))
+	mux.HandleFunc("POST /converge", acting(who, false, func(ctx context.Context, open *stores, in request) (string, error) {
+		return converge(ctx, open, in.Node, in.Yes, in.Digest, in.Filter)
+	}))
+	mux.HandleFunc("POST /adopt", acting(who, false, func(ctx context.Context, open *stores, in request) (string, error) {
+		return adopt(ctx, open, in.Node)
 	}))
 
 	// Anything else is said plainly, because a command surface answering 404 to a verb somebody
 	// expected is indistinguishable from one that is down.
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		refuse(w, http.StatusNotFound, fmt.Errorf(
-			"%s %s is not something this mesh can be asked; it accepts POST /assign and "+
-				"POST /unassign", r.Method, r.URL.Path))
+			"%s %s is not something this mesh can be asked; it accepts POST /assign, "+
+				"POST /unassign, POST /take, POST /converge and POST /adopt", r.Method, r.URL.Path))
 	})
 	return mux
 }
@@ -114,11 +124,17 @@ func commands(who Authenticator) http.Handler {
 type request struct {
 	Node   string `json:"node"`
 	Module string `json:"module"`
+	// Yes, Digest and Filter are converge's and take's: do it rather than preview it, the digest
+	// of the preview it acts on, and (converge) which module loads the mesh's filter.
+	Yes    bool   `json:"yes,omitempty"`
+	Digest string `json:"digest,omitempty"`
+	Filter string `json:"filter,omitempty"`
 }
 
 // acting is the shape every route shares: authenticate, read, act, answer.
 func acting(
 	who Authenticator,
+	needsModule bool,
 	do func(context.Context, *stores, request) (string, error),
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -131,8 +147,12 @@ func acting(
 			refuse(w, http.StatusBadRequest, fmt.Errorf("this is not a request this understands: %w", err))
 			return
 		}
-		if in.Node == "" || in.Module == "" {
-			refuse(w, http.StatusBadRequest, errors.New(`both "node" and "module" are needed`))
+		if in.Node == "" || (needsModule && in.Module == "") {
+			if needsModule {
+				refuse(w, http.StatusBadRequest, errors.New(`both "node" and "module" are needed`))
+			} else {
+				refuse(w, http.StatusBadRequest, errors.New(`"node" is needed`))
+			}
 			return
 		}
 

cmd/mesh-controller/api_test.go

@@ -1,3 +1,5 @@
+//go:build integration
+
 package main
 
 import (

cmd/mesh-controller/apply_failing.go

@@ -0,0 +1,164 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// kindApplyFailing is S21's kind: a machine whose declarations have been refused, or applied only in part,
+// for longer than one apply interval (novox/hq issue 233).
+const kindApplyFailing = "apply-failing"
+
+// applyEvery is how often a node-engine applies what it was last told when nothing new arrives: its
+// ReconcileEvery. A failure still there after one more of them is not one the next apply clears.
+const applyEvery = 5 * time.Minute
+
+// packageManagerKey is how a node-engine names a package manager that does not answer among what failed
+// (mesh-host's probe.go): "the package manager (pacman)".
+const packageManagerKey = "the package manager ("
+
+// watchApplyFailing is S21: **a machine that does not apply what it was sent is said by the mesh, not only
+// to someone who asks for `status`** (novox/hq issue 233, issue 187's family). A workstation refused every
+// declaration for an hour and a half because its package manager did not answer, and the mesh's only word
+// on it was a line in `status`. Raised once the machine's first report of this failure is older than one apply
+// interval **while the machine is heard** — judged by time, not by how many reports said it: a node-engine
+// says a re-apply only when how it went changed, so the same failure is one report however long it lasts.
+// Names the refusal's or the failure's words; cleared by the clean apply the node-engine then says. Not while
+// the machine is silent, asleep or not known: S1 says silent, and asleep is not lost.
+func watchApplyFailing(f *signalFacts) []conditions.Observation {
+	heard := map[string]bool{}
+	for _, m := range f.machines {
+		if !m.asleep() && !m.lastHeard.IsZero() && f.now.Sub(m.lastHeard) <= heartbeatBound(m.every) {
+			heard[m.name] = true
+		}
+	}
+	var out []conditions.Observation
+	said := map[string]bool{}
+	for _, d := range f.doing {
+		if !d.Wrong() || d.Since == nil || f.now.Sub(*d.Since) <= applyEvery || !heard[d.Node] {
+			continue
+		}
+		out = append(out, applyFailing(d, f.now))
+		said[d.Node] = true
+	}
+	// **A module's files the provisioner failed to place are a failed apply too** (novox/hq ADR 0362 §3): its client's
+	// newest word, judged by the same bound — the client says a failure once, and fills again on every change —
+	// on a machine whose node-engine applied what it was sent.
+	failed := map[string][]inventory.ProvReport{}
+	for _, r := range f.provFailed {
+		if r.Status != inventory.ProvFailed || f.now.Sub(r.At) <= applyEvery || !heard[r.Node] || said[r.Node] {
+			continue
+		}
+		failed[r.Node] = append(failed[r.Node], r)
+	}
+	for _, node := range sortedNames(failed) {
+		out = append(out, provisioningFailing(node, failed[node], f.now))
+	}
+	return out
+}
+
+// provisioningFailing is one machine's S21 condition for the modules whose files its provisioner client failed to
+// place.
+func provisioningFailing(m string, failed []inventory.ProvReport, now time.Time) conditions.Observation {
+	sort.Slice(failed, func(a, b int) bool { return failed[a].Module < failed[b].Module })
+	var names, words []string
+	since := failed[0].At
+	for _, r := range failed {
+		names = append(names, r.Module)
+		words = append(words, r.Module+": "+oneLine(orNoReason(r.Reason)))
+		if r.At.Before(since) {
+			since = r.At
+		}
+	}
+	o := conditions.Observation{Scope: conditions.ScopeMachine, ID: m, Kind: kindApplyFailing, Machine: m,
+		Severity: conditions.Warning, Said: strings.Join(words, "; "),
+		Resolved: m + " applies what it is sent again"}
+	o.Summary = fmt.Sprintf("%s's provisioner has failed to place the files of %s since %s (bound %s)", m,
+		strings.Join(names, ", "), since.UTC().Format("2006-01-02 15:04 MST"), ago(applyEvery))
+	o.Headline = m + " is not applying its update"
+	o.Explanation = fmt.Sprintf("The provisioner on %s has not been able to write the files of %s for %s. The "+
+		"details say why.", m, strings.Join(names, ", "), humanDuration(now.Sub(since)))
+	return o
+}
+
+func orNoReason(s string) string {
+	if s == "" {
+		return "no reason given"
+	}
+	return s
+}
+
+// applyFailing is one machine's S21 condition.
+func applyFailing(d inventory.Doing, now time.Time) conditions.Observation {
+	m := d.Node
+	since := d.Since.UTC().Format("2006-01-02 15:04 MST")
+	o := conditions.Observation{Scope: conditions.ScopeMachine, ID: m, Kind: kindApplyFailing, Machine: m,
+		Severity: conditions.Warning, Said: doingWords(d),
+		Resolved: m + " applies what it is sent again"}
+	how := "refused its declaration whole"
+	if d.Outcome != inventory.OutcomeRefused {
+		how = "applied its declaration only in part"
+	}
+	o.Summary = fmt.Sprintf("%s has %s since %s (bound %s): %s", m, how, since, ago(applyEvery), failedNames(d))
+	o.Headline = m + " is not applying its update"
+	o.Explanation = fmt.Sprintf("%s has %s for %s, and trying again has not helped. The details say what fails.",
+		m, plainHow(d), humanDuration(now.Sub(*d.Since)))
+	if tool := unansweringTool(d); tool != "" {
+		o.Summary = fmt.Sprintf("%s: %s does not answer, so no package reaches it; everything else it was sent "+
+			"is applied, since %s (bound %s)", m, tool, since, ago(applyEvery))
+		o.Headline = fmt.Sprintf("%s cannot install packages", m)
+		o.Explanation = fmt.Sprintf("The package manager on %s (%s) has not answered for %s, so no package reaches "+
+			"it. Everything else is still applied, so an update that repairs it can land; if none does, it needs a "+
+			"look on the machine.", m, tool, humanDuration(now.Sub(*d.Since)))
+	}
+	return o
+}
+
+// plainHow is how a machine failed, as the operator reads it.
+func plainHow(d inventory.Doing) string {
+	if d.Outcome == inventory.OutcomeRefused {
+		return "refused every update"
+	}
+	return "applied its updates only in part"
+}
+
+// unansweringTool is the package manager a machine said does not answer, or "".
+func unansweringTool(d inventory.Doing) string {
+	for _, r := range d.Failed {
+		if rest, ok := strings.CutPrefix(r.ID, packageManagerKey); ok {
+			return strings.TrimSuffix(rest, ")")
+		}
+	}
+	return ""
+}
+
+// failedNames is what failed, by name: the refusal, or the failed resources' ids.
+func failedNames(d inventory.Doing) string {
+	if d.Outcome == inventory.OutcomeRefused {
+		return "refused"
+	}
+	ids := make([]string, 0, len(d.Failed))
+	for _, r := range d.Failed {
+		ids = append(ids, r.ID)
+	}
+	sort.Strings(ids)
+	return "failed " + strings.Join(ids, ", ")
+}
+
+// doingWords is the machine's own words on what failed: the evidence, kept inside the mesh.
+func doingWords(d inventory.Doing) string {
+	if d.Outcome == inventory.OutcomeRefused {
+		return "refused: " + oneLine(d.Refused)
+	}
+	var parts []string
+	for _, r := range d.Failed {
+		parts = append(parts, r.ID+": "+oneLine(r.Error))
+	}
+	sort.Strings(parts)
+	return strings.Join(parts, "; ")
+}

cmd/mesh-controller/apply_failing_test.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// unansweringPackageManager is anchor's last report as the workstation's read on 2026-10-04, once its
+// node-engine applies the rest (novox/hq issue 233): the package failed and the package manager did not answer,
+// the same failure on times reports since for before now.
+func unansweringPackageManager(now time.Time, forHowLong time.Duration, times int) inventory.Doing {
+	since := now.Add(-forHowLong)
+	return inventory.Doing{Node: "anchor", Outcome: inventory.OutcomeFailed, At: now.Add(-time.Second),
+		Since: &since, Times: times, Applied: 41, Failed: []inventory.FailedResource{
+			{ID: "apply", Error: `applying "pacman.base": nothing can be said about "base": this is the arch host and ` +
+				"pacman does not answer here. Either this machine is not Arch, or its package database is broken: " +
+				"pacman exited 1: error: config file /etc/pacman.conf could not be read: No such file or directory"},
+			{ID: "the package manager (pacman)", Error: "pacman does not answer here, so every package in this " +
+				"declaration fails and the rest of it is applied (novox/hq issue 233): pacman exited 1: error: config " +
+				"file /etc/pacman.conf could not be read: No such file or directory"}}}
+}
+
+// **A machine whose package manager does not answer is raised by the mesh itself, naming the tool and the
+// probe's words** (novox/hq issue 233): the words in the evidence, the path kept out of the summary.
+func TestAPackageManagerThatDoesNotAnswerIsRaisedNamingItsWords(t *testing.T) {
+	now := time.Date(2026, 10, 4, 14, 0, 0, 0, time.UTC)
+	f := calm(now)
+	f.doing = []inventory.Doing{unansweringPackageManager(now, 90*time.Minute, 18)}
+	got := watchApplyFailing(f)
+	if len(got) != 1 {
+		t.Fatalf("raised %d conditions, want one: %+v", len(got), got)
+	}
+	o := got[0]
+	if o.Key() != "machine.anchor.apply-failing" || o.Machine != "anchor" {
+		t.Errorf("the condition is not the machine's: %s", o.Key())
+	}
+	if !strings.Contains(o.Summary, "pacman does not answer") || !strings.Contains(o.Summary, "since 2026-10-04 12:30") {
+		t.Errorf("the summary does not name the tool and since when: %s", o.Summary)
+	}
+	if strings.Contains(o.Summary, "/etc/") {
+		t.Errorf("the summary carries a path, which belongs in the evidence: %s", o.Summary)
+	}
+	if !strings.Contains(o.Said, "could not be read") {
+		t.Errorf("the evidence does not carry the probe's words: %s", o.Said)
+	}
+	if !strings.Contains(o.Headline, "cannot install packages") || o.Explanation == "" || o.Resolved == "" {
+		t.Errorf("the plain words do not say it: %+v", o)
+	}
+}
+
+// **A whole refusal is raised too**, with the node-engine's words: what the workstation's report said before the
+// node-engine applied the rest.
+func TestARefusalThatGoesOnIsRaised(t *testing.T) {
+	now := time.Date(2026, 10, 4, 14, 0, 0, 0, time.UTC)
+	since := now.Add(-time.Hour)
+	f := calm(now)
+	f.doing = []inventory.Doing{{Node: "anchor", Outcome: inventory.OutcomeRefused, Since: &since, Times: 12,
+		Refused: "this is the arch host and pacman does not answer here", At: now.Add(-time.Minute)}}
+	got := watchApplyFailing(f)
+	if len(got) != 1 || !strings.Contains(got[0].Summary, "refused its declaration whole") ||
+		!strings.Contains(got[0].Said, "pacman does not answer") {
+		t.Fatalf("a refusal that went on for an hour was not raised with its words: %+v", got)
+	}
+}
+
+// **Judged by time while the machine is heard, not by how many reports said it** (review of novox/hq issue 233):
+// a node-engine says the same failure once, so one report an apply interval old is a fault that goes on; one
+// younger is not yet; and a silent or sleeping machine is S1's.
+func TestOneReportOlderThanAnApplyIsRaisedAndAQuietMachineIsNot(t *testing.T) {
+	now := time.Date(2026, 10, 4, 14, 0, 0, 0, time.UTC)
+	f := calm(now)
+	f.doing = []inventory.Doing{unansweringPackageManager(now, 6*time.Minute, 1)}
+	if got := watchApplyFailing(f); len(got) != 1 {
+		t.Errorf("one report of a failure six minutes old was not raised: %+v", got)
+	}
+	f.doing = []inventory.Doing{unansweringPackageManager(now, 4*time.Minute, 1)}
+	if got := watchApplyFailing(f); len(got) != 0 {
+		t.Errorf("a failure four minutes old was raised before one apply could clear it: %+v", got)
+	}
+	f.doing = []inventory.Doing{unansweringPackageManager(now, time.Hour, 1)}
+	f.machines[0].lastHeard = now.Add(-time.Hour)
+	if got := watchApplyFailing(f); len(got) != 0 {
+		t.Errorf("a silent machine was raised for its last report: %+v", got)
+	}
+	f = calm(now)
+	f.doing = []inventory.Doing{unansweringPackageManager(now, time.Hour, 1)}
+	f.doing[0].Node = "a-machine-the-mesh-does-not-know"
+	if got := watchApplyFailing(f); len(got) != 0 {
+		t.Errorf("a machine not heard of was raised: %+v", got)
+	}
+}
+
+// **A failed re-apply followed by a clean one clears S21** (review of novox/hq issue 233): the node-engine says
+// the clean re-apply, the store keeps it as applied with no failure since, and the condition the failure raised
+// is cleared through the keeper on the next tick.
+func TestACleanReapplyAfterAFailedOneClearsTheCondition(t *testing.T) {
+	now := time.Date(2026, 10, 4, 14, 0, 0, 0, time.UTC)
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return now }})
+	defer k.Close(context.Background())
+	w := &watchdogs{keeper: k, started: now.Add(-time.Hour)}
+
+	failing := calm(now)
+	failing.doing = []inventory.Doing{unansweringPackageManager(now, 20*time.Minute, 1)}
+	w.see(t.Context(), failing)
+	open, err := k.Open(t.Context())
+	if err != nil || len(open) != 1 || open[0].Kind != kindApplyFailing {
+		t.Fatalf("the failed re-apply raised %+v (%v), want apply-failing", open, err)
+	}
+
+	clean := calm(now.Add(5 * time.Minute))
+	clean.doing = nil // the clean re-apply recorded: NotDoingWhatTheyWereTold no longer lists the machine
+	w.see(t.Context(), clean)
+	if open, _ := k.Open(t.Context()); len(open) != 0 {
+		t.Fatalf("the condition stayed open after the clean re-apply: %+v", open)
+	}
+}

cmd/mesh-controller/ask.go

@@ -37,13 +37,13 @@ func askCommand(ctx context.Context, args []string) error {
 		arguments = json.RawMessage(positionals[2])
 	}
 
-	server, err := link.Connect(nil, nil)
+	server, err := connectLink(ctx, nil, nil, nil)
 	if err != nil {
 		return err
 	}
 	defer server.Close()
 
-	answer, err := link.Ask(ctx, server.Channel(), module, tool, arguments, *wait)
+	answer, err := link.Ask(ctx, server.Bus(), module, tool, arguments, *wait)
 	if err != nil {
 		return err
 	}

cmd/mesh-controller/asker.go

@@ -0,0 +1,946 @@
+package main
+
+// The controller asks, and acts on the operator's warrant (novox/hq ADR 0259 §6). It holds no channel, no
+// identity and no factor: it asks the router like any other module, and performs the answer chosen with its
+// own grant.
+//
+//   - **For every open, unsilenced condition that needs the operator and names its answers**, one ask is
+//     published on the `operator-channel` seat under the controller's own name: the condition's words, its
+//     actions as options at their levels (Silence acknowledges; Release, Stop, Start and Restart approve),
+//     answered by the operator, expiring after a day (a week when every option only acknowledges). A
+//     condition that clears, is silenced, or changes its answers has its ask cancelled; an ask that expired
+//     unanswered is asked again while the condition lasts; one the router refused is asked again after a wait
+//     that grows with each refusal in a row, at most half an hour, so a refusal is never believed longer. Each ask is kept in the controller's bucket
+//     `asked`, so a restart neither asks twice nor forgets.
+//   - **On a warrant**, heard on the seat's event under the controller's own name (which only the router may
+//     say), the controller acts once per ask: only for an ask it holds, only for the option it offered at
+//     that option's level, and only while the condition is still open. It performs the action as itself —
+//     a silence through its own conditions, any other through the verb the action names — with the warrant's
+//     words as its why, and records it in the hand-act log as the operator's decision, naming the channel,
+//     the ask and the proofs. An ask that ended without a choice is recorded and nothing is done.
+//   - **A warrant it missed** while away is read from the router's record of its asks, under its own name.
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/asks"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The asker's name on the seat: the controller's module.
+const askerName = broker.ControllerSeat
+
+// How long an ask lasts: a day when an answer approves, a week when every answer only acknowledges.
+const (
+	// askApproveFor is a day less a margin, so an ask is never refused at the router for lasting a day and
+	// a moment (the SDK's bound is a day).
+	askApproveFor     = 24*time.Hour - 10*time.Minute
+	askAcknowledgeFor = 7 * 24 * time.Hour
+	// askEvery is how often what is open is asked about again, beside every change.
+	askEvery = time.Minute
+	// askCatchUpAfter is how old an open ask is before the router's record of it is read: a warrant heard
+	// on the event needs no reading.
+	askCatchUpAfter = 2 * time.Minute
+	// askAgainAfterAnswer is how long a condition the operator answered is not asked about again with the
+	// same answers: what was chosen takes a while to clear it, and asking again at once would ask twice.
+	askAgainAfterAnswer = time.Hour
+	// askMostOpen is how many asks the controller holds open at once (the router refuses a fourth): the
+	// most urgent conditions first, then the oldest.
+	askMostOpen = asks.MostOpen
+	// askRefusedRetryMost is the longest a refusal is believed without asking again (novox/hq issue 369): the
+	// router refused while its channels had not yet said they could send, the channels could send twenty
+	// minutes later, and the controller repeated that refusal for eleven hours. A refused ask is asked again
+	// after askEvery, then twice as long after each refusal in a row, never longer than this — and at once when
+	// the channels change.
+	askRefusedRetryMost = 30 * time.Minute
+	// askRefusedCounted is how far back refusals in a row are counted for that wait.
+	askRefusedCounted = 6 * time.Hour
+	// askVerdictWait is how long an ask made again after a refusal waits for the router's word before it is
+	// taken as taken: the router refuses an ask as it reads it, so a refusal comes within seconds. Meanwhile
+	// the condition saying it was not delivered stands as it was, neither cleared nor raised again.
+	askVerdictWait = 2 * time.Minute
+)
+
+// refusedRetryAfter is how long a part refused n times in a row waits before it is asked again.
+func refusedRetryAfter(n int) time.Duration {
+	wait := askEvery
+	for i := 1; i < n && wait < askRefusedRetryMost; i++ {
+		wait *= 2
+	}
+	return min(wait, askRefusedRetryMost)
+}
+
+// What became of an ask, as the controller keeps it.
+const (
+	askOpen      = "open"
+	askCancelled = "cancelled"
+)
+
+// asked is one ask the controller made, as it keeps it.
+type asked struct {
+	ID        string `json:"id"`
+	Condition string `json:"condition"`
+	// Channels is what the channels were when it was asked (asker.channels): an ask the router refused is asked
+	// again at once when the condition's answers or the channels change, and otherwise after a wait that grows
+	// with each refusal in a row (refusedRetryAfter, novox/hq issue 369).
+	Channels string              `json:"channels,omitempty"`
+	Ask      asks.Ask            `json:"ask"`
+	Actions  []conditions.Action `json:"actions"`
+	// Options are the actions by option id.
+	Options map[string]int `json:"options"`
+	State   string         `json:"state"`
+	Opened  time.Time      `json:"opened"`
+	Ended   time.Time      `json:"ended,omitempty"`
+	Warrant *asks.Warrant  `json:"warrant,omitempty"`
+	// Acted is what the controller did on the warrant: empty before it did anything, "acting" while it acts,
+	// then "done", "failed: …" or "nothing: …". Anything but empty is never acted on again.
+	Acted string `json:"acted,omitempty"`
+	// Part is which ask of its condition this is (askPart): empty for the one that carries the condition's
+	// answers, or the authorising ones where it has both; "acknowledge" for its acknowledging answers asked
+	// apart (the review of 2026-10-09, M1).
+	Part string `json:"part,omitempty"`
+	// Rehearsal is an ask started at the controller's terminal (rehearse.go): about no condition, its answers
+	// perform nothing, and the reconciling of conditions leaves it alone.
+	Rehearsal bool `json:"rehearsal,omitempty"`
+	// Proposal is a settings layer proposed through a verb (proposals.go, novox/hq ADR 0277): about no
+	// condition, set on Approve by the serving controller itself, and left alone by the reconciling of conditions.
+	Proposal *settingsProposal `json:"proposal,omitempty"`
+}
+
+// ofACondition says an ask is one of a condition's: not a rehearsal, not a proposal.
+func (r asked) ofACondition() bool { return !r.Rehearsal && r.Proposal == nil }
+
+// partKey is an ask's place among what is asked: its condition and its part.
+func partKey(condition, part string) string { return condition + "#" + part }
+
+// partAcknowledge is the part of a condition asked apart for its acknowledging answers.
+const partAcknowledge = "acknowledge"
+
+// askPart is one ask a condition is asked with: its part, what it is about, and its answers.
+type askPart struct {
+	name    string
+	about   string
+	actions []conditions.Action
+}
+
+// levelOf is an action's level as an option offers it: one that says none is never taken for less than
+// approve.
+func levelOf(act conditions.Action) asks.Level {
+	if act.Level == "" {
+		return asks.Approve
+	}
+	return asks.Level(act.Level)
+}
+
+// partsOf is the asks a condition is asked with (the review of 2026-10-09, M1): one, when its answers are all
+// of one kind; else its authorising answers (Release, Stop, Restart) in one ask, about the condition, and its
+// acknowledging ones (Silence) in another. **An acknowledgement never shares an ask with an approval**: a
+// channel that only acknowledges would otherwise answer the ask, and end the approval with it.
+func partsOf(c conditions.Condition) []askPart {
+	var ack, auth []conditions.Action
+	for _, act := range c.Actions {
+		if levelOf(act) == asks.Acknowledge {
+			ack = append(ack, act)
+		} else {
+			auth = append(auth, act)
+		}
+	}
+	if len(ack) == 0 || len(auth) == 0 {
+		return []askPart{{about: c.Key, actions: c.Actions}}
+	}
+	return []askPart{{about: c.Key, actions: auth},
+		{name: partAcknowledge, about: c.Key + "." + partAcknowledge, actions: ack}}
+}
+
+// askedStore keeps the asks (broker.AskedBucket). **Every write after the first is a compare-and-set** (the
+// review of 2026-10-09, L2): an ask is created once, and changed only over the revision it was read at, the
+// change decided again on what is read — so two controllers, or two deliveries of one warrant, never write
+// over each other, and of two that would act only the one whose write stands does.
+type askedStore interface {
+	Get(ctx context.Context, id string) (*asked, error)
+	// Create keeps a new ask, and refuses one already kept under its id.
+	Create(ctx context.Context, a asked) error
+	// Change applies change to the ask kept under id, by compare-and-set, and says whether its write stood.
+	// change says whether to write at all; on a write that came between, it is asked again on what is read.
+	Change(ctx context.Context, id string, change func(*asked) bool) (bool, error)
+	All(ctx context.Context) ([]asked, error)
+}
+
+// askChangeTries is how often a change is read and tried again when another write came between.
+const askChangeTries = 5
+
+// asker is the controller asking the operator and acting on the answer.
+type asker struct {
+	open    func(ctx context.Context) ([]conditions.Condition, error)
+	silence func(ctx context.Context, key string, d time.Duration, by, why string) error
+	store   askedStore
+	// publish puts a message on a subject's stream, de-duplicated by id.
+	publish func(ctx context.Context, subject string, body []byte, id string) error
+	// call performs an action's verb with its arguments, as the controller.
+	call func(ctx context.Context, a conditions.Action, args map[string]string) error
+	// setLayer sets a proposed settings layer on the operator's warrant (novox/hq ADR 0277); nil cannot.
+	setLayer setOnWarrant
+	// record writes the hand-act log.
+	record func(ctx context.Context, act link.HandAct) error
+	// routerRecord reads the router's record of an ask for a warrant missed; nil reads nothing.
+	routerRecord func(ctx context.Context, id string) (*asks.Warrant, error)
+	// routerHere says whether a router holds the seat and takes asks under the asker's name; nil is yes.
+	routerHere func(ctx context.Context) (bool, error)
+	// grantHeld says whether the bus holds the controller's grant to ask: the user list the bus's machine was
+	// last sent is the one the mesh composes now (novox/hq issue 353). The grant is composed from the router's
+	// assignment and reaches the bus only when that machine is next pushed, so between `assign` and `push`
+	// the record says a router is here and the bus refuses every ask. why says what to do; nil is yes.
+	grantHeld func(ctx context.Context) (held bool, why string, err error)
+	// channels is what the channels are now, as a fingerprint: who holds which kind, promising what.
+	channels func(ctx context.Context) string
+	// raise keeps the asker's own condition (sourceAsker): which conditions needing the operator could not be
+	// asked, and why. Nil raises nothing (a test that does not look).
+	raise func(ctx context.Context, obs []conditions.Observation) error
+	now   func() time.Time
+	logf  func(string, ...any)
+
+	saidNoRouter bool
+	saidNoGrant  bool
+	// saidGrantCaveat is whether a grant held with a caveat was said, so it is said once.
+	saidGrantCaveat bool
+
+	mu     sync.Mutex
+	nudged chan struct{}
+}
+
+func (a *asker) nudge() {
+	if a == nil {
+		return
+	}
+	a.mu.Lock()
+	if a.nudged == nil {
+		a.nudged = make(chan struct{}, 1)
+	}
+	ch := a.nudged
+	a.mu.Unlock()
+	select {
+	case ch <- struct{}{}:
+	default:
+	}
+}
+
+// keep asks until ctx ends: now, on every change of a condition, and every askEvery.
+func (a *asker) keep(ctx context.Context) {
+	a.nudge()
+	tick := time.NewTicker(askEvery)
+	defer tick.Stop()
+	a.mu.Lock()
+	nudged := a.nudged
+	a.mu.Unlock()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+		case <-nudged:
+		}
+		if err := a.reconcile(ctx); err != nil {
+			a.logf("what the operator is asked could not be brought up to date: %v", err)
+		}
+	}
+}
+
+// wants says whether a condition is one to ask about now.
+func wants(c conditions.Condition, now time.Time) bool {
+	return len(c.Actions) > 0 && c.Needs != "" && !c.SilencedAt(now)
+}
+
+func sameAsked(a []conditions.Action, b []conditions.Action) bool {
+	x, _ := json.Marshal(a)
+	y, _ := json.Marshal(b)
+	return string(x) == string(y)
+}
+
+// reconcile brings what is asked in line with what is open.
+func (a *asker) reconcile(ctx context.Context) error {
+	now := a.now()
+	if a.routerHere != nil {
+		here, err := a.routerHere(ctx)
+		if err != nil {
+			return err
+		}
+		if !here {
+			if !a.saidNoRouter {
+				a.logf("no router takes asks under the controller's name (a module declaring %s with its ask "+
+					"named by its caller, assigned): the operator is asked nothing until one is", broker.AsksSeat)
+				a.saidNoRouter = true
+			}
+			open, err := a.open(ctx)
+			if err != nil {
+				return err
+			}
+			var unasked []conditions.Condition
+			for _, c := range open {
+				if wants(c, now) {
+					unasked = append(unasked, c)
+				}
+			}
+			return a.sayUnasked(ctx, unasked, "no router takes the controller's asks: no module holding "+
+				broker.AsksSeat+" that takes an ask under its asker's name is assigned")
+		}
+		a.saidNoRouter = false
+	}
+	if a.grantHeld != nil {
+		held, why, err := a.grantHeld(ctx)
+		if err != nil {
+			return err
+		}
+		if !held {
+			if !a.saidNoGrant {
+				a.logf("the bus does not hold the controller's grant to ask yet: %s; the operator is asked nothing until it does", why)
+				a.saidNoGrant = true
+			}
+			open, err := a.open(ctx)
+			if err != nil {
+				return err
+			}
+			var unasked []conditions.Condition
+			for _, c := range open {
+				if wants(c, now) {
+					unasked = append(unasked, c)
+				}
+			}
+			return a.sayUnasked(ctx, unasked, "the bus does not hold the controller's grant to ask yet: "+why)
+		}
+		if why != "" && !a.saidGrantCaveat {
+			// Held, with a caveat worth one line (an older bus module cannot confirm the reload).
+			a.logf("the controller asks: %s", why)
+			a.saidGrantCaveat = true
+		} else if why == "" {
+			a.saidGrantCaveat = false
+		}
+		a.saidNoGrant = false
+	}
+	channels := ""
+	if a.channels != nil {
+		channels = a.channels(ctx)
+	}
+	open, err := a.open(ctx)
+	if err != nil {
+		return err
+	}
+	all, err := a.store.All(ctx)
+	if err != nil {
+		return err
+	}
+	byCondition := map[string]asked{} // by partKey
+	// What is open and not a condition's — a rehearsal, a proposal — still counts toward what the router holds
+	// open for the controller (askMostOpen); expired unanswered, it is kept so, as the router says it too.
+	otherOpen := 0
+	for _, r := range all {
+		if r.State == askOpen && !r.ofACondition() && !now.Before(r.Ask.Expires) {
+			if _, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+				if x.State != askOpen || x.Acted != "" {
+					return false
+				}
+				x.State, x.Ended, x.Acted = string(asks.OutcomeExpired), now, "nothing: the ask expired unanswered"
+				return true
+			}); err != nil {
+				return err
+			}
+			continue
+		}
+		if r.State == askOpen && !r.ofACondition() {
+			otherOpen++
+		}
+		if r.State == askOpen && r.ofACondition() {
+			k := partKey(r.Condition, r.Part)
+			if prior, held := byCondition[k]; !held || r.Opened.After(prior.Opened) {
+				byCondition[k] = r
+			}
+		}
+	}
+	// A warrant missed while away, read from the router's record: for a condition's ask, and for a proposal's or a
+	// rehearsal's alike.
+	if a.routerRecord != nil {
+		var lookedUp []asked
+		for _, r := range byCondition {
+			lookedUp = append(lookedUp, r)
+		}
+		for _, r := range all {
+			if r.State == askOpen && !r.ofACondition() {
+				lookedUp = append(lookedUp, r)
+			}
+		}
+		for _, r := range lookedUp {
+			if now.Sub(r.Opened) < askCatchUpAfter {
+				continue
+			}
+			if w, err := a.routerRecord(ctx, r.ID); err == nil && w != nil {
+				body, _ := json.Marshal(w)
+				if err := a.Decided(ctx, body); err != nil {
+					return err
+				}
+			}
+		}
+		if all, err = a.store.All(ctx); err != nil {
+			return err
+		}
+		byCondition = map[string]asked{}
+		for _, r := range all {
+			if r.State == askOpen && r.ofACondition() {
+				byCondition[partKey(r.Condition, r.Part)] = r
+			}
+		}
+	}
+	// What the operator answered lately, by condition: not asked again at once; and what the router refused,
+	// newest first: not asked again until the answers or the channels change.
+	answered, refused := map[string]asked{}, map[string]asked{}
+	for _, r := range all {
+		k := partKey(r.Condition, r.Part)
+		if r.State == string(asks.OutcomeChosen) && now.Sub(r.Ended) < askAgainAfterAnswer {
+			answered[k] = r
+		}
+		if r.State == string(asks.OutcomeRefused) {
+			if prior, has := refused[k]; !has || r.Opened.After(prior.Opened) {
+				refused[k] = r
+			}
+		}
+	}
+	// Refusals in a row, by part: those since the last ask that was not refused, within askRefusedCounted.
+	// superseded: a part asked since its last refusal, by an ask the router did not refuse — open, answered,
+	// expired or cancelled. Its refusal is history then, never said again (the review of PR 198: an answered
+	// retry brought the refusal back).
+	inRow, superseded := map[string]int{}, map[string]asked{}
+	for k, last := range refused {
+		for _, r := range all {
+			if partKey(r.Condition, r.Part) == k && r.State != string(asks.OutcomeRefused) && r.State != askUnsent &&
+				r.Opened.After(last.Opened) && r.Opened.After(superseded[k].Opened) {
+				superseded[k] = r
+			}
+		}
+		var since time.Time
+		for _, r := range all {
+			if partKey(r.Condition, r.Part) == k && r.State != string(asks.OutcomeRefused) && r.State != askUnsent &&
+				!r.Opened.After(last.Opened) && r.Opened.After(since) {
+				since = r.Opened
+			}
+		}
+		for _, r := range all {
+			if partKey(r.Condition, r.Part) == k && r.State == string(asks.OutcomeRefused) && r.Opened.After(since) &&
+				now.Sub(r.Opened) < askRefusedCounted {
+				inRow[k]++
+			}
+		}
+	}
+	wanted := map[string]bool{}
+	var unasked []conditions.Condition // refused by the router, and nothing it was refused for changed
+	var refusedWords []string
+	// The most urgent first, then the oldest: those are asked when no more than askMostOpen may be.
+	sort.SliceStable(open, func(i, j int) bool {
+		ui, uj := open[i].Severity == conditions.Urgent, open[j].Severity == conditions.Urgent
+		if ui != uj {
+			return ui
+		}
+		if !open[i].Raised.Equal(open[j].Raised) {
+			return open[i].Raised.Before(open[j].Raised)
+		}
+		return open[i].Key < open[j].Key
+	})
+	openNow := otherOpen
+	for _, c := range open {
+		if !wants(c, now) {
+			continue
+		}
+		for _, p := range partsOf(c) {
+			if r, held := byCondition[partKey(c.Key, p.name)]; held && sameAsked(r.Actions, p.actions) && now.Before(r.Ask.Expires) {
+				openNow++
+			}
+		}
+	}
+	for _, c := range open {
+		if !wants(c, now) {
+			continue
+		}
+		saidUnasked := false
+		for _, p := range partsOf(c) {
+			key := partKey(c.Key, p.name)
+			wanted[key] = true
+			if r, was := refused[key]; was && sameAsked(r.Actions, p.actions) {
+				cur, held := byCondition[key]
+				ended := r.Ended
+				if ended.IsZero() {
+					ended = r.Opened
+				}
+				later, asked := superseded[key]
+				waiting := !held && !asked && r.Channels == channels && now.Sub(ended) < refusedRetryAfter(inRow[key])
+				// Asked again now (the wait over), or lately and the router's word not in yet: said as it was until
+				// that word, so the condition neither clears nor is raised again at each try.
+				retrying := !held && !asked && !waiting
+				verdictDue := held && asked && later.ID == cur.ID && now.Sub(cur.Opened) < askVerdictWait
+				if waiting || retrying || verdictDue {
+					if !saidUnasked {
+						unasked, saidUnasked = append(unasked, c), true
+					}
+					if r.Warrant != nil && r.Warrant.Words != "" {
+						refusedWords = append(refusedWords, r.Warrant.Words)
+					}
+				}
+				if waiting {
+					continue // refused lately, and nothing it was refused for has changed: asked again after the wait
+				}
+			}
+			if r, done := answered[key]; done && sameAsked(r.Actions, p.actions) {
+				if _, held := byCondition[key]; !held {
+					continue
+				}
+			}
+			if r, held := byCondition[key]; held {
+				switch {
+				case !sameAsked(r.Actions, p.actions):
+					if err := a.cancel(ctx, r, "its answers changed"); err != nil {
+						return err
+					}
+				case !now.Before(r.Ask.Expires):
+					// Expired unanswered: the router says so too; asked again below while it lasts.
+					if _, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+						if x.State != askOpen {
+							return false
+						}
+						x.State, x.Ended = string(asks.OutcomeExpired), now
+						return true
+					}); err != nil {
+						return err
+					}
+					openNow--
+				default:
+					continue
+				}
+			}
+			if openNow >= askMostOpen {
+				continue // asked when one of the open ones ends, most urgent first
+			}
+			if err := a.ask(ctx, c, p, channels); err != nil {
+				a.logf("the operator could not be asked about %s: %v", c.Key, err)
+				continue
+			}
+			openNow++
+		}
+	}
+	stillOpen := map[string]conditions.Condition{}
+	for _, c := range open {
+		stillOpen[c.Key] = c
+	}
+	for key, r := range byCondition {
+		if wanted[key] {
+			continue
+		}
+		// **A silence never takes an approval back** (the confirmation review of 2026-10-09, M1). Silence is an
+		// acknowledgement — anyone at the desk may give it — so a condition silenced while its approval is asked
+		// keeps that ask open, unchanged, until it is answered on a channel that proves who answered, or expires.
+		// It is not asked again once it ends, while the silence lasts.
+		if c, open := stillOpen[r.Condition]; open && c.SilencedAt(now) && r.Ask.Highest() != asks.Acknowledge &&
+			now.Before(r.Ask.Expires) && keepsItsAnswers(c, r) {
+			continue
+		}
+		if err := a.cancel(ctx, r, "the condition ended, was silenced or needs nothing now"); err != nil {
+			return err
+		}
+	}
+	why := "the router refused the ask"
+	if len(refusedWords) > 0 {
+		why += ": " + refusedWords[0]
+	}
+	return a.sayUnasked(ctx, unasked, why)
+}
+
+// keepsItsAnswers says a condition still offers the answers an ask kept was asked with.
+func keepsItsAnswers(c conditions.Condition, r asked) bool {
+	for _, p := range partsOf(c) {
+		if partKey(c.Key, p.name) == partKey(r.Condition, r.Part) {
+			return sameAsked(r.Actions, p.actions)
+		}
+	}
+	return false
+}
+
+// sourceAsker raises the asker's own condition.
+const sourceAsker = "asker"
+
+// sayUnasked keeps the asker's one condition: while a condition that needs the operator could not be asked
+// on any channel, said loudly (failure must be loud), cleared when every one could be.
+func (a *asker) sayUnasked(ctx context.Context, unasked []conditions.Condition, why string) error {
+	if a.raise == nil {
+		return nil
+	}
+	var obs []conditions.Observation
+	if len(unasked) > 0 {
+		keys := make([]string, 0, len(unasked))
+		severity := conditions.Warning
+		for _, c := range unasked {
+			keys = append(keys, c.Key)
+			if c.Severity == conditions.Urgent {
+				severity = conditions.Urgent
+			}
+		}
+		sort.Strings(keys)
+		obs = append(obs, conditions.Observation{Scope: conditions.ScopeSeat, ID: broker.AsksSeat, Token: "unasked",
+			Kind: "asks-undelivered", Severity: severity, Source: sourceAsker,
+			Summary: fmt.Sprintf("%d condition(s) that need the operator could not be asked on any channel: %s; %s",
+				len(keys), strings.Join(keys, ", "), why),
+			Headline:    "Questions for you not delivered",
+			Explanation: "The mesh could not send you its questions on any channel.",
+			Needs:       "answer them from the mesh MCP server, and check why no channel carries them.",
+			Resolved:    "The mesh can ask you again"})
+	}
+	if err := a.raise(ctx, obs); err != nil {
+		a.logf("whether the operator could be asked could not be kept as a condition: %v", err)
+	}
+	return nil
+}
+
+// optionID is an action's label as an option's id: "Silence for a week" is silence-for-a-week.
+func optionID(label string) string {
+	var b strings.Builder
+	dash := false
+	for _, r := range strings.ToLower(label) {
+		switch {
+		case r >= 'a' && r <= 'z', r >= '0' && r <= '9':
+			b.WriteRune(r)
+			dash = false
+		case !dash && b.Len() > 0:
+			b.WriteByte('-')
+			dash = true
+		}
+	}
+	return strings.TrimSuffix(b.String(), "-")
+}
+
+// doesWords is what an action does, in the words an option says it with.
+func doesWords(act conditions.Action) string {
+	switch {
+	case act.Arguments["silence"] != "":
+		return "nothing more is said of it for a week"
+	case act.Verb == "mesh-delivery.release":
+		return "the delivery goes on"
+	case act.Verb == "mesh-delivery.stop":
+		return "the delivery ends"
+	case act.Verb == broker.ControllerSeat+".plans" && act.Arguments["go"] != "":
+		return "the delivery starts"
+	case act.Verb == broker.ControllerSeat+".plans" && act.Arguments["stop"] != "":
+		return "the delivery is stopped"
+	case strings.HasSuffix(act.Verb, ".restart"):
+		return "its service is restarted on " + act.Machine
+	}
+	return strings.ToLower(act.Label)
+}
+
+// askText is a condition's words as an ask says them: without where an answer is given when no channel can
+// give it (FromMeshMCPServer), since the ask is answered on a channel and the router says where else.
+func askText(s string) string {
+	for _, with := range []string{", " + FromMeshMCPServer, " " + FromMeshMCPServer} {
+		s = strings.ReplaceAll(s, with, ".")
+	}
+	return strings.ReplaceAll(s, "..", ".")
+}
+
+// askOf is the ask one part of a condition is asked with.
+func askOf(id string, c conditions.Condition, p askPart, now time.Time) (asks.Ask, map[string]int) {
+	q := asks.Ask{ID: id, Headline: c.Headline, Explanation: askText(c.Explanation), Who: asks.Operator,
+		OnExpiry: "nothing is done, and you are asked again while it lasts", About: p.about,
+		Urgent: c.Severity == conditions.Urgent}
+	options := map[string]int{}
+	approves := false
+	for i, act := range p.actions {
+		level := levelOf(act) // an action that says nothing of its level is never taken for less than approve
+		approves = approves || level != asks.Acknowledge
+		oid := optionID(act.Label)
+		options[oid] = i
+		// Every option binds the exact act it stands for (novox/hq ADR 0259 §6): the verb, the machine and
+		// every argument. The warrant then authorises that act and no other.
+		binds, _ := asks.ActDigest(boundAct(act))
+		q.Options = append(q.Options, asks.Option{ID: oid, Label: act.Label, Does: doesWords(act), Level: level,
+			Binds: binds})
+	}
+	q.Expires = now.Add(askAcknowledgeFor)
+	if approves {
+		q.Expires = now.Add(askApproveFor)
+	}
+	return q, options
+}
+
+// boundAct is what an option's Binds digests: the act exactly as the controller will perform it — its verb,
+// machine, level, and each argument as "arg.<name>" — and never its label or words.
+func boundAct(act conditions.Action) asks.Act {
+	out := asks.Act{"verb": act.Verb, "machine": act.Machine, "level": act.Level}
+	for k, v := range act.Arguments {
+		out["arg."+k] = v
+	}
+	return out
+}
+
+func newAskID() string {
+	var b [8]byte
+	_, _ = rand.Read(b[:])
+	return "c" + hex.EncodeToString(b[:])
+}
+
+// askUnsent is an ask kept and never published: asked again at the next look.
+const askUnsent = "unsent"
+
+// ask publishes one ask about a part of a condition, kept before it is published (the review of 2026-10-09,
+// L3): a warrant for it then always finds it, and one whose publishing failed is marked so and asked again.
+func (a *asker) ask(ctx context.Context, c conditions.Condition, p askPart, channels string) error {
+	now := a.now()
+	id := newAskID()
+	q, options := askOf(id, c, p, now)
+	if err := q.Check(now); err != nil {
+		return err
+	}
+	body, err := json.Marshal(q)
+	if err != nil {
+		return err
+	}
+	if err := a.store.Create(ctx, asked{ID: id, Condition: c.Key, Part: p.name, Ask: q, Actions: p.actions,
+		Options: options, State: askOpen, Opened: now, Channels: channels}); err != nil {
+		return fmt.Errorf("the ask could not be kept, so it was not asked: %w", err)
+	}
+	if err := a.publish(ctx, asks.AskSubject(askerName), body, "ask."+id); err != nil {
+		if _, cerr := a.store.Change(ctx, id, func(x *asked) bool {
+			if x.State != askOpen || x.Acted != "" {
+				return false
+			}
+			x.State, x.Ended, x.Acted = askUnsent, a.now(), "nothing: it could not be published: "+err.Error()
+			return true
+		}); cerr != nil {
+			a.logf("the ask %s could not be published, and could not be marked so: %v", id, cerr)
+		}
+		return err
+	}
+	a.logf("asked the operator about %s (%s): %d answer(s)", c.Key, id, len(q.Options))
+	return nil
+}
+
+// cancel takes an ask back: kept cancelled first, so a warrant that comes after is refused, then said to the
+// router; a cancel the router did not hear leaves the ask to expire there, and nothing is done on it here.
+func (a *asker) cancel(ctx context.Context, r asked, why string) error {
+	stood, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+		if x.State != askOpen {
+			return false
+		}
+		x.State, x.Ended = askCancelled, a.now()
+		return true
+	})
+	if err != nil || !stood {
+		return err
+	}
+	body, _ := json.Marshal(map[string]string{"id": r.ID})
+	if err := a.publish(ctx, asks.CancelSubject(askerName), body, "cancel."+r.ID); err != nil {
+		a.logf("the ask %s about %s is taken back here, and the router could not be told (%v): it expires there, "+
+			"and no answer to it is acted on", r.ID, r.Condition, err)
+		return nil
+	}
+	a.logf("took back the ask %s about %s: %s", r.ID, r.Condition, why)
+	return nil
+}
+
+// Decided takes the router's word on one of the controller's asks (link.Decider). An error is returned only
+// when what was decided could not be kept, so the word is held and heard again.
+func (a *asker) Decided(ctx context.Context, body []byte) error {
+	var w asks.Warrant
+	if err := json.Unmarshal(body, &w); err != nil {
+		a.logf("the router's word on an ask could not be read; ignored: %v", err)
+		return nil
+	}
+	if w.Asker != askerName {
+		a.logf("REFUSED a warrant for %s's ask %s: the controller acts only on its own", w.Asker, w.Ask)
+		return nil
+	}
+	r, err := a.store.Get(ctx, w.Ask)
+	if err != nil {
+		return err
+	}
+	if r == nil {
+		a.logf("REFUSED a warrant for the ask %s, which the controller does not hold", w.Ask)
+		return nil
+	}
+	if r.Acted != "" {
+		return nil // heard again: acted on once
+	}
+	now := a.now()
+	if w.Outcome != asks.OutcomeChosen {
+		acted := "nothing: the ask " + string(w.Outcome)
+		if w.Words != "" {
+			acted += ": " + w.Words
+		}
+		if _, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+			if x.Acted != "" {
+				return false
+			}
+			x.State, x.Ended, x.Warrant, x.Acted = string(w.Outcome), now, &w, acted
+			return true
+		}); err != nil {
+			return err
+		}
+		a.logf("the ask %s about %s ended %s; nothing is done", r.ID, r.Condition, w.Outcome)
+		return nil
+	}
+	if r.State != askOpen {
+		// Cancelled, replaced or expired in the controller's own record: no answer to it is acted on.
+		a.logf("REFUSED a warrant for the ask %s, which is %s in the controller's own record", r.ID, r.State)
+		return nil
+	}
+	option, err := w.For(askerName, r.Ask)
+	if err != nil {
+		a.logf("REFUSED a warrant for the ask %s: %v", r.ID, err)
+		return nil
+	}
+	index, offered := r.Options[option.ID]
+	if !offered || index >= len(r.Actions) {
+		a.logf("REFUSED a warrant for the ask %s: it chose %s, which no action stands for", r.ID, option.ID)
+		return nil
+	}
+	act := r.Actions[index]
+	// The act about to be performed is the one the option bound when the controller asked: a record changed
+	// since is refused, never performed.
+	if err := option.Performs(boundAct(act)); err != nil {
+		a.logf("REFUSED a warrant for the ask %s: %v", r.ID, err)
+		return nil
+	}
+	open, err := a.open(ctx)
+	if err != nil {
+		return err
+	}
+	stillOpen := r.Rehearsal || r.Proposal != nil // a rehearsal and a proposal are about no condition
+	for _, c := range open {
+		stillOpen = stillOpen || c.Key == r.Condition
+	}
+	if !stillOpen {
+		// The asker checks the state is still what it asked about before it acts (to-be 46 §10, step 7).
+		if _, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+			if x.State != askOpen || x.Acted != "" {
+				return false
+			}
+			x.State, x.Warrant, x.Ended, x.Acted = string(asks.OutcomeChosen), &w, now,
+				"nothing: the condition ended before the answer"
+			return true
+		}); err != nil {
+			return err
+		}
+		a.logf("%s, for %s, which ended meanwhile: nothing is done", w.Says(), r.Condition)
+		return nil
+	}
+	// Claimed before acting, by compare-and-set: only the delivery whose write stands acts (security review
+	// of 2026-10-08, finding 9). Not by the warrant's message id, which another publisher could take first:
+	// the controller's own record decides.
+	claimed, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+		if x.State != askOpen || x.Acted != "" {
+			return false
+		}
+		x.State, x.Warrant, x.Acted = string(asks.OutcomeChosen), &w, "acting"
+		return true
+	})
+	if err != nil {
+		return err
+	}
+	if !claimed {
+		a.logf("the warrant for the ask %s was already taken by another delivery; nothing more is done", r.ID)
+		return nil
+	}
+	r.Acted = "acting"
+
+	why := fmt.Sprintf("%s (ask %s)", w.Says(), r.ID)
+	args := map[string]string{}
+	for k, v := range act.Arguments {
+		args[k] = v
+	}
+	if v, takes := args["why"]; takes && v == "" {
+		args["why"] = why
+	}
+	var acted error
+	outcome := "done"
+	switch {
+	case r.Rehearsal && act.Verb == rehearsalVerb:
+		// A rehearsal's answer performs nothing: it is recorded below as the operator's decision.
+	case r.Proposal != nil && act.Verb == proposalVerb:
+		// A proposed settings layer, set by this controller itself on Approve (novox/hq ADR 0277): the act's
+		// digest of the values is held to the record's own values before anything is set.
+		outcome, acted = a.decideProposal(ctx, *r, act, w)
+		if acted == nil && outcome != "" && !strings.HasPrefix(outcome, "nothing") {
+			outcome = "done: " + outcome
+		}
+	case act.Arguments["silence"] != "":
+		acted = a.silence(ctx, act.Arguments["silence"], conditions.MaxSilence, byWords(w), why)
+	default:
+		acted = a.call(ctx, act, args)
+	}
+	ended := a.now()
+	if acted != nil {
+		outcome = "failed: " + acted.Error()
+	}
+	r.Ended, r.Acted = ended, outcome
+	if _, err := a.store.Change(ctx, r.ID, func(x *asked) bool {
+		if x.Acted != "acting" {
+			return false
+		}
+		x.Ended, x.Acted = ended, outcome
+		return true
+	}); err != nil {
+		a.logf("%s was acted on (%s), and how it ended could NOT be kept: %v", r.ID, outcome, err)
+	}
+	verbArgs := []string{act.Verb}
+	if act.Machine != "" {
+		verbArgs = append(verbArgs, "on "+act.Machine)
+	}
+	keys := make([]string, 0, len(args))
+	for k := range args {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	for _, k := range keys {
+		if k != "why" {
+			verbArgs = append(verbArgs, k+"="+args[k])
+		}
+	}
+	if err := a.record(ctx, link.HandAct{Verb: handActWarrant, Args: verbArgs, Why: why, By: byWords(w),
+		Cause: conditions.CauseOperatorAnswer, Condition: r.Condition, Via: viaWords(w), Ask: r.ID,
+		Proofs: w.Proofs, RequestedBy: r.Condition, Outcome: r.Acted}); err != nil {
+		a.logf("%s was done, and could NOT be recorded in the hand-act log: %v", why, err)
+	}
+	a.logf("%s: %s", why, r.Acted)
+	return nil
+}
+
+// handActWarrant is the verb an act the operator chose on a warrant is recorded under: a person's decision,
+// never a repair (handActVerbs).
+const handActWarrant = "warrant"
+
+// byWords is who chose, as the hand-act log says it: "the operator, as telegram identity 42".
+func byWords(w asks.Warrant) string {
+	if w.By == nil {
+		return "the operator"
+	}
+	return fmt.Sprintf("the %s, as %s identity %s", w.By.Who, w.By.Kind, w.By.Identity)
+}
+
+// viaWords is the channel an answer came through: its module and kind, and how the sender was known.
+func viaWords(w asks.Warrant) string {
+	if w.By == nil {
+		return w.Channel
+	}
+	via := w.Channel + " (" + w.By.Kind + ")"
+	if w.By.Verified != "" {
+		via += ", " + w.By.Verified
+	}
+	return via
+}
+
+// errNotGranted is an action whose verb the controller's grant does not name.
+var errNotGranted = errors.New("the controller's grant does not name this verb")

cmd/mesh-controller/asker_bus_test.go

@@ -0,0 +1,153 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/asks"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// busAsker is an asker on a real bus's `asked` bucket, counting what it performs: two of them are two
+// controllers sharing one record.
+type busAskerRig struct {
+	mu     sync.Mutex
+	called int
+	acts   int
+	open   []conditions.Condition
+	sent   [][]byte
+}
+
+func (rig *busAskerRig) asker(t *testing.T, conn *nats.Conn, now time.Time) *asker {
+	return &asker{
+		open: func(context.Context) ([]conditions.Condition, error) {
+			rig.mu.Lock()
+			defer rig.mu.Unlock()
+			return rig.open, nil
+		},
+		silence: func(context.Context, string, time.Duration, string, string) error { return nil },
+		store:   busAsked{conn: conn},
+		publish: func(_ context.Context, subject string, body []byte, _ string) error {
+			rig.mu.Lock()
+			defer rig.mu.Unlock()
+			if subject == asks.AskSubject(askerName) {
+				rig.sent = append(rig.sent, body)
+			}
+			return nil
+		},
+		call: func(context.Context, conditions.Action, map[string]string) error {
+			time.Sleep(20 * time.Millisecond) // long enough for the other delivery to arrive meanwhile
+			rig.mu.Lock()
+			defer rig.mu.Unlock()
+			rig.called++
+			return nil
+		},
+		record: func(context.Context, link.HandAct) error {
+			rig.mu.Lock()
+			defer rig.mu.Unlock()
+			rig.acts++
+			return nil
+		},
+		now:  func() time.Time { return now },
+		logf: t.Logf,
+	}
+}
+
+func askedBus(t *testing.T) *nats.Conn {
+	t.Helper()
+	conn, err := nats.Connect(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(conn.Close)
+	js, err := jetstream.New(conn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := js.CreateKeyValue(context.Background(), jetstream.KeyValueConfig{Bucket: broker.AskedBucket}); err != nil {
+		t.Fatal(err)
+	}
+	return conn
+}
+
+// The review of 2026-10-09 (L7): two deliveries of one warrant, to two controllers at once, perform its act
+// exactly once and record it once — the record's compare-and-set decides, never the warrant's message id.
+func TestTwoAnswersAtOnceActOnce(t *testing.T) {
+	conn := askedBus(t)
+	now := time.Date(2026, 10, 9, 14, 0, 0, 0, time.UTC)
+	rig := &busAskerRig{open: []conditions.Condition{heldCondition()}}
+	first, second := rig.asker(t, conn, now), rig.asker(t, conn, now)
+	if err := first.reconcile(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if len(rig.sent) != 1 {
+		t.Fatalf("asked %d times", len(rig.sent))
+	}
+	var q asks.Ask
+	_ = json.Unmarshal(rig.sent[0], &q)
+	release, _ := q.Option("release")
+	w := asks.Warrant{Ask: q.ID, Asker: askerName, About: q.About, Outcome: asks.OutcomeChosen, Option: release.ID,
+		Label: release.Label, Level: release.Level, Channel: "telegram", Proofs: []string{"P1"}, At: now,
+		AskDigest: q.Digest(), By: &asks.Person{Who: asks.Operator, Kind: "telegram", Identity: "42", Verified: "user id verified"}}
+	body, _ := json.Marshal(w)
+	var wg sync.WaitGroup
+	for _, a := range []*asker{first, second, first, second} {
+		wg.Add(1)
+		go func(a *asker) {
+			defer wg.Done()
+			if err := a.Decided(context.Background(), body); err != nil {
+				t.Error(err)
+			}
+		}(a)
+	}
+	wg.Wait()
+	if rig.called != 1 || rig.acts != 1 {
+		t.Fatalf("performed %d time(s), recorded %d time(s)", rig.called, rig.acts)
+	}
+	got, err := busAsked{conn: conn}.Get(context.Background(), q.ID)
+	if err != nil || got == nil || got.Acted != "done" {
+		t.Fatalf("kept as %+v (%v)", got, err)
+	}
+}
+
+// The review of 2026-10-09 (L2): a write decided on a record read earlier never lands over one made since. A
+// cancel read before the answer was acted on leaves the act's record as it is.
+func TestAStaleCancelDoesNotWriteOverAnAct(t *testing.T) {
+	conn := askedBus(t)
+	now := time.Date(2026, 10, 9, 14, 0, 0, 0, time.UTC)
+	rig := &busAskerRig{open: []conditions.Condition{heldCondition()}}
+	a := rig.asker(t, conn, now)
+	if err := a.reconcile(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	var q asks.Ask
+	_ = json.Unmarshal(rig.sent[0], &q)
+	stale, _ := busAsked{conn: conn}.Get(context.Background(), q.ID)
+	release, _ := q.Option("release")
+	w := asks.Warrant{Ask: q.ID, Asker: askerName, About: q.About, Outcome: asks.OutcomeChosen, Option: release.ID,
+		Label: release.Label, Level: release.Level, Channel: "telegram", At: now, AskDigest: q.Digest(),
+		By: &asks.Person{Who: asks.Operator, Kind: "telegram", Identity: "42", Verified: "user id verified"}}
+	body, _ := json.Marshal(w)
+	if err := a.Decided(context.Background(), body); err != nil {
+		t.Fatal(err)
+	}
+	if err := a.cancel(context.Background(), *stale, "the condition ended"); err != nil {
+		t.Fatal(err)
+	}
+	got, _ := busAsked{conn: conn}.Get(context.Background(), q.ID)
+	if got.State != string(asks.OutcomeChosen) || got.Acted != "done" {
+		t.Errorf("a stale cancel wrote over the act: %+v", got)
+	}
+}

cmd/mesh-controller/asker_wire.go

@@ -0,0 +1,589 @@
+package main
+
+// The asker on the bus: its asks in the controller's bucket `asked`, its asks and cancels published on the
+// seat under the controller's name, the verbs a warrant chooses called with the controller's grant, and the
+// router's record of its asks read under its name (novox/hq ADR 0259).
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/asks"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// askerFrom is the serving controller's asker; nil in any other process.
+var askerFrom *asker
+
+// askWithin is how long a verb a warrant chose is given to answer.
+const askWithin = time.Minute
+
+type busAsked struct{ conn *nats.Conn }
+
+func (b busAsked) kv(ctx context.Context) (jetstream.KeyValue, error) {
+	js, err := jetstream.New(b.conn)
+	if err != nil {
+		return nil, err
+	}
+	return js.KeyValue(ctx, broker.AskedBucket)
+}
+
+func (b busAsked) Get(ctx context.Context, id string) (*asked, error) {
+	kv, err := b.kv(ctx)
+	if err != nil {
+		return nil, err
+	}
+	e, err := kv.Get(ctx, id)
+	if errors.Is(err, jetstream.ErrKeyNotFound) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	var r asked
+	return &r, json.Unmarshal(e.Value(), &r)
+}
+
+// Create keeps a new ask under its id, and only where none is kept: never over another.
+func (b busAsked) Create(ctx context.Context, r asked) error {
+	kv, err := b.kv(ctx)
+	if err != nil {
+		return err
+	}
+	body, err := json.Marshal(r)
+	if err != nil {
+		return err
+	}
+	_, err = kv.Create(ctx, r.ID, body)
+	return err
+}
+
+// Change applies change to the ask kept under id by compare-and-set on its key's revision (the review of
+// 2026-10-09, L2): read, changed, and written only over the revision read; when another write came between,
+// read again and asked again, at most askChangeTries times. change says whether to write at all.
+func (b busAsked) Change(ctx context.Context, id string, change func(*asked) bool) (bool, error) {
+	kv, err := b.kv(ctx)
+	if err != nil {
+		return false, err
+	}
+	for try := 0; try < askChangeTries; try++ {
+		e, err := kv.Get(ctx, id)
+		if errors.Is(err, jetstream.ErrKeyNotFound) {
+			return false, nil
+		}
+		if err != nil {
+			return false, err
+		}
+		var r asked
+		if err := json.Unmarshal(e.Value(), &r); err != nil {
+			return false, err
+		}
+		if !change(&r) {
+			return false, nil
+		}
+		body, err := json.Marshal(r)
+		if err != nil {
+			return false, err
+		}
+		if _, err := kv.Update(ctx, id, body, e.Revision()); err != nil {
+			var api *jetstream.APIError
+			if errors.Is(err, jetstream.ErrKeyExists) || (errors.As(err, &api) && api.ErrorCode == jetstream.JSErrCodeStreamWrongLastSequence) {
+				continue
+			}
+			return false, err
+		}
+		return true, nil
+	}
+	return false, fmt.Errorf("the ask %s changed under every one of %d tries", id, askChangeTries)
+}
+
+func (b busAsked) All(ctx context.Context) ([]asked, error) {
+	kv, err := b.kv(ctx)
+	if err != nil {
+		return nil, err
+	}
+	lister, err := kv.ListKeys(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = lister.Stop() }()
+	var out []asked
+	for k := range lister.Keys() {
+		e, err := kv.Get(ctx, k)
+		if err != nil {
+			continue
+		}
+		var r asked
+		if json.Unmarshal(e.Value(), &r) == nil {
+			out = append(out, r)
+		}
+	}
+	return out, nil
+}
+
+// callAction performs an action's verb as the controller, through the grant that names it.
+func callAction(conn *nats.Conn) func(ctx context.Context, a conditions.Action, args map[string]string) error {
+	return func(ctx context.Context, a conditions.Action, args map[string]string) error {
+		seat, verb, ok := strings.Cut(a.Verb, ".")
+		if !ok {
+			return fmt.Errorf("%q names no seat and verb", a.Verb)
+		}
+		body := map[string]any{}
+		for k, v := range args {
+			body[k] = v
+		}
+		if seat == catalogue.DeliverySeat {
+			_, err := askDeliveryOwner(ctx, conn, verb, body)
+			return err
+		}
+		granted := false
+		for _, v := range broker.VerbsTheControllerActsOnAWarrant {
+			granted = granted || (v.Seat == seat && v.Verb == verb)
+		}
+		if !granted {
+			return fmt.Errorf("%s: %w", a.Verb, errNotGranted)
+		}
+		var answer link.Answer
+		var err error
+		if a.Machine != "" {
+			answer, err = link.AskSeatTool(ctx, conn, seat, verb, a.Machine, body, askWithin)
+		} else {
+			answer, err = link.AskMeshSeatTool(ctx, conn, seat, verb, body, askWithin)
+		}
+		if err != nil {
+			return err
+		}
+		if answer.Error != "" {
+			return fmt.Errorf("%s refused: %s", a.Verb, answer.Error)
+		}
+		return nil
+	}
+}
+
+// routerRecordOf reads the router's record of one of the controller's asks, under its name, and answers
+// how it ended when it did: the bucket is the one the asks seat's declarer names as its records.
+func routerRecordOf(conn *nats.Conn, inv *inventory.Inventory) func(ctx context.Context, id string) (*asks.Warrant, error) {
+	return func(ctx context.Context, id string) (*asks.Warrant, error) {
+		bucket, err := asksRecords(ctx, inv)
+		if err != nil || bucket == "" {
+			return nil, err
+		}
+		reply, err := conn.RequestWithContext(ctx, "$JS.API.DIRECT.GET.KV_"+bucket+".$KV."+bucket+"."+askerName+"."+id, nil)
+		if err != nil {
+			return nil, err
+		}
+		if reply.Header.Get("Status") != "" {
+			return nil, nil // none, or not readable: the event says it
+		}
+		var rec struct {
+			State   string        `json:"state"`
+			Warrant *asks.Warrant `json:"warrant"`
+		}
+		if json.Unmarshal(reply.Data, &rec) != nil || rec.State == "open" || rec.Warrant == nil {
+			return nil, nil
+		}
+		return rec.Warrant, nil
+	}
+}
+
+// asksRecords is the bucket the asks seat's declarer keeps its record of asks in.
+func asksRecords(ctx context.Context, inv *inventory.Inventory) (string, error) {
+	declared, err := inv.Catalogue(ctx)
+	if err != nil {
+		return "", err
+	}
+	for _, m := range declared {
+		for _, s := range m.DefinesSeats {
+			if s.Name == broker.AsksSeat && len(s.Records) > 0 {
+				return broker.BucketName(m.Module, s.Records[0]), nil
+			}
+		}
+	}
+	return "", nil
+}
+
+// routerHereIn says whether a module declaring the asks seat, with its ask named by its caller, is assigned:
+// without it nothing takes an ask, and asking would only fill a queue nobody reads.
+func routerHereIn(inv *inventory.Inventory) func(ctx context.Context) (bool, error) {
+	return func(ctx context.Context) (bool, error) {
+		entries, err := inv.Catalogued(ctx)
+		if err != nil {
+			return false, err
+		}
+		for _, e := range entries {
+			for _, s := range e.Manifest.DefinesSeats {
+				if s.Name == broker.AsksSeat && s.NamedByCaller("ask") && len(e.On) > 0 {
+					return true, nil
+				}
+			}
+		}
+		return false, nil
+	}
+}
+
+// grantHeldIn says whether the bus holds the controller's grant to ask (novox/hq issue 353), judged on the two
+// facts that make it so, and failing closed on each:
+//
+//  1. **composed**: the user list the mesh composes now grants the controller itself to publish its ask
+//     (controllerMayAsk) — the controller's own grant, not whether any user of the list changed;
+//  2. **in force**: the bus's own module, on the machine holding the bus, says the user list there allows it
+//     and the server reloaded after that list was written (the nats module's `nats_user_can`, `in_force`) — a
+//     list sent is not a list the bus enforces until it reloads.
+//
+// Anything that cannot be worked out is not held, with why, so the conditions that need the operator are said
+// as undelivered rather than asked into a refusal.
+func grantHeldIn(open *stores, conn *nats.Conn) func(ctx context.Context) (bool, string, error) {
+	return grantHeldBy(composedGrantIn(open), busGrantIn(open, conn), time.Now)
+}
+
+// grantJudge is one of the two facts: whether it holds, and why not.
+type grantJudge func(ctx context.Context) (bool, string, error)
+
+// grantHeldBy is the judgement over the two facts, remembered for grantLookEvery: composing the list resolves
+// the bus's machine whole, and asking the bus's module is a call.
+func grantHeldBy(composed, inForce grantJudge, now func() time.Time) func(ctx context.Context) (bool, string, error) {
+	var mu sync.Mutex
+	var at time.Time
+	var held bool
+	var why string
+	return func(ctx context.Context) (bool, string, error) {
+		mu.Lock()
+		defer mu.Unlock()
+		if !at.IsZero() && now().Sub(at) < grantLookEvery {
+			return held, why, nil
+		}
+		held, why = judgeGrant(ctx, composed, inForce)
+		at = now()
+		return held, why, nil
+	}
+}
+
+// judgeGrant is held only when both facts hold; an error is a fact not known, never a yes. A fact that holds
+// with a caveat (a reload not confirmed) gives that caveat as the why of a yes.
+func judgeGrant(ctx context.Context, composed, inForce grantJudge) (bool, string) {
+	var caveat []string
+	for _, fact := range []struct {
+		judge grantJudge
+		what  string
+	}{{composed, "whether the mesh composes the controller a grant to ask"}, {inForce, "whether the bus enforces it"}} {
+		if fact.judge == nil {
+			return false, fact.what + " is not judged here"
+		}
+		ok, why, err := fact.judge(ctx)
+		if err != nil {
+			return false, fact.what + " could not be worked out: " + err.Error()
+		}
+		if !ok {
+			return false, why
+		}
+		if why != "" {
+			caveat = append(caveat, why)
+		}
+	}
+	return true, strings.Join(caveat, "; ")
+}
+
+// controllerMayAsk says whether the controller's own grant, as composed from these records, lets it publish its
+// ask (ADR 0259 §3: composed while a router that takes asks under its asker's name is assigned).
+func controllerMayAsk(records broker.Records) (bool, error) {
+	users, err := broker.Users(records)
+	if err != nil {
+		return false, err
+	}
+	for _, u := range users {
+		if u.Kind != broker.KindController {
+			continue
+		}
+		perms, err := broker.PermissionsFor(u)
+		if err != nil {
+			return false, err
+		}
+		return broker.MayPublish(perms, asks.AskSubject(askerName)), nil
+	}
+	return false, errors.New("the composition holds no controller")
+}
+
+// composedGrantIn is the first fact, from the mesh's records.
+func composedGrantIn(open *stores) grantJudge {
+	return func(ctx context.Context) (bool, string, error) {
+		if open == nil || open.inventory == nil {
+			return false, "", errors.New("the mesh's records are not open")
+		}
+		records, err := open.inventory.BusRecords(ctx)
+		if err != nil {
+			return false, "", err
+		}
+		may, err := controllerMayAsk(records)
+		if err != nil || may {
+			return may, "", err
+		}
+		return false, "the mesh composes the controller no grant to ask: no router that takes asks under its " +
+			"asker's name is assigned", nil
+	}
+}
+
+// busGrantIn is the second fact, asked of the bus's own module on the machine holding the bus, with the check
+// main made before it (novox/hq issue 353, PR 186: is the user list sent to the bus's machine the one composed
+// now) kept for the cases the module's word does not settle.
+func busGrantIn(open *stores, conn *nats.Conn) grantJudge {
+	ask := func(ctx context.Context) (string, json.RawMessage, error) {
+		if open == nil || open.inventory == nil || conn == nil {
+			return "", nil, errors.New("the mesh's records or the bus are not open")
+		}
+		holders, err := seatHolders(ctx, open.inventory)
+		if err != nil {
+			return "", nil, err
+		}
+		h, held := holders[theBrokerSeat]
+		if !held || h.Node == "" || h.Module == "" {
+			return "", nil, nil
+		}
+		a, err := link.AskModuleToolOn(ctx, conn, h.Module, busUserCanTool, h.Node, map[string]any{
+			"user": broker.ControllerName, "action": "publish", "subject": asks.AskSubject(askerName)}, 15*time.Second)
+		if err != nil {
+			return h.Node, nil, err
+		}
+		if a.Error != "" {
+			return h.Node, nil, errors.New(a.Error)
+		}
+		return h.Node, a.Result, nil
+	}
+	list := func(ctx context.Context) (busListState, error) {
+		if open == nil || open.inventory == nil {
+			return busListState{}, errors.New("the mesh's records are not open")
+		}
+		s, err := brokerListState(ctx, open, nil)
+		if err != nil || s.Machine == "" || !s.Behind {
+			return s, err
+		}
+		step, err := busHeld(ctx, open.inventory, []string{s.Machine})
+		if err != nil {
+			return busListState{}, err
+		}
+		s.BusStep = step[s.Machine]
+		return s, nil
+	}
+	return busGrantBy(ask, list)
+}
+
+// busListState is the user list on the bus's machine as the controller's record knows it: whether the list
+// sent there is behind the one composed now, why it could not be composed, and the bus step a send there waits
+// on (that machine cannot be pushed until a person's `bus upgrade`).
+type busListState struct {
+	Machine    string
+	Behind     bool
+	Uncomposed error
+	BusStep    string
+}
+
+// remedy is the one thing that sends the bus's machine the list composed now: the plan's own reason when it
+// cannot be composed, the bus upgrade while sends there wait on it, and otherwise a push of that machine.
+func (s busListState) remedy(node string) string {
+	if s.Machine != "" {
+		node = s.Machine
+	}
+	switch {
+	case s.Uncomposed != nil:
+		return fmt.Sprintf("the user list for %s cannot be composed (%v); `plan %s` says what to fix first",
+			node, s.Uncomposed, node)
+	case s.BusStep != "":
+		return fmt.Sprintf("sends to %s wait on the bus's planned step, so a push will not carry it: %s", node, s.BusStep)
+	}
+	return fmt.Sprintf("`push %s` carries it", node)
+}
+
+// busGrantBy judges the bus's word, and names for each way it is not held the one thing that makes it held:
+//
+//   - **in force**: held;
+//   - **allowed, from a module older than `in_force`**: held, with the caveat that the reload is not confirmed.
+//     The file allows the publish, and the bus reloads within about 5 s of a change to it, so the worst case is
+//     one ask refused in those seconds, which is asked again (issue 369). The list check is not consulted:
+//     while a bus step is pending the bus's machine cannot be pushed, so any change to the composed list would
+//     read as behind for good and silence every ask until a person's bus upgrade (the review of PR 188);
+//   - **allowed, written, not reloaded** (the module gives both times): wait about 5 s;
+//   - **allowed, in force not known** (the module could not read a time): what is not known, said;
+//   - **not allowed, or the module cannot answer**: the list check decides — the remedy that sends the list
+//     when it is behind (busListState.remedy), and, for a module that cannot answer, held while the list sent
+//     is current, as main judged it.
+//
+// ask answers the machine holding the bus and its module's answer ("" when nothing holds the bus); list is the
+// record's word on the list sent to that machine.
+func busGrantBy(ask func(ctx context.Context) (string, json.RawMessage, error),
+	list func(ctx context.Context) (busListState, error)) grantJudge {
+	return func(ctx context.Context) (bool, string, error) {
+		node, raw, askErr := ask(ctx)
+		if askErr == nil && node == "" {
+			return false, "no module holds the bus, so nothing says what it enforces", nil
+		}
+		var answer busAnswer
+		if askErr == nil {
+			if answer, askErr = readBusAnswer(raw); askErr != nil {
+				askErr = fmt.Errorf("its answer could not be read: %w", askErr)
+			}
+		}
+		if askErr != nil {
+			if node == "" {
+				node = "the bus's machine"
+			}
+			s, err := list(ctx)
+			if err != nil {
+				return false, "", fmt.Errorf("the bus module on %s could not answer (%v), and whether the list sent "+
+					"there is the one composed now could not be worked out: %w", node, askErr, err)
+			}
+			if s.Behind {
+				return false, fmt.Sprintf("the bus module on %s could not answer (%v), and the user list sent there is "+
+					"behind what the mesh composes; %s", node, askErr, s.remedy(node)), nil
+			}
+			return true, fmt.Sprintf("the bus module on %s could not answer (%v); judged by the user list sent there, "+
+				"which is the one composed now", node, askErr), nil
+		}
+		notAllowed := func(older string) (bool, string, error) {
+			s, err := list(ctx)
+			if err != nil {
+				return false, "", fmt.Errorf("the user list on %s does not allow the controller to ask%s, and whether "+
+					"the list sent there is the one composed now could not be worked out: %w", node, older, err)
+			}
+			if s.Behind {
+				return false, fmt.Sprintf("the user list on %s does not allow the controller to ask%s: it is behind "+
+					"what the mesh composes; %s", node, older, s.remedy(node)), nil
+			}
+			return false, fmt.Sprintf("the user list on %s does not allow the controller to ask%s, though the list "+
+				"sent there is the one composed now; %s again", node, older, s.remedy(node)), nil
+		}
+		switch {
+		case answer.InForce == nil && answer.Allowed:
+			return true, fmt.Sprintf("the user list on %s allows the controller to ask, but its reload is not "+
+				"confirmed: the bus module there is older than the answer whether a grant is in force, and the bus "+
+				"upgrade (`bus upgrade`) carries one that confirms it", node), nil
+		case answer.InForce == nil:
+			return notAllowed(" (the bus module there is older than the answer whether a grant is in force)")
+		case !answer.Allowed:
+			return notAllowed("")
+		case *answer.InForce:
+			return true, "", nil
+		case answer.FileWritten != "" && answer.ServerLoaded != "":
+			return false, fmt.Sprintf("the bus on %s has the controller's grant to ask written (%s) but has not "+
+				"reloaded since (last load %s); it reloads in place within about 5 s, so nothing is to be done but wait",
+				node, answer.FileWritten, answer.ServerLoaded), nil
+		}
+		why := answer.Why
+		if why == "" {
+			why = "it gives no reason"
+		}
+		return false, fmt.Sprintf("the user list on %s allows the controller to ask, but whether the bus enforces it "+
+			"is not known: %s", node, why), nil
+	}
+}
+
+// busUserCanTool is the bus module's answer to whether a user may do something, and whether it is in force.
+const busUserCanTool = "nats_user_can"
+
+// busAnswer is the bus module's answer to busUserCanTool; InForce is nil from a module older than that field,
+// and FileWritten and ServerLoaded are given only when it could read both times (mesh-catalog's nats InForce).
+type busAnswer struct {
+	Allowed      bool   `json:"allowed"`
+	InForce      *bool  `json:"in_force"`
+	Why          string `json:"why"`
+	FileWritten  string `json:"file_written"`
+	ServerLoaded string `json:"server_loaded"`
+}
+
+func readBusAnswer(raw json.RawMessage) (busAnswer, error) {
+	var answer busAnswer
+	err := json.Unmarshal(raw, &answer)
+	return answer, err
+}
+
+// grantLookEvery is how often the bus's user list is judged against the one its machine was last sent.
+const grantLookEvery = 30 * time.Second
+
+// channelsIn is what the channels are now, as a fingerprint: each module claiming a kind of the channel
+// bench, where, promising what, and whether of its own account. An ask the router refused is asked again
+// once this changes.
+func channelsIn(inv *inventory.Inventory) func(ctx context.Context) string {
+	return func(ctx context.Context) string {
+		entries, err := inv.Catalogued(ctx)
+		if err != nil {
+			return ""
+		}
+		var parts []string
+		for _, e := range entries {
+			for _, c := range e.Manifest.Claims {
+				if c.Kind == "" || !catalogue.KindedBenches[c.Name] {
+					continue
+				}
+				on := append([]string(nil), e.On...)
+				sort.Strings(on)
+				caps := append([]string(nil), c.Capabilities...)
+				sort.Strings(caps)
+				parts = append(parts, fmt.Sprintf("%s/%s=%s@%s[%s]own:%t", c.Name, c.Kind, e.Manifest.Module,
+					strings.Join(on, ","), strings.Join(caps, ","), e.Manifest.RunsAs != ""))
+			}
+		}
+		sort.Strings(parts)
+		return strings.Join(parts, ";")
+	}
+}
+
+// startAsking makes the serving controller's asker and hands it the router's words.
+func startAsking(ctx context.Context, open *stores, server *link.Server, conn *nats.Conn, keeper *conditions.Keeper) {
+	js, err := jetstream.New(conn)
+	if err != nil {
+		fmt.Printf("the operator cannot be asked: %v\n", err)
+		return
+	}
+	a := servingAsker(open, conn, js, keeper)
+	if err := server.Decides(a); err != nil {
+		fmt.Printf("the operator's answers cannot be heard, so nothing is asked: %v\n", err)
+		return
+	}
+	askerFrom = a
+	go a.keep(ctx)
+}
+
+// servingAsker is the serving controller's asker, wired to the mesh: what it reads, publishes, performs and
+// records, and the judgements it asks by — the bus's grant to ask among them (novox/hq issue 353).
+func servingAsker(open *stores, conn *nats.Conn, js jetstream.JetStream, keeper *conditions.Keeper) *asker {
+	return &asker{
+		open: keeper.Open,
+		silence: func(ctx context.Context, key string, d time.Duration, by, why string) error {
+			_, err := keeper.Silence(ctx, key, d, by, why)
+			return err
+		},
+		store: busAsked{conn: conn},
+		publish: func(ctx context.Context, subject string, body []byte, id string) error {
+			_, err := js.Publish(ctx, subject, body, jetstream.WithMsgID(id))
+			return err
+		},
+		call: callAction(conn),
+		// A proposed settings layer is set by this controller itself on the warrant (novox/hq ADR 0277).
+		setLayer: setLayerIn(open),
+		record: func(ctx context.Context, act link.HandAct) error {
+			_, err := link.RecordHandAct(ctx, conn, act)
+			return err
+		},
+		routerRecord: routerRecordOf(conn, open.inventory),
+		routerHere:   routerHereIn(open.inventory),
+		grantHeld:    grantHeldIn(open, conn),
+		channels:     channelsIn(open.inventory),
+		raise: func(ctx context.Context, obs []conditions.Observation) error {
+			return keeper.Reconcile(ctx, sourceAsker, obs)
+		},
+		now:  time.Now,
+		logf: func(format string, args ...any) { fmt.Printf(format+"\n", args...) },
+	}
+}

cmd/mesh-controller/awaiting_push_integration_test.go

@@ -0,0 +1,182 @@
+//go:build integration
+
+package main
+
+import (
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/overlay"
+)
+
+func TestAModuleAssignedAndNotPushedIsAwaitingAPushNotUncomposable(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aKeeper())
+	pushedBy(t, open, "laptop") // the machine was pushed before; then the module is assigned
+	if _, err := assign(ctx, open, "laptop", "keeper"); err != nil {
+		t.Fatal(err)
+	}
+
+	// The read the rest of the mesh asks still refuses it, with the composer's typed error: nothing
+	// can be compared about a secret that does not exist (status), and nothing here string-matches.
+	plan, settings, err := planFor(ctx, open, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	gens, err := generators(ctx, open)
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = declarationWith(ctx, open, "laptop", plan, settings, gens, Reading)
+	var notMade *catalogue.NotMadeError
+	if !errors.As(err, &notMade) || notMade.Module != "keeper" || notMade.Name != "repository" {
+		t.Fatalf("a read composition did not say which secret is not made, typed: %v", err)
+	}
+	// Foreseen, it composes, names what the push makes, and made nothing.
+	foreseen, err := declarationWith(ctx, open, "laptop", plan, settings, gens, Foreseeing)
+	if err != nil || len(foreseen.foreseen) != 1 || foreseen.foreseen[0] != "keeper/repository" {
+		t.Fatalf("foreseen: %v %v", foreseen.foreseen, err)
+	}
+	if _, held, err := open.inventory.ModuleSecretIfIssued(ctx, "laptop", "keeper", "repository"); err != nil || held {
+		t.Fatalf("asking ahead of the push made the secret (held %v, %v)", held, err)
+	}
+
+	// Within the bound: nothing at all — no urgent, no warning, nobody notified.
+	if got := d1(t, open); len(got) != 0 {
+		t.Fatalf("a machine waiting for a push raised %+v", got)
+	}
+
+	// Past the bound: a warning, not urgent, saying what the push will make.
+	before := awaitingPushBound
+	awaitingPushBound = -time.Minute
+	t.Cleanup(func() { awaitingPushBound = before })
+	got := d1(t, open)
+	if len(got) != 1 || got[0].Key() != "machine.laptop.awaiting-push" || got[0].Severity != conditions.Warning ||
+		!strings.Contains(got[0].Summary, "keeper/repository") || !strings.Contains(got[0].Summary, "push laptop") {
+		t.Fatalf("a machine left un-pushed past the bound: %+v", got)
+	}
+
+	// Pushed: the secret is made and D1 says nothing.
+	pushedBy(t, open, "laptop")
+	if got := d1(t, open); len(got) != 0 {
+		t.Fatalf("a pushed machine still raised %+v", got)
+	}
+}
+
+func TestASecretThePushCannotMakeIsStillUncomposable(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aTalker())
+	if _, err := assign(ctx, open, "laptop", "talker"); err != nil {
+		t.Fatal(err)
+	}
+	got := d1(t, open)
+	if len(got) != 1 || got[0].Key() != "machine.laptop.uncomposable" || got[0].Severity != conditions.Urgent ||
+		!strings.Contains(got[0].Summary, "module issue talker --node laptop") {
+		t.Fatalf("a push that will be refused was not said urgently: %+v", got)
+	}
+
+	// And a machine whose composition fails for anything else, with a secret waiting beside it, is
+	// uncomposable for that — the stand-in hides nothing.
+	register(t, open, aKeeper())
+	if _, err := assign(ctx, open, "anchor", "keeper"); err != nil {
+		t.Fatal(err)
+	}
+	one, two := rivals()
+	register(t, open, one)
+	register(t, open, two)
+	_, _ = assign(ctx, open, "anchor", "rival-one")
+	_, _ = assign(ctx, open, "anchor", "rival-two")
+	keys := map[string]conditions.Severity{}
+	for _, o := range d1(t, open) {
+		keys[o.Key()] = o.Severity
+	}
+	if keys["machine.anchor.uncomposable"] != conditions.Urgent {
+		t.Fatalf("a real failure beside a waiting secret: %v", keys)
+	}
+}
+
+func TestAGivenSecretUnderAnOldKeyIsNotForeseen(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aKeeper())
+	if _, err := assign(ctx, open, "laptop", "keeper"); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.AcceptSecretForModule(ctx, "laptop", "keeper", "repository", "given"); err != nil {
+		t.Fatal(err)
+	}
+	record, err := open.inventory.NodeByName(ctx, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.RecordSealingKey(ctx, record.ID, aPublicKey(t)); err != nil {
+		t.Fatal(err)
+	}
+	got := d1(t, open)
+	if len(got) != 1 || got[0].Key() != "machine.laptop.uncomposable" || !strings.Contains(got[0].Summary, "issue it again") {
+		t.Fatalf("a given secret under an old key: %+v", got)
+	}
+}
+
+func TestAMachineAwaitsAPushSinceItsOldestAssignmentSinceTheLastSend(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aKeeper())
+	pushedBy(t, open, "laptop")
+	sent := time.Now()
+	since, err := open.inventory.AwaitingSince(ctx, "laptop")
+	if err != nil || since.After(sent) {
+		t.Fatalf("nothing assigned since the send: waiting since %v (%v), the send was before %v", since, err, sent)
+	}
+	if _, err := assign(ctx, open, "laptop", "keeper"); err != nil {
+		t.Fatal(err)
+	}
+	since, err = open.inventory.AwaitingSince(ctx, "laptop")
+	if err != nil || since.Before(sent.Add(-time.Second)) {
+		t.Fatalf("assigned after the send: waiting since %v (%v), not from the assignment", since, err)
+	}
+}
+
+func TestALastSendIsReadFromTheSendAndTheReport(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, aKeeper())
+	pushedBy(t, open, "laptop")
+	if _, err := assign(ctx, open, "laptop", "keeper"); err != nil {
+		t.Fatal(err)
+	}
+	sends, err := readDeliveries(ctx, open.inventory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sends["laptop"].settled("keeper", time.Now()) {
+		t.Fatal("a holder assigned and not pushed is expected to answer")
+	}
+	if !sends["laptop"].settled(overlay.Name, time.Now().Add(time.Hour)) {
+		t.Fatal("a module the machine was sent long ago is not expected to answer")
+	}
+	pushedBy(t, open, "laptop")
+	sends, err = readDeliveries(ctx, open.inventory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sends["laptop"].settled("keeper", time.Now()) {
+		t.Fatal("pushed a moment ago and not reported, a holder is already expected")
+	}
+	if !sends["laptop"].settled("keeper", time.Now().Add(reportGrace+time.Minute)) {
+		t.Fatal("pushed past the grace, a holder is not expected")
+	}
+	if _, ok := sends["laptop"].carried["keeper"]; !ok {
+		t.Fatalf("the send's builds do not carry keeper: %v", sends["laptop"].carried)
+	}
+	pushedAndApplied(t, open, "laptop")
+	if sends, err = readDeliveries(ctx, open.inventory); err != nil || !sends["laptop"].settled("keeper", time.Now()) {
+		t.Fatalf("pushed and reported applied, a holder is not expected to answer (%v)", err)
+	}
+}

cmd/mesh-controller/awaiting_push_test.go

@@ -0,0 +1,115 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// Between `assign` and `push` a module's own secrets are not made yet: the push makes them. D1 composed
+// the machine's declaration without making anything, failed on the missing secret, and raised an urgent
+// "nothing can be sent to <machine>" — seen live on 2026-10-06, a desktop notification for a machine
+// the next push sent to without a word (novox/hq issue 275). D1 now composes as the push would, with a
+// stand-in for what the push makes: pending, not broken, and said only past a bound, as a warning.
+
+// aKeeper is a module with an own secret the mesh makes — a backup repository's password.
+func aKeeper() catalogue.Manifest {
+	return catalogue.Manifest{Module: "keeper", Version: "1",
+		OwnSecrets: catalogue.OwnSecrets{"repository": {Path: "/var/lib/mesh/keeper/repository"}},
+		Resources: []map[string]any{
+			{"id": "state", "type": "directory", "path": "/var/lib/mesh/keeper", "mode": "0700"},
+		}}
+}
+
+// pushedBy records a send to a machine as a push does — composed on the send path, so its own secrets
+// are made — without a bus to carry it.
+func pushedBy(t *testing.T, open *stores, node string) string {
+	t.Helper()
+	ctx := t.Context()
+	plan, settings, err := planFor(ctx, open, node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	declared, err := declarationFor(ctx, open, node, plan, settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+	body, err := declared.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	record, err := open.inventory.NodeByName(ctx, node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	digest := digestOf(body)
+	if err := open.inventory.RecordSent(ctx, record.ID, digest, declared.Builds); err != nil {
+		t.Fatal(err)
+	}
+	return digest
+}
+
+// pushedAndApplied is pushedBy, and the machine reporting it applied that declaration.
+func pushedAndApplied(t *testing.T, open *stores, node string) {
+	t.Helper()
+	digest := pushedBy(t, open, node)
+	record, err := open.inventory.NodeByName(t.Context(), node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := open.inventory.RecordDoing(t.Context(), record.ID, inventory.Doing{
+		Outcome: inventory.OutcomeApplied, Declared: digest}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// d1 runs D1 once.
+func d1(t *testing.T, open *stores) []conditions.Observation {
+	t.Helper()
+	got, err := probeDeclarations(t.Context(), &doctor{open: open})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return got
+}
+
+// **THE WINDOW, REPRODUCED**: assigned and not pushed, a module whose own secret the push makes is
+// waiting, not uncomposable; past the bound it is a warning naming what the push makes; pushed, nothing.
+
+// **A REAL FAILURE IS STILL URGENT**: a secret the push would be refused on is not one it will make.
+// A bus credential nobody issued (issue 203) fails the push, so D1 says it — urgent, in the push's words.
+
+// A given secret sealed to a key the machine no longer has is not the mesh's to make again: the push is
+// refused on it, so D1 is too.
+
+// The bound is read from when the machine began waiting: the oldest assignment since its last send.
+
+// **D3 AND D13 WAIT FOR THE SEND**: a holder is expected to answer on a machine once the machine was sent
+// it and had time to report — never between assign and push.
+func TestAHolderIsExpectedOnlyOnceSentAndReported(t *testing.T) {
+	now := time.Now()
+	sent := now.Add(-time.Minute)
+	long := now.Add(-time.Hour)
+	cases := []struct {
+		name string
+		send lastSend
+		want bool
+	}{
+		{"never sent", lastSend{}, false},
+		{"sent without it", lastSend{sent: &long, current: true, carried: map[string]string{"other": "c"}}, false},
+		{"sent with it, not reported yet", lastSend{sent: &sent, carried: map[string]string{"keeper": "c"}}, false},
+		{"sent with it and reported", lastSend{sent: &sent, current: true, carried: map[string]string{"keeper": "c"}}, true},
+		{"sent with it long ago, never reported", lastSend{sent: &long, carried: map[string]string{"keeper": "c"}}, true},
+		{"sent before builds were kept", lastSend{sent: &long, current: true}, true},
+	}
+	for _, c := range cases {
+		if got := c.send.settled("keeper", now); got != c.want {
+			t.Errorf("%s: settled %v, want %v", c.name, got, c.want)
+		}
+	}
+}
+
+// And through the stores: assigned, not in the last send; pushed and reported, carried and settled.

cmd/mesh-controller/backups_before_send_integration_test.go

@@ -0,0 +1,308 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// aBackupSeatOnTheBus is one machine's node-backup holder as a test makes it: it counts the `now` asks it hears and
+// answers `backed-up` with the last night it is told (novox/hq ADR 0404).
+type aBackupSeatOnTheBus struct {
+	mu    sync.Mutex
+	nows  []string
+	night map[string]any // module → lastNight
+}
+
+func (f *aBackupSeatOnTheBus) serve(t *testing.T, conn *nats.Conn, node string) {
+	t.Helper()
+	reply := func(m *nats.Msg, result any) {
+		body, _ := json.Marshal(map[string]any{"result": result, "error": "", "node": node})
+		_ = m.Respond(body)
+	}
+	now, err := conn.Subscribe(link.NodeSeatToolSubject(catalogue.BackupSeat, "now", node), func(m *nats.Msg) {
+		var a struct {
+			Module string `json:"module"`
+		}
+		_ = json.Unmarshal(m.Data, &a)
+		f.mu.Lock()
+		f.nows = append(f.nows, a.Module)
+		f.mu.Unlock()
+		reply(m, map[string]any{"started": a.Module})
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	read, err := conn.Subscribe(link.NodeSeatToolSubject(catalogue.BackupSeat, "backed-up", node), func(m *nats.Msg) {
+		f.mu.Lock()
+		defer f.mu.Unlock()
+		var out []map[string]any
+		for module, n := range f.night {
+			out = append(out, map[string]any{"module": module, "lastNight": n})
+		}
+		reply(m, out)
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = now.Unsubscribe(); _ = read.Unsubscribe() })
+	if err := conn.Flush(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func (f *aBackupSeatOnTheBus) answers(module string, ok bool, words string) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.night = map[string]any{module: map[string]any{"ok": ok, "at": time.Now().UTC().Add(time.Second), "error": words}}
+}
+
+func (f *aBackupSeatOnTheBus) asks() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.nows)
+}
+
+// Acceptance test 3 of design 47, on the controller's side: a delivery plan that moves a module keeping data waits
+// for its backups on both machines before it asks a build; a backup that fails holds it, with the machine, the
+// module and the backup's words, and a condition says the same; the verb the delivery's release calls asks the
+// backups again, and the plan goes on. One bus and one store for the scenarios.
+func TestADeliveryThatMovesABackedUpModuleWaitsForItsBackupAndAFailedOneHoldsItAndIsSaid(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	asked := asksRecorded(t)
+	js, err := broker.Dial(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(js.Close)
+	before := handActConn
+	handActConn = js.Conn()
+	t.Cleanup(func() { handActConn = before })
+
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	register(t, open, catalogue.Manifest{Module: "keeper", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.BackupSeat, Scope: catalogue.ScopeNode, Serves: []string{"backed-up", "now", "restore"}}}})
+	notes, err := catalogue.ParseManifest([]byte(`{"module":"notes","version":"1","data":{"own":[` +
+		`{"id":"files","path":"${dir:files}","class":"valuable","why":"people's notes"}]},` +
+		`"resources":[{"id":"files","type":"directory"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RegisterModule(ctx, notes, inventory.Source{Repository: "novox/mesh-catalog", Seat: "git",
+		Path: "modules/notes", Ref: "main", BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	for _, node := range []string{"anchor", "laptop"} {
+		if _, err := assign(ctx, open, node, "keeper"); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := assign(ctx, open, node, "notes"); err != nil {
+			t.Fatal(err)
+		}
+	}
+	seats := map[string]*aBackupSeatOnTheBus{"anchor": {}, "laptop": {}}
+	for node, s := range seats {
+		s.serve(t, js.Conn(), node)
+	}
+	// Short waits: the bound and the look are variables, so nothing here waits for the minutes of a real backup.
+	wasWithin, wasEvery := backupsWithin, backupsPollEvery
+	backupsWithin, backupsPollEvery = time.Minute, 10*time.Millisecond
+	t.Cleanup(func() { backupsWithin, backupsPollEvery = wasWithin, wasEvery })
+
+	newPlan := func(id string) {
+		t.Helper()
+		p := inventory.Plan{ID: id, Repository: "novox/mesh-catalog", Branch: "main", Commit: "c1", Created: time.Now().UTC(),
+			State: inventory.PlanBuilding, Tiers: [][]string{{"notes"}}, Modules: map[string]*inventory.PlanModule{"notes": {}}}
+		if err := inv.SavePlan(ctx, &p); err != nil {
+			t.Fatal(err)
+		}
+	}
+	read := func(id string) inventory.Plan {
+		t.Helper()
+		p, err := inv.PlanByID(ctx, id)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return p
+	}
+
+	// 1. Both machines are asked; while one has not answered, no build is asked.
+	newPlan("plan-one")
+	advancePlans(ctx, open)
+	if seats["anchor"].asks() != 1 || seats["laptop"].asks() != 1 || len(*asked) != 0 {
+		t.Fatalf("asks anchor=%d laptop=%d builds=%v", seats["anchor"].asks(), seats["laptop"].asks(), *asked)
+	}
+	seats["anchor"].answers("notes", true, "")
+	advancePlans(ctx, open)
+	if len(*asked) != 0 || read("plan-one").Backups.State != inventory.BackupPending {
+		t.Fatalf("a tier was asked while a backup was pending: %v %+v", *asked, read("plan-one").Backups)
+	}
+	seats["laptop"].answers("notes", true, "")
+	advancePlans(ctx, open)
+	if len(*asked) != 1 || read("plan-one").Backups.State != inventory.BackupDone {
+		t.Fatalf("the tier was not asked once every backup was done: %v %+v", *asked, read("plan-one").Backups)
+	}
+	finish := read("plan-one")
+	finish.State = inventory.PlanDone
+	if err := inv.SavePlan(ctx, &finish); err != nil {
+		t.Fatal(err)
+	}
+
+	// 2. A backup that fails holds the plan: not failed, nothing asked, the words kept, a condition raised.
+	seats["anchor"].night, seats["laptop"].night = nil, nil
+	newPlan("plan-two")
+	advancePlans(ctx, open)
+	seats["anchor"].answers("notes", true, "")
+	seats["laptop"].answers("notes", false, "no space left on device")
+	advancePlans(ctx, open)
+	held := read("plan-two")
+	if held.State != inventory.PlanBuilding || held.Backups.State != inventory.BackupFailed || len(*asked) != 1 {
+		t.Fatalf("the plan was not held: %s %+v builds=%v", held.State, held.Backups, *asked)
+	}
+	var failed *inventory.PlanBackup
+	for i := range held.Backups.Asked {
+		if held.Backups.Asked[i].State == inventory.BackupFailed {
+			failed = &held.Backups.Asked[i]
+		}
+	}
+	if failed == nil || failed.Machine != "laptop" || failed.Module != "notes" || failed.Words != "no space left on device" ||
+		strings.Contains(held.Note, "tried again") {
+		t.Fatalf("the failed backup: %+v note=%q", failed, held.Note)
+	}
+	advancePlans(ctx, open) // not retried on the next look
+	if again := read("plan-two"); again.Backups.State != inventory.BackupFailed || len(*asked) != 1 ||
+		seats["laptop"].asks() != 2 {
+		t.Fatalf("a held plan was asked again by itself: %+v builds=%v asks=%d", again.Backups, *asked, seats["laptop"].asks())
+	}
+	said, err := probeBackupHeld(ctx, &doctor{open: open})
+	if err != nil || len(said) != 1 || said[0].Kind != kindBackupHeld || !strings.Contains(said[0].Said, "no space left on device") {
+		t.Fatalf("the condition: %+v %v", said, err)
+	}
+
+	// 3. The verb the release calls: the failed backup is asked again, and only it, and the plan goes on.
+	seats["laptop"].answers("notes", false, "no space left on device")
+	if err := deliveryCommand(ctx, []string{"backups-again", "plan-two", "--why", "a person released it", "--by",
+		"mesh-delivery for jochen"}); err != nil {
+		t.Fatal(err)
+	}
+	if err := deliveryCommand(ctx, []string{"backups-again", "plan-two", "--why", "again"}); err == nil {
+		t.Fatal("a plan with no failed backup was asked again")
+	}
+	seats["laptop"].night = nil
+	advancePlans(ctx, open)
+	if seats["laptop"].asks() != 3 || seats["anchor"].asks() != 2 {
+		t.Fatalf("asked again: laptop=%d anchor=%d", seats["laptop"].asks(), seats["anchor"].asks())
+	}
+	seats["laptop"].answers("notes", true, "")
+	advancePlans(ctx, open)
+	if got := read("plan-two"); got.Backups.State != inventory.BackupDone || len(*asked) != 2 {
+		t.Fatalf("the plan did not go on: %+v builds=%v", got.Backups, *asked)
+	}
+	if said, _ := probeBackupHeld(ctx, &doctor{open: open}); len(said) != 0 {
+		t.Fatalf("the condition stays: %+v", said)
+	}
+}
+
+// Issue 1086: a plan cut from a merge asked its first tier at the cut, so a module keeping data was sent without the
+// backup the plan promised. The cut now takes the backups first (askFirstTierAtCut, batches.go), and the walk's own
+// step asks the tier once they are done.
+func TestAPlanCutFromAMergeOfABackedUpModuleAsksItsBackupAndNotItsTierUntilItIsDone(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	settings := t.TempDir() + "/merge-window.json"
+	if err := os.WriteFile(settings, []byte(`{"merge-window": "90s", "merge-window-at-most": "10m"}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv(mergeWindowFileVar, settings)
+	everyHeadWaits(t)
+	asked := asksRecorded(t)
+	js, err := broker.Dial(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(js.Close)
+	before := handActConn
+	handActConn = js.Conn()
+	t.Cleanup(func() { handActConn = before })
+
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	register(t, open, catalogue.Manifest{Module: "keeper", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.BackupSeat, Scope: catalogue.ScopeNode, Serves: []string{"backed-up", "now", "restore"}}}})
+	if err := inv.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-controller", Version: "1"},
+		inventory.Source{Repository: "novox/mesh-controller", Seat: "git", Ref: "main", BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	notes, err := catalogue.ParseManifest([]byte(`{"module":"notes","version":"1","data":{"own":[` +
+		`{"id":"files","path":"${dir:files}","class":"valuable","why":"people's notes"}]},` +
+		`"resources":[{"id":"files","type":"directory"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RegisterModule(ctx, notes, inventory.Source{Repository: "novox/notes", Seat: "git", Ref: "main",
+		BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	for _, m := range []string{"keeper", "notes"} {
+		if _, err := assign(ctx, open, "anchor", m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	seat := &aBackupSeatOnTheBus{}
+	seat.serve(t, js.Conn(), "anchor")
+	wasWithin, wasEvery := backupsWithin, backupsPollEvery
+	backupsWithin, backupsPollEvery = time.Minute, 10*time.Millisecond
+	t.Cleanup(func() { backupsWithin, backupsPollEvery = wasWithin, wasEvery })
+
+	// 1. A merge of notes is heard and its window closes: the batch is cut through cutBatch.
+	hear(t, open, repoMerge("notes", "c-notes", t0), t0.Add(time.Second))
+	cutAt(t, open, t0.Add(time.Second+90*time.Second))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 {
+		t.Fatalf("%d walk(s)", len(ws))
+	}
+	// 2. Right after the cut no tier is asked, the record has anchor/notes pending, the seat heard one `now`.
+	cut, err := inv.PlanByID(ctx, ws[0].ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(*asked) != 0 || askedInTier(cut) {
+		t.Fatalf("the first tier was asked at the cut: %v %+v", *asked, cut.Modules)
+	}
+	if cut.Backups == nil || cut.Backups.State != inventory.BackupPending || len(cut.Backups.Asked) != 1 ||
+		cut.Backups.Asked[0].Machine != "anchor" || cut.Backups.Asked[0].Module != "notes" {
+		t.Fatalf("the backups of the cut: %+v", cut.Backups)
+	}
+	if seat.asks() != 1 {
+		t.Fatalf("the seat heard %d `now`", seat.asks())
+	}
+	// 3. The backup answers done: the walk's own step asks the first tier, once, and asks no second backup.
+	seat.answers("notes", true, "")
+	advancePlans(ctx, open)
+	advancePlans(ctx, open)
+	after, err := inv.PlanByID(ctx, ws[0].ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(*asked) != 1 || after.Backups.State != inventory.BackupDone || seat.asks() != 1 {
+		t.Fatalf("builds=%v backups=%+v asks=%d", *asked, after.Backups, seat.asks())
+	}
+}

cmd/mesh-controller/batches_integration_test.go

@@ -0,0 +1,698 @@
+//go:build integration
+
+package main
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+func windowed(t *testing.T) *stores {
+	t.Helper()
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	settings := t.TempDir() + "/merge-window.json"
+	if err := os.WriteFile(settings, []byte(`{"merge-window": "90s", "merge-window-at-most": "10m"}`), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv(mergeWindowFileVar, settings)
+	noGroups(t)
+	if err := inv.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-controller", Version: "1"},
+		inventory.Source{Repository: "novox/mesh-controller", Seat: "git", Ref: "main", BuiltFrom: "c0",
+			Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	for _, m := range []struct{ module, repository, path string }{
+		{"app", "novox/mesh-catalog", "modules/app"},
+		{"notes", "novox/mesh-catalog", "modules/notes"},
+		{"one", "novox/one", ""},
+		{"two", "novox/two", ""},
+		{"three", "novox/three", ""},
+	} {
+		if err := inv.RegisterModule(ctx, catalogue.Manifest{Module: m.module, Version: "1"},
+			inventory.Source{Repository: m.repository, Seat: "git", Path: m.path, Ref: "main", BuiltFrom: "c0",
+				Head: "c0"}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return open
+}
+
+func hear(t *testing.T, open *stores, m link.SourceMoved, now time.Time) {
+	t.Helper()
+	if err := (following{open: open}).hearMerge(t.Context(), m, now); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func cutAt(t *testing.T, open *stores, now time.Time) {
+	t.Helper()
+	if err := cutBatchesHeld(t.Context(), open, now); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestTwoMergesSecondsApartAreOneWalkAtTheLaterCommit(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asked := asksWithPaths(t)
+	claude := catalogueMerge("553b7191claude", "app", t0)
+	dunst := catalogueMerge("48bda475dunst", "notes", t0.Add(17*time.Second))
+	hear(t, open, claude, t0.Add(time.Second))
+	hear(t, open, dunst, t0.Add(18*time.Second))
+	if ws, bs := walks(t, open); len(ws) != 0 || len(bs) != 1 {
+		t.Fatalf("within the window: %d walk(s), %d batch(es)", len(ws), len(bs))
+	}
+	cutAt(t, open, t0.Add(18*time.Second+89*time.Second))
+	if ws, _ := walks(t, open); len(ws) != 0 {
+		t.Fatalf("cut before the window closed: %+v", ws)
+	}
+	cutAt(t, open, t0.Add(18*time.Second+90*time.Second))
+	ws, bs := walks(t, open)
+	if len(ws) != 1 || len(bs) != 0 {
+		t.Fatalf("after the window: %d walk(s), %d batch(es)", len(ws), len(bs))
+	}
+	w := ws[0]
+	if w.Commit != dunst.Commit || len(w.Commits) != 1 || w.Commits[0].Commit != dunst.Commit {
+		t.Fatalf("the walk is at %s %+v, not the later commit", w.Commit, w.Commits)
+	}
+	for _, m := range []string{"app", "notes"} {
+		if _, in := w.Modules[m]; !in {
+			t.Fatalf("the walk does not build %s, which one of its merges moved: %v", m, w.Modules)
+		}
+	}
+	want := []inventory.PlanMerge{{Repository: "novox/mesh-catalog", Commit: claude.Commit, Carried: dunst.Commit},
+		{Repository: "novox/mesh-catalog", Commit: dunst.Commit}}
+	if w.Delivery == nil || !slices.EqualFunc(w.Delivery.Merges, want, sameMerge) {
+		t.Fatalf("the walk answers %+v, want %+v", w.Delivery, want)
+	}
+	if len(*asked) != 2 || (*asked)[0][2] != "main" || (*asked)[1][2] != "main" {
+		t.Fatalf("the walk did not ask its modules at the branch, which holds the commit it carries: %v", *asked)
+	}
+	// Heard again, as the bus may hand it over twice: never a second merge, nor a second walk.
+	hear(t, open, claude, t0.Add(5*time.Minute))
+	if ws, bs := walks(t, open); len(ws) != 1 || len(bs) != 0 {
+		t.Fatalf("a merge heard twice made %d walk(s) and %d batch(es)", len(ws), len(bs))
+	}
+}
+
+func TestThreeRepositoriesInOneWindowAreOneWalk(t *testing.T) {
+	open := windowed(t)
+	groupsWaiting(t, "feat/three")
+	asksRecorded(t)
+	for i, r := range []string{"one", "two", "three"} {
+		hear(t, open, fromHead(repoMerge(r, "c-"+r, t0.Add(time.Duration(i)*20*time.Second)), "feat/three"),
+			t0.Add(time.Duration(i)*20*time.Second+time.Second))
+	}
+	cutAt(t, open, t0.Add(41*time.Second+90*time.Second))
+	ws, bs := walks(t, open)
+	if len(ws) != 1 || len(bs) != 0 {
+		t.Fatalf("%d walk(s), %d batch(es)", len(ws), len(bs))
+	}
+	w := ws[0]
+	if len(w.Commits) != 3 || len(w.Delivery.Merges) != 3 {
+		t.Fatalf("the walk carries %+v and answers %+v", w.Commits, w.Delivery.Merges)
+	}
+	for _, r := range []string{"one", "two", "three"} {
+		if w.CommitOf("novox/"+r) != "c-"+r {
+			t.Fatalf("the walk carries %s at %q", r, w.CommitOf("novox/"+r))
+		}
+		if _, in := w.Modules[r]; !in {
+			t.Fatalf("the walk does not build %s: %v", r, w.Modules)
+		}
+	}
+	// Each module's ask is recorded at its own repository's commit.
+	for _, r := range []string{"one", "two", "three"} {
+		q, found, err := open.inventory.BuildRequestByID(t.Context(), w.Modules[r].Build)
+		if err != nil || !found || q.Commit != "c-"+r {
+			t.Fatalf("%s's build was not recorded at its own commit: %+v %v %v", r, q, found, err)
+		}
+	}
+}
+
+func TestAMergeRestartsTheWindowAndTheMaximumClosesIt(t *testing.T) {
+	open := windowed(t)
+	groupsWaiting(t, "feat/both", "feat/busy")
+	asksWithPaths(t)
+	hear(t, open, fromHead(repoMerge("one", "c1", t0), "feat/both"), t0)
+	hear(t, open, fromHead(repoMerge("two", "c2", t0.Add(80*time.Second)), "feat/both"), t0.Add(80*time.Second))
+	cutAt(t, open, t0.Add(100*time.Second))
+	if ws, _ := walks(t, open); len(ws) != 0 {
+		t.Fatal("the window closed 90 seconds after its first merge, not after its last")
+	}
+	cutAt(t, open, t0.Add(170*time.Second))
+	if ws, _ := walks(t, open); len(ws) != 1 || len(ws[0].Commits) != 2 {
+		t.Fatalf("the window did not close 90 seconds after its last merge: %+v", ws)
+	}
+
+	busy := windowed(t)
+	groupsWaiting(t, "feat/both", "feat/busy")
+	asksWithPaths(t)
+	var last time.Time
+	for i := 0; i < 12; i++ {
+		last = t0.Add(time.Duration(i) * time.Minute)
+		repo := []string{"one", "two", "three"}[i%3]
+		hear(t, busy, fromHead(repoMerge(repo, "c"+string(rune('a'+i)), last), "feat/busy"), last)
+		if ws, _ := walks(t, busy); len(ws) > 0 {
+			if i != 10 {
+				t.Fatalf("a busy window closed at merge %d (minute %d), not at its maximum", i, i)
+			}
+			break
+		}
+	}
+	ws, _ := walks(t, busy)
+	if len(ws) != 1 {
+		t.Fatalf("ten minutes of merges a minute apart were never cut: %d walk(s)", len(ws))
+	}
+}
+
+func TestTheAssemblingBatchIsShown(t *testing.T) {
+	open := windowed(t)
+	groupsWaiting(t, "pr/553b7191claude")
+	asksWithPaths(t)
+	var said []inventory.Plan
+	was := inventory.PlanSaved
+	inventory.PlanSaved = func(_ *inventory.Inventory, p inventory.Plan) { said = append(said, p) }
+	t.Cleanup(func() { inventory.PlanSaved = was })
+	now := time.Now().UTC()
+	claude := catalogueMerge("553b7191claude", "app", now.Add(-20*time.Second))
+	claude.Number, claude.Title = 174, "claude-code: an agent proposes a section"
+	dunst := catalogueMerge("48bda475dunst", "notes", now.Add(-2*time.Second))
+	dunst.Number, dunst.Title = 175, "dunst: the font the operator chose"
+	hear(t, open, claude, now.Add(-19*time.Second))
+	hear(t, open, dunst, now.Add(-time.Second))
+	hear(t, open, fromHead(repoMerge("one", "a6bc0931one", now), dunst.Head), now)
+	out := captured(t, func() error { return plansCommand(t.Context(), nil) })
+	lines := strings.Split(out, "\n")
+	first := lines[0]
+	for _, want := range []string{"assembling: ", " s left (at the latest ", "grouped: novox/mesh-catalog@48bda475 " +
+		"(answers 553b7191), novox/one@a6bc0931; plan not yet calculated"} {
+		if !strings.Contains(first, want) {
+			t.Fatalf("plans' first line %q does not say %q", first, want)
+		}
+	}
+	// Under it, one line per repository: the pull request, what it answers, what it moves.
+	if len(lines) < 3 || strings.TrimSpace(lines[1]) != "mesh-catalog #175 dunst: the font the operator chose (answers "+
+		"#174 claude-code: an agent proposes a section) · app, notes" ||
+		strings.TrimSpace(lines[2]) != "one a6bc0931 · one" {
+		t.Fatalf("the grouped list reads %q", lines[1:4])
+	}
+	if len(said) == 0 || said[len(said)-1].State != inventory.PlanAssembling || said[len(said)-1].Delivery.Batch == nil ||
+		len(said[len(said)-1].Delivery.Merges) != 3 {
+		t.Fatalf("the batch was not said as assembling with its merges: %+v", said)
+	}
+}
+
+func captured(t *testing.T, run func() error) string {
+	t.Helper()
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	was := os.Stdout
+	os.Stdout = w
+	runErr := run()
+	os.Stdout = was
+	_ = w.Close()
+	var b bytes.Buffer
+	_, _ = io.Copy(&b, r)
+	if runErr != nil {
+		t.Fatal(runErr)
+	}
+	return b.String()
+}
+
+func TestAMergeDuringAWalkJoinsTheNextBatch(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(90*time.Second))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 || !ws[0].Open() {
+		t.Fatalf("the first batch was not cut: %+v", ws)
+	}
+	first := ws[0]
+	hear(t, open, repoMerge("one", "c2", t0.Add(2*time.Minute)), t0.Add(2*time.Minute))
+	cutAt(t, open, t0.Add(5*time.Minute))
+	ws, bs := walks(t, open)
+	if len(ws) != 1 || len(bs) != 1 || bs[0].State != inventory.PlanQueued || bs[0].Delivery.Batch.Behind != first.ID {
+		t.Fatalf("the merge during the walk: %d walk(s), batches %+v", len(ws), bs)
+	}
+	if got, _ := open.inventory.PlanByID(t.Context(), first.ID); !got.Open() {
+		t.Fatalf("the started walk was %s by the next merge", got.State)
+	}
+	if !strings.HasPrefix(batchWords(bs[0], t0.Add(5*time.Minute)), "queued behind "+first.ID) {
+		t.Fatalf("a queued batch reads %q", batchWords(bs[0], t0.Add(5*time.Minute)))
+	}
+	first.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(t.Context(), &first); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(6*time.Minute))
+	ws, bs = walks(t, open)
+	if len(ws) != 2 || len(bs) != 0 || ws[0].Commit != "c2" {
+		t.Fatalf("the queued batch was not cut when the walk ended: %+v %+v", ws, bs)
+	}
+}
+
+func TestAWaitingWalkIsFoldedIntoTheNextBatch(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-delivery", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}},
+		inventory.Source{Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/mesh-delivery", Ref: "main",
+			BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := open.inventory.Assign(ctx, "anchor", "mesh-delivery"); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(90*time.Second))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 || !ws[0].Waiting() {
+		t.Fatalf("the walk does not wait for its word: %+v", ws)
+	}
+	waiting := ws[0]
+	hear(t, open, repoMerge("one", "c2", t0.Add(2*time.Minute)), t0.Add(2*time.Minute))
+	cutAt(t, open, t0.Add(2*time.Minute+90*time.Second))
+	ws, bs := walks(t, open)
+	if len(bs) != 0 || len(ws) != 2 {
+		t.Fatalf("%d walk(s), %d batch(es)", len(ws), len(bs))
+	}
+	folded, err := open.inventory.PlanByID(ctx, waiting.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	newer := ws[0]
+	if folded.State != inventory.PlanSuperseded || folded.Delivery.TakenOverBy != newer.ID {
+		t.Fatalf("the waiting walk is %s, taken over by %q", folded.State, folded.Delivery.TakenOverBy)
+	}
+	if len(newer.Delivery.Merges) != 2 || newer.CommitOf("novox/one") != "c2" {
+		t.Fatalf("the newer walk answers %+v", newer.Delivery.Merges)
+	}
+	if _, in := newer.Modules["one"]; !in {
+		t.Fatalf("what the folded walk was to build is not built: %v", newer.Modules)
+	}
+}
+
+func TestALateMergeIsAnsweredByTheWalkOfTheLaterOne(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	later := catalogueMerge("48bda475dunst", "notes", t0.Add(17*time.Second))
+	hear(t, open, later, t0.Add(18*time.Second))
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	w := ws[0]
+	w.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &w); err != nil {
+		t.Fatal(err)
+	}
+	// Moves only notes, which the done walk built from the branch after it: answered there, at once.
+	hear(t, open, catalogueMerge("553b7191early", "notes", t0), t0.Add(15*time.Minute))
+	got, _ := open.inventory.PlanByID(ctx, w.ID)
+	if got.State != inventory.PlanDone || len(got.Delivery.Merges) != 2 ||
+		!sameMerge(got.Delivery.Merges[0], inventory.PlanMerge{Repository: "novox/mesh-catalog", Commit: "553b7191early",
+			Carried: later.Commit}) {
+		t.Fatalf("the late merge is not named by the walk that carried it: %+v", got.Delivery.Merges)
+	}
+	// Moves app, which that walk never built: the next batch walks it.
+	hear(t, open, catalogueMerge("1111aaaaapp", "app", t0.Add(time.Second)), t0.Add(16*time.Minute))
+	_, bs := walks(t, open)
+	if len(bs) != 1 || bs[0].Delivery.Merges[0].Commit != "1111aaaaapp" {
+		t.Fatalf("a late merge moving what the walk never built did not join the next batch: %+v", bs)
+	}
+}
+
+func TestAFailedWalkWalksItsEarlierMergesAlone(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asked := asksWithPaths(t)
+	ctx := t.Context()
+	// Made before the cut marks their modules seen, as merges are: walked again, they are news all the same.
+	oldest := catalogueMerge("aaaa0001", "app", t0.Add(-3*time.Minute))
+	middle := catalogueMerge("bbbb0002", "app", t0.Add(-3*time.Minute+10*time.Second))
+	newest := catalogueMerge("cccc0003", "notes", t0.Add(-3*time.Minute+20*time.Second))
+	for i, m := range []link.SourceMoved{oldest, middle, newest} {
+		hear(t, open, m, t0.Add(time.Duration(i)*10*time.Second+time.Second))
+	}
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	failed := ws[0]
+	failed.State, failed.Note = inventory.PlanFailed, "notes failed to build in tier 0"
+	if err := open.inventory.SavePlan(ctx, &failed); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(3*time.Minute))
+	got, _ := open.inventory.PlanByID(ctx, failed.ID)
+	if got.State != inventory.PlanFailed || len(got.Delivery.Merges) != 3 {
+		t.Fatalf("the failed walk's record changed: %s %+v", got.State, got.Delivery.Merges)
+	}
+	ws, _ = walks(t, open)
+	alone := ws[0]
+	if alone.ID == failed.ID || alone.Commit != middle.Commit || len(alone.Delivery.Merges) != 1 ||
+		!sameMerge(alone.Delivery.Merges[0], inventory.PlanMerge{Repository: "novox/mesh-catalog", Commit: middle.Commit}) {
+		t.Fatalf("the newest earlier merge was not walked alone on its own commit: %+v", alone)
+	}
+	if _, in := alone.Modules["app"]; !in || (*asked)[len(*asked)-1] != [3]string{"novox/mesh-catalog", "modules/app",
+		middle.Commit} {
+		t.Fatalf("the merge walked alone does not build app at its own commit: %v, asked %v", alone.Modules, *asked)
+	}
+	// Retried, the failed walk would name merges the search answers now.
+	if _, err := retryPlan(ctx, open, failed.ID); err == nil || !strings.Contains(err.Error(), "walked alone") {
+		t.Fatalf("a failed walk whose merges are searched was retried: %v", err)
+	}
+	alone.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &alone); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(4*time.Minute))
+	ws, bs := walks(t, open)
+	if ws[0].ID != alone.ID || len(bs) != 0 {
+		t.Fatalf("the search went on after a merge was delivered: %+v", ws[0])
+	}
+	done, _ := open.inventory.PlanByID(ctx, alone.ID)
+	if len(done.Delivery.Merges) != 2 || !sameMerge(done.Delivery.Merges[0], inventory.PlanMerge{Repository: "novox/mesh-catalog",
+		Commit: oldest.Commit, Carried: middle.Commit}) {
+		t.Fatalf("the oldest merge is not answered by the walk that delivered the one after it: %+v", done.Delivery.Merges)
+	}
+	// A stopped walk starts no search: a person ended it.
+	hear(t, open, catalogueMerge("dddd0004", "app", t0.Add(5*time.Minute)), t0.Add(5*time.Minute))
+	hear(t, open, catalogueMerge("eeee0005", "notes", t0.Add(5*time.Minute+time.Second)), t0.Add(5*time.Minute+time.Second))
+	cutAt(t, open, t0.Add(8*time.Minute))
+	ws, _ = walks(t, open)
+	if _, err := stopWalk(ctx, open.inventory, ws[0].ID, "mesh-delivery for jochen", "not now"); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(9*time.Minute))
+	if again, _ := walks(t, open); again[0].ID != ws[0].ID {
+		t.Fatalf("a stopped walk's earlier merge was walked alone: %+v", again[0])
+	}
+}
+
+func TestAGroupsOrderBecomesTiersInsideTheWalk(t *testing.T) {
+	for _, grouped := range []bool{true, false} {
+		open := windowed(t)
+		everyHeadWaits(t)
+		asksWithPaths(t)
+		ctx := t.Context()
+		for _, m := range []string{"mesh-host"} {
+			if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: m, Version: "1"},
+				inventory.Source{Repository: "novox/" + m, Seat: "git", Ref: "main", BuiltFrom: "c0", Head: "c0"}); err != nil {
+				t.Fatal(err)
+			}
+		}
+		host := repoMerge("mesh-host", "h1", t0)
+		ctl := repoMerge("mesh-controller", "k1", t0.Add(time.Second))
+		host.Head, ctl.Head = "feat/together", "feat/together"
+		if !grouped {
+			ctl.Head = "feat/alone"
+		}
+		hear(t, open, ctl, t0.Add(2*time.Second))
+		hear(t, open, host, t0.Add(3*time.Second))
+		cutAt(t, open, t0.Add(2*time.Minute))
+		ws, _ := walks(t, open)
+		if len(ws) != 1 {
+			t.Fatalf("%d walks", len(ws))
+		}
+		tiers := ws[0].Tiers
+		if grouped {
+			if len(tiers) != 2 || !slices.Equal(tiers[0], []string{"mesh-host"}) ||
+				!slices.Equal(tiers[1], []string{"mesh-controller"}) {
+				t.Fatalf("the group's order is not the walk's tiers: %v", tiers)
+			}
+		} else if len(tiers) != 1 {
+			t.Fatalf("two merges of no group were ordered: %v", tiers)
+		}
+	}
+}
+
+func TestABatchSurvivesARestart(t *testing.T) {
+	open := windowed(t)
+	groupsWaiting(t, "feat/both")
+	asksWithPaths(t)
+	hear(t, open, fromHead(repoMerge("one", "c1", t0), "feat/both"), t0)
+	hear(t, open, fromHead(repoMerge("two", "c2", t0.Add(30*time.Second)), "feat/both"), t0.Add(30*time.Second))
+
+	// A new controller: nothing of the first one's but the store.
+	again, err := openStores(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(again.Close)
+	hear(t, again, fromHead(repoMerge("one", "c1", t0), "feat/both"), t0.Add(60*time.Second)) // the bus hands it over again
+	cutAt(t, again, t0.Add(119*time.Second))
+	if ws, bs := walks(t, again); len(ws) != 0 || len(bs) != 1 || len(bs[0].Delivery.Merges) != 2 {
+		t.Fatalf("the restarted controller's batch: %d walk(s), %+v", len(ws), bs)
+	}
+	cutAt(t, again, t0.Add(120*time.Second))
+	ws, bs := walks(t, again)
+	if len(ws) != 1 || len(bs) != 0 || len(ws[0].Delivery.Merges) != 2 {
+		t.Fatalf("the restarted controller did not cut the batch at its window: %+v %+v", ws, bs)
+	}
+}
+
+func TestALateMergeOfAOneModuleRepositoryIsNamed(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	c2 := repoMerge("one", "c2", t0.Add(-50*time.Second))
+	hear(t, open, c2, t0)
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	w := ws[0]
+	w.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &w); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, repoMerge("one", "c1", t0.Add(-60*time.Second)), t0.Add(15*time.Minute))
+	got, _ := open.inventory.PlanByID(ctx, w.ID)
+	if len(got.Delivery.Merges) != 2 || !sameMerge(got.Delivery.Merges[0], inventory.PlanMerge{Repository: "novox/one",
+		Commit: "c1", Carried: "c2"}) {
+		t.Fatalf("the late merge was not named by the walk that carried it: %+v", got.Delivery.Merges)
+	}
+
+	// A walk of two that built only two: a late merge of one is not its to name.
+	hear(t, open, repoMerge("two", "d2", t0.Add(16*time.Minute)), t0.Add(16*time.Minute))
+	cutAt(t, open, t0.Add(18*time.Minute))
+	ws, _ = walks(t, open)
+	w = ws[0]
+	delete(w.Modules, "two")
+	w.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &w); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, repoMerge("two", "d1", t0.Add(15*time.Minute)), t0.Add(20*time.Minute))
+	if got, _ := open.inventory.PlanByID(ctx, w.ID); len(got.Delivery.Merges) != 1 {
+		t.Fatalf("a walk that never built what the late merge moves named it: %+v", got.Delivery.Merges)
+	}
+	if _, bs := walks(t, open); len(bs) != 1 || bs[0].Delivery.Merges[0].Commit != "d1" {
+		t.Fatalf("the late merge did not join the next batch: %+v", bs)
+	}
+}
+
+func TestAWalkLetGoBesideAStartedOneStartsOnceItEnded(t *testing.T) {
+	open := windowed(t)
+	asked := asksWithPaths(t)
+	ctx := t.Context()
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(2*time.Minute))
+	started, _ := walks(t, open)
+	waiting := inventory.Plan{ID: "plan-waiting", Repository: "novox/one", Branch: "main", Commit: "d1", Created: t0,
+		State: inventory.PlanBuilding, Tiers: [][]string{{"one"}}, Modules: map[string]*inventory.PlanModule{"one": {}},
+		Delivery: &inventory.PlanDelivery{Awaits: catalogue.DeliverySeat}}
+	if err := open.inventory.SavePlan(ctx, &waiting); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := letGo(ctx, open.inventory, waiting.ID, catalogue.DeliverySeat, "its turn"); err != nil {
+		t.Fatalf("the word was refused beside %s: %v", started[0].ID, err)
+	}
+	before := len(*asked)
+	advanceHeld(ctx, open)
+	got, _ := open.inventory.PlanByID(ctx, waiting.ID)
+	if len(*asked) != before || !strings.Contains(got.Note, "starts once "+started[0].ID) {
+		t.Fatalf("a walk let go beside a started one asked (%d → %d) or does not say it waits: %q", before, len(*asked), got.Note)
+	}
+	// Read as a wait, an hour on: its note on the line, never LATE, and no tier of it late for S3.
+	later := time.Now().Add(time.Hour)
+	if line := planLine(got, later); !strings.Contains(line, "starts once "+started[0].ID) || strings.Contains(line, "LATE") {
+		t.Fatalf("a deferred walk reads %q", line)
+	}
+	facts, _, err := gatherPlans(ctx, open.inventory, later, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range facts {
+		if f.id == got.ID {
+			t.Fatalf("a deferred walk is watched as a tier running late: %+v", f)
+		}
+	}
+	done := started[0]
+	done.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &done); err != nil {
+		t.Fatal(err)
+	}
+	advanceHeld(ctx, open)
+	if len(*asked) != before+1 {
+		t.Fatalf("the walk did not start once the started one ended: asked %v", *asked)
+	}
+}
+
+func TestAMergeOnTheControllersPathNeverSharesABatch(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asked := asksWithPaths(t)
+	ctx := t.Context()
+	if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-delivery", Version: "1",
+		Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}},
+		inventory.Source{Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/mesh-delivery", Ref: "main",
+			BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := open.inventory.Assign(ctx, "anchor", "mesh-delivery"); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, catalogueMerge("aaaa0001", "app", t0), t0)
+	hear(t, open, repoMerge("mesh-controller", "k1", t0.Add(10*time.Second)), t0.Add(10*time.Second))
+	hear(t, open, catalogueMerge("bbbb0002", "notes", t0.Add(20*time.Second)), t0.Add(20*time.Second))
+	_, bs := walks(t, open)
+	var ownBatch, catalogueBatch inventory.Plan
+	for _, b := range bs {
+		if b.OwnPath() {
+			ownBatch = b
+		} else {
+			catalogueBatch = b
+		}
+	}
+	if len(bs) != 2 || ownBatch.ID == "" || catalogueBatch.ID == "" || len(catalogueBatch.Delivery.Merges) != 2 ||
+		len(ownBatch.Delivery.Merges) != 1 {
+		t.Fatalf("a controller merge and two catalogue merges in one window: %+v", bs)
+	}
+	if !strings.Contains(batchWords(ownBatch, t0.Add(30*time.Second)), "own path") {
+		t.Fatalf("the own-path batch does not say so: %q", batchWords(ownBatch, t0.Add(30*time.Second)))
+	}
+	// Both windows closed, the controller's batch is cut first and starts; the catalogue batch queues behind it,
+	// is cut when the controller's walk ended, and waits for its word with both merges.
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, bs := walks(t, open)
+	if len(ws) != 1 || ws[0].Waiting() || ws[0].CommitOf("novox/mesh-controller") != "k1" {
+		t.Fatalf("the controller's batch was not cut first into a started walk: %+v", ws)
+	}
+	ownWalk := ws[0]
+	for _, m := range []string{"app", "notes"} {
+		if _, in := ownWalk.Modules[m]; in {
+			t.Fatalf("the controller's walk builds %s, a catalogue module: it skipped its turn", m)
+		}
+	}
+	if len(bs) != 1 || bs[0].State != inventory.PlanQueued || bs[0].Delivery.Batch.Behind != ownWalk.ID || bs[0].OwnPath() {
+		t.Fatalf("the catalogue batch does not queue behind the controller's walk: %+v", bs)
+	}
+	ownWalk.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &ownWalk); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, t0.Add(3*time.Minute))
+	ws, bs = walks(t, open)
+	if len(bs) != 0 || ws[0].ID != catalogueBatch.ID || !ws[0].Waiting() || len(ws[0].Delivery.Merges) != 2 {
+		t.Fatalf("the catalogue batch was not cut into a waiting walk once the controller's ended: %+v %+v", ws, bs)
+	}
+	for _, m := range []string{"app", "notes"} {
+		if _, in := ws[0].Modules[m]; !in {
+			t.Fatalf("the catalogue walk does not build %s: %v", m, ws[0].Modules)
+		}
+	}
+	for _, a := range *asked {
+		if a[1] == "modules/app" || a[1] == "modules/notes" {
+			t.Fatalf("a catalogue module was asked without the word: %v", *asked)
+		}
+	}
+
+	// A catalogue walk waiting for its word when an own-path batch is cut keeps waiting beside the own-path
+	// walk, is not folded into it, and its word is taken meanwhile: it starts once the own-path walk ended.
+	catalogueWalk := ws[0]
+	hear(t, open, repoMerge("mesh-controller", "k2", t0.Add(4*time.Minute)), t0.Add(4*time.Minute))
+	cutAt(t, open, t0.Add(6*time.Minute))
+	ws, _ = walks(t, open)
+	kept, _ := open.inventory.PlanByID(ctx, catalogueWalk.ID)
+	if !kept.Waiting() || ws[0].CommitOf("novox/mesh-controller") != "k2" || ws[0].Waiting() {
+		t.Fatalf("the waiting catalogue walk was not kept waiting beside the controller's walk: %s %+v", kept.State, ws)
+	}
+	if _, in := ws[0].Modules["app"]; in {
+		t.Fatalf("the controller's walk folded the waiting catalogue walk in: %v", ws[0].Modules)
+	}
+	if _, err := letGo(ctx, open.inventory, catalogueWalk.ID, catalogue.DeliverySeat, "its turn"); err != nil {
+		t.Fatal(err)
+	}
+	before := len(*asked)
+	advanceHeld(ctx, open)
+	if len(*asked) != before {
+		t.Fatalf("the catalogue walk started beside the controller's: asked %v", (*asked)[before:])
+	}
+	own2 := ws[0]
+	own2.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &own2); err != nil {
+		t.Fatal(err)
+	}
+	advanceHeld(ctx, open)
+	if len(*asked) < before+1 || (*asked)[before][1] != "modules/app" {
+		t.Fatalf("the catalogue walk did not start once the controller's ended: %v", (*asked)[before:])
+	}
+}
+
+func TestALateCatalogueMergeIsNotAnsweredByAnOwnPathWalk(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	for _, m := range []struct {
+		module string
+		claims []catalogue.Claim
+	}{
+		{"nats", nil},
+		{"mesh-delivery", []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}},
+	} {
+		if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: m.module, Version: "1", Claims: m.claims},
+			inventory.Source{Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/" + m.module, Ref: "main",
+				BuiltFrom: "c0", Head: "c0"}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if _, err := open.inventory.Assign(ctx, "anchor", "mesh-delivery"); err != nil {
+		t.Fatal(err)
+	}
+	mixed := link.SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "m1xed", MergedAt: t0.Format(time.RFC3339Nano),
+		Paths: []string{"modules/nats/module.json", "modules/app/module.json"}, ModuleDirs: []string{"modules/nats", "modules/app"},
+		ModuleDirsSaid: true}
+	hear(t, open, mixed, t0.Add(time.Second))
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 || ws[0].Waiting() {
+		t.Fatalf("the mixed merge's walk waited, or was not cut: %+v", ws)
+	}
+	done := ws[0]
+	done.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &done); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, catalogueMerge("ear1ier", "app", t0.Add(-30*time.Second)), t0.Add(3*time.Minute))
+	got, _ := open.inventory.PlanByID(ctx, done.ID)
+	_, bs := walks(t, open)
+	if len(got.Delivery.Merges) != 1 || len(bs) != 1 || bs[0].OwnPath() || bs[0].Delivery.Merges[0].Commit != "ear1ier" {
+		t.Fatalf("the late catalogue merge was answered by the own-path walk (%+v) rather than the next catalogue batch (%+v)",
+			got.Delivery.Merges, bs)
+	}
+}

cmd/mesh-controller/batches_test.go

@@ -0,0 +1,293 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"os"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The suite's tests of a merge, but for the merge window's own (this file's), plan the merge as it is heard: a
+// window of nothing closes at once, so a merge with no walk open is cut into its walk at once, as every merge
+// was planned before novox/hq ADR 0276. The window's tests set it through the controller's settings.
+func init() {
+	mergeWindowDefault = 0
+	// No forge in a test: no manifest is found at any commit, so a merge draws no edge of the manifests' change
+	// (delivery_edges.go). A test that wants some replaces these (forgeHolding).
+	manifestAt = func(context.Context, string, string, string, string) (catalogue.Manifest, bool, error) {
+		return catalogue.Manifest{}, false, nil
+	}
+	parentOf = func(context.Context, string, string, string) (string, error) { return "", nil }
+}
+
+// windowed is a mesh whose controller's settings give a merge window of 90 seconds and at most 10 minutes, as its
+// settings file says them, and
+// modules built from the catalogue (app, notes) and from three repositories of their own.
+
+// t0 is the moment a test's clock starts: merges are dated by it, and heard after it.
+var t0 = time.Now().UTC().Truncate(time.Second)
+
+// catalogueMerge is a merge of the catalogue changing one module's directory, made at a moment, from a pull
+// request's head branch of its own, as the forge announces every merge. Whether its head names a delivery group
+// with a member still to merge is mesh-delivery's word, which windowed stubs as no group at all (noGroups); a test
+// whose merges wait for the window as a group's says so (groupsWaiting).
+func catalogueMerge(commit, module string, made time.Time) link.SourceMoved {
+	return link.SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main", Head: "pr/" + commit, Commit: commit,
+		MergedAt: made.Format(time.RFC3339Nano), Paths: []string{"modules/" + module + "/module.json"},
+		ModuleDirs: []string{"modules/" + module}, ModuleDirsSaid: true}
+}
+
+// repoMerge is a merge of a repository of one module's own, from a head branch of its own (catalogueMerge).
+func repoMerge(repo, commit string, made time.Time) link.SourceMoved {
+	return link.SourceMoved{Owner: "novox", Repo: repo, Base: "main", Head: "pr/" + commit, Commit: commit,
+		MergedAt: made.Format(time.RFC3339Nano), Paths: []string{"main.go"}}
+}
+
+// noGroups stubs mesh-delivery's word on groups for a test: no head names a group.
+func noGroups(t *testing.T) {
+	t.Helper()
+	was := deliveryGroupOf
+	deliveryGroupOf = func(context.Context, bool, string) ([]groupMember, bool, error) { return nil, false, nil }
+	t.Cleanup(func() { deliveryGroupOf = was })
+}
+
+// groupsWaiting stubs mesh-delivery's word on groups for a test of the merge window's own timing: each head named
+// is one whose group mesh-delivery cannot say, so a merge from it waits for the window (ADR 0306 decision 2) and
+// nothing holds the batch open; every other head names no group. A group with a member still to merge, which holds
+// its batch open however long it takes (ADR 0418 clause 3), is groupStates'.
+func groupsWaiting(t *testing.T, heads ...string) {
+	t.Helper()
+	was := deliveryGroupOf
+	deliveryGroupOf = func(_ context.Context, _ bool, head string) ([]groupMember, bool, error) {
+		if slices.Contains(heads, head) {
+			return nil, false, errors.New("the test's mesh-delivery does not say")
+		}
+		return nil, false, nil
+	}
+	t.Cleanup(func() { deliveryGroupOf = was })
+}
+
+// everyHeadWaits stubs mesh-delivery's word on groups for a test whose merges each wait for the window as they did
+// before novox/hq ADR 0304: mesh-delivery cannot say any head's group.
+func everyHeadWaits(t *testing.T) {
+	t.Helper()
+	was := deliveryGroupOf
+	deliveryGroupOf = func(context.Context, bool, string) ([]groupMember, bool, error) {
+		return nil, false, errors.New("the test's mesh-delivery does not say")
+	}
+	t.Cleanup(func() { deliveryGroupOf = was })
+}
+
+// groupStates stubs mesh-delivery's word on one group: its members and their states, which a test changes as the
+// members merge.
+func groupStates(t *testing.T, head string, states map[string]string) {
+	t.Helper()
+	groupStatesFrom(t, head, states, true)
+}
+
+// groupStatesFrom is groupStates for a mesh-delivery that does (composed) or does not yet say the group's gate is the
+// composed check's: only the first holds the group's batch open for its last member.
+func groupStatesFrom(t *testing.T, head string, states map[string]string, composed bool) {
+	t.Helper()
+	was := deliveryGroupOf
+	deliveryGroupOf = func(_ context.Context, _ bool, asked string) ([]groupMember, bool, error) {
+		if asked != head {
+			return nil, false, nil
+		}
+		var members []groupMember
+		for repository, state := range states {
+			members = append(members, groupMember{Repository: repository, State: state, Composed: composed})
+		}
+		return members, true, nil
+	}
+	t.Cleanup(func() { deliveryGroupOf = was })
+}
+
+// fromHead is a merge from a head branch a test names: merges from one head are members of one delivery group,
+// related by it (novox/hq ADR 0304 decision 1), so they share a batch whatever else they share.
+func fromHead(m link.SourceMoved, head string) link.SourceMoved {
+	m.Head = head
+	return m
+}
+
+// lone is a merge that names no head: known to be no delivery group's, it waits for no window unless it is
+// related to a batch assembling (ADR 0304 decision 1).
+func lone(m link.SourceMoved) link.SourceMoved {
+	m.Head = ""
+	return m
+}
+
+// hear is a merge heard at a moment.
+
+// cutAt is the cutter looking at a moment.
+
+// walks is every plan record that is a walk, newest first, and the batches not yet cut.
+func walks(t *testing.T, open *stores) (walks, batches []inventory.Plan) {
+	t.Helper()
+	recent, err := open.inventory.RecentPlans(t.Context(), 50)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, p := range recent {
+		if p.Batch() {
+			batches = append(batches, p)
+		} else {
+			walks = append(walks, p)
+		}
+	}
+	return walks, batches
+}
+
+// The replay of issue 362: two catalogue merges 18 seconds apart are one batch, cut once into one walk at the
+// later commit, which names both merges — the earlier carried by the later.
+
+// Merges of three repositories in one window are one walk, one commit for each.
+
+// Each merge restarts the window: a merge at second 80 keeps the batch open until second 170; the window
+// closes at most ten minutes after its first merge however busy.
+
+// `plans` lists the batch being assembled first, in the operator's words: how long is left, when at the latest,
+// what is grouped, and that the plan is not yet calculated. It says so on the bus as plan-moved, too.
+
+// captured is what a command printed.
+
+// A merge heard during a walk it is related to (the same repository, issue 973) joins the next batch, which is
+// cut when the walk ends; the walk that started is never superseded (ADR 0276 decision 4, ADR 0407 decision 4).
+
+// A walk waiting for its delivery's word is folded into the next batch's walk, which answers its merges; it
+// names the walk that took it over.
+
+// A merge heard after a later merge of its branch was walked is answered by that walk when it builds all it
+// moves — named at once on a walk done — and joins the next batch when it does not.
+
+// A failed walk marks nothing delivered: its earlier merges are walked alone, on their own commit, the newest
+// first; the first delivered answers the older ones, and the search stops.
+
+// A delivery group's order holds inside the walk (ADR 0249 unchanged): merges of two repositories from one head
+// branch name, the node-engine's before the controller's, are tiered so; without the group, one tier.
+
+// A restarted controller resumes the window where it stood: the batch, its merges and their times are in the
+// store, a merge handed over again is not doubled, and the batch is cut when its window closes.
+
+// The window's settings reach the controller in its settings file, read at every look; one that says no
+// duration, or no file, is the default.
+func TestTheWindowIsTheControllersSetting(t *testing.T) {
+	file := t.TempDir() + "/merge-window.json"
+	t.Setenv(mergeWindowFileVar, file)
+	for _, c := range []struct {
+		content        string
+		window, atMost time.Duration
+	}{
+		{`{"merge-window": "60s", "merge-window-at-most": "5m"}`, time.Minute, 5 * time.Minute},
+		{`{"merge-window": 30, "merge-window-at-most": ""}`, 30 * time.Second, mergeWindowAtMostDefault},
+		{`{"merge-window": "soon"}`, mergeWindowDefault, mergeWindowAtMostDefault},
+	} {
+		if err := os.WriteFile(file, []byte(c.content), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		if w, m := mergeWindowOf(); w != c.window || m != c.atMost {
+			t.Errorf("%s reads as %s and %s, want %s and %s", c.content, w, m, c.window, c.atMost)
+		}
+	}
+	t.Setenv(mergeWindowFileVar, file+".gone")
+	if w, m := mergeWindowOf(); w != mergeWindowDefault || m != mergeWindowAtMostDefault {
+		t.Errorf("no file reads as %s and %s", w, m)
+	}
+}
+
+// S16 names every merge a waiting walk answers, never one commit a supersession may have ended (issue 362).
+func TestAWaitingWalkNamesTheMergesItAnswers(t *testing.T) {
+	f := calm(t0)
+	f.waits = []waitFacts{{id: "plan-2", repository: "novox/mesh-catalog", commit: "48bda475dunst", awaits: "mesh-delivery",
+		since: t0.Add(-31 * time.Minute), merges: []inventory.PlanMerge{
+			{Repository: "novox/mesh-catalog", Commit: "553b7191claude", Carried: "48bda475dunst"},
+			{Repository: "novox/mesh-catalog", Commit: "48bda475dunst"}}}}
+	got := watchWaits(f)
+	if len(got) != 1 || !strings.Contains(got[0].Summary, "novox/mesh-catalog@553b7191") ||
+		!strings.Contains(got[0].Summary, "novox/mesh-catalog@48bda475") {
+		t.Fatalf("the waiting walk does not name both merges: %+v", got)
+	}
+}
+
+// A merge heard after a later merge of its branch was cut is named by that walk however its modules read since
+// the cut, in a repository of one module (review of this change); a walk that never built what it moves names
+// nothing, and the merge joins the next batch.
+
+// A related walk waits for the delivery's word too: a waiting walk let go beside a started one it is related to
+// (the same repository, issue 973) takes the word and starts once that one ended, asking nothing before.
+
+// A file a merge of the batch removed and a later one brought back is not removed; one removed last is.
+func TestARemovedFileIsTheLastMergesWord(t *testing.T) {
+	ev := func(commit string, paths, removed []string) inventory.BatchedMerge {
+		m := link.SourceMoved{Owner: "novox", Repo: "one", Base: "main", Commit: commit, Paths: paths, Removed: removed}
+		b, _ := json.Marshal(m)
+		return inventory.BatchedMerge{Repository: "novox/one", Branch: "main", Commit: commit, Event: b,
+			Merged: t0.Add(time.Duration(len(commit)) * time.Second)}
+	}
+	got := combinedMerges([]inventory.BatchedMerge{
+		ev("a", []string{"x/module.json", "y/module.json"}, []string{"x/module.json", "y/module.json"}),
+		ev("bb", []string{"x/module.json"}, nil),
+		ev("ccc", []string{"z.go"}, nil)})
+	if len(got) != 1 || got[0].Commit != "ccc" || !slices.Equal(got[0].Removed, []string{"y/module.json"}) ||
+		len(got[0].Paths) != 3 {
+		t.Fatalf("combined as %+v", got)
+	}
+}
+
+// A merge on the controller's own path never shares a batch with one that waits for mesh-delivery's word
+// (decided during the build, 2026-10-10): the two are batches of their own, cut one after the other; a walk on
+// the own path folds no waiting catalogue walk but batches its merges again behind it; the catalogue's walk
+// still waits for the word, so no catalogue delivery skips its turn.
+
+// `plans` names a walk by what it moves (asked by the operator, 2026-10-10): the repository's pull request and
+// title, the modules it moves and the machines running them, then the state words; a record naming no pull
+// request is named by its commit, and a title is cut at fifty runes.
+func TestAPlanLineNamesWhatItMoves(t *testing.T) {
+	now := time.Date(2026, 10, 10, 12, 0, 0, 0, time.UTC)
+	p := inventory.Plan{ID: "plan-1", Repository: "novox/mesh-catalog", Branch: "main", Commit: "c1c1c1c1c1",
+		State: inventory.PlanBuilding, Tiers: [][]string{{"messenger", "telegram"}}, TierEntered: now.Add(-2 * time.Minute),
+		Modules: map[string]*inventory.PlanModule{"messenger": {State: "asked"}, "telegram": {State: "asked"}},
+		Commits: []inventory.PlanCommit{{Repository: "novox/mesh-catalog", Branch: "main", Commit: "c1c1c1c1c1"}},
+		Delivery: &inventory.PlanDelivery{Merges: []inventory.PlanMerge{{Repository: "novox/mesh-catalog",
+			Commit: "c1c1c1c1c1", Number: 175, Title: "a tap shows its outcome", Moves: []string{"telegram", "messenger"}}}}}
+	running := func(module string) []string {
+		if module == "messenger" || module == "telegram" {
+			return []string{"novox"}
+		}
+		return nil
+	}
+	if got, want := planLineOn(p, now, pauseView{}, tierAtLeast, running),
+		"mesh-catalog #175 a tap shows its outcome · messenger, telegram → novox · tier 1 of 1, building for 2m0s"; got != want {
+		t.Fatalf("the line reads %q, want %q", got, want)
+	}
+	if got := planLine(p, now); !strings.HasPrefix(got, "mesh-catalog #175 a tap shows its outcome · messenger, telegram · tier") {
+		t.Fatalf("without the machines the line reads %q", got)
+	}
+	old := p
+	old.Commits, old.Delivery = nil, nil
+	if got := planLine(old, now); !strings.HasPrefix(got, "mesh-catalog c1c1c1c1 · tier 1 of 1") {
+		t.Fatalf("a record naming no pull request reads %q", got)
+	}
+	long := p
+	long.Delivery.Merges[0].Title = strings.Repeat("abcdefghij", 6)
+	if got := planHeadline(long, nil); !strings.Contains(got, "#175 "+strings.Repeat("abcdefghij", 4)+"abcdefghi…") {
+		t.Fatalf("a long title is not cut at fifty runes: %q", got)
+	}
+}
+
+// sameMerge compares what a walk names of a merge: its repository, commit and the commit carrying it.
+func sameMerge(a, b inventory.PlanMerge) bool {
+	return a.Repository == b.Repository && a.Commit == b.Commit && a.Carried == b.Carried
+}
+
+// A catalogue merge heard after a later merge of its branch was walked without the word (a merge that touched
+// the bus too, on the controller's own path) is not answered by that walk while the delivery seat has a holder:
+// its delivery would skip its turn. It joins the next catalogue batch.

cmd/mesh-controller/batches_watch.go

@@ -0,0 +1,153 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// **Every wait of a batch has a bound and a condition** (novox/hq ADR 0276 decision 9): a batch still
+// assembling a minute past its maximum while no walk is open is a cut the controller failed to make (S18),
+// and a batch waiting behind an open walk longer than that walk's bound waits on a walk gone wrong (S19).
+
+// The kinds S18 and S19 raise.
+const (
+	kindBatchNotCut     = "batch-not-cut"
+	kindBatchBehindWalk = "batch-behind-walk"
+	// kindGroupNotMerged is raised for a group whose last member has not merged by the merge window's maximum after
+	// its first (novox/hq ADR 0418 clause 3).
+	kindGroupNotMerged = "group-not-merged"
+)
+
+// batchFacts is one batch not yet cut, as the watchdogs read it.
+type batchFacts struct {
+	id, state, grouped string
+	// atMost is when its window closes at the latest; closed when it closed.
+	atMost, closed time.Time
+	// behind is the open walk it waits behind, and walkBound that walk's bound: a tier's bound for each of its
+	// tiers.
+	behind    string
+	walkBound time.Duration
+	// holds are the groups the batch is held for, by head, with why; created is when the batch was made, the first
+	// merge of the group heard; atMostWindow is the maximum a window may take (the controller's setting).
+	holds        map[string]string
+	created      time.Time
+	atMostWindow time.Duration
+}
+
+// gatherBatches is every batch not yet cut, with the bound of the walk it waits behind.
+func gatherBatches(ctx context.Context, inv *inventory.Inventory, now time.Time) ([]batchFacts, error) {
+	batches, err := inv.Batches(ctx)
+	if err != nil || len(batches) == 0 {
+		return nil, err
+	}
+	bounds, err := measuredTierBounds(ctx, inv, now)
+	if err != nil {
+		return nil, err
+	}
+	var out []batchFacts
+	for _, b := range batches {
+		_, atMostWindow := mergeWindowOf()
+		f := batchFacts{id: b.ID, state: b.State, grouped: groupedWords(b), created: b.Created, atMostWindow: atMostWindow}
+		if w := b.Delivery; w != nil && w.Batch != nil {
+			f.holds = w.Batch.Holds
+			f.atMost, f.closed, f.behind = w.Batch.AtMost, w.Batch.ClosesAt, w.Batch.Behind
+			if f.atMost.Before(f.closed) {
+				f.closed = f.atMost
+			}
+			if w.Batch.CutAtOnce && !b.Created.IsZero() {
+				// Its window closed when it was made, which is its latest too (ADR 0304 decision 1).
+				f.atMost, f.closed = b.Created, b.Created
+			}
+		}
+		if f.behind != "" {
+			if walk, err := inv.PlanByID(ctx, f.behind); err == nil {
+				f.walkBound = bounds.of(walk.Repository) * time.Duration(max(1, len(walk.Tiers)))
+			}
+		}
+		out = append(out, f)
+	}
+	return out, nil
+}
+
+// watchBatchesNotCut is S18: a batch still assembling a minute past its maximum, while no walk is open.
+func watchBatchesNotCut(f *signalFacts) []conditions.Observation {
+	var out []conditions.Observation
+	for _, b := range f.batches {
+		if b.state != inventory.PlanAssembling || b.atMost.IsZero() || f.now.Sub(b.atMost) <= batchLateAfter ||
+			len(b.holds) > 0 { // a batch held for a group waits on a member, which has its own condition
+			continue
+		}
+		late := f.now.Sub(b.atMost)
+		out = append(out, conditions.Observation{Scope: conditions.ScopePlan, ID: b.id, Kind: kindBatchNotCut,
+			Severity: conditions.Warning,
+			Summary: fmt.Sprintf("the batch %s is still assembling %s past its latest close (%s), with no walk open: "+
+				"the controller did not cut it; grouped: %s", b.id, ago(late), b.atMost.UTC().Format(time.RFC3339), b.grouped),
+			Said:     fmt.Sprintf("assembling since %s past its maximum", ago(late)),
+			Headline: "Merged changes are not being delivered",
+			Explanation: fmt.Sprintf("Merges collected for one delivery should have been planned %s ago and were not. "+
+				"Nothing is lost; the mesh keeps them until it plans them.", humanDuration(late)),
+			Resolved: "Merged changes are being delivered again"})
+	}
+	return out
+}
+
+// watchBatchesBehind is S19: a batch waiting behind an open walk longer than that walk's bound, naming it.
+func watchBatchesBehind(f *signalFacts) []conditions.Observation {
+	var out []conditions.Observation
+	for _, b := range f.batches {
+		if b.state != inventory.PlanQueued || b.behind == "" || b.walkBound <= 0 || f.now.Sub(b.closed) <= b.walkBound {
+			continue
+		}
+		in := f.now.Sub(b.closed)
+		out = append(out, conditions.Observation{Scope: conditions.ScopePlan, ID: b.id, Kind: kindBatchBehindWalk,
+			Severity: conditions.Warning,
+			Summary: fmt.Sprintf("the batch %s has waited %s behind the walk %s, longer than that walk's bound (%s); "+
+				"grouped: %s; `plans %s` says where that walk stands", b.id, ago(in), b.behind, ago(b.walkBound),
+				b.grouped, b.behind),
+			Said:     fmt.Sprintf("queued behind %s for %s", b.behind, ago(in)),
+			Headline: "Merged changes wait behind a slow delivery",
+			Explanation: fmt.Sprintf("Merges collected for the next delivery have waited %s for the delivery before "+
+				"them, which is taking longer than it should. Nothing is lost.", humanDuration(in)),
+			Resolved: "Merged changes no longer wait behind a slow delivery"})
+	}
+	return out
+}
+
+// watchGroupsNotMerged is the condition of a batch held for a group whose last member has not merged by the merge
+// window's maximum after the first member merged, naming the member and why (novox/hq ADR 0418 clause 3): nothing of
+// the group is delivered while it waits.
+func watchGroupsNotMerged(f *signalFacts) []conditions.Observation {
+	var out []conditions.Observation
+	for _, b := range f.batches {
+		if len(b.holds) == 0 || b.created.IsZero() || f.now.Sub(b.created) <= b.atMostWindow {
+			continue
+		}
+		heads := make([]string, 0, len(b.holds))
+		for h := range b.holds {
+			heads = append(heads, h)
+		}
+		sort.Strings(heads)
+		var why []string
+		for _, h := range heads {
+			why = append(why, b.holds[h])
+		}
+		waited := f.now.Sub(b.created)
+		out = append(out, conditions.Observation{Scope: conditions.ScopePlan, ID: b.id,
+			Kind: kindGroupNotMerged, Severity: conditions.Warning,
+			Summary: fmt.Sprintf("%s; its first member merged %s ago, past the merge window's maximum (%s), and nothing "+
+				"of the group is delivered while it waits (batch %s)", strings.Join(why, "; "), ago(waited), ago(b.atMostWindow), b.id),
+			Said:     "a group waits for a member that has not merged",
+			Headline: "A change waits for the rest of its group to merge",
+			Explanation: fmt.Sprintf("The changes of a group are delivered together, once the last one is merged. "+
+				"One has not merged in %s. Nothing is lost; the merged ones are kept and delivered with it.",
+				humanDuration(waited)),
+			Resolved: "The group's last change merged"})
+	}
+	return out
+}

cmd/mesh-controller/beside_test.go

@@ -0,0 +1,108 @@
+//go:build integration
+
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// An unrelated closed batch is cut into a walk beside an open one, and that walk asks its first tier at once
+// (issue 973, novox/hq ADR 0407 decision 4): a hotfix is never held by an unrelated delivery.
+func TestAnUnrelatedBatchWalksBesideAnOpenWalk(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(90*time.Second))
+	if ws, _ := walks(t, open); len(ws) != 1 || !ws[0].Open() {
+		t.Fatalf("the first walk is not open: %+v", ws)
+	}
+	heard := t0.Add(100 * time.Second)
+	hear(t, open, lone(repoMerge("two", "c2", heard)), heard)
+	advanceHeld(ctx, open)
+	ws, bs := walks(t, open)
+	if len(ws) != 2 || len(bs) != 0 {
+		t.Fatalf("%d walk(s) and %d batch(es); want the unrelated batch cut beside the open walk", len(ws), len(bs))
+	}
+	for _, w := range ws {
+		if !w.Open() || w.Waiting() || deferred(w) || !askedAny(w) {
+			t.Errorf("%s (%s) is not walking: open %v, deferred %v, asked %v, note %q", w.ID, w.Named(), w.Open(),
+				deferred(w), askedAny(w), w.Note)
+		}
+	}
+}
+
+// A closed batch related to an open walk is queued behind it with the reason, while one that shares nothing is
+// cut beside it; the walk that started is never superseded (ADR 0276 decision 4, issue 973).
+func TestARelatedBatchWaitsBehindTheOpenWalk(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(90*time.Second))
+	first := func() inventory.Plan { ws, _ := walks(t, open); return ws[len(ws)-1] }()
+	heard := t0.Add(100 * time.Second)
+	hear(t, open, lone(repoMerge("one", "c2", heard)), heard)
+	hear(t, open, lone(repoMerge("three", "c3", heard.Add(time.Second))), heard.Add(time.Second))
+	ws, bs := walks(t, open)
+	if len(ws) != 2 || len(bs) != 1 {
+		t.Fatalf("%d walk(s) and %d batch(es); want the unrelated merge walking and the related one queued", len(ws), len(bs))
+	}
+	b := bs[0]
+	words := batchWords(b, heard)
+	if b.State != inventory.PlanQueued || b.Delivery.Batch.Behind != first.ID || b.CommitOf("novox/one") != "c2" ||
+		!strings.Contains(words, "queued behind "+first.ID) || !strings.Contains(words, "both change novox/one") {
+		t.Fatalf("the related batch is %s, behind %q, reading %q", b.State, b.Delivery.Batch.Behind, words)
+	}
+	if got, _ := open.inventory.PlanByID(ctx, first.ID); !got.Open() {
+		t.Fatalf("the started walk was %s by the related merge", got.State)
+	}
+	first.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &first); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, heard.Add(2*time.Second))
+	if _, bs := walks(t, open); len(bs) != 0 {
+		t.Fatalf("the queued batch was not cut once the walk it waited for ended: %+v", bs)
+	}
+}
+
+// A batch on the controller's own path never walks beside another walk, and nothing walks beside it, whatever
+// the two share (issue 973): it replaces the controller, so it goes alone.
+func TestAnOwnPathBatchNeverWalksBeside(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(90*time.Second))
+	ws, _ := walks(t, open)
+	first := ws[0]
+	heard := t0.Add(100 * time.Second)
+	hear(t, open, lone(repoMerge("mesh-controller", "k1", heard)), heard)
+	ws, bs := walks(t, open)
+	if len(ws) != 1 || len(bs) != 1 || !bs[0].OwnPath() || bs[0].State != inventory.PlanQueued ||
+		bs[0].Delivery.Batch.Behind != first.ID || !strings.Contains(batchWords(bs[0], heard), "own path") {
+		t.Fatalf("an own-path batch beside an open walk: %d walk(s), batches %+v", len(ws), bs)
+	}
+	first.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &first); err != nil {
+		t.Fatal(err)
+	}
+	cutAt(t, open, heard.Add(time.Second))
+	ws, _ = walks(t, open)
+	if len(ws) != 2 || !ws[0].Open() || ws[0].CommitOf("novox/mesh-controller") != "k1" {
+		t.Fatalf("the own-path batch was not cut once the walk ended: %+v", ws)
+	}
+	own := ws[0]
+	// Unrelated to the own-path walk by every footprint, a merge still waits for it.
+	later := heard.Add(time.Minute)
+	hear(t, open, lone(repoMerge("two", "c2", later)), later)
+	ws, bs = walks(t, open)
+	if len(ws) != 2 || len(bs) != 1 || bs[0].State != inventory.PlanQueued || bs[0].Delivery.Batch.Behind != own.ID {
+		t.Fatalf("a merge beside the own-path walk: %d walk(s), batches %+v", len(ws), bs)
+	}
+}

cmd/mesh-controller/bindings.go

@@ -0,0 +1,140 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// A binding to data moves only by a person (novox/hq ADR 0232, issue 273).
+//
+// The resolver keeps each consumer of a provision that keeps its data at the provider it was last
+// sent (catalogue/bound.go) and says what it would have moved. This is where that is said: on the
+// push that composed it, and by the self-check's D12 every run, as an urgent condition naming the
+// consumer, both providers and the pin that confirms the move.
+
+// The condition kinds of D12.
+const (
+	// kindBindingKept is a move the resolver refused: the consumer is still where its data is.
+	kindBindingKept = "binding-kept"
+	// kindBindingMoved is a consumer about to be sent another provider than the one on record with
+	// no pin naming it — what the resolver exists to make impossible, said if it ever is not.
+	kindBindingMoved = "binding-moved"
+	// kindBindingMoving is a move a pin asked for, not yet sent: a person's act, said so that the
+	// data is moved before the push that carries it.
+	kindBindingMoving = "binding-moving"
+)
+
+// probeBindingsID is the self-check's id for this probe, and the source of what it raises.
+const probeBindingsID = "D12"
+
+// keptObservation is the urgent condition for one refused move.
+func keptObservation(k catalogue.KeptBinding) conditions.Observation {
+	return conditions.Observation{Scope: conditions.ScopeMachine, ID: bindingID(k.Machine, k.Consumer, k.Provision),
+		Token: kindBindingKept, Kind: kindBindingKept, Machine: k.Machine, Also: otherMachines(k.Machine, k.Bound.Node, k.Would.Node),
+		Severity: conditions.Urgent, Resolver: conditions.ResolverOperator,
+		Summary: fmt.Sprintf("on %s, the mesh %s", k.Machine, k.String())}
+}
+
+func bindingID(machine, consumer, provision string) string {
+	return machine + "." + consumer + "." + provision
+}
+
+func otherMachines(machine string, nodes ...string) []string {
+	var out []string
+	seen := map[string]bool{machine: true}
+	for _, n := range nodes {
+		if n != "" && !seen[n] {
+			seen[n] = true
+			out = append(out, n)
+		}
+	}
+	return out
+}
+
+// reportKept says every move a machine's resolution refused, on the push composing it, and raises its
+// condition at once where this process keeps the conditions: a push is when a person is looking.
+func reportKept(ctx context.Context, plan catalogue.Resolution) {
+	for _, k := range plan.Kept {
+		fmt.Printf("%s: the mesh %s\n", plan.Node, k)
+		if conditionsFrom != nil {
+			o := keptObservation(k)
+			o.Source = probeBindingsID
+			if _, err := conditionsFrom.Observe(ctx, o); err != nil {
+				fmt.Printf("%s: and the condition for it could not be raised: %v\n", plan.Node, err)
+			}
+		}
+	}
+}
+
+// probeBindings is D12: every consumer of a provision that keeps its data is bound where it was last
+// sent, on every machine — the resolver kept it there (said, urgent, until a person pins), or a pin
+// moves it (said, so the data goes first), and never anything else.
+func probeBindings(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	inv := d.open.inventory
+	nodes, err := inv.Nodes(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var out []conditions.Observation
+	for _, n := range nodes {
+		plan, _, err := planFor(ctx, d.open, n.Name)
+		if err != nil {
+			if unresolvable(err) {
+				// D1 says it, with the binding that refused it when that is why.
+				continue
+			}
+			return nil, fmt.Errorf("%s cannot be worked out: %w", n.Name, err)
+		}
+		bound, err := inv.BindingsFor(ctx, n.Name)
+		if err != nil {
+			return nil, err
+		}
+		pins, err := inv.PinsFor(ctx, n.Name)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, bindingFindings(plan, bound, pins)...)
+	}
+	return out, nil
+}
+
+// bindingFindings is what one machine's resolution says against its record.
+func bindingFindings(plan catalogue.Resolution, bound map[string]map[string]catalogue.Chosen,
+	pins map[string]catalogue.Chosen) []conditions.Observation {
+	var out []conditions.Observation
+	for _, k := range plan.Kept {
+		out = append(out, keptObservation(k))
+	}
+	said := map[string]bool{}
+	for _, need := range plan.Needs {
+		if !need.KeepsData || need.ByRecord {
+			continue
+		}
+		was, recorded := bound[need.For][need.Name]
+		now := catalogue.Chosen{Node: need.From, Module: need.Module}
+		if !recorded || was == now || (was.Module == "" && was.Node == now.Node) {
+			continue
+		}
+		id := bindingID(plan.Node, need.For, need.Name)
+		if said[id] {
+			continue
+		}
+		said[id] = true
+		o := conditions.Observation{Scope: conditions.ScopeMachine, ID: id, Machine: plan.Node,
+			Also: otherMachines(plan.Node, was.Node, now.Node), Resolver: conditions.ResolverOperator}
+		if pin, pinned := pins[need.Name]; pinned && pin.Node == now.Node && (pin.Module == "" || pin.Module == now.Module) {
+			o.Token, o.Kind, o.Severity = kindBindingMoving, kindBindingMoving, conditions.Warning
+			o.Summary = fmt.Sprintf("on %s, %s's %s moves from %s to %s at the next push, by the pin — its data "+
+				"is on %s: move it first", plan.Node, need.For, need.Name, was, now, was)
+		} else {
+			o.Token, o.Kind, o.Severity = kindBindingMoved, kindBindingMoved, conditions.Urgent
+			o.Summary = fmt.Sprintf("on %s, %s's %s would be sent %s, and it is bound to %s, where its data is, "+
+				"with no pin naming %s — a move nothing asked for", plan.Node, need.For, need.Name, now, was, now)
+		}
+		out = append(out, o)
+	}
+	return out
+}

cmd/mesh-controller/bindings_integration_test.go

@@ -0,0 +1,102 @@
+//go:build integration
+
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+func TestTheIncidentAConsumerStaysBesideItsDataUntilAPersonPinsIt(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	if _, err := inv.SeedSeats(ctx, catalogue.DefaultSeats()); err != nil {
+		t.Fatal(err)
+	}
+	for _, m := range storeManifests() {
+		register(t, open, m)
+	}
+	assignAll := func(pairs ...[2]string) {
+		for _, a := range pairs {
+			if _, err := assign(ctx, open, a[0], a[1]); err != nil {
+				t.Fatalf("assign %s %s: %v", a[0], a[1], err)
+			}
+		}
+	}
+	// The anchor's store and resolver hold the mesh's seats, on record; the laptop runs its own of each.
+	assignAll([2]string{"anchor", "store"}, [2]string{"anchor", "resolver"})
+	for _, seat := range [][2]string{{"mesh-store", "store"}, {"mesh-dns-resolver", "resolver"}} {
+		if err := inv.HoldSeat(ctx, seat[0], catalogue.ScopeMesh, "anchor", seat[1]); err != nil {
+			t.Fatal(err)
+		}
+	}
+	assignAll([2]string{"laptop", "store"}, [2]string{"laptop", "resolver"}, [2]string{"laptop", "network"},
+		[2]string{"laptop", "board"})
+
+	plan, _, err := planFor(ctx, open, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n := need(t, plan, "board", "postgres-database"); n.From != "laptop" || n.Module != "store" || !n.KeepsData {
+		t.Fatalf("the consumer was bound to %s/%s (keeps data: %v); its data is beside it", n.From, n.Module, n.KeepsData)
+	}
+	if n := need(t, plan, "network", "wildcard-resolution"); n.From != "anchor" || n.KeepsData {
+		t.Fatalf("the resolver was bound to %s (keeps data: %v); its seat is held on anchor (issue 258)", n.From, n.KeepsData)
+	}
+
+	// Sent, and recorded: only the binding to data.
+	bindings := boundToData(plan, nil)
+	if len(bindings) != 1 || bindings[0].Provider != (catalogue.Chosen{Node: "laptop", Module: "store"}) {
+		t.Fatalf("recorded %+v", bindings)
+	}
+	if err := inv.RecordBindings(ctx, "laptop", bindings); err != nil {
+		t.Fatal(err)
+	}
+	if found, err := probeBindings(ctx, &doctor{open: open}); err != nil || len(found) != 0 {
+		t.Fatalf("a mesh bound where it was sent: %+v, %v", found, err)
+	}
+
+	// The laptop's store taken away: refused, not moved to the anchor's empty one.
+	if err := inv.Unassign(ctx, "laptop", "store"); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := planFor(ctx, open, "laptop"); err == nil || !unresolvable(err) ||
+		!strings.Contains(err.Error(), "board on laptop is bound to laptop/store") ||
+		!strings.Contains(err.Error(), "pin laptop postgres-database anchor store") {
+		t.Fatalf("the consumer's store went and it was answered elsewhere: %v", err)
+	}
+
+	// A person pins the anchor's: it moves, said before it is sent, and the record keeps where it was.
+	if err := inv.PinProvision(ctx, "laptop", "postgres-database", "anchor", "store"); err != nil {
+		t.Fatal(err)
+	}
+	plan, _, err = planFor(ctx, open, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n := need(t, plan, "board", "postgres-database"); n.From != "anchor" {
+		t.Fatalf("pinned to the anchor and bound to %s", n.From)
+	}
+	found, err := probeBindings(ctx, &doctor{open: open})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(found) != 1 || found[0].Kind != kindBindingMoving || found[0].Severity != conditions.Warning ||
+		!strings.Contains(found[0].Summary, "board's postgres-database moves from laptop/store to anchor/store") {
+		t.Fatalf("a pinned move is not said before it is sent: %+v", found)
+	}
+	if err := inv.RecordBindings(ctx, "laptop", boundToData(plan, nil)); err != nil {
+		t.Fatal(err)
+	}
+	all, err := inv.Bindings(ctx)
+	if err != nil || len(all) != 1 || all[0].MovedFrom != "laptop/store" {
+		t.Fatalf("%+v, %v", all, err)
+	}
+	if found, err := probeBindings(ctx, &doctor{open: open}); err != nil || len(found) != 0 {
+		t.Fatalf("a move sent is still said: %+v, %v", found, err)
+	}
+}

cmd/mesh-controller/bindings_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// novox/hq issue 273, ADR 0232: a consumer of a provision that keeps its data moves only by a pin.
+
+func storeManifests() []catalogue.Manifest {
+	return []catalogue.Manifest{
+		{Module: "store", Version: "1",
+			Provides: []catalogue.Offer{{Name: "postgres-database", Scope: catalogue.ScopeMesh}},
+			Claims:   []catalogue.Claim{{Name: "mesh-store", Scope: catalogue.ScopeMesh}},
+			Serves:   map[string]map[string]any{"postgres-database": {"port": 5432}},
+			Grants:   map[string]string{"postgres-database": "/var/lib/mesh/store/grants"}},
+		{Module: "resolver", Version: "1",
+			Provides: []catalogue.Offer{{Name: "wildcard-resolution", Scope: catalogue.ScopeMesh}},
+			Claims:   []catalogue.Claim{{Name: "mesh-dns-resolver", Scope: catalogue.ScopeMesh}}},
+		{Module: "network", Version: "1", Requires: []string{"wildcard-resolution"}},
+		{Module: "board", Version: "1", Requires: []string{"postgres-database"}},
+	}
+}
+
+func need(t *testing.T, plan catalogue.Resolution, consumer, provision string) catalogue.Needed {
+	t.Helper()
+	for _, n := range plan.Needs {
+		if n.For == consumer && n.Name == provision {
+			return n
+		}
+	}
+	t.Fatalf("no %s for %s: %+v", provision, consumer, plan.Needs)
+	return catalogue.Needed{}
+}
+
+// The incident through the stores: the laptop runs its own store and a consumer of it, the anchor's
+// store holds the mesh's seat. The consumer stays beside its data, the resolver follows its seat, the
+// binding is recorded as sent, and a pin — only a pin — moves it, said before the push that carries it.
+
+// What one machine's resolution says against its record.
+func TestBindingFindingsSayAKeptMoveAndAMoveNothingAskedFor(t *testing.T) {
+	home, anchor := catalogue.Chosen{Node: "home", Module: "store"}, catalogue.Chosen{Node: "anchor", Module: "store"}
+	plan := catalogue.Resolution{Node: "laptop",
+		Kept: []catalogue.KeptBinding{{Machine: "laptop", Consumer: "board", Provision: "postgres-database",
+			Bound: home, Would: anchor}},
+		Needs: []catalogue.Needed{
+			{Name: "postgres-database", For: "board", From: "home", Module: "store", KeepsData: true},
+			{Name: "postgres-database", For: "game", From: "anchor", Module: "store", KeepsData: true},
+			{Name: "wildcard-resolution", For: "network", From: "anchor", Module: "resolver"},
+		}}
+	bound := map[string]map[string]catalogue.Chosen{
+		"board":   {"postgres-database": home},
+		"game":    {"postgres-database": home},
+		"network": {"wildcard-resolution": {Node: "home", Module: "resolver"}},
+	}
+	found := linted(bindingFindings(plan, bound, nil))
+	if len(found) != 2 {
+		t.Fatalf("found %+v", found)
+	}
+	kept, moved := found[0], found[1]
+	if kept.Kind != kindBindingKept || kept.Severity != conditions.Urgent || kept.Machine != "laptop" ||
+		!strings.Contains(kept.Summary, "would move board's postgres-database from home/store to anchor/store") ||
+		!strings.Contains(kept.Summary, "its data is on home/store") ||
+		!strings.Contains(kept.Summary, "`pin laptop postgres-database anchor store` to confirm a move (and move the data first)") {
+		t.Errorf("kept: %+v", kept)
+	}
+	if moved.Kind != kindBindingMoved || moved.Severity != conditions.Urgent ||
+		!strings.Contains(moved.Summary, "game's postgres-database would be sent anchor/store") {
+		t.Errorf("moved: %+v", moved)
+	}
+	if kept.Key() == moved.Key() {
+		t.Error("two consumers, one condition")
+	}
+}
+
+// A push says the move it refused, and raises its condition at once.
+func TestAPushSaysAKeptMoveAndRaisesItsCondition(t *testing.T) {
+	k, _ := withConditionsInMemory(t)
+	reportKept(t.Context(), catalogue.Resolution{Node: "laptop", Kept: []catalogue.KeptBinding{{Machine: "laptop",
+		Consumer: "board", Provision: "postgres-database", Bound: catalogue.Chosen{Node: "home", Module: "store"},
+		Would: catalogue.Chosen{Node: "anchor", Module: "store"}}}})
+	open, err := k.Open(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(open) != 1 || open[0].Kind != kindBindingKept || open[0].Severity != conditions.Urgent ||
+		open[0].Source != probeBindingsID {
+		t.Fatalf("raised %+v", open)
+	}
+}

cmd/mesh-controller/board.go

@@ -137,6 +137,9 @@ type view struct {
 	Unresolved []blockedMachine
 	// Network is why the private network could not be computed, when it could not.
 	Network string
+	// Adopted is every node still adopted (novox/hq ADR 0100). Not broken: nothing forces the
+	// flip, so a node left adopted is shown rather than read as converged.
+	Adopted []string
 	At      string
 }
 
@@ -181,7 +184,7 @@ type staleModule struct {
 
 func viewOf(asked answers) view {
 	out := view{Machines: len(asked.nodes), At: time.Now().Format("15:04:05"),
-		Network: asked.network}
+		Network: asked.network, Adopted: adoptedNodes(asked.nodes)}
 	var blocked []string
 	for name := range asked.refused {
 		blocked = append(blocked, name)
@@ -311,6 +314,10 @@ new, switched off, or unreachable.</p>
 <p class="quiet">Never told is not out of date: nobody has asked that machine to be anything yet.
 Both are sent by <code>push --behind</code>.</p>
 {{else}}<p class="quiet">Every machine is running what the mesh would send it.</p>{{end}}
+{{if .Adopted}}
+<h2>Which machines are adopted?</h2>
+<ul>{{range .Adopted}}<li><strong>{{.}}</strong> <span class="quiet">adopted — what was found on it is kept until each module is taken</span></li>{{end}}</ul>
+{{end}}
 {{end}}
 
 <footer>Read at {{.At}}. This page holds nothing and changes nothing.</footer>

cmd/mesh-controller/bucket_log_fill.go

@@ -0,0 +1,207 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// **A filling bucket or log is said before it is full** (novox/hq ADR 0297 §6, issue 501).
+//
+// A module's bucket and its log each have a cap on the bus, and when either is full the bus refuses
+// the next write: the module stops doing what it writes for, and nothing said so before. On
+// 2026-10-11 the issue tracker's bucket held a sixth of its cap after two days, growing toward a stop
+// nobody would have heard coming. So the self-check reads every module's bucket and log, and one at
+// fillRaiseAt of its cap or more raises a condition naming the module, the bucket or log, and how full
+// it is.
+//
+// **Cleared by observation below fillClearBelow, not below fillRaiseAt**: a bucket or log hovering at
+// its threshold would otherwise be raised and cleared on every run. Between the two, an open condition
+// is kept and none is raised.
+//
+// **One that cannot be read is said, and the rest are still judged.** An unanswered question about one
+// stream is no reason to know nothing of the others: it is a finding of its own, naming the bucket or
+// log and why, and a fill condition already open for it is kept, because not knowing is not a pass.
+
+// The fill thresholds, in percent of a bucket's or log's cap.
+const (
+	fillRaiseAt    = 75
+	fillClearBelow = 70
+)
+
+// The conditions the fill probe raises: one filling, and one that could not be read.
+const (
+	kindBucketOrLogFilling = "bucket-or-log-filling"
+	kindBucketOrLogUnread  = "bucket-or-log-unread"
+)
+
+// probeFillID is the probe's id in the registry.
+const probeFillID = "D-fill"
+
+// bucketOrLog is one module's bucket or log as the fill probe reads it.
+type bucketOrLog struct {
+	Module string
+	// Kind is `bucket` or `log`; Name its local name; Stream the stream it is on the bus.
+	Kind, Name, Stream string
+}
+
+// filled is how full one bucket or log is, read from the bus.
+type filled struct {
+	Bytes, Max uint64
+}
+
+// percent is how full, in whole percent, rounded down.
+func (f filled) percent() uint64 {
+	if f.Max == 0 {
+		return 0
+	}
+	return f.Bytes * 100 / f.Max
+}
+
+// fillKey is where a bucket's or log's fill condition is kept.
+func fillKey(s bucketOrLog) string { return conditions.Key(conditions.ScopeBus, s.Stream, "filling") }
+
+// fillObservation is what one bucket's or log's fill says: a finding at fillRaiseAt or above, and,
+// while its condition is open, at fillClearBelow or above too; nothing otherwise, which is what clears
+// it. The operator's words are the kind's (plain_words.go); the summary and the evidence name the
+// module, the bucket or log, and the fill.
+func fillObservation(s bucketOrLog, f filled, open bool) (conditions.Observation, bool) {
+	if f.Max == 0 {
+		return conditions.Observation{}, false // one with no cap cannot fill
+	}
+	// Compared in bytes, not rounded percent: 74.9% is not 75%.
+	atRaise := f.Bytes*100 >= f.Max*fillRaiseAt
+	aboveClear := f.Bytes*100 >= f.Max*fillClearBelow
+	if !atRaise && !(open && aboveClear) {
+		return conditions.Observation{}, false
+	}
+	pct := f.percent()
+	return conditions.Observation{
+		Scope: conditions.ScopeBus, ID: s.Stream, Token: "filling", Kind: kindBucketOrLogFilling,
+		Severity: conditions.Warning,
+		Summary: fmt.Sprintf("%s's %s %s holds %s of %s, %d%%: at its cap the bus refuses the module's next write",
+			s.Module, s.Kind, s.Name, mibWords(f.Bytes), mibWords(f.Max), pct),
+		Said: fmt.Sprintf("module %s, %s %s (stream %s): %d of %d bytes, %d%%", s.Module, s.Kind, s.Name,
+			s.Stream, f.Bytes, f.Max, pct),
+	}, true
+}
+
+// unreadObservation says one bucket or log could not be read, and why. Asked over the network, so one
+// look can be wrong: raised on the second look in a row (confirm.go).
+func unreadObservation(s bucketOrLog, why error) conditions.Observation {
+	return conditions.Observation{
+		Scope: conditions.ScopeBus, ID: s.Stream, Token: "unread", Kind: kindBucketOrLogUnread,
+		Severity: conditions.Warning, Confirm: true,
+		Summary: fmt.Sprintf("%s's %s %s could not be read, so how full it is is not known", s.Module, s.Kind, s.Name),
+		Said:    fmt.Sprintf("module %s, %s %s (stream %s): %v", s.Module, s.Kind, s.Name, s.Stream, why),
+	}
+}
+
+// keptFilling is an open fill condition said again for a bucket or log that could not be read this
+// time: not knowing how full it is now is no reason to say it has room. Only ever made from a condition
+// read back as open — its own summary and severity, never words made up for it.
+func keptFilling(s bucketOrLog, open conditions.Condition, why error) conditions.Observation {
+	return conditions.Observation{
+		Scope: conditions.ScopeBus, ID: s.Stream, Token: "filling", Kind: kindBucketOrLogFilling,
+		Severity: open.Severity, Summary: open.Summary,
+		Said: fmt.Sprintf("module %s, %s %s (stream %s): not read this time (%v); kept open as it was",
+			s.Module, s.Kind, s.Name, s.Stream, why),
+	}
+}
+
+// mibWords is a size as a person reads it, in MiB with one decimal.
+func mibWords(b uint64) string {
+	return fmt.Sprintf("%.1f MiB", float64(b)/(1024*1024))
+}
+
+// readFill is how full one bucket or log is on the bus; found false when it is not on the bus.
+type readFill func(ctx context.Context, s bucketOrLog) (f filled, found bool, err error)
+
+// openFill is the fill condition open under a key, if one is, or why it could not be read.
+type openFill func(ctx context.Context, key string) (conditions.Condition, bool, error)
+
+// judgeFills judges every bucket and log on its own: one that cannot be read is said as unread, with
+// its fill condition kept only when that condition was read back and is open — when it cannot be read
+// either, nothing is said of its fill, which the unread finding already covers. Every other is judged
+// by its fill; for one of those, a condition that cannot be read is taken as open, so an unknown never
+// clears a fill measured between fillClearBelow and fillRaiseAt.
+func judgeFills(ctx context.Context, all []bucketOrLog, read readFill, open openFill) []conditions.Observation {
+	var out []conditions.Observation
+	for _, s := range all {
+		f, found, err := read(ctx, s)
+		if err != nil {
+			out = append(out, unreadObservation(s, err))
+			if c, isOpen, cerr := open(ctx, fillKey(s)); cerr == nil && isOpen {
+				out = append(out, keptFilling(s, c, err))
+			}
+			continue
+		}
+		if !found {
+			continue // not on the bus: created on the controller's next raise, and nothing there can fill
+		}
+		_, isOpen, cerr := open(ctx, fillKey(s))
+		isOpen = isOpen || cerr != nil
+		if o, said := fillObservation(s, f, isOpen); said {
+			out = append(out, o)
+		}
+	}
+	sort.SliceStable(out, func(i, j int) bool { return out[i].Key() < out[j].Key() })
+	return out
+}
+
+// declaredBucketsAndLogs is every module's bucket and log the catalogue declares, by its stream.
+func declaredBucketsAndLogs(ctx context.Context, d *doctor) ([]bucketOrLog, error) {
+	buckets, err := d.open.inventory.DeclaredBuckets(ctx)
+	if err != nil {
+		return nil, err
+	}
+	logs, err := d.open.inventory.DeclaredLogs(ctx)
+	if err != nil {
+		return nil, err
+	}
+	var out []bucketOrLog
+	for _, b := range buckets {
+		out = append(out, bucketOrLog{Module: b.Module, Kind: "bucket", Name: b.Name, Stream: "KV_" + b.Bucket()})
+	}
+	for _, l := range logs {
+		out = append(out, bucketOrLog{Module: l.Module, Kind: "log", Name: l.Name, Stream: l.Stream()})
+	}
+	return out, nil
+}
+
+// probeFill reads every module's bucket and log on the bus and says each one filling toward its cap,
+// and each one that could not be read.
+func probeFill(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	all, err := declaredBucketsAndLogs(ctx, d)
+	if err != nil {
+		return nil, err
+	}
+	js := d.js.Context()
+	read := func(ctx context.Context, s bucketOrLog) (filled, bool, error) {
+		if err := ctx.Err(); err != nil {
+			return filled{}, false, err
+		}
+		info, err := js.StreamInfo(s.Stream, nats.Context(ctx))
+		switch {
+		case errors.Is(err, nats.ErrStreamNotFound):
+			return filled{}, false, nil
+		case err != nil:
+			return filled{}, false, err
+		case info.Config.MaxBytes <= 0:
+			return filled{}, true, nil
+		}
+		return filled{Bytes: info.State.Bytes, Max: uint64(info.Config.MaxBytes)}, true, nil
+	}
+	open := func(ctx context.Context, key string) (conditions.Condition, bool, error) {
+		if d.keeper == nil {
+			return conditions.Condition{}, false, nil
+		}
+		return d.keeper.Get(ctx, key)
+	}
+	return judgeFills(ctx, all, read, open), nil
+}

cmd/mesh-controller/bucket_log_fill_test.go

@@ -0,0 +1,165 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// **A filling log or bucket is said at three quarters of its cap and cleared below seven tenths**
+// (novox/hq ADR 0297 §6): raised at 75% naming the module, the bucket or log and its fill; not at 74.9%;
+// kept between 70% and 75% while it is open, and not raised there when it is not; and cleared — said no
+// more — once it reads below 70%, open or not.
+func TestAFillingBucketOrLogIsRaisedAtThreeQuartersAndClearedBelowSevenTenths(t *testing.T) {
+	const mib = 1024 * 1024
+	log := bucketOrLog{Module: "mesh-issues", Kind: "log", Name: "changes", Stream: "LOG_mesh-issues_changes"}
+	bucket := bucketOrLog{Module: "mesh-issues", Kind: "bucket", Name: "issues", Stream: "KV_mesh-issues_issues"}
+	for _, c := range []struct {
+		name  string
+		of    bucketOrLog
+		bytes uint64
+		max   uint64
+		open  bool
+		said  bool
+	}{
+		{"a log at exactly 75%", log, 768 * mib, 1024 * mib, false, true},
+		{"a bucket at exactly 75%", bucket, 48 * mib, 64 * mib, false, true},
+		{"a bucket full", bucket, 64 * mib, 64 * mib, false, true},
+		{"a log just under 75%", log, 768*mib - 1, 1024 * mib, false, false},
+		{"a bucket at 72%, not open", bucket, 64 * mib * 72 / 100, 64 * mib, false, false},
+		{"a bucket at 72%, open: kept", bucket, 64 * mib * 72 / 100, 64 * mib, true, true},
+		{"a log at exactly 70%, open: kept", log, 700 * mib, 1000 * mib, true, true},
+		{"a log just under 70%, open: cleared", log, 700*mib - 1, 1000 * mib, true, false},
+		{"a bucket at 10%, open: cleared", bucket, 64 * mib / 10, 64 * mib, true, false},
+		{"a bucket with no cap", bucket, 100, 0, true, false},
+	} {
+		o, said := fillObservation(c.of, filled{Bytes: c.bytes, Max: c.max}, c.open)
+		if said != c.said {
+			t.Errorf("%s: said %v, want %v", c.name, said, c.said)
+			continue
+		}
+		if !said {
+			continue
+		}
+		if o.Key() != fillKey(c.of) || o.Kind != kindBucketOrLogFilling || o.Severity != conditions.Warning {
+			t.Errorf("%s: raised as %s (%s, %s)", c.name, o.Key(), o.Kind, o.Severity)
+		}
+		for _, part := range []string{c.of.Module, c.of.Kind + " " + c.of.Name, "%", " of "} {
+			if !strings.Contains(o.Summary, part) {
+				t.Errorf("%s: does not name %q: %q", c.name, part, o.Summary)
+			}
+		}
+		if !strings.Contains(o.Said, "bytes") {
+			t.Errorf("%s: the evidence does not say the fill in bytes: %q", c.name, o.Said)
+		}
+	}
+	o, _ := fillObservation(log, filled{Bytes: 800 * mib, Max: 1024 * mib}, false)
+	if !strings.Contains(o.Summary, "800.0 MiB of 1024.0 MiB, 78%") {
+		t.Errorf("the fill is said as %q", o.Summary)
+	}
+}
+
+// **One bucket or log that cannot be read does not stop the others being judged** (review of #231): it is
+// said as unread with its reason, a fill condition open for it is kept, and every other bucket and log
+// is judged by its own fill.
+func TestAnUnreadableBucketOrLogIsSaidAndTheRestAreStillJudged(t *testing.T) {
+	const mib = 1024 * 1024
+	broken := bucketOrLog{Module: "a", Kind: "bucket", Name: "broken", Stream: "KV_a_broken"}
+	brokenOpen := bucketOrLog{Module: "a", Kind: "log", Name: "was-filling", Stream: "LOG_a_was-filling"}
+	full := bucketOrLog{Module: "b", Kind: "log", Name: "changes", Stream: "LOG_b_changes"}
+	empty := bucketOrLog{Module: "c", Kind: "bucket", Name: "quiet", Stream: "KV_c_quiet"}
+	absent := bucketOrLog{Module: "d", Kind: "bucket", Name: "not-yet", Stream: "KV_d_not-yet"}
+	refusal := errors.New("the bus did not answer")
+	read := func(_ context.Context, s bucketOrLog) (filled, bool, error) {
+		switch s {
+		case broken, brokenOpen:
+			return filled{}, false, refusal
+		case full:
+			return filled{Bytes: 900 * mib, Max: 1000 * mib}, true, nil
+		case empty:
+			return filled{Bytes: 1, Max: 64 * mib}, true, nil
+		}
+		return filled{}, false, nil
+	}
+	open := func(_ context.Context, key string) (conditions.Condition, bool, error) {
+		if key == fillKey(brokenOpen) {
+			return conditions.Condition{Key: key, Severity: conditions.Warning,
+				Summary: "a's log was-filling holds 800.0 MiB of 1024.0 MiB, 78%"}, true, nil
+		}
+		return conditions.Condition{}, false, nil
+	}
+	got := map[string]conditions.Observation{}
+	for _, o := range judgeFills(context.Background(), []bucketOrLog{broken, brokenOpen, full, empty, absent}, read, open) {
+		got[o.Key()] = o
+	}
+	for _, s := range []bucketOrLog{broken, brokenOpen} {
+		o, said := got[conditions.Key(conditions.ScopeBus, s.Stream, "unread")]
+		if !said || o.Kind != kindBucketOrLogUnread || !o.Confirm || !strings.Contains(o.Said, refusal.Error()) {
+			t.Errorf("%s could not be read and was said as %+v", s.Stream, o)
+		}
+	}
+	if o, kept := got[fillKey(brokenOpen)]; !kept || !strings.Contains(o.Said, "kept open") {
+		t.Errorf("an open fill condition of a log not read this time was not kept: %+v", o)
+	}
+	if _, said := got[fillKey(broken)]; said {
+		t.Error("a bucket not read and not filling was said filling")
+	}
+	if o, said := got[fillKey(full)]; !said || o.Kind != kindBucketOrLogFilling {
+		t.Errorf("a log at 90%% beside an unreadable one was not judged: %+v", got)
+	}
+	if len(got) != 4 {
+		t.Errorf("said %d findings, want 4 (two unread, one kept, one filling): %v", len(got), got)
+	}
+}
+
+// Both kinds have plain words of their own, which hold to the plain rule (novox/hq ADR 0253).
+func TestAFillingOrUnreadBucketOrLogIsSaidInPlainWords(t *testing.T) {
+	for _, kind := range []string{kindBucketOrLogFilling, kindBucketOrLogUnread} {
+		wording, has := plainWordings[kind]
+		if !has {
+			t.Errorf("%s has no plain words", kind)
+			continue
+		}
+		if why, ok := conditions.PlainWords(wording(conditions.Observation{Kind: kind})); !ok {
+			t.Errorf("%s: %s", kind, why)
+		}
+	}
+}
+
+// **When neither the bucket or log nor its condition can be read, nothing is said of its fill** (second
+// review of #231): the unread finding covers it, and no fill is invented for it. For one that is read and
+// measured between seven tenths and three quarters, a condition that cannot be read is taken as open, so
+// an unknown never clears it.
+func TestNothingIsSaidOfAFillWhenNeitherItNorItsConditionCanBeRead(t *testing.T) {
+	const mib = 1024 * 1024
+	broken := bucketOrLog{Module: "a", Kind: "log", Name: "changes", Stream: "LOG_a_changes"}
+	between := bucketOrLog{Module: "b", Kind: "bucket", Name: "issues", Stream: "KV_b_issues"}
+	read := func(_ context.Context, s bucketOrLog) (filled, bool, error) {
+		if s == broken {
+			return filled{}, false, errors.New("the bus did not answer")
+		}
+		return filled{Bytes: 72 * mib, Max: 100 * mib}, true, nil
+	}
+	open := func(context.Context, string) (conditions.Condition, bool, error) {
+		return conditions.Condition{}, false, errors.New("the conditions bucket did not answer")
+	}
+	got := map[string]conditions.Observation{}
+	for _, o := range judgeFills(context.Background(), []bucketOrLog{broken, between}, read, open) {
+		got[o.Key()] = o
+	}
+	if o, said := got[fillKey(broken)]; said {
+		t.Fatalf("a fill was said for a log whose fill and condition could not be read: %+v", o)
+	}
+	if _, said := got[conditions.Key(conditions.ScopeBus, broken.Stream, "unread")]; !said {
+		t.Error("the log that could not be read was not said as unread")
+	}
+	if _, kept := got[fillKey(between)]; !kept {
+		t.Error("a bucket at 72% whose condition could not be read was cleared")
+	}
+	if len(got) != 2 {
+		t.Errorf("said %d findings, want 2: %v", len(got), got)
+	}
+}

cmd/mesh-controller/build_integration_test.go

@@ -0,0 +1,131 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+func TestABuildHeardIsRecordedAndRegistered(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	manifest, _ := json.Marshal(map[string]any{"module": "shop", "version": "3"})
+	m, _, err := takeIn(ctx, open.inventory, asTheOperator(t, open.inventory, link.BuildResult{
+		ID: "b-1", Repository: "http://forge.internal:20000/novox/shop.git", Path: "modules/shop",
+		Ref: "main", On: "anchor", Commit: "abcdef0123", Manifest: manifest,
+		Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/shop"},
+	}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m.Module != "shop" {
+		t.Fatalf("registered %q", m.Module)
+	}
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, held := shelf["shop"]; !held {
+		t.Fatal("the module a heard build produced is not in the catalogue")
+	}
+	src, err := open.inventory.SourceOf(ctx, "shop")
+	if err != nil || src.Seat != "git" || src.Repository != "novox/shop" || src.BuiltFrom != "abcdef0123" {
+		t.Fatalf("the source is the seat and the path, never the URL: %+v %v", src, err)
+	}
+	builds, err := open.inventory.Builds(ctx, "shop", 5)
+	if err != nil || len(builds) != 1 || builds[0].ID != "b-1" {
+		t.Fatalf("the build is not recorded once: %v %v", builds, err)
+	}
+
+	named, _ := json.Marshal(map[string]any{"module": "idp", "version": "1", "resources": []any{
+		map[string]any{"id": "server", "type": "container", "image": "x@sha256:aa",
+			"env": map[string]any{"KC_HOSTNAME": "https://login.mesh-one.be"}}}})
+	_, _, err = takeIn(ctx, open.inventory, link.BuildResult{
+		ID: "b-2", Repository: "/r", On: "anchor", Commit: "0123456789", Manifest: named})
+	if err == nil || !strings.Contains(err.Error(), "does not register it") {
+		t.Fatalf("a definition naming an installation was taken in: %v", err)
+	}
+	if shelf, _ := open.inventory.Catalogue(ctx); shelf["idp"].Module != "" {
+		t.Fatal("the refused module was registered anyway")
+	}
+	if builds, _ := open.inventory.Builds(ctx, "idp", 5); len(builds) != 1 {
+		t.Fatalf("the refused build was not recorded: %v", builds)
+	}
+
+	_, _, err = takeIn(ctx, open.inventory, link.BuildResult{ID: "b-3", Repository: "/r", On: "anchor", Failed: "no compiler"})
+	if err == nil || !strings.Contains(err.Error(), "no compiler") {
+		t.Fatalf("a failure is said in the builder's words: %v", err)
+	}
+}
+
+func TestABuildAtACommitKeepsTheBranchTheModuleFollows(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	manifest, _ := json.Marshal(map[string]any{"module": "unifi", "version": "1"})
+	result := func(id, ref, commit string) link.BuildResult {
+		return link.BuildResult{ID: id, Repository: "http://forge.internal:20000/novox/mesh-catalog.git",
+			Path: "modules/unifi", Ref: ref, On: "anchor", Commit: commit, Manifest: manifest,
+			Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/mesh-catalog"}}
+	}
+	if _, _, err := takeIn(ctx, open.inventory, asTheOperator(t, open.inventory, result("b-1", "main", "1111111aaaa"))); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := takeIn(ctx, open.inventory, result("b-2", "9c97a8a", "9c97a8a1d2c3")); err != nil {
+		t.Fatal(err)
+	}
+	src, err := open.inventory.SourceOf(ctx, "unifi")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if src.Ref != "main" || src.BuiltFrom != "9c97a8a1d2c3" {
+		t.Errorf("after a build at a commit the module follows %q, built from %q; want main, 9c97a8a1d2c3", src.Ref, src.BuiltFrom)
+	}
+
+	// One new to the catalogue, first built at a commit, follows the default branch.
+	other, _ := json.Marshal(map[string]any{"module": "letta", "version": "1"})
+	r := result("b-3", "deadbeef", "deadbeefcafe")
+	r.Manifest, r.Path = other, "modules/letta"
+	if _, _, err := takeIn(ctx, open.inventory, r); err != nil {
+		t.Fatal(err)
+	}
+	if src, _ := open.inventory.SourceOf(ctx, "letta"); src.Ref != "" {
+		t.Errorf("a module first built at a commit follows %q, want the default branch", src.Ref)
+	}
+}
+
+func TestAnOlderBuildHeardLaterDoesNotReplaceTheNewer(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	older := time.Date(2026, 10, 3, 21, 33, 45, 0, time.UTC)
+	newer := time.Date(2026, 10, 3, 21, 51, 57, 0, time.UTC)
+	result := func(asked time.Time, image string) link.BuildResult {
+		manifest, _ := json.Marshal(map[string]any{"module": "postgres", "version": image})
+		return link.BuildResult{ID: link.NewBuildID(asked), Repository: "http://forge.internal:20000/novox/mesh-catalog.git",
+			Path: "modules/postgres", Ref: "main", On: "anchor", Commit: "efff5415", Manifest: manifest,
+			Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/mesh-catalog"}}
+	}
+	if _, _, err := takeIn(ctx, open.inventory, asTheOperator(t, open.inventory, result(newer, "4bcd5f73"))); err != nil {
+		t.Fatal(err)
+	}
+	_, _, err := takeIn(ctx, open.inventory, result(older, "0ab07fa9"))
+	if !errors.Is(err, inventory.ErrSuperseded) {
+		t.Fatalf("the older request's outcome was taken in as current: %v", err)
+	}
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := shelf["postgres"].Version; got != "4bcd5f73" {
+		t.Errorf("postgres is %q; want the newer request's 4bcd5f73", got)
+	}
+	if builds, _ := open.inventory.Builds(ctx, "postgres", 5); len(builds) != 2 {
+		t.Errorf("the late build was not recorded: %v", builds)
+	}
+}

cmd/mesh-controller/build_seat_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+func claiming(module, seat string, on ...string) inventory.Entry {
+	return inventory.Entry{
+		Manifest: catalogue.Manifest{Module: module, Claims: []catalogue.Claim{{Name: seat}}},
+		On:       on,
+	}
+}
+
+// The controller asks the build role that has a holder (novox/hq ADR 0190 handover): the retired
+// one while only the builder is assigned, the current one from the first build-agent on, and the
+// current one when nothing holds either — where every ask goes once the handover is done.
+func TestTheControllerAsksTheBuildRoleThatHasAHolder(t *testing.T) {
+	onlyTheBuilder := []inventory.Entry{
+		claiming("builder", link.TheBuildMachineBefore, "anchor"),
+		claiming("build-agent", link.TheBuildMachine), // registered, assigned nowhere yet
+	}
+	if got := buildSeatAmong(onlyTheBuilder); got != link.TheBuildMachineBefore {
+		t.Errorf("with only the builder assigned, asked %q", got)
+	}
+	bothHeld := []inventory.Entry{
+		claiming("builder", link.TheBuildMachineBefore, "anchor"),
+		claiming("build-agent", link.TheBuildMachine, "home-server"),
+	}
+	if got := buildSeatAmong(bothHeld); got != link.TheBuildMachine {
+		t.Errorf("with a build-agent assigned anywhere, asked %q", got)
+	}
+	neither := []inventory.Entry{claiming("builder", link.TheBuildMachineBefore)}
+	if got := buildSeatAmong(neither); got != link.TheBuildMachine {
+		t.Errorf("with no holder of either, asked %q, want the current role", got)
+	}
+	if got := buildSeatAmong(nil); got != link.TheBuildMachine {
+		t.Errorf("an empty catalogue asks %q", got)
+	}
+}

cmd/mesh-controller/build_source.go

@@ -0,0 +1,566 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// Where a build may register a module from (novox/hq ADR 0266).
+//
+// A build's outcome registers its module, and a registered module is what the next push sends. Before this,
+// an outcome registered whatever its manifest named, from whichever repository it was built from: an agent
+// that made a repository of its own, committed `modules/sudo/module.json` granting itself a rule without a
+// password, and asked the `build` verb for it had its repository registered as the module `sudo` — whose next
+// push made the agent root on every node. A fork of the node-engine did the same everywhere. The trunk rule
+// (ADR 0238) did not stop it: the trunk it checked was the trunk of the repository built, which was the
+// agent's own.
+//
+// So **an outcome registers a module only from the repository the catalogue already builds that module
+// from**; and a module new to the catalogue only from a repository the catalogue already builds another
+// module from — whose trunk takes a reviewed, approved merge, which is how a merge adds a module (novox/hq
+// issue 300). Anything else — a module moved to another repository, a module from a repository the
+// catalogue has never built — is the operator's, at the controller's terminal: allowed only when the build
+// request was kept as asked there. Judged at the take-in, which every outcome reaches whoever hears it and
+// whichever verb asked it (`build`, `rebuild`, `replay --register`, `assign` with build), and before the ask
+// for a call through a verb, so an agent cannot have a build node run a repository the catalogue does not
+// build from at all.
+
+// errNotItsSource is an outcome refused for where it was built from.
+var errNotItsSource = errors.New("not built from the repository the catalogue builds it from")
+
+// servedVar marks every process the serving controller starts — each verb's command, each child — and the serving
+// process itself, so none of them can read as the operator at the terminal (novox/hq ADR 0266). Set by serve
+// before it answers anything, inherited by every child through os.Environ.
+const servedVar = "MESH_SERVED_BY_THE_CONTROLLER"
+
+// startedAtTheTerminal says this process was started at the controller's terminal: not the serving controller,
+// not anything it started, not a verb's command, not a seat call's. The serving controller marks its own
+// environment (servedVar), so a build asked in it, or by any process it starts, never reads as the terminal's;
+// runVerb also names the verb and the caller.
+//
+// **And a line mesh-cli asked as the controller's terminal** (novox/hq ADR 0272 §4): the serving controller runs it
+// without the served mark and without a verb, names its caller, and marks it with cliTerminalVar — a mark only the
+// mesh-cli path sets and every other command line the controller runs is stripped of (commandEnvironment).
+func startedAtTheTerminal() bool {
+	if os.Getenv(servedVar) != "" || os.Getenv(verbVar) != "" {
+		return false
+	}
+	return os.Getenv(link.CallerVar) == "" || os.Getenv(cliTerminalVar) != ""
+}
+
+// cliTerminalVar marks a command line the serving controller runs as the controller's terminal for mesh-cli.
+const cliTerminalVar = "MESH_CLI_TERMINAL"
+
+// markServed marks this process, and so everything it starts, as the serving controller's.
+func markServed() {
+	if err := os.Setenv(servedVar, "1"); err != nil {
+		panic("the serving controller could not mark its environment: " + err.Error())
+	}
+}
+
+// sourceForms compares sources however each is spelled: a path on a seat's holder (ADR 0111) or a URL — a
+// build asked of a seat's path is registered with the URL composed from it when its outcome does not echo
+// the seat. A seat's path is composed into its URL where the seat's holder is known, so both spellings of
+// one repository are one; where it is not, a seat's path matches only the same seat's same path.
+type sourceForms struct {
+	bases map[string]string // the seat's clone base, `scheme://host:port`, by seat; "" where it is not known
+	base  func(seat string) string
+}
+
+// newSourceForms reads the seats' bases from the mesh once, when first needed.
+func newSourceForms(ctx context.Context, inv *inventory.Inventory) *sourceForms {
+	f := &sourceForms{bases: map[string]string{}}
+	var world *catalogue.World
+	f.base = func(seat string) string {
+		if b, known := f.bases[seat]; known {
+			return b
+		}
+		if world == nil {
+			w := catalogue.World{}
+			if shelf, err := inv.Catalogue(ctx); err == nil {
+				if read, err := theRestOfTheMesh(ctx, inv, shelf, ""); err == nil {
+					w = read
+				}
+			}
+			world = &w
+		}
+		b, err := seatBase(*world, seat)
+		if err != nil {
+			b = ""
+		}
+		f.bases[seat] = b
+		return b
+	}
+	return f
+}
+
+// canonical is one spelling of a repository: lower case, no `.git`, no trailing slash, and a seat's path as
+// the URL its holder serves it at where that is known.
+func (f *sourceForms) canonical(repository, seat string) string {
+	trim := func(s string) string {
+		s = strings.TrimSpace(strings.ToLower(s))
+		s = strings.TrimRight(s, "/")
+		return strings.TrimRight(strings.TrimSuffix(s, ".git"), "/")
+	}
+	if seat == "" {
+		return trim(repository)
+	}
+	if b := f.base(seat); b != "" {
+		return trim(b + "/" + strings.Trim(repository, "/"))
+	}
+	return "seat:" + seat + ":" + trim(strings.Trim(repository, "/"))
+}
+
+// same says two sources are one repository.
+func (f *sourceForms) same(aRepository, aSeat, bRepository, bSeat string) bool {
+	if aRepository == "" || bRepository == "" {
+		return false
+	}
+	return f.canonical(aRepository, aSeat) == f.canonical(bRepository, bSeat)
+}
+
+// buildsFrom says the catalogue builds some module from this repository.
+func (f *sourceForms) buildsFrom(entries []inventory.Entry, repository, seat string) bool {
+	for _, e := range entries {
+		if e.Provided || e.Source.Repository == "" {
+			continue
+		}
+		if f.same(e.Source.Repository, e.Source.Seat, repository, seat) {
+			return true
+		}
+	}
+	return false
+}
+
+// forgeFacts is what the mesh's forge says of a repository a module is registered from (novox/hq ADR 0266).
+type forgeFacts struct {
+	// ID is the forge's own id of the repository: what tells it from one deleted and made again by its name.
+	ID int64
+	// Guarded is whether the branch is protected as a module's trunk must be: no direct push, at least one
+	// required status, and no administrator merging past one. Why says what is missing when it is not.
+	Guarded bool
+	Why     string
+}
+
+// askTheForge asks the forge, through its module's tools on the bus, for a repository's id and its branch's
+// protection, waiting out a forge not served for a moment (novox/hq issue 486). A variable so a test needs no
+// forge.
+var askTheForge = func(ctx context.Context, owner, repo, branch string) (forgeFacts, error) {
+	return forgeWaitedOut(ctx, forgeWait, owner+"/"+repo, func(ctx context.Context) (forgeFacts, error) {
+		return askTheForgeOnce(ctx, owner, repo, branch)
+	})
+}
+
+// waitOut bounds how long a question is asked again while its answer is "not now": a pause of first, doubling
+// to most, for at most bound in all. now and sleep are the clock, so a test waits in no real time.
+type waitOut struct {
+	bound, first, most time.Duration
+	now                func() time.Time
+	sleep              func(context.Context, time.Duration) error
+}
+
+// forgeWait is the registration's wait for the forge (novox/hq issue 486). On 2026-10-11 a build's registration
+// asked the forge while node-tools on the control-node re-served after a rollout of the tool runner, heard
+// "nothing serves gitea.gitea_api", and failed its plan; the forge answered again seconds later. A re-serve takes
+// about 10 s, so 60 s waits one out with room to spare. It is a cap on the whole wait, an ask in flight included:
+// the registration holds the controller's one receive loop while it waits, and a loop held two minutes reads as
+// deaf. The pauses are those the build machine waits the registry with (novox/hq issue 457).
+var forgeWait = waitOut{bound: 60 * time.Second, first: time.Second, most: 10 * time.Second,
+	now: time.Now, sleep: sleepOrDone}
+
+// sleepOrDone pauses for d, or less when ctx ends first.
+func sleepOrDone(ctx context.Context, d time.Duration) error {
+	t := time.NewTimer(d)
+	defer t.Stop()
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-t.C:
+		return nil
+	}
+}
+
+// forgeNotNow is an answer that says the forge's tool is not served now — the tool runner re-serving — not that
+// the forge refused. Only that is asked again: a refusal, an unreadable answer or a repository with no id is the
+// forge's word, and a tool that did not answer in time has already held the receive loop its whole wait.
+func forgeNotNow(err error) bool { return errors.Is(err, link.ErrNothingServes) }
+
+// forgeWaitedOut asks the forge about repository, asking again while it answers "not served now", all of it
+// within w's bound, an ask in flight included (novox/hq issue 486). Past the bound it fails, saying it waited,
+// for how long, and what the forge last said; when the caller's own context ends, it says that instead.
+func forgeWaitedOut(ctx context.Context, w waitOut, repository string,
+	ask func(context.Context) (forgeFacts, error)) (forgeFacts, error) {
+	capped, cancel := context.WithTimeout(ctx, w.bound)
+	defer cancel()
+	began := w.now()
+	pause := w.first
+	for asked := 1; ; asked++ {
+		facts, err := ask(capped)
+		if err == nil {
+			if asked > 1 {
+				fmt.Printf("the forge answered about %s again, after %s (novox/hq issue 486)\n", repository,
+					w.now().Sub(began).Round(time.Second))
+			}
+			return facts, nil
+		}
+		if ctx.Err() != nil {
+			return forgeFacts{}, err // the caller's own context ended: no wait of ours to speak of
+		}
+		gaveUp := func() (forgeFacts, error) {
+			return forgeFacts{}, fmt.Errorf("waited %s for the forge to answer about %s, asking %d times, and it "+
+				"did not (novox/hq issue 486): %w", w.now().Sub(began).Round(time.Second), repository, asked, err)
+		}
+		if capped.Err() != nil {
+			return gaveUp() // the bound ended an ask in flight
+		}
+		if !forgeNotNow(err) {
+			return forgeFacts{}, err
+		}
+		if w.now().Sub(began)+pause > w.bound {
+			return gaveUp()
+		}
+		fmt.Printf("the forge cannot be asked about %s now (%v); asking again in %s, for at most %s in all "+
+			"(novox/hq issue 486)\n", repository, err, pause, w.bound)
+		if serr := w.sleep(capped, pause); serr != nil {
+			if ctx.Err() != nil {
+				return forgeFacts{}, fmt.Errorf("stopped waiting for the forge to answer about %s: %w", repository,
+					ctx.Err())
+			}
+			return gaveUp()
+		}
+		pause = min(2*pause, w.most)
+	}
+}
+
+// askTheForgeOnce asks the forge once, through its module's tools on the bus.
+func askTheForgeOnce(ctx context.Context, owner, repo, branch string) (forgeFacts, error) {
+	js, err := aBus()
+	if err != nil {
+		return forgeFacts{}, err
+	}
+	defer js.Close()
+	bus := link.OverNATS{Conn: js.Conn()}
+	ask := func(tool string, args map[string]any, into any) error {
+		raw, _ := json.Marshal(args)
+		answer, err := link.Ask(ctx, bus, "gitea", tool, raw, 30*time.Second)
+		if err != nil {
+			return err
+		}
+		if answer.Error != "" {
+			return fmt.Errorf("gitea.%s: %s", tool, answer.Error)
+		}
+		return json.Unmarshal(answer.Result, into)
+	}
+	var found struct {
+		Result struct {
+			ID       int64  `json:"id"`
+			FullName string `json:"full_name"`
+		} `json:"result"`
+	}
+	if err := ask("gitea_api", map[string]any{"path": "/repos/" + owner + "/" + repo}, &found); err != nil {
+		return forgeFacts{}, err
+	}
+	if found.Result.ID == 0 {
+		return forgeFacts{}, fmt.Errorf("the forge named no id for %s/%s", owner, repo)
+	}
+	var rules struct {
+		Rules []protectionRule `json:"rules"`
+	}
+	if err := ask("gitea_branch_protection_get", map[string]any{"owner": owner, "repo": repo}, &rules); err != nil {
+		return forgeFacts{}, err
+	}
+	facts := judgedRule(rules.Rules, branch)
+	facts.ID = found.Result.ID
+	return facts, nil
+}
+
+// protectionRule is a branch protection rule as the forge's tool summarises it.
+type protectionRule struct {
+	Rule             string   `json:"rule"`
+	Push             bool     `json:"push"`
+	RequiredStatuses []string `json:"required_statuses"`
+	AdminMayOverride bool     `json:"admin_may_override"`
+}
+
+// judgedRule judges the one rule the forge applies to a branch, as the forge picks it: the rule named for the
+// branch, else the first glob rule, in the forge's order, that covers it (gitea's first matching rule). Never a
+// later rule that happens to be stronger: the forge does not read it.
+func judgedRule(rules []protectionRule, branch string) forgeFacts {
+	var applied *protectionRule
+	for i := range rules {
+		if rules[i].Rule == branch {
+			applied = &rules[i]
+			break
+		}
+	}
+	if applied == nil {
+		for i := range rules {
+			if ruleCovers(rules[i].Rule, branch) {
+				applied = &rules[i]
+				break
+			}
+		}
+	}
+	switch r := applied; {
+	case r == nil:
+		return forgeFacts{Why: fmt.Sprintf("no protection rule covers %s", branch)}
+	case r.Push:
+		return forgeFacts{Why: fmt.Sprintf("the rule %s lets a person push to %s directly", r.Rule, branch)}
+	case len(r.RequiredStatuses) == 0:
+		return forgeFacts{Why: fmt.Sprintf("the rule %s requires no status before a merge into %s", r.Rule, branch)}
+	case r.AdminMayOverride:
+		return forgeFacts{Why: fmt.Sprintf("the rule %s lets an administrator merge into %s past a status", r.Rule, branch)}
+	}
+	return forgeFacts{Guarded: true}
+}
+
+// ruleCovers says a protection rule's name — a branch, or a glob of them — covers a branch, as the forge reads it.
+func ruleCovers(rule, branch string) bool {
+	if rule == branch {
+		return true
+	}
+	if !strings.ContainsAny(rule, "*?[") {
+		return false
+	}
+	var re strings.Builder
+	re.WriteString("^")
+	for i := 0; i < len(rule); i++ {
+		switch c := rule[i]; {
+		case c == '*' && i+1 < len(rule) && rule[i+1] == '*':
+			re.WriteString(".*")
+			i++
+		case c == '*':
+			re.WriteString("[^/]*")
+		case c == '?':
+			re.WriteString("[^/]")
+		default:
+			re.WriteString(regexp.QuoteMeta(string(c)))
+		}
+	}
+	re.WriteString("$")
+	ok, _ := regexp.MatchString(re.String(), branch)
+	return ok
+}
+
+// onTheForge is a source's owner and name on the mesh's own forge (the git seat's holder), and whether it is
+// there at all.
+func (f *sourceForms) onTheForge(repository, seat string) (owner, name string, ok bool) {
+	var rest string
+	switch {
+	case seat == gitSeat:
+		rest = strings.Trim(repository, "/")
+	case seat == "":
+		base := f.base(gitSeat)
+		if base == "" {
+			return "", "", false
+		}
+		url, prefix := f.canonical(repository, ""), f.canonical(base, "")+"/"
+		if !strings.HasPrefix(url, prefix) {
+			return "", "", false
+		}
+		// The case the forge spells it with: the URL as given, past the base.
+		rest = strings.TrimSuffix(strings.Trim(repository[len(prefix):], "/"), ".git")
+	default:
+		return "", "", false
+	}
+	parts := strings.Split(rest, "/")
+	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+		return "", "", false
+	}
+	return parts[0], parts[1], true
+}
+
+// mayRegisterFrom says whether a build's outcome may register module from the source it was built from, and the
+// forge's id of that repository to record (novox/hq ADR 0266). Through any verb, only:
+//
+//   - from the module's registered repository — the same repository by the forge's own id, not only its name; or,
+//     for a module new to the catalogue, from a repository the catalogue builds another module from;
+//   - and from a repository on the mesh's forge whose trunk is protected as a trunk must be: no direct push, at
+//     least one required status, no administrator merging past one.
+//
+// Anything else only when the build request was kept as asked at the controller's terminal, for this very
+// repository and path. path is the module's directory as built; branch the trunk it is registered from.
+func mayRegisterFrom(ctx context.Context, inv *inventory.Inventory, module string, built inventory.Source,
+	buildID, path, branch string) (int64, error) {
+	forms := newSourceForms(ctx, inv)
+	was, err := inv.SourceOf(ctx, module)
+	isNew := errors.Is(err, inventory.ErrNoSuchModule)
+	if err != nil && !isNew {
+		return 0, err
+	}
+	terminal, err := askedHereFor(ctx, inv, forms, buildID, built, path)
+	if err != nil {
+		return 0, err
+	}
+	refuse := func(why string) (int64, error) {
+		return 0, fmt.Errorf("%w: %s. A module is registered from such a source only by a build asked at the "+
+			"controller's terminal, never through a verb: a registered module is what the next push sends, and whoever "+
+			"may call a verb includes agents (novox/hq ADR 0266)", errNotItsSource, why)
+	}
+
+	var why string
+	var alongside []inventory.Entry // the modules a new one's repository already builds
+	switch {
+	case !isNew && forms.same(was.Repository, was.Seat, built.Repository, built.Seat):
+	case !isNew:
+		registered := was.Repository
+		if registered == "" {
+			registered = "no repository (it was handed over by hand)"
+		}
+		why = fmt.Sprintf("%s is built from %s, and this build is of %s", module, sourceWords(registered, was.Seat),
+			sourceWords(built.Repository, built.Seat))
+	default:
+		entries, err := inv.Catalogued(ctx)
+		if err != nil {
+			return 0, err
+		}
+		for _, e := range entries {
+			if !e.Provided && e.Source.Repository != "" &&
+				forms.same(e.Source.Repository, e.Source.Seat, built.Repository, built.Seat) {
+				alongside = append(alongside, e)
+			}
+		}
+		if len(alongside) == 0 {
+			why = fmt.Sprintf("%s is new to the catalogue, and %s is no repository the catalogue builds a module from",
+				module, sourceWords(built.Repository, built.Seat))
+		}
+	}
+	// **Or the move the operator approved** (novox/hq ADR 0420 §7, issue 1025): a known module built from another
+	// repository by a merge, whose pull request mesh-delivery merged on the operator's Approve of that head.
+	// A verb alone, or a merge with no such warrant, is refused as before.
+	movedWhy := ""
+	if why != "" && !terminal && !isNew {
+		accepted, err := approvedMove(ctx, inv, forms, buildID, built)
+		switch {
+		case err == nil:
+			movedWhy, why = accepted, ""
+		case !errors.Is(err, errNotAMerge):
+			fmt.Printf("%s: %s is built from another repository, and no approved move covers this build: %v\n",
+				buildID, module, err)
+		}
+	}
+	if why != "" && !terminal {
+		return refuse(why)
+	}
+
+	owner, name, onForge := forms.onTheForge(built.Repository, built.Seat)
+	if !onForge {
+		if terminal {
+			fmt.Printf("%s: %s is not on the mesh's forge — registered, as asked at the controller's terminal\n",
+				buildID, sourceWords(built.Repository, built.Seat))
+			return 0, nil
+		}
+		return refuse(fmt.Sprintf("%s is not on the mesh's forge, so whether its trunk is protected cannot be read",
+			sourceWords(built.Repository, built.Seat)))
+	}
+	facts, err := askTheForge(ctx, owner, name, branch)
+	if err != nil {
+		if terminal {
+			fmt.Printf("%s: the forge could not be asked about %s/%s (%v) — registered, as asked at the controller's "+
+				"terminal\n", buildID, owner, name, err)
+			return 0, nil
+		}
+		return refuse(fmt.Sprintf("the forge could not say whether %s/%s's %s is protected: %v", owner, name, branch, err))
+	}
+	if terminal {
+		if why != "" || !facts.Guarded {
+			fmt.Printf("%s: %s — registered, as asked at the controller's terminal\n", buildID,
+				strings.Trim(why+"; "+facts.Why, "; "))
+		}
+		return facts.ID, nil
+	}
+	if !facts.Guarded {
+		return refuse(fmt.Sprintf("%s/%s's %s is not protected as a module's trunk must be: %s", owner, name, branch,
+			facts.Why))
+	}
+	// The same repository by the forge's id, not only its name: one deleted and made again is another.
+	recorded := map[string]int64{}
+	// A moved module is registered from the repository the operator approved, not the one it was registered from.
+	if !isNew && movedWhy == "" {
+		id, err := inv.SourceIdentity(ctx, module)
+		if err != nil {
+			return 0, err
+		}
+		recorded[module] = id
+	}
+	for _, e := range alongside {
+		id, err := inv.SourceIdentity(ctx, e.Manifest.Module)
+		if err != nil {
+			return 0, err
+		}
+		recorded[e.Manifest.Module] = id
+	}
+	for m, id := range recorded {
+		if id != 0 && id != facts.ID {
+			return refuse(fmt.Sprintf("%s/%s is not the repository %s was registered from: the forge knows it as "+
+				"repository %d, and %s was registered from repository %d — one of that name deleted and made again",
+				owner, name, m, facts.ID, m, id))
+		}
+	}
+	if movedWhy != "" {
+		fmt.Printf("%s: %s moved from %s to %s/%s — registered at the operator's Approve: %s\n", buildID, module,
+			sourceWords(was.Repository, was.Seat), owner, name, movedWhy)
+	}
+	return facts.ID, nil
+}
+
+// askedHereFor says the build was asked at the controller's terminal, for this repository and this path: a kept
+// request marked so, whose source is the outcome's (novox/hq ADR 0266).
+func askedHereFor(ctx context.Context, inv *inventory.Inventory, forms *sourceForms, buildID string,
+	built inventory.Source, path string) (bool, error) {
+	r, found, err := inv.BuildRequestByID(ctx, buildID)
+	if err != nil || !found || !r.AtTerminal {
+		return false, err
+	}
+	if !forms.same(r.Repository, r.Seat, built.Repository, built.Seat) ||
+		strings.Trim(r.Path, "/") != strings.Trim(path, "/") {
+		fmt.Printf("%s was asked at the terminal of %s at %q, and its outcome is of %s at %q: not the terminal's\n",
+			buildID, sourceWords(r.Repository, r.Seat), r.Path, sourceWords(built.Repository, built.Seat), path)
+		return false, nil
+	}
+	return true, nil
+}
+
+// sourceWords is a source as a person reads it.
+func sourceWords(repository, seat string) string {
+	if seat == "" {
+		return repository
+	}
+	return buildSource{Repository: repository, Seat: seat}.String()
+}
+
+// verbMayAsk refuses, for a call through a verb, a build of a repository the catalogue builds no module from
+// (novox/hq ADR 0266): the build node would run what an agent wrote, and its outcome could never be
+// registered anyway. url is the repository as it is cloned. At the terminal anything may be asked.
+func verbMayAsk(ctx context.Context, source buildSource, url string) error {
+	if startedAtTheTerminal() {
+		return nil
+	}
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	entries, err := open.inventory.Catalogued(ctx)
+	if err != nil {
+		return err
+	}
+	forms := newSourceForms(ctx, open.inventory)
+	if forms.buildsFrom(entries, source.Repository, source.Seat) || forms.buildsFrom(entries, url, "") {
+		return nil
+	}
+	return terminalRefusal("%s is no repository the catalogue builds a module from, and a build of any other is "+
+		"asked at the controller's terminal only, never through a verb: a build node runs what the repository "+
+		"says, and its outcome would register a module the next push sends — whoever may call a verb includes "+
+		"agents (novox/hq ADR 0266). Nothing was asked", source)
+}

cmd/mesh-controller/build_source_integration_test.go

@@ -0,0 +1,353 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/asks"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+func theCatalogue(t *testing.T) *stores {
+	t.Helper()
+	open := aMesh(t)
+	ctx := t.Context()
+	for _, b := range []link.BuildResult{
+		onTrunk("build-sudo", "novox/mesh-catalog", "git", "modules/sudo", map[string]any{"module": "sudo", "version": "1"}),
+		onTrunk("build-host", "novox/mesh-host", "git", "", map[string]any{"module": "mesh-host", "version": "1"}),
+	} {
+		keptAsked(t, open.inventory, b.ID, b.Source.Repository, b.Path, true)
+		if _, _, err := takeIn(ctx, open.inventory, b); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return open
+}
+
+func TestABuildFromAnAgentsRepositoryIsNotRegisteredAsAModuleTheMeshHolds(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	for _, c := range []struct {
+		name, repository, path, module string
+	}{
+		{"its own repository naming sudo", "agent/sudo", "modules/sudo", "sudo"},
+		{"a fork of the catalogue", "agent/mesh-catalog", "modules/sudo", "sudo"},
+		{"a fork of the node-engine", "agent/mesh-host", "", "mesh-host"},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			id := "build-" + strings.ReplaceAll(c.repository, "/", "-")
+			keptAsked(t, open.inventory, id, c.repository, c.path, false) // through the build verb
+			evil := onTrunk(id, c.repository, "git", c.path, map[string]any{"module": c.module, "version": "evil"})
+			_, _, err := takeIn(ctx, open.inventory, evil)
+			if !errors.Is(err, errNotItsSource) {
+				t.Fatalf("a build of %s was taken in as %s: %v", c.repository, c.module, err)
+			}
+			shelf, err := open.inventory.Catalogue(ctx)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got := shelf[c.module].Version; got != "1" {
+				t.Fatalf("%s is now %q, from %s", c.module, got, c.repository)
+			}
+			if _, found, _ := open.inventory.BuildByID(ctx, id); !found {
+				t.Errorf("the refused build %s is not recorded", id)
+			}
+		})
+	}
+}
+
+func TestANewModuleFromARepositoryTheCatalogueDoesNotBuildFromIsNotRegistered(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	keptAsked(t, open.inventory, "build-new", "agent/tools", "", false)
+	_, _, err := takeIn(ctx, open.inventory, onTrunk("build-new", "agent/tools", "git", "",
+		map[string]any{"module": "agent-tools", "version": "1"}))
+	if !errors.Is(err, errNotItsSource) {
+		t.Fatalf("a new module from an agent's repository was taken in: %v", err)
+	}
+	// And one asked of nobody here — an outcome on the bus no request was kept for — the same.
+	_, _, err = takeIn(ctx, open.inventory, onTrunk("build-unasked", "agent/tools", "git", "",
+		map[string]any{"module": "agent-tools", "version": "1"}))
+	if !errors.Is(err, errNotItsSource) {
+		t.Fatalf("an outcome nobody asked for was taken in: %v", err)
+	}
+	if shelf, _ := open.inventory.Catalogue(ctx); shelf["agent-tools"].Module != "" {
+		t.Fatal("the refused module is in the catalogue")
+	}
+}
+
+func TestAtTheTerminalAnotherRepositoryIsRegistered(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	keptAsked(t, open.inventory, "build-moved", "novox/sudo", "", true)
+	if _, _, err := takeIn(ctx, open.inventory, onTrunk("build-moved", "novox/sudo", "git", "",
+		map[string]any{"module": "sudo", "version": "2"})); err != nil {
+		t.Fatalf("a move the operator asked for at the terminal was refused: %v", err)
+	}
+	if src, _ := open.inventory.SourceOf(ctx, "sudo"); src.Repository != "novox/sudo" {
+		t.Fatalf("sudo is built from %q", src.Repository)
+	}
+	if err := open.inventory.RecordBuildRequest(ctx, inventory.BuildRequest{ID: "build-external",
+		Repository: "http://forge.internal:20000/someone/app.git", For: "build", AtTerminal: true}); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := takeIn(ctx, open.inventory, onTrunk("build-external", "someone/app", "", "",
+		map[string]any{"module": "app", "version": "1"})); err != nil {
+		t.Fatalf("a new module the operator asked for at the terminal was refused: %v", err)
+	}
+}
+
+func TestADeliveryFromTheRegisteredRepositoryIsRegistered(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	rebuilt := onTrunk("build-plan", "novox/mesh-catalog", "git", "modules/sudo", map[string]any{"module": "sudo", "version": "2"})
+	if err := open.inventory.RecordBuildRequest(ctx, inventory.BuildRequest{ID: rebuilt.ID,
+		Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/sudo", For: "plan"}); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := takeIn(ctx, open.inventory, rebuilt); err != nil {
+		t.Fatalf("a plan's build of the module's own repository was refused: %v", err)
+	}
+	added := onTrunk("build-merge", "novox/mesh-catalog", "git", "modules/zram", map[string]any{"module": "zram", "version": "1"})
+	if _, _, err := takeIn(ctx, open.inventory, added); err != nil {
+		t.Fatalf("a module a merge added to the catalogue repository was refused: %v", err)
+	}
+	shelf, _ := open.inventory.Catalogue(ctx)
+	if shelf["sudo"].Version != "2" || shelf["zram"].Module == "" {
+		t.Fatalf("not registered: sudo %q, zram %q", shelf["sudo"].Version, shelf["zram"].Module)
+	}
+}
+
+func TestAVerbAsksNoBuildOfARepositoryTheCatalogueDoesNotBuildFrom(t *testing.T) {
+	theCatalogue(t)
+	ctx := t.Context()
+	t.Setenv(verbVar, "build")
+	t.Setenv(link.CallerVar, "node-tools.anchor, through the mesh-controller seat")
+	err := verbMayAsk(ctx, buildSource{Repository: "agent/sudo", Seat: "git"}, "http://forge.internal:20000/agent/sudo.git")
+	var policy *heldAtTheTerminal
+	if !errors.As(err, &policy) {
+		t.Fatalf("a verb's build of an agent's repository was asked: %v", err)
+	}
+	if err := verbMayAsk(ctx, buildSource{Repository: "novox/mesh-catalog", Seat: "git"},
+		"http://forge.internal:20000/novox/mesh-catalog.git"); err != nil {
+		t.Fatalf("a verb's build of the catalogue repository was refused: %v", err)
+	}
+	t.Setenv(verbVar, "")
+	t.Setenv(link.CallerVar, "")
+	if err := verbMayAsk(ctx, buildSource{Repository: "agent/sudo", Seat: "git"}, ""); err != nil {
+		t.Fatalf("the terminal was refused: %v", err)
+	}
+}
+
+func TestARollbackNeverPutsBackABuildFromAnotherRepository(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	inv := open.inventory
+	fork := onTrunk("build-1791500000000000000", "agent/mesh-catalog", "git", "modules/sudo",
+		map[string]any{"module": "sudo", "version": "evil"})
+	fork.Commit = "c0ffee0123456789" // the commit sudo was registered at
+	keptAsked(t, inv, fork.ID, "agent/mesh-catalog", "modules/sudo", false)
+	if _, _, err := takeIn(ctx, inv, fork); !errors.Is(err, errNotItsSource) {
+		t.Fatalf("the fork's build was taken in: %v", err)
+	}
+	// Asked after the registered build, whenever the test runs: an id naming a fixed moment read as older
+	// than the registered build once the clock passed it (2026-10-10 02:40 UTC), and the test failed on main.
+	failed := onTrunk(fmt.Sprintf("build-%d", time.Now().Add(time.Hour).UnixNano()), "novox/mesh-catalog", "git", "modules/sudo",
+		map[string]any{"module": "sudo", "version": "2"})
+	failed.Commit = "badbadbad0123456"
+	if _, _, err := takeIn(ctx, inv, failed); err != nil {
+		t.Fatal(err)
+	}
+	record, _, err := inv.BuildByID(ctx, failed.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	previous, found, err := inv.PreviousBuild(ctx, "sudo", "c0ffee0123456789", record)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if found && previous.ID == fork.ID {
+		t.Fatalf("a rollback would put back the fork's build %s", previous.ID)
+	}
+	if !found || previous.ID != "build-sudo" {
+		t.Fatalf("a rollback puts back %q (found %v), want the registered build-sudo", previous.ID, found)
+	}
+}
+
+func TestATrunkTheForgeDoesNotProtectRegistersNothing(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	theForge.Store("novox/unguarded", forgeFacts{ID: 7, Why: "the rule main lets a person push to main directly"})
+	t.Cleanup(func() { theForge.Delete("novox/unguarded") })
+	first := onTrunk("build-unguarded-1", "novox/unguarded", "git", "", map[string]any{"module": "unguarded", "version": "1"})
+	keptAsked(t, open.inventory, first.ID, "novox/unguarded", "", true)
+	if _, _, err := takeIn(ctx, open.inventory, first); err != nil {
+		t.Fatalf("at the terminal: %v", err)
+	}
+	again := onTrunk("build-unguarded-2", "novox/unguarded", "git", "", map[string]any{"module": "unguarded", "version": "2"})
+	if _, _, err := takeIn(ctx, open.inventory, again); !errors.Is(err, errNotItsSource) ||
+		!strings.Contains(err.Error(), "push to main directly") {
+		t.Fatalf("a rebuild from an unprotected trunk was taken in: %v", err)
+	}
+	theForge.Store("novox/unguarded", errors.New("nothing serves gitea.gitea_api"))
+	if _, _, err := takeIn(ctx, open.inventory, onTrunk("build-unguarded-3", "novox/unguarded", "git", "",
+		map[string]any{"module": "unguarded", "version": "3"})); !errors.Is(err, errNotItsSource) {
+		t.Fatalf("a forge that could not say was read as a protected trunk: %v", err)
+	}
+	if shelf, _ := open.inventory.Catalogue(ctx); shelf["unguarded"].Version != "1" {
+		t.Fatalf("unguarded is %q", shelf["unguarded"].Version)
+	}
+}
+
+func TestARepositoryMadeAgainUnderItsNameIsNotTheModulesSource(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	theForge.Store("novox/remade", forgeFacts{ID: 100, Guarded: true})
+	t.Cleanup(func() { theForge.Delete("novox/remade") })
+	first := onTrunk("build-remade-1", "novox/remade", "git", "", map[string]any{"module": "remade", "version": "1"})
+	keptAsked(t, open.inventory, first.ID, "novox/remade", "", true)
+	if _, _, err := takeIn(ctx, open.inventory, first); err != nil {
+		t.Fatal(err)
+	}
+	if id, _ := open.inventory.SourceIdentity(ctx, "remade"); id != 100 {
+		t.Fatalf("the forge's id was not recorded: %d", id)
+	}
+	theForge.Store("novox/remade", forgeFacts{ID: 101, Guarded: true}) // deleted, and made again by an agent
+	if _, _, err := takeIn(ctx, open.inventory, onTrunk("build-remade-2", "novox/remade", "git", "",
+		map[string]any{"module": "remade", "version": "evil"})); !errors.Is(err, errNotItsSource) ||
+		!strings.Contains(err.Error(), "made again") {
+		t.Fatalf("a repository made again under the name was taken in: %v", err)
+	}
+	// And a new module from it, beside the one registered from the first, the same.
+	if _, _, err := takeIn(ctx, open.inventory, onTrunk("build-remade-3", "novox/remade", "git", "modules/other",
+		map[string]any{"module": "other", "version": "1"})); !errors.Is(err, errNotItsSource) {
+		t.Fatalf("a new module from a repository made again was taken in: %v", err)
+	}
+}
+
+func TestATerminalRequestCoversOnlyWhatItAsked(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	if err := open.inventory.RecordBuildRequest(ctx, inventory.BuildRequest{ID: "build-asked", Repository: "novox/app",
+		Seat: "git", Path: "modules/app", For: "build", AtTerminal: true}); err != nil {
+		t.Fatal(err)
+	}
+	other := onTrunk("build-asked", "agent/sudo", "git", "modules/app", map[string]any{"module": "sudo", "version": "evil"})
+	if _, _, err := takeIn(ctx, open.inventory, other); !errors.Is(err, errNotItsSource) {
+		t.Fatalf("an outcome of another repository under a terminal request's id was taken in: %v", err)
+	}
+	elsewhere := onTrunk("build-asked", "novox/app", "git", "modules/sudo", map[string]any{"module": "sudo", "version": "evil"})
+	if _, _, err := takeIn(ctx, open.inventory, elsewhere); !errors.Is(err, errNotItsSource) {
+		t.Fatalf("an outcome of another path under a terminal request's id was taken in: %v", err)
+	}
+}
+
+func TestTheServingControllerIsNeverTheTerminal(t *testing.T) {
+	t.Setenv(verbVar, "")
+	t.Setenv(link.CallerVar, "")
+	t.Setenv(servedVar, "")
+	if !startedAtTheTerminal() {
+		t.Fatal("a process started by hand is not the terminal")
+	}
+	markServed()
+	if startedAtTheTerminal() {
+		t.Fatal("the serving controller reads as the terminal")
+	}
+	child := exec.Command(os.Args[0], "-test.run=^$")
+	child.Env = os.Environ()
+	if !slices.Contains(child.Env, servedVar+"=1") {
+		t.Fatal("what the serving controller starts does not carry its mark")
+	}
+}
+
+func TestAnUnknownIdentityKeepsTheRecordedOne(t *testing.T) {
+	open := theCatalogue(t)
+	ctx := t.Context()
+	if err := open.inventory.SetSourceIdentity(ctx, "sudo", 100); err != nil {
+		t.Fatal(err)
+	}
+	if err := open.inventory.SetSourceIdentity(ctx, "sudo", 0); err != nil {
+		t.Fatal(err)
+	}
+	if id, _ := open.inventory.SourceIdentity(ctx, "sudo"); id != 100 {
+		t.Fatalf("the recorded id became %d", id)
+	}
+}
+
+func TestAModuleMovesOnTheOperatorsApproveOfTheMergeThatMovedIt(t *testing.T) {
+	const commit = "c0ffee0123456789"
+	for _, c := range []struct {
+		what    string
+		change  func(*anApprovedMerge)
+		unkept  bool
+		request string // who asked: "merge", or "build" through a verb
+		moved   bool
+	}{
+		{what: "the operator's Approve of the merged head", request: "merge", moved: true},
+		{what: "no merge mesh-delivery announced", unkept: true, request: "merge"},
+		{what: "a warrant for other heads", request: "merge", change: func(a *anApprovedMerge) {
+			a.merge.Heads = map[string]string{"novox/mesh-host@aaaaaaaaaaaa": "e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5"}
+		}},
+		{what: "a Decline", request: "merge", change: func(a *anApprovedMerge) {
+			a.warrant.Option, a.warrant.Label, a.merge.Option = "decline", "Decline", "decline"
+		}},
+		{what: "a person who is not the operator", request: "merge", change: func(a *anApprovedMerge) { a.warrant.By.Who = "agent" }},
+		{what: "a build asked through a verb", request: "build"},
+	} {
+		open := theCatalogue(t)
+		ctx := t.Context()
+		inv := open.inventory
+		a := approvedMerge(t)
+		a.merge.Owner, a.merge.Repo, a.merge.Number, a.merge.HeadSHA = "novox", "mesh-host", 7, "a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1a1"
+		if c.change != nil {
+			c.change(&a)
+		}
+		wasKept, wasAsk := keptDeliveryMerge, routerAskOf
+		keptDeliveryMerge = func(_ context.Context, owner, repo string, number int, head string) (deliveryMerge, bool, error) {
+			return a.merge, !c.unkept && owner == "novox" && repo == "mesh-host" && number == 7 && head == a.merge.HeadSHA, nil
+		}
+		routerAskOf = func(_ context.Context, _ *inventory.Inventory, id string) (*asks.Ask, *asks.Warrant, error) {
+			if id != a.merge.AskID {
+				t.Errorf("%s: the router was asked for %q", c.what, id)
+			}
+			return &a.ask, &a.warrant, nil
+		}
+		t.Cleanup(func() { keptDeliveryMerge, routerAskOf = wasKept, wasAsk })
+		event, _ := json.Marshal(map[string]any{"owner": "novox", "repo": "mesh-host", "base": "main", "number": 7,
+			"head_sha": a.merge.HeadSHA, "merge_commit_sha": commit})
+		if _, err := inv.AddMerge(ctx, inventory.BatchedMerge{Repository: "novox/mesh-host", Branch: "main", Commit: commit,
+			Merged: time.Now(), Heard: time.Now(), Event: event}); err != nil {
+			t.Fatal(err)
+		}
+		id := fmt.Sprintf("build-%d", time.Now().Add(time.Hour).UnixNano())
+		if err := inv.RecordBuildRequest(ctx, inventory.BuildRequest{ID: id, Repository: "novox/mesh-host", Seat: "git",
+			Path: "modules/sudo", Ref: "main", Commit: commit, For: c.request}); err != nil {
+			t.Fatal(err)
+		}
+		moved := onTrunk(id, "novox/mesh-host", "git", "modules/sudo", map[string]any{"module": "sudo", "version": "2"})
+		moved.Commit = commit
+		_, _, err := takeIn(ctx, inv, moved)
+		src, _ := inv.SourceOf(ctx, "sudo")
+		switch {
+		case c.moved && err != nil:
+			t.Errorf("%s: the move was refused: %v", c.what, err)
+		case c.moved && src.Repository != "novox/mesh-host":
+			t.Errorf("%s: sudo is built from %q", c.what, src.Repository)
+		case !c.moved && !errors.Is(err, errNotItsSource):
+			t.Errorf("%s: the move was not refused as ADR 0266 has it: %v", c.what, err)
+		case !c.moved && src.Repository != "novox/mesh-catalog":
+			t.Errorf("%s: a refused move changed sudo's source to %q", c.what, src.Repository)
+		}
+	}
+}

cmd/mesh-controller/build_source_test.go

@@ -0,0 +1,128 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"hash/fnv"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The routes to root a review of ADR 0266 found (novox/hq ADR 0266 §7): an agent makes a repository of its
+// own — or forks one the mesh builds from — commits a module.json naming a module the mesh runs everywhere
+// (`sudo`, granting itself a rule without a password; `mesh-host`, the node-engine), and asks the `build` verb
+// for it. Its outcome was registered under that name from the agent's repository, and the next push sent it.
+
+// onTrunk is an outcome of a commit on its repository's trunk, as the build seat says it.
+func onTrunk(id, repository, seat, path string, manifest map[string]any) link.BuildResult {
+	raw, _ := json.Marshal(manifest)
+	r := link.BuildResult{ID: id, Repository: "http://forge.internal:20000/" + repository + ".git", Path: path,
+		Ref: "main", On: "anchor", Commit: "c0ffee0123456789", Manifest: raw,
+		Trunk: "main", OnTrunk: true, Branches: []string{"main"}}
+	if seat != "" {
+		r.Source = &link.SourceOnSeat{Seat: seat, Repository: repository}
+	}
+	return r
+}
+
+// keptAsked keeps a build request as the asker would: through a verb, or at the terminal.
+func keptAsked(t *testing.T, inv *inventory.Inventory, id, repository, path string, atTerminal bool) {
+	t.Helper()
+	if err := inv.RecordBuildRequest(t.Context(), inventory.BuildRequest{ID: id, Repository: repository, Seat: "git",
+		Path: path, For: "build", AtTerminal: atTerminal}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// theCatalogue is a mesh whose sudo is built from the catalogue repository and whose node-engine from its own.
+
+// The operator at the terminal may still move a module, or add one from a new repository.
+
+// The delivery's flow is untouched: a merge's rebuild of a module from its own repository, and a merge adding
+// a module to a repository the catalogue builds from (novox/hq issue 300), are registered with no terminal.
+
+// Through a verb, a build of a repository the catalogue builds nothing from is not even asked: the build node
+// would run what the agent wrote.
+
+// asTheOperator keeps a build as asked at the controller's terminal, as the operator's first build of a module
+// from a repository the catalogue does not yet build from is (novox/hq ADR 0266), and hands it back.
+func asTheOperator(t *testing.T, inv *inventory.Inventory, b link.BuildResult) link.BuildResult {
+	t.Helper()
+	repository, seat := b.Repository, ""
+	if b.Source != nil {
+		repository, seat = b.Source.Repository, b.Source.Seat
+	}
+	if err := inv.RecordBuildRequest(t.Context(), inventory.BuildRequest{ID: b.ID, Repository: repository, Seat: seat,
+		Path: b.Path, For: "build", AtTerminal: true}); err != nil {
+		t.Fatal(err)
+	}
+	return b
+}
+
+// A rollback puts back only a build of the module's own repository: an agent's build of the module's name,
+// recorded and refused, at the very commit the machine ran before (a fork carries it), is never registered by
+// the back door of a failed gate.
+
+// theForge is what the forge says in a test, by owner/name: a repository not named here is protected as a
+// trunk must be, with an id of its own.
+var theForge sync.Map
+
+func init() {
+	askTheForge = func(_ context.Context, owner, repo, _ string) (forgeFacts, error) {
+		if said, ok := theForge.Load(owner + "/" + repo); ok {
+			switch f := said.(type) {
+			case error:
+				return forgeFacts{}, f
+			case forgeFacts:
+				return f, nil
+			}
+		}
+		h := fnv.New32a()
+		_, _ = h.Write([]byte(owner + "/" + repo))
+		return forgeFacts{ID: int64(h.Sum32()), Guarded: true}, nil
+	}
+}
+
+// A module's trunk the forge does not protect — direct pushes, no required status — or a forge that cannot say,
+// registers nothing through a verb: the trunk rule means nothing on a branch anyone pushes to.
+
+// A repository deleted and made again under the module's repository's name is another repository: the forge's
+// id, recorded at registration, tells them apart.
+
+// The terminal's mark is the operator's for the repository and path they asked: an outcome of another, under that
+// build's id, is not theirs.
+
+// The serving controller, and everything it starts, is never the terminal: a build asked in it reads as asked
+// through the mesh even when no verb and no caller is named.
+
+// The forge applies one rule to a branch: the rule named for it, else the first glob that covers it. A stronger
+// rule later in the list is not what guards the branch, and is not read as if it were (the confirmation review).
+func TestTheRuleJudgedIsTheOneTheForgeApplies(t *testing.T) {
+	guarded := protectionRule{Rule: "*", RequiredStatuses: []string{"mesh/merge-gate"}}
+	open := protectionRule{Rule: "main", Push: true, RequiredStatuses: []string{"mesh/merge-gate"}}
+	if f := judgedRule([]protectionRule{guarded, open}, "main"); f.Guarded {
+		t.Error("an exact rule letting pushes was passed over for a glob that guards")
+	}
+	if f := judgedRule([]protectionRule{{Rule: "ma*", RequiredStatuses: nil}, {Rule: "*", RequiredStatuses: []string{"x"}}},
+		"main"); f.Guarded || !strings.Contains(f.Why, "ma*") {
+		t.Errorf("the first glob covering the branch was not the one judged: %+v", f)
+	}
+	if f := judgedRule([]protectionRule{{Rule: "release/*"}, {Rule: "main", RequiredStatuses: []string{"x"}}}, "main"); !f.Guarded {
+		t.Errorf("the rule named for the branch was not judged: %+v", f)
+	}
+	if f := judgedRule(nil, "main"); f.Guarded {
+		t.Error("no rule is no protection")
+	}
+}
+
+// An id the forge could not give keeps the id already recorded.
+
+// **The operator's Approve of a reviewed group registers a moved module from its new repository** (novox/hq ADR 0420 §7,
+// issue 1025). sudo is built from the catalogue; a merge into the repository of node-engine's module, announced by
+// mesh-delivery with the ask it merged on, brings its build from there. Accepted with the operator's Approve of the
+// merged head; refused with no kept merge, a warrant for other heads, a Decline, a person who is not the operator, and
+// through a verb.

cmd/mesh-controller/build_test.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// A build's outcome is taken in the same way whoever hears it (novox/hq issue 176): recorded, and
+// the module registered with its source as the seat and path when the request said so — never the
+// URL. A definition naming an installation is recorded and not registered; a failure is recorded
+// and said.
+
+// novox/hq 04-ISSUES/215: a build asked at a commit is recorded as built from that commit, and the
+// module keeps following the branch it followed — a new one, the default branch.
+
+// novox/hq 04-ISSUES/219: an older request heard after a newer one is recorded and not registered,
+// so a push sends what the newer request built.
+
+func TestABuildIDSaysWhenItWasAsked(t *testing.T) {
+	at := time.Date(2026, 10, 3, 21, 51, 57, 392539762, time.UTC)
+	if got, ok := link.BuildAskedAt(link.NewBuildID(at)); !ok || !got.Equal(at) {
+		t.Errorf("read back %v %v; want %v", got, ok, at)
+	}
+	if got, ok := link.BuildAskedAt("build-1791064317392539762"); !ok || got.Format(time.TimeOnly) != "21:51:57" {
+		t.Errorf("the incident's id reads as %v %v", got, ok)
+	}
+	for _, id := range []string{"b-1", "build-2", "build-", "build-x", ""} {
+		if _, ok := link.BuildAskedAt(id); ok {
+			t.Errorf("%q read as a request time", id)
+		}
+	}
+}

cmd/mesh-controller/bus_step.go

@@ -0,0 +1,410 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The bus as a planned step (novox/hq to-be 45 §8, ADR 0227 rule 8, ADR 0236).
+//
+// **A bus upgrade is never rolled out.** The bus carries every declaration, every report and the
+// controller's own lease; a new bus build that does not come up is a mesh nobody can tell anything,
+// and a version whose data format moved (2.10 → 2.11) cannot be undone by putting the old one back.
+// So nothing sends a new bus build on its own: its policy is `record` whatever anyone says (the
+// catalogue's DerivedUpgrade, and `upgrade` refuses a roll-out), a plan builds it and sends nothing, a
+// cascade holds the machine (ADR 0221), and a push naming that machine is refused while a new bus build
+// waits for it (busHeld). The one way is this verb: a person, with why, the streams snapshotted first,
+// whether it can be reverted said before it starts, the step said as `bus-maintenance` while it runs,
+// and every stream, durable consumer and a round trip checked after (H-bus) — or the step said failed,
+// with its snapshot as the way back.
+
+// busStepProbe is the registry's row for the step; its kinds.
+const (
+	busStepProbe         = "DB"
+	kindBusMaintenance   = "bus-maintenance"
+	kindBusUpgradeFailed = "bus-upgrade-failed"
+)
+
+// busStepBound is how long after its start a bus upgrade must be followed by a healthy bus.
+var busStepBound = 15 * time.Minute
+
+// takeBusSnapshot snapshots every stream before a bus upgrade and answers where the snapshot is: the bus
+// machine's backup holder backs the bus module up now, whose dump is the streams' snapshot (novox/hq ADR
+// 0235). A variable so a test takes none. A person who took one by hand says where with --snapshot-taken,
+// and then none is taken — for a bus whose module does not yet carry the snapshot program.
+var takeBusSnapshot = snapshotTheBusNow
+
+// busPending is what a bus upgrade would do: the bus's module, the machines running it, and, per
+// machine, the build it was last sent against the build the mesh holds. Empty machines: the mesh holds
+// no bus module.
+type busPending struct {
+	module   string
+	machines []string
+	from     map[string]string
+	to       string
+	// same are the commits whose build was made from the same source as the build the mesh holds, or
+	// made the same artifacts and manifest (novox/hq issue 280).
+	same map[string]bool
+}
+
+// moves is whether sending the machine would replace its bus: a build it was not last sent, unless the
+// two builds were made from the same source, or made the same artifacts from the same manifest — a
+// rebuild of the same source for another module's merge changes nothing the machine runs, whatever
+// image digest it made (novox/hq issue 280).
+func (b busPending) moves(machine string) bool {
+	from, known := b.from[machine]
+	if b.module == "" || b.to == "" || (known && sameCommit(from, b.to)) {
+		return false
+	}
+	return !known || !b.same[from]
+}
+
+// pendingBus reads what a bus upgrade would do.
+func pendingBus(ctx context.Context, inv *inventory.Inventory) (busPending, error) {
+	var b busPending
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return b, err
+	}
+	for name, m := range shelf {
+		if catalogue.ProvidesBus(m) {
+			b.module = name
+		}
+	}
+	if b.module == "" {
+		return b, nil
+	}
+	current, err := inv.CurrentBuilds(ctx)
+	if err != nil {
+		return b, err
+	}
+	b.to = current[b.module].Commit
+	if b.machines, err = inv.Running(ctx, b.module); err != nil {
+		return b, err
+	}
+	b.from, b.same = map[string]string{}, map[string]bool{}
+	made, err := inv.BuildFingerprints(ctx, b.module)
+	if err != nil {
+		return b, err
+	}
+	for commit, refs := range made {
+		b.same[commit] = refs != "" && refs == made[b.to]
+	}
+	sources, err := inv.BuildSourceFingerprints(ctx, b.module)
+	if err != nil {
+		return b, err
+	}
+	for commit, src := range sources {
+		if src != "" && src == sources[b.to] {
+			b.same[commit] = true
+		}
+	}
+	for _, n := range b.machines {
+		sent, known, err := inv.SentBuilds(ctx, n)
+		if err != nil {
+			return b, err
+		}
+		if known {
+			if c, carried := sent[b.module]; carried {
+				b.from[n] = c
+			}
+		}
+	}
+	return b, nil
+}
+
+// busHeld names the machines a push may not send because sending them would replace the bus: the
+// planned step's, not a push's (ADR 0236). Said with the remedy.
+func busHeld(ctx context.Context, inv *inventory.Inventory, machines []string) (map[string]string, error) {
+	b, err := pendingBus(ctx, inv)
+	if err != nil {
+		return nil, err
+	}
+	out := map[string]string{}
+	for _, n := range machines {
+		for _, holder := range b.machines {
+			if n == holder && b.moves(n) {
+				out[n] = fmt.Sprintf("sending %s would replace the bus (%s %s → %s), which is a planned step: "+
+					"`bus upgrade --why …` snapshots its streams first and checks them after (novox/hq ADR 0236)",
+					n, b.module, short(orNotKnown(b.from[n])), short(b.to))
+			}
+		}
+	}
+	return out, nil
+}
+
+// busCommand is `bus` — what a bus upgrade would do and how the last went — and `bus upgrade`.
+func busCommand(ctx context.Context, args []string) error {
+	sub := ""
+	if len(args) > 0 && !strings.HasPrefix(args[0], "-") {
+		sub, args = args[0], args[1:]
+	}
+	set := flag.NewFlagSet("bus", flag.ContinueOnError)
+	snapshot := set.String("snapshot-taken", "", "where the streams' snapshot a person took is, while the mesh takes none itself")
+	reversible := set.Bool("reversible", false, "the new version can be undone by putting the old one back")
+	irreversible := set.Bool("irreversible", false, "the new version cannot be undone by putting the old one back, "+
+		"and this is the person's explicit word that it runs anyway")
+	why := addHandActFlags(set)
+	if rest, err := parseAround(set, args); err != nil {
+		return err
+	} else if len(rest) > 0 {
+		return errors.New("bus [upgrade --why … --reversible|--irreversible [--snapshot-taken <where>]]")
+	}
+	switch sub {
+	case "":
+		return busStatus(ctx)
+	case "upgrade":
+	default:
+		return fmt.Errorf("bus says what a bus upgrade would do, or `bus upgrade` — not %q", sub)
+	}
+	// Everything refused before anything is done.
+	if err := why.require("bus upgrade"); err != nil {
+		return err
+	}
+	if *reversible == *irreversible {
+		return errors.New("bus upgrade says, before it starts, whether the new version can be undone by putting the " +
+			"old one back: --reversible, or --irreversible as your explicit word that it runs anyway (to-be 45 §8). " +
+			"Nothing was done")
+	}
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	inv := open.inventory
+	b, err := pendingBus(ctx, inv)
+	if err != nil {
+		return err
+	}
+	if b.module == "" {
+		return errors.New("the mesh holds no module that provides its bus: there is nothing to upgrade")
+	}
+	var moving []string
+	for _, n := range b.machines {
+		if b.moves(n) {
+			moving = append(moving, n)
+		}
+	}
+	if len(moving) == 0 {
+		fmt.Printf("every machine running %s runs the build the mesh holds (%s): nothing to upgrade\n", b.module, short(b.to))
+		return nil
+	}
+	where := strings.TrimSpace(*snapshot)
+	if where == "" {
+		for _, n := range moving {
+			fmt.Printf("snapshotting the bus's streams on %s first (its backup holder, ADR 0235)…\n", n)
+			if where, err = takeBusSnapshot(ctx, b.module, n); err != nil {
+				return fmt.Errorf("the streams could not be snapshotted, so the bus is not replaced: %w — a snapshot "+
+					"taken by hand is said with --snapshot-taken <where>", err)
+			}
+		}
+	}
+	from := map[string]bool{}
+	for _, n := range moving {
+		from[orNotKnown(b.from[n])] = true
+	}
+	step, err := inv.StartBusStep(ctx, inventory.BusStep{Module: b.module, Machines: moving,
+		From: strings.Join(sortedKeys(from), ", "), To: b.to, Snapshot: where, Reversible: *reversible,
+		By: link.Caller(), Why: strings.TrimSpace(*why.why)})
+	if err != nil {
+		return err
+	}
+	cause := "bus-upgrade"
+	if strings.TrimSpace(*why.cause) == "" {
+		why.cause = &cause
+	}
+	why.record(ctx, "bus upgrade", append([]string{b.module}, moving...))
+	fmt.Printf("bus upgrade %d: %s %s → %s on %s; streams snapshotted at %s; %s\n", step.ID, b.module, step.From,
+		short(b.to), strings.Join(moving, ", "), where, map[bool]string{true: "reversible: putting the old build back undoes it",
+			false: "NOT reversible: the snapshot is the only way back"}[*reversible])
+	sent, err := sendRollout(withBusStep(withScope(ctx, sendScope{person: true})), open, moving)
+	if err != nil {
+		_ = inv.EndBusStep(ctx, step.ID, "failed", "the send was refused: "+err.Error())
+		return fmt.Errorf("the bus's machine could not be sent its new build: %w — nothing was replaced", err)
+	}
+	fmt.Printf("sent %s; `bus-maintenance` is open until the bus answers healthy again — every stream, every durable "+
+		"consumer, a round trip to the machines (H-bus) — within %s, or the step is said failed with its snapshot "+
+		"as the way back. `bus` says how it went\n", strings.Join(sent, ", "), busStepBound)
+	return nil
+}
+
+// busStatus is `bus`: what an upgrade would do, and the last step.
+func busStatus(ctx context.Context) error {
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	b, err := pendingBus(ctx, open.inventory)
+	if err != nil {
+		return err
+	}
+	if b.module == "" {
+		fmt.Println("the mesh holds no module that provides its bus")
+	} else {
+		fmt.Printf("the bus is %s, built %s, on %s; never rolled out — a planned step (`bus upgrade`)\n", b.module,
+			short(b.to), orNone(strings.Join(b.machines, ", ")))
+		for _, n := range b.machines {
+			state := "runs it"
+			if b.moves(n) {
+				state = "runs " + short(orNotKnown(b.from[n])) + ": `bus upgrade` replaces it"
+			}
+			fmt.Printf("  %-10s %s\n", n, state)
+		}
+	}
+	fmt.Println("  `bus upgrade` has the bus machine's backup holder snapshot the streams first (ADR 0235)")
+	s, found, err := open.inventory.LatestBusStep(ctx)
+	if err != nil || !found {
+		return err
+	}
+	state := "running since " + s.Started.Local().Format("2006-01-02 15:04")
+	if s.Ended != nil {
+		state = s.Outcome + " at " + s.Ended.Local().Format("2006-01-02 15:04")
+	}
+	fmt.Printf("last step %d: %s → %s on %s by %s (%s): %s; snapshot %s\n", s.ID, s.From, short(s.To),
+		strings.Join(s.Machines, ", "), orNone(s.By), s.Why, state, s.Snapshot)
+	if s.Found != "" {
+		fmt.Printf("  %s\n", s.Found)
+	}
+	return nil
+}
+
+// probeBusStep is DB: a bus upgrade running is said as `bus-maintenance`; the bus healthy again after
+// the machines reported the new build ends it done; past its bound, unhealthy, it ends failed and is
+// said — urgent, with its snapshot — while the bus is still not healthy.
+func probeBusStep(ctx context.Context, d *doctor) ([]conditions.Observation, error) {
+	inv := d.open.inventory
+	s, found, err := inv.LatestBusStep(ctx)
+	if err != nil || !found {
+		return nil, err
+	}
+	if s.Ended != nil && s.Outcome != "failed" {
+		return nil, nil
+	}
+	problems, err := busHealth(ctx, d)
+	if err != nil {
+		return nil, err
+	}
+	reports, err := inv.LastReports(ctx)
+	if err != nil {
+		return nil, err
+	}
+	applied := true
+	for _, r := range reports {
+		for _, n := range s.Machines {
+			if r.Node == n && (!r.Current || r.Outcome != inventory.OutcomeApplied || r.At == nil || r.At.Before(s.Started)) {
+				applied = false
+				problems = append(problems, n+" has not reported the new bus applied")
+			}
+		}
+	}
+	id := s.Module
+	if s.Ended == nil {
+		switch {
+		case applied && len(problems) == 0:
+			return nil, inv.EndBusStep(ctx, s.ID, "done", "the bus answered healthy after the upgrade")
+		case time.Since(s.Started) > busStepBound:
+			found := strings.Join(problems, "; ")
+			if err := inv.EndBusStep(ctx, s.ID, "failed", found); err != nil {
+				return nil, err
+			}
+			s.Found = found
+		default:
+			return []conditions.Observation{{Scope: conditions.ScopeBus, ID: id, Token: "maintenance",
+				Kind: kindBusMaintenance, Severity: conditions.Warning,
+				Summary: fmt.Sprintf("the bus is being upgraded (step %d, %s → %s on %s, by %s: %s); its snapshot is %s",
+					s.ID, s.From, short(s.To), strings.Join(s.Machines, ", "), orNone(s.By), s.Why, s.Snapshot),
+				Said: orNone(strings.Join(problems, "; "))}}, nil
+		}
+	}
+	if len(problems) == 0 {
+		return nil, nil // failed, and healthy since: nothing wrong now
+	}
+	way := "put the old build back"
+	if !s.Reversible {
+		way = "restore the snapshot"
+	}
+	return []conditions.Observation{{Scope: conditions.ScopeBus, ID: id, Token: "upgrade-failed",
+		Kind: kindBusUpgradeFailed, Severity: conditions.Urgent, Resolver: conditions.ResolverOperator,
+		Summary: fmt.Sprintf("the bus upgrade (step %d, %s → %s) did not end healthy within %s: %s — the way back is to %s (%s)",
+			s.ID, s.From, short(s.To), busStepBound, strings.Join(problems, "; "), way, s.Snapshot)}}, nil
+}
+
+func sortedKeys(set map[string]bool) []string {
+	out := make([]string, 0, len(set))
+	for k := range set {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// busSnapshotWithin is how long the bus machine's backup holder is given to take the bus's snapshot.
+var busSnapshotWithin = 15 * time.Minute
+
+// snapshotTheBusNow asks the bus machine's backup holder to back the bus module up now — its dump is
+// the streams' snapshot (novox/hq ADR 0235) — and waits until it says a backup newer than the ask:
+// where the snapshot is, as a person reads it. The serving controller's connection, or one of its own.
+func snapshotTheBusNow(ctx context.Context, module, node string) (string, error) {
+	var where string
+	err := onTheBus(func(conn *nats.Conn) error {
+		asked := time.Now()
+		answer, err := link.AskSeatTool(ctx, conn, catalogue.BackupSeat, "now", node,
+			map[string]any{"module": module}, 30*time.Second)
+		if err != nil {
+			return fmt.Errorf("%s's backup holder was not asked to take the bus's snapshot: %w", node, err)
+		}
+		if answer.Error != "" {
+			return fmt.Errorf("%s's backup holder would not take the bus's snapshot: %s", node, answer.Error)
+		}
+		deadline := time.Now().Add(busSnapshotWithin)
+		for {
+			answer, err := link.AskSeatTool(ctx, conn, catalogue.BackupSeat, "backed-up", node, map[string]any{}, 10*time.Second)
+			if err == nil && answer.Error == "" {
+				if measured, err := readHolder(answer.Result); err == nil {
+					for item, m := range measured[module] {
+						if m.LastBackup != nil && m.LastBackup.After(asked) && m.Error == "" {
+							where = fmt.Sprintf("%s's restore point of %s (%s) taken %s", node, module, item,
+								m.LastBackup.UTC().Format(time.RFC3339))
+							return nil
+						}
+					}
+				}
+			}
+			if time.Now().After(deadline) {
+				return fmt.Errorf("%s's backup holder did not say the bus's snapshot was taken within %s; the bus is "+
+					"not replaced", node, busSnapshotWithin)
+			}
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-time.After(10 * time.Second):
+			}
+		}
+	})
+	return where, err
+}
+
+// errBusWaits is a send refused because it would replace the bus outside its planned step.
+var errBusWaits = errors.New("a new bus build waits for its planned step")
+
+type busStepKey struct{}
+
+// withBusStep marks a send as the bus's planned step: the one send that may replace the bus.
+func withBusStep(ctx context.Context) context.Context {
+	return context.WithValue(ctx, busStepKey{}, true)
+}
+
+func busStepSending(ctx context.Context) bool { on, _ := ctx.Value(busStepKey{}).(bool); return on }

cmd/mesh-controller/bus_users_closed_test.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **Every user's slow consumer is S9's, not the controller's alone** (novox/hq ADR 0357, issue 270). On
+// 2026-10-07 the bus closed two clients on the laptop as slow consumers and nothing raised a condition:
+// the controller heard only its own connection. Said by the bus module and read back, a user the bus
+// closes is one condition naming the module and its machine, raised at the first look and cleared an hour
+// after the last closure.
+func TestAUserTheBusClosedAsASlowConsumerIsOneConditionNamingItsModuleAndMachine(t *testing.T) {
+	closed := time.Date(2026, 10, 14, 12, 0, 0, 0, time.UTC)
+	now := closed.Add(20 * time.Second)
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return now }})
+	t.Cleanup(func() { k.Close(t.Context()) })
+
+	advisories := link.BusClosures([]link.BusClosure{
+		{User: "laptop.claude-code", CID: 10, Reason: "Slow Consumer (Write Deadline)", Opened: closed.Add(-time.Hour),
+			Closed: closed.Add(-10 * time.Minute)},
+		{User: "laptop.claude-code", CID: 44, Reason: "Slow Consumer (Write Deadline)", Opened: closed.Add(-time.Minute),
+			Closed: closed},
+		{User: "anchor.desk", CID: 7, Reason: "Maximum Message Payload Exceeded", Opened: closed.Add(-time.Hour),
+			Closed: closed},
+	}, []string{link.AdvisorySlowConsumer, link.AdvisorySlowConsumer, link.AdvisoryConnectionClosed}, closed.Add(-time.Hour))
+	look := func() {
+		t.Helper()
+		f := &signalFacts{now: now, host: "anchor", advisories: advisories}
+		if err := k.Reconcile(t.Context(), "S9", watchAdvisories(f)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	look()
+
+	slow, found, err := conditions.ReadOne(t.Context(), store, "bus.laptop.claude-code.slow-consumer")
+	if err != nil || !found {
+		t.Fatalf("no slow-consumer condition for the user: %v %v", found, err)
+	}
+	if slow.Subject.Machine != "laptop" || slow.Observations != 2 || !slow.LastObserved.Equal(closed) {
+		t.Fatalf("the slow consumer is said on %q, %d closure(s), last %s: %+v", slow.Subject.Machine, slow.Observations,
+			slow.LastObserved, slow)
+	}
+	if !strings.Contains(slow.Summary, "claude-code on laptop") || strings.Contains(slow.Summary, "laptop.claude-code") {
+		t.Fatalf("the summary does not name the module in words, or carries the dotted user: %q", slow.Summary)
+	}
+	if !strings.Contains(slow.Headline, "Claude-code on laptop") {
+		t.Fatalf("the headline is %q", slow.Headline)
+	}
+	cut, found, err := conditions.ReadOne(t.Context(), store, "bus.anchor.desk.connection-closed")
+	if err != nil || !found || cut.Subject.Machine != "anchor" || !strings.Contains(cut.Summary, "maximum message payload exceeded") {
+		t.Fatalf("the user cut off for breaking the bus's rules: %v %v %+v", found, err, cut)
+	}
+
+	// An hour after the newest closure without another, both clear.
+	now = closed.Add(time.Hour + time.Minute)
+	look()
+	for _, key := range []string{"bus.laptop.claude-code.slow-consumer", "bus.anchor.desk.connection-closed"} {
+		if _, found, _ := k.Get(t.Context(), key); found {
+			t.Fatalf("%s is still open an hour after the last closure", key)
+		}
+	}
+}
+
+// **A read of the bus module's events that fails does not blind S9** (review of #326): the controller's own
+// signals are still said, and the failed read is a condition of its own.
+func TestABusModuleReadThatFailsKeepsTheControllersOwnSignals(t *testing.T) {
+	at := time.Date(2026, 10, 14, 12, 0, 0, 0, time.UTC)
+	f := &signalFacts{now: at.Add(time.Minute), host: "anchor",
+		advisories: []link.Advisory{{Kind: link.AdvisorySlowConsumer, ID: "controller", Said: "the controller fell behind",
+			First: at, Last: at, Count: 1}},
+		busFaultsErr: errors.New("nats: timeout")}
+	keys := map[string]bool{}
+	for _, o := range watchAdvisories(f) {
+		keys[o.Key()] = true
+	}
+	if !keys["bus.controller.slow-consumer"] || !keys["bus.bus-module.bus-faults-unread"] {
+		t.Fatalf("observed %v: the controller's own slow consumer and the unread events, both", keys)
+	}
+	for _, row := range signalsTable {
+		if row.Row == "S9" && row.needs(f) != nil {
+			t.Fatal("the S9 row went blind for a read of the bus module's events")
+		}
+	}
+}

cmd/mesh-controller/bus_waits.go

@@ -0,0 +1,195 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A send held for the bus's planned step (novox/hq issue 336).
+//
+// **A wait only a person can end is said to that person at once.** No send replaces the bus but its planned
+// step (sendToEach, ADR 0236), and the step is a person's `bus upgrade`. So while a new bus build waits, every
+// walk whose tier sends to the bus's machine is refused, and tries again each tick. The refusal was kept only
+// as the walk's note; nothing was raised, and the operator found the hold by asking why a walk did not move.
+// Row S17 raises it on the first tick after the first refusal, in the bus's scope, for the operator: what
+// waits, behind which bus build, since when, and the verb. A walk held only by it is not late, so S3 leaves it
+// out, as it leaves out a walk under a paused build seat. It clears once the bus's machine has been sent the
+// build the mesh holds — the step was taken, and no send is refused for the bus any more — whatever the walks'
+// notes still say. Whether the new bus came up healthy is the step's own condition (probe DB).
+
+// kindBusStepWaiting is S17's kind: bus.<module>.step-waiting.
+const kindBusStepWaiting = "bus-step-waiting"
+
+// busFacts is a new bus build waiting for its planned step, and the sends held for it.
+type busFacts struct {
+	module, to string
+	// from is the build each machine of the bus runs; machines those whose bus the step would replace.
+	from     map[string]string
+	machines []string
+	waits    []busWaitFacts
+}
+
+// busWaitFacts is one walk whose send was refused because it would replace the bus.
+type busWaitFacts struct {
+	plan, repository, commit string
+	// modules are what its tier sends: what waits.
+	modules []string
+	// since is the first refusal: as this controller saw it, or, read back, the save that kept the refusal.
+	since time.Time
+}
+
+// busRefusedFirst is when this controller first saw each walk refused for the bus's step. The walk's note
+// keeps the refusal across a restart; this keeps its moment more exactly than the walk's last save.
+var busRefusedFirst = &firstSeen{at: map[string]time.Time{}}
+
+type firstSeen struct {
+	mu sync.Mutex
+	at map[string]time.Time
+}
+
+// mark keeps the first moment an id was seen.
+func (s *firstSeen) mark(id string, at time.Time) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if _, seen := s.at[id]; !seen {
+		s.at[id] = at
+	}
+}
+
+// of is when an id was first seen; zero when it was not.
+func (s *firstSeen) of(id string) time.Time {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.at[id]
+}
+
+// keepOnly forgets every id not given: a walk no longer held is not held since then.
+func (s *firstSeen) keepOnly(ids map[string]bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for id := range s.at {
+		if !ids[id] {
+			delete(s.at, id)
+		}
+	}
+}
+
+// refusedForTheBus is whether an error is the refusal of a send for the bus's planned step.
+func refusedForTheBus(err error) bool {
+	return err != nil && strings.Contains(err.Error(), errBusWaits.Error())
+}
+
+// busWaitsOf is the sends held for the bus's step, from the open walks: each walk not waiting for its
+// delivery's word whose note keeps a refusal for this very bus build, while the build would still replace
+// the bus on a machine. first is when this controller first saw a walk refused, zero when it did not.
+func busWaitsOf(plans []inventory.Plan, b busPending, first func(string) time.Time) busFacts {
+	f := busFacts{module: b.module, to: b.to, from: b.from}
+	for _, n := range b.machines {
+		if b.moves(n) {
+			f.machines = append(f.machines, n)
+		}
+	}
+	if len(f.machines) == 0 {
+		return f
+	}
+	for _, p := range plans {
+		if !p.Open() || p.Waiting() || !strings.Contains(p.Note, errBusWaits.Error()) || !strings.Contains(p.Note, short(b.to)) {
+			continue
+		}
+		since := p.Updated
+		if seen := first(p.ID); !seen.IsZero() && (since.IsZero() || seen.Before(since)) {
+			since = seen
+		}
+		var modules []string
+		if p.Tier >= 0 && p.Tier < len(p.Tiers) {
+			modules = append(modules, p.Tiers[p.Tier]...)
+		} else {
+			modules = planModules(p)
+		}
+		sort.Strings(modules)
+		f.waits = append(f.waits, busWaitFacts{plan: p.ID, repository: p.Repository, commit: p.Commit, modules: modules,
+			since: since})
+	}
+	sort.Slice(f.waits, func(i, j int) bool { return f.waits[i].since.Before(f.waits[j].since) })
+	return f
+}
+
+// heldByTheBus is the walks of a bus's facts, by id: what S3 leaves out.
+func (b busFacts) heldByTheBus() map[string]bool {
+	out := map[string]bool{}
+	for _, w := range b.waits {
+		out[w.plan] = true
+	}
+	return out
+}
+
+// busUpgradeVerb is the call that ends the wait, as the summary names it: through the mesh MCP server, with
+// why, saying whether the new version can be undone ("reversible": "true") or not ("irreversible": "true").
+const busUpgradeVerb = "`mesh_call mesh-controller.bus {\"upgrade\": \"true\", \"why\": \"…\", \"reversible\" or \"irreversible\": \"true\"}`"
+
+// watchBusWaits is S17: a send held for the bus's planned step, said at once to the operator.
+func watchBusWaits(f *signalFacts) []conditions.Observation {
+	b := f.bus
+	if len(b.waits) == 0 || len(b.machines) == 0 {
+		return nil
+	}
+	since := b.waits[0].since
+	var walks, what []string
+	for _, w := range b.waits {
+		walks = append(walks, fmt.Sprintf("%s (%s %s, tier: %s)", w.plan, w.repository, short(w.commit),
+			strings.Join(w.modules, ", ")))
+		what = append(what, deliveryWhat(w.modules, w.repository))
+	}
+	var from []string
+	for _, n := range b.machines {
+		from = append(from, short(orNotKnown(b.from[n])))
+	}
+	machines := namesWords(b.machines, 3)
+	in := f.now.Sub(since)
+	return []conditions.Observation{{Scope: conditions.ScopeBus, ID: b.module, Token: "step-waiting",
+		Kind: kindBusStepWaiting, Severity: conditions.Warning, Resolver: conditions.ResolverOperator,
+		Machine: b.machines[0], Also: b.machines[1:],
+		Summary: fmt.Sprintf("sends to %s wait for the bus's planned step: a new bus build (%s %s → %s) would replace "+
+			"the bus there, which only a person's %s does; waiting since %s: %s", strings.Join(b.machines, ", "),
+			b.module, strings.Join(sortedUnique(from), ", "), short(b.to), busUpgradeVerb,
+			since.UTC().Format(time.RFC3339), strings.Join(walks, "; ")),
+		Said:     fmt.Sprintf("%d walk(s) refused since %s", len(b.waits), since.UTC().Format(time.RFC3339)),
+		Headline: clipWords("Sends to "+machines+" wait for a bus upgrade", conditions.HeadlineMax),
+		Explanation: clipWords(fmt.Sprintf("A new version of the mesh's message system is built, and only a person "+
+			"installs it. Until then nothing else is sent to %s: %s waits, for %s so far.", machines,
+			namesWords(sortedUnique(what), 3), humanDuration(in)), conditions.ExplanationMax),
+		Needs:    "start the bus upgrade " + FromMeshMCPServer,
+		Resolved: "Resolved: the bus upgrade started, and sends go on"}}
+}
+
+// sortedUnique is a list sorted, each once.
+func sortedUnique(xs []string) []string {
+	seen := map[string]bool{}
+	var out []string
+	for _, x := range xs {
+		if !seen[x] {
+			seen[x] = true
+			out = append(out, x)
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+// clipWords keeps a plain sentence within a bound, at a word.
+func clipWords(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	cut := strings.LastIndex(s[:n-1], " ")
+	if cut <= 0 {
+		cut = n - 1
+	}
+	return s[:cut] + "…"
+}

cmd/mesh-controller/bus_waits_integration_test.go

@@ -0,0 +1,70 @@
+//go:build integration
+
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+func TestASendHeldForTheBusStepIsFoundFromTheWalksItHolds(t *testing.T) {
+	now := time.Date(2026, 10, 8, 18, 30, 0, 0, time.UTC)
+	b := aBusOnAnchor()
+	walk := func(id, repo, note string, updated time.Time) inventory.Plan {
+		return inventory.Plan{ID: id, Repository: repo, Commit: "c0ffee001122", State: inventory.PlanRolling, Tier: 0,
+			Tiers: [][]string{{"mesh-host"}}, Modules: map[string]*inventory.PlanModule{"mesh-host": {}}, Note: note,
+			Updated: updated}
+	}
+	for _, c := range []struct {
+		name  string
+		bus   busPending
+		plans []inventory.Plan
+		first map[string]time.Time
+		want  []string
+		since time.Time
+	}{
+		{"a walk refused for the bus", b,
+			[]inventory.Plan{walk("plan-1", "novox/mesh-host", refusedNote(b, 0), now.Add(-27*time.Minute))}, nil,
+			[]string{"plan-1"}, now.Add(-27 * time.Minute)},
+		{"refused earlier than its last save, as this controller saw it", b,
+			[]inventory.Plan{walk("plan-1", "novox/mesh-host", refusedNote(b, 0), now.Add(-5*time.Minute))},
+			map[string]time.Time{"plan-1": now.Add(-28 * time.Minute)}, []string{"plan-1"}, now.Add(-28 * time.Minute)},
+		{"a walk refused for another reason", b,
+			[]inventory.Plan{walk("plan-1", "novox/mesh-host", "tier 0: the build seat is paused — tried again", now)}, nil,
+			nil, time.Time{}},
+		{"refused for an older bus build than the one held now", func() busPending { o := b; o.to = "99999999cccc"; return o }(),
+			[]inventory.Plan{walk("plan-1", "novox/mesh-host", refusedNote(b, 0), now)}, nil, nil, time.Time{}},
+		{"the bus already runs the build held: its step started", func() busPending {
+			o := aBusOnAnchor()
+			o.from = map[string]string{"anchor": o.to}
+			return o
+		}(), []inventory.Plan{walk("plan-1", "novox/mesh-host", refusedNote(b, 0), now)}, nil, nil, time.Time{}},
+		{"a walk waiting for its delivery's word asks no send", b, func() []inventory.Plan {
+			p := walk("plan-1", "novox/mesh-host", refusedNote(b, 0), now)
+			p.Delivery = &inventory.PlanDelivery{Awaits: "mesh-delivery"}
+			return []inventory.Plan{p}
+		}(), nil, nil, time.Time{}},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			got := busWaitsOf(c.plans, c.bus, func(id string) time.Time { return c.first[id] })
+			var ids []string
+			for _, w := range got.waits {
+				ids = append(ids, w.plan)
+			}
+			if strings.Join(ids, ",") != strings.Join(c.want, ",") {
+				t.Fatalf("held for the bus: %v, want %v", ids, c.want)
+			}
+			if len(c.want) > 0 {
+				if !got.waits[0].since.Equal(c.since) {
+					t.Errorf("waiting since %s, want %s", got.waits[0].since, c.since)
+				}
+				if strings.Join(got.machines, ",") != "anchor" || got.to != b.to || got.module != "nats" {
+					t.Errorf("behind %+v", got)
+				}
+			}
+		})
+	}
+}

cmd/mesh-controller/bus_waits_test.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// novox/hq issue 336: a send held because it would replace the bus outside its planned step waits for a
+// person, so a person is told at once — what waits, behind which bus build, since when, and the verb that
+// ends it — and the wait is not read as a walk running late.
+
+// aBusOnAnchor is a new bus build waiting for its step on anchor: nats 88135ad0 there, 32307bd1 held.
+func aBusOnAnchor() busPending {
+	return busPending{module: "nats", machines: []string{"anchor"}, from: map[string]string{"anchor": "88135ad0aaaa"},
+		to: "32307bd1bbbb", same: map[string]bool{}}
+}
+
+// refusedNote is the note a walk keeps when its send was refused for the bus, as advanceHeld writes it.
+func refusedNote(b busPending, tier int) string {
+	held := "sending anchor would replace the bus (nats " + short(b.from["anchor"]) + " → " + short(b.to) +
+		"), which is a planned step: `bus upgrade --why …` snapshots its streams first and checks them after (novox/hq ADR 0236)"
+	return "tier " + string(rune('0'+tier)) + ": " + errBusWaits.Error() + ": " + held + " — tried again"
+}
+
+// **Said at once, not as lateness, and cleared when the step starts**: the walk held only for the bus raises
+// the bus's condition on the first tick, before any tier bound, naming what waits, the bus build from and to,
+// since when and `bus upgrade`, for the operator; S3 says nothing of it even past its bound; and the
+// condition clears once the bus's machine runs the new build.
+func TestASendHeldForTheBusStepIsSaidAtOnceAndNotAsLateness(t *testing.T) {
+	now := time.Date(2026, 10, 8, 18, 30, 0, 0, time.UTC)
+	b := aBusOnAnchor()
+	held := func(entered time.Duration) *signalFacts {
+		f := calm(now)
+		f.plans = []planFacts{{id: "plan-1", repository: "novox/mesh-host", commit: "c0ffee00", tier: 0, tiers: 1,
+			entered: now.Add(-entered), bound: 30 * time.Minute, waiting: refusedNote(b, 0), bus: true}}
+		f.bus = busFacts{module: "nats", to: b.to, from: b.from, machines: []string{"anchor"},
+			waits: []busWaitFacts{{plan: "plan-1", repository: "novox/mesh-host", commit: "c0ffee001122",
+				modules: []string{"mesh-host"}, since: now.Add(-time.Minute)}}}
+		return f
+	}
+
+	f := held(time.Minute)
+	got := watchBusWaits(f)
+	if len(got) != 1 {
+		t.Fatalf("a send held for the bus a minute ago raised %+v", got)
+	}
+	o := got[0]
+	if o.Key() != "bus.nats.step-waiting" || o.Kind != kindBusStepWaiting || o.Resolver != conditions.ResolverOperator {
+		t.Fatalf("raised %s (%s), resolver %q", o.Key(), o.Kind, o.Resolver)
+	}
+	for _, want := range []string{"anchor", "mesh-host", "88135ad0", "32307bd1", "mesh_call mesh-controller.bus",
+		`"upgrade": "true"`, `"reversible"`, `"irreversible"`, "2026-10-08T18:29:00Z", "plan-1"} {
+		if !strings.Contains(o.Summary, want) {
+			t.Errorf("its summary does not say %q: %s", want, o.Summary)
+		}
+	}
+	if !strings.Contains(o.Explanation, "mesh-host") || !strings.Contains(o.Headline, "bus upgrade") || o.Needs == "" {
+		t.Errorf("its words do not say what waits and what the operator does: %+v", o)
+	}
+	if why, ok := conditions.PlainWords(conditions.Words{Headline: o.Headline, Explanation: o.Explanation,
+		Resolved: o.Resolved, Needs: o.Needs}, "anchor"); !ok {
+		t.Errorf("its words are not plain: %s", why)
+	}
+
+	// Past S3's bound: still the bus's wait, never a stalled walk.
+	late := held(45 * time.Minute)
+	if s3 := watchPlans(late); len(s3) != 0 {
+		t.Fatalf("a walk held only by the bus step was said stalled: %+v", s3)
+	}
+	// A walk held for something else past its bound is still stalled.
+	other := held(45 * time.Minute)
+	other.plans[0].bus = false
+	if s3 := watchPlans(other); len(s3) != 1 {
+		t.Fatalf("a walk held for something else past its bound raised %+v", s3)
+	}
+
+	// Through the keeper: open at the first tick, cleared when the step started.
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store, Teller: &conditions.Told{},
+		Now: func() time.Time { return now }})
+	defer k.Close(context.Background())
+	w := &watchdogs{keeper: k, started: now.Add(-time.Hour)}
+	w.see(t.Context(), held(time.Minute))
+	open, err := k.Open(t.Context())
+	if err != nil || len(open) != 1 || open[0].Key != "bus.nats.step-waiting" {
+		t.Fatalf("after the first tick, open: %+v (%v)", open, err)
+	}
+	started := held(time.Minute)
+	started.bus = busFacts{module: "nats", to: b.to}
+	started.plans[0].bus = false
+	w.see(t.Context(), started)
+	if open, _ := k.Open(t.Context()); len(open) != 0 {
+		t.Fatalf("the step started, and open: %+v", open)
+	}
+}

cmd/mesh-controller/buscertificate.go

@@ -0,0 +1,258 @@
+package main
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"math/big"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/broker"
+)
+
+// The bus's own certificate, made by the mesh rather than borrowed from an image.
+//
+// **The foundation asked a third-party image for a tool it never said must be there** (novox/hq
+// 04-ISSUES/146). The bootstrap made this certificate by running `openssl` inside the broker's
+// image, which worked while the broker was one that happened to carry it and stopped the day the
+// bus changed: the new one has a shell and no openssl, so the step exited 127 and no mesh could be
+// raised. Substituting another image the bundle names does not help — none of them carry it
+// either.
+//
+// So the program that needs a certificate makes one. It is the mesh's own binary, already on the
+// machine at this point in the bootstrap (the schema step ran it), and it needs nothing from the
+// image it writes into but a mounted directory.
+//
+// **Self-signed, and that is the design** — a host pins this server's exact certificate and
+// authenticates with a password (novox/hq ADR 0004). There is no authority above it to ask, and at
+// this moment in a bootstrap there is no mesh to ask one of.
+//
+// Idempotent, because the step is applied again on every reconcile and a second certificate would
+// be one the hosts that pinned the first no longer believe.
+
+// busCertificateNames is what the bus is reached by: the container name on a mesh network, and the
+// loopback address the machine's own foundation dials.
+var busCertificateNames = []string{"mesh-broker"}
+
+const busCertificateLife = 10 * 365 * 24 * time.Hour
+
+// busCertificate makes the bus's certificate in a directory, or says whether one is there.
+//
+//	broker certificate --into /tls           make it if it is not there
+//	broker certificate --check --into /tls   exit non-zero unless a usable pair is
+func busCertificate(args []string) error {
+	into, check := "", false
+	for i := 0; i < len(args); i++ {
+		switch args[i] {
+		case "--check":
+			check = true
+		case "--into":
+			if i+1 >= len(args) {
+				return errors.New("--into needs a directory")
+			}
+			into = args[i+1]
+			i++
+		default:
+			return fmt.Errorf("broker certificate [--check] --into <directory>: %q", args[i])
+		}
+	}
+	if into == "" {
+		return errors.New("broker certificate [--check] --into <directory>")
+	}
+	crt, key := filepath.Join(into, "tls.crt"), filepath.Join(into, "tls.key")
+
+	if usable, err := busCertificateUsable(crt, key); err != nil {
+		return err
+	} else if usable {
+		fmt.Printf("the bus already has a certificate at %s, and it was left alone\n", crt)
+		return nil
+	}
+	if check {
+		// Said as a failure, because that is what the caller asked: a bootstrap's verify runs
+		// this and a false answer is what makes the step run.
+		return fmt.Errorf("no usable certificate and key at %s", into)
+	}
+	return writeBusCertificate(crt, key)
+}
+
+// busCertificateUsable says whether a certificate and its key are both there and parse.
+//
+// Both, and parsed rather than stat'ed: a half-written pair is the state a bootstrap interrupted
+// between the two files leaves behind, and a step that treated it as done would hand the server a
+// certificate with no key and report success.
+func busCertificateUsable(crt, key string) (bool, error) {
+	certPEM, err := os.ReadFile(crt)
+	if errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	keyPEM, err := os.ReadFile(key)
+	if errors.Is(err, os.ErrNotExist) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	if _, err := tlsPairParses(certPEM, keyPEM); err != nil {
+		return false, nil
+	}
+	return true, nil
+}
+
+func tlsPairParses(certPEM, keyPEM []byte) (*x509.Certificate, error) {
+	block, _ := pem.Decode(certPEM)
+	if block == nil || block.Type != "CERTIFICATE" {
+		return nil, errors.New("not a certificate")
+	}
+	certificate, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		return nil, err
+	}
+	keyBlock, _ := pem.Decode(keyPEM)
+	if keyBlock == nil {
+		return nil, errors.New("not a key")
+	}
+	if _, err := x509.ParsePKCS8PrivateKey(keyBlock.Bytes); err != nil {
+		if _, err := x509.ParsePKCS1PrivateKey(keyBlock.Bytes); err != nil {
+			return nil, err
+		}
+	}
+	return certificate, nil
+}
+
+func writeBusCertificate(crt, key string) error {
+	private, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return err
+	}
+	serial, err := rand.Int(rand.Reader, new(big.Int).Lsh(big.NewInt(1), 128))
+	if err != nil {
+		return err
+	}
+	template := &x509.Certificate{
+		SerialNumber:          serial,
+		Subject:               pkix.Name{CommonName: busCertificateNames[0]},
+		DNSNames:              busCertificateNames,
+		IPAddresses:           []net.IP{net.ParseIP("127.0.0.1")},
+		NotBefore:             time.Now().Add(-time.Hour),
+		NotAfter:              time.Now().Add(busCertificateLife),
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+	}
+	der, err := x509.CreateCertificate(rand.Reader, template, template, &private.PublicKey, private)
+	if err != nil {
+		return err
+	}
+	pkcs8, err := x509.MarshalPKCS8PrivateKey(private)
+	if err != nil {
+		return err
+	}
+
+	// **The key first, and only then the certificate**, so the pair a reader finds is never a
+	// certificate whose key has not been written yet — the one order in which an interruption
+	// leaves something that looks finished (novox/hq 04-ISSUES/014, a key present and unusable).
+	if err := os.WriteFile(key, pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: pkcs8}), 0o600); err != nil {
+		return err
+	}
+	if err := os.WriteFile(crt, pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der}), 0o644); err != nil {
+		return err
+	}
+	fmt.Printf("made the bus a certificate for %v, valid until %s\n  %s\n  %s\n",
+		busCertificateNames, template.NotAfter.Format(time.RFC3339), crt, key)
+	return nil
+}
+
+// busAccounts writes the mesh's composed user list to a file.
+//
+// **For genesis, where no declaration can deliver it** (novox/hq 04-ISSUES/146). Everywhere else
+// the list reaches the machine running the bus as a resource of the module that holds it — which
+// requires that machine to be an enrolled node, and at genesis it is not: the first node cannot
+// enrol because the account it would enrol with cannot be composed onto a bus it has no declaration
+// for. The installer breaks that circle by placing the file itself, once, and the module takes the
+// file over from its first push.
+//
+// The same composition, not a second one: this asks the store for the same records and renders them
+// with the same composer the declaration uses. A genesis that hand-wrote an account would be a
+// second statement of who may say what, able to disagree with the first.
+//
+// **It writes to standard output unless told a file**, and that is the point: the control plane
+// composes and says what it composed, and whoever is raising the machine puts it where that
+// machine's bus reads it. A control plane that wrote into the bus's own directory would have to
+// know where that is and how to make the server re-read it — which is the module's knowledge, and
+// the module is what takes this over on the first push.
+//
+//	broker accounts > /var/lib/mesh-bus-conf/accounts.conf
+func busAccounts(ctx context.Context, args []string) error {
+	into := ""
+	for i := 0; i < len(args); i++ {
+		switch args[i] {
+		case "--into":
+			if i+1 >= len(args) {
+				return errors.New("--into needs a file")
+			}
+			into = args[i+1]
+			i++
+		default:
+			return fmt.Errorf("broker accounts --into <file>: %q", args[i])
+		}
+	}
+
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+
+	records, err := open.inventory.BusRecords(ctx)
+	if err != nil {
+		return err
+	}
+	users, err := broker.Users(records)
+	if err != nil {
+		return err
+	}
+	kept, err := open.inventory.BusUsers(ctx)
+	if err != nil {
+		return err
+	}
+	hashes := make(map[string]string, len(kept))
+	for name, u := range kept {
+		hashes[name] = u.PasswordHash
+	}
+	filled, missing := broker.WithPasswords(users, hashes)
+	if len(missing) > 0 {
+		// To standard error, always: the composed file may be going to standard output, and a
+		// remark in the middle of it is a configuration the server refuses to parse.
+		fmt.Fprintf(os.Stderr, "leaving out %d user(s) the mesh has minted no credential for: %s\n",
+			len(missing), strings.Join(missing, ", "))
+	}
+	if len(filled) == 0 {
+		return errors.New("not one user has a credential, so this list would refuse every " +
+			"connection in the mesh")
+	}
+	accounts, err := broker.ComposeAccounts(filled)
+	if err != nil {
+		return err
+	}
+	if into == "" {
+		fmt.Print(accounts)
+		return nil
+	}
+	if err := os.WriteFile(into, []byte(accounts), 0o600); err != nil {
+		return err
+	}
+	fmt.Printf("wrote %d user(s) to %s\n", len(filled), into)
+	return nil
+}

cmd/mesh-controller/buscertificate_test.go

@@ -0,0 +1,121 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// novox/hq 04-ISSUES/146. The bootstrap could not make the bus a certificate: it asked an image for
+// `openssl` and the image it asks has none. What replaces it is this command, so what is checked is
+// what the bootstrap needs from it — a pair a TLS server can actually load, made once and only once.
+
+func TestTheBusCertificateLoadsAsAServersWould(t *testing.T) {
+	into := t.TempDir()
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatalf("the bus could not be given a certificate: %v", err)
+	}
+
+	// The check a cheaper test would not make. The key was present and valid and the server could
+	// not start, once, because nothing loaded the pair the way a server loads it
+	// (novox/hq 04-ISSUES/014).
+	pair, err := tls.LoadX509KeyPair(filepath.Join(into, "tls.crt"), filepath.Join(into, "tls.key"))
+	if err != nil {
+		t.Fatalf("a TLS server cannot load what was written: %v", err)
+	}
+	leaf := pair.Leaf
+	if leaf == nil {
+		if leaf, err = x509.ParseCertificate(pair.Certificate[0]); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := leaf.VerifyHostname("mesh-broker"); err != nil {
+		t.Errorf("the certificate is not for the name the bus is reached by: %v", err)
+	}
+	if len(leaf.IPAddresses) == 0 || leaf.IPAddresses[0].String() != "127.0.0.1" {
+		t.Errorf("the certificate does not cover the loopback address the foundation dials: %v", leaf.IPAddresses)
+	}
+
+	// The key is not readable by anything else on the machine; the certificate is public and is.
+	key, err := os.Stat(filepath.Join(into, "tls.key"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if key.Mode().Perm() != 0o600 {
+		t.Errorf("the key is %v", key.Mode().Perm())
+	}
+	crt, err := os.Stat(filepath.Join(into, "tls.crt"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if crt.Mode().Perm() != 0o644 {
+		t.Errorf("the certificate is %v, which the server runs as another user cannot read", crt.Mode().Perm())
+	}
+}
+
+// **Made once.** The step is applied again on every reconcile, and a second certificate is one the
+// hosts that pinned the first no longer believe (novox/hq ADR 0004).
+func TestTheBusCertificateIsMadeOnce(t *testing.T) {
+	into := t.TempDir()
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatal(err)
+	}
+	first, err := os.ReadFile(filepath.Join(into, "tls.crt"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatal(err)
+	}
+	again, err := os.ReadFile(filepath.Join(into, "tls.crt"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(first) != string(again) {
+		t.Fatal("running it twice replaced the certificate every host had pinned")
+	}
+}
+
+// The verify half: false before, true after, which is what makes the bootstrap run the step at all.
+func TestTheCheckIsFalseUntilThereIsAPair(t *testing.T) {
+	into := t.TempDir()
+	if err := busCertificate([]string{"--check", "--into", into}); err == nil {
+		t.Fatal("an empty directory reported a usable certificate")
+	}
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatal(err)
+	}
+	if err := busCertificate([]string{"--check", "--into", into}); err != nil {
+		t.Fatalf("the certificate it just made does not satisfy its own check: %v", err)
+	}
+}
+
+// A half-written pair is not a pair. An interrupted bootstrap leaves exactly this, and a step that
+// called it done would hand the server a certificate with no key and report success.
+func TestACertificateWithoutItsKeyIsNotUsable(t *testing.T) {
+	into := t.TempDir()
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Remove(filepath.Join(into, "tls.key")); err != nil {
+		t.Fatal(err)
+	}
+	if err := busCertificate([]string{"--check", "--into", into}); err == nil {
+		t.Fatal("a certificate with no key passed the check")
+	}
+	if err := busCertificate([]string{"--into", into}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := tls.LoadX509KeyPair(filepath.Join(into, "tls.crt"), filepath.Join(into, "tls.key")); err != nil {
+		t.Fatalf("it did not replace the unusable pair: %v", err)
+	}
+}
+
+func TestWhereToWriteIsRequired(t *testing.T) {
+	if err := busCertificate(nil); err == nil || !strings.Contains(err.Error(), "--into") {
+		t.Fatalf("it did not ask where to write: %v", err)
+	}
+}

cmd/mesh-controller/busobjects.go

@@ -0,0 +1,247 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// The streams and durable consumers the mesh's own traffic needs, derived once (novox/hq to-be 45 §4,
+// D6 and D7).
+//
+// **What the controller asserts at its start and what the self-check expects to find are one
+// derivation**, run against the bus to make them and against a recorder to list them. Two lists would
+// drift, and a self-check comparing the bus with a second opinion of what should be there would find
+// the drift rather than the fault.
+
+// assertBusObjects brings every stream and consumer into being on r, and answers the machines that
+// can now hear a declaration.
+func assertBusObjects(ctx context.Context, inv *inventory.Inventory, r broker.Raiser) ([]string, error) {
+	nodes, err := inv.Nodes(ctx)
+	if err != nil {
+		return nil, err
+	}
+	names := make([]string, 0, len(nodes))
+	for _, n := range nodes {
+		names = append(names, n.Name)
+	}
+	if err := broker.Raise(r, names); err != nil {
+		return nil, err
+	}
+	// The work queues of the mesh's own roles (novox/hq ADR 0121). The queue before the holder,
+	// deliberately: work queues until somebody arrives to do it, so assigning a build machine a week
+	// after something started asking for builds flushes the backlog instead of having lost it.
+	// With the seats' holders, so each role's work queue gets the consumer its holder takes
+	// work from. Passed as nil until the first live raise, which left the build machine bound to a
+	// consumer nothing had created (2026-09-28).
+	holders, err := seatHolders(ctx, inv)
+	if err != nil {
+		return nil, err
+	}
+	if err := broker.RaiseSeats(r, inventory.MeshSeats(), holders); err != nil {
+		return nil, err
+	}
+	// And how every module hears what it consumes. Derived from the same records the user list is
+	// composed from, so a module the mesh grants a consumer's subjects has that consumer waiting.
+	// Done on every raise, not only when a credential is issued: every module moved onto this bus
+	// by the rollout was issued on the old one, and came up with nothing to bind to (2026-09-28).
+	consumers, records, err := moduleConsumersAndRecords(ctx, inv)
+	if err != nil {
+		return nil, err
+	}
+	// And a grant of a restricted stream that composes nothing, said on every raise and send (novox/hq ADR 0376 §2).
+	sayWithheld(records, "  ")
+	// And the work queues of seats that name their caller or their kind, with each holder's worker
+	// (novox/hq ADR 0259 §3): an ask queues until the router takes it, a channel's work until that kind
+	// takes it.
+	trafficStreams, trafficWorkers, err := seatTrafficObjects(ctx, inv)
+	if err != nil {
+		return nil, err
+	}
+	// And every module's own stream (novox/hq ADR 0363), from the catalogue, before the consumers on it.
+	modStreams, err := inv.DeclaredStreams(ctx)
+	if err != nil {
+		return nil, err
+	}
+	// Every one tried, and every failure named: one module's consumer the bus refuses is no reason
+	// the modules after it in the list hear nothing (novox/hq issue 208, where this runs on each send).
+	var failed []error
+	for _, s := range broker.ModuleStreams(modStreams) {
+		if err := r.EnsureStream(s); err != nil {
+			failed = append(failed, fmt.Errorf("the module stream %s: %w", s.Name, err))
+		}
+	}
+	for _, s := range trafficStreams {
+		if err := r.EnsureStream(s); err != nil {
+			failed = append(failed, fmt.Errorf("the work queue %s: %w", s.Name, err))
+		}
+	}
+	for _, c := range trafficWorkers {
+		if err := r.EnsureConsumer(c); err != nil {
+			failed = append(failed, fmt.Errorf("the worker %s on %s: %w", c.Name, c.Stream, err))
+		}
+	}
+	restricted := map[string]bool{}
+	for _, s := range modStreams {
+		restricted[s.Name] = s.Restricted
+	}
+	for _, c := range consumers {
+		if err := broker.EnsureHeard(r, c.Consumer, restricted[c.Consumer.Stream]); err != nil {
+			failed = append(failed, fmt.Errorf("how %s on %s hears what it consumes: %w", c.Module, c.Node, err))
+		}
+	}
+	// **And a consumer no longer granted loses what it reads through** (novox/hq ADR 0363 §6): every consumer
+	// on a module's stream the composition no longer asks for is removed, on this very send.
+	if p, prunes := r.(broker.Pruner); prunes && len(modStreams) > 0 {
+		var wanted []broker.Consumer
+		for _, c := range consumers {
+			wanted = append(wanted, c.Consumer)
+		}
+		removed, err := broker.PruneHeard(p, modStreams, wanted)
+		if err != nil {
+			failed = append(failed, err)
+		}
+		for _, gone := range removed {
+			fmt.Printf("  removed the consumer %s: its module is no longer granted that stream (novox/hq ADR 0363)\n", gone)
+		}
+	}
+	if len(failed) > 0 {
+		return nil, errors.Join(failed...)
+	}
+	return names, nil
+}
+
+// What raises the condition a send says when the objects it implies could not be asserted, and its kind.
+const (
+	sourceBusObjects         = "bus-objects"
+	kindBusObjectsUnasserted = "bus-objects-unasserted"
+)
+
+// assertOnSend asserts, on the bus a send is about to use, every object assertBusObjects derives —
+// **whenever a declaration is sent, not only when the controller starts** (novox/hq issue 208).
+//
+// A module assigned after the controller started was sent its declaration and found no consumer to
+// bind (`consumer not found`, messenger on 2026-10-06), and a seat holder assigned after it found no
+// worker: the objects a declaration implies were asserted at start and nowhere else, so they existed
+// only for what was assigned before the last restart. The same derivation, not a second list of what
+// a send needs: what start asserts, the self-check expects and a send asserts are one answer. Every
+// part is idempotent, so asserting the whole of it again is the no-op a restart already relies on.
+//
+// **A failure is said and raised, and the send goes on.** The objects are the mesh's, not the
+// machines' being sent: holding every machine back for one consumer that none of them may use would
+// turn one fault into all of them, and the declarations are not what is wrong. It is never silent —
+// said in the send's own output and raised as a condition, which the next send that asserts them
+// clears — and the start-time raise still refuses to serve without them.
+func assertOnSend(ctx context.Context, inv *inventory.Inventory, r broker.Raiser, indent string) error {
+	_, err := assertBusObjects(ctx, inv, r)
+	var observed []conditions.Observation
+	if err != nil {
+		fmt.Printf("%sTHE BUS DOES NOT HOLD WHAT THIS SEND IMPLIES: %v\n", indent, err)
+		fmt.Printf("%s  a module may find no consumer to bind, or a holder no worker; sent anyway, raised as "+
+			"condition %s, and asserted again by the next send\n", indent, unassertedObservation(err).Key())
+		observed = append(observed, unassertedObservation(err))
+	}
+	// Observed when it failed, cleared when it did not: a send that asserted everything is the
+	// observation that the bus holds what it should.
+	if kerr := withKeeper(ctx, func(k *conditions.Keeper) error {
+		return k.Reconcile(ctx, sourceBusObjects, observed)
+	}); kerr != nil {
+		fmt.Printf("%sand whether the bus holds what this send implies could not be kept as a condition: %v\n",
+			indent, kerr)
+	}
+	return err
+}
+
+// unassertedObservation is a send's failure to assert the bus's objects, as a condition.
+func unassertedObservation(err error) conditions.Observation {
+	return conditions.Observation{Scope: conditions.ScopeBus, ID: "objects", Token: "unasserted",
+		Kind: kindBusObjectsUnasserted, Severity: conditions.Warning, Source: sourceBusObjects,
+		Summary: "the bus's streams and consumers could not be asserted when a declaration was sent: " +
+			"a module may find no consumer to bind, or a seat's holder no worker",
+		Said: err.Error()}
+}
+
+// moduleConsumers is every module's durable consumer, from the records the user list is composed from.
+func moduleConsumers(ctx context.Context, inv *inventory.Inventory) ([]broker.ModuleConsumer, error) {
+	consumers, _, err := moduleConsumersAndRecords(ctx, inv)
+	return consumers, err
+}
+
+// moduleConsumersAndRecords is moduleConsumers with the records they were composed from.
+func moduleConsumersAndRecords(ctx context.Context, inv *inventory.Inventory) ([]broker.ModuleConsumer, broker.Records, error) {
+	records, err := inv.BusRecords(ctx)
+	if err != nil {
+		return nil, broker.Records{}, err
+	}
+	users, err := broker.Users(records)
+	if err != nil {
+		return nil, broker.Records{}, err
+	}
+	return broker.ConsumersOf(users), records, nil
+}
+
+// seatTrafficObjects is the work queues and workers of seats that name their caller or their kind, from
+// the records the user list is composed from.
+func seatTrafficObjects(ctx context.Context, inv *inventory.Inventory) ([]broker.Stream, []broker.Consumer, error) {
+	records, err := inv.BusRecords(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	users, err := broker.Users(records)
+	if err != nil {
+		return nil, nil, err
+	}
+	streams, workers := broker.SeatTrafficObjects(users)
+	// And the queue of every such seat the catalogue declares, held or not: work queues from registration,
+	// so what is submitted before a holder is assigned waits for it (the correctness review of 2026-10-08).
+	declared, err := inv.DeclaredTrafficSeats(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	have := map[string]bool{}
+	for _, s := range streams {
+		have[s.Name] = true
+	}
+	for _, s := range broker.TrafficQueues(declared) {
+		if !have[s.Name] {
+			streams = append(streams, s)
+			have[s.Name] = true
+		}
+	}
+	return streams, workers, nil
+}
+
+// moduleConsumerCount is how many modules hear what they consume, for the raise's one line.
+func moduleConsumerCount(ctx context.Context, inv *inventory.Inventory) (int, error) {
+	consumers, err := moduleConsumers(ctx, inv)
+	return len(consumers), err
+}
+
+// expectedBusObjects is every stream and consumer assertBusObjects would make, made nowhere.
+func expectedBusObjects(ctx context.Context, inv *inventory.Inventory) ([]broker.Stream, []broker.Consumer, error) {
+	var rec recordingRaiser
+	if _, err := assertBusObjects(ctx, inv, &rec); err != nil {
+		return nil, nil, fmt.Errorf("what the bus should hold cannot be worked out: %w", err)
+	}
+	return rec.streams, rec.consumers, nil
+}
+
+// recordingRaiser keeps what it was asked to assert and asserts nothing.
+type recordingRaiser struct {
+	streams   []broker.Stream
+	consumers []broker.Consumer
+}
+
+func (r *recordingRaiser) EnsureStream(s broker.Stream) error {
+	r.streams = append(r.streams, s)
+	return nil
+}
+
+func (r *recordingRaiser) EnsureConsumer(c broker.Consumer) error {
+	r.consumers = append(r.consumers, c)
+	return nil
+}

cmd/mesh-controller/busobjects_test.go

@@ -0,0 +1,199 @@
+//go:build integration
+
+package main
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// novox/hq issue 208: the bus's objects a declaration implies are asserted whenever one is sent, not
+// only when the controller starts.
+
+// aCarriedConsumer is the runtime on laptop and, carried by it, a module that consumes an event: the
+// shape of messenger on 2026-10-06, assigned after the controller started.
+func aCarriedConsumer(t *testing.T, open *stores) broker.Consumer {
+	t.Helper()
+	register(t, open, catalogue.Manifest{Module: catalogue.RuntimeModule, Version: "1",
+		OwnSecrets: catalogue.OwnSecrets{"broker": {Path: "/var/lib/mesh/node-tools/broker"}}})
+	register(t, open, catalogue.Manifest{Module: "messenger", Version: "1",
+		Consumes: []string{"billing.order.placed"}})
+	for _, m := range []string{catalogue.RuntimeModule, "messenger"} {
+		if _, err := open.inventory.Assign(t.Context(), "laptop", m); err != nil {
+			t.Fatal(err)
+		}
+	}
+	consumers, err := moduleConsumers(t.Context(), open.inventory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range consumers {
+		if c.Module == "messenger" && c.Node == "laptop" {
+			return c.Consumer
+		}
+	}
+	t.Fatalf("messenger on laptop is derived no consumer: %+v", consumers)
+	return broker.Consumer{}
+}
+
+// aLateHolder is a module holding the build agent's seat on anchor, assigned after the controller
+// started, and the worker its seat's queue should have for it.
+func aLateHolder(t *testing.T, open *stores) broker.Consumer {
+	t.Helper()
+	register(t, open, catalogue.Manifest{Module: "late-builder", Version: "1",
+		Claims: []catalogue.Claim{{Name: "node-build-agent", Scope: catalogue.ScopeNode}}})
+	if _, err := open.inventory.Assign(t.Context(), "anchor", "late-builder"); err != nil {
+		t.Fatal(err)
+	}
+	for _, s := range inventory.MeshSeats() {
+		if s.Name == "node-build-agent" {
+			c, needed := broker.HolderConsumerFor("anchor", "late-builder", s)
+			if !needed {
+				t.Fatal("the build agent's seat needs no worker")
+			}
+			return c
+		}
+	}
+	t.Fatal("the mesh declares no build agent's seat")
+	return broker.Consumer{}
+}
+
+// asserted says whether a recording holds a consumer by stream and name.
+func asserted(rec *recordingRaiser, want broker.Consumer) bool {
+	for _, c := range rec.consumers {
+		if c.Stream == want.Stream && c.Name == want.Name {
+			return true
+		}
+	}
+	return false
+}
+
+// What a send asserts includes what was assigned after the start's assertion: a carried module's
+// consumer and a late holder's worker. The derivation is the start's own, so this holds without a bus.
+func TestASendAssertsWhatWasAssignedAfterStart(t *testing.T) {
+	open := aMesh(t)
+	var atStart recordingRaiser
+	if _, err := assertBusObjects(t.Context(), open.inventory, &atStart); err != nil {
+		t.Fatal(err)
+	}
+	consumer := aCarriedConsumer(t, open)
+	worker := aLateHolder(t, open)
+	if asserted(&atStart, consumer) || asserted(&atStart, worker) {
+		t.Fatal("the start asserted what was not yet assigned; the test proves nothing")
+	}
+	var onSend recordingRaiser
+	if err := assertOnSend(t.Context(), open.inventory, &onSend, ""); err != nil {
+		t.Fatal(err)
+	}
+	if !asserted(&onSend, consumer) {
+		t.Fatalf("messenger's consumer %s on %s is not asserted by the send: %+v", consumer.Name, consumer.Stream, onSend.consumers)
+	}
+	if !asserted(&onSend, worker) {
+		t.Fatalf("the late holder's worker %s on %s is not asserted by the send: %+v", worker.Name, worker.Stream, onSend.consumers)
+	}
+}
+
+// failingRaiser refuses one consumer by name and records everything it was asked.
+type failingRaiser struct {
+	recordingRaiser
+	refuse string
+}
+
+func (f *failingRaiser) EnsureConsumer(c broker.Consumer) error {
+	f.consumers = append(f.consumers, c)
+	if c.Name == f.refuse {
+		return errors.New("nats: API error: code=503 description=insufficient resources")
+	}
+	return nil
+}
+
+// A send whose objects cannot be asserted says so in its output and raises a condition — and the next
+// send that asserts them clears it. The consumers after the refused one are still asked for.
+func TestASendThatCannotAssertTheBusSaysSoAndRaisesACondition(t *testing.T) {
+	open := aMesh(t)
+	consumer := aCarriedConsumer(t, open)
+	worker := aLateHolder(t, open)
+	failing := &failingRaiser{refuse: consumer.Name}
+
+	var sendErr error
+	out := stdoutOf(t, func() error {
+		sendErr = assertOnSend(t.Context(), open.inventory, failing, "  ")
+		return nil
+	})
+	if sendErr == nil || !strings.Contains(sendErr.Error(), "how messenger on laptop hears what it consumes") {
+		t.Fatalf("the failure is not answered: %v", sendErr)
+	}
+	if !strings.Contains(out, "THE BUS DOES NOT HOLD WHAT THIS SEND IMPLIES") ||
+		!strings.Contains(out, "insufficient resources") || !strings.Contains(out, "bus.objects.unasserted") {
+		t.Fatalf("the failure is not said in the send's output:\n%s", out)
+	}
+	if !asserted(&failing.recordingRaiser, worker) {
+		t.Fatal("the seat's worker was not asked for")
+	}
+	c, open1, err := conditionsFrom.Get(t.Context(), "bus.objects.unasserted")
+	if err != nil || !open1 {
+		t.Fatalf("no condition raised: %v", err)
+	}
+	if c.Kind != kindBusObjectsUnasserted || c.Source != sourceBusObjects ||
+		len(c.Evidence) == 0 || !strings.Contains(c.Evidence[0].Said, "insufficient resources") {
+		t.Fatalf("the condition does not say what failed: %+v", c)
+	}
+
+	// The next send asserts them, and that observation clears it.
+	if err := assertOnSend(t.Context(), open.inventory, &recordingRaiser{}, ""); err != nil {
+		t.Fatal(err)
+	}
+	if _, stillOpen, err := conditionsFrom.Get(t.Context(), "bus.objects.unasserted"); err != nil || stillOpen {
+		t.Fatalf("a send that asserted everything left the condition open: %v", err)
+	}
+}
+
+// Against a real bus, through the send's own grant: a module assigned after start has its consumer
+// once a declaration is sent, and a holder assigned after start its seat's worker.
+func TestNatsAModuleAssignedAfterStartGetsItsConsumerAtItsFirstSend(t *testing.T) {
+	url := testbus.URL(t)
+	open := aMesh(t)
+	js, err := broker.Dial(url)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(js.Close)
+	for _, s := range []string{"CONTROL", "NODES", "ASSIGNMENTS", "EVENTS"} {
+		_ = js.Context().DeleteStream(s)
+	}
+	// The controller starting, before either was assigned.
+	if _, err := assertBusObjects(t.Context(), open.inventory, js); err != nil {
+		t.Fatal(err)
+	}
+	consumer := aCarriedConsumer(t, open)
+	worker := aLateHolder(t, open)
+	_ = js.Context().DeleteConsumer(worker.Stream, worker.Name)
+	for _, c := range []broker.Consumer{consumer, worker} {
+		if _, err := js.Context().ConsumerInfo(c.Stream, c.Name); !errors.Is(err, nats.ErrConsumerNotFound) {
+			t.Fatalf("%s on %s exists before any send; the test proves nothing: %v", c.Name, c.Stream, err)
+		}
+	}
+
+	server := link.ConnectNats(js, nil, nil)
+	if err := (overTheBus{open: open, server: server}).grant(t.Context(), nil); err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range []broker.Consumer{consumer, worker} {
+		if _, err := js.Context().ConsumerInfo(c.Stream, c.Name); err != nil {
+			t.Fatalf("%s on %s is not on the bus after a send: %v", c.Name, c.Stream, err)
+		}
+	}
+	if _, raised, _ := conditionsFrom.Get(t.Context(), "bus.objects.unasserted"); raised {
+		t.Fatal("a send that asserted everything raised a condition")
+	}
+}

cmd/mesh-controller/busy.go

@@ -0,0 +1,103 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A first-node gate waits for a busy container (novox/hq ADR 0335 §4).
+//
+// When a machine reports, on what the gate sent it, that a container of a judged module was left running
+// because it said busy, the judging has not started: the build is not yet what runs there. The walk says it
+// waits for a busy container on that machine, counts no pass and no bound, and starts the judging — its
+// Since — at the report that no longer lists the container waiting. The wait is the node-engine's, bounded
+// at 15 minutes; the controller's own bound (busyGateBound past the engine's) is for an engine that stopped
+// reporting while it waited, so no walk waits for ever. An engine older than the field never lists one, and
+// its gate starts as before.
+
+// busyGateSlack is how long past the engine's bound the controller still waits for the report that says the
+// container replaced: a pass of the engine (its asks every 20 seconds) and the report's way here.
+var busyGateSlack = 5 * time.Minute
+
+// busyEngineBound is the node-engine's bound on a wait (novox/hq ADR 0335 §3), counted again here on this
+// controller's clock from when it first read the wait.
+const busyEngineBound = 15 * time.Minute
+
+// busyGateEnds is when the gate stops waiting: the engine's own word on its bound, or this controller's count of
+// it from when it first read the wait, whichever is sooner, and the slack — so neither a clock ahead on the
+// machine nor a wrong word from it holds a walk longer.
+func busyGateEnds(b *inventory.GateBusy) time.Time {
+	until := b.Seen.Add(busyEngineBound)
+	if !b.Until.IsZero() && b.Until.Before(until) {
+		until = b.Until
+	}
+	return until.Add(busyGateSlack)
+}
+
+// busyWait decides, before a judging, whether the gate waits for a busy container on a machine it judges:
+// true while it waits, the gate saying so. False when nothing waits, or no longer: a wait that ended moves the
+// gate's Since to its end. Pure but for the gate it is handed.
+func busyWait(g *inventory.PlanGate, pairs []judged, f gateFacts, now time.Time) bool {
+	if g.Busy != nil && g.Busy.Ended != nil {
+		return false
+	}
+	for _, j := range pairs {
+		b, waits := busyOn(j, f)
+		if !waits {
+			continue
+		}
+		if g.Busy == nil {
+			g.Busy = &inventory.GateBusy{Machine: j.node, Module: j.module, Container: b.Container, Since: b.Since,
+				Seen: now}
+		}
+		if g.Busy.Seen.IsZero() {
+			g.Busy.Seen = now
+		}
+		g.Busy.Until, g.Busy.Said = b.Until, b.Said
+		if now.After(busyGateEnds(g.Busy)) {
+			// The engine said it would have replaced it by now: the judging starts, and finds the module not
+			// yet healthy while the machine still lists it waiting (busyStill), until the gate's own bound.
+			end := now
+			g.Busy.Ended, g.Busy.PastBound = &end, true
+			g.Since, g.Passes, g.LastPass, g.Healthy, g.HealthyAt, g.Applied = &end, 0, nil, nil, nil, nil
+			return false
+		}
+		g.Passes, g.LastPass, g.Last, g.Failing = 0, nil, g.Busy.Words(), nil
+		g.Read(now, false, g.Busy.Words())
+		return true
+	}
+	if g.Busy == nil {
+		return false
+	}
+	// Replaced: the judging starts at the report that said so.
+	end := now
+	if r, said := f.reports[g.Busy.Machine]; said && r.At != nil && r.At.After(g.Busy.Since) && r.At.Before(now) {
+		end = r.At.UTC()
+	}
+	g.Busy.Ended = &end
+	g.Since, g.Passes, g.LastPass, g.Last, g.Healthy, g.HealthyAt, g.Applied = &end, 0, nil, "", nil, nil, nil
+	return false
+}
+
+// busyOn is the container of a judged module its machine last reported, on what the gate sent it, as left
+// running because it said busy.
+func busyOn(j judged, f gateFacts) (inventory.BusyWait, bool) {
+	r, said := f.reports[j.node]
+	if !said || r.At == nil || !f.reportedOn(j.node, r) {
+		return inventory.BusyWait{}, false
+	}
+	return inventory.WaitingFor(r.Busy, j.module)
+}
+
+// busyStill is a judged module whose container its machine still lists waiting once the gate stopped waiting
+// for it: not yet what was sent, so not healthy, whatever its health says of the container still running.
+func busyStill(j judged, f gateFacts) (string, bool) {
+	b, waits := busyOn(j, f)
+	if !waits {
+		return "", false
+	}
+	return fmt.Sprintf("%s still runs its busy container %s, past its node-engine's bound of %s",
+		j.node, b.Container, b.Until.UTC().Format(time.RFC3339)), true
+}

cmd/mesh-controller/busy_test.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A walk whose module's container waits as busy on its first machine says so, and starts that machine's
+// first-machine gate only once the machine reports the container replaced (novox/hq ADR 0335 §4).
+func TestAGateWaitsForABusyContainerAndStartsWhenItIsReplaced(t *testing.T) {
+	sent := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	g := &inventory.PlanGate{Machines: []string{"novox"}, Since: &sent,
+		Sent: map[string]inventory.SentDeclaration{"novox": {Digest: "d1", Sequence: 7}}}
+	pairs := []judged{{module: "build-agent", node: "novox"}, {module: "mesh-controller", node: "novox"}}
+	reported := sent.Add(20 * time.Second)
+	waiting := []inventory.BusyWait{{ID: "build-agent.server", Container: "mesh-build-agent",
+		State: inventory.BusyWaiting, Since: reported, Until: reported.Add(15 * time.Minute),
+		Said: "busy: novox/mesh-controller (check of #280), in hand since 00:58:00Z"}}
+	facts := func(at time.Time, busy []inventory.BusyWait) gateFacts {
+		// As judgeMoves hands it: the report held against the gate's own send.
+		return gateFacts{sent: g.Sent, reports: map[string]inventory.Reported{"novox": {Node: "novox",
+			Outcome: inventory.OutcomeApplied, At: &at, Declared: "d1", ReportedSequence: 7, Busy: busy}}}
+	}
+
+	now := reported.Add(time.Minute)
+	if !busyWait(g, pairs, facts(reported, waiting), now) {
+		t.Fatal("a gate whose module's container waits as busy judged it")
+	}
+	if !g.Since.Equal(sent) || g.Busy == nil || g.Busy.Machine != "novox" || g.Busy.Ended != nil {
+		t.Fatalf("the gate does not keep the wait: %+v %+v", g.Since, g.Busy)
+	}
+	for _, said := range []string{gateLine(g), g.Last} {
+		if !strings.Contains(said, "waits for a busy container on novox") {
+			t.Errorf("the walk does not say it waits for a busy container there: %s", said)
+		}
+	}
+	if !strings.Contains(g.Last, "check of #280") {
+		t.Errorf("the wait does not say what the container holds: %s", g.Last)
+	}
+
+	// Ten minutes on, still busy, within the engine's bound: still waiting, nothing judged, no bound run.
+	now = reported.Add(10 * time.Minute)
+	if !busyWait(g, pairs, facts(reported.Add(9*time.Minute), waiting), now) || g.Passes != 0 {
+		t.Fatalf("the gate stopped waiting within the bound: %+v", g)
+	}
+
+	// The machine reports it replaced: the judging starts at that report.
+	replacedAt := reported.Add(12 * time.Minute)
+	now = replacedAt.Add(5 * time.Second)
+	replaced := []inventory.BusyWait{{ID: "build-agent.server", Container: "mesh-build-agent",
+		State: "replaced-when-idle", Since: reported, Until: reported.Add(15 * time.Minute)}}
+	if busyWait(g, pairs, facts(replacedAt, replaced), now) {
+		t.Fatal("the gate still waits after the container was replaced")
+	}
+	if g.Since == nil || !g.Since.Equal(replacedAt) || g.Busy.Ended == nil || !g.Busy.Ended.Equal(replacedAt) {
+		t.Fatalf("the gate does not start at the report that said it replaced: since %v, %+v", g.Since, g.Busy)
+	}
+	if strings.Contains(gateLine(g), "waits for a busy container") {
+		t.Errorf("a gate judging still says it waits: %s", gateLine(g))
+	}
+	// And a later report listing it waiting again does not hold a gate that started.
+	if busyWait(g, pairs, facts(now, waiting), now.Add(time.Minute)) {
+		t.Error("a gate that started waits again")
+	}
+}
+
+// An engine that stops reporting while it waits holds no walk for ever: past the engine's bound and the slack,
+// the judging starts, and finds the module not yet healthy while its container is still listed waiting.
+func TestAGateWaitsNoLongerThanTheEnginesBound(t *testing.T) {
+	sent := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	g := &inventory.PlanGate{Machines: []string{"novox"}, Since: &sent}
+	pairs := []judged{{module: "build-agent", node: "novox"}}
+	waiting := []inventory.BusyWait{{ID: "build-agent.server", Container: "mesh-build-agent",
+		State: inventory.BusyWaiting, Since: sent, Until: sent.Add(15 * time.Minute)}}
+	f := gateFacts{reports: map[string]inventory.Reported{"novox": {Node: "novox", Outcome: inventory.OutcomeApplied,
+		At: &sent, Current: true, Busy: waiting}}}
+	now := sent.Add(15*time.Minute + busyGateSlack + time.Second)
+	if busyWait(g, pairs, f, now) {
+		t.Fatal("a gate waited past the engine's bound and the slack")
+	}
+	if !g.Busy.PastBound || !g.Since.Equal(now) {
+		t.Fatalf("the gate does not start, said past the bound: %+v %v", g.Busy, g.Since)
+	}
+	if why, still := busyStill(pairs[0], f); !still || !strings.Contains(why, "past its node-engine's bound") {
+		t.Fatalf("a module still running its busy container reads as what was sent: %q", why)
+	}
+}
+
+// A report from an engine older than the field lists nothing: the gate starts at the send, as before; and a
+// report not about the gate's send says nothing of it.
+func TestAGateOfAnEngineThatNeverWaitsStartsAsBefore(t *testing.T) {
+	sent := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	g := &inventory.PlanGate{Machines: []string{"ace"}, Since: &sent,
+		Sent: map[string]inventory.SentDeclaration{"ace": {Digest: "d2", Sequence: 9}}}
+	pairs := []judged{{module: "build-agent", node: "ace"}}
+	at := sent.Add(time.Minute)
+	older := gateFacts{sent: g.Sent, reports: map[string]inventory.Reported{"ace": {Node: "ace", Outcome: inventory.OutcomeApplied,
+		At: &at, Declared: "d2", ReportedSequence: 9}}}
+	if busyWait(g, pairs, older, at) || g.Busy != nil || !g.Since.Equal(sent) {
+		t.Fatalf("a gate on an engine that never waits did not start at the send: %+v %v", g.Busy, g.Since)
+	}
+	elsewhere := gateFacts{sent: g.Sent, reports: map[string]inventory.Reported{"ace": {Node: "ace", Outcome: inventory.OutcomeApplied,
+		At: &at, Declared: "d1", ReportedSequence: 8, Busy: []inventory.BusyWait{{ID: "build-agent.server",
+			State: inventory.BusyWaiting, Until: at.Add(time.Hour)}}}}}
+	if busyWait(g, pairs, elsewhere, at) {
+		t.Fatal("a wait reported about an earlier declaration held the gate")
+	}
+}
+
+// The wait is bounded on this controller's clock: an engine whose clock runs an hour ahead, saying it waits until
+// then, holds the gate no longer than 15 minutes and the slack from when the controller first read the wait.
+func TestAGateWaitIsBoundedOnTheControllersClock(t *testing.T) {
+	seen := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	g := &inventory.PlanGate{Machines: []string{"novox"}, Since: &seen}
+	pairs := []judged{{module: "build-agent", node: "novox"}}
+	ahead := seen.Add(time.Hour)
+	f := gateFacts{reports: map[string]inventory.Reported{"novox": {Node: "novox", Outcome: inventory.OutcomeApplied,
+		At: &seen, Current: true, Busy: []inventory.BusyWait{{ID: "build-agent.server", Container: "mesh-build-agent",
+			State: inventory.BusyWaiting, Since: ahead, Until: ahead.Add(15 * time.Minute)}}}}}
+	if !busyWait(g, pairs, f, seen) || !g.Busy.Seen.Equal(seen) {
+		t.Fatalf("the gate did not start waiting, seen now: %+v", g.Busy)
+	}
+	if !busyWait(g, pairs, f, seen.Add(15*time.Minute+busyGateSlack-time.Second)) {
+		t.Fatal("the gate stopped waiting within the bound on its own clock")
+	}
+	if busyWait(g, pairs, f, seen.Add(15*time.Minute+busyGateSlack+time.Second)) || !g.Busy.PastBound {
+		t.Fatalf("an engine's later word held the gate past the controller's bound: %+v", g.Busy)
+	}
+}
+
+// `plan` says, for a machine whose node-engine is older than the field, each container whose busy is not sent.
+func TestAPlanSaysABusyAnOlderEngineIsNotSent(t *testing.T) {
+	modules := []catalogue.Manifest{{Module: "build-agent", Resources: []map[string]any{
+		{"id": "server", "type": "container", "busy": map[string]any{"command": "mesh-builder busy"}},
+		{"id": "agent-env", "type": "file"}}}}
+	lines := busyNotSent(modules, false)
+	if len(lines) != 1 || !strings.Contains(lines[0], "build-agent.server declares busy") ||
+		!strings.Contains(lines[0], "replaced at once") {
+		t.Fatalf("the plan does not say the busy not sent: %v", lines)
+	}
+	if lines := busyNotSent(modules, true); len(lines) != 0 {
+		t.Fatalf("a busy sent is said as not sent: %v", lines)
+	}
+}

cmd/mesh-controller/calls_verb_integration_test.go

@@ -0,0 +1,36 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+func TestCallsIsServedAndSaysWhatItKeeps(t *testing.T) {
+	handlers, behind, err := seatToolHandlers()
+	if err != nil || len(behind) != 0 {
+		t.Fatalf("%v %v", behind, err)
+	}
+	calls, ok := handlers["calls"]
+	if !ok {
+		t.Fatal("calls is not served")
+	}
+	if _, err := calls(context.Background(), json.RawMessage(`{"node":"anchor"}`)); err == nil ||
+		!strings.Contains(err.Error(), `"node"`) {
+		t.Errorf("calls took an argument it does not declare: %v", err)
+	}
+	if _, err := calls(context.Background(), json.RawMessage(`{"call":"call-0-0"}`)); err == nil ||
+		!strings.Contains(err.Error(), "not across a restart") {
+		t.Errorf("an unknown call was not said plainly: %v", err)
+	}
+	got, err := calls(context.Background(), json.RawMessage(`{}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, listed := got.(map[string]any)["calls"]; !listed {
+		t.Errorf("calls answered %v", got)
+	}
+}

cmd/mesh-controller/calls_verb_test.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// consoleWaits is how long the console waits for an answer (mesh-tools node-tools/internal/bus
+// RequestTimeout) — the shortest wait of a caller the mesh ships.
+const consoleWaits = 30 * time.Second
+
+// **A call's one answer is never later than its caller or the bus allow** (novox/hq issue 265): a
+// holder answers within AnswerWithin, which must be inside both the console's wait and the window the
+// bus gives an answer. Before, the console waited 30s, the bus 60s, and a push ran as long as it ran.
+func TestAVerbAnswersInsideEveryWaitOnIt(t *testing.T) {
+	if link.AnswerWithin >= consoleWaits/2 {
+		t.Errorf("a call answers within %s: not well inside the console's %s", link.AnswerWithin, consoleWaits)
+	}
+	if link.AnswerWithin >= broker.ResponseTTL {
+		t.Errorf("a call answers within %s, after the bus stops permitting an answer at %s", link.AnswerWithin, broker.ResponseTTL)
+	}
+}
+
+// A push — named or through command — answers before it runs: it sends the machine holding the bus
+// first, and the broker reloading its user list forgets the answer it was about to permit.
+func TestAPushAnswersBeforeItSends(t *testing.T) {
+	for _, c := range []struct {
+		verb string
+		args map[string]any
+		want bool
+	}{
+		{"push", map[string]any{"node": "anchor", "why": "w"}, true},
+		{"push", map[string]any{"why": "w"}, true},
+		{"command", map[string]any{"command": "builds"}, false},
+		{"status", map[string]any{}, false},
+		{"assign", map[string]any{"node": "anchor", "module": "m"}, false},
+	} {
+		argv, err := argvFor(c.verb, c.args)
+		if err != nil {
+			t.Fatalf("%s %v: %v", c.verb, c.args, err)
+		}
+		if got := answersFirst(argv); got != c.want {
+			t.Errorf("%s %v answers first: %v, want %v", c.verb, c.args, got, c.want)
+		}
+	}
+}
+
+// `calls` is served, takes a call's id and nothing else, and says plainly when it holds no such call.

cmd/mesh-controller/chain.go

@@ -0,0 +1,181 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/chain"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The chain on the bus (novox/hq ADR 0408, design 47 milestone 5): builds, rollouts and assignments are keys of the
+// bus's key-value store, written by the controller that holds the lease. The tables of the controller's store are
+// copied into them once, by the serving controller at its start, and a kind is read from its bucket only once the move
+// has recorded it (inventory.ChainReads).
+
+// chainHolds is whether this process may write the chain now: the lease's gate, the one every act passes.
+func chainHolds(ctx context.Context) error {
+	_, err := theLease.epoch(ctx)
+	return err
+}
+
+// openTheChain opens the chain's buckets on the bus: the serving controller's connection, or one dialled for a command.
+func openTheChain(ctx context.Context) (*chain.Chain, error) {
+	js, err := aBus()
+	if err != nil {
+		return nil, err
+	}
+	// Not closed: a borrowed connection closes nothing, and a dialled one lasts as long as the command.
+	return chain.OnTheBus(ctx, js.Conn(), chainHolds)
+}
+
+// kindChainMoveRefused is the condition of a move that stopped without switching a kind.
+const kindChainMoveRefused = "chain-move-refused"
+
+// chainMoveRetry is how long a move that failed for want of the bus waits before it tries again.
+const chainMoveRetry = 30 * time.Second
+
+// movingTheChain copies the tables into the buckets and records it, at the serving controller's start: after the buckets
+// exist and the lease is held, before anything reads a kind that has not moved. **The first try is made here, before the
+// controller serves**, so what it serves is read from one place. A move that fails for want of the bus is tried again
+// every half minute while the controller serves from the tables; one that is refused — a count that differs, a value
+// over the bus's largest — is raised as an urgent condition, and the tables stay what is read: nothing is half-switched.
+func movingTheChain(ctx context.Context, inv *inventory.Inventory) {
+	say := func(format string, args ...any) { fmt.Printf("chain: "+format+"\n", args...) }
+	// The first try is made here, before the controller serves; the tries after it, while it serves.
+	if movedOrStopped(ctx, inv, say) {
+		return
+	}
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-time.After(chainMoveRetry):
+			}
+			if movedOrStopped(ctx, inv, say) {
+				return
+			}
+		}
+	}()
+}
+
+// movedOrStopped makes one try at the move and says whether there is nothing more to try: moved, refused, or the controller
+// ending. False for a failure of the kind that is tried again (the bus away, a write not granted yet, the lease not held).
+func movedOrStopped(ctx context.Context, inv *inventory.Inventory, say func(string, ...any)) bool {
+	_, err := inv.MoveChain(ctx, say)
+	var refusal *inventory.Refusal
+	switch {
+	case err == nil:
+		go clearChainMove(ctx)
+		go askAgainSoon(ctx, inv)
+		return true
+	case errors.As(err, &refusal):
+		say("%v", err)
+		go raiseChainMove(ctx, refusal)
+		return true
+	case ctx.Err() != nil:
+		return true
+	}
+	say("the move to the bus did not finish, and the tables are read until it does: %v", err)
+	return false
+}
+
+// chainMoveObservation is the urgent condition for a refused move.
+func chainMoveObservation(r *inventory.Refusal) conditions.Observation {
+	return conditions.Observation{Scope: conditions.ScopeBus, ID: "chain." + r.Kind, Token: kindChainMoveRefused,
+		Kind: kindChainMoveRefused, Severity: conditions.Urgent, Resolver: conditions.ResolverOperator,
+		Summary: "the controller's " + r.Kind + " were not moved to the bus: " + r.Why, Source: "chain move"}
+}
+
+// whenKept runs f once the serving controller keeps conditions: the move runs before they are kept.
+func whenKept(ctx context.Context, f func(k *conditions.Keeper)) {
+	for conditionsFrom == nil {
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(time.Second):
+		}
+	}
+	f(conditionsFrom)
+}
+
+func raiseChainMove(ctx context.Context, r *inventory.Refusal) {
+	whenKept(ctx, func(k *conditions.Keeper) {
+		if _, err := k.Observe(ctx, chainMoveObservation(r)); err != nil {
+			fmt.Printf("chain: the condition for the refused move could not be raised: %v\n", err)
+		}
+	})
+}
+
+func clearChainMove(ctx context.Context) {
+	whenKept(ctx, func(k *conditions.Keeper) {
+		for _, kind := range []string{inventory.KindBuilds, inventory.KindRollouts, inventory.KindAssignments} {
+			key := chainMoveObservation(&inventory.Refusal{Kind: kind}).Key()
+			if _, err := k.Clear(ctx, key, "the "+kind+" are on the bus"); err != nil {
+				fmt.Printf("chain: the condition for the move of the %s could not be cleared: %v\n", kind, err)
+			}
+		}
+	})
+}
+
+// attachTheChain gives the inventory of the serving controller the chain on its connection, then moves what has not moved.
+func attachTheChain(ctx context.Context, inv *inventory.Inventory, server *link.Server) error {
+	bus, ok := server.Bus().(link.OverNATS)
+	if !ok {
+		return errors.New("the chain lives on the bus, and this control plane is not on it")
+	}
+	c, err := chain.OnTheBus(ctx, bus.Conn, chainHolds)
+	if err != nil {
+		return err
+	}
+	inv.UseChain(c)
+	movingTheChain(ctx, inv)
+	return nil
+}
+
+// askAgain asks once more for each build request the move found never handed over (novox/hq issue 981 note 7 Q5): the
+// requests a merge could not ask for, which a person's hand `build` would otherwise have to repeat. **At most once**: a
+// request is claimed before it is asked and settled after, so a crash between loses the ask, which is where it stood.
+func askAgain(ctx context.Context, inv *inventory.Inventory) {
+	pending, err := inv.RequestsToAskAgain(ctx)
+	if err != nil {
+		fmt.Printf("chain: the requests never handed over cannot be read: %v\n", err)
+		return
+	}
+	for _, r := range pending {
+		if claimed, err := inv.ClaimToAskAgain(ctx, r.ID); err != nil || !claimed {
+			if err != nil {
+				fmt.Printf("chain: %s cannot be claimed to be asked again: %v\n", r.ID, err)
+			}
+			continue
+		}
+		id, err := askABuild(ctx, buildSource{Repository: r.Repository, Seat: r.Seat}, r.Path, r.Ref)
+		if err != nil {
+			if serr := inv.AskedAgainAs(ctx, r.ID, "not asked again: "+err.Error()); serr != nil {
+				fmt.Printf("chain: %s was not asked again, and that could not be kept: %v\n", r.ID, serr)
+			}
+			fmt.Printf("chain: %s was never handed over and cannot be asked again: %v\n", r.ID, err)
+			continue
+		}
+		recordBuildRequest(ctx, inv, inventory.BuildRequest{ID: id, Repository: r.Repository, Seat: r.Seat, Path: r.Path,
+			Ref: r.Ref, Commit: r.Commit, For: r.For})
+		if err := inv.AskedAgainAs(ctx, r.ID, id); err != nil {
+			fmt.Printf("chain: %s was asked again as %s, and that could not be kept: %v\n", r.ID, id, err)
+		}
+		fmt.Printf("chain: %s, never handed over, is asked again as %s\n", r.ID, id)
+	}
+}
+
+// askAgainSoon waits for the controller to be serving, which an ask needs, and then asks again.
+func askAgainSoon(ctx context.Context, inv *inventory.Inventory) {
+	select {
+	case <-ctx.Done():
+	case <-time.After(time.Minute):
+		askAgain(ctx, inv)
+	}
+}

cmd/mesh-controller/chain_integration_test.go

@@ -0,0 +1,209 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/chain"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/lease"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **Acceptance 10 of design 47: one read of an assignment names the commit, the build and the rollout that put it there,
+// and one read of the rollout lists the assignments it changed** (novox/hq ADR 0408, issue 1095). It enters by the live
+// trigger — a merge heard, its batch cut into a plan when the window closed, its build answered through the build seat's
+// path, the plan advanced — and writes no key and no row by hand. Only the machine's end of the send is the test's: the send
+// is recorded as the controller records one it made, and the gate's facts are the store's.
+func TestOneReadOfAnAssignmentNamesItsCommitBuildAndRolloutAndOneReadOfTheRolloutListsItsAssignments(t *testing.T) {
+	open := windowed(t)
+	everyHeadWaits(t)
+	asked := asksRecorded(t)
+	ctx := t.Context()
+	inv := open.inventory
+	if _, err := assign(ctx, open, "anchor", "notes"); err != nil {
+		t.Fatal(err)
+	}
+
+	var sent [][]string
+	wasSend := sendRollout
+	sendRollout = func(ctx context.Context, open *stores, names []string) ([]string, error) {
+		sent = append(sent, append([]string(nil), names...))
+		current, err := open.inventory.CurrentBuilds(ctx)
+		if err != nil {
+			return nil, err
+		}
+		for _, node := range names {
+			digest := fmt.Sprintf("d-%s-%d", node, len(sent))
+			if err := open.inventory.RecordSent(ctx, nodeID(t, open, node), digest,
+				map[string]string{"notes": current["notes"].Commit}); err != nil {
+				return nil, err
+			}
+		}
+		return names, nil
+	}
+	t.Cleanup(func() { sendRollout = wasSend })
+	wasGather := gatherGateFacts
+	gatherGateFacts = func(ctx context.Context, open *stores, component string) (gateFacts, error) {
+		f := gateFacts{now: time.Now(), reports: map[string]inventory.Reported{}, engines: map[string]string{},
+			rolledBack: map[string][]lease.Rollback{}, served: map[string]served{}}
+		reports, err := open.inventory.LastReports(ctx)
+		if err != nil {
+			return f, err
+		}
+		for _, r := range reports {
+			f.reports[r.Node] = r
+		}
+		return f, nil
+	}
+	t.Cleanup(func() { gatherGateFacts = wasGather })
+
+	// A merge of notes is heard, and its window closes: the batch is cut into the walk.
+	hear(t, open, catalogueMerge("c-notes", "notes", t0), t0.Add(time.Second))
+	cutAt(t, open, t0.Add(time.Second+90*time.Second))
+	ws, _ := walks(t, open)
+	if len(ws) != 1 {
+		t.Fatalf("%d walk(s) after the cut", len(ws))
+	}
+	rollout := ws[0].ID
+
+	// The walk asks its first tier (at the cut, or at its next step); the build seat answers, and the controller takes the
+	// outcome in as it does.
+	asking, err := inv.PlanByID(ctx, rollout)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for try := 0; try < 3 && (asking.Modules["notes"] == nil || asking.Modules["notes"].Build == ""); try++ {
+		advancePlans(ctx, open)
+		if asking, err = inv.PlanByID(ctx, rollout); err != nil {
+			t.Fatal(err)
+		}
+	}
+	buildID := asking.Modules["notes"].Build
+	if buildID == "" || len(*asked) != 1 || !strings.HasSuffix((*asked)[0], "#"+buildID) {
+		t.Fatalf("the walk asked %v, and notes' build is %q", *asked, buildID)
+	}
+	digest := "sha256:" + strings.Repeat("a", 64)
+	result := outcome(buildID, "modules/notes", "c-notes", "notes", "")
+	result.ReuseKey = "rk-notes"
+	result.Made = []link.MadeArtifact{{Name: "notes", Kind: "image", Reference: "artifact-store://notes/notes@" + digest}}
+	if err := (builds{inv: inv, open: open}).Built(ctx, result); err != nil {
+		t.Fatal(err)
+	}
+
+	// The walk sends the tier to its first machine.
+	for try := 0; try < 3 && len(sent) == 0; try++ {
+		advancePlans(ctx, open)
+	}
+	if !slices.Equal(slices.Concat(sent...), []string{"anchor"}) {
+		t.Fatalf("sent %v", sent)
+	}
+
+	// One read of the assignment.
+	on, err := inv.AssignmentsOn(ctx, "anchor")
+	a, ok := assignmentOf(on, "notes")
+	if err != nil || !ok {
+		t.Fatalf("the assignments of anchor: %+v %v", on, err)
+	}
+	// Beside it a module pulled in by the assignment, which no send of this walk put anywhere.
+	if wireguard, pulled := assignmentOf(on, "mesh-wireguard"); pulled && (wireguard.Build != "" || wireguard.Rollout != "") {
+		t.Fatalf("a module this rollout did not send names a build or a rollout: %+v", wireguard)
+	}
+	if a.Module != "notes" || a.Commit != "c-notes" || a.Build != buildID || a.Rollout != rollout || a.Artifact != digest ||
+		a.Since.IsZero() || a.Assigned.IsZero() || !a.Stands() {
+		t.Fatalf("the assignment names %+v, not commit c-notes, build %s, artifact %s, rollout %s", a, buildID, digest, rollout)
+	}
+	// One read of the rollout.
+	p, err := inv.PlanByID(ctx, rollout)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantChange := chain.Change{Node: "anchor", Module: "notes", After: chain.Ref{Build: buildID, Commit: "c-notes"}}
+	if !slices.Contains(p.Changed, wantChange) || !slices.Contains(p.Builds, buildID) || len(p.Steps) != 1 ||
+		p.Steps[0].Node != "anchor" || p.Steps[0].Sent == nil {
+		t.Fatalf("the rollout lists changed %+v, builds %v, steps %+v; want %+v", p.Changed, p.Builds, p.Steps, wantChange)
+	}
+	// And one read of the build names the same commit, with what it published and its reuse key.
+	built, found, err := inv.BuildByID(ctx, buildID)
+	if err != nil || !found || built.Commit != "c-notes" || built.Module != "notes" {
+		t.Fatalf("the build: %+v %v %v", built, found, err)
+	}
+	lately, err := inv.Builds(ctx, "notes", 1)
+	if err != nil || len(lately) != 1 || lately[0].ReuseKey != "rk-notes" || lately[0].Published == nil ||
+		lately[0].Published.Artifact != digest {
+		t.Fatalf("what the build published: %+v %v", lately, err)
+	}
+	// The verbs say the links.
+	if lines := changedLines(p); len(lines) != 2 || !strings.Contains(lines[1], "anchor/notes") ||
+		!strings.Contains(lines[1], buildID) {
+		t.Fatalf("`plans` says %v", lines)
+	}
+	if lines := runLines(on); len(lines) != 2 || !strings.Contains(lines[1], buildID) || !strings.Contains(lines[1], rollout) {
+		t.Fatalf("`node show` says %v", lines)
+	}
+}
+
+// A machine sent again what it runs says nothing new, and a push by hand with no rollout fills what is missing and blanks
+// nothing (issue 1095).
+func TestASendOfWhatAMachineRunsAlreadyChangesNoLinkOfItsAssignment(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	inv := open.inventory
+	register(t, open, catalogue.Manifest{Module: "notes", Version: "1"})
+	if _, err := assign(ctx, open, "anchor", "notes"); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RecordBuild(ctx, inventory.Build{ID: "build-1", Module: "notes", Commit: "c1", Repository: "novox/notes"}); err != nil {
+		t.Fatal(err)
+	}
+	node := nodeID(t, open, "anchor")
+	inRollout := inventory.WithRollout(ctx, "plan-1", map[string]inventory.RolloutModule{"notes": {Commit: "c1", Build: "build-1"}})
+	if err := inv.RecordSent(inRollout, node, "d1", map[string]string{"notes": "c1"}); err != nil {
+		t.Fatal(err)
+	}
+	// Sent again by hand, with no rollout: the assignment still names the rollout that put the build there.
+	if err := inv.RecordSent(ctx, node, "d2", map[string]string{"notes": "c1"}); err != nil {
+		t.Fatal(err)
+	}
+	on, _ := inv.AssignmentsOn(ctx, "anchor")
+	if a, _ := assignmentOf(on, "notes"); a.Rollout != "plan-1" || a.Build != "build-1" || a.Commit != "c1" {
+		t.Fatalf("the assignment names %+v", on)
+	}
+	// A declaration sent by hand with no builds known says nothing of them.
+	if err := inv.RecordSent(ctx, node, "d3", nil); err != nil {
+		t.Fatal(err)
+	}
+	if on, _ = inv.AssignmentsOn(ctx, "anchor"); runOf(on, "notes").Commit != "c1" {
+		t.Fatalf("a send of unknown builds changed %+v", on)
+	}
+	// A module sent a commit no build is kept of is named by its commit alone.
+	if err := inv.RecordSent(ctx, node, "d4", map[string]string{"notes": "c2"}); err != nil {
+		t.Fatal(err)
+	}
+	if on, _ = inv.AssignmentsOn(ctx, "anchor"); runOf(on, "notes").Commit != "c2" || runOf(on, "notes").Build != "" ||
+		runOf(on, "notes").Rollout != "" {
+		t.Fatalf("the assignment after a push of c2 by hand names %+v", on)
+	}
+}
+
+// assignmentOf is one module's assignment among those of a machine: assigning a module assigns what it requires beside it.
+func assignmentOf(on []chain.Assignment, module string) (chain.Assignment, bool) {
+	for _, a := range on {
+		if a.Module == module {
+			return a, true
+		}
+	}
+	return chain.Assignment{}, false
+}
+
+func runOf(on []chain.Assignment, module string) chain.Assignment {
+	a, _ := assignmentOf(on, module)
+	return a
+}

cmd/mesh-controller/chain_links.go

@@ -0,0 +1,121 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/chain"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// The links a rollout makes (novox/hq ADR 0408 §1, design 47 acceptance 10, issue 1095): the send of a plan's tier puts a
+// build on a machine; the assignment of the module there names the build, its commit and the rollout (written by the record of
+// the send, inventory.RecordSent, from the context a send is made in), and the rollout lists the assignments it changed with the
+// build before and after.
+
+// rolloutModules is what a plan sends of each module: the commit and the build of it.
+func rolloutModules(p *inventory.Plan) map[string]inventory.RolloutModule {
+	out := make(map[string]inventory.RolloutModule, len(p.Modules))
+	for m, s := range p.Modules {
+		if s != nil && s.Commit != "" {
+			out[m] = inventory.RolloutModule{Commit: s.Commit, Build: s.Build}
+		}
+	}
+	return out
+}
+
+// sendingAs is the context a plan's send is made in: what is recorded of the send names this rollout.
+func sendingAs(ctx context.Context, p *inventory.Plan) context.Context {
+	return inventory.WithRollout(ctx, p.ID, rolloutModules(p))
+}
+
+// ranBefore is what each module on a machine ran before a send, as the chain names it: its assignment's build and commit,
+// else the commit the machine was last sent for it. Read before the send, which writes the new ones.
+func ranBefore(ctx context.Context, inv *inventory.Inventory, node string) map[string]chain.Ref {
+	was := map[string]chain.Ref{}
+	if sent, known, err := inv.SentBuilds(ctx, node); err == nil && known {
+		for m, commit := range sent {
+			was[m] = chain.Ref{Commit: commit}
+		}
+	}
+	if ran, err := inv.AssignmentRuns(ctx, node); err == nil {
+		for m, r := range ran {
+			was[m] = r
+		}
+	}
+	return was
+}
+
+// noteChanges writes into a plan that a send to a machine changed the assignments of the modules it carried: the build and
+// commit before and after, the builds the rollout carried, and the step taken. A change noted already for the machine and the
+// module is replaced, so a send made again says it once.
+func noteChanges(p *inventory.Plan, node string, modules []string, was map[string]chain.Ref, at time.Time) {
+	for _, m := range modules {
+		s := p.Modules[m]
+		if s == nil {
+			continue
+		}
+		change := chain.Change{Node: node, Module: m, Before: was[m], After: chain.Ref{Build: s.Build, Commit: s.Commit}}
+		if at := slices.IndexFunc(p.Changed, func(c chain.Change) bool { return c.Node == node && c.Module == m }); at >= 0 {
+			change.Before = p.Changed[at].Before
+			p.Changed[at] = change
+		} else {
+			p.Changed = append(p.Changed, change)
+		}
+		if s.Build != "" && !slices.Contains(p.Builds, s.Build) {
+			p.Builds = append(p.Builds, s.Build)
+		}
+	}
+	if !slices.ContainsFunc(p.Steps, func(s chain.Step) bool { return s.Tier == p.Tier && s.Node == node }) {
+		sent := at.UTC()
+		p.Steps = append(p.Steps, chain.Step{Tier: p.Tier, Node: node, Sent: &sent})
+	}
+}
+
+// refSaid is a build and the commit it was made from as a person reads them; "nothing" for a module that ran none.
+func refSaid(r chain.Ref) string {
+	switch {
+	case r.Build == "" && r.Commit == "":
+		return "nothing"
+	case r.Build == "":
+		return "commit " + short(r.Commit)
+	}
+	return r.Build + " (" + short(r.Commit) + ")"
+}
+
+// changedLines say the assignments a rollout changed: the machine, the module, and the build before and after.
+func changedLines(p inventory.Plan) []string {
+	if len(p.Changed) == 0 {
+		return nil
+	}
+	out := []string{"  changed:"}
+	for _, c := range p.Changed {
+		out = append(out, fmt.Sprintf("    %s/%s  %s → %s", c.Node, c.Module, refSaid(c.Before), refSaid(c.After)))
+	}
+	return out
+}
+
+// runLines say what each module assigned to a machine runs there, as its assignment names it: the build, the commit, the
+// rollout that put it there and since when.
+func runLines(assigned []chain.Assignment) []string {
+	var out []string
+	for _, a := range assigned {
+		if a.Build == "" && a.Commit == "" {
+			continue
+		}
+		line := fmt.Sprintf("    %-22s %s", a.Module, refSaid(chain.Ref{Build: a.Build, Commit: a.Commit}))
+		if a.Rollout != "" {
+			line += ", sent by " + a.Rollout
+		}
+		if !a.Since.IsZero() {
+			line += " at " + a.Since.Local().Format("2006-01-02 15:04")
+		}
+		out = append(out, line)
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return append([]string{"  what they run, as the chain names it:"}, out...)
+}

cmd/mesh-controller/chain_links_test.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/chain"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// **A rollout lists the assignments it changed, each with the build before and after** (ADR 0408 §1, issue 1095): one
+// change for a machine and a module however often the send is noted, the build before kept from the first, the builds the
+// rollout carried once each, and one step for a machine and a tier.
+func TestARolloutListsTheAssignmentsItChangedWithTheBuildBeforeAndAfter(t *testing.T) {
+	at := time.Date(2026, 10, 18, 3, 0, 0, 0, time.UTC)
+	p := inventory.Plan{ID: "plan-1", Tier: 1, Modules: map[string]*inventory.PlanModule{
+		"notes": {Commit: "c2", Build: "b2"}, "wiki": {Commit: "c2w", Build: "b2w"}, "nothing": nil}}
+	was := map[string]chain.Ref{"notes": {Build: "b1", Commit: "c1"}, "wiki": {Commit: "c1w"}}
+
+	noteChanges(&p, "anchor", []string{"notes", "wiki", "nothing"}, was, at)
+	noteChanges(&p, "laptop", []string{"notes"}, nil, at)
+	// The send noted again, after what was sent had become what the machine runs: the first before stands.
+	noteChanges(&p, "anchor", []string{"notes"}, map[string]chain.Ref{"notes": {Build: "b2", Commit: "c2"}}, at.Add(time.Minute))
+
+	want := []chain.Change{
+		{Node: "anchor", Module: "notes", Before: chain.Ref{Build: "b1", Commit: "c1"}, After: chain.Ref{Build: "b2", Commit: "c2"}},
+		{Node: "anchor", Module: "wiki", Before: chain.Ref{Commit: "c1w"}, After: chain.Ref{Build: "b2w", Commit: "c2w"}},
+		{Node: "laptop", Module: "notes", After: chain.Ref{Build: "b2", Commit: "c2"}},
+	}
+	if len(p.Changed) != len(want) {
+		t.Fatalf("changed %+v", p.Changed)
+	}
+	for k := range want {
+		if p.Changed[k] != want[k] {
+			t.Errorf("change %d is %+v, want %+v", k, p.Changed[k], want[k])
+		}
+	}
+	if len(p.Builds) != 2 || p.Builds[0] != "b2" || p.Builds[1] != "b2w" {
+		t.Errorf("builds %v", p.Builds)
+	}
+	if len(p.Steps) != 2 || p.Steps[0].Node != "anchor" || p.Steps[0].Tier != 1 || p.Steps[0].Sent == nil || p.Steps[1].Node != "laptop" {
+		t.Errorf("steps %+v", p.Steps)
+	}
+	lines := changedLines(p)
+	if len(lines) != 4 || !strings.Contains(lines[1], "anchor/notes  b1 (c1) → b2 (c2)") ||
+		!strings.Contains(lines[3], "laptop/notes  nothing → b2 (c2)") {
+		t.Errorf("changed lines %q", lines)
+	}
+	if got := changedLines(inventory.Plan{}); got != nil {
+		t.Errorf("a plan that changed nothing says %q", got)
+	}
+}
+
+func TestWhatAMachineRunsIsSaidAsItsAssignmentNamesIt(t *testing.T) {
+	at := time.Date(2026, 10, 18, 3, 0, 0, 0, time.UTC)
+	lines := runLines([]chain.Assignment{
+		{Node: "anchor", Module: "notes", Build: "b2", Commit: "c2c2c2c2c2c2", Rollout: "plan-1", Since: at},
+		{Node: "anchor", Module: "web", Commit: "c3"},
+		{Node: "anchor", Module: "never-sent"},
+	})
+	if len(lines) != 3 || !strings.Contains(lines[1], "notes") || !strings.Contains(lines[1], "b2 (c2c2c2c2)") ||
+		!strings.Contains(lines[1], "sent by plan-1") || !strings.Contains(lines[2], "web") || !strings.Contains(lines[2], "commit c3") {
+		t.Fatalf("lines %q", lines)
+	}
+	if runLines([]chain.Assignment{{Node: "a", Module: "m"}}) != nil {
+		t.Fatal("a module never sent is said to run something")
+	}
+}

cmd/mesh-controller/changeplan.go

@@ -0,0 +1,221 @@
+package main
+
+import (
+	"fmt"
+	"path"
+	"slices"
+	"sort"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The change plan (novox/hq ADR 0238): **one commit, one plan** — what a change does to the mesh, computed
+// from its diffset (a repository, the branch it merges into, the commit at hand) by the planner, never by
+// a mapping of its own. reachOfMerge answers what moves and what follows it; this adds where each module
+// goes — the deploy plan, machine by machine in the build plan's order — and what is not an ordinary
+// send. A pull request's check posts it with its verdict; the release a merge makes follows the same
+// planner, so the two can be compared.
+
+// policyOf is a module's upgrade policy, as the controller holds it; false when it cannot be read.
+type policyOf func(module string) (inventory.Upgrade, bool)
+
+// changePlanOf is the change plan of a reach: pure, so it is tested without a store.
+func changePlanOf(repository, base, head string, r mergeReach, entries []inventory.Entry, policy policyOf) link.ChangePlan {
+	p := link.ChangePlan{Repository: repository, Base: base, Head: head, Moved: r.Moved(), Dependents: r.Dependents(),
+		New: r.Added, Unread: r.Unread, Tiers: r.Plan.Tiers}
+	byName := map[string]inventory.Entry{}
+	for _, e := range entries {
+		byName[e.Manifest.Module] = e
+	}
+	// The machine holding the bus, whose declaration carries every module's grants (novox/hq issue 490).
+	holder := ""
+	for _, e := range entries {
+		if e.Manifest.BusUsers != "" && e.Manifest.ClaimsSeat(catalogue.BrokerSeat) && len(e.On) > 0 {
+			holder = e.On[0]
+		}
+	}
+	var granting []string
+	machines := map[string]*link.MachinePlan{}
+	machine := func(name string) *link.MachinePlan {
+		if machines[name] == nil {
+			machines[name] = &link.MachinePlan{Machine: name}
+		}
+		return machines[name]
+	}
+	for _, tier := range r.Plan.Tiers {
+		for _, name := range tier {
+			e, held := byName[name]
+			if !held {
+				continue
+			}
+			u, known := policy(name)
+			waits := known && !u.RollOut
+			for _, on := range e.On {
+				if waits {
+					machine(on).Waits = append(machine(on).Waits, name)
+				} else {
+					machine(on).Receives = append(machine(on).Receives, name)
+				}
+			}
+			if !waits && holder != "" && !(len(e.On) == 1 && e.On[0] == holder) && len(e.On) > 0 &&
+				!slices.Contains(granting, name) {
+				granting = append(granting, name)
+			}
+			switch {
+			case (name == "nats" || catalogue.ProvidesBus(e.Manifest)) && len(e.On) > 0:
+				// Said before the merge (novox/hq issue 336): a new bus build holds every send to the bus's machine
+				// until a person takes the step, so merging it is a promise to take it.
+				p.Steps = append(p.Steps, fmt.Sprintf("%s: %s is never sent by an ordinary send, and until %s runs, "+
+					"nothing else is sent to %s either — unless the new build turns out the same as the one running there "+
+					"(issue 280)", busUpgradeNeeded, name, busUpgradeVerb, strings.Join(e.On, ", ")))
+			case name == "nats" || catalogue.ProvidesBus(e.Manifest):
+				p.Steps = append(p.Steps, "a planned bus step: the bus is upgraded by `bus upgrade`, never by an ordinary send")
+			case waits && len(e.On) > 0 && (u.From == catalogue.FromModule || u.From == catalogue.FromData):
+				// Judged per machine by the walk, against the build each was last sent (novox/hq ADR 0377).
+				p.Steps = append(p.Steps, fmt.Sprintf("%s waits for a person: its policy records (%s) — unless on a machine "+
+					"its move recreates none of its containers and moves none of its data, which the walk judges and then sends",
+					name, orNone(u.From)))
+			case waits && len(e.On) > 0:
+				p.Steps = append(p.Steps, fmt.Sprintf("%s waits for a person: its policy records (%s)", name,
+					orNone(u.From)))
+			}
+			if len(e.Manifest.Provides) > 0 && len(e.On) > 0 {
+				var offers []string
+				for _, o := range e.Manifest.Provides {
+					offers = append(offers, o.Name)
+				}
+				p.Steps = append(p.Steps, fmt.Sprintf("%s provides %s: its consumers are sent again after it",
+					name, strings.Join(offers, ", ")))
+			}
+			if e.Manifest.Data != nil && len(e.On) > 0 {
+				p.Steps = append(p.Steps, fmt.Sprintf("%s keeps data (ADR 0233): what it holds is backed up before it moves", name))
+			}
+		}
+	}
+	if len(granting) > 0 {
+		// Said before the merge (novox/hq issue 490): what the walk does when the change alters the bus's
+		// user list. Whether it does is known only once the builds are registered, so it is said as a rule.
+		p.Steps = append(p.Steps, fmt.Sprintf("%s: if this changes what the bus's user list says (a new tool, "+
+			"subject or user), %s is sent that list alone, every build there kept, before %s is judged on its first "+
+			"machine", grantsStepWord, holder, strings.Join(granting, ", ")))
+	}
+	var names []string
+	for name := range machines {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		p.Machines = append(p.Machines, *machines[name])
+	}
+	p.Summary = summaryOf(p)
+	p.Class = changeClassOf(p, entries)
+	return p
+}
+
+// classNone is the class of a change that moves no module: nothing for a walk to move (novox/hq ADR 0313 §2).
+const classNone = "none"
+
+// changeClassOf is a change plan's class (novox/hq ADR 0313 §2): that of the slowest-budgeted module it moves,
+// itself or as a dependent — core when one is on the controller's own path or holds the mesh's resolver, leaf
+// otherwise — and none when it moves nothing. A module it adds a directory for counts by its own class: the
+// catalogue names a module's directory by the module, so the directory's last element is its name. The graph holds
+// no manifest of it yet, so a new module is core by its name alone (on the controller's own path), never by a
+// resolver claim its manifest makes.
+func changeClassOf(p link.ChangePlan, entries []inventory.Entry) string {
+	if len(p.Moved) == 0 && len(p.Dependents) == 0 && len(p.New) == 0 {
+		return classNone
+	}
+	modules := append(append([]string{}, p.Moved...), p.Dependents...)
+	for _, dir := range p.New {
+		if name := path.Base(strings.Trim(dir, "/")); name != "." && name != "/" && name != "" {
+			modules = append(modules, name)
+		}
+	}
+	return classOfModules(modules, entries)
+}
+
+// grantsStepWord names the grants step (novox/hq issue 490): the bus's user list sent alone to the machine
+// holding the bus ahead of a walk's gate. Not the bus step, which replaces the bus itself.
+const grantsStepWord = "grants step"
+
+// busUpgradeNeeded is how a change plan says that merging it holds the bus's machine for a person's step.
+const busUpgradeNeeded = "merging this needs a person's bus upgrade"
+
+// summaryOf is a change plan in one line: what it builds, where it goes, and whether the bus moves.
+func summaryOf(p link.ChangePlan) string {
+	if len(p.Moved) == 0 && len(p.New) == 0 {
+		return "builds nothing: the change touches no module of the mesh's graph"
+	}
+	var parts []string
+	what := strings.Join(p.Moved, ", ")
+	if len(p.Dependents) > 0 {
+		what += fmt.Sprintf(" (+%d dependent(s))", len(p.Dependents))
+	}
+	if len(p.New) > 0 {
+		if what != "" {
+			what += ", "
+		}
+		what += "new: " + strings.Join(p.New, ", ")
+	}
+	var to []string
+	for _, m := range p.Machines {
+		if len(m.Receives) > 0 {
+			to = append(to, m.Machine)
+		}
+	}
+	if len(to) > 0 {
+		parts = append(parts, "builds "+what+" → "+strings.Join(to, ", "))
+	} else {
+		parts = append(parts, "builds "+what+", sent nowhere")
+	}
+	bus := "no bus step"
+	for _, s := range p.Steps {
+		switch {
+		case strings.HasPrefix(s, busUpgradeNeeded):
+			bus = busUpgradeNeeded
+		case strings.HasPrefix(s, "a planned bus step") && bus == "no bus step":
+			bus = "a bus step"
+		}
+	}
+	parts = append(parts, bus)
+	waiting := 0
+	for _, m := range p.Machines {
+		waiting += len(m.Waits)
+	}
+	if waiting > 0 {
+		parts = append(parts, fmt.Sprintf("%d wait(s) for a person", waiting))
+	}
+	return strings.Join(parts, "; ")
+}
+
+// planText is a change plan as a person reads it, for the pull request's comment.
+func planText(p link.ChangePlan) string {
+	var b strings.Builder
+	fmt.Fprintf(&b, "change plan of %s at %.8s into %s: %s\n", p.Repository, p.Head, p.Base, p.Summary)
+	for i, tier := range p.Tiers {
+		fmt.Fprintf(&b, "  tier %d: %s\n", i, strings.Join(tier, ", "))
+	}
+	for _, m := range p.Machines {
+		line := "  " + m.Machine + ": "
+		if len(m.Receives) > 0 {
+			line += "receives " + strings.Join(m.Receives, ", ")
+		}
+		if len(m.Waits) > 0 {
+			if len(m.Receives) > 0 {
+				line += "; "
+			}
+			line += "waits for a person: " + strings.Join(m.Waits, ", ")
+		}
+		b.WriteString(line + "\n")
+	}
+	for _, s := range p.Steps {
+		b.WriteString("  - " + s + "\n")
+	}
+	if len(p.Unread) > 0 {
+		fmt.Fprintf(&b, "  read by no module's build: %s\n", strings.Join(p.Unread, ", "))
+	}
+	return b.String()
+}

cmd/mesh-controller/changeplan_test.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **One commit, one change plan** (novox/hq ADR 0238): the planner's reach, laid out machine by machine in
+// the build plan's order, with what is not an ordinary send said — the bus step, a module that waits for a
+// person, a provider whose consumers follow it.
+func TestAChangePlanSaysWhatEachMachineReceives(t *testing.T) {
+	const catalogue_ = "http://forge.internal:20000/novox/mesh-catalog.git"
+	entry := func(name, path string, on ...string) inventory.Entry {
+		e := fromRepo(name, catalogue_, path)
+		e.Source.BuiltFrom = "old"
+		e.On = on
+		return e
+	}
+	nats := entry("nats", "modules/nats", "anchor")
+	nats.Manifest.Provides = []catalogue.Offer{{Name: "mesh-bus"}}
+	gitea := entry("gitea", "modules/gitea", "anchor")
+	held := entry("photos", "modules/photos", "anchor", "laptop")
+	tools := fromRepo("node-tools", "http://forge.internal:20000/novox/mesh-tools.git", "node-tools")
+	tools.On = []string{"anchor", "laptop"}
+	entries := []inventory.Entry{nats, gitea, held, tools}
+	edges := []inventory.Edge{{From: "node-tools", To: "nats", Kind: inventory.EdgeStandsOn}}
+	policy := func(module string) (inventory.Upgrade, bool) {
+		if module == "photos" {
+			return inventory.Upgrade{RollOut: false, From: "a person"}, true
+		}
+		return inventory.Upgrade{RollOut: true}, true
+	}
+	plan := func(paths ...string) link.ChangePlan {
+		m := link.SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "head", Paths: paths}
+		return changePlanOf("novox/mesh-catalog", "main", "head", reachOfMerge(m, entries, nil, edges), entries, policy)
+	}
+
+	p := plan("modules/gitea/index.ts")
+	if p.Summary != "builds gitea → anchor; no bus step" {
+		t.Errorf("one module's change reads %q", p.Summary)
+	}
+
+	p = plan("modules/nats/Dockerfile", "modules/photos/x.js")
+	if !strings.Contains(p.Summary, "needs a person's bus upgrade") || !strings.Contains(p.Summary, "2 wait(s) for a person") ||
+		!strings.Contains(p.Summary, "(+1 dependent(s))") {
+		t.Errorf("the bus and a held module read %q", p.Summary)
+	}
+	got := map[string]string{}
+	for _, m := range p.Machines {
+		got[m.Machine] = strings.Join(m.Receives, ",") + "|" + strings.Join(m.Waits, ",")
+	}
+	// The bus first, what stands on it after: the build plan's order, per machine.
+	if got["anchor"] != "nats,node-tools|photos" || got["laptop"] != "node-tools|photos" {
+		t.Errorf("the deploy plan reads %v", got)
+	}
+	text := strings.Join(p.Steps, "\n")
+	// Said before the merge (novox/hq issue 336): merging it holds every send to the bus's machine until a
+	// person runs the bus's step, and the verb that does.
+	for _, want := range []string{"merging this needs a person's bus upgrade", "nothing else is sent to anchor",
+		"mesh_call mesh-controller.bus", "the same as the one running there", "photos waits for a person",
+		"nats provides mesh-bus"} {
+		if !strings.Contains(text, want) {
+			t.Errorf("the steps do not say %q:\n%s", want, text)
+		}
+	}
+
+	p = plan("merge-check.sh")
+	if !strings.HasPrefix(p.Summary, "builds nothing") || len(p.Machines) != 0 || strings.Join(p.Unread, ",") != "merge-check.sh" {
+		t.Errorf("a root file's plan reads %+v", p)
+	}
+	if !strings.Contains(planText(p), "read by no module's build: merge-check.sh") {
+		t.Errorf("the plan's text does not say why nothing is built:\n%s", planText(p))
+	}
+}

cmd/mesh-controller/check.go

@@ -0,0 +1,337 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// moduleCheck judges manifests where they are written, with no mesh (novox/hq ADR 0037, issue 148).
+//
+// **The same functions registration runs, and nothing the command line adds** (ADR 0035): the strict
+// parse with every per-manifest problem, then the rules no single manifest can be judged against,
+// over exactly the manifests given. Somebody describing their own application in their own
+// repository runs this before pushing and finds out there, rather than when a running mesh refuses
+// the registration or, later, when a machine applies something that resolved and should not have.
+//
+// **What it cannot know without a store, it says.** The mesh's own seat set is the store's (ADR
+// 0122); this binary carries a compiled copy that the store overrides when loaded, so a claim on a
+// mesh seat is judged fully only at registration. A seat another module declares is unknown unless
+// that module's manifest is passed too. Both are printed as a note, not as a problem — a check that
+// refused what it could not see would teach people to ignore it.
+//
+// **And every identity against every bound it meets** (novox/hq ADR 0225, issue 263): each module's
+// identity, on a machine whose name is `longestMachine` characters, against the bound of every
+// provision it wants that a manifest given here offers. An overflow is refused in the pull request
+// that introduces it — a new requirement, a lowered bound, a longer slug — instead of on the
+// provider's machine when a real machine's name first meets the module's.
+// SomeManifestsVar, set by the merge gate, says the manifests given are only some of their repository's.
+const SomeManifestsVar = "MESH_MODULE_CHECK_SOME"
+
+func moduleCheck(paths []string, out io.Writer) error {
+	return moduleCheckFor(paths, catalogue.DefaultLongestMachine, out)
+}
+
+func moduleCheckFor(paths []string, longestMachine int, out io.Writer) error {
+	if len(paths) == 0 {
+		return errors.New("module check <manifest.json>... — one file per module; pass every " +
+			"manifest of a repository together so the rules between them are checked too")
+	}
+	shelf := catalogue.Shelf{}
+	faulted := map[string]bool{}
+	failed := 0
+	// The list of predefined keys at the root of the repository above each manifest (novox/hq ADR 0348 §7), read
+	// once per repository: a manifest naming a key is judged against the list its own tree holds.
+	lists := map[string]catalogue.PredefinedList{}
+	listOf := func(path string) (catalogue.PredefinedList, error) {
+		root := catalogue.RepositoryRoot(filepath.Dir(path))
+		if root == "" {
+			return nil, nil
+		}
+		if list, read := lists[root]; read {
+			return list, nil
+		}
+		list, err := catalogue.ReadPredefined(root)
+		if err != nil {
+			return nil, err
+		}
+		lists[root] = list
+		return list, nil
+	}
+	for _, path := range paths {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			fmt.Fprintf(out, "%s: %v\n", path, err)
+			failed++
+			continue
+		}
+		list, err := listOf(path)
+		if err != nil {
+			fmt.Fprintf(out, "%s: %v\n", path, err)
+			failed++
+			continue
+		}
+		m, err := catalogue.ParseManifestWith(raw, list)
+		if err == nil {
+			// Each template's text read from the tree beside the manifest, and judged as inline content is
+			// (novox/hq ADR 0349 §2): a missing template is refused by name.
+			m, err = catalogue.WithTemplatesFrom(m, filepath.Dir(path))
+		}
+		if err != nil {
+			fmt.Fprintf(out, "%s: %v\n", path, err)
+			failed++
+			continue
+		}
+		if first, twice := shelf[m.Module]; twice {
+			_ = first
+			fmt.Fprintf(out, "%s: %s was already given; two manifests name one module\n", path, m.Module)
+			failed++
+			continue
+		}
+		// A definition names no installation (novox/hq ADR 0112, ADR 0155): judged here, in the
+		// catalogue-wide test, and at registration, which refuses in the same words.
+		if wrong := catalogue.TrustProblems(m); len(wrong) > 0 {
+			for _, p := range wrong {
+				fmt.Fprintf(out, "%s: %s\n", path, p)
+			}
+			failed += len(wrong)
+			faulted[m.Module] = true
+		}
+		// A module that declares a setting names the keys of its mergeable files (novox/hq ADR 0326 §3,
+		// issue 574): judged where a definition is written, as at registration, never where a stored
+		// build is read again.
+		if wrong := catalogue.WrittenSettingsProblems(m); len(wrong) > 0 {
+			for _, p := range wrong {
+				fmt.Fprintf(out, "%s: %s\n", path, p)
+			}
+			failed += len(wrong)
+			faulted[m.Module] = true
+		}
+		// A module lives whole in one repository (novox/hq ADR 0420 §1, issue 1019): when the check is told the
+		// repository it runs for (MESH_CHECK_REPOSITORY, set by the build's check), an artifact building from
+		// another is refused, as the merge gate refuses it. A run by hand names no repository and judges none.
+		if repo := os.Getenv("MESH_CHECK_REPOSITORY"); repo != "" && m.Build != nil {
+			for _, a := range m.Build.Artifacts {
+				if a.Context != nil && a.Context.Repository != "" && !sameRepository(a.Context.Repository,
+					link.SourceMoved{Owner: ownerOf(repo), Repo: repoOf(repo)}) {
+					fmt.Fprintf(out, "%s: %s builds artifact %s from %s: a module lives whole in one repository "+
+						"(novox/hq ADR 0420 §1)\n", path, m.Module, a.Name, a.Context.Repository)
+					failed++
+					faulted[m.Module] = true
+				}
+			}
+		}
+		if named := catalogue.InstallationProblems(m); len(named) > 0 {
+			for _, p := range named {
+				fmt.Fprintf(out, "%s: %s\n", path, p)
+			}
+			failed += len(named)
+			faulted[m.Module] = true
+		}
+		shelf[m.Module] = m
+	}
+
+	// Between the manifests: a seat declared twice, a use of a seat nothing declares, a claim on
+	// a seat that does not exist. Run only over what parsed, because a problem inside one manifest
+	// has already been said and would be said again here in a worse form.
+	//
+	// **Over some of a repository's manifests, a seat none of them declares is a note** (novox/hq issue 364), as
+	// this command's own word says above: the merge gate passes only the manifests a change touches, and says so
+	// with SomeManifestsVar, so a module that uses or claims a seat another module declares (the operator
+	// channel's, a channel bench) was refused there for a manifest it was not given. Given every manifest — the
+	// catalogue's own check, and registration — it stays a refusal.
+	some := os.Getenv(SomeManifestsVar) != ""
+	problems := catalogue.CatalogueProblems(shelf)
+	sort.Strings(problems)
+	for _, p := range problems {
+		if some && catalogue.IsUndeclaredSeat(p) {
+			fmt.Fprintf(out, "note: %s among the manifests given; registration judges it against the whole catalogue, "+
+				"and passing the declaring module's manifest too judges it here\n", p)
+			continue
+		}
+		fmt.Fprintln(out, p)
+		failed++
+	}
+
+	// Between the manifests too: an identity against the bounds of the provisions it wants, which
+	// only the provider's manifest states.
+	identities := catalogue.IdentityProblems(shelf, longestMachine)
+	sort.Strings(identities)
+	for _, p := range identities {
+		fmt.Fprintln(out, p)
+	}
+	failed += len(identities)
+
+	// And the data each module keeps (novox/hq ADR 0233): a provider that grants says what it keeps for
+	// its consumers, a directory a container writes is declared, and no backup line is written by hand.
+	data := catalogue.DataProblems(shelf)
+	sort.Strings(data)
+	for _, p := range data {
+		fmt.Fprintln(out, p)
+	}
+	failed += len(data)
+
+	var names []string
+	for name := range shelf {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	// **Every long-running resource says how it is ready** (novox/hq ADR 0240 rule 8): warned until the
+	// date, refused from it. The count is the catalogue's: its merge check keeps the number and lets a
+	// change lower it, never raise it.
+	undeclared := 0
+	required := !checkNow().Before(catalogue.HealthRequiredFrom)
+	for _, name := range names {
+		missing := catalogue.Undeclared(shelf[name])
+		undeclared += len(missing)
+		if len(missing) == 0 {
+			continue
+		}
+		if required {
+			for _, id := range missing {
+				fmt.Fprintf(out, "%s: %s stays up and does not say how it is ready: a long-running resource declares "+
+					"health since %s (novox/hq ADR 0240 rule 8)\n", name, id, catalogue.HealthRequiredFrom.Format("2006-01-02"))
+			}
+			failed += len(missing)
+			faulted[name] = true
+		}
+	}
+
+	// **A file that asks for a setting and does not say whether it is trusted counts as trusted** (novox/hq issue
+	// 339): listed and counted, never refused, so an author can opt out a file nothing trusts.
+	unsaid := 0
+	for _, name := range names {
+		unsaid += len(catalogue.UnsaidTrust(shelf[name]))
+	}
+
+	for _, name := range names {
+		m := shelf[name]
+		if faulted[name] {
+			continue
+		}
+		fmt.Fprintf(out, "%s: ok", name)
+		if n := len(m.Tools); n > 0 {
+			fmt.Fprintf(out, ", %d tool(s)", n)
+		}
+		if len(m.Invokes) > 0 {
+			fmt.Fprintf(out, ", invokes %s", joinInvokes(m.Invokes))
+		}
+		// The state it keeps and reads (novox/hq ADR 0201), so a reviewer sees what lands on the bus.
+		if len(m.State) > 0 {
+			kept := make([]string, 0, len(m.State))
+			for _, s := range m.State {
+				kept = append(kept, s.Name)
+			}
+			fmt.Fprintf(out, ", keeps state %s", strings.Join(kept, ", "))
+		}
+		// And the logs it keeps, with their caps (novox/hq ADR 0297).
+		if len(m.Logs) > 0 {
+			kept := make([]string, 0, len(m.Logs))
+			for _, l := range m.Logs {
+				kept = append(kept, fmt.Sprintf("%s (%d MiB)", l.Name, l.Cap()))
+			}
+			fmt.Fprintf(out, ", keeps log %s", strings.Join(kept, ", "))
+		}
+		if len(m.Reads) > 0 {
+			fmt.Fprintf(out, ", reads %s", strings.Join(m.Reads, ", "))
+		}
+		// The data it keeps, by class, so a reviewer sees what the mesh will protect and how.
+		if items := m.DataItems(); len(items) > 0 {
+			kept := make([]string, 0, len(items))
+			for _, it := range items {
+				kept = append(kept, it.ID+" ("+it.Class+")")
+			}
+			fmt.Fprintf(out, ", keeps %s", strings.Join(kept, ", "))
+		}
+		// How what it runs is ready (ADR 0240): each declared check, and what is judged by liveness alone.
+		var checks []string
+		for _, r := range m.Resources {
+			if h, has, _ := catalogue.ReadHealth(r); has {
+				checks = append(checks, fmt.Sprintf("%v by %s", r["id"], catalogue.HealthWords(h)))
+			}
+		}
+		// And its own runtime's, where it runs as its own account (novox/hq ADR 0366).
+		if own, has := catalogue.OwnRuntimeHealth(m); has {
+			if h, _, _ := catalogue.ReadHealth(own); h.Kind != "" {
+				checks = append(checks, fmt.Sprintf("%v by %s", own["id"], catalogue.HealthWords(h)))
+			}
+		}
+		if len(checks) > 0 {
+			fmt.Fprintf(out, ", ready: %s", strings.Join(checks, "; "))
+		}
+		if missing := catalogue.UnsaidTrust(m); len(missing) > 0 {
+			fmt.Fprintf(out, "; WARNING: %s ask(s) for a setting and do(es) not say whether it is trusted, so it counts as "+
+				"trusted: set at the terminal alone; say %q false where nothing trusts it (novox/hq issue 339)",
+				strings.Join(missing, ", "), catalogue.TrustedField)
+		}
+		if missing := catalogue.Undeclared(m); len(missing) > 0 {
+			fmt.Fprintf(out, "; WARNING: %s stay(s) up and say(s) not how it is ready — judged by liveness alone, "+
+				"refused from %s (ADR 0240 rule 8)", strings.Join(missing, ", "), catalogue.HealthRequiredFrom.Format("2006-01-02"))
+		}
+		fmt.Fprintln(out)
+	}
+	// The count the catalogue keeps (ADR 0240 rule 8), in a line its merge check reads.
+	fmt.Fprintf(out, "%s %d\n", UndeclaredHealthLine, undeclared)
+	fmt.Fprintf(out, "%s %d\n", UnsaidTrustLine, unsaid)
+	if failed > 0 {
+		return fmt.Errorf("%d problem(s) in %d manifest(s)", failed, len(paths))
+	}
+	fmt.Fprintf(out, "%d manifest(s) checked. Judged against the seats this binary carries; a claim on "+
+		"one of the mesh's own seats is judged fully at registration, and a seat declared by a "+
+		"module not given here reads as unknown. Identities judged on a %d-character machine name, "+
+		"against the bounds of the providers given here\n", len(paths), longestMachine)
+	return nil
+}
+
+// UndeclaredHealthLine starts the line `module check` says the count of long-running resources without
+// `health` in, over the manifests given: the catalogue's merge check compares it with the number it keeps.
+const UndeclaredHealthLine = "long-running resources without health:"
+
+// UnsaidTrustLine starts the line `module check` says the count of files that ask for a setting and do not say
+// whether it is trusted, and so count as trusted (novox/hq issue 339).
+const UnsaidTrustLine = "files asking for a setting without saying whether it is trusted:"
+
+// checkNow is the clock `module check` judges the date by; a test sets it.
+var checkNow = time.Now
+
+func joinInvokes(invokes []string) string {
+	if len(invokes) == 1 && invokes[0] == "*" {
+		return "every tool"
+	}
+	s := ""
+	for i, t := range invokes {
+		if i > 0 {
+			s += ", "
+		}
+		s += t
+	}
+	return s
+}
+
+// manifestsUnder lists every module.json below a directory, for `module check <dir>`.
+func manifestsUnder(dir string) ([]string, error) {
+	var found []string
+	err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.IsDir() && (d.Name() == "node_modules" || d.Name() == ".git" || d.Name() == "dist") {
+			return filepath.SkipDir
+		}
+		if !d.IsDir() && d.Name() == "module.json" {
+			found = append(found, path)
+		}
+		return nil
+	})
+	sort.Strings(found)
+	return found, err
+}

cmd/mesh-controller/check_builds.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+
+	"github.com/novox/mesh-controller/internal/builder"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// A pull request's check builds go when it closes (novox/hq ADR 0350 §5): the build seat keeps them in the artifact
+// store's scratch namespace for the walk of its merge to take. **Let go of where the moment is heard**: the
+// controller ends the walk answering a merge — after that walk took what it reuses — and the delivery's owner, which
+// hears the forge say a pull request closed unmerged, asks the `forget-checks` verb; both let go through the store,
+// as the controller's own collection does. The build seat's holders let go of anything a week old on their own,
+// so a word lost here leaves a week's builds, never more.
+
+// checkBuildsIn is the scratch namespace as the controller reaches the artifact store.
+func checkBuildsIn(ctx context.Context, inv *inventory.Inventory) (builder.Scratch, error) {
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return nil, err
+	}
+	address, err := artifactStoreAddress(ctx, inv, shelf, "")
+	if err != nil {
+		return nil, err
+	}
+	if address == "" {
+		return nil, errors.New("the artifact store is not on the mesh's network")
+	}
+	return builder.Registry{Address: address}, nil
+}
+
+// forgetChecks lets go of a pull request's check builds and answers what it did.
+var forgetChecks = func(ctx context.Context, inv *inventory.Inventory, pull builder.PullRef) (string, error) {
+	scratch, err := checkBuildsIn(ctx, inv)
+	if err != nil {
+		return "", err
+	}
+	n, err := scratch.Forget(ctx, pull)
+	if err != nil {
+		return "", fmt.Errorf("%s: %d check(s)' builds let go of, and not all: %w", pull, n, err)
+	}
+	return fmt.Sprintf("%s: %d check(s)' builds let go of", pull, n), nil
+}
+
+// forgetChecksOfWalk lets go, on the save that ends a walk, of the check builds of every pull request whose merge
+// it answers: the walk took what it reuses. Said, never fatal.
+func forgetChecksOfWalk(ctx context.Context, inv *inventory.Inventory, p inventory.Plan) {
+	if p.WalkSaid != inventory.WalkEnded || p.Delivery == nil {
+		return
+	}
+	for _, pull := range reuseAskOf(&p).Pulls {
+		said, err := forgetChecks(ctx, inv, builder.PullRef{Owner: pull.Owner, Repo: pull.Repo, Number: pull.Number})
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s: its check builds stay until the week's sweep: %v\n", p.ID, err)
+			continue
+		}
+		fmt.Printf("%s: %s\n", p.ID, said)
+	}
+}
+
+// forgetChecksCommand is `forget-checks <owner> <repo> <number>`: the verb the delivery's owner asks when the forge
+// says a pull request closed unmerged (novox/hq ADR 0350 §5).
+func forgetChecksCommand(ctx context.Context, args []string) error {
+	if len(args) != 3 {
+		return errors.New("forget-checks <owner> <repo> <number>")
+	}
+	number, err := strconv.Atoi(args[2])
+	if err != nil || number <= 0 {
+		return fmt.Errorf("%q is not a pull request's number", args[2])
+	}
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	said, err := forgetChecks(ctx, open.inventory, builder.PullRef{Owner: args[0], Repo: args[1], Number: number})
+	if err != nil {
+		return err
+	}
+	fmt.Println(said)
+	return nil
+}

cmd/mesh-controller/check_builds_integration_test.go

@@ -0,0 +1,102 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+func TestOnlyAWalksAskTakesAChecksBuildAndADryRunNever(t *testing.T) {
+	p := &inventory.Plan{Delivery: &inventory.PlanDelivery{Merges: []inventory.PlanMerge{
+		{Repository: "novox/shop", Number: 7}, {Repository: "http://forge.invalid/novox/web.git", Number: 3},
+		{Repository: "novox/shop", Number: 7}, {Repository: "novox/shop"}}}}
+	asked := reuseAskOf(p)
+	if want := []link.PullRef{{Owner: "novox", Repo: "shop", Number: 7}, {Owner: "novox", Repo: "web", Number: 3}}; !reflect.DeepEqual(asked.Pulls, want) {
+		t.Fatalf("the walk names %+v", asked.Pulls)
+	}
+	walk := withReuse(t.Context(), asked)
+	if reuseAsked(walk, false) != asked {
+		t.Fatal("a walk's ask does not carry its leave")
+	}
+	if reuseAsked(walk, true) != nil {
+		t.Fatal("a dry run carries a leave to take a check's build")
+	}
+	if reuseAsked(t.Context(), false) != nil {
+		t.Fatal("an ask that is not a walk's carries a leave")
+	}
+}
+
+func TestAReusedCheckBuildIsRegisteredByItsDigestAndGatedAsABuiltOne(t *testing.T) {
+	withTheGate(t) // the first-machine gate's own path (novox/hq ADR 0360 keeps it for earlier walks)
+	g := aGateMesh(t)
+	ctx := t.Context()
+	inv := g.open.inventory
+	gateEvery = 0
+
+	digest := "sha256:" + strings.Repeat("c", 64)
+	reused := func(id, reference string) link.BuildResult {
+		manifest := mustJSON(t, catalogue.Manifest{Module: "app", Version: "c3", Resources: []map[string]any{
+			{"id": "svc", "type": "container", "name": "app", "image": reference}}})
+		return link.BuildResult{ID: id, Repository: "novox/mesh-catalog", Path: "modules/app", Ref: "main", On: "anchor",
+			Commit: "c3", Manifest: manifest, Trunk: "main", OnTrunk: true, Branches: []string{"main"},
+			Made:   []link.MadeArtifact{{Name: "server", Kind: "image", Reference: reference}},
+			Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/mesh-catalog"},
+			Reused: "reused from the check of novox/mesh-catalog#9 at head abcdefabcdef (merged into trunk 123456123456): server " + digest,
+			ReusedFrom: &link.ReusedFrom{Pull: link.PullRef{Owner: "novox", Repo: "mesh-catalog", Number: 9},
+				Head: "abcdefabcdef", Trunk: "123456123456", Key: "r1:" + strings.Repeat("1", 64)}}
+	}
+	if _, _, err := takeIn(ctx, inv, reused(link.NewBuildID(time.Now()), "store.internal:5000/scratch/app/server@"+digest)); err == nil ||
+		!strings.Contains(err.Error(), "scratch") {
+		t.Fatalf("a build in the scratch namespace was registered: %v", err)
+	}
+	id := link.NewBuildID(time.Now().Add(time.Second))
+	result := reused(id, "store.internal:5000/app/server@"+digest)
+	if _, _, err := takeIn(ctx, inv, result); err != nil {
+		t.Fatal(err)
+	}
+	current, err := inv.CurrentBuilds(ctx)
+	if err != nil || current["app"].Commit != "c3" {
+		t.Fatalf("the reused build is not what app is registered at: %+v %v", current["app"], err)
+	}
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	raw, _ := json.Marshal(shelf["app"].Resources)
+	if !strings.Contains(string(raw), "app/server@"+digest) {
+		t.Fatalf("app is registered as %s, not by the check's digest in its own namespace", raw)
+	}
+
+	// The walk asked it: the walk keeps what its build did, and its gate judges the registered build.
+	asked := time.Now().UTC()
+	p := g.plan(t)
+	p.Commit = "c3"
+	p.Modules["app"] = &inventory.PlanModule{State: "asked", AskedAt: &asked, Build: id}
+	if err := inv.SavePlan(ctx, &p); err != nil {
+		t.Fatal(err)
+	}
+	planBuiltSaying(ctx, g.open, "app", "c3", "", asked, id, result.MadeWords())
+	p = g.plan(t)
+	if m := p.Modules["app"]; m.State != "built" || !strings.HasPrefix(m.Made, "reused from the check of novox/mesh-catalog#9") {
+		t.Fatalf("the walk keeps %+v", m)
+	}
+	for i := 0; i < 6; i++ {
+		advancePlans(ctx, g.open)
+	}
+	p = g.plan(t)
+	gate := p.Modules["app"].Gate
+	if gate == nil || gate.To != "c3" || gate.Verdict != inventory.GatePassed {
+		t.Fatalf("the gate judged %+v, not the reused build", gate)
+	}
+	if sent, _, _ := inv.SentBuilds(ctx, "anchor"); sent["app"] != "c3" {
+		t.Fatalf("the first machine was sent %v, not the reused build", sent)
+	}
+}

cmd/mesh-controller/check_builds_test.go

@@ -0,0 +1,193 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/builder"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// One build per change (novox/hq ADR 0350), as the controller asks it and takes it in.
+
+// The check of a change is asked to build what a merge of it would move, in the walk's order: a module of the
+// repository checked from the merge, one standing on it from its own repository as the walk builds it, and one
+// that reads the repository through a context not at all. A change that moves no module builds nothing.
+func TestACheckIsAskedToBuildWhatTheMergeWouldMove(t *testing.T) {
+	entries := []inventory.Entry{
+		{Manifest: catalogue.Manifest{Module: "app"}, Source: inventory.Source{Repository: "novox/shop", Seat: "git", Path: "modules/app"}},
+		{Manifest: catalogue.Manifest{Module: "web"}, Source: inventory.Source{Repository: "novox/web", Seat: "git", Ref: "main"}},
+		{Manifest: catalogue.Manifest{Module: "docs"}, Source: inventory.Source{Repository: "novox/docs", Seat: "git"}},
+	}
+	p := link.PullUpdated{Owner: "novox", Repo: "shop", Number: 7, Base: "main", Commit: "abc"}
+	scope := checkScope{Reach: mergeReach{Packaging: entries[2:], Plan: inventory.Plan{Tiers: [][]string{{"app", "docs"}, {"web"}}}}}
+	clone := func(s inventory.Source) (string, error) { return "http://forge.invalid/" + s.Repository + ".git", nil }
+
+	got := checkBuildsOf(p, scope, entries, clone)
+	want := []link.CheckBuild{
+		{Module: "app", Path: "modules/app", Merged: true, Tier: 0},
+		{Module: "docs", Tier: 0, Skip: "its build reads novox/shop through a context, which a check cannot hand the merge"},
+		{Module: "web", Repository: "http://forge.invalid/novox/web.git", Ref: "main", Tier: 1},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("the check is asked to build\n%+v\nwant\n%+v", got, want)
+	}
+	if got := checkBuildsOf(p, checkScope{}, entries, clone); got != nil {
+		t.Fatalf("a change that moves no module asks for builds: %+v", got)
+	}
+}
+
+// A walk's ask carries its leave to take a check's build, naming the pull requests of the merges it answers; a dry
+// run never does, and neither does an ask that is not a walk's.
+
+// A walk ended lets go of its merges' check builds — only once it ended, after it took what it reuses.
+func TestAWalkEndedLetsGoOfItsMergesCheckBuilds(t *testing.T) {
+	var forgot []builder.PullRef
+	was := forgetChecks
+	forgetChecks = func(_ context.Context, _ *inventory.Inventory, pull builder.PullRef) (string, error) {
+		forgot = append(forgot, pull)
+		return "", nil
+	}
+	t.Cleanup(func() { forgetChecks = was })
+	p := inventory.Plan{ID: "plan-1", Delivery: &inventory.PlanDelivery{Merges: []inventory.PlanMerge{
+		{Repository: "novox/shop", Number: 7}}}}
+
+	p.WalkSaid = inventory.WalkStarted
+	forgetChecksOfWalk(t.Context(), nil, p)
+	p.WalkSaid = ""
+	forgetChecksOfWalk(t.Context(), nil, p)
+	if len(forgot) != 0 {
+		t.Fatalf("a walk not ended let go of %v, which it may still take", forgot)
+	}
+	p.WalkSaid = inventory.WalkEnded
+	forgetChecksOfWalk(t.Context(), nil, p)
+	if want := []builder.PullRef{{Owner: "novox", Repo: "shop", Number: 7}}; !reflect.DeepEqual(forgot, want) {
+		t.Fatalf("the walk ended let go of %v", forgot)
+	}
+}
+
+// A build in the scratch namespace is never registered: only the walk's copy in the module's own namespace is.
+func TestABuildInTheScratchNamespaceIsNeverRegistered(t *testing.T) {
+	if got := inScratch([]link.MadeArtifact{{Name: "server", Reference: "store.internal:5000/app/server@sha256:aa"}}); got != "" {
+		t.Fatalf("a module's own build reads as a scratch build: %s", got)
+	}
+	scratch := "store.internal:5000/scratch/app/server@sha256:aa"
+	if got := inScratch([]link.MadeArtifact{{Name: "server", Reference: scratch}}); got != scratch {
+		t.Fatalf("a scratch build was not found: %q", got)
+	}
+	if got := inScratch([]link.MadeArtifact{{Name: "look", Reference: "http://store.internal:5000/v2/scratch/app/look/blobs/sha256:bb"}}); got == "" {
+		t.Fatal("a scratch archive was not found")
+	}
+}
+
+// The walk says per module what it did: "reused from …" or "built: <why>" — and a build seat from before says
+// neither, which is said.
+func TestAWalksBuildSaysWhetherItReusedOrBuilt(t *testing.T) {
+	if got := (link.BuildResult{Reused: "reused from the check of novox/shop#7"}).MadeWords(); got != "reused from the check of novox/shop#7" {
+		t.Fatalf("said %q", got)
+	}
+	if got := (link.BuildResult{BuiltWhy: "no check built it"}).MadeWords(); got != "built: no check built it" {
+		t.Fatalf("said %q", got)
+	}
+	if got := (link.BuildResult{}).MadeWords(); !strings.Contains(got, "predates ADR 0350") {
+		t.Fatalf("said %q", got)
+	}
+}
+
+// A walk's module the check's build stood in for is registered by the digest the check built — the copy in the
+// module's namespace — and the walk keeps "reused from …" for it; its first-node gate judges that registered
+// build as it judges one the walk built. A scratch reference is refused. Needs the store (MESH_TEST_POSTGRES), and
+// is named in testdata/store-tests.
+
+// A walk's leave names the builds its own pull requests' verdicts made at the head each merge merged — never an
+// earlier head's — read once per walk, and none when they cannot be read: the builder takes nothing a verdict does
+// not name (novox/hq ADR 0350 §2, issue 703).
+func TestAWalksLeaveNamesTheBuildsItsPullRequestsVerdictsMade(t *testing.T) {
+	was := checkedBuildsOf
+	forgetWalkVerdicts()
+	t.Cleanup(func() { checkedBuildsOf = was; forgetWalkVerdicts() })
+	var asked [][]link.PullRef
+	pull := link.PullRef{Owner: "novox", Repo: "shop", Number: 7}
+	atHead := link.CheckedBuild{Pull: pull, Check: "build-2", Head: "bbbbbbbbbbbb", Built: link.CheckBuilt{Module: "app", Key: "r1:2"}}
+	earlier := link.CheckedBuild{Pull: pull, Check: "build-1", Head: "aaaaaaaaaaaa", Built: link.CheckBuilt{Module: "app", Key: "r1:1"}}
+	checkedBuildsOf = func(_ context.Context, pulls []link.PullRef) ([]link.CheckedBuild, error) {
+		asked = append(asked, pulls)
+		return []link.CheckedBuild{atHead, earlier}, nil
+	}
+	pulls := []link.PullRef{pull}
+	heads := map[link.PullRef]string{pull: "bbbbbbbbbbbb0123456789"}
+	for range 3 {
+		if got := reuseWithVerdicts(t.Context(), "plan-1", &link.ReuseAsk{Pulls: pulls}, heads); !reflect.DeepEqual(got.Builds,
+			[]link.CheckedBuild{atHead}) {
+			t.Fatalf("the leave names %+v, not only the merged head's build", got.Builds)
+		}
+	}
+	if !reflect.DeepEqual(asked, [][]link.PullRef{pulls}) {
+		t.Fatalf("the verdicts were read %d times for one walk: %v", len(asked), asked)
+	}
+	// A merge whose head was not said takes nothing.
+	if got := reuseWithVerdicts(t.Context(), "plan-1", &link.ReuseAsk{Pulls: pulls}, nil); got.Builds != nil {
+		t.Fatalf("a merge of no said head names %+v", got.Builds)
+	}
+	checkedBuildsOf = func(context.Context, []link.PullRef) ([]link.CheckedBuild, error) {
+		return nil, errors.New("no bus")
+	}
+	if got := reuseWithVerdicts(t.Context(), "plan-2", &link.ReuseAsk{Pulls: pulls}, heads); got.Builds != nil {
+		t.Fatalf("verdicts that could not be read named %+v", got.Builds)
+	}
+}
+
+// A check is handed only the builds earlier checks of its own pull request at its own head made: another pull
+// request's build, or an earlier head's, is never kept (novox/hq issue 703). None when they cannot be read.
+func TestACheckIsHandedOnlyItsOwnHeadsBuilds(t *testing.T) {
+	was := checkedBuildsOf
+	t.Cleanup(func() { checkedBuildsOf = was })
+	pull := link.PullRef{Owner: "novox", Repo: "shop", Number: 7}
+	mine := link.CheckedBuild{Pull: pull, Check: "build-1", Head: "bbbbbbbbbbbb", Built: link.CheckBuilt{Module: "app", Key: "r1:1"}}
+	earlier := link.CheckedBuild{Pull: pull, Check: "build-0", Head: "aaaaaaaaaaaa", Built: link.CheckBuilt{Module: "app", Key: "r1:1"}}
+	another := link.CheckedBuild{Pull: link.PullRef{Owner: "novox", Repo: "shop", Number: 8}, Check: "build-9",
+		Head: "bbbbbbbbbbbb", Built: link.CheckBuilt{Module: "app", Key: "r1:1"}}
+	var asked [][]link.PullRef
+	checkedBuildsOf = func(_ context.Context, pulls []link.PullRef) ([]link.CheckedBuild, error) {
+		asked = append(asked, pulls)
+		return []link.CheckedBuild{mine, earlier, another}, nil
+	}
+	p := link.PullUpdated{Owner: "novox", Repo: "shop", Number: 7, Commit: "bbbbbbbbbbbb0123456789"}
+	builds := []link.CheckBuild{{Module: "app"}}
+	if got := namedForTheCheck(t.Context(), p, builds); !reflect.DeepEqual(got, []link.CheckedBuild{mine}) ||
+		!reflect.DeepEqual(asked, [][]link.PullRef{{pull}}) {
+		t.Fatalf("the check is handed %+v, read for %v", got, asked)
+	}
+	checkedBuildsOf = func(context.Context, []link.PullRef) ([]link.CheckedBuild, error) {
+		return nil, errors.New("no bus")
+	}
+	if got := namedForTheCheck(t.Context(), p, builds); got != nil {
+		t.Fatalf("verdicts that could not be read named %+v", got)
+	}
+}
+
+func forgetWalkVerdicts() {
+	walkVerdicts.Lock()
+	defer walkVerdicts.Unlock()
+	walkVerdicts.read = map[string]verdictsRead{}
+}
+
+// A walk's merged heads are the forge's word for each merge; a merge announced without its head, or a pull request
+// merged at two heads in one walk, has none, and its walk takes no check's build (novox/hq issue 703).
+func TestAWalksMergedHeadsAreTheForgesWord(t *testing.T) {
+	merge := func(number int, head string) inventory.PlanMerge {
+		return inventory.PlanMerge{Repository: "novox/shop", Number: number, Head: head}
+	}
+	p := &inventory.Plan{Delivery: &inventory.PlanDelivery{Merges: []inventory.PlanMerge{
+		merge(7, "aaaaaaaaaaaa1"), merge(8, ""), merge(9, "bbbbbbbbbbbb"), merge(9, "cccccccccccc")}}}
+	heads := mergedHeadsOf(p)
+	shop := func(n int) link.PullRef { return link.PullRef{Owner: "novox", Repo: "shop", Number: n} }
+	if heads[shop(7)] != "aaaaaaaaaaaa1" || heads[shop(8)] != "" || heads[shop(9)] != "" {
+		t.Fatalf("merged heads %v", heads)
+	}
+}

cmd/mesh-controller/check_here.go

@@ -0,0 +1,203 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/builder"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// `check-here` is a pull request's merge check run on the machine at hand **exactly as the build seat
+// runs it** (novox/hq issue 286): the same code (builder.Check), the same ask the controller would make of
+// the seat — the gate's modules and judge by the planner's own answer over the facts snapshot, the
+// repositories beside it at the refs the snapshot says the seat clones them at — in the toolchain image
+// the mesh holds, as the user the build seat runs as, against a throwaway store and bus of the versions
+// the mesh runs.
+//
+// **The build seat is the reference.** A merge-check.sh that passed on an agent's machine failed on the
+// seat for three reasons that were each the agent's environment, never the change: a newer Go whose gofmt
+// lays a file out differently, a sibling checkout at the agent's feature branch where the seat had the
+// commit the mesh runs, and a different user. Run here, a check sees what the seat will.
+//
+//	check-here [--tree <checkout>] [--base main] [--registry <artifact store>] [--forge <url of the owner>]
+//	           [--number <n>] [--user uid:gid] [--facts store|<file>] [--keep]
+//
+// The checkout's HEAD is what is checked, and it must be committed: the seat checks a commit, never a
+// working tree.
+func checkHereCommand(ctx context.Context, args []string) error {
+	set := flag.NewFlagSet("check-here", flag.ContinueOnError)
+	tree := set.String("tree", ".", "the change's checkout; its HEAD is checked")
+	base := set.String("base", "main", "the branch the change would merge into")
+	registry := set.String("registry", os.Getenv("MESH_REGISTRY"), "the artifact store holding the facts and the toolchains")
+	forge := set.String("forge", "", "where the repositories beside it are cloned from, as <forge>/<repository>.git; "+
+		"the checkout's origin without its own name when not given")
+	number := set.Int("number", 0, "the pull request's number, when there is one")
+	// The build seat's service runs as root, and its check containers run as the builder does.
+	user := set.String("user", "0:0", "the user the check's containers run as: the build seat's")
+	keep := set.Bool("keep", false, "keep the workspace afterwards")
+	factsFrom := set.String("facts", "store", "the facts snapshot: `store`, the one the artifact store holds — "+
+		"what the seat reads — or a file")
+	if _, err := parseAround(set, args); err != nil {
+		return err
+	}
+	if *registry == "" {
+		return errors.New("check-here reads the facts and the toolchains from the artifact store: --registry <host:port> or MESH_REGISTRY")
+	}
+	dir, err := filepath.Abs(*tree)
+	if err != nil {
+		return err
+	}
+	git := func(args ...string) (string, error) {
+		cmd := exec.CommandContext(ctx, "git", args...)
+		cmd.Dir = dir
+		out, err := cmd.Output()
+		return strings.TrimSpace(string(out)), err
+	}
+	if dirty, err := git("status", "--porcelain", "--untracked-files=no"); err != nil {
+		return fmt.Errorf("%s is not a checkout: %w", dir, err)
+	} else if dirty != "" {
+		return errors.New("the checkout has changes not committed: the build seat checks a commit, so commit first")
+	}
+	head, err := git("rev-parse", "HEAD")
+	if err != nil {
+		return err
+	}
+	origin, err := git("remote", "get-url", "origin")
+	if err != nil {
+		return fmt.Errorf("the checkout has no origin to say which repository it is: %w", err)
+	}
+	owner, repo, prefix := ownerRepoOf(origin)
+	if *forge == "" {
+		*forge = prefix
+	}
+	if _, err := git("fetch", "--quiet", "origin", *base); err != nil {
+		return fmt.Errorf("cannot fetch %s to say what the change touches: %w", *base, err)
+	}
+	// Without rename detection, so a file moved out of a build source is said under its old name as well:
+	// its going is a change to the build that held it (novox/hq ADR 0267).
+	changedText, err := git("diff", "--name-only", "--no-renames", "origin/"+*base+"...HEAD")
+	if err != nil {
+		return err
+	}
+	var paths, removed []string
+	for _, p := range strings.Split(changedText, "\n") {
+		if p = strings.TrimSpace(p); p == "" {
+			continue
+		}
+		paths = append(paths, p)
+		if _, err := os.Stat(filepath.Join(dir, p)); os.IsNotExist(err) {
+			removed = append(removed, p)
+		}
+	}
+
+	_ = os.Setenv("MESH_REGISTRY", *registry)
+	f, err := readFacts(ctx, *factsFrom)
+	if err != nil {
+		return fmt.Errorf("the facts snapshot cannot be read: %w", err)
+	}
+	entries, read, edges, err := graphOfFacts(f)
+	if err != nil {
+		return err
+	}
+	p := link.PullUpdated{Owner: owner, Repo: repo, Number: *number, Base: *base, Commit: head, Paths: paths,
+		Removed: removed, ModuleDirs: moduleDirsIn(dir, paths), ModuleDirsSaid: true}
+	scope := pullScope(p, entries, read, edges)
+	_, scriptErr := os.Stat(filepath.Join(dir, builder.CheckScript))
+	if !scope.gated() && !scope.Mesh {
+		fmt.Printf("%s: %s, and the repository is not the mesh's: the build seat runs nothing for it\n",
+			owner+"/"+repo, noModuleTouched)
+		return nil
+	}
+	if !scope.gated() && scriptErr != nil {
+		fmt.Printf("%s: %s; %s\n", owner+"/"+repo, noModuleTouched, noMergeCheck)
+		return nil
+	}
+
+	toolchains := map[string]string{}
+	for language, reference := range f.Versions.Toolchains {
+		toolchains[language] = catalogue.Rerouted(reference, *registry)
+	}
+	if len(toolchains) == 0 {
+		return errors.New("the facts snapshot names no toolchain: it was taken by a controller from before " +
+			"issue 286, and the seat's toolchain cannot be known here")
+	}
+	beside := map[string]builder.Beside{}
+	for d, ref := range f.Beside {
+		from := d
+		if d == "mesh-controller-main" {
+			from = "mesh-controller"
+		}
+		beside[d] = builder.Beside{Repository: strings.TrimSuffix(*forge, "/") + "/" + from + ".git", Ref: ref}
+	}
+	id := fmt.Sprintf("check-here-%d", time.Now().UnixNano())
+	spec := builder.CheckSpec{ID: id, Repository: dir, Ref: head, Owner: owner, Repo: repo, Number: *number,
+		Paths: paths, Beside: beside, Modules: scope.Modules, New: scope.New, Manifests: scope.Manifests,
+		Base: *base, Judge: scope.Judge, Toolchain: toolchains["go"], Toolchains: toolchains, User: *user}
+
+	workspace, err := os.MkdirTemp("", "mesh-check-here-")
+	if err != nil {
+		return err
+	}
+	if !*keep {
+		defer removeWorkspace(spec.Toolchain, workspace, *user)
+	}
+	fmt.Fprintf(os.Stderr, "checking %s/%s at %.8s as the build seat would, against the facts of %s, in %s\n",
+		owner, repo, head, f.Taken.Format(time.RFC3339), workspace)
+	v, err := builder.Check(ctx, builder.Command, spec, workspace, *registry, builder.GitCredential{},
+		func(step, message string) {
+			if step != "output" {
+				fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message)
+			}
+		})
+	if err != nil {
+		return fmt.Errorf("the check could not run — on the seat an error, never a pass: %w", err)
+	}
+	fmt.Println(v.Report)
+	fmt.Println()
+	fmt.Printf("mesh/merge-gate: %s — %s\n", strings.ToUpper(v.Gate.Verdict), v.Gate.Summary)
+	if v.Repo != nil {
+		fmt.Printf("mesh/repo-check: %s — %s\n", strings.ToUpper(v.Repo.Verdict), v.Repo.Summary)
+	}
+	for _, l := range []*builder.Layer{v.Gate, v.Repo} {
+		if l != nil && l.Verdict != "pass" && l.Verdict != "warning" {
+			return errors.New("the build seat would not pass this change")
+		}
+	}
+	return nil
+}
+
+// ownerRepoOf reads owner, repository and the owner's URL from a remote: ssh://git@host:222/novox/mesh-host.git
+// → novox, mesh-host, ssh://git@host:222/novox.
+func ownerRepoOf(remote string) (string, string, string) {
+	trimmed := strings.TrimSuffix(strings.TrimSuffix(remote, "/"), ".git")
+	cut := strings.LastIndexAny(trimmed, "/:")
+	if cut < 0 {
+		return "", trimmed, ""
+	}
+	repo, prefix := trimmed[cut+1:], trimmed[:cut]
+	owner := prefix
+	if at := strings.LastIndexAny(prefix, "/:"); at >= 0 {
+		owner = prefix[at+1:]
+	}
+	return owner, repo, prefix
+}
+
+// removeWorkspace removes what the check left, written as the seat's user: by a container of that user
+// when it is not this one.
+func removeWorkspace(image, workspace, user string) {
+	if image != "" && user != fmt.Sprintf("%d:%d", os.Getuid(), os.Getgid()) {
+		// Everything in it — the check's HOME is the workspace, so the toolchain's own files are there too.
+		_ = exec.Command("docker", "run", "--rm", "--user", user, "--volume", workspace+":/workspace", image,
+			"sh", "-c", "rm -rf /workspace/* /workspace/.[!.]*").Run()
+	}
+	_ = os.RemoveAll(workspace)
+}

cmd/mesh-controller/check_siblings.go

@@ -0,0 +1,165 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **A delivery group's member is checked beside the other members' heads** (novox/hq ADR 0382, issue 867).
+//
+// A mesh-host change and a mesh-controller change that need each other could not both pass their own merge checks:
+// each was read beside the other's repository at the commit the mesh runs, which holds neither change. So the
+// controller asks mesh-delivery's `groups` once for every pull request's check it asks (§1), and names, in the ask,
+// the group's other open pull requests into a base of the same name, in a repository the build seat reads beside the
+// check — mesh-lab never — each with its whole head. The build seat reads those repositories at the sibling's merge (§2).
+// A pull request for which mesh-delivery answered and named no sibling is asked exactly as before (§7).
+
+// wholeCommit is a commit as the forge says a head: forty hexadecimal characters.
+var wholeCommit = regexp.MustCompile(`^[0-9a-f]{40}$`)
+
+// besideRepositories are the repositories (lower case, owner/repo) a check reads beside its own, by the directory each
+// is found under — the core's, as besideOf clones them, and mesh-sdk beside the controller; never mesh-lab, which is
+// always read at its trunk.
+func besideRepositories(entries []inventory.Entry) map[string]string {
+	read := map[string]string{}
+	for _, e := range entries {
+		dir, core := coreModules[e.Manifest.Module]
+		if !core || e.Provided || e.Source.Repository == "" {
+			continue
+		}
+		read[nameOf(e.Source.Repository)] = dir
+		if dir == "mesh-controller" && e.Source.Seat != "" {
+			read[nameOf(siblingOf(e.Source.Repository, "mesh-sdk"))] = "mesh-sdk"
+		}
+	}
+	delete(read, "")
+	return read
+}
+
+// nameOf is a recorded repository as owner/repo in lower case, empty when it names no owner.
+func nameOf(repository string) string {
+	owner, repo := sourceOwner(repository), sourceName(repository)
+	if owner == "" || repo == "" {
+		return ""
+	}
+	return strings.ToLower(owner + "/" + repo)
+}
+
+// siblingsFor is the pull request's siblings, as mesh-delivery's groups say them (ADR 0382 §1): the other members of
+// the group its head branch names that are open, unmerged and into a base of its own base's name, in a repository the
+// check reads beside it (beside: the directories the ask already names). The second answer is why they could not be
+// learned, empty when they could: the group's members carry no head or base — a mesh-delivery from before the rule.
+func siblingsFor(p link.PullUpdated, entries []inventory.Entry, beside map[string]link.CheckedOut,
+	lines []groupsLine) ([]link.CheckSibling, string) {
+	own := strings.ToLower(p.Owner + "/" + p.Repo)
+	var group *groupsLine
+	if p.Head == "" {
+		// A recheck (mesh-delivery's `recheck` through `delivery check`) carries no head branch name: the group is the one
+		// whose members hold this very pull request, by repository and number.
+		learnable := false
+		for i := range lines {
+			for _, m := range lines[i].Details {
+				learnable = true
+				if p.Number != 0 && m.Number == p.Number && strings.ToLower(m.Repository) == own {
+					group = &lines[i]
+				}
+			}
+		}
+		if group == nil {
+			for _, l := range lines {
+				if len(l.Details) == 0 && len(l.Members) > 0 && !learnable {
+					return nil, "mesh-delivery named the groups' members without their pull requests (a mesh-delivery from before novox/hq ADR 0382): " +
+						"the group of a pull request announced without its head branch cannot be found"
+				}
+			}
+			return nil, "" // a lone pull request
+		}
+	} else {
+		for i := range lines {
+			if lines[i].ID == p.Head {
+				group = &lines[i]
+			}
+		}
+		if group == nil {
+			return nil, ""
+		}
+	}
+	if len(group.Details) == 0 && len(group.Members) > 0 {
+		return nil, "mesh-delivery named the group's members without their heads and bases (a mesh-delivery from before novox/hq ADR 0382)"
+	}
+	read := besideRepositories(entries)
+	var siblings []link.CheckSibling
+	for _, m := range group.Details {
+		repository := strings.ToLower(m.Repository)
+		if repository == own {
+			continue
+		}
+		if !m.Open {
+			continue
+		}
+		if m.Head == "" || m.Base == "" {
+			return nil, "mesh-delivery named " + m.ID + " without its head or base (a mesh-delivery from before novox/hq ADR 0382)"
+		}
+		dir, readBeside := read[repository]
+		if m.Base != p.Base || !readBeside || dir == "mesh-lab" {
+			continue
+		}
+		if _, there := beside[dir]; !there {
+			continue
+		}
+		head := strings.ToLower(m.Head)
+		if !wholeCommit.MatchString(head) {
+			return nil, fmt.Sprintf("mesh-delivery named %s with a head that is not a whole commit (%q)", m.ID, m.Head)
+		}
+		siblings = append(siblings, link.CheckSibling{Repository: m.Repository, Number: m.Number, Head: head, Base: m.Base, Dir: dir})
+	}
+	sort.Slice(siblings, func(i, j int) bool { return siblings[i].Dir < siblings[j].Dir })
+	return siblings, ""
+}
+
+// withSiblings asks mesh-delivery's `groups` once and says in the request the pull request's siblings, or why they
+// could not be learned (ADR 0382 §1): a check never waits on mesh-delivery past groupAskWithin and never fails for it,
+// so a fix to mesh-delivery is still checked without it.
+func withSiblings(ctx context.Context, request *link.BuildRequest, p link.PullUpdated, entries []inventory.Entry) {
+	lines, err := groupsAsked(ctx, deliverySeatHeld(entries))
+	siblingsFrom(request, p, entries, lines, err)
+}
+
+// siblingsFrom is withSiblings from mesh-delivery's answer already had.
+func siblingsFrom(request *link.BuildRequest, p link.PullUpdated, entries []inventory.Entry, lines []groupsLine, err error) {
+	if request.Check == nil {
+		return
+	}
+	if err != nil {
+		request.Check.SiblingsUnknown = fmt.Sprintf("mesh-delivery did not say the group's pull requests (%v): "+
+			"the check reads no siblings", err)
+		return
+	}
+	request.Check.Siblings, request.Check.SiblingsUnknown = siblingsFor(p, entries, request.Check.Beside, lines)
+}
+
+// composedMember says the pull request is a member of a delivery group whose gate is the composed check's (novox/hq
+// ADR 0403 clauses 1 and 7): the group has two members or more and mesh-delivery says so on its line. The group is
+// found as siblingsFor finds it, by its head branch name, or, for a recheck that carries none, by the pull request's
+// repository and number — not by siblings, which name only what the check reads beside it.
+func composedMember(p link.PullUpdated, lines []groupsLine) bool {
+	own := strings.ToLower(p.Owner + "/" + p.Repo)
+	for _, l := range lines {
+		found := p.Head != "" && l.ID == p.Head
+		for _, m := range l.Details {
+			if p.Head == "" && p.Number != 0 && m.Number == p.Number && strings.ToLower(m.Repository) == own {
+				found = true
+			}
+		}
+		if found {
+			return l.ComposedGate && max(len(l.Details), len(l.Members)) >= 2
+		}
+	}
+	return false
+}

cmd/mesh-controller/check_siblings_test.go

@@ -0,0 +1,248 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **A delivery group's member is checked beside the other members' heads** (novox/hq ADR 0382 §1, §7, issue 867): the
+// controller asks mesh-delivery's `groups` once for every check it asks, and names in the ask the group's other open
+// pull requests into a base of the same name, in a repository the build seat reads beside it — mesh-lab never.
+
+const (
+	headHost       = "1111111111111111111111111111111111111111"
+	headController = "2222222222222222222222222222222222222222"
+	headSDK        = "3333333333333333333333333333333333333333"
+	headLab        = "4444444444444444444444444444444444444444"
+	headHq         = "5555555555555555555555555555555555555555"
+)
+
+func theCoreOnTheGitSeat() []inventory.Entry {
+	onSeat := func(module, repository string) inventory.Entry {
+		e := fromRepo(module, repository, "")
+		e.Source.Seat = "git"
+		return e
+	}
+	nats := onSeat("nats", "novox/mesh-catalog")
+	nats.Source.Path = "modules/nats"
+	held := catalogue.Manifest{Module: "mesh-delivery", Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}}
+	return []inventory.Entry{onSeat("mesh-controller", "novox/mesh-controller"), onSeat("mesh-host", "novox/mesh-host"),
+		onSeat("node-tools", "novox/mesh-tools"), nats, {Manifest: held, On: []string{"anchor"}}}
+}
+
+func besideTheCore() map[string]link.CheckedOut {
+	return map[string]link.CheckedOut{"mesh-controller": {Repository: "c"}, "mesh-host": {Repository: "h"},
+		"mesh-tools": {Repository: "t"}, "mesh-catalog": {Repository: "k"}, "mesh-sdk": {Repository: "s"}, "mesh-lab": {Repository: "l"}}
+}
+
+func member(repository string, number int, head, base string, open bool) memberLine {
+	return memberLine{ID: repository + "@" + head[:12], Repository: repository, State: "checked", Number: number, Head: head,
+		Base: base, Open: open}
+}
+
+func group(id string, members ...memberLine) groupsLine {
+	line := groupsLine{ID: id, Details: members}
+	for _, m := range members {
+		line.Members = append(line.Members, m.ID+" ("+m.State+")")
+	}
+	return line
+}
+
+func TestASiblingIsTheGroupsOtherOpenPullRequestIntoABaseOfTheSameName(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	pull := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Head: "feat/x", Commit: headHost}
+	for _, c := range []struct {
+		what    string
+		lines   []groupsLine
+		want    []string
+		unknown string
+	}{
+		{"the other member, open, same base", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))},
+			[]string{"mesh-controller=novox/mesh-controller#346@" + headController + " onto main"}, ""},
+		{"a member into a base of another name is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "release", true))},
+			nil, ""},
+		{"a member not open (merged or closed) is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", false))},
+			nil, ""},
+		{"mesh-lab is never one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-lab", 5, headLab, "main", true))},
+			nil, ""},
+		{"a repository the check reads nothing of is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/hq", 9, headHq, "main", true))},
+			nil, ""},
+		{"mesh-sdk, read beside the controller, is one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-sdk", 7, headSDK, "main", true))},
+			[]string{"mesh-sdk=novox/mesh-sdk#7@" + headSDK + " onto main"}, ""},
+		{"another group is none of its business", []groupsLine{group("feat/y",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))},
+			nil, ""},
+		{"a group of its own alone has none", []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true))},
+			nil, ""},
+		{"an older mesh-delivery names no heads", []groupsLine{{ID: "feat/x",
+			Members: []string{"novox/mesh-host@111111111111 (checked)", "novox/mesh-controller@222222222222 (checked)"}}},
+			nil, "without their heads and bases"},
+		{"a member without its base", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "", true))},
+			nil, "without its head or base"},
+		{"a head that is no commit", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController[:12]+"zzzzzzzzzzzzzzzzzzzzzzzzzzzz", "main", true))},
+			nil, "not a whole commit"},
+	} {
+		got, unknown := siblingsFor(pull, entries, besideTheCore(), c.lines)
+		var said []string
+		for _, s := range got {
+			said = append(said, s.Dir+"="+s.Repository+"#"+itoa(s.Number)+"@"+s.Head+" onto "+s.Base)
+		}
+		if strings.Join(said, ";") != strings.Join(c.want, ";") {
+			t.Errorf("%s: siblings %v, wanted %v", c.what, said, c.want)
+		}
+		if (c.unknown == "") != (unknown == "") || !strings.Contains(unknown, c.unknown) {
+			t.Errorf("%s: could not learn %q, wanted %q", c.what, unknown, c.unknown)
+		}
+	}
+	// A pull request into a release branch has siblings into the release branch of the same name (ADR 0358 §1).
+	release := pull
+	release.Base = "feat/57"
+	lines := []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "feat/57", true),
+		member("novox/mesh-controller", 346, headController, "feat/57", true), member("novox/mesh-tools", 8, headLab, "main", true))}
+	if got, _ := siblingsFor(release, entries, besideTheCore(), lines); len(got) != 1 || got[0].Dir != "mesh-controller" {
+		t.Errorf("into a release branch: %+v", got)
+	}
+	// A recheck announces the pull request without its head branch: its group is the one holding it (repository, number).
+	pull.Head = ""
+	got, unknown := siblingsFor(pull, entries, besideTheCore(), lines)
+	if len(got) != 1 || got[0].Dir != "mesh-tools" || unknown != "" {
+		t.Errorf("a recheck of a group member: %+v %q", got, unknown)
+	}
+	// A pull request in no group, rechecked, is alone: no sibling, and nothing said.
+	pull.Number = 999
+	if got, unknown := siblingsFor(pull, entries, besideTheCore(), lines); got != nil || unknown != "" {
+		t.Errorf("a lone pull request: %+v %q", got, unknown)
+	}
+	if got, unknown := siblingsFor(pull, entries, besideTheCore(), nil); got != nil || unknown != "" {
+		t.Errorf("no groups at all: %+v %q", got, unknown)
+	}
+	// A mesh-delivery that names members without their pull requests cannot find the group of a recheck: it says so.
+	older := []groupsLine{{ID: "feat/x", Members: []string{"novox/mesh-host@111111111111 (checked)"}}}
+	pull.Number = 114
+	if got, unknown := siblingsFor(pull, entries, besideTheCore(), older); got != nil || unknown == "" {
+		t.Errorf("an older mesh-delivery: %+v %q", got, unknown)
+	}
+}
+
+func itoa(n int) string { b, _ := json.Marshal(n); return string(b) }
+
+// Every check asks mesh-delivery's `groups` once; the ask names the sibling's repository, head and base.
+func TestEveryCheckAsksMeshDeliveryOnceAndNamesItsSiblings(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	asked := 0
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	groupsAsked = func(_ context.Context, held bool) ([]groupsLine, error) {
+		asked++
+		if !held {
+			t.Error("the seat is held, yet it was asked as not held")
+		}
+		return []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true),
+			member("novox/mesh-controller", 346, headController, "main", true))}, nil
+	}
+	request := link.BuildRequest{Check: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Base: "main", Beside: besideTheCore()}}
+	withSiblings(t.Context(), &request, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+	if asked != 1 {
+		t.Fatalf("mesh-delivery was asked %d times for one check", asked)
+	}
+	want := link.CheckSibling{Repository: "novox/mesh-controller", Number: 346, Head: headController, Base: "main", Dir: "mesh-controller"}
+	if got := request.Check.Siblings; len(got) != 1 || got[0] != want || request.Check.SiblingsUnknown != "" {
+		t.Fatalf("the ask names siblings %+v, unknown %q", got, request.Check.SiblingsUnknown)
+	}
+	body, _ := json.Marshal(request.Check)
+	if !strings.Contains(string(body), `"siblings":[{"repository":"novox/mesh-controller","number":346,"head":"`+headController+
+		`","base":"main","dir":"mesh-controller"}]`) {
+		t.Fatalf("on the wire: %s", body)
+	}
+}
+
+// When mesh-delivery does not answer in time (or is not held, or answered without the fields), the check reads no
+// sibling and its request says it could not learn them, so a fix to mesh-delivery is still checked without it.
+func TestWhenMeshDeliveryDoesNotAnswerTheCheckReadsNoSiblingAndSaysSo(t *testing.T) {
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	for _, c := range []struct {
+		what string
+		err  error
+		held bool
+	}{{"it did not answer", context.DeadlineExceeded, true}, {"nothing serves it", errors.New("nothing serves mesh-delivery.groups"), true},
+		{"no holder on record", errors.New("no holder of mesh-delivery is on record to say it"), false}} {
+		entries := theCoreOnTheGitSeat()
+		if !c.held {
+			entries = entries[:4]
+		}
+		groupsAsked = func(_ context.Context, held bool) ([]groupsLine, error) {
+			if held != c.held {
+				t.Errorf("%s: held %v", c.what, held)
+			}
+			return nil, c.err
+		}
+		request := link.BuildRequest{Check: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Base: "main", Beside: besideTheCore()}}
+		withSiblings(t.Context(), &request, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+		if len(request.Check.Siblings) != 0 || !strings.Contains(request.Check.SiblingsUnknown, c.err.Error()) ||
+			!strings.Contains(request.Check.SiblingsUnknown, "reads no siblings") {
+			t.Errorf("%s: siblings %+v, unknown %q", c.what, request.Check.Siblings, request.Check.SiblingsUnknown)
+		}
+	}
+}
+
+// **A pull request for which mesh-delivery answered and named no sibling is asked exactly as before** (ADR 0382 §7):
+// byte for byte the request it was without the rule.
+func TestAPullRequestWithNoSiblingIsAskedByteForByteAsBefore(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	for _, answer := range [][]groupsLine{nil, {group("feat/other", member("novox/mesh-controller", 346, headController, "main", true))},
+		{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true), member("novox/hq", 3, headHq, "main", true))}} {
+		groupsAsked = func(context.Context, bool) ([]groupsLine, error) { return answer, nil }
+		build := func() link.BuildRequest {
+			return link.BuildRequest{ID: "build-1", Repository: "r", Ref: headHost, Check: &link.CheckRequest{Owner: "novox",
+				Repo: "mesh-host", Number: 114, Base: "main", Beside: besideTheCore(), Modules: []string{"mesh-host"}, Judge: "validator"}}
+		}
+		before, _ := json.Marshal(build())
+		after := build()
+		withSiblings(t.Context(), &after, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+		got, _ := json.Marshal(after)
+		if string(before) != string(got) {
+			t.Fatalf("the request changed:\nbefore %s\nafter  %s", before, got)
+		}
+	}
+}
+
+// What the build seat's verdict says of its siblings reaches the forge's holder in the controller's `checked`.
+func TestTheVerdictCarriesTheSiblingsAndWhereTheJudgeCameFrom(t *testing.T) {
+	read := []link.CheckSibling{{Repository: "novox/mesh-controller", Number: 346, Head: headController, Base: "main", BaseCommit: headHost}}
+	c := checkedOf(link.BuildResult{ID: "b", Ref: headHost, Checked: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114},
+		Check: &link.CheckOutcome{Verdict: "pass", Summary: "ok", Siblings: read, JudgeFrom: "sibling novox/mesh-controller#346 merge abc",
+			Validator: "the change's own validator"}})
+	if len(c.Siblings) != 1 || c.Siblings[0] != read[0] || c.JudgeFrom == "" || c.Validator == "" {
+		t.Fatalf("the verdict says %+v", c)
+	}
+	body, _ := json.Marshal(c)
+	for _, want := range []string{`"siblings":[{"repository":"novox/mesh-controller","number":346,"head":"` + headController +
+		`","base":"main","base_commit":"` + headHost + `"}]`, `"judge_from":"sibling novox/mesh-controller#346 merge abc"`} {
+		if !strings.Contains(string(body), want) {
+			t.Fatalf("the verdict lacks %s:\n%s", want, body)
+		}
+	}
+	unknown := checkedOf(link.BuildResult{ID: "b", Check: &link.CheckOutcome{Verdict: "pass", SiblingsUnknown: "mesh-delivery did not answer"}})
+	if body, _ := json.Marshal(unknown); !strings.Contains(string(body), `"siblings_unknown":"mesh-delivery did not answer"`) ||
+		strings.Contains(string(body), `"siblings":`) {
+		t.Fatalf("the verdict that could not learn them says %s", body)
+	}
+}

cmd/mesh-controller/check_test.go

@@ -0,0 +1,161 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/beside"
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// The check anybody can run is the check registration runs (novox/hq issue 148, ADR 0037): a manifest
+// with a known fault is named, and one without passes, with no store opened.
+func TestModuleCheckNamesAFaultAndNeedsNoMesh(t *testing.T) {
+	dir := t.TempDir()
+	good := filepath.Join(dir, "good.json")
+	bad := filepath.Join(dir, "bad.json")
+	os.WriteFile(good, []byte(`{"module":"shop","version":"1","tools":["price"],"invokes":["mesh-catalog.catalog_modules"]}`), 0o600)
+	os.WriteFile(bad, []byte(`{"module":"till","version":"1","invokes":["shop"]}`), 0o600)
+
+	var out bytes.Buffer
+	if err := moduleCheck([]string{good}, &out); err != nil {
+		t.Fatalf("a sound manifest was refused: %v\n%s", err, out.String())
+	}
+	if !strings.Contains(out.String(), "shop: ok, 1 tool(s), invokes mesh-catalog.catalog_modules") {
+		t.Fatalf("the report does not say what it checked:\n%s", out.String())
+	}
+
+	out.Reset()
+	err := moduleCheck([]string{good, bad}, &out)
+	if err == nil {
+		t.Fatal("a manifest invoking a module and no tool passed")
+	}
+	if !strings.Contains(out.String(), `till invokes "shop", which does not name a tool`) {
+		t.Fatalf("the fault is not named in the manifest's words:\n%s", out.String())
+	}
+}
+
+// The rules between manifests run over what was given together: a seat two modules declare is
+// refused, which no single-manifest check can see.
+func TestModuleCheckJudgesBetweenTheManifestsGiven(t *testing.T) {
+	dir := t.TempDir()
+	a := filepath.Join(dir, "a.json")
+	b := filepath.Join(dir, "b.json")
+	os.WriteFile(a, []byte(`{"module":"a","version":"1","seats":[{"name":"printer","scope":"mesh"}]}`), 0o600)
+	os.WriteFile(b, []byte(`{"module":"b","version":"1","seats":[{"name":"printer","scope":"mesh"}]}`), 0o600)
+	var out bytes.Buffer
+	if err := moduleCheck([]string{a, b}, &out); err == nil {
+		t.Fatalf("two declarations of one seat passed:\n%s", out.String())
+	}
+	if !strings.Contains(out.String(), "a seat name means one protocol") {
+		t.Fatalf("the cross-manifest rule was not the one named:\n%s", out.String())
+	}
+}
+
+// The real catalogue passes the command, the way it passes the test that used to be the only check.
+func TestModuleCheckPassesTheCatalogue(t *testing.T) {
+	root := beside.Catalogue(t)
+	paths, err := manifestsUnder(root)
+	if err != nil || len(paths) == 0 {
+		t.Fatalf("no manifests under %s: %v", root, err)
+	}
+	var out bytes.Buffer
+	if err := moduleCheck(paths, &out); err != nil {
+		t.Fatalf("the catalogue does not pass its own check: %v\n%s", err, out.String())
+	}
+}
+
+func TestRegistrationRefusesADefinitionNamingAnInstallation(t *testing.T) {
+	// novox/hq ADR 0155: the check moves to registration once the catalogue passes it. Both
+	// ways in — `module add` and a build's result — go through this, and a name declared on
+	// purpose passes with its reason.
+	named := catalogue.Manifest{Module: "idp", Resources: []map[string]any{
+		{"id": "server", "type": "container", "image": "x@sha256:aa",
+			"env": map[string]any{"KC_HOSTNAME": "https://login.mesh-one.be"}},
+	}}
+	err := namesNoInstallation(named)
+	if err == nil || !strings.Contains(err.Error(), "login.mesh-one.be") ||
+		!strings.Contains(err.Error(), catalogue.NamesOnPurpose) {
+		t.Fatalf("a definition naming an installation is refused with the name and the way out; got %v", err)
+	}
+	meant := catalogue.Manifest{Module: "site", Resources: []map[string]any{
+		{"id": "server", "type": "container", "image": "registry.mesh-one.be/org/site@sha256:cc",
+			catalogue.NamesOnPurpose: map[string]any{
+				"registry.mesh-one.be": "built outside the mesh until its repository is a build source here"}},
+	}}
+	if err := namesNoInstallation(meant); err != nil {
+		t.Fatalf("a name declared on purpose passes; got %v", err)
+	}
+}
+
+// **The controller's own manifest names every verb of its seat** (novox/hq ADR 0132): its tools lagged
+// the seat's verbs for weeks, and `module check` — the gate's first step for a change touching it —
+// refused it. Held here, so a verb added to the table without the manifest fails this repository's
+// own suite rather than its next pull request's gate.
+func TestTheControllersManifestServesEveryVerbOfItsSeat(t *testing.T) {
+	var out strings.Builder
+	if err := moduleCheck([]string{"../../module.json"}, &out); err != nil {
+		t.Fatalf("the controller's own module.json fails module check: %v\n%s", err, out.String())
+	}
+}
+
+// A module that uses a seat another module declares (novox/hq issue 364): refused over the whole catalogue when the
+// declarer is missing, a note when the gate says it gives only the manifests a change touches.
+func TestASeatAnotherModuleDeclaresIsANoteOverSomeManifests(t *testing.T) {
+	dir := t.TempDir()
+	user := filepath.Join(dir, "user.json")
+	os.WriteFile(user, []byte(`{"module":"asker","version":"1","uses":["operator-channel"]}`), 0o600)
+	var out bytes.Buffer
+	if err := moduleCheck([]string{user}, &out); err == nil {
+		t.Fatalf("a use of a seat nothing given declares passed the whole-catalogue check:\n%s", out.String())
+	}
+	t.Setenv(SomeManifestsVar, "1")
+	out.Reset()
+	if err := moduleCheck([]string{user}, &out); err != nil {
+		t.Fatalf("over some manifests the use was refused:\n%s", out.String())
+	}
+	if !strings.Contains(out.String(), "note: asker uses the seat \"operator-channel\"") {
+		t.Fatalf("the note was not said:\n%s", out.String())
+	}
+}
+
+// **A module lives whole in one repository** (novox/hq ADR 0420 §1, issue 1019): `module check`, told the
+// repository it runs for, refuses an artifact whose build context names another; run by hand, it does not know.
+func TestModuleCheckRefusesAnArtifactContextNamingAnotherRepository(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name, context string) string {
+		path := filepath.Join(dir, name+".json")
+		raw := `{"module":"` + name + `","version":"1","build":{"artifacts":[{"name":"server","kind":"image","from":"Dockerfile"` + context + `}]}}`
+		if err := os.WriteFile(path, []byte(raw), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		return path
+	}
+	other := write("other", `,"context":{"seat":"git","repository":"novox/mesh-controller","ref":"main"}`)
+	own := write("own", `,"context":{"seat":"git","repository":"novox/mesh-catalog","ref":"main"}`)
+	none := write("none", ``)
+
+	t.Setenv("MESH_CHECK_REPOSITORY", "novox/mesh-catalog")
+	var out bytes.Buffer
+	if err := moduleCheck([]string{other}, &out); err == nil {
+		t.Fatalf("a context naming another repository passed:\n%s", out.String())
+	}
+	if !strings.Contains(out.String(), "other builds artifact server from novox/mesh-controller: a module lives whole in one repository (novox/hq ADR 0420 §1)") {
+		t.Errorf("the refusal is not in the words of the gate:\n%s", out.String())
+	}
+	for _, path := range []string{own, none} {
+		out.Reset()
+		if err := moduleCheck([]string{path}, &out); err != nil {
+			t.Errorf("%s was refused: %v\n%s", path, err, out.String())
+		}
+	}
+	t.Setenv("MESH_CHECK_REPOSITORY", "")
+	out.Reset()
+	if err := moduleCheck([]string{other}, &out); err != nil {
+		t.Errorf("a local run, with no repository named, refused it: %v\n%s", err, out.String())
+	}
+}

cmd/mesh-controller/checks.go

@@ -0,0 +1,663 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"path"
+	"regexp"
+	"runtime/debug"
+	"slices"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// A pull request's merge check (novox/hq to-be 45 §9, ADR 0237 as amended 2026-10-06): the forge
+// announces every pull request's new head, the controller decides what is checked, asks the build seat to
+// check it, and says the verdict as `checked`, which the forge's holder sets as the pull request's
+// statuses. **Before merge, never after**: every check the mesh had ran after a merge, on a machine.
+//
+// **The mesh's module graph decides, not the repository.** The controller holds the graph — every module,
+// the repository and directory it is built from — and maps the pull request's changed paths onto it by
+// the planner's own answer (reachOfMerge, touchedBy — the one place a changed file is mapped onto modules,
+// for the merge handler, the release planner, the merge gate and this check; issue 280): **a changed file
+// touches exactly the modules whose build reads it** — a module's own directory (the whole repository for
+// one built from its root), or a repository its recipe packages. A file no build reads — a script at the
+// root, a README — touches no module. A directory the change adds a module.json in, which the graph does
+// not hold yet (said by the head, issue 278), is a new module and is checked too.
+//
+//   - touches a module: the build seat runs **the gate** — `mesh/merge-gate`, the touched manifests, every
+//     machine composed with the change, the replays — and the repository's own merge-check.sh beside it;
+//   - touches none, in a repository that is the mesh's (it sources a module on some branch, or shares the
+//     core's owner): the gate is a pass that says so — a fact, not a missing check — and the repository's
+//     own merge-check.sh runs as `mesh/repo-check`, a warning when it has none;
+//   - touches none, anywhere else: the gate is a pass that says so, and nothing more is said.
+//
+// What is checked is decided here and run there (internal/builder/check.go).
+
+// checkTimeout is how long one check may run on the build seat. Said here so the ask's watchdog (S6)
+// and the builder agree on what late means.
+const checkTimeout = 45 * time.Minute
+
+// noModuleTouched is the gate's word for a change that touches nothing of the graph.
+const noModuleTouched = "the change touches no module of the mesh's graph"
+
+// noMergeCheck is the repository layer's word for a repository of the mesh with no merge-check.sh.
+const noMergeCheck = "the repository declares no merge-check.sh: none of its own tests run before it merges"
+
+// coreModules are the modules whose repositories are the mesh's core, by the directory a check finds
+// each beside it — and whose owner is the mesh's own.
+var coreModules = map[string]string{"mesh-controller": "mesh-controller", "mesh-host": "mesh-host",
+	"node-tools": "mesh-tools", "nats": "mesh-catalog"}
+
+// checkScope is what a pull request reaches of the mesh's graph, as the planner reckons it.
+type checkScope struct {
+	// Modules are the modules a merge of the change would move itself — built from the repository into
+	// the pull request's base and reading a changed file, or packaging the repository's source — and
+	// Dependents those the plan would build after them; New the directories it adds a module in.
+	Modules    []string
+	Dependents []string
+	New        []string
+	// Manifests are the moved modules' and the new ones' manifests in the change's tree.
+	Manifests []string
+	// Width is how many modules a merge would build, in how many tiers; Unread the changed files no
+	// module's build reads.
+	Width, Tiers int
+	Unread       []string
+	// Mesh says the repository is the mesh's: modules are built from it on some branch, its owner is the
+	// core's, or the change adds a module to it.
+	Mesh bool
+	// Judge is who judges the gate (link.JudgeSelf, link.JudgeValidator, or the running controller).
+	Judge string
+	// From is a module built from the repository, for how the mesh clones it; nil when none is.
+	From *inventory.Entry
+	// Reach is the planner's whole answer, which the change plan is made from.
+	Reach mergeReach
+}
+
+func (s checkScope) gated() bool { return len(s.Modules)+len(s.New) > 0 }
+
+// pullScope is what a pull request reaches: **the planner's own answer** (reachOfMerge), asked as if the
+// head were merged into the base — never a mapping of its own, so a change to what a merge touches
+// changes what is checked with it (novox/hq ADR 0238).
+func pullScope(p link.PullUpdated, entries []inventory.Entry, read map[string][]inventory.ReadRepository,
+	edges []inventory.Edge) checkScope {
+	m := link.SourceMoved{Owner: p.Owner, Repo: p.Repo, Base: p.Base, CloneURL: p.CloneURL, Commit: p.Commit,
+		Paths: p.Paths, PathsTruncated: p.PathsTruncated, Removed: p.Removed, ModuleDirs: p.ModuleDirs,
+		ModuleDirsSaid: p.ModuleDirsSaid}
+	r := reachOfMerge(m, entries, read, edges)
+	s := checkScope{Modules: r.Moved(), Dependents: r.Dependents(), New: r.Added, Unread: r.Unread,
+		Width: len(r.Plan.Modules), Tiers: len(r.Plan.Tiers), Reach: r}
+	for _, e := range append(append([]inventory.Entry{}, r.Touched...), r.Deleted...) {
+		s.Manifests = append(s.Manifests, path.Join(strings.Trim(e.Source.Path, "/"), moduleManifestFile))
+		switch e.Manifest.Module {
+		case "mesh-controller":
+			s.Judge = link.JudgeSelf
+		case "mesh-host":
+			if s.Judge == "" {
+				s.Judge = link.JudgeValidator
+			}
+		}
+	}
+	for _, d := range r.Added {
+		s.Manifests = append(s.Manifests, path.Join(d, moduleManifestFile))
+	}
+	sort.Strings(s.Manifests)
+	s.Manifests = slices.Compact(s.Manifests)
+
+	// Whose repository it is, for how it is cloned and whether its own check is the mesh's to run.
+	owners := map[string]bool{}
+	for i, e := range entries {
+		if e.Provided {
+			continue
+		}
+		if _, core := coreModules[e.Manifest.Module]; core {
+			if owner := sourceOwner(e.Source.Repository); owner != "" {
+				owners[owner] = true
+			}
+		}
+		if sameRepository(e.Source.Repository, m) && s.From == nil {
+			s.From = &entries[i]
+		}
+	}
+	s.Mesh = s.From != nil || owners[strings.ToLower(p.Owner)] || s.gated()
+	return s
+}
+
+// sourceOwner is the owner of a recorded repository, a path on the git seat or a URL: novox/mesh-host → novox.
+func sourceOwner(repository string) string {
+	parts := strings.Split(strings.Trim(strings.TrimSuffix(repository, ".git"), "/"), "/")
+	if len(parts) < 2 {
+		return ""
+	}
+	return strings.ToLower(parts[len(parts)-2])
+}
+
+// PullUpdated decides a pull request's merge check, and asks for it when there is something to run.
+func (f following) PullUpdated(ctx context.Context, p link.PullUpdated) error {
+	inv := f.open.inventory
+	entries, err := inv.Catalogued(ctx)
+	if err != nil {
+		return err
+	}
+	read, err := readForPlanning(ctx, inv)
+	if err != nil {
+		return err
+	}
+	edges, err := inv.Dependencies(ctx)
+	if err != nil {
+		return err
+	}
+	scope := pullScope(p, entries, read, edges)
+	// **A cycle of edges fails the check, naming every module and edge** (novox/hq ADR 0419 clause 6), a lone pull
+	// request's as a group's composed check is: no order exists for what it changes.
+	alone := orderMember{ID: p.Owner + "/" + p.Repo + "@" + twelve(p.Commit), Repository: p.Owner + "/" + p.Repo, Base: p.Base,
+		Head: p.Commit, Number: p.Number, Paths: p.Paths, PathsTruncated: p.PathsTruncated, Removed: p.Removed, BaseSHA: p.BaseSHA}
+	if failing, cyclic, err := cycleVerdict(ctx, "", []orderMember{alone},
+		map[string]orderReach{alone.ID: {Moved: scope.Modules}}, edges, entries); err != nil {
+		return err
+	} else if cyclic {
+		failing.Commit, failing.Trunk = p.Commit, twelve(p.BaseSHA)
+		fmt.Printf("%s/%s#%d (%.8s): %s\n", p.Owner, p.Repo, p.Number, p.Commit, failing.Summary)
+		sayChecked(ctx, failing)
+		return nil
+	}
+	// **A member of a group whose gate is the composed check's runs its repository's check alone** (novox/hq ADR 0403
+	// clause 1): mesh-delivery is asked once, and says so on the group's line. Told nothing, the pull request is
+	// checked alone, gate included (clause 6).
+	lines, groupsErr := groupsAsked(ctx, deliverySeatHeld(entries))
+	composed := groupsErr == nil && composedMember(p, lines)
+	// The change plan of the commit at hand (ADR 0238): what a merge of it would build and send, posted
+	// with the verdict whatever the verdict is.
+	plan := changePlanOf(p.Owner+"/"+p.Repo, p.Base, p.Commit, scope.Reach, entries, func(module string) (inventory.Upgrade, bool) {
+		u, err := inv.UpgradeOf(ctx, module)
+		return u, err == nil
+	})
+	fmt.Print(planText(plan))
+	direct := directVerdict(p, plan)
+	if composed {
+		scope.Modules, scope.Dependents, scope.New, scope.Manifests = nil, nil, nil, nil
+		composedGate(&direct)
+	}
+	switch {
+	case !scope.gated() && !scope.Mesh:
+		fmt.Printf("%s/%s#%d (%.8s): %s, and the repository is not the mesh's: said, nothing run\n",
+			p.Owner, p.Repo, p.Number, p.Commit, noModuleTouched)
+		sayChecked(ctx, direct)
+		return nil
+	case !scope.gated() && p.MergeCheckSaid && !p.MergeCheck:
+		direct.RepoCheck = &link.CheckLayer{Verdict: "warning", Summary: noMergeCheck}
+		fmt.Printf("%s/%s#%d (%.8s): %s; %s\n", p.Owner, p.Repo, p.Number, p.Commit, noModuleTouched, noMergeCheck)
+		sayChecked(ctx, direct)
+		return nil
+	}
+	request, err := checkRequestFor(ctx, f.open, p, scope, entries)
+	if err != nil {
+		return err
+	}
+	request.Check.Plan = &plan
+	request.Check.Composed = composed
+	// **The group's other open pull requests are read beside it** (novox/hq ADR 0382 §1).
+	siblingsFrom(&request, p, entries, lines, groupsErr)
+	seat := buildSeatHeld(ctx)
+	ask, err := askOverOn(seat)
+	if err != nil {
+		return err
+	}
+	defer ask.Close()
+	if err := ask.Ask(ctx, request); err != nil {
+		return err
+	}
+	// **A newer request replaces the one still waiting, and a newer key stops the one running** (novox/hq ADR 0406 §3, §4,
+	// issue 974): the check queue keeps one request a pull request, and a running check watches its key. Nothing is asked
+	// of the forge here (issue 726).
+	what := "its own merge-check.sh alone: " + noModuleTouched
+	if composed {
+		what = "its own merge-check.sh alone: the gate is its group's composed check's"
+	}
+	if scope.gated() {
+		what = fmt.Sprintf("the gate over %s (a merge would build %d module(s) in %d tier(s))",
+			strings.Join(append(append([]string{}, scope.Modules...), prefixedAll("new:", scope.New)...), ", "),
+			scope.Width, scope.Tiers)
+	}
+	fmt.Printf("%s/%s#%d (%.8s): asked %s to check it before it merges — %s — as %s\n", p.Owner, p.Repo, p.Number,
+		p.Commit, seat, what, request.ID)
+	return nil
+}
+
+// composedWords is what a group member's own verdict says of its gate layer (novox/hq ADR 0403 clause 1).
+const composedWords = "judged by its group's composed check"
+
+// gateComposed is a gate layer's verdict when no gate was run for the member alone: never a pass. Mesh-delivery reads it
+// as the composed check's to judge, and the forge's holder sets no mesh/merge-gate from it.
+const gateComposed = "composed"
+
+// composedGate says a group member's own verdict has no gate of its own: its gate layer, and the verdict that is
+// the gate's, read "composed" in place of a pass.
+func composedGate(c *link.Checked) {
+	c.Verdict, c.Summary = gateComposed, composedWords
+	c.Gate = &link.CheckLayer{Verdict: gateComposed, Summary: composedWords}
+}
+
+// directVerdict is the verdict of a change no build judges — it touches no module, and either the repository is not
+// the mesh's or the head holds no merge-check.sh. **It names the trunk commit it holds for** (novox/hq ADR 0323 §3):
+// the base branch's head the forge announced with the head, so the merge tool can weigh it against the trunk's head
+// and does not refuse it for ever (a verdict naming no trunk is never the trunk's head's). Nothing was built to
+// judge: the trunk commit is the one the forge said the change was announced against.
+func directVerdict(p link.PullUpdated, plan link.ChangePlan) link.Checked {
+	trunk := p.BaseSHA
+	if len(trunk) > 12 {
+		trunk = trunk[:12]
+	}
+	if trunk != "" {
+		plan.Trunk = trunk
+	}
+	return link.Checked{Owner: p.Owner, Repo: p.Repo, Number: p.Number, Commit: p.Commit,
+		ID: link.NewBuildID(time.Now()), Verdict: "pass", Summary: noModuleTouched,
+		Gate: &link.CheckLayer{Verdict: "pass", Summary: noModuleTouched}, Plan: &plan, Trunk: trunk}
+}
+
+// checkRequestFor is the ask for one pull request's head: the repository as the mesh clones it, the head,
+// and what is read beside it.
+func checkRequestFor(ctx context.Context, open *stores, p link.PullUpdated, scope checkScope,
+	entries []inventory.Entry) (link.BuildRequest, error) {
+	shelf := map[string]catalogue.Manifest{}
+	for _, e := range entries {
+		shelf[e.Manifest.Module] = e.Manifest
+	}
+	world, err := theRestOfTheMesh(ctx, open.inventory, shelf, "")
+	if err != nil {
+		return link.BuildRequest{}, err
+	}
+	clone := func(s inventory.Source) (string, error) {
+		if s.Seat == "" {
+			return s.Repository, nil
+		}
+		return clonedFromSeat(world, s.Seat, s.Repository)
+	}
+	// As the mesh clones a module built from it; a repository no module is built from, from the forge.
+	source := inventory.Source{Seat: gitSeat, Repository: p.Owner + "/" + p.Repo}
+	if scope.From != nil {
+		source = scope.From.Source
+	}
+	repository, err := clone(source)
+	if err != nil {
+		return link.BuildRequest{}, err
+	}
+	current, err := open.inventory.CurrentBuilds(ctx)
+	if err != nil {
+		return link.BuildRequest{}, err
+	}
+	beside, err := besideOf(entries, func(module string) string { return current[module].Commit }, clone)
+	if err != nil {
+		return link.BuildRequest{}, err
+	}
+	builds := checkBuildsOf(p, scope, entries, clone)
+	return link.BuildRequest{
+		ID:         link.NewBuildID(time.Now()),
+		Repository: repository,
+		Ref:        p.Commit,
+		Held:       heldBy(ctx),
+		Seats:      seatBases(ctx),
+		Source:     sourceOnSeat(source),
+		Check: &link.CheckRequest{Owner: p.Owner, Repo: p.Repo, Number: p.Number, Base: p.Base, Trunk: p.BaseSHA, Ready: p.Ready,
+			Paths: p.Paths, Beside: beside, Modules: scope.Modules, Dependents: scope.Dependents, New: scope.New,
+			Manifests: scope.Manifests, Judge: scope.Judge, Builds: builds, Named: namedForTheCheck(ctx, p, builds),
+			Running: runningBy(ctx)},
+	}, nil
+}
+
+// besideOf is what a check reads beside its own repository, by the directory it is found under: each core repository
+// by the module the mesh builds from it, at besideRefs. running is the commit the mesh runs of a module.
+func besideOf(entries []inventory.Entry, running func(module string) string,
+	clone func(inventory.Source) (string, error)) (map[string]link.CheckedOut, error) {
+	beside := map[string]link.CheckedOut{}
+	for _, e := range entries {
+		dir, core := coreModules[e.Manifest.Module]
+		if !core || e.Provided || e.Source.Repository == "" {
+			continue
+		}
+		url, err := clone(e.Source)
+		if err != nil {
+			return nil, err
+		}
+		refs := besideRefs(dir, running(e.Manifest.Module))
+		beside[dir] = link.CheckedOut{Repository: url, Ref: refs[dir]}
+		if dir == "mesh-controller" {
+			// The controller's main stays its main: it judges only a check the running controller predates.
+			beside["mesh-controller-main"] = link.CheckedOut{Repository: url, Ref: refs["mesh-controller-main"]}
+			if e.Source.Seat != "" {
+				for _, sibling := range []string{"mesh-lab", "mesh-sdk"} {
+					if url, err := clone(inventory.Source{Seat: e.Source.Seat, Repository: siblingOf(e.Source.Repository,
+						sibling)}); err == nil {
+						beside[sibling] = link.CheckedOut{Repository: url, Ref: refs[sibling]}
+					}
+				}
+			}
+		}
+	}
+	return beside, nil
+}
+
+// trunkOf is the branch a module's source follows: main when it records none, or records a commit.
+func trunkOf(s inventory.Source) string {
+	if t := strings.TrimSpace(followedBranch(s.Ref)); t != "" {
+		return t
+	}
+	return "main"
+}
+
+// sourceName is the name of a recorded repository, a path on the git seat or a URL: novox/mesh-host → mesh-host.
+func sourceName(repository string) string {
+	parts := strings.Split(strings.Trim(strings.TrimSuffix(repository, ".git"), "/"), "/")
+	if len(parts) < 2 {
+		return ""
+	}
+	return parts[len(parts)-1]
+}
+
+// namedForTheCheck are the builds earlier checks of the same pull request at the same head named, read once for the
+// check (novox/hq issue 703): asked again because only the trunk moved, the check keeps what they built of a key
+// still the same. Another pull request's build, or one of an earlier head, is never kept. None when they cannot be
+// read, and the check builds, as before.
+func namedForTheCheck(ctx context.Context, p link.PullUpdated, builds []link.CheckBuild) []link.CheckedBuild {
+	if len(builds) == 0 || p.Commit == "" {
+		return nil
+	}
+	pull := link.PullRef{Owner: p.Owner, Repo: p.Repo, Number: p.Number}
+	read, err := checkedBuildsOf(ctx, []link.PullRef{pull})
+	if err != nil {
+		fmt.Printf("  the earlier checks' builds of %s/%s#%d could not be read, so the check builds: %v\n",
+			p.Owner, p.Repo, p.Number, err)
+		// empty-on-error: said above; a check handed no named build builds every module, as before issue 703
+		return nil
+	}
+	var named []link.CheckedBuild
+	for _, b := range read {
+		if b.Pull == pull && link.SameHead(b.Head, p.Commit) {
+			named = append(named, b)
+		}
+	}
+	return named
+}
+
+// checkBuildsOf are the modules a merge of the change would build, in the walk's order, as the check builds them
+// for the walk to take (novox/hq ADR 0350 §1): a module built from the repository checked, at the branch it merges
+// into, from the merge the check makes; any other — a module standing on one — from its own repository at the
+// branch it follows, as the walk builds it. A module whose build reads the repository checked through a context,
+// or that the merge deletes, cannot be built as the walk would: said, and nothing after it is built. A change that
+// moves no module builds nothing.
+func checkBuildsOf(p link.PullUpdated, scope checkScope, entries []inventory.Entry,
+	clone func(inventory.Source) (string, error)) []link.CheckBuild {
+	if len(scope.Reach.Plan.Tiers) == 0 {
+		return nil
+	}
+	m := link.SourceMoved{Owner: p.Owner, Repo: p.Repo, Base: p.Base, CloneURL: p.CloneURL}
+	byName := map[string]inventory.Entry{}
+	for _, e := range entries {
+		byName[e.Manifest.Module] = e
+	}
+	skip := map[string]string{}
+	for _, e := range scope.Reach.Packaging {
+		skip[e.Manifest.Module] = "its build reads " + p.Owner + "/" + p.Repo + " through a context, which a check " +
+			"cannot hand the merge"
+	}
+	for _, e := range scope.Reach.Deleted {
+		skip[e.Manifest.Module] = "the merge deletes it"
+	}
+	var out []link.CheckBuild
+	for tier, names := range scope.Reach.Plan.Tiers {
+		for _, name := range names {
+			e, known := byName[name]
+			b := link.CheckBuild{Module: name, Tier: tier, Skip: skip[name]}
+			switch {
+			case !known:
+				b.Skip = "the catalogue does not hold it"
+			case b.Skip != "":
+			case sourceIs(e.Source, m):
+				b.Merged, b.Path = true, e.Source.Path
+			default:
+				url, err := clone(e.Source)
+				if err != nil {
+					b.Skip = "its repository cannot be cloned: " + err.Error()
+					break
+				}
+				b.Repository, b.Path, b.Ref = url, e.Source.Path, followedBranch(e.Source.Ref)
+			}
+			out = append(out, b)
+		}
+	}
+	return out
+}
+
+// besideRefs is the ref each repository is cloned at beside a check, by the directory it is found under:
+// a core repository at the commit the mesh runs of the module built from it (`running`) — but the
+// catalogue, whose checkout beside is what tests read its files from, at its main, what the next merge
+// builds from; and beside the controller its main, for a judge the running controller predates, and the
+// lab's main, whose replays every check runs. **One rule, read by the check the controller asks for and by
+// the facts snapshot** (Facts.Beside), so a check run by hand clones what the build seat clones. Beside the
+// controller also the SDK, checked out at the commit the running controller's go.mod pins (sdkPinned), not
+// one a desktop holds (novox/hq issue 449). The checkout only places the clone: the conformance test reads the
+// fixtures at the pin of the tree under check, from the clone's history, so a pull request moving the SDK is
+// judged against the SDK it moves to (internal/link/conformance_test.go).
+func besideRefs(dir, running string) map[string]string {
+	switch dir {
+	case "mesh-catalog":
+		return map[string]string{dir: "main"}
+	case "mesh-controller":
+		return map[string]string{dir: running, "mesh-controller-main": "main", "mesh-lab": "main",
+			"mesh-sdk": sdkPinned()}
+	}
+	return map[string]string{dir: running}
+}
+
+// sdkModule is the Go module of the SDK the controller is built against.
+const sdkModule = "git.novox.be/novox/mesh-sdk/go"
+
+// pseudoCommit is the commit a Go pseudo-version names: v0.1.11-0.20261009143344-f047d0a4a970 → f047d0a4a970.
+var pseudoCommit = regexp.MustCompile(`-([0-9a-f]{12})$`)
+
+// sdkPinned is the ref of the SDK repository this controller was built from, as its go.mod pins it and its
+// build records it: a pseudo-version's commit, or a release's tag (the SDK tags its Go module under go/).
+// "main" only for a binary that records no SDK version — a local replace — which a running controller is
+// not (novox/hq issue 449).
+func sdkPinned() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "main"
+	}
+	for _, dep := range info.Deps {
+		if dep.Path != sdkModule {
+			continue
+		}
+		if dep.Replace != nil {
+			dep = dep.Replace
+		}
+		if m := pseudoCommit.FindStringSubmatch(dep.Version); m != nil {
+			return m[1]
+		}
+		if strings.HasPrefix(dep.Version, "v") {
+			return "go/" + dep.Version
+		}
+	}
+	return "main"
+}
+
+// siblingOf is another repository of the same owner: novox/mesh-controller → novox/mesh-lab.
+func siblingOf(repository, name string) string {
+	if cut := strings.LastIndex(repository, "/"); cut >= 0 {
+		return repository[:cut+1] + name
+	}
+	return name
+}
+
+// sourceOnSeat is a source's seat form, nil for one on no seat.
+func sourceOnSeat(s inventory.Source) *link.SourceOnSeat {
+	if s.Seat == "" {
+		return nil
+	}
+	return &link.SourceOnSeat{Seat: s.Seat, Repository: s.Repository}
+}
+
+// checkEvents is where the serving controller says a check's verdict; nil in a command.
+var checkEvents link.Bus
+
+// maxCheckReport is how much of a check's report travels in its verdict: enough for the failures and
+// the machines, never a log.
+const maxCheckReport = 60 << 10
+
+// checked says a merge check's verdict as the controller's `checked`. Nothing is recorded or
+// registered: a check builds nothing (issue 240's rule for a dry run, kept for a check).
+func checked(ctx context.Context, result link.BuildResult) {
+	// **A check stopped by its key says nothing** (novox/hq ADR 0406 §4, issue 974, review 2): it stopped because the head or
+	// the trunk commit moved on, and the newer request will judge. Said as an error it would name the live head — red
+	// statuses on the forge, a delivery refused — and written to the key it would stand in the newer request's way.
+	if result.Failed == link.SupersededByKey {
+		fmt.Printf("%s: stopped, its pull request's key moved on; the newer check will judge\n", result.ID)
+		return
+	}
+	sayChecked(ctx, checkedOf(result))
+}
+
+// checkedOf is what a check's outcome says: each layer, and an error — never a pass — for a check that
+// could not run.
+func checkedOf(result link.BuildResult) link.Checked {
+	c := link.Checked{ID: result.ID, On: result.On, Commit: result.Ref}
+	if result.Checked != nil {
+		c.Owner, c.Repo, c.Number = result.Checked.Owner, result.Checked.Repo, result.Checked.Number
+	}
+	switch {
+	case result.Check != nil:
+		c.Verdict, c.Summary, c.Report = result.Check.Verdict, result.Check.Summary, result.Check.Report
+		c.Gate, c.RepoCheck = result.Check.Gate, result.Check.RepoCheck
+		// What was judged (novox/hq ADR 0323 §3): the head merged into the trunk commit, and the commits of the
+		// repositories read beside it.
+		c.Trunk, c.Beside, c.Took = result.Check.Trunk, result.Check.Beside, result.Check.Took
+		c.Built = result.Check.Built
+		c.Validator = result.Check.Validator
+		c.Siblings, c.SiblingsUnknown, c.JudgeFrom = result.Check.Siblings, result.Check.SiblingsUnknown, result.Check.JudgeFrom
+		if c.Gate == nil {
+			// A build seat from before the layers: its verdict is the gate's.
+			c.Gate = &link.CheckLayer{Verdict: c.Verdict, Summary: c.Summary}
+		}
+	case result.Failed != "":
+		// The check could not run: an error, never read as a pass — on both layers it was asked for.
+		c.Verdict, c.Summary = "error", "the check could not run: "+firstLine(result.Failed)
+	default:
+		c.Verdict, c.Summary = "error", "the build seat answered the check with no verdict"
+	}
+	if c.Verdict == "" {
+		c.Verdict = "error"
+	}
+	if result.Check == nil {
+		c.Gate = &link.CheckLayer{Verdict: c.Verdict, Summary: c.Summary}
+		c.RepoCheck = &link.CheckLayer{Verdict: c.Verdict, Summary: c.Summary}
+	}
+	// **A group member's own check has no gate of its own** (novox/hq ADR 0403 clause 1): what ran was the repository's
+	// check alone, and its gate layer is "composed", never a pass. A failure or an error stays what it was.
+	if result.Checked != nil && result.Checked.Composed && result.Check != nil && c.Gate != nil &&
+		(c.Gate.Verdict == "pass" || c.Gate.Verdict == "warning") {
+		composedGate(&c)
+	}
+	if result.Checked != nil && c.Gate != nil && len(c.Gate.Modules) == 0 {
+		c.Gate.Modules = append(append([]string{}, result.Checked.Modules...), prefixedAll("new:", result.Checked.New)...)
+	}
+	if result.Checked != nil && c.Gate != nil && len(c.Gate.Dependents) == 0 {
+		c.Gate.Dependents = result.Checked.Dependents
+	}
+	if result.Checked != nil {
+		c.Plan = result.Checked.Plan
+		if c.Plan != nil && c.Trunk != "" {
+			// The kept delivery plan records the trunk commit with its other inputs (ADR 0323 §3).
+			plan := *c.Plan
+			plan.Trunk = c.Trunk
+			c.Plan = &plan
+		}
+		// A delivery group's composed check (novox/hq ADR 0239): every head it judged, this one first.
+		if g := result.Checked; g.Group != "" {
+			c.Group = g.Group
+			c.Members = append(c.Members, link.CheckedMember{Owner: g.Owner, Repo: g.Repo, Number: g.Number,
+				Commit: result.Ref, Trunk: c.Trunk})
+			for _, m := range g.Members {
+				c.Members = append(c.Members, link.CheckedMember{Owner: m.Owner, Repo: m.Repo, Number: m.Number,
+					Commit: m.Ref, Trunk: memberTrunk(result.Check, m)})
+			}
+		}
+	}
+	for _, l := range []*link.CheckLayer{c.Gate, c.RepoCheck} {
+		if l != nil && l.Verdict == "" {
+			l.Verdict = "error"
+		}
+	}
+	// **A check run again says so** (novox/hq issue 594). The summaries are the lines the pull request
+	// shows, clipped by the forge to a few words, so they get only a short marker after the verdict's own
+	// words; the report gets the whole sentence. Layers copied, so the build's own outcome is left as it came.
+	if mark := link.RunMarker(result.Delivery); mark != "" {
+		c.Summary += " " + mark
+		for _, l := range []**link.CheckLayer{&c.Gate, &c.RepoCheck} {
+			if *l != nil {
+				layer := **l
+				layer.Summary += " " + mark
+				*l = &layer
+			}
+		}
+		c.Report = link.Restarted(result.Delivery) + "\n\n" + c.Report
+	}
+	if len(c.Report) > maxCheckReport {
+		c.Report = "…" + c.Report[len(c.Report)-maxCheckReport:]
+	}
+	return c
+}
+
+// memberTrunk is the trunk commit the build seat merged one of a group's heads into (novox/hq ADR 0323 §6), empty
+// when it said none.
+func memberTrunk(outcome *link.CheckOutcome, m link.GroupMember) string {
+	if outcome == nil {
+		return ""
+	}
+	for _, j := range outcome.Members {
+		if strings.EqualFold(j.Owner, m.Owner) && strings.EqualFold(j.Repo, m.Repo) && strings.HasPrefix(m.Ref, j.Commit) {
+			return j.Trunk
+		}
+	}
+	return ""
+}
+
+func prefixedAll(prefix string, items []string) []string {
+	out := make([]string, 0, len(items))
+	for _, i := range items {
+		out = append(out, prefix+i)
+	}
+	return out
+}
+
+// sayChecked says a merge check's verdict on the bus, where the forge's holder hears it.
+func sayChecked(ctx context.Context, c link.Checked) {
+	repo := "none"
+	if c.RepoCheck != nil {
+		repo = strings.ToUpper(c.RepoCheck.Verdict) + " — " + c.RepoCheck.Summary
+	}
+	judged := ""
+	if c.Trunk != "" {
+		judged = " merged into trunk " + c.Trunk
+	}
+	fmt.Printf("%s: %s/%s#%d at %.8s%s checked on %s: gate %s — %s; repository %s\n", c.ID, c.Owner, c.Repo, c.Number,
+		c.Commit, judged, orSomewhere(c.On), strings.ToUpper(c.Verdict), c.Summary, repo)
+	if checkEvents == nil {
+		return
+	}
+	body, err := json.Marshal(c)
+	if err != nil {
+		return
+	}
+	stating, stop := context.WithTimeout(context.WithoutCancel(ctx), 10*time.Second)
+	defer stop()
+	if err := checkEvents.PublishSeatEvent(stating, link.MeshControllerSeat, link.KeyChecked, body); err != nil {
+		fmt.Printf("%s: the verdict could not be said, so the pull request is not told it: %v\n", c.ID, err)
+	}
+}

cmd/mesh-controller/checks_integration_test.go

@@ -0,0 +1,56 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+func TestACheckStoppedByItsKeyIsAnnouncedAsNoVerdict(t *testing.T) {
+	js, err := broker.Dial(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(js.Close)
+	if err := broker.AssertMeshStreams(js); err != nil {
+		t.Fatal(err)
+	}
+	legacy, err := js.Conn().JetStream()
+	if err != nil {
+		t.Fatal(err)
+	}
+	was := checkEvents
+	checkEvents = link.OverNATS{Conn: js.Conn(), JS: legacy}
+	t.Cleanup(func() { checkEvents = was })
+	heard := make(chan *nats.Msg, 4)
+	sub, err := js.Conn().ChanSubscribe(link.SeatEventSubject(link.MeshControllerSeat, link.KeyChecked), heard)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = sub.Unsubscribe() }()
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-catalog", Number: 3}
+	checked(t.Context(), link.BuildResult{ID: "stopped", Ref: "abc", Checked: asked, Failed: link.SupersededByKey})
+	checked(t.Context(), link.BuildResult{ID: "broken", Ref: "abc", Checked: asked, Failed: "the facts snapshot cannot be read"})
+	select {
+	case m := <-heard:
+		var c link.Checked
+		_ = json.Unmarshal(m.Data, &c)
+		if c.ID != "broken" || c.Verdict != "error" {
+			t.Fatalf("the first verdict said is %+v; want only the broken check's error", c)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatal("nothing was said")
+	}
+	select {
+	case m := <-heard:
+		t.Fatalf("a second verdict was said: %s", m.Data)
+	case <-time.After(300 * time.Millisecond):
+	}
+}

cmd/mesh-controller/checks_queue_test.go

@@ -0,0 +1,97 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"testing"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// Acceptance 5 of milestone 2 (novox/hq ADR 0406 §3, issue 974), live, with the store and a real bus: two merges into one
+// repository within a minute, with two open pull requests, leave each pull request with exactly one queued check, by the
+// stream's rule. Each merge moves the trunk, and mesh-delivery asks the controller to check both open pull requests again
+// against it (`delivery check`, which is the controller's own path for a head announced); nothing moves a request, nothing
+// asks the forge, and the queue is read back whole.
+func TestTwoMergesWithinAMinuteLeaveEachOpenPullRequestOneQueuedCheck(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	js, _ := aBuildQueue(t)
+	servingBus.Store(js)
+	t.Cleanup(func() { servingBus.Store(nil) })
+	holdTheDeliverySeat(t, open)
+	was := askDeliveryOwner
+	t.Cleanup(func() { askDeliveryOwner = was })
+	askDeliveryOwner = func(_ context.Context, _ *nats.Conn, verb string, _ map[string]any) (json.RawMessage, error) {
+		if verb != "groups" {
+			t.Fatalf("asked the owner %s", verb)
+		}
+		return json.RawMessage(`[]`), nil
+	}
+	// The repository the two pull requests are into, as a module the mesh builds from it.
+	if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-controller", Version: "1"},
+		inventory.Source{Repository: "novox/mesh-controller", Ref: "main", BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+
+	heads := map[int]string{7: "7777777777777777777777777777777777777777", 8: "8888888888888888888888888888888888888888"}
+	check := func(number int, trunk string) {
+		t.Helper()
+		p := orderMember{ID: fmt.Sprintf("novox/mesh-controller@%.12s", heads[number]), Repository: "novox/mesh-controller",
+			Base: "main", Head: heads[number], Number: number, Paths: []string{"main.go"}, ModuleDirsSaid: true,
+			BaseSHA: trunk, Ready: number == 8}.pull()
+		p.MergeCheck, p.MergeCheckSaid = true, true
+		if err := (following{open: open, oneShot: true}).PullUpdated(ctx, p); err != nil {
+			t.Fatal(err)
+		}
+	}
+	// Announced against the trunk as it stands, then asked again after each of two merges.
+	for _, trunk := range []string{"1111111111111111111111111111111111111111", "2222222222222222222222222222222222222222",
+		"3333333333333333333333333333333333333333"} {
+		check(7, trunk)
+		check(8, trunk)
+	}
+
+	q, err := link.ReadQueue(ctx, js, link.TheBuildMachine)
+	if err != nil {
+		t.Fatal(err)
+	}
+	seen := map[int]string{}
+	for _, a := range q.Asks {
+		c := a.Request.Check
+		if c == nil {
+			t.Fatalf("%s is no check", a.ID)
+		}
+		if _, twice := seen[c.Number]; twice {
+			t.Errorf("pull request %d has two queued checks", c.Number)
+		}
+		seen[c.Number] = c.Trunk
+		if a.State != link.AskWaiting {
+			t.Errorf("%s is %s", a.ID, a.State)
+		}
+		if want := "3333333333333333333333333333333333333333"; c.Trunk != want {
+			t.Errorf("pull request %d is queued against %.8s; want the newest trunk %.8s", c.Number, c.Trunk, want)
+		}
+	}
+	if len(seen) != 2 {
+		t.Fatalf("queued checks for %v; want one for each of the two open pull requests", seen)
+	}
+	// By the streams' own count: the ready one on its stream, the other on its.
+	for stream, want := range map[string]uint64{broker.ChecksReadyStream: 1, broker.ChecksOtherStream: 1} {
+		info, err := js.Context().StreamInfo(stream)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if info.State.Msgs != want {
+			t.Errorf("%s holds %d request(s); want %d", stream, info.State.Msgs, want)
+		}
+	}
+}

cmd/mesh-controller/checks_test.go

@@ -0,0 +1,293 @@
+package main
+
+import (
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **The mesh's module graph decides what a pull request's check runs**, not the repository (novox/hq
+// ADR 0237 as amended): a change is mapped onto the graph by the rule a merge is (issue 278), the gate
+// runs when it touches a module — a new one included — and a repository that is the mesh's and touches
+// none still has its own merge-check.sh run.
+func TestThePullRequestIsMappedOntoTheModuleGraph(t *testing.T) {
+	const catalogue = "http://forge.internal:20000/novox/mesh-catalog.git"
+	const controller = "http://forge.internal:20000/novox/mesh-controller.git"
+	const host = "http://forge.internal:20000/novox/mesh-host.git"
+	photos := fromRepo("photos", "http://forge.internal:20000/novox/photos.git", "")
+	photos.Source.Ref = "nox-mesh"
+	snake := fromRepo("snake", "jschoubben/snake", "")
+	snake.Source.Seat = "git"
+	entries := []inventory.Entry{
+		fromRepo("gitea", catalogue, "modules/gitea"),
+		fromRepo("keycloak", catalogue, "modules/keycloak"),
+		fromRepo("nats", catalogue, "modules/nats"),
+		fromRepo("mesh-controller", controller, ""),
+		fromRepo("mesh-host", host, ""),
+		photos, snake,
+	}
+	pull := func(owner, repo, base string, paths []string, dirs ...string) link.PullUpdated {
+		return link.PullUpdated{Owner: owner, Repo: repo, Base: base, Commit: "abc", Paths: paths,
+			ModuleDirs: dirs, ModuleDirsSaid: true}
+	}
+	for _, c := range []struct {
+		what                   string
+		p                      link.PullUpdated
+		modules, new, manifest string
+		mesh                   bool
+		judge                  string
+	}{
+		{"one module's own files", pull("novox", "mesh-catalog", "main", []string{"modules/gitea/index.ts"}, "modules/gitea"),
+			"gitea", "", "modules/gitea/module.json", true, ""},
+		{"a file no module's build reads touches no module (issue 280)",
+			pull("novox", "mesh-catalog", "main", []string{"merge-check.sh", "README.md"}), "", "", "", true, ""},
+		{"files the announcer could not list: everything built from it",
+			link.PullUpdated{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "abc", PathsTruncated: true,
+				Paths: []string{"README.md"}}, "gitea,keycloak,nats", "",
+			"modules/gitea/module.json,modules/keycloak/module.json,modules/nats/module.json", true, ""},
+		{"a new module, said by the head", pull("novox", "mesh-catalog", "main",
+			[]string{"modules/newmod/index.ts", "modules/newmod/module.json"}, "modules/newmod"),
+			"", "modules/newmod", "modules/newmod/module.json", true, ""},
+		{"the controller judges itself", pull("novox", "mesh-controller", "main", []string{"cmd/x.go"}),
+			"mesh-controller", "", "module.json", true, "self"},
+		{"the node-engine is judged with its validator", pull("novox", "mesh-host", "main", []string{"validate/v.go"}),
+			"mesh-host", "", "module.json", true, "validator"},
+		{"the core's owner, no module: the mesh's, its own check alone", pull("novox", "hq", "main", []string{"README.md"}),
+			"", "", "", true, ""},
+		{"a branch nothing is built from: the mesh's repository, no module", pull("novox", "photos", "master",
+			[]string{"server/x.js"}), "", "", "", true, ""},
+		{"the branch a module is built from", pull("novox", "photos", "nox-mesh", []string{"server/x.js"}),
+			"photos", "", "module.json", true, ""},
+		{"a repository on the forge's seat", pull("jschoubben", "snake", "main", []string{"index.html"}),
+			"snake", "", "module.json", true, ""},
+		{"a repository of nobody's, touching nothing", pull("someone", "dotfiles", "main", []string{"x"}),
+			"", "", "", false, ""},
+		{"a repository adding a module at its root", pull("someone", "newapp", "main", []string{"module.json", "x.js"}),
+			"", ".", "module.json", true, ""},
+	} {
+		s := pullScope(c.p, entries, nil, nil)
+		got := []string{strings.Join(s.Modules, ","), strings.Join(s.New, ","), strings.Join(s.Manifests, ",")}
+		want := []string{c.modules, c.new, c.manifest}
+		for i, what := range []string{"modules", "new", "manifests"} {
+			if got[i] != want[i] {
+				t.Errorf("%s: %s %q, wanted %q", c.what, what, got[i], want[i])
+			}
+		}
+		if s.Mesh != c.mesh || s.Judge != c.judge {
+			t.Errorf("%s: the mesh's %v judged by %q, wanted %v by %q", c.what, s.Mesh, s.Judge, c.mesh, c.judge)
+		}
+		if s.gated() != (c.modules != "" || c.new != "") {
+			t.Errorf("%s: gated %v", c.what, s.gated())
+		}
+	}
+}
+
+// A module whose build packages another repository's source is touched by a change to it.
+func TestAPullRequestTouchesWhatPackagesItsRepository(t *testing.T) {
+	entries := []inventory.Entry{fromRepo("node-tools", "http://forge.internal:20000/novox/mesh-tools.git", "node-tools")}
+	read := map[string][]inventory.ReadRepository{"node-tools": {{Repository: "http://forge.internal:20000/novox/mesh-sdk.git"}}}
+	s := pullScope(link.PullUpdated{Owner: "novox", Repo: "mesh-sdk", Base: "main", Commit: "abc", Paths: []string{"go/x.go"}}, entries, read, nil)
+	if strings.Join(s.Modules, ",") != "node-tools" || len(s.Manifests) != 0 {
+		t.Fatalf("a change to what node-tools packages touched %v (manifests %v)", s.Modules, s.Manifests)
+	}
+}
+
+// Each layer is said; a check that could not run is an error on both, never a pass; a build seat from
+// before the layers is read as the gate.
+func TestAChecksLayersAreEachSaidAndAnErrorIsNeverAPass(t *testing.T) {
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-catalog", Number: 3, Modules: []string{"gitea"}}
+	c := checkedOf(link.BuildResult{ID: "b", Ref: "abc", Checked: asked, Failed: "the facts snapshot cannot be read"})
+	if c.Verdict != "error" || c.Gate == nil || c.Gate.Verdict != "error" || c.RepoCheck == nil || c.RepoCheck.Verdict != "error" {
+		t.Fatalf("a check that could not run said %+v", c)
+	}
+	if strings.Join(c.Gate.Modules, ",") != "gitea" {
+		t.Errorf("the gate names %v", c.Gate.Modules)
+	}
+	c = checkedOf(link.BuildResult{ID: "b", Ref: "abc", Checked: asked, Check: &link.CheckOutcome{Verdict: "warning", Summary: "wide"}})
+	if c.Gate == nil || c.Gate.Verdict != "warning" || c.RepoCheck != nil {
+		t.Fatalf("an outcome without layers said %+v", c)
+	}
+	c = checkedOf(link.BuildResult{ID: "b", Ref: "abc", Checked: asked, Check: &link.CheckOutcome{Verdict: "pass",
+		Gate: &link.CheckLayer{Verdict: "pass"}, RepoCheck: &link.CheckLayer{Verdict: "fail", Summary: "its merge-check.sh failed"}}})
+	if c.RepoCheck.Verdict != "fail" || c.Gate.Verdict != "pass" {
+		t.Fatalf("the layers said %+v / %+v", c.Gate, c.RepoCheck)
+	}
+}
+
+// **The check asks the planner, never a mapping of its own** (novox/hq ADR 0238): what a pull request
+// reaches is reachOfMerge's answer — the same that plans a merge — so a file at the root touches no
+// module in both, and what stands on a touched module is named as its dependents in both.
+func TestAPullRequestReachesWhatAMergeOfItWouldPlan(t *testing.T) {
+	const catalogue = "http://forge.internal:20000/novox/mesh-catalog.git"
+	nats := fromRepo("nats", catalogue, "modules/nats")
+	nats.Source.BuiltFrom = "old"
+	gitea := fromRepo("gitea", catalogue, "modules/gitea")
+	gitea.Source.BuiltFrom = "old"
+	tools := fromRepo("node-tools", "http://forge.internal:20000/novox/mesh-tools.git", "node-tools")
+	entries := []inventory.Entry{nats, gitea, tools}
+	// node-tools stands on the bus's image; a code edge, so a plan takes it along.
+	edges := []inventory.Edge{{From: "node-tools", To: "nats", Kind: inventory.EdgeStandsOn}}
+	read := map[string][]inventory.ReadRepository{}
+
+	for _, c := range []struct {
+		what              string
+		paths             []string
+		moved, dependents string
+		width             int
+		unread            string
+	}{
+		{"a file at the root, read by no build", []string{"merge-check.sh"}, "", "", 0, "merge-check.sh"},
+		{"the bus's own directory", []string{"modules/nats/Dockerfile"}, "nats", "node-tools", 2, ""},
+		{"both, and a README", []string{"modules/gitea/index.ts", "modules/nats/x", "README.md"}, "gitea,nats", "node-tools", 3, "README.md"},
+	} {
+		p := link.PullUpdated{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "head", Paths: c.paths}
+		s := pullScope(p, entries, read, edges)
+		m := link.SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main", Commit: "head", Paths: c.paths}
+		r := reachOfMerge(m, entries, read, edges)
+		if got := strings.Join(s.Modules, ","); got != c.moved || got != strings.Join(r.Moved(), ",") {
+			t.Errorf("%s: the check reaches %q, the planner %v, wanted %q", c.what, got, r.Moved(), c.moved)
+		}
+		if got := strings.Join(s.Dependents, ","); got != c.dependents {
+			t.Errorf("%s: dependents %q, wanted %q", c.what, got, c.dependents)
+		}
+		if s.Width != c.width || s.Width != len(r.Plan.Modules) {
+			t.Errorf("%s: a merge would build %d, the planner says %d, wanted %d", c.what, s.Width, len(r.Plan.Modules), c.width)
+		}
+		if got := strings.Join(s.Unread, ","); got != c.unread {
+			t.Errorf("%s: unread %q, wanted %q", c.what, got, c.unread)
+		}
+	}
+
+	// A repository whose build another module's recipe packages: that module is reached through the
+	// planner's `read`, and what stands on it after it.
+	read["gitea"] = []inventory.ReadRepository{{Repository: "http://forge.internal:20000/novox/mesh-sdk.git"}}
+	s := pullScope(link.PullUpdated{Owner: "novox", Repo: "mesh-sdk", Base: "main", Commit: "head",
+		Paths: []string{"src/index.ts"}}, entries, read, edges)
+	if strings.Join(s.Modules, ",") != "gitea" || len(s.Manifests) != 0 {
+		t.Fatalf("a change to the source gitea packages reaches %v (manifests %v)", s.Modules, s.Manifests)
+	}
+}
+
+// **Only a commit on the trunk is published** (novox/hq ADR 0238): a build of a commit off its repository's
+// default branch — a pull request's head, a branch built by hand, a rebuild or replay of one — is recorded
+// and never registered, so nothing can send it; a check or a dry run never is either.
+func TestABuildOffTheTrunkIsNeverPublished(t *testing.T) {
+	on := link.BuildResult{ID: "b", Commit: "abc", Trunk: "main", OnTrunk: true}
+	if err := publishable(on, ""); err != nil {
+		t.Errorf("a build on the trunk was refused: %v", err)
+	}
+	off := link.BuildResult{ID: "b", Commit: "abc", Trunk: "main"}
+	if err := publishable(off, ""); !errors.Is(err, errOffTheTrunk) || !strings.Contains(err.Error(), "main") {
+		t.Errorf("a build off the trunk was let through: %v", err)
+	}
+	for _, r := range []link.BuildResult{
+		{ID: "c", Trunk: "main", OnTrunk: true, Check: &link.CheckOutcome{Verdict: "pass"}},
+		{ID: "d", Trunk: "main", OnTrunk: true, Checked: &link.CheckRequest{}},
+		{ID: "e", Trunk: "main", OnTrunk: true, DryRun: true},
+	} {
+		if publishable(r, "") == nil {
+			t.Errorf("%s, a check or a dry run, was publishable", r.ID)
+		}
+	}
+	// A module that follows a branch other than the default: that branch is its trunk, and the default
+	// is not.
+	follows := link.BuildResult{ID: "g", Commit: "abc", Trunk: "master", Branches: []string{"nox-mesh"}}
+	if err := publishable(follows, "nox-mesh"); err != nil {
+		t.Errorf("a commit on the branch a module follows was refused: %v", err)
+	}
+	if err := publishable(link.BuildResult{ID: "h", Commit: "abc", Trunk: "master", OnTrunk: true,
+		Branches: []string{"master"}}, "nox-mesh"); err == nil {
+		t.Error("a commit on the default but not on the branch the module follows was published")
+	}
+	if err := publishable(link.BuildResult{ID: "i", Commit: "abc", Trunk: "main", Branches: []string{"feat/x"}}, ""); err == nil {
+		t.Error("a feature branch's commit was published")
+	}
+	// A build seat older than the rule says nothing: let through and said, so the rule can reach the mesh.
+	if err := publishable(link.BuildResult{ID: "f", Commit: "abc"}, ""); err != nil {
+		t.Errorf("a build seat that said nothing was refused: %v", err)
+	}
+}
+
+// **A verdict names the trunk commit it judged** (novox/hq ADR 0323 §3, issue 341): the controller's `checked`
+// carries the head and the trunk commit the build seat merged it into, the commits of the repositories read beside
+// it, how long it took, and the kept delivery plan records the trunk commit with its other inputs. A group's
+// composed check names, per member, the trunk commit that head was merged into (§6).
+func TestAVerdictNamesTheTrunkCommitItJudged(t *testing.T) {
+	plan := &link.ChangePlan{Repository: "novox/mesh-host", Base: "main", Head: "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+		Summary: "builds mesh-host"}
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 66, Base: "main", Plan: plan}
+	c := checkedOf(link.BuildResult{ID: "b", Ref: "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", Checked: asked,
+		Check: &link.CheckOutcome{Verdict: "pass", Took: "4m12s", Head: "dfb1415aaaaa", Trunk: "d28ca95bbbbb",
+			Gate: &link.CheckLayer{Verdict: "pass"}, RepoCheck: &link.CheckLayer{Verdict: "pass"},
+			Beside: map[string]string{"mesh-catalog": "0123456789ab", "mesh-lab": "ba9876543210"}}})
+	if c.Trunk != "d28ca95bbbbb" || c.Commit != "dfb1415aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" {
+		t.Fatalf("the verdict names head %s and trunk %q", c.Commit, c.Trunk)
+	}
+	if c.Beside["mesh-catalog"] != "0123456789ab" || c.Beside["mesh-lab"] != "ba9876543210" {
+		t.Fatalf("the verdict names the repositories read beside it as %v", c.Beside)
+	}
+	if c.Took != "4m12s" {
+		t.Fatalf("the verdict says it took %q", c.Took)
+	}
+	if c.Plan == nil || c.Plan.Trunk != "d28ca95bbbbb" || c.Plan.Head != plan.Head {
+		t.Fatalf("the kept plan records %+v", c.Plan)
+	}
+	if plan.Trunk != "" {
+		t.Fatal("the plan the controller asked with was changed: the verdict's is a copy")
+	}
+
+	group := &link.CheckRequest{Owner: "novox", Repo: "mesh-controller", Number: 7, Base: "main", Group: "feat/x",
+		Members: []link.GroupMember{{Owner: "novox", Repo: "mesh-host", Number: 8, Ref: "cccccccccccc0000", Base: "main"}}}
+	c = checkedOf(link.BuildResult{ID: "g", Ref: "aaaaaaaaaaaa0000", Checked: group, Check: &link.CheckOutcome{
+		Verdict: "pass", Head: "aaaaaaaaaaaa", Trunk: "111111111111", Gate: &link.CheckLayer{Verdict: "pass"},
+		Members: []link.CheckedMember{{Owner: "novox", Repo: "mesh-host", Commit: "cccccccccccc", Trunk: "222222222222"}}}})
+	if len(c.Members) != 2 || c.Members[0].Trunk != "111111111111" || c.Members[1].Trunk != "222222222222" ||
+		c.Members[1].Commit != "cccccccccccc0000" {
+		t.Fatalf("the composed check names its members %+v", c.Members)
+	}
+}
+
+// **The merge made for a check is never registered** (novox/hq ADR 0323 §2): a build of it — a commit on no branch
+// of the forge — is refused, naming the trunk. The rule of ADR 0238 §1 stands unchanged; this holds it for the
+// merge commit a check makes.
+func TestABuildOfACheckMergeIsRefusedNamingTheTrunk(t *testing.T) {
+	merge := link.BuildResult{ID: "b", Commit: "4b5c6d7e8f90aabbccddeeff0011223344556677", Trunk: "main"}
+	err := publishable(merge, "")
+	if !errors.Is(err, errOffTheTrunk) || !strings.Contains(err.Error(), "not on main") {
+		t.Fatalf("a build of a check's merge was answered %v", err)
+	}
+}
+
+// **A verdict no build judges names its trunk commit too** (novox/hq ADR 0323 §3): a change touching no module of a
+// repository with no merge-check.sh (novox/mesh-tools-go) is answered by the controller itself. Naming no trunk, the
+// merge tool refused it, asked again, got the same verdict, and refused for ever.
+func TestADirectVerdictNamesTheTrunkTheForgeAnnounced(t *testing.T) {
+	p := link.PullUpdated{Owner: "novox", Repo: "mesh-tools-go", Number: 3, Base: "main", Commit: "1a2b3c4d5e6f7a8b9c0d",
+		BaseSHA: "7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b"}
+	c := directVerdict(p, link.ChangePlan{Repository: "novox/mesh-tools-go", Base: "main", Head: p.Commit})
+	if c.Trunk != "7a8b9c0d1e2f" || c.Plan == nil || c.Plan.Trunk != "7a8b9c0d1e2f" {
+		t.Fatalf("the direct verdict names trunk %q, its plan %+v", c.Trunk, c.Plan)
+	}
+	if c.Verdict != "pass" || c.Commit != p.Commit {
+		t.Fatalf("the direct verdict is %+v", c)
+	}
+	if c := directVerdict(link.PullUpdated{Owner: "novox", Repo: "x", Commit: "abc"}, link.ChangePlan{}); c.Trunk != "" {
+		t.Fatalf("a forge that said no base head gave the trunk %q", c.Trunk)
+	}
+}
+
+// A head checked again through mesh-delivery (`delivery check --members`, a recheck) reaches the same direct verdict:
+// it names the base head the forge last announced, kept on the member, or the merge tool would refuse it for ever.
+func TestARecheckedHeadsDirectVerdictNamesItsTrunk(t *testing.T) {
+	m := orderMember{ID: "novox/mesh-tools-go@1a2b3c4d5e6f", Repository: "novox/mesh-tools-go", Base: "main",
+		Head: "1a2b3c4d5e6f7a8b9c0d", Number: 3, BaseSHA: "7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b"}
+	if c := directVerdict(m.pull(), link.ChangePlan{}); c.Trunk != "7a8b9c0d1e2f" {
+		t.Fatalf("a rechecked head's direct verdict names trunk %q", c.Trunk)
+	}
+}
+
+// A check stopped by its pull request's key moving on says no verdict (issue 974, review 2): an error said for it would name the
+// live head, and the newer request is the one that judges. A check that failed for any other reason still says its error.

cmd/mesh-controller/collect.go

@@ -0,0 +1,276 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/novox/mesh-controller/internal/artifacts"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// Letting the artifact store go of what the mesh no longer keeps (novox/hq ADR 0189, issue 108).
+//
+// **Run where the records change.** A build is the moment new bytes landed in the store and the
+// moment the keep set moved, so it is the moment to say what may go — and it needs no timer of
+// its own. Reclaiming the bytes is the store's own nightly step; this only decides.
+//
+// **And run when a person asks** (novox/hq ADR 0251): the `collect` verb is the same sweep, with
+// bounds of its own. One implementation, so what a person runs is exactly what a build runs.
+//
+// Never fatal to a build. The build succeeded, the module is registered, and a store that could
+// not be reached is a thing to say rather than a reason to undo any of that. The next build asks
+// again, and the references it could not collect are still uncollected, so nothing is lost by
+// having failed.
+
+// sweepBounds is how much one sweep may ask of the store.
+type sweepBounds struct {
+	// most is how many artifacts it lets go of at most.
+	most int
+	// budget is the longest it keeps its caller waiting.
+	budget time.Duration
+	// platforms is whether an index is let go of with its own platform manifests (novox/hq ADR 0257).
+	// Only a sweep a person confirmed, after its dry run listed what stays and names a platform: the
+	// records cannot see an unrecorded index, or a copy in progress, naming the same platform, and the
+	// store's tools can.
+	platforms bool
+}
+
+// afterBuild are the bounds of the sweep inside somebody's build.
+//
+// **Bounded, because this runs inside somebody's build.** The first sweep of a mesh that has never
+// collected has the whole history to get through, and a person waiting on `build` should not pay for
+// it. What is left over is simply offered again next time — builds are frequent, and the point is
+// that the store stops growing, not that it empties tonight.
+var afterBuild = sweepBounds{most: mostPerSweep, budget: sweepBudget}
+
+// sweepResult is what one sweep did.
+type sweepResult struct {
+	// HoldersWritten is how many kept archives the store now holds by a manifest it did not before.
+	HoldersWritten int
+	// Missing is how many kept archives the store does not have at all.
+	Missing int
+	// Held is whether every kept archive could be asked to be held; false stops the sweep before it
+	// lets anything go.
+	Held bool
+	// LetGo is what the store let go of, and the record now says collected.
+	LetGo []string
+	// Skipped is how many references the sweep will not address (novox/hq issue 226).
+	Skipped int
+	// Indexes is how many eligible indexes a sweep a person did not confirm left for one that is: an
+	// index goes only with its platform manifests (novox/hq ADR 0257 §4).
+	Indexes int
+	// Left is how many eligible references were not asked about this time.
+	Left int
+	// Bounded is whether it stopped at its bounds rather than at a refusal.
+	Bounded bool
+	// Stopped says why the sweep stopped before the end; empty when it did not.
+	Stopped string
+}
+
+// sweep holds every kept archive, then asks the store to let go of each reference in order, records
+// what it let go of, and says what it did.
+func sweep(ctx context.Context, inv *inventory.Inventory, store artifacts.Store, references, kept []string,
+	bounds sweepBounds) sweepResult {
+	within, stop := context.WithTimeout(ctx, bounds.budget)
+	defer stop()
+	var r sweepResult
+
+	// **Hold before letting go** (novox/hq issue 253). The store's collector keeps only what a
+	// manifest names, and archives were published as bare blobs, so every kept archive is first
+	// held by its manifest — which backfills the ones published before holders, a few at a time
+	// as builds come, and is two HEADs each once done. A kept archive that could not be held stops
+	// the sweep before it deletes anything: "everything kept is held" is the precondition the
+	// collector's safety rests on, and a store refusing a hold would refuse the deletes too.
+	// **An index goes with its platform manifests only when a person confirmed it** (novox/hq ADR
+	// 0257), and a kept index keeps its own: which platform manifests the kept indexes name is read
+	// from the store for every repository the sweep will touch, before the first delete. A single
+	// read that fails stops the sweep before it deletes anything, as a kept archive that cannot be
+	// held does. The sweep after a build leaves an eligible index for such a collect, below.
+	store.Spare = nil
+	if bounds.platforms {
+		if inv == nil {
+			r.Stopped = "no records to read which platform manifests a kept index names, so nothing was let go"
+			r.Left = len(references)
+			return r
+		}
+		images, err := inv.KeptImages(ctx)
+		if err == nil {
+			store.Spare, err = store.SpareKeptIndexes(within, images, references)
+		}
+		if err != nil {
+			r.Stopped = fmt.Sprintf("which platform manifests a kept index names could not be read, so nothing was let go: %v", err)
+			r.Left = len(references)
+			return r
+		}
+	}
+
+	wrote, missing, err := holdKept(within, store, kept)
+	r.HoldersWritten, r.Missing = wrote, missing
+	if err != nil {
+		r.Stopped = fmt.Sprintf("not every kept archive could be held, so nothing was let go: %v", err)
+		r.Left = len(references)
+		return r
+	}
+	r.Held = true
+
+	for i, reference := range references {
+		if i >= bounds.most || within.Err() != nil {
+			r.Left = len(references) - i
+			r.Bounded = true
+			if i >= bounds.most {
+				r.Stopped = fmt.Sprintf("asked about %d, the most one sweep asks", bounds.most)
+			} else {
+				r.Stopped = fmt.Sprintf("ran out of its %s", bounds.budget)
+			}
+			break
+		}
+		if !bounds.platforms {
+			// **An index waits for a confirmed collect** (novox/hq ADR 0257 §4). Let go of alone,
+			// its platform manifests would stay in the store and the record would say collected, so
+			// no later sweep would offer it again and they would stay for ever. Left eligible, the
+			// next collect a person confirms takes it with them.
+			index, err := store.IsIndex(within, reference)
+			if err != nil && !errors.Is(err, artifacts.Gone) && !errors.Is(err, artifacts.ErrNotOurs) {
+				r.Stopped = fmt.Sprintf("the artifact store could not say whether %s is an index, so nothing more was asked of it: %v", reference, err)
+				r.Left = len(references) - i
+				break
+			}
+			if index {
+				r.Indexes++
+				continue
+			}
+		}
+		err := store.LetGo(within, reference)
+		if err == nil || errors.Is(err, artifacts.Gone) {
+			// Gone is the outcome wanted, already true. Recorded so the next sweep does not ask
+			// again for ever.
+			r.LetGo = append(r.LetGo, reference)
+			continue
+		}
+		if errors.Is(err, artifacts.ErrNotOurs) {
+			// **A fact about this record, so this record is skipped** (novox/hq issue 226). Not
+			// marked collected — the mesh did not remove it and should not claim to — and not a
+			// reason to stop, because the store was never asked. One of these at the front of
+			// the oldest-first order ended every sweep until this.
+			r.Skipped++
+			if r.Skipped == 1 {
+				fmt.Fprintf(os.Stderr, "the sweep will not address %s and went on: %v\n", reference, err)
+			}
+			continue
+		}
+		// **Stopped at the first refusal by the STORE, not pushed through.** A store that refuses
+		// one refuses all of them — deletion disabled, the store down, the network gone — so
+		// going on would be a hundred identical failures and a hundred identical log lines in
+		// front of whoever was building something.
+		r.Stopped = fmt.Sprintf("the artifact store kept %s, so nothing more was asked of it: %v", reference, err)
+		r.Left = len(references) - i
+		break
+	}
+
+	if len(r.LetGo) > 0 {
+		// Recorded outside `within`: the deletions happened, and losing the record of them because
+		// the sweep ran out of budget would mean asking about them again for ever.
+		if err := inv.MarkCollected(ctx, r.LetGo); err != nil {
+			r.Stopped = fmt.Sprintf("the store let go of %d artifact(s) and the record of it did not keep: %v",
+				len(r.LetGo), err)
+		}
+	}
+	return r
+}
+
+// collect asks the store to let go of everything the mesh made and no longer keeps, and records
+// what it let go of — after a build. Says what it did and what it could not; returns nothing,
+// because nothing upstream should branch on it.
+func collect(ctx context.Context, inv *inventory.Inventory) {
+	references, err := inv.ToCollect(ctx)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not work out what the artifact store may let go of: %v\n", err)
+		return
+	}
+	kept, err := inv.KeptArchives(ctx)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not work out which archives the artifact store keeps: %v\n", err)
+		return
+	}
+	if len(references) == 0 && len(kept) == 0 {
+		return
+	}
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not read the catalogue to find the artifact store: %v\n", err)
+		return
+	}
+	// As the mesh reaches it from the network. Empty means the store is not on the network — on a
+	// mesh being raised it is not yet, and there the store holds one build of anything and has
+	// nothing to collect.
+	address, err := artifactStoreAddress(ctx, inv, shelf, "")
+	if err != nil || address == "" {
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not find the artifact store to collect from: %v\n", err)
+		}
+		return
+	}
+
+	r := sweep(ctx, inv, artifacts.Store{Address: address}, references, kept, afterBuild)
+	if r.HoldersWritten > 0 {
+		fmt.Fprintf(os.Stderr, "the artifact store now holds %d more kept archive(s) by a manifest\n", r.HoldersWritten)
+	}
+	if r.Missing > 0 {
+		fmt.Fprintf(os.Stderr, "%d archive(s) the mesh keeps are not in the artifact store at all; "+
+			"`collection` lists them\n", r.Missing)
+	}
+	if len(r.LetGo) > 0 {
+		fmt.Fprintf(os.Stderr, "the artifact store let go of %d artifact(s) the mesh no longer keeps\n", len(r.LetGo))
+	}
+	if r.Stopped != "" && !r.Bounded {
+		fmt.Fprintln(os.Stderr, r.Stopped)
+	}
+	if r.Held && r.Left > 0 {
+		fmt.Fprintf(os.Stderr, "%d more to collect; the next build asks again\n", r.Left)
+	}
+	if r.Skipped > 0 {
+		fmt.Fprintf(os.Stderr, "%d artifact(s) the sweep will not address were skipped\n", r.Skipped)
+	}
+	if r.Indexes > 0 {
+		fmt.Fprintf(os.Stderr, "%d eligible index(es) wait for a collect a person confirms, which takes their platforms too\n", r.Indexes)
+	}
+}
+
+// holdKept holds every kept archive by its manifest, stopping at the first refusal by the store.
+// Answers how many holders it wrote and how many kept archives the store does not have.
+//
+// A missing archive is counted rather than fatal: there is nothing to hold, and that is a fact
+// for an operator to read (`collection`), not a reason to stop collecting what is not kept. A
+// reference the store cannot be asked about is skipped as the deletion loop skips one
+// (novox/hq issue 226).
+func holdKept(ctx context.Context, store artifacts.Store, kept []string) (wrote, missing int, err error) {
+	for _, reference := range kept {
+		if err := ctx.Err(); err != nil {
+			return wrote, missing, fmt.Errorf("ran out of time before %s: %w", reference, err)
+		}
+		did, err := store.Hold(ctx, reference)
+		switch {
+		case err == nil:
+			if did {
+				wrote++
+			}
+		case errors.Is(err, artifacts.Gone):
+			missing++
+		case errors.Is(err, artifacts.ErrNotOurs):
+		default:
+			return wrote, missing, fmt.Errorf("holding %s: %w", reference, err)
+		}
+	}
+	return wrote, missing, nil
+}
+
+// mostPerSweep is how many artifacts one sweep will ask about. Enough that a mesh building
+// several times a day converges within days of this landing; small enough that no single build
+// waits on the whole backlog.
+const mostPerSweep = 200
+
+// sweepBudget is the longest a sweep will keep a build waiting.
+const sweepBudget = 60 * time.Second

cmd/mesh-controller/collection.go

@@ -0,0 +1,166 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/artifacts"
+)
+
+// What the artifact store keeps, whether each kept archive is held, and what the sweep may let go
+// (novox/hq issue 253, ADR 0189).
+//
+// **The question to answer before the store's collector runs for real.** The collector deletes
+// every blob no manifest names, and archives were published as bare blobs, so the nightly step
+// runs `--dry-run` until every archive the mesh keeps is held by its manifest. The sweep holds
+// them as builds come; this says how far that has got — "0 unheld" is the number that lets the
+// dry run go.
+//
+// Reads and changes nothing: each kept archive is asked about with HEADs only. Reached over the
+// console through the mesh-controller seat's `command` verb (`collection --json`), which needs no
+// new verb in the seat's row.
+
+type collectionReport struct {
+	// Store is the artifact store as this machine reached it; empty when it is not on the network.
+	Store string `json:"store"`
+	// KeptArchives is how many archives the mesh keeps, for either reason.
+	KeptArchives int `json:"kept_archives"`
+	// Held is how many of them the store holds by their manifest.
+	Held int `json:"held"`
+	// Unheld are the kept archives the collector would delete tonight if it ran for real.
+	Unheld []string `json:"unheld"`
+	// Missing are kept archives the store does not have at all.
+	Missing []string `json:"missing"`
+	// Unasked is how many could not be asked about, and why the asking stopped.
+	Unasked int    `json:"unasked"`
+	Stopped string `json:"stopped,omitempty"`
+	// Eligible is what the sweep may let go of: made by the mesh, kept for no reason, not yet
+	// collected — split by kind.
+	Eligible         int `json:"eligible"`
+	EligibleImages   int `json:"eligible_images"`
+	EligibleArchives int `json:"eligible_archives"`
+	// SafeToCollect is whether every kept archive was asked about and every one is held.
+	SafeToCollect bool `json:"safe_to_collect"`
+}
+
+func collectionCommand(ctx context.Context, args []string) error {
+	set := flag.NewFlagSet("collection", flag.ContinueOnError)
+	asJSON := set.Bool("json", false, "answer as JSON")
+	positionals, err := parseAround(set, args)
+	if err != nil {
+		return err
+	}
+	if len(positionals) != 0 {
+		return errors.New("collection [--json]")
+	}
+
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	inv := open.inventory
+
+	kept, err := inv.KeptArchives(ctx)
+	if err != nil {
+		return err
+	}
+	eligible, err := inv.ToCollect(ctx)
+	if err != nil {
+		return err
+	}
+	report := collectionReport{KeptArchives: len(kept), Eligible: len(eligible), Unheld: []string{}, Missing: []string{}}
+	for _, reference := range eligible {
+		if strings.Contains(reference, "/blobs/") {
+			report.EligibleArchives++
+		} else {
+			report.EligibleImages++
+		}
+	}
+
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return err
+	}
+	report.Store, err = artifactStoreAddress(ctx, inv, shelf, "")
+	if err != nil {
+		return err
+	}
+	if report.Store == "" {
+		report.Unasked = len(kept)
+		report.Stopped = "this mesh has no artifact store on its network"
+	} else {
+		report.Unasked, report.Stopped = askHeld(ctx, artifacts.Store{Address: report.Store}, kept, &report)
+	}
+	report.SafeToCollect = report.Unasked == 0 && len(report.Unheld) == 0
+
+	if *asJSON {
+		encoder := json.NewEncoder(os.Stdout)
+		encoder.SetIndent("", "  ")
+		return encoder.Encode(report)
+	}
+	printCollection(report)
+	return nil
+}
+
+// askHeld asks the store about each kept archive, stopping at the first answer that is not about
+// the archive: a store that cannot be reached for one cannot be for the next, and a page of
+// identical failures says less than one line.
+func askHeld(ctx context.Context, store artifacts.Store, kept []string, report *collectionReport) (int, string) {
+	for i, reference := range kept {
+		held, err := store.Held(ctx, reference)
+		switch {
+		case err == nil && held:
+			report.Held++
+		case err == nil:
+			report.Unheld = append(report.Unheld, reference)
+		case errors.Is(err, artifacts.Gone):
+			report.Missing = append(report.Missing, reference)
+		case errors.Is(err, artifacts.ErrNotOurs):
+			// KeptArchives names only the mesh's own; counted as unasked if one ever is not.
+			report.Unasked++
+		default:
+			return report.Unasked + len(kept) - i, fmt.Sprintf("asking about %s: %v", reference, err)
+		}
+	}
+	return report.Unasked, ""
+}
+
+func printCollection(r collectionReport) {
+	store := r.Store
+	if store == "" {
+		store = "(not on the network)"
+	}
+	fmt.Printf("artifact store       %s\n", store)
+	fmt.Printf("kept archives        %d\n", r.KeptArchives)
+	fmt.Printf("  held               %d\n", r.Held)
+	fmt.Printf("  unheld             %d\n", len(r.Unheld))
+	fmt.Printf("  missing            %d\n", len(r.Missing))
+	if r.Unasked > 0 {
+		fmt.Printf("  not asked          %d (%s)\n", r.Unasked, r.Stopped)
+	}
+	fmt.Printf("eligible to let go   %d (%d images, %d archives)\n", r.Eligible, r.EligibleImages, r.EligibleArchives)
+	if len(r.Unheld) > 0 {
+		fmt.Println("\nunheld — the store's collector would delete these; the next build's sweep holds them:")
+		for _, reference := range r.Unheld {
+			fmt.Printf("  %s\n", reference)
+		}
+	}
+	if len(r.Missing) > 0 {
+		fmt.Println("\nmissing — kept by the mesh, not in the store:")
+		for _, reference := range r.Missing {
+			fmt.Printf("  %s\n", reference)
+		}
+	}
+	fmt.Println()
+	if r.SafeToCollect {
+		fmt.Println("every kept archive is held: the store's collector may run for real")
+	} else {
+		fmt.Println("NOT every kept archive is known to be held: keep the store's collector on --dry-run")
+	}
+}

cmd/mesh-controller/composed_member_check_test.go

@@ -0,0 +1,68 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// A member of a group whose gate is the composed check's is asked of the build seat with no module: its repository's
+// check alone (novox/hq ADR 0403 clause 1). With no word from mesh-delivery, or one that does not say the gate is
+// composed, it is checked alone with its gate (clause 6).
+
+func askedForMember(t *testing.T, answer []groupsLine, answerErr error) link.CheckRequest {
+	t.Helper()
+	open := aMesh(t)
+	ctx := t.Context()
+	js, _ := aBuildQueue(t)
+	servingBus.Store(js)
+	t.Cleanup(func() { servingBus.Store(nil) })
+	if err := open.inventory.RegisterModule(ctx, catalogue.Manifest{Module: "mesh-controller", Version: "1"},
+		inventory.Source{Repository: "novox/mesh-controller", Ref: "main", BuiltFrom: "c0", Head: "c0"}); err != nil {
+		t.Fatal(err)
+	}
+	was := groupsAsked
+	groupsAsked = func(context.Context, bool) ([]groupsLine, error) { return answer, answerErr }
+	t.Cleanup(func() { groupsAsked = was })
+	p := link.PullUpdated{Owner: "novox", Repo: "mesh-controller", Number: 346, Base: "main", Head: "feat/x", Commit: headController,
+		Paths: []string{"main.go"}, ModuleDirsSaid: true, MergeCheck: true, MergeCheckSaid: true}
+	if err := (following{open: open, oneShot: true}).PullUpdated(ctx, p); err != nil {
+		t.Fatal(err)
+	}
+	q, err := link.ReadQueue(ctx, js, link.TheBuildMachine)
+	if err != nil || len(q.Asks) != 1 {
+		t.Fatalf("asks %d: %v", len(q.Asks), err)
+	}
+	return *q.Asks[0].Request.Check
+}
+
+func TestAComposedMembersCheckIsItsRepositoryChecksAlone(t *testing.T) {
+	line := group("feat/x", member("novox/mesh-controller", 346, headController, "main", true), member("novox/mesh-catalog", 350, headHost, "main", true))
+	line.ComposedGate = true
+	c := askedForMember(t, []groupsLine{line}, nil)
+	if len(c.Modules) != 0 || len(c.New) != 0 || len(c.Dependents) != 0 || !c.Composed {
+		t.Fatalf("the member's check is asked as %+v; want no module and composed", c)
+	}
+}
+
+func TestAMemberOfAGroupOfAnOlderMeshDeliveryKeepsItsOwnGate(t *testing.T) {
+	line := group("feat/x", member("novox/mesh-controller", 346, headController, "main", true), member("novox/mesh-catalog", 350, headHost, "main", true))
+	c := askedForMember(t, []groupsLine{line}, nil)
+	if !strings.Contains(strings.Join(c.Modules, ","), "mesh-controller") || c.Composed {
+		t.Fatalf("an older mesh-delivery's member is asked as %+v; want its own gate", c)
+	}
+}
+
+func TestAMemberWhoseGroupCannotBeLearnedIsCheckedAloneWithItsGate(t *testing.T) {
+	c := askedForMember(t, nil, context.DeadlineExceeded)
+	if !strings.Contains(strings.Join(c.Modules, ","), "mesh-controller") || c.Composed ||
+		!strings.Contains(c.SiblingsUnknown, "reads no siblings") {
+		t.Fatalf("the member is asked as %+v; want its gate and why its siblings are unknown", c)
+	}
+}

cmd/mesh-controller/composed_verdict_test.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// A delivery group's gate is the composed check's, and its members' own checks run their repository's check alone
+// (novox/hq ADR 0403 clauses 1 and 7). Pure: no store, no bus.
+
+// A member of a group whose line says composed_gate is a composed member; one whose group says nothing of it (an older
+// mesh-delivery), one of a group of a single pull request and a lone pull request are not.
+func TestAMemberOfAComposedGroupIsKnownByTheGroupsLine(t *testing.T) {
+	two := func(composed bool) groupsLine {
+		l := group("feat/x", member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))
+		l.ComposedGate = composed
+		return l
+	}
+	p := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Head: "feat/x", Commit: headHost}
+	recheck := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Commit: headHost}
+	for name, c := range map[string]struct {
+		p     link.PullUpdated
+		lines []groupsLine
+		want  bool
+	}{
+		"composed":                 {p, []groupsLine{two(true)}, true},
+		"a recheck, by its number": {recheck, []groupsLine{two(true)}, true},
+		"an older mesh-delivery":   {p, []groupsLine{two(false)}, false},
+		"another group":            {p, []groupsLine{group("feat/y", member("novox/mesh-host", 1, headHost, "main", true))}, false},
+		"no group":                 {p, nil, false},
+	} {
+		if got := composedMember(c.p, c.lines); got != c.want {
+			t.Errorf("%s: composed %v, want %v", name, got, c.want)
+		}
+	}
+	alone := group("feat/x", member("novox/mesh-host", 114, headHost, "main", true))
+	alone.ComposedGate = true
+	if composedMember(p, []groupsLine{alone}) {
+		t.Error("a group of a single pull request is composed")
+	}
+}
+
+// A composed member's verdict never says its gate passed: the gate layer, and the verdict that is the gate's, read
+// "composed"; a failure or an error stays what it was.
+func TestAComposedMembersVerdictHasNoPassingGate(t *testing.T) {
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114, Composed: true}
+	pass := link.BuildResult{ID: "b", Ref: headHost, Checked: asked, Check: &link.CheckOutcome{Verdict: "pass", Summary: "no module touched",
+		Gate: &link.CheckLayer{Verdict: "pass", Summary: "no module touched"}, RepoCheck: &link.CheckLayer{Verdict: "pass", Summary: "ok"}}}
+	c := checkedOf(pass)
+	if c.Gate == nil || c.Gate.Verdict != "composed" || c.Verdict != "composed" || c.RepoCheck == nil || c.RepoCheck.Verdict != "pass" {
+		t.Fatalf("the member's verdict says %+v gate %+v", c, c.Gate)
+	}
+	asked.Composed = false
+	if c := checkedOf(pass); c.Gate.Verdict != "pass" || c.Verdict != "pass" {
+		t.Fatalf("a member of no composed group has its own gate: %+v", c.Gate)
+	}
+	asked.Composed = true
+	failing := pass
+	failing.Check = &link.CheckOutcome{Verdict: "fail", Summary: "conflict", Gate: &link.CheckLayer{Verdict: "fail", Summary: "conflict"},
+		RepoCheck: &link.CheckLayer{Verdict: "fail", Summary: "conflict"}}
+	if c := checkedOf(failing); c.Gate.Verdict != "fail" || c.Verdict != "fail" {
+		t.Fatalf("a failure was read as composed: %+v", c.Gate)
+	}
+	broken := link.BuildResult{ID: "b", Ref: headHost, Checked: asked, Failed: "the facts snapshot cannot be read"}
+	if c := checkedOf(broken); c.Verdict != "error" || c.Gate.Verdict != "error" {
+		t.Fatalf("an error was read as composed: %+v", c)
+	}
+}
+
+// The composed verdict on the bus carries every member, each with its trunk commit, for the forge's holder to set each
+// member's mesh/merge-gate from it.
+func TestTheComposedVerdictCarriesEveryMember(t *testing.T) {
+	asked := &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114, Group: "feat/x",
+		Members: []link.GroupMember{{Owner: "novox", Repo: "mesh-controller", Number: 346, Ref: headController}}}
+	c := checkedOf(link.BuildResult{ID: "g", Ref: headHost, Checked: asked, Check: &link.CheckOutcome{Verdict: "pass", Summary: "ok",
+		Trunk: "aaaaaaaaaaaa", Members: []link.CheckedMember{{Owner: "novox", Repo: "mesh-controller", Commit: headController[:12], Trunk: "bbbbbbbbbbbb"}}}})
+	body, _ := json.Marshal(c)
+	for _, want := range []string{`"group":"feat/x"`, `"members":[{"owner":"novox","repo":"mesh-host","number":114,"commit":"` + headHost + `","trunk":"aaaaaaaaaaaa"}`,
+		`{"owner":"novox","repo":"mesh-controller","number":346,"commit":"` + headController + `","trunk":"bbbbbbbbbbbb"}`} {
+		if !strings.Contains(string(body), want) {
+			t.Fatalf("the composed verdict lacks %s:\n%s", want, body)
+		}
+	}
+}
+
+// Members whose manifests order their modules in a cycle fail the composed check, naming every module and edge, and no
+// ask is made of the build seat.
+func TestAGroupInACycleFailsItsComposedCheckWithoutABuild(t *testing.T) {
+	members := []orderMember{
+		{ID: "novox/x@" + headHost[:12], Repository: "novox/x", Base: "main", Head: headHost, Number: 7, Paths: []string{"module.json"}},
+		{ID: "novox/y@" + headController[:12], Repository: "novox/y", Base: "main", Head: headController, Number: 9, Paths: []string{"module.json"}},
+	}
+	reach := map[string]orderReach{members[0].ID: {Moved: []string{"mx"}}, members[1].ID: {Moved: []string{"my"}}}
+	was, wasParent := manifestAt, parentOf
+	t.Cleanup(func() { manifestAt, parentOf = was, wasParent })
+	parentOf = func(context.Context, string, string, string) (string, error) { return "", nil }
+	manifestAt = func(_ context.Context, _, repo, _, ref string) (catalogue.Manifest, bool, error) {
+		if ref == "main" {
+			return catalogue.Manifest{}, false, nil // what the pull requests merge into holds no such manifest
+		}
+		if repo == "x" {
+			return catalogue.Manifest{Module: "mx", DefinesSeats: []catalogue.SeatDeclaration{{Name: "s", Serves: []catalogue.Verb{{Name: "a"}}}},
+				Invokes: []string{"seat:s.b"}}, true, nil
+		}
+		return catalogue.Manifest{Module: "my", DefinesSeats: []catalogue.SeatDeclaration{{Name: "s", Serves: []catalogue.Verb{{Name: "b"}}}},
+			Invokes: []string{"seat:s.a"}}, true, nil
+	}
+	c, cyclic, err := cycleVerdict(context.Background(), "feat/cycle", members, reach, []inventory.Edge(nil), nil)
+	if err != nil || !cyclic {
+		t.Fatalf("no cycle found: %v", err)
+	}
+	if c.Verdict != "fail" || c.Group != "feat/cycle" || len(c.Members) != 2 || c.Gate == nil || c.Gate.Verdict != "fail" {
+		t.Fatalf("the verdict is %+v", c)
+	}
+	for _, w := range []string{"mx", "my", "s.a", "s.b"} {
+		if !strings.Contains(c.Summary, w) {
+			t.Errorf("the cycle does not name %s: %s", w, c.Summary)
+		}
+	}
+	// Members with no edge between them are no cycle.
+	manifestsReadMu.Lock()
+	clear(manifestsRead)
+	manifestsReadMu.Unlock()
+	manifestAt = func(context.Context, string, string, string, string) (catalogue.Manifest, bool, error) {
+		return catalogue.Manifest{}, false, nil
+	}
+	if _, cyclic, err := cycleVerdict(context.Background(), "feat/cycle", members, reach, nil, nil); err != nil || cyclic {
+		t.Fatalf("a cycle where there is none: %v %v", cyclic, err)
+	}
+}

cmd/mesh-controller/condition_looks.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+)
+
+// The looks of the open conditions — how often each was observed, when last, its newest evidence — are
+// kept in the controller's store, not the conditions bucket (novox/hq issue 420, ADR 0289 §1): the bucket
+// is written when what a condition says changes, never for a look that saw it as it was.
+
+// storeLooks keeps the conditions' looks in the inventory.
+type storeLooks struct{ inv *inventory.Inventory }
+
+func (s storeLooks) KeepLooks(ctx context.Context, key string, l conditions.Looks) error {
+	evidence, err := json.Marshal(l.Evidence)
+	if err != nil {
+		return err
+	}
+	return s.inv.KeepConditionLooks(ctx, inventory.ConditionLooks{Key: key, Observations: l.Observations,
+		LastObserved: l.LastObserved, Evidence: evidence})
+}
+
+func (s storeLooks) Looked(ctx context.Context, key string) (conditions.Looks, bool, error) {
+	row, kept, err := s.inv.ConditionLooksOf(ctx, key)
+	if err != nil || !kept {
+		return conditions.Looks{}, kept, err
+	}
+	l, err := looksOf(row)
+	return l, err == nil, err
+}
+
+func (s storeLooks) AllLooks(ctx context.Context) (map[string]conditions.Looks, error) {
+	rows, err := s.inv.AllConditionLooks(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make(map[string]conditions.Looks, len(rows))
+	for key, row := range rows {
+		l, err := looksOf(row)
+		if err != nil {
+			return nil, err
+		}
+		out[key] = l
+	}
+	return out, nil
+}
+
+func (s storeLooks) ForgetLooks(ctx context.Context, key string) error {
+	return s.inv.ForgetConditionLooks(ctx, key)
+}
+
+func looksOf(row inventory.ConditionLooks) (conditions.Looks, error) {
+	l := conditions.Looks{Observations: row.Observations, LastObserved: row.LastObserved.UTC()}
+	if len(row.Evidence) > 0 {
+		if err := json.Unmarshal(row.Evidence, &l.Evidence); err != nil {
+			return conditions.Looks{}, fmt.Errorf("the evidence kept for the condition %s cannot be read: %w", row.Key, err)
+		}
+	}
+	return l, nil
+}
+
+// looksHere is where a process that is not the serving controller reads the conditions' looks: the store,
+// opened for it, closed by the function returned. A store that cannot be opened is said on every condition
+// read through it, never read as none.
+func looksHere(ctx context.Context) (conditions.LookStore, func()) {
+	inv, err := openInventory(ctx)
+	if err != nil {
+		return conditions.NoLooks{Err: err}, func() {}
+	}
+	return storeLooks{inv}, inv.Close
+}

cmd/mesh-controller/condition_looks_test.go

@@ -0,0 +1,89 @@
+//go:build integration
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+// **Looks at an unchanged condition write the bucket once, and `conditions` still says how often and when
+// it was seen** (novox/hq issue 420): the looks are in the controller's store, and the verb, run as a
+// process of its own, reads them from there. On 2026-10-10 one open condition had rewritten the bucket 7 003
+// times in two days.
+func TestTheConditionsVerbReadsTheLooksTheBucketNoLongerHolds(t *testing.T) {
+	inv := inventory.ForTest(t)
+	bus := testbus.Start(t)
+	serving, err := broker.Dial(bus.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer serving.Close()
+	if err := serving.EnsureControllerBuckets(); err != nil {
+		t.Fatal(err)
+	}
+	ctx := t.Context()
+	store, history, err := conditions.OnTheBus(ctx, serving.Conn())
+	if err != nil {
+		t.Fatal(err)
+	}
+	k := conditions.NewKeeper(ctx, conditions.Options{Store: store, History: history, Looks: storeLooks{inv}})
+	defer k.Close(context.Background())
+	look := conditions.Observation{Scope: conditions.ScopeMachine, ID: "anchor", Kind: "silent", Machine: "anchor",
+		Severity: conditions.Warning, Summary: "anchor has not been heard from", Source: "S1"}
+	for range 4 {
+		if _, err := k.Observe(ctx, look); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	api, err := jetstream.New(serving.Conn())
+	if err != nil {
+		t.Fatal(err)
+	}
+	stream, err := api.Stream(ctx, "KV_"+broker.ConditionsBucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	info, err := stream.Info(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.State.LastSeq != 1 {
+		t.Fatalf("four looks at one unchanged condition wrote the bucket %d times, want 1", info.State.LastSeq)
+	}
+
+	// The verb as a process other than the serving controller: it reads the bucket and the store.
+	keptBefore := conditionsFrom
+	conditionsFrom = nil
+	defer func() { conditionsFrom = keptBefore }()
+	t.Setenv(broker.NATSVar, bus.ClientURL())
+	t.Setenv(broker.CertificateVar, "")
+	var shown bytes.Buffer
+	if err := showCondition(ctx, []string{"machine.anchor.silent", "--json"}, &shown); err != nil {
+		t.Fatal(err)
+	}
+	var c conditions.Condition
+	if err := json.Unmarshal(shown.Bytes(), &c); err != nil {
+		t.Fatalf("%v: %s", err, shown.String())
+	}
+	if c.Observations != 4 || len(c.Evidence) != 4 || c.LastObserved.IsZero() || c.LooksUnread != "" ||
+		time.Since(c.LastObserved) > time.Minute {
+		t.Fatalf("conditions show reads %d observation(s), %d evidence line(s), last %s (%q)", c.Observations,
+			len(c.Evidence), c.LastObserved, c.LooksUnread)
+	}
+	listed, err := openConditions(ctx)
+	if err != nil || len(listed) != 1 || listed[0].Observations != 4 {
+		t.Fatalf("conditions lists %+v: %v", listed, err)
+	}
+}