Merge pull request '57/P2: The node-engine writes a filled file on the provisioner client's request, and nothing else (issue 668)' (#111) from pkg/57-p2-local-write-verb into feat/57-config-and-provisioning

Review 12004 of mesh-host#111: refusals counted after a said one reached the journal only if the same account was refused again a minute later, and a refusal of another kind hid behind it. The first of each (account, kind) is said at once, and what is counted is said on a timer and when the socket stops. Connections waiting to be judged are bounded below the open-file limit, the busy refusals belong to one Serve, and the tests' ask has a deadline. Issue 668.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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.

cmd/mesh-bootstrap/main.go

@@ -116,6 +116,8 @@ const usage = `mesh-bootstrap — make a bare machine into a mesh
 
   --tools-source     the repository the shared base is built from
   --tools-ref        what of it to build (default main)
+  --tools-go-source  the repository the Go toolchain is built from (default: mesh-tools-go beside --tools-source)
+  --tools-go-ref     what of it to build (default main)
   --catalog-source   the catalogue REPOSITORY, for building its modules;
                      --catalog is the checkout that says what they are
   --catalog-ref      what of it to build (default main)
@@ -308,6 +310,10 @@ func newFlagSet(opts *bootstrap.Options, jsonOut *bool) *flag.FlagSet {
 		"the repository the shared base is built from")
 	set.StringVar(&opts.ToolsSource.Ref, "tools-ref", opts.ToolsSource.Ref,
 		"what of it to build (default main)")
+	set.StringVar(&opts.ToolsGoSource.Repository, "tools-go-source", opts.ToolsGoSource.Repository,
+		"the repository the Go toolchain is built from (default: mesh-tools-go beside --tools-source)")
+	set.StringVar(&opts.ToolsGoSource.Ref, "tools-go-ref", opts.ToolsGoSource.Ref,
+		"what of it to build (default main)")
 	set.StringVar(&opts.CatalogSource.Repository, "catalog-source", opts.CatalogSource.Repository,
 		"the catalogue REPOSITORY, for building its modules — --catalog is the checkout that says what they are")
 	set.StringVar(&opts.CatalogSource.Ref, "catalog-ref", opts.CatalogSource.Ref,

cmd/mesh-host/busy_test.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-host/internal/link"
+)
+
+// A container waiting because it said busy is news when it starts waiting and when it is replaced, never on
+// its output alone (novox/hq ADR 0335): the walk waiting on this machine starts its gate at the report that
+// says it replaced, and a reconcile is otherwise silent.
+func TestABusyWaitIsSaidWhenItStartsAndWhenItEnds(t *testing.T) {
+	quiet := link.Report{Outward: []string{"eth0"}}
+	waiting := link.Report{Outward: []string{"eth0"}, Busy: []link.Busy{{ID: "build-agent.server",
+		Container: "mesh-build-agent", State: "waiting", Said: "building a"}}}
+	still := link.Report{Outward: []string{"eth0"}, Busy: []link.Busy{{ID: "build-agent.server",
+		Container: "mesh-build-agent", State: "waiting", Said: "building b, a minute on"}}}
+	replaced := link.Report{Outward: []string{"eth0"}, Busy: []link.Busy{{ID: "build-agent.server",
+		Container: "mesh-build-agent", State: "replaced-when-idle"}}}
+	if adoptionFingerprint(waiting) == adoptionFingerprint(quiet) {
+		t.Error("a container starting to wait is not news")
+	}
+	if adoptionFingerprint(still) != adoptionFingerprint(waiting) {
+		t.Error("a wait whose output changed reads as news on every ask")
+	}
+	if adoptionFingerprint(replaced) == adoptionFingerprint(waiting) {
+		t.Error("a container replaced after it waited is not news")
+	}
+	if !worthSaying(link.Report{Busy: replaced.Busy}) {
+		t.Error("a replacement after a wait is not worth saying")
+	}
+}
+
+// While a container waits, a pass is asked for every so often, not at the reconcile's five minutes; with
+// nothing waiting, none (novox/hq ADR 0335 §2).
+func TestAWaitIsAskedAgainSoonerThanTheReconcile(t *testing.T) {
+	if BusyAskEvery >= ReconcileEvery || BusyAskEvery > time.Minute {
+		t.Fatalf("a waiting container is asked every %s", BusyAskEvery)
+	}
+	var reconciles atomic.Int32
+	queue := &link.Queue{Reconcile: func(context.Context) (link.Report, bool) {
+		reconciles.Add(1)
+		return link.Report{}, false
+	}}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go queue.Run(ctx)
+	busyWaiting.Store(false)
+	t.Cleanup(func() { busyWaiting.Store(false) })
+	go busyPasses(ctx, queue, 10*time.Millisecond)
+	time.Sleep(100 * time.Millisecond)
+	if n := reconciles.Load(); n != 0 {
+		t.Fatalf("%d passes were asked with nothing waiting", n)
+	}
+	busyWaiting.Store(true)
+	deadline := time.Now().Add(2 * time.Second)
+	for reconciles.Load() == 0 && time.Now().Before(deadline) {
+		time.Sleep(10 * time.Millisecond)
+	}
+	if reconciles.Load() == 0 {
+		t.Fatal("no pass was asked while a container waits")
+	}
+}

cmd/mesh-host/filling.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"context"
+	"crypto/ed25519"
+	"errors"
+	"path/filepath"
+
+	"github.com/novox/mesh-host/internal/apply"
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/filling"
+	"github.com/novox/mesh-host/internal/store"
+	"github.com/novox/mesh-host/internal/system"
+)
+
+// serveFilling writes filled files on the provisioner client's request for as long as this engine serves (novox/hq
+// ADR 0349 §4). A socket that cannot be served is said once, and this engine goes on applying.
+func serveFilling(ctx context.Context, opts options, signer ed25519.PublicKey, say func(string)) {
+	if err := filling.Serve(ctx, filling.Socket, fillingEngine(opts, signer, say), say); err != nil {
+		say("filled files are not written on request on this machine: " + err.Error())
+	}
+}
+
+// fillingEngine is the write of a filled file as this engine does it: the declaration it keeps, verified, read under
+// the apply's lock — the same two locks every apply takes, the process's and the one beside the state — and the file
+// written through the apply (apply.WriteFilled), its outcome recorded in the node's state as an apply's is.
+func fillingEngine(opts options, signer ed25519.PublicKey, say func(string)) *filling.Engine {
+	return &filling.Engine{
+		Declared: func() (*declaration.Declaration, error) {
+			raw, err := store.LoadDeclared(store.DeclaredPath(opts.state), signer)
+			if err != nil {
+				return nil, err
+			}
+			return declaration.Parse(raw)
+		},
+		UIDOf: filling.UIDOf,
+		Lock: func() (func(), error) {
+			applying.Lock()
+			unlock, err := store.Lock(opts.state, nil)
+			if err != nil {
+				applying.Unlock()
+				return nil, err
+			}
+			return func() { unlock(); applying.Unlock() }, nil
+		},
+		Place: func(ctx context.Context, d *declaration.Declaration, path string, content []byte) (string, string, error) {
+			built, err := system.For(builtFor)
+			if err != nil {
+				return "", "", err
+			}
+			known, err := store.Load(opts.state)
+			if err != nil {
+				return "", "", err
+			}
+			report, updated, writeErr := apply.WriteFilled(ctx, built, d, known, path, content, apply.ExecRunner,
+				announceOr(say), apply.KeepIn(filepath.Dir(opts.state)), apply.WindowsIn(filepath.Dir(opts.state)))
+			// Saved whichever way it went, as an apply's: what was written is on the machine either way.
+			if err := store.Save(opts.state, updated); err != nil {
+				return "", "", errors.Join(writeErr, errors.New("written, and the node's state could not be saved: "+
+					err.Error()))
+			}
+			action, digest := "", ""
+			for _, o := range report.Outcomes {
+				if o.Target == path && o.Type == string(declaration.TypeFile) {
+					action = o.Action
+				}
+			}
+			if rec, ok := updated.At(string(declaration.TypeFile), path); ok {
+				digest = rec.Wrote
+			}
+			return action, digest, writeErr
+		},
+	}
+}

cmd/mesh-host/filling_test.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"context"
+	"crypto/ed25519"
+	"encoding/json"
+	"os"
+	"os/user"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-host/internal/filling"
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// Defends novox/hq ADR 0349 §4 (issue 668): a write of a filled file and an apply are one at a time — the write
+// takes the lock the apply holds, and writes only once the apply let it go — and the write is recorded in the
+// node's state as an apply's outcome is.
+func TestAWriteAndAnApplyOfTheSameFileSerialise(t *testing.T) {
+	was := builtFor
+	builtFor = "arch"
+	t.Cleanup(func() { builtFor = was })
+	me, err := user.Current()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if me.Uid == "0" {
+		t.Skip("run as root, whose account is never the provisioner's")
+	}
+	dir := t.TempDir()
+	opts := options{state: filepath.Join(dir, "state.json")}
+	public, private, err := ed25519.GenerateKey(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(dir, "m.conf")
+	raw, err := json.Marshal(map[string]any{"declaration": 1, "provisioner_account": me.Username,
+		"filled_files": []string{path}, "resources": []any{map[string]any{"id": "m.conf", "type": "file",
+			"path": path, "content": "from the declaration\n", "owner-at-runtime": "owned", "owner": me.Username}}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := store.SaveDeclared(store.DeclaredPath(opts.state),
+		store.Declared{Declaration: raw, Signature: ed25519.Sign(private, raw)}); err != nil {
+		t.Fatal(err)
+	}
+	e := fillingEngine(opts, public, func(string) {})
+	uid := uint32(os.Getuid())
+	if err := e.Accepts(uid); err != nil {
+		t.Fatal(err)
+	}
+
+	// An apply holds the lock.
+	applying.Lock()
+	done := make(chan filling.Answer)
+	go func() {
+		done <- e.Write(context.Background(), uid, filling.Request{Path: path, Content: []byte("filled\n")})
+	}()
+	select {
+	case a := <-done:
+		applying.Unlock()
+		t.Fatalf("written while an apply held the lock: %+v", a)
+	case <-time.After(200 * time.Millisecond):
+	}
+	if _, err := os.Stat(path); err == nil {
+		applying.Unlock()
+		t.Fatal("the file was written while an apply held the lock")
+	}
+	applying.Unlock()
+	a := <-done
+	if a.Refused != "" || a.Failed != "" || a.Action != "created" {
+		t.Fatalf("the write after the apply: %+v", a)
+	}
+	got, err := os.ReadFile(path)
+	if err != nil || string(got) != "filled\n" {
+		t.Fatalf("the file holds %q (%v)", got, err)
+	}
+	known, err := store.Load(opts.state)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rec, ok := known.Find("m.conf"); !ok || rec.Wrote != a.Digest || rec.Target != path {
+		t.Errorf("the write is not recorded in the node's state: %+v, answered %q", rec, a.Digest)
+	}
+
+	// And the cross-process lock beside the state too: a write waits for a `reconcile` run by hand.
+	unlock, err := store.Lock(opts.state, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	go func() {
+		done <- e.Write(context.Background(), uid, filling.Request{Path: path, Content: []byte("again\n")})
+	}()
+	select {
+	case a := <-done:
+		unlock()
+		t.Fatalf("written while another process held the apply's lock: %+v", a)
+	case <-time.After(200 * time.Millisecond):
+	}
+	unlock()
+	if a := <-done; a.Action != "updated" {
+		t.Fatalf("the second write: %+v", a)
+	}
+}

cmd/mesh-host/local_network_test.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/novox/mesh-host/internal/link"
+	"github.com/novox/mesh-host/internal/outward"
+	"github.com/novox/mesh-host/internal/profile"
+)
+
+func reportOn(networks ...outward.Network) link.Report {
+	return link.Report{Outward: []string{"eth0"},
+		Profile: profileAsReported(profile.Profile{Machine: &profile.Machine{Networks: networks}})}
+}
+
+// **A change of the networks a machine is attached to is said unasked** (novox/hq ADR 0340 §7): a port
+// reached from the local network is admitted from them, so a laptop that joins another network is said at
+// the next reconcile, not at the next push — and the same networks again are not news.
+func TestAChangedNetworkIsSaidUnasked(t *testing.T) {
+	w := &adoptionWatch{}
+	home := reportOn(outward.Network{Link: "eth0", Network: "192.168.1.0/24"})
+	w.said(home)
+	if w.differs(reportOn(outward.Network{Link: "eth0", Network: "192.168.1.0/24"})) {
+		t.Fatal("the same networks read as a change, so the machine would speak on every reconcile")
+	}
+	if !w.differs(reportOn(outward.Network{Link: "eth0", Network: "10.20.0.0/16"})) {
+		t.Fatal("a machine that moved to another network does not say so until it is pushed to")
+	}
+}

cmd/mesh-host/main.go

@@ -24,6 +24,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"text/tabwriter"
 	"time"
@@ -1259,6 +1260,7 @@ func runLink(ctx context.Context, opts options) error {
 		queue.ReconcileDue()
 	}
 	go holdTheMachine(ctx, queue)
+	go busyPasses(ctx, queue, BusyAskEvery)
 	// And whether what it runs stays up, looked at on its own clock and said when it changes (novox/hq
 	// ADR 0240) — between applies, which is when a container crash-loops.
 	if judging != nil {
@@ -1278,6 +1280,9 @@ func runLink(ctx context.Context, opts options) error {
 	// And mesh-cli is answered on this machine: the account from the kernel, the line asked of the controller
 	// (novox/hq ADR 0272).
 	go serveMeshCLI(aside, queue, say)
+	// And a filled file is written on the provisioner client's request, one at a time with the apply (novox/hq ADR
+	// 0349 §4).
+	go serveFilling(aside, opts, mine.Membership.Signer, say)
 
 	held := link.HoldRoused(aside, membership, queue, say, opts.timeout, rousedBySignal(ctx))
 	// The act in hand finishes and is kept before this process exits: an apply that stood aside with
@@ -1397,6 +1402,18 @@ func adoptionFingerprint(r link.Report) string {
 	// it could only speak when a declaration arrived, and a declaration cannot be composed until it
 	// has spoken: a machine waiting for a push that is waiting for the machine.
 	parts := []string{"firewall=" + r.Firewall, "outward=" + strings.Join(r.Outward, ",")}
+	// **And the networks those links are on** (novox/hq ADR 0340 §7): a port reached from the local
+	// network is admitted from them, so a laptop that joins another network, or a lease that moves, is
+	// said at the next reconcile rather than at the next push or the next day.
+	if networks := attachedNetworksOf(r); networks != "" {
+		parts = append(parts, "networks="+networks)
+	}
+	// And a container waiting because it said busy, or replaced after it waited (novox/hq ADR 0335): the walk
+	// waiting on this machine starts its gate at the report that says it replaced. Not its output, which
+	// may change on every ask.
+	for _, b := range r.Busy {
+		parts = append(parts, "busy "+b.ID+"="+b.State)
+	}
 	for _, h := range r.Held {
 		parts = append(parts, "held "+h.ID+"="+h.Changed)
 	}
@@ -1428,6 +1445,26 @@ func adoptionFingerprint(r link.Report) string {
 	return strings.Join(parts, "\n")
 }
 
+// attachedNetworksOf is the networks a report's profile says the machine is attached to, as one line: the
+// part of what the machine is made of that the filter is composed from (novox/hq ADR 0340).
+func attachedNetworksOf(r link.Report) string {
+	machine, ok := r.Profile["machine"].(map[string]any)
+	if !ok {
+		return ""
+	}
+	networks, ok := machine["networks"].([]any)
+	if !ok {
+		return ""
+	}
+	said := make([]string, 0, len(networks))
+	for _, n := range networks {
+		if entry, ok := n.(map[string]any); ok {
+			said = append(said, fmt.Sprintf("%v %v", entry["link"], entry["network"]))
+		}
+	}
+	return strings.Join(said, ",")
+}
+
 // applyState is how an apply went, as the fingerprint keeps it: refused, clean, or failed with what it did not
 // apply and which keys its failure is said under.
 func applyState(r link.Report) string {
@@ -1613,7 +1650,7 @@ func declaredResolvConf(d *declaration.Declaration) (string, string, bool) {
 	}
 	for _, r := range d.Resources {
 		f, ok := r.(*declaration.File)
-		if !ok || f.Path != network.ResolvConf || f.CreateOnce || f.Into != "" {
+		if !ok || f.Path != network.ResolvConf || f.Seeded() || f.Into != "" {
 			continue
 		}
 		module, ok := liveness.ModuleOf(f.ID)
@@ -1735,8 +1772,10 @@ func judgeWhatRuns(ctx context.Context, j *liveness.Judge, queue *link.Queue, sa
 func healthAsReported(st liveness.Statement, ns *network.Statement) *link.Health {
 	// LibraryContract: this engine reads a resource's declared `health` and judges it (ADR 0240 Phase B), judges a
 	// user's declared `root` (novox/hq ADR 0266), and reads a declaration's identities, groups and libraries
-	// (novox/hq ADR 0328), which is what tells the controller it may be sent any of those fields.
-	h := &link.Health{Contract: link.OwnGroupContract, At: st.At.UTC(), Resources: []link.ResourceHealth{}}
+	// (novox/hq ADR 0328), a container's busy (ADR 0335) and a file's owner-at-runtime and the filled files (ADR
+	// 0349 §5) and the provisioner client's account (ADR 0349 §4), which is what tells the controller it may be sent
+	// any of those fields.
+	h := &link.Health{Contract: link.ProvisionerContract, At: st.At.UTC(), Resources: []link.ResourceHealth{}}
 	for _, r := range st.Resources {
 		h.Resources = append(h.Resources, link.ResourceHealth{Module: r.Module, Resource: r.ID, Kind: r.Kind,
 			Target: r.Target, State: r.State, Reason: r.Reason, Since: r.Since.UTC(), Streak: r.Streak,
@@ -1868,6 +1907,32 @@ func holdTheMachine(ctx context.Context, queue *link.Queue) {
 	}
 }
 
+// busyWaiting is whether the last apply left a container running because it said busy (novox/hq ADR 0335).
+var busyWaiting atomic.Bool
+
+// BusyAskEvery is how often a container waiting because it said busy is asked again (novox/hq ADR 0335 §2):
+// each ask is a pass of its own, so a build that ends is followed by its replacement within this, not
+// within the reconcile's five minutes — and the bound of 15 minutes is met within this of its end.
+const BusyAskEvery = 20 * time.Second
+
+// busyPasses asks for a pass every so often while a container waits because it said busy. **It asks; it
+// does not apply**, as holdTheMachine: the queue's worker does, when its turn comes, so a pass never holds
+// the machine for the wait, and a delivery waiting is that pass's apply.
+func busyPasses(ctx context.Context, queue *link.Queue, every time.Duration) {
+	ticker := time.NewTicker(every)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			if busyWaiting.Load() {
+				queue.ReconcileDue()
+			}
+		}
+	}
+}
+
 // reconcileKept is the reconcile's act, as the queue's worker runs it: hold the machine to what it
 // was last told, read once it is this act's turn, and say what did not go.
 //
@@ -1919,7 +1984,7 @@ func worthSaying(report link.Report) bool {
 	}
 	return len(report.Held) > 0 || report.Firewall != "" || len(report.Outward) > 0 ||
 		len(report.Filters) > 0 || report.FoundFirewall != nil || len(report.Windows) > 0 ||
-		len(report.Rollbacks) > 0
+		len(report.Rollbacks) > 0 || len(report.Busy) > 0
 }
 
 // announceOr is what the apply writes its detail with, given what the caller has to say things with.
@@ -2168,6 +2233,14 @@ func applyAndKeepHeld(ctx context.Context, opts options, raw []byte, signed *sto
 	for _, w := range outcome.Windows {
 		report.Windows = append(report.Windows, link.Window{Step: w.Step, Holds: w.Holds, Since: w.Opened, Until: w.Until})
 	}
+	// And a container left running because it said busy, or replaced after it waited (novox/hq ADR 0335):
+	// the walk waiting on this machine reads it. While one waits, this machine asks it again sooner than its
+	// reconcile (busyPasses).
+	for _, b := range outcome.Busy {
+		report.Busy = append(report.Busy, link.Busy{ID: b.ID, Container: b.Container, State: b.State,
+			Since: b.Since, Until: b.Until, Said: b.Said})
+	}
+	busyWaiting.Store(outcome.Waiting())
 	// And what runs here that nobody asked for (novox/hq ADR 0163).
 	if strays, err := apply.Strays(ctx, apply.ExecRunner, updated); err != nil {
 		fmt.Fprintf(os.Stderr, "mesh-host: applied, and could not list what else runs here: %v\n", err)

cmd/mesh-host/units_test.go

@@ -87,10 +87,11 @@ func TestTheStatementSaysAnAccountJudgedForRoot(t *testing.T) {
 			Groups: []string{"openrazer"}}, State: accounts.Healthy, Since: at},
 	}}
 	h := withAccounts(healthAsReported(liveness.Statement{At: at}, nil), as)
-	// At RootContract or later: an engine that also reads an identity's runner says OwnGroupContract (novox/hq ADR
-	// 0334), one above ADR 0328's LibraryContract.
-	if h.Contract < link.RootContract || link.RootContract != 3 || h.Contract != link.OwnGroupContract ||
-		link.OwnGroupContract != link.LibraryContract+1 {
+	// At RootContract or later: an engine that also reads the provisioner client's account says ProvisionerContract
+	// (novox/hq ADR 0349 §4), one above ADR 0349 §5's OwnershipContract.
+	if h.Contract < link.RootContract || link.RootContract != 3 || h.Contract != link.ProvisionerContract ||
+		link.ProvisionerContract != link.OwnershipContract+1 || link.OwnershipContract != link.BusyContract+1 ||
+		link.BusyContract != link.OwnGroupContract+1 {
 		t.Fatalf("contract %d", h.Contract)
 	}
 	got := map[string]string{}

examples/bundle_test.go

@@ -49,7 +49,7 @@ func TestTheBundleCarriesTheFoundationAndTheControlPlaneAndNothingElse(t *testin
 	}
 	sort.Strings(images)
 
-	want := []string{"mesh-controller", "nats", "postgres"}
+	want := []string{"mesh-controller", "nats", "pgvector"}
 	if strings.Join(images, ",") != strings.Join(want, ",") {
 		t.Fatalf("the bundle carries %v; expected exactly %v.\n\n"+
 			"Adding one is a change to what every first node becomes, and to ADR 0006's "+

examples/foundation-first-node.lock

@@ -28,11 +28,12 @@
 // image, and this file is applied on a machine with no mesh to ask about anything (ADR 0006). The
 // registry prefix is the lab's; the digests are upstream's.
 //
-// The store's data is a NAMED VOLUME, not a directory on the machine. A directory the host
-// creates is owned by root, and the database runs as somebody else inside the container — so it
-// could not write, and the container crash-looped. A named volume lets the image set up its own
-// ownership, and outlives the container, which is what you want for the thing holding the mesh's
-// state.
+// **The store is raised where the `postgres` module keeps it** (novox/hq ADR 0338): the container
+// `postgres`, on the module's pgvector image, its data in the directory /var/lib/mesh-store owned by
+// the image's postgres user, its superuser password read from the module's own-secret file — so the
+// store step adopts it as it runs. Pinned upstream by the module's own digest, not through the lab's
+// registry prefix, because the two must be the same reference (mesh-host internal/bootstrap holds
+// them to each other against the module's manifest).
 
 {
   "declaration": 1,
@@ -83,17 +84,28 @@
       "boot": "enabled",
       "restart-on": ["base-filter"]
     },
+    // The store's data is a directory owned by the image's postgres user (999), made before the
+    // container starts: a directory the runtime made would be root's, and the database could not
+    // write it. Measured on the module's image 2026-10-13: it initialises a new store on a directory
+    // made so (novox/hq ADR 0338 §5).
+    {
+      "id": "store-data",
+      "type": "directory",
+      "path": "/var/lib/mesh-store",
+      "mode": "0700",
+      "owner": "999:70"
+    },
     {
       "id": "store",
       "type": "container",
-      "name": "mesh-store",
-      "image": "192.0.2.250:5000/postgres@sha256:7abf537131b66ed5af448d90653abf1679b0c7e9a1f07efdd4c3108a401b259a",
+      "name": "postgres",
+      "image": "pgvector/pgvector@sha256:cf134a767f474095eeba57e0117be8e568e011a63f33fbf252f14c9b760f8e6f",
       "env": {
         "POSTGRES_PASSWORD": "bootstrap",
         "PGDATA": "/var/lib/postgresql/data/pgdata"
       },
       "ports": ["5432:5432"],
-      "volumes": ["mesh-store-data:/var/lib/postgresql/data"]
+      "volumes": ["/var/lib/mesh-store:/var/lib/postgresql/data"]
     },
     // Over TCP, not the socket. While the store initialises it runs a temporary server on the
     // socket ONLY, then stops it and starts the real one — so a socket check passes, the action
@@ -102,21 +114,21 @@
     {
       "id": "store-ready",
       "type": "action",
-      "in": "mesh-store",
+      "in": "postgres",
       "command": ["sh", "-c", "for i in $(seq 1 180); do pg_isready -h 127.0.0.1 -U postgres >/dev/null 2>&1 && exit 0; sleep 1; done; echo 'the store did not answer within 180s; its own last words follow'; pg_isready -h 127.0.0.1 -U postgres; tail -n 20 /var/lib/postgresql/data/log/*.log 2>/dev/null; exit 1"],
 "verify": ["pg_isready", "-h", "127.0.0.1", "-U", "postgres"]
     },
     {
       "id": "inventory-database",
       "type": "action",
-      "in": "mesh-store",
+      "in": "postgres",
       "command": ["sh", "-c", "psql -U postgres -c 'CREATE DATABASE inventory'"],
       "verify": ["sh", "-c", "psql -U postgres -lqt | cut -d'|' -f1 | grep -qw inventory"]
     },
     {
       "id": "identity-database",
       "type": "action",
-      "in": "mesh-store",
+      "in": "postgres",
       "command": ["sh", "-c", "psql -U postgres -c 'CREATE DATABASE identity'"],
       "verify": ["sh", "-c", "psql -U postgres -lqt | cut -d'|' -f1 | grep -qw identity"]
     },
@@ -126,20 +138,20 @@
     {
       "id": "licences-database",
       "type": "action",
-      "in": "mesh-store",
+      "in": "postgres",
       "command": ["sh", "-c", "psql -U postgres -c 'CREATE DATABASE licences'"],
       "verify": ["sh", "-c", "psql -U postgres -lqt | cut -d'|' -f1 | grep -qw licences"]
     },
     {
       "id": "context-schemas",
       "type": "action",
-      "command": ["docker", "run", "--rm", "--network", "container:mesh-store",
+      "command": ["docker", "run", "--rm", "--network", "container:postgres",
                   "-e", "MESH_STORE_INVENTORY=postgres://postgres:bootstrap@127.0.0.1:5432/inventory?sslmode=disable",
                   "-e", "MESH_STORE_IDENTITY=postgres://postgres:bootstrap@127.0.0.1:5432/identity?sslmode=disable",
         "-e", "MESH_STORE_LICENCES=postgres://postgres:bootstrap@127.0.0.1:5432/licences?sslmode=disable",
                   "192.0.2.250:5000/mesh-controller@sha256:c67db38439ff0aee242b467486765467bb95801f52175fc5727cc4e437338ace",
                   "migrate"],
-      "verify": ["sh", "-c", "docker exec mesh-store psql -U postgres -d inventory -tAc \"select to_regclass('public.node')\" | grep -qx node && docker exec mesh-store psql -U postgres -d identity -tAc \"select to_regclass('public.signing_key')\" | grep -qx signing_key && docker exec mesh-store psql -U postgres -d licences -tAc \"select to_regclass('public.licence')\" | grep -qx licence"]
+      "verify": ["sh", "-c", "docker exec postgres psql -U postgres -d inventory -tAc \"select to_regclass('public.node')\" | grep -qx node && docker exec postgres psql -U postgres -d identity -tAc \"select to_regclass('public.signing_key')\" | grep -qx signing_key && docker exec postgres psql -U postgres -d licences -tAc \"select to_regclass('public.licence')\" | grep -qx licence"]
     },
     // **The bus is raised where the `nats` module keeps it** (novox/hq ADR 0333 §1): the container
     // `mesh-broker-nats`, its configuration and user list in /var/lib/nats-module/conf, its streams in
@@ -209,17 +221,20 @@
       "path": "/var/lib/nats-module/conf/accounts.conf",
       "mode": "0600",
       "create-once": true,
-      "content": "// The first user list, carried by the installer because at genesis there is no mesh to\n// compose one. A bootstrap credential, rotated with the store's and replaced by the\n// controller's own composition from its first start onward.\naccounts {\n  MESH {\n    jetstream: enabled\n    users = [\n      { user: \"controller\", password: \"$2a$10$AHqJgOifIVbU41KmATiMhuXFs8xa7Wl2HuN4UVBCXdN2jIQzjqApy\", permissions: {\n        publish: { allow: [\"$JS.ACK.CONTROL.controller.>\", \"$JS.ACK.EVENTS.controller.>\", \"$JS.ACK.DEAD_LETTER_NOTICES.controller.>\", \"$JS.API.>\", \"$KV.mesh-controller_asked.>\", \"$KV.mesh-controller_calls.>\", \"$KV.mesh-controller_hand-acts.>\", \"$KV.mesh-controller_conditions.>\", \"$KV.mesh-controller_condition-history.>\", \"$KV.mesh-controller_lease.>\", \"$KV.SEAT_MESH_BUILD_MACHINE_cancelled.>\", \"$KV.SEAT_NODE_BUILD_AGENT_cancelled.>\", \"_INBOX.enrol.>\", \"mesh.assignment.>\", \"mesh.mod.*.tool.>\", \"mesh.node.>\", \"mesh.seat.mesh-build-machine.accept.>\", \"mesh.seat.node-build-agent.accept.>\", \"mesh.seat.mesh-build-machine.tool.>\", \"mesh.seat.node-build-agent.tool.>\", \"mesh.seat.mesh-controller.event.applied\", \"mesh.seat.mesh-controller.event.built-before\", \"mesh.seat.mesh-controller.event.refused\", \"mesh.seat.mesh-controller.event.rolled-back\", \"mesh.seat.mesh-controller.event.checked\", \"mesh.seat.mesh-controller.event.plan-moved\", \"mesh.seat.mesh-controller.event.condition-raised\", \"mesh.seat.mesh-controller.event.condition-changed\", \"mesh.seat.mesh-controller.event.condition-cleared\", \"mesh.seat.mesh-controller.event.doctor-heartbeat\", \"mesh.seat.mesh-controller.event.secret-replaced\", \"mesh.seat.mesh-controller.event.healer-acted\", \"$SRV.INFO\", \"mesh.seat.node-intrusion-prevention.tool.banned.*\", \"mesh.seat.node-backup.tool.backed-up.*\", \"mesh.seat.node-backup.tool.now.*\", \"mesh.seat.mesh-delivery.tool.stalled\", \"mesh.seat.mesh-delivery.tool.close\", \"mesh.seat.node-launcher.tool.secret.*\", \"mesh.seat.mesh-delivery.tool.release\", \"mesh.seat.mesh-delivery.tool.stop\", \"mesh.seat.mesh-delivery.tool.times\", \"mesh.seat.mesh-delivery.tool.groups\", \"mesh.seat.node-service-manager.tool.restart.*\", \"mesh.seat.mesh-controller.tool.plans\", \"mesh.events.dead.>\", \"mesh.again.>\"] }\n        subscribe: { allow: [\"$JS.API.>\", \"$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.>\", \"$JS.EVENT.ADVISORY.CONSUMER.DELETED.>\", \"_DELIVER.controller\", \"_DELIVER.controller.>\", \"_INBOX.controller.>\", \"mesh.control.>\", \"mesh.mod.*.event.provisioner.failing\", \"mesh.mod.*.event.provisioner.recovered\", \"mesh.mod.*.event.provisioner.retirement\", \"mesh.mod.gitea.event.pull.merged\", \"mesh.mod.gitea.event.pull.updated\", \"mesh.mod.mesh-catalog.event.catching-up\", \"mesh.mod.mesh-catalog.event.upgraded\", \"mesh.seat.mesh-build-machine.event.built\", \"mesh.seat.node-build-agent.event.built\", \"mesh.seat.operator-channel.event.decided.mesh-controller\", \"mesh.seat.mesh-controller.tool.>\", \"$SRV.PING\", \"$SRV.INFO\", \"$SRV.PING.mesh-controller\", \"$SRV.PING.mesh-controller.>\", \"$SRV.INFO.mesh-controller\", \"$SRV.INFO.mesh-controller.>\", \"$SRV.STATS\", \"$SRV.STATS.mesh-controller\", \"$SRV.STATS.mesh-controller.>\"] }\n        allow_responses: { max: 1, ttl: \"1m\" }\n      } }\n    ]\n  }\n}\n"
+      "content": "// The first user list, carried by the installer because at genesis there is no mesh to\n// compose one. A bootstrap credential, rotated with the store's and replaced by the\n// controller's own composition from its first start onward.\naccounts {\n  MESH {\n    jetstream: enabled\n    users = [\n      { user: \"controller\", password: \"$2a$10$AHqJgOifIVbU41KmATiMhuXFs8xa7Wl2HuN4UVBCXdN2jIQzjqApy\", permissions: {\n        publish: { allow: [\"$JS.ACK.CONTROL.controller.>\", \"$JS.ACK.EVENTS.controller.>\", \"$JS.ACK.DEAD_LETTER_NOTICES.controller.>\", \"$JS.API.>\", \"$KV.mesh-controller_asked.>\", \"$KV.mesh-controller_assignments.>\", \"$KV.mesh-controller_calls.>\", \"$KV.mesh-controller_hand-acts.>\", \"$KV.mesh-controller_conditions.>\", \"$KV.mesh-controller_condition-history.>\", \"$KV.mesh-controller_declared-config.>\", \"$KV.mesh-controller_lease.>\", \"$KV.SEAT_MESH_BUILD_MACHINE_cancelled.>\", \"$KV.SEAT_NODE_BUILD_AGENT_cancelled.>\", \"_INBOX.enrol.>\", \"mesh.assignment.>\", \"mesh.mod.*.tool.>\", \"mesh.node.>\", \"mesh.seat.mesh-build-machine.accept.>\", \"mesh.seat.node-build-agent.accept.>\", \"mesh.seat.mesh-build-machine.tool.>\", \"mesh.seat.node-build-agent.tool.>\", \"mesh.seat.mesh-controller.event.applied\", \"mesh.seat.mesh-controller.event.built-before\", \"mesh.seat.mesh-controller.event.refused\", \"mesh.seat.mesh-controller.event.rolled-back\", \"mesh.seat.mesh-controller.event.checked\", \"mesh.seat.mesh-controller.event.plan-moved\", \"mesh.seat.mesh-controller.event.assignment-changed\", \"mesh.seat.mesh-controller.event.declared-config-changed\", \"mesh.seat.mesh-controller.event.condition-raised\", \"mesh.seat.mesh-controller.event.condition-changed\", \"mesh.seat.mesh-controller.event.condition-cleared\", \"mesh.seat.mesh-controller.event.doctor-heartbeat\", \"mesh.seat.mesh-controller.event.secret-replaced\", \"mesh.seat.mesh-controller.event.healer-acted\", \"$SRV.INFO\", \"mesh.seat.node-intrusion-prevention.tool.banned.*\", \"mesh.seat.node-backup.tool.backed-up.*\", \"mesh.seat.node-backup.tool.now.*\", \"mesh.seat.mesh-delivery.tool.stalled\", \"mesh.seat.mesh-delivery.tool.close\", \"mesh.seat.node-launcher.tool.secret.*\", \"mesh.seat.mesh-delivery.tool.release\", \"mesh.seat.mesh-delivery.tool.stop\", \"mesh.seat.mesh-delivery.tool.times\", \"mesh.seat.mesh-delivery.tool.groups\", \"mesh.seat.node-service-manager.tool.restart.*\", \"mesh.seat.mesh-controller.tool.plans\", \"mesh.events.dead.>\", \"mesh.again.>\"] }\n        subscribe: { allow: [\"$JS.API.>\", \"$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.>\", \"$JS.EVENT.ADVISORY.CONSUMER.DELETED.>\", \"_DELIVER.controller\", \"_DELIVER.controller.>\", \"_INBOX.controller.>\", \"mesh.control.>\", \"mesh.mod.*.event.provisioner.failing\", \"mesh.mod.*.event.provisioner.recovered\", \"mesh.mod.*.event.provisioner.retirement\", \"mesh.mod.gitea.event.pull.merged\", \"mesh.mod.gitea.event.pull.updated\", \"mesh.mod.mesh-catalog.event.catching-up\", \"mesh.mod.mesh-catalog.event.upgraded\", \"mesh.seat.mesh-build-machine.event.built\", \"mesh.seat.node-build-agent.event.built\", \"mesh.seat.operator-channel.event.decided.mesh-controller\", \"mesh.seat.mesh-controller.tool.>\", \"$SRV.PING\", \"$SRV.INFO\", \"$SRV.PING.mesh-controller\", \"$SRV.PING.mesh-controller.>\", \"$SRV.INFO.mesh-controller\", \"$SRV.INFO.mesh-controller.>\", \"$SRV.STATS\", \"$SRV.STATS.mesh-controller\", \"$SRV.STATS.mesh-controller.>\"] }\n        allow_responses: { max: 1, ttl: \"1m\" }\n      } }\n    ]\n  }\n}\n"
     },
     // The upstream server, until the broker step adopts it: the `nats` module's own image, built by the
-    // mesh, takes its place there once, on these same directories (ADR 0333 §3). The published port is the
+    // mesh, takes its place there once, on these same directories (ADR 0333 §3), as the bus's planned
+    // step (ADR 0236). The release is the one the module's image is built on (its NATS_BASE, 2.11.17),
+    // pinned upstream by that same digest: the adoption changes no server release, so it can be undone
+    // by putting the old image back and is said reversible. The published port is the
     // node's bus port, 5671 unless given, which every enrolment token names; the installer gives the
     // module the setting that maps its declared 4222 to it (ADR 0333 §2).
     {
       "id": "broker",
       "type": "container",
       "name": "mesh-broker-nats",
-      "image": "192.0.2.250:5000/nats@sha256:b83efabe3e7def1e0a4a31ec6e078999bb17c80363f881df35edc70fcb6bb927",
+      "image": "nats@sha256:e4bf19f15fd3218814a4e3c9e0064e1334bd8aa20d5984b9f1a0afd084f8cc00",
       "ports": ["5671:4222", "127.0.0.1:8222:8222"],
       "volumes": ["/var/lib/mesh-broker-nats:/data", "/var/lib/nats-module/conf:/etc/nats:ro", "/var/lib/mesh-broker-tls:/tls:ro"],
       "args": ["-c", "/etc/nats/nats.conf", "-js"]
@@ -227,8 +242,8 @@
     {
       "id": "broker-ready",
       "type": "action",
-      "command": ["sh", "-c", "for i in $(seq 1 60); do docker run --rm --network host --entrypoint sh 192.0.2.250:5000/nats@sha256:b83efabe3e7def1e0a4a31ec6e078999bb17c80363f881df35edc70fcb6bb927 -c 'nc -z 127.0.0.1 5671' >/dev/null 2>&1 && exit 0; sleep 1; done; exit 1"],
-      "verify": ["sh", "-c", "docker run --rm --network host --entrypoint sh 192.0.2.250:5000/nats@sha256:b83efabe3e7def1e0a4a31ec6e078999bb17c80363f881df35edc70fcb6bb927 -c 'nc -z 127.0.0.1 5671'"]
+      "command": ["sh", "-c", "for i in $(seq 1 60); do docker run --rm --network host --entrypoint sh nats@sha256:e4bf19f15fd3218814a4e3c9e0064e1334bd8aa20d5984b9f1a0afd084f8cc00 -c 'nc -z 127.0.0.1 5671' >/dev/null 2>&1 && exit 0; sleep 1; done; exit 1"],
+      "verify": ["sh", "-c", "docker run --rm --network host --entrypoint sh nats@sha256:e4bf19f15fd3218814a4e3c9e0064e1334bd8aa20d5984b9f1a0afd084f8cc00 -c 'nc -z 127.0.0.1 5671'"]
     },
     {
       "id": "control-plane",

internal/apply/apply.go

@@ -92,6 +92,11 @@ type Outcome struct {
 	// reads is, for a container, the digest of each file it was created reading, by path — so
 	// the next apply can say which one changed (novox/hq 04-ISSUES/103).
 	reads map[string]string
+	// busySince is, for a container left running because it said busy, when the first apply that would
+	// have replaced it ran (novox/hq ADR 0335): kept in its record, so the bound holds across passes and
+	// across a restart of the node-engine. busy is what the report says of it.
+	busySince *time.Time
+	busy      *BusyWait
 }
 
 // Report is what an apply did, in the order it did it.
@@ -108,6 +113,20 @@ type Report struct {
 	// 224): a machine whose server is stopped at 03:31 because its collector is running is
 	// working, not broken, and the report is where that difference is said.
 	Windows []Window `json:"windows,omitempty"`
+	// Busy is every container this apply left running because it said busy, or replaced after it had
+	// waited (novox/hq ADR 0335): a machine whose walk waits for it says why, and how it ended.
+	Busy []BusyWait `json:"busy,omitempty"`
+}
+
+// Waiting says whether a container of this apply waits to be replaced because it is busy: what makes the
+// node-engine ask again sooner than its reconcile (novox/hq ADR 0335 §2).
+func (r Report) Waiting() bool {
+	for _, b := range r.Busy {
+		if b.State == BusyWaiting {
+			return true
+		}
+	}
+	return false
 }
 
 // Changed reports whether anything about the machine actually moved. An apply that changed
@@ -118,7 +137,10 @@ func (r Report) Changed() bool {
 		// whose account's manager is not running, which nothing moved either (novox/hq ADR 0177);
 		// held still is a container a maintenance window stopped, which the apply did not touch
 		// (novox/hq issue 224).
-		if o.Action != "unchanged" && o.Action != "held" && o.Action != "waiting" && o.Action != heldStill {
+		// waits busy is a container left running because it said busy (novox/hq ADR 0335), which nothing
+		// moved either.
+		if o.Action != "unchanged" && o.Action != "held" && o.Action != "waiting" && o.Action != heldStill &&
+			o.Action != waitsBusy {
 			return true
 		}
 	}
@@ -977,33 +999,7 @@ func ApplyMindingWindows(
 			kept, keptMode, keptOwner = from.Kept, from.KeptMode, from.KeptOwner
 		}
 		// Only now. The record follows the fact, never leads it.
-		known.Record(store.Applied{
-			Origin: origin,
-			ID:     resource.Identity(), Type: string(resource.Kind()),
-			Target: outcome.Target, AppliedAt: time.Now().UTC(),
-			Wrote:        outcome.wrote,
-			Into:         outcome.into,
-			Kept:         kept,
-			KeptMode:     keptMode,
-			KeptOwner:    keptOwner,
-			Reads:        outcome.reads,
-			Stateless:    outcome.stateless,
-			Scope:        outcome.scope,
-			User:         outcome.user,
-			Found:        outcome.found,
-			DeclaredUnit: outcome.declared,
-			Shell:        outcome.shell,
-			Linger:       outcome.linger,
-			Groups:       outcome.groups,
-			Unpacked:     outcome.unpacked,
-			AsFound:      outcome.asFound,
-			Declared:     outcome.asFoundDeclared,
-			FoundAt:      outcome.asFoundAt,
-			Holds:        holds(resource),
-		})
-		if outcome.found != nil {
-			known.DropFound(resource.Identity())
-		}
+		recordApplied(&known, origin, resource, outcome, kept, keptMode, keptOwner)
 		// Its module has been taken, and what was held for it is now the mesh's. A file written
 		// into, or a service whose lifecycle is the machine's, replaced nothing that was found, so
 		// its outcome says what the apply did, not that a cutover happened; a hold from when it was
@@ -1046,10 +1042,13 @@ func ApplyMindingWindows(
 				Action: "forgotten", Detail: detail})
 			log(fmt.Sprintf("  forgotten %s (%s): %s", from.ID, from.Target, detail))
 		}
-		if outcome.Action == heldStill {
+		if outcome.busy != nil {
+			report.Busy = append(report.Busy, *outcome.busy)
+		}
+		if outcome.Action == heldStill || outcome.Action == waitsBusy {
 			// Not changed: nothing about it moved, so nothing that restarts on it restarts.
 			log(fmt.Sprintf("  %s %s (%s): %s", outcome.Action, outcome.ID, outcome.Target, outcome.Detail))
-		} else if outcome.Action != "unchanged" {
+		} else if moved(outcome) {
 			changed[resource.Identity()] = true
 			// With the detail, when there is one: "updated app" says a container was replaced;
 			// which file made that happen is what somebody reading the log at the time needs
@@ -1142,6 +1141,47 @@ func ApplyMindingWindows(
 	return report, known, nil
 }
 
+// recordApplied records what applying a resource did, once it is done: the record follows the fact, never leads it.
+// kept, keptMode and keptOwner are where the original of what it replaced was kept, and how it was found. What an
+// earlier apply found its unit as goes with it.
+func recordApplied(known *store.State, origin string, resource declaration.Resource, outcome Outcome,
+	kept, keptMode, keptOwner string) {
+	known.Record(store.Applied{
+		Origin: origin,
+		ID:     resource.Identity(), Type: string(resource.Kind()),
+		Target: outcome.Target, AppliedAt: time.Now().UTC(),
+		Wrote:        outcome.wrote,
+		Into:         outcome.into,
+		Kept:         kept,
+		KeptMode:     keptMode,
+		KeptOwner:    keptOwner,
+		Reads:        outcome.reads,
+		BusySince:    outcome.busySince,
+		Stateless:    outcome.stateless,
+		Scope:        outcome.scope,
+		User:         outcome.user,
+		Found:        outcome.found,
+		DeclaredUnit: outcome.declared,
+		Shell:        outcome.shell,
+		Linger:       outcome.linger,
+		Groups:       outcome.groups,
+		Unpacked:     outcome.unpacked,
+		AsFound:      outcome.asFound,
+		Declared:     outcome.asFoundDeclared,
+		FoundAt:      outcome.asFoundAt,
+		Holds:        holds(resource),
+	})
+	if outcome.found != nil {
+		known.DropFound(resource.Identity())
+	}
+}
+
+// moved reports whether applying a resource moved it, so what restarts or reloads on it does: anything but
+// unchanged, and not a container held still or waiting for its busy one to say idle.
+func moved(outcome Outcome) bool {
+	return outcome.Action != "unchanged" && outcome.Action != heldStill && outcome.Action != waitsBusy
+}
+
 // afterWhatTheyRead is the resources in declared order, except that **a service comes after every
 // resource it names under restart-on or reload-on** (novox/hq issue 260).
 //
@@ -1591,7 +1631,7 @@ func applyFile(r *declaration.File, previous store.Applied, unseal Unseal, keepF
 	// A seed that is already there is left exactly as it is — whatever has grown in it since is
 	// not the mesh's to put back (novox/hq issue 035). What this host records is what it once
 	// wrote, so a later declaration that changes the seed is not mistaken for drift either.
-	if r.CreateOnce && existed {
+	if r.Seeded() && existed {
 		out.wrote = previous.Wrote
 		if out.wrote == "" {
 			out.wrote = digestOf(string(existing))
@@ -2642,6 +2682,12 @@ func applyContainer(ctx context.Context, r *declaration.Container, run Runner,
 	// (novox/hq 04-ISSUES/009). Recreating is how a container gets restart-on, which a service
 	// already has.
 	reasons := restartedBy(r.RestartOn, changed)
+	// **A replacement owed since a busy wait began is still owed** (novox/hq ADR 0335): a restart-on trigger
+	// counts as changed only in the pass it changed, so a container left running then would otherwise read
+	// unchanged at the next pass, never be replaced, and drop from the report as if it had been.
+	if owed := owedSinceBusy(r, previous); owed != "" {
+		reasons = append(reasons, owed)
+	}
 
 	// What this container was created reading, as last recorded. By its declared id first, and by
 	// its NAME when that id has no record: the bundle's `store` becomes the postgres module's
@@ -2692,6 +2738,8 @@ func applyContainer(ctx context.Context, r *declaration.Container, run Runner,
 	// stop, so a container this apply found stopped by a window is one whose window it can see.
 	if win, held := in.windows.holding(r.Name, time.Now()); held {
 		out.reads = wasReading
+		// A replacement owed since a busy wait stays owed through the window (novox/hq ADR 0335).
+		out.busySince = previous.BusySince
 		out.Action = heldStill
 		out.Detail = fmt.Sprintf("held still by the maintenance window of %s since %s; left as it is, "+
 			"and converged by the first apply after the window closes (novox/hq issue 224)",
@@ -2707,6 +2755,15 @@ func applyContainer(ctx context.Context, r *declaration.Container, run Runner,
 		out.Action = "unchanged"
 		return out, nil
 	case existed:
+		// **A container that says it is busy is asked before it is replaced** (novox/hq ADR 0335 §2): left
+		// running while it says busy, within the bound, and replaced on the first pass it says idle. Only a
+		// running one: a stopped container holds no work in hand.
+		if r.Busy != nil && before.Running {
+			if waits := askBeforeReplacing(ctx, r, run, cri, previous, &out); waits {
+				out.reads = wasReading
+				return out, nil
+			}
+		}
 		if _, err := run(ctx, cri, "rm", "-f", r.Name); err != nil {
 			return out, fmt.Errorf("replacing container %s: %w", r.Name, err)
 		}
@@ -2807,6 +2864,9 @@ func applyContainer(ctx context.Context, r *declaration.Container, run Runner,
 		default:
 			out.Detail = "replaced; a container's configuration is fixed when it is created"
 		}
+		if out.busy != nil {
+			out.Detail += "; " + out.busy.Words()
+		}
 	}
 	return out, nil
 }

internal/apply/busy.go

@@ -0,0 +1,153 @@
+package apply
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+	"unicode/utf8"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// A container that says it is busy is replaced once it is idle, within a bound (novox/hq ADR 0335).
+//
+// **Asked, never waited on.** The apply asks the container once, and while it says busy leaves it running
+// as it is and goes on with everything else of the declaration: the machine's lock is held for one ask,
+// never for the wait. The wait is carried between passes in the container's record (store.Applied's
+// BusySince), so the next pass — the node-engine asks again sooner than its reconcile while anything waits
+// — asks again, and so does a node-engine started again in between: the bound runs from the first apply
+// that would have replaced the container, whoever applied it.
+
+// waitsBusy is the action of a container left running because it said busy (novox/hq ADR 0335 §2). Its own
+// word rather than "unchanged": its declaration moved, and the machine is not yet what was declared.
+const waitsBusy = "waits-busy"
+
+// What a report says of a busy container (novox/hq ADR 0335 §2, §3).
+const (
+	// BusyWaiting is a container left running because it said busy, waiting to be replaced.
+	BusyWaiting = "waiting"
+	// BusyReplacedIdle is a container replaced on the first pass it said idle, after it had waited.
+	BusyReplacedIdle = "replaced-when-idle"
+	// BusyReplacedAtBound is a container still busy at the bound, replaced anyway.
+	BusyReplacedAtBound = "replaced-at-bound"
+)
+
+// BusyWait is one container a busy command held, as a report says it.
+type BusyWait struct {
+	// ID is the resource's id (`<module>.<resource>`), Container its runtime name.
+	ID        string `json:"id"`
+	Container string `json:"container"`
+	// State is BusyWaiting, BusyReplacedIdle or BusyReplacedAtBound.
+	State string `json:"state"`
+	// Since is when the first apply that would have replaced it ran; Until when the bound replaces it.
+	Since time.Time `json:"since"`
+	Until time.Time `json:"until"`
+	// Said is the last output its busy command gave.
+	Said string `json:"said,omitempty"`
+}
+
+// Words is the wait in a sentence, for an outcome's detail and the console.
+func (b BusyWait) Words() string {
+	since := b.Since.UTC().Format(time.RFC3339)
+	said := ""
+	if b.Said != "" {
+		said = "; its busy command last said: " + b.Said
+	}
+	switch b.State {
+	case BusyReplacedAtBound:
+		return fmt.Sprintf("replaced while still busy: it said busy since %s and the bound of %s ran out "+
+			"(novox/hq ADR 0335 §3)%s", since, declaration.BusyBound, said)
+	case BusyReplacedIdle:
+		return fmt.Sprintf("replaced once it said idle, after waiting since %s (novox/hq ADR 0335 §2)%s", since, said)
+	}
+	return fmt.Sprintf("busy: left running and replaced on the first pass it says idle, or at %s at the latest; "+
+		"waiting since %s (novox/hq ADR 0335 §2)%s", b.Until.UTC().Format(time.RFC3339), since, said)
+}
+
+// owedSinceBusy is the reason a container still owes the replacement it was left running for, or empty: its
+// record keeps when its busy wait began, under the same name.
+func owedSinceBusy(r *declaration.Container, previous store.Applied) string {
+	if previous.BusySince == nil || previous.Target != r.Name {
+		return ""
+	}
+	return "the replacement owed since its busy wait began at " + previous.BusySince.UTC().Format(time.RFC3339)
+}
+
+// busyClock is the clock the bound is read on. A test moves it.
+var busyClock = time.Now
+
+// busySaidMost is how much of a busy command's output a report carries: its last lines, enough to say what
+// it held.
+const busySaidMost = 400
+
+// askBeforeReplacing asks a running container that declares busy whether it may be replaced now, and says
+// in out what came of it. True when it waits: out is then the whole outcome of this pass. False when the
+// caller replaces it — idle, or past the bound — with out carrying the wait it ended, if there was one.
+func askBeforeReplacing(ctx context.Context, r *declaration.Container, run Runner, cri string,
+	previous store.Applied, out *Outcome) bool {
+	now := busyClock().UTC()
+	busy, said := askBusy(ctx, r, run, cri)
+	var since time.Time
+	waited := previous.BusySince != nil && previous.Target == r.Name
+	if waited {
+		since = previous.BusySince.UTC()
+		// A wait kept from a clock that has since gone back reads as starting now, never as later: the bound
+		// holds from no later than this pass.
+		if since.After(now) {
+			since = now
+		}
+	}
+	wait := BusyWait{ID: r.ID, Container: r.Name, Since: since, Said: said}
+	switch {
+	case !busy && !waited:
+		// Idle at the first ask: replaced at once, as a container that declares nothing is.
+		return false
+	case !busy:
+		wait.State, wait.Until = BusyReplacedIdle, since.Add(declaration.BusyBound)
+		out.busy = &wait
+		return false
+	}
+	if !waited {
+		since = now
+		wait.Since = now
+	}
+	wait.Until = since.Add(declaration.BusyBound)
+	if !now.Before(wait.Until) {
+		wait.State = BusyReplacedAtBound
+		out.busy = &wait
+		return false
+	}
+	wait.State = BusyWaiting
+	out.Action, out.Detail = waitsBusy, wait.Words()
+	out.busySince, out.busy = &since, &wait
+	return true
+}
+
+// askBusy runs a container's busy command inside it, by its shell, as an exec health check is run: busy is
+// an exit of 0 and nothing else. An ask that could not be made, or did not answer within its timeout, is
+// not busy: the bound is what keeps a container whose command never answers from being held.
+func askBusy(ctx context.Context, r *declaration.Container, run Runner, cri string) (bool, string) {
+	ask, cancel := context.WithTimeout(ctx, r.Busy.Within())
+	defer cancel()
+	output, err := run(ask, cri, "exec", r.Name, "/bin/sh", "-c", r.Busy.Command)
+	said := strings.TrimSpace(output)
+	if err != nil && said == "" {
+		said = err.Error()
+	}
+	return err == nil, lastOf(said, busySaidMost)
+}
+
+// lastOf is the end of a text, at most n bytes, on one line.
+func lastOf(s string, n int) string {
+	s = strings.Join(strings.Fields(s), " ")
+	if len(s) <= n {
+		return s
+	}
+	from := len(s) - n
+	for from < len(s) && !utf8.RuneStart(s[from]) {
+		from++
+	}
+	return "…" + s[from:]
+}

internal/apply/busy_test.go

@@ -0,0 +1,433 @@
+package apply
+
+import (
+	"context"
+	"errors"
+	"path/filepath"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// A container that says it is busy is replaced once it is idle, within a bound (novox/hq ADR 0335). The
+// machine of these tests runs two containers, a build agent that declares `busy` and a web server that
+// does not; every call that replaces a container is counted.
+
+type aBusyMachine struct {
+	mu sync.Mutex
+	// containers is each container's name and the spec it was created with; running whether it runs.
+	containers map[string]string
+	busy       bool   // what the agent's busy command answers
+	said       string // what it prints
+	asked      int
+	calls      []string
+}
+
+func newBusyMachine() *aBusyMachine {
+	return &aBusyMachine{containers: map[string]string{}}
+}
+
+func (m *aBusyMachine) run(_ context.Context, _ string, args ...string) (string, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	switch args[0] {
+	case "info", "image":
+		return "27.0\n", nil
+	case "container": // inspect
+		name := args[len(args)-1]
+		spec, there := m.containers[name]
+		if !there {
+			return "", errors.New("no such container")
+		}
+		return "true\t" + spec, nil
+	case "exec":
+		m.asked++
+		m.calls = append(m.calls, "ask "+args[1])
+		if strings.Join(args[2:], " ") != "/bin/sh -c mesh-builder busy" {
+			return "", errors.New("asked something else: " + strings.Join(args[2:], " "))
+		}
+		if m.busy {
+			return m.said + "\n", nil
+		}
+		return m.said + "\n", errors.New("exited 1")
+	case "rm":
+		name := args[len(args)-1]
+		m.calls = append(m.calls, "rm "+name)
+		delete(m.containers, name)
+	case "run":
+		name := args[slices.Index(args, "--name")+1]
+		m.calls = append(m.calls, "create "+name)
+		for i, a := range args {
+			if a == "--label" && strings.HasPrefix(args[i+1], specLabel+"=") {
+				m.containers[name] = strings.TrimPrefix(args[i+1], specLabel+"=")
+			}
+		}
+	}
+	return "", nil
+}
+
+func (m *aBusyMachine) mark() int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return len(m.calls)
+}
+
+// since is every call since mark that replaced a container, or asked one.
+func (m *aBusyMachine) since(mark int) []string {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return append([]string(nil), m.calls[mark:]...)
+}
+
+func (m *aBusyMachine) answer(busy bool, said string) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.busy, m.said = busy, said
+}
+
+// twoContainers is the declaration at a version: v moves the agent's image tag through its env, w the web's.
+func twoContainers(t *testing.T, agent, web string) *declaration.Declaration {
+	t.Helper()
+	return parse(t, `{"declaration":1,"resources":[
+	  {"id":"build-agent.server","type":"container","name":"mesh-build-agent","image":"`+pinned+`",
+	   "env":{"V":"`+agent+`"},"busy":{"command":"mesh-builder busy","timeout":"5s"}},
+	  {"id":"web.server","type":"container","name":"web","image":"`+pinned+`","env":{"V":"`+web+`"}}
+	]}`)
+}
+
+// atClock moves the bound's clock for one test.
+func atClock(t *testing.T, at *time.Time) {
+	t.Helper()
+	was := busyClock
+	busyClock = func() time.Time { return *at }
+	t.Cleanup(func() { busyClock = was })
+}
+
+func busyOf(r Report, id string) (BusyWait, bool) {
+	for _, b := range r.Busy {
+		if b.ID == id {
+			return b, true
+		}
+	}
+	return BusyWait{}, false
+}
+
+func applyBusy(t *testing.T, m *aBusyMachine, d *declaration.Declaration, known store.State) (Report, store.State) {
+	t.Helper()
+	report, state, err := Apply(context.Background(), archHost(t), d, known, store.OriginDeclared, m.run, nil, nil)
+	if err != nil {
+		t.Fatalf("the apply failed: %v", err)
+	}
+	return report, state
+}
+
+// The decision's first check: an apply that would replace a container whose busy command exits 0 leaves it
+// running, applies the rest, and replaces it on the first pass the command exits non-zero.
+func TestABusyContainerIsLeftRunningAndReplacedOnTheFirstPassItSaysIdle(t *testing.T) {
+	now := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	atClock(t, &now)
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+
+	// A merge moves both: the agent holds a build, the web server holds nothing.
+	m.answer(true, "building novox/mesh-controller (check of #280) since 00:58")
+	mark := m.mark()
+	report, state := applyBusy(t, m, twoContainers(t, "2", "2"), state)
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm web", "create web"}) {
+		t.Fatalf("a busy agent was not left running while the rest applied: %v", got)
+	}
+	o := outcomeOf(report, "build-agent.server")
+	if o.Action != waitsBusy {
+		t.Fatalf("a busy container was reported %q, want %q: %+v", o.Action, waitsBusy, o)
+	}
+	for _, says := range []string{"busy", "first pass it says idle", "check of #280", "ADR 0335"} {
+		if !strings.Contains(o.Detail, says) {
+			t.Errorf("the outcome does not say %q: %s", says, o.Detail)
+		}
+	}
+	if (Report{Outcomes: []Outcome{o}}).Changed() {
+		t.Errorf("a container left running reads as a change: %+v", o)
+	}
+	b, said := busyOf(report, "build-agent.server")
+	if !said || b.State != BusyWaiting || !b.Since.Equal(now) || !b.Until.Equal(now.Add(15*time.Minute)) ||
+		b.Container != "mesh-build-agent" || !strings.Contains(b.Said, "check of #280") {
+		t.Fatalf("the report does not say the agent waits, since when and until when: %+v", report.Busy)
+	}
+	if !report.Waiting() {
+		t.Error("a report with a container waiting does not say so")
+	}
+	if rec, _ := state.Find("build-agent.server"); rec.BusySince == nil || !rec.BusySince.Equal(now) {
+		t.Fatalf("the wait is not kept in the container's record: %+v", rec)
+	}
+
+	// Asked again a minute later, still busy: still left running, the wait counted from the first apply.
+	now = now.Add(time.Minute)
+	mark = m.mark()
+	report, state = applyBusy(t, m, twoContainers(t, "2", "2"), state)
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent"}) {
+		t.Fatalf("a second pass while busy did more than ask: %v", got)
+	}
+	if b, _ := busyOf(report, "build-agent.server"); b.State != BusyWaiting || !b.Since.Equal(now.Add(-time.Minute)) {
+		t.Fatalf("the second pass does not keep the wait from the first apply: %+v", report.Busy)
+	}
+
+	// The build ends: the next pass replaces it, and says it waited.
+	now = now.Add(time.Minute)
+	m.answer(false, "idle")
+	mark = m.mark()
+	report, state = applyBusy(t, m, twoContainers(t, "2", "2"), state)
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm mesh-build-agent", "create mesh-build-agent"}) {
+		t.Fatalf("the agent was not replaced on the first pass it said idle: %v", got)
+	}
+	if o := outcomeOf(report, "build-agent.server"); o.Action != "updated" || !strings.Contains(o.Detail, "once it said idle") {
+		t.Errorf("the replacement does not say it waited: %+v", o)
+	}
+	if b, _ := busyOf(report, "build-agent.server"); b.State != BusyReplacedIdle {
+		t.Errorf("the report does not say the agent was replaced when idle: %+v", report.Busy)
+	}
+	if report.Waiting() {
+		t.Error("a report with nothing waiting says something waits")
+	}
+	if rec, _ := state.Find("build-agent.server"); rec.BusySince != nil {
+		t.Errorf("the wait is still kept after the replacement: %+v", rec)
+	}
+
+	// And the pass after that has nothing to say about it.
+	report, _ = applyBusy(t, m, twoContainers(t, "2", "2"), state)
+	if len(report.Busy) != 0 {
+		t.Errorf("a container replaced is still said: %+v", report.Busy)
+	}
+}
+
+// An idle container is replaced at once, as one that declares nothing is: asked once, nothing waits.
+func TestAnIdleContainerIsReplacedAtOnce(t *testing.T) {
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	m.answer(false, "")
+	mark := m.mark()
+	report, _ := applyBusy(t, m, twoContainers(t, "2", "1"), state)
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm mesh-build-agent", "create mesh-build-agent"}) {
+		t.Fatalf("an idle agent was not replaced at once: %v", got)
+	}
+	if len(report.Busy) != 0 {
+		t.Errorf("an idle container replaced at once is said as a wait: %+v", report.Busy)
+	}
+	// And a container whose declaration did not move is never asked.
+	mark = m.mark()
+	applyBusy(t, m, twoContainers(t, "2", "1"), state)
+	if got := m.since(mark); slices.Contains(got, "ask mesh-build-agent") {
+		t.Errorf("a container nothing replaces was asked: %v", got)
+	}
+}
+
+// Past the bound it is replaced anyway, the report carrying the command's last output — and the bound holds
+// across a restart of the node-engine: the wait is read back from the state on disk.
+func TestABusyContainerIsReplacedAtTheBoundEvenAfterARestart(t *testing.T) {
+	now := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	atClock(t, &now)
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	m.answer(true, "building novox/mesh-host (a check that never ends)")
+	_, state = applyBusy(t, m, twoContainers(t, "2", "1"), state)
+
+	// The node-engine stops and starts again: what it knows is what it saved.
+	path := filepath.Join(t.TempDir(), "state.json")
+	if err := store.Save(path, state); err != nil {
+		t.Fatal(err)
+	}
+	reloaded, err := store.Load(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	now = now.Add(14 * time.Minute)
+	mark := m.mark()
+	report, reloaded := applyBusy(t, m, twoContainers(t, "2", "1"), reloaded)
+	if got := m.since(mark); slices.Contains(got, "rm mesh-build-agent") {
+		t.Fatalf("a container busy within the bound was replaced after a restart: %v", got)
+	}
+	if b, _ := busyOf(report, "build-agent.server"); b.State != BusyWaiting || !b.Since.Equal(now.Add(-14*time.Minute)) {
+		t.Fatalf("a restart started the wait again: %+v", report.Busy)
+	}
+
+	now = now.Add(time.Minute)
+	mark = m.mark()
+	report, _ = applyBusy(t, m, twoContainers(t, "2", "1"), reloaded)
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm mesh-build-agent", "create mesh-build-agent"}) {
+		t.Fatalf("a container still busy at the bound was not replaced: %v", got)
+	}
+	b, _ := busyOf(report, "build-agent.server")
+	if b.State != BusyReplacedAtBound || !strings.Contains(b.Said, "never ends") {
+		t.Fatalf("the report does not say it replaced a busy container, with its last output: %+v", report.Busy)
+	}
+	if o := outcomeOf(report, "build-agent.server"); !strings.Contains(o.Detail, "still busy") ||
+		!strings.Contains(o.Detail, "never ends") {
+		t.Errorf("the outcome does not say a busy container was replaced, with what it said: %s", o.Detail)
+	}
+}
+
+// While one container waits, a send that changes another module on the same machine is applied at once: the
+// apply returns after one ask, and holds nothing for the wait.
+func TestASendToAnotherModuleIsAppliedWhileOneWaits(t *testing.T) {
+	now := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	atClock(t, &now)
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	m.answer(true, "building")
+	_, state = applyBusy(t, m, twoContainers(t, "2", "1"), state)
+
+	// The next send moves only the web server.
+	mark := m.mark()
+	done := make(chan struct{})
+	var report Report
+	go func() {
+		defer close(done)
+		report, _ = applyBusy(t, m, twoContainers(t, "2", "2"), state)
+	}()
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		t.Fatal("an apply while a container waits did not return")
+	}
+	got := m.since(mark)
+	if !slices.Contains(got, "create web") || slices.Contains(got, "rm mesh-build-agent") {
+		t.Fatalf("the other module's send was not applied at once beside the wait: %v", got)
+	}
+	if o := outcomeOf(report, "web.server"); o.Action != "updated" {
+		t.Errorf("the web server was reported %q: %+v", o.Action, o)
+	}
+}
+
+// A container's busy is held to its shape where it arrives.
+func TestBusyIsReadAndHeldToItsShape(t *testing.T) {
+	d := twoContainers(t, "1", "1")
+	c := d.Resources[0].(*declaration.Container)
+	if c.Busy == nil || c.Busy.Command != "mesh-builder busy" || c.Busy.Within() != 5*time.Second {
+		t.Fatalf("busy was not read: %+v", c.Busy)
+	}
+	for name, raw := range map[string]string{
+		"no command":     `"busy":{"command":" "}`,
+		"a long timeout": `"busy":{"command":"x","timeout":"5m"}`,
+		"not a duration": `"busy":{"command":"x","timeout":"soon"}`,
+		"an unknown key": `"busy":{"command":"x","every":"1m"}`,
+		"on a step":      `"run-once":true,"busy":{"command":"x"}`,
+	} {
+		_, err := declaration.Parse([]byte(`{"declaration":1,"resources":[{"id":"a.b","type":"container",` +
+			`"name":"b","image":"` + pinned + `",` + raw + `}]}`))
+		if err == nil {
+			t.Errorf("%s: a busy of that shape was accepted", name)
+		}
+	}
+}
+
+// A replacement owed to a restart-on trigger is still owed after the wait: a trigger that is no file or
+// directory (a service, an identity's or a library's change) is in no container's spec and counts as changed only
+// in the pass it changed, so the container must not read unchanged at the next pass and drop from the report as if
+// replaced (novox/hq ADR 0335).
+func TestAReplacementOwedToARestartTriggerIsMadeOnceIdle(t *testing.T) {
+	now := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	atClock(t, &now)
+	d := parse(t, `{"declaration":1,"resources":[
+	  {"id":"build-agent.server","type":"container","name":"mesh-build-agent","image":"`+pinned+`",
+	   "restart-on":["identity:build-agent"],"busy":{"command":"mesh-builder busy"}}
+	]}`)
+	r := d.Resources[0].(*declaration.Container)
+	in := inputs{declares: map[string]string{}}
+	m := newBusyMachine()
+	m.containers["mesh-build-agent"] = containerSpec(r, in)
+	ctx := context.Background()
+
+	// The trigger moved this pass, and the agent holds a build: left running.
+	m.answer(true, "building")
+	out, err := applyContainer(ctx, r, m.run, map[string]bool{"identity:build-agent": true}, in, store.Applied{})
+	if err != nil || out.Action != waitsBusy || out.busySince == nil {
+		t.Fatalf("a busy container was not left running for its trigger: %+v %v", out, err)
+	}
+	record := store.Applied{ID: r.ID, Target: r.Name, BusySince: out.busySince}
+
+	// The next pass: nothing triggers now, and the replacement is still owed.
+	now = now.Add(time.Minute)
+	m.answer(false, "idle")
+	mark := m.mark()
+	out, err = applyContainer(ctx, r, m.run, map[string]bool{}, in, record)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm mesh-build-agent", "create mesh-build-agent"}) {
+		t.Fatalf("the replacement owed to the trigger was dropped: %v (%+v)", got, out)
+	}
+	if out.busy == nil || out.busy.State != BusyReplacedIdle || out.busySince != nil {
+		t.Fatalf("the replacement does not say it was made once idle: %+v", out)
+	}
+}
+
+// A wait kept from a clock that later went back is never longer than the bound from now.
+func TestAWaitFromAClockThatWentBackIsClampedToNow(t *testing.T) {
+	now := time.Date(2026, 10, 13, 1, 0, 0, 0, time.UTC)
+	atClock(t, &now)
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	m.answer(true, "building")
+	_, state = applyBusy(t, m, twoContainers(t, "2", "1"), state)
+	now = now.Add(-time.Hour) // the clock went back an hour
+	report, _ := applyBusy(t, m, twoContainers(t, "2", "1"), state)
+	b, _ := busyOf(report, "build-agent.server")
+	if b.State != BusyWaiting || b.Since.After(now) || !b.Until.Equal(now.Add(15*time.Minute)) {
+		t.Fatalf("a wait from a later clock is not clamped to now: %+v (now %s)", b, now)
+	}
+}
+
+// An ask that fails — no shell in the image, a timeout, a paused container — is not busy: replaced at once.
+func TestAnAskThatFailsIsIdle(t *testing.T) {
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	failing := func(ctx context.Context, name string, args ...string) (string, error) {
+		if args[0] == "exec" {
+			m.mu.Lock()
+			m.calls = append(m.calls, "ask "+args[1])
+			m.mu.Unlock()
+			return "", errors.New("OCI runtime exec failed: exec: \"/bin/sh\": no such file or directory")
+		}
+		return m.run(ctx, name, args...)
+	}
+	mark := m.mark()
+	report, _, err := Apply(context.Background(), archHost(t), twoContainers(t, "2", "1"), state,
+		store.OriginDeclared, failing, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := m.since(mark); !slices.Equal(got, []string{"ask mesh-build-agent", "rm mesh-build-agent", "create mesh-build-agent"}) {
+		t.Fatalf("an ask that failed held the container: %v", got)
+	}
+	if len(report.Busy) != 0 {
+		t.Errorf("an ask that failed is said as a wait: %+v", report.Busy)
+	}
+}
+
+// A stopped container holds no work: it is replaced without being asked.
+func TestAStoppedContainerIsNotAsked(t *testing.T) {
+	m := newBusyMachine()
+	_, state := applyBusy(t, m, twoContainers(t, "1", "1"), store.State{})
+	m.answer(true, "would say busy")
+	stopped := func(ctx context.Context, name string, args ...string) (string, error) {
+		if args[0] == "container" && args[len(args)-1] == "mesh-build-agent" {
+			out, err := m.run(ctx, name, args...)
+			return strings.Replace(out, "true\t", "false\t", 1), err
+		}
+		return m.run(ctx, name, args...)
+	}
+	mark := m.mark()
+	if _, _, err := Apply(context.Background(), archHost(t), twoContainers(t, "2", "1"), state,
+		store.OriginDeclared, stopped, nil, nil); err != nil && !strings.Contains(err.Error(), "not running") {
+		t.Fatal(err)
+	}
+	got := m.since(mark)
+	if slices.Contains(got, "ask mesh-build-agent") || !slices.Contains(got, "rm mesh-build-agent") {
+		t.Fatalf("a stopped container was asked, or not replaced: %v", got)
+	}
+}

internal/apply/filled.go

@@ -0,0 +1,206 @@
+package apply
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/store"
+	"github.com/novox/mesh-host/internal/system"
+)
+
+// WriteFilled writes what the provisioner's client filled into one file the declaration names as filled (novox/hq
+// ADR 0349 §4), and makes what reads the file take the change, exactly as an apply that changed it would.
+//
+// **The declared file says everything but the content.** Its path, mode, owner and who owns it at runtime are the
+// declaration's; the client's request carries the content alone. So the file is applied as the declared one with
+// that content in place of the declaration's: an owned file whole through applyFile, a seed only when absent, a
+// managed file's keys through applyInto or its block through applyBlock — the same guards on where nothing is
+// placed, the same Keep of an original found there, the same record. What the declaration seals or fills with
+// `${secret:}` the client has already filled, so the content is written as it came; a file that carried a secret
+// keeps the mode a secret is written with when the declaration gives none.
+//
+// **Then what reads it, in the apply's order** (afterWhatTheyRead): a service naming it under restart-on is
+// restarted and under reload-on reloaded, a process or container naming it under restart-on is restarted, and a
+// running container that reads it at creation — an env-file, a file mounted into it — is recreated, because what
+// it read is recorded by digest and this write changed the digest. Each of those is applied and recorded as an
+// apply does, and what moves goes on moving what names it. Nothing else of the declaration is touched.
+//
+// The caller holds the apply's lock: a write and an apply never write one file at once. log is said the path, the
+// action and the digest, never the content.
+func WriteFilled(
+	ctx context.Context,
+	sys system.System,
+	d *declaration.Declaration,
+	known store.State,
+	path string,
+	content []byte,
+	run Runner,
+	log func(string),
+	keep Keep,
+	windows *Windows,
+) (report Report, _ store.State, _ error) {
+	if log == nil {
+		log = func(string) {}
+	}
+	if !d.Fills(path) {
+		return report, known, &Error{Resource: path, Err: fmt.Errorf("this node's declaration does not name %s "+
+			"as a file the provisioner fills, so nothing was written", path)}
+	}
+	var declared []*declaration.File
+	for _, r := range d.Resources {
+		if f, ok := r.(*declaration.File); ok && f.Path == path {
+			declared = append(declared, f)
+		}
+	}
+	if len(declared) != 1 {
+		// The parser refuses a filled path no file declares; two at one path would need the request to say whose
+		// keys or block it carries, and it carries the content only.
+		return report, known, &Error{Resource: path, Err: fmt.Errorf("%d resources declare %s, and a filled file "+
+			"is written for exactly one, so nothing was written", len(declared), path)}
+	}
+	file := filledAs(declared[0], content)
+	if held, isHeld := known.HeldAt(file.ID); isHeld {
+		return report, known, &Error{Resource: file.ID, Err: fmt.Errorf("%s is held as found for a module not "+
+			"yet taken (%s), so nothing was written", path, held.Why)}
+	}
+
+	in := inputs{declares: map[string]string{}, known: &known, windows: windows, away: newStoreAway(windows, log),
+		groups: groupsWanted(d.Resources), handed: Handed{}}
+	refreshRuntimeRoots(ctx)
+	in.refused = refusedPlaces(d.Resources)
+	in.agentHomes = rootNeverHomes(d)
+	in.dirsBefore = map[string]bool{}
+	// A container that reads the file and mounts a library whose disk or mount is not there is held, as a full apply
+	// holds it: not created over the missing disk (novox/hq ADR 0328 §9).
+	in.held = heldLibraries(ctx, d.Libraries)
+	for _, r := range d.Resources {
+		in.declares[r.Identity()] = declaredDigest(r)
+	}
+	changed := map[string]bool{}
+
+	// The file, as the apply loop applies it.
+	was, _ := known.Find(file.ID)
+	var keepFound Keep
+	if (was.ID == "" || was.Target != file.Path) && !known.Recorded(string(declaration.TypeFile), file.Path) {
+		keepFound = keep
+	}
+	outcome, err := applyOne(ctx, sys, file, run, changed, in, was, nil, keepFound)
+	if err != nil {
+		log(fmt.Sprintf("  failed %s (%s): %v", file.ID, file.Path, err))
+		return report, known, &Error{Resource: file.ID, Err: err, Done: report}
+	}
+	recordKeeping(&known, file, outcome, was)
+	report.Outcomes = append(report.Outcomes, outcome)
+	if !moved(outcome) {
+		return report, known, nil
+	}
+	changed[file.ID] = true
+	line := fmt.Sprintf("  %s %s (%s), filled: %s", outcome.Action, file.ID, file.Path, outcome.wrote)
+	if outcome.Detail != "" {
+		line += ": " + outcome.Detail
+	}
+	log(line)
+
+	// What reads it, in the apply's order, each moving what names it in turn.
+	var failures []*Error
+	for _, r := range afterWhatTheyRead(d.Resources) {
+		if r.Identity() == file.ID || !readsChange(r, path, changed) {
+			continue
+		}
+		if _, isHeld := known.HeldAt(r.Identity()); isHeld {
+			log(fmt.Sprintf("  held %s (%s): held as found for a module not yet taken, so it was not restarted "+
+				"for %s", r.Identity(), r.Target(), file.ID))
+			continue
+		}
+		was, _ := known.Find(r.Identity())
+		o, err := applyOne(ctx, sys, r, run, changed, in, was, nil, nil)
+		if err != nil {
+			if o.found != nil {
+				known.KeepFound(r.Identity(), store.OriginDeclared, *o.found)
+			}
+			failures = append(failures, &Error{Resource: r.Identity(), Err: err})
+			log(fmt.Sprintf("  failed %s (%s): %v", r.Identity(), o.Target, err))
+			continue
+		}
+		if o.Action == "waiting" {
+			if o.found != nil {
+				known.KeepFound(r.Identity(), store.OriginDeclared, *o.found)
+			}
+			report.Outcomes = append(report.Outcomes, o)
+			log(fmt.Sprintf("  waiting %s (%s): %s", o.ID, o.Target, o.Detail))
+			continue
+		}
+		recordKeeping(&known, r, o, was)
+		report.Outcomes = append(report.Outcomes, o)
+		if o.busy != nil {
+			report.Busy = append(report.Busy, *o.busy)
+		}
+		if moved(o) {
+			changed[r.Identity()] = true
+			line := fmt.Sprintf("  %s %s (%s)", o.Action, o.ID, o.Target)
+			if o.Detail != "" {
+				line += ": " + o.Detail
+			}
+			log(line)
+		} else if o.Action != "unchanged" {
+			log(fmt.Sprintf("  %s %s (%s): %s", o.Action, o.ID, o.Target, o.Detail))
+		}
+	}
+	if len(failures) > 0 {
+		first := failures[0]
+		first.Done = report
+		first.Others = len(failures) - 1
+		return report, known, first
+	}
+	return report, known, nil
+}
+
+// filledAs is the declared file with the filled content in place of the declaration's.
+func filledAs(declared *declaration.File, content []byte) *declaration.File {
+	f := *declared
+	f.Content, f.Sealed, f.Bytes, f.Secrets = string(content), "", "", nil
+	if f.Mode == "" && (declared.Secret() || len(declared.Secrets) > 0) {
+		// Written as the declaration would have written it: a file carrying a credential is not world-readable.
+		f.Mode = "0600"
+	}
+	return &f
+}
+
+// readsChange reports whether applying r is what makes it take a change of what changed: a service's restart-on or
+// reload-on, a process's or container's restart-on, or a running container that reads path at creation.
+func readsChange(r declaration.Resource, path string, changed map[string]bool) bool {
+	switch res := r.(type) {
+	case *declaration.Service:
+		return len(restartedBy(res.RestartOn, changed)) > 0 || len(restartedBy(res.ReloadOn, changed)) > 0
+	case *declaration.Process:
+		return len(restartedBy(res.RestartOn, changed)) > 0
+	case *declaration.Container:
+		if len(restartedBy(res.RestartOn, changed)) > 0 {
+			return true
+		}
+		if res.RunOnce || res.Schedule != "" {
+			return false
+		}
+		if slices.Contains(res.EnvFile, path) {
+			return true
+		}
+		for _, v := range res.Volumes {
+			if mountSource(v) == path {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// recordKeeping records r as applied, carrying where the original it replaced was kept from its record when this
+// write kept none — for as long as the resource is recorded at the same target, as the apply loop carries it.
+func recordKeeping(known *store.State, r declaration.Resource, o Outcome, was store.Applied) {
+	kept, keptMode, keptOwner := o.kept, o.keptMode, o.keptOwner
+	if kept == "" && was.Target == o.Target {
+		kept, keptMode, keptOwner = was.Kept, was.KeptMode, was.KeptOwner
+	}
+	recordApplied(known, store.OriginDeclared, r, o, kept, keptMode, keptOwner)
+}

internal/apply/filled_library_test.go

@@ -0,0 +1,57 @@
+//go:build linux
+
+package apply
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// A container that reads a filled file and mounts a library whose disk is not there is held by the write verb as a
+// full apply holds it (novox/hq ADR 0328 §9, issue 668): never created or recreated over the missing disk.
+func TestAWriteDoesNotRecreateAContainerHeldForItsLibrary(t *testing.T) {
+	// No folder is given the group: the library's root is absent, and nothing is made.
+	gid := 61000
+	libraries(t, nil, nil)
+	base := t.TempDir()
+	root := filepath.Join(base, "gone", "media")
+	env := filepath.Join(base, "radarr.env")
+	raw := fmt.Sprintf(`{"declaration":1,"provisioner_account":"mesh-node-provisioner","filled_files":[%q],
+	  "groups":[{"name":"mesh-media","gid":%d}],"libraries":[%s],"resources":[
+	  {"id":"radarr.env","type":"file","path":%q,"content":"","mode":"0600","owner-at-runtime":"owned"},
+	  {"id":"radarr.app","type":"container","name":"radarr","image":%q,"env-file":[%q],"volumes":[%q]}]}`,
+		env, gid, libJSON("media", root, gid, true, false, "movies"), env, pinned, env,
+		filepath.Join(root, "movies")+":/movies")
+	d, err := declaration.Parse([]byte(raw))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var ran []string
+	run := func(_ context.Context, name string, args ...string) (string, error) {
+		ran = append(ran, name+" "+strings.Join(args, " "))
+		return "", nil
+	}
+	var state store.State
+	for _, content := range []string{"PORT=1\n", "PORT=2\n"} {
+		var report Report
+		report, state, err = WriteFilled(context.Background(), archHost(t), d, state, env, []byte(content), run,
+			nil, nil, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if o := outcomeOf(report, "radarr.app"); o.Action != "waiting" {
+			t.Errorf("after writing %q the container is %+v, not held for its library", content, o)
+		}
+	}
+	for _, line := range ran {
+		if strings.HasPrefix(line, "docker run") || strings.HasPrefix(line, "docker rm") {
+			t.Errorf("the container was created or removed over a missing disk: %v", ran)
+		}
+	}
+}

internal/apply/filled_test.go

@@ -0,0 +1,268 @@
+package apply
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// Defends novox/hq ADR 0349 §4 (issue 668): the provisioner's client has the node-engine write a file it filled,
+// and the node-engine writes it as an apply of the declared file with that content would — through applyFile,
+// applyInto or applyBlock by who owns it at runtime — and makes what reads it take the change as an apply does.
+
+// filledDecl is a declaration naming path as filled, with the file's fields after id, type and path, and more
+// resources after it.
+func filledDecl(t *testing.T, path, fields, more string) *declaration.Declaration {
+	t.Helper()
+	if more != "" {
+		more = "," + more
+	}
+	return parseTrusted(t, fmt.Sprintf(`{"declaration":1,"provisioner_account":"mesh-node-provisioner",
+	  "filled_files":[%q],"resources":[{"id":"m.conf","type":"file","path":%q,%s}%s]}`, path, path, fields, more))
+}
+
+func TestAWriteOfAPathNotFilledIsRefused(t *testing.T) {
+	dir := t.TempDir()
+	filled := filepath.Join(dir, "filled.conf")
+	other := filepath.Join(dir, "other.conf")
+	d := parseTrusted(t, fmt.Sprintf(`{"declaration":1,"filled_files":[%q],"resources":[
+	  {"id":"m.conf","type":"file","path":%q,"content":"x\n","owner-at-runtime":"owned"},
+	  {"id":"m.other","type":"file","path":%q,"content":"y\n"}
+	]}`, filled, filled, other))
+	for _, path := range []string{other, filepath.Join(dir, "nothing.conf")} {
+		_, state, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, path, []byte("evil\n"),
+			noServices, nil, nil, nil)
+		if err == nil || !strings.Contains(err.Error(), "does not name") {
+			t.Errorf("%s: a write of a path the declaration does not fill was not refused: %v", path, err)
+		}
+		if _, err := os.Stat(path); err == nil && path != other {
+			t.Errorf("%s was written", path)
+		}
+		if len(state.Resources) != 0 {
+			t.Errorf("a refused write recorded something: %+v", state.Resources)
+		}
+	}
+	if _, err := os.Stat(other); err == nil {
+		t.Errorf("%s was written", other)
+	}
+}
+
+// Each ownership is written by the write verb exactly as an apply of the declared file with the same content: the
+// same action, the same bytes on disk, the same mode.
+func TestAFilledFileIsWrittenAsItsOwnershipSays(t *testing.T) {
+	for _, c := range []struct {
+		name, fields, content, before, action string
+	}{
+		{"owned, absent", `"content":"","mode":"0640","owner-at-runtime":"owned"`, "port = 8080\n", "", "created"},
+		{"owned, over what is there", `"content":"","mode":"0640","owner-at-runtime":"owned"`, "port = 8080\n",
+			"port = 1\n", "updated"},
+		{"seed, absent", `"content":"","mode":"0600","owner-at-runtime":"seed"`, "user default on\n", "", "created"},
+		{"seed, present", `"content":"","mode":"0600","owner-at-runtime":"seed"`, "user default on\n",
+			"user default on\nuser app-one on\n", "kept"},
+		{"managed json", `"into":"json","content":"{}","owner-at-runtime":"managed"`,
+			`{"insecure-registries":["10.42.0.1:5000"]}`, machinesOwn, "updated"},
+		{"managed block", `"into":"block","content":"x\n","owner-at-runtime":"managed"`, "10.42.0.1 ace\n",
+			workstationHosts, "updated"},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			at := func() string {
+				path := filepath.Join(t.TempDir(), "the-file")
+				if c.before != "" {
+					if err := os.WriteFile(path, []byte(c.before), 0o644); err != nil {
+						t.Fatal(err)
+					}
+				}
+				return path
+			}
+			written := at()
+			report, state, err := WriteFilled(context.Background(), archHost(t), filledDecl(t, written, c.fields, ""),
+				store.State{}, written, []byte(c.content), noServices, nil, nil, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			applied := at()
+			withContent := strings.Replace(c.fields, fmt.Sprintf(`"content":%q`, contentOf(t, c.fields)),
+				fmt.Sprintf(`"content":%q`, c.content), 1)
+			want, _, err := Apply(context.Background(), archHost(t), filledDecl(t, applied, withContent, ""),
+				store.State{}, store.OriginDeclared, noServices, nil, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got := report.Outcomes[0].Action; got != c.action || got != want.Outcomes[0].Action {
+				t.Errorf("written %s; an apply of the same content %s; want %s", got, want.Outcomes[0].Action, c.action)
+			}
+			if got, apply := readText(t, written), readText(t, applied); got != apply {
+				t.Errorf("written, the file holds\n%q\nan apply of the same content leaves\n%q", got, apply)
+			}
+			if a, b := modeAt(t, written), modeAt(t, applied); a != b {
+				t.Errorf("written mode %o, an apply's %o", a, b)
+			}
+			if rec, ok := state.Find("m.conf"); !ok || rec.Target != written || rec.Origin != store.OriginDeclared {
+				t.Errorf("the write is not recorded as the file's: %+v", rec)
+			}
+		})
+	}
+}
+
+func contentOf(t *testing.T, fields string) string {
+	t.Helper()
+	var holder struct {
+		Content string `json:"content"`
+	}
+	if err := json.Unmarshal([]byte("{"+fields+"}"), &holder); err != nil {
+		t.Fatal(err)
+	}
+	return holder.Content
+}
+
+func modeAt(t *testing.T, path string) os.FileMode {
+	t.Helper()
+	info, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return info.Mode().Perm()
+}
+
+// A file that carried a secret keeps the mode a secret is written with: the client filled the value, and the file
+// is no more readable for it.
+func TestAFilledFileThatCarriedASecretIsNotWorldReadable(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "token.env")
+	d := filledDecl(t, path, `"content":"TOKEN=${secret:token}\n","secrets":{"token":"c2VhbGVk"},"owner-at-runtime":"owned"`, "")
+	if _, _, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, path, []byte("TOKEN=abc\n"),
+		noServices, nil, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	if m := modeAt(t, path); m != 0o600 {
+		t.Errorf("a filled file that carried a secret is mode %o", m)
+	}
+}
+
+func TestAWriteUnderReloadOnReloadsItsProgramOnce(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "daemon.conf")
+	d := filledDecl(t, path, `"content":"","owner-at-runtime":"owned"`,
+		`{"id":"m.daemon","type":"service","unit":"m.service","state":"running","reload-on":["m.conf"]},
+		 {"id":"m.other","type":"service","unit":"other.service","state":"running"}`)
+	var commands []string
+	var said []string
+	_, state, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, path, []byte("level = 1\n"),
+		recordingServices(&commands), func(line string) { said = append(said, line) }, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n := count(commands, "systemctl reload m.service"); n != 1 {
+		t.Errorf("the program was reloaded %d times; commands were %v", n, commands)
+	}
+	joined := strings.Join(commands, "\n")
+	if strings.Contains(joined, "restart m.service") || strings.Contains(joined, "stop m.service") {
+		t.Errorf("the program was restarted, not reloaded: %v", commands)
+	}
+	if strings.Contains(joined, "other.service") {
+		t.Errorf("a service that does not read the file was touched: %v", commands)
+	}
+	if _, ok := state.Find("m.daemon"); !ok {
+		t.Errorf("the reloaded service was not recorded")
+	}
+	// The log says the path and the digest, never the content.
+	for _, line := range said {
+		if strings.Contains(line, "level = 1") {
+			t.Errorf("the content was said: %q", line)
+		}
+	}
+	if !strings.Contains(strings.Join(said, "\n"), digestOf("level = 1\n")) {
+		t.Errorf("the digest was not said: %q", said)
+	}
+
+	// The same content again moves nothing, and reloads nothing.
+	commands = nil
+	report, _, err := WriteFilled(context.Background(), archHost(t), d, state, path, []byte("level = 1\n"),
+		recordingServices(&commands), nil, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if report.Outcomes[0].Action != "unchanged" || count(commands, "reload") != 0 {
+		t.Errorf("an unchanged write reloaded: %v %+v", commands, report.Outcomes)
+	}
+}
+
+func TestAWriteUnderRestartOnRestartsItsProgram(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "daemon.conf")
+	d := filledDecl(t, path, `"content":"","owner-at-runtime":"owned"`,
+		`{"id":"m.daemon","type":"service","unit":"m.service","state":"running","restart-on":["m.conf"]}`)
+	var commands []string
+	if _, _, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, path, []byte("level = 1\n"),
+		recordingServices(&commands), nil, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	// A restart is a stop and a start, once.
+	stops, starts := count(commands, "systemctl stop m.service"), count(commands, "systemctl start m.service")
+	if stops != 1 || starts != 1 {
+		t.Errorf("the program was stopped %d and started %d times; commands were %v", stops, starts, commands)
+	}
+}
+
+// A running container that reads the file at creation is recreated, as an apply recreates it for a changed file.
+func TestAWriteOfAFileAContainerReadsRecreatesIt(t *testing.T) {
+	env := filepath.Join(t.TempDir(), "forge.env")
+	d := filledDecl(t, env, `"content":"","mode":"0600","owner-at-runtime":"owned"`,
+		`{"id":"forge.server","type":"container","name":"forge","image":"`+pinned+`","env-file":["`+env+`"]}`)
+	m := &machine{containers: map[string]*fakeContainer{}}
+	_, state, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, env, []byte("PORT=5432\n"),
+		m.run, nil, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !m.did("docker run") {
+		t.Fatalf("the container was not created: %v", m.asked)
+	}
+	m.asked = nil
+	report, _, err := WriteFilled(context.Background(), archHost(t), d, state, env, []byte("PORT=5433\n"), m.run,
+		nil, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !m.removed("forge") || !m.did("docker run") {
+		t.Fatalf("the container kept what it read before the write: %v", m.asked)
+	}
+	if o := outcomeOf(report, "forge.server"); o.Action != "updated" || !strings.Contains(o.Detail, env) {
+		t.Errorf("the recreate did not say which file changed: %+v", o)
+	}
+}
+
+func count(lines []string, prefix string) int {
+	n := 0
+	for _, l := range lines {
+		if strings.Contains(l, prefix) {
+			n++
+		}
+	}
+	return n
+}
+
+// Two resources declaring one filled path — two modules' blocks in one file — are refused: the request carries the
+// content only, so it cannot say whose block it is, and nothing is written.
+func TestAFilledPathTwoResourcesDeclareIsRefused(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "hosts")
+	if err := os.WriteFile(path, []byte(workstationHosts), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	d := parseTrusted(t, fmt.Sprintf(`{"declaration":1,"filled_files":[%q],"resources":[
+	  {"id":"a.hosts","type":"file","path":%q,"into":"block","content":"10.42.0.1 ace\n","owner-at-runtime":"managed"},
+	  {"id":"b.hosts","type":"file","path":%q,"into":"block","content":"10.42.0.2 g14\n","owner-at-runtime":"managed"}
+	]}`, path, path, path))
+	_, state, err := WriteFilled(context.Background(), archHost(t), d, store.State{}, path, []byte("6.6.6.6 evil\n"),
+		noServices, nil, nil, nil)
+	if err == nil || !strings.Contains(err.Error(), "2 resources declare") {
+		t.Fatalf("a path two resources declare was not refused: %v", err)
+	}
+	if got := readText(t, path); got != workstationHosts || len(state.Resources) != 0 {
+		t.Errorf("something was written or recorded: %q %+v", got, state.Resources)
+	}
+}

internal/apply/library.go

@@ -318,6 +318,17 @@ func heldRoots(verdicts map[string]libraryVerdict, libs []declaration.Library) m
 	return out
 }
 
+// heldLibraries is the root of every library whose disk or mount is not there, with its name, judged now and read
+// only: what a full apply holds its containers for (ADR 0328 §9), for one that judges without applying libraries.
+func heldLibraries(ctx context.Context, libs []declaration.Library) map[string]string {
+	verdicts := map[string]libraryVerdict{}
+	for _, l := range libs {
+		rec, _ := libraryRecord(l.Library)
+		verdicts[l.Library] = assessLibrary(ctx, l, rec)
+	}
+	return heldRoots(verdicts, libs)
+}
+
 // mountsHeld is the library a container waits for: one whose root it mounts, or mounts below, is held.
 func mountsHeld(c *declaration.Container, held map[string]string) string {
 	for _, v := range c.Volumes {
@@ -341,12 +352,7 @@ func WaitingOnLibrary(d *declaration.Declaration) map[string]bool {
 	if d == nil || len(d.Libraries) == 0 {
 		return out
 	}
-	verdicts := map[string]libraryVerdict{}
-	for _, l := range d.Libraries {
-		rec, _ := libraryRecord(l.Library)
-		verdicts[l.Library] = assessLibrary(context.Background(), l, rec)
-	}
-	held := heldRoots(verdicts, d.Libraries)
+	held := heldLibraries(context.Background(), d.Libraries)
 	for _, r := range d.Resources {
 		if c, ok := r.(*declaration.Container); ok && mountsHeld(c, held) != "" {
 			out[c.ID] = true

internal/apply/ownership_test.go

@@ -0,0 +1,129 @@
+package apply
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/novox/mesh-host/internal/store"
+)
+
+// Defends novox/hq ADR 0349 §5 (issue 667): a file that says who owns it at runtime is written as the
+// form it names always was — owned as a whole file whose drift is written back, seed as create-once,
+// managed as only its keys or its marked block. Each is applied beside its old form, through the same
+// drift, and the two must end the same: the same actions, the same bytes on disk.
+
+// ownershipCase is one ownership word and the old form it maps onto.
+type ownershipCase struct {
+	name string
+	// said and old are the resource's fields after id, type and path: with the word, and in the old form.
+	said, old string
+	// before is what is at the path before the first apply; "" leaves the path absent.
+	before string
+	// drift is what the machine writes there between the two applies.
+	drift string
+	// first and second are the actions the old form is known to report.
+	first, second string
+}
+
+func TestEachOwnershipBehavesAsItsOldForm(t *testing.T) {
+	for _, c := range []ownershipCase{
+		{
+			name:  "owned is a whole file whose drift is written back",
+			said:  `"content":"correct\n","mode":"0644","owner-at-runtime":"owned"`,
+			old:   `"content":"correct\n","mode":"0644"`,
+			drift: "someone edited this\n",
+			first: "created", second: "corrected",
+		},
+		{
+			name:  "seed is written once and then the program's",
+			said:  `"content":"user default on\n","mode":"0600","owner-at-runtime":"seed"`,
+			old:   `"content":"user default on\n","mode":"0600","create-once":true`,
+			drift: "user default on\nuser app-one on\n",
+			first: "created", second: "kept",
+		},
+		{
+			name:   "managed json sets only its keys",
+			said:   `"into":"json","content":"{\"insecure-registries\":[\"10.42.0.1:5000\"]}","owner-at-runtime":"managed"`,
+			old:    `"into":"json","content":"{\"insecure-registries\":[\"10.42.0.1:5000\"]}"`,
+			before: machinesOwn,
+			drift:  `{"data-root":"/srv/other","log-opts":{"max-size":"10m"},"insecure-registries":["192.0.2.7:5000"]}`,
+			first:  "updated", second: "corrected",
+		},
+		{
+			name:   "managed block holds only its region",
+			said:   `"into":"block","content":"10.42.0.1 ace\n","owner-at-runtime":"managed"`,
+			old:    `"into":"block","content":"10.42.0.1 ace\n"`,
+			before: workstationHosts,
+			drift:  workstationHosts + "\n" + marked("f", "6.6.6.6 evil\n") + "192.0.2.9 the-machines-own\n",
+			first:  "updated", second: "corrected",
+		},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			saidActions, saidBytes := applyThroughDrift(t, c, c.said)
+			oldActions, oldBytes := applyThroughDrift(t, c, c.old)
+			if saidActions != oldActions {
+				t.Errorf("with the word the actions were %s; the old form's were %s", saidActions, oldActions)
+			}
+			if want := c.first + " " + c.second; oldActions != want {
+				t.Errorf("the old form's actions were %s; known to be %s", oldActions, want)
+			}
+			if saidBytes != oldBytes {
+				t.Errorf("with the word the file ends\n%q\nthe old form's ends\n%q", saidBytes, oldBytes)
+			}
+		})
+	}
+}
+
+// applyThroughDrift applies one file, lets the machine write the case's drift into it, applies again,
+// and says the two actions and what the file holds at the end.
+func applyThroughDrift(t *testing.T, c ownershipCase, fields string) (string, string) {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "the-file")
+	if c.before != "" {
+		if err := os.WriteFile(path, []byte(c.before), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	d := parse(t, fmt.Sprintf(`{"declaration":1,"resources":[{"id":"f","type":"file","path":%q,%s}]}`, path, fields))
+	first, state, err := Apply(context.Background(), archHost(t), d, store.State{}, store.OriginDeclared, noServices, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(path, []byte(c.drift), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	second, _, err := Apply(context.Background(), archHost(t), d, state, store.OriginDeclared, noServices, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return first.Outcomes[0].Action + " " + second.Outcomes[0].Action, readText(t, path)
+}
+
+// A seed said by the word alone, with no create-once beside it, is still kept once present: the word is
+// enough, and the file the program grew is not written back.
+func TestASeedByTheWordAloneKeepsWhatGrew(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "acl.conf")
+	d := parse(t, fmt.Sprintf(`{"declaration":1,"resources":[
+	  {"id":"acl","type":"file","path":%q,"content":"user default on\n","owner-at-runtime":"seed"}
+	]}`, path))
+	_, state, err := Apply(context.Background(), archHost(t), d, store.State{}, store.OriginDeclared, noServices, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(path, []byte("grown\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	report, _, err := Apply(context.Background(), archHost(t), d, state, store.OriginDeclared, noServices, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := report.Outcomes[0].Action; got != "kept" {
+		t.Errorf("a seed was %q", got)
+	}
+	if got := readText(t, path); got != "grown\n" {
+		t.Errorf("what grew in the seed was written over: %q", got)
+	}
+}

internal/bootstrap/bootstrap.go

@@ -174,6 +174,10 @@ type Options struct {
 	// ToolsSource is where the shared base is built from. Everything with code of its own
 	// compiles against it, so it is the first thing the mesh builds for itself.
 	ToolsSource Source
+	// ToolsGoSource is where the Go toolchain is built from (`mesh-tools-go`, ADR 0142): every Go
+	// bundle compiles in it, and genesis's own modules have Go code (issue 616). Empty means the
+	// repository beside ToolsSource named mesh-tools-go, as the mesh keeps it.
+	ToolsGoSource Source
 	// CatalogSource is where the catalogue REPOSITORY is, for building its modules. The catalogue
 	// CHECKOUT (Catalogue, above) says what a module is; this is where a builder clones it.
 	CatalogSource Source

internal/bootstrap/builder_test.go

@@ -38,27 +38,6 @@ func recording(t *testing.T) (*controlRecorder, controlPlane) {
 	return c, controlPlane{container: "temp-mesh-controller", run: c.run, timeout: time.Second}
 }
 
-func TestTheBuildersPackageRegistryPortIsASettingAndNotTheManifest(t *testing.T) {
-	c, control := recording(t)
-	o := Options{Node: "anchor", Ports: FoundationPorts{Packages: 3100}, Wait: time.Second}
-	if _, err := installModule(context.Background(), o, control, BuilderModule,
-		[]byte(theBuildersBinding), quietly); err != nil {
-		t.Fatal(err)
-	}
-	if got := c.settings[BuilderModule+"-settings.json"]; got != `{"serves":{"port":3100}}` {
-		t.Errorf("the builder was told %q about the package registry's port", got)
-	}
-	// The manifest reaches the mesh as the catalogue wrote it. A port rewritten into it here is a
-	// port the next registration from the catalogue silently takes back.
-	if got := c.settings[BuilderModule+"-module.json"]; got != theBuildersBinding {
-		t.Errorf("the installer changed the builder's manifest:\n%s", got)
-	}
-	set, push := c.index("settings set "+BuilderModule), c.index("push anchor")
-	if set < 0 || push < 0 || set > push {
-		t.Fatalf("the port was not set before the push that raises the builder: %v", c.told)
-	}
-}
-
 func TestTheBuilderOnTheDefaultPackagesPortIsToldNothing(t *testing.T) {
 	c, control := recording(t)
 	o := Options{Node: "anchor", Wait: time.Second}

internal/bootstrap/bus_adoption.go

@@ -0,0 +1,179 @@
+package bootstrap
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/novox/mesh-host/internal/declaration"
+)
+
+// Adopting the bus is the mesh's planned step for replacing it (novox/hq ADR 0333 §3, ADR 0236).
+//
+// The adoption replaces the bus's image once: the module's built image takes the place of the upstream
+// one the bundle raised, on the same streams, users and certificate. The controller refuses a push that
+// would replace the bus — "a planned step: `bus upgrade --why …` snapshots its streams first and checks
+// them after" — so genesis stopped at step 18 (issue 590). The installer takes that step: it snapshots the
+// streams itself, because at genesis no backup holder exists to be asked, and hands the snapshot to
+// `bus upgrade`, which sends the machine, opens `bus-maintenance`, and ends the step done only once the
+// bus answers healthy again — every stream, every durable consumer, a round trip (H-bus). The installer
+// waits for that end.
+
+// adoptionWhy is what the step is recorded as, for the record of hand acts and the bus's step.
+const adoptionWhy = "genesis adopts its bus as the nats module (ADR 0333)"
+
+// Where the installer keeps the streams' snapshot before the adoption, and the credential the snapshot
+// program reads while it runs. Beside genesis's own credentials; variables so a test writes elsewhere.
+var (
+	busSnapshotFile       = "/var/lib/mesh-genesis/bus-before-adoption.tar"
+	busSnapshotCredential = "/var/lib/mesh-genesis/bus-snapshot.credential"
+	busCertificateFile    = "/var/lib/mesh-broker-tls/tls.crt"
+	busControllerSecret   = BusControllerFile
+	// busStepWithin bounds the wait for the controller to say the step ended: its own bound (15 min,
+	// mesh-controller busStepBound), and its doctor's next look after that.
+	busStepWithin = 17 * time.Minute
+)
+
+// adoptTheBus sends the nats module to this machine through the bus's planned step. A bus already on the
+// module's image is the module's: it is sent like any module, and nothing is replaced.
+func adoptTheBus(ctx context.Context, o Options, control controlPlane, bus *declaration.Container,
+	say func(string)) error {
+
+	if running := runningImage(ctx, control, bus.Name); running != "" && running != bus.Image {
+		say("  already adopted   " + bus.Name + " — it runs the module's image")
+		_, err := pushNode(ctx, o, control, say)
+		return err
+	}
+	image, err := theModulesBusImage(ctx, o, control)
+	if err != nil {
+		return err
+	}
+	if err := snapshotTheBus(ctx, o, control, image, say); err != nil {
+		return err
+	}
+	say("  restarting        " + bus.Name + " — once, onto the " + BusModule + " module's image, as the bus's " +
+		"planned step; its streams, users and certificate stay where they are (novox/hq ADR 0333 §3, ADR 0236)")
+	if _, err := control.within(2*o.Wait).tell(ctx, "bus", "upgrade", "--why", adoptionWhy,
+		"--reversible", "--snapshot-taken", busSnapshotFile); err != nil {
+		return fmt.Errorf("the bus's planned step was refused, so the bus is not replaced: %w", err)
+	}
+	return nil
+}
+
+// meshBuiltImage is an image the mesh built, as it records it: `artifact-store://<module>/<artifact>@sha256:…`.
+var meshBuiltImage = regexp.MustCompile(`artifact-store://([a-z0-9][a-z0-9-]*/[a-z0-9][a-z0-9-]*@sha256:[0-9a-f]{64})`)
+
+// theModulesBusImage is the nats module's server image, as the build just made it, pulled from this
+// mesh's registry: the image that carries the snapshot program.
+func theModulesBusImage(ctx context.Context, o Options, control controlPlane) (string, error) {
+	said, err := control.tell(ctx, "builds", BusModule, "-n", "1")
+	if err != nil {
+		return "", err
+	}
+	for _, m := range meshBuiltImage.FindAllStringSubmatch(said, -1) {
+		if strings.HasPrefix(m[1], BusModule+"/") {
+			return strings.TrimSuffix(o.Registry, "/") + "/" + m[1], nil
+		}
+	}
+	return "", fmt.Errorf("the mesh says no image it built for the %s module, so its snapshot program cannot "+
+		"be run before the bus is replaced:\n%s", BusModule, indent(strings.TrimSpace(said)))
+}
+
+// snapshotTheBus writes every stream of the running bus to busSnapshotFile with the module's own snapshot
+// program (mesh-catalog modules/nats, ADR 0235), as the controller's account, pinned to the bus's
+// certificate. The credential is written for the program's one run and removed after it.
+func snapshotTheBus(ctx context.Context, o Options, control controlPlane, image string, say func(string)) error {
+	password, err := readCredentialFile(busControllerSecret)
+	if err != nil {
+		return fmt.Errorf("the controller's bus credential is not at %s, so the streams cannot be snapshotted "+
+			"before the bus is replaced: %w", busControllerSecret, err)
+	}
+	fingerprint, err := certificateFingerprint(busCertificateFile)
+	if err != nil {
+		return err
+	}
+	port := o.Ports.orDefaults().Bus
+	server := "tls://127.0.0.1:" + strconv.Itoa(port)
+	credential, err := json.Marshal(map[string]string{"url": server, "fingerprint": fingerprint,
+		"user": busControllerUser, "password": password})
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(busSnapshotCredential, credential, 0o600); err != nil {
+		return fmt.Errorf("the snapshot's credential could not be written: %w", err)
+	}
+	defer os.Remove(busSnapshotCredential)
+
+	script := "docker run --rm -i --network host --entrypoint /usr/local/bin/mesh-nats-snapshot " + image +
+		" snapshot --server " + server + " --credential - < " + busSnapshotCredential + " > " + busSnapshotFile +
+		".partial && mv " + busSnapshotFile + ".partial " + busSnapshotFile
+	running, cancel := context.WithTimeout(ctx, busStepWithin)
+	defer cancel()
+	if out, err := control.run(running, "sh", "-c", script); err != nil {
+		_, _ = control.run(ctx, "rm", "-f", busSnapshotFile+".partial")
+		return fmt.Errorf("the bus's streams could not be snapshotted, so the bus is not replaced: %w\n%s",
+			err, indent(strings.TrimSpace(out)))
+	}
+	say("  snapshotted       every stream of the bus, at " + busSnapshotFile + " (its module's snapshot program)")
+	return nil
+}
+
+// certificateFingerprint is the pin of the bus's certificate: sha256 of its DER, as every machine pins it.
+func certificateFingerprint(path string) (string, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("the bus's certificate is not at %s, so it cannot be pinned for the snapshot: %w", path, err)
+	}
+	block, _ := pem.Decode(raw)
+	if block == nil {
+		return "", fmt.Errorf("%s holds no PEM certificate", path)
+	}
+	sum := sha256.Sum256(block.Bytes)
+	return "sha256:" + hex.EncodeToString(sum[:]), nil
+}
+
+// waitForTheBusStep waits until the controller says the bus's planned step ended: done once the bus
+// answered healthy — every stream, every durable consumer, a round trip — or failed, with its snapshot as
+// the way back. The step's own bound is the controller's; this waits a little past it.
+func waitForTheBusStep(ctx context.Context, o Options, control controlPlane, say func(string)) error {
+	deadline := time.Now().Add(busStepWithin)
+	var last string
+	for {
+		said, err := control.tell(ctx, "bus")
+		if err == nil {
+			for _, line := range strings.Split(said, "\n") {
+				if strings.HasPrefix(strings.TrimSpace(line), "last step ") {
+					last = strings.TrimSpace(line)
+				}
+			}
+			switch {
+			case strings.Contains(last, ": done at "):
+				say("  bus step done     " + last)
+				return nil
+			case strings.Contains(last, ": failed at "):
+				return fmt.Errorf("the bus's planned step ended failed: %s\n%s", last, indent(strings.TrimSpace(said)))
+			}
+		}
+		if !time.Now().Before(deadline) {
+			break
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-time.After(answerEvery):
+		}
+	}
+	if last == "" {
+		return errors.New("the controller says no bus step after the adoption was sent; `mesh-controller bus` says how it stands")
+	}
+	return fmt.Errorf("the bus's planned step did not end within %s: %s", busStepWithin, last)
+}

internal/bootstrap/bus_adoption_test.go

@@ -0,0 +1,135 @@
+package bootstrap
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Defends novox/hq issue 590 at its broker step (ADR 0333 §3, ADR 0236): the adoption replaces the bus's
+// image, and the mesh replaces its bus only as a planned step. A plain push was refused — "sending anchor
+// would replace the bus … a planned step: `bus upgrade --why …`" — and genesis stopped at step 18.
+
+func TestTheBrokerStepAdoptsTheBusThroughItsPlannedStep(t *testing.T) {
+	catalogue := aCatalogue(t, map[string]string{BusModule: aBusModule(theModulesLayout)})
+	rewritten, err := Rewrite(theRealBundle(t), held)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bundleImage := containerNamed(rewritten.Declaration, "mesh-broker-nats").Image
+	upgraded := false
+	var credential []byte
+	runtime := &asked{}
+	agrees := aMeshThatAgrees(nil)
+	runtime.answer = func(name string, args []string) (string, error) {
+		joined := strings.Join(args, " ")
+		switch {
+		case name == "sh" && strings.Contains(joined, "mesh-nats-snapshot"):
+			credential, _ = os.ReadFile(busSnapshotCredential) // as the program reads it
+		case strings.Contains(joined, "bus upgrade --why"):
+			upgraded = true
+		case strings.Contains(joined, "inspect --format {{.Config.Image}} mesh-broker-nats"):
+			if upgraded {
+				return theModulesImage + "\n", nil
+			}
+			return bundleImage + "\n", nil
+		}
+		return agrees(name, args)
+	}
+	_, fetch := aBusThatAdopts()
+	o := installing(t, catalogue)
+	o.CatalogSource = Source{Repository: "git://forge/mesh-catalog.git"}
+	o.Wait = 5 * time.Second
+	said, err := busStepWith(t, o, runtime, fetch)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	snapshot, upgrade := -1, -1
+	for i, c := range runtime.commands {
+		switch {
+		case strings.HasPrefix(c, "sh -c") && strings.Contains(c, "mesh-nats-snapshot"):
+			snapshot = i
+			for _, want := range []string{"127.0.0.1:5000/nats/server@sha256:" + strings.Repeat("4", 64),
+				"snapshot --server tls://127.0.0.1:5671 --credential - < " + busSnapshotCredential,
+				"> " + busSnapshotFile + ".partial && mv " + busSnapshotFile + ".partial " + busSnapshotFile} {
+				if !strings.Contains(c, want) {
+					t.Errorf("the snapshot is not taken with %q: %s", want, c)
+				}
+			}
+		case strings.Contains(c, "/mesh-controller bus upgrade"):
+			upgrade = i
+			if want := "bus upgrade --why " + adoptionWhy + " --reversible --snapshot-taken " + busSnapshotFile; !strings.HasSuffix(c, want) {
+				t.Errorf("the planned step is asked as %q; want it to end %q", c, want)
+			}
+		case strings.HasSuffix(c, "/mesh-controller push anchor"):
+			t.Errorf("the bus's module was sent by a plain push, which the mesh refuses for the bus: %v", runtime.commands)
+		}
+	}
+	if snapshot < 0 || upgrade < 0 || snapshot > upgrade {
+		t.Fatalf("the streams were not snapshotted before the bus's planned step (snapshot %d, upgrade %d): %v",
+			snapshot, upgrade, runtime.commands)
+	}
+	var cred map[string]string
+	if err := json.Unmarshal(credential, &cred); err != nil {
+		t.Fatalf("the snapshot program was given no credential: %v", err)
+	}
+	fingerprint, _ := certificateFingerprint(busCertificateFile)
+	if cred["user"] != "controller" || cred["password"] != "BUS-PW" || cred["fingerprint"] != fingerprint ||
+		cred["url"] != "tls://127.0.0.1:5671" {
+		t.Errorf("the snapshot's credential is %v", cred)
+	}
+	if _, err := os.Stat(busSnapshotCredential); !os.IsNotExist(err) {
+		t.Error("the snapshot's credential was left on the machine")
+	}
+	text := strings.Join(said, "\n")
+	for _, want := range []string{"snapshotted       every stream", "restarting        mesh-broker-nats — once",
+		"bus answers       mesh-broker-nats", "bus step done     last step 1", "adopted           mesh-broker-nats"} {
+		if !strings.Contains(text, want) {
+			t.Errorf("the step did not say %q:\n%s", want, text)
+		}
+	}
+}
+
+// A planned step the controller ends failed is the broker step failing, with the controller's words.
+func TestABusStepThatEndsFailedIsRefused(t *testing.T) {
+	aGenesisBusOnDisk(t)
+	runtime := &asked{answer: func(name string, args []string) (string, error) {
+		return "last step 1: not known → 53e51864 on anchor by installer (x): failed at 2026-10-13 11:59; snapshot s\n" +
+			"  stream KV_x has no messages\n", nil
+	}}
+	control := controlPlane{container: "mesh-controller", run: runtime.run, timeout: time.Second}
+	err := waitForTheBusStep(context.Background(), Options{}, control, quietly)
+	if err == nil || !strings.Contains(err.Error(), "failed at") || !strings.Contains(err.Error(), "KV_x") {
+		t.Fatalf("a failed bus step was not refused with its words: %v", err)
+	}
+}
+
+// The bundle's bus runs the release the module's image is built on, pinned by the same digest, so the
+// adoption changes no server release and is reversible as the step says (ADR 0333 §3).
+func TestTheBundlesBusRunsTheReleaseTheModulesImageIsBuiltOn(t *testing.T) {
+	var m struct {
+		Build struct {
+			On []struct{ Arg, Image string } `json:"on"`
+		} `json:"build"`
+	}
+	if err := json.Unmarshal(theCataloguesModule(t, BusModule), &m); err != nil {
+		t.Fatal(err)
+	}
+	base := ""
+	for _, on := range m.Build.On {
+		if on.Arg == "NATS_BASE" {
+			base = on.Image
+		}
+	}
+	rewritten, err := Rewrite(theRealBundle(t), held)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := containerNamed(rewritten.Declaration, "mesh-broker-nats").Image; got != base {
+		t.Errorf("the bundle raises the bus on %s; the nats module's image is built on %s", got, base)
+	}
+}

internal/bootstrap/genesis_registry_test.go

@@ -0,0 +1,65 @@
+package bootstrap
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Genesis seals the build agent the forge it raised (novox/hq ADR 0336 §3, issue 121): the agent's
+// npm-package-registry requirement is optional and binds only once the gitea module is assigned, after
+// the base, so until then the packages step's genesis document is how the sdk and base steps reach the
+// forge.
+
+func TestThePackagesStepSealsTheGenesisDocumentToTheBuildAgent(t *testing.T) {
+	if BuilderModule != "build-agent" {
+		t.Fatalf("genesis installs %q; the document is the build agent's", BuilderModule)
+	}
+	c, control := recording(t)
+	o := Options{Node: "anchor", Ports: FoundationPorts{Packages: 3100}, Wait: time.Second}
+	doc := genesisRegistry(o.Ports.orDefaults(), "builder-password")
+	if err := deliverGenesisRegistry(context.Background(), o, control, doc, quietly); err != nil {
+		t.Fatal(err)
+	}
+	carried := c.settings["accepting-"+GenesisRegistrySecret]
+	var got GenesisRegistry
+	if err := json.Unmarshal([]byte(carried), &got); err != nil {
+		t.Fatalf("the genesis document carried is not JSON: %q", carried)
+	}
+	want := GenesisRegistry{Scheme: "http", At: "127.0.0.1", Port: 3100, NpmPath: "/api/packages/novox/npm/",
+		As: "mesh-builder", Password: "builder-password"}
+	if got != want {
+		t.Fatalf("the genesis document says %+v, want %+v", got, want)
+	}
+	accept := c.index("secret accept anchor build-agent genesis-package-registry --from /accepting-genesis-package-registry")
+	push := c.index("push anchor")
+	if accept < 0 || push < 0 || accept > push {
+		t.Fatalf("the genesis document was not sealed to the build agent before the push: %v", c.told)
+	}
+}
+
+// What the retired builder was given and the build agent declares neither of: an `npm-password`
+// own-secret and a `serves` setting for its carried binding (ADR 0336 §3).
+func TestNoStepGivesTheBuildAgentAServesSettingOrAnNpmPassword(t *testing.T) {
+	for _, module := range []string{BuilderModule} {
+		c, control := recording(t)
+		o := Options{Node: "anchor", Ports: FoundationPorts{Packages: 3100}, Wait: time.Second}
+		if _, err := installModule(context.Background(), o, control, module, []byte(`{"module":"`+module+`"}`), quietly); err != nil {
+			t.Fatal(err)
+		}
+		if got, set := c.settings[module+"-settings.json"]; set {
+			t.Errorf("%s was given a setting on a node with a non-default packages port: %s", module, got)
+		}
+		if err := deliverGenesisRegistry(context.Background(), o, control,
+			genesisRegistry(o.Ports.orDefaults(), "p"), quietly); err != nil {
+			t.Fatal(err)
+		}
+		for _, told := range c.told {
+			if strings.Contains(told, "npm-password") || strings.Contains(told, "serves") {
+				t.Errorf("genesis told the controller %q", told)
+			}
+		}
+	}
+}

internal/bootstrap/genesis_toolchains_test.go

@@ -0,0 +1,89 @@
+package bootstrap
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Defends novox/hq issue 616: genesis's base step builds the toolchain of every language a module
+// genesis installs is compiled in. It built only mesh-tools, and the store's module, with Go code,
+// stopped genesis at step 17: "this mesh holds no copy of it. Build mesh-tools-go first".
+
+// genesisModules is every catalogue module genesis installs on its own, read from the steps that
+// install them: the registry, the build agent, the store, the bus, the vault, the catalogue and the
+// filter (extras are the operator's choice and come after the base too, but are not genesis's own).
+var genesisModules = []string{RegistryModule, BuilderModule, "postgres", BusModule, "mesh-vault", "mesh-catalog", "nftables"}
+
+// Every genesis module's bundles are compiled in a toolchain the base step builds, read from the real
+// catalogue's manifests: a module that gains a language genesis does not build fails here, not at a
+// genesis.
+func TestTheBaseStepBuildsEveryToolchainAGenesisModuleIsCompiledIn(t *testing.T) {
+	built := map[string]bool{}
+	for _, tc := range genesisToolchains {
+		built[tc.Language] = true
+	}
+	for _, module := range genesisModules {
+		var m struct {
+			Build struct {
+				Artifacts []struct {
+					Name, Kind, Language string
+				} `json:"artifacts"`
+			} `json:"build"`
+		}
+		if err := json.Unmarshal(theCataloguesModule(t, module), &m); err != nil {
+			t.Fatalf("%s: %v", module, err)
+		}
+		for _, a := range m.Build.Artifacts {
+			if a.Kind != "bundle" {
+				continue // an image builds on the bases its Dockerfile names, pinned upstream
+			}
+			if !built[a.Language] {
+				t.Errorf("%s's %q is a %s bundle, and genesis's base step builds no %s toolchain",
+					module, a.Name, a.Language, a.Language)
+			}
+		}
+	}
+}
+
+// And the base step asks for each toolchain's build: the base, then the Go toolchain beside it.
+func TestTheBaseStepBuildsTheGoToolchainBesideTheBase(t *testing.T) {
+	runtime := &asked{answer: aMeshThatAgrees(nil)}
+	control := controlPlane{container: "mesh-controller", run: runtime.run, timeout: time.Second}
+	o := Options{ToolsSource: Source{Repository: "git://192.0.2.30/mesh-tools.git"}}
+	if err := BuildBase(context.Background(), o, control, quietly); err != nil {
+		t.Fatal(err)
+	}
+	var builds []string
+	for _, c := range runtime.commands {
+		if strings.Contains(c, "/mesh-controller build ") {
+			builds = append(builds, c[strings.Index(c, "build "):])
+		}
+	}
+	want := []string{
+		"build git://192.0.2.30/mesh-tools.git --ref main --wait 1200s",
+		"build git://192.0.2.30/mesh-tools-go.git --ref main --wait 1200s",
+	}
+	if strings.Join(builds, "\n") != strings.Join(want, "\n") {
+		t.Fatalf("the base step built\n%s\nand not\n%s", strings.Join(builds, "\n"), strings.Join(want, "\n"))
+	}
+}
+
+func TestTheGoToolchainIsAsGivenOrBesideTheBase(t *testing.T) {
+	for _, c := range []struct{ tools, given, want string }{
+		{"http://forge/novox/mesh-tools.git", "", "http://forge/novox/mesh-tools-go.git"},
+		{"http://forge/novox/mesh-tools", "", "http://forge/novox/mesh-tools-go"},
+		{"http://forge/other/base.git", "http://forge/other/go.git", "http://forge/other/go.git"},
+	} {
+		got, err := toolsGoSource(Options{ToolsSource: Source{Repository: c.tools}, ToolsGoSource: Source{Repository: c.given}})
+		if err != nil || got.Repository != c.want {
+			t.Errorf("tools %s, given %q: %q %v; want %s", c.tools, c.given, got.Repository, err, c.want)
+		}
+	}
+	if _, err := toolsGoSource(Options{ToolsSource: Source{Repository: "http://forge/other/base.git"}}); err == nil ||
+		!strings.Contains(err.Error(), "--tools-go-source") {
+		t.Errorf("a base not named mesh-tools, and no Go toolchain given, was not refused naming the flag: %v", err)
+	}
+}

internal/bootstrap/module.go

@@ -137,7 +137,26 @@ func registerAndAssign(ctx context.Context, o Options, control controlPlane, mod
 // should hold, seals every secret in them and publishes them, and on a first node that is the
 // slowest thing the mesh does.
 func pushNode(ctx context.Context, o Options, control controlPlane, say func(string)) (string, error) {
-	said, err := control.within(o.Wait).tell(ctx, "push", o.Node)
+	return pushing(ctx, o, control, false, say)
+}
+
+// pushNodeApplied is pushNode that returns only once the node reports it applied exactly what it was
+// sent (`push <node> --wait`, novox/hq ADR 0010): for a push whose content the very next step reads
+// on the machine. A plain push returns as soon as the declaration is sent, and the node applies it a
+// moment later (issue 615).
+func pushNodeApplied(ctx context.Context, o Options, control controlPlane, say func(string)) (string, error) {
+	return pushing(ctx, o, control, true, say)
+}
+
+func pushing(ctx context.Context, o Options, control controlPlane, applied bool, say func(string)) (string, error) {
+	args := []string{"push", o.Node}
+	patience := o.Wait
+	if applied {
+		args = append(args, "--wait", o.Wait.String())
+		// The controller's own wait, and time to compose and send before it starts.
+		patience = 2 * o.Wait
+	}
+	said, err := control.within(patience).tell(ctx, args...)
 	if err != nil {
 		return "", fmt.Errorf(
 			"%w\n\nWhat was registered and assigned is registered and assigned, and this node has "+
@@ -145,7 +164,20 @@ func pushNode(ctx context.Context, o Options, control controlPlane, say func(str
 				"at all. Fix what it named and run this installer again: it will find the module "+
 				"already registered and try the push again", err)
 	}
-	say("  pushed            " + o.Node)
+	if applied {
+		say("  pushed            " + o.Node + ", and it applied it")
+	} else {
+		say("  pushed            " + o.Node)
+	}
+	// **Every push may carry a new bus user, and until the adoption the bus hears of it only from here**
+	// (novox/hq issue 608, ADR 0331 §5, ADR 0333 §4). A module's account is minted into the mesh's
+	// records and sealed to this node with the push; the bus reads its user list from a file, and until
+	// the broker step adopts the bus as the nats module nothing but this installer writes that file. The
+	// list was placed only when the node enrolled, so the build agent's account (step 13) never reached
+	// the bus and the agent was refused ("Authorization Violation") until the sdk step gave up.
+	if err := placeUntilAdopted(ctx, control, say); err != nil {
+		return "", err
+	}
 	return strings.TrimSpace(said), nil
 }
 

internal/bootstrap/phase2.go

@@ -25,20 +25,62 @@ import (
 // buildWait bounds one module build. Generous, because the first build compiles a toolchain.
 const buildWait = 20 * time.Minute
 
-// BuildBase asks the mesh to build the shared base every module with code of its own stands on.
+// BuildBase asks the mesh to build the shared base every module with code of its own stands on, and
+// the toolchain of every language genesis's own modules are written in.
 //
 // **First, because until it exists nothing else with code can be built.** Not registered as a
 // module here: it is never assigned — it runs nowhere — and the build itself records what was
 // made, which is all anything downstream reads.
+//
+// **Every toolchain a genesis module compiles in** (novox/hq issue 616). A bundle is compiled in its
+// language's base (mesh-controller internal/builder toolchain.go): TypeScript in mesh-tools, Go in
+// mesh-tools-go. The store's and the bus's modules carry Go code, so a genesis that built only
+// mesh-tools stopped at the store step: "this mesh holds no copy of it. Build mesh-tools-go first".
+// The bases are the ones genesisToolchains names, and a test holds them to the languages of every
+// module genesis installs, read from the catalogue.
 func BuildBase(ctx context.Context, o Options, control controlPlane, say func(string)) error {
 	if o.ToolsSource.Repository == "" {
 		return fmt.Errorf("phase two needs --tools-source: the shared base is built from its " +
 			"own repository, and an installer told nothing cannot know where that is")
 	}
-	say("  building          " + o.ToolsSource.Repository + " at " + refOr(o.ToolsSource.Ref))
-	_, err := control.within(buildWait).tell(ctx,
-		"build", o.ToolsSource.Repository, "--ref", refOr(o.ToolsSource.Ref), "--wait", "1200s")
-	return err
+	goSource, err := toolsGoSource(o)
+	if err != nil {
+		return err
+	}
+	for _, src := range []Source{o.ToolsSource, goSource} {
+		say("  building          " + src.Repository + " at " + refOr(src.Ref))
+		if _, err := control.within(buildWait).tell(ctx,
+			"build", src.Repository, "--ref", refOr(src.Ref), "--wait", "1200s"); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// genesisToolchains is the base each language's bundles compile in, for the languages genesis's own
+// modules are written in — the same pairs as mesh-controller internal/builder toolchain.go — in the
+// order BuildBase builds them.
+var genesisToolchains = []struct{ Language, Base string }{
+	{"typescript", "mesh-tools"},
+	{"go", "mesh-tools-go"},
+}
+
+// toolsGoSource is where the Go toolchain is built from: as given, or the repository beside the base's
+// named mesh-tools-go, which is how the mesh keeps its repositories side by side.
+func toolsGoSource(o Options) (Source, error) {
+	if o.ToolsGoSource.Repository != "" {
+		return o.ToolsGoSource, nil
+	}
+	repo := strings.TrimSuffix(o.ToolsSource.Repository, "/")
+	suffix := ""
+	if strings.HasSuffix(repo, ".git") {
+		repo, suffix = strings.TrimSuffix(repo, ".git"), ".git"
+	}
+	if !strings.HasSuffix(repo, "mesh-tools") {
+		return Source{}, fmt.Errorf("the Go toolchain is built from mesh-tools-go, and --tools-source (%s) is not a "+
+			"repository named mesh-tools to find it beside; give --tools-go-source", o.ToolsSource.Repository)
+	}
+	return Source{Repository: repo + "-go" + suffix, Ref: o.ToolsGoSource.Ref}, nil
 }
 
 // InstallFromCatalogue builds a catalogue module and installs it on this machine.

internal/bootstrap/phase3.go

@@ -84,7 +84,7 @@ func InstallStore(ctx context.Context, o Options, control controlPlane,
 		say); err != nil {
 		return err
 	}
-	say("  adopted           mesh-store — the foundation's store is now the " + module + " module")
+	say("  adopted           " + store.Name + " — the foundation's store is now the " + module + " module")
 	return nil
 }
 
@@ -93,7 +93,8 @@ func InstallStore(ctx context.Context, o Options, control controlPlane,
 // be in it. InstallFromCatalogue is the same sequence without that moment; the store, the broker
 // and the vault each need it or need the shape, and three copies of it drifted.
 func installProvider(ctx context.Context, o Options, control controlPlane, module string,
-	manifest []byte, buildNote string, beforePush func() error, say func(string)) error {
+	manifest []byte, buildNote string, beforePush func() error, say func(string),
+	send ...func() error) error {
 
 	remote := "/" + module + "-module.json"
 	if err := control.carrying(ctx, module+"-module.json", manifest, remote); err != nil {
@@ -132,6 +133,11 @@ func installProvider(ctx context.Context, o Options, control controlPlane, modul
 			return err
 		}
 	}
+	// A module whose first send is not a plain push says how it is sent: the bus, whose replacement is a
+	// planned step (ADR 0236), is sent by that step (adoptTheBus).
+	if len(send) > 0 && send[0] != nil {
+		return send[0]()
+	}
 	_, err := pushNode(ctx, o, control, say)
 	return err
 }
@@ -176,9 +182,10 @@ const BusModule = "nats"
 // **The image is the one thing that changes, once** (ADR 0333 §3). The store's module pins the upstream
 // postgres the foundation runs; the bus's module builds its server image (it carries the mesh's snapshot
 // tool), so no pinned reference can be equal to the foundation's. The applier recreates the container on
-// the module's image, on the same streams, users and certificate. This says so before the push and waits
-// after it until the container runs the module's image and the bus answers, so nothing after this step
-// dials a bus that is restarting.
+// the module's image, on the same streams, users and certificate. The mesh replaces its bus only as a
+// planned step (ADR 0236), so the module is sent by that step: its streams snapshotted first, the restart
+// said, and the installer waits until the container runs the module's image, the bus answers, and the
+// controller ends the step done (bus_adoption.go), so nothing after this step dials a bus that is restarting.
 func InstallBroker(ctx context.Context, o Options, control controlPlane,
 	foundation *declaration.Declaration, fetch func(context.Context, string) (int, string, error),
 	say func(string)) error {
@@ -197,20 +204,15 @@ func InstallBroker(ctx context.Context, o Options, control controlPlane,
 	}
 	say("  adopting          " + bus.Name + " — the bus the foundation raised, its streams kept")
 	if err := installProvider(ctx, o, control, module, manifest, "(the server, adopting the foundation's bus)",
-		func() error {
-			if running := runningImage(ctx, control, bus.Name); running != "" && running != bus.Image {
-				say("  already restarted " + bus.Name + " — it runs the module's image")
-				return nil
-			}
-			say("  restarting        " + bus.Name + " — once, onto the " + module + " module's image; its " +
-				"streams, users and certificate stay where they are (novox/hq ADR 0333 §3)")
-			return nil
-		}, say); err != nil {
+		nil, say, func() error { return adoptTheBus(ctx, o, control, bus, say) }); err != nil {
 		return err
 	}
 	if err := waitForTheAdoptedBus(ctx, o, control, bus, fetch, say); err != nil {
 		return err
 	}
+	if err := waitForTheBusStep(ctx, o, control, say); err != nil {
+		return err
+	}
 	say("  adopted           " + bus.Name + " — the foundation's bus is now the " + module +
 		" module, and its user list is the module's from here on")
 	return nil

internal/bootstrap/phase3_test.go

@@ -69,6 +69,7 @@ func aBusThatAdopts() (*asked, func(context.Context, string) (int, string, error
 func busStepWith(t *testing.T, o Options, runtime *asked,
 	fetch func(context.Context, string) (int, string, error)) ([]string, error) {
 	t.Helper()
+	aGenesisBusOnDisk(t)
 	rewritten, err := Rewrite(theRealBundle(t), held)
 	if err != nil {
 		t.Fatal(err)
@@ -222,7 +223,7 @@ func TestTheBrokerStepSaysTheRestartAndWaitsForTheBusToAnswer(t *testing.T) {
 	runtime.answer = func(name string, args []string) (string, error) {
 		joined := strings.Join(args, " ")
 		switch {
-		case strings.Contains(joined, "push anchor"):
+		case strings.Contains(joined, "bus upgrade --why"):
 			pushed = true
 		case strings.Contains(joined, "inspect --format {{.Config.Image}} mesh-broker-nats"):
 			if !pushed {
@@ -304,7 +305,7 @@ func TestARerunAfterTheAdoptionSaysTheBusIsTheModulesAlready(t *testing.T) {
 		t.Fatal(err)
 	}
 	text := strings.Join(said, "\n")
-	if strings.Contains(text, "restarting") || !strings.Contains(text, "already restarted mesh-broker-nats") {
+	if strings.Contains(text, "restarting") || !strings.Contains(text, "already adopted   mesh-broker-nats") {
 		t.Errorf("a re-run announced a restart, or did not say the bus is the module's already:\n%s", text)
 	}
 }
@@ -417,3 +418,30 @@ func TestTheBundlesBusFilesAreSeeds(t *testing.T) {
 		}
 	}
 }
+
+// aGenesisBusOnDisk puts what the adoption reads on the machine in a test's own directory: the bus's
+// certificate, the controller's bus credential, and where the snapshot goes. The step's wait is short.
+func aGenesisBusOnDisk(t *testing.T) {
+	t.Helper()
+	dir := t.TempDir()
+	cert := filepath.Join(dir, "tls.crt")
+	if err := os.WriteFile(cert, []byte(aCertificatePEM), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	secret := filepath.Join(dir, "bus-controller.secret")
+	if err := os.WriteFile(secret, []byte("BUS-PW"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	was := []string{busSnapshotFile, busSnapshotCredential, busCertificateFile, busControllerSecret}
+	wasWithin := busStepWithin
+	busSnapshotFile, busSnapshotCredential = filepath.Join(dir, "bus.tar"), filepath.Join(dir, "bus.credential")
+	busCertificateFile, busControllerSecret = cert, secret
+	busStepWithin = 50 * time.Millisecond
+	t.Cleanup(func() {
+		busSnapshotFile, busSnapshotCredential, busCertificateFile, busControllerSecret = was[0], was[1], was[2], was[3]
+		busStepWithin = wasWithin
+	})
+}
+
+// aCertificatePEM is a PEM block standing for the bus's certificate; its pin is the sha256 of these bytes.
+const aCertificatePEM = "-----BEGIN CERTIFICATE-----\nAAECAwQFBgcICQ==\n-----END CERTIFICATE-----\n"

internal/bootstrap/phase_packages.go

@@ -2,6 +2,7 @@ package bootstrap
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"os"
@@ -24,7 +25,7 @@ import (
 const (
 	// foundationStore is the foundation's postgres container — the mesh's own memory, raised from the
 	// bundle. gitea's bootstrap database lives here too, so a mesh runs one postgres (issue 051).
-	foundationStore = "mesh-store"
+	foundationStore = "postgres"
 	// giteaBootstrap is the gitea server raised directly at genesis, before gitea is a module —
 	// under the name the gitea MODULE declares for its container, so the module finds it and holds
 	// it rather than raising a second forge beside it (novox/hq ADR 0163, rule 7; issue 090).
@@ -49,8 +50,8 @@ const (
 	packagesTeam = "packages"
 	// giteaAdminUser is the admin the bootstrap creates and the provisioner later authenticates as.
 	giteaAdminUser = "mesh-admin"
-	// builderGiteaUser is the gitea account the builder publishes and pulls with at genesis. It is
-	// the `as` the builder's static package binding names.
+	// builderGiteaUser is the gitea account the build agent publishes and pulls with at genesis: the
+	// `as` of the genesis document (novox/hq ADR 0336 §3). Retiring it is issue 602.
 	builderGiteaUser = "mesh-builder"
 	// giteaDBRole/giteaDBName is gitea's own database in the foundation store.
 	giteaDBRole = "mesh_gitea"
@@ -133,8 +134,8 @@ func RaisePackageRegistry(ctx context.Context, o Options, d Deps, control contro
 		return err
 	}
 
-	say("  delivering the builder its registry credential")
-	if err := deliverBuilderNpm(ctx, o, control, builderPassword, say); err != nil {
+	say("  sealing the build agent the genesis document for the forge it raised")
+	if err := deliverGenesisRegistry(ctx, o, control, genesisRegistry(ports, builderPassword), say); err != nil {
 		return err
 	}
 
@@ -362,27 +363,69 @@ func packagePasswords() (db, admin, builder string, err error) {
 	return db, admin, builder, nil
 }
 
-// deliverBuilderNpm seals the builder's registry password to this node as its `npm-password`
-// own-secret, the same way the control plane's store connections are delivered — carry the value in,
-// `secret accept`, and the next push writes it sealed where the builder reads it.
-func deliverBuilderNpm(ctx context.Context, o Options, control controlPlane, password string,
-	say func(string)) error {
-	at := "/accepting-npm-password"
-	if err := control.carryingSecret(ctx, "mesh-accepting-npm-password", []byte(password), at); err != nil {
-		return err
-	}
-	if _, err := control.tell(ctx, "secret", "accept", o.Node, BuilderModule, "npm-password", "--from", at); err != nil {
-		return err
-	}
-	// Push so the sealed secret reaches the builder, which restarts on it and comes back credentialed.
-	if _, err := control.tell(ctx, "push", o.Node); err != nil {
-		return err
-	}
-	return nil
+// GenesisRegistrySecret is the build agent's own-secret the genesis document is sealed as (novox/hq
+// ADR 0336 §3). The build-agent manifest declares it, issued outside the mesh: only this installer
+// gives one, on genesis's node.
+const GenesisRegistrySecret = "genesis-package-registry"
+
+// GenesisRegistry is the genesis document (novox/hq ADR 0336 §3): the forge this step raised, the port
+// this node gave the package registry, its npm path, and the account this step made with its password.
+// mesh-controller's cmd/mesh-builder reads it under the same field names while the build agent's
+// npm-package-registry requirement is unbound, and prefers the binding once the gitea module is
+// assigned and it binds.
+type GenesisRegistry struct {
+	Scheme   string `json:"scheme"`
+	At       string `json:"at"`
+	Port     int    `json:"port"`
+	NpmPath  string `json:"npm-path"`
+	As       string `json:"as"`
+	Password string `json:"password"`
 }
 
-// PublishTheSDK dispatches a build of the SDK to the builder. The builder has its registry
-// credential by now, so the build's `npm publish` authenticates; the artifact is a `package`, built
+// genesisRegistry is the document for the forge raised here: on the machine's own loopback, where it
+// answers on the host network and where its ROOT_URL says it is (raiseGiteaServer), on the port this
+// node gave the package registry.
+func genesisRegistry(ports FoundationPorts, password string) GenesisRegistry {
+	return GenesisRegistry{Scheme: "http", At: "127.0.0.1", Port: ports.Packages,
+		NpmPath: "/api/packages/" + packagesOrg + "/npm/", As: builderGiteaUser, Password: password}
+}
+
+// deliverGenesisRegistry seals the genesis document to the build agent on this node as its
+// `genesis-package-registry` own-secret (novox/hq ADR 0336 §3), the same way the control plane's store
+// connections are delivered — carry the value in, `secret accept`, and the next push writes it sealed
+// where the build agent reads it.
+//
+// **The build agent's one way to the forge until the registry binds.** Its npm-package-registry
+// requirement is optional (ADR 0336 §1), and nothing provides it until the gitea module is assigned
+// after the base, so the sdk step (15) publishes and the base step (16) resolves with the account in
+// this document. It replaces the retired builder's `npm-password` own-secret and the `serves.port`
+// setting its carried binding took, neither of which the build agent declares.
+func deliverGenesisRegistry(ctx context.Context, o Options, control controlPlane, doc GenesisRegistry,
+	say func(string)) error {
+	raw, err := json.Marshal(doc)
+	if err != nil {
+		return err
+	}
+	at := "/accepting-" + GenesisRegistrySecret
+	if err := control.carryingSecret(ctx, "mesh-accepting-"+GenesisRegistrySecret, raw, at); err != nil {
+		return err
+	}
+	if _, err := control.tell(ctx, "secret", "accept", o.Node, BuilderModule, GenesisRegistrySecret, "--from", at); err != nil {
+		return err
+	}
+	// Push so the sealed document reaches the build agent, which reads it at its next build — and,
+	// like every push before the adoption, the bus hears the users it carries (issue 608).
+	//
+	// **Waited for until the node applied it** (issue 615). The next step asks the build agent to
+	// publish the SDK, and the agent reads the document from the file the node writes when it applies
+	// this push. A push that returned on sending let the ask race the apply: one genesis found the
+	// document in time, the next was refused, "neither its binding nor the genesis document".
+	_, err = pushNodeApplied(ctx, o, control, say)
+	return err
+}
+
+// PublishTheSDK dispatches a build of the SDK to the build agent. The agent has the genesis document by
+// now (novox/hq ADR 0336 §7), so the build's `npm publish` authenticates; the artifact is a `package`, built
 // on a public base, so this needs no toolchain — which is the whole point of doing it before the base.
 func PublishTheSDK(ctx context.Context, o Options, control controlPlane, say func(string)) error {
 	if o.SDKSource.Repository == "" {

internal/bootstrap/ports.go

@@ -117,24 +117,6 @@ const busModulePort = 4222
 // PortsSetting is the controller's settings key for a module's given ports.
 const PortsSetting = "ports"
 
-// ServesSetting is the settings key that carries what a provider serves, inside the one binding a
-// module carries rather than resolves — the builder's package binding (novox/hq 04-ISSUES/085).
-//
-// **A port given at genesis has to be a setting wherever it is read, or something puts it back.**
-// The builder reaches the package registry through a binding written in its own manifest, because
-// at genesis no module yet provides `package-registry` and so there is nothing for the controller
-// to resolve it from. That binding used to be rewritten, as text, when the installer registered the
-// builder — which a later registration from the catalogue undid silently. Set as a node's setting
-// instead, it is held by the controller rather than by the manifest, so re-registering the builder
-// leaves it where it was.
-//
-// **A settings layer is the module's, not one resource's.** The controller lays it over every file
-// of that module which merges as JSON, so `serves` lands in the package binding only because that
-// binding is the builder's one mergeable file. A second mergeable file added to the builder would
-// be given a `serves` key too, meaning nothing to whatever reads it. Worth knowing before adding
-// one.
-const ServesSetting = "serves"
-
 // setFoundationSettings tells the controller the ports this node gave a foundation module — and,
 // on an adopted node, that the registry is reached from anywhere, as a node pulls from it before it
 // has a private-network address (novox/hq ADR 0100). Done after the module is registered and before
@@ -148,13 +130,8 @@ func setFoundationSettings(ctx context.Context, o Options, control controlPlane,
 	if o.Adopted && module == RegistryModule {
 		values["expose"] = map[string]string{strconv.Itoa(DefaultPorts().Registry): "anywhere"}
 	}
-	if packages := o.Ports.orDefaults().Packages; module == BuilderModule &&
-		packages != DefaultPorts().Packages {
-		// The one binding nothing resolves: the builder dials the forge by a number it carries.
-		// The rest of the binding — the provision, the forge it is from, the account it presents —
-		// is the manifest's and stays there.
-		values[ServesSetting] = map[string]int{"port": packages}
-	}
+	// No `serves` setting for the build agent: the port given for the package registry reaches it in
+	// the genesis document (novox/hq ADR 0336 §3), and from the binding once the registry binds.
 	if len(values) == 0 {
 		return nil
 	}

internal/bootstrap/ports_test.go

@@ -68,7 +68,7 @@ func TestGivenPortsMoveOnlyTheMachinesSide(t *testing.T) {
 	if got.Places == 0 {
 		t.Fatal("nothing was rewritten")
 	}
-	storeC := containerNamed(r.Declaration, "mesh-store")
+	storeC := containerNamed(r.Declaration, "postgres")
 	if len(storeC.Ports) != 1 || storeC.Ports[0] != "5433:5432" {
 		t.Errorf("the store publishes %v", storeC.Ports)
 	}
@@ -239,6 +239,12 @@ func (c *controlRecorder) run(_ context.Context, name string, args ...string) (s
 	}
 	if name == "docker" && args[0] == "exec" {
 		c.told = append(c.told, strings.Join(args[3:], " "))
+		if strings.Join(args[3:], " ") == "broker accounts" {
+			return "accounts {}\n", nil // the composed user list, placed after every push (issue 608)
+		}
+	}
+	if name == "sh" {
+		c.told = append(c.told, "placed the bus's users")
 	}
 	return "", nil
 }

internal/bootstrap/push_places_users_test.go

@@ -0,0 +1,134 @@
+package bootstrap
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Defends novox/hq issue 608 (ADR 0331 §5, ADR 0333 §4): until the bus is adopted as the nats module,
+// every push genesis makes is followed by the installer placing the composed user list where the bus
+// reads it, and making the bus re-read it. The build agent's account was minted at step 13 and sealed
+// with that push, and the list was placed only at enrolment, so the bus refused the agent
+// ("Authorization Violation") and genesis stopped at step 15.
+
+// placing answers the controller as a mesh whose bus is or is not the nats module yet, and records
+// what was run, in order.
+func placing(adopted bool) (*asked, controlPlane) {
+	listed := "build-agent          1\n"
+	if adopted {
+		listed += "nats                 1\n"
+	}
+	runtime := &asked{}
+	runtime.answer = func(name string, args []string) (string, error) {
+		joined := strings.Join(args, " ")
+		switch {
+		case name == "sh":
+			return "", nil
+		case strings.HasSuffix(joined, "module list"):
+			return listed, nil
+		case strings.HasSuffix(joined, "broker accounts"):
+			return "accounts {\n  MESH { users = [ { user: \"anchor.build-agent\" } ] }\n}\n", nil
+		}
+		return "", nil
+	}
+	return runtime, controlPlane{container: "mesh-controller", run: runtime.run, timeout: time.Second}
+}
+
+// placedAfterThePush is whether the bus's users were placed — written at the module's bus-users path,
+// the bus told to re-read them — after the push, and how often.
+func placedAfterThePush(t *testing.T, commands []string) int {
+	t.Helper()
+	pushed, placed := -1, 0
+	for i, c := range commands {
+		if strings.Contains(c, "/mesh-controller push anchor") && pushed < 0 {
+			pushed = i
+		}
+		if strings.HasPrefix(c, "sh -c") && strings.Contains(c, busAccounts) &&
+			strings.Contains(c, "kill -s HUP "+busContainer) {
+			if pushed < 0 || i < pushed {
+				t.Fatalf("the bus's users were placed before the push that carries the account: %v", commands)
+			}
+			placed++
+		}
+	}
+	if pushed < 0 {
+		t.Fatalf("nothing was pushed: %v", commands)
+	}
+	return placed
+}
+
+func TestTheBusHearsTheBuildAgentsAccountAfterItsPush(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	runtime, control := placing(false)
+	o := Options{Node: "anchor", Wait: time.Second}
+	if _, err := installModule(context.Background(), o, control, BuilderModule, []byte(`{}`), quietly); err != nil {
+		t.Fatal(err)
+	}
+	if n := placedAfterThePush(t, runtime.commands); n != 1 {
+		t.Fatalf("the bus's users were placed %d time(s) after the build agent's push; once: %v", n, runtime.commands)
+	}
+}
+
+func TestTheGenesisDocumentsPushIsHeardByTheBusToo(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	runtime, control := placing(false)
+	o := Options{Node: "anchor", Wait: time.Second}
+	if err := deliverGenesisRegistry(context.Background(), o, control, genesisRegistry(DefaultPorts(), "pw"), quietly); err != nil {
+		t.Fatal(err)
+	}
+	if n := placedAfterThePush(t, runtime.commands); n != 1 {
+		t.Fatalf("the bus's users were placed %d time(s) after the genesis document's push; once: %v", n, runtime.commands)
+	}
+}
+
+// From the adoption on the nats module writes the list, and the installer does not (ADR 0333 §4).
+func TestOnceTheBusIsTheNatsModulesThePushPlacesNothing(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	runtime, control := placing(true)
+	o := Options{Node: "anchor", Wait: time.Second}
+	if _, err := installModule(context.Background(), o, control, BuilderModule, []byte(`{}`), quietly); err != nil {
+		t.Fatal(err)
+	}
+	if n := placedAfterThePush(t, runtime.commands); n != 0 {
+		t.Fatalf("the installer placed the bus's users over the nats module's: %v", runtime.commands)
+	}
+}
+
+// Defends novox/hq issue 615: the packages step's push is waited for until the node applied it, because
+// the sdk step right after asks the build agent for a build that reads the genesis document from the
+// file that apply writes. A push that returned on sending let the ask race the apply.
+func TestThePackagesStepWaitsUntilTheNodeAppliedTheGenesisDocument(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	runtime, control := placing(false)
+	o := Options{Node: "anchor", Wait: 3 * time.Minute}
+	if err := deliverGenesisRegistry(context.Background(), o, control, genesisRegistry(DefaultPorts(), "pw"), quietly); err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range runtime.commands {
+		if strings.Contains(c, "/mesh-controller push anchor") {
+			if !strings.HasSuffix(c, "push anchor --wait 3m0s") {
+				t.Fatalf("the genesis document's push does not wait for the node to apply it: %s", c)
+			}
+			return
+		}
+	}
+	t.Fatalf("the genesis document was never pushed: %v", runtime.commands)
+}
+
+// Every other push of genesis still returns on sending: only a push whose content the next step reads on
+// the machine waits.
+func TestAnOrdinaryPushDoesNotWait(t *testing.T) {
+	t.Setenv("TMPDIR", t.TempDir())
+	runtime, control := placing(false)
+	o := Options{Node: "anchor", Wait: time.Second}
+	if _, err := installModule(context.Background(), o, control, BuilderModule, []byte(`{}`), quietly); err != nil {
+		t.Fatal(err)
+	}
+	for _, c := range runtime.commands {
+		if strings.Contains(c, "push anchor --wait") {
+			t.Fatalf("an ordinary push waits: %s", c)
+		}
+	}
+}

internal/bootstrap/registry_test.go

@@ -58,8 +58,20 @@ func aMeshThatAgrees(answers map[string]string) func(string, []string) (string,
 			}
 		}
 		switch {
+		case name == "sh" && len(args) == 2 && strings.Contains(args[1], "accounts.conf"):
+			return "", nil // the bus's users placed after a push (issue 608)
+		case name == "sh" && len(args) == 2 && strings.Contains(args[1], "mesh-nats-snapshot"):
+			return "", nil // the streams snapshotted before the bus's planned step (issue 590)
+		case name == "docker" && strings.HasSuffix(joined, "/mesh-controller bus"):
+			return "the bus is nats, built 53e51864, on anchor\nlast step 1: not known → 53e51864 on anchor by installer (" +
+				adoptionWhy + "): done at 2026-10-13 11:40; snapshot " + busSnapshotFile + "\n", nil
+		case name == "docker" && strings.Contains(joined, "/mesh-controller builds nats -n 1"):
+			return "nats  built 53e51864 anchor\n    image      artifact-store://nats/server@sha256:" +
+				strings.Repeat("4", 64) + "\n    bundle     artifact-store://nats/tools/blobs/sha256:" + strings.Repeat("5", 64) + "\n", nil
 		case name != "docker":
 			return "", fmt.Errorf("unexpected program %q", name)
+		case strings.HasSuffix(joined, "broker accounts"):
+			return "accounts {}\n", nil
 		case args[0] == "cp":
 			return "", nil
 		case args[0] == "container":

internal/bootstrap/rootsecrets.go

@@ -47,6 +47,9 @@ const (
 	// StoreSuperuserFile is where the store's superuser password lives on the machine — the
 	// postgres module's own-secret path, so genesis and adoption write the same file.
 	StoreSuperuserFile = "/var/lib/postgres/superuser.secret"
+	// StoreDataDir is where the store keeps its data — the postgres module's data directory, so
+	// genesis raises the store where the module adopts it (novox/hq ADR 0338 §1).
+	StoreDataDir = "/var/lib/mesh-store"
 	// BusControllerFile is where the controller's password on the bus lives on the machine. Not a
 	// module's path: no module reads it — the permanent controller is handed the address the
 	// temporary one was given — and genesis keeps it only so a second run puts the same account
@@ -62,7 +65,7 @@ const (
 	// What the template says, matched exactly. A template that says something else is a template
 	// this installer does not know how to make safe, and it says so rather than guessing.
 	templateStorePassword = `"POSTGRES_PASSWORD": "bootstrap"`
-	templateStoreVolumes  = `"volumes": ["mesh-store-data:/var/lib/postgresql/data"]`
+	templateStoreVolumes  = `"volumes": ["` + StoreDataDir + `:/var/lib/postgresql/data"]`
 	templateStoreURL      = "postgres:bootstrap@"
 
 	// BusURLPlaceholder is the controller's account in its bus address, as the template names it.
@@ -265,8 +268,8 @@ func Masking(say func(string), c RootCredentials) func(string) {
 // RefuseExistingServers stops a run that would put a made credential in front of a store raised
 // by an earlier installer with the template's.
 //
-// The store's password is set by initdb, once, on an empty volume. A machine that already holds
-// `mesh-store-data` and has no credential file was raised with `bootstrap`, and minting a new
+// The store's password is set by initdb, once, on an empty data directory. A machine that already holds
+// a cluster in the store's data directory and has no credential file was raised with `bootstrap`, and minting a new
 // value here would make a bundle that dials with a password the server does not have — failing
 // three steps later, in the schemas, with nothing pointing back here. Refused by name instead,
 // with the way forward.
@@ -278,11 +281,14 @@ func RefuseExistingServers(ctx context.Context, run Runner, c RootCredentials) e
 	if !c.StoreMade {
 		return nil
 	}
-	if _, err := run(ctx, "docker", "volume", "inspect", "mesh-store-data"); err != nil {
-		return nil // no such volume: a fresh machine, which is the case this installer makes
+	// Where the store keeps its data, as the postgres module does (novox/hq ADR 0338 §2): a cluster
+	// there is one initdb already set a password for. The docker volume genesis used before is not
+	// the store's data any more, and a machine holding only that is not refused.
+	if _, err := run(ctx, "test", "-e", StoreDataDir+"/pgdata/PG_VERSION"); err != nil {
+		return nil // no cluster there: a fresh machine, which is the case this installer makes
 	}
 	return fmt.Errorf(
-		"this machine already holds the store's data (volume mesh-store-data) and no credential at %s, so it was raised "+
+		"this machine already holds the store's data (in "+StoreDataDir+") and no credential at %s, so it was raised "+
 			"by an earlier installer with the template's password. A new one made here would not open it. "+
 			"Put the password the store has into %s (0600, the value alone) and run again; then change it "+
 			"on the server and accept the new value — this installer does not rotate a running store",
@@ -311,7 +317,7 @@ func RewriteRoot(r *Rewritten, c RootCredentials) (RootRewrite, error) {
 		return out, err
 	}
 	if bundle, err = replaceOnce(bundle, templateStoreVolumes,
-		`"volumes": ["mesh-store-data:/var/lib/postgresql/data", "`+StoreSuperuserFile+":"+storeSuperuserMount+`:ro"]`,
+		`"volumes": ["`+StoreDataDir+`:/var/lib/postgresql/data", "`+StoreSuperuserFile+":"+storeSuperuserMount+`:ro"]`,
 		"the store's volumes"); err != nil {
 		return out, err
 	}

internal/bootstrap/rootsecrets_test.go

@@ -59,7 +59,7 @@ func TestTheProducedBundleCarriesNoWellKnownCredential(t *testing.T) {
 		switch x := res.(type) {
 		case *declaration.Container:
 			switch x.Name {
-			case "mesh-store":
+			case "postgres":
 				store = true
 				if _, has := x.Env["POSTGRES_PASSWORD"]; has {
 					t.Error("the store still takes its password from its environment")

internal/bootstrap/store_layout_test.go

@@ -0,0 +1,163 @@
+package bootstrap
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-host/internal/declaration"
+)
+
+// Defends novox/hq ADR 0338 (issue 609): genesis raises its store as the postgres module's server, so
+// the store step adopts it as it runs. Until then the bundle raised `mesh-store`, on another image, in a
+// docker volume, and genesis stopped at step 17 of 24.
+
+// theStoreGenesisRaises is the store container of the bundle as the installer applies it: rewritten for
+// this machine's credentials, so its password is the file the module reads too.
+func theStoreGenesisRaises(t *testing.T) *declaration.Container {
+	t.Helper()
+	r := producedBundle(t)
+	store, err := storeIn(r.Declaration)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return store
+}
+
+// The bundle's store is exactly the catalogue's postgres module's server, read from the module's own
+// manifest (ADR 0338 §1): its name, its image (so a drift of either pin fails here), where its data is,
+// and the file its superuser password is read from, with the environment that says so.
+func TestTheBundleRaisesTheStoreAsTheCataloguesPostgresModuleDeclaresIt(t *testing.T) {
+	manifest := theCataloguesModule(t, "postgres")
+	var m struct {
+		Resources []struct {
+			ID      string            `json:"id"`
+			Type    string            `json:"type"`
+			Name    string            `json:"name"`
+			Image   string            `json:"image"`
+			Env     map[string]string `json:"env"`
+			Ports   []string          `json:"ports"`
+			Volumes []string          `json:"volumes"`
+		} `json:"resources"`
+	}
+	if err := json.Unmarshal(manifest, &m); err != nil {
+		t.Fatal(err)
+	}
+	ours := theStoreGenesisRaises(t)
+	found := false
+	for _, r := range m.Resources {
+		if r.Type != "container" || r.ID != "server" {
+			continue
+		}
+		found = true
+		if ours.Name != r.Name {
+			t.Errorf("the bundle raises the store as %q; the module's server is %q", ours.Name, r.Name)
+		}
+		if ours.Image != r.Image {
+			t.Errorf("the bundle raises the store on %s; the module pins %s — the two pins move together", ours.Image, r.Image)
+		}
+		for _, key := range []string{"POSTGRES_PASSWORD_FILE", "PGDATA"} {
+			if ours.Env[key] != r.Env[key] {
+				t.Errorf("the bundle's store has %s=%q; the module's %q", key, ours.Env[key], r.Env[key])
+			}
+		}
+		if _, has := ours.Env["POSTGRES_PASSWORD"]; has {
+			t.Error("the bundle's store takes its password from its environment; the module reads a file")
+		}
+		// The module's own directory for its state is <data root>/<module>, where genesis keeps the
+		// superuser's file (StoreSuperuserFile).
+		var theirs []string
+		for _, v := range r.Volumes {
+			theirs = append(theirs, strings.ReplaceAll(v, "${dir:state}", "/var/lib/postgres"))
+		}
+		if strings.Join(ours.Volumes, " ") != strings.Join(theirs, " ") {
+			t.Errorf("the bundle's store mounts %v; the module's %v", ours.Volumes, theirs)
+		}
+		if strings.Join(ours.Ports, " ") != strings.Join(r.Ports, " ") {
+			t.Errorf("the bundle publishes the store on %v; the module on %v", ours.Ports, r.Ports)
+		}
+		// And the store step's own check agrees: by name and image, before anything is registered.
+		if err := serverMatchesFoundation(manifest, ours, "postgres"); err != nil {
+			t.Errorf("the store step would refuse the store the bundle raises: %v", err)
+		}
+	}
+	if !found {
+		t.Fatal("the postgres module declares no server container")
+	}
+}
+
+// The store's data directory is made by the bundle before the store starts, owned by the image's
+// postgres user, as the module declares it (ADR 0338 §1, and the measurement under its §5).
+func TestTheBundleMakesTheStoresDataDirectoryAsTheModuleDoes(t *testing.T) {
+	r := producedBundle(t)
+	at, store := -1, -1
+	for i, res := range r.Declaration.Resources {
+		if d, ok := res.(*declaration.Directory); ok && d.Path == StoreDataDir {
+			at = i
+			if d.Mode != "0700" || d.Owner != "999:70" {
+				t.Errorf("the store's data directory is made %s %s; the module makes it 0700 999:70", d.Mode, d.Owner)
+			}
+		}
+		if res.Identity() == StoreID {
+			store = i
+		}
+	}
+	if at < 0 || store < 0 || at > store {
+		t.Fatalf("the store's data directory %s is not made before the store (directory at %d, store at %d)", StoreDataDir, at, store)
+	}
+}
+
+// No step of the bundle and no step of the installer names `mesh-store`, which is the seat's name only
+// (ADR 0338 §2): every step that reaches the store reaches the container the bundle raised.
+func TestNoStepReachesTheStoreByTheSeatsName(t *testing.T) {
+	text := string(theRealBundle(t))
+	for _, by := range []string{`"in": "mesh-store"`, `container:mesh-store`, `exec mesh-store`, `"name": "mesh-store"`, `mesh-store-data`} {
+		if strings.Contains(text, by) {
+			t.Errorf("the bundle still reaches the store as %s", by)
+		}
+	}
+	store := theStoreGenesisRaises(t)
+	if foundationStore != store.Name {
+		t.Errorf("the packages step reaches the store as %q; the bundle raises it as %q", foundationStore, store.Name)
+	}
+	r := producedBundle(t)
+	for _, res := range r.Declaration.Resources {
+		if a, ok := res.(*declaration.Action); ok && a.In != "" && a.In != store.Name && strings.Contains(a.ID, "database") {
+			t.Errorf("the step %s reaches the store in %q", a.ID, a.In)
+		}
+	}
+}
+
+// The installer's refusal to raise a store over data it cannot open looks where the store keeps its data
+// (ADR 0338 §2): a cluster there and no credential is refused; the old docker volume alone is not.
+func TestTheRefusalOverExistingDataLooksInTheStoresDirectory(t *testing.T) {
+	made := RootCredentials{Store: "s", Bus: "b", StoreMade: true}
+	machine := func(cluster, volume bool) Runner {
+		return func(_ context.Context, name string, args ...string) (string, error) {
+			joined := name + " " + strings.Join(args, " ")
+			switch {
+			case joined == "test -e "+StoreDataDir+"/pgdata/PG_VERSION":
+				if cluster {
+					return "", nil
+				}
+			case strings.HasPrefix(joined, "docker volume inspect"):
+				if volume {
+					return "[]", nil
+				}
+			}
+			return "", errors.New("exit status 1")
+		}
+	}
+	err := RefuseExistingServers(context.Background(), machine(true, false), made)
+	if err == nil || !strings.Contains(err.Error(), StoreDataDir) {
+		t.Fatalf("a cluster in %s and no credential was not refused naming it: %v", StoreDataDir, err)
+	}
+	if err := RefuseExistingServers(context.Background(), machine(false, true), made); err != nil {
+		t.Fatalf("a machine holding only the old volume was refused: %v", err)
+	}
+	if err := RefuseExistingServers(context.Background(), machine(true, false), RootCredentials{Store: "s"}); err != nil {
+		t.Fatalf("a kept credential was refused: %v", err)
+	}
+}

internal/bootstrap/verify_test.go

@@ -89,7 +89,7 @@ func TestAFoundationThatIsUpAndAnsweringIsAccepted(t *testing.T) {
 	// run-once and scheduled shapes are excluded on purpose — a step that has exited is not a
 	// fault. The name is `temp-mesh-controller` because the permanent one is a module and takes the
 	// plain name (novox/hq ADR 0067), which is what makes the two of them coexist at all.
-	want := []string{"mesh-store", "mesh-broker-nats", "temp-mesh-controller"}
+	want := []string{"postgres", "mesh-broker-nats", "temp-mesh-controller"}
 	if len(verified.Running) != len(want) {
 		t.Fatalf("confirmed %v running, want %v", verified.Running, want)
 	}

internal/declaration/busy.go

@@ -0,0 +1,87 @@
+package declaration
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// Busy is how a long-running container says it holds work that would be lost if it were stopped now
+// (novox/hq ADR 0335 §1): a command run inside it, by its shell, as an exec health check is, that exits 0
+// while it is busy and non-zero when it is idle. Being asked is also the container's notice that it is
+// about to be replaced: from the first ask it takes no new work, so its answer ends once the work in hand
+// ends.
+//
+// **Not part of what the container is.** Busy is not in the container's spec: a changed command changes
+// when the container is replaced, never whether — a container is not recreated for its busy command alone.
+type Busy struct {
+	Command string `json:"command"`
+	// Timeout is how long one ask may take; empty is BusyTimeoutDefault.
+	Timeout string `json:"timeout,omitempty"`
+}
+
+// The bounds of an ask (novox/hq ADR 0335).
+const (
+	BusyTimeoutDefault = 10 * time.Second
+	// BusyTimeoutCeiling is the longest one ask may take: an ask runs inside an apply, and an apply waits
+	// for nothing longer than a look.
+	BusyTimeoutCeiling = time.Minute
+	// BusyBound is how long a container that says busy is left running after the first apply that would
+	// have replaced it (ADR 0335 §3). The node-engine's, not the module's: no module holds its own
+	// replacement for ever.
+	BusyBound = 15 * time.Minute
+)
+
+// UnmarshalJSON reads a busy strictly, as everything a declaration carries is read.
+func (b *Busy) UnmarshalJSON(raw []byte) error {
+	type plain Busy
+	var p plain
+	dec := json.NewDecoder(bytes.NewReader(raw))
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(&p); err != nil {
+		return fmt.Errorf("busy: %w", err)
+	}
+	*b = Busy(p)
+	return nil
+}
+
+// Within is how long one ask may take. Validated on arrival, so an unreadable timeout is the default.
+func (b *Busy) Within() time.Duration {
+	if d, err := time.ParseDuration(b.Timeout); err == nil && d > 0 {
+		return d
+	}
+	return BusyTimeoutDefault
+}
+
+// problems holds a container's busy to its shape: a one-line command, a timeout within its bounds, and only
+// on a container that stays up.
+func (b *Busy) problems(where string, longRunning bool) []string {
+	if b == nil {
+		return nil
+	}
+	var problems []string
+	say := func(format string, args ...any) {
+		problems = append(problems, where+": "+fmt.Sprintf(format, args...))
+	}
+	if !longRunning {
+		say("busy is asked of a container that stays up; a step or a scheduled run is never replaced mid-run")
+	}
+	if strings.TrimSpace(b.Command) == "" {
+		say("busy needs a command")
+	}
+	if strings.ContainsAny(b.Command, "\n\r") {
+		say("busy's command is one line")
+	}
+	if b.Timeout != "" {
+		d, err := time.ParseDuration(b.Timeout)
+		switch {
+		case err != nil:
+			say("busy's timeout is a duration, not %q", b.Timeout)
+		case d <= 0 || d > BusyTimeoutCeiling:
+			say("an ask of busy takes more than nothing and at most %s, not %s", BusyTimeoutCeiling, d)
+		}
+	}
+	return problems
+}

internal/declaration/declaration.go

@@ -237,8 +237,45 @@ type File struct {
 
 	// Owner is the user this belongs to, by name. Absent means root.
 	Owner string `json:"owner,omitempty"`
+
+	// OwnerAtRuntime says who owns the file once it is placed (novox/hq ADR 0349 §5): "owned", the mesh's
+	// whole, written back whenever it differs; "seed", written once and then the program's; or "managed",
+	// only its named keys or its marked block the mesh's, the program keeping the rest.
+	//
+	// **Three words for what the forms above already do.** Owned is an ordinary file, seed is create-once
+	// and managed is a file written into, so the word changes no write: a file that says it is applied
+	// exactly as its old form is, and one that does not say is owned by its old form (Ownership). The word
+	// is what the provisioner's files say of themselves, which the old forms only implied. Seed is enough
+	// alone; managed still needs `into`, which says the format. A word that contradicts the form is refused.
+	OwnerAtRuntime string `json:"owner-at-runtime,omitempty"`
 }
 
+// The words a file says who owns it at runtime with (novox/hq ADR 0349 §5).
+const (
+	RuntimeOwned   = "owned"
+	RuntimeSeed    = "seed"
+	RuntimeManaged = "managed"
+)
+
+// Ownership is who owns the file at runtime: the word it says, or the one its old form implies — a file
+// written into is managed, one created once is a seed, and any other is owned.
+func (f *File) Ownership() string {
+	switch {
+	case f.OwnerAtRuntime != "":
+		return f.OwnerAtRuntime
+	case f.Into != "":
+		return RuntimeManaged
+	case f.CreateOnce:
+		return RuntimeSeed
+	default:
+		return RuntimeOwned
+	}
+}
+
+// Seeded reports whether the file is written only when absent: created once, by create-once or by the
+// word seed.
+func (f *File) Seeded() bool { return f.CreateOnce || f.OwnerAtRuntime == RuntimeSeed }
+
 // Secret reports whether this file arrived sealed, which is what decides both that it must be
 // opened before writing and that its contents must never appear in a report.
 func (f *File) Secret() bool { return f.Sealed != "" }
@@ -320,6 +357,7 @@ func (f *File) validate(where string, _ bool) []string {
 				"secrets or create-once")
 		}
 	}
+	problems = append(problems, f.checkOwnership(where)...)
 	var said []string
 	for name, value := range map[string]string{
 		"content": f.Content, "sealed": f.Sealed, "bytes": f.Bytes,
@@ -361,6 +399,42 @@ func (f *File) validate(where string, _ bool) []string {
 	return append(problems, checkMode(where, f.Mode)...)
 }
 
+// checkOwnership refuses a word that contradicts the file's form (novox/hq ADR 0349 §5): owned is a whole
+// file written back, so not created once nor written into; a seed is a whole file created once, so not
+// written into; managed is a file written into, which says its format. Managed and created once together
+// is already refused by the rule that a file written into is not created once.
+func (f *File) checkOwnership(where string) []string {
+	switch f.OwnerAtRuntime {
+	case "":
+	case RuntimeOwned:
+		var also []string
+		if f.CreateOnce {
+			also = append(also, "create-once")
+		}
+		if f.Into != "" {
+			also = append(also, "into")
+		}
+		if len(also) > 0 {
+			return []string{fmt.Sprintf("%s: owned at runtime is the mesh's whole file, written back whenever it "+
+				"differs, and this also says %s", where, strings.Join(also, " and "))}
+		}
+	case RuntimeSeed:
+		if f.Into != "" {
+			return []string{where + ": a seed is a whole file written once, and this says into; a file the " +
+				"program shares with the mesh is managed"}
+		}
+	case RuntimeManaged:
+		if f.Into == "" {
+			return []string{where + ": a managed file names the format its keys or block are written into, " +
+				"with into \"json\" or \"block\""}
+		}
+	default:
+		return []string{fmt.Sprintf("%s: owner-at-runtime %q; a placed file is %q, %q or %q, or omits it to be "+
+			"owned by its form", where, f.OwnerAtRuntime, RuntimeOwned, RuntimeSeed, RuntimeManaged)}
+	}
+	return nil
+}
+
 // User is a login on the machine.
 //
 // The thing that makes a shell, a chat client or a desktop expressible at all: each is a package
@@ -1239,6 +1313,11 @@ type Container struct {
 	// timing, judged by the node-engine beside liveness. Absent: judged alive or not, and nothing more.
 	Health *Health `json:"health,omitempty"`
 
+	// Busy is how this container says it holds work a replacement would lose (novox/hq ADR 0335): asked
+	// before it is replaced, and while it says busy it is left running, within the bound. Absent: never
+	// busy, and replaced at once, as before.
+	Busy *Busy `json:"busy,omitempty"`
+
 	// RunAs is who the container runs as, resolved by the controller from the module's identity and the
 	// image's declared interface (novox/hq ADR 0325 §2, §3): told by environment (the image reads PUID and
 	// PGID, say) or by the runtime's own user option. Part of the spec, so a change recreates it. Absent: the
@@ -1318,6 +1397,7 @@ func (c *Container) Target() string   { return c.Name }
 
 func (c *Container) validate(where string, _ bool) []string {
 	problems := c.Health.problems(where, true, !c.RunOnce && c.Schedule == "")
+	problems = append(problems, c.Busy.problems(where, !c.RunOnce && c.Schedule == "")...)
 	if c.Name == "" {
 		problems = append(problems, where+": a container needs a name")
 	}
@@ -1559,6 +1639,71 @@ type Declaration struct {
 	// this is its home, whether the operator's warrant to take it was carried out, the sub-paths its modules ask for,
 	// and the tool runner's account to put in its group (§11). Absent is a controller older than ADR 0328.
 	Libraries []Library
+
+	// Filled is the paths of the files the provisioner fills on this machine (novox/hq ADR 0349 §4, §5): each a
+	// file this declaration declares, which says who owns it at runtime. The provisioner's client has the
+	// node-engine write only these. Absent is a controller that hands no file to the provisioner, and every
+	// file is written from the declaration as before.
+	Filled []string
+
+	// Provisioner is the account the provisioner's client runs as on this machine, by name (novox/hq ADR 0349 §4):
+	// the only account whose write of a filled file the node-engine's local write socket accepts. Absent is a
+	// controller that names none, and every such write is refused.
+	Provisioner string
+}
+
+// checkProvisioner refuses a provisioner client's account that is no account name, or is root: the account whose
+// writes the node-engine accepts must be one that could not write the file without it.
+func checkProvisioner(name string) []string {
+	switch {
+	case name == "":
+		return nil
+	case !accountName.MatchString(name):
+		return []string{fmt.Sprintf("provisioner_account %q is not an account name", name)}
+	case name == "root":
+		return []string{"provisioner_account is root; the provisioner's client runs as an account of its own"}
+	}
+	return nil
+}
+
+// Fills reports whether the provisioner fills the file at path on this machine.
+func (d *Declaration) Fills(path string) bool { return slices.Contains(d.Filled, path) }
+
+// checkFilled refuses a filled path that is not a declared file saying who owns it at runtime, or that is named
+// twice or empty. Every file declared at the path must say it: the provisioner writes the path, and a file there
+// the mesh writes some other way would be a second writer of it (ADR 0349 §5).
+func checkFilled(filled []string, resources []Resource) []string {
+	var problems []string
+	files := map[string][]*File{}
+	for _, r := range resources {
+		if f, ok := r.(*File); ok {
+			files[f.Path] = append(files[f.Path], f)
+		}
+	}
+	seen := map[string]bool{}
+	for _, path := range filled {
+		switch {
+		case path == "":
+			problems = append(problems, "filled_files names a file with no path")
+			continue
+		case seen[path]:
+			problems = append(problems, fmt.Sprintf("filled_files names %q twice", path))
+			continue
+		}
+		seen[path] = true
+		if len(files[path]) == 0 {
+			problems = append(problems, fmt.Sprintf("filled_files names %q, and this declaration declares no "+
+				"file there", path))
+			continue
+		}
+		for _, f := range files[path] {
+			if f.OwnerAtRuntime == "" {
+				problems = append(problems, fmt.Sprintf("resource %q: the provisioner fills %q, and a file it "+
+					"fills says who owns it at runtime with owner-at-runtime", f.ID, path))
+			}
+		}
+	}
+	return problems
 }
 
 // Identity is one module's identity, as the controller allocated it (ADR 0328 §4): its user `mesh-<module>` with
@@ -1898,6 +2043,12 @@ type envelope struct {
 	// sends them only to a host whose health says link.LibraryContract.
 	Groups    []Group   `json:"groups,omitempty"`
 	Libraries []Library `json:"libraries,omitempty"`
+	// Filled is optional too (novox/hq ADR 0349 §5), as is a file's `owner-at-runtime`. **An older host refuses
+	// these keys**; a controller sends them only to a host whose health says link.OwnershipContract.
+	Filled []string `json:"filled_files,omitempty"`
+	// Provisioner is optional too (novox/hq ADR 0349 §4). **An older host refuses this key**; a controller sends it
+	// only to a host whose health says link.ProvisionerContract.
+	Provisioner string `json:"provisioner_account,omitempty"`
 }
 
 func parse(raw []byte, allowActions bool) (*Declaration, error) {
@@ -1916,8 +2067,10 @@ func parse(raw []byte, allowActions bool) (*Declaration, error) {
 
 	d := &Declaration{Version: env.Version, For: env.For, Adoption: env.Adoption, Sequence: env.Sequence,
 		Epoch: env.Epoch, LeftOut: env.LeftOut, Generation: env.Generation, PutBack: env.PutBack,
-		Identities: env.Identities, Groups: env.Groups, Libraries: env.Libraries}
+		Identities: env.Identities, Groups: env.Groups, Libraries: env.Libraries, Filled: env.Filled,
+		Provisioner: env.Provisioner}
 	problems := checkIdentities(env.Identities, env.Groups)
+	problems = append(problems, checkProvisioner(env.Provisioner)...)
 	problems = append(problems, checkLibraries(env.Groups, env.Libraries)...)
 	if env.Generation < 0 {
 		// Below zero would read as "none claimed" and pass every refusal of an older generation.
@@ -2009,6 +2162,7 @@ func parse(raw []byte, allowActions bool) (*Declaration, error) {
 	problems = append(problems, checkWhileStopped(d.Resources)...)
 	problems = append(problems, checkAdoption(env.Adoption, d.Resources, allowActions)...)
 	problems = append(problems, checkReplaces(d.Resources)...)
+	problems = append(problems, checkFilled(env.Filled, d.Resources)...)
 	if env.Adoption == nil {
 		for _, r := range d.Resources {
 			if r.Kind() == TypeOpening {

internal/declaration/ownership_test.go

@@ -0,0 +1,130 @@
+package declaration
+
+import (
+	"strings"
+	"testing"
+)
+
+// Defends novox/hq ADR 0349 §5 (issue 667): a file the provisioner places says who owns it at runtime
+// — owned, seed or managed — and the declaration names the files the provisioner fills. The words are
+// read and judged here before any controller sends them.
+
+func TestAFileSaysWhoOwnsItAtRuntime(t *testing.T) {
+	d, err := Parse([]byte(`{"declaration":1,"resources":[
+	  {"id":"o","type":"file","path":"/etc/o","content":"a","owner-at-runtime":"owned"},
+	  {"id":"s","type":"file","path":"/etc/s","content":"a","owner-at-runtime":"seed"},
+	  {"id":"s2","type":"file","path":"/etc/s2","content":"a","owner-at-runtime":"seed","create-once":true},
+	  {"id":"mj","type":"file","path":"/etc/mj","into":"json","content":"{\"k\":1}","owner-at-runtime":"managed"},
+	  {"id":"mb","type":"file","path":"/etc/mb","into":"block","content":"a\n","owner-at-runtime":"managed"}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := map[string]string{"o": RuntimeOwned, "s": RuntimeSeed, "s2": RuntimeSeed, "mj": RuntimeManaged,
+		"mb": RuntimeManaged}
+	for _, r := range d.Resources {
+		f := r.(*File)
+		if f.OwnerAtRuntime != want[f.ID] || f.Ownership() != want[f.ID] {
+			t.Errorf("%s: read as %q, ownership %q; want %q", f.ID, f.OwnerAtRuntime, f.Ownership(), want[f.ID])
+		}
+	}
+}
+
+// A file that does not say is owned by its old form, so the word means exactly what that form does.
+func TestAFileThatDoesNotSayIsOwnedByItsOldForm(t *testing.T) {
+	d, err := Parse([]byte(`{"declaration":1,"resources":[
+	  {"id":"o","type":"file","path":"/etc/o","content":"a"},
+	  {"id":"s","type":"file","path":"/etc/s","content":"a","create-once":true},
+	  {"id":"mj","type":"file","path":"/etc/mj","into":"json","content":"{}"},
+	  {"id":"mb","type":"file","path":"/etc/mb","into":"block","content":"a\n"}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := map[string]string{"o": RuntimeOwned, "s": RuntimeSeed, "mj": RuntimeManaged, "mb": RuntimeManaged}
+	for _, r := range d.Resources {
+		f := r.(*File)
+		if f.OwnerAtRuntime != "" || f.Ownership() != want[f.ID] {
+			t.Errorf("%s: said %q, ownership %q; want unsaid and %q", f.ID, f.OwnerAtRuntime, f.Ownership(), want[f.ID])
+		}
+		if f.Seeded() != (want[f.ID] == RuntimeSeed) {
+			t.Errorf("%s: seeded %v", f.ID, f.Seeded())
+		}
+	}
+}
+
+func TestAnOwnershipThatContradictsTheFileIsRefused(t *testing.T) {
+	for name, c := range map[string]struct{ resource, refusal string }{
+		"another word": {`{"id":"f","type":"file","path":"/etc/x","content":"a","owner-at-runtime":"mine"}`,
+			`owner-at-runtime "mine"`},
+		"owned and create-once": {`{"id":"f","type":"file","path":"/etc/x","content":"a","owner-at-runtime":"owned","create-once":true}`,
+			"create-once"},
+		"owned and into": {`{"id":"f","type":"file","path":"/etc/x","into":"json","content":"{}","owner-at-runtime":"owned"}`,
+			"into"},
+		"seed and into": {`{"id":"f","type":"file","path":"/etc/x","into":"block","content":"a","owner-at-runtime":"seed"}`,
+			"into"},
+		"managed and whole": {`{"id":"f","type":"file","path":"/etc/x","content":"a","owner-at-runtime":"managed"}`,
+			"into"},
+		"managed and create-once": {`{"id":"f","type":"file","path":"/etc/x","into":"json","content":"{}","owner-at-runtime":"managed","create-once":true}`,
+			"create-once"},
+		// The rule that was there before stays: a file written into is never sealed or created once.
+		"managed and sealed": {`{"id":"f","type":"file","path":"/etc/x","into":"json","content":"{}","sealed":"x","owner-at-runtime":"managed"}`,
+			"sealed"},
+	} {
+		_, err := Parse([]byte(`{"declaration":1,"resources":[` + c.resource + `]}`))
+		if err == nil || !strings.Contains(err.Error(), c.refusal) {
+			t.Errorf("%s: want a refusal naming %q, got %v", name, c.refusal, err)
+		}
+	}
+}
+
+func TestTheDeclarationNamesTheFilesTheProvisionerFills(t *testing.T) {
+	d, err := Parse([]byte(`{"declaration":1,"filled_files":["/etc/a","/etc/b"],"resources":[
+	  {"id":"a","type":"file","path":"/etc/a","content":"a","owner-at-runtime":"owned"},
+	  {"id":"b","type":"file","path":"/etc/b","into":"block","content":"b\n","owner-at-runtime":"managed"},
+	  {"id":"c","type":"file","path":"/etc/c","content":"c"}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(d.Filled) != 2 || d.Filled[0] != "/etc/a" || d.Filled[1] != "/etc/b" {
+		t.Fatalf("filled files read as %v", d.Filled)
+	}
+	if !d.Fills("/etc/a") || !d.Fills("/etc/b") || d.Fills("/etc/c") {
+		t.Errorf("Fills: a %v, b %v, c %v", d.Fills("/etc/a"), d.Fills("/etc/b"), d.Fills("/etc/c"))
+	}
+
+	// A declaration that names none fills none, as every declaration before this did.
+	d, err = Parse([]byte(`{"declaration":1,"resources":[{"id":"c","type":"file","path":"/etc/c","content":"c"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d.Filled != nil || d.Fills("/etc/c") {
+		t.Errorf("a declaration naming no filled files fills %v", d.Filled)
+	}
+}
+
+func TestAFilledFileMustBeADeclaredFileThatSaysItsOwner(t *testing.T) {
+	for name, c := range map[string]struct{ filled, resources, refusal string }{
+		"not declared": {`["/etc/none"]`,
+			`{"id":"a","type":"file","path":"/etc/a","content":"a","owner-at-runtime":"owned"}`,
+			`"/etc/none"`},
+		"a directory, not a file": {`["/etc/d"]`,
+			`{"id":"d","type":"directory","path":"/etc/d"}`,
+			`"/etc/d"`},
+		"says no owner": {`["/etc/a"]`,
+			`{"id":"a","type":"file","path":"/etc/a","content":"a"}`,
+			"owner-at-runtime"},
+		"named twice": {`["/etc/a","/etc/a"]`,
+			`{"id":"a","type":"file","path":"/etc/a","content":"a","owner-at-runtime":"owned"}`,
+			"twice"},
+		"no path": {`[""]`,
+			`{"id":"a","type":"file","path":"/etc/a","content":"a","owner-at-runtime":"owned"}`,
+			"no path"},
+	} {
+		_, err := Parse([]byte(`{"declaration":1,"filled_files":` + c.filled + `,"resources":[` + c.resources + `]}`))
+		if err == nil || !strings.Contains(err.Error(), c.refusal) {
+			t.Errorf("%s: want a refusal naming %q, got %v", name, c.refusal, err)
+		}
+	}
+}

internal/declaration/provisioner_test.go

@@ -0,0 +1,37 @@
+package declaration
+
+import (
+	"strings"
+	"testing"
+)
+
+// Defends novox/hq ADR 0349 §4 (issue 668): the declaration names the account the provisioner's client runs as,
+// the only one whose write of a filled file the node-engine accepts. Read here before any controller sends it.
+
+func TestTheDeclarationNamesTheProvisionersAccount(t *testing.T) {
+	d, err := Parse([]byte(`{"declaration":1,"provisioner_account":"mesh-node-provisioner","filled_files":["/etc/a"],
+	  "resources":[{"id":"a","type":"file","path":"/etc/a","content":"a","owner-at-runtime":"owned"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d.Provisioner != "mesh-node-provisioner" {
+		t.Errorf("the provisioner's account read as %q", d.Provisioner)
+	}
+	d, err = Parse([]byte(`{"declaration":1,"resources":[{"id":"a","type":"file","path":"/etc/a","content":"a"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if d.Provisioner != "" {
+		t.Errorf("a declaration naming no account names %q", d.Provisioner)
+	}
+}
+
+func TestAProvisionersAccountThatIsNoAccountIsRefused(t *testing.T) {
+	for name, account := range map[string]string{"root": "root", "not a name": "a b", "a path": "../x"} {
+		_, err := Parse([]byte(`{"declaration":1,"provisioner_account":"` + account + `",
+		  "resources":[{"id":"a","type":"file","path":"/etc/a","content":"a"}]}`))
+		if err == nil || !strings.Contains(err.Error(), "provisioner_account") {
+			t.Errorf("%s: want a refusal naming provisioner_account, got %v", name, err)
+		}
+	}
+}

internal/filling/filling.go

@@ -0,0 +1,512 @@
+// Package filling is the node-engine's narrow local write verb (novox/hq ADR 0349 §4, design 57 P2): a socket on
+// this machine through which the provisioner's client has a file it filled written, and nothing else.
+//
+// **The client fills; the node-engine writes.** The client renders a module's template with the values each domain
+// owns and hands the node-engine the content; the node-engine writes it as the declared file, with the declared
+// file's path, owner, mode and ownership at runtime, and makes what reads it take the change. So the one process that
+// writes the machine's files is still the node-engine, and the client needs no right to write any of them.
+//
+// **Narrow by three checks, each from something the client cannot say for itself.** The account asking, from the
+// kernel (SO_PEERCRED), in this machine's own namespaces, must be the account the node's current declaration names
+// as the provisioner's client's; the path, clean and absolute, must be one the declaration names as filled; and the
+// write takes the apply's lock, so a write and an apply never write one file at once. While the declaration names no
+// account — every declaration before the provisioner's client has one — every write is refused.
+//
+// **No listening control surface** (novox/hq ADR 0004): the socket has no network address. And the content is never
+// said: the journal has the path, the account and the content's digest.
+package filling
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"os/user"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/novox/mesh-host/internal/declaration"
+	"github.com/novox/mesh-host/internal/meshcli"
+)
+
+// Socket is where the node-engine accepts a write of a filled file, beside mesh-cli's socket.
+const Socket = "/run/nox-mesh-host/fill.sock"
+
+// MaxRequest bounds one request, its content encoded in it: a configuration file, never an archive.
+const MaxRequest = 8 << 20
+
+// Request is one write, sent as one JSON object on one line: the path of a filled file and what the client filled
+// into it (base64 in the JSON). The content only: the declaration says everything else about the file.
+type Request struct {
+	Path    string `json:"path"`
+	Content []byte `json:"content"`
+}
+
+// Answer is what came of one request. Refused is a write that was not attempted, with why; Failed one that was
+// attempted and did not complete, with why — the file, or something that reads it. Otherwise Action is what the
+// write did to the file (created, updated, corrected, unchanged, kept) and Digest what the file holds now, as the
+// node-engine records it.
+type Answer struct {
+	Path    string `json:"path,omitempty"`
+	Action  string `json:"action,omitempty"`
+	Digest  string `json:"digest,omitempty"`
+	Refused string `json:"refused,omitempty"`
+	Failed  string `json:"failed,omitempty"`
+}
+
+// Refusal is an answer that nothing was written, and why.
+func Refusal(path, why string) Answer { return Answer{Path: path, Refused: why} }
+
+// Writer is the node-engine's side of the socket.
+type Writer interface {
+	// Accepts judges the asking account before its request is read: nil when the current declaration names it as
+	// the provisioner's client's.
+	Accepts(uid uint32) error
+	// Write judges the request and writes it, holding the apply's lock.
+	Write(ctx context.Context, uid uint32, req Request) Answer
+}
+
+// Engine is the Writer the node-engine serves: the declaration it applies now, read again under the apply's lock.
+type Engine struct {
+	// Declared reads the declaration this node applies now, verified.
+	Declared func() (*declaration.Declaration, error)
+	// UIDOf is the user id of an account, by name, from this machine's user database.
+	UIDOf func(account string) (uint32, error)
+	// Lock takes the apply's lock and returns what releases it: the same the apply takes, so a write and an apply
+	// are one at a time.
+	Lock func() (func(), error)
+	// Place writes the content into the filled file at path, as the declared file, and makes what reads it take the
+	// change. Called holding the lock, with the declaration read under it.
+	Place func(ctx context.Context, d *declaration.Declaration, path string, content []byte) (action, digest string,
+		err error)
+}
+
+// Accepts reads the declaration and judges the account.
+func (e *Engine) Accepts(uid uint32) error {
+	d, err := e.Declared()
+	if err != nil {
+		return fmt.Errorf("this node's declaration cannot be read, so no write is accepted: %w", err)
+	}
+	return JudgeAccount(d, uid, e.UIDOf)
+}
+
+// Write takes the apply's lock, reads the declaration under it, judges the account and the path again — the
+// declaration may have changed since the request was accepted — and writes.
+func (e *Engine) Write(ctx context.Context, uid uint32, req Request) Answer {
+	if err := JudgeShape(req.Path); err != nil {
+		return Refusal(req.Path, err.Error())
+	}
+	unlock, err := e.Lock()
+	if err != nil {
+		return Refusal(req.Path, "the apply's lock could not be taken, so nothing was written: "+err.Error())
+	}
+	defer unlock()
+	d, err := e.Declared()
+	if err != nil {
+		return Refusal(req.Path, "this node's declaration cannot be read, so nothing was written: "+err.Error())
+	}
+	if err := JudgeAccount(d, uid, e.UIDOf); err != nil {
+		return Refusal(req.Path, err.Error())
+	}
+	if err := JudgePath(d, req.Path); err != nil {
+		return Refusal(req.Path, err.Error())
+	}
+	action, digest, err := e.Place(ctx, d, req.Path, req.Content)
+	if err != nil {
+		return Answer{Path: req.Path, Action: action, Digest: digest, Failed: err.Error()}
+	}
+	return Answer{Path: req.Path, Action: action, Digest: digest}
+}
+
+// JudgeAccount refuses every account but the one the declaration names as the provisioner's client's, by its user
+// id here — and every account while the declaration names none.
+func JudgeAccount(d *declaration.Declaration, uid uint32, uidOf func(string) (uint32, error)) error {
+	if d.Provisioner == "" {
+		return errors.New("this node's declaration names no provisioner client's account, so no write is accepted")
+	}
+	want, err := uidOf(d.Provisioner)
+	if err != nil {
+		return fmt.Errorf("the provisioner client's account %s is not on this machine, so no write is accepted: %w",
+			d.Provisioner, err)
+	}
+	if want == 0 {
+		return fmt.Errorf("the provisioner client's account %s is root here, so no write is accepted", d.Provisioner)
+	}
+	if uid != want {
+		return fmt.Errorf("user id %d is not the provisioner client's account %s (user id %d), so nothing was written",
+			uid, d.Provisioner, want)
+	}
+	return nil
+}
+
+// JudgeShape refuses a path that is not clean and absolute: a relative path, `..`, a doubled or trailing slash.
+// Compared as written with the declaration's, a path that is not clean could name a file the declaration does not.
+func JudgeShape(path string) error {
+	switch {
+	case path == "":
+		return errors.New("the request names no path, so nothing was written")
+	case !filepath.IsAbs(path):
+		return fmt.Errorf("%q is not an absolute path, so nothing was written", path)
+	case filepath.Clean(path) != path:
+		return fmt.Errorf("%q is not a clean path (it is %q cleaned), so nothing was written", path,
+			filepath.Clean(path))
+	}
+	return nil
+}
+
+// JudgePath refuses a path that is not clean and absolute, or that the declaration does not name as filled. Where it
+// leads — a link on the way, a place nothing is written — is judged by the write, by the apply's own rules.
+func JudgePath(d *declaration.Declaration, path string) error {
+	if err := JudgeShape(path); err != nil {
+		return err
+	}
+	if !d.Fills(path) {
+		return fmt.Errorf("%s is not a file this node's declaration names as filled, so nothing was written", path)
+	}
+	return nil
+}
+
+// UIDOf is the user id of an account by name, from this machine's user database.
+func UIDOf(account string) (uint32, error) {
+	u, err := user.Lookup(account)
+	if err != nil {
+		return 0, err
+	}
+	id, err := strconv.ParseUint(u.Uid, 10, 32)
+	if err != nil {
+		return 0, fmt.Errorf("user id %q: %w", u.Uid, err)
+	}
+	return uint32(id), nil
+}
+
+// peerOf and sameNamespaces are the kernel's word on the asking process, as mesh-cli's socket reads it. Variables so
+// a test can say.
+var (
+	peerOf         = meshcli.PeerCredentials
+	sameNamespaces = meshcli.SameNamespaces
+)
+
+// within bounds how long an accepted connection may take to say its request, and refusedWithin how long a busy one
+// is read and dropped before its refusal is written (so the client is not answered with a broken pipe). Variables so
+// a test need not wait.
+var (
+	within        = 30 * time.Second
+	refusedWithin = 1 * time.Second
+)
+
+// atOnce bounds the accepted connections served at the same time: one client, writing one file at a time. One over
+// is refused busy. busyWaitingAtOnce bounds how many busy refusals wait for their request at once, per Serve; over it
+// a busy refusal is written at once, as mesh-cli's socket does. judgingAtOnce bounds the callers judged at once, and
+// judgeWaiting the connections waiting to be judged — each an open file, so far below the engine's open-file limit;
+// one over is closed at once, unread. Variables so a test can say.
+var (
+	atOnce            = 4
+	busyWaitingAtOnce = 8
+	judgingAtOnce     = 16
+	judgeWaiting      = 256
+)
+
+// refusalsSaidEvery is how often the refusals counted and not yet said are said: each kind of refusal of each account
+// is said at once the first time, and what follows it within this time is counted and said at its end, or when the
+// socket stops. A variable so a test need not wait.
+var refusalsSaidEvery = time.Minute
+
+// acceptBackoff is how long the socket waits after an accept that failed before it accepts again, at first and at
+// most: a socket that stopped at the first such failure (too many open files, say) would stop the client's writes
+// until the engine restarted. Variables so a test need not wait.
+var (
+	acceptBackoff    = 50 * time.Millisecond
+	acceptBackoffMax = 5 * time.Second
+)
+
+// acceptFrom accepts one connection. A variable so a test can make it fail.
+var acceptFrom = func(l *net.UnixListener) (*net.UnixConn, error) { return l.AcceptUnix() }
+
+// Serve listens on socket until ctx ends, and answers each connection: one request, one answer.
+//
+// The directory is made 0755 and the socket 0666, as mesh-cli's: who may write is judged per connection from the
+// kernel's word, against the current declaration, so the socket needs no account that may not exist yet. **The
+// caller is judged before it holds anything**: one the kernel does not say is the provisioner client's account is
+// answered and closed at once, and only the client's connections are served or wait as busy, so no other account can
+// hold the socket from it. A file at the socket's path that is not a socket is never removed: the engine says so and
+// serves nothing.
+func Serve(ctx context.Context, socket string, w Writer, say func(string)) error {
+	if say == nil {
+		say = func(string) {}
+	}
+	dir := filepath.Dir(socket)
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return fmt.Errorf("the filled files' socket directory: %w", err)
+	}
+	if problem := meshcli.NotOwnDirectory(dir); problem != "" {
+		return fmt.Errorf("filled files are not written on request on this machine: %s", problem)
+	}
+	if err := os.Chmod(dir, 0o755); err != nil {
+		return fmt.Errorf("the filled files' socket directory: %w", err)
+	}
+	if info, err := os.Lstat(socket); err == nil {
+		if info.Mode()&os.ModeSocket == 0 {
+			return fmt.Errorf("%s is there and is not a socket, and the node-engine did not put it there; filled "+
+				"files are not written on request until it is moved", socket)
+		}
+		if err := os.Remove(socket); err != nil {
+			return fmt.Errorf("the socket a previous engine left at %s: %w", socket, err)
+		}
+	}
+	l, err := net.ListenUnix("unix", &net.UnixAddr{Name: socket, Net: "unix"})
+	if err != nil {
+		return fmt.Errorf("listening for filled files at %s: %w", socket, err)
+	}
+	if err := os.Chmod(socket, 0o666); err != nil {
+		l.Close()
+		return fmt.Errorf("opening the filled files' socket: %w", err)
+	}
+	go func() {
+		<-ctx.Done()
+		l.Close()
+	}()
+	slots := make(chan struct{}, atOnce)
+	// Judging reads the declaration: at most judging callers are judged at once, and the rest wait their turn — a
+	// few milliseconds each — rather than being refused, so a flood delays the client's write and never stops it.
+	judging := make(chan struct{}, judgingAtOnce)
+	var waiting atomic.Int64
+	busyWaiting := make(chan struct{}, busyWaitingAtOnce)
+	refusals := &refusalWords{say: say}
+	// Said once everything has stopped: what was counted is never lost with the socket.
+	defer refusals.flush()
+	var wg sync.WaitGroup
+	defer wg.Wait()
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		tick := time.NewTicker(refusalsSaidEvery)
+		defer tick.Stop()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-tick.C:
+				refusals.flush()
+			}
+		}
+	}()
+	backoff := time.Duration(0)
+	for {
+		conn, err := acceptFrom(l)
+		if err != nil {
+			if ctx.Err() != nil {
+				return nil
+			}
+			if errors.Is(err, net.ErrClosed) {
+				return fmt.Errorf("the filled files' socket was closed: %w", err)
+			}
+			// Said, waited for, and accepted again: the failure is the machine's for a moment, not the socket's.
+			backoff = min(max(2*backoff, acceptBackoff), acceptBackoffMax)
+			say(fmt.Sprintf("the filled files' socket could not accept a connection (%v); accepting again in %s",
+				err, backoff))
+			select {
+			case <-ctx.Done():
+				return nil
+			case <-time.After(backoff):
+			}
+			continue
+		}
+		backoff = 0
+		if waiting.Add(1) > int64(judgeWaiting) {
+			// Too many waiting to be judged already: this one is closed unread, and counted.
+			waiting.Add(-1)
+			refusals.said(^uint32(0), "overflow", "too many connections are waiting to be judged; closed unread")
+			conn.Close()
+			continue
+		}
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			// Judged before it holds a slot or is waited for.
+			judging <- struct{}{}
+			uid, ok := judgePeer(conn, w, refusals)
+			<-judging
+			waiting.Add(-1)
+			if !ok {
+				return
+			}
+			readBy := time.Now().Add(within)
+			_ = conn.SetDeadline(readBy)
+			select {
+			case slots <- struct{}{}:
+				defer func() { <-slots }()
+				answer(ctx, conn, uid, w, say)
+			default:
+				busy(conn, readBy, busyWaiting, say)
+			}
+		}()
+	}
+}
+
+// judgePeer reads the asking account from the kernel and judges it. A caller that is not the provisioner client's
+// account is answered with why and closed at once, its request never read: false.
+func judgePeer(conn *net.UnixConn, w Writer, refusals *refusalWords) (uint32, bool) {
+	closeWith := func(uid uint32, kind, why string) (uint32, bool) {
+		refusals.said(uid, kind, why)
+		_ = conn.SetWriteDeadline(time.Now().Add(refusedWithin))
+		_ = json.NewEncoder(conn).Encode(Refusal("", why))
+		conn.Close()
+		return uid, false
+	}
+	uid, pid, err := peerOf(conn)
+	if err != nil {
+		return closeWith(^uint32(0), "unread", "the node-engine could not read which account is asking, so nothing was "+
+			"written: "+err.Error())
+	}
+	if err := sameNamespaces(pid); err != nil {
+		return closeWith(uid, "namespace", "the asking process does not run in this machine's own namespaces, so nothing was "+
+			"written: "+err.Error())
+	}
+	if err := w.Accepts(uid); err != nil {
+		return closeWith(uid, "account", err.Error())
+	}
+	return uid, true
+}
+
+// refusalWords says refused callers in the journal without letting a flood flood it: the first refusal of each kind
+// for each account at once, and those that follow it counted and said by flush — on a timer and when the socket stops
+// — so an account that stops still has its count said, and a refusal of another kind never hides behind one said.
+type refusalWords struct {
+	mu      sync.Mutex
+	say     func(string)
+	pending map[refusalKey]*refusalCount
+}
+
+type refusalKey struct {
+	uid  uint32
+	kind string
+}
+
+type refusalCount struct {
+	n   int
+	why string
+}
+
+func (r *refusalWords) said(uid uint32, kind, why string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.pending == nil {
+		r.pending = map[refusalKey]*refusalCount{}
+	}
+	k := refusalKey{uid, kind}
+	if c, ok := r.pending[k]; ok {
+		c.n++
+		c.why = why
+		return
+	}
+	r.pending[k] = &refusalCount{}
+	r.say(fmt.Sprintf("a filled file's write from %s was refused (%s): %s", who(k), kind, why))
+}
+
+// flush says what was counted since each was last said, and forgets every key, so the next refusal of each is said at
+// once again.
+func (r *refusalWords) flush() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	keys := make([]refusalKey, 0, len(r.pending))
+	for k := range r.pending {
+		keys = append(keys, k)
+	}
+	sort.Slice(keys, func(i, j int) bool {
+		if keys[i].uid != keys[j].uid {
+			return keys[i].uid < keys[j].uid
+		}
+		return keys[i].kind < keys[j].kind
+	})
+	for _, k := range keys {
+		if c := r.pending[k]; c.n > 0 {
+			r.say(fmt.Sprintf("%d more writes of a filled file from %s were refused (%s) since it was last said; the last: %s",
+				c.n, who(k), k.kind, c.why))
+		}
+	}
+	r.pending = nil
+}
+
+// who names a caller by its user id, or says why it has none.
+func who(k refusalKey) string {
+	switch {
+	case k.kind == "overflow":
+		return "a caller not yet judged"
+	case k.uid == ^uint32(0):
+		return "an account that could not be read"
+	}
+	return fmt.Sprintf("user id %d", k.uid)
+}
+
+// answer serves one connection from the provisioner client's account.
+func answer(ctx context.Context, conn *net.UnixConn, uid uint32, w Writer, say func(string)) {
+	var req Request
+	dec := json.NewDecoder(io.LimitReader(conn, MaxRequest))
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(&req); err != nil {
+		// Answered even when the deadline to say it passed: the deadline covered the write too.
+		_ = conn.SetWriteDeadline(time.Now().Add(refusedWithin))
+		reply(conn, Refusal("", "the request could not be read, so nothing was written: "+err.Error()), say)
+		return
+	}
+	// The write waits for the apply's lock as long as an apply takes, and the client waits with it.
+	_ = conn.SetDeadline(time.Time{})
+	a := w.Write(ctx, uid, req)
+	switch {
+	case a.Refused != "":
+		say(fmt.Sprintf("a write of %s from user id %d was refused: %s", req.Path, uid, a.Refused))
+	case a.Failed != "":
+		say(fmt.Sprintf("a write of %s from user id %d failed: %s", req.Path, uid, a.Failed))
+	default:
+		say(fmt.Sprintf("wrote %s for the provisioner's client (user id %d): %s, %s", req.Path, uid, a.Action,
+			a.Digest))
+	}
+	_ = conn.SetWriteDeadline(time.Now().Add(within))
+	reply(conn, a, say)
+}
+
+// busy answers the client's connection over atOnce: its request read and dropped first, briefly, so the client reads
+// the answer rather than a broken pipe — while no more than busyWaiting such refusals wait at once; over that, at once.
+func busy(conn *net.UnixConn, readBy time.Time, busyWaiting chan struct{}, say func(string)) {
+	select {
+	case busyWaiting <- struct{}{}:
+		by := time.Now().Add(refusedWithin)
+		if readBy.Before(by) {
+			by = readBy
+		}
+		_ = conn.SetReadDeadline(by)
+		drain(conn)
+		<-busyWaiting
+	default:
+	}
+	_ = conn.SetWriteDeadline(time.Now().Add(refusedWithin))
+	reply(conn, Refusal("", "busy: other writes are being served; ask again"), say)
+}
+
+// drain reads and drops a request up to its end — the newline after it, the end of the stream or the deadline —
+// and at most MaxRequest bytes, keeping none of it.
+func drain(r io.Reader) {
+	var buf [4096]byte
+	for read := 0; read < MaxRequest; {
+		n, err := r.Read(buf[:])
+		read += n
+		if bytes.IndexByte(buf[:n], '\n') >= 0 || err != nil {
+			return
+		}
+	}
+}
+
+func reply(conn *net.UnixConn, a Answer, say func(string)) {
+	defer conn.Close()
+	if err := json.NewEncoder(conn).Encode(a); err != nil {
+		say("a filled file's answer could not be written back: " + err.Error())
+	}
+}

internal/filling/filling_test.go

@@ -0,0 +1,561 @@
+package filling
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/novox/mesh-host/internal/declaration"
+)
+
+// Defends novox/hq ADR 0349 §4 (issue 668): the node-engine writes a filled file on request only for the provisioner
+// client's account, only for a clean path the current declaration names as filled, and one at a time with the apply.
+
+const provisionerUID = 4242
+
+func declared(t *testing.T, raw string) *declaration.Declaration {
+	t.Helper()
+	d, err := declaration.Parse([]byte(raw))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return d
+}
+
+const withAccount = `{"declaration":1,"provisioner_account":"mesh-node-provisioner","filled_files":["/etc/m/m.conf"],
+  "resources":[{"id":"m.conf","type":"file","path":"/etc/m/m.conf","content":"x","owner-at-runtime":"owned"},
+  {"id":"m.other","type":"file","path":"/etc/m/other.conf","content":"y"}]}`
+
+const withoutAccount = `{"declaration":1,"filled_files":["/etc/m/m.conf"],
+  "resources":[{"id":"m.conf","type":"file","path":"/etc/m/m.conf","content":"x","owner-at-runtime":"owned"}]}`
+
+// engine is an Engine over a fixed declaration, recording what it was asked to place.
+type engine struct {
+	Engine
+	mu     sync.Mutex
+	placed []string
+}
+
+func newEngine(t *testing.T, raw string, lock sync.Locker) *engine {
+	d := declared(t, raw)
+	e := &engine{}
+	e.Engine = Engine{
+		Declared: func() (*declaration.Declaration, error) { return d, nil },
+		UIDOf: func(name string) (uint32, error) {
+			if name == "mesh-node-provisioner" {
+				return provisionerUID, nil
+			}
+			return 0, errors.New("no such account")
+		},
+		Lock: func() (func(), error) { lock.Lock(); return lock.Unlock, nil },
+		Place: func(_ context.Context, _ *declaration.Declaration, path string, content []byte) (string, string, error) {
+			e.mu.Lock()
+			defer e.mu.Unlock()
+			e.placed = append(e.placed, path)
+			return "updated", "digest", nil
+		},
+	}
+	return e
+}
+
+func TestAWriteFromTheProvisionersAccountOfAFilledPathIsPlaced(t *testing.T) {
+	e := newEngine(t, withAccount, &sync.Mutex{})
+	if err := e.Accepts(provisionerUID); err != nil {
+		t.Fatal(err)
+	}
+	a := e.Write(context.Background(), provisionerUID, Request{Path: "/etc/m/m.conf", Content: []byte("x")})
+	if a.Refused != "" || a.Failed != "" || a.Action != "updated" || len(e.placed) != 1 {
+		t.Fatalf("answer %+v, placed %v", a, e.placed)
+	}
+}
+
+func TestAnUndeclaredPathIsRefused(t *testing.T) {
+	e := newEngine(t, withAccount, &sync.Mutex{})
+	for _, path := range []string{"/etc/m/other.conf", "/etc/m/none.conf", "/etc/passwd"} {
+		a := e.Write(context.Background(), provisionerUID, Request{Path: path, Content: []byte("evil")})
+		if a.Refused == "" || !strings.Contains(a.Refused, "not a file this node's declaration names as filled") {
+			t.Errorf("%s: %+v", path, a)
+		}
+	}
+	if len(e.placed) != 0 {
+		t.Errorf("placed %v", e.placed)
+	}
+}
+
+func TestAnotherAccountIsRefused(t *testing.T) {
+	e := newEngine(t, withAccount, &sync.Mutex{})
+	for _, uid := range []uint32{0, 1000, provisionerUID + 1} {
+		if err := e.Accepts(uid); err == nil {
+			t.Errorf("user id %d was accepted", uid)
+		}
+		a := e.Write(context.Background(), uid, Request{Path: "/etc/m/m.conf", Content: []byte("evil")})
+		if a.Refused == "" || !strings.Contains(a.Refused, "is not the provisioner client's account") {
+			t.Errorf("user id %d: %+v", uid, a)
+		}
+	}
+	if len(e.placed) != 0 {
+		t.Errorf("placed %v", e.placed)
+	}
+}
+
+func TestEveryWriteIsRefusedWhileTheDeclarationNamesNoAccount(t *testing.T) {
+	e := newEngine(t, withoutAccount, &sync.Mutex{})
+	if err := e.Accepts(provisionerUID); err == nil || !strings.Contains(err.Error(), "names no provisioner") {
+		t.Errorf("accepted with no account named: %v", err)
+	}
+	a := e.Write(context.Background(), provisionerUID, Request{Path: "/etc/m/m.conf", Content: []byte("x")})
+	if a.Refused == "" || len(e.placed) != 0 {
+		t.Errorf("written with no account named: %+v", a)
+	}
+}
+
+func TestAnAccountThatIsRootHereIsRefused(t *testing.T) {
+	e := newEngine(t, withAccount, &sync.Mutex{})
+	e.UIDOf = func(string) (uint32, error) { return 0, nil }
+	if err := e.Accepts(0); err == nil || !strings.Contains(err.Error(), "root") {
+		t.Errorf("an account that is root here was accepted: %v", err)
+	}
+}
+
+func TestAnUncleanPathIsRefused(t *testing.T) {
+	e := newEngine(t, withAccount, &sync.Mutex{})
+	for _, path := range []string{"", "etc/m/m.conf", "m.conf", "/etc//m/m.conf", "/etc/m/../m/m.conf",
+		"/etc/m/./m.conf", "/etc/m/m.conf/"} {
+		a := e.Write(context.Background(), provisionerUID, Request{Path: path, Content: []byte("x")})
+		if a.Refused == "" {
+			t.Errorf("%q was not refused: %+v", path, a)
+		}
+	}
+	if len(e.placed) != 0 {
+		t.Errorf("placed %v", e.placed)
+	}
+}
+
+// A write waits for an apply holding the apply's lock, and writes only once it is let go.
+func TestAWriteWaitsForTheApply(t *testing.T) {
+	var applying sync.Mutex
+	e := newEngine(t, withAccount, &applying)
+	applying.Lock()
+	done := make(chan Answer)
+	go func() {
+		done <- e.Write(context.Background(), provisionerUID, Request{Path: "/etc/m/m.conf", Content: []byte("x")})
+	}()
+	select {
+	case a := <-done:
+		t.Fatalf("written while the apply held the lock: %+v", a)
+	case <-time.After(100 * time.Millisecond):
+	}
+	e.mu.Lock()
+	n := len(e.placed)
+	e.mu.Unlock()
+	if n != 0 {
+		t.Fatalf("placed while the apply held the lock")
+	}
+	applying.Unlock()
+	if a := <-done; a.Action != "updated" {
+		t.Fatalf("after the apply: %+v", a)
+	}
+}
+
+// fixed is a Writer that accepts one user id and answers every write.
+type fixed struct {
+	uid    uint32
+	mu     sync.Mutex
+	writes []Request
+}
+
+func (f *fixed) Accepts(uid uint32) error {
+	if uid != f.uid {
+		return errors.New("not the provisioner client's account")
+	}
+	return nil
+}
+
+func (f *fixed) Write(_ context.Context, _ uint32, req Request) Answer {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.writes = append(f.writes, req)
+	return Answer{Path: req.Path, Action: "updated", Digest: "d"}
+}
+
+// serve serves w on a socket in a fresh directory and returns its path, and what was said.
+func serve(t *testing.T, w Writer) (string, func() []string) {
+	t.Helper()
+	dir, err := os.MkdirTemp("", "fill")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.RemoveAll(dir) })
+	socket := filepath.Join(dir, "fill.sock")
+	ctx, cancel := context.WithCancel(context.Background())
+	var mu sync.Mutex
+	var said []string
+	stopped := make(chan error)
+	go func() {
+		stopped <- Serve(ctx, socket, w, func(s string) { mu.Lock(); said = append(said, s); mu.Unlock() })
+	}()
+	t.Cleanup(func() {
+		cancel()
+		if err := <-stopped; err != nil {
+			t.Error(err)
+		}
+	})
+	for i := 0; i < 100; i++ {
+		if _, err := os.Stat(socket); err == nil {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	return socket, func() []string { mu.Lock(); defer mu.Unlock(); return append([]string(nil), said...) }
+}
+
+func ask(t *testing.T, socket string, req Request) Answer {
+	t.Helper()
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	// Bounded: a socket that never answers fails the test instead of hanging it.
+	_ = conn.SetDeadline(time.Now().Add(5 * time.Second))
+	if err := json.NewEncoder(conn).Encode(req); err != nil {
+		t.Fatal(err)
+	}
+	var a Answer
+	if err := json.NewDecoder(conn).Decode(&a); err != nil {
+		t.Fatal(err)
+	}
+	return a
+}
+
+// Over a real socket, the kernel says who is asking: this test's own account is the provisioner's here.
+func TestTheSocketWritesForTheAccountTheKernelSays(t *testing.T) {
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, said := serve(t, w)
+	a := ask(t, socket, Request{Path: "/etc/m/m.conf", Content: []byte("secret value")})
+	if a.Refused != "" || a.Action != "updated" || len(w.writes) != 1 || string(w.writes[0].Content) != "secret value" {
+		t.Fatalf("answer %+v, writes %+v", a, w.writes)
+	}
+	for _, line := range said() {
+		if strings.Contains(line, "secret value") {
+			t.Errorf("the content was said: %q", line)
+		}
+	}
+}
+
+func TestTheSocketRefusesAnotherAccountBeforeReadingItsRequest(t *testing.T) {
+	w := &fixed{uid: uint32(os.Getuid()) + 1}
+	socket, said := serve(t, w)
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	// Closed at once, its request never read: the write may meet a closed socket, and the refusal is there to read.
+	_ = json.NewEncoder(conn).Encode(Request{Path: "/etc/m/m.conf", Content: []byte("secret value")})
+	var a Answer
+	if err := json.NewDecoder(conn).Decode(&a); err != nil {
+		t.Fatal(err)
+	}
+	if a.Refused == "" || len(w.writes) != 0 {
+		t.Fatalf("another account was written for: %+v", a)
+	}
+	for _, line := range said() {
+		if strings.Contains(line, "secret value") {
+			t.Errorf("the content was said: %q", line)
+		}
+	}
+}
+
+// floodersAreAnother has the kernel's word say another account for every connection a test binds to a name holding
+// "flood": the test runs as one account, and the socket must tell the client from everyone else.
+func floodersAreAnother(t *testing.T) {
+	t.Helper()
+	was := peerOf
+	peerOf = func(conn *net.UnixConn) (uint32, int32, error) {
+		uid, pid, err := was(conn)
+		if a, ok := conn.RemoteAddr().(*net.UnixAddr); ok && a != nil && strings.Contains(a.Name, "flood") {
+			uid++
+		}
+		return uid, pid, err
+	}
+	t.Cleanup(func() { peerOf = was })
+}
+
+// A flood of connections from another account, each saying nothing and held open, does not stop the client's write:
+// each is refused and closed before it holds anything.
+func TestAFloodFromAnotherAccountDoesNotStopTheClient(t *testing.T) {
+	floodersAreAnother(t)
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, _ := serve(t, w)
+	from := t.TempDir()
+	var flood []*net.UnixConn
+	t.Cleanup(func() {
+		for _, c := range flood {
+			c.Close()
+		}
+	})
+	for i := 0; i < 3*atOnce+busyWaitingCap(); i++ {
+		c, err := net.DialUnix("unix", &net.UnixAddr{Name: filepath.Join(from, fmt.Sprintf("flood-%d", i)), Net: "unix"},
+			&net.UnixAddr{Name: socket, Net: "unix"})
+		if err != nil {
+			t.Fatal(err)
+		}
+		flood = append(flood, c)
+	}
+	start := time.Now()
+	a := ask(t, socket, Request{Path: "/etc/m/m.conf", Content: []byte("x")})
+	if a.Refused != "" || a.Action != "updated" {
+		t.Fatalf("the client's write during a flood: %+v", a)
+	}
+	if took := time.Since(start); took > refusedWithin/2 {
+		t.Errorf("the client's write waited %s behind the flood", took)
+	}
+	// And every flooder was closed: it reads its refusal and then the end.
+	for _, c := range flood {
+		_ = c.SetReadDeadline(time.Now().Add(2 * time.Second))
+		var got Answer
+		if err := json.NewDecoder(c).Decode(&got); err != nil || got.Refused == "" {
+			t.Fatalf("a flooder was not refused at once: %+v %v", got, err)
+		}
+	}
+}
+
+func busyWaitingCap() int { return busyWaitingAtOnce }
+
+// A client that connects and says nothing holds one slot only until within, and another write goes on meanwhile.
+func TestASilentClientDoesNotHoldTheSocket(t *testing.T) {
+	was := within
+	within = 300 * time.Millisecond
+	t.Cleanup(func() { within = was })
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, _ := serve(t, w)
+	silent, err := net.Dial("unix", socket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer silent.Close()
+	if a := ask(t, socket, Request{Path: "/etc/m/m.conf", Content: []byte("x")}); a.Action != "updated" {
+		t.Fatalf("a write beside a silent client: %+v", a)
+	}
+	_ = silent.SetReadDeadline(time.Now().Add(3 * time.Second))
+	var got Answer
+	if err := json.NewDecoder(silent).Decode(&got); err != nil || got.Refused == "" {
+		t.Errorf("the silent client was not let go after within: %+v %v", got, err)
+	}
+}
+
+// A request carrying more than the path and the content is refused: it says what the declaration says.
+func TestARequestWithAnUnknownFieldIsRefused(t *testing.T) {
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, _ := serve(t, w)
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	if _, err := conn.Write([]byte(`{"path":"/etc/m/m.conf","content":"eA==","mode":"0777"}` + "\n")); err != nil {
+		t.Fatal(err)
+	}
+	var a Answer
+	if err := json.NewDecoder(conn).Decode(&a); err != nil {
+		t.Fatal(err)
+	}
+	if a.Refused == "" || !strings.Contains(a.Refused, "mode") || len(w.writes) != 0 {
+		t.Errorf("a request with an unknown field: %+v, writes %v", a, w.writes)
+	}
+}
+
+// An accept that fails is said, waited for and tried again: the socket goes on serving.
+func TestTheSocketGoesOnAfterAnAcceptFails(t *testing.T) {
+	wasAccept, wasBackoff := acceptFrom, acceptBackoff
+	failures := 3
+	var mu sync.Mutex
+	acceptFrom = func(l *net.UnixListener) (*net.UnixConn, error) {
+		mu.Lock()
+		defer mu.Unlock()
+		if failures > 0 {
+			failures--
+			return nil, errors.New("accept: too many open files")
+		}
+		return l.AcceptUnix()
+	}
+	acceptBackoff = time.Millisecond
+	t.Cleanup(func() { acceptFrom, acceptBackoff = wasAccept, wasBackoff })
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, said := serve(t, w)
+	if a := ask(t, socket, Request{Path: "/etc/m/m.conf", Content: []byte("x")}); a.Action != "updated" {
+		t.Fatalf("after failed accepts: %+v", a)
+	}
+	if !strings.Contains(strings.Join(said(), "\n"), "too many open files") {
+		t.Errorf("the failed accepts were not said: %v", said())
+	}
+}
+
+// The socket's directory is given the mode the socket needs, as mesh-cli's is.
+func TestTheSocketsDirectoryIsOpenedToEveryAccount(t *testing.T) {
+	dir, err := os.MkdirTemp("", "fill")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.RemoveAll(dir) })
+	if err := os.Chmod(dir, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	stopped := make(chan error)
+	go func() { stopped <- Serve(ctx, filepath.Join(dir, "fill.sock"), &fixed{}, nil) }()
+	for i := 0; i < 100; i++ {
+		if _, err := os.Stat(filepath.Join(dir, "fill.sock")); err == nil {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	cancel()
+	if err := <-stopped; err != nil {
+		t.Fatal(err)
+	}
+	info, err := os.Stat(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.Mode().Perm() != 0o755 {
+		t.Errorf("the socket's directory is %o", info.Mode().Perm())
+	}
+}
+
+// The first refusal of each kind for each account is said at once; what follows within the time is counted, and the
+// count is said when the time is up, even when the account has stopped.
+func TestRefusalsAreSaidOnceAndTheirCountIsNeverLost(t *testing.T) {
+	var mu sync.Mutex
+	var said []string
+	r := &refusalWords{say: func(s string) { mu.Lock(); said = append(said, s); mu.Unlock() }}
+	for i := 0; i < 3; i++ {
+		r.said(1000, "account", "not the provisioner client's account")
+	}
+	// Another kind from the same account is said at once, not hidden behind the first.
+	r.said(1000, "namespace", "another namespace")
+	if len(said) != 2 || !strings.Contains(said[0], "(account)") || !strings.Contains(said[1], "(namespace)") {
+		t.Fatalf("said at once: %q", said)
+	}
+	// The account stops; the time is up; the two counted are said.
+	r.flush()
+	if len(said) != 3 || !strings.Contains(said[2], "2 more") || !strings.Contains(said[2], "user id 1000") {
+		t.Fatalf("after the time: %q", said)
+	}
+	// And the next refusal is said at once again.
+	r.said(1000, "account", "not the provisioner client's account")
+	if len(said) != 4 {
+		t.Fatalf("after the count was said: %q", said)
+	}
+}
+
+// refusingSocket serves a socket that refuses this test's account, with counted refusals said every every. It returns
+// how to be refused n times, everything said so far, and how to stop it.
+func refusingSocket(t *testing.T, every time.Duration) (func(int), func() string, func()) {
+	t.Helper()
+	was := refusalsSaidEvery
+	refusalsSaidEvery = every
+	dir, err := os.MkdirTemp("", "fill")
+	if err != nil {
+		t.Fatal(err)
+	}
+	socket := filepath.Join(dir, "fill.sock")
+	ctx, cancel := context.WithCancel(context.Background())
+	var mu sync.Mutex
+	var said []string
+	all := func() string { mu.Lock(); defer mu.Unlock(); return strings.Join(said, "\n") }
+	stopped := make(chan error)
+	go func() {
+		stopped <- Serve(ctx, socket, &fixed{uid: uint32(os.Getuid()) + 1},
+			func(s string) { mu.Lock(); said = append(said, s); mu.Unlock() })
+	}()
+	for i := 0; i < 100; i++ {
+		if _, err := os.Stat(socket); err == nil {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	refuse := func(n int) {
+		for i := 0; i < n; i++ {
+			conn, err := net.Dial("unix", socket)
+			if err != nil {
+				t.Fatal(err)
+			}
+			_ = conn.SetDeadline(time.Now().Add(5 * time.Second))
+			var a Answer
+			_ = json.NewDecoder(conn).Decode(&a)
+			conn.Close()
+		}
+	}
+	var once sync.Once
+	stop := func() {
+		once.Do(func() {
+			cancel()
+			if err := <-stopped; err != nil {
+				t.Error(err)
+			}
+			refusalsSaidEvery = was
+			os.RemoveAll(dir)
+		})
+	}
+	t.Cleanup(stop)
+	return refuse, all, stop
+}
+
+// Refusals counted while the socket serves are said on its timer, though the account has stopped asking.
+func TestTheSocketSaysItsCountedRefusalsOnATimer(t *testing.T) {
+	refuse, all, _ := refusingSocket(t, 200*time.Millisecond)
+	refuse(3)
+	// "more writes", not a number: a tick may fall between two refusals and split the count.
+	deadline := time.Now().Add(3 * time.Second)
+	for !strings.Contains(all(), "more writes") && time.Now().Before(deadline) {
+		time.Sleep(20 * time.Millisecond)
+	}
+	if !strings.Contains(all(), "more writes") {
+		t.Fatalf("the counted refusals were not said on the timer: %s", all())
+	}
+}
+
+// Refusals counted when the socket stops are said as it stops.
+func TestTheSocketSaysItsCountedRefusalsWhenItStops(t *testing.T) {
+	refuse, all, stop := refusingSocket(t, time.Hour)
+	refuse(5)
+	if strings.Contains(all(), "4 more") {
+		t.Fatalf("said before the socket stopped: %s", all())
+	}
+	stop()
+	if !strings.Contains(all(), "4 more") {
+		t.Errorf("the refusals counted when the socket stopped were lost: %s", all())
+	}
+}
+
+// A connection over the bound of those waiting to be judged is closed unread, and said.
+func TestAConnectionOverTheWaitingBoundIsClosedUnread(t *testing.T) {
+	was := judgeWaiting
+	judgeWaiting = 0
+	t.Cleanup(func() { judgeWaiting = was })
+	w := &fixed{uid: uint32(os.Getuid())}
+	socket, said := serve(t, w)
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	_ = conn.SetDeadline(time.Now().Add(5 * time.Second))
+	var a Answer
+	if err := json.NewDecoder(conn).Decode(&a); err == nil {
+		t.Fatalf("answered over the bound: %+v", a)
+	}
+	if len(w.writes) != 0 || !strings.Contains(strings.Join(said(), "\n"), "(overflow)") {
+		t.Errorf("writes %v, said %q", w.writes, said())
+	}
+}

internal/link/messages.go

@@ -174,6 +174,14 @@ type Report struct {
 	// broken.
 	Windows []Window `json:"windows,omitempty"`
 
+	// Busy is every container the apply that reports left running because it said busy, and every one it
+	// replaced after it had waited, with how (novox/hq ADR 0335): `waiting`, `replaced-when-idle` or
+	// `replaced-at-bound`, since when, until when at the latest, and the last output of its busy command.
+	// A walk waiting on this machine for a module whose container is listed `waiting` waits for the report
+	// that no longer lists it so: its first-machine gate starts then (ADR 0335 §4). Absent from an engine
+	// older than BusyContract, which never waits.
+	Busy []Busy `json:"busy,omitempty"`
+
 	// Strays is what runs on the machine that the mesh neither wrote nor holds (novox/hq ADR
 	// 0163): containers nobody declared and nobody holds, the ones a cutover leaves behind.
 	Strays []Stray `json:"strays,omitempty"`
@@ -280,6 +288,26 @@ const LibraryContract = 6
 // before it, its presence is what tells the controller this host may be sent `runner` on an identity.
 const OwnGroupContract = 7
 
+// BusyContract is the statement of a host that also reads a container's `busy` (novox/hq ADR 0335): it asks a
+// container that declares it before replacing it, leaves it running while it says busy, within a bound of
+// 15 minutes, and says the wait in its report's `busy`. Like the fields before it, its presence is what tells
+// the controller this host may be sent `busy` on a container; an older host refuses the whole declaration
+// for it.
+const BusyContract = 8
+
+// OwnershipContract is the statement of a host that also reads a file's `owner-at-runtime` and a declaration's
+// `filled_files` (novox/hq ADR 0349 §5): it writes an owned file back on drift, a seed once and a managed file's
+// keys or block only, exactly as their old forms, and refuses a filled path that is not a declared file saying
+// its owner. Like the fields before it, its presence is what tells the controller this host may be sent those
+// fields; an older host refuses the whole declaration for them.
+const OwnershipContract = 9
+
+// ProvisionerContract is the statement of a host that also reads a declaration's `provisioner_account` (novox/hq ADR
+// 0349 §4) and serves the local write socket: it accepts a write of a filled file from that account alone. Its
+// presence is what tells the controller this host may be sent the field; an older host refuses the whole
+// declaration for it.
+const ProvisionerContract = 10
+
 // Health is one statement of every long-running resource's state on this machine (to-be 48 §4). Said in
 // every report, as an event on each change, and again every minute while anything is not healthy — so a
 // lost statement is not a lost fault.
@@ -731,6 +759,17 @@ type Window struct {
 	Until time.Time `json:"until"`
 }
 
+// Busy is one container a busy command held (novox/hq ADR 0335), as a report says it. ID is the resource's
+// id, `<module>.<resource>`.
+type Busy struct {
+	ID        string    `json:"id"`
+	Container string    `json:"container"`
+	State     string    `json:"state"`
+	Since     time.Time `json:"since"`
+	Until     time.Time `json:"until"`
+	Said      string    `json:"said,omitempty"`
+}
+
 // A Stray is a container the mesh neither wrote nor holds (ADR 0163).
 type Stray struct {
 	Kind   string `json:"kind"`

internal/meshcli/peer.go

@@ -0,0 +1,19 @@
+package meshcli
+
+import "net"
+
+// The kernel's word on who is at the other end of a socket, shared with the node-engine's other local socket, the
+// write of a filled file (internal/filling, novox/hq ADR 0349 §4): one reading of it, so the two never judge a peer
+// differently.
+
+// PeerCredentials is the user id and process id of the process at the other end, as the kernel recorded them when
+// it connected (SO_PEERCRED). Nothing the process says is read.
+func PeerCredentials(conn *net.UnixConn) (uint32, int32, error) { return peerCredentials(conn) }
+
+// SameNamespaces refuses a process whose mount or user namespace is not the engine's: a user id is this machine's
+// account only in this machine's namespaces.
+func SameNamespaces(pid int32) error { return namespacesOf(pid) }
+
+// NotOwnDirectory says what is wrong with a socket's directory, or nothing: it must be a directory, not a link,
+// owned by the account the engine runs as.
+func NotOwnDirectory(dir string) string { return notOwnDirectory(dir) }

internal/outward/networks.go

@@ -0,0 +1,92 @@
+package outward
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/netip"
+	"sort"
+)
+
+// Network is one network this machine is directly attached to, and the link it is on (novox/hq ADR
+// 0340 §7): the address and prefix of the network, not of the machine's own address on it.
+//
+// **Every one is said, and the machine judges none of them.** Which count as the machine's local
+// network — private ranges only, never a public subnet, never a link-local one — is the controller's
+// judgement (ADR 0340 §2), made where the filter is composed and shown with why; a machine that left a
+// network out would make that judgement silently.
+type Network struct {
+	Link    string `json:"link"`
+	Network string `json:"network"`
+}
+
+// AddressesOf is the addresses on one link, as address and prefix. A parameter so a test can hold a
+// machine's links without one.
+type AddressesOf func(link string) ([]netip.Prefix, error)
+
+// RealAddresses reads one link's addresses from the kernel.
+func RealAddresses(link string) ([]netip.Prefix, error) {
+	iface, err := net.InterfaceByName(link)
+	if err != nil {
+		return nil, err
+	}
+	addrs, err := iface.Addrs()
+	if err != nil {
+		return nil, err
+	}
+	var out []netip.Prefix
+	for _, a := range addrs {
+		ipnet, ok := a.(*net.IPNet)
+		if !ok {
+			continue
+		}
+		addr, ok := netip.AddrFromSlice(ipnet.IP)
+		if !ok {
+			continue
+		}
+		bits, _ := ipnet.Mask.Size()
+		out = append(out, netip.PrefixFrom(addr.Unmap(), bits))
+	}
+	return out, nil
+}
+
+// Networks is the networks on each of these links — the links that face outside (Links) — sorted by link
+// and network, without repeats. A link that has gone since Links read it has no networks rather than
+// failing the rest; a link whose addresses cannot be read fails, so the machine says the fact is unknown
+// rather than reporting a partial account as the whole.
+func Networks(links []string, addressesOf AddressesOf) ([]Network, error) {
+	if addressesOf == nil {
+		addressesOf = RealAddresses
+	}
+	seen := map[Network]bool{}
+	var out []Network
+	for _, link := range links {
+		prefixes, err := addressesOf(link)
+		if err != nil {
+			if isNoSuchInterface(err) {
+				continue
+			}
+			return nil, fmt.Errorf("cannot read the addresses on %s: %w", link, err)
+		}
+		for _, p := range prefixes {
+			n := Network{Link: link, Network: p.Masked().String()}
+			if !seen[n] {
+				seen[n] = true
+				out = append(out, n)
+			}
+		}
+	}
+	sort.Slice(out, func(i, j int) bool {
+		if out[i].Link != out[j].Link {
+			return out[i].Link < out[j].Link
+		}
+		return out[i].Network < out[j].Network
+	})
+	return out, nil
+}
+
+// isNoSuchInterface is the error net.InterfaceByName gives for a link that is not there.
+func isNoSuchInterface(err error) bool {
+	var op *net.OpError
+	return errors.As(err, &op) && op.Err != nil && op.Err.Error() == "no such network interface"
+}

internal/outward/networks_test.go

@@ -0,0 +1,59 @@
+package outward
+
+import (
+	"errors"
+	"net/netip"
+	"reflect"
+	"testing"
+)
+
+func prefixes(s ...string) []netip.Prefix {
+	var out []netip.Prefix
+	for _, p := range s {
+		out = append(out, netip.MustParsePrefix(p))
+	}
+	return out
+}
+
+// **Each link facing outside says the networks it is attached to** (novox/hq ADR 0340 §7), as the
+// network's address and prefix, never the machine's own address on it — and every one, public and
+// link-local included, because which count is the controller's judgement and said with why.
+func TestEachOutwardLinkSaysTheNetworksItIsOn(t *testing.T) {
+	addrs := map[string][]netip.Prefix{
+		"eth0": prefixes("192.168.1.10/24", "fe80::1/64", "fd12:3456:789a::5/64"),
+		"eth1": prefixes("203.0.113.7/24"),
+		// Not asked: the bridge is not a link facing outside.
+		"docker0": prefixes("172.17.0.1/16"),
+	}
+	got, err := Networks([]string{"eth1", "eth0"}, func(link string) ([]netip.Prefix, error) { return addrs[link], nil })
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []Network{
+		{Link: "eth0", Network: "192.168.1.0/24"},
+		{Link: "eth0", Network: "fd12:3456:789a::/64"},
+		{Link: "eth0", Network: "fe80::/64"},
+		{Link: "eth1", Network: "203.0.113.0/24"},
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %+v\nwant %+v", got, want)
+	}
+}
+
+// A link whose addresses cannot be read fails the whole, so the machine says the fact is unknown rather
+// than reporting part of its networks as all of them.
+func TestAnUnreadableLinkIsNotAPartialAccount(t *testing.T) {
+	_, err := Networks([]string{"eth0"}, func(string) ([]netip.Prefix, error) { return nil, errors.New("denied") })
+	if err == nil {
+		t.Fatal("an unreadable link was reported as having no networks")
+	}
+}
+
+// A link gone between reading the routing table and reading its addresses has no networks, and the
+// rest are still said.
+func TestALinkGoneSinceItWasListedHasNoNetworks(t *testing.T) {
+	got, err := Networks([]string{"gone0"}, RealAddresses)
+	if err != nil || len(got) != 0 {
+		t.Fatalf("got %v, %v", got, err)
+	}
+}

internal/profile/machine.go

@@ -10,6 +10,8 @@ import (
 	"sync"
 	"syscall"
 	"time"
+
+	"github.com/novox/mesh-host/internal/outward"
 )
 
 // Machine is what this machine is made of, as it says itself (novox/hq issue 160): what somebody
@@ -50,6 +52,11 @@ type Machine struct {
 	// Filesystems is each local filesystem mounted, by where, with its size and what is free.
 	Filesystems []Filesystem `json:"filesystems,omitempty"`
 
+	// Networks is every network the machine is directly attached to on a link facing outside it, as the
+	// link and the network's address and prefix (novox/hq ADR 0340 §7): what a port reached from
+	// `local-network` is resolved from. Every one is said; which count is the controller's judgement.
+	Networks []outward.Network `json:"networks,omitempty"`
+
 	// Unknown names each fact that could not be determined, and why.
 	Unknown map[string]string `json:"unknown,omitempty"`
 }
@@ -79,11 +86,12 @@ const (
 	FactTimezone      = "timezone"
 	FactFilesystems   = "filesystems"
 	FactPublicAddress = "public address"
+	FactNetworks      = "networks"
 )
 
 // MachineFacts is every fact Unknown may name, in the order a reader shows them.
 var MachineFacts = []string{FactKernelRelease, FactDistribution, FactVersion, FactProcessor, FactCores,
-	FactThreads, FactMemory, FactVirtual, FactUptime, FactTimezone, FactFilesystems, FactPublicAddress}
+	FactThreads, FactMemory, FactVirtual, FactUptime, FactTimezone, FactFilesystems, FactNetworks, FactPublicAddress}
 
 // publicAddressUnknown is why the public uplink address is not said. A machine behind a NAT cannot see
 // its public address from itself, and asking a service outside the mesh is a dependency the mesh does not
@@ -101,11 +109,24 @@ type Sources struct {
 	// Statfs is (size, free) in bytes of the filesystem mounted at a path.
 	Statfs func(path string) (size, free int64, err error)
 	Now    func() time.Time
+	// Networks is the networks on the links facing outside this machine (novox/hq ADR 0340).
+	Networks func() ([]outward.Network, error)
 }
 
 // RealSources reads this machine.
 func RealSources() Sources {
-	return Sources{Read: os.ReadFile, Readlink: os.Readlink, Run: ExecRunner, Statfs: statfs, Now: time.Now}
+	return Sources{Read: os.ReadFile, Readlink: os.Readlink, Run: ExecRunner, Statfs: statfs, Now: time.Now,
+		Networks: attachedNetworks}
+}
+
+// attachedNetworks is this machine's networks on the links that face outside it, read the way the report
+// reads those links (novox/hq ADR 0140), so the two never disagree about which links those are.
+func attachedNetworks() ([]outward.Network, error) {
+	links, err := outward.Links("", "")
+	if err != nil {
+		return nil, err
+	}
+	return outward.Networks(links, nil)
 }
 
 func statfs(path string) (int64, int64, error) {
@@ -193,6 +214,18 @@ func DescribeMachine(ctx context.Context, src Sources) Machine {
 		}
 	}
 
+	// The networks it is attached to, for the local network (novox/hq ADR 0340): every one on a link facing
+	// outside, or why none is said — never an empty list that reads as a machine on no network.
+	if src.Networks == nil {
+		unknown(FactNetworks, "this node-engine was given no way to read its links")
+	} else if networks, err := src.Networks(); err != nil {
+		unknown(FactNetworks, err.Error())
+	} else if len(networks) == 0 {
+		unknown(FactNetworks, "no link facing outside this machine carries an address")
+	} else {
+		m.Networks = networks
+	}
+
 	unknown(FactPublicAddress, publicAddressUnknown)
 	return m
 }

internal/profile/machine_test.go

@@ -10,6 +10,8 @@ import (
 	"sync/atomic"
 	"testing"
 	"time"
+
+	"github.com/novox/mesh-host/internal/outward"
 )
 
 // The parsing layer, with the machine's files given (novox/hq ADR 0017 allows a fake here and only here);
@@ -40,6 +42,9 @@ func given(read map[string]string) Sources {
 		Run:      func(context.Context, string, ...string) (string, error) { return "none\n", errors.New("exited 1") },
 		Statfs:   func(p string) (int64, int64, error) { return 1000, 400, nil },
 		Now:      func() time.Time { return time.Date(2026, 10, 12, 15, 0, 0, 0, time.UTC) },
+		Networks: func() ([]outward.Network, error) {
+			return []outward.Network{{Link: "eth0", Network: "192.168.1.0/24"}, {Link: "eth1", Network: "203.0.113.0/24"}}, nil
+		},
 	}
 }
 
@@ -92,6 +97,7 @@ func TestMachine_aFactItCannotReadIsSaidUnknownNeverZero(t *testing.T) {
 	src := given(map[string]string{})
 	src.Readlink = func(string) (string, error) { return "", os.ErrNotExist }
 	src.Run = func(context.Context, string, ...string) (string, error) { return "", errors.New("not found") }
+	src.Networks = func() ([]outward.Network, error) { return nil, errors.New("cannot read the routing table") }
 	m := DescribeMachine(context.Background(), src)
 
 	raw, _ := json.Marshal(m)
@@ -183,3 +189,26 @@ func TestAgainstThisMachine_machineSaysWhatItIs(t *testing.T) {
 	raw, _ := json.MarshalIndent(m, "", "  ")
 	t.Logf("%s", raw)
 }
+
+// **The networks it is attached to are among its facts** (novox/hq ADR 0340 §7), every one — the public
+// one too, which the controller judges and never counts — and a machine with none on a link facing
+// outside says why rather than reporting an empty list.
+func TestMachine_saysTheNetworksItIsAttachedTo(t *testing.T) {
+	m := DescribeMachine(context.Background(), given(files))
+	raw, _ := json.Marshal(m)
+	var said struct {
+		Networks []map[string]string `json:"networks"`
+	}
+	_ = json.Unmarshal(raw, &said)
+	if len(said.Networks) != 2 || said.Networks[0]["link"] != "eth0" || said.Networks[0]["network"] != "192.168.1.0/24" ||
+		said.Networks[1]["network"] != "203.0.113.0/24" {
+		t.Fatalf("networks said as %s", raw)
+	}
+
+	src := given(files)
+	src.Networks = func() ([]outward.Network, error) { return nil, nil }
+	m = DescribeMachine(context.Background(), src)
+	if len(m.Networks) != 0 || !strings.Contains(m.Unknown[FactNetworks], "no link facing outside") {
+		t.Fatalf("a machine with no network said %v, unknown %q", m.Networks, m.Unknown[FactNetworks])
+	}
+}

internal/store/store.go

@@ -155,6 +155,11 @@ type Applied struct {
 	// container's spec label; this is the same information kept per file, so that when the spec
 	// no longer matches the host can say WHICH file changed rather than only that something did.
 	Reads map[string]string `json:"reads,omitempty"`
+
+	// BusySince is, for a container left running because it said busy, when the first apply that would
+	// have replaced it ran (novox/hq ADR 0335 §3): kept here, beside the machine's state, so the bound runs
+	// from then across every pass and across a restart of the node-engine. Absent while nothing waits.
+	BusySince *time.Time `json:"busy_since,omitempty"`
 }
 
 // Into is what a file written into held before the mesh's keys, or before the mesh's block.

validate/validate_test.go

@@ -18,7 +18,20 @@ func TestTheValidatorIsTheHosts(t *testing.T) {
 	if problems := Declaration([]byte(ordered)); problems != nil {
 		t.Fatalf("a declaration carrying its order was refused: %v", problems)
 	}
+	// And one carrying a file's owner-at-runtime and the files the provisioner fills (novox/hq ADR 0349 §5): the
+	// reader takes them before any controller sends them.
+	owned := `{"declaration": 1, "filled_files": ["/etc/x"], "resources": [{"id": "f", "type": "file", "path": "/etc/x", "content": "a", "owner-at-runtime": "owned"}]}`
+	if problems := Declaration([]byte(owned)); problems != nil {
+		t.Fatalf("a declaration saying who owns a file at runtime was refused: %v", problems)
+	}
+	// And one naming the provisioner client's account (novox/hq ADR 0349 §4).
+	named := `{"declaration": 1, "provisioner_account": "mesh-node-provisioner", "filled_files": ["/etc/x"], "resources": [{"id": "f", "type": "file", "path": "/etc/x", "content": "a", "owner-at-runtime": "owned"}]}`
+	if problems := Declaration([]byte(named)); problems != nil {
+		t.Fatalf("a declaration naming the provisioner client's account was refused: %v", problems)
+	}
 	for _, bad := range []string{
+		`{"declaration": 1, "provisioner_account": "root", "resources": [{"id": "f", "type": "file", "path": "/etc/x", "content": "a"}]}`,
+		`{"declaration": 1, "filled_files": ["/etc/none"], "resources": [{"id": "f", "type": "file", "path": "/etc/x", "content": "a", "owner-at-runtime": "owned"}]}`,
 		`{"declaration": 1, "resources": []}`,
 		`{"declaration": 99, "resources": [{"id": "d", "type": "directory", "path": "/x"}]}`,
 		`{"declaration": 1, "resources": [{"id": "d", "type": "nothing-the-host-knows"}]}`,