mesh-grants, mesh-delivery-checker: pin the group's mesh-sdk head 3f7957e (issue 774)

modules/assignments-readers

@@ -1,7 +0,0 @@
-# The modules of this repository that still read the controller's assignments (mesh-controller.assignments), each with
-# why. mesh-grants' test (TestGrants, "assignments readers") refuses any other module.json that reads them, and an entry
-# here whose module no longer does: the list only shrinks, and it is empty in the first change after the controller's
-# lease is written to a holder that is no controller (novox/hq ADR 0549 §3, §6; issue 774). Each module named here
-# uses the assignments only while the controller holds the lease (buscompose.LeaseHandedAway), placement alone after it.
-mesh-delivery-assigner  unioned with the placement until the lease write (assign.Placed with handedAway); placement alone after
-mesh-grants             unioned with the placement until the lease write (ReadInputs); placement alone after

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/integration_test.go

@@ -18,11 +18,9 @@ import (
 	"github.com/nats-io/nats.go"
 	"github.com/nats-io/nats.go/jetstream"
 
-	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/announce"
 	"git.novox.be/novox/mesh-sdk/go/asks"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
-	"git.novox.be/novox/mesh-sdk/go/compose/judge"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/process"
 	"git.novox.be/novox/mesh-sdk/go/provider"
@@ -72,11 +70,7 @@ func startBed(t *testing.T, leaveOut string) *bed {
 		if name == leaveOut {
 			continue
 		}
-		cfg := jetstream.KeyValueConfig{Bucket: name, History: 5}
-		if name == delivery.PlacementPulsesBucket {
-			cfg.History, cfg.LimitMarkerTTL = 1, time.Minute // a time to live per key, as the controller makes it (key-ttl)
-		}
-		kv, err := js.CreateKeyValue(ctx, cfg)
+		kv, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: name, History: 5})
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -135,7 +129,9 @@ func (b *bed) startStoppable(t *testing.T) (<-chan error, func()) {
 
 // 1297/B2b: started whole on its credential, the assigner says on the bus every state its manifest declares, each readable,
 // having opened every bucket it names. The states are read from module.json, so a state added there is expected here too.
-func saysWhatItKeeps(t *testing.T, b *bed, done <-chan error) {
+func TestTheAssignerStartsAndSaysWhatItKeeps(t *testing.T) {
+	b := startBed(t, "")
+	done := b.start(t)
 	events, err := b.js.Stream(b.ctx, "EVENTS")
 	if err != nil {
 		t.Fatal(err)
@@ -177,8 +173,8 @@ func saysWhatItKeeps(t *testing.T, b *bed, done <-chan error) {
 // 1297/B2b: a bucket it reads that the bus does not hold stops the start, naming the bucket.
 func TestTheAssignerDoesNotStartWithoutABucketItReads(t *testing.T) {
 	for _, missing := range readBuckets {
-		if missing == delivery.PlacementBucket || sourceOfGrants(missing) {
-			continue // it starts without it, below (the grants' source: main_test.go)
+		if missing == delivery.PlacementBucket {
+			continue // it starts without it, below
 		}
 		b := startBed(t, missing)
 		select {
@@ -227,8 +223,8 @@ func TestTheAssignerDoesNotStartWithoutABucketItReads(t *testing.T) {
 		}
 	}
 
-	// Without the seat's placement state it starts all the same, and once the bucket is made (the controller makes
-	// it from the manifest) it is read with no restart: a module only the placement names is
+	// Review of L2 (D1): without the indexer's placement state it starts all the same, and once the bucket is made (the
+	// indexer and the assigner come in one delivery) it is read with no restart: a module only the placement names is
 	// said as placed by one source only.
 	pb := startBed(t, delivery.PlacementBucket)
 	pdone := pb.start(t)
@@ -301,6 +297,10 @@ func (b *bed) manifest(t *testing.T, module, body string) string {
 // 1297/AC1: against the real bus, a fixture change touching one module on one machine is composed and answered within
 // seconds under the checker's key of the check, naming the machine composed and the mesh-sdk it composed with.
 func TestAChangeIsComposedOnTheBus(t *testing.T) {
+	// The placement answers' bound (ADR 0559 §5), shortened before the program starts and put back after it stops.
+	bound := assign.AnswerBound
+	t.Cleanup(func() { assign.AnswerBound = bound })
+	assign.AnswerBound = 1500 * time.Millisecond
 	b := startBed(t, "")
 	trunk := b.manifest(t, "web", `{"module":"web","version":"1"}`)
 	changed := b.manifest(t, "web", `{"module":"web","version":"2"}`)
@@ -352,6 +352,63 @@ func TestAChangeIsComposedOnTheBus(t *testing.T) {
 	} else if info, err := st.Info(b.ctx); err != nil || info.State.Msgs != 0 {
 		t.Errorf("a group without a mesh-sdk member put %d asks on the Go build seat (%v)", info.State.Msgs, err)
 	}
+
+	// ADR 0559 §5 (issue 1126): a catalogue pull request that places g14 for the first time (the seed's case) is composed
+	// with its candidate placement, touches g14, and waits for g14's answer at its head; g14 answering the same passes it.
+	// A node that does not answer within the bound fails the check, named, at the bound's end with no other event; its later
+	// answer at the same head passes the same heads' composition.
+	record, _ := delivery.EncodeHaveNode(delivery.HaveNode{Record: &delivery.NodeRecord{Node: "g14"}})
+	b.putJSON(t, delivery.HaveBucket, "g14.node", record)
+	placed := func(group string, number int, head string) (string, uint64) {
+		t.Helper()
+		value, err := delivery.EncodePlacementCandidate(delivery.PlacementCandidate{Group: group,
+			Pull:      delivery.Head{Repository: delivery.CatalogueRepository, Number: number, Head: head},
+			Placement: &delivery.Placement{Node: "g14", Modules: []delivery.PlacedModule{{Module: "web"}}}})
+		if err != nil {
+			t.Fatal(err)
+		}
+		key, _ := delivery.PlacementCandidateKey(group, "g14")
+		rev, err := b.buckets[delivery.PlacementCandidatesBucket].Put(b.ctx, key, value)
+		if err != nil {
+			t.Fatal(err)
+		}
+		pull := []delivery.CandidatePull{{Head: delivery.Head{Repository: delivery.CatalogueRepository, Number: number, Head: head}, Modules: []string{}}}
+		hash, _ := delivery.HeadsHash([]delivery.Head{pull[0].Head})
+		cand, err := delivery.EncodeCandidate(delivery.Candidate{Group: group, HeadsHash: hash, Pulls: pull, FPSet: delivery.FingerprintSet(pull)})
+		if err != nil {
+			t.Fatal(err)
+		}
+		ckey, _ := delivery.CandidatesKey(group)
+		b.putJSON(t, delivery.CandidatesBucket, ckey, cand)
+		key, _ = delivery.CompositionKey(group, hash)
+		return key, rev
+	}
+	answer := func(group, head string, rev uint64) {
+		t.Helper()
+		have, err := delivery.EncodeHaveNode(delivery.HaveNode{Record: &delivery.NodeRecord{Node: "g14"},
+			Candidates: map[string]delivery.CandidateAnswer{group: {Head: head, Revision: rev, Verdict: delivery.CandidateSame, Same: []string{"web"}}}})
+		if err != nil {
+			t.Fatal(err)
+		}
+		b.putJSON(t, delivery.HaveBucket, "g14.node", have)
+	}
+	seedHead, lateHead := strings.Repeat("5", 40), strings.Repeat("6", 40)
+	seed, seedRev := placed("feat/seed", 20, seedHead)
+	waiting := b.verdict(t, seed, func(v delivery.CompositionVerdict) bool { return v.State == delivery.CompositionWaits })
+	if !strings.Contains(waiting.Words, "g14") {
+		t.Errorf("the seed's composition waits saying %q, want g14 named", waiting.Words)
+	}
+	answer("feat/seed", seedHead, seedRev)
+	if v := b.verdict(t, seed, func(v delivery.CompositionVerdict) bool { return v.State == delivery.CompositionPass }); !slices.Contains(v.Machines, "g14") {
+		t.Errorf("the seed's composition = %+v, want g14 composed", v)
+	}
+	late, lateRev := placed("feat/late", 21, lateHead)
+	failed := b.verdict(t, late, func(v delivery.CompositionVerdict) bool { return v.State == delivery.CompositionFail })
+	if failed.Machine != "g14" || !strings.Contains(failed.Words, delivery.CompositionUnanswered) {
+		t.Errorf("a node silent past its bound: %+v", failed)
+	}
+	answer("feat/late", lateHead, lateRev)
+	b.verdict(t, late, func(v delivery.CompositionVerdict) bool { return v.State == delivery.CompositionPass })
 }
 
 // get waits for a key of one of the bed's buckets and answers its value.
@@ -1005,196 +1062,3 @@ func TestAHoldWrittenAgainAfterALiftAndARestartIsAskedAgain(t *testing.T) {
 		}
 	}
 }
-
-// bedStore is the runtime's states over the bed's buckets, as the seat's verbs read and write them: the assigner's own by
-// their local names, another module's `<module>.<state>`.
-type bedStore struct{ b *bed }
-
-func (s bedStore) kv(state string) jetstream.KeyValue {
-	if strings.Contains(state, ".") {
-		return s.b.buckets[strings.Replace(state, ".", "_", 1)]
-	}
-	return s.b.buckets[delivery.AssignerModule+"_"+state]
-}
-
-func (s bedStore) get(state, key string) ([]byte, uint64, bool, error) {
-	e, err := s.kv(state).Get(s.b.ctx, key)
-	if err != nil {
-		return nil, 0, false, nil
-	}
-	return e.Value(), e.Revision(), true, nil
-}
-
-func (s bedStore) put(state, key string, value []byte) error {
-	_, err := s.kv(state).Put(s.b.ctx, key, value)
-	return err
-}
-
-func (s bedStore) keys(state string) ([]string, error) {
-	keys, err := s.kv(state).Keys(s.b.ctx)
-	if err != nil && strings.Contains(err.Error(), "no keys") {
-		return nil, nil
-	}
-	return keys, err
-}
-
-func (s bedStore) del(state, key string) error { return s.kv(state).Delete(s.b.ctx, key) }
-
-func (s bedStore) history(string, string) ([]stdio.StateRevision, error) { return nil, nil }
-
-// 1126 (ADR 0567 §2-§6), the seat mesh-placement whole on the bus: a proposal moving web from the anchor to the laptop is
-// proposed through the verb, the assigner finds both nodes must answer, they answer the same in their haves, the
-// operator is asked and approves, and each key is written at a new revision while placement-changed is heard on the
-// assigner's stream naming both nodes. A second proposal laid over the old revision of a key moved since is laid again,
-// and declined, writes nothing and is withdrawn.
-func TestAProposalIsAnsweredApprovedAndWritten(t *testing.T) {
-	b := startBed(t, "")
-	if _, err := b.js.CreateStream(b.ctx, jetstream.StreamConfig{Name: "MOD_" + delivery.AssignerModule + "_placement",
-		Subjects: []string{process.ModuleStreamSubject(delivery.AssignerModule, ">")}}); err != nil {
-		t.Fatal(err)
-	}
-	heard := make(chan delivery.PlacementEvent, 16)
-	nc, err := nats.Connect(b.srv.ClientURL())
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Cleanup(nc.Close)
-	if _, err := nc.Subscribe(process.ModuleStreamSubject(delivery.AssignerModule, delivery.PlacementChangedEvent), func(m *nats.Msg) {
-		var e delivery.PlacementEvent
-		if json.Unmarshal(m.Data, &e) == nil {
-			heard <- e
-		}
-	}); err != nil {
-		t.Fatal(err)
-	}
-	for _, node := range []string{"anchor", "laptop"} {
-		rec, _ := delivery.EncodeHaveNode(delivery.HaveNode{Record: &delivery.NodeRecord{Node: node}})
-		b.putJSON(t, delivery.HaveBucket, node+".node", rec)
-	}
-	b.putJSON(t, delivery.ModulesBucket, "web", []byte(`{"v":1}`))
-	b.putJSON(t, delivery.ModulesBucket, "shell", []byte(`{"v":1}`))
-	place := func(node string, modules ...string) uint64 {
-		p := delivery.Placement{Node: node, Modules: []delivery.PlacedModule{}}
-		for _, m := range modules {
-			p.Modules = append(p.Modules, delivery.PlacedModule{Module: m})
-		}
-		raw, _ := delivery.EncodePlacement(p)
-		key, _ := delivery.PlacementKey(node)
-		rev, err := b.buckets[delivery.PlacementBucket].Put(b.ctx, key, raw)
-		if err != nil {
-			t.Fatal(err)
-		}
-		return rev
-	}
-	anchorRev, laptopRev := place("anchor", "web"), place("laptop", "shell")
-	bound := judge.AnswerBound
-	t.Cleanup(func() { judge.AnswerBound = bound })
-	judge.AnswerBound = 2 * time.Second
-	saysWhatItKeeps(t, b, b.start(t))
-	verbs := newSeatTools(bedStore{b}, func(string, any) (json.RawMessage, error) { return json.RawMessage(`{"ok":true}`), nil })
-	propose := func() delivery.PlacementProposal {
-		t.Helper()
-		got, err := verbs.doPropose(map[string]any{"why": "move web", "changes": `[{"op":"take-off","node":"anchor","module":"web"},` +
-			`{"op":"place","node":"laptop","module":"web"}]`}, "operator@laptop")
-		if err != nil {
-			t.Fatal(err)
-		}
-		return got.(proposed).Proposal
-	}
-	proposalNow := func(id, what string, ok func(delivery.PlacementProposal) bool) delivery.PlacementProposal {
-		t.Helper()
-		var last delivery.PlacementProposal
-		for deadline := time.Now().Add(15 * time.Second); time.Now().Before(deadline); time.Sleep(50 * time.Millisecond) {
-			if e, err := b.buckets[delivery.PlacementProposalsBucket].Get(b.ctx, id); err == nil {
-				if p, err := delivery.DecodePlacementProposal(e.Value()); err == nil {
-					if last = p; ok(p) {
-						return p
-					}
-				}
-			}
-		}
-		t.Fatalf("the proposal %s never was %s: %+v", id, what, last)
-		return last
-	}
-	answerAll := func(p delivery.PlacementProposal) {
-		t.Helper()
-		for _, node := range p.Must {
-			key, _ := delivery.PlacementCandidateKey(p.ID, node)
-			e, err := b.buckets[delivery.PlacementCandidatesBucket].Get(b.ctx, key)
-			if err != nil {
-				t.Fatalf("no candidate %s: %v", key, err)
-			}
-			have, _ := delivery.EncodeHaveNode(delivery.HaveNode{Record: &delivery.NodeRecord{Node: node}, Candidates: map[string]delivery.CandidateAnswer{
-				p.ID: {Proposal: p.ID, Revision: e.Revision(), Verdict: delivery.CandidateSame, Same: []string{"node"}}}})
-			b.putJSON(t, delivery.HaveBucket, node+".node", have)
-		}
-	}
-
-	p := propose()
-	p = proposalNow(p.ID, "told who must answer", func(p delivery.PlacementProposal) bool { return len(p.Must) > 0 })
-	if !slices.Equal(p.Must, []string{"anchor", "laptop"}) {
-		t.Fatalf("must answer = %v, want both nodes", p.Must)
-	}
-	answerAll(p)
-	p = proposalNow(p.ID, "asked", func(p delivery.PlacementProposal) bool { return p.State == delivery.ProposalAsked })
-	akey, _ := delivery.PlacementAskKey(p.ID)
-	b.answer(t, akey, assign.OptionYes)
-	select {
-	case e := <-heard:
-		if e.Proposal.ID != p.ID || len(e.Nodes) != 2 || e.Nodes[0].Before != anchorRev || e.Nodes[1].Before != laptopRev ||
-			e.Nodes[0].After <= anchorRev || e.Warrant == nil || !slices.Equal(e.Nodes[0].Removed, []string{"web"}) {
-			t.Errorf("placement-changed = %+v", e)
-		}
-	case <-time.After(15 * time.Second):
-		t.Fatal("no placement-changed heard")
-	}
-	for node, want := range map[string][]string{"anchor": {}, "laptop": {"shell", "web"}} {
-		key, _ := delivery.PlacementKey(node)
-		e, err := b.buckets[delivery.PlacementBucket].Get(b.ctx, key)
-		if err != nil {
-			t.Fatal(err)
-		}
-		if got, err := delivery.DecodePlacement(e.Value()); err != nil || !slices.Equal(got.Assigned(), want) {
-			t.Errorf("%s = %v, %v, want %v", node, got.Assigned(), err, want)
-		}
-	}
-	if b.hasKey(delivery.PlacementProposalsBucket, p.ID) {
-		t.Error("an applied proposal stays in the state")
-	}
-
-	// A proposal whose key moves before its warrant is laid again; then declined, it writes nothing and ends.
-	q, err := verbs.doPropose(map[string]any{"why": "back", "changes": `[{"op":"take-off","node":"laptop","module":"web"}]`}, "op")
-	if err != nil {
-		t.Fatal(err)
-	}
-	moved := q.(proposed).Proposal
-	place("laptop", "shell", "web") // another writer moved the key
-	relaid := proposalNow(moved.ID, "laid again", func(p delivery.PlacementProposal) bool {
-		return strings.Contains(p.Words, "laid again") && len(p.Must) > 0
-	})
-	answerAll(relaid)
-	proposalNow(moved.ID, "asked", func(p delivery.PlacementProposal) bool { return p.State == delivery.ProposalAsked })
-	akey, _ = delivery.PlacementAskKey(moved.ID)
-	b.answer(t, akey, assign.OptionNo)
-	for deadline := time.Now().Add(15 * time.Second); b.hasKey(delivery.PlacementProposalsBucket, moved.ID); time.Sleep(50 * time.Millisecond) {
-		if time.Now().After(deadline) {
-			t.Fatal("a declined proposal was not ended")
-		}
-	}
-	key, _ := delivery.PlacementKey("laptop")
-	if e, _ := b.buckets[delivery.PlacementBucket].Get(b.ctx, key); e == nil || !strings.Contains(string(e.Value()), "web") {
-		t.Error("a declined proposal wrote its key")
-	}
-
-	// ADR 0567 §4: a node that does not answer fails the verdict once its pulse key's time to live ends, heard on the bus
-	// with no timer of the assigner's, naming it.
-	q, err = verbs.doPropose(map[string]any{"why": "again", "changes": `[{"op":"take-off","node":"laptop","module":"web"}]`}, "op")
-	if err != nil {
-		t.Fatal(err)
-	}
-	silent := q.(proposed).Proposal
-	failed := proposalNow(silent.ID, "failed for a silent node", func(p delivery.PlacementProposal) bool { return p.State == delivery.ProposalFailed })
-	if failed.Verdict == nil || !strings.Contains(strings.Join(failed.Verdict.Fails, "; "), "laptop (offline) did not answer") {
-		t.Errorf("the silent node's verdict = %+v", failed.Verdict)
-	}
-}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/main.go

@@ -8,13 +8,12 @@ package main
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"log"
 	"os"
 	"os/signal"
-	"slices"
+	"sync"
 	"syscall"
 	"time"
 
@@ -23,7 +22,6 @@ import (
 
 	"git.novox.be/novox/mesh-sdk/go/announce"
 	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
 	"git.novox.be/novox/mesh-sdk/go/process"
@@ -51,18 +49,17 @@ func main() {
 // readBuckets are the buckets of other parts the assigner reads, each named in its manifest's reads (the manifest test
 // holds the two lists equal), so the controller's broker grants exactly these.
 var readBuckets = []string{
-	buscompose.ResolvedBucket,
 	provider.AssignmentsBucket,
 	delivery.BuildsBucket,
 	delivery.ControllerGrantsBucket,
-	delivery.PartGrantsBucket,
-	buscompose.LeaseBucket,
 	delivery.ControllerComposedBucket,
 	delivery.AnswersBucket,
 	delivery.BuilderBuildsBucket,
 	delivery.CandidatesBucket,
 	delivery.ManifestsBucket,
 	delivery.ModulesBucket,
+	delivery.PlacementBucket,
+	delivery.PlacementCandidatesBucket,
 	delivery.PresenceBucket,
 	delivery.HaveBucket,
 	delivery.StepsBucket(goBuildModule),
@@ -72,27 +69,14 @@ var readBuckets = []string{
 // their steps in its steps state (novox/hq ADR 0482 clause 4).
 const goBuildModule = "mesh-build-go"
 
-// ownBuckets are the assigner's own states, as its manifest declares them: the seat mesh-placement's three among them
-// (ADR 0567 §1), named after the assigner as every module state is.
+// ownBuckets are the assigner's own states, as its manifest declares them.
 var ownBuckets = []string{delivery.AssignerAsksBucket, delivery.AssignerCompositionsBucket, delivery.AssignerDifferencesBucket,
-	delivery.AssignerPutsBucket, delivery.AssignerWantsBucket, delivery.PlacementBucket, delivery.PlacementProposalsBucket,
-	delivery.PlacementCandidatesBucket, delivery.PlacementPulsesBucket}
-
-// seatBuckets are the seat's states, new with it: until the controller has made them from the manifest and the bus grants
-// them, the assigner starts without them and binds each once the bus says it was created (issue 1790's kind).
-var seatBuckets = []string{delivery.PlacementBucket, delivery.PlacementProposalsBucket, delivery.PlacementCandidatesBucket,
-	delivery.PlacementPulsesBucket}
+	delivery.AssignerPutsBucket, delivery.AssignerWantsBucket}
 
 // keptStates is what the assigner keeps and who may read it (ADR 0495 §2-§3): its wants by the watchman and the view
 // (and the node agent from release 6), its differences by the view, its compositions by the checker, its asks by the view
-// and the teller, its puts by whoever follows one (ADR 0546), and the seat mesh-placement's placement, proposals and
-// candidates by the node agents, the grants part, mesh-config and the view (ADR 0567 §9), and its placement by
-// the builder, the checker and the indexer, through mesh-sdk's toolchain gate (issue 774, ADR 0549 §3).
+// and the teller, its puts by whoever follows one (ADR 0546).
 var keptStates = []announce.State{
-	{Name: delivery.PlacementState, Readable: true},
-	{Name: delivery.PlacementProposalsState, Readable: true},
-	{Name: delivery.PlacementCandidatesState, Readable: true},
-	{Name: delivery.PlacementPulsesState, Readable: true},
 	{Name: "asks", Readable: true},
 	{Name: "compositions", Readable: true},
 	{Name: "differences", Readable: true},
@@ -109,47 +93,16 @@ type buckets map[string]jetstream.KeyValue
 // without it and takes no put further until it starts again (ADR 0546).
 func open(ctx context.Context, js process.BucketOpener, logf func(string, ...any)) (buckets, error) {
 	out := buckets{}
-	// The controller's lease first (ADR 0549 §5, ADR 0561 §3): once it is handed away the seat's placement alone names
-	// where modules run, and the controller's assignments are no bucket the assigner needs. Not granted or not there, the
-	// controller holds it, as before.
-	away, why := false, ""
-	if kv, err := js.KeyValue(ctx, buscompose.LeaseBucket); err != nil {
-		logf("the bucket %s cannot be opened (%v): the controller is taken to hold its lease, so the assignments are read beside the placement", buscompose.LeaseBucket, err)
-	} else {
-		out[buscompose.LeaseBucket] = kv
-		e, gerr := kv.Get(ctx, buscompose.ControllerLeaseKey)
-		var raw []byte
-		if gerr == nil {
-			raw = e.Value()
-		}
-		if errors.Is(gerr, jetstream.ErrKeyNotFound) {
-			gerr = nil
-		}
-		away, why = buscompose.LeaseHandedAway(raw, raw != nil, gerr)
-	}
 	for _, name := range append(append([]string{}, readBuckets...), ownBuckets...) {
-		if name == buscompose.LeaseBucket {
-			continue
-		}
 		kv, err := js.KeyValue(ctx, name)
-		if name == provider.AssignmentsBucket && err != nil && away {
-			logf("the bucket %s cannot be opened (%v), and none is needed: %s, so the seat's placement alone is read", name, err, why)
-			continue
-		}
 		if name == delivery.AssignerPutsBucket && err != nil {
 			logf("the bucket %s cannot be opened (%v): no put is taken further until the assigner starts again", name, err)
 			continue
 		}
-		if slices.Contains(seatBuckets, name) && err != nil {
-			// The seat's states come in the same delivery as this assigner (ADR 0567 §1): without placement the controller's
-			// assignments alone name where modules run, as before any placement was written (ADR 0549 §5).
-			logf("the bucket %s cannot be opened (%v): it is bound once the bus says it was made", name, err)
-			continue
-		}
-		if sourceOfGrants(name) && err != nil {
-			// The grants part's grants and the controller's lease choose where grants are read from (issue 774): without
-			// them the controller's grants are read, as before the lease is handed away.
-			logf("the bucket %s cannot be opened (%v): the controller's grants are read until the assigner starts again", name, err)
+		if name == delivery.PlacementBucket && err != nil {
+			// The indexer's placement state comes with the second milestone (ADR 0549 §2): without it the controller's
+			// assignments alone name where modules run, as before any placement was read (ADR 0549 §5).
+			logf("the bucket %s cannot be opened (%v): the controller's assignments alone are read until the assigner starts again", name, err)
 			continue
 		}
 		if err != nil {
@@ -160,12 +113,6 @@ func open(ctx context.Context, js process.BucketOpener, logf func(string, ...any
 	return out, nil
 }
 
-// sourceOfGrants says the bucket is one of the two that choose the grants' source, the grants part's grants and the
-// controller's lease: neither stops the assigner when it is not there (delivery.GrantSource).
-func sourceOfGrants(name string) bool {
-	return name == delivery.PartGrantsBucket || name == buscompose.LeaseBucket
-}
-
 // run is the program: it returns when ctx ends or the bus cannot be used.
 func run(ctx context.Context, getenv func(string) string, logOut io.Writer) error {
 	logger := log.New(logOut, "mesh-delivery-assigner: ", log.LstdFlags)
@@ -192,14 +139,10 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	if err := said.Keeps(keptStates...); err != nil {
 		logger.Printf("what the assigner keeps could not be said on the bus, so its readers are not granted until it is: %v", err)
 	}
-	thisNode = account.Node
 	logger.Printf("started on the account %s, reading %d buckets", account.User, len(kvs))
 	return follow(ctx, js, conn, kvs, sayVia(ctx, js), emitting{said}, logger)
 }
 
-// thisNode is the node this process runs on, as its credential names it: said with each of the seat's events.
-var thisNode string
-
 // emitting is the process connection as the puts' caller: its calls, and its events with no options.
 type emitting struct{ *process.Conn }
 
@@ -208,20 +151,15 @@ func (e emitting) Emit(eventType string, body any) error { return e.Conn.Emit(ev
 // watched are the buckets whose every value a pass reads; the manifests are read by digest when a pass needs one, and
 // watched only for keys, so a manifest that arrives wakes a composition that waits for it.
 var watched = []string{
-	buscompose.ResolvedBucket,
 	provider.AssignmentsBucket,
 	delivery.ControllerGrantsBucket,
-	delivery.PartGrantsBucket,
-	buscompose.LeaseBucket,
 	delivery.ControllerComposedBucket,
 	delivery.AnswersBucket,
 	delivery.BuilderBuildsBucket,
 	delivery.CandidatesBucket,
 	delivery.ModulesBucket,
 	delivery.PlacementBucket,
-	delivery.PlacementProposalsBucket,
 	delivery.PlacementCandidatesBucket,
-	delivery.PlacementPulsesBucket,
 	delivery.PresenceBucket,
 	delivery.HaveBucket,
 	delivery.AssignerAsksBucket,
@@ -276,13 +214,7 @@ func follow(ctx context.Context, js jetstream.JetStream, nc process.Subscriber,
 					if e.Operation() == jetstream.KeyValuePut {
 						value = e.Value()
 					}
-					before := w.grantsBucket()
 					w.putEntry(name, e.Key(), value, e.Revision(), e.Created())
-					if name == buscompose.LeaseBucket && w.grantsBucket() == before {
-						// The controller renews its lease every few seconds: only a change of where grants are read from
-						// makes a pass (delivery.GrantSource).
-						continue
-					}
 					wake()
 				}
 			}
@@ -324,7 +256,7 @@ func follow(ctx context.Context, js jetstream.JetStream, nc process.Subscriber,
 	}
 	started := 0
 	for _, name := range watched {
-		if kvs[name] == nil && (slices.Contains(seatBuckets, name) || sourceOfGrants(name) || name == provider.AssignmentsBucket) {
+		if kvs[name] == nil && (name == delivery.PlacementBucket || name == delivery.PlacementCandidatesBucket) {
 			continue // not on the bus at this start (open said so)
 		}
 		started++
@@ -339,32 +271,24 @@ func follow(ctx context.Context, js jetstream.JetStream, nc process.Subscriber,
 	if err := watch(delivery.ManifestsBucket, jetstream.MetaOnly()); err != nil {
 		return err
 	}
-	// The seat's states arrive with the same delivery as this assigner (ADR 0567 §1): one not on the bus at this start is
-	// bound once the bus says it was created, and watched from then on, with no restart (issue 1790's kind). Until then the
-	// controller's assignments alone name where modules run (ADR 0549 §5).
+	// The indexer's placement state arrives with the same delivery as this assigner (ADR 0549 §2): when it is not on the
+	// bus at this start it is bound once the bus says it was created, and watched from then on, with no restart (issue
+	// 1790's kind). Until then the controller's assignments alone name where modules run (ADR 0549 §5).
 	type appeared struct {
 		name string
 		kv   jetstream.KeyValue
 	}
-	placementAppeared := make(chan appeared, len(seatBuckets)+2)
-	for _, name := range seatBuckets {
-		if kvs[name] == nil && js != nil {
-			process.AwaitBucket(ctx, js, nc, name, "the seat mesh-placement waits for it",
-				logger.Printf).Ready(func(kv jetstream.KeyValue) { placementAppeared <- appeared{name, kv} })
-		}
+	placementAppeared := make(chan appeared, 2)
+	if kvs[delivery.PlacementBucket] == nil && js != nil {
+		process.AwaitBucket(ctx, js, nc, delivery.PlacementBucket, "the controller's assignments alone are read",
+			logger.Printf).Ready(func(kv jetstream.KeyValue) { placementAppeared <- appeared{delivery.PlacementBucket, kv} })
 	}
-	// And the two that choose where grants are read from, with the same delivery as the grants part that writes one.
-	for _, name := range []string{delivery.PartGrantsBucket, buscompose.LeaseBucket} {
-		if kvs[name] == nil && js != nil {
-			name := name
-			process.AwaitBucket(ctx, js, nc, name, "the controller's grants are read",
-				logger.Printf).Ready(func(kv jetstream.KeyValue) { placementAppeared <- appeared{name, kv} })
-		}
+	// So are the placement candidates (ADR 0559 §3), with the same delivery as the indexer that writes them.
+	if kvs[delivery.PlacementCandidatesBucket] == nil && js != nil {
+		process.AwaitBucket(ctx, js, nc, delivery.PlacementCandidatesBucket, "no change's placement is composed",
+			logger.Printf).Ready(func(kv jetstream.KeyValue) { placementAppeared <- appeared{delivery.PlacementCandidatesBucket, kv} })
 	}
 	takePlacement := func(a appeared) error {
-		if kvs[a.name] != nil {
-			return nil // bound already, by the other of its two events
-		}
 		kvs[a.name] = a.kv
 		logger.Printf("the bucket %s is open and watched", a.name)
 		return watch(a.name)
@@ -379,16 +303,11 @@ func follow(ctx context.Context, js jetstream.JetStream, nc process.Subscriber,
 		}
 	}
 	p := &passer{kvs: kvs, w: w, logf: logger.Printf, say: say, said: map[string]bool{}, answeredAt: map[string]uint64{}}
+	p.wakeAt = wakeAtVia(ctx, wake)
 	p.asks = newComposeAsks(ctx, buildrun.Asker{Publisher: buildrun.JetStreamAsks{JS: js}, Waiter: buildrun.JetStreamAsks{JS: js}}, wake, logger.Printf)
 	if bus != nil && kvs[delivery.AssignerPutsBucket] != nil {
 		p.acts = newPutActs(bus, wake, logger.Printf)
 	}
-	if bus != nil {
-		p.seat = newSeatActs(bus, wake, logger.Printf)
-	}
-	if js != nil {
-		p.publish = streamPublisher(ctx, js, thisNode)
-	}
 	wake()
 	for {
 		select {
@@ -403,28 +322,36 @@ func follow(ctx context.Context, js jetstream.JetStream, nc process.Subscriber,
 			}
 		case <-dirty:
 			reopenPuts(p)
-			// The grants part makes the seat's buckets in the pass that seals the list granting them, so their creation can
-			// be said before this credential may hear it: every pass, itself started by a watched change, binds each one the
-			// bus now holds, and says the seat waits while one is missing.
-			var unbound []string
-			for _, name := range seatBuckets {
-				if kvs[name] != nil || js == nil {
-					continue
-				}
-				if kv, err := js.KeyValue(ctx, name); err == nil {
-					if err := takePlacement(appeared{name, kv}); err != nil {
-						return err
-					}
-					continue
-				}
-				unbound = append(unbound, name)
-			}
-			p.sayWaits(unbound)
 			p.pass(ctx)
 		}
 	}
 }
 
+// wakeAtVia asks wake once at each time it is given, as a context's deadline (ADR 0437 §8: no timer), each time once.
+func wakeAtVia(ctx context.Context, wake func()) func(time.Time) {
+	var mu sync.Mutex
+	asked := map[int64]bool{}
+	return func(at time.Time) {
+		mu.Lock()
+		defer mu.Unlock()
+		if asked[at.UnixNano()] {
+			return
+		}
+		asked[at.UnixNano()] = true
+		go func() {
+			bound, cancel := context.WithDeadline(ctx, at)
+			defer cancel()
+			<-bound.Done()
+			mu.Lock()
+			delete(asked, at.UnixNano())
+			mu.Unlock()
+			if ctx.Err() == nil {
+				wake()
+			}
+		}()
+	}
+}
+
 // PutsReopenEvery is how often, at most, a pass opens the puts' bucket again while it is not open.
 var PutsReopenEvery = time.Minute
 

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/main_test.go

@@ -17,19 +17,13 @@ import (
 	"github.com/nats-io/nats.go/jetstream"
 
 	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/provider"
 )
 
 // 1297/B2a: the buckets the program opens are exactly the manifest's reads and states, as the broker names them
 // (`<module>.<state>` read as the bucket `<module>_<state>`), so it is granted what it reads and reads nothing else.
 func TestOpensWhatItsManifestNames(t *testing.T) {
-	// 1297/B2a: without a credential the program does not start, and says why.
-	if err := run(context.Background(), func(string) string { return "" }, io.Discard); err == nil || !strings.Contains(err.Error(), "MESH_BROKER_FILE") {
-		t.Errorf("run without a credential = %v", err)
-	}
 	raw, err := os.ReadFile(filepath.Join("..", "..", "module.json"))
 	if err != nil {
 		t.Fatal(err)
@@ -64,30 +58,20 @@ func TestOpensWhatItsManifestNames(t *testing.T) {
 	}
 	// ADR 0546: whatever keeps the puts' bucket from opening (not there, not granted, no answer in time), the assigner opens
 	// the rest and starts, writing wants; any other bucket it cannot open stops the start, named.
-	// Issue 774 (ADR 0549 §5): the controller's lease not granted, the assigner starts taking it as the controller's; the
-	// assignments refused while the controller holds it stop the start, and once it is handed away they are not needed.
-	handed := []byte(`{"handed-to":"the operator's hand-over","handed-by":"person.jochen"}`)
 	for _, c := range []struct {
 		missing string
 		err     error
 		starts  bool
-		lease   []byte
-		said    string
 	}{
-		{delivery.AssignerPutsBucket, jetstream.ErrBucketNotFound, true, nil, "no put is taken further"},
-		{delivery.AssignerPutsBucket, errors.New("nats: permissions violation for subscription to \"$JS.API.STREAM.INFO.KV_mesh-delivery-assigner_puts\""), true, nil, "no put is taken further"},
-		{delivery.AssignerPutsBucket, context.DeadlineExceeded, true, nil, "no put is taken further"},
-		{delivery.AssignerWantsBucket, errors.New("nats: permissions violation"), false, nil, ""},
-		// Issue 774: the grants part's grants and the controller's lease choose the grants' source; neither stops the start.
-		{delivery.PartGrantsBucket, jetstream.ErrBucketNotFound, true, nil, "the controller's grants are read"},
-		{buscompose.LeaseBucket, errors.New("nats: permissions violation"), true, nil, "taken to hold its lease"},
-		{provider.AssignmentsBucket, errors.New("nats: permissions violation"), false, []byte(`{"instance":"novox/1"}`), ""},
-		{provider.AssignmentsBucket, errors.New("nats: permissions violation"), true, handed, "the seat's placement alone is read"},
+		{delivery.AssignerPutsBucket, jetstream.ErrBucketNotFound, true},
+		{delivery.AssignerPutsBucket, errors.New("nats: permissions violation for subscription to \"$JS.API.STREAM.INFO.KV_mesh-delivery-assigner_puts\""), true},
+		{delivery.AssignerPutsBucket, context.DeadlineExceeded, true},
+		{delivery.AssignerWantsBucket, errors.New("nats: permissions violation"), false},
 	} {
 		var logged string
-		kvs, err := open(context.Background(), refusingJS{missing: c.missing, err: c.err, lease: c.lease}, func(f string, a ...any) { logged += fmt.Sprintf(f, a...) })
+		kvs, err := open(context.Background(), refusingJS{missing: c.missing, err: c.err}, func(f string, a ...any) { logged = fmt.Sprintf(f, a...) })
 		switch {
-		case c.starts && (err != nil || kvs[c.missing] != nil || len(kvs) != len(readBuckets)+len(ownBuckets)-1 || !strings.Contains(logged, c.said)):
+		case c.starts && (err != nil || kvs[c.missing] != nil || len(kvs) != len(readBuckets)+len(ownBuckets)-1 || !strings.Contains(logged, "no put is taken further")):
 			t.Errorf("%s refused with %v: the start answered %v, %d buckets, logged %q", c.missing, c.err, err, len(kvs), logged)
 		case !c.starts && (err == nil || !strings.Contains(err.Error(), "grant of "+c.missing)): // 1945: named with its grant
 			t.Errorf("%s refused with %v: the start answered %v", c.missing, c.err, err)
@@ -121,23 +105,26 @@ func TestOpensWhatItsManifestNames(t *testing.T) {
 	}
 }
 
+// 1297/B2a: without a credential the program does not start, and says why.
+func TestNoCredential(t *testing.T) {
+	err := run(context.Background(), func(string) string { return "" }, io.Discard)
+	if err == nil || !strings.Contains(err.Error(), "MESH_BROKER_FILE") {
+		t.Errorf("run without a credential = %v", err)
+	}
+}
+
 // refusingJS opens every bucket but one, which it refuses with err.
 type refusingJS struct {
 	jetstream.JetStream
 	missing string
 	err     error
-	lease   []byte // the controller's lease, when it holds one
 }
 
 func (r refusingJS) KeyValue(_ context.Context, name string) (jetstream.KeyValue, error) {
 	if name == r.missing {
 		return nil, r.err
 	}
-	kv := &memKV{values: map[string][]byte{}}
-	if name == buscompose.LeaseBucket && r.lease != nil {
-		kv.values[buscompose.ControllerLeaseKey] = r.lease
-	}
-	return kv, nil
+	return &memKV{values: map[string][]byte{}}, nil
 }
 
 // watchKV is a memKV whose watch hands its entries and then the marker that all stands was handed, or ends at once when

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/pass.go

@@ -40,20 +40,12 @@ type passer struct {
 	// noWant is, by node and module, the reason last said why the node gets no want for the module (issue 1945): a reason is
 	// said in the journal when it appears or changes, and its clearing when the node has a want again; one line per change.
 	noWant map[string]string
-	// unreached is, by node and module, the words last said why a wanted module may not be reached there (issue 1960: its
-	// provider is down, which holds no want): said once per words, and once more when it is reached again.
-	unreached map[string]string
 	// nodeFailed is, by node and module, the words of the condition last raised for a failure that is the node's own (ADR 0557
 	// §1, issue 1496): raised once per words, cleared once when it ends.
 	nodeFailed map[string]string
-	// The seat mesh-placement's holder (seat.go, ADR 0567): its calls of the controller (nil: none is made), how it says
-	// the seat's events (nil: none is said), the proposals it said, and what Intended computed by proposal and base.
-	seat         *seatActs
-	publish      publisher
-	saidProposed map[string]bool
-	// saidWaits is the last said of the seat's wait for its states (sayWaits).
-	saidWaits string
-	intended  map[string]map[string]map[string]bool
+	// wakeAt asks a pass at a time: the end of a placement candidate's answer bound (ADR 0559 §5), as a context's deadline
+	// (ADR 0437 §8: no timer). Nil asks none.
+	wakeAt func(at time.Time)
 }
 
 func (p *passer) clock() time.Time {
@@ -64,7 +56,6 @@ func (p *passer) clock() time.Time {
 }
 
 func (p *passer) pass(ctx context.Context) {
-	p.placementSeat(ctx)
 	p.compositions(ctx)
 	p.wants(ctx)
 	p.puts(ctx)
@@ -129,7 +120,7 @@ func (p *passer) wants(ctx context.Context) {
 		}
 	}
 	wanted := p.w.wantsOf()
-	frozen := p.sayPlacement(p.withCalls(p.w.placementDiffers()))
+	frozen := p.sayPlacement(p.w.placementDiffers())
 	placed := p.w.placedNodes()
 	puts := p.putsByModule()
 	p.staleAsks(ctx, trunk)
@@ -149,8 +140,6 @@ func (p *passer) wants(ctx context.Context) {
 	stale := map[string]neitherOne{}
 	left := map[string]string{}
 	defer func() { p.sayNeither(neither, stale, left) }()
-	// Where grants are read from, once for the pass: the grants part's while the lease is handed away (issue 774).
-	grants := p.w.grantsBucket()
 	for name := range names {
 		fp := trunk[name].FP2
 		name := name
@@ -166,7 +155,7 @@ func (p *passer) wants(ctx context.Context) {
 			},
 			GrantedAt: func(fp string) bool {
 				key, err := delivery.ControllerGrantKey(name, fp)
-				return err == nil && p.w.has(grants, key)
+				return err == nil && p.w.has(delivery.ControllerGrantsBucket, key)
 			},
 			Restored: func(node string) bool {
 				key, err := delivery.RestoreAskKey(node, name, fp)
@@ -182,8 +171,8 @@ func (p *passer) wants(ctx context.Context) {
 			hold, _ := delivery.HoldAskKey(name, fp)
 			m.Released = p.answeredWith(hold, "release")
 			m.Kept = p.answeredWith(hold, "keep")
-			m.Built, m.Held, m.Granted = p.w.built(name, fp), p.w.has(delivery.AssignerWantsBucket, held) && !m.Released, p.w.has(grants, grant)
-			if raw := p.w.value(grants, grant); raw != nil {
+			m.Built, m.Held, m.Granted = p.w.built(name, fp), p.w.has(delivery.AssignerWantsBucket, held) && !m.Released, p.w.has(delivery.ControllerGrantsBucket, grant)
+			if raw := p.w.value(delivery.ControllerGrantsBucket, grant); raw != nil {
 				if g, err := delivery.DecodeControllerGrant(raw); err == nil {
 					m.GrantedOn = func(node string) bool { return assign.GrantNamesNode(g, node, name) }
 				}
@@ -201,7 +190,6 @@ func (p *passer) wants(ctx context.Context) {
 		gatherNeither(neither, name, out)
 		leftNeither(left, m, wanted[name], out)
 		p.sayNoWant(name, m.Nodes, wanted[name], out)
-		p.sayUnreached(name, m.Nodes, out)
 		p.sayNodeFailed(name, fp, m.Nodes, nodes, out, first)
 		if first {
 			startClears(stale, m, out)
@@ -280,26 +268,6 @@ func (p *passer) sayNoWant(module string, nodes []string, before map[string]deli
 	}
 }
 
-// sayUnreached says in the journal, once per words, that a module is wanted on a node and may not be reached there, since
-// no provider of what it requires runs healthy (rule 5, which holds no want: issue 1960), and once when it is reached again.
-func (p *passer) sayUnreached(module string, nodes []string, out assign.Outcome) {
-	if p.unreached == nil {
-		p.unreached = map[string]string{}
-	}
-	for _, node := range nodes {
-		key := node + "." + module
-		why, last := out.Unreached[node], p.unreached[key]
-		switch {
-		case why != "" && why != last:
-			p.logf("%s on %s is wanted and may not be reached: %s", module, node, why)
-			p.unreached[key] = why
-		case why == "" && last != "":
-			p.logf("%s on %s is reached: its providers run healthy", module, node)
-			delete(p.unreached, key)
-		}
-	}
-}
-
 // sayNodeFailed raises, once per node and words, the condition of a failed health check of a module's newest fingerprint fp
 // that is the node's own, since fp runs healthy elsewhere and is not held (ADR 0557 §1, issue 1496), and says it in the journal;
 // it clears the condition once when the node no longer fails alone, or is no longer one of the module's nodes. The first pass
@@ -514,6 +482,9 @@ func (p *passer) compositions(ctx context.Context) {
 			} else {
 				v = assign.Compose(*mesh, ch, p.sdk, time.Since(began))
 			}
+			if ch.Placement != nil && v.State != delivery.CompositionWaits {
+				v = p.answers(*mesh, ch, v)
+			}
 		}
 		if before, err := delivery.DecodeCompositionVerdict(written[out]); err == nil {
 			before.Took, before.V = v.Took, 0
@@ -525,6 +496,40 @@ func (p *passer) compositions(ctx context.Context) {
 	}
 }
 
+// answers judges every placed node's answer to the change's placement into v (ADR 0559 §5). While a node has not answered
+// within the bound the verdict waits, and the pass at the bound's end is asked (wakeAt), so a silent node is failed then,
+// named, and a later answer of the same head is judged on its own have's change.
+func (p *passer) answers(mesh assign.Mesh, ch assign.Change, v delivery.CompositionVerdict) delivery.CompositionVerdict {
+	trunkPlaced := map[string]delivery.Placement{}
+	for key, value := range p.w.read(delivery.PlacementBucket) {
+		node, err := delivery.ParsePlacementKey(key)
+		if err != nil {
+			continue
+		}
+		if pl, err := delivery.DecodePlacement(value); err == nil && pl.Node == node {
+			trunkPlaced[node] = pl
+		}
+	}
+	fps := map[string]string{}
+	for name, m := range p.w.trunk() {
+		if m.FP2 != "" {
+			fps[name] = m.FP2
+		} else if m.FP != "" {
+			fps[name] = m.FP
+		}
+	}
+	intended, notes := assign.Intended(mesh.Input, trunkPlaced, ch.Placement, fps)
+	a := assign.JudgeAnswers(ch.Placement, assign.PlacedNodes(trunkPlaced, ch.Placement), p.w.candidateAnswers(ch.Group), intended, p.w.online(), p.clock())
+	v = assign.WithAnswers(v, a)
+	if v.State != delivery.CompositionWaits {
+		v.Warnings = append(v.Warnings, notes...)
+	}
+	if a.Waits && p.wakeAt != nil {
+		p.wakeAt(a.Until)
+	}
+	return v
+}
+
 // put writes one key of the assigner's own bucket; a write that fails is said and made again at the next pass.
 func (p *passer) put(ctx context.Context, bucket, key string, encode func() ([]byte, error)) {
 	value, err := encode()

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/pass_test.go

@@ -13,7 +13,6 @@ import (
 	"github.com/nats-io/nats.go/jetstream"
 
 	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/provider"
@@ -136,9 +135,6 @@ func (m *memKV) Update(_ context.Context, key string, value []byte, revision uin
 type memStore map[string]*memKV
 
 func (s memStore) get(state, key string) ([]byte, uint64, bool, error) {
-	if s[state] == nil {
-		return nil, 0, false, nil
-	}
 	v, ok := s[state].values[key]
 	return v, uint64(len(v)), ok, nil
 }
@@ -857,7 +853,7 @@ func aPairOneSourceNamesAloneGetsNoWantAndOneCondition(t *testing.T) {
 	p.sayPlacement(p.w.placementDiffers())
 	if !slices.Equal(got["g14"], []string{"a"}) || !frozen["g14.b"] || !frozen["g14.c"] || frozen["g14.a"] || len(said) != 2 ||
 		said[0].State != asks.StateRaised || !strings.Contains(said[0].Explanation, "the controller's assignments names b on g14") ||
-		!strings.Contains(said[1].Explanation, "the seat mesh-placement's placement names c on g14") {
+		!strings.Contains(said[1].Explanation, "the catalogue's placement names c on g14") {
 		t.Fatalf("one source alone: assigned %v, frozen %v, said %+v", got, frozen, said)
 	}
 	place("g14", "a", "b", "c")
@@ -877,24 +873,6 @@ func aPairOneSourceNamesAloneGetsNoWantAndOneCondition(t *testing.T) {
 	if m.Input == nil || len(m.Input.Nodes) != 1 || !slices.Equal(m.Input.Nodes[0].Assigned, []string{"a", "b", "c"}) || m.Input.Nodes[0].Place.Key != "k" {
 		t.Errorf("the check's input from the bus: %+v (%q)", m.Input, m.InputUnread)
 	}
-
-	// Issue 774 (ADR 0549 §5, §6): once the controller's lease is handed away the placement alone names where modules
-	// run: a pair in the placement only gets its want and no condition, and one in the assignments only is no module of
-	// the node. A lease that goes back to a controller brings the comparison back.
-	place("n2", "d")
-	assigned("g14", "e")
-	p.w.put(buscompose.LeaseBucket, buscompose.ControllerLeaseKey, []byte(`{"handed-to":"the operator's hand-over","handed-by":"person.jochen"}`))
-	got, all := p.w.assigned()
-	if !slices.Equal(got["n2"], []string{"d"}) || !slices.Equal(got["g14"], []string{"a", "b", "c"}) || len(all) != 0 {
-		t.Errorf("handed away: assigned %v, assignments %v; want the placement alone", got, all)
-	}
-	if frozen := p.sayPlacement(p.w.placementDiffers()); len(frozen) != 0 || len(said) != 4 {
-		t.Errorf("handed away: frozen %v, said %+v; want no condition", frozen, said[4:])
-	}
-	p.w.put(buscompose.LeaseBucket, buscompose.ControllerLeaseKey, []byte(`{"instance":"novox/1","epoch":58}`))
-	if frozen := p.sayPlacement(p.w.placementDiffers()); !frozen["n2.d"] || !frozen["g14.e"] {
-		t.Errorf("a controller's lease again: frozen %v; want both pairs held", frozen)
-	}
 }
 
 // 1126 (ADR 0547 §2 to §4): a node the catalogue places composes its own: its wants name the build alone and its own want

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/puts.go

@@ -213,7 +213,8 @@ func (p *passer) putWorld(node, module string, put delivery.Put, manifest catalo
 
 // composedFor is the composition of module for node at fp and whether the grant at fp names the node's accounts: the one
 // place a put reads them (ADR 0546 clause 4). Today their writer is the controller (mesh-controller_composed and
-// mesh-controller_grants); the grants are the grants part's while the controller's lease is handed away (grantsBucket).
+// mesh-controller_grants); when composing and grants move out of the controller into delivery's own parts, this reads them
+// from their new owner and nothing else changes.
 func (p *passer) composedFor(node, module, fp string) (*delivery.ComposedDigest, bool) {
 	var out *delivery.ComposedDigest
 	if d, ok := p.w.composed(node, module, fp); ok {
@@ -221,7 +222,7 @@ func (p *passer) composedFor(node, module, fp string) (*delivery.ComposedDigest,
 	}
 	granted := false
 	if gkey, err := delivery.ControllerGrantKey(module, fp); err == nil {
-		if raw := p.w.value(p.w.grantsBucket(), gkey); raw != nil {
+		if raw := p.w.value(delivery.ControllerGrantsBucket, gkey); raw != nil {
 			if g, err := delivery.DecodeControllerGrant(raw); err == nil {
 				granted = g.NamesNode(node, module)
 			}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/seat.go

@@ -1,810 +0,0 @@
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"maps"
-	"reflect"
-	"sort"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/nats-io/nats.go"
-	"github.com/nats-io/nats.go/jetstream"
-
-	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/catalogue"
-	"git.novox.be/novox/mesh-sdk/go/compose"
-	"git.novox.be/novox/mesh-sdk/go/compose/frombus"
-	"git.novox.be/novox/mesh-sdk/go/compose/judge"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/process"
-
-	"mesh-delivery-assigner/internal/assign"
-)
-
-// The seat mesh-placement's holder in the assigner's process (novox/hq ADR 0567 §2-§8): each pass follows every open
-// proposal one step, from what the world holds. A proposal the verbs wrote is said (placement-proposed); the nodes it
-// must hear from are found by composing every node with and without it, and those its key does not change get a reached
-// candidate; their answers are judged (placement-judged) and, on a passing verdict, the operator is asked to approve it;
-// on the warrant each changed key is written by compare-and-set at the revision it was laid over (placement-changed),
-// and the controller's assignments are kept in step through its verbs until the lease write. A key moved meanwhile
-// lays the proposal again; a decline, an expiry or a withdrawal ends it (placement-withdrawn). Every event is said on the
-// assigner's own stream, so only this process says them. Nothing polls: the wake at an answer's bound is the one wake.
-
-// publisher says one of the seat's events on the assigner's stream, under a message id the bus keeps one of.
-type publisher func(event string, body any, id string) error
-
-// streamPublisher publishes on mesh.stream.mesh-delivery-assigner.event.<event>, with the headers an emit carries.
-func streamPublisher(ctx context.Context, js jetstream.JetStream, node string) publisher {
-	return func(event string, body any, id string) error {
-		data, err := json.Marshal(body)
-		if err != nil {
-			return err
-		}
-		msg := nats.NewMsg(process.ModuleStreamSubject(delivery.AssignerModule, event))
-		msg.Header.Set("x-event-id", id)
-		msg.Header.Set("x-source", delivery.AssignerModule)
-		msg.Header.Set("x-node", node)
-		msg.Header.Set("x-time", time.Now().UTC().Format(time.RFC3339Nano))
-		msg.Header.Set("content-type", "application/json")
-		msg.Data = data
-		_, err = js.PublishMsg(ctx, msg, jetstream.WithMsgID(id))
-		return err
-	}
-}
-
-// seatActs keeps what the seat's calls of the controller came to while this process runs: the export read again at a
-// seed's warrant, and each call that keeps the controller's assignments in step (§8).
-type seatActs struct {
-	mu     sync.Mutex
-	bus    caller
-	wake   func()
-	logf   func(string, ...any)
-	export map[string]exportCheck
-	// calls is, by pair (node and module, or node and provision for a pin), what the last call for it came to.
-	calls map[string]string
-}
-
-// exportCheck is the export read again for one proposal: running, its answer, or why it was not read.
-type exportCheck struct {
-	running bool
-	export  map[string]delivery.Placement
-	err     string
-}
-
-func newSeatActs(bus caller, wake func(), logf func(string, ...any)) *seatActs {
-	return &seatActs{bus: bus, wake: wake, logf: logf, export: map[string]exportCheck{}, calls: map[string]string{}}
-}
-
-// exportOf is the export read again for a proposal, asked once in the background.
-func (a *seatActs) exportOf(id string) exportCheck {
-	a.mu.Lock()
-	defer a.mu.Unlock()
-	if c, ok := a.export[id]; ok {
-		return c
-	}
-	a.export[id] = exportCheck{running: true}
-	go func() {
-		defer a.wake()
-		raw, err := a.bus.Call(exportCall, map[string]any{})
-		c := exportCheck{}
-		if err != nil {
-			c.err = "the controller's placement-export did not answer: " + err.Error()
-		} else if c.export, err = assign.ExportOf(raw); err != nil {
-			c.err = err.Error()
-		}
-		a.mu.Lock()
-		a.export[id] = c
-		a.mu.Unlock()
-	}()
-	return exportCheck{running: true}
-}
-
-// forget drops what is kept of a proposal's export, so a later warrant reads it again.
-func (a *seatActs) forget(id string) {
-	if a == nil {
-		return
-	}
-	a.mu.Lock()
-	delete(a.export, id)
-	a.mu.Unlock()
-}
-
-// record records once, in the controller's hand-act log, that placement was written on the operator's warrant (§5): the
-// router's record of the teller's ask says who chose and how (ADR 0274).
-func (a *seatActs) record(warrant string) {
-	if a == nil || warrant == "" {
-		return
-	}
-	ask, _, _ := strings.Cut(warrant, "@")
-	go func() {
-		if _, err := a.bus.Call("seat:"+catalogue.ControllerSeatName+".warranted", map[string]any{"asker": delivery.TellerModule, "ask": ask}); err != nil {
-			a.logf("the placement's warrant %s is not recorded in the hand-act log: %v", ask, err)
-		}
-	}()
-}
-
-// handAct records a hand-back in the controller's hand-act log (§7).
-func (a *seatActs) handAct(prop delivery.PlacementProposal) {
-	go func() {
-		if _, err := a.bus.Call(handActCall, map[string]any{"what": "mesh-placement hand-back of " + strings.Join(prop.Nodes(), ", "),
-			"why": prop.Why, "cause": "asked by " + prop.By + ", approved by the operator"}); err != nil {
-			a.logf("the hand-back %s is not recorded in the hand-act log: %v", prop.ID, err)
-		}
-	}()
-}
-
-// callAll makes the controller's calls in order in the background, each said in the journal and kept by its pair.
-func (a *seatActs) callAll(calls []assign.ControllerCall) {
-	if len(calls) == 0 {
-		return
-	}
-	a.mu.Lock()
-	for _, c := range calls {
-		a.calls[c.Node+"."+c.Module] = c.Key() + " is asked"
-	}
-	a.mu.Unlock()
-	go func() {
-		defer a.wake()
-		for _, c := range calls {
-			words := c.Key() + " answered"
-			if _, err := a.bus.Call("seat:"+catalogue.ControllerSeatName+"."+c.Verb, c.Args); err != nil {
-				words = c.Key() + " refused: " + err.Error()
-			}
-			a.logf("keeping the controller in step with placement: %s", words)
-			a.mu.Lock()
-			a.calls[c.Node+"."+c.Module] = words
-			a.mu.Unlock()
-		}
-	}()
-}
-
-// callOf is what the last call for a pair came to, "" when none was made.
-func (a *seatActs) callOf(node, module string) string {
-	if a == nil {
-		return ""
-	}
-	a.mu.Lock()
-	defer a.mu.Unlock()
-	return a.calls[node+"."+module]
-}
-
-// withCalls names, on each pair the two sources do not both name, the call the assigner made for it (§8).
-func (p *passer) withCalls(pairs []assign.Pair) []assign.Pair {
-	for i := range pairs {
-		pairs[i].Call = p.seat.callOf(pairs[i].Node, pairs[i].Module)
-	}
-	return pairs
-}
-
-// sayWaits raises, once, that the seat waits for the states not yet bound, and clears it once, when all are.
-func (p *passer) sayWaits(unbound []string) {
-	c := assign.SeatWaitsCondition(unbound)
-	state := string(c.State) + c.Summary
-	if p.say == nil || p.said[c.Key] && p.saidWaits == state {
-		return
-	}
-	if c.State == asks.StateCleared && p.saidWaits == "" {
-		return // nothing was raised by this process
-	}
-	if err := p.say(c); err != nil {
-		p.logf("that the seat waits for its states could not be said, and is said at the next pass: %v", err)
-		return
-	}
-	p.said[c.Key], p.saidWaits = true, state
-}
-
-// seatPlacements is every node's placement key and its revision, as the watch holds them.
-func (p *passer) seatPlacements() (map[string]delivery.Placement, map[string]uint64) {
-	out, revs := map[string]delivery.Placement{}, map[string]uint64{}
-	for key, value := range p.w.read(delivery.PlacementBucket) {
-		node, err := delivery.ParsePlacementKey(key)
-		if err != nil {
-			continue
-		}
-		if pl, err := delivery.DecodePlacement(value); err == nil && pl.Node == node {
-			out[node], revs[node] = pl, p.w.metaOf(delivery.PlacementBucket, key).revision
-		}
-	}
-	return out, revs
-}
-
-// candidatesOf is a proposal's candidates by node, with their keys' revisions and the newest write.
-func (p *passer) candidatesOf(id string) (map[string]delivery.PlacementCandidate, map[string]uint64, time.Time) {
-	out, revs := map[string]delivery.PlacementCandidate{}, map[string]uint64{}
-	var newest time.Time
-	for key, value := range p.w.read(delivery.PlacementCandidatesBucket) {
-		pid, node, err := delivery.ParsePlacementCandidateKey(key)
-		if err != nil || pid != id {
-			continue
-		}
-		c, err := delivery.DecodePlacementCandidate(value)
-		if err != nil {
-			continue
-		}
-		meta := p.w.metaOf(delivery.PlacementCandidatesBucket, key)
-		out[node], revs[node] = c, meta.revision
-		if meta.at.After(newest) {
-			newest = meta.at
-		}
-	}
-	return out, revs, newest
-}
-
-// answersTo is, by node, each node's answer to the proposal in its `<node>.node` have.
-func (p *passer) answersTo(id string) map[string]*delivery.CandidateAnswer {
-	out := map[string]*delivery.CandidateAnswer{}
-	for key, value := range p.w.read(delivery.HaveBucket) {
-		node, _, isNode, err := delivery.ParseHaveKey(key)
-		if err != nil || !isNode {
-			continue
-		}
-		h, err := delivery.DecodeHaveNode(value)
-		if err != nil {
-			continue
-		}
-		if a, ok := h.Candidates[id]; ok {
-			out[node] = &a
-		}
-	}
-	return out
-}
-
-// placementSeat takes every open proposal one step further.
-func (p *passer) placementSeat(ctx context.Context) {
-	for _, b := range seatBuckets {
-		if p.kvs[b] == nil {
-			return
-		}
-	}
-	if p.saidProposed == nil {
-		p.saidProposed, p.intended = map[string]bool{}, map[string]map[string]map[string]bool{}
-	}
-	current, revs := p.seatPlacements()
-	ids := make([]string, 0)
-	raws := p.w.read(delivery.PlacementProposalsBucket)
-	for id := range raws {
-		ids = append(ids, id)
-	}
-	sort.Strings(ids)
-	for _, id := range ids {
-		prop, err := delivery.DecodePlacementProposal(raws[id])
-		if err != nil || prop.ID != id {
-			p.logf("the proposal %s cannot be read, so it is left: %v", id, err)
-			continue
-		}
-		p.stepProposal(ctx, prop, p.w.metaOf(delivery.PlacementProposalsBucket, id).revision, current, revs)
-	}
-}
-
-// pulse writes a bound's key with its time to live (§4): its expiry, heard on the watch as the server's delete marker,
-// is the event that ends the wait. Written again over one that stands, so its time starts anew.
-func (p *passer) pulse(ctx context.Context, key string, ttl time.Duration) {
-	kv := p.kvs[delivery.PlacementPulsesBucket]
-	_ = kv.Delete(ctx, key)
-	rev, err := kv.Create(ctx, key, []byte(`{}`), jetstream.KeyTTL(ttl))
-	if err != nil {
-		p.logf("the bound %s is not written, so its wait ends at once: %v", key, err)
-		return
-	}
-	p.w.putEntry(delivery.PlacementPulsesBucket, key, []byte(`{}`), rev, p.clock())
-}
-
-// pulsing says whether a bound's key stands.
-func (p *passer) pulsing(key string) bool { return p.w.has(delivery.PlacementPulsesBucket, key) }
-
-// deletePulses deletes every bound of a proposal.
-func (p *passer) deletePulses(ctx context.Context, id string) {
-	for key := range p.w.read(delivery.PlacementPulsesBucket) {
-		if strings.HasSuffix(key, "."+id) || strings.Contains(key, "."+id+".") {
-			if err := p.kvs[delivery.PlacementPulsesBucket].Delete(ctx, key); err == nil {
-				p.w.put(delivery.PlacementPulsesBucket, key, nil)
-			}
-		}
-	}
-}
-
-// ask raises (or raises again) a proposal's authorising ask and its bound, and answers the proposal asked.
-func (p *passer) ask(ctx context.Context, prop delivery.PlacementProposal, akey, brief string) (delivery.PlacementProposal, bool) {
-	a, err := assign.PlacementAsk(akey, prop, brief, assign.PlacementAsking(prop, p.clock()), p.clock())
-	if err != nil {
-		p.logf("the ask about the proposal %s is not written: %v", prop.ID, err)
-		return prop, false
-	}
-	p.put(ctx, delivery.AssignerAsksBucket, akey, func() ([]byte, error) { return delivery.EncodeAssignerAsk(akey, a) })
-	if pk, err := delivery.PulseAskKey(prop.ID); err == nil {
-		p.pulse(ctx, pk, a.Ask.Expires.Sub(p.clock()))
-	}
-	prop.State, prop.Ask = delivery.ProposalAsked, a.Ask.ID
-	return prop, true
-}
-
-// stepProposal takes one proposal one step further.
-func (p *passer) stepProposal(ctx context.Context, prop delivery.PlacementProposal, rev uint64, current map[string]delivery.Placement, revs map[string]uint64) {
-	if !p.saidProposed[prop.ID] && prop.State == delivery.ProposalAnswering && prop.Verdict == nil {
-		p.sayEvent(delivery.PlacementProposedEvent, delivery.PlacementEvent{Proposal: prop}, prop.ID)
-		p.saidProposed[prop.ID] = true
-	}
-	if prop.Withdrawn != "" {
-		p.endProposal(ctx, prop, prop.Withdrawn)
-		return
-	}
-	akey, _ := delivery.PlacementAskKey(prop.ID)
-	again := !prop.Again.IsZero() && (prop.Verdict == nil || prop.Again.After(prop.Verdict.At))
-	if prop.State == delivery.ProposalAsked {
-		askPulse, _ := delivery.PulseAskKey(prop.ID)
-		switch {
-		case p.answeredWith(akey, assign.OptionYes):
-			if prop.HandBack {
-				p.handBack(ctx, prop, akey, revs)
-			} else {
-				p.warranted(ctx, prop, rev, akey, current, revs)
-			}
-			return
-		case p.answeredWith(akey, assign.OptionNo):
-			p.endProposal(ctx, prop, "declined by the operator")
-			return
-		case !p.pulsing(askPulse) && !again:
-			p.endProposal(ctx, prop, "its ask expired unanswered")
-			return
-		}
-	}
-	if prop.HandBack {
-		// The operator's alone (§7): no node answers it; its ask is raised at once, and again on again.
-		if prop.State != delivery.ProposalAsked || again {
-			brief := fmt.Sprintf("%s (asked by %s): every node's placement key is deleted, %s, and each node returns to the "+
-				"controller's compositions; the history is kept", prop.Why, prop.By, strings.Join(prop.Nodes(), ", "))
-			now := p.clock().UTC()
-			prop.Verdict = &delivery.PlacementVerdict{State: delivery.VerdictPass, At: now}
-			if prop, ok := p.ask(ctx, prop, akey, brief); ok {
-				p.writeProposal(ctx, prop, rev)
-			}
-		}
-		return
-	}
-	if moved(prop, revs) {
-		p.layAgain(ctx, prop, rev, current, revs, "a key it was laid over moved since")
-		return
-	}
-	cands, candRevs, written := p.candidatesOf(prop.ID)
-	if len(prop.Must) == 0 {
-		p.mustAnswer(ctx, prop, rev, current, cands)
-		return
-	}
-	for _, node := range prop.Must {
-		if _, ok := cands[node]; !ok {
-			return // a candidate just written is not heard yet: its watch wakes the next pass
-		}
-	}
-	if written.After(prop.Written) {
-		prop.Written = written
-	}
-	pulsing := map[string]bool{}
-	for _, node := range prop.Must {
-		if k, err := delivery.PulseAnswerKey(prop.ID, node); err == nil {
-			pulsing[node] = p.pulsing(k)
-		}
-	}
-	v := judge.JudgeAnswers(prop, p.intendedOf(prop, current, cands), p.answersTo(prop.ID), candRevs, p.w.online(), pulsing, p.clock())
-	if prop.Verdict != nil && sameVerdict(*prop.Verdict, v) && !again {
-		return
-	}
-	prop.Verdict = &v
-	switch v.State {
-	case delivery.VerdictFail:
-		prop.State, prop.Ask = delivery.ProposalFailed, ""
-	case delivery.VerdictWaits:
-		prop.State, prop.Ask = delivery.ProposalAnswering, ""
-	case delivery.VerdictPass:
-		if prop.State != delivery.ProposalAsked || again {
-			var ok bool
-			if prop, ok = p.ask(ctx, prop, akey, judge.Brief(prop, v)); !ok {
-				return
-			}
-			if again {
-				prop.Words = "judged and asked again (again)"
-			}
-		}
-	}
-	if p.writeProposal(ctx, prop, rev) {
-		p.sayEvent(delivery.PlacementJudgedEvent, delivery.PlacementEvent{Proposal: prop},
-			fmt.Sprintf("%s.judged.%d", prop.ID, v.At.UnixNano()))
-	}
-}
-
-// sameVerdict says two verdicts say the same, their time aside.
-func sameVerdict(a, b delivery.PlacementVerdict) bool {
-	a.At, b.At = time.Time{}, time.Time{}
-	return reflect.DeepEqual(a, b)
-}
-
-// moved says whether a key the proposal changes is no longer at the revision it was laid over.
-func moved(prop delivery.PlacementProposal, revs map[string]uint64) bool {
-	for node, base := range prop.Base {
-		if revs[node] != base {
-			return true
-		}
-	}
-	return false
-}
-
-// intended is, by proposal and the revisions it was laid over, what Intended computed, kept while this process runs.
-func (p *passer) intendedOf(prop delivery.PlacementProposal, current map[string]delivery.Placement, cands map[string]delivery.PlacementCandidate) map[string]map[string]bool {
-	key := fmt.Sprint(prop.ID, prop.Base)
-	if got, ok := p.intended[key]; ok {
-		return got
-	}
-	got, _, _ := p.compute(prop, current, cands)
-	p.intended[key] = got
-	return got
-}
-
-// compute composes every node with the current placement and with the proposal laid over it (judge.Intended).
-func (p *passer) compute(prop delivery.PlacementProposal, current map[string]delivery.Placement, cands map[string]delivery.PlacementCandidate) (map[string]map[string]bool, []string, []string) {
-	laid := map[string]*delivery.Placement{}
-	for _, node := range prop.Nodes() {
-		if c, ok := cands[node]; ok && !c.Reached {
-			laid[node] = c.Placement
-		}
-	}
-	get := kvGetter(p.kvs[delivery.ManifestsBucket])
-	r := worldReader{w: p.w, manifests: get}
-	var now, with *compose.Input
-	if in, err := frombus.Input(context.Background(), r, frombus.Mesh{}, frombus.Scope{Every: true}); err == nil {
-		now = &in
-	}
-	if in, err := frombus.Input(context.Background(), r, frombus.Mesh{}, frombus.Scope{Every: true, Placements: laid}); err == nil {
-		with = &in
-	}
-	nodes := map[string]bool{}
-	for n := range current {
-		nodes[n] = true
-	}
-	if records, err := r.Records(context.Background()); err == nil {
-		for n := range records {
-			nodes[n] = true
-		}
-	}
-	names := make([]string, 0, len(nodes))
-	for n := range nodes {
-		names = append(names, n)
-	}
-	fps := map[string]string{}
-	for name, m := range p.w.trunk() {
-		if m.FP2 != "" {
-			fps[name] = m.FP2
-		}
-	}
-	return judge.Intended(now, with, current, laid, names, fps)
-}
-
-// mustAnswer finds the nodes the proposal must hear from (§3), writes a reached candidate for each whose key it does not
-// change, and writes them into the proposal.
-func (p *passer) mustAnswer(ctx context.Context, prop delivery.PlacementProposal, rev uint64, current map[string]delivery.Placement, cands map[string]delivery.PlacementCandidate) {
-	for _, node := range prop.Nodes() {
-		if _, ok := cands[node]; !ok {
-			return // the verbs write the candidates before the proposal: wait to hear them
-		}
-	}
-	intended, must, notes := p.compute(prop, current, cands)
-	p.intended[fmt.Sprint(prop.ID, prop.Base)] = intended
-	for _, node := range must {
-		if _, ok := cands[node]; ok {
-			continue
-		}
-		key, err := delivery.PlacementCandidateKey(prop.ID, node)
-		if err != nil {
-			continue
-		}
-		c := delivery.PlacementCandidate{Proposal: prop.ID, Reached: true}
-		if pl, ok := current[node]; ok {
-			c.Placement = &pl
-		}
-		p.put(ctx, delivery.PlacementCandidatesBucket, key, func() ([]byte, error) { return delivery.EncodePlacementCandidate(c) })
-	}
-	for _, node := range must {
-		if k, err := delivery.PulseAnswerKey(prop.ID, node); err == nil {
-			p.pulse(ctx, k, judge.AnswerBound)
-		}
-	}
-	prop.Must = must
-	if len(notes) > 0 {
-		prop.Words = strings.TrimPrefix(prop.Words+"; "+strings.Join(notes, "; "), "; ")
-	}
-	p.writeProposal(ctx, prop, rev)
-}
-
-// layAgain lays a proposal over the keys as they stand now (§5: a key moved): its candidates are written again, the
-// nodes that must answer found again, and it is judged and asked again; a proposal that no longer lays ends.
-func (p *passer) layAgain(ctx context.Context, prop delivery.PlacementProposal, rev uint64, current map[string]delivery.Placement, revs map[string]uint64, why string) {
-	held, recorded := p.lays(ctx)
-	again, laid, findings := assign.Propose(assign.ProposeIn{ID: prop.ID, By: prop.By, Why: prop.Why, At: prop.At, Changes: prop.Changes,
-		Current: current, Revisions: revs, Held: held, Recorded: recorded,
-		Seed: prop.Seed, ExportDigest: prop.ExportDigest, Leased: p.w.handedAway()})
-	if len(findings) > 0 {
-		p.endProposal(ctx, prop, why+", and laid over the keys now it is refused: "+strings.Join(findings, "; "))
-		return
-	}
-	p.deleteCandidates(ctx, prop.ID)
-	p.deletePulses(ctx, prop.ID)
-	for _, node := range again.Nodes() {
-		key, _ := delivery.PlacementCandidateKey(prop.ID, node)
-		c := delivery.PlacementCandidate{Proposal: prop.ID, Placement: laid[node]}
-		p.put(ctx, delivery.PlacementCandidatesBucket, key, func() ([]byte, error) { return delivery.EncodePlacementCandidate(c) })
-	}
-	again.Written, again.Words = p.clock().UTC(), why+": laid again over the keys as they stand, to be judged and asked again"
-	p.seat.forget(prop.ID)
-	p.writeProposal(ctx, again, rev)
-}
-
-// lays is what a proposal is checked against, as the verbs check it: the modules the indexer holds, by key, and the
-// nodes with a record.
-func (p *passer) lays(ctx context.Context) (func(string) bool, func(string) bool) {
-	held := map[string]bool{}
-	for key := range p.w.read(delivery.ModulesBucket) {
-		if name, err := delivery.ParseModulesKey(key); err == nil {
-			held[name] = true
-		}
-	}
-	records, _ := worldReader{w: p.w}.Records(ctx)
-	return func(m string) bool { return held[m] }, func(n string) bool { _, ok := records[n]; return ok }
-}
-
-// warranted writes an approved proposal (§5): for the seed, after the export is read again and found unchanged (§7);
-// each changed key by compare-and-set at the revision it was laid over; then the warrant recorded, the candidates and the
-// proposal deleted, placement-changed said, and the controller kept in step (§8).
-func (p *passer) warranted(ctx context.Context, prop delivery.PlacementProposal, rev uint64, akey string, current map[string]delivery.Placement, revs map[string]uint64) {
-	if err := p.performs(akey, assign.PlacementAct(prop)); err != nil {
-		p.endProposal(ctx, prop, "its warrant does not bind these changes, so nothing is written: "+err.Error())
-		return
-	}
-	answer, _ := p.w.answer(akey)
-	if prop.Seed {
-		if p.seat == nil {
-			return
-		}
-		c := p.seat.exportOf(prop.ID)
-		switch {
-		case c.running:
-			return // its answer wakes the next pass
-		case c.err != "":
-			if words := "the export cannot be read again at the warrant: " + c.err; prop.Words != words {
-				prop.Words = words
-				p.writeProposal(ctx, prop, rev)
-			}
-			return
-		case delivery.ExportDigest(c.export) != prop.ExportDigest:
-			p.endProposal(ctx, prop, "the controller's export changed since the seed was proposed: the new export is proposed as the seed")
-			p.proposeSeed(ctx, prop, c.export)
-			return
-		}
-	}
-	if moved(prop, revs) {
-		p.layAgain(ctx, prop, rev, current, revs, "a key moved since it was approved, so its warrant is spent")
-		return
-	}
-	cands, _, _ := p.candidatesOf(prop.ID)
-	laid := map[string]*delivery.Placement{}
-	for _, node := range prop.Nodes() {
-		laid[node] = cands[node].Placement
-	}
-	writes, err := assign.Writes(prop, laid)
-	if err != nil {
-		p.logf("the proposal %s cannot be written: %v", prop.ID, err)
-		return
-	}
-	kv := p.kvs[delivery.PlacementBucket]
-	var changes []delivery.PlacementChange
-	writtenLaid := map[string]*delivery.Placement{}
-	after := maps.Clone(current)
-	afterRevs := maps.Clone(revs)
-	for _, w := range writes {
-		var rev2 uint64
-		var err error
-		switch {
-		case w.Value == nil:
-			err = kv.Delete(ctx, w.Key, jetstream.LastRevision(w.Base))
-		default:
-			raw, encErr := delivery.EncodePlacement(*w.Value)
-			if encErr != nil {
-				err = encErr
-			} else if w.Base == 0 {
-				rev2, err = kv.Create(ctx, w.Key, raw)
-			} else {
-				rev2, err = kv.Update(ctx, w.Key, raw, w.Base)
-			}
-		}
-		if err != nil {
-			// Another writer came first (a hand-back): what is written stands and is followed through; the rest is laid
-			// again over the keys as this write left them.
-			p.logf("placement %s is not written at revision %d (%v): the rest of the proposal %s is laid again", w.Key, w.Base, err, prop.ID)
-			p.followWrite(prop, answer, changes, current, writtenLaid)
-			if rest, ok := assign.Rest(prop, writtenLaid); ok {
-				p.layAgain(ctx, rest, rev, after, afterRevs, "a key moved while it was written, after "+strings.Join(sortedNodes(writtenLaid), ", ")+" were")
-			} else {
-				p.endProposal(ctx, prop, "a key moved while it was written: "+err.Error())
-			}
-			return
-		}
-		before := current[w.Node]
-		now := delivery.Placement{Node: w.Node}
-		if w.Value != nil {
-			now = *w.Value
-			after[w.Node] = *w.Value
-		} else {
-			delete(after, w.Node)
-		}
-		afterRevs[w.Node] = rev2
-		c := delivery.ChangeOf(before, now)
-		c.Before, c.After = w.Base, rev2
-		changes = append(changes, c)
-		writtenLaid[w.Node] = w.Value
-	}
-	p.deleteCandidates(ctx, prop.ID)
-	p.deletePulses(ctx, prop.ID)
-	_ = p.kvs[delivery.PlacementProposalsBucket].Delete(ctx, prop.ID)
-	p.w.put(delivery.PlacementProposalsBucket, prop.ID, nil)
-	p.followWrite(prop, answer, changes, current, writtenLaid)
-}
-
-// followWrite follows the keys a warrant wrote: the warrant recorded, placement-changed said, and, until the lease
-// write, the controller's assignments kept in step for them (§8). The seed calls no controller verb: it is what the
-// controller holds already (§9).
-func (p *passer) followWrite(prop delivery.PlacementProposal, answer delivery.Answer, changes []delivery.PlacementChange,
-	before map[string]delivery.Placement, written map[string]*delivery.Placement) {
-	if len(changes) == 0 {
-		return
-	}
-	p.seat.record(answer.Warrant)
-	p.sayChanged(prop, answer, changes)
-	if p.seat != nil && !p.w.handedAway() && !prop.Seed {
-		p.seat.callAll(assign.ControllerCalls(before, written, prop.ID, answer.Warrant))
-	}
-}
-
-func sortedNodes(m map[string]*delivery.Placement) []string {
-	out := make([]string, 0, len(m))
-	for n := range m {
-		out = append(out, n)
-	}
-	sort.Strings(out)
-	return out
-}
-
-// handBack deletes every key on the operator's warrant (§7) at the revision the hand-back read, records it in the
-// controller's hand-act log and says placement-changed; every node returns to the controller's compositions. A key moved
-// since ends it, and the operator hands back again.
-func (p *passer) handBack(ctx context.Context, prop delivery.PlacementProposal, akey string, revs map[string]uint64) {
-	if err := p.performs(akey, assign.PlacementAct(prop)); err != nil {
-		p.endProposal(ctx, prop, "its warrant does not bind this hand-back, so nothing is deleted: "+err.Error())
-		return
-	}
-	answer, _ := p.w.answer(akey)
-	current, _ := p.seatPlacements()
-	var changes []delivery.PlacementChange
-	for _, node := range prop.Nodes() {
-		key, _ := delivery.PlacementKey(node)
-		if err := p.kvs[delivery.PlacementBucket].Delete(ctx, key, jetstream.LastRevision(prop.Base[node])); err != nil {
-			p.sayChanged(prop, answer, changes)
-			p.endProposal(ctx, prop, fmt.Sprintf("%s moved since the hand-back was asked (%v): hand back again", key, err))
-			return
-		}
-		c := delivery.ChangeOf(current[node], delivery.Placement{Node: node})
-		c.Before = prop.Base[node]
-		changes = append(changes, c)
-	}
-	if p.seat != nil {
-		p.seat.handAct(prop)
-	}
-	p.seat.record(answer.Warrant)
-	_ = p.kvs[delivery.PlacementProposalsBucket].Delete(ctx, prop.ID)
-	p.w.put(delivery.PlacementProposalsBucket, prop.ID, nil)
-	p.deletePulses(ctx, prop.ID)
-	p.sayChanged(prop, answer, changes)
-}
-
-// sayChanged says placement-changed for the keys written.
-func (p *passer) sayChanged(prop delivery.PlacementProposal, answer delivery.Answer, changes []delivery.PlacementChange) {
-	if len(changes) == 0 {
-		return
-	}
-	at := p.clock().UTC()
-	if _, when, ok := strings.Cut(answer.Warrant, "@"); ok {
-		if t, err := time.Parse(time.RFC3339Nano, when); err == nil {
-			at = t
-		}
-	}
-	delivery.SortChanges(changes)
-	p.sayEvent(delivery.PlacementChangedEvent, delivery.PlacementEvent{Proposal: prop, Nodes: changes,
-		Warrant: &delivery.PlacementWarrant{Warrant: answer.Warrant, Words: answer.Words, At: at}}, prop.ID+".changed")
-}
-
-// proposeSeed proposes an export as the seed again, by the same proposer and why.
-func (p *passer) proposeSeed(ctx context.Context, was delivery.PlacementProposal, export map[string]delivery.Placement) {
-	held, recorded := p.lays(ctx)
-	now := p.clock()
-	seed, laid, findings := assign.Propose(assign.ProposeIn{ID: delivery.NewProposalID(now), By: was.By, Why: was.Why, At: now,
-		Changes: assign.SeedChanges(export), Current: map[string]delivery.Placement{}, Revisions: map[string]uint64{},
-		Held: held, Recorded: recorded, Seed: true, ExportDigest: delivery.ExportDigest(export), Leased: p.w.handedAway()})
-	if len(findings) > 0 {
-		p.logf("the new export is not proposed as the seed: %s", strings.Join(findings, "; "))
-		return
-	}
-	for _, node := range seed.Nodes() {
-		key, _ := delivery.PlacementCandidateKey(seed.ID, node)
-		c := delivery.PlacementCandidate{Proposal: seed.ID, Placement: laid[node]}
-		p.put(ctx, delivery.PlacementCandidatesBucket, key, func() ([]byte, error) { return delivery.EncodePlacementCandidate(c) })
-	}
-	seed.Written = now.UTC()
-	p.writeProposal(ctx, seed, 0)
-}
-
-// endProposal ends a proposal: its ask, its candidates and its key deleted, and placement-withdrawn said carrying it
-// whole with why it ended.
-func (p *passer) endProposal(ctx context.Context, prop delivery.PlacementProposal, why string) {
-	if akey, err := delivery.PlacementAskKey(prop.ID); err == nil && p.w.has(delivery.AssignerAsksBucket, akey) {
-		if err := p.kvs[delivery.AssignerAsksBucket].Delete(ctx, akey); err == nil {
-			p.w.put(delivery.AssignerAsksBucket, akey, nil)
-		}
-	}
-	p.deleteCandidates(ctx, prop.ID)
-	p.deletePulses(ctx, prop.ID)
-	if err := p.kvs[delivery.PlacementProposalsBucket].Delete(ctx, prop.ID); err != nil && !errors.Is(err, context.Canceled) {
-		p.logf("the proposal %s is not deleted, and is ended at the next pass: %v", prop.ID, err)
-		return
-	}
-	p.w.put(delivery.PlacementProposalsBucket, prop.ID, nil)
-	p.seat.forget(prop.ID)
-	p.logf("the proposal %s ends: %s", prop.ID, why)
-	p.sayEvent(delivery.PlacementWithdrawnEvent, delivery.PlacementEvent{Proposal: prop, Ended: why}, prop.ID+".withdrawn")
-}
-
-// deleteCandidates deletes every candidate of a proposal.
-func (p *passer) deleteCandidates(ctx context.Context, id string) {
-	for key := range p.w.read(delivery.PlacementCandidatesBucket) {
-		if pid, _, err := delivery.ParsePlacementCandidateKey(key); err == nil && pid == id {
-			if err := p.kvs[delivery.PlacementCandidatesBucket].Delete(ctx, key); err == nil {
-				p.w.put(delivery.PlacementCandidatesBucket, key, nil)
-			}
-		}
-	}
-}
-
-// writeProposal writes a proposal over the revision the pass read, by compare-and-set: a verb that marked it meanwhile
-// (withdraw, again) wins, and the next pass reads that. It says whether it wrote.
-func (p *passer) writeProposal(ctx context.Context, prop delivery.PlacementProposal, rev uint64) bool {
-	raw, err := delivery.EncodePlacementProposal(prop)
-	if err != nil {
-		p.logf("the proposal %s is not written: %v", prop.ID, err)
-		return false
-	}
-	kv := p.kvs[delivery.PlacementProposalsBucket]
-	var at uint64
-	if rev == 0 {
-		at, err = kv.Create(ctx, prop.ID, raw)
-	} else {
-		at, err = kv.Update(ctx, prop.ID, raw, rev)
-	}
-	if err != nil {
-		if !errors.Is(err, context.Canceled) {
-			p.logf("the proposal %s is not written, and is taken further at the next pass: %v", prop.ID, err)
-		}
-		return false
-	}
-	p.w.putEntry(delivery.PlacementProposalsBucket, prop.ID, raw, at, p.clock())
-	return true
-}
-
-// say says one of the seat's events, said in the journal when the bus refuses it.
-func (p *passer) sayEvent(event string, body delivery.PlacementEvent, id string) {
-	if p.publish == nil {
-		return
-	}
-	if err := p.publish(event, body, id); err != nil {
-		p.logf("%s of %s is not said: %v", event, body.Proposal.ID, err)
-	}
-}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/seat_tools.go

@@ -1,543 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"errors"
-	"fmt"
-	"sort"
-	"strings"
-	"time"
-
-	stdio "git.novox.be/novox/mesh-sdk/go"
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
-	"git.novox.be/novox/mesh-sdk/go/catalogue"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-
-	"mesh-delivery-assigner/internal/assign"
-)
-
-// The seat mesh-placement's seven verbs (novox/hq ADR 0567 §10), served through the tool runner beside the put tools: a
-// process never serves (ADR 0436). They read every state the seat keeps and write what a person asks of it: a proposal
-// and its candidates (propose, adopt), a proposal marked to end (withdraw) or to be judged again (again), and the keys
-// deleted (hand-back). Everything that follows a proposal — composing it, judging the answers, the ask, the write at the
-// warrant and the seat's events on its stream — is the assigner's process's (seat.go), started by these writes.
-
-// seatStore is what the seat's verbs need of the states: the runtime's, or a test's.
-type seatStore interface {
-	store
-	del(state, key string) error
-	history(state, key string) ([]stdio.StateRevision, error)
-}
-
-func (runtimeStore) del(state, key string) error { return stdio.State(state).Delete(key) }
-
-func (runtimeStore) history(state, key string) ([]stdio.StateRevision, error) {
-	return stdio.State(state).History(key)
-}
-
-// The states the verbs read, as the runtime names them: the seat's own by their local names, the others'
-// `<module>.<state>`.
-const (
-	modulesState = delivery.IndexerModule + ".modules"
-	haveState    = "node-engine.have"
-)
-
-// seatTools serves the seat's verbs over a store, asking the controller through ask (stdio.Ask, or a test's).
-type seatTools struct {
-	st  seatStore
-	ask func(key string, body any) (json.RawMessage, error)
-	now func() time.Time
-}
-
-func newSeatTools(st seatStore, ask func(string, any) (json.RawMessage, error)) *seatTools {
-	return &seatTools{st: st, ask: ask, now: time.Now}
-}
-
-// keyed is one placement key as a verb answers it.
-type keyed struct {
-	Placement delivery.Placement `json:"placement"`
-	Revision  uint64             `json:"revision"`
-}
-
-// placements reads every node's placement and its key's revision.
-func (s *seatTools) placements() (map[string]delivery.Placement, map[string]uint64, error) {
-	keys, err := s.st.keys(delivery.PlacementState)
-	if err != nil {
-		return nil, nil, fmt.Errorf("placement cannot be listed: %w", err)
-	}
-	out, revs := map[string]delivery.Placement{}, map[string]uint64{}
-	for _, key := range keys {
-		node, err := delivery.ParsePlacementKey(key)
-		if err != nil {
-			continue
-		}
-		raw, rev, found, err := s.st.get(delivery.PlacementState, key)
-		if err != nil {
-			return nil, nil, fmt.Errorf("placement of %s cannot be read: %w", node, err)
-		}
-		if !found {
-			continue
-		}
-		p, err := delivery.DecodePlacement(raw)
-		if err != nil {
-			return nil, nil, fmt.Errorf("placement of %s cannot be read: %w", node, err)
-		}
-		out[node], revs[node] = p, rev
-	}
-	return out, revs, nil
-}
-
-// lays is what a proposal is checked against: the modules the indexer holds and the nodes with a record.
-func (s *seatTools) lays() (func(string) bool, func(string) bool, error) {
-	mods, err := s.st.keys(modulesState)
-	if err != nil {
-		return nil, nil, fmt.Errorf("the indexer's modules cannot be listed: %w", err)
-	}
-	held := map[string]bool{}
-	for _, k := range mods {
-		if name, err := delivery.ParseModulesKey(k); err == nil {
-			held[name] = true
-		}
-	}
-	haves, err := s.st.keys(haveState)
-	if err != nil {
-		return nil, nil, fmt.Errorf("the nodes' records cannot be listed: %w", err)
-	}
-	recorded := map[string]bool{}
-	for _, k := range haves {
-		node, _, isNode, err := delivery.ParseHaveKey(k)
-		if err != nil || !isNode {
-			continue
-		}
-		if raw, _, found, err := s.st.get(haveState, k); err == nil && found {
-			if h, err := delivery.DecodeHaveNode(raw); err == nil && h.Record != nil {
-				recorded[node] = true
-			}
-		}
-	}
-	return func(m string) bool { return held[m] }, func(n string) bool { return recorded[n] }, nil
-}
-
-// proposal reads one open proposal.
-func (s *seatTools) proposal(id string) (delivery.PlacementProposal, error) {
-	if err := delivery.CheckProposalID(id); err != nil {
-		return delivery.PlacementProposal{}, err
-	}
-	raw, _, found, err := s.st.get(delivery.PlacementProposalsState, id)
-	if err != nil {
-		return delivery.PlacementProposal{}, fmt.Errorf("the proposal %s cannot be read: %w", id, err)
-	}
-	if !found {
-		return delivery.PlacementProposal{}, fmt.Errorf("no proposal %s is open: mesh-placement.proposals lists those that are", id)
-	}
-	return delivery.DecodePlacementProposal(raw)
-}
-
-// write writes a proposal laid by assign.Propose: each candidate, then the proposal, whose write the assigner's process
-// takes as the event to compose and judge it.
-func (s *seatTools) write(p delivery.PlacementProposal, laid map[string]*delivery.Placement) error {
-	p.Written = s.now().UTC()
-	for _, node := range p.Nodes() {
-		key, err := delivery.PlacementCandidateKey(p.ID, node)
-		if err != nil {
-			return err
-		}
-		raw, err := delivery.EncodePlacementCandidate(delivery.PlacementCandidate{Proposal: p.ID, Placement: laid[node]})
-		if err != nil {
-			return err
-		}
-		if err := s.st.put(delivery.PlacementCandidatesState, key, raw); err != nil {
-			return fmt.Errorf("the candidate %s is not written: %w", key, err)
-		}
-	}
-	raw, err := delivery.EncodePlacementProposal(p)
-	if err != nil {
-		return err
-	}
-	if err := s.st.put(delivery.PlacementProposalsState, p.ID, raw); err != nil {
-		return fmt.Errorf("the proposal %s is not written: %w", p.ID, err)
-	}
-	return nil
-}
-
-// proposed is what propose and adopt answer.
-type proposed struct {
-	Proposal delivery.PlacementProposal `json:"proposal"`
-	Follow   string                     `json:"follow"`
-}
-
-func followProposal(id string) string {
-	return fmt.Sprintf("the nodes it touches answer it; mesh-placement.proposals with id %q says where it stands, and the "+
-		"operator is asked to approve it once its verdict passes", id)
-}
-
-// changesOf reads propose's changes: a JSON array, given as one or as its text.
-func changesOf(v any) ([]delivery.PlacementProposalChange, error) {
-	var raw []byte
-	switch c := v.(type) {
-	case string:
-		raw = []byte(c)
-	case nil:
-		return nil, errors.New("propose names its changes")
-	default:
-		var err error
-		if raw, err = json.Marshal(c); err != nil {
-			return nil, err
-		}
-	}
-	var out []delivery.PlacementProposalChange
-	dec := json.NewDecoder(strings.NewReader(string(raw)))
-	dec.DisallowUnknownFields()
-	if err := dec.Decode(&out); err != nil {
-		return nil, fmt.Errorf("the changes are no list of changes: %w", err)
-	}
-	return out, nil
-}
-
-// doPropose is the verb propose (§2).
-func (s *seatTools) doPropose(args map[string]any, by string) (any, error) {
-	changes, err := changesOf(args["changes"])
-	if err != nil {
-		return nil, err
-	}
-	for _, c := range changes {
-		if c.Op == delivery.OpSeed {
-			return nil, errors.New("the seed is adopt's alone: propose takes place, take-off, pin, unpin, hold, unhold, decide and config")
-		}
-	}
-	current, revs, err := s.placements()
-	if err != nil {
-		return nil, err
-	}
-	held, recorded, err := s.lays()
-	if err != nil {
-		return nil, err
-	}
-	now := s.now()
-	p, laid, findings := assign.Propose(assign.ProposeIn{ID: delivery.NewProposalID(now), By: by, Why: arg(args, "why"), At: now,
-		Changes: changes, Current: current, Revisions: revs, Held: held, Recorded: recorded, Leased: s.leased()})
-	if len(findings) > 0 {
-		return nil, fmt.Errorf("the proposal is refused: %s", strings.Join(findings, "; "))
-	}
-	if err := s.write(p, laid); err != nil {
-		return nil, err
-	}
-	return proposed{Proposal: p, Follow: followProposal(p.ID)}, nil
-}
-
-// doWithdraw is the verb withdraw (§2): the proposal is marked, and the assigner deletes it and its candidates and says
-// placement-withdrawn carrying it whole.
-func (s *seatTools) doWithdraw(args map[string]any, by string) (any, error) {
-	why := arg(args, "why")
-	if why == "" {
-		return nil, errors.New("withdraw says why: it is kept in the event that ends the proposal")
-	}
-	p, err := s.proposal(arg(args, "id"))
-	if err != nil {
-		return nil, err
-	}
-	p.Withdrawn = fmt.Sprintf("withdrawn by %s: %s", by, why)
-	raw, err := delivery.EncodePlacementProposal(p)
-	if err != nil {
-		return nil, err
-	}
-	if err := s.st.put(delivery.PlacementProposalsState, p.ID, raw); err != nil {
-		return nil, fmt.Errorf("the proposal %s is not withdrawn: %w", p.ID, err)
-	}
-	return map[string]any{"proposal": p.ID, "withdrawn": p.Withdrawn}, nil
-}
-
-// doAgain is the verb again (§10): the proposal is marked, and the assigner judges it now and raises its ask again
-// when its verdict passes.
-func (s *seatTools) doAgain(args map[string]any) (any, error) {
-	p, err := s.proposal(arg(args, "id"))
-	if err != nil {
-		return nil, err
-	}
-	p.Again = s.now().UTC()
-	raw, err := delivery.EncodePlacementProposal(p)
-	if err != nil {
-		return nil, err
-	}
-	if err := s.st.put(delivery.PlacementProposalsState, p.ID, raw); err != nil {
-		return nil, fmt.Errorf("the proposal %s is not asked again: %w", p.ID, err)
-	}
-	return map[string]any{"proposal": p.ID, "again": p.Again, "follow": followProposal(p.ID)}, nil
-}
-
-// exportCall is the controller's verb the seed is read from, by request and reply on its seat (§7).
-const exportCall = "seat:" + catalogue.ControllerSeatName + ".placement-export"
-
-// doAdopt is the verb adopt (§7): the controller's export proposed whole as the seed.
-func (s *seatTools) doAdopt(args map[string]any, by string) (any, error) {
-	current, _, err := s.placements()
-	if err != nil {
-		return nil, err
-	}
-	if len(current) > 0 {
-		return nil, fmt.Errorf("placement is taken over already (%d keys): propose a change instead, or hand it back first", len(current))
-	}
-	if ids, err := s.st.keys(delivery.PlacementProposalsState); err == nil {
-		for _, id := range ids {
-			if p, err := s.proposal(id); err == nil && p.Seed {
-				return nil, fmt.Errorf("the seed %s is open: withdraw it first, or answer its ask", id)
-			}
-		}
-	}
-	raw, err := s.ask(exportCall, map[string]any{})
-	if err != nil {
-		return nil, fmt.Errorf("the controller's placement-export did not answer: %w", err)
-	}
-	export, err := assign.ExportOf(raw)
-	if err != nil {
-		return nil, err
-	}
-	held, recorded, err := s.lays()
-	if err != nil {
-		return nil, err
-	}
-	now := s.now()
-	p, laid, findings := assign.Propose(assign.ProposeIn{ID: delivery.NewProposalID(now), By: by, Why: arg(args, "why"), At: now,
-		Changes: assign.SeedChanges(export), Current: map[string]delivery.Placement{}, Revisions: map[string]uint64{},
-		Held: held, Recorded: recorded, Seed: true, ExportDigest: delivery.ExportDigest(export), Leased: s.leased()})
-	if len(findings) > 0 {
-		return nil, fmt.Errorf("the seed is refused: %s", strings.Join(findings, "; "))
-	}
-	if err := s.write(p, laid); err != nil {
-		return nil, err
-	}
-	return proposed{Proposal: p, Follow: followProposal(p.ID)}, nil
-}
-
-// leased says the controller's lease is handed away (mesh-sdk buscompose.LeaseHandedAway, ADR 0561 §3; issue 774): the lease
-// write of ADR 0547 that ends keeping the controller in step (ADR 0567 §8). A lease not read, a controller's, expired or
-// unreadable, is not handed away.
-func (s *seatTools) leased() bool {
-	raw, _, found, err := s.st.get(buscompose.ControllerLease, buscompose.ControllerLeaseKey)
-	away, _ := buscompose.LeaseHandedAway(raw, found && raw != nil, err)
-	return away
-}
-
-// handActCall records a hand act in the controller's hand-act log.
-const handActCall = "seat:" + catalogue.ControllerSeatName + ".hand-act"
-
-// doHandBack is the verb hand-back (§7): the operator's alone, so it is asked as a proposal is. It writes a hand-back
-// proposal naming every key at its revision; the assigner raises its authorising ask and, on its warrant, deletes the keys,
-// records the hand act and says placement-changed; every node returns to the controller's compositions.
-func (s *seatTools) doHandBack(args map[string]any, by string) (any, error) {
-	if s.leased() {
-		return nil, errors.New("placement is the mesh's alone since the lease write: there is no controller to hand it back to")
-	}
-	why := arg(args, "why")
-	if why == "" {
-		return nil, errors.New("hand-back says why: it is recorded with the hand act")
-	}
-	if by == "" {
-		return nil, errors.New("the runtime names no caller: a hand-back is made by someone")
-	}
-	_, revs, err := s.placements()
-	if err != nil {
-		return nil, err
-	}
-	if len(revs) == 0 {
-		return nil, errors.New("there is no placement key to hand back")
-	}
-	now := s.now()
-	p := delivery.PlacementProposal{ID: delivery.NewProposalID(now), By: by, Why: why, At: now.UTC(), Written: now.UTC(),
-		HandBack: true, Base: revs, State: delivery.ProposalAnswering}
-	raw, err := delivery.EncodePlacementProposal(p)
-	if err != nil {
-		return nil, err
-	}
-	if err := s.st.put(delivery.PlacementProposalsState, p.ID, raw); err != nil {
-		return nil, fmt.Errorf("the hand-back is not written: %w", err)
-	}
-	return proposed{Proposal: p, Follow: "the operator is asked to approve it; on the warrant every key is deleted and each " +
-		"node returns to the controller's compositions"}, nil
-}
-
-// placementAnswer is what the verb placement answers.
-type placementAnswer struct {
-	Keys    map[string]keyed `json:"keys,omitempty"`
-	Nodes   []string         `json:"nodes,omitempty"`
-	Count   int              `json:"count"`
-	History int              `json:"history-per-key"`
-	Changes []historyEntry   `json:"changes,omitempty"`
-	Older   string           `json:"older,omitempty"`
-}
-
-// historyEntry is one change of a key in the state's revisions.
-type historyEntry struct {
-	Node     string                   `json:"node"`
-	Revision uint64                   `json:"revision"`
-	At       time.Time                `json:"at"`
-	Change   delivery.PlacementChange `json:"change"`
-	Deleted  bool                     `json:"deleted,omitempty"`
-}
-
-// doPlacement is the verb placement (§10, §6): one node's key, one module's nodes, or every key; with history, the
-// changes in order from the revisions the state keeps.
-func (s *seatTools) doPlacement(args map[string]any) (any, error) {
-	all, revs, err := s.placements()
-	if err != nil {
-		return nil, err
-	}
-	node, module := arg(args, "node"), arg(args, "module")
-	out := placementAnswer{Keys: map[string]keyed{}, Count: len(all), History: delivery.PlacementHistory}
-	for n, p := range all {
-		if node != "" && n != node {
-			continue
-		}
-		if module != "" && !strings.Contains(" "+strings.Join(p.Assigned(), " ")+" ", " "+module+" ") {
-			continue
-		}
-		out.Keys[n] = keyed{Placement: p, Revision: revs[n]}
-		out.Nodes = append(out.Nodes, n)
-	}
-	sort.Strings(out.Nodes)
-	if node != "" && len(out.Keys) == 0 && arg(args, "history") != "true" {
-		return nil, fmt.Errorf("%s has no placement key", node)
-	}
-	if arg(args, "history") != "true" {
-		return out, nil
-	}
-	nodes := out.Nodes
-	if node != "" {
-		nodes = []string{node}
-	} else if module == "" {
-		nodes = nil
-		for n := range all {
-			nodes = append(nodes, n)
-		}
-		sort.Strings(nodes)
-	}
-	for _, n := range nodes {
-		key, err := delivery.PlacementKey(n)
-		if err != nil {
-			return nil, err
-		}
-		revisions, err := s.st.history(delivery.PlacementState, key)
-		if err != nil {
-			return nil, fmt.Errorf("the history of %s cannot be read: %w", key, err)
-		}
-		var before delivery.Placement
-		for _, r := range revisions {
-			e := historyEntry{Node: n, Revision: r.Revision, At: r.At}
-			after := delivery.Placement{}
-			if r.Op == "" || r.Op == "put" || r.Op == "PUT" {
-				if p, err := delivery.DecodePlacement(r.Value); err == nil {
-					after = p
-				}
-			} else {
-				e.Deleted = true
-			}
-			e.Change = delivery.ChangeOf(before, after)
-			e.Change.Before, e.Change.After = 0, r.Revision
-			before = after
-			if module != "" && !strings.Contains(" "+strings.Join(append(append(e.Change.Added, e.Change.Removed...), e.Change.Changed...), " ")+" ", " "+module+" ") {
-				continue
-			}
-			out.Changes = append(out.Changes, e)
-		}
-	}
-	out.Older = fmt.Sprintf("the state keeps %d revisions of each key; an older change is in its placement-changed event on "+
-		"the assigner's stream %s, kept %d days", delivery.PlacementHistory, delivery.PlacementStream, delivery.PlacementStreamDays)
-	return out, nil
-}
-
-// openProposal is one open proposal as the verb proposals answers it: the proposal (its changes, base revisions,
-// verdict with the differences and the answers it judged, its ask), its candidates by node with their revisions, and
-// every node's answer now.
-type openProposal struct {
-	Proposal   delivery.PlacementProposal          `json:"proposal"`
-	Candidates map[string]uint64                   `json:"candidates"`
-	Answers    map[string]delivery.CandidateAnswer `json:"answers,omitempty"`
-}
-
-// doProposals is the verb proposals (§10).
-func (s *seatTools) doProposals(args map[string]any) (any, error) {
-	ids, err := s.st.keys(delivery.PlacementProposalsState)
-	if err != nil {
-		return nil, fmt.Errorf("the proposals cannot be listed: %w", err)
-	}
-	cands, err := s.st.keys(delivery.PlacementCandidatesState)
-	if err != nil {
-		return nil, fmt.Errorf("the candidates cannot be listed: %w", err)
-	}
-	haves, err := s.st.keys(haveState)
-	if err != nil {
-		return nil, fmt.Errorf("the nodes' haves cannot be listed: %w", err)
-	}
-	answers := map[string]map[string]delivery.CandidateAnswer{} // by proposal, then node
-	for _, k := range haves {
-		node, _, isNode, err := delivery.ParseHaveKey(k)
-		if err != nil || !isNode {
-			continue
-		}
-		raw, _, found, err := s.st.get(haveState, k)
-		if err != nil || !found {
-			continue
-		}
-		h, err := delivery.DecodeHaveNode(raw)
-		if err != nil {
-			continue
-		}
-		for id, a := range h.Candidates {
-			if answers[id] == nil {
-				answers[id] = map[string]delivery.CandidateAnswer{}
-			}
-			answers[id][node] = a
-		}
-	}
-	sort.Strings(ids)
-	out := []openProposal{}
-	for _, id := range ids {
-		if want := arg(args, "id"); want != "" && want != id {
-			continue
-		}
-		p, err := s.proposal(id)
-		if err != nil {
-			return nil, err
-		}
-		o := openProposal{Proposal: p, Candidates: map[string]uint64{}, Answers: answers[id]}
-		for _, k := range cands {
-			pid, node, err := delivery.ParsePlacementCandidateKey(k)
-			if err != nil || pid != id {
-				continue
-			}
-			if _, rev, found, err := s.st.get(delivery.PlacementCandidatesState, k); err == nil && found {
-				o.Candidates[node] = rev
-			}
-		}
-		out = append(out, o)
-	}
-	if arg(args, "id") != "" && len(out) == 0 {
-		return nil, fmt.Errorf("no proposal %s is open", arg(args, "id"))
-	}
-	return map[string]any{"proposals": out}, nil
-}
-
-// tools are the seat's verbs as the runtime serves them, each named <seat>.<verb> (the tool runner serves a seat's verb
-// only from a tool of that name), with the seat's own schemas.
-func (s *seatTools) tools() []stdio.Tool {
-	seat, _ := catalogue.SeatNamed(catalogue.PlacementSeat)
-	input := map[string]map[string]any{}
-	description := map[string]string{}
-	for _, v := range seat.Serves {
-		input[v.Name], description[v.Name] = v.Input, v.Description
-	}
-	run := map[string]func(map[string]any) (any, error){
-		catalogue.PlacementVerbPlacement: s.doPlacement,
-		catalogue.PlacementVerbProposals: s.doProposals,
-		catalogue.PlacementVerbPropose:   func(a map[string]any) (any, error) { return s.doPropose(a, stdio.CallerOf(a)) },
-		catalogue.PlacementVerbWithdraw:  func(a map[string]any) (any, error) { return s.doWithdraw(a, stdio.CallerOf(a)) },
-		catalogue.PlacementVerbAgain:     s.doAgain,
-		catalogue.PlacementVerbAdopt:     func(a map[string]any) (any, error) { return s.doAdopt(a, stdio.CallerOf(a)) },
-		catalogue.PlacementVerbHandBack:  func(a map[string]any) (any, error) { return s.doHandBack(a, stdio.CallerOf(a)) },
-	}
-	var out []stdio.Tool
-	for _, v := range seat.Serves {
-		out = append(out, stdio.Tool{Name: catalogue.PlacementSeat + "." + v.Name, Description: description[v.Name], Input: input[v.Name], Run: run[v.Name]})
-	}
-	return out
-}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/seat_tools_test.go

@@ -1,167 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"os"
-	"slices"
-	"strings"
-	"testing"
-	"time"
-
-	stdio "git.novox.be/novox/mesh-sdk/go"
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
-	"git.novox.be/novox/mesh-sdk/go/catalogue"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-func (s memStore) del(state, key string) error {
-	delete(s[state].values, key)
-	return nil
-}
-
-func (s memStore) history(state, key string) ([]stdio.StateRevision, error) {
-	v, ok := s[state].values[key]
-	if !ok {
-		return nil, nil
-	}
-	return []stdio.StateRevision{{Key: key, Value: v, Revision: uint64(len(v)), Op: "put"}}, nil
-}
-
-// ADR 0567 §2, §7, §10: the seat's seven verbs over the states. propose lays a proposal and writes it with its candidates,
-// or refuses naming every finding and writes nothing; withdraw and again mark it for the holder; adopt proposes the
-// controller's export whole as the seed, once; hand-back records the hand act and deletes every key; placement and
-// proposals read every state the seat keeps, and history names the stream for what the state no longer keeps.
-func TestTheSeatsVerbs(t *testing.T) {
-	anchor := delivery.Placement{V: delivery.Version, Node: "anchor", Modules: []delivery.PlacedModule{{Module: "web"}}}
-	st := memStore{}
-	for _, state := range []string{delivery.PlacementState, delivery.PlacementProposalsState, delivery.PlacementCandidatesState, modulesState, haveState} {
-		st[state] = &memKV{values: map[string][]byte{}}
-	}
-	for _, m := range []string{"web", "shell"} {
-		st[modulesState].values[m] = []byte("{}")
-	}
-	for _, n := range []string{"anchor", "laptop"} {
-		raw, _ := delivery.EncodeHaveNode(delivery.HaveNode{Record: &delivery.NodeRecord{Node: n}})
-		st[haveState].values[n+".node"] = raw
-	}
-	export, _ := json.Marshal(map[string]any{"anchor": anchor})
-	var asked []string
-	s := newSeatTools(st, func(key string, body any) (json.RawMessage, error) {
-		asked = append(asked, key)
-		if key == exportCall {
-			out, _ := json.Marshal(map[string]any{"ok": true, "output": string(export)})
-			return out, nil
-		}
-		return json.RawMessage(`{"ok":true}`), nil
-	})
-	s.now = func() time.Time { return time.Date(2026, 10, 28, 20, 0, 0, 0, time.UTC) }
-
-	// adopt: the export proposed whole as the seed, once.
-	got, err := s.doAdopt(map[string]any{"why": "take over"}, "operator@laptop")
-	if err != nil {
-		t.Fatal(err)
-	}
-	seed := got.(proposed).Proposal
-	if !seed.Seed || seed.ExportDigest != delivery.ExportDigest(map[string]delivery.Placement{"anchor": anchor}) || !slices.Equal(asked, []string{exportCall}) ||
-		len(st[delivery.PlacementCandidatesState].values) != 1 || st[delivery.PlacementProposalsState].values[seed.ID] == nil {
-		t.Fatalf("adopt = %+v, asked %v", seed, asked)
-	}
-	if _, err := s.doAdopt(map[string]any{"why": "again"}, "op"); err == nil || !strings.Contains(err.Error(), "is open") {
-		t.Errorf("a second adopt with a seed open: %v", err)
-	}
-	// withdraw and again mark the proposal; the holder ends or judges it.
-	if _, err := s.doWithdraw(map[string]any{"id": seed.ID, "why": "not yet"}, "op"); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := s.doAgain(map[string]any{"id": seed.ID}); err != nil {
-		t.Fatal(err)
-	}
-	if p, err := s.proposal(seed.ID); err != nil || !strings.Contains(p.Withdrawn, "not yet") || p.Again.IsZero() {
-		t.Errorf("marked = %+v, %v", p, err)
-	}
-	if _, err := s.doWithdraw(map[string]any{"id": "p-none", "why": "x"}, "op"); err == nil {
-		t.Error("an unknown proposal was withdrawn")
-	}
-	delete(st[delivery.PlacementProposalsState].values, seed.ID) // the holder ended it
-	st[delivery.PlacementCandidatesState].values = map[string][]byte{}
-
-	// propose: refused whole, naming every finding; a valid move laid over the keys at their revisions.
-	raw, _ := delivery.EncodePlacement(anchor)
-	st[delivery.PlacementState].values["placement.anchor"] = raw
-	if _, err := s.doPropose(map[string]any{"why": "x", "changes": `[{"op":"place","node":"anchor","module":"ghost"},{"op":"hold","node":"anchor","module":"web","claim":"x"}]`}, "op"); err == nil ||
-		!strings.Contains(err.Error(), "ghost") || !strings.Contains(err.Error(), "lease write") || len(st[delivery.PlacementProposalsState].values) != 0 {
-		t.Errorf("a refused proposal: %v", err)
-	}
-	if _, err := s.doPropose(map[string]any{"why": "x", "changes": `[{"op":"swap","node":"anchor"}]`}, "op"); err == nil {
-		t.Error("an unknown change was taken")
-	}
-	got, err = s.doPropose(map[string]any{"why": "move web", "changes": []any{
-		map[string]any{"op": "take-off", "node": "anchor", "module": "web"}, map[string]any{"op": "place", "node": "laptop", "module": "web"}}}, "operator@laptop")
-	if err != nil {
-		t.Fatal(err)
-	}
-	move := got.(proposed).Proposal
-	if move.By != "operator@laptop" || move.Base["anchor"] != uint64(len(raw)) || move.Base["laptop"] != 0 || len(st[delivery.PlacementCandidatesState].values) != 2 {
-		t.Fatalf("propose = %+v", move)
-	}
-
-	// placement and proposals read every state the seat keeps (§10); history names the stream for what is older.
-	reads := map[string]bool{}
-	pa, err := s.doPlacement(map[string]any{"module": "web", "history": "true"})
-	if a := pa.(placementAnswer); err != nil || !slices.Equal(a.Nodes, []string{"anchor"}) || len(a.Changes) != 1 || !strings.Contains(a.Older, delivery.PlacementStream) {
-		t.Errorf("placement of web = %+v, %v", pa, err)
-	} else {
-		reads[delivery.PlacementState], reads["stream "+delivery.PlacementStream] = true, true
-	}
-	if _, err := s.doPlacement(map[string]any{"node": "laptop"}); err == nil {
-		t.Error("a node with no key was answered")
-	}
-	ps, err := s.doProposals(map[string]any{"id": move.ID})
-	if list := ps.(map[string]any)["proposals"].([]openProposal); err != nil || len(list) != 1 || len(list[0].Candidates) != 2 {
-		t.Errorf("proposals = %+v, %v", ps, err)
-	} else {
-		reads[delivery.PlacementProposalsState], reads[delivery.PlacementCandidatesState] = true, true
-	}
-	raw0, err := readManifest()
-	if err != nil {
-		t.Fatal(err)
-	}
-	for _, state := range raw0.State {
-		if slices.Contains([]string{delivery.PlacementState, delivery.PlacementProposalsState, delivery.PlacementCandidatesState}, state.Name) && !reads[state.Name] {
-			t.Errorf("no verb reads the seat's state %s", state.Name)
-		}
-	}
-	for _, stream := range raw0.Streams {
-		if !reads["stream "+stream.Name] {
-			t.Errorf("no verb reads the seat's stream %s", stream.Name)
-		}
-	}
-
-	// hand-back: the operator's alone, written as a hand-back proposal naming every key at its revision, for the assigner
-	// to ask; nothing is deleted by the verb.
-	got, err = s.doHandBack(map[string]any{"why": "back"}, "op")
-	if hb := got.(proposed).Proposal; err != nil || !hb.HandBack || hb.Base["anchor"] != uint64(len(raw)) || len(st[delivery.PlacementState].values) != 1 {
-		t.Errorf("hand-back = %+v, %v", got, err)
-	}
-	// Issue 774 (ADR 0567 §8): once the controller's lease is handed away a change its verbs cannot take is proposed, and
-	// there is no controller to hand placement back to.
-	st[buscompose.ControllerLease] = &memKV{values: map[string][]byte{buscompose.ControllerLeaseKey: []byte(`{"handed-to":"the operator's hand-over","handed-by":"person.jochen"}`)}}
-	if _, err := s.doPropose(map[string]any{"why": "hold", "changes": `[{"op":"hold","node":"anchor","module":"web","claim":"node-shell","scope":"node"}]`}, "op"); err != nil {
-		t.Errorf("a hold after the lease write: %v", err)
-	}
-	if _, err := s.doHandBack(map[string]any{"why": "back"}, "op"); err == nil || !strings.Contains(err.Error(), "since the lease write") {
-		t.Errorf("a hand-back after the lease write: %v", err)
-	}
-	if tools := s.tools(); len(tools) != 7 || tools[2].Name != "mesh-placement.propose" || tools[2].Run == nil || tools[2].Input == nil {
-		t.Errorf("the seat's verbs as served: %+v", tools)
-	}
-}
-
-// readManifest is the module's manifest, read as the controller reads it.
-func readManifest() (catalogue.Manifest, error) {
-	raw, err := os.ReadFile("../../module.json")
-	if err != nil {
-		return catalogue.Manifest{}, err
-	}
-	return catalogue.ParseManifest(raw)
-}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/tools.go

@@ -18,8 +18,8 @@ import (
 
 // The assigner's tools (novox/hq ADR 0546), served through the tool runner from its bundle: a process never serves (ADR
 // 0436, mesh-sdk process). They write and read the puts; the assigner's process takes each put further (puts.go) and says
-// every step as the event put. They are the module's own tools; the seat mesh-placement's verbs are served beside them
-// (seat_tools.go, ADR 0567 §10).
+// every step as the event put. They are the module's own tools, not a seat's verbs: a new seat needs a change of the
+// controller, which takes none; they become the verbs of a seat once composing leaves the controller.
 
 // putsState is the assigner's state of puts, as the runtime names a module's own state.
 const putsState = "puts"
@@ -351,7 +351,7 @@ func serveTools() error {
 			time.Sleep(wait)
 		}
 	}()
-	return stdio.Serve("", append(s.tools(), newSeatTools(runtimeStore{}, stdio.Ask).tools()...))
+	return stdio.Serve("", s.tools())
 }
 
 // shortFP is a fingerprint's first twelve hex digits.

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/world.go

@@ -13,7 +13,6 @@ import (
 
 	"github.com/nats-io/nats.go/jetstream"
 
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/compose"
 	"git.novox.be/novox/mesh-sdk/go/compose/frombus"
@@ -193,41 +192,24 @@ func (w *world) manifest(ctx context.Context, get getter, digest string) parsed
 	return p
 }
 
-// assigned is each node's modules both the controller's assignments and the seat mesh-placement's placement name, in name order
+// assigned is each node's modules both the controller's assignments and the indexer's placement name, in name order
 // (ADR 0549 §5; the assignments alone before any placement was read), with every open assignment by node and module.
-// Once the controller's lease is handed away it is the seat's placement alone, with no assignment (ADR 0549 §5, §6).
 func (w *world) assigned() (map[string][]string, map[string]assignment) {
-	// A lease handed away before any placement was read keeps the assignments as they last stood, never an empty mesh:
-	// the lease write's own check refuses that order (ADR 0547 §11).
-	placed, seeded := w.placed()
 	byAssignment, all := w.assignedByController()
-	if away := w.handedAway(); away && seeded {
-		both, _ := assign.Placed(byAssignment, placed, seeded, away)
-		return both, map[string]assignment{}
-	}
-	both, _ := assign.Placed(byAssignment, placed, seeded, false)
+	placed, seeded := w.placed()
+	both, _ := assign.Placed(byAssignment, placed, seeded)
 	return both, all
 }
 
-// placementDiffers is every pair the controller's assignments and the seat's placement do not both name: none once
-// the controller's lease is handed away, since the placement is then the one source.
+// placementDiffers is every pair the controller's assignments and the indexer's placement do not both name.
 func (w *world) placementDiffers() []assign.Pair {
-	placed, seeded := w.placed()
 	byAssignment, _ := w.assignedByController()
-	_, differ := assign.Placed(byAssignment, placed, seeded, w.handedAway())
+	placed, seeded := w.placed()
+	_, differ := assign.Placed(byAssignment, placed, seeded)
 	return differ
 }
 
-// handedAway says the controller's lease is handed to a holder that is no controller (mesh-sdk buscompose.LeaseHandedAway,
-// ADR 0561 §3): from then the seat mesh-placement's placement alone names where modules run (ADR 0549 §5). A lease not read (its
-// bucket not granted or not there), a controller's, expired or unreadable, is not handed away.
-func (w *world) handedAway() bool {
-	raw, found := w.read(buscompose.LeaseBucket)[buscompose.ControllerLeaseKey]
-	away, _ := buscompose.LeaseHandedAway(raw, found && raw != nil, nil)
-	return away
-}
-
-// placed is each node's modules in the seat's placement (ADR 0567 §1), and whether any placement key was read: a key
+// placed is each node's modules in the indexer's placement (ADR 0549 §2), and whether any placement key was read: a key
 // that does not read places nothing on its node and is said by the indexer's own read tool.
 func (w *world) placed() (map[string][]string, bool) {
 	out := map[string][]string{}
@@ -246,7 +228,7 @@ func (w *world) placed() (map[string][]string, bool) {
 	return out, len(values) > 0
 }
 
-// placedNodes is every node the seat's placement names (ADR 0567 §1): those compose their own modules (ADR 0547 §2),
+// placedNodes is every node the indexer's placement names (ADR 0549 §2): those compose their own modules (ADR 0547 §2),
 // so their wants name the build alone and the seventh rule does not hold them.
 func (w *world) placedNodes() map[string]bool {
 	placed, _ := w.placed()
@@ -320,7 +302,7 @@ func (w *world) mesh(ctx context.Context, manifests getter) assign.Mesh {
 	return m
 }
 
-// worldReader is what the assigner watched as frombus reads the bus: the seat's placement, the indexer's modules, each node's
+// worldReader is what the assigner watched as frombus reads the bus: the indexer's placement and modules, each node's
 // record in its own have key, the manifests by digest; the check reads no config value, own secret or credential (the
 // composition it asks resolves, and stands in for what it does not carry).
 type worldReader struct {
@@ -376,25 +358,7 @@ func (r worldReader) Manifest(ctx context.Context, digest string) ([]byte, error
 	return []byte(m.JSON), nil
 }
 
-// Values is one module's config values on one node as mesh-config resolved them, each a value its source lays
-// (catalogue.LaidValue): the holder composes every node a proposal touches with them (ADR 0567 §9).
-func (r worldReader) Values(_ context.Context, node, module string) (map[string]any, error) {
-	var out map[string]any
-	prefix := node + "." + module + "."
-	for key, raw := range r.w.read(buscompose.ResolvedBucket) {
-		name, ok := strings.CutPrefix(key, prefix)
-		if !ok || strings.Contains(name, ".") {
-			continue
-		}
-		if v, laid := catalogue.LaidValue(raw); laid {
-			if out == nil {
-				out = map[string]any{}
-			}
-			out[name] = v
-		}
-	}
-	return out, nil
-}
+func (worldReader) Values(context.Context, string, string) (map[string]any, error) { return nil, nil }
 
 func (worldReader) OwnSecrets(context.Context, string) ([]compose.OwnSecretRow, error) {
 	return nil, nil
@@ -404,8 +368,8 @@ func (worldReader) Credentials(context.Context, string, []compose.CredentialKey,
 	return nil, nil, nil
 }
 
-// Build and Archive are read only for a node composing itself (frombus.Scope without Every): the check of every node
-// composes from the manifests the indexer read, and reads no build and no archive.
+// Build, Archive and Served are read only for a node composing itself (frombus.Scope without Every): the check of every
+// node composes from the manifests the indexer read, reads no build and no archive, and reads no config value.
 func (worldReader) Build(context.Context, string, string) (*delivery.BuilderBuild, error) {
 	return nil, nil
 }
@@ -414,18 +378,8 @@ func (worldReader) Archive(_ context.Context, url, _ string) ([]byte, error) {
 	return nil, fmt.Errorf("the composition check reads no archive (%s)", url)
 }
 
-func (r worldReader) Served(ctx context.Context, node, module string, keys []string) (map[string]any, error) {
-	all, err := r.Values(ctx, node, module)
-	var out map[string]any
-	for _, k := range keys {
-		if v, ok := all[k]; ok {
-			if out == nil {
-				out = map[string]any{}
-			}
-			out[k] = v
-		}
-	}
-	return out, err
+func (worldReader) Served(context.Context, string, string, []string) (map[string]any, error) {
+	return nil, nil
 }
 
 // change is a candidate's change for the composition check, or why the composition waits for it.
@@ -477,9 +431,77 @@ func (w *world) change(ctx context.Context, manifests getter, c delivery.Candida
 			sort.Strings(ch.Twice[name])
 		}
 	}
+	cp, waits := w.placementOf(ctx, manifests, c)
+	if waits != "" {
+		return ch, waits
+	}
+	ch.Placement = cp
 	return ch, ""
 }
 
+// placementOf is the change's own placement (ADR 0559 §5): the indexer's placement candidates of the group's catalogue
+// pull request, with the input the nodes compose from with them laid over the trunk's placement. None when the group has
+// no catalogue pull request or it changes no placement file. It waits while a key names another head than the group's.
+func (w *world) placementOf(ctx context.Context, manifests getter, c delivery.Candidate) (*assign.ChangePlacement, string) {
+	var pull *delivery.CandidatePull
+	for i := range c.Pulls {
+		if delivery.SameRepository(c.Pulls[i].Repository, delivery.CatalogueRepository) {
+			pull = &c.Pulls[i]
+		}
+	}
+	if pull == nil {
+		return nil, ""
+	}
+	cp := &assign.ChangePlacement{Placements: map[string]*delivery.Placement{}, Revisions: map[string]uint64{}, Head: pull.Head.Head}
+	for key, value := range w.read(delivery.PlacementCandidatesBucket) {
+		group, node, err := delivery.ParsePlacementCandidateKey(key)
+		if err != nil || group != c.Group {
+			continue
+		}
+		pc, err := delivery.DecodePlacementCandidate(value)
+		if err != nil || pc.Pull.Number != pull.Number || !delivery.SameRepository(pc.Pull.Repository, pull.Repository) {
+			continue
+		}
+		if pc.Pull.Head != pull.Head.Head {
+			return nil, fmt.Sprintf("the indexer holds the placement candidates of %s#%d at %s, not yet at its head %s", pull.Repository, pull.Number, pc.Pull.Head, pull.Head.Head)
+		}
+		meta := w.metaOf(delivery.PlacementCandidatesBucket, key)
+		cp.Placements[node], cp.Revisions[node] = pc.Placement, meta.revision
+		if meta.at.After(cp.Written) {
+			cp.Written = meta.at
+		}
+	}
+	if len(cp.Placements) == 0 {
+		return nil, ""
+	}
+	in, err := frombus.Input(ctx, worldReader{w: w, manifests: manifests}, frombus.Mesh{}, frombus.Scope{Every: true, Placements: cp.Placements})
+	if err != nil {
+		cp.Unread = err.Error()
+	} else {
+		cp.Input = &in
+	}
+	return cp, ""
+}
+
+// candidateAnswers is, by node, each node's answer to the group's placement candidates in its `<node>.node` have.
+func (w *world) candidateAnswers(group string) map[string]*delivery.CandidateAnswer {
+	out := map[string]*delivery.CandidateAnswer{}
+	for key, value := range w.read(delivery.HaveBucket) {
+		node, _, isNode, err := delivery.ParseHaveKey(key)
+		if err != nil || !isNode {
+			continue
+		}
+		h, err := delivery.DecodeHaveNode(value)
+		if err != nil {
+			continue
+		}
+		if a, ok := h.Candidates[group]; ok {
+			out[node] = &a
+		}
+	}
+	return out
+}
+
 // online is, by node, whether the watchman holds the node online.
 func (w *world) online() map[string]bool {
 	out := map[string]bool{}
@@ -563,16 +585,6 @@ func (w *world) value(bucket, key string) []byte {
 	return w.values[bucket][key]
 }
 
-// grantsBucket is the bucket the grants are read from now (delivery.GrantSource): the grants part's while the controller's
-// lease is handed away, as the lease bucket's key says it (buscompose.LeaseHandedAway), the controller's in every other
-// case, a lease not held here included.
-func (w *world) grantsBucket() string {
-	raw := w.value(buscompose.LeaseBucket, buscompose.ControllerLeaseKey)
-	away, _ := buscompose.LeaseHandedAway(raw, raw != nil, nil)
-	bucket, _ := delivery.GrantSource(away)
-	return bucket
-}
-
 // has says whether a bucket holds a key now.
 func (w *world) has(bucket, key string) bool {
 	w.mu.Lock()

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/world_test.go

@@ -6,9 +6,7 @@ import (
 	"slices"
 	"strings"
 	"testing"
-	"time"
 
-	"git.novox.be/novox/mesh-sdk/go/buscompose"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 
 	"mesh-delivery-assigner/internal/assign"
@@ -50,7 +48,6 @@ func pull(repo string, number int, modules map[string]delivery.CandidateModule)
 // module with no manifest in the preview as removed, a mesh-sdk member's head, and a module the trunk holds from
 // another repository as defined twice.
 func TestTheChangeOfACandidate(t *testing.T) {
-	theWorldCountsTheValuesAKeyTakes(t)
 	f := fakeManifests{}
 	web := f.add(t, "web", `{"module":"web","version":"2"}`)
 	mail := f.add(t, "mail", `{"module":"mail","version":"1"}`)
@@ -116,7 +113,7 @@ func TestAManifestFallingBackToAPredefinedKeyIsReadable(t *testing.T) {
 }
 
 // Review round 1 (items 3 and 4): the world counts the values a key takes, so a have written again after an answer is seen.
-func theWorldCountsTheValuesAKeyTakes(t *testing.T) {
+func TestTheWorldCountsTheValuesAKeyTakes(t *testing.T) {
 	w := newWorld()
 	w.put(delivery.HaveBucket, "ace.web", []byte(`{"v":1}`))
 	w.put(delivery.HaveBucket, "ace.web", []byte(`{"v":1}`))
@@ -127,40 +124,4 @@ func theWorldCountsTheValuesAKeyTakes(t *testing.T) {
 	if got := w.changed(delivery.HaveBucket, "gone"); got != 0 {
 		t.Errorf("changed = %d for a key never seen", got)
 	}
-	// Issue 774: grants are read from the grants part's bucket only while the controller's lease is handed away: a grant
-	// only the part holds lets a node's put through then, and with a controller's lease (or none, or an unreadable one) it
-	// holds it, a grant only the controller holds being the one that counts instead.
-	fp := delivery.SourcePrefix2 + strings.Repeat("d", 64)
-	gkey, _ := delivery.ControllerGrantKey("web", fp)
-	grant, _ := delivery.EncodeControllerGrant(delivery.ControllerGrant{Accounts: []string{"ace.web"}})
-	for _, row := range []struct {
-		name, lease          string
-		inPart, inController bool
-		bucket               string
-		granted              bool
-	}{
-		{"handed away, the part's grant", `{"handed-to":"the operator's hand-over"}`, true, false, delivery.PartGrantsBucket, true},
-		{"handed away, only the controller's grant", `{"handed-to":"x"}`, false, true, delivery.PartGrantsBucket, false},
-		{"a controller holds it, only the part's grant", `{"instance":"novox/1","epoch":3}`, true, false, delivery.ControllerGrantsBucket, false},
-		{"a controller holds it, its own grant", `{"instance":"novox/1"}`, false, true, delivery.ControllerGrantsBucket, true},
-		{"no lease read", ``, true, false, delivery.ControllerGrantsBucket, false},
-		{"an unreadable lease", `[1]`, true, false, delivery.ControllerGrantsBucket, false},
-	} {
-		p := newPasser(buckets{}, time.Now())
-		if row.lease != "" {
-			p.w.put(buscompose.LeaseBucket, buscompose.ControllerLeaseKey, []byte(row.lease))
-		}
-		if row.inPart {
-			p.w.put(delivery.PartGrantsBucket, gkey, grant)
-		}
-		if row.inController {
-			p.w.put(delivery.ControllerGrantsBucket, gkey, grant)
-		}
-		if got := p.w.grantsBucket(); got != row.bucket {
-			t.Errorf("%s: grants are read from %s, want %s", row.name, got, row.bucket)
-		}
-		if _, granted := p.composedFor("ace", "web", fp); granted != row.granted {
-			t.Errorf("%s: granted = %v, want %v", row.name, granted, row.granted)
-		}
-	}
 }

modules/mesh-delivery-assigner/go.mod

@@ -3,7 +3,7 @@ module mesh-delivery-assigner
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027201213-7a8e9f970648
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-delivery-assigner/go.sum

@@ -1,5 +1,7 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a h1:nhRFmtdcI4VkghGUdJhpt1BnPuTQcekioOIRzW8fcG0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952 h1:TmveT3Bija643RGWkilvkzP/h8UWlVvHFZZtQfJK5oU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027201213-7a8e9f970648 h1:XoMsgg9kSgjQWa86NZM8h8OpxJ2kovxcMS2C0i6WSVU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027201213-7a8e9f970648/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-delivery-assigner/internal/assign/candidates.go

@@ -0,0 +1,242 @@
+package assign
+
+import (
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/compose"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+// A change's own placement (novox/hq ADR 0559 §5, issue 1126): a catalogue pull request that changes placement files has
+// the indexer's placement candidates, one key `<group>.<node>` for each node whose file at its head differs from the
+// trunk's. The check composes the change with those placements laid over the trunk's (frombus, Scope.Placements), counts
+// every such node among the machines it touches, and then reads each placed node's own answer in its `<node>.node`
+// have: it fails on what a node composes differently that the change does not intend, on a refusal, and on a node
+// placed at the head or on the trunk that has not answered at the head within AnswerBound of the keys being written.
+
+// AnswerBound is how long the check waits for every placed node's answer after the candidate keys were written (ADR 0559
+// §5): a node asleep or away is named past it, never passed. A variable so a test on the bus can shorten it.
+var AnswerBound = 10 * time.Minute
+
+// ChangePlacement is the change's own placement, read from the indexer's placement candidates of its group.
+type ChangePlacement struct {
+	// Placements is by node the candidate placement; nil when the head removes the node's file.
+	Placements map[string]*delivery.Placement
+	// Revisions is by node the revision of its candidate key: the answer to it names that revision.
+	Revisions map[string]uint64
+	// Head is the catalogue pull request's head the candidates were read at, and Written when the newest key was written.
+	Head    string
+	Written time.Time
+	// Input is the trunk's composition input with Placements laid over it (frombus.Input, Scope.Placements), its catalogue
+	// the trunk's; nil with Unread saying why when it could not be read.
+	Input  *compose.Input
+	Unread string
+}
+
+// Nodes is every node the change's placement names, sorted.
+func (p *ChangePlacement) Nodes() []string {
+	if p == nil {
+		return nil
+	}
+	out := make([]string, 0, len(p.Placements))
+	for node := range p.Placements {
+		out = append(out, node)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// Intended is, by node the trunk places, the modules whose composition the change's placement changes: those it adds,
+// removes or whose placed entry differs, and those whose composition (with the trunk's catalogue, the same stand-ins
+// either side) differs between the trunk's input and the change's (delivery.CompareComposed), the node's own named
+// "node". A node the trunk does not place yet has none (ADR 0559 §5: at the seed every node must answer the same). fps
+// gives the build each module is composed at, the trunk's. A node whose compositions cannot be made either side keeps
+// the modules its placement entries name, and is said in notes.
+func Intended(trunk *compose.Input, trunkPlaced map[string]delivery.Placement, cp *ChangePlacement, fps map[string]string) (intended map[string]map[string]bool, notes []string) {
+	intended = map[string]map[string]bool{}
+	if cp == nil {
+		return intended, nil
+	}
+	for _, node := range cp.Nodes() {
+		before, placed := trunkPlaced[node]
+		if !placed {
+			continue
+		}
+		set := map[string]bool{}
+		after := cp.Placements[node]
+		var afterModules []delivery.PlacedModule
+		if after != nil {
+			afterModules = after.Modules
+		}
+		entries := map[string]delivery.PlacedModule{}
+		for _, m := range before.Modules {
+			entries[m.Module] = m
+		}
+		seen := map[string]bool{}
+		for _, m := range afterModules {
+			seen[m.Module] = true
+			if e, ok := entries[m.Module]; !ok || !reflect.DeepEqual(e, m) {
+				set[m.Module] = true
+			}
+		}
+		for name := range entries {
+			if !seen[name] {
+				set[name] = true
+			}
+		}
+		if trunk != nil && cp.Input != nil {
+			was, _, _, errB := compose.CompositionsShadow(*trunk, node, fps)
+			now, _, _, errA := compose.CompositionsShadow(*cp.Input, node, fps)
+			if errA == nil && errB == nil {
+				running := make([]delivery.Composed, 0, len(was))
+				for _, c := range was {
+					running = append(running, c)
+				}
+				cmp := delivery.CompareComposed(now, running)
+				for _, d := range cmp.Differs {
+					set[d.Module] = true
+				}
+				for _, d := range cmp.Added {
+					set[d.Module] = true
+				}
+				for _, m := range cmp.Removed {
+					set[m] = true
+				}
+			} else {
+				notes = append(notes, fmt.Sprintf("what the change intends on %s is read from its placement file alone: its compositions cannot be made (trunk: %v; change: %v)", node, errB, errA))
+			}
+		}
+		intended[node] = set
+	}
+	return intended, notes
+}
+
+// Answered is what the placed nodes answered: the failures to name, the nodes that have not answered, and the notes.
+type Answered struct {
+	Fails    []string
+	Silent   []string
+	Machine  string
+	Waits    bool
+	Until    time.Time
+	Warnings []string
+}
+
+// JudgeAnswers reads each placed node's answer to the change's placement (ADR 0559 §5). placed is every node placed at
+// the head or on the trunk; answers is by node its HaveNode.Candidates entry for the group, nil when it has none; online
+// says whether the watchman holds the node online. An answer counts when it names the candidates' head and, for a node
+// with a key of its own, that key's revision. It fails on a refusal, on a module that differs, is added or is removed
+// that intended does not name, and, from Written plus AnswerBound on, on every node with no answer that counts, named,
+// asleep or not; before that the check waits for them.
+func JudgeAnswers(cp *ChangePlacement, placed []string, answers map[string]*delivery.CandidateAnswer, intended map[string]map[string]bool, online map[string]bool, now time.Time) Answered {
+	var out Answered
+	if cp == nil {
+		return out
+	}
+	failAt := func(node, words string) {
+		if out.Machine == "" {
+			out.Machine = node
+		}
+		out.Fails = append(out.Fails, words)
+	}
+	for _, node := range placed {
+		a := answers[node]
+		rev, keyed := cp.Revisions[node]
+		if a == nil || a.Head != cp.Head || (keyed && a.Revision != rev) {
+			out.Silent = append(out.Silent, node)
+			continue
+		}
+		if a.Refused != "" {
+			failAt(node, fmt.Sprintf("%s cannot compose the candidate placement: %s", node, a.Refused))
+			continue
+		}
+		for _, r := range a.Refusals {
+			failAt(node, fmt.Sprintf("%s refuses the candidate placement for %s: %s", node, r.Module, r.Why))
+		}
+		want := intended[node]
+		for _, d := range a.Differs {
+			if !want[d.Module] {
+				failAt(node, fmt.Sprintf("%s composes %s differently with the candidate placement, which the change does not intend: %s", node, d.Module, d.Why))
+			}
+		}
+		for _, d := range a.Added {
+			if !want[d.Module] {
+				failAt(node, fmt.Sprintf("%s would run %s with the candidate placement, which the change does not intend", node, d.Module))
+			}
+		}
+		for _, m := range a.Removed {
+			if !want[m] {
+				failAt(node, fmt.Sprintf("%s would stop running %s with the candidate placement, which the change does not intend", node, m))
+			}
+		}
+	}
+	if len(out.Silent) == 0 {
+		return out
+	}
+	out.Until = cp.Written.Add(AnswerBound)
+	named := make([]string, len(out.Silent))
+	for i, node := range out.Silent {
+		named[i] = node
+		if !online[node] {
+			named[i] = node + " (offline)"
+		}
+	}
+	if now.Before(out.Until) {
+		out.Waits = true
+		out.Warnings = append(out.Warnings, fmt.Sprintf("waits for the answers of %s to the candidate placement at %s, until %s",
+			strings.Join(named, ", "), short(cp.Head), out.Until.UTC().Format(time.RFC3339)))
+		return out
+	}
+	for _, node := range out.Silent {
+		if out.Machine == "" {
+			out.Machine = node
+		}
+	}
+	out.Fails = append(out.Fails, fmt.Sprintf("%s %s (%s after the candidate keys were written at %s)",
+		strings.Join(named, ", "), delivery.CompositionUnanswered, AnswerBound, cp.Written.UTC().Format(time.RFC3339)))
+	return out
+}
+
+// PlacedNodes is every node placed at the head or on the trunk: the trunk's placed nodes with the change's placement laid
+// over them (a node whose file the head removes stays, as the trunk places it), sorted.
+func PlacedNodes(trunkPlaced map[string]delivery.Placement, cp *ChangePlacement) []string {
+	set := map[string]bool{}
+	for node := range trunkPlaced {
+		set[node] = true
+	}
+	if cp != nil {
+		for node, p := range cp.Placements {
+			if p != nil {
+				set[node] = true
+			}
+		}
+	}
+	out := make([]string, 0, len(set))
+	for node := range set {
+		out = append(out, node)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// WithAnswers is v with the placed nodes' answers judged in: a fail adds its failures (the words of nodes not heard end
+// with delivery.CompositionUnanswered, so the checker takes a later composition of the same heads in when they answer), a
+// wait makes a passing verdict wait (a composition that waits composed no machine), and a failing one stands.
+func WithAnswers(v delivery.CompositionVerdict, a Answered) delivery.CompositionVerdict {
+	if len(a.Fails) > 0 {
+		if v.State == delivery.CompositionFail {
+			v.Words += "; " + strings.Join(a.Fails, "; ")
+		} else {
+			v.State, v.Words, v.Machine = delivery.CompositionFail, strings.Join(a.Fails, "; "), a.Machine
+		}
+		return v
+	}
+	if a.Waits && v.State == delivery.CompositionPass {
+		return delivery.CompositionVerdict{Group: v.Group, Heads: v.Heads, State: delivery.CompositionWaits, SDK: v.SDK, Took: v.Took,
+			Words: strings.Join(a.Warnings, "; ")}
+	}
+	return v
+}

modules/mesh-delivery-assigner/internal/assign/compose.go

@@ -59,13 +59,15 @@ type Change struct {
 	// Members the head of each member by repository: what a composer at the group's mesh-sdk reads (issues 1622, 1623).
 	Digests map[string]string
 	Members map[string]string
+	// Placement is the change's own placement, read from the indexer's placement candidates of the group (ADR 0559 §5);
+	// nil when the group changes no placement file.
+	Placement *ChangePlacement
 }
 
 // Touched is the machines a change touches (ADR 0446 clause 3): those running a module the change moves, adds or
 // removes, those running a consumer of a provision such a module provides (before or after), and those running a
 // provider of a provision such a module requires after the change. A module the change adds that is assigned nowhere
-// touches no machine. A change of placement is no change of a repository (ADR 0567 §4): the seat
-// mesh-placement judges it.
+// touches no machine. Every node whose placement the change changes is touched too (ADR 0559 §5, changing ADR 0446 §3).
 func Touched(m Mesh, c Change) []string {
 	moved := map[string]bool{}
 	for name := range c.Manifests {
@@ -99,6 +101,11 @@ func Touched(m Mesh, c Change) []string {
 			}
 		}
 	}
+	for _, node := range c.Placement.Nodes() {
+		if !slices.Contains(out, node) {
+			out = append(out, node)
+		}
+	}
 	sort.Strings(out)
 	return out
 }
@@ -171,6 +178,25 @@ func Compose(m Mesh, c Change, sdk string, took time.Duration) delivery.Composit
 		delete(changed, name)
 	}
 	after := input(changed, m.Assigned)
+	if c.Placement != nil {
+		// A change of placement is composed over the input the nodes compose from, its placement laid over the trunk's
+		// (frombus, ADR 0559 §5): the trunk as the nodes compose it where the catalogue places them, the change's
+		// manifests over the trunk's catalogue.
+		if m.Input != nil {
+			trunk = *m.Input
+			trunk.Catalogue = withOverlay(m.Input.Catalogue, m.Manifests)
+		}
+		if c.Placement.Input == nil {
+			failAt("", "the change's placement cannot be composed: the input with it cannot be read from the bus: "+c.Placement.Unread)
+		} else {
+			after = *c.Placement.Input
+			cat := withOverlay(c.Placement.Input.Catalogue, changed)
+			for _, name := range c.Removed {
+				delete(cat, name)
+			}
+			after.Catalogue = cat
+		}
+	}
 	for _, node := range machines {
 		_, before := compose.Resolve(trunk, node)
 		_, now := compose.Resolve(after, node)

modules/mesh-delivery-assigner/internal/assign/compose_test.go

@@ -4,6 +4,7 @@ import (
 	"slices"
 	"strings"
 	"testing"
+	"time"
 
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
@@ -57,6 +58,79 @@ func TestAMachineTheChangeBreaksFails(t *testing.T) {
 	if v.State != delivery.CompositionFail || v.Machine != "ace" || !strings.Contains(v.Words, "database") {
 		t.Fatalf("composition = %+v, want a fail on ace naming the provision nothing provides", v)
 	}
+
+	// ADR 0559 §5 (issue 1126): a change of placement composes its placement laid over the trunk's input and fails naming
+	// the node it breaks: a module no manifest names placed on g14; ace,
+	// is no longer composed with it; a placement whose input cannot be read fails; a placement that breaks nothing passes, g14 touched.
+	m := meshOf()
+	placed := func(assigned map[string][]string) *ChangePlacement {
+		in := input(m.Manifests, assigned)
+		return &ChangePlacement{Placements: map[string]*delivery.Placement{"g14": {Node: "g14"}}, Input: &in}
+	}
+	for _, row := range []struct {
+		name    string
+		cp      *ChangePlacement
+		state   string
+		machine string
+		words   string
+	}{
+		{"a placement that breaks g14", placed(map[string][]string{"ace": {"mail", "store"}, "g14": {"web", "ghost"}}), delivery.CompositionFail, "g14", "ghost"},
+		{"a placement whose input is not read", &ChangePlacement{Placements: map[string]*delivery.Placement{"g14": nil}, Unread: "no record of g14"}, delivery.CompositionFail, "", "no record of g14"},
+		{"a placement that breaks nothing", placed(map[string][]string{"ace": {"mail", "store"}, "g14": {"web"}}), delivery.CompositionPass, "", ""},
+	} {
+		v := Compose(m, Change{Group: "g", Heads: "0123456789ab", Placement: row.cp}, "sdk", 0)
+		if v.State != row.state || v.Machine != row.machine || !strings.Contains(v.Words, row.words) || !slices.Contains(v.Machines, "g14") {
+			t.Errorf("%s: %+v", row.name, v)
+		}
+	}
+
+	// ADR 0559 §5: the placed nodes' answers. ace is placed on the trunk and its candidate moves web there (intended);
+	// g14 is not placed on the trunk (the seed), so nothing is intended there; novox is placed and unchanged.
+	at := time.Date(2026, 10, 27, 2, 0, 0, 0, time.UTC)
+	cp := &ChangePlacement{Head: "h2", Written: at, Revisions: map[string]uint64{"ace": 7, "g14": 8},
+		Placements: map[string]*delivery.Placement{"ace": {Node: "ace"}, "g14": {Node: "g14"}}}
+	intended := map[string]map[string]bool{"ace": {"web": true}}
+	same := func(rev uint64) *delivery.CandidateAnswer {
+		return &delivery.CandidateAnswer{Head: "h2", Revision: rev, Verdict: delivery.CandidateSame, Same: []string{"mail"}}
+	}
+	placedNodes := []string{"ace", "g14", "novox"}
+	for _, row := range []struct {
+		name    string
+		answers map[string]*delivery.CandidateAnswer
+		now     time.Time
+		state   string
+		words   string
+	}{
+		{"all the same", map[string]*delivery.CandidateAnswer{"ace": same(7), "g14": same(8), "novox": same(0)}, at, delivery.CompositionPass, ""},
+		{"a module added where intended", map[string]*delivery.CandidateAnswer{"ace": {Head: "h2", Revision: 7, Verdict: delivery.CandidateDiffers,
+			Added: []delivery.ModuleAdded{{Module: "web", Unissued: []string{"its own secret"}}}}, "g14": same(8), "novox": same(0)}, at, delivery.CompositionPass, ""},
+		{"a module differing where not intended", map[string]*delivery.CandidateAnswer{"ace": {Head: "h2", Revision: 7, Verdict: delivery.CandidateDiffers,
+			Differs: []delivery.ModuleDiffers{{Module: "mail", Why: "the port differs"}}}, "g14": same(8), "novox": same(0)}, at, delivery.CompositionFail, "ace composes mail differently"},
+		{"a node's first placement file with a module differing", map[string]*delivery.CandidateAnswer{"ace": same(7), "g14": {Head: "h2", Revision: 8, Verdict: delivery.CandidateDiffers,
+			Differs: []delivery.ModuleDiffers{{Module: "web", Why: "a binding differs"}}}, "novox": same(0)}, at, delivery.CompositionFail, "g14 composes web differently"},
+		{"a refusal", map[string]*delivery.CandidateAnswer{"ace": same(7), "g14": {Head: "h2", Revision: 8, Verdict: delivery.CandidateRefused,
+			Refusals: []delivery.ModuleRefused{{Module: "web", Why: "no own secret"}}}, "novox": same(0)}, at, delivery.CompositionFail, "g14 refuses"},
+		{"a node not answering, within its bound", map[string]*delivery.CandidateAnswer{"ace": same(7), "novox": same(0)}, at.Add(AnswerBound - time.Second), delivery.CompositionWaits, "g14 (offline)"},
+		{"an answer of an earlier revision, past its bound", map[string]*delivery.CandidateAnswer{"ace": same(6), "g14": same(8), "novox": same(0)}, at.Add(AnswerBound), delivery.CompositionFail, "ace " + delivery.CompositionUnanswered},
+		{"its later answer", map[string]*delivery.CandidateAnswer{"ace": same(7), "g14": same(8), "novox": same(0)}, at.Add(time.Hour), delivery.CompositionPass, ""},
+	} {
+		pass := delivery.CompositionVerdict{Group: "g", Heads: "0123456789ab", State: delivery.CompositionPass, SDK: "sdk", Machines: []string{"ace", "g14"}}
+		v := WithAnswers(pass, JudgeAnswers(cp, placedNodes, row.answers, intended, map[string]bool{"ace": true, "novox": true}, row.now))
+		if v.State != row.state || !strings.Contains(v.Words, row.words) {
+			t.Errorf("%s: %+v", row.name, v)
+		}
+		if _, err := delivery.EncodeCompositionVerdict(v); err != nil {
+			t.Errorf("%s: the verdict cannot be written: %v", row.name, err)
+		}
+	}
+	trunk := map[string]delivery.Placement{"ace": {Node: "ace", Modules: []delivery.PlacedModule{{Module: "mail"}}}, "novox": {Node: "novox"}}
+	if got := PlacedNodes(trunk, &ChangePlacement{Placements: map[string]*delivery.Placement{"novox": nil, "g14": {Node: "g14"}}}); !slices.Equal(got, []string{"ace", "g14", "novox"}) {
+		t.Errorf("placed at the head or on the trunk = %v", got)
+	}
+	got, _ := Intended(nil, trunk, &ChangePlacement{Placements: map[string]*delivery.Placement{"ace": {Node: "ace", Modules: []delivery.PlacedModule{{Module: "mail", Ports: map[string]int{"25": 2525}}, {Module: "web"}}}, "g14": {Node: "g14", Modules: []delivery.PlacedModule{{Module: "web"}}}}}, nil)
+	if !got["ace"]["mail"] || !got["ace"]["web"] || len(got["g14"]) != 0 {
+		t.Errorf("intended = %v, want ace's mail and web, nothing on g14 the trunk does not place", got)
+	}
 }
 
 // 1297/B3c: what was already broken on the trunk is said and fails nothing.
@@ -109,6 +183,10 @@ func TestTouched(t *testing.T) {
 	if got := Touched(m, Change{Manifests: map[string]catalogue.Manifest{"store": m.Manifests["store"]}}); !slices.Equal(got, []string{"ace", "g14"}) {
 		t.Errorf("touched by store with a consumer on g14 = %v", got)
 	}
+	// ADR 0559 §5: every node whose placement the change changes is touched, its file removed or not.
+	if got := Touched(m, Change{Placement: &ChangePlacement{Placements: map[string]*delivery.Placement{"novox": nil, "shanks": {Node: "shanks"}}}}); !slices.Equal(got, []string{"novox", "shanks"}) {
+		t.Errorf("touched by a placement = %v", got)
+	}
 	c := Change{Group: "g", Heads: "0123456789ab", Manifests: map[string]catalogue.Manifest{"new": {Module: "new", Version: "1"}}}
 	if v := Compose(m, c, "sdk", 0); len(v.Machines) != 0 || !hasWarning(v, "touches no machine") || v.State != delivery.CompositionPass {
 		t.Errorf("an added module assigned nowhere: %+v", v)

modules/mesh-delivery-assigner/internal/assign/composer.go

@@ -50,6 +50,17 @@ func HeadJob(m Mesh, c Change) (delivery.ComposeJob, error) {
 		fromClaims = len(in.Holdings) == 0
 	}
 	changeCase := composer.Case{Name: CaseChange, Manifests: change}
+	if c.Placement != nil {
+		// The change's own placement, laid over the input's in the change case (ADR 0559 §5; composer.Case's Placements):
+		// a node the input does not hold yet is added bare, so the composer places it.
+		changeCase.Placements = c.Placement.Placements
+		in.Nodes = slices.Clone(in.Nodes)
+		for _, node := range c.Placement.Nodes() {
+			if !slices.ContainsFunc(in.Nodes, func(n compose.Node) bool { return n.Name == node }) {
+				in.Nodes = append(in.Nodes, compose.Node{Name: node})
+			}
+		}
+	}
 	req := composer.Request{V: composer.Version, Input: in, Depth: composer.DepthResolve,
 		HoldingsFromClaims: fromClaims, Machines: Touched(m, c),
 		Cases: []composer.Case{{Name: CaseTrunk, Manifests: trunk}, changeCase}}

modules/mesh-delivery-assigner/internal/assign/composer_test.go

@@ -120,6 +120,22 @@ func TestAGroupWithAnSDKMemberAsksTheComposerAtItsHead(t *testing.T) {
 		len(placed.Input.Holdings) != 1 || placed.HoldingsFromClaims {
 		t.Errorf("the placed check's request = %+v, holdings from claims %v", placed.Input, placed.HoldingsFromClaims)
 	}
+
+	// ADR 0559 §5: a change of placement composes its own placement in the change case alone (composer.Case's Placements),
+	// a node the input does not hold yet added bare so the composer places it, and the node touched.
+	c.Placement = &ChangePlacement{Placements: map[string]*delivery.Placement{"novox": {Node: "novox"}}}
+	candJob, err := HeadJob(m, c)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cand, err := composer.Decode(candJob.Request)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cand.Cases[0].Placements != nil || cand.Cases[1].Placements["novox"] == nil || len(cand.Input.Nodes) != 2 || cand.Input.Nodes[1].Name != "novox" ||
+		!slices.Equal(cand.Machines, []string{"g14", "novox"}) || len(m.Input.Nodes) != 1 {
+		t.Errorf("the placement's request = cases %+v, nodes %+v, machines %v", cand.Cases, cand.Input.Nodes, cand.Machines)
+	}
 }
 
 // 1622/AC2, AC3: a catalogue member using a field only the SDK head reads passes with the head's composer, and the

modules/mesh-delivery-assigner/internal/assign/placement.go

@@ -2,49 +2,33 @@ package assign
 
 import (
 	"fmt"
-	"slices"
 	"sort"
-	"strings"
 
 	"git.novox.be/novox/mesh-sdk/go/asks"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 )
 
 // Until ADR 0547's third milestone two sources name which module runs on which node: the controller's assignments and
-// the seat mesh-placement's placement (ADR 0549 §5, ADR 0567 §8). The assigner writes wants only for a pair both name:
+// the indexer's placement, read from the catalogue (ADR 0549 §5). The assigner writes wants only for a pair both name:
 // for a pair one source names alone it writes no want and touches none it wrote before, so nothing moves and nothing is
-// removed on one source's word, and it raises a condition naming the pair until both agree. After an approved proposal
-// the assigner keeps the controller in step itself, calling its assign, unassign, pin and unpin; a call refused or not
-// yet answered leaves the pair differing, and the condition names the call (Pair.Call). Before the first placement key
-// is written the controller's assignments are the one source, as before. From the lease write (the controller's lease
-// handed away) the placement is the one source.
+// removed on one source's word, and it raises a condition naming the pair until both agree. Before the first placement
+// file reaches the indexer (no placement key at all) the controller's assignments are the one source, as before.
 
 // Pair is a module on a node that one source names and the other does not; Only says which: OnlyAssignments or
 // OnlyPlacement.
 type Pair struct {
 	Node, Module, Only string
-	// Call is what became of the assigner's call of the controller's verb for the pair, in words, when it made one.
-	Call string
 }
 
 // The source that names a pair alone.
 const (
 	OnlyAssignments = "the controller's assignments"
-	OnlyPlacement   = "the seat mesh-placement's placement"
+	OnlyPlacement   = "the catalogue's placement"
 )
 
 // Placed is, by node, the modules both sources name, in name order, and every pair one names alone, by node then
-// module. With no placement read yet (seeded false) it is the assignments, and no pair differs. Once the controller's
-// lease is handed away (handedAway, ADR 0549 §5, §6) it is the placement alone, in name order, and no pair differs: the
-// assignments are then a source of nothing.
-func Placed(assigned, placed map[string][]string, seeded, handedAway bool) (map[string][]string, []Pair) {
-	if handedAway && seeded {
-		out := make(map[string][]string, len(placed))
-		for node, modules := range placed {
-			out[node] = slices.Sorted(slices.Values(modules))
-		}
-		return out, nil
-	}
+// module. With no placement read yet (seeded false) it is the assignments, and no pair differs.
+func Placed(assigned, placed map[string][]string, seeded bool) (map[string][]string, []Pair) {
 	if !seeded {
 		return assigned, nil
 	}
@@ -95,7 +79,7 @@ func PlacementCondition(p Pair, raised bool) asks.Condition {
 	subject := asks.Scope{Scope: "module", ID: p.Module, Machine: p.Node}
 	if !raised {
 		return asks.Condition{Key: key, Subject: subject, State: asks.StateCleared,
-			Resolved: fmt.Sprintf("the controller's assignments and the seat's placement agree on %s on %s.", p.Module, p.Node)}
+			Resolved: fmt.Sprintf("the controller's assignments and the catalogue's placement agree on %s on %s.", p.Module, p.Node)}
 	}
 	headline := fmt.Sprintf("%s on %s is placed by one source only", p.Module, p.Node)
 	if n := len([]rune(headline)); n > asks.HeadlineLength {
@@ -103,12 +87,9 @@ func PlacementCondition(p Pair, raised bool) asks.Condition {
 	}
 	var needs string
 	if p.Only == OnlyAssignments {
-		needs = fmt.Sprintf("propose placing %s on %s (mesh-placement.propose), or unassign it at the controller", p.Module, p.Node)
+		needs = fmt.Sprintf("add %s to the catalogue's placement file of %s, or unassign it at the controller", p.Module, p.Node)
 	} else {
-		needs = fmt.Sprintf("assign %s to %s at the controller, as the approved placement says, or propose taking it off", p.Module, p.Node)
-	}
-	if p.Call != "" {
-		needs += "; the assigner's call: " + p.Call
+		needs = fmt.Sprintf("assign %s to %s at the controller, as the merged placement file says", p.Module, p.Node)
 	}
 	return asks.Condition{Key: key, Severity: asks.SeverityUrgent, Subject: subject, State: asks.StateRaised,
 		Summary: headline, Headline: headline, Needs: needs,
@@ -116,17 +97,3 @@ func PlacementCondition(p Pair, raised bool) asks.Condition {
 			"name a module on a node (ADR 0549 §5): the assigner writes no want for it there and leaves the one it wrote before, so "+
 			"nothing moves or is removed. This clears once both name it or neither does.", asks.NeedsYou, needs, p.Only, p.Module, p.Node)}
 }
-
-// SeatWaitsCondition is the assigner's word on the seat mesh-placement while a state of the seat is not bound (ADR 0567
-// §1): raised naming each, cleared when none is left.
-func SeatWaitsCondition(unbound []string) asks.Condition {
-	key := delivery.AssignerModule + ".seat-states"
-	subject := asks.Scope{Scope: "module", ID: delivery.AssignerModule}
-	if len(unbound) == 0 {
-		return asks.Condition{Key: key, Subject: subject, State: asks.StateCleared, Resolved: "the seat mesh-placement holds all its states."}
-	}
-	why := "the seat waits for its states: " + strings.Join(unbound, ", ") + " are not on the bus or not granted yet"
-	return asks.Condition{Key: key, Severity: asks.SeverityWarning, Subject: subject, State: asks.StateRaised,
-		Summary: "the seat waits for its states", Headline: "the seat waits for its states",
-		Explanation: asks.NothingToDo + " " + why + "; each is bound at the next pass once it is, with no restart."}
-}

modules/mesh-delivery-assigner/internal/assign/seat.go

@@ -1,296 +0,0 @@
-package assign
-
-import (
-	"encoding/json"
-	"fmt"
-	"sort"
-	"strings"
-	"time"
-
-	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-// The seat mesh-placement (novox/hq ADR 0567), held by the assigner beside its wants: placement is its state
-// `placement`, changed only by a proposal (§2) the nodes it touches answer (§3), judged (§4) and written on the
-// operator's Approve at the revision it was laid over (§5). What here decides; the tools and the passes do.
-
-// ProposeIn is what a proposal is laid over: its id, who and why, its changes; every node's current placement and the
-// revision of its key; which modules the indexer holds and which nodes have a record; and, for the seed, the export's
-// digest.
-type ProposeIn struct {
-	ID, By, Why  string
-	At           time.Time
-	Changes      []delivery.PlacementProposalChange
-	Current      map[string]delivery.Placement
-	Revisions    map[string]uint64
-	Held         func(module string) bool
-	Recorded     func(node string) bool
-	Seed         bool
-	ExportDigest string
-	// Leased says the lease write of ADR 0547 has happened (the controller's lease handed away, mesh-sdk
-	// buscompose.LeaseHandedAway; issue 774), after which the controller's assignments are read no more (§8): until then
-	// the holder keeps the controller in step and refuses what its verbs cannot take.
-	Leased bool
-}
-
-// Propose lays a proposal over the current keys (§2): the proposal (state answering, each changed node's base revision),
-// the laid placement of every node whose key it changes, and every finding, which refuses it whole: a change the
-// controller's verbs cannot take before the lease write (§8), a change that does not fit its node, and what
-// CheckPlacements refuses of the result laid over every placement (two modules on one host port, a provider not placed,
-// a seat held once held twice, two nodes with one address, two hubs, a module the indexer does not hold, a node with no
-// record). A key whose value the proposal leaves as it is changes nothing and is not laid.
-func Propose(in ProposeIn) (delivery.PlacementProposal, map[string]*delivery.Placement, []string) {
-	p := delivery.PlacementProposal{ID: in.ID, By: strings.TrimSpace(in.By), Why: strings.TrimSpace(in.Why), At: in.At.UTC(),
-		Changes: in.Changes, Seed: in.Seed, ExportDigest: in.ExportDigest, Base: map[string]uint64{}, State: delivery.ProposalAnswering}
-	var findings []string
-	if p.By == "" {
-		findings = append(findings, "the runtime names no caller: a proposal is made by someone")
-	}
-	if p.Why == "" {
-		findings = append(findings, "a proposal says why: it is shown to the operator")
-	}
-	if len(in.Changes) == 0 {
-		findings = append(findings, "a proposal changes something: it names no change")
-	}
-	for i, c := range in.Changes {
-		if (c.Op == delivery.OpSeed) != in.Seed {
-			findings = append(findings, fmt.Sprintf("change %d: the seed is adopt's alone, and never mixed with other changes", i+1))
-			continue
-		}
-		if !in.Leased {
-			if why := c.BeforeLease(); why != "" {
-				findings = append(findings, fmt.Sprintf("change %d: %s", i+1, why))
-			}
-		}
-	}
-	laid, lay := delivery.LayChanges(in.Current, in.Changes)
-	findings = append(findings, lay...)
-	all := map[string]delivery.Placement{}
-	for node, pl := range in.Current {
-		all[node] = pl
-	}
-	out := map[string]*delivery.Placement{}
-	for node, pl := range laid {
-		if before, ok := in.Current[node]; ok && delivery.SamePlacement(before, pl) {
-			continue
-		}
-		pl := pl
-		all[node] = pl
-		out[node] = &pl
-		p.Base[node] = in.Revisions[node]
-	}
-	if len(findings) == 0 && len(out) == 0 {
-		findings = append(findings, "the changes leave every placement as it is")
-	}
-	held, recorded := in.Held, in.Recorded
-	if held == nil {
-		held = func(string) bool { return false }
-	}
-	if recorded == nil {
-		recorded = func(string) bool { return false }
-	}
-	for _, r := range delivery.CheckPlacements(all, held, recorded) {
-		findings = append(findings, r)
-	}
-	return p, out, findings
-}
-
-// Write is one key a warrant writes (§5): the node, its key, the revision it is written at (0: it has none, so it is
-// created) and its value (nil: it is deleted).
-type Write struct {
-	Node, Key string
-	Base      uint64
-	Value     *delivery.Placement
-}
-
-// Writes is every key a proposal writes, by node order.
-func Writes(p delivery.PlacementProposal, laid map[string]*delivery.Placement) ([]Write, error) {
-	var out []Write
-	for _, node := range p.Nodes() {
-		key, err := delivery.PlacementKey(node)
-		if err != nil {
-			return nil, err
-		}
-		out = append(out, Write{Node: node, Key: key, Base: p.Base[node], Value: laid[node]})
-	}
-	return out, nil
-}
-
-// ControllerCall is one call of the controller's seat verbs the holder makes after writing an approved proposal, until
-// the lease write (§8): assign, unassign, pin or unpin, with its arguments.
-type ControllerCall struct {
-	Verb string
-	Args map[string]any
-	// Node and Module name the pair the call keeps in step (a pin names no module).
-	Node, Module string
-}
-
-// Key names the call, as the condition of its pair says it.
-func (c ControllerCall) Key() string {
-	return fmt.Sprintf("mesh-controller.%s %s %s", c.Verb, c.Node, c.Module)
-}
-
-// ControllerCalls is every call that brings the controller's assignments and pins to the placement after: assign for a
-// module placed on a node before not, unassign for one taken off, pin for a pin set or changed, unpin for one removed,
-// each naming the proposal and its warrant in its why. In node order, unassigns before assigns, so a module moved
-// between nodes is first taken off.
-func ControllerCalls(before map[string]delivery.Placement, after map[string]*delivery.Placement, proposal, warrant string) []ControllerCall {
-	why := fmt.Sprintf("placement proposal %s, approved (%s)", proposal, warrant)
-	nodes := make([]string, 0, len(after))
-	for node := range after {
-		nodes = append(nodes, node)
-	}
-	sort.Strings(nodes)
-	var off, on, pins []ControllerCall
-	for _, node := range nodes {
-		was, now := before[node], delivery.Placement{}
-		if a := after[node]; a != nil {
-			now = *a
-		}
-		had, has := map[string]bool{}, map[string]bool{}
-		for _, m := range was.Modules {
-			had[m.Module] = true
-		}
-		for _, m := range now.Modules {
-			has[m.Module] = true
-			if !had[m.Module] {
-				on = append(on, ControllerCall{Verb: "assign", Node: node, Module: m.Module, Args: map[string]any{"node": node, "module": m.Module}})
-			}
-		}
-		for _, m := range was.Modules {
-			if !has[m.Module] {
-				off = append(off, ControllerCall{Verb: "unassign", Node: node, Module: m.Module, Args: map[string]any{"node": node, "module": m.Module}})
-			}
-		}
-		for _, provision := range sortedKeys(now.Pins) {
-			to := now.Pins[provision]
-			if old, ok := was.Pins[provision]; !ok || old != to {
-				pins = append(pins, ControllerCall{Verb: "pin", Node: node, Module: provision,
-					Args: map[string]any{"node": node, "provision": provision, "from": to.Node, "module": to.Module}})
-			}
-		}
-		for _, provision := range sortedKeys(was.Pins) {
-			if _, ok := now.Pins[provision]; !ok {
-				pins = append(pins, ControllerCall{Verb: "unpin", Node: node, Module: provision, Args: map[string]any{"node": node, "provision": provision}})
-			}
-		}
-	}
-	out := append(append(off, on...), pins...)
-	for i := range out {
-		out[i].Args["why"] = why
-	}
-	return out
-}
-
-// PlacementAct is the act an approved proposal's yes binds: writing exactly its changes at its base revisions.
-func PlacementAct(p delivery.PlacementProposal) asks.Act {
-	return asks.Act{"placement": "write", "proposal": p.ID, "changes": delivery.ChangesDigest(p)}
-}
-
-// PlacementAsking is a proposal's asking number: each judging that raises its ask again (again, a key moved) is
-// another asking, under an id of its own.
-func PlacementAsking(p delivery.PlacementProposal, at time.Time) int {
-	return int(at.Unix())
-}
-
-// PlacementAsk is the authorising ask about a proposal (§5): an Approve that binds its act, so only a channel that
-// proves who answered takes it, with the brief of the verdict by node (judge.Brief) as its explanation.
-func PlacementAsk(key string, p delivery.PlacementProposal, brief string, asking int, now time.Time) (delivery.AssignerAsk, error) {
-	binds, err := asks.ActDigest(PlacementAct(p))
-	if err != nil {
-		return delivery.AssignerAsk{}, err
-	}
-	nodes := p.Nodes()
-	headline := fmt.Sprintf("Change placement on %s?", strings.Join(nodes, ", "))
-	if p.Seed {
-		headline = "Take placement over from the controller?"
-	}
-	if n := len([]rune(headline)); n > asks.HeadlineLength {
-		headline = fmt.Sprintf("Change placement on %d machines?", len(nodes))
-	}
-	return delivery.AssignerAsk{Ask: asks.Ask{
-		ID:          delivery.AskingID(key, asking),
-		Headline:    headline,
-		Explanation: brief,
-		Options: []asks.Option{
-			{ID: OptionYes, Label: "Approve", Does: "the placement of " + strings.Join(nodes, ", ") + " is written as proposed",
-				Level: asks.Approve, Binds: binds},
-			{ID: OptionNo, Label: "Decline", Does: "nothing is written, and the proposal ends", Level: asks.Acknowledge},
-		},
-		Who:      asks.Operator,
-		Expires:  now.Add(asks.ApproveLasts),
-		OnExpiry: "nothing is written, and the proposal ends",
-		About:    key,
-	}, Asking: asking}, nil
-}
-
-// ExportOf reads the controller's answer to placement-export (§7): its verb answers what the command printed, the
-// JSON of every node's placement, in `output` (the controller's verbAnswer; `answer` when it carries it as data). A
-// refused or unreadable answer is an error naming it.
-func ExportOf(raw []byte) (map[string]delivery.Placement, error) {
-	var a struct {
-		Output string          `json:"output"`
-		OK     *bool           `json:"ok"`
-		Answer json.RawMessage `json:"answer"`
-	}
-	if err := json.Unmarshal(raw, &a); err != nil {
-		return nil, fmt.Errorf("the controller's placement-export answered no verb answer: %w", err)
-	}
-	if a.OK != nil && !*a.OK {
-		return nil, fmt.Errorf("the controller's placement-export refused: %s", strings.TrimSpace(a.Output))
-	}
-	var byNode map[string]json.RawMessage
-	if len(a.Answer) > 0 && string(a.Answer) != "null" {
-		if err := json.Unmarshal(a.Answer, &byNode); err != nil {
-			return nil, fmt.Errorf("the controller's placement-export is no placement by node: %w", err)
-		}
-	} else if err := json.NewDecoder(strings.NewReader(a.Output)).Decode(&byNode); err != nil {
-		// The command prints its JSON first; what its standard error said after it is left.
-		return nil, fmt.Errorf("the controller's placement-export printed no placement by node: %w", err)
-	}
-	out := map[string]delivery.Placement{}
-	for node, rawP := range byNode {
-		p, err := delivery.DecodePlacement(rawP)
-		if err != nil {
-			return nil, fmt.Errorf("the controller's placement-export of %s cannot be read: %w", node, err)
-		}
-		if p.Node != node {
-			return nil, fmt.Errorf("the controller's placement-export names %s under %s", p.Node, node)
-		}
-		out[node] = p
-	}
-	if len(out) == 0 {
-		return nil, fmt.Errorf("the controller's placement-export names no node")
-	}
-	return out, nil
-}
-
-// SeedChanges is the seed's changes: every node's placement of the export, whole, in node order.
-func SeedChanges(export map[string]delivery.Placement) []delivery.PlacementProposalChange {
-	var out []delivery.PlacementProposalChange
-	for _, node := range sortedKeys(export) {
-		p := export[node]
-		out = append(out, delivery.PlacementProposalChange{Op: delivery.OpSeed, Node: node, Whole: &p})
-	}
-	return out
-}
-
-// Rest is what a proposal leaves to write once the keys of written are: its changes of the other nodes, to be laid again
-// over the keys as the write left them (§5: a key moved while it was written). False when nothing is left.
-func Rest(p delivery.PlacementProposal, written map[string]*delivery.Placement) (delivery.PlacementProposal, bool) {
-	rest := p
-	rest.Changes, rest.Base = nil, map[string]uint64{}
-	for _, c := range p.Changes {
-		if _, done := written[c.Node]; !done {
-			rest.Changes = append(rest.Changes, c)
-		}
-	}
-	for node, base := range p.Base {
-		if _, done := written[node]; !done {
-			rest.Base[node] = base
-		}
-	}
-	rest.Must, rest.Verdict, rest.Ask, rest.State = nil, nil, "", delivery.ProposalAnswering
-	return rest, len(rest.Changes) > 0
-}

modules/mesh-delivery-assigner/internal/assign/seat_test.go

@@ -1,157 +0,0 @@
-package assign
-
-import (
-	"encoding/json"
-	"slices"
-	"strings"
-	"testing"
-	"time"
-
-	"git.novox.be/novox/mesh-sdk/go/asks"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-// ADR 0567 §2, §5, §7, §8: what the seat's holder decides of a proposal: every refusal named at once, a valid one laid
-// with the base revision of each key it changes, the writes at those revisions, the controller's calls that keep its
-// assignments in step, the authorising ask bound to the changes, and the export read as the controller answers it.
-func TestThePlacementSeatDecides(t *testing.T) {
-	anchor := delivery.Placement{V: delivery.Version, Node: "anchor", Decided: delivery.NodeDecided{Hub: true, Address: "10.0.0.1"},
-		Modules: []delivery.PlacedModule{{Module: "store", Ports: map[string]int{"5432": 5432}}, {Module: "web"}}}
-	laptop := delivery.Placement{V: delivery.Version, Node: "laptop", Decided: delivery.NodeDecided{Address: "10.0.0.2"}, Modules: []delivery.PlacedModule{{Module: "shell"}}}
-	in := func(changes ...delivery.PlacementProposalChange) ProposeIn {
-		return ProposeIn{ID: "p-one", By: "operator@laptop", Why: "move web", At: time.Unix(1, 0), Changes: changes,
-			Current: map[string]delivery.Placement{"anchor": anchor, "laptop": laptop}, Revisions: map[string]uint64{"anchor": 4, "laptop": 9},
-			Held:     func(m string) bool { return m != "ghost" },
-			Recorded: func(n string) bool { return n == "anchor" || n == "laptop" }}
-	}
-	move := []delivery.PlacementProposalChange{{Op: delivery.OpTakeOff, Node: "anchor", Module: "web"}, {Op: delivery.OpPlace, Node: "laptop", Module: "web"}}
-	p, laid, findings := Propose(in(move...))
-	if len(findings) != 0 || p.State != delivery.ProposalAnswering || p.Base["anchor"] != 4 || p.Base["laptop"] != 9 ||
-		!slices.Equal(laid["laptop"].Assigned(), []string{"shell", "web"}) || !slices.Equal(laid["anchor"].Assigned(), []string{"store"}) {
-		t.Fatalf("a move: %+v, %+v, %v", p, laid, findings)
-	}
-	if _, err := delivery.EncodePlacementProposal(p); err != nil {
-		t.Fatalf("the proposal cannot be written: %v", err)
-	}
-	for name, c := range map[string]struct {
-		in   ProposeIn
-		want string
-	}{
-		"a port before the lease": {in(delivery.PlacementProposalChange{Op: delivery.OpPlace, Node: "laptop", Module: "web", Ports: map[string]int{"80": 8080}}), "lease write"},
-		"a holding":               {in(delivery.PlacementProposalChange{Op: delivery.OpHold, Node: "anchor", Module: "store", Claim: "mesh-store", Scope: "mesh"}), "lease write"},
-		"a binding":               {in(delivery.PlacementProposalChange{Op: delivery.OpPlace, Node: "laptop", Module: "web", Bindings: map[string]delivery.Provider{"db": {Node: "anchor", Module: "store"}}}), "lease write"},
-		"a config place":          {in(delivery.PlacementProposalChange{Op: delivery.OpConfig, Node: "anchor", Module: "web", Layer: map[string]any{"places": []any{}}}), "lease write"},
-		"a config access":         {in(delivery.PlacementProposalChange{Op: delivery.OpConfig, Node: "anchor", Module: "web", MeshWide: map[string]any{"accesses": []any{}}}), "lease write"},
-		"a module not held":       {in(delivery.PlacementProposalChange{Op: delivery.OpPlace, Node: "laptop", Module: "ghost"}), "the indexer holds no module ghost"},
-		"a node with no record":   {in(delivery.PlacementProposalChange{Op: delivery.OpPlace, Node: "stranger", Module: "web"}), "stranger is a node with no record"},
-		"nothing changes":         {in(delivery.PlacementProposalChange{Op: delivery.OpPlace, Node: "anchor", Module: "web"}), "leave every placement as it is"},
-		"no why":                  {func() ProposeIn { i := in(move...); i.Why = " "; return i }(), "says why"},
-		"no caller":               {func() ProposeIn { i := in(move...); i.By = ""; return i }(), "names no caller"},
-		"a seed by hand":          {in(delivery.PlacementProposalChange{Op: delivery.OpSeed, Node: "laptop", Whole: &laptop}), "adopt's alone"},
-		"a pin of nobody placed":  {in(delivery.PlacementProposalChange{Op: delivery.OpPin, Node: "laptop", Provision: "db", Provider: &delivery.Provider{Node: "laptop", Module: "store"}}), "not placed there"},
-	} {
-		if _, _, f := Propose(c.in); !slices.ContainsFunc(f, func(s string) bool { return strings.Contains(s, c.want) }) {
-			t.Errorf("%s: findings %v, want one naming %q", name, f, c.want)
-		}
-	}
-
-	// A module's config values may be proposed before the lease write (§13); once the lease is written every change is
-	// the state's alone, and none waits.
-	if _, _, f := Propose(in(delivery.PlacementProposalChange{Op: delivery.OpConfig, Node: "anchor", Module: "web", Values: map[string]any{"puid": 1}})); len(f) != 0 {
-		t.Errorf("config values before the lease write: %v", f)
-	}
-	for _, c := range []delivery.PlacementProposalChange{
-		{Op: delivery.OpPlace, Node: "laptop", Module: "web", Ports: map[string]int{"80": 8080}, Bindings: map[string]delivery.Provider{"db": {Node: "anchor", Module: "store"}}},
-		{Op: delivery.OpConfig, Node: "anchor", Module: "web", Layer: map[string]any{"places": []any{}}},
-		{Op: delivery.OpDecide, Node: "laptop", Field: "site", Value: json.RawMessage(`"attic"`)},
-		{Op: delivery.OpHold, Node: "anchor", Module: "store", Claim: "node-shell", Scope: "node"},
-	} {
-		leased := in(c)
-		leased.Leased = true
-		if _, _, f := Propose(leased); len(f) != 0 {
-			t.Errorf("after the lease write %s is refused: %v", c.Op, f)
-		}
-	}
-
-	// A key moved while the warrant wrote: what is left to write is the other nodes' changes, to be laid and asked again.
-	if rest, ok := Rest(p, map[string]*delivery.Placement{"anchor": laid["anchor"]}); !ok || len(rest.Changes) != 1 || rest.Changes[0].Node != "laptop" ||
-		len(rest.Base) != 1 || rest.State != delivery.ProposalAnswering || rest.Must != nil {
-		t.Errorf("the rest = %+v, %v", rest, ok)
-	}
-	if _, ok := Rest(p, laid); ok {
-		t.Error("a proposal written whole leaves something to write")
-	}
-
-	// The seat says it waits while one of its states is not bound, naming it, and clears once all are.
-	for _, unbound := range [][]string{{delivery.PlacementPulsesBucket}, nil} {
-		c := SeatWaitsCondition(unbound)
-		if _, err := asks.EncodeCondition(c); err != nil || (len(unbound) > 0) != (c.State == asks.StateRaised) ||
-			(len(unbound) > 0 && !strings.Contains(c.Explanation, "the seat waits for its states: "+delivery.PlacementPulsesBucket)) {
-			t.Errorf("waiting for %v: %+v, %v", unbound, c, err)
-		}
-	}
-
-	// Issue 1126: the seed places the private network, which no repository holds; it is the mesh's own, and passes.
-	wired := laptop
-	wired.Modules = append(slices.Clone(laptop.Modules), delivery.PlacedModule{Module: "mesh-wireguard"})
-	seed := in(SeedChanges(map[string]delivery.Placement{"laptop": wired})...)
-	seed.Seed, seed.ExportDigest, seed.Current, seed.Revisions = true, "sha256:x", map[string]delivery.Placement{}, map[string]uint64{}
-	seed.Held = func(m string) bool { return m != "mesh-wireguard" } // the indexer holds every module but it
-	if _, _, f := Propose(seed); len(f) != 0 {
-		t.Errorf("a seed placing the private network is refused: %v", f)
-	}
-
-	writes, err := Writes(p, laid)
-	if err != nil || len(writes) != 2 || writes[0].Key != "placement.anchor" || writes[0].Base != 4 || writes[1].Base != 9 {
-		t.Fatalf("writes = %+v, %v", writes, err)
-	}
-	pinned := *laid["laptop"]
-	pinned.Pins = map[string]delivery.Provider{"db": {Node: "anchor", Module: "store"}}
-	calls := ControllerCalls(map[string]delivery.Placement{"anchor": anchor, "laptop": laptop},
-		map[string]*delivery.Placement{"anchor": laid["anchor"], "laptop": &pinned}, "p-one", "w1@t")
-	var said []string
-	for _, c := range calls {
-		said = append(said, c.Key())
-		if !strings.Contains(c.Args["why"].(string), "p-one") {
-			t.Errorf("%s does not name the proposal: %v", c.Key(), c.Args)
-		}
-	}
-	if !slices.Equal(said, []string{"mesh-controller.unassign anchor web", "mesh-controller.assign laptop web", "mesh-controller.pin laptop db"}) {
-		t.Errorf("the controller's calls = %v", said)
-	}
-
-	a, err := PlacementAsk("placement.p-one", p, "move web (proposed by operator@laptop)", 7, time.Unix(100, 0))
-	if err != nil || a.Ask.Check(time.Unix(100, 0)) != nil || a.Ask.Options[0].Level != asks.Approve || a.Ask.Options[0].Performs(PlacementAct(p)) != nil {
-		t.Fatalf("the ask = %+v, %v", a, err)
-	}
-	q := p
-	q.Changes = append(slices.Clone(p.Changes), delivery.PlacementProposalChange{Op: delivery.OpUnpin, Node: "laptop", Provision: "x"})
-	if a.Ask.Options[0].Performs(PlacementAct(q)) == nil {
-		t.Error("the ask's yes binds changes it was not asked about")
-	}
-
-	export, _ := json.Marshal(map[string]any{"anchor": anchor, "laptop": laptop})
-	for name, c := range map[string]struct {
-		raw  string
-		want int
-	}{
-		"in output":  {`{"ok":true,"output":` + quote(string(export)+"\n") + `}`, 2},
-		"as answer":  {`{"ok":true,"output":"","answer":` + string(export) + `}`, 2},
-		"refused":    {`{"ok":false,"output":"no store"}`, 0},
-		"no node":    {`{"ok":true,"output":"{}"}`, 0},
-		"no version": {`{"ok":true,"output":"{\"anchor\":{\"node\":\"anchor\",\"modules\":[]}}"}`, 0},
-	} {
-		got, err := ExportOf([]byte(c.raw))
-		if len(got) != c.want || (c.want == 0) != (err != nil) {
-			t.Errorf("%s: %d nodes, %v", name, len(got), err)
-		}
-	}
-	if seed := SeedChanges(map[string]delivery.Placement{"laptop": laptop, "anchor": anchor}); len(seed) != 2 || seed[0].Node != "anchor" || seed[0].Op != delivery.OpSeed {
-		t.Errorf("the seed's changes = %+v", seed)
-	}
-}
-
-func quote(s string) string {
-	raw, _ := json.Marshal(s)
-	return string(raw)
-}

modules/mesh-delivery-assigner/internal/assign/wants.go

@@ -89,15 +89,14 @@ func Canary(nodes []string, online map[string]bool) string {
 
 // Holds is whether every rule holds for moving node's want for m to m.FP, and if not, the first rule that does not,
 // with why (ADR 0429 §6). Rule 4, at most `step` others ahead, always holds: the mesh keeps no step, and step 0 is no
-// limit (ADR 0528 clause 3). Rule 5, every provider healthy, holds no want (issue 1960): a module whose provider is down
-// is wanted all the same, and said as not reached (Unreached), since a site runs while the proxy in front of it is
-// down and one module never blocks another.
+// limit (ADR 0528 clause 3).
 func Holds(m Module, node string, n Nodes) (bool, int, string) {
 	return holds(m, node, n, true)
 }
 
-// holds is Holds; with ordering false it leaves out the canary (3), which orders a move among nodes, and keeps those
-// without which there is nothing to want: the build done, not held, the grant and the composition.
+// holds is Holds; with ordering false it leaves out the two rules that order a move among nodes and modules, the canary (3)
+// and the providers (5), and keeps those without which there is nothing to want: the build done, not held, the grant and the
+// composition.
 func holds(m Module, node string, n Nodes, ordering bool) (bool, int, string) {
 	switch {
 	case !m.Built:
@@ -113,6 +112,11 @@ func holds(m Module, node string, n Nodes, ordering bool) (bool, int, string) {
 		case node != canary && !healthy(n.Haves[canary][m.Name], m.FP):
 			return false, delivery.RuleCanary, fmt.Sprintf("the canary %s does not run %s healthy yet", canary, short(m.FP))
 		}
+		for _, provision := range m.Manifest.Requires {
+			if ok, why := providedHealthy(provision, node, n); !ok {
+				return false, delivery.RuleProviders, why
+			}
+		}
 	}
 	if !m.Granted {
 		return false, delivery.RuleGrant, fmt.Sprintf("the controller has not issued the credential of %s for %s", m.Name, short(m.FP))
@@ -153,17 +157,6 @@ func providedHealthy(provision, node string, n Nodes) (bool, string) {
 	return false, fmt.Sprintf("no provider of %s runs healthy on %s or at its canary", provision, node)
 }
 
-// unreached is why m on node may be wanted and not reached: the first provision it requires that no provider runs
-// healthy on node or at its canary (rule 5, said and never holding a want; issue 1960); empty when all do.
-func unreached(m Module, node string, n Nodes) string {
-	for _, provision := range m.Manifest.Requires {
-		if ok, why := providedHealthy(provision, node, n); !ok {
-			return why
-		}
-	}
-	return ""
-}
-
 // keepsData says whether a module holds data a set-back would lose: an own item of a class that keeps (irreplaceable,
 // valuable or rebuildable; cache and none do not).
 func keepsData(m catalogue.Manifest) bool {
@@ -193,9 +186,6 @@ type Outcome struct {
 	Restore []string
 	// Rules is, by node, the rule holding the node back from m.FP and why.
 	Rules map[string]Holding
-	// Unreached is, by node, why the module may be wanted there and not reached: no provider of a provision it requires runs
-	// healthy (rule 5, issue 1960). It holds no want back; the pass says it.
-	Unreached map[string]string
 	// Neither is, by node, the nodes the module is assigned to that run it (or whose have names it), hold no want for it after this
 	// pass and are not held (a held module is on the held list), with the rule holding the first want back: the node's own composition does not hold a module with a fingerprint of the new form, so such a module is on
 	// neither list and nothing applies it on that node (issue 1945). A module with no fingerprint of the new form goes with the node's
@@ -311,34 +301,27 @@ func Wants(m Module, n Nodes, wants map[string]delivery.Want, lastHealthy map[st
 		}
 		ok, rule, words := Holds(mm, node, n)
 		target := m.FP
-		if have, ran := n.Haves[node][m.Name]; !ok && (!had || before.Removed) && rule == delivery.RuleCanary {
-			// The canary orders a move, never the first want of a node that does not run the module (issue 1960: de-spiegel,
-			// link2pay and photos on novox were left with no want). A node that runs an older fingerprint of the new form,
-			// composed and granted, gets its first want at what it runs, and rule 3 then orders its move to F as from any want.
-			// A node that runs an old-form build, which no want can name, stays under the canary (issue 1945, a design limit):
-			// its first want names F once the canary runs F healthy. Any other node that runs it (F itself, or an older
-			// fingerprint with no composition or grant) gets F by the rules without which there is nothing to want.
-			older := ran && runs(have) && have.FP != m.FP && strings.HasPrefix(have.FP, delivery.SourcePrefix2)
-			if older {
-				_, composed := m.composition(node, have.FP)
-				older = composed && m.GrantedAt != nil && m.GrantedAt(have.FP)
-			}
-			oldForm := ran && runs(have) && have.FP != m.FP && !strings.HasPrefix(have.FP, delivery.SourcePrefix2)
-			switch {
-			case older:
-				ok, target = true, have.FP
-			case oldForm:
-				// held back by rule 3 as written: on neither list until the canary runs F healthy
-			default:
+		if have, ran := n.Haves[node][m.Name]; !ok && (!had || before.Removed) && (rule == delivery.RuleCanary || rule == delivery.RuleProviders) && runs(have) {
+			// A node that runs the module and has no want for it has no want the ordering rules could hold it back to: holding its first
+			// want back leaves the module on neither list, since the node's own composition gives up every module with a fingerprint of
+			// the new form (issue 1945: on g14 the bundles of clipmenu, screen-lock and every module requiring x11-display were removed
+			// and never made again, because xorg's health is unknown and screen-lock's canary never ran it healthy). Its first want names
+			// what it runs, never a newer fingerprint, so the canary is never passed over: F when it runs F (by the rules without which
+			// there is nothing to want), or an older fingerprint of the new form whose composition and grant exist. Rules 3 and 5 then
+			// order the move from it as from any want.
+			switch _, composed := m.composition(node, have.FP); {
+			case !ran:
+			case have.FP == m.FP:
 				ok, rule, words = holds(mm, node, n, false)
+			case !strings.HasPrefix(have.FP, delivery.SourcePrefix2):
+				// An old-form build (not src2:) has no composition, so no want can ever name it: its first want names F, and only by every
+				// rule as usual, the canary (3) and the providers (5) included, which here hold it back. Nothing is written and the module
+				// stays on neither list until the canary runs F healthy; then Holds passes and the want names F (issue 1945, a design
+				// limit set by the lead: the canary stays in force and old-form modules leave neither list by themselves).
+			case composed && m.GrantedAt != nil && m.GrantedAt(have.FP):
+				ok, target = true, have.FP
 			}
 		}
-		if why := unreached(m, node, n); why != "" {
-			if out.Unreached == nil {
-				out.Unreached = map[string]string{}
-			}
-			out.Unreached[node] = why
-		}
 		if ok && target == m.FP && len(out.NodeFailed) > 0 && !(had && !before.Removed && before.FP == m.FP) &&
 			n.Haves[node][m.Name].FP != m.FP {
 			// While a node fails F alone, F reaches no further node: a node that neither wants nor runs F gets no new want

modules/mesh-delivery-assigner/internal/assign/wants_test.go

@@ -65,6 +65,9 @@ func TestEachRuleHoldsTheWantBack(t *testing.T) {
 		delivery.RuleCanary: func(_ *Module, n *Nodes) {
 			n.Haves["ace"]["mail"] = delivery.Have{FP: fOld, Phase: delivery.PhaseRunning, Health: delivery.HealthOK}
 		},
+		delivery.RuleProviders: func(_ *Module, n *Nodes) {
+			n.Haves["ace"]["store"] = delivery.Have{FP: fpOf('s'), Phase: delivery.PhaseRunning, Health: delivery.HealthWaits}
+		},
 		delivery.RuleGrant: func(m *Module, _ *Nodes) { m.Granted = false },
 		delivery.RuleComposed: func(m *Module, _ *Nodes) {
 			m.Composed = func(string, string) (delivery.ComposedDigest, bool) { return delivery.ComposedDigest{}, false }
@@ -83,50 +86,6 @@ func TestEachRuleHoldsTheWantBack(t *testing.T) {
 			t.Errorf("rule %d broken: g14's want is %+v", rule, w)
 		}
 	}
-	// 1960: rule 5 holds no want, and no module is left without a first want for a provider down or a node offline; the
-	// provider down is said (Unreached). novox on 2026-10-29: route-proxy down held de-spiegel and link2pay, minio not
-	// healthy held photos, and novox offline left a module with no canary.
-	for _, c := range []struct {
-		name, module, provision, provider string
-		have                              *delivery.Have // what novox runs of the module; nil: a new assignment
-		before                            map[string]delivery.Want
-		online                            bool
-		want                              string
-	}{
-		{"de-spiegel, route-proxy down, old form", "de-spiegel", "route", "route-proxy",
-			&delivery.Have{FP: "build-1", Phase: delivery.PhaseRunning, Health: delivery.HealthUnknown}, nil, true, fNew},
-		{"link2pay, route-proxy down, new assignment", "link2pay", "route", "route-proxy", nil, nil, true, fNew},
-		{"photos, minio not healthy, moving its want", "photos", "s3-bucket", "minio",
-			&delivery.Have{FP: fOld, Phase: delivery.PhaseRunning, Health: delivery.HealthOK},
-			map[string]delivery.Want{"novox": {FP: fOld, Composed: dig(fOld)}}, true, fNew},
-		{"novox offline, no canary, new assignment", "link2pay", "route", "route-proxy", nil, nil, false, fNew},
-		{"novox offline, no canary, moving its want", "photos", "s3-bucket", "minio",
-			&delivery.Have{FP: fOld, Phase: delivery.PhaseRunning, Health: delivery.HealthOK},
-			map[string]delivery.Want{"novox": {FP: fOld, Composed: dig(fOld)}}, false, fOld},
-	} {
-		m := Module{Name: c.module, FP: fNew, Built: true, Granted: true, Composed: composedEverywhere, Nodes: []string{"novox"},
-			Manifest: catalogue.Manifest{Module: c.module, Requires: []string{c.provision}}}
-		n := Nodes{Online: map[string]bool{"novox": c.online}, Haves: map[string]map[string]delivery.Have{"novox": {
-			c.provider: {FP: fpOf('p'), Phase: delivery.PhaseFailed, Health: delivery.HealthFailed}}},
-			Providers: map[string]map[string][]string{c.provision: {c.provider: {"novox"}}}}
-		if c.have != nil {
-			n.Haves["novox"][c.module] = *c.have
-		}
-		out := Wants(m, n, c.before, nil)
-		w, written := out.Wants["novox"]
-		if !written {
-			w = c.before["novox"]
-		}
-		if w.FP != c.want || w.Removed {
-			t.Errorf("%s: novox's want = %+v, want %s", c.name, w, short(c.want))
-		}
-		if _, on := out.Neither["novox"]; on {
-			t.Errorf("%s: on neither list: %+v", c.name, out.Neither)
-		}
-		if c.online && !strings.Contains(out.Unreached["novox"], c.provision) {
-			t.Errorf("%s: the provider down is not said: %q", c.name, out.Unreached["novox"])
-		}
-	}
 
 	// 1126/AC-SW1, AC-SW2, AC-SW3: a want written Self while g14 was placed, kept by a rule after the placement is gone, names
 	// the controller's composition of the fingerprint the rule keeps (on 2026-10-27 g14's systemd-resolved, held, and forticlient,
@@ -149,7 +108,7 @@ func TestEachRuleHoldsTheWantBack(t *testing.T) {
 		{name: "rule 5 at F", before: fNew, set: func(m *Module, n *Nodes) {
 			atF(m, n)
 			n.Haves["ace"]["store"] = delivery.Have{FP: fpOf('s'), Phase: delivery.PhaseRunning, Health: delivery.HealthWaits}
-		}, want: delivery.Want{FP: fNew, Composed: dig(fNew)}},
+		}, want: delivery.Want{FP: fNew, Composed: dig(fNew)}, rule: delivery.RuleProviders},
 		{name: "rule 3 at F", before: fNew, set: func(m *Module, n *Nodes) {
 			atF(m, n)
 			n.Haves["ace"]["mail"] = delivery.Have{FP: fOld, Phase: delivery.PhaseRunning, Health: delivery.HealthOK}
@@ -1003,12 +962,10 @@ func x11() (Module, Nodes) {
 func TestANodeRunningAModuleWithNoWantGetsItsFirstWantAtWhatItRuns(t *testing.T) {
 	m, n := x11()
 	out := Wants(m, n, nil, nil)
-	// 1960: the providers rule holds no want: the canary g14 gets F, its provider's health unknown said
-	if w := out.Wants["g14"]; w.FP != fNew || out.Unreached["g14"] == "" {
-		t.Errorf("g14's want = %+v (unreached %q), want F, the provider said", w, out.Unreached["g14"])
-	}
-	if w := out.Wants["shanks"]; w.FP != fOld || w.Composed != dig(fOld) || w.Newest != fNew || w.Rule != delivery.RuleCanary {
-		t.Errorf("shanks's want = %+v, want its first want at the fingerprint it runs, held back from F by the canary", w)
+	for _, node := range []string{"g14", "shanks"} {
+		if w := out.Wants[node]; w.FP != fOld || w.Composed != dig(fOld) || w.Newest != fNew || w.Rule == 0 {
+			t.Errorf("%s's want = %+v, want its first want at the fingerprint it runs, held back from F", node, w)
+		}
 	}
 	if len(out.Neither) != 0 {
 		t.Errorf("left on neither list: %+v", out.Neither)
@@ -1046,22 +1003,11 @@ func TestNoFirstWantWithoutTheCompositionAndGrantOfWhatItRuns(t *testing.T) {
 		m, n := x11()
 		change(&m, &n)
 		out := Wants(m, n, nil, nil)
-		if what == "an old-form build" {
-			// the canary g14 does not run F healthy: no want, on neither list by rule 3 (issue 1945)
-			if w, ok := out.Wants["shanks"]; ok {
-				t.Errorf("%s: shanks got a want: %+v", what, w)
-			}
-			if h, ok := out.Neither["shanks"]; !ok || h.Rule != delivery.RuleCanary {
-				t.Errorf("%s: shanks on neither list = %+v (named %v), want rule 3", what, h, ok)
-			}
-			continue
+		if w, ok := out.Wants["shanks"]; ok {
+			t.Errorf("%s: shanks got a want: %+v", what, w)
 		}
-		// 1960: no want can name what it runs, so its first want names F rather than none: never on neither list
-		if w := out.Wants["shanks"]; w.FP != fNew {
-			t.Errorf("%s: shanks's want = %+v, want F", what, w)
-		}
-		if h, ok := out.Neither["shanks"]; ok {
-			t.Errorf("%s: shanks on neither list = %+v", what, h)
+		if h, ok := out.Neither["shanks"]; !ok || h.Rule == 0 {
+			t.Errorf("%s: shanks on neither list = %+v (named %v)", what, h, ok)
 		}
 	}
 	m, n := x11()
@@ -1070,12 +1016,10 @@ func TestNoFirstWantWithoutTheCompositionAndGrantOfWhatItRuns(t *testing.T) {
 	if len(out.Neither) != 0 {
 		t.Errorf("nodes holding a want named on neither list: %+v", out.Neither)
 	}
-	// the canary g14 moves to F (its provider's health no rule); shanks waits for it
-	if w := out.Wants["shanks"]; w.FP != "" && w.FP != fOld {
-		t.Errorf("shanks's want moved from its want past the canary: %+v", w)
-	}
-	if w := out.Wants["g14"]; w.FP != fNew {
-		t.Errorf("the canary g14's want = %+v, want F", w)
+	for node, w := range out.Wants {
+		if w.FP != fOld {
+			t.Errorf("%s's want moved from its want past the ordering rules: %+v", node, w)
+		}
 	}
 }
 
@@ -1086,12 +1030,11 @@ func TestANewAssignmentWaitingIsNotOnNeitherList(t *testing.T) {
 	m, n := x11()
 	delete(n.Haves["shanks"], "screen-lock")
 	out := Wants(m, n, nil, nil)
-	// 1960: the canary orders moves, never a first want: the new assignment is wanted at F
-	if w := out.Wants["shanks"]; w.FP != fNew {
-		t.Errorf("a new assignment while the canary does not run F: %+v, want F", w)
+	if w, ok := out.Wants["shanks"]; ok {
+		t.Errorf("a new assignment waiting for the canary got a want: %+v", w)
 	}
 	if _, ok := out.Neither["shanks"]; ok {
-		t.Errorf("a new assignment is named on neither list: %+v", out.Neither)
+		t.Errorf("a new assignment waiting for the canary is named on neither list: %+v", out.Neither)
 	}
 	m.Built = false
 	if out := Wants(m, n, nil, nil); len(out.Neither) != 1 || out.Neither["g14"].Rule != delivery.RuleBuildDone {
@@ -1133,7 +1076,7 @@ func TestANewAssignmentWaitingIsNotOnNeitherList(t *testing.T) {
 // 1945/AC21: a node whose have names an old-form build (no fingerprint of the new form, so no composition of it) can never be
 // named in a want at what it runs; its first want names F, under the canary rule as usual and with everything F needs and the
 // providers rule. Given the canary runs F healthy, shanks's first want names F; given it does not yet, shanks gets no want and
-// stays on neither list; the providers hold no want (issue 1960). The old-form node that is itself the canary gets F once its providers run healthy.
+// stays on neither list. The old-form node that is itself the canary gets F once its providers run healthy.
 func TestAnOldFormNodeGetsItsFirstWantAtFOnlyUnderTheCanary(t *testing.T) {
 	oldForm := func(n Nodes, node string) {
 		n.Haves[node]["screen-lock"] = delivery.Have{FP: "build-1792260876956849831", Phase: delivery.PhaseRunning, Health: delivery.HealthUnknown}
@@ -1167,16 +1110,16 @@ func TestAnOldFormNodeGetsItsFirstWantAtFOnlyUnderTheCanary(t *testing.T) {
 	if h, ok := out.Neither["shanks"]; !ok || h.Rule != delivery.RuleCanary {
 		t.Errorf("canary not healthy on F: shanks on neither list = %+v (named %v), want rule 3", h, ok)
 	}
-	// 1960: the canary healthy on F but the providers not healthy on shanks: F all the same, the provider down said
+	// the canary healthy on F but the providers not healthy on shanks: rule 5 still holds it back
 	m, n = x11()
 	oldForm(n, "shanks")
 	n.Haves["g14"]["screen-lock"] = delivery.Have{FP: fNew, Phase: delivery.PhaseRunning, Health: delivery.HealthOK}
 	out = Wants(m, n, nil, nil)
-	if w := out.Wants["shanks"]; w.FP != fNew || out.Unreached["shanks"] == "" {
-		t.Errorf("providers not healthy: shanks's want = %+v (unreached %q), want F, the provider said", w, out.Unreached["shanks"])
+	if w, ok := out.Wants["shanks"]; ok {
+		t.Errorf("providers not healthy: shanks got a want: %+v", w)
 	}
-	if _, on := out.Neither["shanks"]; on {
-		t.Errorf("providers not healthy: shanks on neither list: %+v", out.Neither)
+	if h := out.Neither["shanks"]; h.Rule != delivery.RuleProviders {
+		t.Errorf("providers not healthy: shanks on neither list = %+v, want rule 5", h)
 	}
 	// F not granted: nothing, even with the canary healthy
 	m, n = x11()

modules/mesh-delivery-assigner/manifest_test.go

@@ -7,7 +7,6 @@ import (
 	"testing"
 
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
-	"git.novox.be/novox/mesh-sdk/go/delivery"
 )
 
 func load(t *testing.T) catalogue.Manifest {
@@ -33,9 +32,9 @@ func TestManifest(t *testing.T) {
 	}
 	reads := slices.Clone(m.Reads)
 	slices.Sort(reads)
-	want := []string{"mesh-build-go.steps", "mesh-config.resolved", "mesh-controller.assignments", "mesh-controller.builds", "mesh-controller.composed", "mesh-controller.grants", "mesh-controller.lease",
+	want := []string{"mesh-build-go.steps", "mesh-controller.assignments", "mesh-controller.builds", "mesh-controller.composed", "mesh-controller.grants",
 		"mesh-delivery-builder.builds", "mesh-delivery-indexer.candidates", "mesh-delivery-indexer.manifests",
-		"mesh-delivery-indexer.modules", "mesh-delivery-teller.answers", "mesh-delivery-watchman.presence", "mesh-grants.grants", "node-engine.have"}
+		"mesh-delivery-indexer.modules", "mesh-delivery-indexer.placement", "mesh-delivery-indexer.placement-candidates", "mesh-delivery-teller.answers", "mesh-delivery-watchman.presence", "node-engine.have"}
 	if !reflect.DeepEqual(reads, want) {
 		t.Errorf("reads = %v, want exactly %v", reads, want)
 	}
@@ -43,8 +42,7 @@ func TestManifest(t *testing.T) {
 	for _, s := range m.State {
 		states[s.Name] = s.History
 	}
-	if want := map[string]int{"asks": 5, "compositions": 5, "differences": 64, "puts": 20, "wants": 20,
-		"placement": 64, "proposals": 5, "candidates": 5, "pulses": 0}; !reflect.DeepEqual(states, want) {
+	if want := map[string]int{"asks": 5, "compositions": 5, "differences": 64, "puts": 20, "wants": 20}; !reflect.DeepEqual(states, want) {
 		t.Errorf("state = %v, want %v", states, want)
 	}
 	if _, ok := m.OwnSecrets["broker"]; !ok || len(m.OwnSecrets) != 1 {
@@ -59,27 +57,12 @@ func TestManifest(t *testing.T) {
 		t.Errorf("uses = %v, want exactly node-build-go and operator-channel", m.Uses)
 	}
 	// ADR 0546: it serves its own tools (put, release, puts) from its bundle through the tool runner (the artifact loads the
-	// module), says each put's step as the event put, and calls the controller's warranted and the bus node's backup holder.
-	// ADR 0567 §1, §6-§10: it holds the seat mesh-placement, serving its seven verbs; keeps the seat's events on its stream
-	// placement for 30 days; calls the controller's export, its four verbs that keep its assignments in step and its
-	// hand-act log; and reads mesh-config's resolved values to compose every node a proposal touches.
-	if len(m.Claims) != 1 || m.Claims[0].Name != catalogue.PlacementSeat || m.Claims[0].At() != catalogue.ScopeMesh ||
-		!slices.Equal(m.Claims[0].Serves, []string{"placement", "proposals", "propose", "withdraw", "again", "adopt", "hand-back"}) {
-		t.Errorf("the assigner claims %+v, want mesh-placement with its seven verbs", m.Claims)
+	// module), claims no seat (a new seat needs a change of the controller), says each put's step as the event put, and
+	// calls the controller's warranted and the bus node's backup holder.
+	if len(m.Claims) != 0 || !slices.Equal(m.Tools, []string{"assigner_put", "assigner_release", "assigner_puts"}) {
+		t.Errorf("the assigner claims %v and serves tools %v, want no claim and its three put tools", m.Claims, m.Tools)
 	}
-	if seat, _ := catalogue.SeatNamed(catalogue.PlacementSeat); catalogue.CanHold(m, seat) != nil {
-		t.Errorf("the assigner cannot hold the seat: %v", catalogue.CanHold(m, seat))
-	}
-	if !slices.Equal(m.Tools, []string{"assigner_put", "assigner_release", "assigner_puts"}) {
-		t.Errorf("the assigner serves tools %v, want its three put tools", m.Tools)
-	}
-	if len(m.Streams) != 1 || m.Streams[0].Name != delivery.PlacementStream || m.Streams[0].MaxAgeDays != delivery.PlacementStreamDays ||
-		!slices.Equal(slices.Sorted(slices.Values(m.Streams[0].Events)), slices.Sorted(slices.Values(delivery.PlacementEvents))) {
-		t.Errorf("streams = %+v, want placement carrying the seat's four events for %d days", m.Streams, delivery.PlacementStreamDays)
-	}
-	if want := []string{"seat:mesh-controller.assign", "seat:mesh-controller.hand-act", "seat:mesh-controller.pin",
-		"seat:mesh-controller.placement-export", "seat:mesh-controller.unassign", "seat:mesh-controller.unpin",
-		"seat:mesh-controller.warranted", "seat:node-backup.backed-up", "seat:node-backup.now"}; !slices.Equal(slices.Sorted(slices.Values(m.Invokes)), want) {
+	if want := []string{"seat:mesh-controller.warranted", "seat:node-backup.backed-up", "seat:node-backup.now"}; !slices.Equal(slices.Sorted(slices.Values(m.Invokes)), want) {
 		t.Errorf("invokes = %v, want %v", m.Invokes, want)
 	}
 	if !slices.Equal(m.Emits, []string{"put"}) {

modules/mesh-delivery-assigner/module.json

@@ -2,36 +2,20 @@
   "module": "mesh-delivery-assigner",
   "version": "1",
   "slug": "assigner",
-  "claims": [
-    {
-      "name": "mesh-placement",
-      "scope": "mesh",
-      "serves": [
-        "placement",
-        "proposals",
-        "propose",
-        "withdraw",
-        "again",
-        "adopt",
-        "hand-back"
-      ]
-    }
-  ],
   "reads": [
     "mesh-build-go.steps",
-    "mesh-config.resolved",
     "mesh-controller.assignments",
     "mesh-controller.builds",
     "mesh-controller.composed",
     "mesh-controller.grants",
-    "mesh-controller.lease",
     "mesh-delivery-builder.builds",
     "mesh-delivery-indexer.candidates",
     "mesh-delivery-indexer.manifests",
     "mesh-delivery-indexer.modules",
+    "mesh-delivery-indexer.placement",
+    "mesh-delivery-indexer.placement-candidates",
     "mesh-delivery-teller.answers",
     "mesh-delivery-watchman.presence",
-    "mesh-grants.grants",
     "node-engine.have"
   ],
   "uses": [
@@ -39,15 +23,9 @@
     "operator-channel"
   ],
   "invokes": [
-    "seat:mesh-controller.assign",
-    "seat:mesh-controller.hand-act",
-    "seat:mesh-controller.pin",
-    "seat:mesh-controller.placement-export",
-    "seat:mesh-controller.unassign",
-    "seat:mesh-controller.unpin",
     "seat:mesh-controller.warranted",
-    "seat:node-backup.backed-up",
-    "seat:node-backup.now"
+    "seat:node-backup.now",
+    "seat:node-backup.backed-up"
   ],
   "emits": [
     "put"
@@ -58,28 +36,12 @@
     "assigner_puts"
   ],
   "state": [
-    { "name": "placement", "history": 64 },
-    { "name": "proposals", "history": 5 },
-    { "name": "candidates", "history": 5 },
-    { "name": "pulses", "key-ttl": true },
     { "name": "asks", "history": 5 },
     { "name": "compositions", "history": 5 },
     { "name": "differences", "history": 64 },
     { "name": "puts", "history": 20 },
     { "name": "wants", "history": 20 }
   ],
-  "streams": [
-    {
-      "name": "placement",
-      "events": [
-        "placement-proposed",
-        "placement-judged",
-        "placement-changed",
-        "placement-withdrawn"
-      ],
-      "max-age-days": 30
-    }
-  ],
   "own-secrets": {
     "broker": "${dir:state}/broker"
   },

modules/mesh-delivery-builder/cmd/mesh-delivery-builder-tools/main.go

@@ -7,7 +7,6 @@ package main
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -25,8 +24,8 @@ import (
 type queueAsker func(key string, value []byte) (json.RawMessage, error)
 
 // Tools are the builder's tools: stuck reads, askAgain writes the reasks value, queue writes a queues value and waits for
-// the builder's read, buildAgain writes a reasks value of mode build and waits for the builder's answer.
-func Tools(r build.StuckReader, askAgain func(key string, value []byte) error, queue, buildAgain queueAsker, now func() time.Time) []stdio.Tool {
+// the builder's read.
+func Tools(r build.StuckReader, askAgain func(key string, value []byte) error, queue queueAsker, now func() time.Time) []stdio.Tool {
 	str := func(args map[string]any, k string) string { s, _ := args[k].(string); return strings.TrimSpace(s) }
 	return []stdio.Tool{
 		{Name: build.StuckTool,
@@ -58,70 +57,6 @@ func Tools(r build.StuckReader, askAgain func(key string, value []byte) error, q
 				return map[string]any{"key": key, "asked": true,
 					"next": "the builder answers in " + build.ReAsksState + "." + key + "; " + build.StuckTool + " shows the answer and the new ask"}, nil
 			}},
-		{Name: build.BuildAgainTool,
-			Description: "Build a failed key again (rebuild a module, build a failed key again): the builder writes the key of module and " +
-				"fingerprint building as a new revision of the same key and asks the build seats, as it does by itself when it looks at a module " +
-				"again (ADR 0429 clause 18). Answers the new revision and the ask id of each build module (go, node, image). Refuses a key that " +
-				"is not failed, and says why: done (nothing to do), or waiting (building or queued: " + build.AskAgainTool + " asks its waiting asks " +
-				"again); a key failed for a reason the builder never retries on the same fingerprint (a pin missing, a version taken, digests that " +
-				"differ) and a fingerprint its module no longer has are refused too. Use it for a key builder_stuck does not show, which failed.",
-			Input: map[string]any{"type": "object", "required": []string{"module", "fp", "why"}, "properties": map[string]any{
-				"module": map[string]any{"type": "string", "description": "the module's name"},
-				"fp":     map[string]any{"type": "string", "description": "its new-form fingerprint, src2:<hex>"},
-				"why":    map[string]any{"type": "string", "description": "why it is built again, in plain words"}}},
-			Run: func(args map[string]any) (any, error) {
-				key, value, err := build.NewBuildAgain(str(args, "module"), str(args, "fp"), str(args, "why"), stdio.CallerOf(args), now())
-				if err != nil {
-					return nil, err
-				}
-				raw, err := buildAgain(key, value)
-				if err != nil {
-					return nil, err
-				}
-				r, err := build.DecodeReAsk(raw)
-				if err != nil {
-					return nil, err
-				}
-				if r.Refused {
-					return nil, errors.New(r.Answer)
-				}
-				if r.Failed != "" {
-					return nil, errors.New(r.Answer)
-				}
-				if r.Revision == 0 && !r.Pending {
-					return nil, fmt.Errorf("the builder answered neither a new revision nor a refusal (an older builder?): %s", r.Answer)
-				}
-				return map[string]any{"key": key, "revision": r.Revision, "asks": r.Asks, "answer": r.Answer,
-					"next": build.StuckTool + " shows the key and its asks while they wait"}, nil
-			}},
-		{Name: build.AnnounceAgainTool,
-			Description: "Announce a done build again (take in again, compose again): the builder writes the done key of module and fingerprint " +
-				"again, unchanged, as a new revision of the same key (its content, artifacts and manifest stay identical), so the controller's " +
-				"take-in hears it and composes the module and writes its grant again. Use it when a done build was taken in but its composition " +
-				"or grant is gone and every want is refused for it. Answers the new revision. Refuses a key that is not done: " + build.BuildAgainTool +
-				" builds a failed key again, " + build.AskAgainTool + " asks a waiting key's asks again.",
-			Input: map[string]any{"type": "object", "required": []string{"module", "fp", "why"}, "properties": map[string]any{
-				"module": map[string]any{"type": "string", "description": "the module's name"},
-				"fp":     map[string]any{"type": "string", "description": "its new-form fingerprint, src2:<hex>"},
-				"why":    map[string]any{"type": "string", "description": "why it is announced again, in plain words"}}},
-			Run: func(args map[string]any) (any, error) {
-				key, value, err := build.NewAnnounceAgain(str(args, "module"), str(args, "fp"), str(args, "why"), stdio.CallerOf(args), now())
-				if err != nil {
-					return nil, err
-				}
-				raw, err := buildAgain(key, value)
-				if err != nil {
-					return nil, err
-				}
-				r, err := build.DecodeReAsk(raw)
-				if err != nil {
-					return nil, err
-				}
-				if r.Refused || r.Revision == 0 {
-					return nil, errors.New(r.Answer)
-				}
-				return map[string]any{"key": key, "revision": r.Revision, "answer": r.Answer}, nil
-			}},
 		{Name: build.SeatQueueTool,
 			Description: "What waits on a build seat's stream (SEAT_NODE_BUILD_<LANGUAGE>), as the builder reads it: the stream's message count and " +
 				"sequences, and per kind (delivery, check, recheck) its messages oldest first, at most limit each, with sequence, ask id, when asked " +
@@ -152,17 +87,8 @@ func Tools(r build.StuckReader, askAgain func(key string, value []byte) error, q
 
 // askQueue writes the queues value at key and waits, on a watch of the key, at most bound for the builder's answer.
 func askQueue(s stdio.KeptState, bound time.Duration) queueAsker {
-	return askKept(s, build.QueuesState, build.QueuesBucket, "the read", bound, func(v []byte) bool {
-		a, err := build.DecodeQueueAsk(v)
-		return err == nil && !a.Answered.IsZero()
-	})
-}
-
-// askKept writes a value at key of a state the builder watches and answers there, and waits, on a watch of the key, at most
-// bound for a value written after it that answered says is the builder's answer.
-func askKept(s stdio.KeptState, state, bucket, what string, bound time.Duration, answered func([]byte) bool) queueAsker {
 	return func(key string, value []byte) (json.RawMessage, error) {
-		heard := make(chan json.RawMessage, 1)
+		answered := make(chan json.RawMessage, 1)
 		var rev uint64
 		var mu sync.Mutex
 		if err := s.Watch(key, func(c stdio.StateChange) error {
@@ -172,34 +98,36 @@ func askKept(s stdio.KeptState, state, bucket, what string, bound time.Duration,
 			if c.Op != "put" || mine == 0 || c.Revision <= mine {
 				return nil
 			}
-			if answered(c.Value) {
+			if a, err := build.DecodeQueueAsk(c.Value); err == nil && !a.Answered.IsZero() {
 				select {
-				case heard <- c.Value:
+				case answered <- c.Value:
 				default:
 				}
 			}
 			return nil
 		}); err != nil {
-			return nil, fmt.Errorf("watching %s.%s: %w", state, key, err)
+			return nil, fmt.Errorf("watching %s.%s: %w", build.QueuesState, key, err)
 		}
 		r, err := s.Put(key, json.RawMessage(value))
 		if err != nil {
-			return nil, fmt.Errorf("%s could not be written to %s: %w", what, bucket, err)
+			return nil, fmt.Errorf("the read could not be written to %s: %w", build.QueuesBucket, err)
 		}
 		mu.Lock()
 		rev = r
 		mu.Unlock()
 		// The watch may have heard the answer before the revision was known: read it once too.
-		if e, err := s.Get(key); err == nil && e != nil && e.Revision > r && answered(e.Value) {
-			return e.Value, nil
+		if e, err := s.Get(key); err == nil && e != nil && e.Revision > r {
+			if a, err := build.DecodeQueueAsk(e.Value); err == nil && !a.Answered.IsZero() {
+				return e.Value, nil
+			}
 		}
 		wait, cancel := context.WithTimeout(context.Background(), bound) // a context's bound, no timer (ADR 0437 §8)
 		defer cancel()
 		select {
-		case v := <-heard:
+		case v := <-answered:
 			return v, nil
 		case <-wait.Done():
-			return nil, fmt.Errorf("the builder did not answer %s.%s within %s: it is not running, or cannot read %s", state, key, bound, bucket)
+			return nil, fmt.Errorf("the builder did not answer %s.%s within %s: it is not running, or cannot read %s", build.QueuesState, key, bound, build.QueuesBucket)
 		}
 	}
 }
@@ -246,11 +174,7 @@ func main() {
 		_, err := reasks.Put(key, json.RawMessage(value))
 		return err
 	}
-	buildAgain := askKept(reasks, build.ReAsksState, build.ReAsksBucket, "the request", 25*time.Second, func(v []byte) bool {
-		a, err := build.DecodeReAsk(v)
-		return err == nil && !a.Answered.IsZero()
-	})
-	if err := stdio.Serve("", Tools(r, put, askQueue(stdio.State(build.QueuesState), 25*time.Second), buildAgain, time.Now)); err != nil {
+	if err := stdio.Serve("", Tools(r, put, askQueue(stdio.State(build.QueuesState), 25*time.Second), time.Now)); err != nil {
 		fmt.Fprintf(os.Stderr, "[mesh-delivery-builder-tools] %v\n", err)
 		os.Exit(1)
 	}

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/main.go

@@ -92,16 +92,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	hearing := buildrun.NewDeadLetterHearing(ctx, buildrun.JetStreamDeadLetters{JS: js}, delivery.AskLanguages, dead, logger.Printf,
 		buildrun.SayHearing(ctx, hearingKV, logger.Printf))
 	defer hearing.Stop()
-	// Each ask's step is heard by its own watch and, at every step end of its build module and every reconnect, read
-	// (buildrun.HearEnds): a watch that goes deaf loses no end (the lost check of 2026-10-28).
-	var buildModules []string
-	for _, l := range delivery.AskLanguages {
-		if m, err := delivery.BuildModuleOf(l); err == nil {
-			buildModules = append(buildModules, m)
-		}
-	}
-	heard := buildrun.HearEnds(ctx, asks, asks, buildModules, logger.Printf)
-	conn.SetReconnectHandler(func(*nats.Conn) { hearing.Again(); heard.Nudge("") })
+	conn.SetReconnectHandler(func(*nats.Conn) { hearing.Again() })
 	// The builder asks the controller, as its own account, whether the artifact store still holds a done key's blobs
 	// (the seat verb held, novox/hq issue 1937) before it leaves the key done.
 	calls, err := process.Connect(cred, nats.Name(cred.Node+"."+cred.Module+".calls"), nats.RetryOnFailedConnect(true))
@@ -111,7 +102,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	defer calls.Close()
 	b := &build.Builder{
 		Claimer: build.Claimer{Store: kvStore{builds}, By: cred.Node + "." + cred.Module},
-		Asks:    buildrun.Asker{Publisher: asks, Waiter: buildrun.LostAskWaiter{Inner: heard, Dead: dead, Hearing: hearing}, Bound: bound},
+		Asks:    buildrun.Asker{Publisher: asks, Waiter: buildrun.LostAskWaiter{Inner: asks, Dead: dead, Hearing: hearing}, Bound: bound},
 		Held:    heldOnTheBus{js},
 		// An ask that can no longer be answered is asked again (issue 1945), read at the step bound: a context's bound.
 		Gone:       heldOnTheBus{js},
@@ -153,11 +144,11 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	}
 	// The toolchains first, so a build that starts from the first modules value finds the nodes.
 	watch := newToolchainWatch(ctx, js, tools, b.NodesChanged, logger)
-	// Only the toolchain reports of nodes the catalogue places the build module on count (issue 1940, ADR 0549 §3): the
-	// placement is settled first, so the toolchains settle through the gate already knowing it.
-	gate := buildrun.NewToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, tools.Put, logger.Printf)
+	// Only the toolchain reports of nodes the build module is assigned to count (issue 1940): the controller's
+	// assignments are settled first, so the toolchains settle through the gate already knowing them.
+	gate := newToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, tools.Put, logger.Printf)
 	watch.put = gate.Toolchain
-	placementErrs, err := buildrun.FollowPlacement(ctx, js, gate, b.NodesChanged, logger.Printf)
+	assignErrs, err := watchAssignments(ctx, js, gate, b.NodesChanged, logger)
 	if err != nil {
 		return err
 	}
@@ -254,7 +245,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		return nil
 	case err := <-errs:
 		return err
-	case err := <-placementErrs:
+	case err := <-assignErrs:
 		return err
 	case err := <-watch.errs:
 		return err

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/reasks.go

@@ -18,14 +18,8 @@ import (
 // askAgainer is the part of the builder a reasks value asks through.
 type askAgainer interface {
 	AskAgain(key, why string) []string
-	BuildAgain(ctx context.Context, module, fp, why, by string, bound time.Duration) build.BuildAgainResult
-	AnnounceAgain(ctx context.Context, module, fp, why, by string) build.BuildAgainResult
 }
 
-// buildAgainBound is how long the builder waits for the claim and the asks of a key built again by hand; the tool waits
-// longer for the builder's answer.
-const buildAgainBound = 15 * time.Second
-
 // reAsked answers one value of the reasks state (the tool builder_ask_again, issue 1945): a value not yet answered asks the
 // key's waiting lanes again and is written back, by compare-and-set at its revision, with what the builder did. A value
 // answered already (this builder's own write) or deleted is left.
@@ -41,15 +35,6 @@ func reAsked(ctx context.Context, b askAgainer, kv jetstream.KeyValue, e jetstre
 	if r.Answer != "" {
 		return
 	}
-	if r.Mode == build.ModeBuild {
-		// The answer comes when the claim and the asks are written, so it is made beside the watch, not in it.
-		go builtAgain(ctx, b, kv, e, r, logf)
-		return
-	}
-	if r.Mode == build.ModeAnnounce {
-		announcedAgain(ctx, b, kv, e, r, logf)
-		return
-	}
 	asked := b.AskAgain(e.Key(), r.Why)
 	if len(asked) == 0 {
 		r.Answer = "no ask of this key waits in this builder now (it is not building, or its build has not reached its ask yet): nothing was asked; builder_stuck shows where it stands"
@@ -89,52 +74,3 @@ func emitAskedAgain(ctx context.Context, js jetstream.JetStream, cred process.Ac
 	}
 	return nil
 }
-
-// builtAgain answers a reasks value of mode build (the tool builder_build_again, issue 1126 note 72): the failed key is
-// built again as a new revision, and the value is written back with the revision and the asks put, or why nothing was done.
-func builtAgain(ctx context.Context, b askAgainer, kv jetstream.KeyValue, e jetstream.KeyValueEntry, r build.ReAsk, logf func(string, ...any)) {
-	res := b.BuildAgain(ctx, r.Module, r.FP, r.Why, r.By, buildAgainBound)
-	switch {
-	case res.Refused != "":
-		r.Answer, r.Refused = res.Refused, true
-	case res.Failed != "":
-		r.Answer, r.Revision, r.Failed = fmt.Sprintf("the key is written building as revision %d, and the build failed before any ask was put: %s", res.Revision, res.Failed), res.Revision, res.Failed
-	default:
-		r.Pending = res.Revision == 0
-		r.Answer, r.Revision, r.Asks = "built again: the key is written building as revision "+fmt.Sprint(res.Revision)+" and its asks are put", res.Revision, res.Asks
-		if res.Pending != "" {
-			r.Answer = res.Pending
-			if res.Revision != 0 {
-				r.Answer = "built again: the key is written building as revision " + fmt.Sprint(res.Revision) + "; " + res.Pending
-			}
-		}
-	}
-	r.Answered = time.Now().UTC()
-	logf("%s: build again asked by %s (%s): %s", e.Key(), r.By, r.Why, r.Answer)
-	data, err := json.Marshal(r)
-	if err != nil {
-		return
-	}
-	if _, err := kv.Update(ctx, e.Key(), data, e.Revision()); err != nil && !errors.Is(err, jetstream.ErrKeyExists) && !errors.Is(err, jetstream.ErrKeyRevisionMismatch) {
-		logf("%s.%s: the answer could not be written: %v", build.ReAsksState, e.Key(), err)
-	}
-}
-
-// announcedAgain answers a reasks value of mode announce (the tool builder_announce_again): the done key is written again
-// unchanged, and the value is written back with the new revision, or why nothing was done.
-func announcedAgain(ctx context.Context, b askAgainer, kv jetstream.KeyValue, e jetstream.KeyValueEntry, r build.ReAsk, logf func(string, ...any)) {
-	res := b.AnnounceAgain(ctx, r.Module, r.FP, r.Why, r.By)
-	if res.Refused != "" {
-		r.Answer, r.Refused = res.Refused, true
-	} else {
-		r.Revision, r.Answer = res.Revision, fmt.Sprintf("announced again: the done key is written again, unchanged, as revision %d", res.Revision)
-	}
-	r.Answered = time.Now().UTC()
-	data, err := json.Marshal(r)
-	if err != nil {
-		return
-	}
-	if _, err := kv.Update(ctx, e.Key(), data, e.Revision()); err != nil && !errors.Is(err, jetstream.ErrKeyExists) && !errors.Is(err, jetstream.ErrKeyRevisionMismatch) {
-		logf("%s.%s: the answer could not be written: %v", build.ReAsksState, e.Key(), err)
-	}
-}

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/refused_test.go

@@ -1,73 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"log"
-	"strings"
-	"testing"
-
-	"git.novox.be/novox/mesh-sdk/go/process"
-
-	"github.com/nats-io/nats.go/jetstream"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
-)
-
-// 1945 (a part exits at start for a bucket it works without): a bus that refuses every toolchains bucket leaves the
-// watch unstarted and the part running, said; a refused bucket it cannot work without is an error naming the bucket and
-// its grant. The gate over the seat's placement, and its refusal, are mesh-sdk's (buildrun.ToolchainGate,
-// issue 774).
-func TestARefusedBucketIsSaidAndThePartGoesOn(t *testing.T) {
-	set := &buildrun.ToolchainSet{}
-	var logs bytes.Buffer
-	logger := log.New(&logs, "", 0)
-	refused := refusingBus{err: errors.New("nats: permissions violation for publish to $JS.API.CONSUMER.CREATE.KV_mesh-build-node_toolchains")}
-	if err := newToolchainWatch(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, set, func(context.Context) {}, logger).start(); err != nil {
-		t.Errorf("a refused toolchains bucket stopped the start: %v", err)
-	}
-	if !strings.Contains(logs.String(), "cannot be read") {
-		t.Errorf("the refusals were not said: %q", logs.String())
-	}
-	if _, err := process.EssentialBucket(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, "builder", "mesh-delivery-indexer_modules", "work"); err == nil ||
-		!strings.Contains(err.Error(), "grant of mesh-delivery-indexer_modules") {
-		t.Errorf("a refused bucket the part needs: %v, want an error naming its grant", err)
-	}
-	// The gate's source (the previews' trunk heads): refused at start, the builder goes on, and a candidate asking a trunk
-	// head is told why and opens it again then.
-	src := &trunkSource{ctx: context.Background(), js: refusingBus{refuseOpen: true, err: refused.err}, heads: &sourceHeads{}, errs: make(chan error, 1), logf: logger.Printf}
-	src.start()
-	if _, err := src.head(context.Background(), 7, "novox/mesh-catalog"); err == nil || !strings.Contains(err.Error(), delivery.SourceBucket) {
-		t.Errorf("a trunk head with the source refused: %v, want why", err)
-	}
-	if src.opened {
-		t.Error("a refused source counts as opened, so it is never opened again")
-	}
-}
-
-// refusingBus is a bus that refuses: every open (refuseOpen), or every watch of a bucket it opens, with err.
-type refusingBus struct {
-	refuseOpen bool
-	err        error
-}
-
-func (r refusingBus) KeyValue(context.Context, string) (jetstream.KeyValue, error) {
-	if r.refuseOpen {
-		return nil, r.err
-	}
-	return refusedWatch{err: r.err}, nil
-}
-
-type refusedWatch struct {
-	jetstream.KeyValue
-	err error
-}
-
-func (r refusedWatch) WatchAll(context.Context, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
-	return nil, r.err
-}
-func (r refusedWatch) Watch(context.Context, string, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
-	return nil, r.err
-}

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/standing.go

@@ -0,0 +1,211 @@
+package main
+
+// This file is the same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker (issue 1940): it moves
+// to mesh-sdk go/delivery/buildrun once mesh-sdk can be delivered again, since a change of mesh-sdk waits on the very
+// toolchain agreement this file repairs.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"maps"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/provider"
+)
+
+// A build module writes <node>.<language> of its toolchains state on every node it runs on, and nothing deletes the key
+// when the module is unassigned from a node: the controller writes no module's state, and the module is gone. A report of
+// a node the build module no longer runs on is therefore not a builder (issue 1940: mesh-build-node unassigned from ace
+// on 2026-10-23 left ace.typescript at v26.12.0, and every Node fingerprint said "builders disagree").
+//
+// toolchainGate stands between the toolchains buckets and what takes their entries in (the indexer's PutToolchain, a
+// buildrun.ToolchainSet): an entry is passed on only while the controller's assignments (mesh-controller_assignments,
+// key <node>.<module>) hold an open assignment of its build module on its node, and only once it was written since that
+// assignment; it is passed on as deleted otherwise, said once, and passed on when its node writes it again. A report
+// written before the assignment is the one an earlier run of the module left (issue 1940, 2026-10-25 20:56: mesh-build-node
+// assigned to ace again brought ace.typescript v26.12.0 of 2026-10-23 back into the agreement, before the module ran
+// there, and the controller's take-in refused every module "builders disagree"). Until the assignments are settled (or where they cannot
+// be read) every entry is passed on, as before. Builders that run and report different versions still disagree: that
+// refusal is the guard of novox/hq ADR 0465, and it stays.
+type toolchainGate struct {
+	mu       sync.Mutex
+	modules  map[string]bool                                           // the build modules whose toolchains pass the gate
+	forward  func(module, key string, value []byte, deleted bool) bool // answers whether it changed what it holds
+	logf     func(format string, a ...any)
+	known    bool                         // the assignments are settled
+	standing map[string]time.Time         // <node>.<module> with an open assignment -> since when it stands
+	raw      map[string]map[string][]byte // module -> toolchains key -> value, as the bucket holds it
+	left     map[string]string            // <module>/<key> -> why it was said left out, so each reason is said once
+}
+
+func newToolchainGate(modules []string, forward func(module, key string, value []byte, deleted bool) bool, logf func(string, ...any)) *toolchainGate {
+	g := &toolchainGate{modules: map[string]bool{}, forward: forward, logf: logf, standing: map[string]time.Time{},
+		raw: map[string]map[string][]byte{}, left: map[string]string{}}
+	for _, m := range modules {
+		g.modules[m] = true
+	}
+	return g
+}
+
+// Toolchain takes one change of a build module's toolchains bucket in and answers whether what it passed on changed.
+func (g *toolchainGate) Toolchain(module, key string, value []byte, deleted bool) bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	if g.raw[module] == nil {
+		g.raw[module] = map[string][]byte{}
+	}
+	if deleted {
+		delete(g.raw[module], key)
+	} else {
+		g.raw[module][key] = value
+	}
+	return g.pass(module, key)
+}
+
+// Assignment takes one change of the controller's assignments in (at is when the bus wrote that revision) and answers
+// whether what it passed on changed.
+func (g *toolchainGate) Assignment(key string, value []byte, deleted bool, at time.Time) bool {
+	node, module, ok := strings.Cut(key, ".")
+	if !ok || !g.modules[module] {
+		return false
+	}
+	assigned, open := openAssignment(value)
+	open = open && !deleted
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	was, stood := g.standing[key]
+	since := assigned
+	if since.IsZero() {
+		// A value with no time of its own (an assignment a module pulled in) stands since the revision that opened it.
+		since = at
+		if stood {
+			since = was
+		}
+	}
+	if open == stood && (!open || since.Equal(was)) {
+		return false
+	}
+	if open {
+		g.standing[key] = since
+	} else {
+		delete(g.standing, key)
+	}
+	if !g.known {
+		return false
+	}
+	changed := false
+	for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+		if n, _, err := delivery.ParseToolchainKey(k); err == nil && n == node {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// Settled says the assignments are read: from now on only the reports of assigned nodes pass. It answers whether what it
+// passed on changed.
+func (g *toolchainGate) Settled() bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	g.known = true
+	changed := false
+	for _, module := range slices.Sorted(maps.Keys(g.raw)) {
+		for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// pass hands one key on as it stands: its value when its node is assigned and wrote it since (or the assignments are not
+// known), deleted otherwise. The caller holds mu.
+func (g *toolchainGate) pass(module, key string) bool {
+	value, held := g.raw[module][key]
+	if !held {
+		return g.forward(module, key, nil, true)
+	}
+	node, _, err := delivery.ParseToolchainKey(key)
+	why := ""
+	if err == nil && g.known {
+		why = g.leftOut(module, node, value)
+	}
+	if why == "" {
+		delete(g.left, module+"/"+key)
+		return g.forward(module, key, value, false)
+	}
+	if g.left[module+"/"+key] != why {
+		g.left[module+"/"+key] = why
+		g.logf("%s.%s is left out of the agreed toolchain: %s (issue 1940)", delivery.ToolchainsBucket(module), key, why)
+	}
+	return g.forward(module, key, nil, true)
+}
+
+// leftOut is why a node's report is no builder's, or empty when it counts: its node has no open assignment of the module,
+// or the report was written before that assignment. A value that is no toolchain is passed on for its reader to refuse.
+// The caller holds mu.
+func (g *toolchainGate) leftOut(module, node string, value []byte) string {
+	since, open := g.standing[node+"."+module]
+	if !open {
+		return fmt.Sprintf("%s has no assignment on %s, so it is no builder", module, node)
+	}
+	tc, err := delivery.DecodeToolchain(value)
+	if err == nil && tc.At.Before(since) {
+		return fmt.Sprintf("it was written at %s, before %s's assignment on %s at %s: it counts once %s writes it again",
+			tc.At.UTC().Format(time.RFC3339), module, node, since.UTC().Format(time.RFC3339), node)
+	}
+	return ""
+}
+
+// openAssignment is whether a value of the controller's assignments holds an assignment that stands (one that has not
+// ended and has no state: a pending one is not on the machine yet; mesh-controller internal/chain Assignment), and when
+// it was assigned, zero where the value does not say.
+func openAssignment(value []byte) (time.Time, bool) {
+	var a struct {
+		Assigned time.Time `json:"assigned"`
+		Ended    time.Time `json:"ended"`
+		State    string    `json:"state"`
+	}
+	if json.Unmarshal(value, &a) != nil {
+		return time.Time{}, false
+	}
+	return a.Assigned, a.Ended.IsZero() && a.State == ""
+}
+
+// watchAssignments settles the controller's assignments into the gate, says them settled, and follows them; changed is
+// told whenever what the gate passes on changed. Where the bucket cannot be read (not there, or this module may not read
+// it) it says so and the gate passes every report on, as before; an error of the watch after that ends on the channel.
+func watchAssignments(ctx context.Context, js bucketOpener, gate *toolchainGate, changed func(context.Context), logger *log.Logger) (<-chan error, error) {
+	errs := make(chan error, 1)
+	kv, err := js.KeyValue(ctx, provider.AssignmentsBucket)
+	if err != nil {
+		// Not fatal: an indexer, builder or checker that stops for it stops every delivery (a grant comes with a delivery).
+		logger.Printf("the bucket %s cannot be read, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	each := func(e jetstream.KeyValueEntry) { gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) }
+	w, err := settle(ctx, kv, each)
+	if err != nil {
+		// Not fatal either (issue 1945): a watch the bus refuses is the same missing grant as a refused read.
+		logger.Printf("the bucket %s cannot be watched, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	if gate.Settled() {
+		changed(ctx)
+	}
+	go func() {
+		errs <- follow(ctx, w, func(e jetstream.KeyValueEntry) {
+			if gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) {
+				changed(ctx)
+			}
+		})
+	}()
+	return errs, nil
+}

modules/mesh-delivery-builder/cmd/mesh-delivery-builder/standing_test.go

@@ -0,0 +1,228 @@
+package main
+
+// The same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker, as standing.go is (issue 1940).
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"strings"
+	"testing"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/process"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
+)
+
+func gateReport(t *testing.T, node, version string) (string, []byte) {
+	t.Helper()
+	key, err := delivery.ToolchainKey(node, "typescript")
+	if err != nil {
+		t.Fatal(err)
+	}
+	value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: time.Unix(0, 0).UTC()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return key, value
+}
+
+func agreedOf(set *buildrun.ToolchainSet) (string, string) {
+	tc, none := delivery.AgreedToolchain(set.Entries("typescript"))
+	return tc.Version, none
+}
+
+// The live case of issue 1940: mesh-build-node was unassigned from ace, whose report stayed at v26.12.0 while the
+// three nodes it runs on report v26.12.1. Without the assignments every report counts (and they disagree); with them
+// ace's is left out and the three agree; assigned to ace again, its report counts again and the guard refuses again.
+func TestAnUnassignedBuildNodesReportIsNoBuilder(t *testing.T) {
+	set := &buildrun.ToolchainSet{}
+	var said []string
+	gate := newToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, f) })
+	for node, version := range map[string]string{"ace": "v26.12.0", "g14": "v26.12.1", "novox": "v26.12.1", "shanks": "v26.12.1"} {
+		key, value := gateReport(t, node, version)
+		gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree") {
+		t.Fatalf("before the assignments are read every report counts, so they disagree; got %q", none)
+	}
+	for _, node := range []string{"g14", "novox", "shanks"} {
+		gate.Assignment(node+"."+buildrun.NodeBuildModule, []byte(`{"node":"`+node+`","module":"mesh-build-node"}`), false, time.Time{})
+	}
+	gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","ended":"2026-10-23T08:00:00Z"}`), false, time.Time{})
+	gate.Assignment("ace.mesh-build-go", []byte(`{"node":"ace","module":"mesh-build-go"}`), false, time.Time{}) // another module's: no matter
+	if !gate.Settled() {
+		t.Fatal("settling the assignments left ace's report out, so what was passed on changed")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("the assigned nodes agree on v26.12.1; got %q, %q", v, none)
+	}
+	if len(said) != 1 {
+		t.Fatalf("ace's report is said left out once; said %v", said)
+	}
+	// ace reports again while unassigned (an old value seen again): still left out.
+	key, value := gateReport(t, "ace", "v26.12.0")
+	if gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+		t.Fatal("an unassigned node's report changed what was passed on")
+	}
+	// Assigned to ace again: its report counts, and the builders really disagree: the guard stays.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node"}`), false, time.Time{}) {
+		t.Fatal("assigning ace again passed nothing on")
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+		t.Fatalf("builders that run different versions still disagree; got %q", none)
+	}
+	// The assignment's key deleted, or a pending one written: no assignment stands, and ace's report goes again.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","state":"pending"}`), false, time.Time{}) {
+		t.Fatal("a pending assignment is no assignment on the machine")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("got %q, %q", v, none)
+	}
+	gate.Assignment("ace.mesh-build-node", nil, true, time.Time{})
+	if v, _ := agreedOf(set); v != "v26.12.1" {
+		t.Fatalf("got %q", v)
+	}
+	// A report deleted from the bucket goes whether its node is assigned or not.
+	key, _ = gateReport(t, "g14", "v26.12.1")
+	if !gate.Toolchain(buildrun.NodeBuildModule, key, nil, true) {
+		t.Fatal("deleting g14's report passed nothing on")
+	}
+	if n := len(set.Entries("typescript")); n != 2 {
+		t.Fatalf("novox and shanks are left; got %d entries", n)
+	}
+
+	// 1945 (a part exits at start for a bucket it works without): a bus that refuses the assignments' watch, or every
+	// toolchains bucket, leaves the watches unstarted and the part running, said; a refused bucket it cannot work without
+	// is an error naming the bucket and its grant.
+	var logs bytes.Buffer
+	logger := log.New(&logs, "", 0)
+	refused := refusingBus{err: errors.New("nats: permissions violation for publish to $JS.API.CONSUMER.CREATE.KV_mesh-controller_assignments")}
+	if _, err := watchAssignments(context.Background(), refused, newToolchainGate(nil, set.Put, t.Logf), func(context.Context) {}, logger); err != nil {
+		t.Errorf("a refused watch of the assignments stopped the start: %v", err)
+	}
+	if err := newToolchainWatch(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, set, func(context.Context) {}, logger).start(); err != nil {
+		t.Errorf("a refused toolchains bucket stopped the start: %v", err)
+	}
+	if !strings.Contains(logs.String(), "cannot be watched") || !strings.Contains(logs.String(), "cannot be read") {
+		t.Errorf("the refusals were not said: %q", logs.String())
+	}
+	if _, err := process.EssentialBucket(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, "builder", "mesh-delivery-indexer_modules", "work"); err == nil ||
+		!strings.Contains(err.Error(), "grant of mesh-delivery-indexer_modules") {
+		t.Errorf("a refused bucket the part needs: %v, want an error naming its grant", err)
+	}
+	// The gate's source (the previews' trunk heads): refused at start, the builder goes on, and a candidate asking a trunk
+	// head is told why and opens it again then.
+	src := &trunkSource{ctx: context.Background(), js: refusingBus{refuseOpen: true, err: refused.err}, heads: &sourceHeads{}, errs: make(chan error, 1), logf: logger.Printf}
+	src.start()
+	if _, err := src.head(context.Background(), 7, "novox/mesh-catalog"); err == nil || !strings.Contains(err.Error(), delivery.SourceBucket) {
+		t.Errorf("a trunk head with the source refused: %v, want why", err)
+	}
+	if src.opened {
+		t.Error("a refused source counts as opened, so it is never opened again")
+	}
+}
+
+// refusingBus is a bus that refuses: every open (refuseOpen), or every watch of a bucket it opens, with err.
+type refusingBus struct {
+	refuseOpen bool
+	err        error
+}
+
+func (r refusingBus) KeyValue(context.Context, string) (jetstream.KeyValue, error) {
+	if r.refuseOpen {
+		return nil, r.err
+	}
+	return refusedWatch{err: r.err}, nil
+}
+
+type refusedWatch struct {
+	jetstream.KeyValue
+	err error
+}
+
+func (r refusedWatch) WatchAll(context.Context, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
+	return nil, r.err
+}
+func (r refusedWatch) Watch(context.Context, string, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
+	return nil, r.err
+}
+
+// A build node's report counts from the first one it writes since its assignment: a newly assigned node that has not
+// reported changes nothing, and the report an earlier run left on the bus (issue 1940, 2026-10-25 20:56: ace.typescript
+// v26.12.0 of 2026-10-23 06:29, mesh-build-node assigned to ace again at 20:56:45) is left out, said once, until the node
+// writes it again. An assignment whose value names no time stands since the revision that opened it.
+func TestANewlyAssignedNodeCountsFromItsReport(t *testing.T) {
+	left := time.Date(2026, 10, 23, 6, 29, 18, 0, time.UTC)      // ace's report from its earlier run
+	assigned := time.Date(2026, 10, 25, 19, 56, 45, 0, time.UTC) // mesh-build-node assigned to ace again
+	report := func(t *testing.T, node, version string, at time.Time) (string, []byte) {
+		key, _ := gateReport(t, node, version)
+		value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: at})
+		if err != nil {
+			t.Fatal(err)
+		}
+		return key, value
+	}
+	for _, c := range []struct {
+		name       string
+		assignment string    // ace's assignment value
+		revision   time.Time // when the bus wrote it
+		at         time.Time // when ace wrote its report
+		counts     bool
+	}{
+		{"no report yet, then one", `{}`, time.Time{}, time.Now(), true},
+		{"a report left before the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, left, false},
+		{"a report left before a value with no time", `{"node":"ace","module":"mesh-build-node"}`, assigned, left, false},
+		{"a report written since the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, assigned.Add(30 * time.Second), true},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			set := &buildrun.ToolchainSet{}
+			var said []string
+			gate := newToolchainGate([]string{buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, fmt.Sprintf(f, a...)) })
+			for _, node := range []string{"g14", "novox", "shanks"} {
+				gate.Assignment(node+".mesh-build-node", []byte(`{}`), false, time.Time{})
+				key, value := gateReport(t, node, "v26.12.1")
+				gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+			}
+			gate.Settled()
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision) {
+				t.Fatal("an assignment with no report passed something on")
+			}
+			key, value := report(t, "ace", "v26.12.0", c.at)
+			if got := gate.Toolchain(buildrun.NodeBuildModule, key, value, false); got != c.counts {
+				t.Fatalf("ace's report passed on: %v, want %v", got, c.counts)
+			}
+			// A rewrite of the assignment that does not move it changes nothing, and nothing is said again.
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision.Add(time.Minute)) {
+				t.Fatal("the same assignment written again changed what was passed on")
+			}
+			v, none := agreedOf(set)
+			if c.counts {
+				if !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+					t.Fatalf("ace's own report counts and disagrees; got %q, %q", v, none)
+				}
+				return
+			}
+			if v != "v26.12.1" || none != "" {
+				t.Fatalf("ace's left report is no builder's, so g14, novox and shanks agree; got %q, %q", v, none)
+			}
+			if len(said) != 1 || !strings.Contains(said[0], "before mesh-build-node's assignment on ace at 2026-10-25T19:56:45Z") {
+				t.Fatalf("said %q, want once why ace's report is left out", said)
+			}
+			// ace writes its report again since it was assigned: it counts.
+			key, value = report(t, "ace", "v26.12.1", assigned.Add(time.Minute))
+			if !gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+				t.Fatal("ace's new report was not passed on")
+			}
+			if n := len(set.Entries("typescript")); n != 4 {
+				t.Fatalf("four builders report; got %d", n)
+			}
+		})
+	}
+}

modules/mesh-delivery-builder/go.mod

@@ -3,7 +3,7 @@ module mesh-delivery-builder
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-delivery-builder/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a h1:nhRFmtdcI4VkghGUdJhpt1BnPuTQcekioOIRzW8fcG0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952 h1:TmveT3Bija643RGWkilvkzP/h8UWlVvHFZZtQfJK5oU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-delivery-builder/internal/build/announce.go

@@ -1,53 +0,0 @@
-package build
-
-import (
-	"context"
-	"errors"
-	"fmt"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-// **A done build is announced again by hand** (recovery of photos and link2pay on novox, 2026-10-29). The controller takes a
-// build in when a write of the build key reaches its take-in consumer, and composes then; a done key is never written again
-// by the builder, so a composition or a grant lost afterwards could not be made again by any tool. AnnounceAgain writes the
-// done key again with its own bytes, as a new revision of the same key: its content, state, artifacts and manifest stay
-// identical, and only the write is new. Who asked and why is in the builder's log and in the reasks answer.
-
-// AnnounceAgain rewrites the done key of module at fp unchanged, as a new revision, and answers the revision. A key that is
-// not done is refused with why: failed (builder_build_again builds it) or waiting (builder_ask_again).
-func (b *Builder) AnnounceAgain(ctx context.Context, module, fp, why, by string) BuildAgainResult {
-	b.init()
-	key, err := delivery.BuilderBuildKey(module, fp)
-	if err != nil {
-		return BuildAgainResult{Refused: err.Error()}
-	}
-	value, rev, found, err := b.Claimer.Store.Get(ctx, key)
-	if err != nil {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s cannot be read: %v", key, err)}
-	}
-	if !found {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s has no build key: nothing to announce", key)}
-	}
-	cur, err := delivery.DecodeBuilderBuild(value)
-	if err != nil {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s holds what is not a build: %v", key, err)}
-	}
-	switch cur.State {
-	case delivery.BuildDone:
-	case delivery.BuildFailed:
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is failed, not done: %s builds it again", key, BuildAgainTool)}
-	default:
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is %q, not done: %s asks its waiting asks again", key, cur.State, AskAgainTool)}
-	}
-	// Compare-and-set at the revision read: a build written meanwhile is not overwritten.
-	nrev, err := b.Claimer.Store.Update(ctx, key, value, rev)
-	if err != nil {
-		if errors.Is(err, ErrConflict) {
-			return BuildAgainResult{Refused: fmt.Sprintf("%s changed while it was announced: read it again", key)}
-		}
-		return BuildAgainResult{Refused: fmt.Sprintf("%s could not be written: %v", key, err)}
-	}
-	b.logf("%s: done, announced again by %s (revision %d): %s", key, by, nrev, why)
-	return BuildAgainResult{Revision: nrev}
-}

modules/mesh-delivery-builder/internal/build/announce_test.go

@@ -1,49 +0,0 @@
-package build
-
-import (
-	"bytes"
-	"context"
-	"strings"
-	"testing"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-func TestAnnounceAgainRewritesOnlyADoneKeyUnchanged(t *testing.T) { // recovery of photos and link2pay, 2026-10-29
-	for _, c := range []struct {
-		name   string
-		key    *delivery.BuilderBuild
-		fp     string
-		refuse string
-	}{
-		{name: "a done key is written again, unchanged, as a new revision", key: &delivery.BuilderBuild{State: delivery.BuildDone, Step: "built"}},
-		{name: "a failed key is refused, builder_build_again is for it", refuse: "builder_build_again", key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "x"}},
-		{name: "a building key is refused, builder_ask_again is for it", refuse: "builder_ask_again", key: &delivery.BuilderBuild{State: delivery.BuildBuilding, By: "novox.builder", Step: "asked"}},
-		{name: "a key with no build is refused", refuse: "has no build key"},
-		{name: "a fingerprint that is not one is refused", refuse: "fingerprint", fp: "nope"},
-	} {
-		t.Run(c.name, func(t *testing.T) {
-			r := newRig(t, goBundle)
-			var rev uint64
-			if c.key != nil {
-				c.key.Manifest = manifestD
-				rev = putBuild(t, r.st, r.key, *c.key)
-			}
-			before := bytes.Clone(r.st.vals[r.key])
-			fp := fp1
-			if c.fp != "" {
-				fp = c.fp
-			}
-			res := r.b.AnnounceAgain(context.Background(), "m", fp, "grant lost", "shanks.lead")
-			if c.refuse != "" {
-				if !strings.Contains(res.Refused, c.refuse) || res.Revision != 0 || r.st.revs[r.key] != rev || !bytes.Equal(r.st.vals[r.key], before) {
-					t.Fatalf("answer %+v, key at revision %d (was %d); want refused with %q and nothing written", res, r.st.revs[r.key], rev, c.refuse)
-				}
-				return
-			}
-			if res.Refused != "" || res.Revision <= rev || r.st.revs[r.key] != res.Revision || !bytes.Equal(r.st.vals[r.key], before) {
-				t.Fatalf("answer %+v, key at revision %d (was %d); want a new revision and the same bytes", res, r.st.revs[r.key], rev)
-			}
-		})
-	}
-}

modules/mesh-delivery-builder/internal/build/buildagain.go

@@ -1,183 +0,0 @@
-package build
-
-import (
-	"context"
-	"fmt"
-	"maps"
-	"strings"
-	"time"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
-)
-
-// **A failed key is built again by hand** (novox/hq issue 1126 note 72; ADR 0429 clause 18: "a fingerprint is built again
-// only when its build key failed, as a new revision of the same key"). The builder does it by itself whenever it looks at a
-// module again (a modules value, a change of the toolchains, artifacts-gone, a moved trunk): Claimer.Claim writes a failed
-// key building as a new revision and the build asks the build seats. Nothing looks at an unchanged module on its own, so a key
-// that failed (a node refused the build, a toolchain was missing) stayed failed until the module changed. The tool
-// builder_build_again (BuildAgain) makes the builder look at one module now, which does exactly that and no more: it keeps
-// the claim's rules, so a key failed for a reason the builder never retries on the same fingerprint stays refused.
-
-// BuildAgainResult is the builder's answer to a request to build a key again.
-type BuildAgainResult struct {
-	// Refused is why nothing was done, "" when the key was written building as a new revision.
-	Refused string
-	// Revision is the revision the claim wrote; Asks are the ask ids put by language, as far as they were put within the bound.
-	Revision uint64
-	Asks     map[string]string
-	// Pending says the builder had not claimed the key, or not put every ask, when it answered: not a refusal.
-	Pending string
-	// Failed is the error of the key when the build ended failed before its asks were put (a plan that cannot be read, a
-	// toolchain not agreed): the new revision was written, and nothing was asked.
-	Failed string
-}
-
-// handWatch follows one request to build a key again until its asks are put.
-type handWatch struct {
-	rev   uint64
-	lanes int
-	asks  map[string]string
-	done  chan struct{}
-	shut  bool
-	// ended is set when the look ended before the asks were all put.
-	ended bool
-}
-
-// settle closes done once the claim is written and every lane has put its ask. Call with b.mu held.
-func (w *handWatch) settle() {
-	if !w.shut && w.rev > 0 && w.lanes >= 0 && len(w.asks) >= w.lanes {
-		w.shut = true
-		close(w.done)
-	}
-}
-
-func (b *Builder) hand(key string, f func(w *handWatch)) {
-	b.mu.Lock()
-	defer b.mu.Unlock()
-	if w := b.hands[key]; w != nil {
-		f(w)
-	}
-}
-
-func (b *Builder) handClaimed(key string, rev uint64) {
-	b.hand(key, func(w *handWatch) { w.rev = rev; w.settle() })
-}
-
-func (b *Builder) handLanes(key string, n int) {
-	b.hand(key, func(w *handWatch) { w.lanes = n; w.settle() })
-}
-
-func (b *Builder) handAsk(key, language, id string) {
-	b.hand(key, func(w *handWatch) { w.asks[language] = id; w.settle() })
-}
-
-// handEnded ends the watch of a request whose look ended: it wrote no claim, or the build ended.
-func (b *Builder) handEnded(key string) {
-	b.hand(key, func(w *handWatch) {
-		if !w.shut {
-			w.shut, w.ended = true, true
-			close(w.done)
-		}
-	})
-}
-
-// BuildAgain builds the failed key of module at fp again, as the builder does by itself: the key is written building as a
-// new revision and the build module asks are put on the build seats. It answers once the asks are put, or at bound. A key
-// that is not failed is refused with why: done (nothing to do) or waiting (builder_ask_again asks its waiting asks again).
-// ctx is the builder's own context: the build it starts lives on it.
-func (b *Builder) BuildAgain(ctx context.Context, module, fp, why, by string, bound time.Duration) BuildAgainResult {
-	b.init()
-	key, err := delivery.BuilderBuildKey(module, fp)
-	if err != nil {
-		return BuildAgainResult{Refused: err.Error()}
-	}
-	value, _, found, err := b.Claimer.Store.Get(ctx, key)
-	if err != nil {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s cannot be read: %v", key, err)}
-	}
-	if !found {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s has no build key: nothing failed. The builder builds a fingerprint by itself once the indexer writes it to its module", key)}
-	}
-	cur, err := delivery.DecodeBuilderBuild(value)
-	if err != nil {
-		return BuildAgainResult{Refused: fmt.Sprintf("%s holds what is not a build: %v", key, err)}
-	}
-	switch {
-	case cur.State == delivery.BuildDone:
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is done: nothing to do", key)}
-	case cur.State == delivery.BuildBuilding || cur.State == delivery.BuildQueued:
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is waiting (%s: %s): %s asks its waiting asks again", key, cur.State, cur.Step, AskAgainTool)}
-	case cur.State != delivery.BuildFailed:
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is %q, not failed", key, cur.State)}
-	case delivery.FailedUntilChanged(cur.Error) || strings.HasPrefix(cur.Error, buildrun.DigestsDifferPrefix):
-		return BuildAgainResult{Refused: fmt.Sprintf("%s failed for a reason the builder does not retry on the same fingerprint, it waits for another fingerprint: %s", key, cur.Error)}
-	}
-	// One critical section: the key is refused when it is looked at or asked already, the module still has the fingerprint,
-	// and the watch and the look are registered before anything else can take the key.
-	w := &handWatch{lanes: -1, asks: map[string]string{}, done: make(chan struct{})}
-	b.mu.Lock()
-	m, known := b.known[module]
-	switch {
-	case !known || m.FP2 != fp:
-		b.mu.Unlock()
-		return BuildAgainResult{Refused: fmt.Sprintf("module %s does not have the fingerprint %s now (a newer one superseded it, or its modules value is not read yet): the builder builds the module's current fingerprint", module, fp)}
-	case m.Manifest == "":
-		b.mu.Unlock()
-		return BuildAgainResult{Refused: fmt.Sprintf("module %s names no manifest at %s yet, so the builder looks at nothing", module, fp)}
-	case b.inflight[key] || b.hands[key] != nil:
-		b.mu.Unlock()
-		return BuildAgainResult{Refused: fmt.Sprintf("%s is being looked at by this builder now (or asked again by hand): wait for it to end", key)}
-	}
-	b.hands[key] = w
-	b.inflight[key] = true
-	b.mu.Unlock()
-	defer func() {
-		b.mu.Lock()
-		if b.hands[key] == w {
-			delete(b.hands, key)
-		}
-		b.mu.Unlock()
-	}()
-	b.logf("%s: failed (%s); built again by hand, asked by %s: %s", key, cur.Error, by, why)
-	b.startOnce(ctx, key, module, m)
-	wait, stop := context.WithTimeout(ctx, bound) // a context's bound for a person's answer (ADR 0437 §8)
-	defer stop()
-	select {
-	case <-w.done:
-	case <-wait.Done():
-	}
-	b.mu.Lock()
-	res := BuildAgainResult{Revision: w.rev, Asks: maps.Clone(w.asks)}
-	ended, shut, lanes := w.ended, w.shut, w.lanes
-	b.mu.Unlock()
-	switch {
-	case res.Revision == 0 && shut:
-		res.Refused = fmt.Sprintf("the builder looked at %s and wrote nothing (a toolchain moved, the claim was lost or could not be written): its log says why", key)
-	case res.Revision == 0:
-		res.Pending = fmt.Sprintf("the builder has not claimed %s within %s: it waits behind other builds; builder_stuck shows where it stands", key, bound)
-	case ended && len(res.Asks) < max(lanes, 0)+boolInt(lanes < 0):
-		// The look ended before every ask was put: say how the key stands, not that it was asked.
-		if v, _, found, err := b.Claimer.Store.Get(ctx, key); err == nil && found {
-			if cur, err := delivery.DecodeBuilderBuild(v); err == nil {
-				switch cur.State {
-				case delivery.BuildFailed:
-					res.Failed = cur.Error
-				case delivery.BuildDone:
-				default:
-					res.Pending = fmt.Sprintf("the look ended with the key %s (%s) before every ask was put: its log says why", cur.State, cur.Step)
-				}
-			}
-		}
-	case !shut:
-		res.Pending = fmt.Sprintf("the key is building at revision %d, and not every ask was put within %s; builder_stuck shows the asks", res.Revision, bound)
-	}
-	return res
-}
-
-func boolInt(b bool) int {
-	if b {
-		return 1
-	}
-	return 0
-}

modules/mesh-delivery-builder/internal/build/run.go

@@ -89,8 +89,6 @@ type Builder struct {
 	held map[string]bool
 	// waiting are the lanes that wait for an ask's step, by build key and language: AskAgain asks through them.
 	waiting map[string]map[string]chan string
-	// hands are the requests to build a key again by hand that wait for the claim and its asks (BuildAgain), by build key.
-	hands map[string]*handWatch
 }
 
 type planned struct {
@@ -108,7 +106,6 @@ func (b *Builder) init() {
 		b.cands, b.via, b.trunkFP = map[string]delivery.Candidate{}, map[string]via{}, map[string]bool{}
 		b.known, b.inflight, b.again, b.plans, b.tried = map[string]delivery.Module{}, map[string]bool{}, map[string]delivery.Module{}, map[string]planned{}, map[string]bool{}
 		b.published, b.held, b.waiting = map[string]bool{}, map[string]bool{}, map[string]map[string]chan string{}
-		b.hands = map[string]*handWatch{}
 	})
 }
 
@@ -375,35 +372,9 @@ func (b *Builder) consider(ctx context.Context, module string, m delivery.Module
 	}()
 }
 
-// startOnce looks at the module for a key the caller has set inflight already (BuildAgain): the by-hand look runs once, and
-// a look the builder queued for the key meanwhile (again) still runs after it, as consider's loop does.
-func (b *Builder) startOnce(ctx context.Context, key, module string, m delivery.Module) {
-	b.wg.Add(1)
-	go func() {
-		defer b.wg.Done()
-		b.sem <- struct{}{}
-		defer func() { <-b.sem }()
-		for {
-			b.try(ctx, module, m)
-			b.mu.Lock()
-			next, more := b.again[key]
-			delete(b.again, key)
-			if !more || ctx.Err() != nil {
-				delete(b.inflight, key)
-				b.mu.Unlock()
-				return
-			}
-			b.mu.Unlock()
-			m = next // a look the builder queued meanwhile is not lost (consider's rule); it is not a second by-hand build
-		}
-	}()
-}
-
 // try claims the fingerprint and builds it, writing the key done or failed. A build that ends because ctx did is left
 // building by this builder: it takes it again when it starts (ADR 0478 clause 5).
 func (b *Builder) try(ctx context.Context, module string, m delivery.Module) {
-	key, _ := delivery.BuilderBuildKey(module, m.FP2)
-	defer b.handEnded(key)
 	plan, planErr, read := b.planOf(ctx, m.Manifest)
 	nothing := read && planErr == nil && len(plan.Tasks) == 0
 	if planErr == nil && !nothing {
@@ -414,6 +385,7 @@ func (b *Builder) try(ctx context.Context, module string, m delivery.Module) {
 			return
 		}
 	}
+	key, _ := delivery.BuilderBuildKey(module, m.FP2)
 	b.mu.Lock()
 	trunk := b.trunkFP[key]
 	first := !b.tried[key]
@@ -428,7 +400,6 @@ func (b *Builder) try(ctx context.Context, module string, m delivery.Module) {
 	if cl == nil {
 		return
 	}
-	b.handClaimed(key, cl.Rev)
 	if cl.Unasked != nil {
 		b.logf("%v", cl.Unasked)
 	}
@@ -564,9 +535,6 @@ func (b *Builder) build(ctx context.Context, module string, m delivery.Module, p
 		// One ask builds each fingerprint's part of a build module, on whichever node pulls it (ADR 0525 §3).
 		lanes = append(lanes, &lane{module: bm, tasks: tasks, toolchain: toolchain, digests: map[string]string{}, references: map[string]string{}})
 	}
-	if key, err := delivery.BuilderBuildKey(module, m.FP2); err == nil {
-		b.handLanes(key, len(lanes))
-	}
 	var wg sync.WaitGroup
 	for _, l := range lanes {
 		wg.Add(1)
@@ -749,11 +717,7 @@ func (n *askNotes) note(ctx context.Context, language, id, step string) error {
 		v.Asks = map[string]string{}
 	}
 	v.Asks[language] = id
-	if err := n.b.Claimer.Finish(ctx, n.cl, v); err != nil {
-		return err
-	}
-	n.b.handAsk(n.cl.Key, language, id)
-	return nil
+	return n.b.Claimer.Finish(ctx, n.cl, v)
 }
 
 // runLane puts the lane's part of the build as one ask on its build seat's stream (the delivery stream for a trunk key, the

modules/mesh-delivery-builder/internal/build/run_test.go

@@ -691,129 +691,18 @@ func TestABuildAskWaitingInItsStreamIsNotBounded(t *testing.T) {
 		byHand bool
 		always bool // Gone says every ask cannot be answered, not only the first
 		dead   bool // DEAD_LETTERS keeps the first ask: the seat gave it up (issue 734)
-		deaf   bool // the ask's own watch hears nothing though its step ends (the lost check of 2026-10-28)
 		puts   int
 		done   bool
 		asking int // the asking the event says, 0 when none is said
-		// again, when set, is a request to build the key again by hand (BuildAgain, issue 1126 note 72) of the key as
-		// it stands (key, absent when nil), the module known at known's fingerprint ("" for the rig's): refuse is a part of why it
-		// is refused, "" when it is built again as a new revision and its ask id answered.
-		again  bool
-		key    *delivery.BuilderBuild
-		known  string
-		refuse string
-		// edit changes the module the builder has read, busy marks the key looked at (1) or asked by hand (2), failed is a part of
-		// the error the key then holds when its build ends before its asks are put.
-		edit   func(m *delivery.Module)
-		busy   int
-		failed string
-		// during is a look of the builder's own at the module while the by-hand build runs: it still runs afterwards.
-		during bool
 	}{
-		{name: "build again: a look the builder queued during the by-hand build still runs afterwards", again: true, during: true,
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a key looked at by the builder now is refused, not built twice", again: true, refuse: "is being looked at", busy: 1,
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a key already asked by hand is refused, its watch kept", again: true, refuse: "is being looked at", busy: 2,
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a module with no manifest is refused", again: true, refuse: "names no manifest", edit: func(m *delivery.Module) { m.Manifest = "" },
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a toolchain that moved writes nothing and is said at once", again: true, refuse: "wrote nothing",
-			edit: func(m *delivery.Module) {
-				m.Toolchains = map[string]delivery.ToolchainUsed{"go": {Version: "go1.0", Recipe: "1"}}
-			},
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a build that fails before its asks says the key failed, not that it was asked", again: true, failed: "cannot be read",
-			edit: func(m *delivery.Module) { m.Manifest = mdigest('b') },
-			key:  &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
-		{name: "build again: a failed key is written building as a new revision and asks the seat", again: true,
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: the step failed: no tun"}},
-		{name: "build again: a done key is refused, nothing to do", again: true, refuse: "is done: nothing to do",
-			key: &delivery.BuilderBuild{State: delivery.BuildDone, Step: "built"}},
-		{name: "build again: a building key is refused, builder_ask_again is for it", again: true, refuse: "is waiting",
-			key: &delivery.BuilderBuild{State: delivery.BuildBuilding, By: "novox.builder", Step: "asked mesh-build-go", Asks: map[string]string{delivery.AskGo: "mvl0frv18d1960"}}},
-		{name: "build again: a key failed for a pin missing is refused, it waits for another fingerprint", again: true, refuse: "does not retry",
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: delivery.NotPinned + "web"}},
-		{name: "build again: a key with no build is refused", again: true, refuse: "has no build key"},
-		{name: "build again: a fingerprint its module no longer has is refused", again: true, refuse: "does not have the fingerprint", known: "src2:" + strings.Repeat("9", 64),
-			key: &delivery.BuilderBuild{State: delivery.BuildFailed, Error: "ace: no tun"}},
 		{name: "given up by its stream: asked again under a new id and done from it", puts: 2, done: true, asking: 2},
 		{name: "asked again by hand: the same, with no check bound", byHand: true, puts: 2, done: true, asking: 2},
 		{name: "given up into DEAD_LETTERS: its wait ends failed with the words and it is asked again at once", dead: true, puts: 2, done: true, asking: 2},
-		{name: "its step ended while its watch was deaf: read at its build module's next step end, done with no new ask", deaf: true, puts: 1, done: true},
 		{name: "never answerable: failed after its askings", askings: 2, always: true, puts: 2},
 		{name: "taken over at its last asking: failed, not asked again", askings: 3, always: true, step: "asked mesh-build-go again (asking 3): x", puts: 0},
 	} {
 		t.Run(c.name, func(t *testing.T) { // 1945
 			r := newRig(t, goBundle)
-			if c.again {
-				var rev uint64
-				if c.key != nil {
-					c.key.Manifest = manifestD
-					rev = putBuild(t, r.st, r.key, *c.key)
-				}
-				m, err := delivery.DecodeModule(moduleValue(t, "modules/m"))
-				if err != nil {
-					t.Fatal(err)
-				}
-				if c.known != "" {
-					m.FP2 = c.known
-				}
-				if c.edit != nil {
-					c.edit(&m)
-				}
-				r.b.init()
-				var stored atomic.Int64
-				if c.during {
-					r.asks.Answer = nil
-					r.b.Stored = func(context.Context, []string) ([]string, error) { stored.Add(1); return nil, nil }
-				}
-				switch c.busy {
-				case 1:
-					r.b.inflight[r.key] = true
-				case 2:
-					r.b.hands[r.key] = &handWatch{}
-				}
-				r.b.known["m"] = m // the builder has read the modules value, and looks at nothing until asked
-				log := &logged{}
-				r.b.Logf = log.logf
-				res := r.b.BuildAgain(context.Background(), "m", fp1, "no tun on ace", "shanks.lead", 2*time.Second)
-				if c.during {
-					// The trunk's modules value arrives while the by-hand build waits for its ask: it is queued, and run after it.
-					r.b.Module(context.Background(), "m", moduleValue(t, "modules/m"))
-					r.asks.End(r.answer(waitForAsks(t, r, 1)[0]))
-					r.b.Wait()
-					if v := valueOf(t, r.st, r.key); v.State != delivery.BuildDone || res.Revision <= rev || stored.Load() != 1 {
-						t.Fatalf("key %+v, answer %+v, %d asks of the store; want built from the new revision and the queued look run once after it", v, res, stored.Load())
-					}
-					return
-				}
-				r.b.Wait()
-				after := r.st.revs[r.key]
-				if c.refuse != "" {
-					if !strings.Contains(res.Refused, c.refuse) || res.Revision != 0 || len(r.asks.Asks()) != 0 || after != rev {
-						t.Fatalf("refused %q (revision %d, %d asks, key at revision %d was %d); want refused with %q and nothing written or asked", res.Refused, res.Revision, len(r.asks.Asks()), after, rev, c.refuse)
-					}
-					return
-				}
-				if c.failed != "" {
-					if !strings.Contains(res.Failed, c.failed) || res.Revision <= rev || len(res.Asks) != 0 || len(r.asks.Asks()) != 0 {
-						t.Fatalf("answer %+v after %d asks; want a new revision (was %d), no ask and the key's failure %q", res, len(r.asks.Asks()), rev, c.failed)
-					}
-					return
-				}
-				asks := r.asks.Asks()
-				if res.Refused != "" || res.Pending != "" || res.Revision <= rev || len(asks) != 1 || res.Asks[delivery.AskGo] != asks[0].ID {
-					t.Fatalf("answer %+v after %d asks; want the new revision (was %d) and the ask id of the one ask", res, len(asks), rev)
-				}
-				if v := valueOf(t, r.st, r.key); v.State != delivery.BuildDone || after <= res.Revision {
-					t.Errorf("the key = %+v at revision %d; want built from the new revision %d", v, after, res.Revision)
-				}
-				if !log.has(r.key, "built again by hand", "no tun on ace", "shanks.lead") {
-					t.Errorf("the why is not logged: %v", log.lines)
-				}
-				return
-			}
 			r.asks.Answer = nil
 			r.b.Askings = c.askings
 			var said []AskedAgain
@@ -831,12 +720,7 @@ func TestABuildAskWaitingInItsStreamIsNotBounded(t *testing.T) {
 			if c.dead {
 				r.b.Asks = buildrun.Asker{Publisher: r.asks, Waiter: buildrun.LostAskWaiter{Inner: r.asks, Dead: dead}, Bound: 2 * time.Second}
 			}
-			var heard *buildrun.HeardEnds
-			if c.deaf {
-				heard = &buildrun.HeardEnds{Inner: silentWatch{}, Read: r.asks}
-				r.b.Asks = buildrun.Asker{Publisher: r.asks, Waiter: heard, Bound: 2 * time.Second}
-			}
-			if !c.byHand && !c.dead && !c.deaf {
+			if !c.byHand && !c.dead {
 				gone.why = func(a delivery.StepAsk) string {
 					if c.always || a.ID == first || first == "" {
 						return "it waits first in line while a node took a later ask"
@@ -858,16 +742,7 @@ func TestABuildAskWaitingInItsStreamIsNotBounded(t *testing.T) {
 					}
 				}
 			}
-			if c.deaf {
-				r.asks.End(r.answer(waitForAsks(t, r, 1)[0]))
-				for deadline := time.Now().Add(2 * time.Second); heard.Waiting() == 0; time.Sleep(time.Millisecond) {
-					if time.Now().After(deadline) {
-						t.Fatal("no ask is waited on")
-					}
-				}
-				heard.Nudge(buildrun.GoBuildModule) // a step of mesh-build-go ended
-			}
-			if c.done && !c.deaf {
+			if c.done {
 				asks := waitForAsks(t, r, c.puts)
 				if first == "" && !c.byHand {
 					first = asks[0].ID
@@ -892,7 +767,7 @@ func TestABuildAskWaitingInItsStreamIsNotBounded(t *testing.T) {
 			mu.Lock()
 			defer mu.Unlock()
 			// Note 62: the old message of an ask asked again because its stream gave it up is dropped from the stream.
-			if gone.mu.Lock(); c.done && !c.byHand && !c.dead && !c.deaf && (len(gone.dropped) != 1 || gone.dropped[0] != first) {
+			if gone.mu.Lock(); c.done && !c.byHand && !c.dead && (len(gone.dropped) != 1 || gone.dropped[0] != first) {
 				t.Errorf("dropped %v from the stream, want the old ask %s", gone.dropped, first)
 			}
 			gone.mu.Unlock()
@@ -1102,10 +977,3 @@ func TestATakeOverThatCannotReadTheStreamWaitsForTheAsk(t *testing.T) {
 		t.Fatalf("the key = %+v after %d asks, want done from the ask's step, none put", v, len(r.asks.Asks()))
 	}
 }
-
-// silentWatch is a watch of an ask's step that stays open and hears nothing.
-type silentWatch struct{}
-
-func (silentWatch) WatchAsk(context.Context, string, string) (<-chan delivery.Step, error) {
-	return make(chan delivery.Step), nil
-}

modules/mesh-delivery-builder/internal/build/stuck.go

@@ -22,11 +22,6 @@ import (
 const (
 	StuckTool    = "builder_stuck"
 	AskAgainTool = "builder_ask_again"
-	// BuildAgainTool builds a failed key again by hand (issue 1126 note 72): it writes a reasks value of Mode ModeBuild.
-	BuildAgainTool = "builder_build_again"
-	// AnnounceAgainTool writes a done key again unchanged, so the controller takes it in and composes again: a reasks value
-	// of Mode ModeAnnounce.
-	AnnounceAgainTool = "builder_announce_again"
 	// ReAsksState is the builder's state of asks to ask again: the bucket mesh-delivery-builder_reasks, keyed as the build key.
 	ReAsksState  = "reasks"
 	ReAsksBucket = delivery.BuilderModule + "_" + ReAsksState
@@ -41,27 +36,8 @@ type ReAsk struct {
 	At       time.Time `json:"at"`
 	Answer   string    `json:"answer,omitempty"`
 	Answered time.Time `json:"answered,omitzero"`
-	// Mode is ModeBuild for a request to build a failed key again (BuildAgainTool); empty for an ask asked again.
-	Mode   string `json:"mode,omitempty"`
-	Module string `json:"module,omitempty"`
-	FP     string `json:"fp,omitempty"`
-	// Refused, Revision and Asks are the builder's answer to a ModeBuild request: why it did nothing, or the key's new
-	// revision (building) and the ask ids it put by language.
-	Refused bool `json:"refused,omitempty"`
-	// Pending says the builder answered before the key was claimed or all its asks were put: neither a refusal nor done.
-	// Failed is the error of a key written building that failed before its asks were put.
-	Pending  bool              `json:"pending,omitempty"`
-	Failed   string            `json:"failed,omitempty"`
-	Revision uint64            `json:"revision,omitempty"`
-	Asks     map[string]string `json:"asks,omitempty"`
 }
 
-// ModeBuild is the Mode of a reasks value that asks the key to be built again, not its waiting asks to be asked again.
-const ModeBuild = "build"
-
-// ModeAnnounce is the Mode of a reasks value that asks a done key to be announced again.
-const ModeAnnounce = "announce"
-
 // DecodeReAsk reads a reasks value.
 func DecodeReAsk(data []byte) (ReAsk, error) {
 	var r ReAsk
@@ -87,32 +63,6 @@ func NewReAsk(module, fp, why, by string, at time.Time) (string, []byte, error)
 	return key, data, err
 }
 
-// NewBuildAgain is the value builder_build_again writes for a module's fingerprint: its key and the value.
-func NewBuildAgain(module, fp, why, by string, at time.Time) (string, []byte, error) {
-	key, err := delivery.BuilderBuildKey(module, fp)
-	if err != nil {
-		return "", nil, err
-	}
-	if strings.TrimSpace(why) == "" {
-		return "", nil, errors.New("say why the key is built again (why)")
-	}
-	data, err := json.Marshal(ReAsk{V: 1, Why: strings.TrimSpace(why), By: by, At: at.UTC(), Mode: ModeBuild, Module: module, FP: fp})
-	return key, data, err
-}
-
-// NewAnnounceAgain is the value builder_announce_again writes for a module's fingerprint: its key and the value.
-func NewAnnounceAgain(module, fp, why, by string, at time.Time) (string, []byte, error) {
-	key, err := delivery.BuilderBuildKey(module, fp)
-	if err != nil {
-		return "", nil, err
-	}
-	if strings.TrimSpace(why) == "" {
-		return "", nil, errors.New("say why the done build is announced again (why)")
-	}
-	data, err := json.Marshal(ReAsk{V: 1, Why: strings.TrimSpace(why), By: by, At: at.UTC(), Mode: ModeAnnounce, Module: module, FP: fp})
-	return key, data, err
-}
-
 // StateRead is a state the tools read: its keys, and a key's value with when it was written (zero when not known).
 type StateRead struct {
 	Keys func() ([]string, error)

modules/mesh-delivery-builder/manifest_test.go

@@ -92,8 +92,8 @@ func TestManifestDeclarations(t *testing.T) { // 1607/AC1
 	}
 	// 1887/A4c: the builder chooses no node, so it reads neither presence nor have, invokes no build module's tool and
 	// holds no capacity; it puts asks on the three build seats and reads their steps (ADR 0525 §1, §4, §5).
-	if want := []string{"mesh-build-go.steps", "mesh-build-go.toolchains", "mesh-build-image.steps", "mesh-build-node.steps", "mesh-build-node.toolchains",
-		"mesh-delivery-assigner.placement", "mesh-delivery-gate.source", "mesh-delivery-indexer.candidates", "mesh-delivery-indexer.manifests", "mesh-delivery-indexer.modules"}; !reflect.DeepEqual(sorted(m.Reads), want) {
+	if want := []string{"mesh-build-go.steps", "mesh-build-go.toolchains", "mesh-build-image.steps", "mesh-build-node.steps", "mesh-build-node.toolchains", "mesh-controller.assignments",
+		"mesh-delivery-gate.source", "mesh-delivery-indexer.candidates", "mesh-delivery-indexer.manifests", "mesh-delivery-indexer.modules"}; !reflect.DeepEqual(sorted(m.Reads), want) {
 		t.Errorf("reads = %v, want %v", m.Reads, want)
 	}
 	if want := []string{"node-build-go", "node-build-image", "node-build-node"}; !reflect.DeepEqual(sorted(m.Uses), want) {
@@ -116,7 +116,7 @@ func TestManifestDeclarations(t *testing.T) { // 1607/AC1
 		t.Errorf("secrets-owner = %q", m.SecretsOwner)
 	}
 	// 1945: the builder's tools (builder_seat_queue: note 62), served by its tools bundle, and the event it says when it asks an ask again.
-	if want := []string{"builder_announce_again", "builder_ask_again", "builder_build_again", "builder_seat_queue", "builder_stuck"}; !reflect.DeepEqual(sorted(m.Tools), want) {
+	if want := []string{"builder_ask_again", "builder_seat_queue", "builder_stuck"}; !reflect.DeepEqual(sorted(m.Tools), want) {
 		t.Errorf("tools = %v, want %v", m.Tools, want)
 	}
 	if want := []string{"build.asked-again"}; !reflect.DeepEqual(m.Emits, want) {

modules/mesh-delivery-builder/module.json

@@ -3,9 +3,7 @@
   "version": "1",
   "slug": "builder",
   "tools": [
-    "builder_announce_again",
     "builder_ask_again",
-    "builder_build_again",
     "builder_seat_queue",
     "builder_stuck"
   ],
@@ -33,7 +31,7 @@
     "mesh-build-image.steps",
     "mesh-build-node.steps",
     "mesh-build-node.toolchains",
-    "mesh-delivery-assigner.placement",
+    "mesh-controller.assignments",
     "mesh-delivery-gate.source",
     "mesh-delivery-indexer.candidates",
     "mesh-delivery-indexer.manifests",

modules/mesh-delivery-checker/cmd/mesh-delivery-checker-tools/main.go

@@ -1,6 +1,6 @@
 // Command mesh-delivery-checker-tools serves the checker's read tools (novox/hq ADR 0484 clause 13, issue 1686): the runtime
 // launches it for a call, it reads the checker's verdicts and kept states and the indexer's candidates through the checker's
-// state and reads. It writes only the tries (the try's tools) and, asking a check again by hand, one verdict. The checker is the other program: it serves no tool (ADR 0437 §4).
+// state and reads, and writes nothing. The checker is the other program: it serves no tool (ADR 0437 §4).
 package main
 
 import (
@@ -250,24 +250,6 @@ func Tools(r check.Reader) []stdio.Tool {
 	}
 }
 
-// RecoveryTools are the tools that steer a check by hand (tools-are-how-a-module-is-spoken-to): ask a check again whose
-// wait judged nothing (the lost check of 2026-10-28). They write the checker's verdicts through w.
-func RecoveryTools(r check.Reader, w check.VerdictEntry) []stdio.Tool {
-	str := func(args map[string]any, k string) string { s, _ := args[k].(string); return s }
-	return []stdio.Tool{{Name: check.AskAgainTool,
-		Description: "Ask a candidate's check again by hand, whose verdict stays running while nothing runs for it (" + check.StatusReadTool + " names it " +
-			"under lost): its verdict is ended as asked again, saying why, and the checker, which hears its verdicts, stops the wait that judged nothing " +
-			"and asks the check anew, whole. Refused for a group with no candidate, a verdict that is not running (a pass or failure stands until a push or " +
-			"a trunk move), and while a step of its pull requests can still run on a build module (its end judges it). The checker reads a step that " +
-			"ended while its watch was deaf by itself at the next step end of its build module; this is for what that does not reach.",
-		Input: map[string]any{"type": "object", "required": []string{"group", "why"}, "properties": map[string]any{
-			"group": map[string]any{"type": "string", "description": "the delivery group's branch name"},
-			"why":   map[string]any{"type": "string", "description": "why it is asked again, in words; kept in the verdict it ends"}}},
-		Run: func(args map[string]any) (any, error) {
-			return r.AskAgain(w, str(args, "group"), str(args, "why"))
-		}}}
-}
-
 // stepBound is the checker's step bound as the checker reads it (MESH_CHECKER_STEP_BOUND), its default when unset or not a
 // duration.
 func stepBound() time.Duration {
@@ -282,8 +264,7 @@ func main() {
 		PreviewState: read(stdio.State("previews")),
 		StepStates:   map[string]check.StateRead{"mesh-build-go": read(stdio.State("mesh-build-go.steps")), "mesh-build-node": read(stdio.State("mesh-build-node.steps"))},
 		HaveState:    read(stdio.State("node-engine.have")), StepBound: stepBound(),
-		TurnState: read(stdio.State("mesh-delivery-gate.turns")), HearingState: read(stdio.State(buildrun.HearingState)),
-		AskState: read(stdio.State(check.AsksState))}
+		TurnState: read(stdio.State("mesh-delivery-gate.turns")), HearingState: read(stdio.State(buildrun.HearingState))}
 	r.Runs = runsOf{read(stdio.State("mesh-delivery-indexer.modules"))} // the node-engine at the commit the mesh runs, as the checker reads it
 	tries := stdio.State(check.TriesState)
 	source := stdio.State("mesh-delivery-gate.source")
@@ -311,20 +292,7 @@ func main() {
 		return err
 	}}
 	trying := Trying{Tries: store, Ender: store, Trunks: trunks}
-	verdicts := stdio.State("verdicts")
-	written := stateStore{entry: func(key string) (json.RawMessage, uint64, error) {
-		reads.Add(1)
-		e, err := verdicts.Get(key)
-		if err != nil || e == nil {
-			return nil, 0, err
-		}
-		return e.Value, e.Revision, nil
-	}, update: func(key string, value []byte, revision uint64) error {
-		_, err := verdicts.Update(key, json.RawMessage(value), revision)
-		return err
-	}}
-	tools := append(append(append(Tools(r), TryTools(trying)...), SeatTryTools(trying)...), RecoveryTools(r, written)...)
-	if err := stdio.Serve("", logged(tools)); err != nil {
+	if err := stdio.Serve("", logged(append(append(Tools(r), TryTools(trying)...), SeatTryTools(trying)...))); err != nil {
 		fmt.Fprintf(os.Stderr, "[mesh-delivery-checker-tools] %v\n", err)
 		os.Exit(1)
 	}

modules/mesh-delivery-checker/cmd/mesh-delivery-checker-tools/main_test.go

@@ -23,14 +23,6 @@ func TestTheToolsServedAreTheFiveReadTools(t *testing.T) {
 	if !slices.Equal(names, want) {
 		t.Errorf("tools = %v, want %v", names, want)
 	}
-	// The recovery tool beside them asks a lost check again; with nothing to write it refuses.
-	recovery := RecoveryTools(check.Reader{}, nil)
-	if len(recovery) != 1 || recovery[0].Name != check.AskAgainTool || recovery[0].Description == "" {
-		t.Errorf("recovery tools = %+v", recovery)
-	}
-	if _, err := recovery[0].Run(map[string]any{"group": "feat/x", "why": "lost"}); err == nil {
-		t.Errorf("%s answered with no state to write", check.AskAgainTool)
-	}
 	// With nothing to read from a tool says so and changes nothing.
 	for _, tl := range Tools(check.Reader{}) {
 		if tl.Name == check.StatusReadTool {

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/bus.go

@@ -9,7 +9,6 @@ import (
 
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/process"
 
 	"mesh-delivery-checker/internal/check"
 )
@@ -131,55 +130,3 @@ func (m manifestReader) Manifest(ctx context.Context, digest string) (catalogue.
 func parseManifest(raw string) (catalogue.Manifest, error) {
 	return catalogue.ParseManifestForInputs([]byte(raw))
 }
-
-// awaitedKV is a bucket that may appear after the start (process.AwaitBucket) as a check.KV: a call while it is not on the
-// bus fails saying so.
-type awaitedKV struct{ b *process.AwaitedBucket }
-
-func (a awaitedKV) kv() (kvStore, error) {
-	kv := a.b.KV()
-	if kv == nil {
-		return kvStore{}, errors.New("the bucket is not on the bus yet")
-	}
-	return kvStore{kv}, nil
-}
-
-func (a awaitedKV) Get(ctx context.Context, key string) ([]byte, uint64, bool, error) {
-	s, err := a.kv()
-	if err != nil {
-		return nil, 0, false, err
-	}
-	return s.Get(ctx, key)
-}
-
-func (a awaitedKV) Create(ctx context.Context, key string, value []byte) (uint64, error) {
-	s, err := a.kv()
-	if err != nil {
-		return 0, err
-	}
-	return s.Create(ctx, key, value)
-}
-
-func (a awaitedKV) Update(ctx context.Context, key string, value []byte, revision uint64) (uint64, error) {
-	s, err := a.kv()
-	if err != nil {
-		return 0, err
-	}
-	return s.Update(ctx, key, value, revision)
-}
-
-func (a awaitedKV) Keys(ctx context.Context) ([]string, error) {
-	s, err := a.kv()
-	if err != nil {
-		return nil, err
-	}
-	return s.Keys(ctx)
-}
-
-func (a awaitedKV) Delete(ctx context.Context, key string) error {
-	s, err := a.kv()
-	if err != nil {
-		return err
-	}
-	return s.Delete(ctx, key)
-}

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/integration_test.go

@@ -89,8 +89,6 @@ type fakeBuildModules struct {
 	// beside is, by workspace, the siblings the fetch placed in it as `<owner/repo> <commit>`, sorted: a digest echoes them
 	// (1929/AC2; mesh-sdk buildstep.besideOf), or the level runs whole and keeps nothing.
 	beside map[string][]string
-	// names are the nodes' names the last check ask carried, for the names check (ADR 0567 §12).
-	names []string
 }
 
 func (f *fakeBuildModules) count(tool string) int {
@@ -193,14 +191,7 @@ func (f *fakeBuildModules) serve(t *testing.T, module string, kept jetstream.Key
 	}
 	p := &buildstep.Puller{Source: &buildstep.JetStreamAsks{JS: f.js, Language: language}, Language: language, Node: "n1", Put: put,
 		Capacity: func() int { return 2 }, PullWait: 200 * time.Millisecond,
-		Run: func(ctx context.Context, a delivery.StepAsk) (any, error) {
-			if a.Check != nil {
-				f.mu.Lock()
-				f.names = a.Check.NodeNames
-				f.mu.Unlock()
-			}
-			return buildstep.RunAsk(ctx, steps, a)
-		}}
+		Run: func(ctx context.Context, a delivery.StepAsk) (any, error) { return buildstep.RunAsk(ctx, steps, a) }}
 	go func() { _ = p.Pull(f.ctx) }()
 }
 
@@ -343,7 +334,6 @@ func startBed(t *testing.T) *bed {
 		t.Fatal(err)
 	}
 	b.setOnline(t, "n1", true)
-	b.setNode(t, "n1")
 	for _, module := range []string{"mesh-build-go", "mesh-build-node"} {
 		b.setHealth(t, "n1", module)
 	}
@@ -376,20 +366,6 @@ func (b *bed) setOnline(t *testing.T, node string, online bool) {
 	}
 }
 
-// setNode writes the node's record in the node-engine's have, as the node-engine does, so the checker names it in each
-// check ask (ADR 0567 §12); with no record the checker asks no check.
-func (b *bed) setNode(t *testing.T, node string) {
-	t.Helper()
-	data, err := delivery.EncodeNodeRecord(delivery.NodeRecord{V: 1, Node: node})
-	if err != nil {
-		t.Fatal(err)
-	}
-	key, _ := delivery.HaveNodeKey(node)
-	if _, err := b.buckets[delivery.HaveBucket].Put(b.ctx, key, data); err != nil {
-		t.Fatal(err)
-	}
-}
-
 func (b *bed) setHealth(t *testing.T, node, module string) {
 	t.Helper()
 	data, err := delivery.EncodeHave(delivery.Have{Phase: delivery.PhaseRunning, Health: delivery.HealthOK})
@@ -517,12 +493,6 @@ func TestCheckerJudgesACandidateAndOwesItsStatus(t *testing.T) { // N6/AC5, 1300
 	if v.Composition == nil || v.Composition.State != delivery.CompositionNotRun || len(v.Machines) != 1 || v.Machines[0] != "n1" {
 		t.Errorf("composition %+v machines %v", v.Composition, v.Machines)
 	}
-	b.fake.mu.Lock()
-	names := b.fake.names
-	b.fake.mu.Unlock()
-	if len(names) != 1 || names[0] != "n1" {
-		t.Errorf("the check ask named the nodes %v, want [n1] from the have's node record", names)
-	}
 	o := b.owed(t, 7, head1, "success")
 	if o.Context != delivery.StatusContextCheck || !strings.HasPrefix(o.Text, "pass 111111111111 on aaaaaaaaaaaa") || !strings.Contains(o.Text, "unit 2 run") {
 		t.Errorf("owed = %+v", o)
@@ -827,8 +797,7 @@ func TestTheCheckerSaysOwedReadableOnTheBus(t *testing.T) { // R2-1
 		break
 	}
 	if said.Module != "mesh-delivery-checker" || said.Node != "n1" || !said.Keeps("owed") || !said.Readable("owed") ||
-		!said.Readable("previews") || !said.Readable("verdicts") || !said.Readable("kept") || !said.Readable("tries") || said.Readable("hearing") ||
-		!said.Keeps("asks") || said.Readable("asks") || len(said.States) != 7 {
-		t.Fatalf("the checker said %+v, want its seven states, asks and hearing its own, with kept, owed, previews, tries and verdicts readable, tries by the delivery view (1929/AC4; 1887 A5b; build_usage)", said)
+		!said.Readable("previews") || !said.Readable("verdicts") || !said.Readable("kept") || !said.Readable("tries") || said.Readable("hearing") || len(said.States) != 6 {
+		t.Fatalf("the checker said %+v, want its six states with kept, owed, previews, tries and verdicts readable, tries by the delivery view (1929/AC4; 1887 A5b; build_usage)", said)
 	}
 }

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/judge.go

@@ -2,16 +2,12 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"sort"
 	"strings"
 	"sync"
 
-	"github.com/nats-io/nats.go/jetstream"
-
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
-	"git.novox.be/novox/mesh-sdk/go/process"
 
 	"mesh-delivery-checker/internal/check"
 )
@@ -29,46 +25,11 @@ type judgeDeps struct {
 	builds   check.BuildStates
 	// compositions is the assigner's bucket of compositions; nil leaves every composition not run.
 	compositions check.CompositionReader
-	// nodes names every node with a record; nil hands no names.
-	nodes *nodeNames
-	logf  func(format string, args ...any)
-}
-
-// nodeNames reads every node's name from the node-engine's have, one key `<node>.node` per node with a record (novox/hq
-// ADR 0567 §12), at each ask: a node enrolled since is named in the next check.
-type nodeNames struct{ kv jetstream.KeyValue }
-
-// openNodeNames opens the node-engine's have for the nodes' names alone: it is not watched, so no check waits on a node.
-func openNodeNames(ctx context.Context, js process.BucketOpener, logf func(string, ...any)) *nodeNames {
-	return &nodeNames{kv: process.OptionalBucket(ctx, js, delivery.HaveBucket, "no check is asked until it is: the names check needs the nodes' names", logf)}
-}
-
-func (n nodeNames) Names(ctx context.Context) ([]string, error) {
-	if n.kv == nil {
-		return nil, fmt.Errorf("the bucket %s could not be opened at the checker's start", delivery.HaveBucket)
-	}
-	lister, err := n.kv.ListKeysFiltered(ctx, "*."+delivery.HaveNodeWord)
-	if err != nil {
-		return nil, err
-	}
-	var out []string
-	for key := range lister.Keys() {
-		if node, _, isNode, err := delivery.ParseHaveKey(key); err == nil && isNode {
-			out = append(out, node)
-		}
-	}
-	sort.Strings(out)
-	return out, nil
+	logf         func(format string, args ...any)
 }
 
 func newJudge(d judgeDeps) check.Judge {
-	var nodes interface {
-		Names(ctx context.Context) ([]string, error)
-	}
-	if d.nodes != nil {
-		nodes = d.nodes
-	}
-	return &check.Examiner{Nodes: nodes, Compositions: d.compositions, Asks: d.asks, Toolchains: d.tools,
+	return &check.Examiner{Compositions: d.compositions, Asks: d.asks, Toolchains: d.tools,
 		Kept: check.Kept{Store: d.kept}, Previews: d.previews, Modules: d.repos, Packages: d.repos, Forge: d.forge, Runs: d.repos, Builds: d.builds, Announce: d.announce, Trunks: d.trunks, Logf: d.logf}
 }
 

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/main.go

@@ -69,8 +69,6 @@ var keptStates = []announce.State{
 	// design limit 1); the checker alone writes them (ADR 0444 clause 5).
 	// Whether DEAD_LETTERS is heard (issue 734): read by the checker's own status tool alone.
 	{Name: "hearing"},
-	// The asks each running check put (check.AsksState): read by the checker's own checker_ask_again alone.
-	{Name: "asks"},
 	{Name: "kept", Readable: true},
 	{Name: "owed", Readable: true},
 	{Name: "previews", Readable: true},
@@ -146,14 +144,9 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	hearing := buildrun.NewDeadLetterHearing(ctx, buildrun.JetStreamDeadLetters{JS: js}, []string{delivery.AskGo, delivery.AskNode}, dead,
 		logger.Printf, buildrun.SayHearing(ctx, hearingKV, logger.Printf))
 	defer hearing.Stop()
-	// Each ask's step is heard by its own watch and, at every step end of its build module and every reconnect, read
-	// (buildrun.HearEnds): a watch that goes deaf loses no end (the lost check of 2026-10-28).
-	heard := buildrun.HearEnds(ctx, asks, asks, []string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, logger.Printf)
-	conn.SetReconnectHandler(func(*nats.Conn) { hearing.Again(); heard.Nudge("") })
-	waiter := buildrun.LostAskWaiter{Inner: heard, Dead: dead, Hearing: hearing}
-	asksKV := process.AwaitBucket(ctx, js, conn, check.AsksBucket, "checker_ask_again refuses every check, as it cannot tell whether its ask waits in a stream", logger.Printf)
+	conn.SetReconnectHandler(func(*nats.Conn) { hearing.Again() })
+	waiter := buildrun.LostAskWaiter{Inner: asks, Dead: dead, Hearing: hearing}
 	ch := &check.Checker{
-		Asks:     awaitedKV{asksKV},
 		Verdicts: kvStore{buckets[delivery.CheckerVerdictsBucket]},
 		Owed:     kvStore{buckets[delivery.CheckerOwedBucket]},
 		Trunks:   trunks,
@@ -201,18 +194,17 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		kept: kvStore{buckets[delivery.CheckerKeptBucket]}, previews: kvStore{buckets[delivery.PreviewsBucket]},
 		repos: repos, builds: builds, forge: forgeReads{call: caller.Call}, logf: logger.Printf,
 		announce: announce, compositions: compositions,
-		nodes: openNodeNames(ctx, js, logger.Printf),
 	})
 	ch.Announce = announce
 	tryer.Judge = ch.Judge
 
 	// The toolchains first, so a check that starts from the first candidate finds the nodes.
 	watch := newToolchainWatch(ctx, js, tools, ch.NodesChanged, logger)
-	// Only the toolchain reports of nodes the catalogue places the build module on count (issue 1940, ADR 0549 §3): the
-	// placement is settled first, so the toolchains settle through the gate already knowing it.
-	gate := buildrun.NewToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, tools.Put, logger.Printf)
+	// Only the toolchain reports of nodes the build module is assigned to count (issue 1940): the controller's
+	// assignments are settled first, so the toolchains settle through the gate already knowing them.
+	gate := newToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, tools.Put, logger.Printf)
 	watch.put = gate.Toolchain
-	placementErrs, err := buildrun.FollowPlacement(ctx, js, gate, ch.NodesChanged, logger.Printf)
+	assignErrs, err := watchAssignments(ctx, js, gate, ch.NodesChanged, logger)
 	if err != nil {
 		return err
 	}
@@ -338,21 +330,6 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 			}
 		})
 	}()
-	// The checker's own verdicts, updates only, in one watch: one checker_ask_again wrote asks its check again
-	// (Checker.VerdictWritten); a deleted key of heads a candidate holds is judged again (Checker.VerdictDeleted, issue 1733).
-	vw, err := buckets[delivery.CheckerVerdictsBucket].WatchAll(ctx, jetstream.UpdatesOnly())
-	if err != nil {
-		return fmt.Errorf("the checker's verdicts cannot be watched, so no check can be asked again by hand and a deleted verdict would never be written again: %w", err)
-	}
-	go func() {
-		errs <- follow(ctx, vw, func(e jetstream.KeyValueEntry) {
-			if opOf(e) {
-				ch.VerdictWritten(ctx, e.Key(), e.Value())
-			} else {
-				ch.VerdictDeleted(ctx, e.Key())
-			}
-		})
-	}()
 	logger.Printf("started on %s", cred.Node)
 	go func() { errs <- follow(ctx, w, each) }()
 	select {
@@ -362,7 +339,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		return nil
 	case err := <-errs:
 		return err
-	case err := <-placementErrs:
+	case err := <-assignErrs:
 		return err
 	case err := <-watch.errs:
 		return err

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/nodes_test.go

@@ -7,8 +7,7 @@ import (
 )
 
 // 1912: with checks as asks on the build seats' streams, the stream redelivers a lost node's ask (ADR 0525 §6), so the
-// checker program watches no node-engine have to start again a check that failed for want of a node. It reads the have's
-// keys only for the nodes' names at each ask (judge.go, novox/hq ADR 0567 §12).
+// checker program opens no node-engine have to start again a check that failed for want of a node.
 func TestTheCheckerWatchesNoHave(t *testing.T) {
 	raw, err := os.ReadFile("main.go")
 	if err != nil {

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/refused_test.go

@@ -1,62 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"log"
-	"strings"
-	"testing"
-
-	"git.novox.be/novox/mesh-sdk/go/process"
-
-	"github.com/nats-io/nats.go/jetstream"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
-)
-
-// 1945 (a part exits at start for a bucket it works without): a bus that refuses every toolchains bucket leaves the
-// watch unstarted and the part running, said; a refused bucket it cannot work without is an error naming the bucket and
-// its grant. The gate over the seat's placement, and its refusal, are mesh-sdk's (buildrun.ToolchainGate,
-// issue 774).
-func TestARefusedBucketIsSaidAndThePartGoesOn(t *testing.T) {
-	set := &buildrun.ToolchainSet{}
-	var logs bytes.Buffer
-	logger := log.New(&logs, "", 0)
-	refused := refusingBus{err: errors.New("nats: permissions violation for publish to $JS.API.CONSUMER.CREATE.KV_mesh-build-node_toolchains")}
-	if err := newToolchainWatch(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, set, func(context.Context) {}, logger).start(); err != nil {
-		t.Errorf("a refused toolchains bucket stopped the start: %v", err)
-	}
-	if !strings.Contains(logs.String(), "cannot be read") {
-		t.Errorf("the refusals were not said: %q", logs.String())
-	}
-	if _, err := process.EssentialBucket(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, "checker", "mesh-delivery-indexer_modules", "work"); err == nil ||
-		!strings.Contains(err.Error(), "grant of mesh-delivery-indexer_modules") {
-		t.Errorf("a refused bucket the part needs: %v, want an error naming its grant", err)
-	}
-}
-
-// refusingBus is a bus that refuses: every open (refuseOpen), or every watch of a bucket it opens, with err.
-type refusingBus struct {
-	refuseOpen bool
-	err        error
-}
-
-func (r refusingBus) KeyValue(context.Context, string) (jetstream.KeyValue, error) {
-	if r.refuseOpen {
-		return nil, r.err
-	}
-	return refusedWatch{err: r.err}, nil
-}
-
-type refusedWatch struct {
-	jetstream.KeyValue
-	err error
-}
-
-func (r refusedWatch) WatchAll(context.Context, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
-	return nil, r.err
-}
-func (r refusedWatch) Watch(context.Context, string, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
-	return nil, r.err
-}

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/standing.go

@@ -0,0 +1,211 @@
+package main
+
+// This file is the same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker (issue 1940): it moves
+// to mesh-sdk go/delivery/buildrun once mesh-sdk can be delivered again, since a change of mesh-sdk waits on the very
+// toolchain agreement this file repairs.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"maps"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/provider"
+)
+
+// A build module writes <node>.<language> of its toolchains state on every node it runs on, and nothing deletes the key
+// when the module is unassigned from a node: the controller writes no module's state, and the module is gone. A report of
+// a node the build module no longer runs on is therefore not a builder (issue 1940: mesh-build-node unassigned from ace
+// on 2026-10-23 left ace.typescript at v26.12.0, and every Node fingerprint said "builders disagree").
+//
+// toolchainGate stands between the toolchains buckets and what takes their entries in (the indexer's PutToolchain, a
+// buildrun.ToolchainSet): an entry is passed on only while the controller's assignments (mesh-controller_assignments,
+// key <node>.<module>) hold an open assignment of its build module on its node, and only once it was written since that
+// assignment; it is passed on as deleted otherwise, said once, and passed on when its node writes it again. A report
+// written before the assignment is the one an earlier run of the module left (issue 1940, 2026-10-25 20:56: mesh-build-node
+// assigned to ace again brought ace.typescript v26.12.0 of 2026-10-23 back into the agreement, before the module ran
+// there, and the controller's take-in refused every module "builders disagree"). Until the assignments are settled (or where they cannot
+// be read) every entry is passed on, as before. Builders that run and report different versions still disagree: that
+// refusal is the guard of novox/hq ADR 0465, and it stays.
+type toolchainGate struct {
+	mu       sync.Mutex
+	modules  map[string]bool                                           // the build modules whose toolchains pass the gate
+	forward  func(module, key string, value []byte, deleted bool) bool // answers whether it changed what it holds
+	logf     func(format string, a ...any)
+	known    bool                         // the assignments are settled
+	standing map[string]time.Time         // <node>.<module> with an open assignment -> since when it stands
+	raw      map[string]map[string][]byte // module -> toolchains key -> value, as the bucket holds it
+	left     map[string]string            // <module>/<key> -> why it was said left out, so each reason is said once
+}
+
+func newToolchainGate(modules []string, forward func(module, key string, value []byte, deleted bool) bool, logf func(string, ...any)) *toolchainGate {
+	g := &toolchainGate{modules: map[string]bool{}, forward: forward, logf: logf, standing: map[string]time.Time{},
+		raw: map[string]map[string][]byte{}, left: map[string]string{}}
+	for _, m := range modules {
+		g.modules[m] = true
+	}
+	return g
+}
+
+// Toolchain takes one change of a build module's toolchains bucket in and answers whether what it passed on changed.
+func (g *toolchainGate) Toolchain(module, key string, value []byte, deleted bool) bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	if g.raw[module] == nil {
+		g.raw[module] = map[string][]byte{}
+	}
+	if deleted {
+		delete(g.raw[module], key)
+	} else {
+		g.raw[module][key] = value
+	}
+	return g.pass(module, key)
+}
+
+// Assignment takes one change of the controller's assignments in (at is when the bus wrote that revision) and answers
+// whether what it passed on changed.
+func (g *toolchainGate) Assignment(key string, value []byte, deleted bool, at time.Time) bool {
+	node, module, ok := strings.Cut(key, ".")
+	if !ok || !g.modules[module] {
+		return false
+	}
+	assigned, open := openAssignment(value)
+	open = open && !deleted
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	was, stood := g.standing[key]
+	since := assigned
+	if since.IsZero() {
+		// A value with no time of its own (an assignment a module pulled in) stands since the revision that opened it.
+		since = at
+		if stood {
+			since = was
+		}
+	}
+	if open == stood && (!open || since.Equal(was)) {
+		return false
+	}
+	if open {
+		g.standing[key] = since
+	} else {
+		delete(g.standing, key)
+	}
+	if !g.known {
+		return false
+	}
+	changed := false
+	for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+		if n, _, err := delivery.ParseToolchainKey(k); err == nil && n == node {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// Settled says the assignments are read: from now on only the reports of assigned nodes pass. It answers whether what it
+// passed on changed.
+func (g *toolchainGate) Settled() bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	g.known = true
+	changed := false
+	for _, module := range slices.Sorted(maps.Keys(g.raw)) {
+		for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// pass hands one key on as it stands: its value when its node is assigned and wrote it since (or the assignments are not
+// known), deleted otherwise. The caller holds mu.
+func (g *toolchainGate) pass(module, key string) bool {
+	value, held := g.raw[module][key]
+	if !held {
+		return g.forward(module, key, nil, true)
+	}
+	node, _, err := delivery.ParseToolchainKey(key)
+	why := ""
+	if err == nil && g.known {
+		why = g.leftOut(module, node, value)
+	}
+	if why == "" {
+		delete(g.left, module+"/"+key)
+		return g.forward(module, key, value, false)
+	}
+	if g.left[module+"/"+key] != why {
+		g.left[module+"/"+key] = why
+		g.logf("%s.%s is left out of the agreed toolchain: %s (issue 1940)", delivery.ToolchainsBucket(module), key, why)
+	}
+	return g.forward(module, key, nil, true)
+}
+
+// leftOut is why a node's report is no builder's, or empty when it counts: its node has no open assignment of the module,
+// or the report was written before that assignment. A value that is no toolchain is passed on for its reader to refuse.
+// The caller holds mu.
+func (g *toolchainGate) leftOut(module, node string, value []byte) string {
+	since, open := g.standing[node+"."+module]
+	if !open {
+		return fmt.Sprintf("%s has no assignment on %s, so it is no builder", module, node)
+	}
+	tc, err := delivery.DecodeToolchain(value)
+	if err == nil && tc.At.Before(since) {
+		return fmt.Sprintf("it was written at %s, before %s's assignment on %s at %s: it counts once %s writes it again",
+			tc.At.UTC().Format(time.RFC3339), module, node, since.UTC().Format(time.RFC3339), node)
+	}
+	return ""
+}
+
+// openAssignment is whether a value of the controller's assignments holds an assignment that stands (one that has not
+// ended and has no state: a pending one is not on the machine yet; mesh-controller internal/chain Assignment), and when
+// it was assigned, zero where the value does not say.
+func openAssignment(value []byte) (time.Time, bool) {
+	var a struct {
+		Assigned time.Time `json:"assigned"`
+		Ended    time.Time `json:"ended"`
+		State    string    `json:"state"`
+	}
+	if json.Unmarshal(value, &a) != nil {
+		return time.Time{}, false
+	}
+	return a.Assigned, a.Ended.IsZero() && a.State == ""
+}
+
+// watchAssignments settles the controller's assignments into the gate, says them settled, and follows them; changed is
+// told whenever what the gate passes on changed. Where the bucket cannot be read (not there, or this module may not read
+// it) it says so and the gate passes every report on, as before; an error of the watch after that ends on the channel.
+func watchAssignments(ctx context.Context, js bucketOpener, gate *toolchainGate, changed func(context.Context), logger *log.Logger) (<-chan error, error) {
+	errs := make(chan error, 1)
+	kv, err := js.KeyValue(ctx, provider.AssignmentsBucket)
+	if err != nil {
+		// Not fatal: an indexer, builder or checker that stops for it stops every delivery (a grant comes with a delivery).
+		logger.Printf("the bucket %s cannot be read, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	each := func(e jetstream.KeyValueEntry) { gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) }
+	w, err := settle(ctx, kv, each)
+	if err != nil {
+		// Not fatal either (issue 1945): a watch the bus refuses is the same missing grant as a refused read.
+		logger.Printf("the bucket %s cannot be watched, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	if gate.Settled() {
+		changed(ctx)
+	}
+	go func() {
+		errs <- follow(ctx, w, func(e jetstream.KeyValueEntry) {
+			if gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) {
+				changed(ctx)
+			}
+		})
+	}()
+	return errs, nil
+}

modules/mesh-delivery-checker/cmd/mesh-delivery-checker/standing_test.go

@@ -0,0 +1,218 @@
+package main
+
+// The same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker, as standing.go is (issue 1940).
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"strings"
+	"testing"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/process"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
+)
+
+func gateReport(t *testing.T, node, version string) (string, []byte) {
+	t.Helper()
+	key, err := delivery.ToolchainKey(node, "typescript")
+	if err != nil {
+		t.Fatal(err)
+	}
+	value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: time.Unix(0, 0).UTC()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return key, value
+}
+
+func agreedOf(set *buildrun.ToolchainSet) (string, string) {
+	tc, none := delivery.AgreedToolchain(set.Entries("typescript"))
+	return tc.Version, none
+}
+
+// The live case of issue 1940: mesh-build-node was unassigned from ace, whose report stayed at v26.12.0 while the
+// three nodes it runs on report v26.12.1. Without the assignments every report counts (and they disagree); with them
+// ace's is left out and the three agree; assigned to ace again, its report counts again and the guard refuses again.
+func TestAnUnassignedBuildNodesReportIsNoBuilder(t *testing.T) {
+	set := &buildrun.ToolchainSet{}
+	var said []string
+	gate := newToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, f) })
+	for node, version := range map[string]string{"ace": "v26.12.0", "g14": "v26.12.1", "novox": "v26.12.1", "shanks": "v26.12.1"} {
+		key, value := gateReport(t, node, version)
+		gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree") {
+		t.Fatalf("before the assignments are read every report counts, so they disagree; got %q", none)
+	}
+	for _, node := range []string{"g14", "novox", "shanks"} {
+		gate.Assignment(node+"."+buildrun.NodeBuildModule, []byte(`{"node":"`+node+`","module":"mesh-build-node"}`), false, time.Time{})
+	}
+	gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","ended":"2026-10-23T08:00:00Z"}`), false, time.Time{})
+	gate.Assignment("ace.mesh-build-go", []byte(`{"node":"ace","module":"mesh-build-go"}`), false, time.Time{}) // another module's: no matter
+	if !gate.Settled() {
+		t.Fatal("settling the assignments left ace's report out, so what was passed on changed")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("the assigned nodes agree on v26.12.1; got %q, %q", v, none)
+	}
+	if len(said) != 1 {
+		t.Fatalf("ace's report is said left out once; said %v", said)
+	}
+	// ace reports again while unassigned (an old value seen again): still left out.
+	key, value := gateReport(t, "ace", "v26.12.0")
+	if gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+		t.Fatal("an unassigned node's report changed what was passed on")
+	}
+	// Assigned to ace again: its report counts, and the builders really disagree: the guard stays.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node"}`), false, time.Time{}) {
+		t.Fatal("assigning ace again passed nothing on")
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+		t.Fatalf("builders that run different versions still disagree; got %q", none)
+	}
+	// The assignment's key deleted, or a pending one written: no assignment stands, and ace's report goes again.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","state":"pending"}`), false, time.Time{}) {
+		t.Fatal("a pending assignment is no assignment on the machine")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("got %q, %q", v, none)
+	}
+	gate.Assignment("ace.mesh-build-node", nil, true, time.Time{})
+	if v, _ := agreedOf(set); v != "v26.12.1" {
+		t.Fatalf("got %q", v)
+	}
+	// A report deleted from the bucket goes whether its node is assigned or not.
+	key, _ = gateReport(t, "g14", "v26.12.1")
+	if !gate.Toolchain(buildrun.NodeBuildModule, key, nil, true) {
+		t.Fatal("deleting g14's report passed nothing on")
+	}
+	if n := len(set.Entries("typescript")); n != 2 {
+		t.Fatalf("novox and shanks are left; got %d entries", n)
+	}
+
+	// 1945 (a part exits at start for a bucket it works without): a bus that refuses the assignments' watch, or every
+	// toolchains bucket, leaves the watches unstarted and the part running, said; a refused bucket it cannot work without
+	// is an error naming the bucket and its grant.
+	var logs bytes.Buffer
+	logger := log.New(&logs, "", 0)
+	refused := refusingBus{err: errors.New("nats: permissions violation for publish to $JS.API.CONSUMER.CREATE.KV_mesh-controller_assignments")}
+	if _, err := watchAssignments(context.Background(), refused, newToolchainGate(nil, set.Put, t.Logf), func(context.Context) {}, logger); err != nil {
+		t.Errorf("a refused watch of the assignments stopped the start: %v", err)
+	}
+	if err := newToolchainWatch(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, set, func(context.Context) {}, logger).start(); err != nil {
+		t.Errorf("a refused toolchains bucket stopped the start: %v", err)
+	}
+	if !strings.Contains(logs.String(), "cannot be watched") || !strings.Contains(logs.String(), "cannot be read") {
+		t.Errorf("the refusals were not said: %q", logs.String())
+	}
+	if _, err := process.EssentialBucket(context.Background(), refusingBus{refuseOpen: true, err: refused.err}, "checker", "mesh-delivery-indexer_modules", "work"); err == nil ||
+		!strings.Contains(err.Error(), "grant of mesh-delivery-indexer_modules") {
+		t.Errorf("a refused bucket the part needs: %v, want an error naming its grant", err)
+	}
+}
+
+// refusingBus is a bus that refuses: every open (refuseOpen), or every watch of a bucket it opens, with err.
+type refusingBus struct {
+	refuseOpen bool
+	err        error
+}
+
+func (r refusingBus) KeyValue(context.Context, string) (jetstream.KeyValue, error) {
+	if r.refuseOpen {
+		return nil, r.err
+	}
+	return refusedWatch{err: r.err}, nil
+}
+
+type refusedWatch struct {
+	jetstream.KeyValue
+	err error
+}
+
+func (r refusedWatch) WatchAll(context.Context, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
+	return nil, r.err
+}
+func (r refusedWatch) Watch(context.Context, string, ...jetstream.WatchOpt) (jetstream.KeyWatcher, error) {
+	return nil, r.err
+}
+
+// A build node's report counts from the first one it writes since its assignment: a newly assigned node that has not
+// reported changes nothing, and the report an earlier run left on the bus (issue 1940, 2026-10-25 20:56: ace.typescript
+// v26.12.0 of 2026-10-23 06:29, mesh-build-node assigned to ace again at 20:56:45) is left out, said once, until the node
+// writes it again. An assignment whose value names no time stands since the revision that opened it.
+func TestANewlyAssignedNodeCountsFromItsReport(t *testing.T) {
+	left := time.Date(2026, 10, 23, 6, 29, 18, 0, time.UTC)      // ace's report from its earlier run
+	assigned := time.Date(2026, 10, 25, 19, 56, 45, 0, time.UTC) // mesh-build-node assigned to ace again
+	report := func(t *testing.T, node, version string, at time.Time) (string, []byte) {
+		key, _ := gateReport(t, node, version)
+		value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: at})
+		if err != nil {
+			t.Fatal(err)
+		}
+		return key, value
+	}
+	for _, c := range []struct {
+		name       string
+		assignment string    // ace's assignment value
+		revision   time.Time // when the bus wrote it
+		at         time.Time // when ace wrote its report
+		counts     bool
+	}{
+		{"no report yet, then one", `{}`, time.Time{}, time.Now(), true},
+		{"a report left before the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, left, false},
+		{"a report left before a value with no time", `{"node":"ace","module":"mesh-build-node"}`, assigned, left, false},
+		{"a report written since the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, assigned.Add(30 * time.Second), true},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			set := &buildrun.ToolchainSet{}
+			var said []string
+			gate := newToolchainGate([]string{buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, fmt.Sprintf(f, a...)) })
+			for _, node := range []string{"g14", "novox", "shanks"} {
+				gate.Assignment(node+".mesh-build-node", []byte(`{}`), false, time.Time{})
+				key, value := gateReport(t, node, "v26.12.1")
+				gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+			}
+			gate.Settled()
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision) {
+				t.Fatal("an assignment with no report passed something on")
+			}
+			key, value := report(t, "ace", "v26.12.0", c.at)
+			if got := gate.Toolchain(buildrun.NodeBuildModule, key, value, false); got != c.counts {
+				t.Fatalf("ace's report passed on: %v, want %v", got, c.counts)
+			}
+			// A rewrite of the assignment that does not move it changes nothing, and nothing is said again.
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision.Add(time.Minute)) {
+				t.Fatal("the same assignment written again changed what was passed on")
+			}
+			v, none := agreedOf(set)
+			if c.counts {
+				if !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+					t.Fatalf("ace's own report counts and disagrees; got %q, %q", v, none)
+				}
+				return
+			}
+			if v != "v26.12.1" || none != "" {
+				t.Fatalf("ace's left report is no builder's, so g14, novox and shanks agree; got %q, %q", v, none)
+			}
+			if len(said) != 1 || !strings.Contains(said[0], "before mesh-build-node's assignment on ace at 2026-10-25T19:56:45Z") {
+				t.Fatalf("said %q, want once why ace's report is left out", said)
+			}
+			// ace writes its report again since it was assigned: it counts.
+			key, value = report(t, "ace", "v26.12.1", assigned.Add(time.Minute))
+			if !gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+				t.Fatal("ace's new report was not passed on")
+			}
+			if n := len(set.Entries("typescript")); n != 4 {
+				t.Fatalf("four builders report; got %d", n)
+			}
+		})
+	}
+}

modules/mesh-delivery-checker/go.mod

@@ -3,7 +3,7 @@ module mesh-delivery-checker
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027220144-3f7957e16972
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-delivery-checker/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a h1:nhRFmtdcI4VkghGUdJhpt1BnPuTQcekioOIRzW8fcG0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027220144-3f7957e16972 h1:iYDYv4HpV1ic20Ban0MaOErryQfNT8ngjlh0bKW6sCU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027220144-3f7957e16972/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-delivery-checker/internal/check/askagain.go

@@ -1,198 +0,0 @@
-package check
-
-import (
-	"context"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"strings"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-// **A check is asked again by hand** (the lost check of 2026-10-28; tools-are-how-a-module-is-spoken-to: every recovery
-// has a tool). checker_ask_again ends a candidate's running verdict, whose wait judged nothing, with AskedAgainWords and
-// the why; the checker hears it on its watch of its verdicts (Checker.VerdictWritten), ends the check of those heads
-// running in it, and claims and asks it anew, a whole check (IsEnded). It is refused while a step of the candidate's pull
-// requests can still run (checker_status's running_steps): that step's end judges it; and while an ask the check put is
-// still in its build seat's stream, taken by no node (it has no step key yet): asking again then would run the check twice
-// (issue 1791's kind). The checker keeps the asks each running check put in its state asks (AsksState, by verdict key).
-// An ask is not put again under its own id instead: the stream de-duplicates an id within its window, so the copy waiting
-// stays and the new one is dropped, and past the window both would run; nothing takes a put ask back (buildrun.Asker).
-
-// AsksState is the checker's state of the asks each running check put, by verdict key (CheckAsks); AsksBucket its bucket.
-const (
-	AsksState  = "asks"
-	AsksBucket = delivery.CheckerModule + "_" + AsksState
-)
-
-// CheckAsks are the asks a check put, in order, as the state asks keeps them while it runs; its end deletes the key.
-type CheckAsks struct {
-	Asks []string `json:"asks"`
-}
-
-// AsksKV is the state asks: a KV whose key a check's end deletes, so the state holds only the checks that run.
-type AsksKV interface {
-	KV
-	Delete(ctx context.Context, key string) error
-}
-
-// forgetAsks deletes the asks a check put at its end; one that cannot be deleted is said, and the next check of the same
-// heads writes the key anew.
-func (ch *Checker) forgetAsks(ctx context.Context, key string) {
-	if err := ch.Asks.Delete(ctx, key); err != nil {
-		ch.logf("%s: the asks it put could not be forgotten at its end: %v", key, err)
-	}
-}
-
-// recordAsks keeps the asks a check put under its verdict key; nil Asks keeps nothing. A record that cannot be written
-// is said: checker_ask_again then refuses the check, as it cannot tell whether its ask waits in a stream.
-func (ch *Checker) recordAsks(ctx context.Context, key string, asks []string) {
-	if ch.Asks == nil {
-		return
-	}
-	data, err := json.Marshal(CheckAsks{Asks: asks})
-	if err == nil {
-		_, err = putOnce(ctx, ch.Asks, key, data, func(cur []byte) bool { return string(cur) == string(data) })
-	}
-	if err != nil {
-		ch.logf("%s: the asks it put cannot be kept (%v), so %s refuses it", key, err, AskAgainTool)
-	}
-}
-
-// AskAgainTool asks a candidate's check again by hand.
-const AskAgainTool = "checker_ask_again"
-
-// AskedAgainWords open the words of a verdict AskAgainTool wrote; the why follows.
-const AskedAgainWords = EndedWords + "asked again by hand (" + AskAgainTool + "): "
-
-// errAskedAgain is the cause a running check is ended with when its verdict was asked again by hand.
-var errAskedAgain = errors.New("its verdict was asked again by hand (" + AskAgainTool + ")")
-
-// IsAskedAgain says whether a verdict was written by AskAgainTool.
-func IsAskedAgain(v delivery.Verdict) bool {
-	return IsEnded(v) && strings.HasPrefix(v.Failed.Words, AskedAgainWords)
-}
-
-// VerdictEntry is the verdicts state as the ask-again tool writes it: a key's value and revision (nil and 0 for none),
-// and a compare-and-set.
-type VerdictEntry interface {
-	Entry(key string) (json.RawMessage, uint64, error)
-	Update(key string, value []byte, revision uint64) error
-}
-
-// AskedAgain is the answer of AskAgainTool.
-type AskedAgain struct {
-	Key  string `json:"key"`
-	Was  string `json:"was"`
-	Said string `json:"said"`
-	Note string `json:"note"`
-}
-
-// AskAgain ends the running verdict of the group's candidate as asked again by hand, saying why. It refuses a group with
-// no candidate, a verdict that is not running (a pass or a failure stands until a push or a trunk move), one a step of
-// whose pull requests can still run, and one whose asks are not known or one of which no node took yet.
-func (r Reader) AskAgain(w VerdictEntry, group, why string) (AskedAgain, error) {
-	why = strings.TrimSpace(why)
-	if group == "" || why == "" {
-		return AskedAgain{}, fmt.Errorf("give the group and why it is asked again")
-	}
-	if w == nil {
-		return AskedAgain{}, fmt.Errorf("the verdicts state cannot be written here")
-	}
-	c, ok := r.candidate(group)
-	if !ok {
-		return AskedAgain{}, fmt.Errorf("no candidate is held for the group %q", group)
-	}
-	key, err := delivery.CheckerVerdictKey(c.Group, c.HeadsHash)
-	if err != nil {
-		return AskedAgain{}, err
-	}
-	raw, rev, err := w.Entry(key)
-	if err != nil {
-		return AskedAgain{}, fmt.Errorf("%s cannot be read: %w", key, err)
-	}
-	if len(raw) == 0 {
-		return AskedAgain{}, fmt.Errorf("%s holds no verdict: the checker claims its check when it looks at the candidate (%s)", key, StatusReadTool)
-	}
-	v, err := delivery.DecodeVerdict(raw)
-	if err != nil {
-		return AskedAgain{}, fmt.Errorf("%s holds what is not a verdict: %w", key, err)
-	}
-	if v.State != delivery.VerdictRunning {
-		return AskedAgain{}, fmt.Errorf("%s is %s, not running: a verdict stands until a push or a trunk move asks it again", key, v.State)
-	}
-	steps := r.readSteps()
-	for _, rs := range steps.running {
-		if asksOf(c, rs.What) {
-			return AskedAgain{}, fmt.Errorf("a step of it runs: %s %s on %s since %s (%s); its end judges it", rs.Module, rs.ID, rs.Node, rs.Since, rs.What)
-		}
-	}
-	if r.AskState.Get == nil {
-		return AskedAgain{}, fmt.Errorf("the checker's asks are not readable here, so whether its ask waits in a build seat's stream cannot be told")
-	}
-	kept, err := r.AskState.Get(key)
-	var put CheckAsks
-	if err == nil && len(kept) > 0 {
-		err = json.Unmarshal(kept, &put)
-	}
-	if err != nil || len(put.Asks) == 0 {
-		return AskedAgain{}, fmt.Errorf("the checker names no ask of %s (%v), so whether one waits in a build seat's stream cannot be told; asking again could run it twice", key, err)
-	}
-	taken := map[string]bool{}
-	for _, s := range steps.all {
-		taken[s.step.ID] = true
-	}
-	for _, id := range put.Asks {
-		if !taken[id] {
-			return AskedAgain{}, fmt.Errorf("its ask %s waits in its build seat's stream, taken by no node yet: asking again would run it twice; "+
-				"the seats' backlog is in mesh-delivery-view.build_usage", id)
-		}
-	}
-	words := AskedAgainWords + why
-	ended := delivery.Verdict{Group: v.Group, Heads: v.Heads, Trunk: v.Trunk, State: delivery.VerdictFail,
-		Failed: delivery.FailedFirst{Machine: "checker", Words: words}}
-	data, err := delivery.EncodeVerdict(ended)
-	if err != nil {
-		return AskedAgain{}, err
-	}
-	if err := w.Update(key, data, rev); err != nil {
-		return AskedAgain{}, fmt.Errorf("%s changed while it was asked again, so it was not; read it again: %w", key, err)
-	}
-	return AskedAgain{Key: key, Was: v.State, Said: words,
-		Note: "the checker hears it on its watch of its verdicts, ends the wait that judged nothing and asks the check anew, whole; " +
-			VerdictsReadTool + " shows it running again"}, nil
-}
-
-// VerdictWritten takes a change of the checker's verdicts in (its watch, updates only): a verdict AskAgainTool wrote ends
-// the check of those heads running in this process, which then considers them again; with none running, the candidate
-// that holds them is considered at once. Any other verdict is the checker's own, and left.
-func (ch *Checker) VerdictWritten(ctx context.Context, key string, value []byte) {
-	v, err := delivery.DecodeVerdict(value)
-	if err != nil || !IsAskedAgain(v) {
-		return
-	}
-	ch.init()
-	ch.mu.Lock()
-	if l, ok := ch.live[key]; ok {
-		l.end(errAskedAgain)
-		ch.mu.Unlock()
-		ch.logf("%s: %s; the check running for it is ended and asked again", key, v.Failed.Words)
-		return
-	}
-	var group string
-	var cand delivery.Candidate
-	for k, c := range ch.known {
-		if vk, err := delivery.CheckerVerdictKey(c.Group, c.HeadsHash); err == nil && vk == key {
-			group, cand = k, c
-			break
-		}
-	}
-	ch.mu.Unlock()
-	if group == "" {
-		ch.logf("%s: %s, but no candidate holds these heads, so nothing is asked", key, v.Failed.Words)
-		return
-	}
-	ch.logf("%s: %s; asked again", key, v.Failed.Words)
-	ch.consider(ctx, group, cand)
-}

modules/mesh-delivery-checker/internal/check/case.go

@@ -115,7 +115,7 @@ func CaseOf(c delivery.Candidate, trunk map[string]string) *Case {
 	for _, p := range c.Pulls {
 		switch head, known := trunk[p.Repository]; {
 		case !known || head == "":
-			cs.Left = append(cs.Left, fmt.Sprintf("%s#%d: %s", p.Repository, p.Number, UntrunkedWordsOf([]string{p.Repository})))
+			cs.Left = append(cs.Left, fmt.Sprintf("%s#%d: the trunk head of %s is not known", p.Repository, p.Number, p.Repository))
 		default:
 			cs.Pulls = append(cs.Pulls, Pull{Repository: p.Repository, Number: p.Number, Head: p.Head.Head, Trunk: head, Modules: p.Modules, Fps: p.Fps})
 			cs.Trunk[p.Repository] = head
@@ -133,42 +133,6 @@ func CaseOf(c delivery.Candidate, trunk map[string]string) *Case {
 	return cs
 }
 
-// UntrunkedWords open the words of a verdict, and of a status, of a pull request that cannot be judged because the gate's
-// source.main names no trunk head of its repository (issue 1422): never a failure of the change, and judged whole once the
-// trunk head is known. It is said loudly, never left silently "new".
-const UntrunkedWords = "cannot be judged: the trunk head of "
-
-// UntrunkedWordsOf are those words for the repositories whose trunk head is not known, in order, each named once.
-func UntrunkedWordsOf(repos []string) string {
-	rs := slices.Clone(repos)
-	slices.Sort(rs)
-	rs = slices.Compact(rs)
-	return UntrunkedWords + strings.Join(rs, ", ") + " is not known: the gate's source.main names none, so there is no commit to merge it onto"
-}
-
-// IsUntrunked says whether a verdict says its heads cannot be judged for want of a trunk head (UntrunkedWords).
-func IsUntrunked(v delivery.Verdict) bool {
-	return v.State == delivery.VerdictFail && v.Failed.Machine == "checker" && strings.HasPrefix(v.Failed.Words, UntrunkedWords)
-}
-
-// leftOf are the pull requests of a candidate whose repository has no trunk head known, with Trunk empty, in repository and
-// number order; nil when every repository's is known.
-func leftOf(c delivery.Candidate, trunk map[string]string) []Pull {
-	var out []Pull
-	for _, p := range c.Pulls {
-		if trunk[p.Repository] == "" {
-			out = append(out, Pull{Repository: p.Repository, Number: p.Number, Head: p.Head.Head, Modules: p.Modules, Fps: p.Fps})
-		}
-	}
-	sort.SliceStable(out, func(i, j int) bool {
-		if out[i].Repository != out[j].Repository {
-			return out[i].Repository < out[j].Repository
-		}
-		return out[i].Number < out[j].Number
-	})
-	return out
-}
-
 // GateHeads is the hash the gate matches the members an Approve covers by (mesh-catalog mesh-delivery-gate onestatus.go
 // headsOf): delivery.HeadsHash over every pull request of the candidate, hq's included, as
 // `<owner/name lowercase>#<number>=<full head sha lowercase>`. A lone pull request is a group of one. Empty for a candidate

modules/mesh-delivery-checker/internal/check/checker.go

@@ -79,8 +79,6 @@ type Checker struct {
 	}
 	// Bound is how long one check may run; none when 0 (DefaultBound).
 	Bound time.Duration
-	// Asks keeps the asks each running check put, by verdict key (AsksState), for checker_ask_again; nil keeps none.
-	Asks AsksKV
 	// Link is the base of the address a status points at; the verdict key follows.
 	Link string
 	// Announce says a status was written (EventOwedWritten); nil says nothing.
@@ -250,35 +248,6 @@ func (ch *Checker) Candidate(ctx context.Context, key string, value []byte) {
 	ch.consider(ctx, key, c)
 }
 
-// VerdictDeleted takes the delete of a verdict key in (the checker's watch of its verdicts, issue 1733): the gate asks the
-// operator's Approve only on a verdict, so heads a candidate holds are never left without one. A check of them running in
-// this process writes its verdict anew at its end; otherwise the candidate is considered at once and judged again (or said
-// again to be unjudgeable). A key no candidate holds is said and left.
-func (ch *Checker) VerdictDeleted(ctx context.Context, key string) {
-	ch.init()
-	ch.mu.Lock()
-	if ch.inflight[key] {
-		ch.mu.Unlock()
-		ch.logf("%s: deleted while its check runs; its end writes it anew", key)
-		return
-	}
-	var group string
-	var cand delivery.Candidate
-	for k, c := range ch.known {
-		if vk, err := delivery.CheckerVerdictKey(c.Group, c.HeadsHash); err == nil && vk == key {
-			group, cand = k, c
-			break
-		}
-	}
-	ch.mu.Unlock()
-	if group == "" {
-		ch.logf("%s: deleted, and no candidate holds these heads, so nothing is judged", key)
-		return
-	}
-	ch.logf("%s: deleted; its heads are judged again", key)
-	ch.consider(ctx, group, cand)
-}
-
 // Forget takes a candidate out (its key was deleted): a check of its heads still running is ended, as no candidate holds
 // them any more.
 func (ch *Checker) Forget(key string) {
@@ -326,17 +295,9 @@ func (ch *Checker) heads() map[string]string {
 }
 
 func (ch *Checker) consider(ctx context.Context, key string, c delivery.Candidate) {
-	heads := ch.heads()
-	if left := leftOf(c, heads); len(left) > 0 {
-		// A pull request the checker cannot claim (its repository's trunk head is not known) leaves its whole group
-		// unjudged, said in a failure verdict (issue 1422, issue 1733): the gate asks the Approve only on a verdict, and a
-		// pass of the other members would let the group merge with that one never checked.
-		ch.untrunked(ctx, c, left)
-		return
-	}
-	cs := CaseOf(c, heads)
+	cs := CaseOf(c, ch.heads())
 	if cs == nil {
-		return // no pull request at all: nothing to judge
+		return // nothing to judge: no trunk known
 	}
 	cs.Queued = ch.now()
 	ch.mu.Lock()
@@ -363,11 +324,7 @@ func (ch *Checker) consider(ctx context.Context, key string, c delivery.Candidat
 			delete(ch.again, vkey)
 			delete(ch.live, vkey)
 			ch.mu.Unlock()
-			again := errors.Is(context.Cause(run), errAskedAgain)
 			end(nil)
-			if again && ctx.Err() == nil {
-				ch.consider(ctx, key, ch.candidate(key, c)) // asked again by hand (AskAgainTool): claimed anew
-			}
 		}()
 		for {
 			// Every check is asked at once: the build seats' streams hold the backlog, a new head's check and a check after a
@@ -394,76 +351,6 @@ func (ch *Checker) consider(ctx context.Context, key string, c delivery.Candidat
 	}()
 }
 
-// untrunked says, loudly, that pull requests of a candidate cannot be judged because the gate's source.main names no trunk
-// head of their repository (issue 1422): its verdict key holds a failure that says so, whatever it held before (a running
-// verdict left by a check that can no longer run, or a verdict judged on a trunk that is no longer named: issue 1733), which
-// checker_verdicts and checker_status show; and every pull request of the candidate gets the status error with
-// UntrunkedWords, the members whose trunk is known too, as their group is not judged. It is logged once per head: when a
-// status or the verdict is written, never at a look that finds them already said. Once the trunk head is known the verdict
-// is stale (it names no trunk) and the heads are judged whole (prepare, claim).
-func (ch *Checker) untrunked(ctx context.Context, c delivery.Candidate, left []Pull) {
-	key, err := delivery.CheckerVerdictKey(c.Group, c.HeadsHash)
-	if err != nil {
-		ch.logf("candidates of %s: no verdict key for heads %q, so it cannot be said that they cannot be judged: %v", c.Group, c.HeadsHash, err)
-		return
-	}
-	repos := make([]string, 0, len(left))
-	for _, p := range left {
-		repos = append(repos, p.Repository)
-	}
-	words := UntrunkedWordsOf(repos)
-	v := delivery.Verdict{Group: c.Group, Heads: GateHeads(c), Trunk: map[string]string{}, State: delivery.VerdictFail,
-		Failed: delivery.FailedFirst{Machine: "checker", Words: words}}
-	data, err := delivery.EncodeVerdict(v)
-	if err != nil {
-		ch.logf("%s: %s, and the verdict cannot say so: %v", key, words, err)
-		return
-	}
-	said, err := putOnce(ctx, ch.Verdicts, key, data, func(cur []byte) bool {
-		held, err := delivery.DecodeVerdict(cur)
-		return err == nil && IsUntrunked(held) && held.Failed.Words == words // the same words stand; anything else is replaced
-	})
-	if err != nil {
-		ch.logf("%s: %s, and the verdict cannot say so: %v", key, words, err)
-	}
-	for _, cp := range c.Pulls {
-		okey, err := delivery.CheckerOwedKey(cp.Repository, cp.Number, cp.Head.Head)
-		if err != nil {
-			ch.logf("%s: %v", key, err)
-			continue
-		}
-		o := delivery.Owed{Act: delivery.OwedStatus, Context: delivery.StatusContextCheck, State: "error",
-			Target: strings.TrimSuffix(ch.Link, "/") + "/" + key, Text: clipLine(words, MaxLine)}
-		data, err := delivery.EncodeCheckerOwed(o)
-		if err != nil {
-			ch.logf("%s: the status of %s cannot be written: %v", key, okey, err)
-			continue
-		}
-		wrote, err := putOnce(ctx, ch.Owed, okey, data, func(cur []byte) bool {
-			held, err := delivery.DecodeCheckerOwed(cur)
-			o.V = delivery.Version
-			return err == nil && delivery.SameOwed(held, o)
-		})
-		if err != nil {
-			ch.logf("%s: the status of %s cannot be written: %v", key, okey, err)
-			continue
-		}
-		if wrote {
-			said = true
-			if ch.Announce != nil {
-				ch.Announce(ctx, EventOwedWritten, okey)
-			}
-		}
-	}
-	if said {
-		names := make([]string, 0, len(left))
-		for _, p := range left {
-			names = append(names, fmt.Sprintf("%s#%d@%s", p.Repository, p.Number, short12(p.Head)))
-		}
-		ch.logf("%s: %s %s; the verdict and every status of its group say so (error), and it is judged once the trunk head is known", key, strings.Join(names, ", "), words)
-	}
-}
-
 // The kinds of a check (ADR 0536 §4): a head never judged and a head asked again after a failure of the nodes are asked on
 // the build seats' check stream; a carry, a verdict moved to a newer trunk or sibling commit by its package digests (ADR 0548
 // §5), on the recheck stream, pulled after.
@@ -493,8 +380,8 @@ func (ch *Checker) prepare(ctx context.Context, cs *Case) {
 		return
 	case IsConflictFailure(v):
 		return // a head git refused: its next check is whole (ADR 0548 §7)
-	case IsEnded(v), IsUntrunked(v):
-		return // ended unjudged when its heads went (issue 1890), or never judged for want of a trunk head (issue 1422): checked whole
+	case IsEnded(v):
+		return // ended unjudged when its heads went (issue 1890): held again, they are checked whole
 	}
 	cs.Kind = KindTrunk
 	if v.State == delivery.VerdictPass && ch.stale(v, cs) {
@@ -747,20 +634,10 @@ func (ch *Checker) try(ctx, run context.Context, key string, cs *Case) {
 		return
 	}
 	began := ch.now()
-	if cs.Watch == nil && ch.Asks != nil {
-		cs.Watch = func(_ string, step *delivery.Step) {
-			if step == nil { // put: kept before its wait starts
-				ch.recordAsks(ctx, cs.Key, cs.Asks())
-			}
-		}
-		defer ch.forgetAsks(ctx, cs.Key)
-	}
 	ch.writeOwed(ctx, cs, delivery.Verdict{State: delivery.VerdictRunning}, Outcome{})
 	out := ch.judge(run, cs)
-	// An ask the build seat gave up on, or whose step the build module's next process ended because it was replaced under
-	// it, judged nothing (issue 734, IsLostAsk): the check is asked again under the same claim, its status pending, and after
-	// LostAskTries it fails as not heard, judged again when the nodes change. A step that ended while its watch was deaf is
-	// read at the next nudge (HeardEnds) and judged.
+	// An ask the build seat gave up on judged nothing (issue 734): the check is asked again under the same claim, its status
+	// pending, and after LostAskTries it fails as not heard, judged again when the nodes change.
 	for try := 1; IsLostAsk(out.Verdict) && run.Err() == nil; try++ {
 		if try >= LostAskTries {
 			out.Verdict.Failed.Words = strings.TrimSpace(out.Verdict.Failed.Words + "\nasked " + fmt.Sprint(LostAskTries) +
@@ -770,8 +647,8 @@ func (ch *Checker) try(ctx, run context.Context, key string, cs *Case) {
 		ch.logf("%s: %s; asked again (%d of %d)", cs.Key, out.Verdict.Failed.Words, try+1, LostAskTries)
 		out = ch.judge(run, cs)
 	}
-	if ctx.Err() != nil || errors.Is(context.Cause(run), errAskedAgain) {
-		return // the checker stops, or the verdict was asked again by hand, which wrote it: its next check claims it anew
+	if ctx.Err() != nil {
+		return
 	}
 	var why superseded
 	if errors.As(context.Cause(run), &why) {
@@ -812,13 +689,8 @@ func (ch *Checker) try(ctx, run context.Context, key string, cs *Case) {
 		}
 	}
 	if _, err := ch.Verdicts.Update(ctx, cs.Key, data, cl.rev); err != nil {
-		if _, _, found, gerr := ch.Verdicts.Get(ctx, cs.Key); gerr == nil && !found {
-			_, err = ch.Verdicts.Create(ctx, cs.Key, data) // its key was deleted while it ran (issue 1733): written anew
-		}
-		if err != nil {
-			ch.logf("%s: the verdict could not be written: %v", cs.Key, err)
-			return
-		}
+		ch.logf("%s: the verdict could not be written: %v", cs.Key, err)
+		return
 	}
 	if IsNodesFailure(v) {
 		ch.mu.Lock()

modules/mesh-delivery-checker/internal/check/checker_test.go

@@ -239,119 +239,14 @@ func TestAnUnheardForgeFailsWithTheReasonAndIsJudgedAgainWhenTheNodesChange(t *t
 	}
 }
 
-// Issue 1422: a pull request of a repository the gate's source.main names no trunk head of (one never merged through the
-// gate) is never dropped silently. It is not judged, its verdict says it cannot be judged and why, its status is error with
-// those words, checker_status names it, and the log says it once per head. Once its trunk head is known it is judged whole;
-// in a group, the members whose trunk is known are judged and the others' status says why they are not.
-func TestARepositoryWithNoTrunkCannotBeJudgedLoudlyUntilItsTrunkIsKnown(t *testing.T) { // N6/AC6, ADR 0484 clause 11, 1422
+func TestARepositoryWithNoTrunkGetsNoVerdict(t *testing.T) { // N6/AC6, ADR 0484 clause 11
 	ctx, j := context.Background(), passJudge()
 	r := newRig(t, j)
-	var logged []string
-	r.ch.Logf = func(f string, a ...any) { logged = append(logged, fmt.Sprintf(f, a...)) }
-	const unknown = "novox/unknown"
-	cand := candidateOf(t, "feat/y", pullOf(unknown, 4, head1))
-	key := keyOf(t, "feat/y", cand)
-	r.ch.Candidate(ctx, "feat/y", cand)
+	r.ch.Candidate(ctx, "feat/y", candidateOf(t, "feat/y", pullOf("novox/unknown", 4, head1)))
 	r.ch.Wait()
-	r.ch.Reconsider(ctx) // looked at again: nothing is written or said twice
-	r.ch.NodesChanged(ctx)
-	r.ch.Wait()
-	v := r.verdict(t, key)
-	if j.count() != 0 || !IsUntrunked(v) || !strings.Contains(v.Failed.Words, "the trunk head of "+unknown+" is not known") {
-		t.Fatalf("judged %d times, verdict %+v, want none judged and a verdict that says it cannot be judged", j.count(), v)
+	if j.count() != 0 || len(r.verdicts.vals) != 0 || len(r.owed.vals) != 0 {
+		t.Errorf("judged %d times, %d verdicts, %d statuses, want none", j.count(), len(r.verdicts.vals), len(r.owed.vals))
 	}
-	if s := owedState(t, r, unknown, 4, head1); s != "error" {
-		t.Errorf("%s#4 owes %q, want error", unknown, s)
-	}
-	if n := countWith(logged, "cannot be judged"); n != 1 {
-		t.Errorf("said %d times in the log, want once for the head: %q", n, logged)
-	}
-	reader := func() Reader {
-		ckey, _ := delivery.CandidatesKey("feat/y")
-		return Reader{CandidateState: fakeState{ckey: cand}.read(), VerdictState: fakeState(r.verdicts.vals).read(),
-			Trunks: func() (map[string]string, error) { return r.trunks.Heads(), nil }}
-	}
-	st, err := reader().Status()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if why := st.CannotBeJudged["feat/y"]; !strings.Contains(why, unknown) || len(st.Waiting[KindNew]) != 0 || len(st.Unjudged) != 0 {
-		t.Errorf("cannot_be_judged %v, waiting %v, unjudged %v: want feat/y named as cannot be judged, not as new", st.CannotBeJudged, st.Waiting, st.Unjudged)
-	}
-	if rows, _, err := reader().Verdicts("feat/y"); err != nil || len(rows) != 1 || !strings.Contains(rows[0].Reports[unknown+"#4"], "cannot be judged") {
-		t.Errorf("checker_verdicts %+v (%v), want the report of %s#4 to say it cannot be judged", rows, err, unknown)
-	}
-
-	// Its trunk head becomes known: the heads are judged whole, the same key rewritten, the status success.
-	r.setTrunks(t, map[string]string{repoA: trunkA, repoSDK: trunkS, unknown: trunkA2})
-	r.ch.TrunkMoved(ctx)
-	r.ch.Wait()
-	if v := r.verdict(t, key); j.count() != 1 || v.State != delivery.VerdictPass || v.Trunk[unknown] != trunkA2 {
-		t.Errorf("judged %d times, verdict %+v, want one pass on %s", j.count(), v, trunkA2)
-	}
-	if s := owedState(t, r, unknown, 4, head1); s != "success" {
-		t.Errorf("%s#4 owes %q once its trunk is known, want success", unknown, s)
-	}
-
-	// Issue 1733: the gate asks the Approve only on a verdict, so no candidate is left without one. A group with a member
-	// whose trunk is not known is not judged in part: its verdict fails naming that repository, and every status says so; a
-	// running verdict left for heads that cannot be judged is replaced; a verdict key deleted is judged again on its delete.
-	for _, row := range []struct {
-		name    string
-		pulls   []delivery.CandidatePull
-		running bool // a running verdict is left under the key first
-		deleted bool // the key is deleted after its verdict
-		judged  int
-		want    string // the verdict's state, and for a failure the repository it names
-	}{
-		{name: "a member the checker cannot claim", pulls: []delivery.CandidatePull{pullOf(repoA, 9, head2), pullOf("novox/other", 2, head2)}, want: "novox/other"},
-		{name: "a running verdict left for heads that cannot be judged", pulls: []delivery.CandidatePull{pullOf(unknown, 5, head2)}, running: true, want: unknown},
-		{name: "a verdict key deleted", pulls: []delivery.CandidatePull{pullOf(repoA, 5, head2)}, deleted: true, judged: 2, want: delivery.VerdictPass},
-	} {
-		t.Run(row.name, func(t *testing.T) {
-			j := passJudge()
-			r := newRig(t, j)
-			cand := candidateOf(t, "feat/z", row.pulls...)
-			key := keyOf(t, "feat/z", cand)
-			if row.running {
-				group, heads, _ := delivery.ParseCheckerVerdictKey(key)
-				raw, _ := delivery.EncodeVerdict(delivery.Verdict{Group: group, Heads: heads, State: delivery.VerdictRunning})
-				_, _ = r.verdicts.Create(ctx, key, raw)
-			}
-			r.ch.Candidate(ctx, "feat%2Fz", cand)
-			r.ch.Wait()
-			if row.deleted {
-				_ = r.verdicts.Delete(ctx, key)
-				r.ch.VerdictDeleted(ctx, key) // the watch of the verdicts hands the delete over
-				r.ch.Wait()
-			}
-			v := r.verdict(t, key)
-			if row.want == delivery.VerdictPass {
-				if v.State != delivery.VerdictPass || j.count() != row.judged {
-					t.Errorf("verdict %s after %d judgings, want a pass after %d", v.State, j.count(), row.judged)
-				}
-				return
-			}
-			if !IsUntrunked(v) || !strings.Contains(v.Failed.Words, row.want) || j.count() != 0 {
-				t.Errorf("verdict %+v after %d judgings, want a failure naming %s and none judged", v, j.count(), row.want)
-			}
-			for _, p := range row.pulls {
-				if s := owedState(t, r, p.Repository, p.Number, p.Head.Head); s != "error" {
-					t.Errorf("%s#%d owes %q, want error", p.Repository, p.Number, s)
-				}
-			}
-		})
-	}
-}
-
-func countWith(lines []string, words string) int {
-	n := 0
-	for _, l := range lines {
-		if strings.Contains(l, words) {
-			n++
-		}
-	}
-	return n
 }
 
 // 1887/A10, ADR 0527 §2: hq is judged as any repository, its checks Go tests, and its pull request gets a verdict and a

modules/mesh-delivery-checker/internal/check/examiner_test.go

@@ -5,7 +5,6 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -273,36 +272,8 @@ func TestACleanMergeIsFetchedAtItsTrunkAndBothLevelsPass(t *testing.T) { // 1679
 			t.Errorf("%s was not kept", k)
 		}
 	}
-
-	// ADR 0567 §12: every check ask carries every node's name for the names check; a check whose names cannot be read, or
-	// that reads none, is not asked and fails saying so.
-	for _, c := range []struct {
-		names []string
-		err   error
-		fails string
-	}{{[]string{"anchor", "laptop"}, nil, ""}, {nil, nil, "no node record"}, {nil, errors.New("no bucket"), "no bucket"}} {
-		b := newBench(t)
-		b.ex.Nodes = namesOf{c.names, c.err}
-		out := b.judge(t, caseOf(t, pullOf(repoA, 7, head1)))
-		asks := b.asks.Asks()
-		if c.fails != "" {
-			if out.Verdict.State != delivery.VerdictFail || len(asks) != 0 || !strings.Contains(out.Verdict.Failed.Words, c.fails) {
-				t.Errorf("names %v, %v: verdict %+v, %d asks", c.names, c.err, out.Verdict, len(asks))
-			}
-		} else if len(asks) == 0 || strings.Join(asks[0].Check.NodeNames, ",") != "anchor,laptop" {
-			t.Errorf("the check ask carries the names %v", asks)
-		}
-	}
 }
 
-// namesOf is the nodes' names as a test gives them.
-type namesOf struct {
-	names []string
-	err   error
-}
-
-func (n namesOf) Names(context.Context) ([]string, error) { return n.names, n.err }
-
 func TestOnlyThePackageWithoutAKeptVerdictRuns(t *testing.T) { // 1288/AC1
 	b := newBench(t)
 	b.digest[delivery.LevelUnit] = Digested{Level: "unit", Packages: map[string]string{"fixture/slow": digA, "fixture/other": digC}}

modules/mesh-delivery-checker/internal/check/fakes_test.go

@@ -60,11 +60,3 @@ func (m *memKV) Keys(context.Context) ([]string, error) {
 	sort.Strings(keys)
 	return keys, nil
 }
-
-func (m *memKV) Delete(_ context.Context, key string) error {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	delete(m.vals, key)
-	delete(m.revs, key)
-	return nil
-}

modules/mesh-delivery-checker/internal/check/judge.go

@@ -110,14 +110,8 @@ type Examiner struct {
 	// waiting until the assigner wrote a verdict that does not wait, or ctx ends (ADR 0528 clause 5, issue 1297); nil
 	// leaves the composition not run.
 	Compositions CompositionReader
-	// Nodes names every node with a record, read from each `<node>.node` of the node-engine's have (novox/hq ADR 0567
-	// §12): every check ask carries them (CheckJob.NodeNames) for the names check, so no repository lists them. A check
-	// whose names cannot be read, or that reads none, is not asked and fails saying so; nil hands no names.
-	Nodes interface {
-		Names(ctx context.Context) ([]string, error)
-	}
-	Now  func() time.Time
-	Logf func(format string, args ...any)
+	Now          func() time.Time
+	Logf         func(format string, args ...any)
 }
 
 // CompositionReader answers the assigner's composition of a check by the check's key, waiting until the assigner wrote
@@ -409,16 +403,6 @@ func (st *state) askNeeding(ctx context.Context, t *target, merged *[]Fetched, l
 	p := t.pull
 	placed := len(needs) > 0
 	job := &delivery.CheckJob{Fetch: t.fetchArgs, Levels: levels, Kept: true, Packages: packages}
-	if st.j.Nodes != nil {
-		names, err := st.j.Nodes.Names(ctx)
-		if err == nil && len(names) == 0 {
-			err = fmt.Errorf("no node record is on the bus")
-		}
-		if err != nil {
-			return fail(t.module, fmt.Sprintf("the check of %s#%d is not asked: the nodes' names the names check needs cannot be read: %v", p.Repository, p.Number, err))
-		}
-		job.NodeNames = names
-	}
 	if t.runner != "" {
 		job.Runner, job.RunnerWhen = t.runner, buildGoDir
 	}

modules/mesh-delivery-checker/internal/check/lostask.go

@@ -3,7 +3,6 @@ package check
 import (
 	"strings"
 
-	"git.novox.be/novox/mesh-sdk/go/buildstep"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
 )
@@ -20,13 +19,9 @@ import (
 // judged again when the nodes change.
 const LostAskTries = 3
 
-// IsLostAsk says whether a verdict failed because its ask judged nothing: the build seat gave it up (buildrun.LostWords), or
-// the build module that ran its step was replaced under it, and its next process ended the step it left running
-// (buildstep.RestartReason; a delivery of the build module, as on 2026-10-28). Neither is the change's failure: the check
-// is asked again, as for a given-up ask.
+// IsLostAsk says whether a verdict failed because the build seat gave its ask up (buildrun.LostWords).
 func IsLostAsk(v delivery.Verdict) bool {
-	return v.State == delivery.VerdictFail && (strings.Contains(v.Failed.Words, buildrun.LostWords) ||
-		strings.Contains(v.Failed.Words, buildstep.RestartReason))
+	return v.State == delivery.VerdictFail && strings.Contains(v.Failed.Words, buildrun.LostWords)
 }
 
 // IsNotTaken says whether a verdict failed because no build node took its ask within the bound (buildrun.NotTakenWords).

modules/mesh-delivery-checker/internal/check/lostask_test.go

@@ -8,7 +8,6 @@ import (
 	"testing"
 	"time"
 
-	"git.novox.be/novox/mesh-sdk/go/buildstep"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
 )
@@ -142,206 +141,30 @@ func TestAnAskGivenUpOrNeverTakenEndsItsTryAsErrorAndItsHeadIsAskedAnew(t *testi
 	})
 }
 
-// troubled is the build seat as a check meets it when its step's end does not reach its wait: the first `restarts` asks'
-// steps are ended by the build module's next process (buildstep.RestartReason), and the first `deaf` asks' watches hear
-// nothing though their steps end (the lost check of 2026-10-28). Its steps state is read through AskSteps and Steps.
-type troubled struct {
-	*buildrun.FakeAsks
-	answer func(delivery.StepAsk) delivery.Step
-
-	mu             sync.Mutex
-	restarts, deaf int
-	deafIDs        map[string]bool
-	steps          map[string]delivery.Step
-}
-
-func (tr *troubled) PublishAsk(ctx context.Context, subject, id string, data []byte) error {
-	if err := tr.FakeAsks.PublishAsk(ctx, subject, id, data); err != nil {
-		return err
-	}
-	a, err := delivery.DecodeStepAsk(data)
-	if err != nil {
-		return err
-	}
-	step := tr.answer(a)
-	step.What = buildstep.AskWhat(a)
-	tr.mu.Lock()
-	if tr.restarts > 0 {
-		tr.restarts--
-		step.State, step.Reason, step.Result = delivery.StepFailed, buildstep.RestartReason, nil
-	}
-	deaf := tr.deaf > 0
-	if deaf {
-		tr.deaf--
-		tr.deafIDs[id] = true
-	}
-	tr.steps[id] = step
-	tr.mu.Unlock()
-	if !deaf {
-		tr.Write(step)
-	}
-	return nil
-}
-
-func (tr *troubled) WatchAsk(ctx context.Context, module, askID string) (<-chan delivery.Step, error) {
-	tr.mu.Lock()
-	deaf := tr.deafIDs[askID]
-	tr.mu.Unlock()
-	if deaf {
-		return make(chan delivery.Step), nil // open, and silent for good
-	}
-	return tr.FakeAsks.WatchAsk(ctx, module, askID)
-}
-
-func (tr *troubled) AskSteps(_ context.Context, _, askID string) ([]delivery.Step, error) {
-	tr.mu.Lock()
-	defer tr.mu.Unlock()
-	if s, ok := tr.steps[askID]; ok {
-		return []delivery.Step{s}, nil
-	}
-	return nil, nil
-}
-
-// Steps is the steps state as the read tools read it, with running in place of every step the hand has not let end.
-func (tr *troubled) Steps(running bool) StateRead {
-	tr.mu.Lock()
-	defer tr.mu.Unlock()
-	vals := map[string]json.RawMessage{}
-	for id, s := range tr.steps {
-		if running {
-			s.State, s.Ended, s.Started = delivery.StepRunning, time.Time{}, time.Now()
-		}
-		raw, _ := delivery.EncodeStep(s)
-		vals[s.Node+"."+id] = raw
-	}
-	return StateRead{Keys: func() ([]string, error) {
-		var out []string
-		for k := range vals {
-			out = append(out, k)
-		}
-		return out, nil
-	}, Get: func(k string) (json.RawMessage, error) { return vals[k], nil }}
-}
-
-// kvRead is a bucket in memory as the read tools read it, live.
-func kvRead(kv *memKV) StateRead {
-	return StateRead{Keys: func() ([]string, error) { return kv.Keys(context.Background()) },
-		Get: func(k string) (json.RawMessage, error) {
-			v, _, _, err := kv.Get(context.Background(), k)
-			return v, err
-		}}
-}
-
-// asVerdicts is the rig's verdicts as the ask-again tool reads and writes them.
-type asVerdicts struct{ kv *memKV }
-
-func (a asVerdicts) Entry(key string) (json.RawMessage, uint64, error) {
-	v, rev, _, err := a.kv.Get(context.Background(), key)
-	return v, rev, err
-}
-func (a asVerdicts) Update(key string, value []byte, revision uint64) error {
-	_, err := a.kv.Update(context.Background(), key, value, revision)
-	return err
-}
-
-// Issue 734 and the lost check of 2026-10-28: a check whose ask judged nothing is asked again, and one whose step ended
-// unheard is judged. Given up by the build seat once, or its step ended by the build module's next process after a
-// delivery replaced it, the check is asked again under its claim and passes; given up every time it fails loudly as not
-// heard, judged again when the nodes change. A step whose watch went deaf is read at the next step end of its build module
-// (a nudge) and judged with no new ask; one no event reaches is named lost by checker_status, refused by checker_ask_again
-// while its step still runs, and asked again by it once its step ended.
-func TestACheckWhoseAskJudgedNothingIsAskedAgainOrRead(t *testing.T) {
+// Issue 734: a pull request's check whose ask the build seat gave up on is asked again under its claim, its status
+// pending, and judged; one given up every time fails as not heard and is judged again when the nodes change.
+func TestACheckWhoseAskWasGivenUpIsAskedAgain(t *testing.T) {
 	ctx := context.Background()
 	for _, row := range []struct {
-		name                 string
-		lose, restarts, deaf int
-		how                  string // "nudge": a step of the build module ends; "hand": checker_ask_again
-		state                string
-		asks                 int
+		lose  int
+		state string
+		asks  int
 	}{
-		{name: "given up once", lose: 1, state: delivery.VerdictPass, asks: 2},
-		{name: "given up every time", lose: LostAskTries, state: delivery.VerdictFail, asks: LostAskTries},
-		{name: "its build module replaced under it", restarts: 1, state: delivery.VerdictPass, asks: 2},
-		{name: "replaced under every ask", restarts: LostAskTries, state: delivery.VerdictFail, asks: LostAskTries},
-		{name: "its watch deaf, a step of its build module ends", deaf: 1, how: "nudge", state: delivery.VerdictPass, asks: 1},
-		{name: "its watch deaf, asked again by hand", deaf: 1, how: "hand", state: delivery.VerdictPass, asks: 2},
-		{name: "its watch deaf, asked again by hand after its build module replaced it", deaf: 1, restarts: 1, how: "hand", state: delivery.VerdictPass, asks: 2},
+		{1, delivery.VerdictPass, 2},
+		{LostAskTries, delivery.VerdictFail, LostAskTries},
 	} {
-		t.Run(row.name, func(t *testing.T) {
-			b := newBench(t)
-			var asked func() int
-			var heard *buildrun.HeardEnds
-			var tr *troubled
-			if row.lose > 0 {
-				l := losing(b, row.lose)
-				asked = func() int { return len(l.Asks()) }
-			} else {
-				tr = &troubled{FakeAsks: &buildrun.FakeAsks{}, answer: b.answer, restarts: row.restarts, deaf: row.deaf,
-					deafIDs: map[string]bool{}, steps: map[string]delivery.Step{}}
-				heard = &buildrun.HeardEnds{Inner: tr, Read: tr}
-				b.ex.Asks = buildrun.Asker{Publisher: tr, Waiter: heard, Bound: 5 * time.Second}
-				asked = func() int { return len(tr.Asks()) }
-			}
-			r := newRig(t, b.ex)
-			asksKept := newMemKV()
-			r.ch.Asks = asksKept
-			cand := candidateOf(t, "feat/x", pullOf(repoA, 7, head1))
-			key := keyOf(t, "feat/x", cand)
-			r.ch.Candidate(ctx, "feat%2Fx", cand)
-			if row.deaf > 0 {
-				for deadline := time.Now().Add(2 * time.Second); heard.Waiting() == 0 && time.Now().Before(deadline); {
-					time.Sleep(2 * time.Millisecond)
-				}
-				if v := r.verdict(t, key); v.State != delivery.VerdictRunning {
-					t.Fatalf("a check whose step ended unheard = %s, want running until it is read", v.State)
-				}
-			}
-			switch row.how {
-			case "nudge":
-				heard.Nudge(buildrun.NodeBuildModule) // another build module's step: not this one's to read
-				heard.Nudge(buildrun.GoBuildModule)
-			case "hand":
-				cands := newMemKV()
-				ckey, _ := delivery.CandidatesKey("feat/x")
-				_, _ = cands.Create(ctx, ckey, cand)
-				none := StateRead{Keys: func() ([]string, error) { return nil, nil }, Get: func(string) (json.RawMessage, error) { return nil, nil }}
-				rd := Reader{CandidateState: kvRead(cands), VerdictState: kvRead(r.verdicts), AskState: kvRead(asksKept),
-					StepStates: map[string]StateRead{buildrun.GoBuildModule: none}} // no node took its ask yet
-				if _, err := rd.AskAgain(asVerdicts{r.verdicts}, "feat/x", "its watch went deaf"); err == nil || !strings.Contains(err.Error(), "waits in its build seat's stream") {
-					t.Errorf("asked again while its ask waits in the stream (issue 1791's kind): %v", err)
-				}
-				rd.StepStates[buildrun.GoBuildModule] = tr.Steps(true)
-				if _, err := rd.AskAgain(asVerdicts{r.verdicts}, "feat/x", "its watch went deaf"); err == nil || !strings.Contains(err.Error(), "a step of it runs") {
-					t.Errorf("asked again while its step runs: %v", err)
-				}
-				rd.StepStates[buildrun.GoBuildModule] = tr.Steps(false)
-				if st, _ := rd.Status(); !strings.Contains(st.Lost["feat/x"], AskAgainTool) {
-					t.Errorf("status lost = %v, want feat/x named with %s", st.Lost, AskAgainTool)
-				}
-				got, err := rd.AskAgain(asVerdicts{r.verdicts}, "feat/x", "its watch went deaf")
-				if err != nil || got.Key != key || !strings.HasPrefix(got.Said, AskedAgainWords) {
-					t.Fatalf("asked again = %+v, %v", got, err)
-				}
-				raw, _, _, _ := r.verdicts.Get(ctx, key)
-				r.ch.VerdictWritten(ctx, key, raw) // the checker's watch of its verdicts hands it over
-			}
-			r.ch.Wait()
-			v := r.verdict(t, key)
-			if v.State != row.state || asked() != row.asks {
-				t.Errorf("verdict %s (%s) after %d asks, want %s after %d", v.State, v.Failed.Words, asked(), row.state, row.asks)
-			}
-			if _, _, kept, _ := asksKept.Get(ctx, key); kept {
-				t.Errorf("the asks of the ended check are still kept under %s", key)
-			}
-			if row.state == delivery.VerdictFail && (!IsLostAsk(v) || !IsNodesFailure(v)) {
-				t.Errorf("a check that judged nothing every time = %q, want lost and judged again when the nodes change", v.Failed.Words)
-			}
-			if row.how == "hand" {
-				rd := Reader{VerdictState: kvRead(r.verdicts), CandidateState: kvRead(newMemKV())}
-				if _, err := rd.AskAgain(asVerdicts{r.verdicts}, "feat/x", "again"); err == nil {
-					t.Error("a judged check was asked again")
-				}
-			}
-		})
+		b := newBench(t)
+		l := losing(b, row.lose)
+		r := newRig(t, b.ex)
+		cand := candidateOf(t, "feat/x", pullOf(repoA, 7, head1))
+		r.ch.Candidate(ctx, "feat%2Fx", cand)
+		r.ch.Wait()
+		v := r.verdict(t, keyOf(t, "feat/x", cand))
+		if v.State != row.state || len(l.Asks()) != row.asks {
+			t.Errorf("lose %d: verdict %s (%s) after %d asks, want %s after %d", row.lose, v.State, v.Failed.Words, len(l.Asks()), row.state, row.asks)
+		}
+		if row.state == delivery.VerdictFail && (!IsLostAsk(v) || !IsNodesFailure(v)) {
+			t.Errorf("a check given up every time = %q, want lost and judged again when the nodes change", v.Failed.Words)
+		}
 	}
 }

modules/mesh-delivery-checker/internal/check/read.go

@@ -47,9 +47,7 @@ type Reader struct {
 	Runs interface{ CommitOf(module string) string }
 	// HearingState is the checker's state hearing: whether it hears DEAD_LETTERS (issue 734).
 	HearingState StateRead
-	// AskState is the checker's state asks: the asks each running check put (AsksState), which checker_ask_again reads.
-	AskState StateRead
-	Now      func() time.Time
+	Now          func() time.Time
 }
 
 // VerdictRead is a verdict as stored with the full report of the status of each pull request it judged (Report), when the
@@ -88,11 +86,6 @@ func (r Reader) read(key string, raw json.RawMessage) (VerdictRead, error) {
 	cs := CaseOf(c, v.Trunk)
 	out.Reports = map[string]string{}
 	if cs == nil {
-		if IsUntrunked(v) {
-			for _, p := range leftOf(c, v.Trunk) {
-				out.Reports[pullKey(p)] = v.Failed.Words
-			}
-		}
 		return out, nil
 	}
 	for _, p := range cs.Pulls {
@@ -308,8 +301,6 @@ type RunningStep struct {
 	ID     string `json:"id"`
 	Tool   string `json:"tool"`
 	Since  string `json:"since,omitempty"`
-	// What says what the step is (buildstep.AskWhat): an ask's kind, repository@head and levels.
-	What string `json:"what,omitempty"`
 }
 
 // LeftStep is a key a build module left running that no step behind it runs any more, and why.
@@ -332,12 +323,6 @@ type Status struct {
 	// HeldByTurn are the candidates whose check an approved merge's turn holds off (ADR 0548 §3), by group: the repository and
 	// the group of the merge that waits. Their check is claimed when that turn goes.
 	HeldByTurn map[string]string `json:"held_by_turn"`
-	// CannotBeJudged are the candidates no pull request of which can be judged, by group, with why: the gate's source.main
-	// names no trunk head of their repositories (issue 1422). They are judged once it does; until then their status is error.
-	CannotBeJudged map[string]string `json:"cannot_be_judged"`
-	// Lost are the candidates whose verdict is running while no step of theirs can still run and their newest step ended, by
-	// group, with that step: nothing will judge them (the lost check of 2026-10-28); checker_ask_again asks one again.
-	Lost map[string]string `json:"lost"`
 	// DeadLetters says whether the checker hears the asks the build seats give up on (issue 734): deaf, a try or check
 	// whose ask is given up waits until its bound.
 	DeadLetters DeadLettersHeard `json:"dead_letters"`
@@ -401,11 +386,63 @@ func heldBy(t *Turns, c delivery.Candidate, heads map[string]string) string {
 
 // Status reads the build modules' steps and the candidates against their verdicts.
 func (r Reader) Status() (Status, error) {
-	st := Status{RunningByNode: map[string]int{}, Lost: map[string]string{}}
-	read := r.readSteps()
-	st.Running, st.LeftRunning, st.Notes = read.running, read.left, read.notes
-	for _, rs := range st.Running {
-		st.RunningByNode[rs.Node]++
+	st := Status{RunningByNode: map[string]int{}}
+	mods := make([]string, 0, len(r.StepStates))
+	for m := range r.StepStates {
+		mods = append(mods, m)
+	}
+	sort.Strings(mods)
+	st.Running, st.LeftRunning = []RunningStep{}, []LeftStep{}
+	now, bound := time.Now(), r.StepBound
+	if r.Now != nil {
+		now = r.Now()
+	}
+	if bound <= 0 {
+		bound = DefaultStepBound
+	}
+	for _, m := range mods {
+		sr := r.StepStates[m]
+		if sr.Keys == nil || sr.Get == nil {
+			continue
+		}
+		keys, err := sr.Keys()
+		if err != nil {
+			st.Notes = append(st.Notes, "the steps of "+m+" cannot be listed: "+err.Error())
+			continue
+		}
+		// A step that runs started lately: the newest ids are read first, at most MaxReads of them.
+		newestFirst(keys)
+		keys, cut := capKeys(keys, "")
+		if cut != "" {
+			st.Notes = append(st.Notes, "the steps of "+m+": read the newest "+fmt.Sprint(MaxReads)+" of its keys; a step older than those is not shown")
+		}
+		steps := make([]delivery.Step, len(keys))
+		isRunning := make([]bool, len(keys))
+		_ = parallel(len(keys), func(i int) error {
+			raw, err := sr.Get(keys[i])
+			if err != nil || len(raw) == 0 {
+				return nil
+			}
+			step, err := delivery.DecodeStep(raw)
+			steps[i], isRunning[i] = step, err == nil && step.State == delivery.StepRunning
+			return nil
+		})
+		for i := range keys {
+			if !isRunning[i] {
+				continue
+			}
+			step := steps[i]
+			rs := RunningStep{Module: m, Node: step.Node, ID: step.ID, Tool: step.Tool}
+			if !step.Started.IsZero() {
+				rs.Since = step.Started.UTC().Format("2006-01-02T15:04:05Z")
+			}
+			if why := r.leftWhy(m, step, now, bound); why != "" {
+				st.LeftRunning = append(st.LeftRunning, LeftStep{RunningStep: rs, Why: why})
+				continue
+			}
+			st.Running = append(st.Running, rs)
+			st.RunningByNode[step.Node]++
+		}
 	}
 	if r.HaveState.Get == nil {
 		st.Notes = append(st.Notes, "the node-engine's have is not readable here, so a step is not checked against its build module being on its node")
@@ -415,7 +452,7 @@ func (r Reader) Status() (Status, error) {
 	}
 	st.Unjudged = []string{}
 	st.Waiting = map[string][]string{KindNew: {}, KindNodes: {}, KindTrunk: {}}
-	st.HeldByTurn, st.CannotBeJudged = map[string]string{}, map[string]string{}
+	st.HeldByTurn = map[string]string{}
 	turns := r.turns(&st)
 	var heads map[string]string
 	if r.Trunks == nil {
@@ -466,15 +503,6 @@ func (r Reader) Status() (Status, error) {
 				continue
 			}
 			c, raw := row.c, row.raw
-			if heads != nil && len(leftOf(c, heads)) > 0 {
-				// Nothing of it can be judged now, whatever its verdict says (issue 1422): never counted as waiting.
-				var repos []string
-				for _, p := range leftOf(c, heads) {
-					repos = append(repos, p.Repository)
-				}
-				st.CannotBeJudged[c.Group] = UntrunkedWordsOf(repos)
-				continue
-			}
 			if len(raw) == 0 {
 				st.Unjudged = append(st.Unjudged, c.Group)
 				st.Waiting[KindNew] = append(st.Waiting[KindNew], c.Group)
@@ -485,16 +513,9 @@ func (r Reader) Status() (Status, error) {
 			}
 			v, err := delivery.DecodeVerdict(raw)
 			switch {
-			case err != nil:
-			case v.State == delivery.VerdictRunning:
-				if why := read.lostWhy(c); why != "" {
-					st.Lost[c.Group] = why
-				}
+			case err != nil || v.State == delivery.VerdictRunning:
 			case IsNodesFailure(v):
 				st.Waiting[KindNodes] = append(st.Waiting[KindNodes], c.Group)
-			case IsUntrunked(v):
-				// Its trunk head is known now: it waits for its whole check.
-				st.Waiting[KindNew] = append(st.Waiting[KindNew], c.Group)
 			case heads != nil:
 				if cs := CaseOf(c, heads); cs != nil && (!sameTrunk(v.Trunk, cs.Trunk) || besideMoved(v.Beside, besideAt(heads, r.Runs))) {
 					st.Waiting[KindTrunk] = append(st.Waiting[KindTrunk], c.Group)
@@ -510,118 +531,6 @@ func (r Reader) Status() (Status, error) {
 	return st, nil
 }
 
-// stepsRead is what the build modules' steps states hold: the steps that can still run, those left running, and every
-// ask step read, by module, for the candidate it belongs to (stepsOf).
-type stepsRead struct {
-	running []RunningStep
-	left    []LeftStep
-	all     []moduleStep
-	notes   []string
-}
-
-type moduleStep struct {
-	module string
-	step   delivery.Step
-}
-
-// readSteps reads the newest MaxReads keys of each build module's steps state.
-func (r Reader) readSteps() stepsRead {
-	out := stepsRead{running: []RunningStep{}, left: []LeftStep{}}
-	mods := make([]string, 0, len(r.StepStates))
-	for m := range r.StepStates {
-		mods = append(mods, m)
-	}
-	sort.Strings(mods)
-	now, bound := time.Now(), r.StepBound
-	if r.Now != nil {
-		now = r.Now()
-	}
-	if bound <= 0 {
-		bound = DefaultStepBound
-	}
-	for _, m := range mods {
-		sr := r.StepStates[m]
-		if sr.Keys == nil || sr.Get == nil {
-			continue
-		}
-		keys, err := sr.Keys()
-		if err != nil {
-			out.notes = append(out.notes, "the steps of "+m+" cannot be listed: "+err.Error())
-			continue
-		}
-		// A step that runs started lately: the newest ids are read first, at most MaxReads of them.
-		newestFirst(keys)
-		keys, cut := capKeys(keys, "")
-		if cut != "" {
-			out.notes = append(out.notes, "the steps of "+m+": read the newest "+fmt.Sprint(MaxReads)+" of its keys; a step older than those is not shown")
-		}
-		steps := make([]delivery.Step, len(keys))
-		decoded := make([]bool, len(keys))
-		_ = parallel(len(keys), func(i int) error {
-			raw, err := sr.Get(keys[i])
-			if err != nil || len(raw) == 0 {
-				return nil
-			}
-			step, err := delivery.DecodeStep(raw)
-			steps[i], decoded[i] = step, err == nil
-			return nil
-		})
-		for i := range keys {
-			if !decoded[i] {
-				continue
-			}
-			step := steps[i]
-			out.all = append(out.all, moduleStep{module: m, step: step})
-			if step.State != delivery.StepRunning {
-				continue
-			}
-			rs := RunningStep{Module: m, Node: step.Node, ID: step.ID, Tool: step.Tool, What: step.What}
-			if !step.Started.IsZero() {
-				rs.Since = step.Started.UTC().Format("2006-01-02T15:04:05Z")
-			}
-			if why := r.leftWhy(m, step, now, bound); why != "" {
-				out.left = append(out.left, LeftStep{RunningStep: rs, Why: why})
-				continue
-			}
-			out.running = append(out.running, rs)
-		}
-	}
-	return out
-}
-
-// asksOf says whether a step is an ask of one of the candidate's pull requests: its What names `<repository>@<head12>`
-// (buildstep.AskWhat).
-func asksOf(c delivery.Candidate, what string) bool {
-	for _, p := range c.Pulls {
-		if p.Repository != "" && strings.Contains(what, p.Repository+"@"+short12(p.Head.Head)) {
-			return true
-		}
-	}
-	return false
-}
-
-// lostWhy says why a candidate whose verdict is running has a check that nothing will judge, or "": no step of its pull
-// requests can still run, and its newest one ended.
-func (s stepsRead) lostWhy(c delivery.Candidate) string {
-	for _, rs := range s.running {
-		if asksOf(c, rs.What) {
-			return ""
-		}
-	}
-	var last *delivery.Step
-	for i := range s.all {
-		st := s.all[i].step
-		if st.State != delivery.StepRunning && asksOf(c, st.What) && (last == nil || st.Ended.After(last.Ended)) {
-			last = &s.all[i].step
-		}
-	}
-	if last == nil {
-		return "" // its ask waits in its build seat's stream: no node took it yet
-	}
-	return fmt.Sprintf("its verdict is running, but no step of it runs: its last step %s on %s ended %s at %s and no verdict followed; %s asks it again",
-		last.ID, last.Node, last.State, last.Ended.UTC().Format(time.RFC3339), AskAgainTool)
-}
-
 // DefaultStepBound is how long one check ask's step may run once a build node took it (its key written running; the fetch,
 // the digests and the levels), never counting its wait in the stream; past it the check fails naming the node.
 const DefaultStepBound = 30 * time.Minute

modules/mesh-delivery-checker/internal/check/read_test.go

@@ -36,7 +36,6 @@ func (f fakeState) read() StateRead {
 func readerOf(t *testing.T) (Reader, string) {
 	t.Helper()
 	r := newRig(t, passJudge())
-	r.setTrunks(t, map[string]string{repoA: trunkA, repoSDK: trunkS, hqRepo: trunkA2})
 	cand := candidateOf(t, "feat/x", pullOf(repoA, 7, head1), pullOf(hqRepo, 3, head2))
 	r.ch.Candidate(context.Background(), "feat%2Fx", cand)
 	r.ch.Wait()

modules/mesh-delivery-checker/manifest_test.go

@@ -98,11 +98,11 @@ func TestManifestDeclarations(t *testing.T) { // 1678/AC1
 		t.Errorf("module = %q", m.Module)
 	}
 	// delivery.CheckerKeptHistory, CheckerOwedHistory, PreviewsHistory, CheckerVerdictsHistory; the names follow the SDK's buckets.
-	if want := []state{{Name: "asks", History: 1}, {Name: "hearing", History: 1}, {Name: "kept", History: 1}, {Name: "owed", History: 5}, {Name: "previews", History: 5}, {Name: "tries", History: 1}, {Name: "verdicts", History: 5}}; !reflect.DeepEqual(m.State, want) {
+	if want := []state{{Name: "hearing", History: 1}, {Name: "kept", History: 1}, {Name: "owed", History: 5}, {Name: "previews", History: 5}, {Name: "tries", History: 1}, {Name: "verdicts", History: 5}}; !reflect.DeepEqual(m.State, want) {
 		t.Errorf("state = %+v, want %+v", m.State, want)
 	}
-	if want := []string{"mesh-build-go.steps", "mesh-build-go.toolchains", "mesh-build-node.steps", "mesh-build-node.toolchains",
-		"mesh-delivery-assigner.compositions", "mesh-delivery-assigner.placement", "mesh-delivery-builder.builds", "mesh-delivery-gate.source", "mesh-delivery-gate.turns", "mesh-delivery-indexer.candidates",
+	if want := []string{"mesh-build-go.steps", "mesh-build-go.toolchains", "mesh-build-node.steps", "mesh-build-node.toolchains", "mesh-controller.assignments",
+		"mesh-delivery-assigner.compositions", "mesh-delivery-builder.builds", "mesh-delivery-gate.source", "mesh-delivery-gate.turns", "mesh-delivery-indexer.candidates",
 		"mesh-delivery-indexer.manifests", "mesh-delivery-indexer.modules", "mesh-delivery-watchman.presence", "node-engine.have"}; !reflect.DeepEqual(sorted(m.Reads), want) {
 		t.Errorf("reads = %v, want %v", m.Reads, want)
 	}
@@ -129,9 +129,8 @@ func TestManifestDeclarations(t *testing.T) { // 1678/AC1
 		t.Errorf("streams = %+v, want %+v", m.Streams, want)
 	}
 	// The read tools (issue 1686) are served by the tools bundle, not by the checker's process.
-	// The try's tools (ADR 0501 §5; the end by hand, issue 734) beside them: mesh-controller's try calls them. A lost check
-	// is asked again by hand (checker_ask_again).
-	if want := []string{"checker_ask_again", "checker_kept", "checker_previews", "checker_pull", "checker_status", "checker_try", "checker_try_end", "checker_try_read", "checker_verdicts"}; !reflect.DeepEqual(sorted(m.Tools), want) {
+	// The try's tools (ADR 0501 §5; the end by hand, issue 734) beside them: mesh-controller's try calls them.
+	if want := []string{"checker_kept", "checker_previews", "checker_pull", "checker_status", "checker_try", "checker_try_end", "checker_try_read", "checker_verdicts"}; !reflect.DeepEqual(sorted(m.Tools), want) {
 		t.Errorf("tools = %v, want %v", m.Tools, want)
 	}
 	// The try is the checker's own seat's verbs (ADR 0547 §10, issue 774), served beside the tools by the same code.

modules/mesh-delivery-checker/module.json

@@ -21,7 +21,6 @@
     { "name": "checks", "events": ["preview.**", "owed.**"] }
   ],
   "state": [
-    { "name": "asks", "history": 1 },
     { "name": "hearing", "history": 1 },
     { "name": "kept", "history": 1 },
     { "name": "owed", "history": 5 },
@@ -34,8 +33,8 @@
     "mesh-build-go.toolchains",
     "mesh-build-node.steps",
     "mesh-build-node.toolchains",
+    "mesh-controller.assignments",
     "mesh-delivery-assigner.compositions",
-    "mesh-delivery-assigner.placement",
     "mesh-delivery-builder.builds",
     "mesh-delivery-gate.source",
     "mesh-delivery-gate.turns",
@@ -50,7 +49,6 @@
     "node-build-node"
   ],
   "tools": [
-    "checker_ask_again",
     "checker_kept",
     "checker_previews",
     "checker_pull",

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/call.go

@@ -91,6 +91,28 @@ func treesVia(ctx context.Context, call caller) bridge.Trees {
 	}
 }
 
+// listedVia asks the forge for the files directly under one directory of a commit through call: gitea_commit_trees with
+// listed (issue 1126), answer {listed: {directory: {name: blob id}}}.
+func listedVia(ctx context.Context, call caller) bridge.Listed {
+	return func(owner, repo, sha, dir string) (map[string]string, error) {
+		raw, err := call(ctx, commitTreesTool, map[string]any{"owner": owner, "repo": repo, "sha": sha, "listed": []string{dir}})
+		if err != nil {
+			return nil, err
+		}
+		var a struct {
+			Listed map[string]map[string]string `json:"listed"`
+		}
+		if err := json.Unmarshal(raw, &a); err != nil {
+			return nil, fmt.Errorf("the answer of %s is not {listed}: %w", commitTreesTool, err)
+		}
+		if a.Listed == nil {
+			// A forge module from before listed answers none: placement cannot be read, never read as empty.
+			return nil, fmt.Errorf("the answer of %s lists no directory; the forge module does not list yet", commitTreesTool)
+		}
+		return a.Listed[dir], nil
+	}
+}
+
 // getFileTool is the forge's tool for one file at a ref (mesh-catalog modules/gitea tools/index.ts gitea_get_file):
 // arguments owner, repo, path and ref, answer {file: {path, ref, sha, size, content}}, the content decoded to text
 // (client.ts getFile). A path the forge does not have fails with `Gitea API <path>: 404 <body>` (client.ts request).

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/integration_test.go

@@ -72,17 +72,11 @@ accounts {
             "mesh.mod.gitea.tool.gitea_open_pulls"
             "mesh.mod.gitea.tool.gitea_open_pulls.*"
             "$JS.API.CONSUMER.CREATE.KV_mesh-delivery-forge-bridge_performed.>"
-            "$JS.API.CONSUMER.CREATE.KV_mesh-delivery-forge-bridge_inputs.>"
             "$JS.API.CONSUMER.DELETE.KV_mesh-delivery-forge-bridge_performed.>"
-            "$JS.API.CONSUMER.DELETE.KV_mesh-delivery-forge-bridge_inputs.>"
             "$JS.API.DIRECT.GET.KV_mesh-delivery-forge-bridge_performed.>"
-            "$JS.API.DIRECT.GET.KV_mesh-delivery-forge-bridge_inputs.>"
             "$JS.API.STREAM.INFO.KV_mesh-delivery-forge-bridge_performed"
-            "$JS.API.STREAM.INFO.KV_mesh-delivery-forge-bridge_inputs"
             "$JS.FC.KV_mesh-delivery-forge-bridge_performed.>"
-            "$JS.FC.KV_mesh-delivery-forge-bridge_inputs.>"
             "$KV.mesh-delivery-forge-bridge_performed.>"
-            "$KV.mesh-delivery-forge-bridge_inputs.>"
             "$JS.API.CONSUMER.CREATE.KV_mesh-delivery-gate_merges.>"
             "$JS.API.CONSUMER.DELETE.KV_mesh-delivery-gate_merges.>"
             "$JS.API.DIRECT.GET.KV_mesh-delivery-gate_merges.>"
@@ -225,7 +219,7 @@ func startBed(t *testing.T, openReply string, prepare func(ctx context.Context,
 	}
 	// Its other state bucket, and the gate's buckets the bridge reads, made by the controller from the gate's manifest
 	// (mesh-sdk go/delivery MergesBucket, OwedBucket with their histories).
-	for name, history := range map[string]uint8{performedBucket: 1, inputsBucket: 1, delivery.MergesBucket: delivery.MergesHistory, delivery.OwedBucket: delivery.OwedHistory} {
+	for name, history := range map[string]uint8{performedBucket: 1, delivery.MergesBucket: delivery.MergesHistory, delivery.OwedBucket: delivery.OwedHistory} {
 		if _, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: name, History: history}); err != nil {
 			t.Fatal(err)
 		}

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/kept.go

@@ -1,81 +0,0 @@
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"log"
-	"regexp"
-	"sync"
-	"time"
-
-	"github.com/nats-io/nats.go/jetstream"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-
-	"mesh-delivery-forge-bridge/internal/bridge"
-)
-
-// inputsBucket is the module's state bucket inputs (manifest state entry inputs): what the bridge read of a module
-// directory, its manifest and lock-file hashes, by the directory's git tree hash, so a merge reads the forge only for the
-// directories it changed (issue 1126; internal/bridge kept.go). A tree hash names its bytes, so a value is never stale;
-// a merge adds a value only for each directory it changed (a few kilobytes each).
-const inputsBucket = delivery.ForgeBridgeModule + "_inputs"
-
-// keptTimeout bounds one read or write of the bucket: the bucket is a saving, never a reason to fail a merge.
-const keptTimeout = 2 * time.Second
-
-var treeHash = regexp.MustCompile(`^[0-9a-f]{40}$|^[0-9a-f]{64}$`)
-
-// kept is the bridge's Kept: in memory always, and in the bucket inputs when it is on the bus, so the first merge after a
-// start reads only what changed too. A value the bucket cannot give or take is read from the forge, and said.
-type kept struct {
-	kv     jetstream.KeyValue // nil when the bucket is not on the bus
-	logger *log.Logger
-	mu     sync.Mutex
-	mem    map[string]bridge.Inputs
-}
-
-func newKept(kv jetstream.KeyValue, logger *log.Logger) *kept {
-	return &kept{kv: kv, logger: logger, mem: map[string]bridge.Inputs{}}
-}
-
-func (k *kept) Get(tree string) (bridge.Inputs, bool) {
-	k.mu.Lock()
-	in, ok := k.mem[tree]
-	k.mu.Unlock()
-	if ok || k.kv == nil || !treeHash.MatchString(tree) {
-		return in, ok
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), keptTimeout)
-	defer cancel()
-	e, err := k.kv.Get(ctx, tree)
-	if err != nil {
-		return bridge.Inputs{}, false // not kept (or not readable): read from the forge
-	}
-	if err := json.Unmarshal(e.Value(), &in); err != nil || in.Manifest == "" {
-		k.logger.Printf("%s.%s cannot be read, so its directory is read from the forge: %v", inputsBucket, tree, err)
-		return bridge.Inputs{}, false
-	}
-	k.mu.Lock()
-	k.mem[tree] = in
-	k.mu.Unlock()
-	return in, true
-}
-
-func (k *kept) Put(tree string, in bridge.Inputs) {
-	k.mu.Lock()
-	k.mem[tree] = in
-	k.mu.Unlock()
-	if k.kv == nil || !treeHash.MatchString(tree) {
-		return
-	}
-	data, err := json.Marshal(in)
-	if err != nil {
-		return
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), keptTimeout)
-	defer cancel()
-	if _, err := k.kv.Put(ctx, tree, data); err != nil {
-		k.logger.Printf("%s.%s is not kept, so the next merge reads its directory from the forge again: %v", inputsBucket, tree, err)
-	}
-}

modules/mesh-delivery-forge-bridge/cmd/mesh-delivery-forge-bridge/main.go

@@ -67,8 +67,8 @@ type publisher interface {
 // handle turns one event into its message on FORGE and acknowledges it. An event it cannot read is terminated, never
 // redelivered, and the log names its subject and why. A message it could not write stays unacknowledged: the server
 // delivers it again (the server's ack wait is the only clock).
-func handle(ctx context.Context, m delivered, pub publisher, trees bridge.Trees, files bridge.Files, kept bridge.Kept, logger *log.Logger) {
-	msg, err := bridge.ConvertKept(m.Subject(), m.Data(), trees, files, kept)
+func handle(ctx context.Context, m delivered, pub publisher, trees bridge.Trees, files bridge.Files, list bridge.Listed, logger *log.Logger) {
+	msg, err := bridge.ConvertWith(m.Subject(), m.Data(), trees, files, list)
 	switch {
 	case errors.Is(err, bridge.ErrRetry):
 		logger.Printf("%v; heard again in %s", err, retryDelay)
@@ -96,9 +96,6 @@ func handle(ctx context.Context, m delivered, pub publisher, trees bridge.Trees,
 		logger.Printf("%s: %s could not be written on FORGE, left for redelivery: %v", m.Subject(), msg.Event, err)
 		return
 	}
-	if msg.Said != "" {
-		logger.Printf("%s: %s", m.Subject(), msg.Said)
-	}
 	_ = m.Ack()
 }
 
@@ -163,8 +160,6 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		return err
 	}
 	go onReconnect(ctx, again, said, logger)
-	// What a merge read of each module directory, by its tree (issue 1126): a merge reads only the directories it changed.
-	inputs := newKept(process.OptionalBucket(ctx, js, inputsBucket, "a merge's module directories are kept in memory only, so the first merge after a start reads every one", logger.Printf), logger)
 	cons, err := cred.EventConsumer(ctx, js, eventsStream)
 	if err != nil {
 		// Essential: the forge's events are what the bridge carries.
@@ -175,7 +170,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 			// Bounded: the turn is held, and no sync or other event goes on without it.
 			hctx, cancel := context.WithTimeout(ctx, syncDeadline)
 			defer cancel()
-			handle(hctx, m, rec, treesVia(hctx, call), filesVia(hctx, call), inputs, logger)
+			handle(hctx, m, rec, treesVia(hctx, call), filesVia(hctx, call), listedVia(hctx, call), logger)
 		})
 	}, logger.Printf)
 	if err != nil {

modules/mesh-delivery-forge-bridge/go.mod

@@ -3,7 +3,7 @@ module mesh-delivery-forge-bridge
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028174713-38dbe1d3a388
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-delivery-forge-bridge/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028174713-38dbe1d3a388 h1:ycu/sNieTdLpD3bzhZOCXdzcoqXUOxPRmqWV019REpo=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028174713-38dbe1d3a388/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952 h1:TmveT3Bija643RGWkilvkzP/h8UWlVvHFZZtQfJK5oU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-delivery-forge-bridge/internal/bridge/bridge.go

@@ -54,8 +54,6 @@ var LockFiles = []string{"go.sum", "package-lock.json"}
 type Message struct {
 	Event string
 	Data  []byte
-	// Said is what the bridge did that the log says, beside writing the message; empty for none.
-	Said string
 }
 
 // The subjects of the forge module's events the bridge writes pull messages for (mesh-catalog modules/gitea,
@@ -86,6 +84,20 @@ type pull struct {
 	PathsTruncated bool      `json:"paths_truncated"`
 }
 
+// touchesPlacement says whether a pull request may change a placement file: a changed path under
+// delivery.PlacementDir, or paths the forge did not say or cut (the safe direction: the files are read).
+func (p pull) touchesPlacement() bool {
+	if p.Paths == nil || p.PathsTruncated {
+		return true
+	}
+	for _, path := range *p.Paths {
+		if strings.HasPrefix(path, delivery.PlacementDir+"/") {
+			return true
+		}
+	}
+	return false
+}
+
 func unreadable(subject, why string, args ...any) error {
 	return fmt.Errorf("%w: %s: %s", ErrUnreadable, subject, fmt.Sprintf(why, args...))
 }
@@ -95,12 +107,19 @@ func unreadable(subject, why string, args ...any) error {
 // the trunk asks trees once and becomes a merged message; a merge into any other branch is a closed pull message, as the
 // pull request left its group. A forge that cannot say is ErrRetry; a merge with no module.json is ErrNoModules.
 func Convert(subject string, data []byte, trees Trees, files Files) (Message, error) {
-	return ConvertKept(subject, data, trees, files, nil)
+	return ConvertWith(subject, data, trees, files, nil)
 }
 
-// ConvertKept is Convert; with kept, a merge reads the forge only for the module directories whose tree hash kept
-// does not hold, and keeps what it read (kept.go).
-func ConvertKept(subject string, data []byte, trees Trees, files Files, kept Kept) (Message, error) {
+// Listed asks the forge for the files directly under one directory of a commit, by name to blob id (gitea_commit_trees
+// with listed); a directory the commit lacks lists none.
+type Listed func(owner, repo, sha, dir string) (map[string]string, error)
+
+// ConvertWith is Convert; with list, a merge of the catalogue repository (delivery.CatalogueRepository) also carries every
+// placement file of its merge commit (novox/hq ADR 0549 §2, issue 1126), read whole or not at all: a forge that cannot
+// say is ErrRetry, as for the manifests, so the indexer never takes a part of placement for all of it. So does an
+// updated pull request of the catalogue that touches placement/ (touchesPlacement), with every placement file at its
+// head, which the indexer writes as placement candidates (ADR 0549 §4: the nodes it places answer it before it merges).
+func ConvertWith(subject string, data []byte, trees Trees, files Files, list Listed) (Message, error) {
 	var action string
 	switch subject {
 	case UpdatedSubject:
@@ -127,16 +146,7 @@ func ConvertKept(subject string, data []byte, trees Trees, files Files, kept Kep
 		return Message{}, unreadable(subject, "no branch")
 	}
 	if subject == MergedSubject && p.Base == Trunk {
-		return merged(subject, p, trees, files, kept)
-	}
-	said := ""
-	if action == delivery.PullUpdated && p.Base != "" && p.Base != Trunk {
-		// The checker judges pull requests into main only, and source.main names main's head only (novox/hq ADR 0484 §11): a
-		// pull request into another base is no candidate, as it is none at the start (OpenPulls) and at its merge. It is
-		// written closed, so a candidate an older head made is taken out, and said (issue 1422).
-		action = delivery.PullClosed
-		said = fmt.Sprintf("%s/%s#%d at %s is into %s, not %s: written closed, so it is no candidate; the checker judges pull requests into %s only (novox/hq ADR 0484 §11)",
-			p.Owner, p.Repo, p.Number, p.HeadSHA[:12], p.Base, Trunk, Trunk)
+		return merged(subject, p, trees, files, list)
 	}
 	f := delivery.Forge{Kind: delivery.ForgePull, Repository: p.Owner + "/" + p.Repo, Branch: p.Head, Number: p.Number,
 		Head: p.HeadSHA, Action: action}
@@ -148,6 +158,13 @@ func ConvertKept(subject string, data []byte, trees Trees, files Files, kept Kep
 			return Message{}, fmt.Errorf("%w: %s: the manifests of %s/%s at the head %s: %v", ErrRetry, subject, p.Owner, p.Repo, p.HeadSHA, err)
 		}
 	}
+	if action == delivery.PullUpdated && list != nil && delivery.SameRepository(f.Repository, delivery.CatalogueRepository) && p.touchesPlacement() {
+		var err error
+		if f.Placements, err = placementsOf(p.Owner, p.Repo, p.HeadSHA, list, files); err != nil {
+			return Message{}, fmt.Errorf("%w: %s: the placement files of %s at the head %s: %v", ErrRetry, subject, f.Repository, p.HeadSHA, err)
+		}
+		f.PlacementsRead = true
+	}
 	event, err := delivery.ForgeEvent(f.Repository, delivery.ForgePull)
 	if err != nil {
 		return Message{}, unreadable(subject, "%v", err)
@@ -156,7 +173,7 @@ func ConvertKept(subject string, data []byte, trees Trees, files Files, kept Kep
 	if err != nil {
 		return Message{}, unreadable(subject, "%v", err)
 	}
-	return Message{Event: event, Data: body, Said: said}, nil
+	return Message{Event: event, Data: body}, nil
 }
 
 // MaxReadsInFlight is how many files of the forge inputsOf asks for at once. A merge into a repository of many
@@ -169,7 +186,6 @@ const MaxReadsInFlight = 8
 type read struct {
 	dir, path string
 	manifest  bool
-	asked     bool
 	raw       []byte
 	err       error
 }
@@ -183,14 +199,6 @@ type read struct {
 // order the calls finish in, and the error is that of the first failing file in the order of dirs and LockFiles. After
 // a failure no further file is asked for, and inputsOf returns only when every call it started has returned.
 func inputsOf(owner, repo, ref string, dirs []string, files Files) (manifests map[string]string, locks map[string]map[string]string, err error) {
-	manifests, locks, _, err = inputsRead(owner, repo, ref, dirs, files)
-	return manifests, locks, err
-}
-
-// inputsRead is inputsOf, and also answers, on a failure too, the directories whose manifest and lock files were all
-// read, with their manifests and lock hashes: a merge keeps them by their tree, so its next try reads only the rest
-// (issue 1126).
-func inputsRead(owner, repo, ref string, dirs []string, files Files) (manifests map[string]string, locks map[string]map[string]string, whole []string, err error) {
 	at := func(dir, name string) string {
 		if dir == "" {
 			return name
@@ -219,7 +227,6 @@ func inputsRead(owner, repo, ref string, dirs []string, files Files) (manifests
 			<-slots
 			break
 		}
-		r.asked = true
 		wg.Add(1)
 		go func(r *read) {
 			defer func() { <-slots; wg.Done() }()
@@ -234,16 +241,10 @@ func inputsRead(owner, repo, ref string, dirs []string, files Files) (manifests
 	wg.Wait()
 	manifests = map[string]string{}
 	locks = map[string]map[string]string{}
-	broken := map[string]bool{} // a directory with a file not read (failed, or never asked after a failure)
 	for _, r := range reads {
 		switch {
 		case r.err != nil && (r.manifest || !errors.Is(r.err, ErrNotFound)):
-			broken[r.dir] = true
-			if err == nil {
-				err = fmt.Errorf("%s: %w", r.path, r.err)
-			}
-		case r.err == nil && r.raw == nil && !r.asked:
-			broken[r.dir] = true
+			return nil, nil, fmt.Errorf("%s: %w", r.path, r.err)
 		case r.err != nil: // a lock file the forge does not have
 		case r.manifest:
 			manifests[r.dir] = string(r.raw)
@@ -255,29 +256,17 @@ func inputsRead(owner, repo, ref string, dirs []string, files Files) (manifests
 			locks[r.dir][path.Base(r.path)] = hex.EncodeToString(sum[:])
 		}
 	}
-	for _, dir := range dirs {
-		if !broken[dir] {
-			whole = append(whole, dir)
-		}
-	}
-	if err != nil {
-		for dir := range broken {
-			delete(manifests, dir)
-			delete(locks, dir)
-		}
-		return manifests, locks, whole, err
-	}
 	if len(manifests) == 0 {
 		manifests = nil
 	}
 	if len(locks) == 0 {
 		locks = nil
 	}
-	return manifests, locks, whole, nil
+	return manifests, locks, nil
 }
 
 // merged is the merged message of a merge into the trunk: the trees of the merge commit, asked once.
-func merged(subject string, p pull, trees Trees, files Files, kept Kept) (Message, error) {
+func merged(subject string, p pull, trees Trees, files Files, list Listed) (Message, error) {
 	if !sha40.MatchString(p.MergeSHA) {
 		return Message{}, unreadable(subject, "the merge commit %q is not 40 hex digits", p.MergeSHA)
 	}
@@ -294,20 +283,9 @@ func merged(subject string, p pull, trees Trees, files Files, kept Kept) (Messag
 		names = append(names, dir)
 	}
 	slices.Sort(names)
-	manifests, locks, toRead := keptInputs(names, dirs, kept)
-	read, readLocks, whole, err := inputsRead(p.Owner, p.Repo, p.MergeSHA, toRead, files)
+	manifests, locks, err := inputsOf(p.Owner, p.Repo, p.MergeSHA, names, files)
 	if err != nil {
-		keep(whole, dirs, read, readLocks, kept) // what was read whole is not asked again at the next try
-		return Message{}, fmt.Errorf("%w: %s: the manifests of %s at the merge commit %s (%d of %d module directories read from the forge, the others kept by their tree): %v", ErrRetry, subject, repository, p.MergeSHA, len(toRead), len(names), err)
-	}
-	keep(toRead, dirs, read, readLocks, kept)
-	maps.Copy(manifests, read)
-	maps.Copy(locks, readLocks)
-	if len(manifests) == 0 {
-		manifests = nil
-	}
-	if len(locks) == 0 {
-		locks = nil
+		return Message{}, fmt.Errorf("%w: %s: the manifests of %s at the merge commit %s: %v", ErrRetry, subject, repository, p.MergeSHA, err)
 	}
 	event, err := delivery.ForgeEvent(repository, delivery.ForgeMerged)
 	if err != nil {
@@ -315,6 +293,12 @@ func merged(subject string, p pull, trees Trees, files Files, kept Kept) (Messag
 	}
 	f := delivery.Forge{Kind: delivery.ForgeMerged, Repository: repository, Branch: p.Head, Number: p.Number,
 		Head: p.HeadSHA, Merge: p.MergeSHA, Root: root, Trees: dirs, Manifests: manifests, Locks: locks}
+	if list != nil && delivery.SameRepository(repository, delivery.CatalogueRepository) {
+		if f.Placements, err = placementsOf(p.Owner, p.Repo, p.MergeSHA, list, files); err != nil {
+			return Message{}, fmt.Errorf("%w: %s: the placement files of %s at the merge commit %s: %v", ErrRetry, subject, repository, p.MergeSHA, err)
+		}
+		f.PlacementsRead = true
+	}
 	body, err := delivery.EncodeForge(f)
 	if err != nil {
 		return Message{}, unreadable(subject, "%v", err)
@@ -412,3 +396,30 @@ func OpenMessage(answer []byte) (Message, error) {
 	}
 	return Message{Event: delivery.OpenEvent(), Data: body}, nil
 }
+
+// placementsOf is every placement file of the catalogue at a commit, by node, its bytes exact: each `<node>.json` directly
+// under delivery.PlacementDir. A file whose name is no node is left out and the rest read; the catalogue's check refuses
+// such a file before it merges (ADR 0549 §1). Nil when there is none.
+func placementsOf(owner, repo, sha string, list Listed, files Files) (map[string]string, error) {
+	names, err := list(owner, repo, sha, delivery.PlacementDir)
+	if err != nil {
+		return nil, err
+	}
+	var out map[string]string
+	for _, name := range slices.Sorted(maps.Keys(names)) {
+		file := delivery.PlacementDir + "/" + name
+		node, ok := delivery.PlacementFileNode(file)
+		if !ok {
+			continue
+		}
+		raw, err := files(owner, repo, file, sha)
+		if err != nil {
+			return nil, fmt.Errorf("%s: %w", file, err)
+		}
+		if out == nil {
+			out = map[string]string{}
+		}
+		out[node] = string(raw)
+	}
+	return out, nil
+}

modules/mesh-delivery-forge-bridge/internal/bridge/bridge_test.go

@@ -110,21 +110,6 @@ func TestClosedBecomesAClosedPullMessage(t *testing.T) { // 1235/AC4
 	if !delivery.SameForge(f, want) {
 		t.Errorf("message = %+v, want %+v", f, want)
 	}
-	// Issue 1422, ADR 0484 §11: a head pushed to a pull request into another base is written closed, read nothing for, and said;
-	// one into main is no closed message, and an event naming no base is written as before.
-	msg, err = Convert(updatedSubject, updated(map[string]any{"base": "nox-mesh"}), nil, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if f, err = delivery.DecodeForge(msg.Data); err != nil || !delivery.SameForge(f, want) || !strings.Contains(msg.Said, "is into nox-mesh, not main") {
-		t.Errorf("an update into nox-mesh is %+v (%v), said %q; want it closed and said", f, err, msg.Said)
-	}
-	for _, base := range []any{"main", nil} {
-		msg, err = Convert(updatedSubject, updated(map[string]any{"base": base}), nil, anyFiles)
-		if f, _ = delivery.DecodeForge(msg.Data); err != nil || f.Action != delivery.PullUpdated || msg.Said != "" {
-			t.Errorf("an update with base %v is %+v (%v), said %q; want it updated", base, f, err, msg.Said)
-		}
-	}
 }
 
 func TestUnreadableEventsWriteNothing(t *testing.T) { // 1235/AC5

modules/mesh-delivery-forge-bridge/internal/bridge/files_test.go

@@ -79,26 +79,47 @@ func TestMergedCarriesManifestsAndLocks(t *testing.T) { // 1448/AC1
 	if want := map[string]map[string]string{"modules/a": {"go.sum": hexSum(sum)}}; !reflect.DeepEqual(f.Locks, want) {
 		t.Errorf("locks = %v, want %v", f.Locks, want)
 	}
-	// ADR 0567: placement is the seat mesh-placement's: a merge of the catalogue carries no placement file and asks the
-	// forge for none.
-	forge.calls = nil
-	msg, err = Convert(mergedSubject, mergedBody(map[string]any{"repo": "mesh-catalog"}), treesOf(&calls, "r0", map[string]string{"modules/a": "t1"}, nil), forge.get)
+	if f.Placements != nil || f.PlacementsRead {
+		t.Errorf("a merge of another repository than the catalogue carries placement: %v", f.Placements)
+	}
+
+	// Issue 1126 (ADR 0549 §2): a merge of the catalogue carries every placement file of its merge commit, by node; a file
+	// whose name is no node is left out; a listing or a file the forge cannot give is a retry, never a part.
+	catalogue := mergedBody(map[string]any{"repo": "mesh-catalog"})
+	forge.have["placement/ace.json"] = []byte(`{"v":1,"node":"ace","modules":[]}`)
+	forge.have["placement/g14.json"] = []byte(`{"v":1,"node":"g14","modules":[{"module":"zsh"}]}`)
+	listing := map[string]string{"ace.json": "b1", "g14.json": "b2", "README.md": "b3", "a.b.json": "b4"}
+	var listedAt []string
+	list := func(owner, repo, sha, dir string) (map[string]string, error) {
+		listedAt = append(listedAt, owner+"/"+repo+"@"+sha+":"+dir)
+		return listing, nil
+	}
+	msg, err = ConvertWith(mergedSubject, catalogue, treesOf(&calls, "r0", map[string]string{"modules/a": "t1"}, nil), forge.get, list)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if f, err = delivery.DecodeForge(msg.Data); err != nil {
 		t.Fatal(err)
 	}
-	if len(f.RetiredPlacements) > 0 || f.RetiredRead || strings.Contains(string(msg.Data), `"placements`) {
-		t.Errorf("a merge of the catalogue carries placement: %s", msg.Data)
+	want := map[string]string{"ace": `{"v":1,"node":"ace","modules":[]}`, "g14": `{"v":1,"node":"g14","modules":[{"module":"zsh"}]}`}
+	if !f.PlacementsRead || !reflect.DeepEqual(f.Placements, want) || !reflect.DeepEqual(listedAt, []string{"novox/mesh-catalog@" + merge + ":placement"}) {
+		t.Errorf("placements = %v (read %v), listed at %v", f.Placements, f.PlacementsRead, listedAt)
 	}
-	for _, c := range forge.calls {
-		if strings.HasPrefix(c.path, "placement") {
-			t.Errorf("the forge was asked for %s", c.path)
-		}
+	listing = map[string]string{}
+	if msg, err = ConvertWith(mergedSubject, catalogue, treesOf(&calls, "r0", map[string]string{"modules/a": "t1"}, nil), forge.get, list); err != nil {
+		t.Fatal(err)
+	}
+	if f, _ = delivery.DecodeForge(msg.Data); !f.PlacementsRead || f.Placements != nil {
+		t.Errorf("a catalogue with no placement file says it read none: %v, %v", f.Placements, f.PlacementsRead)
+	}
+	listing = map[string]string{"gone.json": "b5"}
+	if _, err := ConvertWith(mergedSubject, catalogue, treesOf(&calls, "r0", map[string]string{"modules/a": "t1"}, nil), forge.get, list); !errors.Is(err, ErrRetry) || !strings.Contains(err.Error(), "placement/gone.json") {
+		t.Errorf("a placement file the forge cannot give: %v", err)
+	}
+	failing := func(_, _, _, _ string) (map[string]string, error) { return nil, errors.New("forge down") }
+	if _, err := ConvertWith(mergedSubject, catalogue, treesOf(&calls, "r0", map[string]string{"modules/a": "t1"}, nil), forge.get, failing); !errors.Is(err, ErrRetry) {
+		t.Errorf("a listing the forge cannot give: %v", err)
 	}
-	// Issue 1126: a merge reads the forge only for the module directories whose tree changed.
-	t.Run("a merge reads only the directories whose tree changed", mergeReadsOnlyChangedDirs)
 }
 
 func TestPullWithKnownDirsCarriesTheSameAtTheHead(t *testing.T) { // 1448/AC2
@@ -125,6 +146,55 @@ func TestPullWithKnownDirsCarriesTheSameAtTheHead(t *testing.T) { // 1448/AC2
 	if f.Manifests != nil || f.Locks != nil || len(forge.calls) != 0 {
 		t.Errorf("manifests %v locks %v calls %v", f.Manifests, f.Locks, forge.calls)
 	}
+
+	// Issue 1126 (ADR 0549 §4): an updated pull request of the catalogue that touches placement/ carries every placement
+	// file at its head, read whole or not at all; one that touches none, or of another repository, carries none and lists
+	// nothing; paths the forge did not say or cut are read as touching; a closed one carries none.
+	forge = &forgeFiles{have: map[string][]byte{"modules/a/module.json": manifest,
+		"placement/ace.json": []byte(`{"v":1,"node":"ace","modules":[]}`), "placement/g14.json": []byte(`{"v":1,"node":"g14","modules":[]}`)}}
+	listing := map[string]string{"ace.json": "b1", "g14.json": "b2", "README.md": "b3"}
+	var listedAt []string
+	list := func(owner, repo, sha, dir string) (map[string]string, error) {
+		listedAt = append(listedAt, owner+"/"+repo+"@"+sha+":"+dir)
+		return listing, nil
+	}
+	all := map[string]string{"ace": `{"v":1,"node":"ace","modules":[]}`, "g14": `{"v":1,"node":"g14","modules":[]}`}
+	catalogue := map[string]any{"repo": "mesh-catalog", "paths": []string{"placement/g14.json"}}
+	for _, row := range []struct {
+		name    string
+		subject string
+		body    map[string]any
+		want    map[string]string
+		read    bool
+	}{
+		{"a catalogue pull touching placement", updatedSubject, catalogue, all, true},
+		{"a catalogue pull touching no placement", updatedSubject, map[string]any{"repo": "mesh-catalog"}, nil, false},
+		{"a catalogue pull whose paths are cut", updatedSubject, map[string]any{"repo": "mesh-catalog", "paths_truncated": true}, all, true},
+		{"a catalogue pull whose paths are not said", updatedSubject, map[string]any{"repo": "mesh-catalog", "paths": nil}, all, true},
+		{"another repository's pull touching placement/", updatedSubject, map[string]any{"paths": []string{"placement/g14.json"}}, nil, false},
+		{"a closed catalogue pull", closedSubject, catalogue, nil, false},
+	} {
+		listedAt = nil
+		body := updated(row.body)
+		msg, err := ConvertWith(row.subject, body, nil, forge.get, list)
+		if err != nil {
+			t.Fatalf("%s: %v", row.name, err)
+		}
+		f, err := delivery.DecodeForge(msg.Data)
+		if err != nil {
+			t.Fatalf("%s: %v", row.name, err)
+		}
+		if f.PlacementsRead != row.read || !reflect.DeepEqual(f.Placements, row.want) || (len(listedAt) > 0) != row.read {
+			t.Errorf("%s: placements %v (read %v), listed %v", row.name, f.Placements, f.PlacementsRead, listedAt)
+		}
+		if row.read && listedAt[0] != "novox/mesh-catalog@"+head+":placement" {
+			t.Errorf("%s: listed at %v, want the head", row.name, listedAt)
+		}
+	}
+	listing = map[string]string{"gone.json": "b5"}
+	if _, err := ConvertWith(updatedSubject, updated(catalogue), nil, forge.get, list); !errors.Is(err, ErrRetry) || !strings.Contains(err.Error(), "placement/gone.json") {
+		t.Errorf("a placement file the forge cannot give at the head: %v", err)
+	}
 }
 
 func TestAForgeErrorOrAMissingManifestIsRetryAndALockNotFoundIsLeftOut(t *testing.T) { // 1448/AC3
@@ -299,73 +369,3 @@ func TestOneFailingFileIsRetryAndEveryCallHasReturnedBeforeTheReadDoes(t *testin
 		t.Errorf("err = %v, want ErrRetry", err)
 	}
 }
-
-// memKept is a Kept in memory.
-type memKept map[string]Inputs
-
-func (k memKept) Get(tree string) (Inputs, bool) { in, ok := k[tree]; return in, ok }
-func (k memKept) Put(tree string, in Inputs)     { k[tree] = in }
-
-// Issue 1126 (mesh-catalog#535; issue 1458 met the kind first): a merge reads the forge only for the module directories
-// whose tree changed. Its message is the same as one read whole; a directory whose tree is kept costs no read.
-func mergeReadsOnlyChangedDirs(t *testing.T) {
-	manifest, sum := real(t, "module.json"), real(t, "go.sum")
-	forge := &forgeFiles{have: map[string][]byte{"modules/a/module.json": manifest, "modules/a/go.sum": sum, "modules/b/module.json": []byte(`{"module":"b"}`)}}
-	kept := memKept{}
-	var calls []call
-	first, err := ConvertKept(mergedSubject, mergedBody(nil), treesOf(&calls, "r0", map[string]string{"modules/a": "t1", "modules/b": "t2"}, nil), forge.get, kept)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(forge.calls) != 6 {
-		t.Fatalf("the first merge read %d files, want 6 (a manifest and two lock files for each directory)", len(forge.calls))
-	}
-	// The next merge changes modules/b alone: only its three files are read, and the message equals one read whole.
-	forge.calls = nil
-	forge.have["modules/b/module.json"] = []byte(`{"module":"b","v":2}`)
-	trees := map[string]string{"modules/a": "t1", "modules/b": "t3"}
-	next, err := ConvertKept(mergedSubject, mergedBody(nil), treesOf(&calls, "r1", trees, nil), forge.get, kept)
-	if err != nil {
-		t.Fatal(err)
-	}
-	for _, c := range forge.calls {
-		if !strings.HasPrefix(c.path, "modules/b/") {
-			t.Errorf("%s was read although its directory's tree is kept", c.path)
-		}
-	}
-	if len(forge.calls) != 3 {
-		t.Errorf("the second merge read %d files, want 3", len(forge.calls))
-	}
-	whole, err := Convert(mergedSubject, mergedBody(nil), treesOf(&calls, "r1", trees, nil), forge.get)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if string(next.Data) != string(whole.Data) {
-		t.Errorf("the message from kept inputs differs from one read whole:\n%s\n%s", next.Data, whole.Data)
-	}
-	if string(first.Data) == string(next.Data) {
-		t.Error("the second merge's message did not change")
-	}
-	// A failed read keeps the directories it read whole and nothing of the one that failed, so the next try reads only the
-	// rest: a merge too large for one try's bound converges over its tries.
-	kept2 := memKept{}
-	failing := &forgeFiles{have: forge.have, errs: map[string]error{"modules/b/module.json": errors.New("context deadline exceeded")}}
-	if _, err := ConvertKept(mergedSubject, mergedBody(nil), treesOf(&calls, "r1", trees, nil), failing.get, kept2); !errors.Is(err, ErrRetry) {
-		t.Fatalf("err = %v, want ErrRetry", err)
-	}
-	if _, ok := kept2["t1"]; !ok || len(kept2) != 1 { // modules/a's files are asked first, before the failure is seen
-		t.Errorf("a failed read kept %v, want modules/a's tree t1 alone", kept2)
-	}
-	failing.calls = nil
-	failing.errs = nil
-	again, err := ConvertKept(mergedSubject, mergedBody(nil), treesOf(&calls, "r1", trees, nil), failing.get, kept2)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if string(again.Data) != string(whole.Data) {
-		t.Errorf("the message of the try after a failure differs from one read whole")
-	}
-	if len(failing.calls) != 3 {
-		t.Errorf("the try after a failure read %d files, want only modules/b's 3", len(failing.calls))
-	}
-}

modules/mesh-delivery-forge-bridge/internal/bridge/kept.go

@@ -1,57 +0,0 @@
-package bridge
-
-// A merge of a repository of many modules read three files of the forge for every module, whatever the merge changed:
-// the catalogue's 140 modules are 420 reads, which no longer fit the 30 s bound of a handled event while the forge is
-// busy after a merge, so the merged message of mesh-catalog#535 was never written and the indexer never saw it (issue
-// 1126; issue 1458 met the same kind at 131 modules and raised the reads in flight). A directory's git tree hash names
-// every byte under it, so the manifest and the lock-file hashes read once at a tree hash are those of every later commit
-// whose directory has the same tree: a merge reads the forge only for the directories it changed.
-
-// Inputs is what the bridge read of one module directory at one tree hash: its manifest and its lock files' hex sha256
-// by name (none when it has none).
-type Inputs struct {
-	Manifest string            `json:"manifest"`
-	Locks    map[string]string `json:"locks,omitempty"`
-}
-
-// Kept holds Inputs by a directory's git tree hash (the bridge's state bucket inputs). Get answers false for a tree it
-// does not hold or cannot read; Put is best effort: a value it could not keep is read from the forge next time.
-type Kept interface {
-	Get(tree string) (Inputs, bool)
-	Put(tree string, in Inputs)
-}
-
-// keptInputs splits dirs into the inputs kept for their tree hash and the directories still to read from the forge.
-func keptInputs(dirs []string, trees map[string]string, kept Kept) (manifests map[string]string, locks map[string]map[string]string, read []string) {
-	manifests, locks = map[string]string{}, map[string]map[string]string{}
-	for _, dir := range dirs {
-		tree := trees[dir]
-		if kept == nil || tree == "" {
-			read = append(read, dir)
-			continue
-		}
-		in, ok := kept.Get(tree)
-		if !ok {
-			read = append(read, dir)
-			continue
-		}
-		manifests[dir] = in.Manifest
-		if len(in.Locks) > 0 {
-			locks[dir] = in.Locks
-		}
-	}
-	return manifests, locks, read
-}
-
-// keep puts what was read of each directory under its tree hash.
-func keep(dirs []string, trees map[string]string, manifests map[string]string, locks map[string]map[string]string, kept Kept) {
-	if kept == nil {
-		return
-	}
-	for _, dir := range dirs {
-		raw, ok := manifests[dir]
-		if tree := trees[dir]; ok && tree != "" {
-			kept.Put(tree, Inputs{Manifest: raw, Locks: locks[dir]})
-		}
-	}
-}

modules/mesh-delivery-forge-bridge/manifest_test.go

@@ -103,12 +103,11 @@ func TestManifestDeclarations(t *testing.T) { // 1235/AC1
 	if m.SecretsOwner != "mesh-delivery-forge-bridge" {
 		t.Errorf("secrets-owner = %q", m.SecretsOwner)
 	}
-	// Three buckets: the head last written on FORGE for each pull request, so a sync writes only what differs (ADR 0443
-	// §5), the revision of each key of the gate's buckets the bridge performed, so a key is performed once per
-	// revision (ADR 0437 §8; issue 1341), and what a merge read of each module directory by its tree, so a merge reads
-	// the forge only for the directories it changed (issue 1126).
-	if !reflect.DeepEqual(m.State, []state{{Name: "heads", History: 1}, {Name: "performed", History: 1}, {Name: "inputs", History: 1}}) { // 1279/AC6, 1341, 1126
-		t.Errorf("state = %+v, want the buckets heads, performed and inputs", m.State)
+	// Two buckets: the head last written on FORGE for each pull request, so a sync writes only what differs (ADR 0443
+	// §5), and the revision of each key of the gate's buckets the bridge performed, so a key is performed once per
+	// revision (ADR 0437 §8; issue 1341).
+	if !reflect.DeepEqual(m.State, []state{{Name: "heads", History: 1}, {Name: "performed", History: 1}}) { // 1279/AC6, 1341
+		t.Errorf("state = %+v, want the buckets heads and performed", m.State)
 	}
 	// No other state, no bus, no seat, no tool, no event (ADR 0437 §4; ADR 0521: no check.status).
 	for _, k := range []string{"logs", "emits", "claims", "provides", "requires", "uses", "defines-seats", "tools", "seat", "seats"} {

modules/mesh-delivery-forge-bridge/module.json

@@ -12,8 +12,7 @@
   ],
   "state": [
     { "name": "heads", "history": 1 },
-    { "name": "performed", "history": 1 },
-    { "name": "inputs", "history": 1 }
+    { "name": "performed", "history": 1 }
   ],
   "reads": [
     "mesh-delivery-gate.merges",

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer-tools/main.go

@@ -29,9 +29,7 @@ func Tools(ask asker, now func() time.Time) []stdio.Tool {
 			Description: "Take a registered module in now: the indexer reads its manifest from the repository and commit the controller's " +
 				"build records register it from (at the head the gate's source names, when it names one), whatever it tried before, and " +
 				"writes it to its modules state as a merge would. For a module registered from outside the indexed repositories whose " +
-				"repository the forge could not read (a 404 before the forge's account could read it). A module the indexer holds " +
-				"whose record stands behind the head the gate's source names (a merge whose merged message never reached the " +
-				"indexer) is read again at that head and written when it changed. Answers stored, from which " +
+				"repository the forge could not read (a 404 before the forge's account could read it). Answers stored, from which " +
 				"repository, commit and path, or why not (held already, no registration, the forge's error, no manifest there). " +
 				"The indexer reads such a module again by itself on the next source revision and merged message; this asks now. " +
 				"indexer_module (mesh-delivery-view) reads the result.",
@@ -49,6 +47,25 @@ func Tools(ask asker, now func() time.Time) []stdio.Tool {
 				}
 				return a.Result, nil
 			}},
+		{Name: index.PlacementRereadTool,
+			Description: "Read the catalogue's placement files again now (novox/hq ADR 0559 §8): the indexer asks the forge for the trunk's head and " +
+				"every open catalogue pull request's, and writes its states placement (placement.<node>) and placement-candidates (<group>.<node>) " +
+				"as a merge and a pull request's head would, only where a key differs; a candidate key whose file no longer differs, or whose pull " +
+				"request is closed, is deleted. The recovery for a forge message the indexer missed. Answers the heads read, the keys written or " +
+				"deleted in each state, or why nothing was (the forge could not say). indexer_placement (mesh-delivery-view) reads the result.",
+			Input: map[string]any{"type": "object", "properties": map[string]any{
+				"why": map[string]any{"type": "string", "description": "why it is read again now, in plain words"}}},
+			Run: func(args map[string]any) (any, error) {
+				key, value, err := index.NewPlacementReread(str(args, "why"), stdio.CallerOf(args), now())
+				if err != nil {
+					return nil, err
+				}
+				a, err := ask(key, value)
+				if err != nil {
+					return nil, err
+				}
+				return a.Reread, nil
+			}},
 	}
 }
 

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/integration_test.go

@@ -578,39 +578,23 @@ func TestIndexerJudgesAnUnreadableVerdictAgainAtStart(t *testing.T) { // 1923/AC
 	}
 }
 
-// TestIndexerCountsOnlyThePlacedBuildNodesToolchains (issue 1940, issue 774): the toolchains bucket holds the report of
-// n2, where the catalogue no longer places mesh-build-go, at another version than n1's, as ace's v26.12.0 stayed beside
-// the v26.12.1 of the nodes mesh-build-node runs on. The indexer gives the merged module a fingerprint from n1's
-// toolchain alone; when the placement puts mesh-build-go on n2 again, its report written since counts and the builders
-// disagree (the guard stays); when it is taken off again, the fingerprint comes back. No restart, no timer: the
-// placement's watch (ADR 0549 §3), not the controller's assignments.
-func TestIndexerCountsOnlyThePlacedBuildNodesToolchains(t *testing.T) {
+// TestIndexerCountsOnlyTheAssignedBuildNodesToolchains (issue 1940): the toolchains bucket holds the report of n2, where
+// mesh-build-go was unassigned (its assignment ended) at another version than n1's, as ace's v26.12.0 stayed beside the
+// v26.12.1 of the nodes mesh-build-node runs on. The indexer gives the merged module a fingerprint from n1's toolchain
+// alone; when the controller assigns mesh-build-go to n2 again, its report counts and the builders disagree (the guard
+// stays); when the assignment ends again, the fingerprint comes back. No restart, no timer: the assignments' watch.
+func TestIndexerCountsOnlyTheAssignedBuildNodesToolchains(t *testing.T) {
 	manifest, err := os.ReadFile("../../internal/index/testdata/catalogue-a67f0196-avahi.module.json")
 	if err != nil {
 		t.Fatal(err)
 	}
 	const goSum = "3b5028f0c1e9bde04dd766abd63eb5931bc516bae695cf46f00abcd8510b0381"
-	var placement, toolchains jetstream.KeyValue
-	place := func(ctx context.Context, t *testing.T, node string, modules ...string) {
-		p := delivery.Placement{Node: node}
-		for _, m := range modules {
-			p.Modules = append(p.Modules, delivery.PlacedModule{Module: m})
-		}
-		key, _ := delivery.PlacementKey(node)
-		value, err := delivery.EncodePlacement(p)
-		if err != nil {
-			t.Fatal(err)
-		}
-		if _, err := placement.Put(ctx, key, value); err != nil {
-			t.Fatal(err)
-		}
-	}
+	var assignments jetstream.KeyValue
 	js, ctx, _, modules := startIndexer(t, func(context.Context, jetstream.KeyValue) {}, func(ctx context.Context, js jetstream.JetStream) {
 		kv, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: delivery.ToolchainsBucket("mesh-build-go"), History: 1})
 		if err != nil {
 			t.Fatal(err)
 		}
-		toolchains = kv
 		for node, version := range map[string]string{"n1": "go1.27.3", "n2": "go1.27.2"} {
 			key, _ := delivery.ToolchainKey(node, "go")
 			value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "go", Version: version, Recipe: "1", At: time.Now()})
@@ -621,12 +605,18 @@ func TestIndexerCountsOnlyThePlacedBuildNodesToolchains(t *testing.T) {
 				t.Fatal(err)
 			}
 		}
-		// The seat mesh-placement's placement, as the assigner writes it (ADR 0567): n1 places mesh-build-go, n2 nothing.
-		if placement, err = js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: delivery.PlacementBucket, History: delivery.PlacementHistory}); err != nil {
+		// The controller's assignments mirror, in its layout (mesh-controller internal/chain Assignment).
+		if assignments, err = js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: "mesh-controller_assignments", History: 1}); err != nil {
 			t.Fatal(err)
 		}
-		place(ctx, t, "n1", "mesh-build-go")
-		place(ctx, t, "n2")
+		for key, value := range map[string]string{
+			"n1.mesh-build-go": `{"node":"n1","module":"mesh-build-go","assigned":"2026-10-20T08:00:00Z"}`,
+			"n2.mesh-build-go": `{"node":"n2","module":"mesh-build-go","assigned":"2026-10-20T08:00:00Z","ended":"2026-10-23T08:00:00Z"}`,
+		} {
+			if _, err := assignments.Put(ctx, key, []byte(value)); err != nil {
+				t.Fatal(err)
+			}
+		}
 	})
 	data, err := delivery.EncodeForge(delivery.Forge{Kind: delivery.ForgeMerged, Repository: "novox/mesh-catalog", Branch: "feat/x", Number: 302,
 		Head: "0123456789abcdef0123456789abcdef01234567", Merge: "89abcdef0123456789abcdef0123456789abcdef", Root: "r0",
@@ -657,22 +647,16 @@ func TestIndexerCountsOnlyThePlacedBuildNodesToolchains(t *testing.T) {
 	if !agreed(held) {
 		t.Fatalf("within 5 s avahi has fp2 %q, none2 %q, toolchains %v: want a fingerprint of n1's go1.27.3 alone", held.FP2, held.None2, held.Toolchains)
 	}
-	place(ctx, t, "n2", "mesh-build-go")
-	key, _ := delivery.ToolchainKey("n2", "go")
-	value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "go", Version: "go1.27.2", Recipe: "1", At: time.Now().Add(time.Second)})
-	if err != nil {
+	if _, err := assignments.Put(ctx, "n2.mesh-build-go", []byte(`{"node":"n2","module":"mesh-build-go","assigned":"2026-10-24T08:00:00Z"}`)); err != nil {
 		t.Fatal(err)
 	}
-	if _, err := toolchains.Put(ctx, key, value); err != nil {
-		t.Fatal(err)
-	}
-	// n2's report, written since its placement, counts: the builders disagree. A fingerprint already computed is kept
+	// n2's report, written since its assignment, counts: the builders disagree. A fingerprint already computed is kept
 	// (issue 1940), and only a new one needs the agreement: a merge moving avahi gets none until they agree.
 	time.Sleep(500 * time.Millisecond)
 	if e, err := modules.Get(ctx, "avahi"); err != nil {
 		t.Fatal(err)
 	} else if m, err := delivery.DecodeModule(e.Value()); err != nil || m.FP2 != held.FP2 {
-		t.Fatalf("after n2's placement avahi has fp2 %q, none2 %q: want its fingerprint %q kept", m.FP2, m.None2, held.FP2)
+		t.Fatalf("after n2's assignment avahi has fp2 %q, none2 %q: want its fingerprint %q kept", m.FP2, m.None2, held.FP2)
 	}
 	moved := strings.Replace(string(data), `"newtree"`, `"movedtree"`, 1)
 	if moved == string(data) {
@@ -685,10 +669,12 @@ func TestIndexerCountsOnlyThePlacedBuildNodesToolchains(t *testing.T) {
 		return m.FP2 == "" && strings.HasPrefix(m.None2, "builders disagree: go1.27.2 recipe 1 on n2")
 	}
 	if m := read(disagree); !disagree(m) {
-		t.Fatalf("within 5 s of a merge after n2's placement avahi has fp2 %q, none2 %q: want the builders to disagree", m.FP2, m.None2)
+		t.Fatalf("within 5 s of a merge after n2's assignment avahi has fp2 %q, none2 %q: want the builders to disagree", m.FP2, m.None2)
+	}
+	if _, err := assignments.Put(ctx, "n2.mesh-build-go", []byte(`{"node":"n2","module":"mesh-build-go","ended":"2026-10-24T09:00:00Z"}`)); err != nil {
+		t.Fatal(err)
 	}
-	place(ctx, t, "n2")
 	if m := read(agreed); !agreed(m) {
-		t.Fatalf("within 5 s of n2's placement taken away avahi has fp2 %q, none2 %q", m.FP2, m.None2)
+		t.Fatalf("within 5 s of n2's unassignment avahi has fp2 %q, none2 %q", m.FP2, m.None2)
 	}
 }

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/main.go

@@ -18,13 +18,11 @@ import (
 	"os"
 	"os/signal"
 	"syscall"
-	"time"
 
 	"github.com/nats-io/nats.go"
 	"github.com/nats-io/nats.go/jetstream"
 
 	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
 	"git.novox.be/novox/mesh-sdk/go/process"
 
 	"mesh-delivery-indexer/internal/index"
@@ -147,50 +145,25 @@ type delivered interface {
 	Ack() error
 	DoubleAck(ctx context.Context) error
 	Term() error
-	Metadata() (*jetstream.MsgMetadata, error)
 }
 
 // handle takes one message of FORGE into the candidates and acknowledges it. A message it can never read is terminated,
 // never redelivered, and the log names its subject and why. A write that failed stays unacknowledged: the server
-// delivers it again (the server's ack wait is the only clock). Each message handled is written to the heard state
-// (index.Heard; nil, or a state not on the bus yet, writes none), so indexer_heard reads what the indexer heard of FORGE.
-func handle(ctx context.Context, m delivered, ix *index.Indexer, heard index.Store, logger *log.Logger) {
-	h := index.Heard{Subject: m.Subject()}
-	if md, err := m.Metadata(); err == nil && md != nil {
-		h.Sequence, h.Delivered, h.Published = md.Sequence.Stream, md.NumDelivered, md.Timestamp.UTC()
-	}
-	defer func() {
-		if heard == nil {
-			return
-		}
-		h.Handled = time.Now().UTC()
-		if err := index.WriteHeard(ctx, heard, h); err != nil && !errors.Is(err, process.ErrNotYet) {
-			logger.Printf("%s: sequence %d is not written to the heard state: %v", h.Subject, h.Sequence, err)
-		}
-	}()
+// delivers it again (the server's ack wait is the only clock).
+func handle(ctx context.Context, m delivered, ix *index.Indexer, logger *log.Logger) {
 	f, err := delivery.DecodeForge(m.Data())
 	if err != nil {
 		logger.Printf("%s: not a forge message, dropped: %v", m.Subject(), err)
-		h.Outcome, h.Words = index.HeardDropped, err.Error()
 		_ = m.Term()
 		return
 	}
-	h.Kind, h.Repository, h.Number, h.Branch, h.Commit = f.Kind, f.Repository, f.Number, f.Branch, f.Head
-	if f.Merge != "" {
-		h.Commit = f.Merge
-	}
-	applied, err := ix.ApplyMessage(ctx, f)
-	h.Written, h.Late = applied.Written, applied.Late
-	switch {
+	switch err := ix.Apply(ctx, f); {
 	case errors.Is(err, index.ErrUnreadable):
 		logger.Printf("%s: %v; dropped", m.Subject(), err)
-		h.Outcome, h.Words = index.HeardDropped, err.Error()
 		_ = m.Term()
 	case err != nil:
 		logger.Printf("%s: %s#%d left for redelivery: %v", m.Subject(), f.Repository, f.Number, err)
-		h.Outcome, h.Words = index.HeardLeft, err.Error()
 	default:
-		h.Outcome = index.HeardApplied
 		// Waits for the server, so the consumer's info no longer counts the message as unacknowledged when the fill that
 		// follows asks whether the stream is applied (issue 1280); a failed ack is redelivered after the ack wait, which
 		// kicks the fill again.
@@ -274,6 +247,12 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	// Its taken state (ADR 0556 clause 1) is bound when it appears, as every state a delivery adds (issue 1790): until then
 	// a merge's taken key is said and not written, and the rest of the indexer runs.
 	taken := process.AwaitBucket(ctx, js, conn, delivery.TakenBucket, "no repository's taken key is written", logger.Printf)
+	// Its placement state (ADR 0549 §2) is bound when it appears, as every state a delivery adds (issue 1790): until then a
+	// catalogue merge's placement is said and not written, and the rest of the indexer runs.
+	placement := process.AwaitBucket(ctx, js, conn, delivery.PlacementBucket, "no catalogue merge's placement is written", logger.Printf)
+	// Its placement candidates (issue 1126, ADR 0549 §4) are bound the same way: until the state appears a catalogue pull
+	// request's placement is said and not written, so no node answers it and its check names every placed node as silent.
+	placementCandidates := process.AwaitBucket(ctx, js, conn, delivery.PlacementCandidatesBucket, "no catalogue pull request's placement candidate is written", logger.Printf)
 	// The controller's build records only name the directory of a module whose key names none (fillPaths): without them
 	// such a module waits for its path, every other is indexed (issue 1945).
 	builds := process.OptionalBucket(ctx, js, delivery.BuildsBucket, "a module whose key names no directory is not given one from the controller's build records until the indexer starts again", logger.Printf)
@@ -305,7 +284,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 	defer calls.Close()
 	ix := &index.Indexer{Store: kvStore{candidates}, Modules: kvStore{modules}, Manifests: kvStore{manifests}, Taken: awaitedStore{taken}, Builds: known, Logf: logger.Printf,
 		Named: namedVia(calls.Call), Trunk: trunkVia(calls.Call), Contains: containsVia(calls.Call), Read: readVia(calls.Call),
-		ReadOpen: openVia(calls.Call)}
+		Placement: awaitedStore{placement}, PlacementCandidates: awaitedStore{placementCandidates}, ReadPlacement: placementVia(calls.Call), Say: func(event string, body any) error { return calls.Emit(event, body) }}
 	// The gate's source bucket (mesh-delivery-gate_source) comes with the gate (release 3e, novox/hq ADR 0450 §1): its key
 	// main is the mesh's source revision, which stamps the modules (issue 1344). Where it does not exist yet the indexer does
 	// not wait for it (that needs a timer, ADR 0437 §8): it says so, and is started again with the gate.
@@ -322,14 +301,14 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 			go func() { sourceErrs <- follow(ctx, sw, each) }()
 		}
 	}
-	// Only the toolchain reports of nodes the catalogue places the build module on count (issue 1940, ADR 0549 §3): the
-	// placement is settled first, so the toolchains settle through the gate already knowing it.
-	gate := buildrun.NewToolchainGate(sortedModules(), ix.PutToolchain, logger.Printf)
-	placementErrs, err := buildrun.FollowPlacement(ctx, js, gate, func(ctx context.Context) {
+	// Only the toolchain reports of nodes the build module is assigned to count (issue 1940): the controller's
+	// assignments are settled first, so the toolchains settle through the gate already knowing them.
+	gate := newToolchainGate(sortedModules(), ix.PutToolchain, logger.Printf)
+	assignErrs, err := watchAssignments(ctx, js, gate, func(ctx context.Context) {
 		if err := ix.Recompute(ctx); err != nil {
-			logger.Printf("writing the modules again after the placement of a build module changed: %v", err)
+			logger.Printf("writing the modules again after an assignment of a build module changed: %v", err)
 		}
-	}, logger.Printf)
+	}, logger)
 	if err != nil {
 		return err
 	}
@@ -425,13 +404,17 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		// Essential: the forge's merges are what the indexer indexes.
 		return fmt.Errorf("the consumer %s_%s on %s cannot be read (%v): the indexer hears no merge without it, so it stops; where the bus refused it or did not answer, this module's consumes (made by the controller with its grant) have not reached the bus yet", cred.Node, cred.Module, forgeStream, err)
 	}
-	// A merge applied while the taken state was missing gets its taken key (issue 1280): when the state appears (Ready runs
-	// once, now or then), and after each applied message. The gate's source heads never move a key (issue 1126).
+	// A merge applied while the taken state was missing, and the gate's heads once the forge stream is applied whole, get
+	// their taken key (issue 1280): when the state appears (Ready runs once, now or then), and after each applied message.
+	ix.Drained = func(ctx context.Context) (bool, error) {
+		info, err := cons.Info(ctx)
+		if err != nil {
+			return false, err
+		}
+		return info.NumPending == 0 && info.NumAckPending == 0, nil
+	}
 	taken.Ready(func(jetstream.KeyValue) { ix.KickFill(ctx) })
-	// What the indexer heard of FORGE (issue 1126 note 76) is bound when its state appears, as every state a delivery adds
-	// (issue 1790): until then no message is written there, and the rest of the indexer runs.
-	heard := awaitedStore{process.AwaitBucket(ctx, js, conn, index.HeardBucket, "no FORGE message the indexer handles is written for indexer_heard", logger.Printf)}
-	cc, err := process.HearEvents(cons, func(m jetstream.Msg) { handle(ctx, m, ix, heard, logger); ix.KickFill(ctx) }, logger.Printf)
+	cc, err := process.HearEvents(cons, func(m jetstream.Msg) { handle(ctx, m, ix, logger); ix.KickFill(ctx) }, logger.Printf)
 	if err != nil {
 		return err
 	}
@@ -443,7 +426,7 @@ func run(ctx context.Context, getenv func(string) string, logOut io.Writer) erro
 		return err
 	case err := <-sourceErrs:
 		return err
-	case err := <-placementErrs:
+	case err := <-assignErrs:
 		return err
 	case err := <-tools.errs:
 		return err

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/main_test.go

@@ -3,13 +3,9 @@ package main
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"log"
 	"strings"
 	"testing"
-	"time"
-
-	"github.com/nats-io/nats.go/jetstream"
 
 	"git.novox.be/novox/mesh-sdk/go/delivery"
 
@@ -33,21 +29,6 @@ func (f *fakeMsg) DoubleAck(context.Context) error {
 }
 func (f *fakeMsg) Term() error { f.termd++; return nil }
 
-// Metadata is the stream's word on the message: its sequence 41, delivered a second time (issue 1126 note 76).
-func (f *fakeMsg) Metadata() (*jetstream.MsgMetadata, error) {
-	return &jetstream.MsgMetadata{Sequence: jetstream.SequencePair{Stream: 41, Consumer: 7}, NumDelivered: 2, Timestamp: time.Date(2026, 10, 28, 13, 7, 42, 0, time.UTC)}, nil
-}
-
-// heardOf is the indexer's record of the last FORGE message it handled (index.HeardKey).
-func heardOf(t *testing.T, st *memStore) index.Heard {
-	t.Helper()
-	var h index.Heard
-	if err := json.Unmarshal(st.vals[index.HeardKey], &h); err != nil {
-		t.Fatalf("heard.%s = %q: %v", index.HeardKey, st.vals[index.HeardKey], err)
-	}
-	return h
-}
-
 type memStore struct{ vals map[string][]byte }
 
 func (m *memStore) Get(_ context.Context, k string) ([]byte, uint64, bool, error) {
@@ -76,32 +57,21 @@ func TestAMessageIsIndexedAndAcked(t *testing.T) { // 1238/AC2 (unit part)
 	data, _ := delivery.EncodeForge(delivery.Forge{Kind: delivery.ForgePull, Repository: "novox/mesh-delivery", Branch: "feat/x", Number: 12, Head: head,
 		Action: delivery.PullUpdated, Dirs: []string{"modules/a"}, DirsKnown: true})
 	m := &fakeMsg{subject: "mesh.stream.mesh-delivery-forge-bridge.event.forge.novox.mesh-delivery.pull", data: data}
-	heard := &memStore{vals: map[string][]byte{}}
-	handle(context.Background(), m, ix, heard, log.New(&bytes.Buffer{}, "", 0))
+	handle(context.Background(), m, ix, log.New(&bytes.Buffer{}, "", 0))
 	c, err := delivery.DecodeCandidate(st.vals["feat/x"])
 	if err != nil || len(c.Pulls) != 1 || c.Pulls[0].Modules[0] != "a" || m.acked != 1 || m.doubled != 1 || m.termd != 0 {
 		t.Errorf("candidate %+v err %v acked %d terminated %d", c, err, m.acked, m.termd)
 	}
-	// Issue 1126 note 76: what the indexer heard of FORGE is readable (indexer_heard): subject, sequence, deliveries, time,
-	// repository, commit and what it did.
-	if h := heardOf(t, heard); h.Subject != m.subject || h.Sequence != 41 || h.Delivered != 2 || h.Published.Hour() != 13 || h.Kind != delivery.ForgePull ||
-		h.Repository != "novox/mesh-delivery" || h.Number != 12 || h.Commit != head || h.Outcome != index.HeardApplied || h.Handled.IsZero() {
-		t.Errorf("heard = %+v", h)
-	}
 }
 
 func TestAMessageThatIsNoForgeMessageIsTerminatedAndLogged(t *testing.T) { // 1238 (never redelivered)
 	var logs bytes.Buffer
 	st := &memStore{vals: map[string][]byte{}}
 	m := &fakeMsg{subject: "mesh.stream.mesh-delivery-forge-bridge.event.forge.x.y.pull", data: []byte(`{"v":1,"kind":"pull"}`)}
-	heard := &memStore{vals: map[string][]byte{}}
-	handle(context.Background(), m, &index.Indexer{Store: st, Builds: index.NewBuilds()}, heard, log.New(&logs, "", 0))
+	handle(context.Background(), m, &index.Indexer{Store: st, Builds: index.NewBuilds()}, log.New(&logs, "", 0))
 	if m.termd != 1 || m.acked != 0 || len(st.vals) != 0 || !strings.Contains(logs.String(), m.subject) {
 		t.Errorf("terminated %d acked %d keys %d log %q", m.termd, m.acked, len(st.vals), logs.String())
 	}
-	if h := heardOf(t, heard); h.Outcome != index.HeardDropped || h.Sequence != 41 || h.Words == "" {
-		t.Errorf("heard = %+v", h)
-	}
 }
 
 func TestTheSourceMainKeyIsTakenAtItsRevision(t *testing.T) { // 1344/AC1 (the watch's side: key, revision, value)

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/named.go

@@ -171,35 +171,108 @@ func readVia(call toolCaller) func(ctx context.Context, repository, sha, dir str
 	}
 }
 
-// The forge's tool for the open pull requests, and the trunk branch they are open into.
+// The forge's tools the placement reread asks (indexer_placement_reread, novox/hq ADR 0559 §8): a repository's branches
+// with their commits, and every open pull request with its branch and head.
 const (
-	openPullsTool = "gitea.gitea_open_pulls"
-	trunkBranch   = "main"
+	listBranchesTool = "gitea.gitea_list_branches"
+	openPullsTool    = "gitea.gitea_open_pulls"
+	placementTrunk   = "main"
 )
 
-// openVia asks the forge which pull requests into the trunk are open now (gitea_open_pulls), every repository's.
-func openVia(call toolCaller) func(ctx context.Context) ([]delivery.OpenPull, error) {
-	return func(context.Context) ([]delivery.OpenPull, error) {
-		raw, err := call(openPullsTool, map[string]any{})
+// placementVia reads the catalogue's placement now through call: the trunk's head (gitea_list_branches), every placement
+// file at it, and each open pull request of the catalogue into the trunk (gitea_open_pulls) with every placement file at
+// its head, each read whole or not at all (gitea_commit_trees with listed, gitea_get_file).
+func placementVia(call toolCaller) func(ctx context.Context) (index.PlacementRead, error) {
+	owner, repo, _ := strings.Cut(delivery.CatalogueRepository, "/")
+	filesAt := func(sha string) (map[string]string, error) {
+		raw, err := call(commitTreesTool, map[string]any{"owner": owner, "repo": repo, "sha": sha, "listed": []string{delivery.PlacementDir}})
 		if err != nil {
 			return nil, err
 		}
+		var a struct {
+			Listed map[string]map[string]string `json:"listed"`
+		}
+		if err := json.Unmarshal(raw, &a); err != nil || a.Listed == nil {
+			return nil, fmt.Errorf("the answer of %s lists no directory: %v", commitTreesTool, err)
+		}
+		var out map[string]string
+		for name := range a.Listed[delivery.PlacementDir] {
+			file := delivery.PlacementDir + "/" + name
+			node, ok := delivery.PlacementFileNode(file)
+			if !ok {
+				continue
+			}
+			raw, err := call(getFileTool, map[string]string{"owner": owner, "repo": repo, "path": file, "ref": sha})
+			if err != nil {
+				return nil, fmt.Errorf("%s at %s: %w", file, sha, err)
+			}
+			var f struct {
+				File *struct {
+					Content *string `json:"content"`
+				} `json:"file"`
+			}
+			if err := json.Unmarshal(raw, &f); err != nil || f.File == nil || f.File.Content == nil {
+				return nil, fmt.Errorf("the answer of %s for %s is not {file: {content}}: %v", getFileTool, file, err)
+			}
+			if out == nil {
+				out = map[string]string{}
+			}
+			out[node] = *f.File.Content
+		}
+		return out, nil
+	}
+	return func(context.Context) (index.PlacementRead, error) {
+		raw, err := call(listBranchesTool, map[string]string{"owner": owner, "repo": repo})
+		if err != nil {
+			return index.PlacementRead{}, err
+		}
+		var b struct {
+			Branches []struct {
+				Name   string `json:"name"`
+				Commit string `json:"commit"`
+			} `json:"branches"`
+		}
+		if err := json.Unmarshal(raw, &b); err != nil {
+			return index.PlacementRead{}, fmt.Errorf("the answer of %s is not {branches}: %w", listBranchesTool, err)
+		}
+		var out index.PlacementRead
+		for _, br := range b.Branches {
+			if br.Name == placementTrunk {
+				out.Trunk = br.Commit
+			}
+		}
+		if out.Trunk == "" {
+			return index.PlacementRead{}, fmt.Errorf("%s names no branch %s of %s", listBranchesTool, placementTrunk, delivery.CatalogueRepository)
+		}
+		if out.Files, err = filesAt(out.Trunk); err != nil {
+			return index.PlacementRead{}, err
+		}
+		raw, err = call(openPullsTool, map[string]any{})
+		if err != nil {
+			return index.PlacementRead{}, err
+		}
 		var o struct {
 			Pulls *[]struct {
-				Owner  string `json:"owner"`
-				Repo   string `json:"repo"`
-				Number int    `json:"number"`
-				Base   string `json:"base"`
+				Owner   string `json:"owner"`
+				Repo    string `json:"repo"`
+				Number  int    `json:"number"`
+				Base    string `json:"base"`
+				Head    string `json:"head"`
+				HeadSHA string `json:"head_sha"`
 			} `json:"pulls"`
 		}
 		if err := json.Unmarshal(raw, &o); err != nil || o.Pulls == nil {
-			return nil, fmt.Errorf("the answer of %s is not {pulls}: %v", openPullsTool, err)
+			return index.PlacementRead{}, fmt.Errorf("the answer of %s is not {pulls}: %v", openPullsTool, err)
 		}
-		out := []delivery.OpenPull{}
 		for _, p := range *o.Pulls {
-			if p.Base == trunkBranch && p.Number > 0 {
-				out = append(out, delivery.OpenPull{Repository: p.Owner + "/" + p.Repo, Number: p.Number})
+			if !delivery.SameRepository(p.Owner+"/"+p.Repo, delivery.CatalogueRepository) || p.Base != placementTrunk || p.Number <= 0 || p.Head == "" || p.HeadSHA == "" {
+				continue
 			}
+			files, err := filesAt(p.HeadSHA)
+			if err != nil {
+				return index.PlacementRead{}, fmt.Errorf("%s#%d: %w", delivery.CatalogueRepository, p.Number, err)
+			}
+			out.Pulls = append(out.Pulls, index.PullPlacement{Branch: p.Head, Number: p.Number, Head: p.HeadSHA, Files: files})
 		}
 		return out, nil
 	}

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/standing.go

@@ -0,0 +1,211 @@
+package main
+
+// This file is the same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker (issue 1940): it moves
+// to mesh-sdk go/delivery/buildrun once mesh-sdk can be delivered again, since a change of mesh-sdk waits on the very
+// toolchain agreement this file repairs.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"maps"
+	"slices"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go/jetstream"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/provider"
+)
+
+// A build module writes <node>.<language> of its toolchains state on every node it runs on, and nothing deletes the key
+// when the module is unassigned from a node: the controller writes no module's state, and the module is gone. A report of
+// a node the build module no longer runs on is therefore not a builder (issue 1940: mesh-build-node unassigned from ace
+// on 2026-10-23 left ace.typescript at v26.12.0, and every Node fingerprint said "builders disagree").
+//
+// toolchainGate stands between the toolchains buckets and what takes their entries in (the indexer's PutToolchain, a
+// buildrun.ToolchainSet): an entry is passed on only while the controller's assignments (mesh-controller_assignments,
+// key <node>.<module>) hold an open assignment of its build module on its node, and only once it was written since that
+// assignment; it is passed on as deleted otherwise, said once, and passed on when its node writes it again. A report
+// written before the assignment is the one an earlier run of the module left (issue 1940, 2026-10-25 20:56: mesh-build-node
+// assigned to ace again brought ace.typescript v26.12.0 of 2026-10-23 back into the agreement, before the module ran
+// there, and the controller's take-in refused every module "builders disagree"). Until the assignments are settled (or where they cannot
+// be read) every entry is passed on, as before. Builders that run and report different versions still disagree: that
+// refusal is the guard of novox/hq ADR 0465, and it stays.
+type toolchainGate struct {
+	mu       sync.Mutex
+	modules  map[string]bool                                           // the build modules whose toolchains pass the gate
+	forward  func(module, key string, value []byte, deleted bool) bool // answers whether it changed what it holds
+	logf     func(format string, a ...any)
+	known    bool                         // the assignments are settled
+	standing map[string]time.Time         // <node>.<module> with an open assignment -> since when it stands
+	raw      map[string]map[string][]byte // module -> toolchains key -> value, as the bucket holds it
+	left     map[string]string            // <module>/<key> -> why it was said left out, so each reason is said once
+}
+
+func newToolchainGate(modules []string, forward func(module, key string, value []byte, deleted bool) bool, logf func(string, ...any)) *toolchainGate {
+	g := &toolchainGate{modules: map[string]bool{}, forward: forward, logf: logf, standing: map[string]time.Time{},
+		raw: map[string]map[string][]byte{}, left: map[string]string{}}
+	for _, m := range modules {
+		g.modules[m] = true
+	}
+	return g
+}
+
+// Toolchain takes one change of a build module's toolchains bucket in and answers whether what it passed on changed.
+func (g *toolchainGate) Toolchain(module, key string, value []byte, deleted bool) bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	if g.raw[module] == nil {
+		g.raw[module] = map[string][]byte{}
+	}
+	if deleted {
+		delete(g.raw[module], key)
+	} else {
+		g.raw[module][key] = value
+	}
+	return g.pass(module, key)
+}
+
+// Assignment takes one change of the controller's assignments in (at is when the bus wrote that revision) and answers
+// whether what it passed on changed.
+func (g *toolchainGate) Assignment(key string, value []byte, deleted bool, at time.Time) bool {
+	node, module, ok := strings.Cut(key, ".")
+	if !ok || !g.modules[module] {
+		return false
+	}
+	assigned, open := openAssignment(value)
+	open = open && !deleted
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	was, stood := g.standing[key]
+	since := assigned
+	if since.IsZero() {
+		// A value with no time of its own (an assignment a module pulled in) stands since the revision that opened it.
+		since = at
+		if stood {
+			since = was
+		}
+	}
+	if open == stood && (!open || since.Equal(was)) {
+		return false
+	}
+	if open {
+		g.standing[key] = since
+	} else {
+		delete(g.standing, key)
+	}
+	if !g.known {
+		return false
+	}
+	changed := false
+	for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+		if n, _, err := delivery.ParseToolchainKey(k); err == nil && n == node {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// Settled says the assignments are read: from now on only the reports of assigned nodes pass. It answers whether what it
+// passed on changed.
+func (g *toolchainGate) Settled() bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	g.known = true
+	changed := false
+	for _, module := range slices.Sorted(maps.Keys(g.raw)) {
+		for _, k := range slices.Sorted(maps.Keys(g.raw[module])) {
+			changed = g.pass(module, k) || changed
+		}
+	}
+	return changed
+}
+
+// pass hands one key on as it stands: its value when its node is assigned and wrote it since (or the assignments are not
+// known), deleted otherwise. The caller holds mu.
+func (g *toolchainGate) pass(module, key string) bool {
+	value, held := g.raw[module][key]
+	if !held {
+		return g.forward(module, key, nil, true)
+	}
+	node, _, err := delivery.ParseToolchainKey(key)
+	why := ""
+	if err == nil && g.known {
+		why = g.leftOut(module, node, value)
+	}
+	if why == "" {
+		delete(g.left, module+"/"+key)
+		return g.forward(module, key, value, false)
+	}
+	if g.left[module+"/"+key] != why {
+		g.left[module+"/"+key] = why
+		g.logf("%s.%s is left out of the agreed toolchain: %s (issue 1940)", delivery.ToolchainsBucket(module), key, why)
+	}
+	return g.forward(module, key, nil, true)
+}
+
+// leftOut is why a node's report is no builder's, or empty when it counts: its node has no open assignment of the module,
+// or the report was written before that assignment. A value that is no toolchain is passed on for its reader to refuse.
+// The caller holds mu.
+func (g *toolchainGate) leftOut(module, node string, value []byte) string {
+	since, open := g.standing[node+"."+module]
+	if !open {
+		return fmt.Sprintf("%s has no assignment on %s, so it is no builder", module, node)
+	}
+	tc, err := delivery.DecodeToolchain(value)
+	if err == nil && tc.At.Before(since) {
+		return fmt.Sprintf("it was written at %s, before %s's assignment on %s at %s: it counts once %s writes it again",
+			tc.At.UTC().Format(time.RFC3339), module, node, since.UTC().Format(time.RFC3339), node)
+	}
+	return ""
+}
+
+// openAssignment is whether a value of the controller's assignments holds an assignment that stands (one that has not
+// ended and has no state: a pending one is not on the machine yet; mesh-controller internal/chain Assignment), and when
+// it was assigned, zero where the value does not say.
+func openAssignment(value []byte) (time.Time, bool) {
+	var a struct {
+		Assigned time.Time `json:"assigned"`
+		Ended    time.Time `json:"ended"`
+		State    string    `json:"state"`
+	}
+	if json.Unmarshal(value, &a) != nil {
+		return time.Time{}, false
+	}
+	return a.Assigned, a.Ended.IsZero() && a.State == ""
+}
+
+// watchAssignments settles the controller's assignments into the gate, says them settled, and follows them; changed is
+// told whenever what the gate passes on changed. Where the bucket cannot be read (not there, or this module may not read
+// it) it says so and the gate passes every report on, as before; an error of the watch after that ends on the channel.
+func watchAssignments(ctx context.Context, js bucketOpener, gate *toolchainGate, changed func(context.Context), logger *log.Logger) (<-chan error, error) {
+	errs := make(chan error, 1)
+	kv, err := js.KeyValue(ctx, provider.AssignmentsBucket)
+	if err != nil {
+		// Not fatal: an indexer, builder or checker that stops for it stops every delivery (a grant comes with a delivery).
+		logger.Printf("the bucket %s cannot be read, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	each := func(e jetstream.KeyValueEntry) { gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) }
+	w, err := settle(ctx, kv, each)
+	if err != nil {
+		// Not fatal either (issue 1945): a watch the bus refuses is the same missing grant as a refused read.
+		logger.Printf("the bucket %s cannot be watched, so every node's toolchain report counts, an unassigned build node's too (issue 1940): %v", provider.AssignmentsBucket, err)
+		return errs, nil
+	}
+	if gate.Settled() {
+		changed(ctx)
+	}
+	go func() {
+		errs <- follow(ctx, w, func(e jetstream.KeyValueEntry) {
+			if gate.Assignment(e.Key(), e.Value(), !opOf(e), e.Created()) {
+				changed(ctx)
+			}
+		})
+	}()
+	return errs, nil
+}

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/standing_test.go

@@ -0,0 +1,165 @@
+package main
+
+// The same in mesh-delivery-indexer, mesh-delivery-builder and mesh-delivery-checker, as standing.go is (issue 1940).
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/delivery/buildrun"
+)
+
+func gateReport(t *testing.T, node, version string) (string, []byte) {
+	t.Helper()
+	key, err := delivery.ToolchainKey(node, "typescript")
+	if err != nil {
+		t.Fatal(err)
+	}
+	value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: time.Unix(0, 0).UTC()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return key, value
+}
+
+func agreedOf(set *buildrun.ToolchainSet) (string, string) {
+	tc, none := delivery.AgreedToolchain(set.Entries("typescript"))
+	return tc.Version, none
+}
+
+// The live case of issue 1940: mesh-build-node was unassigned from ace, whose report stayed at v26.12.0 while the
+// three nodes it runs on report v26.12.1. Without the assignments every report counts (and they disagree); with them
+// ace's is left out and the three agree; assigned to ace again, its report counts again and the guard refuses again.
+func TestAnUnassignedBuildNodesReportIsNoBuilder(t *testing.T) {
+	set := &buildrun.ToolchainSet{}
+	var said []string
+	gate := newToolchainGate([]string{buildrun.GoBuildModule, buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, f) })
+	for node, version := range map[string]string{"ace": "v26.12.0", "g14": "v26.12.1", "novox": "v26.12.1", "shanks": "v26.12.1"} {
+		key, value := gateReport(t, node, version)
+		gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree") {
+		t.Fatalf("before the assignments are read every report counts, so they disagree; got %q", none)
+	}
+	for _, node := range []string{"g14", "novox", "shanks"} {
+		gate.Assignment(node+"."+buildrun.NodeBuildModule, []byte(`{"node":"`+node+`","module":"mesh-build-node"}`), false, time.Time{})
+	}
+	gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","ended":"2026-10-23T08:00:00Z"}`), false, time.Time{})
+	gate.Assignment("ace.mesh-build-go", []byte(`{"node":"ace","module":"mesh-build-go"}`), false, time.Time{}) // another module's: no matter
+	if !gate.Settled() {
+		t.Fatal("settling the assignments left ace's report out, so what was passed on changed")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("the assigned nodes agree on v26.12.1; got %q, %q", v, none)
+	}
+	if len(said) != 1 {
+		t.Fatalf("ace's report is said left out once; said %v", said)
+	}
+	// ace reports again while unassigned (an old value seen again): still left out.
+	key, value := gateReport(t, "ace", "v26.12.0")
+	if gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+		t.Fatal("an unassigned node's report changed what was passed on")
+	}
+	// Assigned to ace again: its report counts, and the builders really disagree: the guard stays.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node"}`), false, time.Time{}) {
+		t.Fatal("assigning ace again passed nothing on")
+	}
+	if _, none := agreedOf(set); !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+		t.Fatalf("builders that run different versions still disagree; got %q", none)
+	}
+	// The assignment's key deleted, or a pending one written: no assignment stands, and ace's report goes again.
+	if !gate.Assignment("ace.mesh-build-node", []byte(`{"node":"ace","module":"mesh-build-node","state":"pending"}`), false, time.Time{}) {
+		t.Fatal("a pending assignment is no assignment on the machine")
+	}
+	if v, none := agreedOf(set); v != "v26.12.1" || none != "" {
+		t.Fatalf("got %q, %q", v, none)
+	}
+	gate.Assignment("ace.mesh-build-node", nil, true, time.Time{})
+	if v, _ := agreedOf(set); v != "v26.12.1" {
+		t.Fatalf("got %q", v)
+	}
+	// A report deleted from the bucket goes whether its node is assigned or not.
+	key, _ = gateReport(t, "g14", "v26.12.1")
+	if !gate.Toolchain(buildrun.NodeBuildModule, key, nil, true) {
+		t.Fatal("deleting g14's report passed nothing on")
+	}
+	if n := len(set.Entries("typescript")); n != 2 {
+		t.Fatalf("novox and shanks are left; got %d entries", n)
+	}
+}
+
+// A build node's report counts from the first one it writes since its assignment: a newly assigned node that has not
+// reported changes nothing, and the report an earlier run left on the bus (issue 1940, 2026-10-25 20:56: ace.typescript
+// v26.12.0 of 2026-10-23 06:29, mesh-build-node assigned to ace again at 20:56:45) is left out, said once, until the node
+// writes it again. An assignment whose value names no time stands since the revision that opened it.
+func TestANewlyAssignedNodeCountsFromItsReport(t *testing.T) {
+	left := time.Date(2026, 10, 23, 6, 29, 18, 0, time.UTC)      // ace's report from its earlier run
+	assigned := time.Date(2026, 10, 25, 19, 56, 45, 0, time.UTC) // mesh-build-node assigned to ace again
+	report := func(t *testing.T, node, version string, at time.Time) (string, []byte) {
+		key, _ := gateReport(t, node, version)
+		value, err := delivery.EncodeToolchain(delivery.Toolchain{Language: "typescript", Version: version, Recipe: "f59571cf4be75adf", At: at})
+		if err != nil {
+			t.Fatal(err)
+		}
+		return key, value
+	}
+	for _, c := range []struct {
+		name       string
+		assignment string    // ace's assignment value
+		revision   time.Time // when the bus wrote it
+		at         time.Time // when ace wrote its report
+		counts     bool
+	}{
+		{"no report yet, then one", `{}`, time.Time{}, time.Now(), true},
+		{"a report left before the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, left, false},
+		{"a report left before a value with no time", `{"node":"ace","module":"mesh-build-node"}`, assigned, left, false},
+		{"a report written since the assignment", `{"node":"ace","module":"mesh-build-node","assigned":"2026-10-25T19:56:45Z"}`, assigned, assigned.Add(30 * time.Second), true},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			set := &buildrun.ToolchainSet{}
+			var said []string
+			gate := newToolchainGate([]string{buildrun.NodeBuildModule}, set.Put, func(f string, a ...any) { said = append(said, fmt.Sprintf(f, a...)) })
+			for _, node := range []string{"g14", "novox", "shanks"} {
+				gate.Assignment(node+".mesh-build-node", []byte(`{}`), false, time.Time{})
+				key, value := gateReport(t, node, "v26.12.1")
+				gate.Toolchain(buildrun.NodeBuildModule, key, value, false)
+			}
+			gate.Settled()
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision) {
+				t.Fatal("an assignment with no report passed something on")
+			}
+			key, value := report(t, "ace", "v26.12.0", c.at)
+			if got := gate.Toolchain(buildrun.NodeBuildModule, key, value, false); got != c.counts {
+				t.Fatalf("ace's report passed on: %v, want %v", got, c.counts)
+			}
+			// A rewrite of the assignment that does not move it changes nothing, and nothing is said again.
+			if gate.Assignment("ace.mesh-build-node", []byte(c.assignment), false, c.revision.Add(time.Minute)) {
+				t.Fatal("the same assignment written again changed what was passed on")
+			}
+			v, none := agreedOf(set)
+			if c.counts {
+				if !strings.HasPrefix(none, "builders disagree: v26.12.0 recipe f59571cf4be75adf on ace") {
+					t.Fatalf("ace's own report counts and disagrees; got %q, %q", v, none)
+				}
+				return
+			}
+			if v != "v26.12.1" || none != "" {
+				t.Fatalf("ace's left report is no builder's, so g14, novox and shanks agree; got %q, %q", v, none)
+			}
+			if len(said) != 1 || !strings.Contains(said[0], "before mesh-build-node's assignment on ace at 2026-10-25T19:56:45Z") {
+				t.Fatalf("said %q, want once why ace's report is left out", said)
+			}
+			// ace writes its report again since it was assigned: it counts.
+			key, value = report(t, "ace", "v26.12.1", assigned.Add(time.Minute))
+			if !gate.Toolchain(buildrun.NodeBuildModule, key, value, false) {
+				t.Fatal("ace's new report was not passed on")
+			}
+			if n := len(set.Entries("typescript")); n != 4 {
+				t.Fatalf("four builders report; got %d", n)
+			}
+		})
+	}
+}

modules/mesh-delivery-indexer/cmd/mesh-delivery-indexer/takein.go

@@ -14,6 +14,7 @@ import (
 // takerIn is the part of the indexer a takeins value asks through.
 type takerIn interface {
 	TakeIn(ctx context.Context, module string) index.TakenIn
+	RereadPlacement(ctx context.Context) index.PlacementReread
 }
 
 // takenIn answers one value of the takeins state (the tool indexer_take_in, issue 1945): a value not yet answered takes the
@@ -31,9 +32,15 @@ func takenIn(ctx context.Context, ix takerIn, kv jetstream.KeyValue, e jetstream
 	if !a.Answered.IsZero() {
 		return
 	}
-	r := ix.TakeIn(ctx, a.Module)
-	a.Result, a.Answered = &r, time.Now().UTC()
-	logf("%s: a take-in asked by %s (%s): %s", a.Module, a.By, a.Why, r.Answer)
+	if a.Placement {
+		r := ix.RereadPlacement(ctx)
+		a.Reread, a.Answered = &r, time.Now().UTC()
+		logf("a placement reread asked by %s (%s): %s", a.By, a.Why, r.Answer)
+	} else {
+		r := ix.TakeIn(ctx, a.Module)
+		a.Result, a.Answered = &r, time.Now().UTC()
+		logf("%s: a take-in asked by %s (%s): %s", a.Module, a.By, a.Why, r.Answer)
+	}
 	data, err := json.Marshal(a)
 	if err != nil {
 		return

modules/mesh-delivery-indexer/go.mod

@@ -3,7 +3,7 @@ module mesh-delivery-indexer
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-delivery-indexer/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a h1:nhRFmtdcI4VkghGUdJhpt1BnPuTQcekioOIRzW8fcG0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029200316-22c9ddd32b6a/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952 h1:TmveT3Bija643RGWkilvkzP/h8UWlVvHFZZtQfJK5oU=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261027193820-8ad9372b1952/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-delivery-indexer/internal/index/candidates.go

@@ -65,10 +65,19 @@ type Indexer struct {
 	// Contains says whether a commit is the second or an ancestor of it (gitea.gitea_contains).
 	Contains func(ctx context.Context, repository, commit, in string) (bool, error)
 	Logf     func(format string, args ...any)
-	// ReadOpen asks the forge which pull requests into the trunk are open now (gitea_open_pulls). A catalogue pull message
-	// that finds the candidates of another pull request asks it and deletes those of a pull request no longer open, so a
-	// closed message the indexer missed heals at the next one (issue 1126); nil asks none.
-	ReadOpen func(ctx context.Context) ([]delivery.OpenPull, error)
+	// Placement is the placement bucket (delivery.PlacementBucket, ADR 0549 §2); nil writes no placement.
+	Placement Store
+	// PlacementCandidates is the placement candidates bucket (delivery.PlacementCandidatesBucket, issue 1126); nil writes
+	// no candidate (placement_candidates.go).
+	PlacementCandidates Store
+	// ReadPlacement asks the forge for the catalogue's placement now, at the trunk's head and each open pull request's
+	// (indexer_placement_reread, ADR 0559 §8); nil rereads none.
+	ReadPlacement func(ctx context.Context) (PlacementRead, error)
+	// Say says one of the indexer's events (placement-changed); nil says none.
+	Say func(event string, body any) error
+	// Drained says whether the indexer has applied every message of the forge stream (the consumer has none pending and none
+	// unacknowledged); FillTaken writes the source's heads only then. Nil fills none from the source (taken.go).
+	Drained func(ctx context.Context) (bool, error)
 
 	mu         sync.Mutex // guards source, toolchains and previews, which the watches and the forge messages all reach
 	source     sourceNow
@@ -96,54 +105,47 @@ func (ix *Indexer) logf(format string, args ...any) {
 // by compare-and-set on the revision read, and read again on a conflict. A lone pull request is a group of one. A
 // merged message also writes the fingerprint of each module of its repository (modules.go).
 func (ix *Indexer) Apply(ctx context.Context, f delivery.Forge) error {
-	_, err := ix.ApplyMessage(ctx, f)
-	return err
-}
-
-// ApplyMessage is Apply, and answers which modules a merged message wrote and kept (for the indexer's heard state). Each
-// applied merged message is said in one line: its repository, commit and pull request, and the modules written.
-func (ix *Indexer) ApplyMessage(ctx context.Context, f delivery.Forge) (Applied, error) {
-	var applied Applied
 	if f.Kind == delivery.ForgeOpen {
-		return applied, ix.applyOpen(ctx, f)
+		return ix.applyOpen(ctx, f)
 	}
 	if f.Kind != delivery.ForgePull && f.Kind != delivery.ForgeMerged {
-		return applied, nil
+		return nil
 	}
 	if f.Kind == delivery.ForgeMerged && ix.Modules != nil {
-		w, err := ix.applyMerged(ctx, f)
-		applied = Applied{Written: w.written, Late: w.late}
-		if err != nil {
-			return applied, err
+		if err := ix.applyMerged(ctx, f); err != nil {
+			return err
 		}
-		ix.logf("%s", w.said(f.Number))
-		if w.late == "" { // a late message leaves the taken key, which names a later merge
-			if err := ix.writeTakenKnown(ctx, f, w.asked); err != nil {
-				return applied, err
-			}
+		if err := ix.writeTaken(ctx, f); err != nil {
+			return err
 		}
 		ix.kickRetry(ctx) // a registered module the forge could not read is read again on a merge, in the background (issue 1945)
 	}
+	if err := ix.applyPlacement(ctx, f); err != nil {
+		return err
+	}
+	if err := ix.applyPlacementCandidates(ctx, f); err != nil {
+		return err
+	}
 	var digests map[string]string
 	var held map[string]delivery.Module
 	if f.Kind == delivery.ForgePull {
 		var err error
 		if digests, err = ix.keepManifests(ctx, f); err != nil {
-			return applied, err
+			return err
 		}
 		if held, err = ix.heldModules(ctx); err != nil {
-			return applied, err
+			return err
 		}
 	}
 	if trunkLike[f.Branch] {
 		ix.logf("%s#%d: its branch %q is no delivery group, so no candidate", f.Repository, f.Number, f.Branch)
-		return applied, nil
+		return nil
 	}
 	key, err := delivery.CandidatesKey(f.Branch)
 	if err != nil {
-		return applied, fmt.Errorf("%w: %s#%d: %v", ErrUnreadable, f.Repository, f.Number, err)
+		return fmt.Errorf("%w: %s#%d: %v", ErrUnreadable, f.Repository, f.Number, err)
 	}
-	return applied, write(ctx, ix.Store, key, func(value []byte, found bool) ([]byte, bool, error) {
+	return write(ctx, ix.Store, key, func(value []byte, found bool) ([]byte, bool, error) {
 		var cur *delivery.Candidate
 		if found {
 			c, err := delivery.DecodeCandidate(value)
@@ -178,6 +180,14 @@ func (ix *Indexer) applyOpen(ctx context.Context, f delivery.Forge) error {
 	for _, p := range f.Open {
 		named[p] = true
 	}
+	if ix.PlacementCandidates != nil {
+		// A pull request the forge no longer has open keeps no placement candidate (issue 1126).
+		if err := ix.dropPlacementCandidates(ctx, func(_ string, c delivery.PlacementCandidate) bool {
+			return !named[delivery.OpenPull{Repository: c.Pull.Repository, Number: c.Pull.Number}]
+		}, "its pull request is not open"); err != nil {
+			return err
+		}
+	}
 	keys, err := ix.Store.Keys(ctx)
 	if err != nil {
 		return fmt.Errorf("listing the candidates: %w", err)

modules/mesh-delivery-indexer/internal/index/heard.go

@@ -1,60 +0,0 @@
-package index
-
-import (
-	"context"
-	"encoding/json"
-	"time"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-// What the indexer heard of the forge bridge's stream FORGE (issue 1126 note 76): no tool read FORGE's messages, so a merge
-// written back over a later one could not be traced to a late or repeated message. The indexer writes, for each message
-// it handles, one value under the key forge of its state heard: the message's subject, stream sequence, how often the
-// server delivered it, when it was published and handled, what it names and what the indexer did with it. The state keeps
-// the last 64 values (its history); mesh-delivery-view's indexer_heard reads them, newest first, with their times.
-const (
-	HeardState  = "heard"
-	HeardBucket = delivery.IndexerModule + "_" + HeardState
-	HeardKey    = "forge"
-	// What the indexer did with a message.
-	HeardApplied = "applied"
-	HeardLeft    = "left for redelivery"
-	HeardDropped = "dropped"
-)
-
-// Heard is one FORGE message as the indexer handled it.
-type Heard struct {
-	V          int       `json:"v"`
-	Subject    string    `json:"subject"`
-	Sequence   uint64    `json:"sequence"`            // the stream's sequence of the message
-	Delivered  uint64    `json:"delivered,omitempty"` // how often the server delivered it to the indexer, this time included
-	Published  time.Time `json:"published,omitzero"`
-	Handled    time.Time `json:"handled"`
-	Kind       string    `json:"kind,omitempty"`
-	Repository string    `json:"repository,omitempty"`
-	Number     int       `json:"number,omitempty"`
-	Branch     string    `json:"branch,omitempty"`
-	Commit     string    `json:"commit,omitempty"` // the merge commit of a merged message, else the pull request's head
-	Outcome    string    `json:"outcome"`
-	Words      string    `json:"words,omitempty"`   // why it was left or dropped
-	Written    []string  `json:"written,omitempty"` // the modules a merged message wrote
-	Late       string    `json:"late,omitempty"`    // the taken merge a merged message is older than: nothing of it was written (order.go)
-}
-
-// Applied is what Apply did with a merged message's modules: the keys written, and, for a message older than the
-// repository's taken merge, that merge (nothing was written).
-type Applied struct {
-	Written []string
-	Late    string
-}
-
-// WriteHeard writes h as the newest value of heard.forge.
-func WriteHeard(ctx context.Context, st Store, h Heard) error {
-	h.V = 1
-	data, err := json.Marshal(h)
-	if err != nil {
-		return err
-	}
-	return write(ctx, st, HeardKey, func([]byte, bool) ([]byte, bool, error) { return data, false, nil })
-}

modules/mesh-delivery-indexer/internal/index/manifests_test.go

@@ -43,6 +43,8 @@ func withManifests(f delivery.Forge, manifests map[string]string, locks map[stri
 }
 
 func TestAMergedManifestIsKeptByItsDigestAndNamedByTheModule(t *testing.T) { // 1449/AC1
+	// A merge's placement files are written as its manifests are (issue 1126): folded here to hold the count.
+	placementIsWrittenAtAMergeOnlyWhereItChanged(t)
 	avahi := catalogueManifest(t, "avahi")
 	ix, mods, manifests := manifestsIndexer(t, rec(t, "build-1", "avahi", catalogueRepo, "modules/avahi", "main", "", "2026-10-19T09:00:00Z", aInputs))
 	f := withManifests(mergedMsg(catalogueRepo, map[string]string{"modules/avahi": "newtree"}), map[string]string{"modules/avahi": avahi}, nil)

modules/mesh-delivery-indexer/internal/index/modules.go

@@ -24,30 +24,21 @@ import (
 // clause 7). Two directories naming one module write the one the bucket holds, or the first by name, and say the other.
 // A value the module already holds but for its commit is not written again: its commit stays the one its fingerprint first
 // appeared at (writeOverlay), so a merge writes only the modules it changes.
-//
-// A merge never moves a module backwards (order.go): a merged message older than the repository's taken merge writes and
-// deletes nothing, and is said; it is asked once, before anything is written.
-func (ix *Indexer) applyMerged(ctx context.Context, f delivery.Forge) (*mergeWrite, error) {
+func (ix *Indexer) applyMerged(ctx context.Context, f delivery.Forge) error {
 	return ix.applyManifests(ctx, f, true)
 }
 
 // applyManifests is applyMerged; drop says whether the modules of the repository the message holds no manifest for are
 // deleted. A message that names only some of a repository's modules (a registered module read on its own, registered.go)
 // drops none.
-func (ix *Indexer) applyManifests(ctx context.Context, f delivery.Forge, drop bool) (*mergeWrite, error) {
-	w := newMergeWrite(f)
-	if drop {
-		if err := ix.lateMerge(ctx, w); err != nil || w.late != "" {
-			return w, err
-		}
-	}
+func (ix *Indexer) applyManifests(ctx context.Context, f delivery.Forge, drop bool) error {
 	digests, err := ix.keepManifests(ctx, f)
 	if err != nil {
-		return w, err
+		return err
 	}
 	held, err := ix.heldModules(ctx)
 	if err != nil {
-		return w, err
+		return err
 	}
 	objects, namedErr := ix.namedObjects(ctx, f)
 	overlay := map[string]delivery.Module{}
@@ -102,11 +93,11 @@ func (ix *Indexer) applyManifests(ctx context.Context, f delivery.Forge, drop bo
 	// (issue 1900). A message that carries no manifests (an older writer) or one that cannot be read whole says nothing.
 	if drop && len(f.Manifests) > 0 && every {
 		if err := ix.dropRemoved(ctx, f.Repository, held, func(key string, _ delivery.Module) bool { return named[key] }); err != nil {
-			return w, err
+			return err
 		}
 	}
 	// What this merge moved reaches the modules standing on it (a base's tree, build-agent's fingerprint), in the graph's order.
-	return w, ix.recomputeWith(ctx, overlay, w)
+	return ix.recomputeWith(ctx, overlay)
 }
 
 // baseFP answers the new-form fingerprint of a base module as modules.<base> holds it, or why it has none.

modules/mesh-delivery-indexer/internal/index/modules_test.go

@@ -3,8 +3,6 @@ package index
 import (
 	"context"
 	"encoding/json"
-	"errors"
-	"fmt"
 	"path"
 	"strings"
 	"testing"
@@ -99,17 +97,10 @@ func TestAnUnchangedModuleWritesNothing(t *testing.T) { // 1239 (unchanged value
 		commit map[string]string
 		// taken is the merge the repository's taken key names after then (issue 1280, ADR 0556 clause 1).
 		taken string
-		// err says then fails (the message is left for redelivery); said is a line the indexer's log (or that error) must hold.
-		err  bool
-		said string
-		// contains, when set, is the forge's order, and asks how often then asks it (one question per merged message).
-		contains func(context.Context, string, string, string) (bool, error)
-		asks     int
 	}{
 		{name: "the same merge again", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: merge,
 			then: func(ix *Indexer) error { return ix.Apply(context.Background(), mergedMsg(repo, three)) }},
 		{name: "a merge touching one of three modules", writes: 1, commit: map[string]string{"a": next, "b": merge, "c": merge}, taken: next,
-			said: "novox/mesh-delivery at cccccccccccc (#12): merged message applied; modules written: a",
 			then: func(ix *Indexer) error {
 				m := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
 				m.Merge = next
@@ -148,30 +139,32 @@ func TestAnUnchangedModuleWritesNothing(t *testing.T) { // 1239 (unchanged value
 		{name: "a source head whose merge was not applied is not a taken key", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: "",
 			then: func(ix *Indexer) error { // the forge stream still holds the merge: the consumer is not drained
 				delete(ix.Taken.(*memStore).vals, takenKey(repo))
+				ix.Drained = func(context.Context) (bool, error) { return false, nil }
 				if err := ix.ApplySource(context.Background(), 8, sourceOf(repo, next)); err != nil {
 					return err
 				}
 				return ix.FillTaken(context.Background())
 			}},
-		// Issue 1126 (mesh-catalog#535): the forge bridge never wrote the merged message of 9fd9569, so the forge stream was
-		// drained with the merge not applied; the source head moved the key all the same, and the view said the merge was
-		// on the machines. A key moves only by a merge applied (ADR 0556 clause 1), never by the source's word.
-		{name: "a source head of a drained forge stream whose merge was never heard leaves the key", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: merge,
-			then: func(ix *Indexer) error {
-				ix.Contains = func(_ context.Context, _, commit, in string) (bool, error) { return commit == merge && in == next, nil }
-				if err := ix.ApplySource(context.Background(), 8, sourceOf(repo, next)); err != nil {
-					return err
-				}
-				return ix.FillTaken(context.Background())
-			}},
-		{name: "a source head of a drained forge stream fills no missing key", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: "",
+		{name: "a source head of a drained forge stream fills a missing key", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: next,
 			then: func(ix *Indexer) error {
 				delete(ix.Taken.(*memStore).vals, takenKey(repo))
+				ix.Drained = func(context.Context) (bool, error) { return true, nil }
 				if err := ix.ApplySource(context.Background(), 8, sourceOf(repo, next)); err != nil {
 					return err
 				}
 				return ix.FillTaken(context.Background())
 			}},
+		{name: "filling from an older source head leaves a later key", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: next,
+			then: func(ix *Indexer) error {
+				ix.Contains = func(_ context.Context, _, commit, in string) (bool, error) { return commit == merge && in == next, nil }
+				m := mergedMsg(repo, three)
+				m.Merge = next
+				if err := ix.Apply(context.Background(), m); err != nil {
+					return err
+				}
+				ix.Drained = func(context.Context) (bool, error) { return true, nil }
+				return ix.FillTaken(context.Background()) // the source still names merge
+			}},
 		{name: "an earlier merge heard again after a later one leaves taken", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: merge,
 			then: func(ix *Indexer) error {
 				ix.Contains = func(_ context.Context, _, commit, in string) (bool, error) { return commit == next && in == merge, nil }
@@ -179,78 +172,6 @@ func TestAnUnchangedModuleWritesNothing(t *testing.T) { // 1239 (unchanged value
 				m.Merge = next
 				return ix.Apply(context.Background(), m)
 			}},
-		// Issue 1126 note 76: mesh-catalog's merge 9cdac09a was written back over the later 69056948, rolling kernel and
-		// mesh-build-image back on the nodes. A merge never moves a module backwards: the held commit must be in the incoming one.
-		{name: "an earlier merge heard again after a later one moves no module back", writes: 1, commit: map[string]string{"a": next, "b": merge, "c": merge}, taken: next,
-			said: "the merged message is older than taken.novox/mesh-delivery at cccccccccccc",
-			then: func(ix *Indexer) error {
-				ix.Contains = func(_ context.Context, _, commit, in string) (bool, error) {
-					return commit == in || commit == merge && in == next, nil
-				}
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
-				later.Merge = next
-				if err := ix.Apply(context.Background(), later); err != nil {
-					return err
-				}
-				return ix.Apply(context.Background(), mergedMsg(repo, three))
-			}},
-		{name: "an earlier merge that lacks a later merge's module deletes nothing", writes: 1, commit: map[string]string{"a": merge, "d": next}, taken: next,
-			said: "the merged message is older than taken.novox/mesh-delivery at cccccccccccc",
-			then: func(ix *Indexer) error {
-				ix.Contains = func(_ context.Context, _, commit, in string) (bool, error) {
-					return commit == in || commit == merge && in == next, nil
-				}
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA", "modules/b": "treeB", "modules/c": "treeC", "modules/d": "treeD"})
-				later.Merge = next
-				if err := ix.Apply(context.Background(), later); err != nil {
-					return err
-				}
-				return ix.Apply(context.Background(), mergedMsg(repo, three))
-			}},
-		// Review round 2: a 502 whose words carry "404" inside a sha is no not-found; the late message is left for redelivery.
-		{name: "a late message whose order the forge fails with a 502 writes nothing and is left for redelivery", writes: 1, commit: map[string]string{"a": next, "b": merge, "c": merge}, taken: next, err: true,
-			said: "502 Bad Gateway",
-			then: func(ix *Indexer) error {
-				ix.Contains = func(context.Context, string, string, string) (bool, error) { return false, nil }
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
-				later.Merge = next
-				if err := ix.Apply(context.Background(), later); err != nil {
-					return err
-				}
-				ix.Contains = func(context.Context, string, string, string) (bool, error) {
-					return false, errors.New("Gitea API /repos/x/y/compare/aaa404aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb: 502 Bad Gateway")
-				}
-				return ix.Apply(context.Background(), mergedMsg(repo, three))
-			}},
-		{name: "a forge that cannot say the order writes nothing and leaves the message for redelivery", writes: 0, commit: map[string]string{"a": merge}, taken: merge, err: true,
-			said: "cannot be read",
-			then: func(ix *Indexer) error {
-				ix.Contains = func(context.Context, string, string, string) (bool, error) {
-					return false, errors.New("the forge did not answer")
-				}
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
-				later.Merge = next
-				return ix.Apply(context.Background(), later)
-			}},
-		// Review of 77d738d: only a merge older than the one taken in is kept back. A diverged or rewritten history, or a
-		// taken merge the forge no longer has, is not older, and one question per message is asked.
-		{name: "a merge of a diverged history is written, asking the forge once", writes: 1, commit: map[string]string{"a": next, "b": merge, "c": merge}, taken: next,
-			contains: func(context.Context, string, string, string) (bool, error) { return false, nil }, asks: 1,
-			then: func(ix *Indexer) error {
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
-				later.Merge = next
-				return ix.Apply(context.Background(), later)
-			}},
-		{name: "a taken merge the forge no longer has stops no later merge", writes: 1, commit: map[string]string{"a": next, "b": merge, "c": merge}, taken: next,
-			said: "is not known to be older",
-			then: func(ix *Indexer) error {
-				ix.Contains = func(context.Context, string, string, string) (bool, error) {
-					return false, errors.New("gitea_contains: the forge answered: 404 Not Found")
-				}
-				later := mergedMsg(repo, map[string]string{"modules/a": "treeA2", "modules/b": "treeB", "modules/c": "treeC"})
-				later.Merge = next
-				return ix.Apply(context.Background(), later)
-			}},
 		{name: "a later source revision of another repository's merge", writes: 0, commit: map[string]string{"a": merge, "b": merge, "c": merge}, taken: merge,
 			then: func(ix *Indexer) error {
 				return ix.ApplySource(context.Background(), 9, delivery.Source{Group: "g", Heads: map[string]string{repo: merge, "novox/mesh-catalog": otherMerge}})
@@ -268,27 +189,8 @@ func TestAnUnchangedModuleWritesNothing(t *testing.T) { // 1239 (unchanged value
 				t.Fatal(err)
 			}
 			writes := mods.writes
-			asks := 0
-			if tc.contains != nil {
-				ix.Contains = func(ctx context.Context, repo, commit, in string) (bool, error) {
-					asks++
-					return tc.contains(ctx, repo, commit, in)
-				}
-			}
-			var said strings.Builder
-			ix.Logf = func(format string, args ...any) { fmt.Fprintf(&said, format+"\n", args...) }
-			err := tc.then(ix)
-			if tc.contains != nil && asks != tc.asks {
-				t.Errorf("the forge was asked %d times, want %d", asks, tc.asks)
-			}
-			if (err != nil) != tc.err {
-				t.Fatalf("then = %v, want an error %v", err, tc.err)
-			}
-			if err != nil {
-				said.WriteString(err.Error()) // what handle logs as left for redelivery
-			}
-			if !strings.Contains(said.String(), tc.said) {
-				t.Errorf("the log %q does not say %q", said.String(), tc.said)
+			if err := tc.then(ix); err != nil {
+				t.Fatal(err)
 			}
 			if got := mods.writes - writes; got != tc.writes {
 				t.Errorf("%d values written, want %d", got, tc.writes)

modules/mesh-delivery-indexer/internal/index/order.go

@@ -1,118 +0,0 @@
-package index
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"slices"
-	"strings"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-	"git.novox.be/novox/mesh-sdk/go/process"
-)
-
-// A merge never moves a module backwards (issue 1126, note 76). The indexer wrote mesh-catalog's merge 9cdac09a back over
-// the later 69056948 for kernel and mesh-build-image: applyManifests and writeOverlay wrote whatever commit a merged
-// message carried, so a late or repeated message rolled the modules, and the nodes that want them, back.
-//
-// The question is whether the incoming commit is OLDER: the forge says the incoming commit is in the later one and the
-// two differ (Contains(incoming, in: later)). Only then is it kept back. A diverged or rewritten history answers no, and
-// is written forward; a commit the forge no longer has (a 404) is not known to be older, is written, and said. A forge
-// that cannot say for another reason (a timeout) writes nothing and is an error: the server delivers the message again.
-//
-//   - A merged message asks once, before it writes anything: is its merge older than the repository's taken merge (the
-//     last merge applied whole, taken.go)? Then the whole message is late: no module is written or deleted, the taken key
-//     stays, and the log says so.
-//   - A take-in of a held module asks once for that module: is the source's head older than the module's record
-//     (takeInHeld)?
-
-// mergeWrite is one merge's write of the modules: its repository and commit, whether it is late (older than the taken
-// merge), the taken merge it was compared with and the answer, and the module keys written, for the line the indexer says
-// per applied merged message.
-type mergeWrite struct {
-	repository, merge string
-	late              string // the taken merge this one is older than, or ""
-	asked             string // the taken merge the order was asked against, or "" when none was asked
-	written           []string
-}
-
-func newMergeWrite(f delivery.Forge) *mergeWrite {
-	return &mergeWrite{repository: f.Repository, merge: f.Merge}
-}
-
-// notFound says the forge answered that a commit it was asked about does not exist: gitea's status ": 404 ", matched as
-// readVia matches it (cmd/mesh-delivery-indexer named.go). A bare "404" is not enough: the error's words carry both shas,
-// and a 502 naming a sha with 404 in it would read as not older and write a late message backwards. The thorough form,
-// a typed not-found answered by gitea_contains, is noted on issue 1126.
-func notFound(err error) bool { return err != nil && strings.Contains(err.Error(), ": 404 ") }
-
-// older says commit is older than later: the forge says commit is in later and the two differ. A commit the forge does not
-// have is not known to be older (false, said); a forge that cannot say otherwise is an error. Without a forge to ask
-// (Contains nil) nothing is older.
-func (ix *Indexer) older(ctx context.Context, repository, commit, later string) (bool, error) {
-	if ix.Contains == nil || commit == "" || later == "" || commit == later {
-		return false, nil
-	}
-	in, err := ix.Contains(ctx, repository, commit, later)
-	if notFound(err) {
-		ix.logf("%s: the forge does not have %.12s or %.12s (a rewritten history?), so %.12s is not known to be older and is written: %v", repository, commit, later, commit, err)
-		return false, nil
-	}
-	if err != nil {
-		return false, fmt.Errorf("%s: whether %.12s is older than %.12s cannot be read, so nothing of it is written (a merge never moves a module backwards, issue 1126): %w", repository, commit, later, err)
-	}
-	return in, nil
-}
-
-// lateMerge asks, before a merged message writes anything, whether its merge is older than the repository's taken merge
-// (one forge call). A taken state not on the bus yet, or no taken key, asks nothing.
-func (ix *Indexer) lateMerge(ctx context.Context, w *mergeWrite) error {
-	if ix.Taken == nil || w.merge == "" {
-		return nil
-	}
-	key, err := delivery.RepositoryKey(w.repository)
-	if err != nil {
-		return nil // writeTaken says it
-	}
-	value, _, found, err := ix.Taken.Get(ctx, key)
-	if errors.Is(err, process.ErrNotYet) || !found {
-		return nil
-	}
-	if err != nil {
-		return fmt.Errorf("taken.%s: %w", key, err)
-	}
-	cur, err := delivery.DecodeTaken(value)
-	if err != nil || cur.Merge == "" || cur.Merge == w.merge {
-		return nil
-	}
-	old, err := ix.older(ctx, w.repository, w.merge, cur.Merge)
-	if err != nil {
-		return err
-	}
-	w.asked = cur.Merge
-	if old {
-		w.late = cur.Merge
-		ix.logf("%s at %.12s: the merged message is older than taken.%s at %.12s, so no module is written or deleted (a late or repeated message; a merge never moves a module backwards, issue 1126)",
-			w.repository, w.merge, key, cur.Merge)
-	}
-	return nil
-}
-
-// wrote records a module key the merge wrote.
-func (w *mergeWrite) wrote(key string) {
-	if w != nil && !slices.Contains(w.written, key) {
-		w.written = append(w.written, key)
-	}
-}
-
-// said is the line of an applied merged message: its repository, commit and pull request, and the modules written.
-func (w *mergeWrite) said(number int) string {
-	if w.late != "" {
-		return fmt.Sprintf("%s at %.12s (#%d): merged message applied as late: older than the taken %.12s, nothing written", w.repository, w.merge, number, w.late)
-	}
-	written := "none"
-	if len(w.written) > 0 {
-		written = strings.Join(slices.Sorted(slices.Values(w.written)), ", ")
-	}
-	return fmt.Sprintf("%s at %.12s (#%d): merged message applied; modules written: %s", w.repository, w.merge, number, written)
-}

modules/mesh-delivery-indexer/internal/index/placement.go

@@ -0,0 +1,123 @@
+package index
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"maps"
+	"slices"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/process"
+)
+
+// Placement of modules on nodes (novox/hq ADR 0549 §2, issue 1126): at each merge of the catalogue the forge bridge
+// carries every placement file of the merge commit, and the indexer writes each node's key `placement.<node>` in its
+// state `placement` only when it differs (the revision alone is no change), deletes the key of a node whose file is
+// gone, and says `placement-changed` for each node it wrote or deleted, naming the modules added, removed or changed.
+// A merge that changes no placement writes nothing and says nothing.
+//
+// A file that does not read as a placement, or names another node than its file, is said in the log and its key is left
+// as it was: the catalogue's own check refuses such a file before it merges (ADR 0549 §1), so it is a fault of that
+// check, and a node keeps composing from the placement it had rather than from none.
+
+// applyPlacement takes the placement files of a merged message in; a message that read none (another repository, an
+// older bridge) changes nothing.
+func (ix *Indexer) applyPlacement(ctx context.Context, f delivery.Forge) error {
+	if ix.Placement == nil || f.Kind != delivery.ForgeMerged || !f.PlacementsRead {
+		return nil
+	}
+	keys, err := ix.Placement.Keys(ctx)
+	if errors.Is(err, process.ErrNotYet) {
+		// The state is not on the bus yet: said, and the merge's candidates are still taken out (issue 1790's binding
+		// writes the next catalogue merge's placement once it appears).
+		ix.logf("%s at %s: its placement files are not written: %v", f.Repository, f.Merge, err)
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("reading the placement keys: %w", err)
+	}
+	gone := map[string]bool{}
+	for _, key := range keys {
+		if node, err := delivery.ParsePlacementKey(key); err == nil {
+			gone[node] = true
+		}
+	}
+	var refused []string
+	for _, node := range slices.Sorted(maps.Keys(f.Placements)) {
+		delete(gone, node)
+		next, err := delivery.DecodePlacement([]byte(f.Placements[node]))
+		if err == nil && next.Node != node {
+			err = fmt.Errorf("the file of %s names the node %q", node, next.Node)
+		}
+		if err != nil {
+			refused = append(refused, node)
+			ix.logf("%s at %s: the placement file of %s is refused and placement.%s is left as it was (the catalogue's check should have refused it): %v",
+				f.Repository, f.Merge, node, node, err)
+			continue
+		}
+		next.Revision = f.Merge
+		if err := ix.writePlacement(ctx, node, &next); err != nil {
+			return err
+		}
+	}
+	for _, node := range slices.Sorted(maps.Keys(gone)) {
+		if err := ix.writePlacement(ctx, node, nil); err != nil {
+			return err
+		}
+	}
+	if len(refused) > 0 {
+		// Said, and the merge's candidates are still taken out: a refused file holds nobody's delivery.
+		ix.logf("%s at %s: the placement files of %v do not read; their keys are left as they were", f.Repository, f.Merge, refused)
+	}
+	return nil
+}
+
+// writePlacement writes one node's key, or deletes it for next nil, only when it differs, and says what changed.
+func (ix *Indexer) writePlacement(ctx context.Context, node string, next *delivery.Placement) error {
+	key, err := delivery.PlacementKey(node)
+	if err != nil {
+		return err
+	}
+	var change *delivery.PlacementChange
+	err = write(ctx, ix.Placement, key, func(value []byte, found bool) ([]byte, bool, error) {
+		change = nil
+		var before delivery.Placement
+		if found {
+			cur, err := delivery.DecodePlacement(value)
+			if err != nil {
+				ix.logf("placement.%s holds what is not a placement, written again: %v", node, err)
+			} else {
+				before = cur
+			}
+		}
+		if next == nil {
+			if !found {
+				return nil, false, nil
+			}
+			c := delivery.ChangeOf(before, delivery.Placement{Node: node})
+			change = &c
+			return nil, true, nil
+		}
+		if found && delivery.SamePlacement(before, *next) {
+			return nil, false, nil
+		}
+		data, err := delivery.EncodePlacement(*next)
+		if err != nil {
+			return nil, false, err
+		}
+		c := delivery.ChangeOf(before, *next)
+		change = &c
+		return data, false, nil
+	})
+	if err != nil || change == nil {
+		return err
+	}
+	if ix.Say != nil {
+		if err := ix.Say(delivery.PlacementChangedEvent, *change); err != nil {
+			// The key is written: a reader that watches it hears the change; the event is said loudly as not said.
+			ix.logf("placement.%s is written, and %s could not be said: %v", node, delivery.PlacementChangedEvent, err)
+		}
+	}
+	return nil
+}

modules/mesh-delivery-indexer/internal/index/placement_candidates.go

@@ -0,0 +1,302 @@
+package index
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"maps"
+	"slices"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/process"
+)
+
+// Placement candidates (issue 1126; novox/hq ADR 0549 §4: a placement change passes the composition check before any
+// node sees it). An updated pull request of the catalogue that touches placement/ carries every placement file at its
+// head (the forge bridge, PlacementsRead). For each node whose file at the head differs from the trunk's key
+// `placement.<node>` (SamePlacement, the revision left out), or whose file the head removes, the indexer writes the key
+// `<group>.<node>` of its state `placement-candidates`; a node whose file is the trunk's has none, and a key the head no
+// longer needs is deleted. The key is written only when its value changes, so its write is the node's event to compose
+// in shadow and answer. When the pull request closes or merges, or an open message no longer names it, its keys are
+// deleted, and so are they when a head the forge says the changes of (DirsKnown) carries no placement: it touches none.
+// A pull message that says nothing of its head (a resend of the open pull requests) leaves them as they are.
+//
+// A file at the head that does not read as a placement, or names another node, is said in the log and that node gets no
+// key (one it had is deleted): the catalogue's own check refuses the pull request (ADR 0549 §1), and a node answers no
+// candidate that is not one.
+
+// applyPlacementCandidates takes one forge message into the placement candidates.
+func (ix *Indexer) applyPlacementCandidates(ctx context.Context, f delivery.Forge) error {
+	if ix.PlacementCandidates == nil || !delivery.SameRepository(f.Repository, delivery.CatalogueRepository) || trunkLike[f.Branch] {
+		return nil
+	}
+	if f.Kind == delivery.ForgeMerged || f.Action == delivery.PullClosed {
+		return ix.dropPlacementCandidates(ctx, func(_ string, c delivery.PlacementCandidate) bool {
+			return c.Group == f.Branch && delivery.SameRepository(c.Pull.Repository, f.Repository) && c.Pull.Number == f.Number
+		}, fmt.Sprintf("%s#%d %s", f.Repository, f.Number, map[bool]string{true: "merged", false: "closed"}[f.Kind == delivery.ForgeMerged]))
+	}
+	if f.Kind != delivery.ForgePull {
+		return nil
+	}
+	if !f.PlacementsRead {
+		if f.DirsKnown {
+			// The forge said what this head changes (its directories and paths) and the bridge read no placement: the head
+			// changes no placement file, so a key an earlier head left goes (ADR 0559 §3).
+			return ix.dropPlacementCandidates(ctx, func(_ string, c delivery.PlacementCandidate) bool {
+				return c.Group == f.Branch && delivery.SameRepository(c.Pull.Repository, f.Repository) && c.Pull.Number == f.Number
+			}, fmt.Sprintf("%s#%d at %s changes no placement file", f.Repository, f.Number, f.Head))
+		}
+		return nil
+	}
+	trunk, err := ix.trunkPlacements(ctx)
+	if err != nil {
+		ix.logf("%s#%d at %s: its placement candidates are not written: %v", f.Repository, f.Number, f.Head, err)
+		return nil
+	}
+	nodes := map[string]bool{}
+	for node := range f.Placements {
+		nodes[node] = true
+	}
+	for node := range trunk {
+		nodes[node] = true
+	}
+	pull := delivery.Head{Repository: f.Repository, Number: f.Number, Head: f.Head}
+	for _, node := range slices.Sorted(maps.Keys(nodes)) {
+		key, err := delivery.PlacementCandidateKey(f.Branch, node)
+		if err != nil {
+			return fmt.Errorf("%w: %s#%d: %v", ErrUnreadable, f.Repository, f.Number, err)
+		}
+		var next *delivery.PlacementCandidate // nil: no key for this node
+		raw, atHead := f.Placements[node]
+		before, inTrunk := trunk[node]
+		switch {
+		case atHead:
+			p, err := delivery.DecodePlacement([]byte(raw))
+			if err == nil && p.Node != node {
+				err = fmt.Errorf("the file of %s names the node %q", node, p.Node)
+			}
+			if err != nil {
+				ix.logf("%s#%d at %s: the placement file of %s is refused, so %s has no placement candidate (the catalogue's check refuses the pull request): %v",
+					f.Repository, f.Number, f.Head, node, node, err)
+				break
+			}
+			if inTrunk && delivery.SamePlacement(before, p) {
+				break
+			}
+			next = &delivery.PlacementCandidate{Group: f.Branch, Pull: pull, Placement: &p}
+		case inTrunk:
+			next = &delivery.PlacementCandidate{Group: f.Branch, Pull: pull} // the head removes the node's file
+		}
+		if err := ix.writePlacementCandidate(ctx, key, next); err != nil {
+			return err
+		}
+	}
+	// A node the head and the trunk both no longer name keeps no key of this group.
+	return ix.dropPlacementCandidates(ctx, func(node string, c delivery.PlacementCandidate) bool {
+		return c.Group == f.Branch && delivery.SameRepository(c.Pull.Repository, f.Repository) && c.Pull.Number == f.Number && !nodes[node]
+	}, fmt.Sprintf("%s#%d at %s", f.Repository, f.Number, f.Head))
+}
+
+// trunkPlacements is every node's placement in the trunk's state placement, by node.
+func (ix *Indexer) trunkPlacements(ctx context.Context) (map[string]delivery.Placement, error) {
+	out := map[string]delivery.Placement{}
+	if ix.Placement == nil {
+		return nil, errors.New("the indexer reads no placement state")
+	}
+	keys, err := ix.Placement.Keys(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("reading the placement keys: %w", err)
+	}
+	for _, key := range keys {
+		node, err := delivery.ParsePlacementKey(key)
+		if err != nil {
+			continue
+		}
+		value, _, found, err := ix.Placement.Get(ctx, key)
+		if err != nil {
+			return nil, fmt.Errorf("reading %s: %w", key, err)
+		}
+		if !found {
+			continue
+		}
+		p, err := delivery.DecodePlacement(value)
+		if err != nil {
+			return nil, fmt.Errorf("%s holds what is not a placement: %w", key, err)
+		}
+		out[node] = p
+	}
+	return out, nil
+}
+
+// writePlacementCandidate writes one candidate key, or deletes it for next nil, only when it changes.
+func (ix *Indexer) writePlacementCandidate(ctx context.Context, key string, next *delivery.PlacementCandidate) error {
+	var data []byte
+	if next != nil {
+		var err error
+		if data, err = delivery.EncodePlacementCandidate(*next); err != nil {
+			return fmt.Errorf("%w: %s.%s: %v", ErrUnreadable, delivery.PlacementCandidatesState, key, err)
+		}
+	}
+	err := write(ctx, ix.PlacementCandidates, key, func(value []byte, found bool) ([]byte, bool, error) {
+		switch {
+		case next == nil:
+			return nil, found, nil
+		case found && string(value) == string(data):
+			return nil, false, nil
+		}
+		return data, false, nil
+	})
+	if errors.Is(err, process.ErrNotYet) {
+		ix.logf("%s.%s is not written: %v", delivery.PlacementCandidatesState, key, err)
+		return nil
+	}
+	return err
+}
+
+// dropPlacementCandidates deletes every candidate key whose node and value gone says, and says each with why.
+func (ix *Indexer) dropPlacementCandidates(ctx context.Context, gone func(node string, c delivery.PlacementCandidate) bool, why string) error {
+	keys, err := ix.PlacementCandidates.Keys(ctx)
+	if errors.Is(err, process.ErrNotYet) {
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("reading the placement candidate keys: %w", err)
+	}
+	for _, key := range keys {
+		_, node, err := delivery.ParsePlacementCandidateKey(key)
+		if err != nil {
+			continue
+		}
+		dropped := false
+		err = write(ctx, ix.PlacementCandidates, key, func(value []byte, found bool) ([]byte, bool, error) {
+			if !found {
+				return nil, false, nil
+			}
+			c, err := delivery.DecodePlacementCandidate(value)
+			if err != nil {
+				ix.logf("%s.%s holds what is not a placement candidate, deleted: %v", delivery.PlacementCandidatesState, key, err)
+				return nil, true, nil
+			}
+			dropped = gone(node, c)
+			return nil, dropped, nil
+		})
+		if err != nil {
+			return err
+		}
+		if dropped {
+			ix.logf("%s.%s is deleted: %s", delivery.PlacementCandidatesState, key, why)
+		}
+	}
+	return nil
+}
+
+// PlacementRead is the catalogue's placement as the forge has it now (indexer_placement_reread, ADR 0559 §8): the trunk's
+// head and every placement file at it, by node, and each open pull request into the trunk with its own.
+type PlacementRead struct {
+	Trunk string
+	Files map[string]string
+	Pulls []PullPlacement
+}
+
+// PullPlacement is one open catalogue pull request and every placement file at its head, by node.
+type PullPlacement struct {
+	Branch string
+	Number int
+	Head   string
+	Files  map[string]string
+}
+
+// PlacementReread is the answer of indexer_placement_reread: the heads read, the keys written or deleted in each state,
+// and in words what happened.
+type PlacementReread struct {
+	Trunk      string   `json:"trunk,omitempty"`
+	Pulls      []string `json:"pulls,omitempty"`
+	Placement  []string `json:"placement"`
+	Candidates []string `json:"candidates"`
+	Answer     string   `json:"answer"`
+}
+
+// RereadPlacement reads the catalogue's placement now, at the trunk's head and at the head of each open catalogue pull
+// request, and writes placement and placement-candidates as a merged and a pull message would (ADR 0549 §2, ADR 0559
+// §3), only where a key differs; a candidate key of a pull request that is no longer open, or whose file no longer
+// differs at its head, is deleted. It is the recovery for a forge message the indexer missed (ADR 0559 §8).
+func (ix *Indexer) RereadPlacement(ctx context.Context) PlacementReread {
+	out := PlacementReread{Placement: []string{}, Candidates: []string{}}
+	if ix.ReadPlacement == nil || ix.Placement == nil || ix.PlacementCandidates == nil {
+		out.Answer = "the indexer reads no placement here: it has no forge reader or no placement state"
+		return out
+	}
+	read, err := ix.ReadPlacement(ctx)
+	if err != nil {
+		out.Answer = "the forge could not say the catalogue's placement, nothing is written: " + err.Error()
+		return out
+	}
+	out.Trunk = read.Trunk
+	before := revisions(ctx, ix.Placement)
+	beforeC := revisions(ctx, ix.PlacementCandidates)
+	if err := ix.applyPlacement(ctx, delivery.Forge{Kind: delivery.ForgeMerged, Repository: delivery.CatalogueRepository, Merge: read.Trunk,
+		Placements: read.Files, PlacementsRead: true}); err != nil {
+		out.Answer = "the trunk's placement could not be written: " + err.Error()
+		return out
+	}
+	open := map[int]bool{}
+	var failed []string
+	for _, p := range read.Pulls {
+		open[p.Number] = true
+		out.Pulls = append(out.Pulls, fmt.Sprintf("%s#%d at %s", delivery.CatalogueRepository, p.Number, p.Head))
+		f := delivery.Forge{Kind: delivery.ForgePull, Repository: delivery.CatalogueRepository, Branch: p.Branch, Number: p.Number, Head: p.Head,
+			Action: delivery.PullUpdated, Placements: p.Files, PlacementsRead: true}
+		if err := ix.applyPlacementCandidates(ctx, f); err != nil {
+			failed = append(failed, fmt.Sprintf("#%d: %v", p.Number, err))
+		}
+	}
+	if err := ix.dropPlacementCandidates(ctx, func(_ string, c delivery.PlacementCandidate) bool {
+		return delivery.SameRepository(c.Pull.Repository, delivery.CatalogueRepository) && !open[c.Pull.Number]
+	}, "its pull request is not open (indexer_placement_reread)"); err != nil {
+		failed = append(failed, err.Error())
+	}
+	out.Placement = changed(before, revisions(ctx, ix.Placement))
+	out.Candidates = changed(beforeC, revisions(ctx, ix.PlacementCandidates))
+	switch {
+	case len(failed) > 0:
+		out.Answer = "read at the trunk's head " + read.Trunk + "; some candidates are not written: " + fmt.Sprint(failed)
+	case len(out.Placement)+len(out.Candidates) == 0:
+		out.Answer = "read at the trunk's head " + read.Trunk + " and every open catalogue pull request's: every key was as the forge has it, nothing written"
+	default:
+		out.Answer = fmt.Sprintf("read at the trunk's head %s and every open catalogue pull request's: %d placement keys and %d candidate keys written or deleted",
+			read.Trunk, len(out.Placement), len(out.Candidates))
+	}
+	return out
+}
+
+// revisions is every key of a store with its revision; a state not on the bus yet has none.
+func revisions(ctx context.Context, st Store) map[string]uint64 {
+	out := map[string]uint64{}
+	keys, err := st.Keys(ctx)
+	if err != nil {
+		return out
+	}
+	for _, key := range keys {
+		if _, rev, found, err := st.Get(ctx, key); err == nil && found {
+			out[key] = rev
+		}
+	}
+	return out
+}
+
+// changed is every key written, created or deleted between two revisions maps, sorted.
+func changed(before, after map[string]uint64) []string {
+	out := []string{}
+	for key, rev := range after {
+		if before[key] != rev {
+			out = append(out, key)
+		}
+	}
+	for key := range before {
+		if _, ok := after[key]; !ok {
+			out = append(out, key)
+		}
+	}
+	slices.Sort(out)
+	return out
+}

modules/mesh-delivery-indexer/internal/index/placement_test.go

@@ -0,0 +1,201 @@
+package index
+
+import (
+	"context"
+	"reflect"
+	"slices"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+)
+
+// ADR 0549 §2 (issue 1126): a merge changing one node's file writes that key alone and says one event; a merge with no
+// placement change writes nothing and says nothing; a node whose file is gone loses its key and says its modules
+// removed; a file that does not read leaves its key; a message that read no placement changes none.
+func placementIsWrittenAtAMergeOnlyWhereItChanged(t *testing.T) {
+	ctx := context.Background()
+	ix, _, logs := newIndexer(t)
+	place := newMem()
+	ix.Placement = place
+	var said []delivery.PlacementChange
+	ix.Say = func(event string, body any) error {
+		if event != delivery.PlacementChangedEvent {
+			t.Errorf("said %s", event)
+		}
+		said = append(said, body.(delivery.PlacementChange))
+		return nil
+	}
+	merged := func(merge string, files map[string]string) delivery.Forge {
+		return delivery.Forge{V: delivery.Version, Kind: delivery.ForgeMerged, Repository: delivery.CatalogueRepository, Branch: "main",
+			Number: 7, Head: "h", Merge: merge, Root: "r", Trees: map[string]string{"": "t"}, Placements: files, PlacementsRead: true}
+	}
+	ace := `{"v":1,"node":"ace","modules":[{"module":"plex"}]}`
+	g14 := `{"v":1,"node":"g14","modules":[{"module":"zsh"}]}`
+	written := func(node string) (delivery.Placement, uint64) {
+		t.Helper()
+		v, ok := place.vals["placement."+node]
+		if !ok {
+			return delivery.Placement{}, 0
+		}
+		p, err := delivery.DecodePlacement(v)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return p, place.revs["placement."+node]
+	}
+
+	if err := ix.Apply(ctx, merged("m1", map[string]string{"ace": ace, "g14": g14})); err != nil {
+		t.Fatal(err)
+	}
+	if p, _ := written("ace"); p.Revision != "m1" || !reflect.DeepEqual(p.Assigned(), []string{"plex"}) || len(said) != 2 {
+		t.Fatalf("first merge: %+v, said %v", p, said)
+	}
+	_, aceRev := written("ace")
+
+	said = nil
+	if err := ix.Apply(ctx, merged("m2", map[string]string{"ace": ace, "g14": g14})); err != nil {
+		t.Fatal(err)
+	}
+	if p, rev := written("ace"); rev != aceRev || p.Revision != "m1" || len(said) != 0 {
+		t.Errorf("a merge with no placement change wrote %+v (revision %d, was %d) and said %v", p, rev, aceRev, said)
+	}
+
+	said = nil
+	if err := ix.Apply(ctx, merged("m3", map[string]string{"ace": ace, "g14": `{"v":1,"node":"g14","modules":[{"module":"zsh"},{"module":"xterm"}]}`})); err != nil {
+		t.Fatal(err)
+	}
+	if _, rev := written("ace"); rev != aceRev || len(said) != 1 || said[0].Node != "g14" || said[0].Revision != "m3" ||
+		!reflect.DeepEqual(said[0].Added, []string{"xterm"}) {
+		t.Errorf("one file changed: ace's revision %d (was %d), said %+v", rev, aceRev, said)
+	}
+
+	said = nil
+	if err := ix.Apply(ctx, merged("m4", map[string]string{"ace": ace, "g14": `{"v":1,"node":"ace","modules":[]}`})); err != nil {
+		t.Fatal(err)
+	}
+	if p, _ := written("g14"); len(p.Modules) != 2 || len(said) != 0 || !strings.Contains(logs.String(), "the placement file of %s is refused") {
+		t.Errorf("a file naming another node replaced the key: %+v, said %v, logs %s", p, said, logs)
+	}
+
+	said = nil
+	if err := ix.Apply(ctx, merged("m5", map[string]string{"ace": ace})); err != nil {
+		t.Fatal(err)
+	}
+	if _, rev := written("g14"); rev != 0 || len(said) != 1 || !reflect.DeepEqual(said[0].Removed, []string{"xterm", "zsh"}) {
+		t.Errorf("a file removed: g14's key at revision %d, said %+v", rev, said)
+	}
+
+	said = nil
+	unread := merged("m6", nil)
+	unread.PlacementsRead = false
+	if err := ix.Apply(ctx, unread); err != nil {
+		t.Fatal(err)
+	}
+	if p, _ := written("ace"); p.Revision != "m1" || len(said) != 0 {
+		t.Errorf("a message that read no placement changed it: %+v, %v", p, said)
+	}
+
+	// Issue 1126 (ADR 0549 §4), placement candidates: the trunk now places ace alone. A catalogue pull request writes
+	// `<group>.<node>` for each node whose file at its head differs from the trunk's, or that the head removes, and only
+	// when the value changes; a pull message that read no placement, or a pull request changing none, writes nothing; a
+	// file that does not read gets no key; a merge, a close or an open message not naming it deletes its keys.
+	cands := newMem()
+	ix.PlacementCandidates = cands
+	said = nil
+	pullOf := func(branch string, number int, head string, files map[string]string) delivery.Forge {
+		return delivery.Forge{V: delivery.Version, Kind: delivery.ForgePull, Repository: delivery.CatalogueRepository, Branch: branch,
+			Number: number, Head: head, Action: delivery.PullUpdated, Placements: files, PlacementsRead: files != nil}
+	}
+	candidate := func(key string) (delivery.PlacementCandidate, uint64, bool) {
+		t.Helper()
+		v, ok := cands.vals[key]
+		if !ok {
+			return delivery.PlacementCandidate{}, 0, false
+		}
+		c, err := delivery.DecodePlacementCandidate(v)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return c, cands.revs[key], true
+	}
+	keys := func() string { k, _ := cands.Keys(ctx); slices.Sort(k); return strings.Join(k, ",") }
+	g14New := `{"v":1,"node":"g14","modules":[{"module":"zsh"}]}`
+	for _, row := range []struct {
+		name string
+		f    delivery.Forge
+		keys string
+	}{
+		{"a pull request adding g14", pullOf("feat/p", 9, h1, map[string]string{"ace": ace, "g14": g14New}), "feat/p.g14"},
+		{"the same head again", pullOf("feat/p", 9, h1, map[string]string{"ace": ace, "g14": g14New}), "feat/p.g14"},
+		{"a pull message that read no placement", pullOf("feat/p", 9, h2, nil), "feat/p.g14"},
+		{"a pull request changing no placement", pullOf("feat/q", 10, h1, map[string]string{"ace": ace}), "feat/p.g14"},
+		{"a new head removing ace", pullOf("feat/p", 9, h2, map[string]string{"g14": g14New}), "feat/p.ace,feat/p.g14"},
+		{"a head whose g14 file does not read", pullOf("feat/p", 9, h3, map[string]string{"g14": `{"v":1,"node":"ace","modules":[]}`}), "feat/p.ace"},
+		{"the head adding g14 again", pullOf("feat/p", 9, h2, map[string]string{"g14": g14New}), "feat/p.ace,feat/p.g14"},
+		{"a head the forge says changes no placement file", func() delivery.Forge { f := pullOf("feat/p", 9, h3, nil); f.DirsKnown = true; return f }(), ""},
+		{"the head adding g14 and removing ace again", pullOf("feat/p", 9, h2, map[string]string{"g14": g14New}), "feat/p.ace,feat/p.g14"},
+		{"an open message not naming it", delivery.Forge{V: delivery.Version, Kind: delivery.ForgeOpen, Open: []delivery.OpenPull{{Repository: delivery.CatalogueRepository, Number: 10}}}, ""},
+		{"the pull request heard again", pullOf("feat/p", 9, h2, map[string]string{"g14": g14New}), "feat/p.ace,feat/p.g14"},
+		{"its merge", func() delivery.Forge {
+			m := merged("m7", map[string]string{"g14": g14New})
+			m.Branch, m.Number = "feat/p", 9
+			return m
+		}(), ""},
+	} {
+		_, revBefore, _ := candidate("feat/p.g14")
+		if err := ix.Apply(ctx, row.f); err != nil {
+			t.Fatalf("%s: %v", row.name, err)
+		}
+		if got := keys(); got != row.keys {
+			t.Errorf("%s: keys %q, want %q", row.name, got, row.keys)
+		}
+		c, rev, ok := candidate("feat/p.g14")
+		switch row.name {
+		case "a pull request adding g14":
+			if !ok || c.Group != "feat/p" || c.Pull != (delivery.Head{Repository: delivery.CatalogueRepository, Number: 9, Head: h1}) || c.Placement == nil ||
+				!reflect.DeepEqual(c.Placement.Assigned(), []string{"zsh"}) {
+				t.Errorf("%s: %+v", row.name, c)
+			}
+		case "the same head again", "a pull message that read no placement", "a pull request changing no placement":
+			if rev != revBefore {
+				t.Errorf("%s: feat/p.g14 written again (revision %d, was %d)", row.name, rev, revBefore)
+			}
+		case "a new head removing ace":
+			if a, _, _ := candidate("feat/p.ace"); a.Placement != nil || a.Pull.Head != h2 || c.Pull.Head != h2 {
+				t.Errorf("%s: ace %+v, g14 at %s", row.name, a, c.Pull.Head)
+			}
+		}
+	}
+	if p, _ := written("g14"); len(p.Modules) != 1 || p.Revision != "m7" {
+		t.Errorf("the merge's trunk placement of g14: %+v", p)
+	}
+
+	// ADR 0559 §8, indexer_placement_reread: a reread with nothing changed writes nothing; one after a missed merge and a
+	// missed head writes those keys; one after a missed revert deletes the candidate; a forge that cannot say writes nothing.
+	g14Other := `{"v":1,"node":"g14","modules":[{"module":"zsh"},{"module":"htop"}]}`
+	for _, row := range []struct {
+		name             string
+		read             PlacementRead
+		err              error
+		placement, cands []string
+	}{
+		{"nothing changed", PlacementRead{Trunk: "m7", Files: map[string]string{"g14": g14New}}, nil, []string{}, []string{}},
+		{"a missed merge and a missed head", PlacementRead{Trunk: "m8", Files: map[string]string{"g14": g14New, "ace": ace},
+			Pulls: []PullPlacement{{Branch: "feat/r", Number: 11, Head: h1, Files: map[string]string{"g14": g14Other, "ace": ace}}}}, nil,
+			[]string{"placement.ace"}, []string{"feat/r.g14"}},
+		{"a missed revert", PlacementRead{Trunk: "m8", Files: map[string]string{"g14": g14New, "ace": ace},
+			Pulls: []PullPlacement{{Branch: "feat/r", Number: 11, Head: h2, Files: map[string]string{"g14": g14New, "ace": ace}}}}, nil,
+			[]string{}, []string{"feat/r.g14"}},
+		{"a forge that cannot say", PlacementRead{}, context.DeadlineExceeded, []string{}, []string{}},
+	} {
+		ix.ReadPlacement = func(context.Context) (PlacementRead, error) { return row.read, row.err }
+		r := ix.RereadPlacement(ctx)
+		if !reflect.DeepEqual(r.Placement, row.placement) || !reflect.DeepEqual(r.Candidates, row.cands) || r.Answer == "" {
+			t.Errorf("%s: %+v", row.name, r)
+		}
+	}
+	if keys() != "" {
+		t.Errorf("after the reread of a revert, candidates %q", keys())
+	}
+}

modules/mesh-delivery-indexer/internal/index/registered.go

@@ -45,12 +45,6 @@ type taken struct {
 }
 
 func (ix *Indexer) indexRegistered(ctx context.Context, r Registration, force bool) (taken, error) {
-	return ix.indexAt(ctx, r, force, false)
-}
-
-// indexAt is indexRegistered; reread also reads a module the modules state holds (a person's take-in of a held module
-// whose record stands behind the head the gate's source names, issue 1126).
-func (ix *Indexer) indexAt(ctx context.Context, r Registration, force, reread bool) (taken, error) {
 	if ix.Modules == nil || ix.Read == nil {
 		return taken{why: "the indexer reads no forge or writes no modules"}, nil
 	}
@@ -61,7 +55,7 @@ func (ix *Indexer) indexAt(ctx context.Context, r Registration, force, reread bo
 	}
 	if _, _, found, err := ix.Modules.Get(ctx, key); err != nil {
 		return taken{}, fmt.Errorf("modules.%s: %w", key, err)
-	} else if found && !reread {
+	} else if found {
 		ix.markRead(r.Module)
 		return taken{held: true, why: "the modules state holds it already: a merge to its repository writes it from now on"}, nil
 	}
@@ -129,7 +123,7 @@ func (ix *Indexer) indexAt(ctx context.Context, r Registration, force, reread bo
 	if l := read.Locks[dir]; len(l) > 0 {
 		f.Locks = map[string]map[string]string{dir: l}
 	}
-	if _, err := ix.applyManifests(ctx, f, false); err != nil {
+	if err := ix.applyManifests(ctx, f, false); err != nil {
 		return t, err
 	}
 	if _, _, found, err := ix.Modules.Get(ctx, key); err != nil {
@@ -210,9 +204,6 @@ type TakenIn struct {
 // controller's records, or whose every registration could not be read or holds no manifest of it, is answered with why.
 func (ix *Indexer) TakeIn(ctx context.Context, module string) TakenIn {
 	out := TakenIn{Module: module}
-	if again, ok := ix.takeInHeld(ctx, module); ok {
-		return again
-	}
 	if ix.Builds == nil {
 		out.Answer = "the indexer reads no controller's build records, so it knows no registration"
 		return out
@@ -282,69 +273,3 @@ func (ix *Indexer) IndexRegisteredAll(ctx context.Context) error {
 	}
 	return first
 }
-
-// takeInHeld reads again, at the head the gate's source names for its repository, a module the modules state holds whose
-// record stands at another commit, and writes it as a merge would (only when it changed). It is the recovery for a merge
-// whose merged message never reached the indexer (issue 1126: mesh-catalog#535's message was given up by the forge bridge
-// after its reads timed out, and mesh-vault's record stayed at the merge before). It answers false where it does not
-// apply: no such module held, or no head named, or the record at that head already.
-func (ix *Indexer) takeInHeld(ctx context.Context, module string) (TakenIn, bool) {
-	out := TakenIn{Module: module}
-	key, err := delivery.ModulesKey(module)
-	if err != nil || ix.Modules == nil {
-		return out, false
-	}
-	value, _, found, err := ix.Modules.Get(ctx, key)
-	if err != nil || !found {
-		return out, false
-	}
-	cur, err := delivery.DecodeModule(value)
-	if err != nil || cur.Repository == "" || cur.Path == "" {
-		return out, false
-	}
-	head := ""
-	ix.mu.Lock()
-	for repo, h := range ix.source.heads {
-		if delivery.SameRepository(repo, cur.Repository) && h != "" {
-			head = h
-		}
-	}
-	ix.mu.Unlock()
-	if head == "" || head == cur.Commit {
-		return out, false
-	}
-	// Never backwards (order.go): a source head older than the record (a merge applied before the source moved) is never
-	// read and written back over it. A diverged or rewritten history, or a record whose commit the forge no longer has, is
-	// not older and is read; where the forge cannot say otherwise, nothing is read. One forge call.
-	old, why := true, "the forge cannot be asked"
-	if ix.Contains != nil {
-		var err error
-		if old, err = ix.older(ctx, cur.Repository, head, cur.Commit); err != nil {
-			old, why = true, err.Error()
-		} else if old {
-			why = fmt.Sprintf("%.12s is older than its record at %.12s", head, cur.Commit)
-		}
-	}
-	if old {
-		out.Held, out.Repository, out.Commit, out.Path = true, cur.Repository, cur.Commit, cur.Path
-		out.Answer = fmt.Sprintf("held; the source names another head, %.12s, and not one newer than its record (%s), so it is not read again", head, why)
-		return out, true
-	}
-	t, err := ix.indexAt(ctx, Registration{Module: module, Repository: cur.Repository, Path: cur.Path, Commit: head}, true, true)
-	out.Held, out.Repository, out.Commit, out.Path = true, t.repository, t.commit, pathOf(t.dir)
-	switch {
-	case err != nil:
-		out.Answer = "held, and not read again at the source's head: " + err.Error()
-	case !t.stored:
-		out.Answer = "held, and not read again at the source's head: " + t.why
-	default:
-		after, _, _, _ := ix.Modules.Get(ctx, key)
-		out.Stored = true
-		if string(after) == string(value) {
-			out.Answer = fmt.Sprintf("held, and read again from %s at %s: unchanged there, so its record stands", t.repository, t.commit)
-		} else {
-			out.Answer = fmt.Sprintf("held, read again from %s at %s and written to the modules state: it changed since %.12s", t.repository, t.commit, cur.Commit)
-		}
-	}
-	return out, true
-}