Merge pull request 'buscompose: the grants part may create a placed module's declared buckets, logs and streams, creation only (issue 1790, ADR 0547 clause 1 exception)' (#86) from fix/1790-grants-create-buckets into main

BucketStreamConfig and ModuleStreamConfig are the stream configurations the controller's
CreateOrUpdateKeyValue (BucketConfig) and StreamConfigFor assert at its start, pure, for the
grants part's create of a bucket or stream a manifest declares and the bus lacks. A log already
has Log.Config. Never used for an update.

Issue: 1790

go/buildstep/askrun.go

@@ -208,9 +208,6 @@ func (s AskSteps) level(ctx context.Context, job delivery.CheckJob, level string
 		_ = json.Unmarshal(r, &t)
 		return t.Passed, nil
 	}
-	// Every test step of the level runs, also after one that did not pass, so one check names every failing test of the
-	// level and not only the first (issue 1921); the level as a whole passes only when each of its steps did.
-	all := true
 	if s.Digest == nil {
 		// A module with no digest (Node) tests each module directory of the tree, those whose tests changed first.
 		for _, priority := range []bool{true, false} {
@@ -222,12 +219,14 @@ func (s AskSteps) level(ctx context.Context, job delivery.CheckJob, level string
 				if err != nil {
 					return false, fmt.Errorf("the %s level of %s: %w", level, dir, err)
 				}
-				all = all && passed
+				if !passed {
+					return false, nil
+				}
 			}
 		}
-		return all, nil
+		return true, nil
 	}
-	todo, whole, keepRunner := s.plan(ctx, job, level, f, runner, withRunner, la)
+	todo, all, keepRunner := s.plan(ctx, job, level, f, runner, withRunner, la)
 	if !keepRunner {
 		runner = "" // an installed module that ignores the runner judges the level as it judges any other (ADR 0535 §2)
 	}
@@ -236,7 +235,7 @@ func (s AskSteps) level(ctx context.Context, job delivery.CheckJob, level string
 		if job.Run != "" {
 			args["run"] = job.Run
 		}
-		if whole {
+		if all {
 			if priority {
 				continue // nothing to put first: the level runs whole after
 			}
@@ -256,9 +255,11 @@ func (s AskSteps) level(ctx context.Context, job delivery.CheckJob, level string
 		if err != nil {
 			return false, fmt.Errorf("the %s level: %w", level, err)
 		}
-		all = all && passed // the packages left still run (issue 1921)
+		if !passed {
+			return false, nil
+		}
 	}
-	return all, nil
+	return true, nil
 }
 
 // release removes an ask's workspace, saying a failure: the module's sweep removes it later.

go/buildstep/askrun_test.go

@@ -109,9 +109,9 @@ func TestRunAskRefusesAnotherToolchain(t *testing.T) {
 	}
 }
 
-// 1887/A3, A5a: a check ask runs the levels of one check after one fetch: it digests the unit level, takes the kept
-// verdicts, tests the packages whose tests changed first, then the rest also after a failure (issue 1921), and runs no
-// level after one that did not pass (ADR 0484 clause 13).
+// 1887/A3, A5a, issue 1887 design limit 1: a check ask runs the levels of one check after one fetch: it digests the unit
+// level, takes the kept verdicts, tests the packages whose tests changed first, and stops at the first failure, running
+// no later level.
 func TestRunAskChecksTheLevelsOfOneCheck(t *testing.T) {
 	r := &recorder{
 		fetch:   map[string]any{"workspace": "/w", "changed": []string{"pkg/b/b_test.go"}},
@@ -126,8 +126,7 @@ func TestRunAskChecksTheLevelsOfOneCheck(t *testing.T) {
 	got := strings.Join(r.calls, "\n")
 	want := `fetch {"base":"` + runCommit + `","commit":"` + runCommit + `","repository":"novox/x"}
 digest {"level":"unit","workspace":"/w"}
-test {"level":"unit","packages":["x/pkg/b"],"workspace":"/w"}
-test {"level":"unit","packages":["x/pkg/a"],"workspace":"/w"}`
+test {"level":"unit","packages":["x/pkg/b"],"workspace":"/w"}`
 	if got != want {
 		t.Fatalf("calls:\n%s\nwant:\n%s", got, want)
 	}
@@ -136,7 +135,7 @@ test {"level":"unit","packages":["x/pkg/a"],"workspace":"/w"}`
 		t.Fatalf("levels %+v, want the unit level alone", a.Levels)
 	}
 	u := a.Levels[0]
-	if u.Level != delivery.LevelUnit || len(u.Kept) != 1 || u.Kept[0].Package != "x/pkg/k" || u.Kept[0].Tests != 7 || len(u.Tests) != 2 || u.Digest == nil {
+	if u.Level != delivery.LevelUnit || len(u.Kept) != 1 || u.Kept[0].Package != "x/pkg/k" || u.Kept[0].Tests != 7 || len(u.Tests) != 1 || u.Digest == nil {
 		t.Fatalf("the unit level %+v", u)
 	}
 }
@@ -204,42 +203,3 @@ func TestRunAskChecksNodeModulesAndConflicts(t *testing.T) {
 		t.Fatalf("a conflict: %v %v", err, r.calls)
 	}
 }
-
-// Issue 1921: a failure in the packages whose tests changed does not stop the level: the other packages still run, so two
-// failing packages, one changed and one not, are two test results of the one level, and the level does not pass. A Node
-// check runs every module directory after one fails too.
-func TestRunAskRunsEveryPackageAfterAFailure(t *testing.T) {
-	r := &recorder{
-		fetch:   map[string]any{"workspace": "/w", "changed": []string{"pkg/b/b_test.go"}},
-		digests: map[string]string{"x/pkg/a": "d-a", "x/pkg/b": "d-b"},
-		tests:   map[string]bool{"x/pkg/a": false, "x/pkg/b": false},
-	}
-	out, err := RunAsk(context.Background(), r.steps(), ask(delivery.CheckJob{Levels: []string{delivery.LevelIntegration, delivery.LevelUnit},
-		Fetch: map[string]any{"repository": "novox/x", "commit": runCommit}}))
-	if err != nil {
-		t.Fatal(err)
-	}
-	a := out.(delivery.CheckAnswer)
-	if len(a.Levels) != 1 || len(a.Levels[0].Tests) != 2 {
-		t.Fatalf("levels %+v, want the one level with both packages' results", a.Levels)
-	}
-	for i, raw := range a.Levels[0].Tests {
-		var res struct{ Passed bool }
-		if err := json.Unmarshal(raw, &res); err != nil || res.Passed {
-			t.Errorf("result %d %s, want a failure", i, raw)
-		}
-	}
-
-	r = &recorder{fetch: map[string]any{"workspace": "/w", "modules": []string{"a", "b"}, "changed": []string{"b/test/x.test.ts"}},
-		tests: map[string]bool{"a": true, "b": false}}
-	s := r.steps()
-	s.Digest = nil
-	out, err = RunAsk(context.Background(), s, ask(delivery.CheckJob{Levels: []string{delivery.LevelUnit, delivery.LevelIntegration},
-		Fetch: map[string]any{"repository": "novox/x", "commit": runCommit}}))
-	if err != nil {
-		t.Fatal(err)
-	}
-	if a := out.(delivery.CheckAnswer); len(r.calls) != 3 || len(a.Levels) != 1 || len(a.Levels[0].Tests) != 2 {
-		t.Fatalf("calls %v, levels %+v: want both directories of the unit level and no integration level", r.calls, a.Levels)
-	}
-}

go/buildstep/capacity.go

@@ -42,11 +42,20 @@ func NodeCapacity(path, fallback, node string, logf func(string, ...any)) func()
 			}
 			setting, _ = s[CapacitySetting].(string)
 		}
-		caps, err := buildrun.ParseCapacity(setting)
+		n, err := capacityOf(setting, node)
 		if err != nil {
-			say("%v, so %s pulls nothing", fmt.Errorf("the build capacity: %w", err), node)
+			say("%v, so %s pulls nothing", err, node)
 			return 0
 		}
-		return (&buildrun.Places{Capacity: caps}).CapacityOf(node)
+		return n
 	}
 }
+
+// capacityOf is node's capacity in a setting's `<node>=<asks>` pairs: DefaultCapacity for a node it does not name.
+func capacityOf(setting, node string) (int, error) {
+	caps, err := buildrun.ParseCapacity(setting)
+	if err != nil {
+		return 0, fmt.Errorf("the build capacity: %w", err)
+	}
+	return (&buildrun.Places{Capacity: caps}).CapacityOf(node), nil
+}

go/buildstep/pull.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 )
 
@@ -64,10 +65,17 @@ type Puller struct {
 	PullWait  time.Duration
 	Heartbeat time.Duration
 	Logf      func(format string, args ...any)
-	// Load reads one key of the module's steps state (nil and no error when it is absent). When set, Pull reads the
-	// node's pause key (delivery.PauseKey) before it pulls, and Pause and Resume write it with Put, so a pause outlives
-	// a restart.
+	// Load reads one key of the state the node's pause is kept in (nil and no error when it is absent). When set, Pull
+	// reads the node's pause key (delivery.PauseKey) before it pulls, and Pause and Resume write it with PausePut, so a
+	// pause outlives a restart.
 	Load func(key string) ([]byte, error)
+	// PausePut writes the node's pause key: the module's pauses state (delivery.PausesState), which has no age, so a
+	// pause never ends by itself while the steps state drops its old keys. Put when nil.
+	PausePut Put
+	// WatchConfig, when set, follows the module's config value `capacity` (CapacitySetting) as mesh-config resolves it
+	// for this node, and wakes the puller on each change (watchCapacity): WatchConfigServed in a module, a test's own
+	// double. Until it hands a value the puller judges by Capacity.
+	WatchConfig func(key string, handle func(stdio.ProvisionChange) error) error
 
 	mu      sync.Mutex
 	inHand  int
@@ -75,6 +83,9 @@ type Puller struct {
 	paused  bool
 	wake    chan struct{}
 	once    sync.Once
+	// watched is the capacity the config watch handed last, used in place of Capacity once hasWatched.
+	watched    int
+	hasWatched bool
 }
 
 func (p *Puller) init() {
@@ -113,7 +124,11 @@ func (p *Puller) setPaused(paused bool, by string) error {
 		if err != nil {
 			return err
 		}
-		if _, err := p.Put(key, json.RawMessage(raw)); err != nil {
+		put := p.PausePut
+		if put == nil {
+			put = p.Put
+		}
+		if _, err := put(key, json.RawMessage(raw)); err != nil {
 			return fmt.Errorf("buildstep: writing the pause of %s: %w", p.Node, err)
 		}
 	}
@@ -186,13 +201,29 @@ func (p *Puller) Running() []RunningAsk {
 
 // room says whether the puller may take one more ask now.
 func (p *Puller) room() bool {
-	capacity := 0
-	if p.Capacity != nil {
+	ok, _, _ := p.roomNow()
+	return ok
+}
+
+// roomNow is room, with the capacity and the asks in hand it was judged on.
+func (p *Puller) roomNow() (ok bool, capacity, inHand int) {
+	p.mu.Lock()
+	watched, has := p.watched, p.hasWatched
+	p.mu.Unlock()
+	if has {
+		capacity = watched
+	} else if p.Capacity != nil {
 		capacity = p.Capacity()
 	}
 	p.mu.Lock()
 	defer p.mu.Unlock()
-	return !p.paused && p.inHand < capacity
+	return !p.paused && p.inHand < capacity, capacity, p.inHand
+}
+
+// CapacityNow is the capacity the puller judges by: the config watch's last value, else Capacity.
+func (p *Puller) CapacityNow() int {
+	_, capacity, _ := p.roomNow()
+	return capacity
 }
 
 // Pull takes and runs asks until ctx ends. An ask still running then is neither ended nor acknowledged: the stream
@@ -203,8 +234,11 @@ func (p *Puller) Pull(ctx context.Context) error {
 		return errors.New("buildstep: a puller needs its source, its steps' put and its run")
 	}
 	if err := p.restore(); err != nil {
-		return err // pulling on a pause that cannot be read could build on a node paused on purpose
+		// An unreadable pause degrades to not paused, said once: a puller that stops silently is the worse failure, and a
+		// node kept from building is held by its capacity (0), not by a pause.
+		p.logf("the pause of %s cannot be read: %v; pulling as not paused", p.Node, err)
 	}
+	go p.watchCapacity() // WatchConfigServed waits for Serve, which a module starts after its pull
 	wait := p.PullWait
 	if wait <= 0 {
 		wait = DefaultPullWait
@@ -213,12 +247,17 @@ func (p *Puller) Pull(ctx context.Context) error {
 		if err := ctx.Err(); err != nil {
 			return err
 		}
-		if !p.room() {
+		if ok, capacity, inHand := p.roomNow(); !ok {
+			// Parked until something wakes it: a capacity change (the config watch), a resume, or a step's end. Every
+			// park logs once, so a puller that sits idle says why (issue 1887).
+			p.logf("the %s puller on %s parks: %d of capacity %d in hand, paused %v", p.Language, p.Node, inHand, capacity, p.Paused())
 			select {
 			case <-ctx.Done():
 				return ctx.Err()
 			case <-p.wake:
 			}
+			_, capacity, inHand = p.roomNow()
+			p.logf("the %s puller on %s wakes: %d of capacity %d in hand, paused %v", p.Language, p.Node, inHand, capacity, p.Paused())
 			continue
 		}
 		msg, err := p.next(ctx, wait)
@@ -348,3 +387,59 @@ func (p *Puller) run(ctx context.Context, msg *Pulled, ask delivery.StepAsk, key
 		p.logf("the ask %s ended on %s and its acknowledgement failed: %v", ask.ID, p.Node, aerr)
 	}
 }
+
+// watchCapacity follows the module's config value `capacity` when WatchConfig is set (issue 1887, 2026-10-25: g14's
+// puller started at capacity 0 sat parked with capacity 2 set, because nothing woke it to read its settings file
+// again). The value comes as mesh-config resolved it for this node, the event of the change itself: the runtime hands
+// the value now and then each change its machine's provisioner client says moved, so nothing polls, and the puller does
+// not wait for the node-engine to fill its settings file again. Each value handed is kept, used in place of Capacity,
+// and wakes the puller. A watch that cannot start leaves the puller on Capacity, said once.
+func (p *Puller) watchCapacity() {
+	if p.WatchConfig == nil {
+		return
+	}
+	err := p.WatchConfig(CapacitySetting, func(c stdio.ProvisionChange) error {
+		n, why := p.capacityFrom(c)
+		p.mu.Lock()
+		before, had := p.watched, p.hasWatched
+		p.watched, p.hasWatched = n, true
+		p.mu.Unlock()
+		switch {
+		case why != "":
+			p.logf("the %s puller on %s pulls nothing: %s", p.Language, p.Node, why)
+		case !had || before != n:
+			p.logf("the %s build capacity of %s is %d, as mesh-config resolved it", p.Language, p.Node, n)
+		}
+		p.Wake()
+		return nil
+	})
+	if err != nil {
+		p.logf("the %s build capacity of %s cannot be followed on the bus, so it is read from the settings file when the "+
+			"puller wakes: %v", p.Language, p.Node, err)
+	}
+}
+
+// WatchConfigServed is stdio.WatchConfig once Serve has the runtime's channel (stdio.Served): a build module starts its
+// pull before it serves, and a watch asked before that would be refused.
+func WatchConfigServed(key string, handle func(stdio.ProvisionChange) error) error {
+	<-stdio.Served()
+	return stdio.WatchConfig(key, handle)
+}
+
+// capacityFrom is the node's capacity in one value the watch handed, and why it is 0 when it cannot be read.
+func (p *Puller) capacityFrom(c stdio.ProvisionChange) (int, string) {
+	if c.Refused != "" {
+		return 0, "its capacity is no longer answered: " + c.Refused
+	}
+	setting := ""
+	if len(c.Value) > 0 && string(c.Value) != "null" {
+		if err := json.Unmarshal(c.Value, &setting); err != nil {
+			return 0, fmt.Sprintf("its capacity %s is not a string", c.Value)
+		}
+	}
+	n, err := capacityOf(setting, p.Node)
+	if err != nil {
+		return 0, err.Error()
+	}
+	return n, ""
+}

go/buildstep/pull_capacity_test.go

@@ -0,0 +1,39 @@
+package buildstep
+
+import (
+	"encoding/json"
+	"sync"
+	"testing"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+)
+
+// configWatch is a double of stdio.WatchConfig: it hands the value now at the start, as the runtime does, and a test
+// hands each change after with set.
+type configWatch struct {
+	mu     sync.Mutex
+	value  string
+	handle func(stdio.ProvisionChange) error
+	asked  string
+}
+
+func (w *configWatch) watch(key string, handle func(stdio.ProvisionChange) error) error {
+	w.mu.Lock()
+	w.asked, w.handle = key, handle
+	value := w.value
+	w.mu.Unlock()
+	return handle(stdio.ProvisionChange{Kind: "config", Key: key, Value: json.RawMessage(`"` + value + `"`)})
+}
+
+func (w *configWatch) set(t *testing.T, value string) {
+	t.Helper()
+	w.mu.Lock()
+	handle, key := w.handle, w.asked
+	w.mu.Unlock()
+	if handle == nil {
+		t.Fatal("the puller watches no config value")
+	}
+	if err := handle(stdio.ProvisionChange{Kind: "config", Key: key, Value: json.RawMessage(`"` + value + `"`)}); err != nil {
+		t.Fatal(err)
+	}
+}

go/buildstep/pull_test.go

@@ -3,11 +3,15 @@ package buildstep
 import (
 	"context"
 	"encoding/json"
+	"errors"
+	"fmt"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
+	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 )
 
@@ -175,36 +179,85 @@ func (k *kv) load(key string) ([]byte, error) {
 	return k.vals[key], nil
 }
 
-// 1887/A2b, 1887/AC-zero: at capacity 0 the puller takes nothing; a capacity raised takes effect at the next pull.
+// 1887/A2b, 1887/AC-zero, 1887/AC-wake: at capacity 0 the puller takes nothing; a capacity raised takes effect at the
+// next pull, or, with the config watch (g14 idle at capacity 2, 2026-10-25), at once when the value moves, with no
+// pause, resume or step end to wake it; a refused value pulls nothing, and a watch that cannot start leaves the
+// settings file's capacity.
 func TestPullAtCapacityZeroTakesNothing(t *testing.T) {
-	src, st := NewFakeAsks(), &kv{}
-	_ = src.PublishAsk(testAsk(delivery.AskDelivery))
-	var mu sync.Mutex
-	capacity := 0
-	p := &Puller{Source: src, Language: delivery.AskGo, Node: "novox", Put: st.put, PullWait: 10 * time.Millisecond,
-		Capacity: func() int { mu.Lock(); defer mu.Unlock(); return capacity },
-		Run:      func(ctx context.Context, a delivery.StepAsk) (any, error) { return nil, nil }}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	go p.Pull(ctx)
-	time.Sleep(50 * time.Millisecond)
-	if src.Waiting(delivery.AskDelivery) != 1 {
-		t.Fatal("a node at capacity 0 took an ask")
+	t.Run("settings file", func(t *testing.T) {
+		src, st := NewFakeAsks(), &kv{}
+		_ = src.PublishAsk(testAsk(delivery.AskDelivery))
+		var mu sync.Mutex
+		capacity := 0
+		p := &Puller{Source: src, Language: delivery.AskGo, Node: "novox", Put: st.put, PullWait: 10 * time.Millisecond,
+			Capacity: func() int { mu.Lock(); defer mu.Unlock(); return capacity },
+			Run:      func(ctx context.Context, a delivery.StepAsk) (any, error) { return nil, nil }}
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		go p.Pull(ctx)
+		time.Sleep(50 * time.Millisecond)
+		if src.Waiting(delivery.AskDelivery) != 1 {
+			t.Fatal("a node at capacity 0 took an ask")
+		}
+		mu.Lock()
+		capacity = 1
+		mu.Unlock()
+		p.Wake()
+		waitFor(t, "the ask taken at capacity 1", func() bool { a, _, _ := src.Fates(); return len(a) == 1 })
+	})
+	t.Run("config watch wakes", func(t *testing.T) {
+		src, st := NewFakeAsks(), newSteps()
+		_ = src.PublishAsk(testAsk(delivery.AskDelivery))
+		w := &configWatch{value: "shanks=3,g14=0"}
+		p := &Puller{Source: src, Language: delivery.AskGo, Node: "g14", Put: st.put, PullWait: 10 * time.Millisecond,
+			Capacity:    func() int { return 0 }, // the settings file, not refilled yet
+			WatchConfig: w.watch,
+			Run:         func(ctx context.Context, a delivery.StepAsk) (any, error) { return nil, nil }}
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		go p.Pull(ctx)
+		waitFor(t, "the watch of the capacity", func() bool { w.mu.Lock(); defer w.mu.Unlock(); return w.handle != nil })
+		time.Sleep(30 * time.Millisecond)
+		if src.Waiting(delivery.AskDelivery) != 1 {
+			t.Fatal("a node at capacity 0 took an ask")
+		}
+		if w.asked != CapacitySetting {
+			t.Fatalf("the puller watches %q, want %q", w.asked, CapacitySetting)
+		}
+		w.set(t, "shanks=3,g14=2")
+		waitFor(t, "the ask taken once the capacity moved to 2", func() bool { a, _, _ := src.Fates(); return len(a) == 1 })
+	})
+	for _, c := range []struct {
+		name  string
+		watch func(string, func(stdio.ProvisionChange) error) error
+		room  bool
+	}{
+		{"refused value leaves no room", func(key string, handle func(stdio.ProvisionChange) error) error {
+			return handle(stdio.ProvisionChange{Kind: "config", Key: key, Refused: "the module is no longer on g14"})
+		}, false},
+		{"watch that cannot start keeps the settings file", func(string, func(stdio.ProvisionChange) error) error {
+			return errors.New("no runtime")
+		}, true},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			p := &Puller{Source: NewFakeAsks(), Language: delivery.AskGo, Node: "g14", Put: newSteps().put,
+				Capacity: func() int { return 1 }, WatchConfig: c.watch,
+				Run: func(ctx context.Context, a delivery.StepAsk) (any, error) { return nil, nil }}
+			p.watchCapacity()
+			if p.room() != c.room {
+				t.Fatalf("room = %v, want %v", p.room(), c.room)
+			}
+		})
 	}
-	mu.Lock()
-	capacity = 1
-	mu.Unlock()
-	p.Wake()
-	waitFor(t, "the ask taken at capacity 1", func() bool { a, _, _ := src.Fates(); return len(a) == 1 })
 }
 
 // 1887/A2b: a paused puller takes nothing, its pause is kept on the pause key, and a puller started again on that state
 // stays paused until resumed.
 func TestPullPauseOutlivesARestart(t *testing.T) {
-	src, st := NewFakeAsks(), &kv{}
+	src, st, steps := NewFakeAsks(), &kv{}, &kv{}
 	run := func(ctx context.Context, a delivery.StepAsk) (any, error) { return nil, nil }
-	p := &Puller{Source: src, Language: delivery.AskGo, Node: "shanks", Put: st.put, Load: st.load, PullWait: 10 * time.Millisecond,
-		Capacity: func() int { return 2 }, Run: run}
+	p := &Puller{Source: src, Language: delivery.AskGo, Node: "shanks", Put: steps.put, PausePut: st.put, Load: st.load,
+		PullWait: 10 * time.Millisecond, Capacity: func() int { return 2 }, Run: run}
 	if err := p.Pause("the operator"); err != nil {
 		t.Fatal(err)
 	}
@@ -213,9 +266,12 @@ func TestPullPauseOutlivesARestart(t *testing.T) {
 	if v, err := delivery.DecodePause(raw); err != nil || !v.Paused || v.By != "the operator" {
 		t.Fatalf("the pause key holds %s (%v)", raw, err)
 	}
+	if raw, _ := steps.load(key); raw != nil {
+		t.Fatalf("the pause was written in the steps state, whose keys age out: %s", raw)
+	}
 	// The restart: a new puller on the same state.
-	again := &Puller{Source: src, Language: delivery.AskGo, Node: "shanks", Put: st.put, Load: st.load, PullWait: 10 * time.Millisecond,
-		Capacity: func() int { return 2 }, Run: run}
+	again := &Puller{Source: src, Language: delivery.AskGo, Node: "shanks", Put: steps.put, PausePut: st.put, Load: st.load,
+		PullWait: 10 * time.Millisecond, Capacity: func() int { return 2 }, Run: run}
 	_ = src.PublishAsk(testAsk(delivery.AskDelivery))
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -228,6 +284,27 @@ func TestPullPauseOutlivesARestart(t *testing.T) {
 		t.Fatal(err)
 	}
 	waitFor(t, "the ask taken after the resume", func() bool { a, _, _ := src.Fates(); return len(a) == 1 })
+
+	t.Run("a pause that cannot be read is said and pulled as not paused", func(t *testing.T) {
+		src := NewFakeAsks()
+		var said atomic.Value
+		p := &Puller{Source: src, Language: delivery.AskGo, Node: "shanks", Put: steps.put, PausePut: st.put,
+			Load:     func(string) ([]byte, error) { return nil, errors.New("no runtime yet") },
+			PullWait: 10 * time.Millisecond, Capacity: func() int { return 2 }, Run: run,
+			Logf: func(f string, a ...any) {
+				if m := fmt.Sprintf(f, a...); strings.Contains(m, "cannot be read") {
+					said.Store(m)
+				}
+			}}
+		_ = src.PublishAsk(testAsk(delivery.AskDelivery))
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		go p.Pull(ctx)
+		waitFor(t, "the ask taken", func() bool { a, _, _ := src.Fates(); return len(a) == 1 })
+		if m, _ := said.Load().(string); !strings.Contains(m, "pulling as not paused") {
+			t.Fatalf("the unreadable pause was not said: %q", m)
+		}
+	})
 }
 
 // 1887/A2c: a long step tells the bus it is still being worked; a holder that stops mid-step neither ends nor

go/buildstep/seat_tools.go

@@ -14,11 +14,7 @@ func SeatTools(seat, what string, p *Puller) []stdio.Tool {
 			Run:   func(map[string]any) (any, error) { return run() }}
 	}
 	current := func() (any, error) {
-		capacity := 0
-		if p.Capacity != nil {
-			capacity = p.Capacity()
-		}
-		return map[string]any{"node": p.Node, "capacity": capacity, "running": p.Running(), "paused": p.Paused()}, nil
+		return map[string]any{"node": p.Node, "capacity": p.CapacityNow(), "running": p.Running(), "paused": p.Paused()}, nil
 	}
 	return []stdio.Tool{
 		verb("current", "The "+what+" asks this node runs now (each one's id, kind and when it started), its build capacity, "+

go/buscompose/agreement.go

@@ -0,0 +1,125 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// Do the emitters and the consumers of a catalogue agree?
+//
+// **The check that was missing** (novox/hq 04-ISSUES/127). Every manifest was individually
+// well-formed and every derivation individually correct, and no cross-module subscription in the
+// mesh matched anything: a consumer's declaration derived into a namespace nobody publishes to.
+// Nothing failed, because a subscription that matches nothing is not an error — it is silence.
+//
+// The comparison has to be over the whole catalogue, because the two halves live in different
+// manifests, and it cannot simply demand that every consumed event have a live emitter: a module
+// may be installed long before the one whose events it wants. So the rule is narrower and still
+// catches this: **where the emitter is present, it must emit what the consumer asked for.**
+
+// AConsumer is one module's interest in another's events, as this check needs it.
+type AConsumer struct {
+	Module   string
+	Consumes []string
+}
+
+// AnEmitter is one module's events.
+type AnEmitter struct {
+	Module string
+	Emits  []string
+}
+
+// Disagreements are the consumed events whose emitter is in the catalogue and does not emit them.
+//
+// Returned as sentences rather than as structs: every one of them is read by a person deciding
+// whether a manifest or a catalogue is wrong, and a pair of names without the reason is a puzzle.
+func Disagreements(emitters []AnEmitter, consumers []AConsumer, seats []DeclaredSeat) []string {
+	emits := map[string]map[string]bool{}
+	for _, e := range emitters {
+		if emits[e.Module] == nil {
+			emits[e.Module] = map[string]bool{}
+		}
+		for _, name := range e.Emits {
+			emits[e.Module][name] = true
+		}
+	}
+	// A seat's events are published by its holder under the seat's name, so a consumer naming the
+	// seat is naming something real even though no module declares it as its own.
+	for _, s := range seats {
+		if len(s.Emits) == 0 {
+			continue
+		}
+		if emits[s.Name] == nil {
+			emits[s.Name] = map[string]bool{}
+		}
+		for _, name := range s.Emits {
+			emits[s.Name][name] = true
+		}
+	}
+
+	var out []string
+	for _, c := range consumers {
+		for _, pattern := range c.Consumes {
+			emitter, event, named := strings.Cut(pattern, ".")
+			// Every event from everyone, or every event from one module: both are deliberate and
+			// neither names a particular event to check.
+			if !named || emitter == "*" || emitter == catalogueTheRest || event == catalogueTheRest {
+				continue
+			}
+			known, present := emits[emitter]
+			if !present {
+				// Not installed here, which is ordinary: a module lives in its own repository and
+				// may be registered later. Nothing to compare, so nothing to say.
+				continue
+			}
+			if matchesAny(event, known) {
+				continue
+			}
+			out = append(out, fmt.Sprintf(
+				"%s consumes %q and %s emits %s — so that subscription would match nothing, and "+
+					"nothing would report it",
+				c.Module, pattern, emitter, listOf(known)))
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+// matchesAny says whether one of an emitter's event names satisfies a consumer's pattern.
+func matchesAny(pattern string, emitted map[string]bool) bool {
+	want := strings.Split(pattern, ".")
+	for name := range emitted {
+		if matches(want, strings.Split(name, ".")) {
+			return true
+		}
+	}
+	return false
+}
+
+func matches(pattern, name []string) bool {
+	for i, part := range pattern {
+		if part == catalogueTheRest {
+			return i < len(name)
+		}
+		if i >= len(name) {
+			return false
+		}
+		if part != "*" && part != name[i] {
+			return false
+		}
+	}
+	return len(pattern) == len(name)
+}
+
+func listOf(names map[string]bool) string {
+	if len(names) == 0 {
+		return "nothing"
+	}
+	out := make([]string, 0, len(names))
+	for n := range names {
+		out = append(out, n)
+	}
+	sort.Strings(out)
+	return strings.Join(out, ", ")
+}

go/buscompose/announced.go

@@ -0,0 +1,82 @@
+package buscompose
+
+import (
+	"sort"
+	"strings"
+
+	"git.novox.be/novox/mesh-sdk/go/announce"
+)
+
+// Who may read a module's state is what the module announced (novox/hq ADR 0495 clauses 2 and 3, ADR 0513 §3; issue
+// 1790). A module says on the bus which states it keeps and which others may read (announce.Subject); the controller
+// keeps the last word of each (announce.KeptBucket) and grants a reader's `reads: <owner>.<name>` only when the owner
+// announced that state readable. An owner that has announced nothing yet is read as before, from the reader's `reads`
+// (the transition, until every module announces), and is named as not yet announced.
+
+// StatesAnnouncedBucket is the controller's bucket of the last announcement of each module (announce.KeptBucket).
+const StatesAnnouncedBucket = announce.KeptBucket
+
+// controllerReadable are the controller's states others may read: the record mirrors (the packages each node declares
+// among them, which the pacman module reads, ADR 0507 §5), the chain's buckets, and the grants issued and the
+// compositions' digests, which the assigner reads (ADR 0528 clause 2, ADR 0539 clause 6).
+var controllerReadable = []string{MirrorAssignments, MirrorDeclaredConfig, MirrorPredefined, ChainBuilds, ChainRollouts,
+	MirrorDeclaredPackages, ControllerGrants, ControllerComposed}
+
+// ControllerAnnouncement is what the controller announces it keeps (ADR 0495 clause 2): every bucket of its own by its local
+// name, the ones others may read marked readable. It announces itself, as any module does from its code.
+func ControllerAnnouncement(node string) announce.States {
+	s := announce.States{Module: ControllerSeat, Node: node}
+	readable := map[string]bool{}
+	for _, n := range controllerReadable {
+		readable[n] = true
+	}
+	for _, bucket := range ControllerBuckets() {
+		local, mine := strings.CutPrefix(bucket, ControllerSeat+"_")
+		if !mine {
+			continue
+		}
+		s.States = append(s.States, announce.State{Name: local, Readable: readable[local]})
+	}
+	sort.Slice(s.States, func(i, j int) bool { return s.States[i].Name < s.States[j].Name })
+	return s
+}
+
+// ReadsAnnounced splits a reader's `reads` (`<owner>.<name>`) by what each owner announced: granted when the owner
+// announced the state readable, or announced nothing yet (the transition); refused when the owner announced and did
+// not announce that state readable.
+func ReadsAnnounced(reads []string, announced map[string]announce.States) (granted, refused []string) {
+	for _, r := range reads {
+		owner, name, ok := strings.Cut(r, ".")
+		s, said := announced[owner]
+		switch {
+		case !ok || !said || s.Readable(name):
+			granted = append(granted, r)
+		default:
+			refused = append(refused, r)
+		}
+	}
+	return granted, refused
+}
+
+// NotAnnounced are the owners some module reads the state of and that have announced nothing yet, sorted: read from the
+// readers' `reads` as before, until they announce.
+func NotAnnounced(r Records) []string {
+	seen := map[string]bool{}
+	var out []string
+	for _, ds := range r.Assigned {
+		for _, d := range ds {
+			for _, read := range append(append([]string(nil), d.Reads...), d.ReadsRefused...) {
+				owner, _, ok := strings.Cut(read, ".")
+				if !ok || seen[owner] {
+					continue
+				}
+				if _, said := r.Announced[owner]; !said {
+					seen[owner] = true
+					out = append(out, owner)
+				}
+			}
+		}
+	}
+	sort.Strings(out)
+	return out
+}

go/buscompose/buildbacklog.go

@@ -0,0 +1,47 @@
+package buscompose
+
+import "git.novox.be/novox/mesh-sdk/go/delivery"
+
+// The view alone reads the build seats' queues (novox/hq ADR 0525 §2, issue 1887 A8a): the shared workers' counts and the
+// oldest waiting ask, to show the backlog. It may not publish an ask: only the builder and the checker ask, by their seat use.
+// The watchman is granted nothing here: a waiting ask has no pulse, a taken one is read from the build module's steps (issue
+// 1908). Nothing is a wildcard over a stream or a worker.
+const (
+	// ViewModule is the module of the delivery view (mesh-delivery-view).
+	ViewModule = "mesh-delivery-view"
+	// BuilderModule is the module of the builder (mesh-delivery-builder).
+	BuilderModule = "mesh-delivery-builder"
+)
+
+// BuildAskReads are the API subjects the builder requests when it takes over, at its start, a key naming an ask (issue
+// 1910): each build seat's stream's information and its messages by sequence, to tell whether the ask is on its stream.
+// Reads only: no consumer, no pull, no acknowledgement; the builder puts its asks by its seat use, as before.
+func BuildAskReads() []string {
+	var out []string
+	for _, lang := range delivery.AskLanguages {
+		if stream, err := delivery.AskStream(lang); err == nil {
+			out = append(out, "$JS.API.STREAM.INFO."+stream, "$JS.API.STREAM.MSG.GET."+stream)
+		}
+	}
+	return out
+}
+
+// BuildBacklogReads are the API subjects the view requests: the information of each build seat's stream and of each of its
+// shared workers (delivery.AskStream, delivery.AskWorker), and the message of the stream by sequence. Reads only: no
+// message is pulled, none acknowledged, none published.
+func BuildBacklogReads() []string {
+	var out []string
+	for _, lang := range delivery.AskLanguages {
+		stream, err := delivery.AskStream(lang)
+		if err != nil {
+			continue
+		}
+		out = append(out, "$JS.API.STREAM.INFO."+stream, "$JS.API.STREAM.MSG.GET."+stream)
+		for _, kind := range delivery.AskKinds {
+			if w, err := delivery.AskWorker(lang, kind); err == nil {
+				out = append(out, "$JS.API.CONSUMER.INFO."+stream+"."+w)
+			}
+		}
+	}
+	return out
+}

go/buscompose/buscompose_test.go

@@ -0,0 +1,102 @@
+package buscompose
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// Defends issue 1377 and novox/hq ADR 0547 §5: this is the controller's bus composer copied, and it composes byte for
+// byte what the controller's composes. testdata/controller-user-lists.json was written by the controller's own
+// internal/broker (mesh-controller branch fix/1945-mesh-grants-publishes-memberships, and fix/1790-grants-create-buckets for the grants part creating declared streams), lists and memberships, from fixtures_test.go compiled there unchanged; composed.conf is the
+// controller's golden of the whole server configuration. A row that differs is the copy drifting from the controller,
+// which is a fault while both compose (until the controller loses its lease, ADR 0547 §13).
+func TestTheCopiedComposerComposesAsTheControllers(t *testing.T) {
+	raw, err := os.ReadFile(filepath.Join("testdata", "controller-user-lists.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var want []struct {
+		Name, List  string
+		Missing     []string
+		Err         string
+		Memberships json.RawMessage
+	}
+	if err := json.Unmarshal(raw, &want); err != nil {
+		t.Fatal(err)
+	}
+	fixtures := UserListFixtures()
+	if len(want) != len(fixtures) {
+		t.Fatalf("%d fixtures, %d lists the controller composed", len(fixtures), len(want))
+	}
+	for i, f := range fixtures {
+		t.Run(f.Name, func(t *testing.T) {
+			if want[i].Name != f.Name {
+				t.Fatalf("fixture %q against the controller's %q", f.Name, want[i].Name)
+			}
+			list, missing, err := ComposedFor(f)
+			got := ""
+			if err != nil {
+				got = err.Error()
+			}
+			if got != want[i].Err {
+				t.Fatalf("error %q, the controller's %q", got, want[i].Err)
+			}
+			if strings.Join(missing, ",") != strings.Join(want[i].Missing, ",") {
+				t.Errorf("left out %v, the controller %v", missing, want[i].Missing)
+			}
+			if list != want[i].List {
+				t.Errorf("the list differs from the controller's:\n%s", list)
+			}
+			// And every membership the records issue, as the controller's MembershipFor makes it (ADR 0547 §5): the
+			// grants part publishes them.
+			raw, err := json.Marshal(MembershipsFor(f))
+			if err != nil {
+				t.Fatal(err)
+			}
+			var gotM, wasM any
+			if err := json.Unmarshal(raw, &gotM); err != nil {
+				t.Fatal(err)
+			}
+			if err := json.Unmarshal(want[i].Memberships, &wasM); err != nil {
+				t.Fatal(err)
+			}
+			if !reflect.DeepEqual(gotM, wasM) {
+				t.Errorf("the memberships differ from the controller's:\n%s", raw)
+			}
+		})
+	}
+	t.Run("the controller's golden server configuration", func(t *testing.T) {
+		seat := Seat{Name: "telegram-sender", Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}}
+		got, err := Compose(
+			Server{ClientPort: 4222, MonitoringPort: 8222, StoreDir: "/data",
+				TLSCert: "/tls/tls.crt", TLSKey: "/tls/tls.key", TLSCA: "/tls/ca.crt"},
+			[]Principal{
+				{Kind: KindController, PasswordHash: "$2a$11$cccccccccccccccccccccc"},
+				{Kind: KindEnrolment, Node: "one", PasswordHash: "$2a$11$eeeeeeeeeeeeeeeeeeeeee"},
+				{Kind: KindNode, Node: "one", PasswordHash: "$2a$11$nnnnnnnnnnnnnnnnnnnnnn"},
+				{Kind: KindModule, Node: "one", Module: "telegram", Holds: []Seat{seat},
+					Serves: []string{"status"}, PasswordHash: "$2a$11$tttttttttttttttttttttt"},
+				{Kind: KindModule, Node: "two", Module: "shop", Uses: []Seat{seat},
+					Emits: []string{"order.placed"}, PasswordHash: "$2a$11$ssssssssssssssssssssss"},
+				{Kind: KindModule, Node: "two", Module: "audit",
+					Consumes: []string{"shop.order.placed"}, PasswordHash: "$2a$11$aaaaaaaaaaaaaaaaaaaaaa"},
+				{Kind: KindModule, Node: "one", Module: WatchmanModule, PasswordHash: "$2a$11$wwwwwwwwwwwwwwwwwwwwww"},
+				{Kind: KindModule, Node: "one", Module: "nats", SnapshotsTheBus: true,
+					Serves: []string{"nats_streams"}, PasswordHash: "$2a$11$bbbbbbbbbbbbbbbbbbbbbb"},
+			})
+		if err != nil {
+			t.Fatal(err)
+		}
+		want, err := os.ReadFile(filepath.Join("testdata", "composed.conf"))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got != string(want) {
+			t.Errorf("the configuration differs from the controller's golden:\n%s", got)
+		}
+	})
+}

go/buscompose/callers.go

@@ -0,0 +1,117 @@
+package buscompose
+
+import (
+	"regexp"
+	"strings"
+)
+
+// A tool call names its caller (novox/hq issue 365, by ADR 0259 §3's precedent for asks).
+//
+//	mesh.mod.<module>.call.<tool>[.<node>].<caller>
+//	mesh.seat.<seat>.call.<verb>[.<node>].<caller>
+//
+// The last token is the bus user that published the call, and each user is granted these subjects with its own
+// name there and no other — the caller is a fact the server enforces, and the tool runtime hands it to the
+// module from the subject a call arrived on (mesh-tools node-tools internal/bus caller.go holds the same shape).
+//
+// **A kind of its own, `call`, not the `tool` subject with a token appended.** Every grant to call a tool is a
+// wildcard over the `tool` kind — `.tool.<t>.*` for the instance on any machine, `mesh.mod.*.tool.>` for every
+// tool — and either would match a `tool` subject with any caller appended, so a caller could name another.
+// Under `call` nothing is granted but the caller-named subjects. No stream's filter covers it: a tool call is
+// never persisted (design 25 §3).
+//
+// **Derived from the `tool` grants, in one place** (callerNamed): wherever a principal may call or answer a
+// tool, it may call it in its own name, or answer it naming any caller — so no kind of principal is left
+// unable to call in its own name, and a new grant to call is one in both shapes by construction.
+//
+// The `tool` grants stay beside these for one release, so every caller and every runtime moves without a gap:
+// their retirement is hq issue 464.
+const CallKind = "call"
+
+var userName = regexp.MustCompile(`^[A-Za-z0-9_-]+(\.[A-Za-z0-9_-]+)*$`)
+
+// CallerToken is a bus user's name as the last token of a call it publishes: each dot written `~`, which no part
+// of a user's name may hold (safeSubject), so the token names that user and no other. "" for a name that is not
+// a user's.
+func CallerToken(user string) string {
+	if !userName.MatchString(user) {
+		return ""
+	}
+	return strings.ReplaceAll(user, ".", "~")
+}
+
+// toolGrant splits a grant on the `tool` kind — `mesh.mod.<m>.tool.<rest>` or `mesh.seat.<s>.tool.<rest>`, any
+// part possibly a wildcard — at the kind; ok is false for any other subject.
+func toolGrant(subject string) (head, rest string, ok bool) {
+	parts := strings.SplitN(subject, ".", 5)
+	if len(parts) != 5 || parts[0] != "mesh" || (parts[1] != "mod" && parts[1] != "seat") || parts[3] != "tool" ||
+		parts[2] == "" || parts[4] == "" {
+		return "", "", false
+	}
+	return parts[0] + "." + parts[1] + "." + parts[2], parts[4], true
+}
+
+// CalledSubject is where a call to a tool subject goes naming its caller; "" when the subject is not a tool's
+// or the user is not a bus user.
+func CalledSubject(subject, user string) string {
+	head, rest, ok := toolGrant(subject)
+	token := CallerToken(user)
+	if !ok || token == "" || strings.ContainsAny(rest, "*>") {
+		return ""
+	}
+	return head + "." + CallKind + "." + rest + "." + token
+}
+
+// CalledPattern is what a holder answering a tool subject also subscribes, to hear the calls that name their
+// caller: the same address under the `call` kind, any caller last. "" for a subject that is not a tool's.
+func CalledPattern(subject string) string {
+	head, rest, ok := toolGrant(subject)
+	if !ok || strings.ContainsAny(rest, "*>") {
+		return ""
+	}
+	return head + "." + CallKind + "." + rest + ".*"
+}
+
+// calledPublish is a grant to call on the `tool` kind, as the same grant in the caller's own name: its last
+// token the caller's, and nothing that reaches past it. A `>` is every tail a call carries — the tool alone or
+// the tool and the machine — so it becomes both, each ending in the caller.
+func calledPublish(grant, token string) []string {
+	head, rest, ok := toolGrant(grant)
+	if !ok || token == "" {
+		return nil
+	}
+	base := head + "." + CallKind + "."
+	switch {
+	case rest == ">":
+		return []string{base + "*." + token, base + "*.*." + token}
+	case strings.HasSuffix(rest, ".>"):
+		return []string{base + strings.TrimSuffix(rest, ">") + "*." + token}
+	}
+	return []string{base + rest + "." + token}
+}
+
+// calledSubscribe is a grant to answer on the `tool` kind, as the same grant for the calls naming any caller.
+func calledSubscribe(grant string) []string {
+	head, rest, ok := toolGrant(grant)
+	if !ok {
+		return nil
+	}
+	base := head + "." + CallKind + "."
+	if strings.HasSuffix(rest, ">") {
+		return []string{base + rest}
+	}
+	return []string{base + rest + ".*"}
+}
+
+// callerNamed adds, beside a principal's grants on the `tool` kind, the same grants under `call`: to publish in
+// its own name, to subscribe naming anybody.
+func callerNamed(user string, pub, sub []string) ([]string, []string) {
+	token := CallerToken(user)
+	for _, g := range pub {
+		pub = append(pub, calledPublish(g, token)...)
+	}
+	for _, g := range sub {
+		sub = append(sub, calledSubscribe(g)...)
+	}
+	return unique(pub), unique(sub)
+}

go/buscompose/cancelled.go

@@ -0,0 +1,11 @@
+package buscompose
+
+import "strings"
+
+// A seat's cancelled set (novox/hq ADR 0219) is a bucket the mesh no longer raises or grants (R4g, ADR 0525 clause 6): the
+// controller asks no work queue, so nothing is cancelled. A bus that still holds one is not reported as state nothing declares.
+
+// IsCancelledSet says a bucket is a seat's cancelled set rather than a module's state.
+func IsCancelledSet(bucket string) bool {
+	return strings.HasPrefix(bucket, "SEAT_") && strings.HasSuffix(bucket, "_cancelled")
+}

go/buscompose/composed.go

@@ -0,0 +1,196 @@
+package buscompose
+
+import (
+	"context"
+	"fmt"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// The compositions' buckets (novox/hq ADR 0539 clauses 2 and 4): one per node, `composed-<node>`, holding that node's
+// compositions, which only that node's node-engine reads, since a composition can carry a sealed value (ADR 0488 §2's
+// reason); and `mesh-controller_composed`, holding each composition's digest and the judgement of its move, which the
+// assigner reads. The controller writes both, by compare-and-set while it holds the lease; each keeps five revisions
+// of a key. The names and layouts are mesh-sdk's (delivery.ComposedBucketFor, ControllerComposedBucket, ComposedKey).
+
+// ControllerComposed is the local name of the compositions' digests, as a reader names it in `reads` after
+// `mesh-controller.`: delivery.ControllerComposedBucket.
+const ControllerComposed = "composed"
+
+// ComposedValueBytes is the most a composition may hold: a file over 64 KiB travels by digest, so a module's
+// composition is far smaller; just under the server's largest message, which also carries the subject and headers.
+const ComposedValueBytes = 1<<20 - 8<<10
+
+// ComposedBucketBytes is a node's composition bucket's size: five revisions of every module's compositions of the node.
+const ComposedBucketBytes = 256 << 20
+
+// ComposedDigestsBytes is the size of the bucket of digests: a value of a few hundred bytes per node, module and
+// fingerprint kept.
+const ComposedDigestsBytes = 64 << 20
+
+// ComposedConfig is a node's composition bucket as the controller asserts it.
+func ComposedConfig(node string) (jetstream.KeyValueConfig, error) {
+	bucket, err := delivery.ComposedBucketFor(node)
+	if err != nil {
+		return jetstream.KeyValueConfig{}, err
+	}
+	return jetstream.KeyValueConfig{
+		Bucket: bucket,
+		Description: "the compositions of " + node + " (novox/hq ADR 0539): each module's resources for this node at one " +
+			"fingerprint, and the node's own, signed; written by the controller alone, read by this node's node-engine " +
+			"alone; deleted when outside the module's five newest fingerprints and named by no want",
+		History:      delivery.ComposedHistory,
+		MaxValueSize: ComposedValueBytes,
+		MaxBytes:     ComposedBucketBytes,
+		Storage:      jetstream.FileStorage,
+	}, nil
+}
+
+// ComposedDigestsConfig is the bucket of the compositions' digests as the controller asserts it.
+func ComposedDigestsConfig() jetstream.KeyValueConfig {
+	return jetstream.KeyValueConfig{
+		Bucket: delivery.ControllerComposedBucket,
+		Description: "each composition's digest and the judgement of its move from what the node runs (novox/hq ADR 0539 " +
+			"clauses 2 and 14): written by the controller alone, read by the assigner",
+		History:      delivery.ControllerComposedHistory,
+		MaxValueSize: 4 << 10,
+		MaxBytes:     ComposedDigestsBytes,
+		Storage:      jetstream.FileStorage,
+	}
+}
+
+// EnsureComposed creates the bucket of digests and each named node's composition bucket if absent and brings their
+// options to match. An update, never a delete.
+func EnsureComposed(ctx context.Context, js jetstream.JetStream, nodes ...string) error {
+	if _, err := js.CreateOrUpdateKeyValue(ctx, ComposedDigestsConfig()); err != nil {
+		return fmt.Errorf("asserting bucket %s: %w", delivery.ControllerComposedBucket, err)
+	}
+	for _, node := range nodes {
+		cfg, err := ComposedConfig(node)
+		if err != nil {
+			return err
+		}
+		if _, err := js.CreateOrUpdateKeyValue(ctx, cfg); err != nil {
+			return fmt.Errorf("asserting bucket %s: %w", cfg.Bucket, err)
+		}
+	}
+	return nil
+}
+
+// ComposedWrites is what the controller publishes to write a node's compositions: the bucket's own subjects.
+func ComposedWrites(node string) (string, error) {
+	bucket, err := delivery.ComposedBucketFor(node)
+	if err != nil {
+		return "", err
+	}
+	return "$KV." + bucket + ".>", nil
+}
+
+// ComposedReads is what a node's node-engine publishes to follow its wants and compositions (ADR 0539 clauses 1, 2 and
+// 9): every key of its own composition bucket, and its own wants (`want.<node>.<module>` and `want.<node>.node`) in the
+// assigner's bucket; nothing of another node's, nor the bucket of digests.
+func ComposedReads(node string) ([]string, error) {
+	bucket, err := delivery.ComposedBucketFor(node)
+	if err != nil {
+		return nil, err
+	}
+	if !safeSubject.MatchString(node) {
+		return nil, fmt.Errorf("%q cannot be part of a subject: a permission is a subject pattern, and this would widen it", node)
+	}
+	return append(readGrants(bucket, ""), readGrants(delivery.AssignerWantsBucket, "want."+node+".>")...), nil
+}
+
+// VerbsTheNodeAgentAsks are the seat verbs a node's node-engine calls of its own machine while it applies a want (ADR
+// 0539 clause 16, ADR 0429 §14): its backup holder backs a data module up before it moves, and says when it was. Asked
+// of its own machine only, `mesh.seat.<seat>.tool.<verb>.<node>`.
+var VerbsTheNodeAgentAsks = []SeatVerb{{Seat: "node-backup", Verb: "now"}, {Seat: "node-backup", Verb: "backed-up"}}
+
+// NodeAgentAsks are the subjects of VerbsTheNodeAgentAsks for one node.
+func NodeAgentAsks(node string) ([]string, error) {
+	if !safeSubject.MatchString(node) {
+		return nil, fmt.Errorf("%q cannot be part of a subject: a permission is a subject pattern, and this would widen it", node)
+	}
+	var out []string
+	for _, v := range VerbsTheNodeAgentAsks {
+		out = append(out, "mesh.seat."+v.Seat+".tool."+v.Verb+"."+node)
+	}
+	return out, nil
+}
+
+// NodeAgentHears are the events a node's node-engine subscribes while it applies a want: the backup holder's word that a
+// backup is taken (`backed-up`), from whichever module holds node-backup on its machine (restic today).
+var NodeAgentHears = []string{"mesh.mod." + BackupHolderModule + ".event.backed-up"}
+
+// BackupHolderModule is the module that holds node-backup on every node, restic: the one whose word a node-engine hears.
+// A second holder of the seat is a change of this grant.
+const BackupHolderModule = "restic"
+
+// administers says a person may invoke every tool (`*`): the operator.
+func administers(invokes []string) bool {
+	for _, i := range invokes {
+		if i == "*" {
+			return true
+		}
+	}
+	return false
+}
+
+// HandPathWrites is what the operator's account publishes for release 6's hand path (ADR 0539 clauses 2 and 10): a want
+// of any node, written and read back, in the assigner's bucket; each named node's compositions; the digests; and each
+// node's object bucket for a file over 64 KiB, whose put reads an object's metadata and purges a replaced one's chunks.
+func HandPathWrites(nodes []string) ([]string, error) {
+	out := append([]string{"$KV." + delivery.AssignerWantsBucket + ".want.>"}, readGrants(delivery.AssignerWantsBucket, "want.>")...)
+	out = append(out, "$KV."+delivery.ControllerComposedBucket+".>")
+	out = append(out, readGrants(delivery.ControllerComposedBucket, "")...)
+	for _, node := range nodes {
+		w, err := ComposedWrites(node)
+		if err != nil {
+			return nil, err
+		}
+		bucket, _ := delivery.ComposedBucketFor(node)
+		out = append(out, w)
+		out = append(out, readGrants(bucket, "")...)
+		files, err := DeclarationFilesWrites(node)
+		if err != nil {
+			return nil, err
+		}
+		stream := "OBJ_" + DeclarationFilesBucket + node
+		out = append(out, files, "$JS.API.STREAM.INFO."+stream, "$JS.API.DIRECT.GET."+stream+".>",
+			"$JS.API.STREAM.MSG.GET."+stream, "$JS.API.STREAM.PURGE."+stream)
+	}
+	return out, nil
+}
+
+// DeclarationsStream is the stream of each node's last declaration, `mesh.node.<node>.declare` (issue 107). Release 6
+// sends none (ADR 0539 clauses 5 and 11): the stream is kept, with each node's consumer, only so a node away during the
+// switch finds its last declaration and with it the new node-engine; the controller deletes it once every node's have
+// names the new node-engine, and from then on neither asserts it nor any node's consumer on it; nor makes it again once
+// it is gone from the bus for any reason, since a stream made anew would hold no node's last declaration (issue 1945).
+const DeclarationsStream = "NODES"
+
+// RaiseAfterDeclarations is Raise once the declarations' stream is retired: the mesh's streams and consumers but the
+// declarations' stream, and no node's consumer of a declaration.
+func RaiseAfterDeclarations(r Raiser) error {
+	for _, s := range MeshStreams() {
+		if s.Name == DeclarationsStream {
+			continue
+		}
+		if err := r.EnsureStream(s); err != nil {
+			return fmt.Errorf("asserting stream %s: %w", s.Name, err)
+		}
+	}
+	return AssertMeshConsumers(r)
+}
+
+// TakeInConsumer is the durable consumer the controller takes done keys in from, on the stream of each of TakeInBuckets
+// (novox/hq ADR 0544 §1).
+const TakeInConsumer = "mesh-controller-take-in"
+
+// TakeInBuckets are the buckets the take-in consumes: the indexer's modules (each module's trunk value) and the builder's
+// builds (each build's key).
+var TakeInBuckets = []string{delivery.ModulesBucket, delivery.BuilderBuildsBucket}
+
+// ConfigFollowConsumer is the durable consumer the controller follows mesh-config's resolved values with, on that
+// bucket's stream (novox/hq ADR 0545).
+const ConfigFollowConsumer = "mesh-controller-config-follow"

go/buscompose/controller_buckets.go

@@ -0,0 +1,247 @@
+package buscompose
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// The controller's own key-value buckets (novox/hq to-be 45 §1, §6, §7).
+//
+// **What the controller must remember across its own restart, it keeps on the bus.** A call's
+// outcome lived in the memory of the process that served it (novox/hq issue 265), so a controller
+// replaced while a push ran answered "no such call" for the one thing its caller had been told to
+// ask about. The bus already outlives the controller and is the shape ADR 0201 gives a module's
+// current state: one value per key, written by one owner, read by anybody granted it. These are the
+// controller's, written by it alone — the writers table of to-be 45 §1 — and asserted on every start
+// like the streams, so a bus raised from nothing has them before the first call is served.
+
+// CallsBucket keeps every call of the mesh's own verbs and what came of it; HandActsBucket every act
+// a person did by hand, with why; ConditionsBucket every condition open now (to-be 45 §2), one key
+// each, and ConditionHistoryBucket every transition of one — raised, changed, silenced, cleared —
+// for ninety days.
+//
+// **The history is a bucket of its own** because its keys expire and an open condition's must not:
+// a bucket has one age for every key, and a condition open longer than the history is kept would
+// otherwise vanish from the store while still true.
+var (
+	CallsBucket            = BucketName(ControllerSeat, "calls")
+	HandActsBucket         = BucketName(ControllerSeat, "hand-acts")
+	ConditionsBucket       = BucketName(ControllerSeat, "conditions")
+	ConditionHistoryBucket = BucketName(ControllerSeat, "condition-history")
+	// LeaseBucket holds the controller's lease (to-be 45 §6): one key, `holder`, which the instance
+	// allowed to act writes by compare-and-set and renews; its revision when taken is the epoch.
+	LeaseBucket = BucketName(ControllerSeat, "lease")
+	// AskedBucket keeps what the controller asked the operator about its conditions (novox/hq ADR 0259):
+	// each ask by its id, its options and the actions they stand for, how it ended and whether the
+	// controller acted on its warrant — so a restart neither asks twice nor acts twice.
+	AskedBucket = BucketName(ControllerSeat, "asked")
+	// DeliveryMergesBucket holds the merges mesh-delivery announced it made, each with the ask whose Approve it merged
+	// on (novox/hq ADR 0420 §7, issue 1025): per merge a key `<owner>/<repo>/<number>/<head sha>` holding the
+	// announcement, kept DeliveryMergesKeptFor. What lets the build of a moved module register it from its new
+	// repository: the controller reads the ask's warrant from the router and accepts only the operator's Approve of
+	// those heads. Written by the controller alone, from the announcement, when it holds the lease.
+	DeliveryMergesBucket = BucketName(ControllerSeat, "delivery-merges")
+)
+
+// DeliveryMergesKeptFor is how long a merge mesh-delivery announced is kept: a week, as the events are.
+const DeliveryMergesKeptFor = 7 * 24 * time.Hour
+
+// The controller's record mirrors (novox/hq ADR 0289, design 54, design 57 package F3): a bucket per kind of
+// record, one key per record, written from the store by the lease holder only when the record changed, with
+// one event on the controller's seat per write. Read by whatever names them in `reads` as
+// `mesh-controller.<mirror>` (ADR 0201 §1), written by nobody else. **No secret in either** (ADR 0201): an
+// assignment's value names its module and node; a module's declared config is what its manifest, which is
+// public, declares.
+//
+// AssignmentsBucket holds which module is assigned to which node, keyed `<node>.<module>`; and
+// DeclaredConfigBucket each registered module's config declarations as its manifest holds them, keyed by
+// the module: what mesh-config resolves a config value from (ADR 0348 clauses 2 and 4); and PredefinedBucket the
+// list of predefined keys the mesh published (the newest trunk build's of the catalogue, ADR 0348 §7), one key
+// `list`: what mesh-config publishes as mesh-config_predefined (design 57 K3, issue 662).
+var (
+	AssignmentsBucket    = BucketName(ControllerSeat, MirrorAssignments)
+	DeclaredConfigBucket = BucketName(ControllerSeat, MirrorDeclaredConfig)
+	PredefinedBucket     = BucketName(ControllerSeat, MirrorPredefined)
+	// DeclaredPackagesBucket holds, keyed by the node, each package the modules assigned to it declare, present or absent,
+	// with the declaring modules: what the pacman module's verbs read to say a package is declared (ADR 0507 §5).
+	DeclaredPackagesBucket = BucketName(ControllerSeat, MirrorDeclaredPackages)
+)
+
+// The mirrors' local names, as a reader names them in `reads` after `mesh-controller.`.
+const (
+	MirrorAssignments    = "assignments"
+	MirrorDeclaredConfig = "declared-config"
+	MirrorPredefined     = "predefined"
+	// MirrorDeclaredPackages is the local name of the packages each node's modules declare (ADR 0507 §5, issue 1840/S3).
+	MirrorDeclaredPackages = "declared-packages"
+)
+
+// The chain's buckets (novox/hq ADR 0408, issue 1089): builds, rollouts and assignments are one chain kept on the bus
+// alone, one bucket each, one key per record, written by the lease holder by compare-and-set. The assignments bucket is
+// AssignmentsBucket above, which keeps its name and its readers (ADR 0408 §3). Nothing is removed from them (§4), they keep
+// ChainHistory earlier revisions of every key (§5), and a value is never cut (§6).
+var (
+	BuildsBucket   = BucketName(ControllerSeat, ChainBuilds)
+	RolloutsBucket = BucketName(ControllerSeat, ChainRollouts)
+)
+
+// **The assignments bucket keeps the marker age (MirrorMarkerTTL) it was made with as a mirror.** A stream that allows
+// messages an age cannot be made to disallow them (the server refuses the update: "message TTL status can not be
+// disabled", nats-server stream.go), so asserting the bucket without the age would fail the controller's start on a
+// mesh that has the bucket. The chain never purges or removes a key (ADR 0408 §4), so no marker is ever written and the
+// age ends nothing; it is kept only so the stream's configuration stays one the server accepts.
+//
+// The chain buckets' local names, as a reader names them in `reads` after `mesh-controller.`.
+const (
+	ChainBuilds   = "builds"
+	ChainRollouts = "rollouts"
+)
+
+// The chain buckets' bounds. ChainHistory is the bus's largest history (ADR 0408 §5). A value is at most ChainValueBytes,
+// just under the server's largest message of a mebibyte, which also carries the subject and the headers (ADR 0408 §6):
+// the controller writes none larger and the move refuses to. The buckets' size is the arithmetic of the survey of
+// issue 981: 8585 builds of 1 to 40 KB, 1049 rollouts of about 2 KB a revision and 64 revisions, so 512 MiB for the two
+// that grow, and the assignments, 285 of under a kilobyte, 64 MiB.
+const (
+	ChainHistory         = 64
+	ChainValueBytes      = 1<<20 - 8<<10
+	ChainBuildsBytes     = 512 << 20
+	ChainRolloutsBytes   = 512 << 20
+	ChainAssignmentBytes = 64 << 20
+)
+
+// GrantsBucket holds, keyed `<module>.<fingerprint hex>`, each fingerprint of a module whose bus credential the controller
+// has issued (novox/hq ADR 0528 clause 2, ADR 0429 §6 rule 6, issue 1394): written by the controller alone once the bus's
+// user list composed with the module's manifest at that fingerprint was sent to the bus's machine; read by the assigner,
+// whose sixth rule moves a node's want to a fingerprint only once its grant exists. The name and layout are mesh-sdk's
+// (delivery.ControllerGrantsBucket, ControllerGrantKey).
+var GrantsBucket = BucketName(ControllerSeat, ControllerGrants)
+
+// ControllerGrants is the grants bucket's local name, as a reader names it in `reads` after `mesh-controller.`.
+const ControllerGrants = "grants"
+
+// ChainBuckets are the three buckets of the chain: builds, rollouts and assignments.
+func ChainBuckets() []string { return []string{BuildsBucket, RolloutsBucket, AssignmentsBucket} }
+
+// MirrorsWrittenByAnother are the controller's mirrors whose writer is not the controller, each with its reason: the rule
+// that a mirror is written by the controller alone (TestTheMirrorsListAndTheWritersTableAgree) has these exceptions and no
+// other.
+var MirrorsWrittenByAnother = map[string]string{}
+
+// The mirrors' caps (design 54 §5): one value per key, no age, 64 KiB a value, 64 MiB a bucket.
+const (
+	MirrorValueBytes = 64 << 10
+	MirrorBytes      = 64 << 20
+	// MirrorMarkerTTL is the longest a purge's marker is kept (design 54 §2): the bucket allows a
+	// per-message age for it, and the writer gives each marker a day.
+	MirrorMarkerTTL = 24 * time.Hour
+)
+
+// PlanStateBuckets are the buckets of the plans' state that release 6 deletes (novox/hq ADR 0539 clause 13): the merge
+// window's clock, the silent sends' waits and the building plans' hold. The controller deletes each at its first start
+// and says it once (composed_start.go); none is asserted, granted or written any more.
+var PlanStateBuckets = []string{BucketName(ControllerSeat, "merge-window"), BucketName(ControllerSeat, "rollout-silent"),
+	BucketName(ControllerSeat, "plans-building")}
+
+// AskedKeptFor is how long an ask is kept after it was made: a month, as the router keeps its own.
+const AskedKeptFor = 30 * 24 * time.Hour
+
+// LeaseTTL is how long the lease's key lives unrenewed (to-be 45 §6): fifteen seconds, renewed
+// every five. The bucket's age, so the bus forgets a holder that stopped renewing.
+const LeaseTTL = 15 * time.Second
+
+// The bounds to-be 45 §6 sets for calls: the last thousand, or fourteen days, whichever is fewer.
+// A call is two keys — its record, and its answer apart so a listing does not read every answer —
+// so the stream holds twice as many messages as it keeps calls.
+const (
+	KeptCallsDurably = 1000
+	CallsKeptFor     = 14 * 24 * time.Hour
+	// CallAnswerBytes is the most of one answer kept: a whole declaration is far smaller, and an
+	// answer larger is cut and says so.
+	CallAnswerBytes = 64 << 10
+	// HandActsKeptFor is as long as a condition's history (to-be 45 §2): an act by hand is read
+	// back beside what it addressed.
+	HandActsKeptFor = 90 * 24 * time.Hour
+	// ConditionHistoryKeptFor is how long a condition's transitions are kept (to-be 45 §2).
+	ConditionHistoryKeptFor = 90 * 24 * time.Hour
+)
+
+// IsControllerBucket says a bucket is the controller's own, not a module's state nothing declares.
+func IsControllerBucket(bucket string) bool {
+	return bucket == CallsBucket || bucket == HandActsBucket || bucket == ConditionsBucket ||
+		bucket == ConditionHistoryBucket || bucket == LeaseBucket || bucket == AskedBucket ||
+		bucket == AssignmentsBucket || bucket == DeclaredConfigBucket || bucket == PredefinedBucket ||
+		bucket == DeclaredPackagesBucket ||
+		bucket == DeliveryMergesBucket || bucket == BuildsBucket || bucket == RolloutsBucket ||
+		bucket == delivery.HaveBucket || bucket == StatesAnnouncedBucket ||
+		bucket == GrantsBucket || bucket == delivery.ControllerComposedBucket
+}
+
+// ControllerBuckets are the controller's own buckets, in the order they are asserted.
+func ControllerBuckets() []string {
+	return []string{LeaseBucket, CallsBucket, HandActsBucket, ConditionsBucket, ConditionHistoryBucket, AskedBucket,
+		AssignmentsBucket, DeclaredConfigBucket, PredefinedBucket, DeclaredPackagesBucket,
+		DeliveryMergesBucket, BuildsBucket, RolloutsBucket, delivery.HaveBucket, StatesAnnouncedBucket, GrantsBucket,
+		delivery.ControllerComposedBucket}
+}
+
+// ControllerBucketsAsserter is what raising the controller's buckets needs of a connection.
+type ControllerBucketsAsserter interface {
+	EnsureControllerBuckets() error
+}
+
+// chainBucket is the options of a bucket of the chain: sixty-four revisions of each key, no age, a value up to
+// ChainValueBytes, on disk.
+func chainBucket(bucket, why string, bytes int64, markers time.Duration) jetstream.KeyValueConfig {
+	return jetstream.KeyValueConfig{
+		Bucket:         bucket,
+		Description:    why,
+		History:        ChainHistory,
+		MaxValueSize:   ChainValueBytes,
+		MaxBytes:       bytes,
+		Storage:        jetstream.FileStorage,
+		LimitMarkerTTL: markers,
+	}
+}
+
+// EnsureLeaseBucket creates the lease's bucket if absent and brings its options to match (to-be 45
+// §6). **Before the lease is taken, by any candidate**: it is the lease's own precondition, and asserting
+// a bucket that exists changes nothing. File storage, so its revisions — the epochs — outlive a restart of
+// the bus; one raised again from nothing is moved past the highest epoch issued when the lease is taken.
+func EnsureLeaseBucket(ctx context.Context, js jetstream.JetStream) error {
+	if _, err := js.CreateOrUpdateKeyValue(ctx, jetstream.KeyValueConfig{
+		Bucket: LeaseBucket,
+		Description: "the controller's lease (novox/hq to-be 45 §6): the key `holder`, written by compare-and-set " +
+			"by the one controller instance that may act and renewed every five seconds; its revision when taken " +
+			"is the epoch every declaration and plan write carries",
+		History:      1,
+		TTL:          LeaseTTL,
+		MaxValueSize: 4 << 10,
+		MaxBytes:     1 << 20,
+		Storage:      jetstream.FileStorage,
+	}); err != nil {
+		return fmt.Errorf("asserting bucket %s: %w", LeaseBucket, err)
+	}
+	return nil
+}
+
+// HaveBucketConfig is the options of the have bucket (novox/hq ADR 0429 §1): delivery.HaveHistory revisions of each
+// key, no age, 64 MiB on disk like the assignments. A module's have is JSON of about 500 bytes, but a node's own key
+// carries its whole facts (its profile among them), several kilobytes on a desktop: a value is as large as the chain's
+// buckets take, since a value is never cut (novox/hq ADR 0408 §6, issue 1162).
+func HaveBucketConfig() jetstream.KeyValueConfig {
+	return jetstream.KeyValueConfig{
+		Bucket: delivery.HaveBucket,
+		Description: "what each machine has of each module, one key `<node>.<module>` (and `<node>.node` for the machine's " +
+			"own facts) (novox/hq ADR 0429, design 47): written by each machine's node-engine under its own node's keys " +
+			"alone, never by the controller; read by the delivery view and the watchman",
+		History:      delivery.HaveHistory,
+		MaxValueSize: ChainValueBytes,
+		MaxBytes:     64 << 20,
+		Storage:      jetstream.FileStorage,
+	}
+}

go/buscompose/create.go

@@ -0,0 +1,88 @@
+package buscompose
+
+import (
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// The streams a manifest declares, as the server is asked to create them (novox/hq ADR 0547 §5, issue 1790): the
+// grants part creates each one the bus does not hold yet, with what the controller asserts at its start, so the two
+// make the same stream. Pure. Only a create is ever asked with these: a stream the bus holds is never updated by the
+// grants part (CreateStreamGrants grants no update).
+
+// BucketStreamConfig is a module's bucket as the stream the controller's CreateOrUpdateKeyValue makes of its options
+// (mesh-controller internal/broker BucketConfig, with no marker age held): the client library's key-value shape
+// (rollup, no delete, direct reads, discard new, a duplicate window of two minutes or the age when shorter) with the
+// mesh's caps, file storage and one replica.
+func BucketStreamConfig(b Bucket) jetstream.StreamConfig {
+	history := b.History
+	if history < 1 {
+		history = 1
+	}
+	age := time.Duration(b.TTLSeconds) * time.Second
+	dupes := 2 * time.Minute
+	if age > 0 && age < dupes {
+		dupes = age
+	}
+	cfg := jetstream.StreamConfig{
+		Name:              "KV_" + b.Bucket(),
+		Description:       b.Why(),
+		Subjects:          []string{"$KV." + b.Bucket() + ".>"},
+		MaxMsgsPerSubject: int64(history),
+		MaxBytes:          StateMaxBytes,
+		MaxAge:            age,
+		MaxMsgSize:        StateMaxValueBytes,
+		Storage:           jetstream.FileStorage,
+		Replicas:          1,
+		AllowRollup:       true,
+		DenyDelete:        true,
+		Duplicates:        dupes,
+		MaxMsgs:           -1,
+		MaxConsumers:      -1,
+		AllowDirect:       true,
+		Discard:           jetstream.DiscardNew,
+	}
+	if b.KeyTTL {
+		cfg.AllowMsgTTL, cfg.SubjectDeleteMarkerTTL = true, KeyTTLMarkerTTL
+	}
+	return cfg
+}
+
+// ModuleStreamConfig is a module's own stream as the controller asserts it (mesh-controller internal/broker
+// StreamConfigFor of ModuleStream.Stream).
+func ModuleStreamConfig(m ModuleStream) jetstream.StreamConfig {
+	s := m.Stream()
+	cfg := jetstream.StreamConfig{
+		Name:              s.Name,
+		Subjects:          s.Subjects,
+		Retention:         jetstream.LimitsPolicy,
+		MaxAge:            time.Duration(s.MaxAge) * time.Second,
+		MaxMsgsPerSubject: int64(s.MaxMsgsPerSubject),
+		Description:       s.Why,
+		AllowDirect:       s.Direct,
+		AllowMsgTTL:       s.AllowMsgTTL,
+	}
+	if s.Retention == RetentionWorkQueue {
+		cfg.Retention = jetstream.WorkQueuePolicy
+	}
+	if s.Restricted || s.WorkQueue {
+		cfg.Metadata = map[string]string{}
+		if s.Restricted {
+			cfg.Metadata[RestrictedMetadata] = "true"
+		}
+		if s.WorkQueue {
+			cfg.Metadata[WorkQueueMetadata] = "true"
+		}
+	}
+	if s.MaxBytes > 0 {
+		cfg.MaxBytes = s.MaxBytes
+	}
+	if s.DiscardNew {
+		cfg.Discard = jetstream.DiscardNew
+	}
+	if s.DuplicatesSeconds > 0 {
+		cfg.Duplicates = time.Duration(s.DuplicatesSeconds) * time.Second
+	}
+	return cfg
+}

go/buscompose/create_test.go

@@ -0,0 +1,46 @@
+package buscompose
+
+import (
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// Defends issue 1790 (ADR 0547 §5): the grants part creates a declared bucket and stream as the controller asserts them.
+func TestDeclaredStreamsAreCreatedAsTheControllerAssertsThem(t *testing.T) {
+	plain := BucketStreamConfig(Bucket{Module: "mesh-vault", Name: "bus-accounts"})
+	keyed := BucketStreamConfig(Bucket{Module: "m", Name: "presence", History: 5, TTLSeconds: 60, KeyTTL: true})
+	queue := ModuleStreamConfig(ModuleStream{Module: "b", Name: "ASKS", Events: []string{"ask"}, MaxAgeDays: 7, MaxMiB: 32,
+		WorkQueue: true, Duplicates: 1})
+	for _, row := range []struct {
+		what      string
+		got, want any
+	}{
+		{"bucket name", plain.Name, "KV_mesh-vault_bus-accounts"},
+		{"bucket subjects", plain.Subjects[0], "$KV.mesh-vault_bus-accounts.>"},
+		{"bucket history defaults to one", plain.MaxMsgsPerSubject, int64(1)},
+		{"bucket cap", plain.MaxBytes, int64(StateMaxBytes)},
+		{"bucket value cap", plain.MaxMsgSize, int32(StateMaxValueBytes)},
+		{"bucket duplicate window", plain.Duplicates, 2 * time.Minute},
+		{"bucket discards new", plain.Discard, jetstream.DiscardNew},
+		{"bucket direct and rollup, no delete", plain.AllowDirect && plain.AllowRollup && plain.DenyDelete, true},
+		{"bucket without key ttl", plain.AllowMsgTTL, false},
+		{"history", keyed.MaxMsgsPerSubject, int64(5)},
+		{"age", keyed.MaxAge, time.Minute},
+		{"duplicate window under the age", keyed.Duplicates, time.Minute},
+		{"key ttl markers", keyed.SubjectDeleteMarkerTTL, KeyTTLMarkerTTL},
+		{"key ttl", keyed.AllowMsgTTL, true},
+		{"queue retention", queue.Retention, jetstream.WorkQueuePolicy},
+		{"queue subjects", queue.Subjects[0], "mesh.stream.b.event.ask"},
+		{"queue age", queue.MaxAge, 7 * 24 * time.Hour},
+		{"queue cap", queue.MaxBytes, int64(32 << 20)},
+		{"queue discards new", queue.Discard, jetstream.DiscardNew},
+		{"queue duplicates", queue.Duplicates, time.Hour},
+		{"queue metadata", queue.Metadata[WorkQueueMetadata] + queue.Metadata[RestrictedMetadata], "truetrue"},
+	} {
+		if row.got != row.want {
+			t.Errorf("%s: %v, want %v", row.what, row.got, row.want)
+		}
+	}
+}

go/buscompose/creates_streams_test.go

@@ -0,0 +1,77 @@
+package buscompose
+
+import "testing"
+
+// Defends issue 1790 and novox/hq ADR 0547 §5 (the operator, 2026-10-26 08:54): the grants part may create the stream
+// of each bucket, log and stream a placed module's manifest declares, by its own name, and read it back; nothing
+// wider, nothing updated or deleted, and no other principal so. Held byte-equal in the controller's copy.
+func TestTheGrantsPartCreatesOnlyDeclaredStreams(t *testing.T) {
+	records := Records{
+		Nodes: []string{"novox"},
+		Assigned: map[string][]Declared{"novox": {
+			{Module: "mesh-delivery-builder",
+				State:   []Bucket{{Module: "mesh-delivery-builder", Name: "steps", History: 5}},
+				Logs:    []Log{{Module: "mesh-delivery-builder", Name: "builds"}},
+				Streams: []ModuleStream{{Module: "mesh-delivery-builder", Name: "BUILDASKS", Events: []string{"ask"}}}},
+			{Module: GrantsModule, State: []Bucket{{Module: GrantsModule, Name: "assertions"}}},
+		}},
+	}
+	users, err := Users(records)
+	if err != nil {
+		t.Fatal(err)
+	}
+	perms := map[string]Permissions{}
+	for _, u := range users {
+		if u.Kind != KindModule {
+			continue
+		}
+		p, err := PermissionsFor(u)
+		if err != nil {
+			t.Fatalf("%s: %v", u.Username(), err)
+		}
+		perms[u.Module] = p
+	}
+	for _, row := range []struct {
+		who, subject string
+		may          bool
+	}{
+		{GrantsModule, "$JS.API.STREAM.CREATE.KV_mesh-delivery-builder_steps", true},
+		{GrantsModule, "$JS.API.STREAM.INFO.KV_mesh-delivery-builder_steps", true},
+		{GrantsModule, "$JS.API.STREAM.CREATE.LOG_mesh-delivery-builder_builds", true},
+		{GrantsModule, "$JS.API.STREAM.CREATE.BUILDASKS", true},
+		{GrantsModule, "$JS.API.STREAM.CREATE.KV_mesh-grants_assertions", true},
+		{GrantsModule, "$JS.API.STREAM.UPDATE.KV_mesh-delivery-builder_steps", false},
+		{GrantsModule, "$JS.API.STREAM.DELETE.KV_mesh-delivery-builder_steps", false},
+		{GrantsModule, "$JS.API.STREAM.PURGE.KV_mesh-delivery-builder_steps", false},
+		{GrantsModule, "$JS.API.STREAM.CREATE.KV_mesh-delivery-builder_undeclared", false},
+		{GrantsModule, "$JS.API.STREAM.CREATE.EVENTS", false},
+		{GrantsModule, "$JS.API.STREAM.CREATE.ASSIGNMENTS", false},
+		{GrantsModule, "$JS.API.STREAM.INFO.EVENTS", false},
+		{"mesh-delivery-builder", "$JS.API.STREAM.CREATE.KV_mesh-delivery-builder_steps", false},
+	} {
+		if got := MayPublish(perms[row.who], row.subject); got != row.may {
+			t.Errorf("%s may publish %s: %v, want %v", row.who, row.subject, got, row.may)
+		}
+	}
+	// A name that is no plain token is never granted, and a module other than the grants part is never granted one.
+	if got := CreateStreamGrants([]string{"*", ">", "KV_a.b", "KV_a_b"}); len(got) != 2 {
+		t.Errorf("grants for wildcard names: %v", got)
+	}
+	other, err := PermissionsFor(Principal{Kind: KindModule, Node: "novox", Module: "shop", CreatesStreams: []string{"KV_shop_x"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if MayPublish(other, "$JS.API.STREAM.CREATE.KV_shop_x") {
+		t.Error("a module other than the grants part was granted a create")
+	}
+	// The writers table refuses the grants part an update, and a create of a stream it was not given.
+	g := Principal{Kind: KindModule, Node: "novox", Module: GrantsModule, CreatesStreams: []string{"KV_a_b"}}
+	if err := CheckWriters(g, []string{"$JS.API.STREAM.CREATE.KV_a_b"}); err != nil {
+		t.Errorf("the declared create refused: %v", err)
+	}
+	for _, refused := range []string{"$JS.API.STREAM.UPDATE.KV_a_b", "$JS.API.STREAM.CREATE.KV_a_c", "$JS.API.STREAM.CREATE.*"} {
+		if CheckWriters(g, []string{refused}) == nil {
+			t.Errorf("%s was not refused", refused)
+		}
+	}
+}

go/buscompose/declaration_files.go

@@ -0,0 +1,111 @@
+package buscompose
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// The object buckets a declaration's large files travel in (novox/hq ADR 0486, issues 1696 and 1697): **one bucket for each
+// node**, `declaration-files-<node>`.
+//
+// **The controller alone writes them, and a node-engine reads an object by its name from its own bucket** (ADR 0486 §2): its
+// account may neither list the bucket nor write it, no account may touch another node's, and no other account has any access.
+// Why a bucket each: a subject pattern cannot tell a name from a wildcard. A grant of `...M.*` matches a publish to the literal
+// subject `...M.*` too (probed on nats-server 2.11.17 by the review of this issue: a node created a consumer filtered on
+// `$O.<bucket>.C.*` and read every object of the bucket), so in one shared bucket a node could read every other node's files.
+// With a bucket each, the same trick reads only the node's own files, which are the files of its own declaration.
+//
+// A bucket of the bus's object store is a stream, OBJ_<bucket>, whose messages are the objects' metadata
+// (`$O.<bucket>.M.<base64 of the name>`) and chunks (`$O.<bucket>.C.<nuid>`).
+
+// DeclarationFilesBucket is the prefix of the buckets' names, which mesh-sdk fixes for the node-engine and the controller alike.
+const DeclarationFilesBucket = declaration.FileBucketPrefix
+
+// DeclarationFilesBucketOf is the bucket a node's files are in: mesh-sdk's FileBucketFor, the one place the name is composed. A
+// node name it refuses (one that could carry a subject wildcard or separator into a grant) is an error, never a bucket.
+func DeclarationFilesBucketOf(node string) (string, error) { return declaration.FileBucketFor(node) }
+
+// DeclarationFilesStreamOf is the stream under a node's bucket: mesh-sdk's FileStreamFor.
+func DeclarationFilesStreamOf(node string) (string, error) { return declaration.FileStreamFor(node) }
+
+// DeclarationFilesMaxBytes is a bucket's size: the objects are immutable and regenerable, and one node's hold well under a hundred
+// megabytes.
+const DeclarationFilesMaxBytes = 1 << 30
+
+// DeclarationFilesKeptFor is how long an object stays after no node's latest declaration names it (ADR 0486 §3).
+const DeclarationFilesKeptFor = 24 * time.Hour
+
+// DeclarationFilesWrites is the one pattern the controller may publish to write a node's bucket: every object's metadata and
+// chunks. The server's API for the stream is the controller's `$JS.API.>`.
+func DeclarationFilesWrites(node string) (string, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return "", err
+	}
+	return "$O." + bucket + ".>", nil
+}
+
+// DeclarationFilesReads is what a node-engine's account may publish to read an object of its own bucket by its name, and nothing
+// more. The set is the one node-engine's own call (mesh-host internal/link FileObject) makes, for B the node's bucket and S its
+// stream (issue 1697, notes 4 and 5):
+//
+//   - the object's metadata, by a direct get of the last message of the one subject that names it. **Only the suffixed
+//     form**: the bare `$JS.API.DIRECT.GET.S` takes a sequence number and would read any message of the stream.
+//   - the ordered consumer on that object's chunks: `$JS.API.CONSUMER.CREATE.S.<name>.$O.B.C.<nuid>`. **Not `S.>`**:
+//     a consumer filtered on `$O.B.M.>` would read every object's name.
+//   - the flow-control replies of that consumer, without which a large object stalls at the flow-control window.
+//   - the consumer's deletion, best effort: the consumer's inactivity threshold removes it if this is refused.
+//
+// **Never granted:** STREAM.INFO (a `subjects_filter` of `>` lists every name), STREAM.MSG.GET (any message by its sequence), a
+// publish to `$O.B.>` (a write), and any subject of another node's stream. A literal `*` in a subject matches the grant's `*`: it
+// reaches the objects of this node's own bucket and no other (above).
+func DeclarationFilesReads(node string) ([]string, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return nil, err
+	}
+	stream, err := DeclarationFilesStreamOf(node)
+	if err != nil {
+		return nil, err
+	}
+	return []string{
+		"$JS.API.DIRECT.GET." + stream + ".$O." + bucket + ".M.*",
+		"$JS.API.CONSUMER.CREATE." + stream + ".*.$O." + bucket + ".C.*",
+		"$JS.API.CONSUMER.DELETE." + stream + ".*",
+		"$JS.FC." + stream + ".>",
+	}, nil
+}
+
+// EnsureDeclarationFiles is the same on a JetStream the caller holds.
+func EnsureDeclarationFiles(ctx context.Context, js jetstream.JetStream, nodes ...string) error {
+	for _, node := range nodes {
+		cfg, err := DeclarationFilesConfig(node)
+		if err != nil {
+			return err
+		}
+		if _, err := js.CreateOrUpdateObjectStore(ctx, cfg); err != nil {
+			return fmt.Errorf("asserting the object bucket %s: %w", cfg.Bucket, err)
+		}
+	}
+	return nil
+}
+
+// DeclarationFilesConfig is a node's bucket as the controller asserts it.
+func DeclarationFilesConfig(node string) (jetstream.ObjectStoreConfig, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return jetstream.ObjectStoreConfig{}, err
+	}
+	return jetstream.ObjectStoreConfig{
+		Bucket: bucket,
+		Description: "the contents of the files over 64 KiB of the declaration of " + node + ", each under the hex of its sha256 " +
+			"digest (novox/hq ADR 0486): written by the controller alone, read by the node-engine of that node by name, removed " +
+			"a day after the node's latest declaration no longer names it",
+		MaxBytes: DeclarationFilesMaxBytes,
+		Storage:  jetstream.FileStorage,
+	}, nil
+}

go/buscompose/derived.go

@@ -0,0 +1,357 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// Streams and consumers derived from what modules declare.
+//
+// The mesh's own four exist before any module does (streams.go). Everything here is the other
+// half: a seat's stream comes into being when the module declaring it is **registered**, and a
+// consumer when a module is **assigned** — which is why ADR 0116's task 1.4 had to be narrowed to
+// the foundation set. Neither has happened at genesis.
+//
+// All of it is a pure function of declarations. The controller is still the only writer; this is
+// only what it writes.
+
+// A Consumer is a durable subscription the controller creates on a module's behalf. A module
+// declares what it reacts to, never how delivery works, so it does not name these and cannot
+// misconfigure them.
+type Consumer struct {
+	Name   string
+	Stream string
+	// Filters are the subjects this consumer receives. One consumer per module with several
+	// filters, rather than one per consumed event: its ack subject is derived from its name, and
+	// a module with five consumers would need five ack permissions to ack its own deliveries.
+	Filters []string
+	// Queue is the queue group, set for a seat's worker so that "exactly one holder" survives a
+	// seat later being relaxed to several. Authority and delivery are kept separate on purpose.
+	Queue string
+	// Push asks the server to deliver to a subject rather than wait to be pulled.
+	//
+	// For the mesh's own consumer, where the controller wants every message to arrive in the one
+	// loop it already runs: pulling would mean a second goroutine fetching batches and handing
+	// them over, and a loop that acts on one message at a time is the property the store window
+	// depends on. A queue group implies this, because a group has nothing to pull from.
+	Push bool
+	// TakesOverFrom names a consumer of the same stream whose filter this one takes over (issue 973): made while
+	// that consumer still filters this one's subject, it starts after what that consumer has acknowledged, so a
+	// message the old one held unacknowledged is not lost to the change. Otherwise it starts as FromNow says.
+	TakesOverFrom string
+	// DeliverSubject, when set, is where a push consumer delivers instead of DeliverSubjectFor's.
+	DeliverSubject string
+	// AckWaitSeconds before an unacknowledged delivery is redelivered.
+	AckWaitSeconds int
+	// MaxDeliver is how often a message is handed over before the consumer gives it up; zero for no
+	// bound. What a consumer gives up is kept in DEAD_LETTERS by the controller (novox/hq issue 330).
+	MaxDeliver int
+	// MaxAckPending is how many deliveries the server lets stand unacknowledged at once; zero for
+	// the server's default, which is many. **One, for a consumer handled one at a time**
+	// (novox/hq issue 175): a handler that builds for minutes keeps its own message alive with a
+	// heartbeat, but everything handed over behind it times out unacknowledged and comes back —
+	// and a merge that came back rebuilt what it had just built, five times over on 2026-09-30.
+	// With one outstanding, the server holds the rest, and the heartbeat is keeping the message.
+	MaxAckPending int
+	// FromNow makes a consumer that does not exist yet start at the stream's end rather than its
+	// beginning (novox/hq issue 248). For a consumer that reacts to announcements — a merge, a build's
+	// outcome — on a stream that keeps a week of them: the server's default, everything the stream
+	// holds, replays every merge and every build of that week as if it had just happened. A consumer
+	// that exists keeps where it is, whatever this says; only its making is decided here.
+	FromNow bool
+	Why     string
+	// Resettable says why this consumer may be re-made to deliver from now by the mesh itself, with
+	// nobody asked (novox/hq to-be 45 §7, healer H4): what a reset drops, something else catches up.
+	// Empty for every consumer where nothing would — a module's, whose events would be lost to it.
+	// Not a property of the consumer on the bus: nothing here is sent to the server.
+	Resettable string
+}
+
+// seatStreamName is the stream holding a seat's inbound work. Named after the seat rather than
+// the module holding it, because the holder can change and the queued work must not care — which
+// is the whole reason a caller addresses a seat instead of a module.
+func seatStreamName(seat string) string { return "SEAT_" + upperSnake(seat) }
+
+// SeatStreams is one work queue per declared seat, created when the declaring module is
+// registered rather than when it is assigned.
+//
+// **The stream exists before anyone holds the seat, and that is the point.** Work queues until a
+// holder appears, so installing the telegram module a week after something started sending to it
+// flushes the backlog instead of having lost it. A stream created at assignment would make "the
+// holder is not here yet" mean "your messages are gone".
+func SeatStreams(seats []DeclaredSeat) []Stream {
+	sorted := append([]DeclaredSeat(nil), seats...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].Name < sorted[j].Name })
+
+	var out []Stream
+	for _, s := range sorted {
+		if len(s.Accepts) == 0 {
+			// A seat that only emits and serves needs no stream: its events ride EVENTS and its
+			// tools are core request/reply, which is never persisted.
+			continue
+		}
+		retain := s.RetainSeconds
+		if retain == 0 {
+			retain = 7 * 24 * 60 * 60
+		}
+		out = append(out, Stream{
+			Name:      seatStreamName(s.Name),
+			Subjects:  []string{"mesh.seat." + s.Name + ".accept.>"},
+			Retention: RetentionWorkQueue,
+			MaxAge:    retain,
+			Why: fmt.Sprintf("work submitted to the %s seat; one holder consumes it, and it "+
+				"queues while nobody does", s.Name),
+		})
+	}
+	return out
+}
+
+// A DeclaredSeat is a seat as the catalogue knows it. Mirrored here rather than imported so this
+// package stays free of the catalogue's own types — the same reason the host mirrors the
+// contracts instead of importing the sdk.
+type DeclaredSeat struct {
+	Name    string
+	Accepts []string
+	// Emits are the verbs the seat's holder publishes under the seat's own name. An event about a
+	// role belongs here rather than in the holder's namespace, because the name then outlives
+	// whoever fills it (novox/hq ADR 0121, 04-ISSUES/127).
+	Emits []string
+	// Serves are the verbs the holder answers, request and reply.
+	Serves        []string
+	RetainSeconds int
+	// PulledByKind is Seat's: a worker per accepted kind, derived from the holders' seat traffic, not here.
+	PulledByKind bool
+}
+
+// ConsumerFor is the durable consumer a module's declarations imply, or false when it subscribes
+// to nothing and needs none.
+//
+// One per module, with every consumed subject as a filter, because its ack permission is derived
+// from its name: a module with a consumer per event would need an ack permission per consumer,
+// and the permission list would stop being derivable from the declaration.
+func ConsumerFor(p Principal) (Consumer, bool) {
+	// A module that reacts to anything — a module's events or a role's (novox/hq ADR 0121). Watching
+	// a role was missing here, so the one module that does it got no consumer at all: it started,
+	// connected, and its graph stayed empty with nothing anywhere reporting why.
+	// And one that hears its own answers on a seat it uses (novox/hq ADR 0259 §3): an asker's warrants.
+	hearsItsOwn := len(SeatTrafficOf(p.Module, nil, p.Uses, nil).Subscribe) > 0
+	hearsAStream := false
+	for _, h := range p.Hears {
+		if len(h.Filters) > 0 {
+			hearsAStream = true
+		}
+	}
+	if p.Kind != KindModule || (len(p.Consumes) == 0 && len(p.Watches) == 0 && !hearsItsOwn && !hearsAStream) {
+		return Consumer{}, false
+	}
+	perms, err := PermissionsFor(p)
+	if err != nil {
+		return Consumer{}, false
+	}
+	// Events, wherever they live: a module's own namespace, and the namespace of any role it watches
+	// (novox/hq ADR 0121). Tool subjects and inboxes are subscribed directly and are not a consumer's
+	// business, which is why this is a filter and not the whole list.
+	var filters []string
+	for _, s := range perms.Subscribe {
+		// Not a module stream's, which its own consumer on that stream hears (novox/hq ADR 0363).
+		if strings.Contains(s, ".event.") && !strings.HasPrefix(s, moduleStreamPrefix) {
+			filters = append(filters, s)
+		}
+	}
+	// **A module that hears only a module's stream still has one here** (novox/hq ADR 0363 §7): what it
+	// gives up on there is delivered again under `mesh.again.<consumer>.` on EVENTS, and only this filters it.
+	if len(filters) == 0 && !hearsAStream {
+		return Consumer{}, false
+	}
+	sort.Strings(filters)
+	// And the events given up on and delivered again to this consumer alone (novox/hq issue 330).
+	filters = append(filters, AgainFilter(consumerDurable(p)))
+	return Consumer{
+		Name:           consumerDurable(p),
+		Stream:         consumerStream(p),
+		Filters:        filters,
+		AckWaitSeconds: 30,
+		MaxDeliver:     5,
+		// From now, as the controller's own consumers have been since issue 248: a module made on a stream that
+		// keeps a week replays none of it. What a part needs of the present it reads from its owner
+		// (novox/hq ADR 0443 §1, §3). A consumer that exists keeps its place whatever this says.
+		FromNow: true,
+		Why: "what " + p.Module + " declared it consumes; after max-deliver it gives an event up, and the " +
+			"controller keeps it in DEAD_LETTERS until a person delivers it again or drops it",
+	}, true
+}
+
+// ModuleConsumer is one module's durable consumer, with the module and node it is for.
+type ModuleConsumer struct {
+	Node, Module string
+	Consumer     Consumer
+}
+
+// ConsumersOf is every module's durable consumer the composed users imply: each module user's, and
+// each module a runtime carries — a carried module with no account of its own is no user (novox/hq
+// issue 195), and its consumer is still the controller's to make, since the runtime reads it on the
+// module's behalf (ADR 0198). One per module and node, whichever of the two named it first.
+func ConsumersOf(users []Principal) []ModuleConsumer {
+	var out []ModuleConsumer
+	seen := map[string]bool{}
+	add := func(p Principal) {
+		key := p.Node + "/" + p.Module
+		if seen[key] {
+			return
+		}
+		c, needed := ConsumerFor(p)
+		// **A module with a work-queue consumer of its own needs no other reason to be visited here**
+		// (novox/hq ADR 0436 §1, §2, §6): mesh-mail's sender consumes and watches nothing of its own, so
+		// ConsumerFor alone would have found nothing needed and skipped it before its one queue consumer
+		// was ever composed.
+		if !needed && len(p.Queues) == 0 {
+			return
+		}
+		seen[key] = true
+		if needed {
+			out = append(out, ModuleConsumer{Node: p.Node, Module: p.Module, Consumer: c})
+			// And one on each module stream it hears (novox/hq ADR 0363 §5).
+			for _, h := range p.Hears {
+				if len(h.Filters) == 0 {
+					continue
+				}
+				out = append(out, ModuleConsumer{Node: p.Node, Module: p.Module, Consumer: heardConsumer(p, h)})
+			}
+		}
+		// And the one durable consumer of each of its own work-queue streams, for the one process its
+		// bus.queues names (novox/hq ADR 0436 §1, §2, §6).
+		for _, q := range p.Queues {
+			out = append(out, ModuleConsumer{Node: p.Node, Module: p.Module, Consumer: QueueConsumer(p, q)})
+		}
+	}
+	for _, p := range users {
+		if p.Kind == KindModule {
+			add(p)
+		}
+	}
+	for _, p := range users {
+		if p.Kind != KindNodeTools {
+			continue
+		}
+		for _, d := range p.Carries {
+			// **A carried module's work-queue consumer is still the controller's to make** (novox/hq ADR
+			// 0436 §1, §2, §6), the same reason its ordinary consumer is (ADR 0198): mesh-mail has no
+			// account of its own (NoAccount) and is carried here, but its process does, and the consumer
+			// it reads through must exist and survive PruneHeard whether or not the module itself speaks.
+			add(Principal{Kind: KindModule, Node: p.Node, Module: d.Module, Emits: d.Emits,
+				Consumes: d.Consumes, Serves: d.Serves, Holds: d.Holds, Uses: d.Uses, Watches: d.Watches,
+				Streams: d.Streams, Hears: ComposedHears(d), Queues: d.Queues})
+		}
+	}
+	return out
+}
+
+// HolderConsumerFor is the worker a seat's holders share on that seat's work queue.
+//
+// **One worker for every holder, and each holder pulls one ask when it is idle** (novox/hq ADR
+// 0190). The seat is *authority* — who may be the telegram sender — and the worker is *delivery*,
+// kept separate so that relaxing one changes nothing about the other: a node-scoped seat has a
+// holder per machine, and all of them take from this one consumer, so the work is shared without
+// any holder knowing about the others. Pulled rather than pushed because a push consumer hands the
+// next ask to whichever subscriber the server picks, busy or not, and a pulled one is asked for by
+// a holder that has just become free. Which is also what ends the race issue 186 describes — asks
+// delivered behind the one being worked, expiring unacknowledged and dropped after the fifth
+// redelivery: nothing is delivered that nobody asked for. A long build keeps its own ask alive
+// (stillWorking); the ack wait is for a holder that died.
+func HolderConsumerFor(node, module string, seat DeclaredSeat) (Consumer, bool) {
+	if len(seat.Accepts) == 0 || seat.PulledByKind {
+		// A seat pulled by kind has a worker per kind, which its holders' seat traffic derives (SeatTrafficObjects): one
+		// worker filtered on every accept would overlap them on the work queue.
+		return Consumer{}, false
+	}
+	return Consumer{
+		Name:           "SEAT_" + upperSnake(seat.Name) + "_worker",
+		Stream:         seatStreamName(seat.Name),
+		Filters:        []string{"mesh.seat." + seat.Name + ".accept.>"},
+		AckWaitSeconds: 60,
+		MaxDeliver:     5,
+		// As many in flight as there are holders working, which pulling bounds by itself: a holder
+		// fetches one and fetches again only after it acknowledged. The server's default stands.
+		Why: fmt.Sprintf("%s on %s holds %s; every holder pulls one ask at a time from this worker "+
+			"and acknowledges after the work is done, so a crash mid-work redelivers rather than "+
+			"loses and an idle holder is the one that takes the next ask", module, node, seat.Name),
+	}, true
+}
+
+// NodeConsumer is the durable consumer a node reads its own declaration through.
+//
+// **Derived from a node existing, and created by the controller, because a host cannot create it.**
+// A host's account may subscribe its own declaration subject and publish its own ack subject, and
+// reaches no part of the JetStream API — which is correct (the controller is the only writer of
+// consumer definitions, design 25 §3) and means the consumer must be waiting before the host binds
+// to it. Named after the node, because the node's ack grant is `$JS.ACK.NODES.<node>.>` and a
+// consumer named anything else is one the host cannot acknowledge a delivery from.
+//
+// **No max-deliver, and a long ack wait.** A declaration is settled only after the node has applied
+// it and reported, which is minutes on a machine pulling images; and a declaration the mesh cannot
+// get a node to accept is not one to give up on, because the stream keeps only the newest per node
+// anyway — so there is exactly one message per node to redeliver, for as long as that node is away.
+func NodeConsumer(node string) Consumer {
+	return Consumer{
+		Name:           node,
+		Stream:         "NODES",
+		Filters:        []string{"mesh.node." + node + ".declare"},
+		Push:           true,
+		AckWaitSeconds: 300,
+		Why: "how " + node + " hears what it should be; last-per-subject, so a node that was away " +
+			"gets exactly the current declaration and nothing older",
+	}
+}
+
+// AssertNodeConsumers brings every known node's declaration consumer into being.
+//
+// Asserted on start as well as created at enrolment, for the reason the streams are: a mesh raised
+// from a restored backup, or one whose bus was recreated, has node records and no consumers, and a
+// node whose consumer is missing hears nothing while everything else about it looks correct.
+func AssertNodeConsumers(e Ensurer, nodes []string) error {
+	for _, n := range nodes {
+		if err := e.EnsureConsumer(NodeConsumer(n)); err != nil {
+			return fmt.Errorf("asserting how %s hears its declaration: %w", n, err)
+		}
+	}
+	return nil
+}
+
+// AllOverlaps reports subject filters claimed by more than one stream, across the mesh's own and
+// every derived one.
+//
+// NATS refuses an overlapping stream rather than merging it (verified against nats-server 2.10:
+// "subjects overlap with an existing stream"), so this is not a subtle divergence — it is a
+// registration that fails. Catching it here names both streams, before a half-applied mesh does.
+func AllOverlaps(seats []DeclaredSeat) []string {
+	all := append(MeshStreams(), SeatStreams(seats)...)
+	seen := map[string]string{}
+	var clashes []string
+	for _, s := range all {
+		for _, subject := range s.Subjects {
+			if first, ok := seen[subject]; ok {
+				clashes = append(clashes, fmt.Sprintf("%s and %s both claim %s", first, s.Name, subject))
+				continue
+			}
+			seen[subject] = s.Name
+		}
+	}
+	sort.Strings(clashes)
+	return clashes
+}
+
+// upperSnake makes a stream name from a seat name. NATS stream names may not contain a dot,
+// a space or a wildcard, and a hyphen is legal but reads badly beside the mesh's own.
+func upperSnake(s string) string {
+	out := []rune(s)
+	for i, r := range out {
+		switch {
+		case r >= 'a' && r <= 'z':
+			out[i] = r - 32
+		case r == '-' || r == '.':
+			out[i] = '_'
+		}
+	}
+	return string(out)
+}

go/buscompose/doc.go

@@ -0,0 +1,12 @@
+// Package buscompose is the bus's composer: who may say what on the bus, as the user list and the server configuration
+// the bus loads, derived from the mesh's records (Users, WithPasswords, ComposeAccounts, Compose), with the grants,
+// streams, state and logs it composes them from.
+//
+// **A copy of the controller's internal/broker, composer half** (issue 1377, novox/hq ADR 0547 §5), taken at
+// mesh-controller 7cd4d18b with the grants part's membership grant of f67d1553 (ADR 0547 §5) and its grant to create the streams manifests declare (issue 1790): the bus client (jetstream.go), the broker's address from the environment (broker.go, onnats.go
+// but its one constant) and the two methods on that client are left out; the lease's two subjects are copied in
+// (nats.go). The controller keeps its own copy, unchanged, until it loses its lease at ADR 0547's third milestone, so
+// for that time two composers state who may say what and must say the same: TestTheCopiedComposerComposesAsTheControllers
+// holds this copy to lists the controller's own code wrote from the same fixtures. A change to what is granted is made
+// here and, while the controller composes, in the controller's copy too, never in one alone.
+package buscompose

go/buscompose/fixtures_test.go

@@ -0,0 +1,119 @@
+package buscompose
+
+// The fixtures the copied bus composer is held to (issue 1377, ADR 0547 §5): the same source is compiled into the
+// controller's internal/broker to write the expected lists, and into mesh-sdk's buscompose to compare against them.
+
+// UserListFixture is one mesh's records, and the hashes its accounts carry.
+type UserListFixture struct {
+	Name    string
+	Records Records
+	// Hashless are users given no hash, so they are left out and named.
+	Hashless []string
+}
+
+func fixtureTelegramSeat() Seat {
+	return Seat{Name: "telegram-sender", Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}}
+}
+
+// UserListFixtures are the meshes, from the controller's own tests' records outward.
+func UserListFixtures() []UserListFixture {
+	return []UserListFixture{
+		{Name: "empty"},
+		{Name: "the controller's someRecords", Records: Records{
+			Nodes: []string{"two", "one"},
+			Assigned: map[string][]Declared{
+				"one": {{Module: "telegram", Serves: []string{"status"}}},
+				"two": {{Module: "shop", Emits: []string{"order.placed"}}},
+			},
+			Enrolling: []string{"three"},
+			People:    map[string][]string{"ada": {"mesh-catalog.catalog_tools"}},
+		}},
+		{Name: "seats, consumers, people and a hashless user", Hashless: []string{"two.audit"}, Records: Records{
+			Nodes: []string{"one", "two"},
+			Assigned: map[string][]Declared{
+				"one": {
+					{Module: "telegram", Holds: []Seat{fixtureTelegramSeat()}, Serves: []string{"status"}},
+					{Module: "nats", SnapshotsTheBus: true, Serves: []string{"nats_streams"}},
+					{Module: "mesh-watchman"},
+					{Module: "mesh-grants", Emits: []string{"membership-changed"}},
+				},
+				"two": {
+					{Module: "shop", Uses: []Seat{fixtureTelegramSeat()}, Emits: []string{"order.placed"}},
+					{Module: "audit", Consumes: []string{"shop.order.placed"}},
+				},
+			},
+			People:          map[string][]string{"ada": {"*"}, "bob": {"shop.status"}},
+			Interchangeable: map[string]bool{"shop": true},
+		}},
+		{Name: "state, logs, streams, queues and processes", Records: Records{
+			Nodes: []string{"ace", "novox"},
+			Assigned: map[string][]Declared{
+				"novox": {
+					{Module: "mesh-delivery-builder", Emits: []string{"built"},
+						State: []Bucket{{Module: "mesh-delivery-builder", Name: "steps", History: 5},
+							{Module: "mesh-delivery-builder", Name: "presence", PerMachine: true, KeyTTL: true, TTLSeconds: 60}},
+						Logs:    []Log{{Module: "mesh-delivery-builder", Name: "builds", MaxMiB: 64}},
+						Streams: []ModuleStream{{Module: "mesh-delivery-builder", Name: "asks", Events: []string{"ask"}, MaxAgeDays: 7, MaxMiB: 32, WorkQueue: true}},
+						Queues:  []QueueOwner{{Process: "worker", Stream: "asks", MaxDeliver: 5}},
+						Processes: []ProcessPrincipal{{Process: "worker", Emits: []string{"built"},
+							Queues: []QueueOwner{{Process: "worker", Stream: "asks", MaxDeliver: 5}},
+							State:  []string{"steps"}, Invokes: []string{"gitea.gitea_commit"}}},
+						Invokes: []string{"gitea.gitea_commit"},
+					},
+					{Module: "mesh-delivery-view", Reads: []string{"mesh-delivery-builder.steps"},
+						KeyedReads: []KeyedRead{{Read: "mesh-delivery-builder.presence", Key: "novox"}}},
+					// The grants part, which may create every stream declared here (ADR 0547 §5, issue 1790).
+					{Module: "mesh-grants", Emits: []string{"membership-changed"},
+						State: []Bucket{{Module: "mesh-grants", Name: "assertions", History: 5}}},
+				},
+				"ace": {
+					{Module: "plex", Serves: []string{"plex_status"}, Checks: []string{"plex.plex_status"}},
+					{Module: "silent", NoAccount: true},
+				},
+			},
+			RootFree: map[string]bool{"ace": true},
+		}},
+	}
+}
+
+// HashOf is the stand-in hash a fixture's user carries.
+func HashOf(user string) string {
+	h := "$2a$11$"
+	for len(h) < 29 {
+		h += user
+	}
+	return h[:29] + "fixturefixturefixturefixture00"
+}
+
+// ComposedFor is a fixture's user list as the composer writes it, and the users left out.
+func ComposedFor(f UserListFixture) (string, []string, error) {
+	users, err := Users(f.Records)
+	if err != nil {
+		return "", nil, err
+	}
+	hashes := map[string]string{}
+	skip := map[string]bool{}
+	for _, u := range f.Hashless {
+		skip[u] = true
+	}
+	for _, u := range users {
+		if !skip[u.Username()] {
+			hashes[u.Username()] = HashOf(u.Username())
+		}
+	}
+	filled, missing := WithPasswords(users, hashes)
+	list, err := ComposeAccounts(filled)
+	return list, missing, err
+}
+
+// MembershipsFor is every membership a fixture's records issue, by `<node>.<module>`, as the composer makes them.
+func MembershipsFor(f UserListFixture) map[string]Membership {
+	where := PlacementsOf(f.Records, f.Records.Interchangeable)
+	out := map[string]Membership{}
+	for node, ds := range f.Records.Assigned {
+		for _, d := range ds {
+			out[node+"."+d.Module] = MembershipFor(node, d, where)
+		}
+	}
+	return out
+}

go/buscompose/log.go

@@ -0,0 +1,184 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// A module's log on the bus (novox/hq ADR 0297): its record of operations, each entry appended under
+// a key and kept as long as the log is.
+//
+// A log follows a bucket in every respect (ADR 0201): the module names it locally, the mesh derives
+// its stream and subjects, the controller creates it from the catalogue on every raise and from
+// registration, never a module, and **no path of the mesh removes one** — a log whose declaration
+// is gone is reported, as a bucket is. Unlike a bucket, a log is its owner's alone: no other module
+// reads it, so there is no read of a log to grant or issue.
+//
+// Pure, but for the stream's configuration, which is the server's own type so that what is tested
+// is exactly what is sent; jetstream.go is the part that asks a server.
+
+// The mesh's caps on a log: what an entry's value may weigh, what a message on the log's stream may
+// weigh — the value and its headers, which the server counts in a message's size, so a value of the
+// full size still fits with the expected-last-sequence header an append carries — and what a log holds
+// when its module says nothing and at most.
+const (
+	LogMaxEntryBytes   = 256 * 1024
+	LogMaxMessageBytes = LogMaxEntryBytes + 4*1024
+	LogDefaultMiB      = 1024
+	LogMostMiB         = 8192
+)
+
+// A Log is one module's declared log as the bus holds it.
+type Log struct {
+	Module string
+	Name   string
+	// MaxMiB is its cap in MiB; zero is LogDefaultMiB.
+	MaxMiB int
+}
+
+// LogStreamPrefix starts every log's stream name, which no other stream of the mesh's starts with.
+const LogStreamPrefix = "LOG_"
+
+// LogStreamName is the stream a module's log lives in: `LOG_<module>_<name>`. The module and the
+// local name are each one token with no underscore, so two modules can never derive one stream.
+func LogStreamName(module, name string) string { return LogStreamPrefix + module + "_" + name }
+
+// LogSubject is the subject a log's entries are published under, without the key: an entry for key K
+// is on `<LogSubject>.<K>`.
+func LogSubject(module, name string) string { return "mesh.log." + module + "." + name }
+
+// Stream is this log's stream name.
+func (l Log) Stream() string { return LogStreamName(l.Module, l.Name) }
+
+// Subject is this log's subject, without the key.
+func (l Log) Subject() string { return LogSubject(l.Module, l.Name) }
+
+// MaxBytes is this log's cap in bytes.
+func (l Log) MaxBytes() int64 {
+	mib := l.MaxMiB
+	if mib <= 0 {
+		mib = LogDefaultMiB
+	}
+	return int64(mib) * 1024 * 1024
+}
+
+// Why is carried into the server's description of the stream, so somebody reading the server's own
+// state finds whose it is and why it is kept.
+func (l Log) Why() string {
+	return fmt.Sprintf("%s's log %q (novox/hq ADR 0297): its record of operations, one entry per operation "+
+		"under its key, appended by %s alone and kept as long as the log; never removed by the mesh, because "+
+		"it is data", l.Module, l.Name, l.Module)
+}
+
+// Config is the stream a log is, field by field as novox/hq ADR 0297 fixes it: a file stream kept by
+// limits, with no maximum age and no cap per key, whose message is an entry's value and 4 KiB of
+// headers at most, that refuses a new entry when full rather than
+// drop an old one, and that refuses deleting an entry or purging it. Direct gets are allowed, which
+// is how the runtime reads it.
+func (l Log) Config() jetstream.StreamConfig {
+	return jetstream.StreamConfig{
+		Name:              l.Stream(),
+		Description:       l.Why(),
+		Subjects:          []string{l.Subject() + ".>"},
+		Storage:           jetstream.FileStorage,
+		Retention:         jetstream.LimitsPolicy,
+		MaxAge:            0,
+		MaxMsgs:           -1,
+		MaxMsgsPerSubject: -1,
+		MaxBytes:          l.MaxBytes(),
+		MaxMsgSize:        LogMaxMessageBytes,
+		Discard:           jetstream.DiscardNew,
+		AllowDirect:       true,
+		DenyDelete:        true,
+		DenyPurge:         true,
+		Replicas:          1,
+	}
+}
+
+// logsIssuedFor is every log a module's code may reach, as its membership lists them: its own.
+func logsIssuedFor(d Declared) []LogIssued {
+	var out []LogIssued
+	for _, l := range d.Logs {
+		if !safeSubject.MatchString(d.Module) || !safeSubject.MatchString(l.Name) {
+			continue
+		}
+		out = append(out, LogIssued{Name: l.Name, Stream: LogStreamName(d.Module, l.Name),
+			Subject: LogSubject(d.Module, l.Name), Writes: true})
+	}
+	return out
+}
+
+// logGrants is what a principal publishes to reach the logs its module keeps: for each, appending
+// under the log's subjects, binding to its stream, and reading it directly. Nothing more — the
+// runtime reads a log by direct gets alone and makes no consumer on it — and nothing of any other
+// module's log, because a log is its owner's alone. Replies come on the principal's inbox, as for a
+// bucket.
+func logGrants(module string, names []string) []string {
+	if !safeSubject.MatchString(module) {
+		return nil
+	}
+	var out []string
+	for _, name := range names {
+		if !safeSubject.MatchString(name) {
+			continue
+		}
+		stream := LogStreamName(module, name)
+		out = append(out,
+			LogSubject(module, name)+".>",
+			"$JS.API.STREAM.INFO."+stream,
+			"$JS.API.DIRECT.GET."+stream,
+			"$JS.API.DIRECT.GET."+stream+".>")
+	}
+	return out
+}
+
+// logNames is the local names of a module's logs.
+func logNames(logs []Log) []string {
+	out := make([]string, 0, len(logs))
+	for _, l := range logs {
+		out = append(out, l.Name)
+	}
+	return out
+}
+
+// A LogAsserter is the part of a JetStream connection log assertion needs. It has no way to remove a
+// log, by design: nothing the mesh runs asks for one.
+type LogAsserter interface {
+	// EnsureLog creates the log's stream if absent and brings its configuration to match if present,
+	// never deleting or recreating it.
+	EnsureLog(l Log) error
+	// LogStreams is every log stream on the server: every stream named with LogStreamPrefix.
+	LogStreams() ([]string, error)
+}
+
+// RaiseLogs asserts every declared log and answers the log streams on the server that nothing
+// declares any more.
+//
+// **Those are reported, never removed** (novox/hq ADR 0297 §2, ADR 0201 §15–16): a log is a module's
+// record, and a manifest edited, a module renamed or unassigned is an ordinary day's work that must
+// not take a record with it. Removing one is a person's act, outside the mesh.
+func RaiseLogs(a LogAsserter, logs []Log) (undeclared []string, err error) {
+	sorted := append([]Log(nil), logs...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].Stream() < sorted[j].Stream() })
+	declared := map[string]bool{}
+	for _, l := range sorted {
+		if err := a.EnsureLog(l); err != nil {
+			return nil, fmt.Errorf("asserting %s's log %q: %w", l.Module, l.Name, err)
+		}
+		declared[l.Stream()] = true
+	}
+	names, err := a.LogStreams()
+	if err != nil {
+		return nil, fmt.Errorf("listing the bus's logs: %w", err)
+	}
+	for _, n := range names {
+		if strings.HasPrefix(n, LogStreamPrefix) && !declared[n] {
+			undeclared = append(undeclared, n)
+		}
+	}
+	sort.Strings(undeclared)
+	return undeclared, nil
+}

go/buscompose/membership.go

@@ -0,0 +1,178 @@
+package buscompose
+
+import (
+	"slices"
+	"sort"
+	"strings"
+)
+
+// What the mesh issues an assignment to serve and to reach (novox/hq ADR 0160).
+//
+// A module's code names its tools and its events; **where they land is the mesh's to decide**, and
+// it decided it twice — once in the runtime, once here, by one rule compiled into both. Now the
+// controller composes a membership for every module on every machine and publishes it to a subject
+// only that assignment reads; the runtime serves exactly what the membership says, and the account's
+// grant is the same composition read the other way. The shape issued today is the shape the mesh
+// already had, so nothing moves when a membership first arrives; only who decides it moves.
+
+// Placements is where every module runs, for deciding which instance answers for the module.
+type Placements struct {
+	// Nodes is each module's machines.
+	Nodes map[string][]string
+	// Interchangeable is each module whose definition says its instances are the same anywhere,
+	// so the module's plain subject is issued to all of them in one queue.
+	Interchangeable map[string]bool
+	// Kinds is every kind held of a kinded bench, by whom and with what capabilities (ADR 0259 §5).
+	Kinds []KindHeld
+}
+
+// AnswersForTheModule says whether an instance of a module on one machine is issued the module's
+// plain subject: when it is the only instance, or when the definition says instances are
+// interchangeable. A stateful module on two machines gets only its machines' subjects, so a call
+// that names none reaches nothing rather than the wrong store.
+func (p Placements) AnswersForTheModule(module string) bool {
+	return len(p.Nodes[module]) <= 1 || p.Interchangeable[module]
+}
+
+// MembershipFor composes one assignment's membership from what it declared and where everything
+// runs. The subjects are the ones PermissionsFor grants, derived here once more only until the
+// grant itself is read from the membership — which is the next step, not this one.
+func MembershipFor(node string, d Declared, where Placements) Membership {
+	own := "mesh.mod." + d.Module
+	m := Membership{
+		Node: node, Module: d.Module,
+		Emits: own + ".event.{event}",
+		Tools: own + ".tool.tools",
+	}
+	// This machine's address always; the module's when this instance answers for the module.
+	m.Serves = append(m.Serves, Served{Subject: own + ".tool.{tool}." + node})
+	if where.AnswersForTheModule(d.Module) {
+		m.Serves = append(m.Serves, Served{Subject: own + ".tool.{tool}", Queue: "serve." + d.Module})
+	}
+	for _, s := range d.Holds {
+		if servedOnlyByTheController(s) {
+			continue // answered by the serving controller alone, never through a membership
+		}
+		for _, verb := range s.Serves {
+			m.Seats = append(m.Seats, SeatServed{Seat: s.Name, Verb: verb, Subject: seatToolSubject(s, verb, node)})
+		}
+	}
+	m.State = stateIssuedFor(d, node)
+	m.Logs = logsIssuedFor(d)
+	m.Streams = streamsIssuedFor(d)
+	m.Hears = HeardIssuedFor(node, d)
+	m.Waits = waitsIssuedFor(d)
+	t := SeatTrafficOf(d.Module, d.Holds, d.Uses, d.Watches)
+	for _, s := range append(append([]Seat{}, d.Uses...), d.Watches...) {
+		if !s.Kinded {
+			continue
+		}
+		for _, k := range where.Kinds {
+			if k.Seat == s.Name && !kindListed(t.Kinds, k) {
+				t.Kinds = append(t.Kinds, k)
+			}
+		}
+	}
+	if len(t.Publish)+len(t.Subscribe)+len(t.Answers)+len(t.Workers)+len(t.Records)+len(t.Kinds) > 0 {
+		m.SeatTraffic = &t
+	}
+	if len(d.Invokes) > 0 {
+		m.Reaches = map[string][]string{}
+		for _, t := range d.Invokes {
+			if t == "*" || strings.HasPrefix(t, "seat:") {
+				continue // every tool, or a role's: addressed by name, not resolved per instance
+			}
+			module, tool, ok := strings.Cut(t, ".")
+			if !ok {
+				continue
+			}
+			var reach []string
+			if where.AnswersForTheModule(module) {
+				reach = append(reach, "mesh.mod."+module+".tool."+tool)
+			}
+			nodes := append([]string{}, where.Nodes[module]...)
+			sort.Strings(nodes)
+			for _, n := range nodes {
+				reach = append(reach, "mesh.mod."+module+".tool."+tool+"."+n)
+			}
+			m.Reaches[t] = reach
+		}
+	}
+	return m
+}
+
+// PlacementsOf reads where everything runs from the records the bus's accounts are composed from.
+func PlacementsOf(r Records, interchangeable map[string]bool) Placements {
+	p := Placements{Nodes: map[string][]string{}, Interchangeable: interchangeable}
+	for node, declared := range r.Assigned {
+		for _, d := range declared {
+			p.Nodes[d.Module] = append(p.Nodes[d.Module], node)
+		}
+	}
+	for _, nodes := range p.Nodes {
+		sort.Strings(nodes)
+	}
+	// Where the router runs: a verified sender is believed only while its machine is root-free too. A router
+	// placed nowhere, or on more than one machine, frees nothing.
+	var routerNodes []string
+	for node, declared := range r.Assigned {
+		for _, d := range declared {
+			for _, s := range d.Holds {
+				if s.Name == routerSeat && !slices.Contains(routerNodes, node) {
+					routerNodes = append(routerNodes, node)
+				}
+			}
+		}
+	}
+	routerFree := len(routerNodes) == 1 && r.RootFree[routerNodes[0]]
+	for node, declared := range r.Assigned {
+		for _, d := range declared {
+			for _, s := range d.Holds {
+				if s.Kinded && s.Kind != "" {
+					p.Kinds = append(p.Kinds, KindHeld{Seat: s.Name, Kind: s.Kind, Module: d.Module, Node: node,
+						Capabilities: placedCapabilities(s.Capabilities, d.RunsAs, routerFree && r.RootFree[node])})
+				}
+			}
+		}
+	}
+	sort.Slice(p.Kinds, func(i, j int) bool {
+		a, b := p.Kinds[i], p.Kinds[j]
+		if a.Seat != b.Seat {
+			return a.Seat < b.Seat
+		}
+		if a.Kind != b.Kind {
+			return a.Kind < b.Kind
+		}
+		return a.Node < b.Node
+	})
+	return p
+}
+
+// routerSeat is the seat the router of asks holds (novox/hq ADR 0259 §3).
+const routerSeat = "operator-channel"
+
+// placedCapabilities is what a kind's claim promises, as far as its placement lets the router believe it
+// (novox/hq ADR 0259 §8): `verified-sender` only from a holder that runs as an account of its own, on a bus
+// account of its own — never one the machine's runtime carries as the operator's account — and only while
+// its machine and the router's were root-free when composed (rootFree; the review of 2026-10-09, H3). The
+// membership carrying it is composed at a push, so it can outlive a pass that later fails: the router asks
+// the controller's root-free verb again before it honours an approval, and that is the check that holds.
+func placedCapabilities(declared []string, runsAs string, rootFree bool) []string {
+	var out []string
+	for _, c := range declared {
+		if c == "verified-sender" && (runsAs == "" || !rootFree) {
+			continue
+		}
+		out = append(out, c)
+	}
+	return out
+}
+
+func kindListed(list []KindHeld, k KindHeld) bool {
+	for _, x := range list {
+		if x.Seat == k.Seat && x.Kind == k.Kind && x.Module == k.Module && x.Node == k.Node {
+			return true
+		}
+	}
+	return false
+}

go/buscompose/modstreams.go

@@ -0,0 +1,343 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// A module's own stream on the bus (novox/hq ADR 0363).
+//
+// A module declares a stream as it declares a log: named locally, created by the controller from the
+// catalogue on every raise and every send, never removed by the mesh. Its events are published on
+// `mesh.stream.<module>.event.<event>`, a subject space the shared EVENTS stream (`mesh.mod.*.event.>`)
+// does not take — the bus refuses two streams claiming one subject, so a module's stream cannot share
+// EVENTS' — and a consumer hears it through a durable consumer of its own on that stream, named as on
+// EVENTS. Pure; the controller's raise asserts what is composed here.
+
+// moduleStreamPrefix starts every subject a module's own stream takes.
+const moduleStreamPrefix = "mesh.stream."
+
+// ModuleStreamSubject is where a module's event on its own stream lands: `mesh.stream.<module>.event.<event>`.
+// The token before `.event.` is the emitter, as on EVENTS, so a runtime reads the same key from it.
+func ModuleStreamSubject(module, event string) string {
+	return moduleStreamPrefix + module + ".event." + event
+}
+
+// OnAModuleStream says a subject is one a module's own stream takes.
+func OnAModuleStream(subject string) bool { return strings.HasPrefix(subject, moduleStreamPrefix) }
+
+// WirePattern is a local event pattern as the bus spells it: `**` is `>`.
+func WirePattern(local string) string {
+	parts := strings.Split(local, ".")
+	for i, p := range parts {
+		if p == "**" {
+			parts[i] = ">"
+		}
+	}
+	return strings.Join(parts, ".")
+}
+
+// A ModuleStream is one module's declared stream as the bus holds it.
+type ModuleStream struct {
+	Module string
+	// Name is its name on the bus, `MAIL`.
+	Name string
+	// Events are the events it carries, as the bus spells them (WirePattern).
+	Events     []string
+	MaxAgeDays int
+	MaxMiB     int
+	// Restricted says a trusted config value of the module grants who hears it (ADR 0363 §4).
+	Restricted bool
+	// WorkQueue says this stream holds ADR 0436 §6's work-queue retention: a message is removed once a
+	// consumer acknowledges it, and the bus refuses a new one when full rather than dropping its oldest.
+	WorkQueue bool
+	// Duplicates is the work-queue's duplicate window in hours (novox/hq ADR 0436 §6); meaningless unless
+	// WorkQueue.
+	Duplicates int
+}
+
+// Subjects are the subjects the stream takes.
+func (s ModuleStream) Subjects() []string {
+	var out []string
+	for _, e := range s.Events {
+		out = append(out, ModuleStreamSubject(s.Module, e))
+	}
+	sort.Strings(out)
+	return out
+}
+
+// Stream is the stream the controller asserts: kept by limits, its age and size the module's, dropping
+// its oldest when full — a consumer that was away catches up within the age, and the module's own record
+// answers for anything older.
+func (s ModuleStream) Stream() Stream {
+	why := fmt.Sprintf("%s's own stream (novox/hq ADR 0363): its events, kept %d days and at most %d MiB so a "+
+		"consumer that was away catches up", s.Module, s.MaxAgeDays, s.MaxMiB)
+	if s.Restricted {
+		why += "; heard only by the consumers its trusted config value grants"
+	}
+	if s.WorkQueue {
+		why += "; a work-queue (novox/hq ADR 0436 §6): a message is removed once its one consumer " +
+			"acknowledges it, and a full stream refuses a new one rather than dropping what it holds"
+	}
+	out := Stream{
+		Name:      s.Name,
+		Subjects:  s.Subjects(),
+		Retention: RetentionLimits,
+		MaxAge:    s.MaxAgeDays * 24 * 60 * 60,
+		MaxBytes:  int64(s.MaxMiB) * 1024 * 1024,
+		Why:       why,
+		// Said on the bus, so a dead letter kept from it ages out with it (novox/hq ADR 0376 §3).
+		Restricted: s.Restricted,
+	}
+	if s.WorkQueue {
+		out.Retention = RetentionWorkQueue
+		out.DiscardNew = true
+		out.DuplicatesSeconds = s.Duplicates * 60 * 60
+		// Said on the bus too, reusing the one flag a restricted stream's dead letters already age and hide
+		// by (novox/hq ADR 0436 §6, ADR 0376 §3-4): a work-queue stream's grant is always empty (ADR 0436
+		// §6 refuses one that carries a grant), so this never collides with a trusted-config restriction.
+		out.Restricted = true
+		// And its own metadata, apart from the bus's work-queue retention SEAT_* and other mesh-internal
+		// streams share without being one of this clause's: only this flag says a dead letter kept from the
+		// stream is drop-only (novox/hq ADR 0436 §6), never the stream's Retention alone.
+		out.WorkQueue = true
+	}
+	return out
+}
+
+// QueueOwner is the one process of a module that is the durable consumer of one of its own work-queue
+// streams (novox/hq ADR 0436 §1, §2, §6): named in that process's bus.queues, and checked at registration
+// to be the only one (catalogue.WorkQueueStreamProblems).
+type QueueOwner struct {
+	// Process is the process resource's id — its bus account's name, with the node and module (novox/hq ADR
+	// 0436 §2).
+	Process string
+	// Stream is the work-queue stream's name on the bus.
+	Stream string
+	// MaxDeliver bounds how many times a message is handed over before it is given up as a dead letter
+	// (novox/hq ADR 0436 §6).
+	MaxDeliver int
+}
+
+// QueueConsumer is the durable consumer the one process a module's bus.queues names is granted on its own
+// work-queue stream (novox/hq ADR 0436 §1, §2, §6): no filter, since it is the stream's only consumer —
+// unlike heardConsumer, which is one of possibly several hearing a module's ordinary stream.
+func QueueConsumer(p Principal, q QueueOwner) Consumer {
+	return Consumer{
+		Name:           p.Node + "_" + p.Module + "_" + q.Process,
+		Stream:         q.Stream,
+		AckWaitSeconds: 30,
+		MaxDeliver:     q.MaxDeliver,
+		Why: fmt.Sprintf("%s's process %s is the one consumer %s's bus.queues names for its work-queue "+
+			"stream %s (novox/hq ADR 0436 §6); after max-deliver %d it gives a message up, and the "+
+			"controller keeps it in %s, offered only drop", p.Module, q.Process, p.Module, q.Stream,
+			q.MaxDeliver, DeadLettersStream),
+	}
+}
+
+// ModuleStreams is every declared module stream as the controller asserts it, in name order.
+func ModuleStreams(declared []ModuleStream) []Stream {
+	sorted := append([]ModuleStream(nil), declared...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].Name < sorted[j].Name })
+	out := make([]Stream, 0, len(sorted))
+	for _, s := range sorted {
+		out = append(out, s.Stream())
+	}
+	return out
+}
+
+// Heard is a module's stream another module hears, and the subjects it hears of it: its `consumes`
+// within the stream and, for a restricted stream, within what the provider's trusted config value grants it
+// (ADR 0363 §5). Composed only with at least one subject.
+type Heard struct {
+	Stream  string
+	Emitter string
+	Filters []string
+	// Restricted says the stream is restricted by its provider's trusted config value (ADR 0363 §4): then it
+	// is heard only by a module on an account of its own (ADR 0376 §1, ComposedHears).
+	Restricted bool
+}
+
+// ComposedHears is what of a module's hearing the controller composes (novox/hq ADR 0376 §1): every stream it
+// hears, but a restricted one only for a module that runs in a runtime of its own on a bus account of its own
+// (`runs-as`, ADR 0259). **The tool runner never hears a restricted stream**: a module it carries reaches the bus
+// through the tool runner's account, which every agent session on that machine reaches the bus as too, so a
+// consumer, its grants or its bind word composed there would hand the stream to any session. A module that
+// declares no `runs-as` and keeps its own container credential gets none either: only `runs-as` is an account
+// the mesh keeps from agents.
+func ComposedHears(d Declared) []Heard {
+	if d.RunsAs != "" {
+		return d.Hears
+	}
+	var out []Heard
+	for _, h := range d.Hears {
+		if !h.Restricted {
+			out = append(out, h)
+		}
+	}
+	return out
+}
+
+// Withheld is a restricted stream a grant gives a module that the controller composes nothing for, because the
+// module has no account of its own (novox/hq ADR 0376 §2): said in `doctor` and in the controller's log, never
+// silent.
+type Withheld struct {
+	Node, Module, Stream, Emitter string
+}
+
+// Said is a withheld hearing in the operator's words: the module, the stream and the remedy.
+func (w Withheld) Said() string {
+	return fmt.Sprintf("%s on %s is granted part of %s's restricted stream %s, and hears none of it: it is carried "+
+		"by the machine's tool runner, whose bus account every agent session there shares, so nothing is composed "+
+		"for it. Declare runs-as in %s's manifest, so it runs as an account of its own (novox/hq ADR 0376)",
+		w.Module, w.Node, w.Emitter, w.Stream, w.Module)
+}
+
+// WithheldOf is every granted hearing of a restricted stream composed for nothing, by machine and module.
+func WithheldOf(r Records) []Withheld {
+	var out []Withheld
+	for _, node := range sortedCopy(r.Nodes) {
+		for _, d := range r.Assigned[node] {
+			if d.RunsAs != "" {
+				continue
+			}
+			for _, h := range d.Hears {
+				if h.Restricted && len(h.Filters) > 0 {
+					out = append(out, Withheld{Node: node, Module: d.Module, Stream: h.Stream, Emitter: h.Emitter})
+				}
+			}
+		}
+	}
+	return out
+}
+
+// heardConsumer is the durable consumer a module hears a module's stream through: named as its consumer
+// on EVENTS, on that stream, with the subjects it was granted as its filters.
+func heardConsumer(p Principal, h Heard) Consumer {
+	filters := append([]string(nil), h.Filters...)
+	sort.Strings(filters)
+	return Consumer{
+		Name:           consumerDurable(p),
+		Stream:         h.Stream,
+		Filters:        filters,
+		AckWaitSeconds: 30,
+		MaxDeliver:     5,
+		// From now, like a module's consumer on EVENTS (novox/hq ADR 0443 §1).
+		FromNow: true,
+		Why: "what " + p.Module + " consumes of " + h.Emitter + "'s stream " + h.Stream + " and is granted " +
+			"(novox/hq ADR 0363); after max-deliver it gives an event up, and the controller keeps it in " +
+			"DEAD_LETTERS until a person delivers it again or drops it",
+	}
+}
+
+// heardGrants are what a principal publishes to read and acknowledge the consumers it hears module streams
+// through: asking about each, pulling from it, acknowledging it — its own name on each stream, no other's.
+func heardGrants(p Principal, hears []Heard) []string {
+	var out []string
+	durable := consumerDurable(p)
+	for _, h := range hears {
+		if !safeSubject.MatchString(h.Stream) || len(h.Filters) == 0 {
+			continue
+		}
+		out = append(out,
+			"$JS.API.CONSUMER.INFO."+h.Stream+"."+durable,
+			"$JS.API.CONSUMER.MSG.NEXT."+h.Stream+"."+durable,
+			"$JS.ACK."+h.Stream+"."+durable+".>")
+	}
+	return out
+}
+
+// ownStreamGrants are the subjects a module publishes its own streams' events on, and no other's.
+func ownStreamGrants(module string, streams []ModuleStream) []string {
+	var out []string
+	for _, s := range streams {
+		if s.Module != module {
+			continue
+		}
+		out = append(out, s.Subjects()...)
+	}
+	return out
+}
+
+// streamsIssuedFor is every stream of its own a module's membership names.
+func streamsIssuedFor(d Declared) []StreamIssued {
+	var out []StreamIssued
+	for _, s := range d.Streams {
+		if s.Module != d.Module || !safeSubject.MatchString(d.Module) {
+			continue
+		}
+		out = append(out, StreamIssued{Stream: s.Name, Events: append([]string(nil), s.Events...),
+			Subject: ModuleStreamSubject(d.Module, "{event}")})
+	}
+	return out
+}
+
+// HeardIssuedFor is every module stream an assignment hears, as its membership names it.
+func HeardIssuedFor(node string, d Declared) []HeardIssued {
+	var out []HeardIssued
+	// A restricted stream's bind word only for a module of its own account (novox/hq ADR 0376 §1).
+	for _, h := range ComposedHears(d) {
+		if len(h.Filters) == 0 {
+			continue
+		}
+		out = append(out, HeardIssued{Stream: h.Stream, Consumer: node + "_" + d.Module})
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Stream < out[j].Stream })
+	return out
+}
+
+// Pruner is the part of a JetStream connection that removes a module's consumer on a module's stream it
+// may no longer hear (ADR 0363 §6). Optional: what only records what it is asked to assert has none.
+type Pruner interface {
+	ConsumerNames(stream string) ([]string, error)
+	RemoveConsumer(stream, name string) error
+}
+
+// PruneHeard removes, from each module stream, every durable consumer the composition no longer asks for,
+// and answers what it removed as `<stream>/<consumer>`. A consumer that loses its grant loses what it reads
+// through, whatever its runtime still holds; a stream that does not exist yet has nothing to remove.
+func PruneHeard(p Pruner, streams []ModuleStream, wanted []Consumer) ([]string, error) {
+	keep := map[string]bool{}
+	for _, c := range wanted {
+		keep[c.Stream+"/"+c.Name] = true
+	}
+	var removed []string
+	for _, s := range streams {
+		names, err := p.ConsumerNames(s.Name)
+		if err != nil {
+			return removed, fmt.Errorf("listing the consumers on %s: %w", s.Name, err)
+		}
+		for _, n := range names {
+			if keep[s.Name+"/"+n] {
+				continue
+			}
+			if err := p.RemoveConsumer(s.Name, n); err != nil {
+				return removed, fmt.Errorf("removing %s's consumer on %s, which is no longer granted: %w", n, s.Name, err)
+			}
+			removed = append(removed, s.Name+"/"+n)
+		}
+	}
+	return removed, nil
+}
+
+// EnsureHeard asserts a consumer on a module's stream (ADR 0363 §5, §6). **On a restricted stream, a consumer
+// the bus will not bring to match is removed**: a pull consumer delivers to whoever pulls it, so one left with
+// its wider filters after a narrowing was refused would keep handing over what the grant no longer names,
+// whatever the user list now says. The next assertion makes it again with the granted filters. The refusal is
+// returned either way, saying what was done, so the send says it and raises it.
+func EnsureHeard(r Raiser, c Consumer, restricted bool) error {
+	err := r.EnsureConsumer(c)
+	if err == nil || !restricted {
+		return err
+	}
+	p, prunes := r.(Pruner)
+	if !prunes {
+		return fmt.Errorf("%w; it could not be removed here, and may still deliver more than it is granted", err)
+	}
+	if rerr := p.RemoveConsumer(c.Stream, c.Name); rerr != nil {
+		return fmt.Errorf("%w; REMOVING IT FAILED TOO, so it may still deliver more than it is granted: %v", err, rerr)
+	}
+	return fmt.Errorf("%w; REMOVED, so it delivers nothing it is no longer granted: the next assertion makes it "+
+		"again with its granted filters (novox/hq ADR 0363 §6)", err)
+}

go/buscompose/onnats.go

@@ -0,0 +1,5 @@
+package buscompose
+
+// NATSVar names the environment variable that says the controller is on the bus (mesh-controller internal/broker
+// onnats.go); kept with the composer for the readiness it composes.
+const NATSVar = "MESH_BUS_NATS"

go/buscompose/process_grants.go

@@ -0,0 +1,52 @@
+package buscompose
+
+// The bus account of one process of a module that declares bus (novox/hq ADR 0436 §1, §2, §3, §5).
+//
+// **Never the module's own account's grants, never the tool runner's.** A process's authority is read
+// straight from its bus declaration — its emits, its queue's consumer, its state, whether it reads the
+// records of its module's own asks, and the tools and seat verbs it calls — and nothing else: it holds no
+// seat, serves no tool, hears no module stream, and answers nothing a caller asked (§3). Modelled on
+// provisionerGrants, the other kind of process account the mesh mints (ADR 0349 clauses 6 and 11).
+
+// processGrants is one process's whole authority: to publish, and to subscribe.
+func processGrants(p Principal) (pub, sub []string, err error) {
+	// 1. Its own events, under its module's own namespace — the same subjects the module's own principal
+	// would publish them on, had it declared them there instead (novox/hq ADR 0436 §1).
+	own := "mesh.mod." + p.Module
+	for _, e := range p.Emits {
+		pub = append(pub, own+".event."+e)
+	}
+
+	// 2. The one durable consumer of each work-queue stream its bus names (novox/hq ADR 0436 §1, §2, §6):
+	// asked about, pulled from and acknowledged, by the same name ConsumersOf composes the consumer under
+	// (QueueConsumer) — and no other stream's.
+	for _, q := range p.Queues {
+		consumer := p.Node + "_" + p.Module + "_" + q.Process
+		pub = append(pub,
+			"$JS.API.CONSUMER.INFO."+q.Stream+"."+consumer,
+			"$JS.API.CONSUMER.MSG.NEXT."+q.Stream+"."+consumer,
+			"$JS.ACK."+q.Stream+"."+consumer+".>")
+	}
+
+	// 3. Its module's own state, by the local names its bus names alone — never the whole of what the
+	// module keeps (novox/hq ADR 0436 §1), read and written as stateGrants gives any module's own bucket.
+	pub = append(pub, stateGrants(stateAccess{Module: p.Module, Node: p.Node, Keeps: p.State})...)
+
+	// 4. The router's records of its module's own asks (novox/hq ADR 0436 §1, ADR 0259 §3): the same
+	// direct-get subjects a module's own principal reads for the seats its Uses names that keep them —
+	// read here from the one list, so the two cannot disagree.
+	if p.Asks {
+		pub = append(pub, SeatTrafficOf(p.Module, nil, p.Uses, nil).Records...)
+	}
+
+	// 5. The tools and seat verbs it calls (novox/hq ADR 0152, ADR 0436 §1): the same derivation a
+	// module's own principal's invokes takes, so `callerNamed` (applied to every non-controller principal)
+	// adds the caller-named `call` variants for it exactly as it would for a module.
+	invoked, err := invokedSubjects(p.Invokes)
+	if err != nil {
+		return nil, nil, err
+	}
+	pub = append(pub, invoked...)
+
+	return pub, sub, nil
+}

go/buscompose/provisioner.go

@@ -0,0 +1,217 @@
+package buscompose
+
+import (
+	"errors"
+	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"strings"
+
+	"github.com/nats-io/nats.go"
+)
+
+// The provisioner client's own bus account (novox/hq ADR 0349 clauses 6 and 11, design 57 package P3).
+//
+// **Not the tool runner's account.** The client fills a machine's files and asks the vault for the secrets that
+// machine's declaration names; the vault hands a secret only to an account of its own, because a call under the
+// tool runner's account cannot be told from an agent's on that machine (ADR 0305 §3, §12). So each machine that
+// runs the client has a principal of its own, KindProvisioner, named for the machine, and granted what the client
+// does and nothing else: read its own machine's keys in each domain's bucket, write its own machine's keys of the
+// provisioner server's needs, applied and collections (design 57 P4), read the server's registry, say what it
+// applied on its own machine, and ask the vault in its own name.
+
+// NodeProvisionerSeat is the seat the provisioner client holds on every machine (ADR 0349 clause 3).
+const NodeProvisionerSeat = "node-provisioner"
+
+// ProvisionerSecret is the own secret of the module running the client that its bus account is delivered in, as
+// `broker` is a module's own (novox/hq issue 195): a module that claims NodeProvisionerSeat and declares no own
+// secret of this name has nowhere to read an account, and is given none.
+const ProvisionerSecret = "provisioner-broker"
+
+// ConfigResolvedBucket is the config domain's resolved values, keyed `<node>.<module>.<key>` (ADR 0348, research
+// 051): mesh-config's state `resolved`, written by mesh-config alone.
+var ConfigResolvedBucket = BucketName("mesh-config", "resolved")
+
+// ProvisionerReads are the domains' buckets a provisioner client reads its own machine's keys of, each keyed
+// `<node>.…` (research 051): placement, the controller's assignments mirror (`<node>.<module>`), whose value carries
+// the provisioner's plan of a module handed to it (inventory.Provisioning, design 57 P5); and config,
+// mesh-config's resolved values. **Named one by one**, as the controller's asks are: a domain that moves to the
+// provisioner adds its bucket here, and a bucket not named is one the client cannot read.
+var ProvisionerReads = []string{ConfigResolvedBucket}
+
+// ProvisionerReadsWhole are the buckets a provisioner client reads every key of: the controller's assignments mirror,
+// where a provider's consumers are bound to it in their own machines' plans, which the provider machine's client
+// reads to fill ${consumers:<provision>} with each one's credential (novox/hq ADR 0373, issue 679). It holds placement
+// and plans, never a secret's value; the client writes none of it.
+var ProvisionerReadsWhole = []string{AssignmentsBucket}
+
+// BoundState is a providing module's state of entries, one per consumer (mesh-sdk go/provider, issue 678): a
+// consumer's machine's client reads its own keys of it, `<node>.<module>.<provision>[.<local>]`, to fill
+// ${bound:<provision>:<key>} (issue 679).
+const BoundState = "bound"
+
+// ProvisionerServerModule is the module holding the seat mesh-provisioner once for the mesh (ADR 0349 clause 3,
+// design 57 P4), whose buckets the clients write their own machine's keys of.
+const ProvisionerServerModule = "mesh-provisioner"
+
+// The provisioner server's buckets (ADR 0349 clause 3): its state, created by the controller from its manifest
+// like any module's, and written by its own account whole.
+var (
+	// ProvisionerRegistryBucket is which domain answers which kind of placeholder, keyed by the kind; the
+	// server's alone, read whole by every client.
+	ProvisionerRegistryBucket = BucketName(ProvisionerServerModule, "registry")
+	// ProvisionerNeedsBucket is what each module on each machine needs, `<node>.<module>.<kind>.<name>`.
+	ProvisionerNeedsBucket = BucketName(ProvisionerServerModule, "needs")
+	// ProvisionerAppliedBucket is what is applied where, `<node>.<module>`.
+	ProvisionerAppliedBucket = BucketName(ProvisionerServerModule, "applied")
+	// ProvisionerCollectBucket is the items of every collection, `<node>.<collection>.<contributor>`.
+	ProvisionerCollectBucket = BucketName(ProvisionerServerModule, "collect")
+)
+
+// ProvisionerWrites are the server's buckets a client writes, and reads, its own machine's keys of (`<node>.>`)
+// and no other's: the needs it records, what it applied, and the items of the collections on its machine. A
+// client cannot write another machine's needs, or say another machine applied a file.
+var ProvisionerWrites = []string{ProvisionerNeedsBucket, ProvisionerAppliedBucket, ProvisionerCollectBucket}
+
+// VerbsTheProvisionerAsksTheVault are the vault's verbs a provisioner client asks in its own name (ADR 0349
+// clause 11): `get`, a secret its machine's declaration names, answered sealed to the asker's key. On the subject
+// that names its caller, so the vault knows which machine's client asks from the bus's word.
+var VerbsTheProvisionerAsksTheVault = []SeatVerb{{Seat: "mesh-vault", Verb: "get"}}
+
+// VaultSecretChangedSubject is where the vault says a secret it holds changed (`secret-changed`: which, by whom,
+// when, its generation; never a value, ADR 0349 clause 11), as link.EventSubject addresses mesh-vault's event. A
+// provisioner client listens to it so a rotated secret reaches its file without a new declaration (design 57 V4):
+// it asks the vault again, in its own name, for a secret its machine's declaration names.
+const VaultSecretChangedSubject = "mesh.mod.mesh-vault.event.secret-changed"
+
+// ProvisionerAppliedSubject is where a machine's client says what it applied for one module, applied or failed
+// with the reason (ADR 0349 clauses 4 and 15): `prov.applied.<node>.<module>`.
+func ProvisionerAppliedSubject(node, module string) string {
+	return "prov.applied." + node + "." + module
+}
+
+// ProvisionerAskSubject is where a machine's tool runner asks that machine's provisioner client for a config value
+// or a non-secret bound value of a module it carries, naming the module from the bundle that asks (novox/hq ADR
+// 0370 §1, §3, §4; issue 685): `prov.ask.<node>`, which the client subscribes and the tool runner's account of the
+// same machine alone may publish. The bus proves only that the tool runner asks; the module is the runtime's word,
+// so the client answers no secret here (ADR 0370 §2).
+func ProvisionerAskSubject(node string) string { return "prov.ask." + node }
+
+// ProvisionerChangedSubject is where a machine's client says that a value of one module it answers moved, so the
+// tool runner asks again for the module's code's watches (ADR 0349 §14, ADR 0370 §1): `prov.changed.<node>.<module>`,
+// carrying which value and never the value itself, heard by that machine's tool runner alone.
+func ProvisionerChangedSubject(node, module string) string {
+	return "prov.changed." + node + "." + module
+}
+
+// provisionerGrants is a provisioner client's whole authority: to publish, and to subscribe.
+func provisionerGrants(p Principal) (pub, sub []string, err error) {
+	if p.Node == "" {
+		// Refused rather than composed into `$KV.<bucket>..>`, a pattern no machine's keys are under, and a
+		// name every nameless client would share.
+		return nil, nil, errors.New("a provisioner client names no machine, so it would have no keys of its own " +
+			"to read and an account it shared with every other")
+	}
+	for _, bucket := range ProvisionerReads {
+		pub = append(pub, machineKeysRead(bucket, p.Node)...)
+	}
+	for _, bucket := range ProvisionerReadsWhole {
+		pub = append(pub, wholeBucketRead(bucket)...)
+	}
+	for _, bucket := range p.BoundBuckets {
+		module, name, ok := strings.Cut(bucket, "_")
+		if !ok || name != BoundState || !safeSubject.MatchString(module) || strings.Contains(module, "_") {
+			return nil, nil, fmt.Errorf("%q is not a provider's bucket of entries, <module>_%s", bucket, BoundState)
+		}
+		pub = append(pub, machineKeysRead(bucket, p.Node)...)
+	}
+	// The server's buckets (design 57 P4): its own machine's keys of the needs, the applied and the
+	// collections, read and written, `$KV.<bucket>.<node>.>` and nothing wider; and the registry, read whole,
+	// which says which domain answers which kind and is the same for every machine.
+	for _, bucket := range ProvisionerWrites {
+		pub = append(pub, machineKeysRead(bucket, p.Node)...)
+		pub = append(pub, "$KV."+bucket+"."+p.Node+".>")
+	}
+	pub = append(pub, wholeBucketRead(ProvisionerRegistryBucket)...)
+	// Its own node's own have, `<node>.node`, read and never written, and no other key of the bucket: it fills every
+	// module again when the node-engine moves to a new composition of the node's own (issue 1945), since an apply can
+	// leave a filled file as the composition had it.
+	pub = append(pub, readGrants(delivery.HaveBucket, p.Node+".node")...)
+	pub = append(pub, "prov.applied."+p.Node+".>")
+	token := CallerToken(p.Username())
+	if token == "" {
+		return nil, nil, fmt.Errorf("%q cannot name a caller", p.Username())
+	}
+	for _, v := range VerbsTheProvisionerAsksTheVault {
+		pub = append(pub, "mesh.seat."+v.Seat+"."+CallKind+"."+v.Verb+"."+token)
+	}
+	// What moved of a value it answers its own machine's tool runner (ADR 0370 §1), under its own machine's name.
+	pub = append(pub, "prov.changed."+p.Node+".>")
+	// Its own reply space, for the vault's answers and its reads' and watches' deliveries; what the vault says
+	// changed; and its own machine's tool runner asking it for a module's config and non-secret bound values (ADR
+	// 0370 §3), which it answers on the ask's reply and nowhere else.
+	return pub, []string{p.inbox(), VaultSecretChangedSubject, ProvisionerAskSubject(p.Node)}, nil
+}
+
+// machineKeysRead is reading every key of a bucket under one machine's name, `<node>.>`, and no other key: a
+// direct get of a key's own subject, and a consumer whose filter is under it — the server's create-with-filter
+// form, which it holds to the filter the subject names (as stateGrants does for one key, novox/hq ADR 0260).
+// Binding, deleting a consumer and flow control cannot be narrowed by key and read no value.
+func machineKeysRead(bucket, node string) []string {
+	stream := "KV_" + bucket
+	keys := "$KV." + bucket + "." + node + ".>"
+	return []string{
+		"$JS.API.STREAM.INFO." + stream,
+		"$JS.API.DIRECT.GET." + stream + "." + keys,
+		"$JS.API.CONSUMER.CREATE." + stream + ".*." + keys,
+		"$JS.API.CONSUMER.DELETE." + stream + ".>",
+		"$JS.FC." + stream + ".>",
+	}
+}
+
+// wholeBucketRead is reading every key of a bucket and writing none: what stateGrants grants a module for a
+// bucket it `reads`.
+func wholeBucketRead(bucket string) []string {
+	stream := "KV_" + bucket
+	return []string{
+		"$JS.API.STREAM.INFO." + stream,
+		"$JS.API.DIRECT.GET." + stream + ".>",
+		"$JS.API.CONSUMER.CREATE." + stream + ".>",
+		"$JS.API.CONSUMER.DELETE." + stream + ".>",
+		"$JS.FC." + stream + ".>",
+	}
+}
+
+// LastProvApplied is what a machine's provisioner client last said of one module's files, as it published it on
+// ProvisionerAppliedSubject and ProvAppliedStream keeps it (design 57 P6): false when it has said nothing of it in
+// the stream's week.
+func LastProvApplied(js nats.JetStreamContext, node, module string) ([]byte, bool, error) {
+	msg, err := js.GetLastMsg(ProvAppliedStream, ProvisionerAppliedSubject(node, module))
+	if errors.Is(err, nats.ErrMsgNotFound) {
+		return nil, false, nil
+	}
+	if err != nil {
+		return nil, false, fmt.Errorf("what %s's provisioner client said of %s cannot be read: %w", node, module, err)
+	}
+	return msg.Data, true, nil
+}
+
+// ProvAppliedReports is the newest word of every machine's provisioner client on every module it said one of, kept by
+// ProvAppliedStream, by subject (`prov.applied.<node>.<module>`).
+func ProvAppliedReports(js nats.JetStreamContext) (map[string][]byte, error) {
+	info, err := js.StreamInfo(ProvAppliedStream, &nats.StreamInfoRequest{SubjectsFilter: ProvAppliedSubjects})
+	if err != nil {
+		return nil, fmt.Errorf("the provisioner clients' reports cannot be listed: %w", err)
+	}
+	out := map[string][]byte{}
+	for subject := range info.State.Subjects {
+		msg, err := js.GetLastMsg(ProvAppliedStream, subject)
+		if errors.Is(err, nats.ErrMsgNotFound) {
+			continue // aged out between the two reads
+		}
+		if err != nil {
+			return nil, fmt.Errorf("the provisioner client's report on %s cannot be read: %w", subject, err)
+		}
+		out[subject] = msg.Data
+	}
+	return out, nil
+}

go/buscompose/raise.go

@@ -0,0 +1,73 @@
+package buscompose
+
+import "fmt"
+
+// Bringing the bus's own objects into being, in the one order that works.
+//
+// **Asserted on every start rather than created once at genesis.** A stream somebody deleted, a mesh
+// raised from a restored backup, or a bus whose data directory was replaced all have records and no
+// objects — and a node whose consumer is missing hears nothing while everything else about it looks
+// correct. Idempotence is the whole requirement, and the parts are already idempotent; this is the
+// order they have to be asked in.
+
+// Raiser is everything asserting the bus's objects needs of a connection to it.
+type Raiser interface {
+	Asserter
+	Ensurer
+}
+
+// Raise asserts the mesh's streams, the controller's own consumers, and one consumer per node.
+//
+// **The order is not a preference.** A consumer on a stream that does not exist is refused, and the
+// refusal names the stream rather than the order — so somebody reading it goes looking for a deleted
+// stream instead of a reversed pair of lines. Nodes last, because the one a node reads lives on a
+// stream the mesh's own set defines.
+func Raise(r Raiser, nodes []string) error {
+	if err := AssertMeshStreams(r); err != nil {
+		return err
+	}
+	if err := AssertMeshConsumers(r); err != nil {
+		return err
+	}
+	if err := AssertNodeConsumers(r, nodes); err != nil {
+		return err
+	}
+	return nil
+}
+
+// RaiseSeats asserts one work queue per declared seat, and the worker of whoever holds it.
+//
+// Separate from Raise because it is answered by a different question: the mesh's own objects exist
+// because the mesh does, and a seat's exist because a module declaring one was registered. Kept
+// beside it so the order is visible — a holder's worker needs the seat's stream, and a seat's stream
+// needs nothing.
+func RaiseSeats(r Raiser, seats []DeclaredSeat, holders map[string]Holder) error {
+	for _, s := range SeatStreams(seats) {
+		if err := r.EnsureStream(s); err != nil {
+			return fmt.Errorf("asserting the work queue for %s: %w", s.Name, err)
+		}
+	}
+	for _, s := range seats {
+		h, held := holders[s.Name]
+		if !held {
+			// **The stream exists and the consumer does not, on purpose.** Work queues until a
+			// holder appears, so installing the module a week after something started sending to it
+			// flushes the backlog instead of having lost it.
+			continue
+		}
+		c, needed := HolderConsumerFor(h.Node, h.Module, s)
+		if !needed {
+			continue
+		}
+		if err := r.EnsureConsumer(c); err != nil {
+			return fmt.Errorf("asserting how %s on %s works %s: %w", h.Module, h.Node, s.Name, err)
+		}
+	}
+	return nil
+}
+
+// Holder is which module on which machine holds a seat.
+type Holder struct {
+	Node   string
+	Module string
+}

go/buscompose/readiness.go

@@ -0,0 +1,139 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// Whether a mesh could move its bus, and what is missing if not.
+//
+// **Asked before anything moves, and answerable from records alone.** The rollout moves every node at
+// once (novox/hq ADR 0116 step 5), so there is no partial state to inspect afterwards and no half to
+// roll back: either the mesh was ready or it was not. That makes a readiness question the most
+// valuable thing here — it costs nothing, it can be asked of a running mesh any number of times, and
+// every answer is a thing somebody can go and fix.
+//
+// Deliberately pure. It is handed what the mesh knows and returns sentences; nothing here connects to
+// anything, so it can be asked on a workstation about a mesh it has never reached.
+
+// Readiness is what the mesh knows about its own ability to move.
+type Readiness struct {
+	// TheBus is the address the mesh's own traffic would move to, empty when nothing names one.
+	TheBus string
+	// ServerStanding is whether a bus is reachable at that address, as somebody checked.
+	ServerStanding bool
+	// Holder is the node running the module that holds the bus seat, empty when nothing does.
+	Holder string
+	// AccountsComposed is whether that node has been sent the composed user list.
+	AccountsComposed bool
+	// Nodes is every machine the mesh knows.
+	Nodes []string
+	// Credentialled is which of them has a credential for the new bus.
+	Credentialled map[string]bool
+	// Modules is every assigned module, as `<node>/<module>`.
+	Modules []string
+	// ModuleCredentialled is which of those has one.
+	ModuleCredentialled map[string]bool
+}
+
+// NotReady is every reason this mesh cannot move its bus yet, in the order somebody would fix them.
+//
+// Empty means ready. **Each entry names one thing and what to do about it**, because a readiness check
+// that says "not ready" is a check nobody can act on — and this is read at the point where the next
+// step is irreversible.
+func NotReady(r Readiness) []string {
+	var why []string
+
+	if strings.TrimSpace(r.TheBus) == "" {
+		why = append(why, "nothing names the bus to move to: set "+NATSVar+" on the control node "+
+			"to the address the new server answers on")
+	}
+	if !r.ServerStanding {
+		why = append(why, "no bus is answering at that address. Step 2 of the change raises it beside "+
+			"the one the mesh is on, carrying nothing — assign the module that holds "+
+			"mesh-broker and push the machine that runs it")
+	}
+	if r.Holder == "" {
+		why = append(why, "no machine holds mesh-broker, so nothing would compose the bus's user "+
+			"list. Assign the module that claims it")
+	} else if !r.AccountsComposed {
+		why = append(why, fmt.Sprintf(
+			"%s holds mesh-broker and has not been sent the composed user list, so the bus would "+
+				"refuse every connection. `push %s`", r.Holder, r.Holder))
+	}
+
+	// A node with no credential cannot come back after the move, and a node that cannot come back is
+	// a machine the mesh has lost until somebody goes to it.
+	var missing []string
+	for _, n := range r.Nodes {
+		if !r.Credentialled[n] {
+			missing = append(missing, n)
+		}
+	}
+	sort.Strings(missing)
+	if len(missing) > 0 {
+		why = append(why, fmt.Sprintf(
+			"%d machine(s) have no credential for the new bus and would not come back: %s. Each needs "+
+				"one minted before the move, not after — after, there is no bus to ask over",
+			len(missing), strings.Join(missing, ", ")))
+	}
+
+	// A module without one keeps running and stops being reachable, which is a smaller fault and still
+	// one somebody should choose rather than discover.
+	var quiet []string
+	for _, m := range r.Modules {
+		if !r.ModuleCredentialled[m] {
+			quiet = append(quiet, m)
+		}
+	}
+	sort.Strings(quiet)
+	if len(quiet) > 0 {
+		why = append(why, fmt.Sprintf(
+			"%d module(s) have no credential for the new bus: %s. Each keeps serving and stops "+
+				"answering tools and hearing events until it is issued one",
+			len(quiet), strings.Join(quiet, ", ")))
+	}
+
+	return why
+}
+
+// WhatMoves is what the rollout would do, in order, for somebody reading before they commit.
+//
+// **Written out rather than summarised.** This is the one step with nothing to inspect afterwards, so
+// the last useful moment to disagree with it is while reading this.
+func WhatMoves(r Readiness) []string {
+	out := []string{
+		fmt.Sprintf("compose the bus's user list and send it to %s", holderOr(r.Holder)),
+		fmt.Sprintf("move this control plane to %s, and confirm it is heard", busOr(r.TheBus)),
+	}
+	nodes := append([]string(nil), r.Nodes...)
+	sort.Strings(nodes)
+	for _, n := range nodes {
+		out = append(out, fmt.Sprintf("move %s, and confirm it reports", n))
+	}
+	if len(r.Modules) > 0 {
+		out = append(out, fmt.Sprintf("move %d module runtime(s), and confirm each answers",
+			len(r.Modules)))
+	}
+	// **The old broker goes, and it goes last** (novox/hq ADR 0131). AMQP is not a provision, so once
+	// every machine reports on the new bus nothing of the mesh is left speaking to it, and its module
+	// is unassigned. Said as a step so nobody reads the move as leaving a second bus behind.
+	out = append(out, "then unassign the old broker's module: AMQP is not a provision (ADR 0131), and "+
+		"once every machine reports on the new bus nothing of the mesh speaks to it")
+	return out
+}
+
+func holderOr(node string) string {
+	if node == "" {
+		return "whichever machine holds mesh-broker"
+	}
+	return node
+}
+
+func busOr(address string) string {
+	if address == "" {
+		return "the new bus"
+	}
+	return address
+}

go/buscompose/sdk_membership.go

@@ -0,0 +1,38 @@
+package buscompose
+
+import (
+	"git.novox.be/novox/mesh-sdk/go/membership"
+	"git.novox.be/novox/mesh-sdk/go/process"
+)
+
+// The membership the mesh issues an assignment (novox/hq ADR 0160), its subject, its stream, the bare address and the
+// pin are mesh-sdk's, public so that a module's program outside this Go module, the route proxy, reads them too
+// (novox/hq ADR 0480 clause 4, issue 1633). This package keeps no second copy: what follows only names them where the
+// controller already did.
+type (
+	Membership   = membership.Membership
+	Served       = membership.Served
+	SeatServed   = membership.SeatServed
+	StateIssued  = membership.StateIssued
+	LogIssued    = membership.LogIssued
+	Worker       = membership.Worker
+	SeatTraffic  = membership.SeatTraffic
+	KindHeld     = membership.KindHeld
+	StreamIssued = membership.StreamIssued
+	HeardIssued  = membership.HeardIssued
+	WaitIssued   = membership.WaitIssued
+)
+
+// AssignmentsStream holds every assignment's membership, the newest per subject.
+const AssignmentsStream = membership.AssignmentsStream
+
+var (
+	// MembershipSubject is where an assignment's own membership is published.
+	MembershipSubject = membership.Subject
+	// CredentialIn reads the user and password out of a bus address, and the address without them.
+	CredentialIn = membership.CredentialIn
+	// BareAddress is a bus address with any credential stripped.
+	BareAddress = membership.BareAddress
+	// PinnedToFingerprint accepts exactly the certificate with this SHA-256 and no other.
+	PinnedToFingerprint = process.PinnedToFingerprint
+)

go/buscompose/seattraffic.go

@@ -0,0 +1,290 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+)
+
+// What a module may say and take on the seats it holds, uses and watches, beyond tools (novox/hq ADR
+// 0259 §3, to-be 46 §10).
+//
+// Three rules are added to the ones a seat always had, each a subject whose last token names who may
+// publish it, granted to that publisher alone — the way a node seat's event about a machine carries the
+// machine (ADR 0219):
+//
+//   - **A verb named by its caller** (`by-caller`). A user of the seat submits that accept, and hears that
+//     event, under its own module's name and no other: `accept.ask.<module>`, `event.decided.<module>`. The
+//     holder takes every caller's accept and says the event to any caller. So an ask's asker is a fact the
+//     server enforces, and a warrant reaches only the asker it is for.
+//   - **A kinded bench** (ADR 0234 §2). A holder claims one kind and takes its own kind's accepts, says its
+//     own kind's events and asks its own kind's proofs, and nothing of another kind; a user submits to any
+//     kind. Each kind has its own worker on the seat's queue, so a holder that is away keeps its work and
+//     holds up no other kind.
+//   - **A proof** (`proofs`): core request and reply on `mesh.seat.<seat>.proof.<verb>.<kind>`. No stream's
+//     subjects cover it, so what travels there — a code typed by the operator — is never persisted. A kinded
+//     holder asks with its own kind; the modules that watch the seat answer.
+//
+// And one read: **a holder's records**, a bucket the seat names, read by each user under its own name only
+// (`$KV.<bucket>.<module>.>`), so an asker reads the state of its own asks and no other asker's.
+
+// BuildAskMaxDeliver bounds the deliveries of a build seat's ask (issue 1907): mesh-sdk delivery.AskMaxDeliver, written
+// here as the broker mirrors the catalogue rather than importing it.
+const BuildAskMaxDeliver = 5
+
+// KindedBenches are the seats that may be kinded (ADR 0234 §2): making another is a decision, recorded.
+var KindedBenches = map[string]bool{"channel": true, "intake": true}
+
+// WorkerName is the worker a seat's holders pull from: one for the seat, or one per kind on a kinded bench.
+func WorkerName(seat, kind string) string {
+	if kind == "" {
+		return "SEAT_" + upperSnake(seat) + "_worker"
+	}
+	return "SEAT_" + upperSnake(seat) + "_" + upperSnake(kind) + "_worker"
+}
+
+func namesVerb(list []string, s string) bool {
+	for _, x := range list {
+		if x == s {
+			return true
+		}
+	}
+	return false
+}
+
+// SeatTrafficOf derives one module's seat traffic from the seats it holds, uses and watches. Only seats
+// carrying one of the rules above are read: every other seat is composed as it always was.
+func SeatTrafficOf(module string, holds, uses, watches []Seat) SeatTraffic {
+	var t SeatTraffic
+	for _, s := range holds {
+		if !s.isNewTraffic() {
+			continue
+		}
+		kind := ""
+		if s.Kinded {
+			kind = s.Kind
+			if kind == "" || !safeSubject.MatchString(kind) {
+				// A kinded claim without a usable kind is refused at registration; here it is granted
+				// nothing, which is the same answer at the last place it could be asked.
+				continue
+			}
+		}
+		if len(s.Accepts) > 0 && s.PulledByKind {
+			// One worker per accepted kind, which every holder pulls in the order of Accepts (ADR 0525 §4, ADR 0536 §4):
+			// `SEAT_<SEAT>_<KIND>_worker`, filtered to `accept.<kind>` (mesh-sdk delivery.AskWorker).
+			for _, a := range s.Accepts {
+				t.Workers = append(t.Workers, Worker{Stream: seatStreamName(s.Name), Consumer: WorkerName(s.Name, a),
+					Filter: "mesh.seat." + s.Name + ".accept." + a})
+			}
+		} else if len(s.Accepts) > 0 {
+			stream := seatStreamName(s.Name)
+			filter := "mesh.seat." + s.Name + ".accept.>"
+			if kind != "" {
+				filter = "mesh.seat." + s.Name + ".accept.*." + kind
+			}
+			t.Workers = append(t.Workers, Worker{Stream: stream, Consumer: WorkerName(s.Name, kind), Filter: filter})
+		}
+		for _, a := range s.Accepts {
+			switch {
+			case kind != "":
+				t.Subscribe = append(t.Subscribe, seatSubject(s, "accept", a+"."+kind))
+			case namesVerb(s.ByCaller, a):
+				t.Subscribe = append(t.Subscribe, seatSubject(s, "accept", a+".*"))
+			}
+		}
+		for _, e := range s.Emits {
+			switch {
+			case kind != "":
+				t.Publish = append(t.Publish, seatSubject(s, "event", e+"."+kind))
+			case namesVerb(s.ByCaller, e):
+				t.Publish = append(t.Publish, seatSubject(s, "event", e+".*"))
+			}
+		}
+		if kind != "" {
+			for _, v := range s.Proofs {
+				t.Publish = append(t.Publish, seatSubject(s, "proof", v+"."+kind))
+			}
+		}
+	}
+	for _, s := range uses {
+		if !s.isNewTraffic() {
+			continue
+		}
+		for _, a := range s.Accepts {
+			switch {
+			case namesVerb(s.ByCaller, a):
+				t.Publish = append(t.Publish, seatSubject(s, "accept", a+"."+module))
+			case s.Kinded && module == s.DeclaredBy:
+				// Work for a kind is put on its queue by the bench's own router, and by no other user.
+				t.Publish = append(t.Publish, seatSubject(s, "accept", a+".*"))
+			}
+		}
+		for _, e := range s.Emits {
+			if namesVerb(s.ByCaller, e) {
+				t.Subscribe = append(t.Subscribe, seatSubject(s, "event", e+"."+module))
+			}
+		}
+		for _, b := range s.Records {
+			if !safeSubject.MatchString(b) {
+				continue
+			}
+			t.Records = append(t.Records, "$JS.API.DIRECT.GET.KV_"+b+".$KV."+b+"."+module+".>")
+		}
+	}
+	for _, w := range watches {
+		if w.Kinded {
+			for _, e := range w.Emits {
+				t.Subscribe = append(t.Subscribe, seatSubject(w, "event", e+".*"))
+			}
+			if module == w.DeclaredBy {
+				// A code is answered by the bench's own router, and by no other watcher.
+				for _, v := range w.Proofs {
+					t.Answers = append(t.Answers, seatSubject(w, "proof", v+".*"))
+				}
+			}
+		}
+	}
+	t.Publish = unique(t.Publish)
+	t.Subscribe = unique(t.Subscribe)
+	t.Answers = unique(t.Answers)
+	t.Records = unique(t.Records)
+	sort.Slice(t.Workers, func(i, j int) bool { return t.Workers[i].Consumer < t.Workers[j].Consumer })
+	return t
+}
+
+// seatTrafficGrants is the bus permissions seat traffic needs: the subjects themselves, and the JetStream API a
+// worker is pulled and acknowledged through and a record is read through.
+func seatTrafficGrants(t SeatTraffic) (pub, sub []string) {
+	pub = append(pub, t.Publish...)
+	sub = append(sub, t.Subscribe...)
+	sub = append(sub, t.Answers...)
+	for _, w := range t.Workers {
+		pub = append(pub,
+			"$JS.API.CONSUMER.INFO."+w.Stream+"."+w.Consumer,
+			"$JS.API.CONSUMER.MSG.NEXT."+w.Stream+"."+w.Consumer,
+			"$JS.ACK."+w.Stream+"."+w.Consumer+".>")
+	}
+	pub = append(pub, t.Records...)
+	return pub, sub
+}
+
+// isNewTraffic says whether a seat carries any of the rules above, so a seat that carries none is
+// composed exactly as before them.
+func (s Seat) isNewTraffic() bool {
+	return s.Kinded || len(s.ByCaller) > 0 || len(s.Proofs) > 0 || len(s.Records) > 0 || s.PulledByKind
+}
+
+// plainVerbs is a seat's accepts or emits with those the rules above compose taken out: a verb named by
+// its caller and every verb of a kinded bench are composed by SeatTrafficOf and nowhere else.
+func plainVerbs(s Seat, verbs []string) []string {
+	if s.Kinded {
+		return nil
+	}
+	var out []string
+	for _, v := range verbs {
+		if !namesVerb(s.ByCaller, v) {
+			out = append(out, v)
+		}
+	}
+	return out
+}
+
+// SeatTrafficObjects is the work queues and workers the seat traffic of every composed user implies
+// (novox/hq ADR 0259 §3): a queue for each seat a holder takes work from, and each holder's worker on it —
+// one per kind on a kinded bench, filtered to that kind, so the kinds never take each other's work. Only
+// seats carrying the rules above; the mesh's own seats' queues are RaiseSeats'.
+func SeatTrafficObjects(users []Principal) ([]Stream, []Consumer) {
+	streams := map[string]Stream{}
+	consumers := map[string]Consumer{}
+	add := func(module string, holds []Seat) {
+		for _, w := range SeatTrafficOf(module, holds, nil, nil).Workers {
+			seat, byKind := "", false
+			for _, s := range holds {
+				if seatStreamName(s.Name) == w.Stream {
+					seat, byKind = s.Name, s.PulledByKind
+				}
+			}
+			streams[w.Stream] = Stream{
+				Name:      w.Stream,
+				Subjects:  []string{"mesh.seat." + seat + ".accept.>"},
+				Retention: RetentionWorkQueue,
+				MaxAge:    7 * 24 * 60 * 60,
+				Why:       "work submitted to the " + seat + " seat; its holders take it, each kind its own, and it queues while nobody does",
+			}
+			c := Consumer{
+				Name:           w.Consumer,
+				Stream:         w.Stream,
+				Filters:        []string{w.Filter},
+				AckWaitSeconds: 60,
+				// No bound on redelivery: a channel away for a day keeps its work, offered again later and
+				// later by its holder's runtime (novox/hq ADR 0259; the correctness review of 2026-10-08).
+				MaxDeliver: 0,
+				Why: module + " holds " + seat + "; it pulls one ask at a time and acknowledges once it has " +
+					"recorded it, so a crash redelivers rather than loses",
+			}
+			if byKind {
+				// A build seat's ask is offered a bounded number of times (issue 1907): the holder that takes it past
+				// mesh-sdk delivery.AskRuns ends it failed saying it is poison, and the bound stops a run that kills
+				// every node it reaches even when that holder dies too.
+				c.MaxDeliver = BuildAskMaxDeliver
+				c.Why = module + " holds " + seat + "; each holder pulls an ask when it has a free slot, and an ask that " +
+					"no run ends is offered at most " + fmt.Sprint(BuildAskMaxDeliver) + " times, its step failed as poison"
+			}
+			consumers[w.Consumer] = c
+		}
+	}
+	for _, p := range users {
+		switch p.Kind {
+		case KindModule:
+			add(p.Module, p.Holds)
+		case KindNodeTools:
+			for _, d := range p.Carries {
+				add(d.Module, d.Holds)
+			}
+		}
+	}
+	var ss []Stream
+	for _, s := range streams {
+		ss = append(ss, s)
+	}
+	sort.Slice(ss, func(i, j int) bool { return ss[i].Name < ss[j].Name })
+	var cs []Consumer
+	for _, c := range consumers {
+		cs = append(cs, c)
+	}
+	sort.Slice(cs, func(i, j int) bool { return cs[i].Name < cs[j].Name })
+	return ss, cs
+}
+
+// trustedTraffic is why a module's seat traffic is the trusted holder's (novox/hq ADR 0259 §8), or "": it
+// says a seat's event to one caller each (a warrant), or holds a kind of a kinded bench that proves its sender.
+func trustedTraffic(d Declared) string {
+	for _, s := range d.Holds {
+		for _, e := range s.Emits {
+			if namesVerb(s.ByCaller, e) {
+				return "it says " + s.Name + "'s " + e + " to one caller each"
+			}
+		}
+		if s.Kinded && namesVerb(s.Capabilities, "verified-sender") {
+			return "it holds " + s.Name + " of kind " + s.Kind + ", which proves its sender"
+		}
+	}
+	return ""
+}
+
+// TrafficQueues is the work queue of every seat naming its caller or its kind that accepts work, held or not
+// (novox/hq ADR 0259 §3): what is submitted before a holder is assigned waits for it.
+func TrafficQueues(seats []Seat) []Stream {
+	var out []Stream
+	seen := map[string]bool{}
+	for _, s := range seats {
+		if len(s.Accepts) == 0 || !s.isNewTraffic() || seen[s.Name] {
+			continue
+		}
+		seen[s.Name] = true
+		out = append(out, Stream{Name: seatStreamName(s.Name), Subjects: []string{"mesh.seat." + s.Name + ".accept.>"},
+			Retention: RetentionWorkQueue, MaxAge: 7 * 24 * 60 * 60,
+			Why: "work submitted to the " + s.Name + " seat; its holders take it, each kind its own, and it queues while nobody does"})
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Name < out[j].Name })
+	return out
+}

go/buscompose/state.go

@@ -0,0 +1,265 @@
+package buscompose
+
+import (
+	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/announce"
+	"sort"
+	"strings"
+	"time"
+)
+
+// A module's state on the bus (novox/hq ADR 0201, design 32 §4, design 25 §3).
+//
+// A module names the state it keeps (`state`) and the state of others it reads (`reads`), and each
+// is a key-value bucket: the server's own last-per-subject stream with direct reads, delete markers
+// and watches, which is the state relationship the mesh already uses for declarations, opened to
+// modules. The controller creates every bucket from the catalogue — from registration, like a
+// seat's stream, so a reader may watch before the owner runs anywhere — and no module can.
+//
+// Pure, like everything else in this package that decides what the bus holds; jetstream.go is the
+// part that asks a server.
+
+// The mesh's caps on a bucket, the same for every module: a value is a piece of state, not a file,
+// and a bucket that grew without bound would be one module filling the bus's disk for everyone.
+const (
+	StateMaxValueBytes = 256 * 1024
+	StateMaxBytes      = 64 * 1024 * 1024
+)
+
+// A Bucket is one module's declared state as the bus holds it.
+type Bucket struct {
+	Module string
+	Name   string
+	// History is how many values a key keeps; zero is one.
+	History int
+	// TTLSeconds is how long a value lives; zero is until replaced or deleted.
+	TTLSeconds int
+	// PerMachine says each machine's instance writes only the key named for its machine (novox/hq ADR
+	// 0260), and is granted that key and no other.
+	PerMachine bool
+	// KeyTTL says the bucket allows a time to live per key (novox/hq ADR 0433 §1): its owner writes each key with its
+	// own, and the server writes a delete marker, kept KeyTTLMarkerTTL, when it ends.
+	KeyTTL bool
+}
+
+// KeyTTLMarkerTTL is how long the marker an expired key leaves is kept: long enough for a watcher to hear it.
+const KeyTTLMarkerTTL = time.Minute
+
+// BucketName is the bucket a module's state lives in: the module and the local name joined by an
+// underscore, which neither may contain, so two modules can never derive one bucket.
+func BucketName(module, name string) string { return module + "_" + name }
+
+// Bucket is this bucket's name on the bus.
+func (b Bucket) Bucket() string { return BucketName(b.Module, b.Name) }
+
+// Why is carried into the server's description of the bucket, so somebody reading the server's
+// own state finds whose it is and why it is kept.
+func (b Bucket) Why() string {
+	return fmt.Sprintf("%s's state %q (novox/hq ADR 0201): its current value per key, written by %s, "+
+		"read by whatever declares it reads it; kept when %s is unassigned, because it is data",
+		b.Module, b.Name, b.Module, b.Module)
+}
+
+// bucketOfRead is the bucket a read names, `<module>.<name>`, or false when it names none.
+func bucketOfRead(read string) (string, bool) {
+	at := strings.LastIndex(read, ".")
+	if at <= 0 || at == len(read)-1 {
+		return "", false
+	}
+	module, name := read[:at], read[at+1:]
+	if !safeSubject.MatchString(module) || !safeSubject.MatchString(name) {
+		return "", false
+	}
+	return BucketName(module, name), true
+}
+
+// readGrants is what reaching a bucket's keys needs: binding to it, a direct get, an ordered consumer for listing and
+// watching and the deletion of that consumer and its flow control. key is one key's subject tail, a pattern such as
+// `one.>` for a prefix of keys, or empty for every key. The bucket is made with AllowDirect, so a get is the direct get
+// and never the stream's message get.
+func readGrants(bucket, key string) []string {
+	stream := "KV_" + bucket
+	out := []string{"$JS.API.STREAM.INFO." + stream}
+	if key == "" {
+		out = append(out,
+			"$JS.API.DIRECT.GET."+stream+".>",
+			"$JS.API.CONSUMER.CREATE."+stream+".>")
+	} else {
+		out = append(out,
+			"$JS.API.DIRECT.GET."+stream+".$KV."+bucket+"."+key,
+			"$JS.API.CONSUMER.CREATE."+stream+".*.$KV."+bucket+"."+key)
+	}
+	return append(out,
+		"$JS.API.CONSUMER.DELETE."+stream+".>",
+		"$JS.FC."+stream+".>")
+}
+
+// NodeKeysGrants is what a node's node-engine is granted of a bucket it writes by node, `<node>.>` and no other key
+// (novox/hq ADR 0429 §1: each key one writer, enforced by credentials): the writes of those keys and what a get,
+// create, update and watch of them need. The node name is checked as every subject token is.
+func NodeKeysGrants(bucket, node string) ([]string, error) {
+	if !safeSubject.MatchString(node) {
+		return nil, fmt.Errorf("%q cannot be part of a subject: a permission is a subject pattern, and this would widen it", node)
+	}
+	return append([]string{"$KV." + bucket + "." + node + ".>"}, readGrants(bucket, node+".>")...), nil
+}
+
+// stateGrants is what a principal publishes to reach the state its modules keep and read: for every
+// bucket, binding to it, reading a key directly, and an ordered consumer for listing and watching,
+// created and deleted on the bucket's own stream, with its flow control answered; for a bucket an
+// owner keeps, writing under the bucket's own subjects too.
+//
+// **Measured against a running server, 2026-10-04** (novox/hq research 024), and each one is there
+// because leaving it out failed: without STREAM.INFO nothing binds; without DIRECT.GET nothing is
+// read; without CONSUMER.CREATE no key is listed and nothing is watched; without CONSUMER.DELETE a
+// watch cannot be stopped and lingers on the server. A write outside these is refused by the server
+// — and reaches the writer as a timeout, not a refusal, which is why the runtime refuses first.
+//
+// **One key, where the state is per machine** (novox/hq ADR 0260). The owner's instance on a machine
+// writes and reads the key named for that machine, and a holder granted a read for its machine reads
+// that key: a direct get of the key's own subject, and a consumer whose filter is that subject — the
+// server's create-with-filter form, which a client uses for a watch of one key and which the server
+// holds to the filter it names. What cannot be narrowed by key: binding (STREAM.INFO), deleting a
+// consumer (named at random by the client) and flow control; none of them reads or writes a value.
+func stateGrants(a stateAccess) []string {
+	var out []string
+	read := func(bucket, key string) { out = append(out, readGrants(bucket, key)...) }
+	machineKey := ""
+	if safeSubject.MatchString(a.Node) {
+		machineKey = a.Node
+	}
+	perMachine := map[string]bool{}
+	for _, n := range a.PerMachine {
+		perMachine[n] = true
+	}
+	for _, name := range a.Keeps {
+		if !safeSubject.MatchString(name) {
+			continue
+		}
+		bucket := BucketName(a.Module, name)
+		if perMachine[name] {
+			if machineKey == "" {
+				continue // a machine with no usable name reaches none of it
+			}
+			read(bucket, machineKey)
+			out = append(out, "$KV."+bucket+"."+machineKey)
+			continue
+		}
+		read(bucket, "")
+		out = append(out, "$KV."+bucket+".>")
+	}
+	// **And it says what it keeps** (novox/hq ADR 0495 clause 2, issue 1790): a module keeping state announces it on its
+	// own event subject, from its code; refused, its readers are read as before.
+	if len(a.Keeps) > 0 && safeSubject.MatchString(a.Module) {
+		out = append(out, announce.Subject(a.Module))
+	}
+	for _, r := range a.Reads {
+		if bucket, ok := bucketOfRead(r); ok {
+			read(bucket, "")
+		}
+	}
+	for _, k := range a.KeyedReads {
+		if bucket, ok := bucketOfRead(k.Read); ok && safeSubject.MatchString(k.Key) {
+			read(bucket, k.Key)
+		}
+	}
+	return out
+}
+
+// KeyedRead is one key of another module's state a principal reads, and no other key of it.
+type KeyedRead struct {
+	Read string `json:"read"`
+	Key  string `json:"key"`
+}
+
+// stateAccess is what one principal may do with state: the module's own buckets (some per machine),
+// what it reads whole, and what it reads for its machine's key alone.
+type stateAccess struct {
+	Module, Node      string
+	Keeps, PerMachine []string
+	Reads             []string
+	KeyedReads        []KeyedRead
+}
+
+// perMachineNames is the local names of a module's buckets keyed by machine.
+func perMachineNames(buckets []Bucket) []string {
+	var out []string
+	for _, b := range buckets {
+		if b.PerMachine {
+			out = append(out, b.Name)
+		}
+	}
+	return out
+}
+
+// stateIssuedFor is every bucket a module's code may reach on a machine, as its membership lists them.
+func stateIssuedFor(d Declared, node string) []StateIssued {
+	var out []StateIssued
+	for _, b := range d.State {
+		issued := StateIssued{Name: b.Name, Bucket: BucketName(d.Module, b.Name), Writes: true}
+		if b.PerMachine {
+			issued.Key = node
+		}
+		out = append(out, issued)
+	}
+	for _, r := range d.Reads {
+		if bucket, ok := bucketOfRead(r); ok {
+			out = append(out, StateIssued{Name: r, Bucket: bucket})
+		}
+	}
+	for _, k := range d.KeyedReads {
+		if bucket, ok := bucketOfRead(k.Read); ok {
+			out = append(out, StateIssued{Name: k.Read, Bucket: bucket, Key: k.Key})
+		}
+	}
+	return out
+}
+
+// stateNames is the local names of a module's own buckets.
+func stateNames(buckets []Bucket) []string {
+	out := make([]string, 0, len(buckets))
+	for _, b := range buckets {
+		out = append(out, b.Name)
+	}
+	return out
+}
+
+// A BucketAsserter is the part of a JetStream connection bucket assertion needs.
+type BucketAsserter interface {
+	// EnsureBucket creates the bucket if absent and brings its options to match if present, never
+	// discarding what it holds.
+	EnsureBucket(b Bucket) error
+	// BucketNames is every key-value bucket on the server.
+	BucketNames() ([]string, error)
+}
+
+// RaiseBuckets asserts every declared bucket and answers the buckets on the server that nothing
+// declares any more.
+//
+// **Those are reported, never removed** (novox/hq ADR 0201, ADR 0030): what a module stored is
+// data, and a manifest edited, a module renamed or a catalogue entry dropped is an ordinary day's
+// work that must not take data with it. Removing one is a person's act.
+func RaiseBuckets(a BucketAsserter, buckets []Bucket) (undeclared []string, err error) {
+	sorted := append([]Bucket(nil), buckets...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].Bucket() < sorted[j].Bucket() })
+	declared := map[string]bool{}
+	for _, b := range sorted {
+		if err := a.EnsureBucket(b); err != nil {
+			return nil, fmt.Errorf("asserting %s's state %q: %w", b.Module, b.Name, err)
+		}
+		declared[b.Bucket()] = true
+	}
+	names, err := a.BucketNames()
+	if err != nil {
+		return nil, fmt.Errorf("listing the bus's state: %w", err)
+	}
+	for _, n := range names {
+		// A seat's cancelled set is the mesh's own (novox/hq ADR 0219), not a module's state; so are
+		// the controller's own buckets (novox/hq to-be 45 §1).
+		if !declared[n] && !IsCancelledSet(n) && !IsControllerBucket(n) {
+			undeclared = append(undeclared, n)
+		}
+	}
+	sort.Strings(undeclared)
+	return undeclared, nil
+}

go/buscompose/streams.go

@@ -0,0 +1,612 @@
+package buscompose
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// The mesh's own streams.
+//
+// **These and no more** (novox/hq ADR 0116 task 1.4, as revised by ADR 0118; the two that keep what a
+// consumer gave up on added for issue 330). An earlier
+// reading had the controller create *every* stream at genesis, from a fixed set. That is only the
+// mesh's own half: a seat's streams are created when the module declaring it is registered, and a
+// module's durable consumers when it is assigned — neither of which has happened at genesis. What
+// is here is the foundation, which exists before any module does.
+//
+// The controller is the only writer of stream definitions (design 25 §3). A module declares
+// nothing about them and cannot reach the JetStream API to make one.
+
+// Retention is how a stream decides what to keep, which is the whole of what distinguishes the
+// mesh's four relationships on the wire (design 29 §4).
+type Retention string
+
+const (
+	// RetentionWorkQueue: a message is removed once a consumer acknowledges it. Exactly one
+	// worker does the work, and a worker that dies has its message redelivered.
+	RetentionWorkQueue Retention = "workqueue"
+	// RetentionLastPerSubject: only the newest message on each subject survives. This is the
+	// state shape — a node that was away gets exactly the current declaration and nothing older.
+	RetentionLastPerSubject Retention = "last_per_subject"
+	// RetentionLimits: kept until it ages or the stream fills. Events, where a subscriber that
+	// was down catches up and nobody is obliged to act.
+	RetentionLimits Retention = "limits"
+)
+
+// A Stream is one of the mesh's own, as the controller asserts it.
+type Stream struct {
+	Name      string
+	Subjects  []string
+	Retention Retention
+	// MaxAge in seconds, zero for unbounded. Per stream — JetStream has no per-subject age,
+	// which is why differing retention between modules would mean a stream each.
+	MaxAge int
+	// MaxMsgsPerSubject caps each subject independently, so one noisy emitter cannot push
+	// another's events out of a shared stream. Verified: with a cap of 3, ten messages on one
+	// subject and one on another leave four in the stream, not three.
+	MaxMsgsPerSubject int
+	// Why is carried into the assertion so an operator reading the server's own state finds the
+	// reason there, rather than only in a repository they may not have.
+	Why string
+	// Direct lets a client read a subject's last message without a consumer, which is how a
+	// runtime reads its own membership with no JetStream API beyond one request (ADR 0160).
+	Direct bool
+	// MaxBytes bounds the stream's size, zero for unbounded. With DiscardNew a full stream refuses
+	// what comes next rather than dropping what it holds: the publisher is told, and says so.
+	MaxBytes   int64
+	DiscardNew bool
+	// DuplicatesSeconds is the window in which a message id published twice is kept once; zero for the
+	// server's default (two minutes).
+	DuplicatesSeconds int
+	// AllowMsgTTL lets a message carry a time to live of its own (`Nats-TTL`), for what must not outlive the
+	// stream it came from (novox/hq ADR 0376 §3, §5).
+	AllowMsgTTL bool
+	// Restricted marks a module's stream restricted by a grant (novox/hq ADR 0363 §4), in the stream's own
+	// metadata, so whoever keeps one of its messages reads it from the bus (ADR 0376 §3).
+	Restricted bool
+	// WorkQueue marks a module stream declared retention: work-queue (novox/hq ADR 0436 §6), in the
+	// stream's own metadata, so a dead letter kept from it is read as drop-only from the bus, by the
+	// declaration and not by the bus's work-queue retention alone — which SEAT_* and other mesh-internal
+	// streams share without being one of ADR 0436's, and whose dead letters are still delivered again
+	// (ADR 0264 §4).
+	WorkQueue bool
+}
+
+// RestrictedMetadata is the key a restricted stream's metadata says it under.
+const RestrictedMetadata = "mesh-restricted"
+
+// WorkQueueMetadata is the key a module stream declared retention: work-queue (novox/hq ADR 0436 §6) says
+// it under: never set by a mesh-internal work-queue stream (a seat's, a check's), only by Stream.WorkQueue.
+const WorkQueueMetadata = "mesh-work-queue"
+
+// What a durable consumer gave up on is kept (novox/hq issue 330, design 25 §3).
+//
+// **The server says it and keeps it; the controller copies it.** A consumer that handed a message over
+// as often as it may stops offering it and publishes `$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES` with
+// the stream and the message's sequence. DeadLetterNoticesStream captures those advisories as the
+// server publishes them, so one said while no controller listens is still there when one starts. The
+// controller's consumer on it fetches the given-up message by its sequence, while the source stream
+// still holds it, and keeps a copy in DeadLettersStream under DeadLetterSubject, with the consumer,
+// the subject, how often it was handed over and when it was given up. It stays there until a person
+// delivers it again or drops it, with why; a condition is open for as long as it does.
+const (
+	DeadLetterNoticesStream = "DEAD_LETTER_NOTICES"
+	DeadLettersStream       = "DEAD_LETTERS"
+	// MaxDeliveriesAdvisories is the subject the server says a given-up message on.
+	MaxDeliveriesAdvisories = "$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.>"
+	deadLetterPrefix        = "mesh.events.dead."
+	againPrefix             = "mesh.again."
+	// DeadLettersBytes bounds the kept copies. Full, the stream refuses the next copy, which is said
+	// as the consumer's condition; it never drops one it holds.
+	DeadLettersBytes = 256 << 20
+)
+
+// DeadLetterSubject is where a message one consumer gave up on is kept: `mesh.events.dead.<stream>.<consumer>`.
+func DeadLetterSubject(stream, consumer string) string {
+	return deadLetterPrefix + stream + "." + consumer
+}
+
+// DeadLetterOf is the stream and consumer a kept message's subject names; false for any other subject.
+func DeadLetterOf(subject string) (stream, consumer string, ok bool) {
+	rest, found := strings.CutPrefix(subject, deadLetterPrefix)
+	if !found {
+		return "", "", false
+	}
+	stream, consumer, ok = strings.Cut(rest, ".")
+	return stream, consumer, ok && stream != "" && consumer != "" && !strings.Contains(consumer, ".")
+}
+
+// AgainSubject is where an event given up on is delivered again to the one consumer that gave it up,
+// and to nobody else: `mesh.again.<consumer>.` and the original subject without its `mesh.`. Every
+// consumer on EVENTS filters its own (AgainFilter), and a module's runtime reads the event's key from
+// the tokens around `.event.`, so the handler sees the same key it saw the first time.
+func AgainSubject(consumer, original string) string {
+	return againPrefix + consumer + "." + strings.TrimPrefix(original, "mesh.")
+}
+
+// AgainFilter is the one consumer's share of the subjects events are delivered again on.
+func AgainFilter(consumer string) string { return againPrefix + consumer + ".>" }
+
+// OriginalOfAgain is the subject an event delivered again was first published on; false for a subject
+// that is not one delivered again.
+func OriginalOfAgain(subject string) (string, bool) {
+	rest, found := strings.CutPrefix(subject, againPrefix)
+	if !found {
+		return "", false
+	}
+	_, original, ok := strings.Cut(rest, ".")
+	if !ok || original == "" {
+		return "", false
+	}
+	return "mesh." + original, true
+}
+
+// MeshStreams is the foundation set, in the order a person reads it.
+//
+// **CONTROL names its subjects rather than taking `mesh.control.>`**, because heartbeats live
+// under that prefix and must not be persisted: a lost heartbeat is the next heartbeat, and a
+// stream of them is a stream of the least valuable messages the mesh sends, competing for the
+// same retention as the ones that matter.
+//
+// **EVENTS filters on the `event` token**, which is the reason that token exists. A module's
+// namespace carries both its events and its tool calls; a filter of `mesh.mod.*.>` would persist
+// every tool invocation in the mesh, and a tool call must never be persisted (design 25 §3 keeps
+// tools on core NATS, where a lost call is a timeout the caller already handles).
+func MeshStreams() []Stream {
+	return []Stream{
+		{
+			Name: "CONTROL",
+			// A build's outcome is no longer here: it is the build-machine seat's own event, so one
+			// publish reaches whoever asked, the controller and the catalogue (novox/hq ADR 0121).
+			Subjects:  []string{"mesh.control.*.report", "mesh.control.enrol"},
+			Retention: RetentionWorkQueue,
+			Why: "the store-window guarantee (ADR 0083): the controller naks with a delay while its " +
+				"store is away and the message is redelivered; nothing is dropped",
+		},
+		{
+			Name:      "NODES",
+			Subjects:  []string{"mesh.node.*.declare"},
+			Retention: RetentionLastPerSubject,
+			Why: "one declaration per node, always the newest; a node that sees sequence n refuses " +
+				"n-1 by construction (issue 107)",
+		},
+		{
+			Name:      AssignmentsStream,
+			Subjects:  []string{"mesh.assignment.*.*"},
+			Retention: RetentionLastPerSubject,
+			Direct:    true,
+			Why: "one membership per assignment, always the newest: what the mesh issued this module " +
+				"on this machine to serve and to reach (ADR 0160); read directly by the runtime it is for",
+		},
+		{
+			Name: EventsStream,
+			// A seat's own events ride here too: they are 1:many like any event, and the
+			// `event` token keeps them clear of both the seat's work queue (`accept`) and its
+			// tools (`tool`), which must not be persisted.
+			// And an event given up on, delivered again to the one consumer that gave it up
+			// (novox/hq issue 330): under `mesh.again.<consumer>.`, which only that consumer filters.
+			Subjects:          []string{"mesh.mod.*.event.>", "mesh.seat.*.event.>", againPrefix + ">"},
+			Retention:         RetentionLimits,
+			MaxAge:            7 * 24 * 60 * 60,
+			MaxMsgsPerSubject: 10000,
+			// A restricted dead letter delivered again keeps what is left of its stream's age (ADR 0376 §5).
+			AllowMsgTTL: true,
+			Why: "a subscriber that was down catches up; tool traffic under the same prefix is " +
+				"excluded by the event token; per-subject caps keep a noisy emitter from " +
+				"evicting a quiet one without splitting the stream",
+		},
+		{
+			Name:      DeadLetterNoticesStream,
+			Subjects:  []string{MaxDeliveriesAdvisories},
+			Retention: RetentionWorkQueue,
+			MaxAge:    7 * 24 * 60 * 60,
+			Why: "the server's word that a consumer gave up on a message, kept until the controller has " +
+				"copied the message into DEAD_LETTERS (novox/hq issue 330); a week, the longest the source " +
+				"streams keep what they are about",
+		},
+		{
+			Name:              DeadLettersStream,
+			Subjects:          []string{deadLetterPrefix + ">"},
+			Retention:         RetentionLimits,
+			MaxBytes:          DeadLettersBytes,
+			DiscardNew:        true,
+			DuplicatesSeconds: 24 * 60 * 60,
+			AllowMsgTTL:       true,
+			Why: "every message a consumer gave up on, with its consumer, subject, deliveries and when, kept " +
+				"until a person delivers it again or drops it with why (novox/hq issue 330); no age but a restricted " +
+				"stream's message, which ages out with its stream (ADR 0376), and full it refuses the next copy " +
+				"rather than drop one it holds",
+		},
+		{
+			Name:      ProvAppliedStream,
+			Subjects:  []string{ProvAppliedSubjects},
+			Retention: RetentionLastPerSubject,
+			Direct:    true,
+			MaxAge:    7 * 24 * 60 * 60,
+			Why: "each machine's provisioner client's newest word on each module's files, applied, waiting or " +
+				"failed with the reason (novox/hq ADR 0349 §4): what a walk's end and a gate wait for (ADR 0362, " +
+				"ADR 0349 §15), read by subject; a week, as the events are",
+		},
+	}
+}
+
+// ProvAppliedStream keeps what each machine's provisioner client last said of each module's files, newest per
+// subject (novox/hq ADR 0349 §4, ADR 0362, design 57 P6): `prov.applied.<node>.<module>` lies outside `mesh.*`, so
+// no other stream captures it, and a report said while no controller listened is still there to be read.
+const ProvAppliedStream = "PROV_APPLIED"
+
+// ProvAppliedSubjects is every machine's client's reports: `prov.applied.<node>.<module>`, a module's name dots and
+// all (ProvisionerAppliedSubject).
+const ProvAppliedSubjects = "prov.applied.>"
+
+// eventsTheControllerFollows are the events the controller's events consumer takes: all it follows but the forge's
+// merges, which the merges consumer takes (MergesConsumerName).
+func eventsTheControllerFollows() []string {
+	var out []string
+	for _, subject := range ControllerFollows {
+		if subject != ControllerFollows[3] {
+			out = append(out, subject)
+		}
+	}
+	return append(out, ControllerHears...)
+}
+
+// DeliverSubjectFor is where a push consumer's messages land.
+//
+// **Per consumer, which means per stream as well as per name** (novox/hq 04-ISSUES/146). A push
+// consumer delivers onto an ordinary subject, and everything subscribed to that subject gets a
+// copy. The controller holds a consumer called `controller` on CONTROL and another called
+// `controller` on EVENTS; while both were given `_DELIVER.controller`, the one process holding
+// both subscriptions acted on every message twice — a joining machine was enrolled twice from one
+// request, and the second enrolment minted a credential that replaced the one the machine had just
+// been handed. Every report and every followed event doubled the same way, silently: nothing is
+// redelivered, no count is wrong, the work simply happens twice.
+//
+// The stream belongs in it because the pair is what identifies a consumer — the server scopes a
+// durable's name to its stream, and this subject was the one place that scoping was dropped. It
+// stays inside what a controller may already subscribe (`_DELIVER.controller.>`).
+func DeliverSubjectFor(c Consumer) string {
+	if c.DeliverSubject != "" {
+		return c.DeliverSubject
+	}
+	return "_DELIVER." + c.Name + "." + c.Stream
+}
+
+// An Asserter is the part of a JetStream connection stream assertion needs. Narrow on purpose: it
+// keeps this testable without a server, and keeps the client library out of everything that only
+// wants to know what the streams are.
+type Asserter interface {
+	// EnsureStream creates the stream if absent and updates it to match if present. It must be
+	// idempotent: the controller asserts on every start, not only at genesis.
+	EnsureStream(s Stream) error
+}
+
+// AssertMeshStreams brings the foundation set into being, in order, and says which one failed
+// rather than that something did.
+//
+// Asserted on every start rather than created once at genesis, because a stream that was deleted,
+// or a mesh raised from a restored backup, must converge rather than run without the guarantee
+// its messages assume. Idempotence is the whole requirement.
+func AssertMeshStreams(a Asserter) error {
+	for _, s := range MeshStreams() {
+		if err := a.EnsureStream(s); err != nil {
+			return fmt.Errorf("asserting stream %s: %w", s.Name, err)
+		}
+	}
+	return nil
+}
+
+// Overlaps reports subject filters claimed by more than one stream.
+//
+// **Corrected against the server**: an earlier version of this comment said NATS accepts
+// overlapping streams and stores the message twice. It does not — it refuses the second stream
+// with "subjects overlap with an existing stream" (verified against nats-server 2.10). The check
+// still earns its place, for a different reason: the server's refusal arrives when the controller
+// is applying, naming one stream, at a moment when the mesh is half-configured. This one arrives
+// where the set is written, names both, and cannot reach a running mesh.
+//
+// It also decides a design question. Because overlap is refused rather than merged, a shared
+// EVENTS stream and a per-module stream cannot coexist — the module's would be refused — so
+// "one stream for most, its own for a module that wants different retention" is not an option
+// the server allows. It is all of one or all of the other.
+func Overlaps() []string {
+	seen := map[string]string{}
+	var clashes []string
+	for _, s := range MeshStreams() {
+		for _, subject := range s.Subjects {
+			if first, ok := seen[subject]; ok {
+				clashes = append(clashes, fmt.Sprintf("%s and %s both claim %s", first, s.Name, subject))
+				continue
+			}
+			seen[subject] = s.Name
+		}
+	}
+	sort.Strings(clashes)
+	return clashes
+}
+
+// The mesh's own consumers.
+//
+// A seat's streams and a module's consumers are derived from declarations (derived.go). These two
+// are not: **the controller is not a module and files no manifest**, so its authority and its
+// subscriptions cannot come from a declaration that does not exist. They are named here, where the
+// mesh's own streams are named, and narrowly — a controller subscribing `mesh.mod.*.event.>` would
+// hear every event in the mesh, which it has no business doing and which would make its permission
+// list stop explaining anything.
+
+// ControllerName is the controller's durable consumer on each stream it reads, and the name its
+// ack subject is derived from (nats.go: `$JS.ACK.<stream>.controller.>`).
+const ControllerName = "controller"
+
+// MergesConsumerName is the controller's durable consumer of the forge's merged event on EVENTS, apart from the
+// events consumer (novox/hq ADR 0407 decision 3, issue 973). A merge is never dropped, so this consumer has no
+// max-deliver, which would send a merge held five times to DEAD_LETTERS to wait for a person, and no healer
+// resets it, which would drop the merges it holds. A consumer of its own because both of those are properties of
+// a consumer, not of a subject.
+const MergesConsumerName = "controller-merges"
+
+// ControllerSeat is the role the control plane holds, and ControllerStates are the facts it states
+// under it (novox/hq ADR 0134).
+//
+// **Written here as well as in `link`, and a test keeps them agreeing.** `link` imports `broker`, so
+// `broker` cannot import `link`; a grant naming a subject the controller never publishes is authority
+// nobody uses, and a controller publishing one the grant omits is refused at the moment it has
+// something to say.
+const ControllerSeat = "mesh-controller"
+
+var ControllerStates = []string{"applied", "refused", "built-before",
+	// What is wrong, said as it changes (novox/hq to-be 45 §2): a condition raised, changed in
+	// severity, resolver or silence, and cleared. The operator-channel's holder and any other surface
+	// consume them; the controller tells nobody itself.
+	"condition-raised", "condition-changed", "condition-cleared",
+	// And the self-check's heartbeat, at the end of every run (to-be 45 §4, S10): watched from a
+	// machine that is not the control node, so the controller going quiet is itself said.
+	"doctor-heartbeat",
+	// And a value given by hand, replaced after its module's first good start (novox/hq ADR 0228).
+	"secret-replaced",
+	// And every act a healer takes on a condition (novox/hq to-be 45 §7, Phase 3): a repair the mesh
+	// made by itself is said like one a person made, never quietly.
+	"healer-acted",
+	// And a build put back after its gate failed on its first machine (novox/hq ADR 0236, to-be 45 §8).
+	"rolled-back",
+	// And a pull request's merge check, judged (novox/hq to-be 45 §9): what the forge's holder sets as
+	// the pull request's status, and anybody else may read.
+	"checked",
+	// (A walk kept in a new state and a tier sent to a machine are gone with the plans, novox/hq ADR 0539.)
+	// And a key of a record mirror written or removed (novox/hq ADR 0289, design 54 §3): the assignments and
+	// each registered module's declared config (design 57 F3).
+	"assignment-changed", "declared-config-changed", "predefined-changed",
+	// And a builder's key not taken in because the artifact store does not hold what it names (novox/hq issue 1937).
+	"artifacts-gone",
+	// And a bucket of the plans' state deleted at the controller's first start, and the declarations' stream once no node
+	// reads one (novox/hq ADR 0539 clauses 11 and 13).
+	"bucket-deleted"}
+
+// BusAdvisories are what the bus server says about the mesh's own account that the controller
+// reads (novox/hq to-be 45 §3, S9): a durable consumer that handed a message over as often as it
+// may and gave up on it, and one that was deleted. Read-only: an advisory is the server's to
+// publish, and the controller's subscription changes nothing on the bus.
+var BusAdvisories = []string{
+	"$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.>",
+	"$JS.EVENT.ADVISORY.CONSUMER.DELETED.>",
+}
+
+// ControllerFollows are the events the controller reacts to: the catalogue saying a module's
+// current version moved, and a catalogue that has just started saying it may have missed builds.
+//
+// **Derived the same way a module's subscription is**, from the emitter and the bare local event
+// name, rather than written out. They were written out while the catalogue still spelled its events
+// as the old bus's routing keys, and the moment those were converted (novox/hq 04-ISSUES/127) a
+// hard-coded pair became a controller listening to a subject nothing publishes — the same fault, from
+// the other side. Deriving them means the conversion could not leave these behind.
+var ControllerFollows = []string{
+	moduleEventSubject("mesh-catalog", "upgraded"),
+	moduleEventSubject("mesh-catalog", "catching-up"),
+	// A build's outcome, which is the build-machine role's own event now (ADR 0121) rather than a
+	// message on the control branch. Same three audiences, one publish: whoever asked, this, and the
+	// catalogue.
+	seatEventSubject("node-build-agent", "built"),
+	// The forge's merges: what moved a source, so the mesh builds what that source produces
+	// without anybody telling it (novox/hq 04-ISSUES/131). Appended, because the index is a name.
+	moduleEventSubject("gitea", "pull.merged"),
+	// The retired build role's outcome too, while the handover runs (novox/hq ADR 0190): the one
+	// build machine keeps answering on its seat until build-agent replaces it, and the outcome that
+	// registers build-agent itself comes from there. Appended, for the same reason as above; goes
+	// with the retired seat row.
+	seatEventSubject("mesh-build-machine", "built"),
+	// **Every provider's standing** (novox/hq ADR 0224): a consumer it has failed for minutes, and
+	// that consumer recovered. The one pattern on this list, and a narrow one — two named events,
+	// from whichever module provides — because the rule is about every provider, and a list of
+	// providers here would be a list somebody forgets to extend. On 2026-10-05 the identity provider
+	// failed every consumer for a day and only its journal said so (issue 179). Appended, because
+	// the index is a name.
+	moduleEventSubject("*", ProvisionerFailing),
+	moduleEventSubject("*", ProvisionerRecovered),
+	// **What becomes of a consumer the mesh stopped asking for** (novox/hq ADR 0230): retired, waiting
+	// for a person, re-enabled, deleted — a provider's third word, from whichever module provides.
+	// Appended, because the index is a name.
+	moduleEventSubject("*", ProvisionerRetirement),
+	// **A pull request's head, announced** (novox/hq to-be 45 §9): what the controller asks the build
+	// seat to check before it merges — every machine of the facts snapshot composed with the change.
+	// Appended, because the index is a name.
+	moduleEventSubject("gitea", "pull.updated"),
+	// **The operator's answers to what the controller asked** (novox/hq ADR 0259): the router's warrant, or
+	// the end of an ask without one, said to the controller alone under its own name. On the stream, so a
+	// controller that was away hears what was decided meanwhile. Appended, because the index is a name.
+	DecidedSubject,
+}
+
+// ControllerHears are events the controller's events consumer takes beside the ones it follows, and that need no
+// subscribe grant of their own. **A push consumer delivers onto its deliver subject** (`_DELIVER.controller.>`, already
+// granted), so the subject a consumer filters on is never one the controller subscribes: listing this one in
+// ControllerFollows would add a subscribe grant the installer's carried user list, which lives in mesh-host, would
+// have to carry too (TestTheInstallersFirstUserListIsWhatTheControllerWouldCompose), for nothing the consumer uses.
+//
+// A merge mesh-delivery made, announced (novox/hq ADR 0420 §7, issue 1025): with the ask whose Approve it merged on and
+// the heads that Approve covered, kept a week to read the warrant a moved module's registration needs.
+var ControllerHears = []string{DeliveryMergedSubject}
+
+// DeliveryMergedEvent is the event a module says when it merged a pull request.
+const DeliveryMergedEvent = "merged"
+
+// DeliveryMergedSubject is where the delivery's owner says it merged a pull request: one wildcard subject, the
+// module that claims the delivery seat being whichever the catalogue says (novox/hq ADR 0437 §3). Who said it is
+// read from the subject, and whether it claims the seat is the controller's to check.
+var DeliveryMergedSubject = moduleEventSubject("*", DeliveryMergedEvent)
+
+// DeliveryMergedSubjectOf is where one module says it merged a pull request.
+func DeliveryMergedSubjectOf(module string) string {
+	return moduleEventSubject(module, DeliveryMergedEvent)
+}
+
+// AsksSeat is the seat an ask is made on and its warrant heard from (novox/hq ADR 0259): the router's.
+const AsksSeat = "operator-channel"
+
+// DecidedSubject is where the router says the controller's warrants: the seat's event named by the
+// controller as its caller.
+var DecidedSubject = seatEventSubject(AsksSeat, "decided."+ControllerSeat)
+
+// The provider standing events, by their local names. Written here as well as in the catalogue
+// (catalogue.ProvisionerEvents), which this package cannot import; a test keeps them agreeing.
+const (
+	ProvisionerFailing    = "provisioner.failing"
+	ProvisionerRecovered  = "provisioner.recovered"
+	ProvisionerRetirement = "provisioner.retirement"
+)
+
+// moduleEventSubject is where one module's event lands. The same derivation PermissionsFor uses, so
+// what the controller subscribes and what the emitter is permitted to publish cannot drift apart.
+func moduleEventSubject(module, event string) string {
+	return "mesh.mod." + module + ".event." + event
+}
+
+// seatEventSubject is where a role's own event lands, derived the same way a holder's permission is.
+func seatEventSubject(seat, verb string) string {
+	return "mesh.seat." + seat + ".event." + verb
+}
+
+// EventsStream holds every module's and every role's events, a build's log among them.
+const EventsStream = "EVENTS"
+
+// MeshConsumers is what the controller consumes, in the order a person reads it.
+//
+// **Unlimited redelivery on CONTROL, deliberately.** The store window's bound is the controller's,
+// not the server's (window.go): a message is held with a nak-and-delay until the controller either
+// takes it or gives up and says so. A max-deliver here would give up on a push that was being
+// held through a store restart — the exact message the stream exists to protect — some minutes
+// before the controller had finished deciding about it.
+func MeshConsumers() []Consumer {
+	return ControllerConsumers()
+}
+
+// ControllerConsumers are the consumers the controller's own event loop takes from: MeshConsumers without the build
+// seat's check workers, which the builders take from and the loop never does (issue 1063). A consumer added to the
+// controller is counted here without a change elsewhere.
+func ControllerConsumers() []Consumer {
+	return []Consumer{
+		{
+			Name:           ControllerName,
+			Stream:         "CONTROL",
+			Push:           true,
+			AckWaitSeconds: 30,
+			Why: "the controller is the single consumer of what nodes say; explicit ack and no " +
+				"max-deliver, because the store window's bound is the controller's own",
+		},
+		// The forge's merges (novox/hq ADR 0407 decision 3, issue 973): never dropped, so no max-deliver and no
+		// reset; a merge the controller cannot record yet is held with a growing delay until it can. **Asserted before
+		// the events consumer**, which stops filtering merges: the order of this list is the order of assertion.
+		{
+			Name:   MergesConsumerName,
+			Stream: "EVENTS",
+			// Within what the controller may subscribe already (`_DELIVER.controller.>`).
+			DeliverSubject: "_DELIVER." + ControllerName + ".merges",
+			Filters:        []string{ControllerFollows[3]},
+			Push:           true,
+			AckWaitSeconds: 30,
+			MaxAckPending:  1,
+			FromNow:        true,
+			TakesOverFrom:  ControllerName,
+			Why: "the forge's merges, one at a time; no max-deliver and never reset, because a merge is never " +
+				"dropped and no person releases one",
+		},
+		{
+			Name:           ControllerName,
+			Stream:         "EVENTS",
+			Filters:        append(eventsTheControllerFollows(), AgainFilter(ControllerName)),
+			Push:           true,
+			AckWaitSeconds: 30,
+			MaxDeliver:     5,
+			// One at a time (novox/hq issue 175): acting on a merge builds for minutes, and an
+			// announcement handed over behind it must wait on the server, not time out on the
+			// client and come back to be acted on again.
+			MaxAckPending: 1,
+			FromNow:       true,
+			// **The one consumer the mesh resets by itself** (healer H4, issue 248): it fell a week
+			// behind once and held every merge after it. What a reset drops is caught up elsewhere — a
+			// build's outcome from the build records a plan settles from (issue 214), a provider's failing
+			// word by the provider saying it again every quarter of an hour (ADR 0224). **Not the merges**:
+			// they are the merges consumer's below, which a reset leaves alone (ADR 0407 decision 3).
+			Resettable: "what it drops is caught up: build outcomes from the build records (issue 214), a " +
+				"provider's failing word said again (ADR 0224); the forge's merges are not its, they have a " +
+				"consumer of their own that no reset touches",
+			Why: "the events the mesh's own controller reacts to, one at a time; after " +
+				"max-deliver it gives the event up, and the controller keeps it in DEAD_LETTERS until " +
+				"a person delivers it again or drops it",
+		},
+		// What the server said a consumer gave up on (novox/hq issue 330): copied into DEAD_LETTERS and
+		// acknowledged. No max-deliver: a notice the controller could not copy is offered again, and said.
+		{
+			Name:           ControllerName,
+			Stream:         DeadLetterNoticesStream,
+			Push:           true,
+			AckWaitSeconds: 30,
+			Why: "the controller copies each message a consumer gave up on into DEAD_LETTERS; no max-deliver, " +
+				"because a notice it gave up on would lose the message it is about",
+		},
+	}
+}
+
+// NoticesConsumer is the controller's consumer on DEAD_LETTER_NOTICES (novox/hq issue 330).
+func NoticesConsumer() Consumer {
+	for _, c := range MeshConsumers() {
+		if c.Stream == DeadLetterNoticesStream {
+			return c
+		}
+	}
+	panic("the mesh's consumers carry none on " + DeadLetterNoticesStream)
+}
+
+// AssertServingConsumers are the controller's own consumers its serving cannot go without: all but the
+// one on DEAD_LETTER_NOTICES, which the keeper of dead letters asserts and retries by itself, so a fault
+// there never stops the controller serving (novox/hq issue 330).
+func AssertServingConsumers(e Ensurer) error {
+	for _, c := range MeshConsumers() {
+		if c.Stream == DeadLetterNoticesStream {
+			continue
+		}
+		if err := e.EnsureConsumer(c); err != nil {
+			return fmt.Errorf("asserting consumer %s on %s: %w", c.Name, c.Stream, err)
+		}
+	}
+	return nil
+}
+
+// Ensurer is the part of a JetStream connection consumer assertion needs, narrow for the reason
+// Asserter is.
+type Ensurer interface {
+	EnsureConsumer(c Consumer) error
+}
+
+// AssertMeshConsumers brings the controller's own consumers into being, and says which one failed.
+//
+// After the streams, necessarily: a consumer on a stream that does not exist is refused, and the
+// refusal names the stream rather than the order.
+func AssertMeshConsumers(e Ensurer) error {
+	for _, c := range MeshConsumers() {
+		if err := e.EnsureConsumer(c); err != nil {
+			return fmt.Errorf("asserting consumer %s on %s: %w", c.Name, c.Stream, err)
+		}
+	}
+	return nil
+}

go/buscompose/testdata/composed.conf

@@ -0,0 +1,78 @@
+# Composed by the mesh controller. Do not edit: the next composition overwrites it.
+# Accounts and permissions are derived from what each module declares and nothing
+# else (novox/hq ADR 0043, design 29 §2).
+
+port: 4222
+http: 127.0.0.1:8222
+
+tls {
+  cert_file: "/tls/tls.crt"
+  key_file: "/tls/tls.key"
+  ca_file: "/tls/ca.crt"
+}
+
+jetstream {
+  store_dir: "/data"
+}
+
+# The mesh's users, composed by the controller. Do not edit: the next
+# composition overwrites it. Permissions are derived from what each module
+# declares and nothing else (novox/hq ADR 0043, design 29 §2).
+
+accounts {
+  MESH {
+    jetstream: enabled
+    imports = [
+      { stream: { account: "$SYS", subject: "$SYS.ACCOUNT.MESH.CONNECT" }, to: "mesh.bus.connect" }
+      { stream: { account: "$SYS", subject: "$SYS.ACCOUNT.MESH.DISCONNECT" }, to: "mesh.bus.disconnect" }
+      { service: { account: "$SYS", subject: "$SYS.REQ.ACCOUNT.MESH.CONNZ" }, to: "mesh.bus.connz" }
+    ]
+    users = [
+      { user: "controller", password: "$2a$11$cccccccccccccccccccccc", permissions: {
+        publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.DEAD_LETTER_NOTICES.controller.>", "$JS.ACK.EVENTS.controller-merges.>", "$JS.ACK.EVENTS.controller.>", "$JS.ACK.KV_mesh-delivery-builder_builds.mesh-controller-take-in.>", "$JS.ACK.KV_mesh-delivery-indexer_modules.mesh-controller-take-in.>", "$JS.API.>", "$KV.mesh-controller_asked.>", "$KV.mesh-controller_assignments.>", "$KV.mesh-controller_builds.>", "$KV.mesh-controller_calls.>", "$KV.mesh-controller_composed.>", "$KV.mesh-controller_condition-history.>", "$KV.mesh-controller_conditions.>", "$KV.mesh-controller_declared-config.>", "$KV.mesh-controller_declared-packages.>", "$KV.mesh-controller_delivery-merges.>", "$KV.mesh-controller_grants.>", "$KV.mesh-controller_hand-acts.>", "$KV.mesh-controller_lease.>", "$KV.mesh-controller_predefined.>", "$KV.mesh-controller_rollouts.>", "$KV.mesh-controller_states-announced.>", "$SRV.INFO", "_INBOX.enrol.>", "mesh.again.>", "mesh.assignment.>", "mesh.events.dead.>", "mesh.mod.*.tool.>", "mesh.mod.mesh-controller.event.states", "mesh.node.>", "mesh.seat.mesh-controller.event.applied", "mesh.seat.mesh-controller.event.artifacts-gone", "mesh.seat.mesh-controller.event.assignment-changed", "mesh.seat.mesh-controller.event.bucket-deleted", "mesh.seat.mesh-controller.event.built-before", "mesh.seat.mesh-controller.event.checked", "mesh.seat.mesh-controller.event.condition-changed", "mesh.seat.mesh-controller.event.condition-cleared", "mesh.seat.mesh-controller.event.condition-raised", "mesh.seat.mesh-controller.event.declared-config-changed", "mesh.seat.mesh-controller.event.doctor-heartbeat", "mesh.seat.mesh-controller.event.healer-acted", "mesh.seat.mesh-controller.event.predefined-changed", "mesh.seat.mesh-controller.event.refused", "mesh.seat.mesh-controller.event.rolled-back", "mesh.seat.mesh-controller.event.secret-replaced", "mesh.seat.mesh-controller.tool.plans", "mesh.seat.mesh-controller.tool.push", "mesh.seat.mesh-controller.tool.upgrade", "mesh.seat.mesh-delivery.tool.close", "mesh.seat.mesh-delivery.tool.groups", "mesh.seat.mesh-delivery.tool.release", "mesh.seat.mesh-delivery.tool.stalled", "mesh.seat.mesh-delivery.tool.stop", "mesh.seat.mesh-delivery.tool.times", "mesh.seat.node-backup.tool.backed-up.*", "mesh.seat.node-backup.tool.now.*", "mesh.seat.node-intrusion-prevention.tool.banned.*", "mesh.seat.node-launcher.tool.secret.*", "mesh.seat.node-service-manager.tool.restart.*", "mesh.seat.operator-channel.tool.tell"] }
+        subscribe: { allow: ["$JS.API.>", "$JS.EVENT.ADVISORY.CONSUMER.DELETED.>", "$JS.EVENT.ADVISORY.CONSUMER.MAX_DELIVERIES.>", "$SRV.INFO", "$SRV.INFO.mesh-controller", "$SRV.INFO.mesh-controller.>", "$SRV.PING", "$SRV.PING.mesh-controller", "$SRV.PING.mesh-controller.>", "$SRV.STATS", "$SRV.STATS.mesh-controller", "$SRV.STATS.mesh-controller.>", "_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.mesh-controller.tool.>", "mesh.seat.node-build-agent.event.built", "mesh.seat.operator-channel.event.decided.mesh-controller"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+      { user: "enrol.one", password: "$2a$11$eeeeeeeeeeeeeeeeeeeeee", permissions: {
+        publish: { allow: ["mesh.control.enrol"] }
+        subscribe: { allow: ["_INBOX.enrol.one.>"] }
+      } }
+      { user: "node.one", password: "$2a$11$nnnnnnnnnnnnnnnnnnnnnn", permissions: {
+        publish: { allow: ["$JS.ACK.NODES.one.>", "$JS.API.CONSUMER.CREATE.KV_composed-one.>", "$JS.API.CONSUMER.CREATE.KV_mesh-delivery-assigner_wants.*.$KV.mesh-delivery-assigner_wants.want.one.>", "$JS.API.CONSUMER.CREATE.KV_node-engine_have.*.$KV.node-engine_have.one.>", "$JS.API.CONSUMER.CREATE.OBJ_declaration-files-one.*.$O.declaration-files-one.C.*", "$JS.API.CONSUMER.DELETE.KV_composed-one.>", "$JS.API.CONSUMER.DELETE.KV_mesh-delivery-assigner_wants.>", "$JS.API.CONSUMER.DELETE.KV_node-engine_have.>", "$JS.API.CONSUMER.DELETE.OBJ_declaration-files-one.*", "$JS.API.CONSUMER.INFO.NODES.one", "$JS.API.DIRECT.GET.KV_composed-one.>", "$JS.API.DIRECT.GET.KV_mesh-delivery-assigner_wants.$KV.mesh-delivery-assigner_wants.want.one.>", "$JS.API.DIRECT.GET.KV_node-engine_have.$KV.node-engine_have.one.>", "$JS.API.DIRECT.GET.OBJ_declaration-files-one.$O.declaration-files-one.M.*", "$JS.API.STREAM.INFO.KV_composed-one", "$JS.API.STREAM.INFO.KV_mesh-delivery-assigner_wants", "$JS.API.STREAM.INFO.KV_node-engine_have", "$JS.FC.KV_composed-one.>", "$JS.FC.KV_mesh-delivery-assigner_wants.>", "$JS.FC.KV_node-engine_have.>", "$JS.FC.OBJ_declaration-files-one.>", "$KV.node-engine_have.one.>", "$SRV.PING.node-tools.one", "mesh.control.one.>", "mesh.seat.node-backup.call.backed-up.one.node~one", "mesh.seat.node-backup.call.now.one.node~one", "mesh.seat.node-backup.tool.backed-up.one", "mesh.seat.node-backup.tool.now.one"] }
+        subscribe: { allow: ["_DELIVER.one", "_DELIVER.one.>", "_INBOX.node.one.>", "mesh.mod.restic.event.backed-up", "mesh.node.one.ask.access-act", "mesh.node.one.ask.hand-over", "mesh.node.one.ask.judge-directories", "mesh.node.one.ask.move-secret", "mesh.node.one.ask.report", "mesh.node.one.ask.setuid-search", "mesh.node.one.declare"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+      { user: "one.mesh-delivery-watchman", password: "$2a$11$wwwwwwwwwwwwwwwwwwwwww", permissions: {
+        publish: { allow: ["$JS.ACK.EVENTS.one_mesh-delivery-watchman.>", "$JS.API.CONSUMER.INFO.EVENTS.one_mesh-delivery-watchman", "$JS.API.CONSUMER.MSG.NEXT.EVENTS.one_mesh-delivery-watchman", "$JS.API.DIRECT.GET.ASSIGNMENTS.mesh.assignment.one.mesh-delivery-watchman", "mesh.bus.connz"] }
+        subscribe: { allow: ["$SRV.INFO", "$SRV.INFO.mesh-delivery-watchman", "$SRV.INFO.mesh-delivery-watchman.>", "$SRV.PING", "$SRV.PING.mesh-delivery-watchman", "$SRV.PING.mesh-delivery-watchman.>", "$SRV.STATS", "$SRV.STATS.mesh-delivery-watchman", "$SRV.STATS.mesh-delivery-watchman.>", "_INBOX.one.mesh-delivery-watchman.>", "mesh.assignment.one.mesh-delivery-watchman", "mesh.bus.connect", "mesh.bus.disconnect", "mesh.mod.mesh-delivery-watchman.call.>", "mesh.mod.mesh-delivery-watchman.tool.>"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+      { user: "one.nats", password: "$2a$11$bbbbbbbbbbbbbbbbbbbbbb", permissions: {
+        publish: { allow: ["$JS.API.STREAM.INFO.*", "$JS.API.STREAM.NAMES", "$JS.API.STREAM.SNAPSHOT.*", "$JS.SNAPSHOT.ACK.>"] }
+        subscribe: { allow: ["_INBOX.one.nats.>"] }
+      } }
+      { user: "one.telegram", password: "$2a$11$tttttttttttttttttttttt", permissions: {
+        publish: { allow: ["$JS.ACK.EVENTS.one_telegram.>", "$JS.ACK.SEAT_TELEGRAM_SENDER.SEAT_TELEGRAM_SENDER_worker.>", "$JS.API.CONSUMER.INFO.EVENTS.one_telegram", "$JS.API.CONSUMER.INFO.SEAT_TELEGRAM_SENDER.SEAT_TELEGRAM_SENDER_worker", "$JS.API.CONSUMER.MSG.NEXT.EVENTS.one_telegram", "$JS.API.CONSUMER.MSG.NEXT.SEAT_TELEGRAM_SENDER.SEAT_TELEGRAM_SENDER_worker", "$JS.API.DIRECT.GET.ASSIGNMENTS.mesh.assignment.one.telegram", "mesh.seat.telegram-sender.event.delivered", "mesh.seat.telegram-sender.event.failed"] }
+        subscribe: { allow: ["$SRV.INFO", "$SRV.INFO.telegram", "$SRV.INFO.telegram.>", "$SRV.PING", "$SRV.PING.telegram", "$SRV.PING.telegram.>", "$SRV.STATS", "$SRV.STATS.telegram", "$SRV.STATS.telegram.>", "_INBOX.one.telegram.>", "mesh.assignment.one.telegram", "mesh.mod.telegram.call.>", "mesh.mod.telegram.tool.>", "mesh.seat.telegram-sender.accept.send"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+      { user: "two.audit", password: "$2a$11$aaaaaaaaaaaaaaaaaaaaaa", permissions: {
+        publish: { allow: ["$JS.ACK.EVENTS.two_audit.>", "$JS.API.CONSUMER.INFO.EVENTS.two_audit", "$JS.API.CONSUMER.MSG.NEXT.EVENTS.two_audit", "$JS.API.DIRECT.GET.ASSIGNMENTS.mesh.assignment.two.audit"] }
+        subscribe: { allow: ["$SRV.INFO", "$SRV.INFO.audit", "$SRV.INFO.audit.>", "$SRV.PING", "$SRV.PING.audit", "$SRV.PING.audit.>", "$SRV.STATS", "$SRV.STATS.audit", "$SRV.STATS.audit.>", "_INBOX.two.audit.>", "mesh.assignment.two.audit", "mesh.mod.audit.call.>", "mesh.mod.audit.tool.>", "mesh.mod.shop.event.order.placed"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+      { user: "two.shop", password: "$2a$11$ssssssssssssssssssssss", permissions: {
+        publish: { allow: ["$JS.ACK.EVENTS.two_shop.>", "$JS.API.CONSUMER.INFO.EVENTS.two_shop", "$JS.API.CONSUMER.MSG.NEXT.EVENTS.two_shop", "$JS.API.DIRECT.GET.ASSIGNMENTS.mesh.assignment.two.shop", "mesh.mod.shop.event.order.placed", "mesh.seat.telegram-sender.accept.send"] }
+        subscribe: { allow: ["$SRV.INFO", "$SRV.INFO.shop", "$SRV.INFO.shop.>", "$SRV.PING", "$SRV.PING.shop", "$SRV.PING.shop.>", "$SRV.STATS", "$SRV.STATS.shop", "$SRV.STATS.shop.>", "_INBOX.two.shop.>", "mesh.assignment.two.shop", "mesh.mod.shop.call.>", "mesh.mod.shop.tool.>"] }
+        allow_responses: { max: 1, ttl: "1m" }
+      } }
+    ]
+  }
+  "$SYS" {
+    exports = [
+      { stream: "$SYS.ACCOUNT.MESH.CONNECT", accounts: ["MESH"] }
+      { stream: "$SYS.ACCOUNT.MESH.DISCONNECT", accounts: ["MESH"] }
+      { service: "$SYS.REQ.ACCOUNT.MESH.CONNZ", accounts: ["MESH"] }
+    ]
+  }
+}

go/buscompose/users.go

@@ -0,0 +1,451 @@
+package buscompose
+
+import (
+	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/announce"
+	"slices"
+	"sort"
+)
+
+// Every user the composed file should contain, derived from what the mesh knows.
+//
+// **The list is derived, never kept.** A stored user list would be a second account of who may
+// reach the bus, able to disagree with the records it came from — and the disagreement would be
+// invisible, because both would look internally consistent. So this is a pure function of the
+// mesh's records, run again every time the file is written.
+//
+// Records are mirrored into this package's own types rather than imported from the catalogue, for
+// the reason DeclaredSeat is: composing authority is a different job from parsing a manifest, and
+// this package stays free of the other's types so a change to a manifest field cannot quietly widen
+// a permission.
+
+// Declared is one module on one node, as composing its authority needs it.
+type Declared struct {
+	Module   string
+	Emits    []string
+	Consumes []string
+	Serves   []string
+	// Holds are the seats this module claims, with the protocol each seat declares. A seat the
+	// mesh defines for itself declares no protocol, so holding one grants nothing on the bus —
+	// which is right: those seats are about who does a job, not about who may say what.
+	Holds []Seat
+	// Uses are the seats this module sends to.
+	Uses []Seat
+	// Issued are the tools that answer a credential its software issued, one per offer that says so (novox/hq
+	// ADR 0305): the controller is granted to ask each in its own name, and no other tool so.
+	Issued []string
+	// Watches are the seats whose events it consumes.
+	Watches []Seat
+	// Invokes are the tools it calls, `<module>.<tool>` or `*` (novox/hq ADR 0152).
+	Invokes []string
+	// Waits are the event families a session may wait on through the tool runner, the tool runner's module's
+	// alone (novox/hq ADR 0367 §2): its account subscribes them for a call, through no consumer.
+	Waits []Wait
+	// State is the state it keeps, each a bucket its instances write (novox/hq ADR 0201).
+	State []Bucket
+	// Logs are the logs it keeps, each a stream its instances append to (novox/hq ADR 0297).
+	Logs []Log
+	// Streams are the streams it owns, each its events' one place (novox/hq ADR 0363).
+	Streams []ModuleStream
+	// Queues are its own work-queue streams and the one process each is the consumer of (novox/hq ADR 0436
+	// §1, §2, §6): one durable consumer per entry, named `<node>_<module>_<process id>`.
+	Queues []QueueOwner
+	// Hears are the module streams it hears on this machine, each with the subjects it was granted
+	// (novox/hq ADR 0363 §5); HearsAStream says its `consumes` names a module that owns a stream, granted
+	// or not, so its membership is issued again when a grant changes.
+	Hears        []Heard
+	HearsAStream bool
+	// Reads are other modules' state it reads, each `<module>.<name>` (novox/hq ADR 0201).
+	Reads []string
+	// ReadsRefused are the reads its manifest names that the owner's announcement does not make readable (novox/hq ADR
+	// 0495 clause 3, issue 1790): granted nothing, kept to be said.
+	ReadsRefused []string
+	// KeyedReads are keys of other modules' state it reads, each one key alone: what a seat's holder is
+	// granted for the pieces the modules beside it offer (novox/hq ADR 0260).
+	KeyedReads []KeyedRead
+	// NoAccount says the module declares no own secret named broker, so no account could ever be
+	// delivered to it and nothing can connect as it (novox/hq issue 195). Said in the negative so a
+	// record that does not say is composed as it always was.
+	NoAccount bool
+	// SnapshotsTheBus says the module holds mesh-broker — it is the bus — and so is the one module
+	// granted the snapshot API, to copy the bus's streams for the night's backup (novox/hq ADR 0235).
+	SnapshotsTheBus bool
+	// Checks are the module's own tools its health asks, each `<module>.<tool>` (novox/hq ADR 0240, to-be
+	// 48 §3): the machine's node-engine asks them of its own node tools, and is granted that and no more.
+	Checks []string
+	// Loads says the module has a compiled bundle whose entrypoints the machine's tool runtime loads and runs
+	// (novox/hq ADR 0175; issue 1329): a helper that reaches the bus on the runner's account, so the runner
+	// must carry the module although it declares no tools.
+	Loads bool
+	// RunsAs is the account the module runs as in a runtime of its own (novox/hq ADR 0259 §8): it is never
+	// carried by the machine's runtime, and reaches the bus on its own account.
+	RunsAs string
+	// ProvisionsNode says the module runs the machine's provisioner client: it claims NodeProvisionerSeat and
+	// declares the own secret ProvisionerSecret its account is delivered in (novox/hq ADR 0349 clause 11, design 57
+	// P3). The client is given a bus account of its own, never the module's or the tool runner's.
+	ProvisionsNode bool
+	// Processes are this module's own processes that declare bus (novox/hq ADR 0436 §1), each getting a
+	// principal of its own: granted exactly what its bus says, and nothing of this module's other grants —
+	// composed whether or not the module itself has an account (NoAccount), because a process account is
+	// delivered in its own secret, broker-<process id>, never the module's `broker`.
+	Processes []ProcessPrincipal
+}
+
+// ProcessPrincipal is one process of a module that declares bus (novox/hq ADR 0436 §1, §2), as the broker
+// composes its own account from: its own emits, its own work-queue consumers, its own state, whether it
+// reads the router's records of its module's own asks, and the tools and seat verbs it calls.
+type ProcessPrincipal struct {
+	// Process is the process resource's id, naming the account <node>.<module>.<process id>.
+	Process string
+	// Emits are the events this process may publish, named as the module's own Emits are.
+	Emits []string
+	// Queues are the module's own work-queue streams this process is the one consumer of.
+	Queues []QueueOwner
+	// State is the module's own state, by local name, this process reads and writes.
+	State []string
+	// Asks says whether this process reads the records of its module's own asks (novox/hq ADR 0259 §3), on
+	// whichever seats the module uses that keep them (the router's, operator-channel, among others).
+	Asks bool
+	// Invokes are the tools and seat verbs this process calls, each <module>.<tool> or a role's
+	// seat:<seat>.<verb>, or * for every tool on the mesh.
+	Invokes []string
+}
+
+// Records is what composing a user list needs to know about the mesh, and nothing more.
+type Records struct {
+	// Nodes is every machine the mesh knows. Each gets a host user.
+	Nodes []string
+	// Assigned is the modules on each node, as they declare themselves.
+	Assigned map[string][]Declared
+	// Enrolling is every node with a live token — one enrolment user each, because the inbox an
+	// answer goes to is scoped to the token and a shared one is one machine reading another's
+	// sealed credentials (design 25 §6).
+	Enrolling []string
+	// People is each person's name against the tools they may invoke, `*` for an administrator.
+	People map[string][]string
+	// Interchangeable is each module whose definition says its instances are the same anywhere
+	// (ADR 0160), which decides whether the module's plain subject is issued to every instance.
+	Interchangeable map[string]bool
+	// RootFree is each machine judged root-free when this was composed (novox/hq ADR 0259 §8): it names an
+	// account agents run as, judged unable to become root by its node-engine, and serves no login shell
+	// execute. A machine absent is not free: no record of a pass is no pass.
+	RootFree map[string]bool
+	// Announced is each module's last announcement of the states it keeps (novox/hq ADR 0495, issue 1790), as the
+	// controller keeps it; a module absent has announced nothing yet. Nil where none was read.
+	Announced map[string]announce.States
+}
+
+// Users is every user the composed file should contain, in the order it will be written.
+//
+// The controller is always first and always present: a mesh whose own controller is not in the file
+// is a mesh that cannot be told anything, and there is no state of the records in which that is
+// correct.
+func Users(r Records) ([]Principal, error) {
+	out := []Principal{{Kind: KindController, Uses: asksSeatOf(r), AsksIssued: issuedOf(r), AsksTheVault: vaultVerbsOf(r),
+		AsksTheConfig: servedOf(r, VerbsTheControllerAsksTheConfig), FilesFor: sortedCopy(r.Nodes)}}
+
+	for _, node := range sortedCopy(r.Nodes) {
+		witness := false
+		var checks []string
+		for _, d := range r.Assigned[node] {
+			if d.Module == controllerModule {
+				witness = true
+			}
+			checks = append(checks, d.Checks...)
+		}
+		out = append(out, Principal{Kind: KindNode, Node: node, WitnessesController: witness, Checks: checks,
+			MovesIntoTheVault: servesMoveIn(r), StatesItsKeyToTheVault: servesVerb(r, VaultNodeKey)})
+		// **And the machine's provisioner client, on an account of its own** (novox/hq ADR 0349 clause 11): one
+		// per machine that runs it, delivered to the module running it.
+		for _, d := range r.Assigned[node] {
+			if d.ProvisionsNode {
+				out = append(out, Principal{Kind: KindProvisioner, Node: node, Module: d.Module,
+					BoundBuckets: boundBucketsOf(r)})
+				break
+			}
+		}
+		// **Where the runtime is assigned, the machine gets one runtime principal in place of the
+		// runtime module's own** (novox/hq ADR 0175, to-be 38). It carries every module on the
+		// node: its serving grants are the union of theirs. Every other module keeps its own
+		// principal — a module still serving tools from its own container holds its own
+		// credential until it moves, and the two serve side by side in the meantime.
+		runtimeHere := false
+		for _, d := range r.Assigned[node] {
+			if d.Module == RuntimeModule {
+				runtimeHere = true
+			}
+		}
+		for _, d := range r.Assigned[node] {
+			// **A process account is its own, delivered in its own secret** (broker-<process id>, novox/hq
+			// ADR 0436 §1, §2), never the module's `broker` — so it is composed whether or not the module
+			// itself has an account, and is never carried by the machine's runtime, which runs as the
+			// operator's account (ADR 0436 §5): added here, before either of those is judged.
+			for _, pr := range d.Processes {
+				out = append(out, Principal{
+					Kind: KindProcess, Node: node, Module: d.Module, Process: pr.Process,
+					Emits: pr.Emits, Queues: pr.Queues, State: pr.State, Uses: d.Uses, Asks: pr.Asks,
+					Invokes: pr.Invokes,
+				})
+			}
+			if runtimeHere && d.Module == RuntimeModule {
+				continue
+			}
+			// **A module with nowhere to read an account is no user** (novox/hq issue 195). `module
+			// issue` refuses it one (issue 078: an account nothing reads is an orphan), so its user
+			// could only ever be left out of the file for want of a password — and every such module
+			// was named, on every status and plan, as a credential the mesh had not minted. Where the
+			// runtime is, it speaks for the module; where it is not, the module cannot speak at all,
+			// and a user would not change that.
+			if d.NoAccount {
+				continue
+			}
+			out = append(out, Principal{
+				Kind: KindModule, Node: node, Module: d.Module,
+				Emits: d.Emits, Consumes: d.Consumes, Serves: d.Serves,
+				Holds: d.Holds, Uses: d.Uses, Watches: d.Watches, Invokes: d.Invokes,
+				State: stateNames(d.State), Reads: d.Reads, SnapshotsTheBus: d.SnapshotsTheBus,
+				PerMachine: perMachineNames(d.State), KeyedReads: d.KeyedReads,
+				Logs: logNames(d.Logs), Streams: d.Streams, Hears: ComposedHears(d), Queues: d.Queues,
+			})
+			// **The grants part creates what a manifest declares** (novox/hq ADR 0547 §5; the operator, 2026-10-26
+			// 08:54): every placed module's buckets, logs and streams, each by its stream's name.
+			if d.Module == GrantsModule {
+				out[len(out)-1].CreatesStreams = declaredStreamsOf(r)
+			}
+			// **The vault's holder asks the desks and the issuing providers itself** (issue 723), under the
+			// account its own runtime runs on (ADR 0259 §8's runs-as): the one module granted it.
+			if holdsSeat(d, VaultSeat) {
+				out[len(out)-1].AsksTheDesk = true
+				out[len(out)-1].AsksIssued = issuedOf(r)
+			}
+		}
+		if runtimeHere {
+			var carried []Declared
+			for _, d := range r.Assigned[node] {
+				if d.RunsAs == "" && runnerServes(d) {
+					// Never a restricted stream for what the tool runner carries (novox/hq ADR 0376 §1).
+					d.Hears = ComposedHears(d)
+					carried = append(carried, d)
+				}
+			}
+			out = append(out, Principal{Kind: KindNodeTools, Node: node, Module: RuntimeModule, Carries: carried})
+		}
+	}
+	for _, node := range sortedCopy(r.Enrolling) {
+		out = append(out, Principal{Kind: KindEnrolment, Node: node})
+	}
+	for _, person := range sortedNames(r.People) {
+		p := Principal{Kind: KindPerson, Module: person, Invokes: r.People[person]}
+		if administers(p.Invokes) {
+			// The operator's hand path writes each node's compositions (ADR 0539 clause 10).
+			p.FilesFor = sortedCopy(r.Nodes)
+		}
+		out = append(out, p)
+	}
+
+	// Refused here rather than discovered by the server. Two users with one name is a file the
+	// server reads as one of them, and which one depends on the order — so a module assigned to a
+	// node twice, or a person named after nothing, is a composition that must not be written.
+	seen := map[string]string{}
+	for _, p := range out {
+		name := p.Username()
+		if name == "" || name == "." {
+			return nil, fmt.Errorf("a %s user has no name, so nothing could authenticate as it", p.Kind)
+		}
+		if first, already := seen[name]; already {
+			return nil, fmt.Errorf(
+				"two users would be called %q (a %s and a %s): the server would read the file as "+
+					"one of them, and which one depends on the order", name, first, p.Kind)
+		}
+		seen[name] = string(p.Kind)
+	}
+	return out, nil
+}
+
+// WithPasswords fills each user's hash from what the mesh minted, and says which users have none.
+//
+// **Separated from Users because they fail differently.** A user missing from the records is a bug
+// in deriving them; a user with no password is a step that has not happened yet — a module assigned
+// but never given a credential, a node enrolled before this existed. The second is ordinary and its
+// remedy is to mint one, so it is named rather than returned as an error, and the caller decides
+// whether a partial composition is worth writing.
+func WithPasswords(principals []Principal, hashes map[string]string) (filled []Principal, missing []string) {
+	for _, p := range principals {
+		hash, ok := hashes[p.Username()]
+		if !ok || hash == "" {
+			missing = append(missing, p.Username())
+			continue
+		}
+		p.PasswordHash = hash
+		filled = append(filled, p)
+	}
+	return filled, missing
+}
+
+func sortedCopy(in []string) []string {
+	out := append([]string(nil), in...)
+	sort.Strings(out)
+	return out
+}
+
+func sortedNames(in map[string][]string) []string {
+	out := make([]string, 0, len(in))
+	for k := range in {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// controllerModule is the controller's module: the machine assigned it witnesses its upgrades.
+const controllerModule = "mesh-controller"
+
+// asksSeatOf is the seat an ask is made on, as its holder declares it (novox/hq ADR 0259): the controller
+// asks the operator through it like any other user, and is granted what its declaration names for a caller.
+// None while nothing holds it.
+// issuedOf is every tool of a module assigned anywhere that answers a credential its software issued, as
+// `<module>.<tool>` (novox/hq ADR 0305): what the controller asks in its own name, and nothing beside.
+func issuedOf(r Records) []string {
+	seen := map[string]bool{}
+	var out []string
+	for _, node := range sortedCopy(r.Nodes) {
+		for _, d := range r.Assigned[node] {
+			for _, t := range d.Issued {
+				if key := d.Module + "." + t; !seen[key] {
+					seen[key] = true
+					out = append(out, key)
+				}
+			}
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+func asksSeatOf(r Records) []Seat {
+	for _, node := range sortedCopy(r.Nodes) {
+		for _, d := range r.Assigned[node] {
+			for _, s := range d.Holds {
+				if s.Name == AsksSeat && namesVerb(s.ByCaller, "ask") {
+					seat := s
+					seat.Kind, seat.Capabilities = "", nil
+					return []Seat{seat}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// VaultSeat is the vault's seat: its holder alone asks the desks and the issuing providers in its own name.
+const VaultSeat = "mesh-vault"
+
+func holdsSeat(d Declared, seat string) bool {
+	for _, s := range d.Holds {
+		if s.Name == seat {
+			return true
+		}
+	}
+	return false
+}
+
+// vaultVerbsOf are the vault's intake verbs its holder serves, as the records say (issue 675): what the controller
+// is granted to ask it in its own name. None while no holder serves them.
+func vaultVerbsOf(r Records) []string { return servedOf(r, VerbsTheControllerAsksTheVault) }
+
+// servedOf are the verbs of asked that a seat's holder serves, as the records say, by name.
+func servedOf(r Records, asked []SeatVerb) []string {
+	seen := map[string]bool{}
+	var out []string
+	for _, node := range sortedCopy(r.Nodes) {
+		for _, d := range r.Assigned[node] {
+			for _, s := range d.Holds {
+				for _, v := range asked {
+					if s.Name == v.Seat && slices.Contains(s.Serves, v.Verb) && !seen[v.Verb] {
+						seen[v.Verb] = true
+						out = append(out, v.Verb)
+					}
+				}
+			}
+		}
+	}
+	sort.Strings(out)
+	return out
+}
+
+// servesMoveIn says the vault's holder serves move-in, as the records say (issue 676): what lets each machine's
+// node-engine ask it in its own name.
+func servesMoveIn(r Records) bool { return servesVerb(r, VaultMoveIn) }
+
+// servesVerb says a holder of verb's seat serves it, as the records say.
+func servesVerb(r Records, verb SeatVerb) bool {
+	for _, node := range r.Nodes {
+		for _, d := range r.Assigned[node] {
+			for _, s := range d.Holds {
+				if s.Name == verb.Seat && slices.Contains(s.Serves, verb.Verb) {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+
+// boundBucketsOf is every provider's bucket of entries, `<module>_bound` (mesh-sdk go/provider, issue 678): the state
+// named bound of every module placed anywhere, once each, in name order. A consumer on any machine may be bound to
+// it, so each machine's provisioner client reads its own keys of each (issue 679).
+func boundBucketsOf(r Records) []string {
+	seen := map[string]bool{}
+	for _, mods := range r.Assigned {
+		for _, d := range mods {
+			for _, b := range d.State {
+				if b.Name == BoundState {
+					seen[b.Bucket()] = true
+				}
+			}
+		}
+	}
+	out := make([]string, 0, len(seen))
+	for b := range seen {
+		out = append(out, b)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// runnerServes says the machine's tool runner has something of this module to serve (novox/hq ADR 0436 §1,
+// ADR 0437 §4, issue 1329): tools or loads it answers, a seat it holds, event families a session waits on,
+// a bundle the runtime loads (Loads), or a check its health asks. A module with none of these is a process of its own on its own credential, and
+// carrying it would hand every session on the machine the runner's account with that module's state, seat
+// traffic and streams. A module with no account of its own (NoAccount) is spoken for by the runner, so it
+// stays carried, and so does the runtime module itself. Whether the module has its own broker secret is not
+// the test: a module with tools and its own credential is still carried (ADR 0175).
+func runnerServes(d Declared) bool {
+	return d.Module == RuntimeModule || d.NoAccount || d.Loads || len(d.Serves) > 0 || len(d.Holds) > 0 || len(d.Waits) > 0 || len(d.Checks) > 0
+}
+
+// declaredStreamsOf is the stream of every bucket, log and stream a module placed anywhere declares, once each, in name
+// order (novox/hq ADR 0547 §5, issue 1790): `KV_<module>_<state>`, `LOG_<module>_<log>` and each module stream's own
+// name. What the grants part may create, and nothing beside.
+func declaredStreamsOf(r Records) []string {
+	seen := map[string]bool{}
+	for _, mods := range r.Assigned {
+		for _, d := range mods {
+			for _, b := range d.State {
+				seen["KV_"+b.Bucket()] = true
+			}
+			for _, l := range d.Logs {
+				seen[l.Stream()] = true
+			}
+			for _, s := range d.Streams {
+				seen[s.Name] = true
+			}
+		}
+	}
+	out := make([]string, 0, len(seen))
+	for s := range seen {
+		out = append(out, s)
+	}
+	sort.Strings(out)
+	return out
+}

go/buscompose/waits.go

@@ -0,0 +1,94 @@
+package buscompose
+
+import (
+	"fmt"
+	"strings"
+)
+
+// What a session may wait on through the mesh MCP server (novox/hq ADR 0367).
+//
+// **A grant apart from `consumes`, and the tool runner's alone.** The tool runner's module names in its
+// manifest the event families a session may wait on, one by one; the runtime's account is granted a plain
+// subscription on those subjects and nothing wider — no durable consumer, no queue of its own — and its
+// membership names the same list, from which `mesh_wait` refuses any other. Both are read from this one
+// composition, so the grant and what the tool runner offers cannot disagree, and nothing but the manifest
+// adds a family (§6).
+
+// Wait is one event family the tool runner's module declares: its name as the manifest gives it, and the
+// emitter — a seat or a module — and the event, as the inventory resolved them.
+type Wait struct {
+	// Name is the family as the manifest names it, `<emitter>.<event>`: what a session asks for.
+	Name    string
+	Emitter string
+	// Seat says the emitter is a seat, whose events live under the seat's namespace (novox/hq ADR 0121).
+	Seat bool
+	// Event is the event, with any further token the subject carries: `decided.claude-code`, the asker of a
+	// seat that names it last (ADR 0259 §3).
+	Event string
+	// Last names what the seat's event subject ends in — "kind" for a kinded bench, "asker" for a seat naming
+	// its caller (ADR 0259 §3) — and is empty for an event that ends at its name. A family needing it is waited
+	// on with it given, and refused without.
+	Last string
+}
+
+// WaitSubject is where a family's events land. Each token is checked before it becomes a subject: a
+// wildcard, a dot inside a name or an empty token would widen the grant.
+func WaitSubject(w Wait) (string, error) {
+	if !safeSubject.MatchString(w.Emitter) {
+		return "", fmt.Errorf("%q cannot name an emitter of a waited event: it would widen the subject", w.Emitter)
+	}
+	for _, t := range strings.Split(w.Event, ".") {
+		if !safeSubject.MatchString(t) {
+			return "", fmt.Errorf("%q cannot name a waited event: each of its names is plain, never a wildcard "+
+				"(novox/hq ADR 0367 §2)", w.Event)
+		}
+	}
+	if w.Last != "" && !strings.Contains(w.Event, ".") {
+		return "", fmt.Errorf("%s names no %s: %s's events are said for each %s, so a family is %s.%s.<%s>; "+
+			"without it no event would ever be heard (novox/hq ADR 0367 §5)",
+			w.Name, w.Last, w.Emitter, w.Last, w.Emitter, w.Event, w.Last)
+	}
+	if w.Seat {
+		return "mesh.seat." + w.Emitter + ".event." + w.Event, nil
+	}
+	return "mesh.mod." + w.Emitter + ".event." + w.Event, nil
+}
+
+// waitGrants is the subscription the tool runner's account is granted for its module's families, and an
+// error for a carried module other than the tool runner's that declares any (ADR 0367 §2).
+func waitGrants(carries []Declared) ([]string, error) {
+	var sub []string
+	for _, d := range carries {
+		if len(d.Waits) == 0 {
+			continue
+		}
+		if d.Module != RuntimeModule {
+			return nil, fmt.Errorf("%s declares what a session waits on; only %s, the tool runner's module, "+
+				"does (novox/hq ADR 0367 §2)", d.Module, RuntimeModule)
+		}
+		for _, w := range d.Waits {
+			s, err := WaitSubject(w)
+			if err != nil {
+				return nil, err
+			}
+			sub = append(sub, s)
+		}
+	}
+	return sub, nil
+}
+
+// waitsIssuedFor is the families a membership names: the tool runner's module's, and nobody else's.
+func waitsIssuedFor(d Declared) []WaitIssued {
+	if d.Module != RuntimeModule {
+		return nil
+	}
+	var out []WaitIssued
+	for _, w := range d.Waits {
+		s, err := WaitSubject(w)
+		if err != nil {
+			continue // refused where the account is composed, which names it
+		}
+		out = append(out, WaitIssued{Event: w.Name, Subject: s})
+	}
+	return out
+}

go/buscompose/writers.go

@@ -0,0 +1,320 @@
+package buscompose
+
+import (
+	"fmt"
+	"slices"
+	"strings"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+// The writers table (novox/hq to-be 45 §1, ADR 0227 rule 1), compiled in.
+//
+// **Every kind of state the core keeps has one writer; anyone else asks it.** The table is the design's,
+// row for row, with what each row writes on the bus where it writes there. Two things read it: the
+// composition of every principal's grants (PermissionsFor), which **refuses a grant that lets a
+// principal publish on a subject another writes** — so a second writer cannot be granted by accident,
+// and the composition says which state and whose — and the test beside it, which walks the rows
+// against the design's list and the composition of a whole mesh. Changing a writer is a change to
+// this table, through a decision.
+
+// WriterRow is one row of the writers table.
+type WriterRow struct {
+	State  string
+	Writer string
+	KeptIn string
+	Others string
+	// Subjects are the bus subjects a write of this state is a publish to; none for state kept off the
+	// bus (the controller's store, a module's own) or not built yet.
+	Subjects []string
+	// Writes says a principal granted a publish pattern overlapping Subjects is this state's writer —
+	// given the pattern, because a machine writes its own report and no other's.
+	Writes func(p Principal, pattern string) bool
+	// Shared says why more than one principal may publish here; empty for one writer.
+	Shared string
+}
+
+// isController, and the other writers' tests, are who a row's writer is as a principal.
+func isController(p Principal, _ string) bool { return p.Kind == KindController }
+
+// createsDeclared is the controller, or the grants part creating one stream a manifest declares, by its own name: the
+// create alone, never an update or a delete (novox/hq ADR 0547 §5; the operator, 2026-10-26 08:54).
+func createsDeclared(p Principal, pattern string) bool {
+	if isController(p, pattern) {
+		return true
+	}
+	name, ok := strings.CutPrefix(pattern, "$JS.API.STREAM.CREATE.")
+	return ok && p.Kind == KindModule && p.Module == GrantsModule && slices.Contains(p.CreatesStreams, name) &&
+		safeSubject.MatchString(name)
+}
+
+// ownMachine is a node writing a subject whose third token is its own name, and no wildcard there.
+func ownMachine(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	return p.Kind == KindNode && len(tokens) > 2 && tokens[2] == p.Node
+}
+
+// holdsSeatOf is a principal holding the seat a `mesh.seat.<seat>.…` pattern names: its module's own
+// principal, or the node tools carrying a module that holds it (ADR 0175, the runtime is its modules).
+func holdsSeatOf(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	if len(tokens) < 3 {
+		return false
+	}
+	seat := tokens[2]
+	holds := func(seats []Seat) bool {
+		return slices.ContainsFunc(seats, func(s Seat) bool { return s.Name == seat })
+	}
+	switch p.Kind {
+	case KindModule:
+		return holds(p.Holds)
+	case KindNodeTools:
+		return slices.ContainsFunc(p.Carries, func(d Declared) bool { return holds(d.Holds) })
+	}
+	return false
+}
+
+// ownModule is a module publishing under its own name, or the node tools carrying it.
+func ownModule(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	if len(tokens) < 3 {
+		return false
+	}
+	module := tokens[2]
+	switch p.Kind {
+	case KindModule:
+		return p.Module == module
+	case KindNodeTools:
+		return slices.ContainsFunc(p.Carries, func(d Declared) bool { return d.Module == module })
+	}
+	return false
+}
+
+// ownAnnouncer is a module, a process of it or the node tools carrying it saying what that module keeps, or the
+// controller saying what it keeps itself (novox/hq ADR 0495 clause 2): each under its own name alone.
+func ownAnnouncer(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	if len(tokens) < 3 {
+		return false
+	}
+	switch p.Kind {
+	case KindController:
+		return tokens[2] == ControllerSeat
+	case KindProcess:
+		return p.Module == tokens[2]
+	}
+	return ownModule(p, pattern)
+}
+
+// ownProvisioner is a machine's provisioner client saying a report about its own machine: the third token of
+// `prov.applied.<node>.…` is its machine (novox/hq ADR 0349 §4, design 57 P3).
+func ownProvisioner(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	return p.Kind == KindProvisioner && len(tokens) > 3 && tokens[2] == p.Node
+}
+
+// ownNodeKeys is a node writing the have keys of its own node: `$KV.<bucket>.<node>.…`, the node in the third token
+// and no wildcard there (novox/hq ADR 0429 §1).
+func ownNodeKeys(p Principal, pattern string) bool {
+	tokens := strings.Split(pattern, ".")
+	return p.Kind == KindNode && len(tokens) > 2 && tokens[2] == p.Node
+}
+
+// kvOf is a bucket's write subjects.
+func kvOf(bucket string) []string { return []string{"$KV." + bucket + ".>"} }
+
+// WritersTable is to-be 45 §1, in its order.
+var WritersTable = []WriterRow{
+	{State: "a machine's declaration", Writer: "controller (lease holder)", KeptIn: "the bus, last per subject",
+		Others: "read", Subjects: []string{"mesh.node.*.declare"}, Writes: isController},
+	// The operator's hand-over of a directory used as found, asked of the machine's engine at the controller's
+	// terminal (novox/hq issue 356). One publisher; and because a responder can still reach the subject through a
+	// reply, the ask is signed with the mesh's key and the engine verifies it — the row bounds who is granted the
+	// publish, the signature who is believed.
+	{State: "a hand-over asked of a machine", Writer: "controller, at its terminal", KeptIn: "the machine, beside its state",
+		Others:   "the engine verifies the mesh's signature and records it, or refuses",
+		Subjects: []string{"mesh.node.*.ask.hand-over"}, Writes: isController},
+	// The operator asking a machine's engine for a fresh search for setuid programs, at the controller's
+	// terminal (novox/hq issue 361): signed as a hand-over is, under a signing context of its own.
+	{State: "a fresh setuid search asked of a machine", Writer: "controller, at its terminal",
+		KeptIn: "the machine, which throws its last search away", Others: "the engine verifies the mesh's signature and starts it, or refuses",
+		Subjects: []string{"mesh.node.*.ask.setuid-search"}, Writes: isController},
+	// A read-only judgement of a machine's declared directories asked of its engine (novox/hq issue 358): signed as a
+	// hand-over is, under a signing context of its own. It changes nothing on the machine.
+	{State: "a judgement of a machine's directories asked of it", Writer: "controller",
+		KeptIn: "nowhere: the engine answers it and keeps nothing", Others: "the engine verifies the mesh's signature and answers, or refuses",
+		Subjects: []string{"mesh.node.*.ask.judge-directories"}, Writes: isController},
+	{State: "a machine's applied state and its report", Writer: "the node-engine's apply queue",
+		KeptIn: "the machine; the report on the bus", Others: "the reconcile and a delivery enqueue, never apply",
+		// And its health statement between reports (novox/hq ADR 0240): the same writer stating the same
+		// machine, inside the grant it already had (`mesh.control.<its own>.>`). And a line mesh-cli was given
+		// on the machine (novox/hq ADR 0272): the node is what the controller judges the terminal by, so that
+		// subject is this machine's engine's alone.
+		Subjects: []string{"mesh.control.*.report", "mesh.control.*.health", "mesh.control.*.cli"}, Writes: ownMachine},
+	{State: "the controller lease", Writer: "the controller instance holding it", KeptIn: "key-value " + LeaseBucket,
+		Others: "a candidate waits", Subjects: kvOf(LeaseBucket), Writes: isController},
+	// The merges mesh-delivery announced, for a moved module's registration (ADR 0420 §7), written by the lease holder.
+	{State: "the merges mesh-delivery announced", Writer: "controller (lease holder)",
+		KeptIn: "key-value " + DeliveryMergesBucket, Others: "read at a moved module's registration",
+		Subjects: kvOf(DeliveryMergesBucket), Writes: isController},
+	// And the compositions (novox/hq ADR 0539 clauses 2 and 4): each node's in its own bucket, which only that node's
+	// node-engine reads, and each digest with the judgement of its move, which the assigner reads.
+	{State: "the compositions and their digests", Writer: "controller (lease holder), compare-and-set",
+		KeptIn:   "key-value composed-<node> for each node, and " + delivery.ControllerComposedBucket,
+		Others:   "a node-engine reads its own node's; the assigner reads the digests",
+		Subjects: kvOf(delivery.ControllerComposedBucket), Writes: isControllerOrTheHandPath},
+	{State: "conditions", Writer: "controller", KeptIn: "key-value " + ConditionsBucket + " (and its history, " +
+		ConditionHistoryBucket + "); how often each was observed, when last and its newest evidence in the " +
+		"controller's store, so a look that changes nothing writes no bucket", Others: "raise or clear only through observations the controller reads",
+		Subjects: append(kvOf(ConditionsBucket), kvOf(ConditionHistoryBucket)...), Writes: isController},
+	{State: "calls and their outcomes", Writer: "controller", KeptIn: "key-value " + CallsBucket,
+		Others: "read by id", Subjects: kvOf(CallsBucket), Writes: isController},
+	{State: "the hand-act log", Writer: "controller, through the verbs that act", KeptIn: "key-value " + HandActsBucket,
+		Others: "—", Subjects: kvOf(HandActsBucket), Writes: isController},
+	// What the healers did (novox/hq to-be 45 §7, Phase 3): the controller's alone, in its store — the
+	// budgets and the mesh-wide brake are counted from it, so a controller restarting cannot reset them.
+	{State: "the healers' acts and their brake", Writer: "controller (lease holder), each act begun before it is made",
+		KeptIn: "the controller's store", Others: "read through healers; each act said as healer-acted and in its condition's tried"},
+	{State: "stream definitions and bus permissions", Writer: "controller", KeptIn: "the bus", Others: "—",
+		// A stream's definition, and a durable consumer's by the API that names it so. Not every
+		// consumer create: a module watching its own bucket makes and deletes an ordered consumer on the
+		// bucket's stream (ADR 0201), which defines nothing the mesh keeps.
+		Subjects: []string{"$JS.API.STREAM.CREATE.>", "$JS.API.STREAM.UPDATE.>", "$JS.API.STREAM.DELETE.>",
+			"$JS.API.CONSUMER.DURABLE.CREATE.>"},
+		Writes: createsDeclared,
+		Shared: "the grants part creates a stream a manifest declares, by its name, and never updates or deletes one (novox/hq ADR 0547 §5; the operator, 2026-10-26 08:54)"},
+	{State: "builds and their outcomes", Writer: "the build seat's holder", KeptIn: "its own state",
+		Others:   "the controller asks",
+		Subjects: []string{"mesh.seat.node-build-agent.event.built", "mesh.seat.mesh-build-machine.event.built"},
+		Writes:   holdsSeatOf,
+		Shared:   "every machine holding the build seat answers the asks it took; each outcome names its ask"},
+	// What a module keeps and who may read it (novox/hq ADR 0495 clauses 2 and 3, issue 1790): said by the module, kept by
+	// the controller.
+	{State: "a module's states announced", Writer: "the module itself, from its code, under its own name",
+		KeptIn: "the bus (EVENTS)", Others: "the controller keeps the last of each and grants readers from it",
+		Subjects: []string{"mesh.mod.*.event.states"}, Writes: ownAnnouncer},
+	{State: "the states announced", Writer: "controller, from each module's announcement",
+		KeptIn: "key-value " + StatesAnnouncedBucket, Others: "the composition of the bus's users reads it",
+		Subjects: kvOf(StatesAnnouncedBucket), Writes: isController},
+	{State: "a merge announced", Writer: "one announcer per forge (the hook, or the poll when the hook is absent — never both)",
+		KeptIn: "the bus", Others: "—", Subjects: []string{"mesh.mod.*.event.pull.merged"}, Writes: ownModule},
+	// A pull request's head, before it merges (novox/hq to-be 45 §9): the same one announcer.
+	{State: "a pull request's head announced", Writer: "the forge's announcer, the one that announces its merges",
+		KeptIn: "the bus", Others: "the controller asks the build seat to check it", Subjects: []string{"mesh.mod.*.event.pull.updated"},
+		Writes: ownModule},
+	{State: "a pull request's merge check", Writer: "the build seat's holder that ran it, said as the controller's `checked`",
+		KeptIn: "the bus", Others: "the forge's holder sets it as the pull request's status"},
+	{State: "a provider's standing", Writer: "the provider", KeptIn: "the provider's events",
+		Others: "the controller keeps the newest word as a condition",
+		Subjects: []string{"mesh.mod.*.event.provisioner.failing", "mesh.mod.*.event.provisioner.recovered",
+			"mesh.mod.*.event.provisioner.retirement"},
+		Writes: ownModule},
+	{State: "the operator-channel's open messages", Writer: "the seat's holder", KeptIn: "its own key-value state",
+		Others: "—"},
+	{State: "the facts snapshot", Writer: "controller", KeptIn: "the artifact store, facts/latest",
+		Others: "the build seat reads"},
+	// What a consumer gave up on (novox/hq issue 330): copied by the controller from the server's notice,
+	// and delivered again or dropped only through its verb, with why.
+	{State: "a message a consumer gave up on", Writer: "controller", KeptIn: "the bus, the stream " + DeadLettersStream,
+		Others:   "read, delivered again or dropped through the controller's dead-letters verb",
+		Subjects: []string{deadLetterPrefix + ">", againPrefix + ">"}, Writes: isController},
+	// The record mirrors (novox/hq ADR 0289 §9, design 54 §2): rows of this table, so a grant that lets
+	// anything else write them is refused at composition. Built so far: the assignments and each registered
+	// module's declared config (design 57 F3), and the list of predefined keys kept (design 57 K3).
+	{State: "the assignments mirror", Writer: "controller (lease holder): the verbs that assign, and the sends that record what runs; " +
+		"a mirror of its store only until the assignments are moved to the bus (novox/hq ADR 0408)",
+		KeptIn: "key-value " + AssignmentsBucket + ", the record once moved", Others: "read through `reads` as mesh-controller." + MirrorAssignments,
+		Subjects: kvOf(AssignmentsBucket), Writes: isController},
+	// The chain (novox/hq ADR 0408): builds and rollouts beside the assignments above, which keep their bucket. Not
+	// mirrors of the store but the record, written by the lease holder by compare-and-set and removed by nobody.
+	{State: "the builds of the chain", Writer: "controller (lease holder), compare-and-set on the key's revision",
+		KeptIn: "key-value " + BuildsBucket + ", sixty-four revisions of each key, none removed",
+		Others: "read through `reads` as mesh-controller." + ChainBuilds, Subjects: kvOf(BuildsBucket), Writes: isController},
+	{State: "the rollouts of the chain", Writer: "controller (lease holder), compare-and-set on the key's revision",
+		KeptIn: "key-value " + RolloutsBucket + ", sixty-four revisions of each key, none removed",
+		Others: "read through `reads` as mesh-controller." + ChainRollouts, Subjects: kvOf(RolloutsBucket), Writes: isController},
+	// The grants issued (novox/hq ADR 0528 clause 2, issue 1394): the controller's, read by the assigner for its sixth rule.
+	{State: "the grants issued", Writer: "controller (lease holder), once the bus's user list carrying a module's manifest at a fingerprint was sent",
+		KeptIn: "key-value " + GrantsBucket + ", one key a module's fingerprint, none removed",
+		Others: "read through `reads` as mesh-controller." + ControllerGrants, Subjects: kvOf(GrantsBucket), Writes: isController},
+	// What each machine has of each module (novox/hq ADR 0429 §1, design 47): written by that machine's node-engine under
+	// its own node's keys, never by the controller; the view and the watchman read it.
+	{State: "a machine's have", Writer: "the node-engine of the machine, under its own keys `<node>.>`",
+		KeptIn: "key-value " + delivery.HaveBucket + ", twenty revisions of each key",
+		Others: "read through `reads` as node-engine.have", Subjects: kvOf(delivery.HaveBucket), Writes: ownNodeKeys},
+	// The contents of a declaration's files over 64 KiB (novox/hq ADR 0486 §2): the controller alone writes the bucket, each
+	// object under the digest of its content; a node-engine reads one by its name, with no list and no write.
+	{State: "a declaration's large files", Writer: "controller, each object under the sha256 digest of its content; the " +
+		"operator's account on release 6's hand path alone (ADR 0539 clause 10)",
+		KeptIn: "the object bucket " + DeclarationFilesBucket + "-<node> of each node, an object removed a day after the " +
+			"node's latest declaration no longer names it",
+		Others:   "a node-engine reads an object of its own bucket by its name and may neither list the bucket nor write it",
+		Subjects: []string{"$O.*.>"}, Writes: isControllerOrTheHandPath},
+	{State: "the declared-config mirror", Writer: "controller (lease holder), from its store, only on a change",
+		KeptIn: "key-value " + DeclaredConfigBucket, Others: "read through `reads` as mesh-controller." + MirrorDeclaredConfig,
+		Subjects: kvOf(DeclaredConfigBucket), Writes: isController},
+	{State: "the predefined-keys mirror", Writer: "controller (lease holder), from its store, only on a change",
+		KeptIn: "key-value " + PredefinedBucket, Others: "read through `reads` as mesh-controller." + MirrorPredefined,
+		Subjects: kvOf(PredefinedBucket), Writes: isController},
+	{State: "the declared-packages mirror", Writer: "controller (lease holder), from the composition of each node, only on a change",
+		KeptIn: "key-value " + DeclaredPackagesBucket, Others: "read through `reads` as mesh-controller." + MirrorDeclaredPackages,
+		Subjects: kvOf(DeclaredPackagesBucket), Writes: isController},
+	// What a machine's provisioner client placed of a module's files (novox/hq ADR 0349 §4, design 57 P6): its own
+	// machine's word alone, which a walk's end and a gate wait for (ADR 0362, ADR 0349 §15). Kept newest per module
+	// in the stream ProvAppliedStream, and by the client in the provisioner server's `applied` bucket.
+	{State: "a module's files placed on a machine", Writer: "that machine's provisioner client",
+		KeptIn: "the bus, the stream " + ProvAppliedStream + ", newest per module; and key-value " +
+			ProvisionerAppliedBucket,
+		Others:   "the controller reads it at a walk's end and a gate; a failure is that machine's failed apply",
+		Subjects: []string{"prov.applied.*.>"}, Writes: ownProvisioner},
+}
+
+// CheckWriters refuses a grant that lets a principal publish on a subject the writers table gives
+// another writer (to-be 45 §1): which state, whose, and the pattern that would make a second writer.
+func CheckWriters(p Principal, publish []string) error {
+	var problems []string
+	for _, pattern := range publish {
+		for _, row := range WritersTable {
+			if row.Writes == nil {
+				continue
+			}
+			for _, subject := range row.Subjects {
+				if !SubjectsOverlap(pattern, subject) || row.Writes(p, pattern) {
+					continue
+				}
+				problems = append(problems, fmt.Sprintf("%s may publish %s, which writes %s (%s), whose writer is %s",
+					p.Username(), pattern, row.State, subject, row.Writer))
+			}
+		}
+	}
+	if len(problems) == 0 {
+		return nil
+	}
+	return fmt.Errorf("a second writer would be granted (novox/hq to-be 45 §1, one writer per piece of state):\n  %s",
+		strings.Join(problems, "\n  "))
+}
+
+// SubjectsOverlap says some subject matches both patterns: `*` is one token, `>` one or more to the end.
+func SubjectsOverlap(a, b string) bool {
+	x, y := strings.Split(a, "."), strings.Split(b, ".")
+	for i := 0; ; i++ {
+		switch {
+		case i == len(x) && i == len(y):
+			return true
+		case i == len(x) || i == len(y):
+			return false
+		case x[i] == ">" || y[i] == ">":
+			return true
+		case x[i] == "*" || y[i] == "*" || x[i] == y[i]:
+			continue
+		default:
+			return false
+		}
+	}
+}
+
+// isControllerOrTheHandPath is the controller, or the operator's account (a person who may invoke every tool) writing
+// release 6's hand path: the one second writer ADR 0539 clauses 2 and 10 name, for a composition made by hand.
+func isControllerOrTheHandPath(p Principal, pattern string) bool {
+	return isController(p, pattern) || (p.Kind == KindPerson && administers(p.Invokes))
+}

go/catalogue/delivery_seat.go

@@ -9,7 +9,26 @@ package catalogue
 // DeliverySeat is the seat mesh-delivery holds.
 const DeliverySeat = "mesh-delivery"
 
-// deliveryVerbs are the delivery seat's tools: six that read, and the acts of a person, a reviewer and healer H2.
+// RemovedDeliveryVerbs are the delivery seat's verbs release 6 removed (novox/hq ADR 0539 clause 17): with no plan the
+// gate keeps the merge's states and derives nothing after the merge. Each stays in deliveryVerbs as an optional row
+// with no input, so the holder of before and the holder of release 6 both hold the seat and a caller is answered by
+// name with its replacement, given here.
+var RemovedDeliveryVerbs = map[string]string{
+	"times":          "the delivery view (nox-delivery): each machine's want and have, and since when",
+	"what-if":        "the merge check's composition, which composes every machine a change touches",
+	"release":        "the assigner's asks (hold, restore, backup, record), answered on the phone or in the delivery view",
+	"stop":           "a bad fingerprint is held and its canary set back by the assigner (ADR 0429 §6, ADR 0539 clause 18)",
+	"retire-history": "nothing to retire: the gate keeps no delivery after its merge",
+}
+
+// deliveryRemovedInR6 is the row of a verb release 6 removed from the delivery seat.
+func deliveryRemovedInR6(name string) Verb {
+	return Verb{Name: name, Description: "Removed in R6 (ADR 0539): refused by name, naming its replacement: " +
+		RemovedDeliveryVerbs[name], Input: schema(nil, nil), Optional: true}
+}
+
+// deliveryVerbs are the delivery seat's tools: what reads the merges and checks, and the acts of a person and healer H2
+// on a merge (ADR 0539 clause 17).
 func deliveryVerbs() []Verb {
 	return []Verb{
 		{Name: "deliveries", Description: "Every delivery not final, and those that ended in the last day, one line " +
@@ -18,15 +37,7 @@ func deliveryVerbs() []Verb {
 			Input: schema(map[string]string{"state": "one state, e.g. delivering or held",
 				"repository": "owner/repository", "group": "a group's id (its branch name)",
 				"all": "\"true\": the final ones of the last thirty days too"}, nil, "all")},
-		// Delivery time against the delivery budgets (novox/hq ADR 0282): what probe D16 reads, optional until its
-		// holder serves it.
-		{Name: "times", Description: "Delivery time: from a merge to every machine of its walk running the build. " +
-			"Each class's delivery budget (a leaf module three minutes, a core module ten), the last days' median and " +
-			"worst, how many within and over, the newest delivery of each class, every delivery over its budget with its " +
-			"longest phase, and the delivered ones whose time is not known. Given a delivery's id, its time phase by phase.",
-			Input: schema(map[string]string{"days": "how many days back (default 7)", "id": "one delivery's id: its phases"}, nil),
-			// Optional until mesh-delivery serves it: its holder lives in the catalogue (design 33 §7).
-			Optional: true},
+		deliveryRemovedInR6("times"),
 		{Name: "show", Description: "One delivery or group whole: its delivery plan (what it builds, what each " +
 			"machine receives, what is not an ordinary send), every transition with when and why, the machine " +
 			"steps of its walk, its group and its order.",
@@ -35,12 +46,7 @@ func deliveryVerbs() []Verb {
 			"(declared, built by, version skew, engine before controller, by name), its composed check and its " +
 			"state, derived from its members.",
 			Input: schema(map[string]string{"all": "\"true\": the groups that ended too"}, nil, "all")},
-		{Name: "what-if", Description: "The delivery plan a change would have, asked of the controller's planner " +
-			"and kept nowhere: the modules it moves and their dependents in tiers, what each machine would receive, " +
-			"the steps that are not an ordinary send.",
-			Input: schema(map[string]string{"repository": "owner/repository",
-				"paths": "the files it changes, comma-separated, from the repository's root",
-				"base":  "the branch it merges into (default main)"}, []string{"repository", "paths"})},
+		deliveryRemovedInR6("what-if"),
 		{Name: "checks", Description: "What the mesh's checks said of a pull request's head or of one commit: each " +
 			"of the commit's mesh statuses (mesh/check, the one a main requires from R4e, hq's mesh/repo-check, " +
 			"mesh/delivery, …) with its state, " +
@@ -62,40 +68,13 @@ func deliveryVerbs() []Verb {
 			"controller is asked for its check. With why.",
 			Input: schema(map[string]string{"id": "the delivery's id", "why": "why, kept with the transition"},
 				[]string{"id", "why"})},
-		{Name: "release", Description: "A person's word that a held delivery goes on: it starts delivering. With why.",
-			Input: schema(map[string]string{"id": "the delivery's id", "why": "why, kept with the transition"},
-				[]string{"id", "why"})},
-		{Name: "stop", Description: "Stop a delivery that is not final, with why; its walk is ended through the " +
-			"controller, and in a group every member after it is stopped too, naming it.",
-			Input: schema(map[string]string{"id": "the delivery's id", "why": "why, kept with the transition"},
-				[]string{"id", "why"})},
+		deliveryRemovedInR6("release"),
+		deliveryRemovedInR6("stop"),
 		{Name: "close", Description: "Healer H2's verb: take the one transition the table names for a delivery held " +
 			"past its bound. Refused for any other.",
 			Input: schema(map[string]string{"id": "the delivery's id", "why": "the condition it answers"},
 				[]string{"id", "why"})},
-		{Name: "retire-history", Description: "Retire held deliveries that are history, on a person's word, with " +
-			"why: each made from the forge's word for a merge on the trunk heard long after it happened — replayed " +
-			"when the holder first held the seat — with no walk of it open. Never released, delivered or put back: " +
-			"retired, final. One by id, refused when the rule does not take it; or every held one, of one " +
-			"repository when named, answering how many it retired and naming those it left held. dry \"true\" " +
-			"answers what it would do and changes nothing.",
-			Input: schema(map[string]string{"why": "why, kept with every transition",
-				"id":         "one delivery's id; every held one when empty",
-				"repository": "owner/repository: only its held deliveries",
-				"dry":        "\"true\": what it would retire, changing nothing"}, []string{"why"}, "dry"),
-			// Added after the seat's holder shipped (novox/hq issue 313): optional until mesh-delivery serves it.
-			Optional: true},
-		{Name: "mark-ready", Description: "A reviewer's word that a delivery's head is approved: the holder puts the " +
-			"label mesh/ready on its pull request and then writes \"ready at <head>\", the order the forge counts, " +
-			"as the mesh's own forge account, naming who reviewed it and why. Refused when the delivery's commit is " +
-			"no longer its pull request's head. mesh-delivery then merges it once its checks pass (novox/hq ADR 0364).",
-			Input: schema(map[string]string{"id": "the delivery's id (owner/repository@commit): the head reviewed",
-				"reviewed-by": "who reviewed it, as who@node", "why": "the review's verdict in a line"},
-				[]string{"id", "reviewed-by", "why"}),
-			// Kept one more release, optional (novox/hq issue 1022): mesh-delivery no longer serves it, but the manifest
-			// it still has on the mesh does until its catalogue member merges, and a seat refuses a holder that serves
-			// a verb it does not promise. The next release removes this entry.
-			Optional: true},
+		deliveryRemovedInR6("retire-history"),
 	}
 }
 

go/catalogue/delivery_seat_test.go

@@ -58,107 +58,3 @@ func TestTheDeliverySeatPromisesChecks(t *testing.T) {
 		t.Fatalf("a holder without %s: %v", before[0], err)
 	}
 }
-
-// The seat retires history on a person's word (novox/hq issue 313): `retire-history`, with why, one delivery by
-// id or every held one, dry to see first. Added after the holder shipped, it is optional, so the holder that
-// does not serve it yet still holds the seat, and one that does is not refused for a verb the seat lacks.
-func TestTheDeliverySeatPromisesRetireHistoryOptionally(t *testing.T) {
-	seat, _ := SeatNamed(DeliverySeat)
-	var retire *Verb
-	for i := range seat.Serves {
-		if seat.Serves[i].Name == "retire-history" {
-			retire = &seat.Serves[i]
-		}
-	}
-	if retire == nil || !retire.Optional {
-		t.Fatalf("the delivery seat promises %v, retire-history optionally", VerbNames(seat.Serves))
-	}
-	props, _ := retire.Input["properties"].(map[string]any)
-	for _, arg := range []string{"why", "id", "repository", "dry"} {
-		if _, has := props[arg]; !has {
-			t.Errorf("retire-history takes no %q", arg)
-		}
-	}
-	if req, _ := retire.Input["required"].([]string); !reflect.DeepEqual(req, []string{"why"}) {
-		t.Errorf("retire-history requires %v, wanted only why", req)
-	}
-	var without []string
-	for _, v := range VerbNames(seat.Serves) {
-		if v != "retire-history" {
-			without = append(without, v)
-		}
-	}
-	m := Manifest{Module: "mesh-delivery", Claims: []Claim{{Name: DeliverySeat, Scope: ScopeMesh, Serves: without}}}
-	if err := CanHold(m, seat); err != nil {
-		t.Fatalf("a holder without retire-history yet: %v", err)
-	}
-	m.Claims[0].Serves = VerbNames(seat.Serves)
-	if err := CanHold(m, seat); err != nil {
-		t.Fatalf("a holder serving retire-history: %v", err)
-	}
-}
-
-// The seat says delivery times (novox/hq ADR 0282, issue 382): `times`, over some days or for one delivery. Added
-// after the holder shipped, it is optional, so the holder that does not serve it yet still holds the seat, and one
-// that does is not refused for a verb the seat lacks.
-func TestTheDeliverySeatPromisesTimesOptionally(t *testing.T) {
-	seat, _ := SeatNamed(DeliverySeat)
-	var times *Verb
-	for i := range seat.Serves {
-		if seat.Serves[i].Name == "times" {
-			times = &seat.Serves[i]
-		}
-	}
-	if times == nil || !times.Optional {
-		t.Fatalf("the delivery seat promises %v, times optionally", VerbNames(seat.Serves))
-	}
-	props, _ := times.Input["properties"].(map[string]any)
-	for _, arg := range []string{"days", "id"} {
-		if _, has := props[arg]; !has {
-			t.Errorf("times takes no %q", arg)
-		}
-	}
-	var without []string
-	for _, v := range VerbNames(seat.Serves) {
-		if v != "times" {
-			without = append(without, v)
-		}
-	}
-	m := Manifest{Module: "mesh-delivery", Claims: []Claim{{Name: DeliverySeat, Scope: ScopeMesh, Serves: without}}}
-	if err := CanHold(m, seat); err != nil {
-		t.Fatalf("a holder without times yet: %v", err)
-	}
-	m.Claims[0].Serves = VerbNames(seat.Serves)
-	if err := CanHold(m, seat); err != nil {
-		t.Fatalf("a holder serving times: %v", err)
-	}
-}
-
-// The seat still promises `mark-ready`, optionally, for one more release (issue 1022); it was added by novox/hq issue 913: `mark-ready`, with the delivery's id, who reviewed it
-// and why, so a reviewer marks a pull request through one audited verb, label and comment in the order the forge
-// counts, instead of two raw forge calls. Added after the holder shipped, it is optional.
-func TestTheDeliverySeatPromisesMarkReadyOptionally(t *testing.T) {
-	seat, _ := SeatNamed(DeliverySeat)
-	var mark *Verb
-	for i := range seat.Serves {
-		if seat.Serves[i].Name == "mark-ready" {
-			mark = &seat.Serves[i]
-		}
-	}
-	if mark == nil || !mark.Optional {
-		t.Fatalf("the delivery seat promises %v, mark-ready optionally", VerbNames(seat.Serves))
-	}
-	if req, _ := mark.Input["required"].([]string); !reflect.DeepEqual(req, []string{"id", "reviewed-by", "why"}) {
-		t.Errorf("mark-ready requires %v, wanted id, reviewed-by and why", req)
-	}
-	var without []string
-	for _, v := range VerbNames(seat.Serves) {
-		if v != "mark-ready" {
-			without = append(without, v)
-		}
-	}
-	m := Manifest{Module: "mesh-delivery", Claims: []Claim{{Name: DeliverySeat, Scope: ScopeMesh, Serves: without}}}
-	if err := CanHold(m, seat); err != nil {
-		t.Fatalf("a holder without mark-ready yet: %v", err)
-	}
-}

go/catalogue/seats.go

@@ -110,15 +110,18 @@ var defaultSeats = append([]Seat{
 			"rolled-back",
 			// A pull request's merge check, judged (novox/hq to-be 45 §9).
 			"checked",
-			// A walk kept in a new state, for the delivery it walks (novox/hq ADR 0239).
+			// A walk kept in a new state, and a tier sent to a machine: kept until the catalogue's main consumes them no
+			// more; nothing emits them (ADR 0539).
 			"plan-moved",
-			// A tier sent to a machine, once the send is kept (novox/hq ADR 0406 §5, issue 974).
 			"sent",
 			// A key of a record mirror written or removed (novox/hq ADR 0289, design 54 §3; design 57 F3).
 			"assignment-changed", "declared-config-changed", "predefined-changed",
 			// A builder's key not taken in because the artifact store does not hold an artifact it names (novox/hq
 			// issue 1937): the builder builds it again.
-			"artifacts-gone"},
+			"artifacts-gone",
+			// A bucket of a state this release deleted, deleted at the controller's first start (novox/hq ADR 0539
+			// clause 13): the merge window's, the silent sends' and the building plans' hold, each said once.
+			"bucket-deleted"},
 		Serves: ControllerVerbs},
 	// The store's first verbs (novox/hq ADR 0159): the smallest set that makes the store askable,
 	// served by whichever module holds the seat with tools of these names.

go/catalogue/verbs.go

@@ -74,6 +74,29 @@ func VerbNames(verbs []Verb) []string {
 	return out
 }
 
+// RemovedControllerVerbs are the controller seat's verbs release 6 removed (novox/hq ADR 0539, ADR 0429 §8): no
+// delivery plan, batch, tier or push exists, so nothing starts, stops, retries, follows or reads one. Each stays in
+// ControllerVerbs as a row with no input, so a caller is answered by name with its replacement, given here.
+var RemovedControllerVerbs = map[string]string{
+	"plans": "the delivery view (nox-delivery): each machine's want and have, read from the assigner's wants and the " +
+		"node-engine's haves",
+	"plan": "the node's compositions: mesh-controller_composed holds each module's digest and judgement per node, and " +
+		"mesh-hand-compose prints one module's composition for one node",
+	"push": "a want: the assigner writes want.<node>.<module> by its rules, and by hand the operator's credential writes " +
+		"it, naming a kept composition (ADR 0539 clause 10)",
+	"deliver":                "nothing to start: a merged change reaches each machine by its want",
+	"delivery-stop":          "a bad fingerprint is held and its canary set back by the assigner (ADR 0429 §6, ADR 0539 clause 18)",
+	"delivery-backups-again": "the assigner's backup ask, answered on the phone or in the delivery view (ADR 0539 clause 16)",
+	"delivery-walks":         "the delivery view (nox-delivery) and the wants, haves and compositions on the bus",
+	"delivery-order":         "no order to keep: each module reaches its machines by its own want, its providers first by rule 5",
+}
+
+// removedInR6 is the row of a verb release 6 removed from the controller's seat: no input, refused by name.
+func removedInR6(name string) Verb {
+	return Verb{Name: name, Description: "Removed in R6 (ADR 0539): refused by name, naming its replacement: " +
+		RemovedControllerVerbs[name], Input: schema(nil, nil)}
+}
+
 // ControllerSeatName is the seat the control plane holds, whose tools are the mesh's own verbs.
 const ControllerSeatName = "mesh-controller"
 
@@ -115,87 +138,23 @@ var ControllerVerbs = []Verb{
 			"log":    "a build's id (as `builds` lists it): print what the build machine said, line by line",
 			"limit":  "how many builds to list (default 20); not with log",
 		}, nil)},
-	{Name: "plans", Description: "What the last merges produced and where each stands (novox/hq ADR 0162): " +
-		"the tiers, the tier a plan is at, what it waits for and since when; one plan whole, given its id; " +
-		"or, given wait, one plan followed until it moves.",
-		Input: schema(map[string]string{
-			"id": "a plan's id (as `plans` lists them): that plan, tier by tier",
-			"wait": "a plan's id: wait until it moves, then answer it as data — the plan, and what ended the wait " +
-				"(moved, tier, done, or bound); ask again to follow it further (novox/hq issue 229)",
-			"until": "with wait: moved (any change, the default), tier (it reaches another tier) or done (it ends)",
-			"bound": "with wait: how long to wait at most, as 15s or seconds — 20s, the default, is the longest, " +
-				"inside what a call is answered within",
-			"stop":  "a plan's id: stop it — what was asked still builds, nothing further is asked",
-			"close": "a plan's id: close a plan that will not move again, as failed by hand (novox/hq issue 254)",
-			"retry": "a failed plan's id: ask its failed builds again under new ids, and carry the plan on from that tier (novox/hq ADR 0219)",
-			"go": "a walk's id that waits for its delivery's word: start it by hand, in place of mesh-delivery — with why, " +
-				"recorded in the hand-act log (novox/hq ADR 0239)",
-			"repository": "owner/repository: the plan a merge there would produce, saving nothing (what-if); with paths or modules",
-			"paths":      "with repository: the files the merge would change, comma-separated, from the repository's root",
-			"modules":    "with repository: or the modules it would change, comma-separated",
-			"module-dirs": "with repository and paths: the directories holding a module.json at the commit, comma-separated, " +
-				"as the forge's announcer says them (novox/hq issue 278); without it, a directory is a module only when the paths hold its manifest",
-			"data": "with repository and paths: true answers the change plan as data, the document delivery-plan answers " +
-				"(moved, dependents, new, tiers, machines with what each receives and waits for, steps, summary, class, head, base); " +
-				"without it the answer is text (novox/hq ADR 0450 §2)",
-			"head":    "with data: the commit at hand",
-			"base":    "with data: the branch it merges into (default main)",
-			"removed": "with data: the files among paths the change deletes, comma-separated",
-			"limit":   "how many plans to list (default 10); only when listing",
-			"why":     "with stop, close or go: why it is done by hand — required, and recorded in the hand-act log (novox/hq to-be 45 §7)",
-			"cause":   "with stop, close or go: the cause in a word, or a condition's kind (optional)",
-		}, nil, "data")},
+	removedInR6("plans"),
 	// The verbs the delivery's owner asks with (novox/hq ADR 0239): the planner's answer, a group's order and
 	// composed check, and the start and end of a walk. Callable by a person too; mesh-delivery is who needs them.
 	{Name: "delivery-plan", Description: "Removed in R4e (ADR 0501 §5 / ADR 0503 §3): refused by name, naming its replacement",
 		Input: schema(nil, nil)},
-	{Name: "delivery-order", Description: "A delivery group's order (novox/hq ADR 0419): its members in the order " +
-		"they are delivered, every pair and why — built by, verb before caller, version skew, engine before " +
-		"controller — read from the module graph and the manifests' change alone; no `after:` line is read. The " +
-		"cycle, with every module and edge of it, is the one refusal.",
-		Input: schema(map[string]string{"members": "the members, as JSON: [{id, repository, base, head, number, paths, " +
-			"module_dirs, module_dirs_said, removed}]"}, []string{"members"})},
+	removedInR6("delivery-order"),
 	{Name: "delivery-check", Description: "Answers that the checker (mesh-delivery-checker) judges a group (novox/hq " +
 		"ADR 0503 §3); asks nothing. Its inputs stay, since hq's repository check still names it (ADR 0513 §4).",
 		Input: schema(map[string]string{"group": "the group's id (none for one head checked again)",
 			"members": "the members, as JSON, as delivery-order takes them",
 			"ready":   "\"true\" when the pull request is marked ready: its check is queued before every other check (novox/hq ADR 0406 §3)"},
 			[]string{"members"})},
-	{Name: "deliver", Description: "The delivery's word that a walk waiting for it may start (novox/hq ADR 0239): its " +
-		"first tier is asked at the controller's next pass. Refused for a walk that waits for nobody.",
-		Input: schema(map[string]string{"plan": "the walk's id", "why": "what lets it go: its turn, a person's release"},
-			[]string{"plan"})},
-	{Name: "delivery-stop", Description: "End a walk on its delivery's word (novox/hq ADR 0239): failed, said as stopped " +
-		"by whom and why; what it asked still builds and registers, nothing further is asked or sent. Given merges to " +
-		"leave out, every other merge the walk answered is walked again — in the open batch of its kind, or a new one — " +
-		"without them, without each later merge of their repository, which contains one, and without each merge moving " +
-		"a module one moves, each left out too and named (novox/hq ADR 0299); a batch not yet cut drops the merges. The " +
-		"answer names the batch, the merges walked again, the merges left out, the modules the stopped walk sent that " +
-		"stay on their machines, and the merges elsewhere that will still deliver a stopped change.",
-		Input: schema(map[string]string{"plan": "the walk's id", "why": "why", "by": "who stopped the delivery",
-			"without": "merges to leave out, <repository>@<commit>, comma-separated"},
-			[]string{"plan", "why"})},
-	{Name: "delivery-backups-again", Description: "Ask again the backups a walk was held for (novox/hq ADR 0404 " +
-		"decision 4): a walk whose backup before its send failed or did not answer is held, nothing asked or sent; this " +
-		"clears those failed backups and the next look at the plans asks them again, and only them. Refused for a walk " +
-		"with no failed backup. The delivery's release calls it. The answer names the walk and the backups asked again.",
-		Input: schema(map[string]string{"plan": "the held walk's id", "why": "a person's reason, as release passes it",
-			"by": "who released the delivery"}, []string{"plan", "why"})},
-	{Name: "delivery-walks", Description: "The walks the controller keeps (novox/hq ADR 0239): every open one and the " +
-		"last ended ones, each whole — its tiers, each module's state, first machines and first-node gate with its readings, and its " +
-		"phases from its merge to every machine running it (novox/hq ADR 0282) — and whether the delivery seat has a " +
-		"holder on record. Given a plan, that one.",
-		Input: schema(map[string]string{"plan": "one walk's id", "limit": "how many ended walks beside the open ones (default 50)"},
-			nil)},
-	{Name: "plan", Description: "What one machine would run, and why: the declaration the mesh would send it — " +
-		"or, with files, the files it would be given; or, with diff, what a push would change there against what " +
-		"it was last sent: resources added, removed and changed, a container's changed fields (it is recreated), " +
-		"and any mount whose directory on the machine would move (novox/hq ADR 0217).",
-		Input: schema(map[string]string{
-			"node":  "the machine's name",
-			"files": "\"true\": the files this machine would be given, instead of the declaration as JSON",
-			"diff":  "\"true\": what a push would change on this machine, against what it was last sent; not with files",
-		}, []string{"node"}, "files", "diff")},
+	removedInR6("deliver"),
+	removedInR6("delivery-stop"),
+	removedInR6("delivery-backups-again"),
+	removedInR6("delivery-walks"),
+	removedInR6("plan"),
 	{Name: "assign", Description: "Put a module on a machine. Refused with the mesh's own words when it cannot resolve there, " +
 		"or when a seat its resources are applied through is held by nothing on the machine (novox/hq ADR 0207). " +
 		"A module not registered yet is looked for (novox/hq issue 325, ADR 0261): while its build runs — a merge " +
@@ -221,22 +180,7 @@ var ControllerVerbs = []Verb{
 		}, []string{"node", "provision", "from", "module"})},
 	{Name: "unpin", Description: "Take that choice back, putting the question to the mesh again.",
 		Input: schema(map[string]string{"node": "the machine's name", "provision": "the provision"}, []string{"node", "provision"})},
-	{Name: "push", Description: "Send one machine everything it should be. With no machine named it is a push of the " +
-		"WHOLE mesh — every machine that is behind — and the answer says so first; behind says that outright. " +
-		"Answers at once that it is running, with a call id: `calls` with that id says what it sent and, for a " +
-		"machine named, how that machine applied it — applied, refused with its reason, or each failed resource — " +
-		"once it reports within wait (a push can reload the bus, which then refuses any answer still to come). A push by hand is a repair, " +
-		"and says why: recorded in the hand-act log (novox/hq to-be 45 §7). A machine whose push would give a " +
-		"running module's data another directory is held and named, the others sent (novox/hq ADR 0217): read " +
-		"`plan` with diff, and name the machine with move to send it.",
-		Input: schema(map[string]string{
-			"node":   "the machine's name; without it, every machine that is behind",
-			"move":   "with node: the modules whose data may move with this push, comma-separated (optional)",
-			"wait":   "with node: how long the call waits for the machine to report how it applied what it was sent, as \"90s\" or \"2m\"; \"0\" waits for nothing; without it, the controller's setting push-wait (optional)",
-			"behind": "\"true\": every machine that is behind, the whole mesh — the same as naming none, said outright; not with node",
-			"why":    "why this is pushed by hand: recorded in the hand-act log",
-			"cause":  "the cause in a word, or a condition's kind — the word a second push for the same reason uses (optional)",
-		}, []string{"why"}, "behind")},
+	removedInR6("push"),
 	{Name: "rotate", Description: "Replace a credential. A pair credential, by provision (and a consuming machine and module, " +
 		"else every holder): both ends are re-sent together. Or a module's own secret, by machine, module and " +
 		"name: made anew and the machine sent, so the module starts again on it — for a secret its definition " +
@@ -457,26 +401,22 @@ var ControllerVerbs = []Verb{
 			"probe":   "one probe's id (D14): its verdict alone, with every finding — the verdict shows at most twenty a probe",
 		}, nil, "run", "probes", "signals")},
 	// How a module's new builds reach its machines, and the bus's planned step (novox/hq ADR 0236).
-	{Name: "upgrade", Description: "How each module's new builds reach its machines (novox/hq ADR 0236): rolled " +
-		"out one machine first and judged there at the gate, then the rest — or recorded, waiting for a person's " +
-		"push — with where that comes from (a person, the module, the bus, its irreplaceable data, the default) and " +
-		"why. With module, that one; with policy, a person's choice for it — roll-out, record (with why) or default " +
-		"to take the choice back. The bus is never rolled out.",
+	{Name: "upgrade", Description: "Whether each module's new builds wait for a person (novox/hq ADR 0236, ADR 0539 clause 14): " +
+		"for a module of policy record, the assigner writes no want naming a composition judged to recreate a container or move " +
+		"data until the operator answers its ask; with where the policy comes from (a person, the module, the bus, its " +
+		"irreplaceable data, the default) and why. With module, that one; with policy, a person's choice for it — roll-out, " +
+		"record (with why) or default to take the choice back. The bus is never moved by the assigner (ADR 0539 clause 15).",
 		Input: schema(map[string]string{
-			"module":   "one module",
-			"policy":   "with module: roll-out, record or default",
-			"together": "\"true\": with roll-out, every machine at once instead of one machine first",
-			"why":      "with policy or release-backlog: why — required for record and for a release, kept",
-			"backlog":  "\"true\": every build waiting for a gate, per machine — what a release plan would send",
-			"release-backlog": "\"true\": release what waits now, one machine at a time, each judged — after a release " +
-				"plan failed, the mesh waits for this; with why",
-			"cause": "with release-backlog: the cause in a word (optional)",
-		}, nil, "together", "backlog", "release-backlog")},
-	{Name: "bus", Description: "The bus as a planned step (novox/hq to-be 45 §8, ADR 0236): what a bus upgrade " +
-		"would do — the bus's build on each machine against the one the mesh holds — and how the last step went. " +
-		"With upgrade, start one: a person's act with why, after the streams are snapshotted (snapshot-taken says " +
-		"where, while the mesh takes none itself), saying first whether it can be reverted; bus-maintenance is open " +
-		"while it runs and every stream, consumer and a round trip are checked after.",
+			"module": "one module",
+			"policy": "with module: roll-out, record or default",
+			"why":    "with policy: why — required for record, kept",
+		}, nil)},
+	{Name: "bus", Description: "The bus as a person's step (novox/hq to-be 45 §8, ADR 0236, ADR 0539 clause 15): what a bus " +
+		"upgrade would do — the bus's build on each machine against the one the mesh holds — and how the last step went. " +
+		"With upgrade, check one: a person's act with why, after the streams are snapshotted (snapshot-taken says where, " +
+		"while the mesh takes none itself), saying first whether it can be reverted; then it answers the want the operator " +
+		"writes with the operator's credential, want.<node>.<bus module>, recorded — nothing is sent, and the assigner never " +
+		"moves the bus.",
 		Input: schema(map[string]string{
 			"upgrade":        "\"true\": start the bus's upgrade",
 			"why":            "with upgrade: why — required, recorded in the hand-act log",

go/catalogue/verbs_r6_test.go

@@ -0,0 +1,115 @@
+package catalogue
+
+import (
+	"strings"
+	"testing"
+)
+
+// 1943/AC4: the controller's seat no longer offers a verb that starts, stops, retries, follows or reads a delivery
+// plan, nor a push: each is a row with no input whose description refuses it by name and names its replacement, and
+// each is in the removed list the holder answers from. upgrade keeps its policy and drops the plan's backlog.
+func TestTheControllerSeatHasNoPlanVerbs(t *testing.T) {
+	rows := map[string]Verb{}
+	for _, v := range ControllerVerbs {
+		rows[v.Name] = v
+	}
+	gone := []string{"plans", "plan", "push", "deliver", "delivery-stop", "delivery-backups-again", "delivery-walks", "delivery-order"}
+	for _, name := range gone {
+		v, ok := rows[name]
+		if !ok {
+			t.Errorf("%s is not in the table, so a caller is not answered by name", name)
+			continue
+		}
+		replacement, removed := RemovedControllerVerbs[name]
+		if !removed || replacement == "" {
+			t.Errorf("%s is not in the removed list with its replacement", name)
+		}
+		if !strings.HasPrefix(v.Description, "Removed in R6 (ADR 0539): refused by name") || !strings.Contains(v.Description, replacement) {
+			t.Errorf("%s = %q, want refused by name, naming %q", name, v.Description, replacement)
+		}
+		if props, _ := v.Input["properties"].(map[string]any); len(props) > 0 {
+			t.Errorf("%s still takes %v", name, props)
+		}
+	}
+	props, _ := rows["upgrade"].Input["properties"].(map[string]any)
+	for _, arg := range []string{"together", "backlog", "release-backlog", "cause"} {
+		if _, has := props[arg]; has {
+			t.Errorf("upgrade still takes %s, a plan's", arg)
+		}
+	}
+	for _, arg := range []string{"module", "policy", "why"} {
+		if _, has := props[arg]; !has {
+			t.Errorf("upgrade no longer takes %s", arg)
+		}
+	}
+	for _, word := range []string{"rolled", "gate", "backlog", "push"} {
+		if strings.Contains(rows["upgrade"].Description, word) {
+			t.Errorf("upgrade's description still speaks of %q: %q", word, rows["upgrade"].Description)
+		}
+	}
+	if !strings.Contains(rows["bus"].Description, "want") {
+		t.Errorf("bus does not say the operator writes the bus's want: %q", rows["bus"].Description)
+	}
+	for name := range RemovedControllerVerbs {
+		if v := rows[name]; !strings.HasPrefix(v.Description, "Removed in R6") {
+			t.Errorf("%s is in the removed list and its row says %q", name, v.Description)
+		}
+	}
+}
+
+// 1943/AC4: the delivery seat keeps the merge's verbs and no longer offers times, what-if, release, stop or
+// retire-history: each is a row with no input, optional so the holder of before and the holder of release 6 both hold
+// the seat, refusing it by name; mark-ready, served by nobody since issue 1022, is gone.
+func TestTheDeliverySeatHasNoPlanVerbs(t *testing.T) {
+	seat, ok := SeatNamed(DeliverySeat)
+	if !ok {
+		t.Fatal("the delivery seat is not in the set")
+	}
+	rows := map[string]Verb{}
+	for _, v := range seat.Serves {
+		rows[v.Name] = v
+	}
+	for _, name := range []string{"times", "what-if", "release", "stop", "retire-history"} {
+		v, ok := rows[name]
+		replacement, removed := RemovedDeliveryVerbs[name]
+		if !ok || !removed || replacement == "" {
+			t.Errorf("%s: in the table %v, in the removed list %v", name, ok, removed)
+			continue
+		}
+		if !strings.HasPrefix(v.Description, "Removed in R6 (ADR 0539): refused by name") || !strings.Contains(v.Description, replacement) || !v.Optional {
+			t.Errorf("%s = %q (optional %v), want an optional row refusing it by name", name, v.Description, v.Optional)
+		}
+		if props, _ := v.Input["properties"].(map[string]any); len(props) > 0 {
+			t.Errorf("%s still takes %v", name, props)
+		}
+	}
+	if _, ok := rows["mark-ready"]; ok {
+		t.Errorf("mark-ready is still promised")
+	}
+	for _, kept := range []string{"deliveries", "show", "groups", "checks", "table", "recheck", "close", "stalled"} {
+		if v, ok := rows[kept]; !ok || strings.HasPrefix(v.Description, "Removed") {
+			t.Errorf("%s is not kept (ADR 0539 clause 17)", kept)
+		}
+	}
+	gate := Manifest{Module: "mesh-delivery", Claims: []Claim{{Name: DeliverySeat, Scope: ScopeMesh,
+		Serves: []string{"deliveries", "show", "groups", "checks", "table", "stalled", "recheck", "close"}}}}
+	if err := CanHold(gate, seat); err != nil {
+		t.Errorf("the gate of release 6 cannot hold the seat: %v", err)
+	}
+	gate.Claims[0].Serves = append(gate.Claims[0].Serves, "times", "what-if", "release", "stop", "retire-history")
+	if err := CanHold(gate, seat); err != nil {
+		t.Errorf("the gate of release 5 cannot hold the seat: %v", err)
+	}
+}
+
+// 1943 (for 1945/AC14): the controller's seat says a bucket it deleted at its first start as its event, bucket-deleted
+// (ADR 0539 clause 13).
+func TestTheControllerSaysABucketItDeleted(t *testing.T) {
+	seat, ok := SeatNamed(ControllerSeatName)
+	if !ok {
+		t.Fatal("no controller seat")
+	}
+	if !SeatSays(seat.Emits, "bucket-deleted") {
+		t.Errorf("the controller's seat does not emit bucket-deleted: %v", seat.Emits)
+	}
+}

go/cmd/mesh-hand-compose/main.go

@@ -0,0 +1,209 @@
+// mesh-hand-compose composes one module for one node by hand, from the inputs the controller keeps, and signs it with the
+// operator's key, for the hand path of novox/hq ADR 0539 clause 10: a fingerprint the controller never composed (a
+// hand build), while the controller cannot compose its own fix. It composes with mesh-sdk's composition, the one the
+// controller writes with (compose.Compositions), and prints the composition, its key and its digest; only with -write
+// does it write them, with the operator's credential: the composition into the node's bucket composed-<node>, each
+// file over 64 KiB into the node's object bucket, and the digest into mesh-controller_composed. The want is the
+// operator's next act, naming that digest; each act is recorded in the hand-act log.
+//
+//	mesh-hand-compose -input <inputs.json> -node <node> -module <module> -fp <src2:...> -key <operator key>
+//	             [-write -nats <url> -creds <operator credential>]
+//
+// The inputs are a compose.Input as JSON. The key is the operator's ed25519 private key, PKCS#8 in PEM; the
+// node-engine trusts it beside the controller's (ADR 0539 clause 3).
+package main
+
+import (
+	"context"
+	"crypto/ed25519"
+	"crypto/x509"
+	"encoding/json"
+	"encoding/pem"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/compose"
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+func main() {
+	if err := run(os.Args[1:], os.Stdout); err != nil {
+		fmt.Fprintln(os.Stderr, "mesh-hand-compose:", err)
+		os.Exit(1)
+	}
+}
+
+// printed is what mesh-hand-compose prints: where the composition goes, its digest, the composition, and whether it was
+// written.
+type printed struct {
+	Bucket      string          `json:"bucket"`
+	Key         string          `json:"key"`
+	Digest      string          `json:"digest"`
+	Composition json.RawMessage `json:"composition"`
+	Objects     []string        `json:"objects,omitempty"`
+	Written     bool            `json:"written"`
+	Next        string          `json:"next"`
+}
+
+func run(args []string, stdout io.Writer) error {
+	fs := flag.NewFlagSet("mesh-hand-compose", flag.ContinueOnError)
+	input := fs.String("input", "", "the controller's kept inputs, a compose.Input as JSON")
+	node := fs.String("node", "", "the node to compose for")
+	module := fs.String("module", "", "the module to compose")
+	fp := fs.String("fp", "", "the module's fingerprint, src2: and 64 hex digits")
+	keyFile := fs.String("key", "", "the operator's ed25519 private key, PKCS#8 in PEM")
+	write := fs.Bool("write", false, "write the composition, its files and its digest, with the operator's credential")
+	url := fs.String("nats", nats.DefaultURL, "with -write: the bus")
+	creds := fs.String("creds", "", "with -write: the operator's credential file")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+	switch {
+	case *input == "" || *node == "" || *module == "" || *fp == "":
+		return errors.New("-input, -node, -module and -fp are each required")
+	case *keyFile == "":
+		return errors.New("-key is required: a composition made by hand is signed by the operator's key, and the node-engine applies no other")
+	case *write && *creds == "":
+		return errors.New("-write needs -creds: the operator's credential is the only hand writer of a composition")
+	}
+	key, err := readKey(*keyFile)
+	if err != nil {
+		return err
+	}
+	key2, err := delivery.ComposedKey(*node, *module, *fp)
+	if err != nil {
+		return err
+	}
+	bucket, err := delivery.ComposedBucketFor(*node)
+	if err != nil {
+		return err
+	}
+	raw, err := os.ReadFile(*input)
+	if err != nil {
+		return err
+	}
+	var in compose.Input
+	if err := json.Unmarshal(raw, &in); err != nil {
+		return fmt.Errorf("the inputs in %s are not a compose.Input: %w", *input, err)
+	}
+	all, _, err := compose.Compositions(in, *node, map[string]string{*module: *fp}, compose.Reading)
+	if err != nil {
+		return err
+	}
+	c, ok := all[key2]
+	if !ok {
+		return fmt.Errorf("%s does not run %s: its composition holds none of it", *node, *module)
+	}
+	c, objects, err := c.ByDigest()
+	if err != nil {
+		return err
+	}
+	if c, err = delivery.SignComposed(c, key); err != nil {
+		return err
+	}
+	encoded, err := delivery.EncodeComposed(c)
+	if err != nil {
+		return err
+	}
+	digest, err := delivery.ComposedDigestOf(c)
+	if err != nil {
+		return err
+	}
+	out := printed{Bucket: bucket, Key: key2, Digest: digest, Composition: encoded,
+		Next: fmt.Sprintf("write want.%s.%s naming fp %s and composed %s with the operator's credential, and record each act in the hand-act log", *node, *module, *fp, digest)}
+	for d := range objects {
+		out.Objects = append(out.Objects, d)
+	}
+	if *write {
+		if err := writeIt(*url, *creds, *node, bucket, key2, encoded, digest, objects); err != nil {
+			return err
+		}
+		out.Written = true
+	}
+	enc := json.NewEncoder(stdout)
+	enc.SetIndent("", "  ")
+	return enc.Encode(out)
+}
+
+func readKey(path string) (ed25519.PrivateKey, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	block, _ := pem.Decode(raw)
+	if block == nil {
+		return nil, fmt.Errorf("%s holds no PEM block", path)
+	}
+	parsed, err := x509.ParsePKCS8PrivateKey(block.Bytes)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", path, err)
+	}
+	key, ok := parsed.(ed25519.PrivateKey)
+	if !ok {
+		return nil, fmt.Errorf("%s is not an ed25519 key", path)
+	}
+	return key, nil
+}
+
+// writeIt writes the files by digest, then the composition, then its digest: a reader that finds the digest finds the
+// composition and its files already there.
+func writeIt(url, creds, node, bucket, key string, encoded []byte, digest string, objects map[string][]byte) error {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+	defer cancel()
+	nc, err := nats.Connect(url, nats.UserCredentials(creds), nats.Name("mesh-hand-compose"))
+	if err != nil {
+		return err
+	}
+	defer nc.Close()
+	js, err := jetstream.New(nc)
+	if err != nil {
+		return err
+	}
+	if len(objects) > 0 {
+		filesBucket, err := declaration.FileBucketFor(node)
+		if err != nil {
+			return err
+		}
+		store, err := js.ObjectStore(ctx, filesBucket)
+		if err != nil {
+			return fmt.Errorf("the node's object bucket %s: %w", filesBucket, err)
+		}
+		for d, body := range objects {
+			name, err := declaration.ObjectName(d)
+			if err != nil {
+				return err
+			}
+			if _, err := store.PutBytes(ctx, name, body); err != nil {
+				return fmt.Errorf("the file %s: %w", d, err)
+			}
+		}
+	}
+	composed, err := js.KeyValue(ctx, bucket)
+	if err != nil {
+		return fmt.Errorf("the bucket %s: %w", bucket, err)
+	}
+	if _, err := composed.Put(ctx, key, encoded); err != nil {
+		return fmt.Errorf("%s in %s: %w", key, bucket, err)
+	}
+	value, err := delivery.EncodeComposedDigest(delivery.ComposedDigest{Digest: digest, Judgement: delivery.JudgedCannot,
+		Words: "composed by hand with mesh-hand-compose (ADR 0539 clause 10): the operator writes the want"})
+	if err != nil {
+		return err
+	}
+	digests, err := js.KeyValue(ctx, delivery.ControllerComposedBucket)
+	if err != nil {
+		return fmt.Errorf("the bucket %s: %w", delivery.ControllerComposedBucket, err)
+	}
+	if _, err := digests.Put(ctx, key, value); err != nil {
+		return fmt.Errorf("%s in %s: %w", key, delivery.ControllerComposedBucket, err)
+	}
+	return nil
+}

go/cmd/mesh-hand-compose/main_test.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"bytes"
+	"crypto/ed25519"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/json"
+	"encoding/pem"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/compose"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/overlay"
+)
+
+// aMesh is the Input of mesh-controller's aMesh, as mesh-sdk's compose tests make it (compose/fixture_test.go): two
+// machines on the private network, the module the mesh provides for itself assigned to both. The manifest is the one
+// the controller provides (overlay.Manifest), read back as the catalogue reads it.
+func aMesh(t *testing.T) compose.Input {
+	t.Helper()
+	var m catalogue.Manifest
+	b, _ := json.Marshal(overlay.Manifest())
+	if err := json.Unmarshal(b, &m); err != nil {
+		t.Fatal(err)
+	}
+	in := compose.Input{Catalogue: map[string]catalogue.Manifest{overlay.Name: m}}
+	for i, name := range []string{"anchor", "laptop"} {
+		pub, _, _ := ed25519.GenerateKey(rand.Reader)
+		in.Nodes = append(in.Nodes, compose.Node{Name: name,
+			Place:    compose.Place{Key: base64.StdEncoding.EncodeToString(pub), Endpoint: name + ".example:51820", Site: "here", Hub: name == "anchor", Address: []string{"10.77.0.1", "10.77.0.2"}[i]},
+			Assigned: []string{overlay.Name}, Capabilities: map[string]bool{"container-runtime": true, "wireguard": true, "systemd": true}})
+	}
+	return in
+}
+
+func writeKey(t *testing.T, dir string) ed25519.PublicKey {
+	t.Helper()
+	pub, priv, _ := ed25519.GenerateKey(rand.Reader)
+	der, err := x509.MarshalPKCS8PrivateKey(priv)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "operator.key"), pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: der}), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	return pub
+}
+
+// 1943/AC5: mesh-hand-compose, given the kept inputs, a node, a module and its fingerprint, prints that module's
+// composition for that node signed by the operator's key and its digest: its resources are the controller's for that
+// module on that node (compose.Compose), and it verifies against the operator's key. Without --write it writes nothing.
+func TestMeshComposeGivesTheControllersResourcesSignedByTheOperator(t *testing.T) {
+	dir := t.TempDir()
+	in := aMesh(t)
+	raw, err := json.Marshal(in)
+	if err != nil {
+		t.Fatal(err)
+	}
+	input := filepath.Join(dir, "input.json")
+	if err := os.WriteFile(input, raw, 0o600); err != nil {
+		t.Fatal(err)
+	}
+	operator := writeKey(t, dir)
+	fp := delivery.SourcePrefix2 + strings.Repeat("a", 64)
+
+	var out bytes.Buffer
+	if err := run([]string{"-input", input, "-node", "laptop", "-module", overlay.Name, "-fp", fp,
+		"-key", filepath.Join(dir, "operator.key")}, &out); err != nil {
+		t.Fatal(err)
+	}
+	var printed struct {
+		Key         string          `json:"key"`
+		Bucket      string          `json:"bucket"`
+		Digest      string          `json:"digest"`
+		Composition json.RawMessage `json:"composition"`
+		Written     bool            `json:"written"`
+	}
+	if err := json.Unmarshal(out.Bytes(), &printed); err != nil {
+		t.Fatalf("%s: %v", out.String(), err)
+	}
+	c, err := delivery.DecodeComposed(printed.Composition)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if digest, err := delivery.VerifyComposed(c, []ed25519.PublicKey{operator}); err != nil || digest != printed.Digest {
+		t.Errorf("the composition verifies %q, %v against the operator's key; printed %s", digest, err, printed.Digest)
+	}
+	wantKey, _ := delivery.ComposedKey("laptop", overlay.Name, fp)
+	if printed.Key != wantKey || printed.Bucket != "composed-laptop" || printed.Written {
+		t.Errorf("printed key %s in %s, written %v", printed.Key, printed.Bucket, printed.Written)
+	}
+
+	d, _, err := compose.Compose(in, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var want, got []string
+	for _, r := range d.Resources {
+		want = append(want, r["id"].(string))
+	}
+	for _, r := range c.Resources {
+		var head struct{ ID string }
+		_ = json.Unmarshal(r, &head)
+		got = append(got, head.ID)
+	}
+	sort.Strings(want)
+	sort.Strings(got)
+	if len(got) == 0 || strings.Join(got, " ") != strings.Join(want, " ") {
+		t.Errorf("mesh-hand-compose gives %v, the controller's composition %v", got, want)
+	}
+}
+
+// 1943/AC5: mesh-hand-compose refuses what it cannot compose, naming why: no key, a fingerprint not of the new form, a
+// module the node does not run, a node the mesh does not have.
+func TestMeshComposeRefuses(t *testing.T) {
+	dir := t.TempDir()
+	raw, _ := json.Marshal(aMesh(t))
+	input := filepath.Join(dir, "input.json")
+	_ = os.WriteFile(input, raw, 0o600)
+	writeKey(t, dir)
+	key := filepath.Join(dir, "operator.key")
+	fp := delivery.SourcePrefix2 + strings.Repeat("a", 64)
+	for _, c := range []struct {
+		args []string
+		why  string
+	}{
+		{[]string{"-input", input, "-node", "laptop", "-module", overlay.Name, "-fp", fp}, "-key"},
+		{[]string{"-input", input, "-node", "laptop", "-module", overlay.Name, "-fp", "src2:1", "-key", key}, "fingerprint"},
+		{[]string{"-input", input, "-node", "laptop", "-module", "mesh-mail", "-fp", fp, "-key", key}, "does not run mesh-mail"},
+		{[]string{"-input", input, "-node", "nowhere", "-module", overlay.Name, "-fp", fp, "-key", key}, "nowhere"},
+		{[]string{"-input", input, "-node", "laptop", "-module", overlay.Name, "-fp", fp, "-key", key, "-write"}, "-creds"},
+	} {
+		var out bytes.Buffer
+		if err := run(c.args, &out); err == nil || !strings.Contains(err.Error(), c.why) {
+			t.Errorf("mesh-hand-compose %v = %v, want a refusal saying %q", c.args, err, c.why)
+		}
+	}
+}

go/compose/composed.go

@@ -0,0 +1,94 @@
+package compose
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+// Compositions is one node's compositions (novox/hq ADR 0539 clauses 1 and 2): its declaration composed over in, as
+// the controller composes it, split into each module's composition at the fingerprint fps gives it and the node's own
+// (`<node>.node`), by key (delivery.ComposedKey). Each resource says its module, whatever the node reported it reads.
+// A module fps gives no fingerprint for is not composed and is named in skipped, so a caller composing one module
+// (mesh-hand-compose) gets that one. Each module's Data says whether its manifest declares data. The compositions are not
+// signed and not yet by digest: the writer does both (delivery.SignComposed, Composed.ByDigest).
+func Compositions(in Input, node string, fps map[string]string, mode Mode) (out map[string]delivery.Composed, skipped []string, err error) {
+	reading := in
+	reading.Nodes = append([]Node(nil), in.Nodes...)
+	found := false
+	for i := range reading.Nodes {
+		if reading.Nodes[i].Name == node {
+			reading.Nodes[i].ReadsModules = true
+			found = true
+		}
+	}
+	if !found {
+		return nil, nil, fmt.Errorf("compose: the mesh has no node %q", node)
+	}
+	d, problems, err := ComposeIn(reading, node, mode)
+	if err != nil {
+		return nil, nil, err
+	}
+	if len(problems) > 0 {
+		return nil, nil, fmt.Errorf("compose: %s's declaration is refused by the node-engine's validator: %v", node, problems)
+	}
+	body, err := d.Body()
+	if err != nil {
+		return nil, nil, err
+	}
+	var envelope struct {
+		Resources   []json.RawMessage     `json:"resources"`
+		Adoption    *declaration.Adoption `json:"adoption"`
+		Filled      []string              `json:"filled_files"`
+		Provisioner string                `json:"provisioner_account"`
+	}
+	if err := json.Unmarshal(body, &envelope); err != nil {
+		return nil, nil, err
+	}
+	var kept []json.RawMessage
+	keptPaths := map[string]bool{}
+	left := map[string]bool{}
+	for _, raw := range envelope.Resources {
+		var head struct {
+			Module string `json:"module"`
+			Type   string `json:"type"`
+			Path   string `json:"path"`
+		}
+		if err := json.Unmarshal(raw, &head); err != nil {
+			return nil, nil, err
+		}
+		if _, ok := fps[head.Module]; head.Module != "" && !ok {
+			left[head.Module] = true
+			continue
+		}
+		if head.Type == string(declaration.TypeFile) {
+			keptPaths[head.Path] = true
+		}
+		kept = append(kept, raw)
+	}
+	var filled []string
+	for _, p := range envelope.Filled {
+		if keptPaths[p] {
+			filled = append(filled, p)
+		}
+	}
+	out, err = delivery.SplitComposed(node, kept, fps, filled,
+		delivery.NodeOwn{Adoption: envelope.Adoption, Provisioner: envelope.Provisioner})
+	if err != nil {
+		return nil, nil, err
+	}
+	for key, c := range out {
+		if m, ok := in.Catalogue[c.Module]; ok && c.Module != "" {
+			c.Data = len(m.DataItems()) > 0
+			out[key] = c
+		}
+	}
+	for m := range left {
+		skipped = append(skipped, m)
+	}
+	sort.Strings(skipped)
+	return out, skipped, nil
+}

go/compose/composed_test.go

@@ -0,0 +1,88 @@
+package compose
+
+import (
+	"encoding/json"
+	"sort"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+func fpFor(c byte) string { return delivery.SourcePrefix2 + strings.Repeat(string(c), 64) }
+
+// 1943/AC5: a node's compositions are its declaration as Compose gives it, split by the module each resource belongs
+// to: every resource once, each in its module's composition at the fingerprint given, the module's ownership said on
+// it; a module given no fingerprint is named as skipped and composed nowhere.
+func TestCompositionsAreTheDeclarationSplitByModule(t *testing.T) {
+	in := aSmallMesh(t)
+	d, _, err := Compose(in, "laptop")
+	if err != nil {
+		t.Fatal(err)
+	}
+	var want []string
+	for _, r := range d.Resources {
+		want = append(want, r["type"].(string)+":"+r["id"].(string))
+	}
+	sort.Strings(want)
+
+	fps := map[string]string{"mesh-wireguard": fpFor('a'), "files": fpFor('b')}
+	out, skipped, err := Compositions(in, "laptop", fps, Foreseeing)
+	if err != nil || len(skipped) != 0 {
+		t.Fatalf("Compositions = %v, skipped %v", err, skipped)
+	}
+	var got []string
+	for key, c := range out {
+		node, module, fp, isNode, err := delivery.ParseComposedKey(key)
+		if err != nil || node != "laptop" || module != c.Module || fp != c.FP || (isNode != (module == "")) {
+			t.Errorf("key %s holds %s at %s (%v)", key, c.Module, c.FP, err)
+		}
+		if !isNode && fp != fps[module] {
+			t.Errorf("%s is composed at %s, given %s", module, fp, fps[module])
+		}
+		if _, err := delivery.EncodeComposed(c); err != nil {
+			t.Errorf("%s: %v", key, err)
+		}
+		for _, raw := range c.Resources {
+			var r struct{ ID, Type, Module string }
+			_ = json.Unmarshal(raw, &r)
+			if r.Module != module {
+				t.Errorf("%s holds %s of %q", key, r.ID, r.Module)
+			}
+			got = append(got, r.Type+":"+r.ID)
+		}
+	}
+	sort.Strings(got)
+	if strings.Join(got, " ") != strings.Join(want, " ") {
+		t.Errorf("the compositions hold %v, the declaration %v", got, want)
+	}
+
+	one, skipped, err := Compositions(in, "laptop", map[string]string{"files": fpFor('b')}, Foreseeing)
+	if err != nil || strings.Join(skipped, ",") != "mesh-wireguard" {
+		t.Fatalf("one module: %v, skipped %v", err, skipped)
+	}
+	for _, c := range one {
+		if c.Module == "mesh-wireguard" {
+			t.Errorf("a module given no fingerprint was composed")
+		}
+	}
+	if _, _, err := Compositions(in, "nowhere", fps, Foreseeing); err == nil {
+		t.Errorf("a node the mesh does not have was composed")
+	}
+}
+
+// 1943/AC1: the upgrade policies and sources a composition's value may name are the catalogue's own words.
+func TestTheComposedPoliciesAreTheCatalogues(t *testing.T) {
+	for _, p := range []string{catalogue.PolicyRoll, catalogue.PolicyTogether, catalogue.PolicyRecord} {
+		for _, from := range []string{catalogue.FromPerson, catalogue.FromModule, catalogue.FromBus, catalogue.FromData, catalogue.FromDefault} {
+			v := delivery.ComposedDigest{Digest: "sha256:" + strings.Repeat("a", 64), Judgement: delivery.JudgedNeither, Policy: p, PolicyFrom: from}
+			if _, err := delivery.EncodeComposedDigest(v); err != nil {
+				t.Errorf("%s from %s: %v", p, from, err)
+			}
+		}
+	}
+	if delivery.PolicyRecord != catalogue.PolicyRecord {
+		t.Errorf("delivery.PolicyRecord = %q, the catalogue's %q", delivery.PolicyRecord, catalogue.PolicyRecord)
+	}
+}

go/declaration/resource.go

@@ -0,0 +1,47 @@
+package declaration
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// ParseResource reads one resource as Parse reads each of a declaration's resources: by its type, strictly, refusing
+// a field its kind does not use and anything its kind refuses, and never an action (the link may not carry one, ADR
+// 0005). It judges the resource alone: what Parse judges across resources (an opening on a node not adopted, the
+// files the provisioner fills, what replaces what) is for the whole a node applies (novox/hq ADR 0539 clause 1: a
+// composition is one module's resources, and a node applies its compositions together with its own key).
+func ParseResource(raw json.RawMessage) (Resource, error) {
+	var head struct {
+		ID   string `json:"id"`
+		Type Type   `json:"type"`
+	}
+	if err := json.Unmarshal(raw, &head); err != nil {
+		return nil, &RefusalError{Problems: []string{"not a resource: " + err.Error()}}
+	}
+	where := "resource"
+	if head.ID == "" {
+		return nil, &RefusalError{Problems: []string{where + ": no id. Identity is what lets the host know this is " +
+			"the same resource it applied last time"}}
+	}
+	where = fmt.Sprintf("resource %q", head.ID)
+	resource := newOf(head.Type)
+	if resource == nil {
+		return nil, &RefusalError{Problems: []string{fmt.Sprintf("%s: unknown type %q. This host understands %s",
+			where, head.Type, vocabulary())}}
+	}
+	if unknown := unknownFields(raw, resource); len(unknown) > 0 {
+		var problems []string
+		for _, field := range unknown {
+			problems = append(problems, fmt.Sprintf("%s: a %s does not use %q, and it is set. Refused rather "+
+				"than ignored", where, head.Type, field))
+		}
+		return nil, &RefusalError{Problems: problems}
+	}
+	if err := json.Unmarshal(raw, resource); err != nil {
+		return nil, &RefusalError{Problems: []string{fmt.Sprintf("%s: %s", where, err)}}
+	}
+	if problems := resource.validate(where, false); len(problems) > 0 {
+		return nil, &RefusalError{Problems: problems}
+	}
+	return resource, nil
+}

go/delivery/assigner.go

@@ -1,6 +1,7 @@
 package delivery
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"reflect"
@@ -16,6 +17,10 @@ import (
 // only compared; the node agent applying them is release 6 (ADR 0429 §7). Only the assigner's credential writes these
 // buckets; the watchman, the view and the controller read them.
 //
+// **Release 6** (ADR 0539 clauses 1, 6 and 16): a want also names the digest of the one composition it allows, written
+// only once that composition exists (the seventh rule, RuleComposed), and carries the answer to a failed backup; the
+// node's own want `want.<node>.node` names the digest of the node's own composition (NodeWant).
+//
 // **The bucket is the first word, the key the rest** (as the builder's `builds.<module>.<fp>` is the key
 // `<module>.<fp>` in its builds bucket): the differences bucket's keys are `<node>.<module>`. The wants bucket holds
 // two kinds of key, so each keeps its word: `want.<node>.<module>` and `held.<module>.<fingerprint hex>`.
@@ -50,7 +55,33 @@ func WantKey(node, module string) (string, error) {
 	return wantWord + "." + have, nil
 }
 
-// ParseWantKey is the inverse of WantKey; it refuses a held key, a have key and any key of another bucket, naming it.
+// WantNodeKey is the key, in AssignerWantsBucket, of a node's own want: `want.<node>.node`, naming the digest of the
+// node's own composition (ADR 0539 clause 6; ADR 0429 §4's node key). The assigner writes it once the node's own
+// composition exists.
+func WantNodeKey(node string) (string, error) {
+	own, err := HaveNodeKey(node)
+	if err != nil {
+		return "", err
+	}
+	return wantWord + "." + own, nil
+}
+
+// ParseWantNodeKey is the inverse of WantNodeKey; it refuses a module's want key and any key of another bucket,
+// naming it.
+func ParseWantNodeKey(key string) (node string, err error) {
+	rest, ok := strings.CutPrefix(key, wantWord+".")
+	if !ok {
+		return "", fmt.Errorf("delivery: %q is not a node's own want key, want.<node>.node", key)
+	}
+	node, _, isNode, err := ParseHaveKey(rest)
+	if err != nil || !isNode {
+		return "", fmt.Errorf("delivery: %q is not a node's own want key, want.<node>.node", key)
+	}
+	return node, nil
+}
+
+// ParseWantKey is the inverse of WantKey; it refuses a held key, a have key, the node's own want key and any key of
+// another bucket, naming it.
 func ParseWantKey(key string) (node, module string, err error) {
 	rest, ok := strings.CutPrefix(key, wantWord+".")
 	if !ok {
@@ -100,7 +131,8 @@ func ParseDifferenceKey(key string) (node, module string, err error) {
 	return node, module, nil
 }
 
-// The six rules of ADR 0429 §6, by number, as a want or a difference names the one that holds a node back.
+// The rules of ADR 0429 §6 and ADR 0539 clause 6, by number, as a want or a difference names the one that holds a node
+// back.
 const (
 	RuleBuildDone = 1 // the build of F is done
 	RuleNotHeld   = 2 // F is not held
@@ -108,15 +140,25 @@ const (
 	RuleStep      = 4 // at most step other nodes are ahead (step 0: no limit, ADR 0528 §3)
 	RuleProviders = 5 // every provider the module requires runs healthy on that node, or at its canary
 	RuleGrant     = 6 // the module's credential for F exists (grants.<module>.<fp>)
+	RuleComposed  = 7 // the module's composition for that node at F exists (mesh-controller_composed, ADR 0539 §6)
 )
 
 func checkRule(rule int, of string) error {
-	if rule < RuleBuildDone || rule > RuleGrant {
-		return fmt.Errorf("delivery: %s names the rule %d, which is not one of the six (1 to 6)", of, rule)
+	if rule < RuleBuildDone || rule > RuleComposed {
+		return fmt.Errorf("delivery: %s names the rule %d, which is not one of the seven (1 to 7)", of, rule)
 	}
 	return nil
 }
 
+// The answers a want carries to a failed backup before an apply (ADR 0539 clause 16): the node agent reads them from
+// its own want and from nothing else.
+const (
+	// BackupAgain is the answer to back the module up again before the apply.
+	BackupAgain = "again"
+	// BackupSkip is the answer to go on without a backup.
+	BackupSkip = "skip"
+)
+
 func checkFingerprint(fp, of string) error {
 	if _, err := FingerprintKeyPart(fp); err != nil {
 		return fmt.Errorf("delivery: %s: %w", of, err)
@@ -124,29 +166,54 @@ func checkFingerprint(fp, of string) error {
 	return nil
 }
 
-// Want is a node's want for a module: the fingerprint FP the node should run, or Removed for a module that left the
-// node's modules (then FP is empty). When the module's newest fingerprint is not yet allowed on this node, Newest names
-// it and Rule the rule that holds the node back; both are empty when FP is the newest. Words say why in a sentence.
-// The entry's own time says since when.
+// Want is a node's want for a module: the fingerprint FP the node should run and the digest Composed of the one
+// composition of it the node may apply (ADR 0539 clause 1), or Removed for a module that left the node's modules (then
+// both are empty). When the module's newest fingerprint is not yet allowed on this node, Newest names it and Rule the
+// rule that holds the node back; both are empty when FP is the newest. Backup is the answer to a failed backup before
+// the apply, BackupAgain or BackupSkip (clause 16), empty when none was asked. Words say why in a sentence. The
+// entry's own time says since when.
 type Want struct {
-	V       int    `json:"v"`
-	FP      string `json:"fp,omitempty"`
-	Removed bool   `json:"removed,omitempty"`
-	Newest  string `json:"newest,omitempty"`
-	Rule    int    `json:"rule,omitempty"`
-	Words   string `json:"words,omitempty"`
+	V        int    `json:"v"`
+	FP       string `json:"fp,omitempty"`
+	Composed string `json:"composed,omitempty"`
+	Removed  bool   `json:"removed,omitempty"`
+	Newest   string `json:"newest,omitempty"`
+	Rule     int    `json:"rule,omitempty"`
+	Backup   string `json:"backup,omitempty"`
+	Words    string `json:"words,omitempty"`
+	// Put says the want was written by a put (ADR 0546), and Hold that the put holds it: the rules pass over it until it
+	// is released. A put's want names no newest fingerprint or rule.
+	Put  bool `json:"put,omitempty"`
+	Hold bool `json:"hold,omitempty"`
 }
 
 func (w Want) check() error {
 	if w.Removed {
-		if w.FP != "" || w.Newest != "" || w.Rule != 0 {
-			return fmt.Errorf("delivery: a removed want names no fingerprint and no rule")
+		if w.FP != "" || w.Composed != "" || w.Newest != "" || w.Rule != 0 || w.Backup != "" || w.Put || w.Hold {
+			return fmt.Errorf("delivery: a removed want names no fingerprint, composition, rule, backup answer or put")
 		}
 		return nil
 	}
+	if w.Hold && !w.Put {
+		return fmt.Errorf("delivery: only a put holds a want")
+	}
+	if w.Put && (w.Newest != "" || w.Rule != 0) {
+		return fmt.Errorf("delivery: a put's want is held back by no rule")
+	}
 	if err := checkFingerprint(w.FP, "a want's fingerprint"); err != nil {
 		return err
 	}
+	if w.Composed == "" {
+		return fmt.Errorf("delivery: the want of %s names no composition: a want names the digest of the one composition it allows (ADR 0539 clause 1)", w.FP)
+	}
+	if err := checkDigest(w.Composed, "a want's composition digest"); err != nil {
+		return err
+	}
+	switch w.Backup {
+	case "", BackupAgain, BackupSkip:
+	default:
+		return fmt.Errorf("delivery: the backup answer %q is not %s or %s", w.Backup, BackupAgain, BackupSkip)
+	}
 	if w.Newest == "" && w.Rule == 0 {
 		return nil
 	}
@@ -236,6 +303,41 @@ func DecodeWant(data []byte) (Want, error) {
 // SameWant says whether two wants are the same value, so the assigner writes only when they differ.
 func SameWant(a, b Want) bool { return a == b }
 
+// NodeWant is a node's own want (WantNodeKey): the digest Composed of the node's own composition it may apply. Words
+// say why in a sentence.
+type NodeWant struct {
+	V        int    `json:"v"`
+	Composed string `json:"composed"`
+	Words    string `json:"words,omitempty"`
+}
+
+// EncodeNodeWant is w as JSON at Version; it refuses a digest not of the sha256 form.
+func EncodeNodeWant(w NodeWant) ([]byte, error) {
+	if err := checkDigest(w.Composed, "the node's own want's composition digest"); err != nil {
+		return nil, err
+	}
+	w.V = Version
+	return json.Marshal(w)
+}
+
+// DecodeNodeWant reads a node's own want; it refuses an unknown version (ErrUnknownVersion), a field a node's own want
+// does not have (a fingerprint among them), and what EncodeNodeWant refuses.
+func DecodeNodeWant(data []byte) (NodeWant, error) {
+	if err := checkVersion(data); err != nil {
+		return NodeWant{}, err
+	}
+	var w NodeWant
+	d := json.NewDecoder(bytes.NewReader(data))
+	d.DisallowUnknownFields()
+	if err := d.Decode(&w); err != nil {
+		return NodeWant{}, fmt.Errorf("delivery: a node's own want does not fit its shape: %w", err)
+	}
+	if err := checkDigest(w.Composed, "the node's own want's composition digest"); err != nil {
+		return NodeWant{}, err
+	}
+	return w, nil
+}
+
 // EncodeHeld is h as JSON at Version; it refuses a node name a key refuses.
 func EncodeHeld(h Held) ([]byte, error) {
 	if err := h.check(); err != nil {

go/delivery/assigner_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"strings"
 	"testing"
+	"time"
 )
 
 // 1297/B1a: a want key round-trips through its parser; a held key, a have key and a node's own key are refused,
@@ -74,9 +75,10 @@ func TestDifferenceKey(t *testing.T) {
 // 1297/B1a: wants, holds and differences round-trip through their encoders unchanged, at Version.
 func TestAssignerValuesRoundTrip(t *testing.T) {
 	wants := []Want{
-		{FP: fp2of('a')},
-		{FP: fp2of('a'), Newest: fp2of('b'), Rule: RuleCanary, Words: "the canary ace does not run it healthy yet"},
+		{FP: fp2of('a'), Composed: hashOf('1')},
+		{FP: fp2of('a'), Composed: hashOf('1'), Newest: fp2of('b'), Rule: RuleCanary, Words: "the canary ace does not run it healthy yet"},
 		{Removed: true, Words: "the module left g14"},
+		{FP: fp2of('a'), Composed: hashOf('1'), Put: true, Hold: true, Words: "put by the operator: the bus's user list"},
 	}
 	for _, w := range wants {
 		data, err := EncodeWant(w)
@@ -89,6 +91,24 @@ func TestAssignerValuesRoundTrip(t *testing.T) {
 			t.Errorf("want %+v came back %+v, %v", w, got, err)
 		}
 	}
+	at := time.Date(2026, 10, 25, 21, 0, 0, 0, time.UTC)
+	p := Put{FP: fp2of('a'), Hold: true, Why: "the bus's user list", By: "shanks.node-tools", At: at}.Said(at, PutAsked, "put asked")
+	p = p.Said(at, PutAsked, "put asked").Said(at.Add(time.Second), PutWanted, "want written")
+	p.Composed = hashOf('1')
+	if len(p.Steps) != 2 || p.Step != PutWanted || PutEnded(p.Step) || !PutEnded(PutReleased) {
+		t.Errorf("a put's steps are %+v at %s", p.Steps, p.Step)
+	}
+	pkey, _ := PutKey("novox", "nats")
+	if n, m, err := ParsePutKey(pkey); err != nil || n != "novox" || m != "nats" {
+		t.Errorf("the put key %s reads %s %s, %v", pkey, n, m, err)
+	}
+	pdata, err := EncodePut(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if gotP, err := DecodePut(pdata); err != nil || gotP.FP != p.FP || gotP.Step != PutWanted || len(gotP.Steps) != 2 || !gotP.Hold {
+		t.Errorf("the put came back %+v, %v", gotP, err)
+	}
 	h := Held{Node: "ace", Words: "its health check failed: connection refused"}
 	data, err := EncodeHeld(h)
 	if err != nil {
@@ -127,7 +147,10 @@ func TestAssignerValuesRefused(t *testing.T) {
 		{Removed: true, FP: fp2of('a')},
 		{FP: fp2of('a'), Newest: fp2of('b')},
 		{FP: fp2of('a'), Newest: fp2of('a'), Rule: 3},
-		{FP: fp2of('a'), Newest: fp2of('b'), Rule: 7},
+		{FP: fp2of('a'), Composed: hashOf('1'), Newest: fp2of('b'), Rule: 8},
+		{FP: fp2of('a'), Composed: hashOf('1'), Hold: true},
+		{FP: fp2of('a'), Composed: hashOf('1'), Put: true, Newest: fp2of('b'), Rule: 3},
+		{Removed: true, Put: true},
 	} {
 		if _, err := EncodeWant(w); err == nil {
 			t.Errorf("EncodeWant(%+v) accepted", w)
@@ -148,6 +171,19 @@ func TestAssignerValuesRefused(t *testing.T) {
 			t.Errorf("EncodeDifference(%+v) accepted", d)
 		}
 	}
+	for _, p := range []Put{
+		{FP: fp2of('a'), Why: "w", Step: "walking"},
+		{FP: fp2of('a'), Step: PutAsked},
+		{FP: "src2:abc", Why: "w", Step: PutAsked},
+		{FP: fp2of('a'), Why: "w", Step: PutWanted, Composed: "sha256:x"},
+	} {
+		if _, err := EncodePut(p); err == nil {
+			t.Errorf("EncodePut(%+v) accepted", p)
+		}
+	}
+	if _, _, err := ParsePutKey("ace.node"); err == nil {
+		t.Errorf("a node's own key was read as a put")
+	}
 	if _, err := DecodeWant([]byte(`{"v":2,"fp":"` + fp2of('a') + `"}`)); !errors.Is(err, ErrUnknownVersion) {
 		t.Errorf("a want of version 2 was read: %v", err)
 	}
@@ -262,4 +298,20 @@ func TestControllerGrant(t *testing.T) {
 	if _, err := EncodeControllerGrant(ControllerGrant{Accounts: []string{""}}); err == nil {
 		t.Errorf("a grant naming an empty account was accepted")
 	}
+	g := ControllerGrant{Accounts: []string{"ace.mesh-build-go", "shanks.mesh-mail.reader"}}
+	for _, c := range []struct {
+		g            ControllerGrant
+		node, module string
+		names        bool
+	}{
+		{g, "ace", "mesh-build-go", true},
+		{g, "shanks", "mesh-mail", true},
+		{g, "g14", "mesh-build-go", false},
+		{g, "ace", "mesh-build", false},
+		{ControllerGrant{}, "novox", "nats", true},
+	} {
+		if got := c.g.NamesNode(c.node, c.module); got != c.names {
+			t.Errorf("%v names %s.%s: %v, want %v", c.g.Accounts, c.node, c.module, got, c.names)
+		}
+	}
 }

go/delivery/checker.go

@@ -139,25 +139,16 @@ type FailedFirst struct {
 	Words   string `json:"words,omitempty"`
 }
 
-// MaxFailures is the most entries a verdict's Failures holds (issue 1921): fifty tests named one by one, and an entry
-// after them saying how many more failed.
-const MaxFailures = 50
-
 // Verdict is the value of a verdict key: the group and its heads hash, the trunk head of each repository it was judged
 // against (repository to full sha), the State (running, pass or fail), what failed first, the tests run and kept per
 // level, each part's time, the machines composed and the mesh-sdk version the composition ran with (ADR 0446 clause 5).
 type Verdict struct {
-	V      int               `json:"v"`
-	Group  string            `json:"group"`
-	Heads  string            `json:"heads"`
-	Trunk  map[string]string `json:"trunk,omitempty"`
-	State  string            `json:"state"`
-	Failed FailedFirst       `json:"failed,omitzero"`
-	// Failures names every test that failed, in the order judged, each with the first line of its words (issue 1921):
-	// Failed keeps the first one's words whole, and a check that ran every test says all it found here. At most
-	// MaxFailures entries, the last of a longer list saying how many more failed. Absent in a value written before it,
-	// and from a verdict whose failure is no test.
-	Failures []FailedFirst          `json:"failures,omitempty"`
+	V        int                    `json:"v"`
+	Group    string                 `json:"group"`
+	Heads    string                 `json:"heads"`
+	Trunk    map[string]string      `json:"trunk,omitempty"`
+	State    string                 `json:"state"`
+	Failed   FailedFirst            `json:"failed,omitzero"`
 	Levels   map[string]LevelResult `json:"levels,omitempty"`
 	Took     Took                   `json:"took,omitzero"`
 	Machines []string               `json:"machines,omitempty"`
@@ -231,12 +222,6 @@ func (v Verdict) check() error {
 		}
 	}
 	named := v.Failed.Test != "" || v.Failed.Machine != ""
-	if len(v.Failures) > 0 && v.State != VerdictFail {
-		return fmt.Errorf("delivery: a %s verdict names no failures", v.State)
-	}
-	if len(v.Failures) > MaxFailures+1 {
-		return fmt.Errorf("delivery: the verdict names %d failures, more than %d and the count of the rest", len(v.Failures), MaxFailures)
-	}
 	switch v.State {
 	case VerdictRunning:
 		if v.Failed != (FailedFirst{}) {

go/delivery/checker_test.go

@@ -3,7 +3,6 @@ package delivery
 import (
 	"encoding/json"
 	"errors"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -601,38 +600,3 @@ func TestPreviewOfAHeadInConflict(t *testing.T) {
 		t.Errorf("the old reader: %+v %v", old, err)
 	}
 }
-
-// Issue 1921: a failed verdict names every failed test in Failures and reads back the same; an older reader's value
-// without it reads too; Failures on a verdict that is no fail, and more than MaxFailures and the count of the rest, are
-// refused.
-func TestVerdictNamesEveryFailure(t *testing.T) {
-	v := passVerdict()
-	v.State = VerdictFail
-	v.Failed = FailedFirst{Test: "integration: x/a.TestA", Words: "a_test.go:9: want 1, got 2\nmore"}
-	v.Failures = []FailedFirst{{Test: "integration: x/a.TestA", Words: "a_test.go:9: want 1, got 2"}, {Test: "integration: x/b.TestB", Words: "b_test.go:3: boom"}}
-	data, err := EncodeVerdict(v)
-	if err != nil {
-		t.Fatal(err)
-	}
-	got, err := DecodeVerdict(data)
-	v.V = Version
-	if err != nil || !SameVerdict(got, v) || !strings.Contains(string(data), `"failures":[{"test":"integration: x/a.TestA"`) {
-		t.Fatalf("%s: %+v %v", data, got, err)
-	}
-	old := strings.Replace(string(data), string(data[strings.Index(string(data), `,"failures":`):strings.Index(string(data), `,"levels":`)]), "", 1)
-	if got, err := DecodeVerdict([]byte(old)); err != nil || len(got.Failures) != 0 || got.Failed != v.Failed {
-		t.Fatalf("a value without failures: %+v %v (%s)", got, err, old)
-	}
-	p := passVerdict()
-	p.Failures = v.Failures
-	if _, err := EncodeVerdict(p); err == nil {
-		t.Error("a pass with failures was written")
-	}
-	v.Failures = make([]FailedFirst, MaxFailures+2)
-	for i := range v.Failures {
-		v.Failures[i] = FailedFirst{Test: "unit: x.T" + strconv.Itoa(i)}
-	}
-	if _, err := EncodeVerdict(v); err == nil {
-		t.Error("a verdict naming more than MaxFailures and the rest was written")
-	}
-}

go/delivery/composed.go

@@ -0,0 +1,241 @@
+package delivery
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// The controller's compositions (novox/hq ADR 0539 clauses 1 to 4). A **composition** is one module's resources
+// composed for one node at one fingerprint, written by the controller, which keeps the inputs. It lives in a bucket of
+// each node, `composed-<node>`, which only that node's node-engine reads (a composition can carry a sealed value), under
+// `<node>.<module>.<fingerprint hex>`, and the node's own resources (adoption, firewall openings, accounts, the
+// resolver, identities and groups) under `<node>.node`. Beside it, under the same key in `mesh-controller_composed`,
+// which the assigner reads, the controller writes the composition's digest and its judgement of the move from the
+// composition the node runs now (ComposedDigest). The controller writes both by compare-and-set while it holds the
+// lease; the operator's credential is a second writer on the hand path alone (clause 10, mesh-hand-compose).
+//
+// A composition is derived state (clause 4): its key and its digest are deleted by the controller when its fingerprint
+// is no longer among the module's five newest and no want names it, and each bucket keeps five revisions of a key.
+const (
+	// ComposedBucketPrefix starts the name of a node's bucket of compositions, ComposedBucketFor(node).
+	ComposedBucketPrefix = "composed-"
+	// ComposedHistory is the revisions a node's composition bucket keeps per key (ADR 0539 clause 4).
+	ComposedHistory = 5
+	// ControllerModule is the module of the controller, the writer of the compositions.
+	ControllerModule = "mesh-controller"
+	// ControllerComposedBucket is the controller's bucket of each composition's digest and judgement, `<owner
+	// module>_<name>`, read by the assigner (ADR 0539 clauses 2 and 6).
+	ControllerComposedBucket = ControllerModule + "_composed"
+	// ControllerComposedHistory is the revisions that bucket keeps per key.
+	ControllerComposedHistory = 5
+	// ComposedKeep is how many of a module's newest fingerprints keep their compositions though no want names them
+	// (ADR 0539 clause 4).
+	ComposedKeep = 5
+)
+
+// nodeWord is the last part of a node's own key, in the have bucket and in a node's composition bucket alike.
+const nodeWord = "node"
+
+var bucketNode = regexp.MustCompile(`^[A-Za-z0-9_-]+$`)
+
+// ComposedBucketFor is the name of a node's bucket of compositions, "composed-<node>", as declaration.FileBucketFor
+// names a node's object bucket (ADR 0488 §4). The node name must be one a bucket and a subject token accept: letters,
+// digits, '_' and '-'.
+func ComposedBucketFor(node string) (string, error) {
+	if node == "" {
+		return "", fmt.Errorf("delivery: the node name is empty; a node's composition bucket is named for its node")
+	}
+	if !bucketNode.MatchString(node) {
+		return "", fmt.Errorf("delivery: the node name %q is not one a bucket accepts: letters, digits, '_' and '-' only", node)
+	}
+	return ComposedBucketPrefix + node, nil
+}
+
+// ComposedKey is the key, in ComposedBucketFor(node) and in ControllerComposedBucket, of a module's composition for a
+// node at a fingerprint: `<node>.<module>.<hex>`, the hex being the fingerprint's key part (FingerprintKeyPart). A
+// module named `node` is refused, since `<node>.node` is the node's own key.
+func ComposedKey(node, module, fingerprint string) (string, error) {
+	have, err := HaveKey(node, module)
+	if err != nil {
+		return "", err
+	}
+	part, err := FingerprintKeyPart(fingerprint)
+	if err != nil {
+		return "", err
+	}
+	return have + "." + part, nil
+}
+
+// ComposedNodeKey is the key of a node's own composition: `<node>.node`.
+func ComposedNodeKey(node string) (string, error) {
+	return HaveNodeKey(node)
+}
+
+// ParseComposedKey is the inverse of ComposedKey and ComposedNodeKey: isNode is true for `<node>.node`, with module
+// and fingerprint empty. It refuses any other shape, naming the key.
+func ParseComposedKey(key string) (node, module, fingerprint string, isNode bool, err error) {
+	refused := func(why error) (string, string, string, bool, error) {
+		return "", "", "", false, fmt.Errorf("delivery: %q is not a composition key, <node>.<module>.<fingerprint hex> or <node>.node: %w", key, why)
+	}
+	parts := strings.Split(key, ".")
+	switch len(parts) {
+	case 2:
+		if parts[1] != nodeWord {
+			return refused(fmt.Errorf("a module's composition names its fingerprint"))
+		}
+		if err := checkName("node", parts[0]); err != nil {
+			return refused(err)
+		}
+		return parts[0], "", "", true, nil
+	case 3:
+		node, module, isNode, err := ParseHaveKey(parts[0] + "." + parts[1])
+		if err != nil {
+			return refused(err)
+		}
+		if isNode {
+			return refused(fmt.Errorf("the node's own key names no fingerprint"))
+		}
+		fp, err := ParseFingerprintKeyPart(parts[2])
+		if err != nil {
+			return refused(err)
+		}
+		return node, module, fp, false, nil
+	}
+	return refused(fmt.Errorf("it has %d parts", len(parts)))
+}
+
+// Judgement is the controller's judgement of a move from the composition a node runs, as its have names it, to a new
+// one (ADR 0539 clauses 2 and 14, by ADR 0377 §3's tests).
+type Judgement string
+
+// The judgements of a move.
+const (
+	// JudgedRecreates is a move that recreates a container.
+	JudgedRecreates Judgement = "recreates"
+	// JudgedMovesData is a move that gives the module's data another place.
+	JudgedMovesData Judgement = "moves-data"
+	// JudgedNeither is a move that does neither, and the judgement of a composition the node never ran.
+	JudgedNeither Judgement = "neither"
+	// JudgedCannot is a move that cannot be judged, because the composition the node runs is gone or cannot be read.
+	JudgedCannot Judgement = "cannot-judge"
+	// JudgedUnchanged is a composition equal to the module's slice of the declaration the node last applied, for a node
+	// whose have names no composition yet (the first want at the switch, novox/hq ADR 0540 clause 9): applying it
+	// changes nothing on the node, so it needs no person's yes.
+	JudgedUnchanged Judgement = "unchanged"
+)
+
+var digestForm = regexp.MustCompile(`^sha256:[0-9a-f]{64}$`)
+
+func checkDigest(digest, of string) error {
+	if !digestForm.MatchString(digest) {
+		return fmt.Errorf("delivery: %s %q is not sha256:<64 lowercase hex digits>", of, digest)
+	}
+	return nil
+}
+
+// ComposedDigest is the value, in ControllerComposedBucket, beside a composition: its Digest (ComposedDigestOf), and
+// the Judgement of the move to it from the composition the node runs now, whose digest is Against (empty when the node
+// runs no composition of the module). Words say why, and are required for a move that cannot be judged. Rewritten when
+// the node's have changes.
+//
+// Policy is the module's upgrade policy as the controller holds it (ADR 0236, ADR 0539 clause 14), with PolicyFrom
+// where it comes from and PolicyWhy why: the assigner holds a move of a module of policy record from it, the operator's
+// own choice (`upgrade` with policy) included. Rewritten when the policy changes. Empty on a composition made by hand
+// (mesh-hand-compose), whose want the operator writes.
+type ComposedDigest struct {
+	V         int       `json:"v"`
+	Digest    string    `json:"digest"`
+	Judgement Judgement `json:"judgement"`
+	Against   string    `json:"against,omitempty"`
+	Words     string    `json:"words,omitempty"`
+	// UserListOnly says the composition differs from the one the node's have names only in the bus's user list (the
+	// bus module's file `<module>.bus-users`), whatever the judgement says of its mount: the assigner writes such a
+	// revision into the bus node's want at once, outside the record hold, at the fingerprint the node runs (ADR 0539
+	// clause 7).
+	UserListOnly bool   `json:"user-list-only,omitempty"`
+	Policy       string `json:"policy,omitempty"`
+	PolicyFrom   string `json:"policy-from,omitempty"`
+	PolicyWhy    string `json:"policy-why,omitempty"`
+}
+
+// The upgrade policies and their sources a composition's value names: catalogue.PolicyRoll, PolicyTogether and
+// PolicyRecord, and catalogue.FromPerson, FromModule, FromBus, FromData and FromDefault, the same words (the compose
+// package's test holds them equal; this package does not import the catalogue).
+var (
+	composedPolicies    = []string{"roll", "together", "record"}
+	composedPolicyFroms = []string{"person", "module", "the bus", "irreplaceable data", "default"}
+)
+
+func oneOf(v string, of []string) bool {
+	for _, o := range of {
+		if v == o {
+			return true
+		}
+	}
+	return false
+}
+
+func (c ComposedDigest) check() error {
+	if err := checkDigest(c.Digest, "the composition's digest"); err != nil {
+		return err
+	}
+	if c.Against != "" {
+		if err := checkDigest(c.Against, "the digest a move is judged against"); err != nil {
+			return err
+		}
+	}
+	switch c.Judgement {
+	case JudgedRecreates, JudgedMovesData:
+		if c.Against == "" {
+			return fmt.Errorf("delivery: a move judged %s names the composition it is judged against", c.Judgement)
+		}
+	case JudgedNeither, JudgedUnchanged:
+	case JudgedCannot:
+		if c.Words == "" {
+			return fmt.Errorf("delivery: a move that cannot be judged says why")
+		}
+	default:
+		return fmt.Errorf("delivery: the judgement %q is not %s, %s, %s, %s or %s", c.Judgement, JudgedRecreates,
+			JudgedMovesData, JudgedNeither, JudgedCannot, JudgedUnchanged)
+	}
+	if c.Policy != "" || c.PolicyFrom != "" {
+		if !oneOf(c.Policy, composedPolicies) {
+			return fmt.Errorf("delivery: the upgrade policy %q is not one of %v", c.Policy, composedPolicies)
+		}
+		if !oneOf(c.PolicyFrom, composedPolicyFroms) {
+			return fmt.Errorf("delivery: the upgrade policy's source %q is not one of %v", c.PolicyFrom, composedPolicyFroms)
+		}
+	}
+	return nil
+}
+
+// PolicyRecord is the policy whose moves the assigner holds for a person's yes (ADR 0539 clause 14).
+const PolicyRecord = "record"
+
+// EncodeComposedDigest is c as JSON at Version; it refuses an unknown judgement, a digest not of the sha256 form, a
+// move judged to recreate or move data against nothing, and a move that cannot be judged without its reason.
+func EncodeComposedDigest(c ComposedDigest) ([]byte, error) {
+	if err := c.check(); err != nil {
+		return nil, err
+	}
+	c.V = Version
+	return json.Marshal(c)
+}
+
+// DecodeComposedDigest reads the value beside a composition; it refuses an unknown version (ErrUnknownVersion) and
+// what EncodeComposedDigest refuses.
+func DecodeComposedDigest(data []byte) (ComposedDigest, error) {
+	var c ComposedDigest
+	if err := decode(data, &c); err != nil {
+		return ComposedDigest{}, err
+	}
+	if err := c.check(); err != nil {
+		return ComposedDigest{}, err
+	}
+	return c, nil
+}
+
+// SameComposedDigest says whether two values are the same, so the controller writes only when they differ.
+func SameComposedDigest(a, b ComposedDigest) bool { return a == b }

go/delivery/composed_keys_test.go

@@ -0,0 +1,125 @@
+package delivery
+
+import (
+	"errors"
+	"strings"
+	"testing"
+)
+
+// 1943/AC1: a node's composition bucket is named for the node, and a node with no name, or one a bucket refuses,
+// is refused, naming why.
+func TestComposedBucketFor(t *testing.T) {
+	b, err := ComposedBucketFor("ace")
+	if err != nil || b != "composed-ace" {
+		t.Fatalf("ComposedBucketFor(ace) = %q, %v", b, err)
+	}
+	for _, bad := range []string{"", "a.b", "a*", "a b", "a>"} {
+		if _, err := ComposedBucketFor(bad); err == nil || !strings.Contains(err.Error(), "node") {
+			t.Errorf("ComposedBucketFor(%q) = %v, want a refusal naming the node", bad, err)
+		}
+	}
+}
+
+// 1943/AC1: a module's composition key and the node's own key round-trip through one parser; an empty node, a
+// module named node, a bad fingerprint and a key of another shape are refused, naming why.
+func TestComposedKeys(t *testing.T) {
+	fp := fp2of('c')
+	key, err := ComposedKey("ace", "mesh-mail", fp)
+	if err != nil || key != "ace.mesh-mail."+strings.Repeat("c", 64) {
+		t.Fatalf("ComposedKey = %q, %v", key, err)
+	}
+	node, module, back, isNode, err := ParseComposedKey(key)
+	if err != nil || node != "ace" || module != "mesh-mail" || back != fp || isNode {
+		t.Errorf("ParseComposedKey(%q) = %q, %q, %q, %v, %v", key, node, module, back, isNode, err)
+	}
+	own, err := ComposedNodeKey("ace")
+	if err != nil || own != "ace.node" {
+		t.Fatalf("ComposedNodeKey = %q, %v", own, err)
+	}
+	node, module, back, isNode, err = ParseComposedKey(own)
+	if err != nil || node != "ace" || module != "" || back != "" || !isNode {
+		t.Errorf("ParseComposedKey(%q) = %q, %q, %q, %v, %v", own, node, module, back, isNode, err)
+	}
+
+	refusals := []struct {
+		node, module, fp, why string
+	}{
+		{"", "mesh-mail", fp, "node name is empty"},
+		{"ace", "node", fp, `"node" is refused`},
+		{"ace", "", fp, "module name is empty"},
+		{"ace", "mesh-mail", "src2:abc", "not a fingerprint of the new form"},
+		{"ace", "mesh-mail", "src1:" + strings.Repeat("c", 64), "not a fingerprint of the new form"},
+		{"a.b", "mesh-mail", fp, "node name"},
+	}
+	for _, r := range refusals {
+		if _, err := ComposedKey(r.node, r.module, r.fp); err == nil || !strings.Contains(err.Error(), r.why) {
+			t.Errorf("ComposedKey(%q, %q, %q) = %v, want a refusal saying %q", r.node, r.module, r.fp, err, r.why)
+		}
+	}
+	if _, err := ComposedNodeKey(""); err == nil {
+		t.Errorf("ComposedNodeKey(\"\") accepted")
+	}
+	for _, bad := range []string{"", "ace", "ace.mesh-mail", "ace.node.x", "ace.mesh-mail.abc", ".mesh-mail." + strings.Repeat("c", 64),
+		"ace.node." + strings.Repeat("c", 64), "ace.mesh-mail." + strings.Repeat("c", 64) + ".x", "want.ace.mesh-mail"} {
+		if _, _, _, _, err := ParseComposedKey(bad); err == nil || !strings.Contains(err.Error(), "\""+bad+"\"") {
+			t.Errorf("ParseComposedKey(%q) = %v, want a refusal naming it", bad, err)
+		}
+	}
+}
+
+// 1943/AC1: the controller's value beside a composition, its digest and the judgement of the move, round-trips; an
+// unknown judgement, a digest not of the sha256 form, a move judged against nothing, a cannot-judge without its
+// reason, and an upgrade policy or source outside the catalogue's words are refused, naming why; an unknown version is
+// refused as one. The module's upgrade policy and its source ride beside the judgement, for the assigner's hold.
+func TestComposedDigestValue(t *testing.T) {
+	digest := "sha256:" + strings.Repeat("d", 64)
+	against := "sha256:" + strings.Repeat("e", 64)
+	for _, v := range []ComposedDigest{
+		{Digest: digest, Judgement: JudgedNeither},
+		{Digest: digest, Judgement: JudgedNeither, Against: against},
+		{Digest: digest, Judgement: JudgedRecreates, Against: against, Words: "the container's image changes"},
+		{Digest: digest, Judgement: JudgedMovesData, Against: against},
+		{Digest: digest, Judgement: JudgedCannot, Words: "the composition the node runs is gone"},
+		{Digest: digest, Judgement: JudgedUnchanged, Words: "equal to the declaration the node last applied"},
+		{Digest: digest, Judgement: JudgedNeither, Policy: "record", PolicyFrom: "person", PolicyWhy: "the operator: its data"},
+		{Digest: digest, Judgement: JudgedNeither, Policy: "roll", PolicyFrom: "default"},
+		{Digest: digest, Judgement: JudgedNeither, Against: against, UserListOnly: true, Words: "only the bus's user list changes"},
+	} {
+		raw, err := EncodeComposedDigest(v)
+		if err != nil {
+			t.Fatalf("EncodeComposedDigest(%+v): %v", v, err)
+		}
+		back, err := DecodeComposedDigest(raw)
+		v.V = Version
+		if err != nil || !SameComposedDigest(back, v) {
+			t.Errorf("round trip of %+v = %+v, %v", v, back, err)
+		}
+	}
+	refusals := []struct {
+		v   ComposedDigest
+		why string
+	}{
+		{ComposedDigest{Digest: digest, Judgement: "maybe"}, `judgement "maybe"`},
+		{ComposedDigest{Digest: digest}, `judgement ""`},
+		{ComposedDigest{Digest: "sha256:abc", Judgement: JudgedNeither}, "not sha256"},
+		{ComposedDigest{Judgement: JudgedNeither}, "not sha256"},
+		{ComposedDigest{Digest: digest, Judgement: JudgedRecreates}, "against"},
+		{ComposedDigest{Digest: digest, Judgement: JudgedMovesData}, "against"},
+		{ComposedDigest{Digest: digest, Judgement: JudgedCannot}, "why"},
+		{ComposedDigest{Digest: digest, Judgement: JudgedNeither, Against: "sha256:zz"}, "not sha256"},
+		{ComposedDigest{Digest: digest, Judgement: JudgedNeither, Policy: "sometimes", PolicyFrom: "person"}, `policy "sometimes"`},
+		{ComposedDigest{Digest: digest, Judgement: JudgedNeither, Policy: "record"}, `source ""`},
+		{ComposedDigest{Digest: digest, Judgement: JudgedNeither, PolicyFrom: "person"}, `policy ""`},
+	}
+	for _, r := range refusals {
+		if _, err := EncodeComposedDigest(r.v); err == nil || !strings.Contains(err.Error(), r.why) {
+			t.Errorf("EncodeComposedDigest(%+v) = %v, want a refusal saying %q", r.v, err, r.why)
+		}
+	}
+	if _, err := DecodeComposedDigest([]byte(`{"v":2,"digest":"` + digest + `","judgement":"neither"}`)); !errors.Is(err, ErrUnknownVersion) {
+		t.Errorf("version 2 = %v, want ErrUnknownVersion", err)
+	}
+	if _, err := DecodeComposedDigest([]byte(`{"v":1,"digest":"` + digest + `","judgement":"perhaps"}`)); err == nil {
+		t.Errorf("an unknown judgement was read")
+	}
+}

go/delivery/composed_signature.go

@@ -0,0 +1,100 @@
+package delivery
+
+import (
+	"crypto/ed25519"
+	"encoding/base64"
+	"fmt"
+)
+
+// A composition's signature (novox/hq ADR 0539 clause 3): the controller signs each composition it writes with its
+// key, and the operator signs one made by hand with mesh-hand-compose with theirs. The node-engine trusts exactly these two
+// signers and applies nothing of a composition whose signature fails or whose signer is neither. The signature is an
+// ed25519 signature, as a declaration's is, of the composition's digest (ComposedDigestOf) after a context line, so a
+// signature made for anything else never verifies here.
+const composedSigningContext = "novox composition v1\n"
+
+// Signature is who signed a composition and the signature: Signer the signer's ed25519 public key and Sig the
+// signature, both in standard base64.
+type Signature struct {
+	Signer string `json:"signer"`
+	Sig    string `json:"sig"`
+}
+
+func (s Signature) check() error {
+	if key, err := base64.StdEncoding.DecodeString(s.Signer); err != nil || len(key) != ed25519.PublicKeySize {
+		return fmt.Errorf("delivery: a composition's signer %q is not an ed25519 public key in base64", s.Signer)
+	}
+	if sig, err := base64.StdEncoding.DecodeString(s.Sig); err != nil || len(sig) != ed25519.SignatureSize {
+		return fmt.Errorf("delivery: a composition's signature is not an ed25519 signature in base64")
+	}
+	return nil
+}
+
+// SignComposed is c signed with key: its digest signed, and the key's public half named as the signer. A signature c
+// already carries is replaced.
+func SignComposed(c Composed, key ed25519.PrivateKey) (Composed, error) {
+	if len(key) != ed25519.PrivateKeySize {
+		return Composed{}, fmt.Errorf("delivery: the key to sign a composition with is not an ed25519 private key")
+	}
+	return SignComposedBy(c, key.Public().(ed25519.PublicKey), func(message []byte) ([]byte, error) {
+		return ed25519.Sign(key, message), nil
+	})
+}
+
+// SignComposedBy is SignComposed for a signer that keeps its private half to itself (the controller's identity store
+// signs a message and hands back the signature): sign signs the message it is given with the key whose public half is
+// signer. A signature that does not verify against signer is refused, so a composition is never written signed by a
+// key other than the one it names.
+func SignComposedBy(c Composed, signer ed25519.PublicKey, sign func(message []byte) ([]byte, error)) (Composed, error) {
+	if len(signer) != ed25519.PublicKeySize {
+		return Composed{}, fmt.Errorf("delivery: the signer of a composition is not an ed25519 public key")
+	}
+	c.Signature = nil
+	digest, err := ComposedDigestOf(c)
+	if err != nil {
+		return Composed{}, err
+	}
+	message := []byte(composedSigningContext + digest)
+	sig, err := sign(message)
+	if err != nil {
+		return Composed{}, err
+	}
+	if !ed25519.Verify(signer, message, sig) {
+		return Composed{}, fmt.Errorf("delivery: the signature made for the composition of %q on %s does not verify against its signer", c.Module, c.Node)
+	}
+	c.Signature = &Signature{Signer: base64.StdEncoding.EncodeToString(signer), Sig: base64.StdEncoding.EncodeToString(sig)}
+	return c, nil
+}
+
+// VerifyComposed is c's digest when c is signed by one of the trusted keys and its signature verifies against its
+// digest; otherwise it refuses, saying why, and nothing of c is to be applied: an unsigned composition, one whose
+// signer is not a trusted key, and one changed after it was signed.
+func VerifyComposed(c Composed, trusted []ed25519.PublicKey) (string, error) {
+	if c.Signature == nil {
+		return "", fmt.Errorf("delivery: the composition of %q on %s is unsigned, and only a signed one is applied", c.Module, c.Node)
+	}
+	if err := c.Signature.check(); err != nil {
+		return "", err
+	}
+	signer, _ := base64.StdEncoding.DecodeString(c.Signature.Signer)
+	var key ed25519.PublicKey
+	for _, t := range trusted {
+		if t.Equal(ed25519.PublicKey(signer)) {
+			key = t
+		}
+	}
+	if key == nil {
+		return "", fmt.Errorf("delivery: the composition of %q on %s is signed by %s, which is not a trusted signer (the controller's key or the operator's)",
+			c.Module, c.Node, c.Signature.Signer)
+	}
+	digest, err := ComposedDigestOf(c)
+	if err != nil {
+		return "", err
+	}
+	sig, _ := base64.StdEncoding.DecodeString(c.Signature.Sig)
+	if !ed25519.Verify(key, []byte(composedSigningContext+digest), sig) {
+		return "", fmt.Errorf("delivery: the composition of %q on %s does not match its signature: it was changed after it was signed, or signed for another",
+			c.Module, c.Node)
+	}
+	return digest, nil
+}

go/delivery/composed_signature_test.go

@@ -0,0 +1,103 @@
+package delivery
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+func aSigningKey(t *testing.T) (ed25519.PublicKey, ed25519.PrivateKey) {
+	t.Helper()
+	pub, priv, err := ed25519.GenerateKey(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return pub, priv
+}
+
+func aComposition() Composed {
+	return Composed{Node: "ace", Module: "m", FP: fp2of('a'), Resources: []json.RawMessage{
+		json.RawMessage(`{"id":"m.f","type":"file","module":"m","path":"/etc/m","content":"x"}`)}}
+}
+
+// 1943/AC5: a composition signed by the controller's key or by the operator's verifies against the two trusted keys,
+// keeps its digest, and survives its encoding; one signed by another key, unsigned, or changed by one byte after it was
+// signed does not verify, and nothing of it is to be applied.
+func TestACompositionIsSignedByATrustedKey(t *testing.T) {
+	controllerPub, controller := aSigningKey(t)
+	operatorPub, operator := aSigningKey(t)
+	_, stranger := aSigningKey(t)
+	trusted := []ed25519.PublicKey{controllerPub, operatorPub}
+	c := aComposition()
+	want, _ := ComposedDigestOf(c)
+
+	for name, key := range map[string]ed25519.PrivateKey{"controller": controller, "operator": operator} {
+		signed, err := SignComposed(c, key)
+		if err != nil {
+			t.Fatalf("%s: %v", name, err)
+		}
+		raw, err := EncodeComposed(signed)
+		if err != nil {
+			t.Fatal(err)
+		}
+		back, err := DecodeComposed(raw)
+		if err != nil {
+			t.Fatal(err)
+		}
+		digest, err := VerifyComposed(back, trusted)
+		if err != nil || digest != want {
+			t.Errorf("%s's signature: %q, %v; want the digest %s", name, digest, err, want)
+		}
+		if d, _ := ComposedDigestOf(back); d != want {
+			t.Errorf("%s's signature changed the digest: %s", name, d)
+		}
+
+		changed := strings.Replace(string(raw), `"content":"x"`, `"content":"y"`, 1)
+		if changed == string(raw) {
+			t.Fatal("the test changed nothing")
+		}
+		if tampered, err := DecodeComposed([]byte(changed)); err != nil {
+			t.Fatal(err)
+		} else if _, err := VerifyComposed(tampered, trusted); err == nil || !strings.Contains(err.Error(), "signature") {
+			t.Errorf("%s: a composition changed by one byte verified: %v", name, err)
+		}
+	}
+
+	byStranger, _ := SignComposed(c, stranger)
+	if _, err := VerifyComposed(byStranger, trusted); err == nil || !strings.Contains(err.Error(), "not a trusted") {
+		t.Errorf("a stranger's signature = %v, want refused as no trusted signer", err)
+	}
+	if _, err := VerifyComposed(c, trusted); err == nil || !strings.Contains(err.Error(), "unsigned") {
+		t.Errorf("an unsigned composition = %v, want refused", err)
+	}
+	signed, _ := SignComposed(c, controller)
+	forged := signed
+	forged.Signature = &Signature{Signer: signed.Signature.Signer, Sig: byStranger.Signature.Sig}
+	if _, err := VerifyComposed(forged, trusted); err == nil {
+		t.Errorf("a stranger's signature under the controller's name verified")
+	}
+	if _, err := EncodeComposed(Composed{Node: "ace", Module: "m", FP: fp2of('a'), Resources: c.Resources,
+		Signature: &Signature{Signer: "not base64!", Sig: "x"}}); err == nil {
+		t.Errorf("a signature naming no key was encoded")
+	}
+}
+
+// 1943/AC5: a signer that keeps its private half signs through a function, and the composition verifies as one signed
+// with the key; a function that signs with another key than the one named is refused.
+func TestACompositionIsSignedByAKeptKey(t *testing.T) {
+	pub, priv := aSigningKey(t)
+	_, other := aSigningKey(t)
+	c := aComposition()
+	signed, err := SignComposedBy(c, pub, func(m []byte) ([]byte, error) { return ed25519.Sign(priv, m), nil })
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := VerifyComposed(signed, []ed25519.PublicKey{pub}); err != nil {
+		t.Errorf("a composition signed through the function does not verify: %v", err)
+	}
+	if _, err := SignComposedBy(c, pub, func(m []byte) ([]byte, error) { return ed25519.Sign(other, m), nil }); err == nil {
+		t.Errorf("a signature by another key than the one named was accepted")
+	}
+}

go/delivery/composed_value.go

@@ -0,0 +1,330 @@
+package delivery
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+)
+
+// NodeOwn is what a node's own composition (`<node>.node`) carries beside its resources: what the declaration says of
+// the node as a whole (novox/hq ADR 0539 clause 2: adoption, accounts, identities and groups). A module's composition
+// carries none of it.
+type NodeOwn struct {
+	// Adoption says the node is adopted and which of its modules are taken (ADR 0100, ADR 0103); nil for a converged node.
+	Adoption *declaration.Adoption `json:"adoption,omitempty"`
+	// Identities is the identity of every module assigned to the node (ADR 0328 §4), Groups and Libraries every library
+	// it is reached by (ADR 0328 §3).
+	Identities []declaration.Identity `json:"identities,omitempty"`
+	Groups     []declaration.Group    `json:"groups,omitempty"`
+	Libraries  []declaration.Library  `json:"libraries,omitempty"`
+	// Provisioner is the account the provisioner's client runs as on the node (ADR 0349 §4).
+	Provisioner string `json:"provisioner_account,omitempty"`
+}
+
+func (o NodeOwn) empty() bool {
+	return o.Adoption == nil && len(o.Identities) == 0 && len(o.Groups) == 0 && len(o.Libraries) == 0 && o.Provisioner == ""
+}
+
+// Composed is a composition (ADR 0539 clause 1): one module's resources composed for one node at one fingerprint, or,
+// with Module and FP empty, the node's own resources and parts (Own). Each resource is a declaration resource as the
+// node-engine reads it, saying its module; it is kept as JSON and written canonically (its keys sorted, its spacing
+// dropped), so its digest (ComposedDigestOf) is a function of its content alone. Data says the module declares data,
+// so the node agent backs it up before it moves (ADR 0429 §14). Filled names the files of the module the provisioner
+// fills (ADR 0349 §5). A file over 64 KiB travels by digest and size (ByDigest), its content in the node's object
+// bucket (ADR 0539 clause 4).
+type Composed struct {
+	V         int
+	Node      string
+	Module    string
+	FP        string
+	Data      bool
+	Resources []json.RawMessage
+	Filled    []string
+	Own       NodeOwn
+	// Signature is the controller's or, made by hand, the operator's (ADR 0539 clause 3, SignComposed); it signs the
+	// digest and is never part of it.
+	Signature *Signature
+}
+
+// composedWire is a composition as it is written.
+type composedWire struct {
+	V         int               `json:"v"`
+	Node      string            `json:"node"`
+	Module    string            `json:"module,omitempty"`
+	FP        string            `json:"fp,omitempty"`
+	Data      bool              `json:"data,omitempty"`
+	Resources []json.RawMessage `json:"resources"`
+	Filled    []string          `json:"filled_files,omitempty"`
+	Own       *NodeOwn          `json:"own,omitempty"`
+	Signature *Signature        `json:"signature,omitempty"`
+}
+
+// canonicalJSON is raw with its object keys sorted and its spacing dropped, its numbers kept as written.
+func canonicalJSON(raw json.RawMessage) (json.RawMessage, error) {
+	var v any
+	d := json.NewDecoder(bytes.NewReader(raw))
+	d.UseNumber()
+	if err := d.Decode(&v); err != nil {
+		return nil, err
+	}
+	if _, err := d.Token(); err != io.EOF {
+		return nil, fmt.Errorf("more after the value")
+	}
+	return json.Marshal(v)
+}
+
+func (c Composed) check() error {
+	if _, err := HaveNodeKey(c.Node); err != nil {
+		return err
+	}
+	if c.Module == "" {
+		if c.FP != "" {
+			return fmt.Errorf("delivery: the node's own composition names no fingerprint, and this one names %s", c.FP)
+		}
+		// It carries the filled paths of its own files, those of a module with no fingerprint of the new form moved
+		// into it (issue 1945), and never a module's data.
+		if c.Data {
+			return fmt.Errorf("delivery: the node's own composition holds no module's data")
+		}
+	} else {
+		if _, err := ComposedKey(c.Node, c.Module, c.FP); err != nil {
+			return err
+		}
+		if !c.Own.empty() {
+			return fmt.Errorf("delivery: the composition of %s carries the node's own parts, which only <node>.node carries", c.Module)
+		}
+	}
+	seen := map[string]bool{}
+	files := map[string][]*declaration.File{}
+	for _, raw := range c.Resources {
+		r, err := declaration.ParseResource(raw)
+		if err != nil {
+			return fmt.Errorf("delivery: the composition of %q on %s: %w", c.Module, c.Node, err)
+		}
+		if seen[r.Identity()] {
+			return fmt.Errorf("delivery: the composition of %q on %s holds the resource %q twice", c.Module, c.Node, r.Identity())
+		}
+		seen[r.Identity()] = true
+		if r.DeclaredModule() != c.Module {
+			return fmt.Errorf("delivery: the resource %q is of %q, and this is the composition of %q on %s",
+				r.Identity(), r.DeclaredModule(), c.Module, c.Node)
+		}
+		if f, ok := r.(*declaration.File); ok {
+			if f.TravelsByDigest() {
+				return fmt.Errorf("delivery: the file %q is over %d bytes and travels by digest (ByDigest), not whole",
+					f.ID, declaration.FileReferenceThreshold)
+			}
+			files[f.Path] = append(files[f.Path], f)
+		}
+	}
+	// A file the provisioner fills says no content, so a composition that does not say it is filled would have the
+	// node-engine write it empty (issue 1945, live on 2026-10-25): refused, naming it.
+	filledHere := make(map[string]bool, len(c.Filled))
+	for _, path := range c.Filled {
+		filledHere[path] = true
+	}
+	for path, fs := range files {
+		for _, f := range fs {
+			if f.OwnerAtRuntime == declaration.RuntimeOwned && !filledHere[path] && !saysContent(f) {
+				return fmt.Errorf("delivery: the file %q says no content and the composition of %q on %s does not say "+
+					"the provisioner fills %s: the node-engine would write it empty", f.ID, c.Module, c.Node, path)
+			}
+		}
+	}
+	for _, path := range c.Filled {
+		if len(files[path]) == 0 {
+			return fmt.Errorf("delivery: the composition of %q fills %q, and declares no file there", c.Module, path)
+		}
+		for _, f := range files[path] {
+			if f.OwnerAtRuntime == "" {
+				return fmt.Errorf("delivery: the file %q is filled by the provisioner and says no owner-at-runtime", f.ID)
+			}
+		}
+	}
+	if c.Signature != nil {
+		if err := c.Signature.check(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// saysContent says a file names what to write: content, bytes, a digest or a sealed value. A file the provisioner fills
+// names none of them.
+func saysContent(f *declaration.File) bool {
+	return f.Content != "" || f.Bytes != "" || f.Digest != "" || f.Sealed != "" || f.VaultSealed != nil
+}
+
+// wire is c checked and made canonical, ready to marshal.
+func (c Composed) wire() (composedWire, error) {
+	if err := c.check(); err != nil {
+		return composedWire{}, err
+	}
+	w := composedWire{V: Version, Node: c.Node, Module: c.Module, FP: c.FP, Data: c.Data, Filled: c.Filled,
+		Signature: c.Signature, Resources: make([]json.RawMessage, len(c.Resources))}
+	for i, r := range c.Resources {
+		canon, err := canonicalJSON(r)
+		if err != nil {
+			return composedWire{}, fmt.Errorf("delivery: a resource of %q is not JSON: %w", c.Module, err)
+		}
+		w.Resources[i] = canon
+	}
+	if !c.Own.empty() {
+		own := c.Own
+		w.Own = &own
+	}
+	return w, nil
+}
+
+// EncodeComposed is c as JSON at Version, each resource canonical. It refuses a composition whose node or fingerprint
+// a key refuses, a resource its kind refuses (an action among them), a resource of another module, a module's
+// composition carrying the node's own parts, a file over 64 KiB carried whole, and a filled path no file declares.
+func EncodeComposed(c Composed) ([]byte, error) {
+	w, err := c.wire()
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(w)
+}
+
+// DecodeComposed reads a composition; it refuses an unknown version (ErrUnknownVersion), a field it does not know, and
+// what EncodeComposed refuses.
+func DecodeComposed(data []byte) (Composed, error) {
+	if err := checkVersion(data); err != nil {
+		return Composed{}, err
+	}
+	var w composedWire
+	d := json.NewDecoder(bytes.NewReader(data))
+	d.DisallowUnknownFields()
+	if err := d.Decode(&w); err != nil {
+		return Composed{}, fmt.Errorf("delivery: a composition does not fit its shape: %w", err)
+	}
+	c := Composed{V: w.V, Node: w.Node, Module: w.Module, FP: w.FP, Data: w.Data, Resources: w.Resources,
+		Filled: w.Filled, Signature: w.Signature}
+	if w.Own != nil {
+		c.Own = *w.Own
+	}
+	if err := c.check(); err != nil {
+		return Composed{}, err
+	}
+	return c, nil
+}
+
+// ComposedDigestOf is a composition's digest, "sha256:<hex>", of its encoding without its signature. A want names it
+// (ADR 0539 clause 1), the controller writes it beside the composition, and the signature signs it.
+func ComposedDigestOf(c Composed) (string, error) {
+	c.Signature = nil
+	raw, err := EncodeComposed(c)
+	if err != nil {
+		return "", err
+	}
+	sum := sha256.Sum256(raw)
+	return "sha256:" + hex.EncodeToString(sum[:]), nil
+}
+
+// SameComposed says whether two compositions are the same value, their signatures included, so the controller writes
+// only when they differ.
+func SameComposed(a, b Composed) bool {
+	ra, errA := EncodeComposed(a)
+	rb, errB := EncodeComposed(b)
+	return errA == nil && errB == nil && bytes.Equal(ra, rb)
+}
+
+// ByDigest is c with every file over 64 KiB given by its digest and size, and the content of each by digest, for the
+// writer to put in the node's object bucket (declaration.FileBucketFor) under declaration.ObjectName before it writes
+// the composition (ADR 0539 clause 4, ADR 0488 §3). A file that is sealed, filled with secrets or written into another
+// stays as it is (declaration.File.TravelsByDigest).
+func (c Composed) ByDigest() (Composed, map[string][]byte, error) {
+	out := c
+	out.Resources = make([]json.RawMessage, len(c.Resources))
+	objects := map[string][]byte{}
+	for i, raw := range c.Resources {
+		out.Resources[i] = raw
+		r, err := declaration.ParseResource(raw)
+		if err != nil {
+			return Composed{}, nil, err
+		}
+		f, ok := r.(*declaration.File)
+		if !ok || !f.TravelsByDigest() {
+			continue
+		}
+		ref, body, err := f.AsReference()
+		if err != nil {
+			return Composed{}, nil, err
+		}
+		var fields map[string]json.RawMessage
+		if err := json.Unmarshal(raw, &fields); err != nil {
+			return Composed{}, nil, err
+		}
+		delete(fields, "content")
+		delete(fields, "bytes")
+		fields["digest"], _ = json.Marshal(ref.Digest)
+		fields["size"], _ = json.Marshal(ref.Size)
+		rewritten, err := json.Marshal(fields)
+		if err != nil {
+			return Composed{}, nil, err
+		}
+		out.Resources[i] = rewritten
+		objects[ref.Digest] = body
+	}
+	return out, objects, nil
+}
+
+// SplitComposed splits a node's composed resources into its compositions, by key (ComposedKey, ComposedNodeKey): each
+// resource into the composition of the module it says, under that module's fingerprint in fps, and a resource that
+// says no module into the node's own, with own. Each filled path goes with the module whose file declares it. The order
+// of the resources is kept within each composition. A resource of a module fps names no fingerprint for is refused,
+// naming it. Data is the caller's to set, from the module's manifest.
+func SplitComposed(node string, resources []json.RawMessage, fps map[string]string, filled []string, own NodeOwn) (map[string]Composed, error) {
+	nodeKey, err := ComposedNodeKey(node)
+	if err != nil {
+		return nil, err
+	}
+	out := map[string]Composed{nodeKey: {Node: node, Own: own, Resources: []json.RawMessage{}}}
+	pathOf := map[string]string{}
+	for _, raw := range resources {
+		var head struct {
+			ID     string `json:"id"`
+			Type   string `json:"type"`
+			Module string `json:"module"`
+			Path   string `json:"path"`
+		}
+		if err := json.Unmarshal(raw, &head); err != nil {
+			return nil, fmt.Errorf("delivery: a resource of %s is not JSON: %w", node, err)
+		}
+		key := nodeKey
+		if head.Module != "" {
+			fp, ok := fps[head.Module]
+			if !ok {
+				return nil, fmt.Errorf("delivery: the resource %q is of %q, whose fingerprint on %s is not given", head.ID, head.Module, node)
+			}
+			if key, err = ComposedKey(node, head.Module, fp); err != nil {
+				return nil, err
+			}
+			if _, ok := out[key]; !ok {
+				out[key] = Composed{Node: node, Module: head.Module, FP: fp}
+			}
+		}
+		if head.Type == string(declaration.TypeFile) && head.Module != "" {
+			pathOf[head.Path] = key
+		}
+		c := out[key]
+		c.Resources = append(c.Resources, raw)
+		out[key] = c
+	}
+	for _, path := range filled {
+		key, ok := pathOf[path]
+		if !ok {
+			return nil, fmt.Errorf("delivery: the provisioner fills %q on %s, and no module's file declares it", path, node)
+		}
+		c := out[key]
+		c.Filled = append(c.Filled, path)
+		out[key] = c
+	}
+	return out, nil
+}

go/delivery/composed_value_test.go

@@ -0,0 +1,364 @@
+package delivery
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+)
+
+// capturedDeclaration is a node's declaration as the controller's `plan` verb answered it on 2026-10-24 at 16:19
+// (testdata/declaration-<node>.json.gz; the resources carrying a sealed value or a secret taken out, and the filled
+// files that named them), never typed by hand.
+type capturedDeclaration struct {
+	Builds      map[string]string `json:"builds"`
+	Resources   []json.RawMessage `json:"resources"`
+	Filled      []string          `json:"filled_files"`
+	Provisioner string            `json:"provisioner_account"`
+}
+
+func readCaptured(t *testing.T, node string) capturedDeclaration {
+	t.Helper()
+	f, err := os.Open("testdata/declaration-" + node + ".json.gz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	z, err := gzip.NewReader(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	raw, err := io.ReadAll(z)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var c capturedDeclaration
+	if err := json.Unmarshal(raw, &c); err != nil {
+		t.Fatal(err)
+	}
+	return c
+}
+
+// fpOfBuild stands for each module's fingerprint in a captured declaration, which names builds, not fingerprints.
+func fpOfBuild(build string) string {
+	var b strings.Builder
+	for b.Len() < 64 {
+		b.WriteString(fmt.Sprintf("%x", []byte(build)))
+	}
+	return SourcePrefix2 + b.String()[:64]
+}
+
+func splitCaptured(t *testing.T, node string, c capturedDeclaration) map[string]Composed {
+	t.Helper()
+	fps := map[string]string{}
+	for m, b := range c.Builds {
+		fps[m] = fpOfBuild(b)
+	}
+	// mesh-wireguard's resources are composed with no build of it named; its fingerprint is the indexer's, as every
+	// module's is, and stood in for here by its name.
+	for _, r := range c.Resources {
+		var head struct {
+			Module string `json:"module"`
+		}
+		_ = json.Unmarshal(r, &head)
+		if _, ok := fps[head.Module]; head.Module != "" && !ok {
+			fps[head.Module] = fpOfBuild(head.Module)
+		}
+	}
+	split, err := SplitComposed(node, c.Resources, fps, c.Filled, NodeOwn{Provisioner: c.Provisioner})
+	if err != nil {
+		t.Fatalf("SplitComposed(%s): %v", node, err)
+	}
+	return split
+}
+
+func canonical(t *testing.T, raw json.RawMessage) string {
+	t.Helper()
+	var v any
+	d := json.NewDecoder(bytes.NewReader(raw))
+	d.UseNumber()
+	if err := d.Decode(&v); err != nil {
+		t.Fatal(err)
+	}
+	out, _ := json.Marshal(v)
+	return string(out)
+}
+
+// 1943/AC2: each module's slice of a captured declaration of each node, and the node's own resources, round-trip
+// through the composition's encoding with the same digest; together they are the declaration's resources, each once,
+// each in the composition of the module it says.
+func TestCompositionsOfACapturedDeclaration(t *testing.T) {
+	t.Parallel()
+	for _, node := range []string{"ace", "g14"} {
+		t.Run(node, func(t *testing.T) {
+			t.Parallel()
+			oneCapturedDeclaration(t, node)
+		})
+	}
+}
+
+func oneCapturedDeclaration(t *testing.T, node string) {
+	{
+		c := readCaptured(t, node)
+		split := splitCaptured(t, node, c)
+		modules := map[string]bool{}
+		for m := range c.Builds {
+			modules[m] = true
+		}
+		var union []string
+		for key, comp := range split {
+			n, module, fp, isNode, err := ParseComposedKey(key)
+			if err != nil || n != node || comp.Node != node || comp.Module != module || comp.FP != fp {
+				t.Fatalf("%s: key %q holds %s/%s/%s (%v)", node, key, comp.Node, comp.Module, comp.FP, err)
+			}
+			if !isNode && !modules[module] && module != "mesh-wireguard" {
+				t.Errorf("%s: a composition of %s, which the declaration names no build of", node, module)
+			}
+			raw, err := EncodeComposed(comp)
+			if err != nil {
+				t.Fatalf("%s: EncodeComposed(%s): %v", node, key, err)
+			}
+			back, err := DecodeComposed(raw)
+			if err != nil {
+				t.Fatalf("%s: DecodeComposed(%s): %v", node, key, err)
+			}
+			if !SameComposed(back, comp) {
+				t.Errorf("%s: %s did not round-trip", node, key)
+			}
+			// SameComposed encodes both, so the digest of what was read back, a hash of its encoding, is the one written.
+			if d, err := ComposedDigestOf(back); err != nil || !digestForm.MatchString(d) {
+				t.Errorf("%s: %s digests %q (%v)", node, key, d, err)
+			}
+			for _, r := range back.Resources {
+				var head struct {
+					Module string `json:"module"`
+				}
+				_ = json.Unmarshal(r, &head)
+				if head.Module != module {
+					t.Errorf("%s: %s holds a resource of %q", node, key, head.Module)
+				}
+				union = append(union, canonical(t, r))
+			}
+		}
+		var want []string
+		for _, r := range c.Resources {
+			want = append(want, canonical(t, r))
+		}
+		sort.Strings(union)
+		sort.Strings(want)
+		if strings.Join(union, "\n") != strings.Join(want, "\n") {
+			t.Errorf("%s: the compositions hold %d resources, the declaration %d, or they differ", node, len(union), len(want))
+		}
+	}
+}
+
+// 1943/AC2: one changed byte of a resource is another digest; the same composition written with its keys in another
+// order is the same digest.
+func TestComposedDigestFollowsTheContent(t *testing.T) {
+	c := readCaptured(t, "g14")
+	split := splitCaptured(t, "g14", c)
+	var comp Composed
+	for _, v := range split {
+		if v.Module != "" && len(v.Resources) > 1 {
+			comp = v
+			break
+		}
+	}
+	d1, _ := ComposedDigestOf(comp)
+	var m map[string]json.RawMessage
+	_ = json.Unmarshal(comp.Resources[0], &m)
+	var keys []string
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Sort(sort.Reverse(sort.StringSlice(keys)))
+	var parts []string
+	for _, k := range keys {
+		parts = append(parts, fmt.Sprintf("%q :  %s", k, m[k]))
+	}
+	reordered := json.RawMessage("{ " + strings.Join(parts, ",\n ") + " }")
+	shuffled := comp
+	shuffled.Resources = append([]json.RawMessage{reordered}, comp.Resources[1:]...)
+	if d2, _ := ComposedDigestOf(shuffled); d2 != d1 {
+		t.Errorf("the same resources in another order and spacing digest %s and %s", d1, d2)
+	}
+	changed := comp
+	changed.Resources = append([]json.RawMessage{json.RawMessage(strings.Replace(canonical(t, comp.Resources[0]), `"id":"`, `"id":"x`, 1))}, comp.Resources[1:]...)
+	if d3, _ := ComposedDigestOf(changed); d3 == d1 {
+		t.Errorf("a changed resource kept its digest")
+	}
+	revised := comp
+	revised.Data = !comp.Data
+	if d4, _ := ComposedDigestOf(revised); d4 == d1 {
+		t.Errorf("a changed data flag kept its digest")
+	}
+}
+
+// 1943/AC2: a file over 64 KiB is carried by digest and size, its content handed back to be put in the node's object
+// bucket; a composition that carries such a file whole is refused.
+func TestAComposedFileOver64KiBIsCarriedByDigest(t *testing.T) {
+	c := readCaptured(t, "g14")
+	split := splitCaptured(t, "g14", c)
+	var comp Composed
+	var at int
+	for _, v := range split {
+		for i, r := range v.Resources {
+			var f map[string]any
+			_ = json.Unmarshal(r, &f)
+			if f["type"] == "file" && v.Module != "" && f["bytes"] == nil && f["into"] == nil {
+				comp, at = v, i
+				break
+			}
+		}
+		if comp.Module != "" {
+			break
+		}
+	}
+	var f map[string]any
+	_ = json.Unmarshal(comp.Resources[at], &f)
+	// Grown past the threshold from a captured file: no captured file of this node is over 64 KiB.
+	body := strings.Repeat("x", declaration.FileReferenceThreshold+1)
+	f["content"] = body
+	big, _ := json.Marshal(f)
+	comp.Resources = append([]json.RawMessage{}, comp.Resources...)
+	comp.Resources[at] = big
+	if _, err := EncodeComposed(comp); err == nil || !strings.Contains(err.Error(), "by digest") {
+		t.Fatalf("a file over 64 KiB carried whole = %v, want refused", err)
+	}
+	byDigest, objects, err := comp.ByDigest()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var ref map[string]any
+	_ = json.Unmarshal(byDigest.Resources[at], &ref)
+	digest := declaration.DigestOf([]byte(body))
+	if ref["digest"] != digest || ref["size"] != float64(len(body)) || ref["content"] != nil {
+		t.Errorf("the file became %v, want digest %s and size %d", ref, digest, len(body))
+	}
+	if string(objects[digest]) != body || len(objects) != 1 {
+		t.Errorf("the objects handed back are %d, want the file's content under its digest", len(objects))
+	}
+	if _, err := EncodeComposed(byDigest); err != nil {
+		t.Errorf("the composition by digest is refused: %v", err)
+	}
+}
+
+// 1943/AC2: an unknown version is refused as one; a module's composition carrying the node's own parts, a resource of
+// another module, a resource its kind refuses, or no fingerprint, is refused, naming why.
+func TestComposedRefusals(t *testing.T) {
+	fp := fp2of('a')
+	file := json.RawMessage(`{"id":"m.f","type":"file","module":"m","path":"/etc/m","content":"x"}`)
+	ok := Composed{Node: "ace", Module: "m", FP: fp, Resources: []json.RawMessage{file}}
+	raw, err := EncodeComposed(ok)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := DecodeComposed(bytes.Replace(raw, []byte(`"v":1`), []byte(`"v":2`), 1)); !errors.Is(err, ErrUnknownVersion) {
+		t.Errorf("version 2 = %v, want ErrUnknownVersion", err)
+	}
+	refusals := []struct {
+		c   Composed
+		why string
+	}{
+		{Composed{Node: "ace", Module: "m", Resources: []json.RawMessage{file}}, "fingerprint"},
+		{Composed{Node: "", Module: "m", FP: fp, Resources: []json.RawMessage{file}}, "node name is empty"},
+		{Composed{Node: "ace", Module: "other", FP: fp, Resources: []json.RawMessage{file}}, `of "m"`},
+		{Composed{Node: "ace", Module: "m", FP: fp, Resources: []json.RawMessage{file}, Own: NodeOwn{Provisioner: "p"}}, "node's own"},
+		{Composed{Node: "ace", FP: fp, Resources: []json.RawMessage{}}, "names no fingerprint"},
+		{Composed{Node: "ace", Resources: []json.RawMessage{file}}, `of "m"`},
+		{Composed{Node: "ace", Module: "m", FP: fp, Resources: []json.RawMessage{json.RawMessage(`{"id":"m.f","type":"file","module":"m","path":"/etc/m","content":"x","image":"y"}`)}}, `"image"`},
+		{Composed{Node: "ace", Module: "m", FP: fp, Resources: []json.RawMessage{json.RawMessage(`{"id":"m.a","type":"action","module":"m"}`)}}, "action"},
+	}
+	for _, r := range refusals {
+		if _, err := EncodeComposed(r.c); err == nil || !strings.Contains(err.Error(), r.why) {
+			t.Errorf("EncodeComposed(%s/%s) = %v, want a refusal saying %q", r.c.Node, r.c.Module, err, r.why)
+		}
+	}
+}
+
+// 1943/AC2 (issue 1150): a module whose name holds a dot keys its have, its want and its composition escaped, and the
+// parsers give its name back; a name with a wildcard, whitespace or an escape of its own is still refused.
+func TestADottedModuleKeysEscaped(t *testing.T) {
+	fp := fp2of('f')
+	have, err := HaveKey("ace", "novox.be")
+	if err != nil || have != "ace.novox=2ebe" {
+		t.Fatalf("HaveKey = %q, %v", have, err)
+	}
+	if n, m, isNode, err := ParseHaveKey(have); err != nil || n != "ace" || m != "novox.be" || isNode {
+		t.Errorf("ParseHaveKey(%q) = %q, %q, %v, %v", have, n, m, isNode, err)
+	}
+	want, err := WantKey("ace", "novox.be")
+	if err != nil || want != "want.ace.novox=2ebe" {
+		t.Fatalf("WantKey = %q, %v", want, err)
+	}
+	if n, m, err := ParseWantKey(want); err != nil || n != "ace" || m != "novox.be" {
+		t.Errorf("ParseWantKey(%q) = %q, %q, %v", want, n, m, err)
+	}
+	comp, err := ComposedKey("ace", "novox.be", fp)
+	if err != nil || comp != "ace.novox=2ebe."+strings.Repeat("f", 64) {
+		t.Fatalf("ComposedKey = %q, %v", comp, err)
+	}
+	if n, m, back, _, err := ParseComposedKey(comp); err != nil || n != "ace" || m != "novox.be" || back != fp {
+		t.Errorf("ParseComposedKey(%q) = %q, %q, %q, %v", comp, n, m, back, err)
+	}
+	for _, bad := range []string{"m*", "m x", "m=2e", "m>", ".m", "m.", "a..b"} {
+		if _, err := HaveKey("ace", bad); err == nil {
+			t.Errorf("HaveKey(ace, %q) accepted", bad)
+		}
+	}
+	for _, bad := range []string{"ace.m=2", "ace.m=2E", "ace.m=41", "ace.=6eode"} {
+		if _, _, _, err := ParseHaveKey(bad); err == nil {
+			t.Errorf("ParseHaveKey(%q) accepted", bad)
+		}
+	}
+}
+
+// The node's own composition carries the filled paths of the files moved into it, the files of a module with no
+// fingerprint of the new form: the provisioner fills them all the same (issue 1945, live on 2026-10-25: the paths were
+// dropped and the node-engine wrote those files empty). It still holds no module's data.
+func TestTheNodesOwnCompositionCarriesTheFilledPathsOfItsFiles(t *testing.T) {
+	filled := json.RawMessage(`{"id":"power.unit","type":"file","path":"/etc/systemd/system/p.service","mode":"0644","owner-at-runtime":"owned"}`)
+	own := Composed{Node: "ace", Resources: []json.RawMessage{filled}, Filled: []string{"/etc/systemd/system/p.service"},
+		Own: NodeOwn{Provisioner: "mesh-provisioner-client"}}
+	raw, err := EncodeComposed(own)
+	if err != nil {
+		t.Fatalf("the node's own composition with a filled file: %v", err)
+	}
+	back, err := DecodeComposed(raw)
+	if err != nil || len(back.Filled) != 1 {
+		t.Fatalf("read back: %v %v", back.Filled, err)
+	}
+	if _, err := EncodeComposed(Composed{Node: "ace", Data: true, Resources: []json.RawMessage{filled},
+		Filled: own.Filled}); err == nil {
+		t.Error("the node's own composition was let hold a module's data")
+	}
+}
+
+// A file the provisioner fills says no content: in a composition that does not say it is filled, the node-engine would
+// write it empty. Such a composition is refused, in the node's own as in a module's (issue 1945).
+func TestAFileWithNoContentThatIsNotFilledIsRefused(t *testing.T) {
+	fp := fp2of('a')
+	for _, c := range []Composed{
+		{Node: "ace", Resources: []json.RawMessage{json.RawMessage(
+			`{"id":"power.unit","type":"file","path":"/etc/p","mode":"0644","owner-at-runtime":"owned"}`)}},
+		{Node: "ace", Module: "m", FP: fp, Resources: []json.RawMessage{json.RawMessage(
+			`{"id":"m.f","type":"file","module":"m","path":"/etc/m","mode":"0644","owner-at-runtime":"owned"}`)}},
+	} {
+		if _, err := EncodeComposed(c); err == nil || !strings.Contains(err.Error(), "empty") {
+			t.Errorf("%s/%s: %v, want a refusal saying it would be written empty", c.Node, c.Module, err)
+		}
+	}
+	// A file that says its content, even an empty one, is written as it says.
+	if _, err := EncodeComposed(Composed{Node: "ace", Resources: []json.RawMessage{json.RawMessage(
+		`{"id":"x.f","type":"file","path":"/etc/x","mode":"0644","content":""}`)}}); err != nil {
+		t.Errorf("a file that says it is empty: %v", err)
+	}
+}

go/delivery/delivery.go

@@ -11,7 +11,8 @@
 // `node`. A presence key is `<node>` for a node and `part.<part>.<instance>` for a part's instance, so a node may
 // not be named `part`. A pulse key is `<bucket>.<key>`: the full name of the bucket watched, then that bucket's key,
 // which may hold dots, so it splits at the first dot. A name is refused when it is empty or holds a dot, a wildcard,
-// whitespace or a character a bus key refuses, and the error names it.
+// whitespace or a character a bus key refuses, and the error names it; but a module's name may hold dots between its
+// parts (`novox.be`), and keys with each dot escaped as EscapeName writes it (`novox=2ebe`, issue 1150).
 //
 // **Values** are JSON of under about 500 bytes, each carrying its version in `v`. A reader refuses a value whose
 // version is missing or one it does not know, with an error that is ErrUnknownVersion (research 063 section 05
@@ -35,7 +36,7 @@
 // builder's build keys (builder.go) and the checker's verdicts and kept verdicts (checker.go). A manifests value is the
 // one exception to the size above: a manifest is up to about 21 KB, whole, byte for byte.
 //
-// Standard library only, and this module's own asks package.
+// Standard library only, and this module's own asks and declaration packages (a composition holds declaration resources).
 package delivery
 
 import (
@@ -89,6 +90,10 @@ const (
 	// for which it had written a have key; the key is never deleted (issue 1369, ADR 0408 §4), so a reader can tell
 	// that the module stopped.
 	PhaseRemoved Phase = "removed"
+	// PhaseHeld is a module whose backup before an apply failed: it keeps running what it has, nothing of the new
+	// composition is applied, and the node waits for the answer in its want (novox/hq ADR 0539 clause 16). Detail
+	// carries the backup's own words.
+	PhaseHeld Phase = "held"
 )
 
 // Health is what the module's own check says.
@@ -164,13 +169,45 @@ func HaveKey(node, module string) (string, error) {
 	if err := checkName("node", node); err != nil {
 		return "", err
 	}
-	if err := checkName("module", module); err != nil {
+	part, err := moduleKeyPart(module)
+	if err != nil {
 		return "", err
 	}
 	if module == "node" {
 		return "", fmt.Errorf(`delivery: the module name "node" is refused: %s.node is the node's own key`, node)
 	}
-	return node + "." + module, nil
+	return node + "." + part, nil
+}
+
+var moduleNameOK = regexp.MustCompile(`^[-/_a-zA-Z0-9]+(\.[-/_a-zA-Z0-9]+)*$`)
+
+// moduleKeyPart is a module's name as a key part (issue 1150): a name may hold a dot (`novox.be`), which a key part
+// may not, so a dot is escaped as EscapeName writes it (`novox=2ebe`); a name of letters, digits, `-`, `/` and `_` keys
+// as it is. A name that is empty, or holds a wildcard, whitespace, `=`, or an empty part between dots, is refused.
+func moduleKeyPart(module string) (string, error) {
+	if module == "" {
+		return "", fmt.Errorf("delivery: the module name is empty")
+	}
+	if !moduleNameOK.MatchString(module) {
+		return "", fmt.Errorf("delivery: the module name %q holds a wildcard, whitespace, '=', an empty part between dots or a character a key refuses", module)
+	}
+	return EscapeName(module), nil
+}
+
+// parseModuleKeyPart is the inverse of moduleKeyPart; it refuses a part that is not the one moduleKeyPart writes for
+// its name (an escape of a character that keys as it is, an upper-case escape, an escape of a refused character).
+func parseModuleKeyPart(part string) (string, error) {
+	if err := checkName("module", part); err != nil {
+		return "", err
+	}
+	module, err := UnescapeName(part)
+	if err != nil {
+		return "", err
+	}
+	if back, err := moduleKeyPart(module); err != nil || back != part {
+		return "", fmt.Errorf("delivery: the module part %q is not a module name as a key writes it", part)
+	}
+	return module, nil
 }
 
 // HaveNodeKey is the key, in HaveBucket, of a node's own facts: `<node>.node`.
@@ -190,12 +227,13 @@ func ParseHaveKey(key string) (node, module string, isNode bool, err error) {
 	if err := checkName("node", node); err != nil {
 		return "", "", false, fmt.Errorf("delivery: %q is not a have key: %w", key, err)
 	}
-	if err := checkName("module", module); err != nil {
-		return "", "", false, fmt.Errorf("delivery: %q is not a have key: %w", key, err)
-	}
 	if module == "node" {
 		return node, "", true, nil
 	}
+	module, err = parseModuleKeyPart(module)
+	if err != nil {
+		return "", "", false, fmt.Errorf("delivery: %q is not a have key: %w", key, err)
+	}
 	return node, module, false, nil
 }
 
@@ -282,24 +320,52 @@ func PulseTTL(moveAge time.Duration) (ttl time.Duration, stalled bool) {
 // Have is a module's state on a node, written by that node's node-engine under HaveKey. FP is the module's
 // fingerprint once the indexer exists (design 47 release 3); until then Build is the build the node was sent, and
 // the view compares by build.
+//
+// Composed is the digest of the composition the node runs for the module (novox/hq ADR 0539 clause 9): the
+// controller judges a move against it (clause 14), and the assigner reads it to know a want was applied.
 type Have struct {
-	V      int    `json:"v"`
-	FP     string `json:"fp,omitempty"`
-	Build  string `json:"build,omitempty"`
-	Phase  Phase  `json:"phase"`
-	Health Health `json:"health"`
-	Detail string `json:"detail,omitempty"`
+	V        int    `json:"v"`
+	FP       string `json:"fp,omitempty"`
+	Composed string `json:"composed,omitempty"`
+	Build    string `json:"build,omitempty"`
+	Phase    Phase  `json:"phase"`
+	Health   Health `json:"health"`
+	Detail   string `json:"detail,omitempty"`
+	// UserList is what the node-engine of the node holding mesh-broker wrote of the bus's user list, in the have of the
+	// bus module (novox/hq ADR 0547 §7, §8). Nil on every other have.
+	UserList *UserListWritten `json:"user-list,omitempty"`
+}
+
+// UserListWritten is the bus's user list as the node-engine of the bus node wrote it to the bus module's file, applied
+// alone and with no want (novox/hq ADR 0547 §8): where it was taken from, what that source holds, and what the file
+// holds now. The bus reloads the file itself when its digest changes (the module's entrypoint), so Digest is the list
+// the bus loads. Wanted differs from Digest only while a write failed, and Error says why.
+type UserListWritten struct {
+	// Source is the key the list was taken from: the controller's composition of the bus module for this node
+	// (`<node>.<module>.<fp>`), or the grants part's `user-list` once it took over.
+	Source   string `json:"source"`
+	Revision uint64 `json:"revision"`
+	// Wanted is the digest of the list the source holds, `sha256:<hex>`.
+	Wanted string `json:"wanted"`
+	// Digest is the digest of the file on the machine after the write, `sha256:<hex>`; empty when there is none.
+	Digest string    `json:"digest,omitempty"`
+	Users  int       `json:"users"`
+	At     time.Time `json:"at"`
+	Error  string    `json:"error,omitempty"`
 }
 
 // HaveNode is a node's own facts, written under HaveNodeKey. Each field is the node-engine's own JSON, carried whole:
 // this package names the facts and does not type them.
+//
+// Composed is the digest of the node's own composition it runs (ADR 0539 clause 9).
 type HaveNode struct {
-	V       int             `json:"v"`
-	Windows json.RawMessage `json:"windows,omitempty"`
-	Busy    json.RawMessage `json:"busy,omitempty"`
-	Strays  json.RawMessage `json:"strays,omitempty"`
-	Filters json.RawMessage `json:"filters,omitempty"`
-	Profile json.RawMessage `json:"profile,omitempty"`
+	V        int             `json:"v"`
+	Composed string          `json:"composed,omitempty"`
+	Windows  json.RawMessage `json:"windows,omitempty"`
+	Busy     json.RawMessage `json:"busy,omitempty"`
+	Strays   json.RawMessage `json:"strays,omitempty"`
+	Filters  json.RawMessage `json:"filters,omitempty"`
+	Profile  json.RawMessage `json:"profile,omitempty"`
 }
 
 // Presence is whether a node or a part's instance is online; the entry's own time says since when. The watchman
@@ -347,9 +413,14 @@ func decode(data []byte, into any) error {
 
 func (h Have) check() error {
 	switch h.Phase {
-	case PhaseBackingUp, PhaseApplying, PhaseChecking, PhaseRunning, PhaseFailed, PhaseRemoved:
+	case PhaseBackingUp, PhaseApplying, PhaseChecking, PhaseRunning, PhaseFailed, PhaseRemoved, PhaseHeld:
 	default:
-		return fmt.Errorf("delivery: phase %q is not backing-up, applying, checking, running, failed or removed", h.Phase)
+		return fmt.Errorf("delivery: phase %q is not backing-up, applying, checking, running, failed, removed or held", h.Phase)
+	}
+	if h.Composed != "" {
+		if err := checkDigest(h.Composed, "the have's composition digest"); err != nil {
+			return err
+		}
 	}
 	switch h.Health {
 	case HealthOK, HealthFailed, HealthWaits, HealthUnknown:
@@ -420,11 +491,23 @@ func DecodePulse(data []byte) (Pulse, error) {
 }
 
 // SameHave says whether two haves are the same value, so a writer writes only when they differ.
-func SameHave(a, b Have) bool { return a == b }
+func SameHave(a, b Have) bool {
+	ua, ub := a.UserList, b.UserList
+	a.UserList, b.UserList = nil, nil
+	if a != b || (ua == nil) != (ub == nil) {
+		return false
+	}
+	if ua == nil {
+		return true
+	}
+	x, y := *ua, *ub
+	x.At, y.At = time.Time{}, time.Time{}
+	return x == y && ua.At.Equal(ub.At)
+}
 
 // SameHaveNode says whether two node facts are the same value, comparing each carried JSON without its spacing.
 func SameHaveNode(a, b HaveNode) bool {
-	return a.V == b.V && sameJSON(a.Windows, b.Windows) && sameJSON(a.Busy, b.Busy) &&
+	return a.V == b.V && a.Composed == b.Composed && sameJSON(a.Windows, b.Windows) && sameJSON(a.Busy, b.Busy) &&
 		sameJSON(a.Strays, b.Strays) && sameJSON(a.Filters, b.Filters) && sameJSON(a.Profile, b.Profile)
 }
 

go/delivery/delivery_test.go

@@ -3,6 +3,7 @@ package delivery
 import (
 	"encoding/json"
 	"errors"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -149,6 +150,24 @@ func TestRoundTrip(t *testing.T) {
 			t.Fatalf("got %+v want %+v", out, in)
 		}
 	})
+	t.Run("have with the user list", func(t *testing.T) {
+		at := time.Date(2026, 10, 25, 21, 40, 0, 0, time.UTC)
+		in := Have{FP: "f1", Phase: PhaseRunning, Health: HealthOK, UserList: &UserListWritten{Source: "novox.nats.f1",
+			Revision: 7, Wanted: "sha256:ab", Digest: "sha256:ab", Users: 93, At: at}}
+		b, err := EncodeHave(in)
+		if err != nil {
+			t.Fatal(err)
+		}
+		hasV1(t, b)
+		out, err := DecodeHave(b)
+		if err != nil {
+			t.Fatal(err)
+		}
+		in.V = Version
+		if !reflect.DeepEqual(out, in) || !out.UserList.At.Equal(at) {
+			t.Fatalf("got %+v want %+v", out, in)
+		}
+	})
 	t.Run("have node", func(t *testing.T) {
 		in := HaveNode{Windows: json.RawMessage(`{"a":1}`), Busy: json.RawMessage(`true`)}
 		b, err := EncodeHaveNode(in)
@@ -275,6 +294,18 @@ func TestSame(t *testing.T) {
 	if SameHave(a, b) {
 		t.Error("different haves same")
 	}
+	// The user list is compared by what it says, never by where it is held (ADR 0547 §8).
+	at := time.Date(2026, 10, 25, 21, 0, 0, 0, time.UTC)
+	ua, ub := a, a
+	ua.UserList = &UserListWritten{Source: "k", Revision: 1, Wanted: "sha256:a", Digest: "sha256:a", Users: 2, At: at}
+	ub.UserList = &UserListWritten{Source: "k", Revision: 1, Wanted: "sha256:a", Digest: "sha256:a", Users: 2, At: at.In(time.Local)}
+	if !SameHave(ua, ub) || SameHave(ua, a) {
+		t.Error("equal user lists differ, or one said and one not are the same")
+	}
+	ub.UserList.Revision = 2
+	if SameHave(ua, ub) {
+		t.Error("different user lists same")
+	}
 	n := HaveNode{V: 1, Busy: json.RawMessage(`true`)}
 	if !SameHaveNode(n, HaveNode{V: 1, Busy: json.RawMessage(`true`)}) || SameHaveNode(n, HaveNode{V: 1}) {
 		t.Error("have node")

go/delivery/grants.go

@@ -73,3 +73,20 @@ func DecodeControllerGrant(data []byte) (ControllerGrant, error) {
 
 // SameControllerGrant says whether two grants are the same value.
 func SameControllerGrant(a, b ControllerGrant) bool { return reflect.DeepEqual(a, b) }
+
+// NamesNode says whether the grant names module's accounts on node: its own `<node>.<module>` or a process's
+// `<node>.<module>.<process>`. A grant that names no account (a module that does not speak on the bus) names every
+// node. The assigner wants a node only once the grant names its account (issue 1945), and a put waits for it (ADR
+// 0546 clause 4).
+func (g ControllerGrant) NamesNode(node, module string) bool {
+	if len(g.Accounts) == 0 {
+		return true
+	}
+	own := node + "." + module
+	for _, a := range g.Accounts {
+		if a == own || strings.HasPrefix(a, own+".") {
+			return true
+		}
+	}
+	return false
+}

go/delivery/put.go

@@ -0,0 +1,148 @@
+package delivery
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+)
+
+// A put (novox/hq ADR 0546): one version of a module put on one node by the assigner's tool `assigner_put`. Each put is the
+// key `<node>.<module>` of the assigner's state puts, which holds the version asked, the hold, why, and each step the
+// assigner took or waits on, so a reader watches the key to follow it. The want the put writes carries Put (and Hold),
+// so the assigner's rules pass over that key while the put holds it.
+
+// AssignerPutsBucket is the assigner's bucket of puts, `<owner module>_puts`.
+const AssignerPutsBucket = AssignerModule + "_puts"
+
+// AssignerPutsHistory is the revisions the puts bucket keeps per key: each step of a put is one.
+const AssignerPutsHistory = 20
+
+// A put's steps, in the order they are taken (ADR 0546 clauses 3 to 9). A put stands at the last step written.
+const (
+	// PutAsked is a put written by the tool, not taken up by a pass yet.
+	PutAsked = "asked"
+	// PutBuild waits for the builder's build at the fingerprint.
+	PutBuild = "build"
+	// PutCompose waits for the controller's composition (and grant) at the fingerprint.
+	PutCompose = "compose"
+	// PutPerson waits for the operator's answer to the ask about the move.
+	PutPerson = "person"
+	// PutSnapshot waits for the bus's streams to be snapshotted after the operator's yes.
+	PutSnapshot = "snapshot"
+	// PutWanted is the want written: the node's have has not reached it yet.
+	PutWanted = "wanted"
+	// PutHolding is a held put whose have runs it healthy: the want stays until released.
+	PutHolding = "holding"
+	// PutDone is a put without hold whose have ran it healthy: the rules write the want again.
+	PutDone = "done"
+	// PutReleased is a put released by the tool `assigner_release`.
+	PutReleased = "released"
+	// PutRefused is a put that cannot go on: a build that failed, an answer no, a snapshot not taken. Its words say why.
+	PutRefused = "refused"
+)
+
+// PutEnded says a put at this step is over: nothing more is done for it and the rules own the want.
+func PutEnded(step string) bool {
+	return step == PutDone || step == PutReleased || step == PutRefused
+}
+
+// PutStep is one step a put took: when, which, and what was done or waits, in a sentence.
+type PutStep struct {
+	At    time.Time `json:"at"`
+	Step  string    `json:"step"`
+	Words string    `json:"words"`
+}
+
+// PutStepsKept is how many steps a put keeps, newest last.
+const PutStepsKept = 16
+
+// Put is the value of a key of AssignerPutsBucket.
+type Put struct {
+	V int `json:"v"`
+	// FP is the fingerprint put, of the new form.
+	FP string `json:"fp"`
+	// Hold keeps the want at FP until released.
+	Hold bool   `json:"hold,omitempty"`
+	Why  string `json:"why"`
+	// By is who asked, as the bus named the caller; "unproven" when it named none.
+	By string    `json:"by,omitempty"`
+	At time.Time `json:"at"`
+	// Step is where the put stands now, one of the Put* steps; Words say it in a sentence.
+	Step  string `json:"step"`
+	Words string `json:"words,omitempty"`
+	// Composed is the digest of the composition the want names, once known.
+	Composed string `json:"composed,omitempty"`
+	// Ask is the key, in AssignerAsksBucket, of the ask about the move, once asked.
+	Ask string `json:"ask,omitempty"`
+	// Snapshot says where the bus's streams were snapshotted, once they were.
+	Snapshot string `json:"snapshot,omitempty"`
+	// Steps are the steps taken, oldest first, at most PutStepsKept.
+	Steps []PutStep `json:"steps,omitempty"`
+}
+
+// Said is p at step with words, the step added to its steps when it differs from the last one.
+func (p Put) Said(at time.Time, step, words string) Put {
+	if p.Step == step && p.Words == words {
+		return p
+	}
+	p.Step, p.Words = step, words
+	p.Steps = append(append([]PutStep(nil), p.Steps...), PutStep{At: at.UTC(), Step: step, Words: words})
+	if len(p.Steps) > PutStepsKept {
+		p.Steps = p.Steps[len(p.Steps)-PutStepsKept:]
+	}
+	return p
+}
+
+func (p Put) check() error {
+	if err := checkFingerprint(p.FP, "a put's fingerprint"); err != nil {
+		return err
+	}
+	if p.Why == "" {
+		return fmt.Errorf("delivery: a put says why")
+	}
+	switch p.Step {
+	case PutAsked, PutBuild, PutCompose, PutPerson, PutSnapshot, PutWanted, PutHolding, PutDone, PutReleased, PutRefused:
+	default:
+		return fmt.Errorf("delivery: %q is not a step of a put", p.Step)
+	}
+	if p.Composed != "" {
+		return checkDigest(p.Composed, "a put's composition digest")
+	}
+	return nil
+}
+
+// PutKey is the key, in AssignerPutsBucket, of the put of module on node: `<node>.<module>`.
+func PutKey(node, module string) (string, error) {
+	return HaveKey(node, module)
+}
+
+// ParsePutKey reads a PutKey.
+func ParsePutKey(key string) (node, module string, err error) {
+	node, module, isNode, err := ParseHaveKey(key)
+	if err == nil && isNode {
+		err = fmt.Errorf("delivery: %q is a node's own key, and no put", key)
+	}
+	return node, module, err
+}
+
+// EncodePut is p as JSON at Version; it refuses a fingerprint not of the new form, a put that says no why and an
+// unknown step.
+func EncodePut(p Put) ([]byte, error) {
+	if err := p.check(); err != nil {
+		return nil, err
+	}
+	p.V = Version
+	return json.Marshal(p)
+}
+
+// DecodePut reads a put; it refuses an unknown version (ErrUnknownVersion) and what EncodePut refuses.
+func DecodePut(data []byte) (Put, error) {
+	var p Put
+	if err := decode(data, &p); err != nil {
+		return Put{}, err
+	}
+	if err := p.check(); err != nil {
+		return Put{}, err
+	}
+	return p, nil
+}

go/delivery/stepasks.go

@@ -535,9 +535,13 @@ func ParseAskStepKey(key string) (node, askID string, err error) {
 	return node, askID, nil
 }
 
-// PauseKey is the key, in a build module's StepsBucket, that keeps whether the module on node takes asks:
+// PausesState is the state a build module keeps its nodes' pause keys in. It has no age, unlike StepsState, whose keys
+// are per step and dropped after their age: a pause kept among the steps would end by itself.
+const PausesState = "pauses"
+
+// PauseKey is the key, in a build module's PausesState, that keeps whether the module on node takes asks:
 // `paused.<node>` (issue 1887's design limit 2: every holder pulls from one shared worker, so a node's pause is its holder
-// not fetching, kept here so a restart keeps it). A pause key is never an ask's step key: its second part is a node.
+// not fetching, kept so a restart keeps it). A pause key is never an ask's step key: its second part is a node.
 func PauseKey(node string) (string, error) {
 	if err := checkName("node", node); err != nil {
 		return "", err

go/delivery/view_answers.go

@@ -32,19 +32,27 @@ const (
 	AskKindHold = "hold"
 	// AskKindRestore is the kind of the assigner's ask about a data module set back.
 	AskKindRestore = "restore"
+	// AskKindBackup is the kind of the assigner's ask about a backup before an apply that failed: back up again, or go
+	// on without one (novox/hq ADR 0539 clause 16).
+	AskKindBackup = "backup"
+	// AskKindRecord is the kind of the assigner's ask about a move a person must allow, for a module of policy record:
+	// a composition judged to recreate a container or move data, or one that cannot be judged (ADR 0539 clause 14).
+	AskKindRecord = "record"
 
 	viewWord = "view"
 )
 
 // AskKey is an ask's key read whole: its Kind, and the parts its kind has: a merge's Group and heads Hash, a hold's
-// Module and fingerprint FP, a restore's Node, Module and FP.
+// Module and fingerprint FP, a restore's and a backup's Node, Module and FP, a record's Node, Module and the digest
+// Composed of the composition it would allow.
 type AskKey struct {
-	Kind   string
-	Group  string
-	Hash   string
-	Node   string
-	Module string
-	FP     string
+	Kind     string
+	Group    string
+	Hash     string
+	Node     string
+	Module   string
+	FP       string
+	Composed string
 }
 
 // AskNeedsProof says whether an ask of this kind must prove who answered it, so the view may not answer it: the
@@ -53,10 +61,11 @@ func AskNeedsProof(kind string) (bool, error) {
 	switch kind {
 	case AskKindMerge:
 		return true, nil
-	case AskKindHold, AskKindRestore:
+	case AskKindHold, AskKindRestore, AskKindBackup, AskKindRecord:
 		return false, nil
 	}
-	return false, fmt.Errorf("delivery: %q is not a kind of ask, %s, %s or %s", kind, AskKindMerge, AskKindHold, AskKindRestore)
+	return false, fmt.Errorf("delivery: %q is not a kind of ask, %s, %s, %s, %s or %s", kind, AskKindMerge, AskKindHold,
+		AskKindRestore, AskKindBackup, AskKindRecord)
 }
 
 // HoldAskKey is the key, in AssignerAsksBucket, of the ask about a module's held fingerprint: `hold.<module>.<hex>`.
@@ -81,7 +90,32 @@ func RestoreAskKey(node, module, fingerprint string) (string, error) {
 	return AskKindRestore + "." + node + "." + key, nil
 }
 
-// ParseAnyAskKey reads an ask key of any kind (MergeAskKey, HoldAskKey, RestoreAskKey); it refuses an unknown kind
+// BackupAskKey is the key, in AssignerAsksBucket, of the ask about a module's failed backup on a node before it applies
+// a fingerprint: `backup.<node>.<module>.<hex>`.
+func BackupAskKey(node, module, fingerprint string) (string, error) {
+	key, err := ComposedKey(node, module, fingerprint)
+	if err != nil {
+		return "", err
+	}
+	return AskKindBackup + "." + key, nil
+}
+
+// RecordAskKey is the key, in AssignerAsksBucket, of the ask about a move of a module on a node to the composition
+// whose digest it names: `record.<node>.<module>.<digest hex>`, so a new revision at the same fingerprint is asked
+// again (ADR 0539 clause 14).
+func RecordAskKey(node, module, composed string) (string, error) {
+	have, err := HaveKey(node, module)
+	if err != nil {
+		return "", err
+	}
+	if err := checkDigest(composed, "a record ask's composition digest"); err != nil {
+		return "", err
+	}
+	return AskKindRecord + "." + have + "." + strings.TrimPrefix(composed, "sha256:"), nil
+}
+
+// ParseAnyAskKey reads an ask key of any kind (MergeAskKey, HoldAskKey, RestoreAskKey, BackupAskKey, RecordAskKey); it
+// refuses an unknown kind
 // and a key whose parts do not fit its kind, naming the key.
 func ParseAnyAskKey(key string) (AskKey, error) {
 	kind, rest, _ := strings.Cut(key, ".")
@@ -114,6 +148,26 @@ func ParseAnyAskKey(key string) (AskKey, error) {
 			return refused(err)
 		}
 		return AskKey{Kind: kind, Node: node, Module: module, FP: fp}, nil
+	case AskKindBackup:
+		node, module, fp, isNode, err := ParseComposedKey(rest)
+		if err != nil || isNode {
+			return refused(fmt.Errorf("a backup ask is backup.<node>.<module>.<fingerprint hex>"))
+		}
+		return AskKey{Kind: kind, Node: node, Module: module, FP: fp}, nil
+	case AskKindRecord:
+		parts := strings.Split(rest, ".")
+		if len(parts) != 3 {
+			return refused(fmt.Errorf("a record ask is record.<node>.<module>.<digest hex>"))
+		}
+		node, module, isNode, err := ParseHaveKey(parts[0] + "." + parts[1])
+		if err != nil || isNode {
+			return refused(fmt.Errorf("a record ask is record.<node>.<module>.<digest hex>"))
+		}
+		composed := "sha256:" + parts[2]
+		if err := checkDigest(composed, "a record ask's composition digest"); err != nil {
+			return refused(err)
+		}
+		return AskKey{Kind: kind, Node: node, Module: module, Composed: composed}, nil
 	}
 	_, err := AskNeedsProof(kind)
 	return refused(err)
@@ -229,9 +283,15 @@ func ViewAnswerFits(a ViewAnswer, ask AssignerAsk) error {
 	if a.Asking != ask.Ask.ID {
 		return fmt.Errorf("delivery: the view's answer is to the asking %s, and the ask stands at the asking %s", a.Asking, ask.Ask.ID)
 	}
-	if _, ok := ask.Ask.Option(a.Option); !ok {
+	o, ok := ask.Ask.Option(a.Option)
+	if !ok {
 		return fmt.Errorf("delivery: the view's answer chose %q, which the asking %s does not offer", a.Option, ask.Ask.ID)
 	}
+	if o.Level != "" && o.Level != asks.Acknowledge {
+		// An option that authorises is answered on a channel that proves who answered (ADR 0259 §5, ADR 0546 clause 8),
+		// never in the view, which proves nobody.
+		return fmt.Errorf("delivery: the view's answer chose %q, an option of level %s, which only a channel that proves who answered takes", a.Option, o.Level)
+	}
 	return nil
 }
 

go/delivery/view_answers_test.go

@@ -158,4 +158,11 @@ func TestViewAnswerFits(t *testing.T) {
 	if err := ViewAnswerFits(ViewAnswer{Asking: first.Ask.ID, Option: "restore"}, first); err == nil {
 		t.Errorf("an option the ask does not offer fits")
 	}
+	// An option that authorises is never answered in the view (ADR 0546 clause 8).
+	approving := first
+	approving.Ask.Options = append([]asks.Option(nil), first.Ask.Options...)
+	approving.Ask.Options[0].Level = asks.Approve
+	if err := ViewAnswerFits(answer, approving); err == nil || !strings.Contains(err.Error(), "approve") {
+		t.Errorf("the view answered an option of level approve: %v", err)
+	}
 }

go/delivery/want_composed_test.go

@@ -0,0 +1,176 @@
+package delivery
+
+import (
+	"strings"
+	"testing"
+)
+
+func hashOf(c byte) string { return "sha256:" + digestOf(c) }
+
+// 1943/AC3: a want naming its fingerprint and the digest of the composition it allows round-trips, and so does one
+// carrying the answer to a failed backup; a want naming a fingerprint without a digest, a digest not of the sha256
+// form, a removed want naming a digest, an unknown backup answer and a rule past the seventh are refused.
+func TestAWantNamesItsComposition(t *testing.T) {
+	for _, w := range []Want{
+		{FP: fp2of('a'), Composed: hashOf('1')},
+		{FP: fp2of('a'), Composed: hashOf('1'), Backup: BackupAgain},
+		{FP: fp2of('a'), Composed: hashOf('1'), Backup: BackupSkip, Words: "the operator: go on without a backup"},
+		{FP: fp2of('a'), Composed: hashOf('1'), Newest: fp2of('b'), Rule: RuleComposed, Words: "no composition of b for ace yet"},
+		{Removed: true},
+	} {
+		raw, err := EncodeWant(w)
+		if err != nil {
+			t.Fatalf("EncodeWant(%+v): %v", w, err)
+		}
+		back, err := DecodeWant(raw)
+		w.V = Version
+		if err != nil || !SameWant(back, w) {
+			t.Errorf("want %+v came back %+v, %v", w, back, err)
+		}
+	}
+	refusals := []struct {
+		w   Want
+		why string
+	}{
+		{Want{FP: fp2of('a')}, "names no composition"},
+		{Want{FP: fp2of('a'), Composed: "sha256:12"}, "not sha256"},
+		{Want{Removed: true, Composed: hashOf('1')}, "removed want names no"},
+		{Want{FP: fp2of('a'), Composed: hashOf('1'), Backup: "later"}, `backup answer "later"`},
+		{Want{Removed: true, Backup: BackupAgain}, "removed want names no"},
+		{Want{FP: fp2of('a'), Composed: hashOf('1'), Newest: fp2of('b'), Rule: 8}, "rule 8"},
+	}
+	for _, r := range refusals {
+		if _, err := EncodeWant(r.w); err == nil || !strings.Contains(err.Error(), r.why) {
+			t.Errorf("EncodeWant(%+v) = %v, want a refusal saying %q", r.w, err, r.why)
+		}
+	}
+	if _, err := DecodeWant([]byte(`{"v":1,"fp":"` + fp2of('a') + `"}`)); err == nil || !strings.Contains(err.Error(), "names no composition") {
+		t.Errorf("a want of release 5, naming no composition, was read: %v", err)
+	}
+	if RuleComposed != 7 {
+		t.Errorf("RuleComposed = %d, want the seventh rule", RuleComposed)
+	}
+}
+
+// 1943/AC3: the node's own want is `want.<node>.node` and round-trips through its parser, while a module named node is
+// still refused a want key; its value names the digest of the node's own composition and no fingerprint.
+func TestTheNodesOwnWant(t *testing.T) {
+	key, err := WantNodeKey("ace")
+	if err != nil || key != "want.ace.node" {
+		t.Fatalf("WantNodeKey = %q, %v", key, err)
+	}
+	if node, err := ParseWantNodeKey(key); err != nil || node != "ace" {
+		t.Errorf("ParseWantNodeKey(%q) = %q, %v", key, node, err)
+	}
+	if _, err := WantKey("ace", "node"); err == nil {
+		t.Errorf(`WantKey(ace, "node") accepted`)
+	}
+	if _, _, err := ParseWantKey(key); err == nil {
+		t.Errorf("ParseWantKey read the node's own want as a module's")
+	}
+	for _, bad := range []string{"want.ace.mesh-mail", "want.node", "ace.node", "want.a.b.node", ""} {
+		if _, err := ParseWantNodeKey(bad); err == nil || !strings.Contains(err.Error(), "\""+bad+"\"") {
+			t.Errorf("ParseWantNodeKey(%q) = %v, want a refusal naming it", bad, err)
+		}
+	}
+	if _, err := WantNodeKey(""); err == nil {
+		t.Errorf("WantNodeKey(\"\") accepted")
+	}
+	w := NodeWant{Composed: hashOf('2'), Words: "the node's own composition"}
+	raw, err := EncodeNodeWant(w)
+	if err != nil {
+		t.Fatal(err)
+	}
+	back, err := DecodeNodeWant(raw)
+	w.V = Version
+	if err != nil || back != w {
+		t.Errorf("node want came back %+v, %v", back, err)
+	}
+	for _, bad := range []NodeWant{{}, {Composed: "sha256:1"}} {
+		if _, err := EncodeNodeWant(bad); err == nil {
+			t.Errorf("EncodeNodeWant(%+v) accepted", bad)
+		}
+	}
+	if _, err := DecodeNodeWant([]byte(`{"v":1,"composed":"` + hashOf('2') + `","fp":"` + fp2of('a') + `"}`)); err == nil {
+		t.Errorf("a node want naming a fingerprint was read")
+	}
+}
+
+// 1943/AC3: a have held after a failed backup, naming the composition it runs, round-trips; so does the node's own have
+// naming its composition; a have's digest not of the sha256 form is refused.
+func TestAHaveNamesItsComposition(t *testing.T) {
+	for _, h := range []Have{
+		{FP: fp2of('a'), Composed: hashOf('3'), Phase: PhaseHeld, Health: HealthOK, Detail: "the backup failed: no space left"},
+		{FP: fp2of('a'), Composed: hashOf('3'), Phase: PhaseRunning, Health: HealthOK},
+	} {
+		raw, err := EncodeHave(h)
+		if err != nil {
+			t.Fatalf("EncodeHave(%+v): %v", h, err)
+		}
+		back, err := DecodeHave(raw)
+		h.V = Version
+		if err != nil || !SameHave(back, h) {
+			t.Errorf("have %+v came back %+v, %v", h, back, err)
+		}
+	}
+	if _, err := EncodeHave(Have{Composed: "sha256:x", Phase: PhaseRunning, Health: HealthOK}); err == nil || !strings.Contains(err.Error(), "not sha256") {
+		t.Errorf("a have naming a bad digest = %v", err)
+	}
+	n := HaveNode{Composed: hashOf('4')}
+	raw, err := EncodeHaveNode(n)
+	if err != nil {
+		t.Fatal(err)
+	}
+	back, err := DecodeHaveNode(raw)
+	n.V = Version
+	if err != nil || !SameHaveNode(back, n) {
+		t.Errorf("node have came back %+v, %v", back, err)
+	}
+	if SameHaveNode(n, HaveNode{V: Version, Composed: hashOf('5')}) {
+		t.Errorf("node haves naming two compositions are the same")
+	}
+}
+
+// 1943/AC3: the assigner's backup ask (back up again, or go on without one, ADR 0539 clause 16) and its record ask (a
+// move a person must allow, clause 14) key by node, module and fingerprint or composition, round-trip through
+// ParseAnyAskKey, and the view may answer both.
+func TestTheBackupAndRecordAsks(t *testing.T) {
+	fp, digest := fp2of('a'), hashOf('6')
+	backup, err := BackupAskKey("ace", "mesh-mail", fp)
+	if err != nil || backup != "backup.ace.mesh-mail."+strings.Repeat("a", 64) {
+		t.Fatalf("BackupAskKey = %q, %v", backup, err)
+	}
+	record, err := RecordAskKey("ace", "mesh-mail", digest)
+	if err != nil || record != "record.ace.mesh-mail."+strings.Repeat("6", 64) {
+		t.Fatalf("RecordAskKey = %q, %v", record, err)
+	}
+	if got, err := ParseAnyAskKey(backup); err != nil || got != (AskKey{Kind: AskKindBackup, Node: "ace", Module: "mesh-mail", FP: fp}) {
+		t.Errorf("ParseAnyAskKey(%q) = %+v, %v", backup, got, err)
+	}
+	if got, err := ParseAnyAskKey(record); err != nil || got != (AskKey{Kind: AskKindRecord, Node: "ace", Module: "mesh-mail", Composed: digest}) {
+		t.Errorf("ParseAnyAskKey(%q) = %+v, %v", record, got, err)
+	}
+	for _, kind := range []string{AskKindBackup, AskKindRecord} {
+		if proof, err := AskNeedsProof(kind); err != nil || proof {
+			t.Errorf("AskNeedsProof(%s) = %v, %v; the view may answer it", kind, proof, err)
+		}
+	}
+	for _, k := range []string{backup, record} {
+		if _, err := ViewAnswerKey(k); err != nil {
+			t.Errorf("the view may not answer %s: %v", k, err)
+		}
+	}
+	for _, bad := range [][3]string{{"", "mesh-mail", fp}, {"ace", "node", fp}, {"ace", "mesh-mail", "src2:1"}} {
+		if _, err := BackupAskKey(bad[0], bad[1], bad[2]); err == nil {
+			t.Errorf("BackupAskKey(%v) accepted", bad)
+		}
+	}
+	if _, err := RecordAskKey("ace", "mesh-mail", "sha256:1"); err == nil {
+		t.Errorf("a record ask naming a bad digest was keyed")
+	}
+	for _, bad := range []string{"backup.ace.mesh-mail", "record.ace.mesh-mail.12", "record.ace." + strings.Repeat("6", 64)} {
+		if _, err := ParseAnyAskKey(bad); err == nil {
+			t.Errorf("ParseAnyAskKey(%q) accepted", bad)
+		}
+	}
+}

go/process/account_test.go

@@ -1,11 +1,16 @@
 package process
 
 import (
+	"context"
 	"encoding/json"
+	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/nats-io/nats.go/jetstream"
 )
 
 // 1171/AC2: given an account file broker-<process id> in the controller's form {url, fingerprint, node,
@@ -46,6 +51,28 @@ func TestReadAccountToleratesNoClaimsAtAll(t *testing.T) {
 // 1171/AC2: a file missing url, user or password is refused, naming the field; the password never appears
 // in the error even when it is the field present and another is missing.
 func TestReadAccountRefusesAFileMissingAField(t *testing.T) {
+	t.Run("1945: a refused bucket stops a start only when the part cannot work without it", func(t *testing.T) {
+		refusal := errors.New("nats: permissions violation for publish to $JS.API.STREAM.INFO.KV_mesh-delivery-gate_source")
+		for _, c := range []struct {
+			name string
+			err  error
+		}{{"refused", refusal}, {"not answered", context.DeadlineExceeded}} {
+			var said []string
+			logf := func(f string, a ...any) { said = append(said, fmt.Sprintf(f, a...)) }
+			if kv := OptionalBucket(context.Background(), refusingBus{c.err}, "b", "b is not heard", logf); kv != nil {
+				t.Errorf("%s: an optional bucket answered %v", c.name, kv)
+			}
+			NotWatched(logf, "b", c.err, "b is not heard")
+			if len(said) != 2 || !strings.Contains(said[0], c.err.Error()) || !strings.Contains(said[1], "cannot be watched") {
+				t.Errorf("%s: said %q", c.name, said)
+			}
+			if _, err := EssentialBucket(context.Background(), refusingBus{c.err}, "builder", "b", "build"); err == nil ||
+				!strings.Contains(err.Error(), "grant of b") || !strings.Contains(err.Error(), "the builder cannot build") {
+				t.Errorf("%s: an essential bucket: %v", c.name, err)
+			}
+		}
+	})
+
 	for _, tc := range []struct {
 		field  string
 		values map[string]any
@@ -82,3 +109,8 @@ func writeAccount(t *testing.T, fields map[string]any) string {
 	}
 	return path
 }
+
+// refusingBus refuses every bucket with err.
+type refusingBus struct{ err error }
+
+func (r refusingBus) KeyValue(context.Context, string) (jetstream.KeyValue, error) { return nil, r.err }

go/process/buckets.go

@@ -0,0 +1,55 @@
+package process
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// **A part does not stop for a bucket it can work without** (novox/hq issue 1945, met twice on 2026-10-25: the delivery
+// builder exited on a refused read of the gate's source and crash-looped). A grant reaches the bus with a delivery, so a
+// bucket, a watch or a consumer the bus refuses, or times out on, at start is often only not granted yet: exiting for it
+// stops the part until a person's hand. A part opens what it cannot do its job at all without with EssentialBucket, which
+// stops its start with an error naming the bucket and its grant, and everything else with OptionalBucket, which says what
+// is not heard and goes on; a watch the bus refuses on an optional bucket is said with NotWatched. Here, beside State,
+// because this is where a process opens what it keeps and reads on the bus; the parts that open buckets with their own
+// JetStream (the delivery parts) take the same three.
+
+// BucketOpener is the part of the bus a start opens buckets with: a jetstream.JetStream, or a test's fake.
+type BucketOpener interface {
+	KeyValue(ctx context.Context, bucket string) (jetstream.KeyValue, error)
+}
+
+// EssentialBucket opens a bucket part cannot work without (it cannot `does` without it); its error is EssentialErr's.
+func EssentialBucket(ctx context.Context, js BucketOpener, part, name, does string) (jetstream.KeyValue, error) {
+	kv, err := js.KeyValue(ctx, name)
+	if err != nil {
+		return nil, EssentialErr(part, name, does, err)
+	}
+	return kv, nil
+}
+
+// EssentialErr is the error of a bucket, consumer or stream named name that part cannot work without: it says what part
+// cannot do, that it stops, and the grant to look at.
+func EssentialErr(part, name, does string, err error) error {
+	return fmt.Errorf("%s cannot be read (%v): the %s cannot %s without it, so it stops; where the bus refused it or did not "+
+		"answer, this module's grant of %s (its manifest's reads, state or consumes, issued with its credential) has not "+
+		"reached the bus yet", name, err, part, does, name)
+}
+
+// OptionalBucket opens a bucket the part works without: any error is said with what is not heard (without), and nil
+// answered.
+func OptionalBucket(ctx context.Context, js BucketOpener, name, without string, logf func(string, ...any)) jetstream.KeyValue {
+	kv, err := js.KeyValue(ctx, name)
+	if err != nil {
+		logf("the bucket %s cannot be read (%v): %s", name, err, without)
+		return nil
+	}
+	return kv
+}
+
+// NotWatched says that an optional bucket opened but its watch was refused or not answered: what is not heard.
+func NotWatched(logf func(string, ...any), name string, err error, without string) {
+	logf("the bucket %s cannot be watched (%v): %s", name, err, without)
+}

go/stdio.go

@@ -154,8 +154,15 @@ const CodeChanged = -32010
 var (
 	current   *channel
 	currentMu sync.Mutex
+	// served is closed once Serve has the runtime's channel (Served).
+	served     = make(chan struct{})
+	servedOnce sync.Once
 )
 
+// Served is closed once Serve has the runtime's channel, so code started before Serve can wait for it instead of
+// asking again until the runtime takes it: a watch of a config value, a subscribe.
+func Served() <-chan struct{} { return served }
+
 // Serve answers the runtime on stdin and stdout until stdin closes. An empty name serves as the
 // module the runtime named in MESH_SERVED_MODULE.
 func Serve(name string, tools []Tool) error {
@@ -180,6 +187,7 @@ func ServeOn(name string, tools []Tool, in io.Reader, out io.Writer) error {
 	currentMu.Lock()
 	current = c
 	currentMu.Unlock()
+	servedOnce.Do(func() { close(served) })
 	// What the bundle said it keeps is announced once it serves: the runtime answers the publish on this channel, so
 	// it is asked from beside the loop that reads the answer.
 	go func() { _ = announce1() }()

go/stdio_test.go

@@ -16,6 +16,22 @@ func TestABundleEmitsThroughTheRuntimeAndServesAsItsModule(t *testing.T) {
 	t.Setenv(ServedAs, "chime")
 	t.Setenv("MESH_MODULE", "chime")
 	t.Setenv("MESH_NODE", "anchor")
+	// 1887/AC-wake: Served closes once Serve has the runtime's channel, not before; the globals are put back after.
+	oldServed := served
+	served, servedOnce = make(chan struct{}), sync.Once{}
+	t.Cleanup(func() {
+		served, servedOnce = oldServed, sync.Once{}
+		select {
+		case <-oldServed: // it was closed: its Once is spent too
+			servedOnce.Do(func() {})
+		default:
+		}
+	})
+	select {
+	case <-Served():
+		t.Fatal("Served closed before Serve")
+	default:
+	}
 	inR, inW := io.Pipe()
 	outR, outW := io.Pipe()
 	go func() {
@@ -50,6 +66,11 @@ func TestABundleEmitsThroughTheRuntimeAndServesAsItsModule(t *testing.T) {
 	if got := next()["result"].(map[string]any)["serverInfo"].(map[string]any)["name"]; got != "chime" {
 		t.Fatalf("served as %v, want the module the runtime named", got)
 	}
+	select {
+	case <-Served():
+	case <-time.After(2 * time.Second):
+		t.Fatal("Served did not close once serving")
+	}
 	send(map[string]any{"jsonrpc": "2.0", "id": 2, "method": "tools/call", "params": map[string]any{"name": "ring", "arguments": map[string]any{}}})
 	asked := next()
 	if asked["method"] != "mesh/publish" {