cmd/mesh-controller/busobjects.go

@@ -32,6 +32,13 @@ func assertBusObjects(ctx context.Context, inv *inventory.Inventory, r broker.Ra
 	if err := broker.Raise(r, names); err != nil {
 		return nil, err
 	}
+	// And each node's bucket for the files of its declaration that travel by digest (novox/hq ADR 0486 §4), so a node finds its own
+	// whenever the bus is up.
+	if files, ok := r.(interface{ EnsureDeclarationFiles(nodes []string) error }); ok {
+		if err := files.EnsureDeclarationFiles(names); err != nil {
+			return nil, err
+		}
+	}
 	// The work queues of the mesh's own roles (novox/hq ADR 0121). The queue before the holder,
 	// deliberately: work queues until somebody arrives to do it, so assigning a build machine a week
 	// after something started asking for builds flushes the backlog instead of having lost it.

cmd/mesh-controller/compose_sdk.go

@@ -200,6 +200,7 @@ func composeQuestion(ctx context.Context, open *stores, node string, mode compos
 	}
 	sayFound(ctx, d)
 	out := sendableOf(d)
+	out.fileReferences = readsFileReferences(in.Input, node)
 	if !withOrder {
 		out.Sequence, out.Epoch, out.Generation = 0, 0, 0
 	}
@@ -281,6 +282,7 @@ func composeSendValidated(ctx context.Context, open *stores, node string) (senda
 		if len(left) == 0 && len(in.wouldMake) == 0 {
 			sayFound(ctx, d)
 			out := sendableOf(d)
+			out.fileReferences = readsFileReferences(in.Input, node)
 			// The sender stamps the order it allots (order.stamp); a composition for a send carries none of its own.
 			out.Sequence, out.Epoch, out.Generation = 0, 0, 0
 			here, _ := nodeOf(in.Input, node)

cmd/mesh-controller/declaration_capability_integration_test.go

@@ -0,0 +1,110 @@
+//go:build integration
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	sdkdecl "git.novox.be/novox/mesh-sdk/go/declaration"
+	"git.novox.be/novox/mesh-sdk/go/overlay"
+
+	"git.novox.be/novox/mesh-sdk/go/compose"
+)
+
+// 1696/AC2, ADR 0486 §5: a node is sent a file by digest only when its profile reports the capability. A node whose profile lacks
+// it, and a node the mesh has no profile of, are sent every content inline; a node that reports it is sent the reference. The test
+// goes through composeQuestion and composeSend, the two places readsFileReferences is read (compose_sdk.go).
+func TestAFileTravelsByDigestOnlyToANodeThatReportsTheCapability(t *testing.T) {
+	open := aMesh(t) // anchor and laptop report no file-references
+	ctx := t.Context()
+	big := strings.Repeat("0123456789abcdef", 8<<10) // 128 KiB
+	register(t, open, catalogue.Manifest{Module: "bigfile", Version: "1",
+		Resources: []map[string]any{{"id": "blob", "type": "file", "path": "/etc/bigfile/blob", "mode": "0644", "content": big}}})
+
+	// reader reports the capability; bare has never reported a profile at all.
+	for i, n := range []struct {
+		name    string
+		profile map[string]any
+	}{
+		{"reader", map[string]any{"capabilities": []any{
+			map[string]any{"name": "container-runtime", "present": true},
+			map[string]any{"name": "systemd", "present": true},
+			map[string]any{"name": sdkdecl.FileReferencesCapability, "present": true}}}},
+		{"bare", nil},
+	} {
+		record, err := open.inventory.AddNode(ctx, n.name)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := open.inventory.SetPlace(ctx, n.name, n.name+".example:51820", "here", false, fmt.Sprintf("10.77.0.%d", i+10)); err != nil {
+			t.Fatal(err)
+		}
+		if n.profile != nil {
+			if err := open.inventory.RecordProfile(ctx, record.ID, n.profile); err != nil {
+				t.Fatal(err)
+			}
+		}
+		if err := open.inventory.RecordSealingKey(ctx, record.ID, aPublicKey(t)); err != nil {
+			t.Fatal(err)
+		}
+		if err := open.inventory.RecordOverlayKey(ctx, record.ID, aPublicKey(t)); err != nil {
+			t.Fatal(err)
+		}
+		if _, err := open.inventory.Assign(ctx, n.name, overlay.Name); err != nil {
+			t.Fatal(err)
+		}
+	}
+	for _, node := range []string{"laptop", "reader", "bare"} {
+		if _, err := assign(ctx, open, node, "bigfile"); err != nil {
+			t.Fatalf("assign %s: %v", node, err)
+		}
+	}
+
+	byDigest := map[string]bool{"laptop": false, "bare": false, "reader": true}
+	for node, want := range byDigest {
+		asked, _, err := composeQuestion(ctx, open, node, compose.Reading, false)
+		if err != nil {
+			t.Fatalf("%s: %v", node, err)
+		}
+		sent, err := composeSend(ctx, open, node)
+		if err != nil {
+			t.Fatalf("%s: %v", node, err)
+		}
+		for what, s := range map[string]sendable{"question": asked, "send": sent} {
+			if s.fileReferences != want {
+				t.Fatalf("%s, %s: fileReferences %v, want %v", node, what, s.fileReferences, want)
+			}
+			body, err := s.Body()
+			if err != nil {
+				t.Fatal(err)
+			}
+			var got struct {
+				Resources []map[string]any `json:"resources"`
+			}
+			if err := json.Unmarshal(body, &got); err != nil {
+				t.Fatal(err)
+			}
+			var found bool
+			for _, r := range got.Resources {
+				if r["path"] != "/etc/bigfile/blob" {
+					continue
+				}
+				found = true
+				inline := r["content"] == big
+				if want && (inline || r["digest"] == nil || r["size"] == nil) {
+					t.Fatalf("%s, %s: a node that reads references is sent the content inline", node, what)
+				}
+				if !want && (!inline || r["digest"] != nil) {
+					t.Fatalf("%s, %s: a node that does not report the capability is sent a reference", node, what)
+				}
+			}
+			if !found {
+				t.Fatalf("%s, %s: the file is not in the declaration", node, what)
+			}
+		}
+	}
+}

cmd/mesh-controller/declaration_files.go

@@ -0,0 +1,253 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+
+	"git.novox.be/novox/mesh-sdk/go/compose"
+	sdkdecl "git.novox.be/novox/mesh-sdk/go/declaration"
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/conditions"
+)
+
+// **A declaration's large files travel by their digest to a node that can read one** (novox/hq ADR 0486 §1, §5, issue 1696).
+//
+// The declaration to a node that reports sdkdecl.FileReferencesCapability carries, in place of the content of every
+// file resource of more than sdkdecl.FileReferenceThreshold bytes that may travel so (File.TravelsByDigest: plain content or
+// bytes, not sealed, not filled with secrets, not written into another file), its sha256 digest and size. The content is put
+// into the bucket of the bus under the hex of the digest before the declaration is sent. A node that does not report the
+// capability is sent every content inline, as before: an older node-engine refuses a field it does not know, whole.
+
+// readsFileReferences says the node reports the capability of reading a file given by digest (ADR 0486 §5). A node the mesh has
+// no profile of reads none.
+func readsFileReferences(in compose.Input, node string) bool {
+	n, ok := nodeOf(in, node)
+	return ok && n.Capabilities[sdkdecl.FileReferencesCapability]
+}
+
+// referencing is the resources as a node that reads references is sent them, and the content of each file that went by
+// digest, by the name of its object (the hex of its digest). The resources it is given are not changed. A file that does not
+// travel by digest is passed as it is.
+func referencing(resources []map[string]any) ([]map[string]any, map[string][]byte, error) {
+	out := make([]map[string]any, len(resources))
+	var objects map[string][]byte
+	for i, r := range resources {
+		out[i] = r
+		if kind, _ := r["type"].(string); kind != string(sdkdecl.TypeFile) {
+			continue
+		}
+		// Cheap first: only a file with a content or bytes of the size is worth reading whole.
+		content, _ := r["content"].(string)
+		bytesField, _ := r["bytes"].(string)
+		if len(content) <= sdkdecl.FileReferenceThreshold && len(bytesField) <= sdkdecl.FileReferenceThreshold {
+			continue
+		}
+		raw, err := json.Marshal(r)
+		if err != nil {
+			return nil, nil, fmt.Errorf("resource %v: %w", r["id"], err)
+		}
+		var f sdkdecl.File
+		if err := json.Unmarshal(raw, &f); err != nil {
+			return nil, nil, fmt.Errorf("resource %v is not a file the controller can read: %w", r["id"], err)
+		}
+		if !f.TravelsByDigest() {
+			continue
+		}
+		ref, body, err := f.AsReference()
+		if err != nil {
+			return nil, nil, err
+		}
+		name, err := sdkdecl.ObjectName(ref.Digest)
+		if err != nil {
+			return nil, nil, err
+		}
+		with := make(map[string]any, len(r)+2)
+		for k, v := range r {
+			with[k] = v
+		}
+		delete(with, "content")
+		delete(with, "bytes")
+		with["digest"], with["size"] = ref.Digest, ref.Size
+		out[i] = with
+		if objects == nil {
+			objects = map[string][]byte{}
+		}
+		objects[name] = body
+	}
+	return out, objects, nil
+}
+
+// namedObjects are the objects of the bucket a body names: the object name of every file resource given by reference,
+// with its size. It reads a declaration as the node does, so it also reads the latest one the bus holds.
+func namedObjects(body []byte) (map[string]int64, error) {
+	var envelope struct {
+		Resources []struct {
+			Type   string `json:"type"`
+			Digest string `json:"digest"`
+			Size   int64  `json:"size"`
+		} `json:"resources"`
+	}
+	if err := json.Unmarshal(body, &envelope); err != nil {
+		return nil, err
+	}
+	var out map[string]int64
+	for _, r := range envelope.Resources {
+		if r.Type != string(sdkdecl.TypeFile) || r.Digest == "" {
+			continue
+		}
+		name, err := sdkdecl.ObjectName(r.Digest)
+		if err != nil {
+			return nil, err
+		}
+		if out == nil {
+			out = map[string]int64{}
+		}
+		out[name] = r.Size
+	}
+	return out, nil
+}
+
+// objectStore is what putting the objects needs of a node's bucket.
+type objectStore interface {
+	// Has says whether an object of that name is there, complete, and whether it carries the sweep's mark of being named by no
+	// node's latest declaration.
+	Has(ctx context.Context, name string) (have, marked bool, err error)
+	// Put writes the object under that name, replacing one of the same name (and so erasing its mark).
+	Put(ctx context.Context, name string, content []byte) error
+}
+
+// putObjects makes sure every object of the declaration is in the bucket before the declaration that names it is sent: a node
+// that reads the declaration finds each object. An object already there (the same content, the same name) is not written again,
+// **unless the sweep marked it unnamed**: then it is written again, so the mark that would have it removed is gone with the
+// old object (issue 1696, review: a mark read just before a send must not take an object the send relies on). Refuses on the
+// first it cannot put, naming it, so the declaration is not sent.
+func putObjects(ctx context.Context, store objectStore, objects map[string][]byte) error {
+	names := make([]string, 0, len(objects))
+	for name := range objects {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		have, marked, err := store.Has(ctx, name)
+		if err != nil {
+			return fmt.Errorf("whether the object %s is in the bucket: %w", name[:12], err)
+		}
+		if have && !marked {
+			continue
+		}
+		if err := store.Put(ctx, name, objects[name]); err != nil {
+			return fmt.Errorf("putting the object %s (%d bytes) in the bucket: %w", name[:12], len(objects[name]), err)
+		}
+	}
+	return nil
+}
+
+// busObjects is a node's bucket on the controller's own connection.
+type busObjects struct{ store jetstream.ObjectStore }
+
+// openBucket opens the bucket of a node's files, making it first if it is not there (it is asserted for every node at the
+// controller's start; a node adopted since is covered here).
+func openBucket(ctx context.Context, conn *nats.Conn, node string) (busObjects, error) {
+	js, err := jetstream.New(conn)
+	if err != nil {
+		return busObjects{}, err
+	}
+	bucket, err := broker.DeclarationFilesBucketOf(node)
+	if err != nil {
+		return busObjects{}, fmt.Errorf("the object bucket of node %q: %w", node, err)
+	}
+	store, err := js.ObjectStore(ctx, bucket)
+	if errors.Is(err, jetstream.ErrBucketNotFound) {
+		if err = broker.EnsureDeclarationFiles(ctx, js, node); err == nil {
+			store, err = js.ObjectStore(ctx, bucket)
+		}
+	}
+	if err != nil {
+		return busObjects{}, fmt.Errorf("the object bucket %s: %w", bucket, err)
+	}
+	return busObjects{store}, nil
+}
+
+func (b busObjects) Has(ctx context.Context, name string) (bool, bool, error) {
+	info, err := b.store.GetInfo(ctx, name)
+	switch {
+	case errors.Is(err, jetstream.ErrObjectNotFound):
+		return false, false, nil
+	case err != nil:
+		return false, false, err
+	}
+	_, marked := info.Metadata[declarationUnnamed]
+	return !info.Deleted, marked, nil
+}
+
+func (b busObjects) Put(ctx context.Context, name string, content []byte) error {
+	_, err := b.store.PutBytes(ctx, name, content)
+	return err
+}
+
+// filesLocks hold a node's bucket for one act at a time in this process: a send puts its objects and publishes the declaration that
+// names them under the node's lock, and the sweep judges the node's bucket under the same one, so the sweep never removes an
+// object between a send's put and its declaration. Another process (a person's push) is covered by the put erasing a mark and by
+// the sweep looking at an object again just before it removes it.
+var filesLocks sync.Map
+
+func lockFilesOf(node string) func() {
+	l, _ := filesLocks.LoadOrStore(node, &sync.Mutex{})
+	mu := l.(*sync.Mutex)
+	mu.Lock()
+	return mu.Unlock
+}
+
+// kindFilesNotPut is a node whose files that travel by digest could not be put in its bucket, send after send.
+const kindFilesNotPut = "declaration-files-not-put"
+
+// filesNotPutAfter is how many sends in a row may fail to put before the condition is raised: the first send to the machine holding
+// the bus fails for want of the grant that very send delivers, and says so, and is not yet a fault.
+const filesNotPutAfter = 2
+
+var (
+	filesFailMu sync.Mutex
+	filesFailed = map[string]int{}
+)
+
+func filesNotPutObservation(node, summary string) conditions.Observation {
+	return conditions.Observation{Scope: conditions.ScopeMachine, ID: node, Kind: kindFilesNotPut, Token: kindFilesNotPut,
+		Machine: node, Severity: conditions.Warning, Source: "sends", Summary: summary}
+}
+
+// notePut records how putting a send's objects went: a failure counts, the second in a row raises the condition, a success
+// clears the count and the condition.
+func notePut(ctx context.Context, node string, put error) {
+	filesFailMu.Lock()
+	if put == nil {
+		delete(filesFailed, node)
+	} else {
+		filesFailed[node]++
+	}
+	n := filesFailed[node]
+	filesFailMu.Unlock()
+	keeper := conditionsFrom
+	if keeper == nil {
+		return
+	}
+	key := filesNotPutObservation(node, "").Key()
+	switch {
+	case put == nil:
+		if _, err := keeper.Clear(ctx, key, node+" was sent its files by digest"); err != nil {
+			fmt.Printf("the condition %s could not be cleared: %v\n", key, err)
+		}
+	case n >= filesNotPutAfter:
+		summary := fmt.Sprintf("%s's files that travel by digest could not be put in its bucket %d sends in a row, so it is sent them "+
+			"inline: %v", node, n, put)
+		if _, err := keeper.Observe(ctx, filesNotPutObservation(node, summary)); err != nil {
+			fmt.Printf("the condition %s could not be raised: %v\n", key, err)
+		}
+	}
+}

cmd/mesh-controller/declaration_files_integration_test.go

@@ -0,0 +1,246 @@
+//go:build integration
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+
+	sdkdecl "git.novox.be/novox/mesh-sdk/go/declaration"
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/link"
+	"github.com/novox/mesh-controller/internal/testbus"
+)
+
+type sigOf struct{}
+
+func (sigOf) Sign(context.Context, []byte) ([]byte, error) { return make([]byte, 64), nil }
+
+// 1696/AC7 (ADR 0486 §1): on a real bus with its default largest message of 1 MiB, a declaration whose files add up to more than
+// 3 MiB is sent as references, its objects are in the bucket, each fetched back whole and verified against the digest and size the
+// declaration names; the same declaration inline is refused by the controller, naming size and limit. A changed byte in an object
+// fails the verification.
+func TestADeclarationOfMoreThanThreeMiBIsSentByReferenceOnARealBus(t *testing.T) { // 1696/AC7
+	s := testbus.Start(t)
+	conn, err := nats.Connect(s.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	nc, err := conn.JetStream()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := nc.AddStream(&nats.StreamConfig{Name: "NODES", Subjects: []string{"mesh.node.*.declare"},
+		MaxMsgsPerSubject: 1}); err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	api, err := jetstream.New(conn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := broker.EnsureDeclarationFiles(ctx, api, "novox"); err != nil {
+		t.Fatal(err)
+	}
+	// Run twice: an assertion of an existing bucket is no error and no change.
+	if err := broker.EnsureDeclarationFiles(ctx, api, "novox"); err != nil {
+		t.Fatalf("asserting the bucket again: %v", err)
+	}
+
+	var resources []map[string]any
+	for i := 0; i < 3; i++ {
+		resources = append(resources, aFileResource("big-"+string(rune('a'+i)), contentOf("big"+string(rune('a'+i)), 1200<<10)))
+	}
+	resources = append(resources, aFileResource("small", "tiny\n"))
+	inline := sendable{Resources: resources}
+	byDigest := sendable{fileReferences: true, Resources: resources}
+
+	bus := link.OverNATS{Conn: conn, JS: nc}
+	body, err := inline.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := link.Declare(ctx, bus, sigOf{}, "novox", body, 5*time.Second); err == nil ||
+		!strings.Contains(err.Error(), "1048576") || strings.Contains(err.Error(), "maximum payload exceeded") {
+		t.Fatalf("the inline declaration of more than 3 MiB: %v", err)
+	}
+
+	bucket, err := openBucket(ctx, conn, "novox")
+	if err != nil {
+		t.Fatal(err)
+	}
+	objects, err := byDigest.objects()
+	if err != nil || len(objects) != 3 {
+		t.Fatalf("objects: %d %v", len(objects), err)
+	}
+	if err := putObjects(ctx, bucket, objects); err != nil {
+		t.Fatal(err)
+	}
+	if err := putObjects(ctx, bucket, objects); err != nil {
+		t.Fatalf("putting them again: %v", err)
+	}
+	refBody, err := byDigest.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := link.Declare(ctx, bus, sigOf{}, "novox", refBody, 5*time.Second); err != nil {
+		t.Fatalf("the declaration by reference: %v", err)
+	}
+
+	// What the stream holds for the node is the reference form, and it names exactly the three objects.
+	latest, err := latestDeclarations(ctx, conn, []string{"novox", "ace"})
+	if err != nil || len(latest) != 1 {
+		t.Fatalf("the latest declarations: %v %v", len(latest), err)
+	}
+	named, err := namedByLatest("novox", latest["novox"])
+	if err != nil || len(named) != 3 {
+		t.Fatalf("what the latest declaration names: %v %v", named, err)
+	}
+	novoxBucket, err := broker.DeclarationFilesBucketOf("novox")
+	if err != nil {
+		t.Fatal(err)
+	}
+	store, err := api.ObjectStore(ctx, novoxBucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var envelope struct {
+		Resources []sdkdecl.File `json:"resources"`
+	}
+	if err := json.Unmarshal(refBody, &envelope); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range envelope.Resources {
+		if !f.IsReference() {
+			continue
+		}
+		name, _ := sdkdecl.ObjectName(f.Digest)
+		got, err := store.GetBytes(ctx, name)
+		if err != nil {
+			t.Fatalf("the object of %s: %v", f.ID, err)
+		}
+		if err := f.Verify(got); err != nil {
+			t.Errorf("the object does not verify: %v", err)
+		}
+		got[len(got)/2] ^= 1
+		if err := f.Verify(got); err == nil {
+			t.Errorf("a changed byte in the object of %s passed the verification", f.ID)
+		}
+	}
+
+	// The sweep against the real bucket: all named, nothing marked; a fourth object named by none is marked, kept a day less a
+	// minute, and removed at the day.
+	extra := bytes.Repeat([]byte("x"), 100)
+	extraName := strings.Repeat("e", 64)
+	if err := putObjects(ctx, bucket, map[string][]byte{extraName: extra}); err != nil {
+		t.Fatal(err)
+	}
+	b := busSweptBucket{store}
+	t0 := time.Now()
+	if r, err := sweepDeclarationFiles(ctx, b, named, t0); err != nil || r.Marked != 1 || r.Removed != 0 || r.Kept != 3 {
+		t.Fatalf("first sweep: %+v %v", r, err)
+	}
+	if r, err := sweepDeclarationFiles(ctx, b, named, t0.Add(24*time.Hour-time.Minute)); err != nil || r.Removed != 0 {
+		t.Fatalf("a minute short of a day: %+v %v", r, err)
+	}
+	if r, err := sweepDeclarationFiles(ctx, b, named, t0.Add(24*time.Hour+time.Second)); err != nil || r.Removed != 1 {
+		t.Fatalf("a day after: %+v %v", r, err)
+	}
+	if infos, err := store.List(ctx); err != nil || len(infos) != 3 {
+		t.Fatalf("the bucket holds %d objects (%v), want the 3 the declaration names", len(infos), err)
+	}
+}
+
+// 1696/AC8 on a real bucket: the sweep removes an object only if it still carries the mark it judged it by. An object marked
+// unnamed, then put again by a send (which erases the mark), is kept when the sweep deletes it by the old mark.
+func TestTheSweepsDeleteLeavesAnObjectASendPutAgainAfterItWasMarked(t *testing.T) { // 1696/AC8
+	s := testbus.Start(t)
+	conn, err := nats.Connect(s.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	bucket, err := openBucket(ctx, conn, "novox")
+	if err != nil {
+		t.Fatal(err)
+	}
+	name := strings.Repeat("a", 64)
+	content := map[string][]byte{name: bytes.Repeat([]byte("y"), 100)}
+	if err := putObjects(ctx, bucket, content); err != nil {
+		t.Fatal(err)
+	}
+	b := busSweptBucket{bucket.store}
+	judged := time.Now().Add(-25 * time.Hour).Truncate(time.Second)
+	if err := b.MarkUnnamed(ctx, name, judged); err != nil {
+		t.Fatal(err)
+	}
+	if _, marked, err := bucket.Has(ctx, name); err != nil || !marked {
+		t.Fatalf("the object was not marked: %v %v", marked, err)
+	}
+	// The sweep has read the mark; a send now puts the object again, which erases it.
+	if err := putObjects(ctx, bucket, content); err != nil {
+		t.Fatal(err)
+	}
+	if have, marked, err := bucket.Has(ctx, name); err != nil || !have || marked {
+		t.Fatalf("a send did not put the marked object again: have %v marked %v %v", have, marked, err)
+	}
+	gone, err := b.Delete(ctx, name, judged)
+	if err != nil || gone {
+		t.Fatalf("the sweep deleted by an old mark: gone %v, %v", gone, err)
+	}
+	if have, _, err := bucket.Has(ctx, name); err != nil || !have {
+		t.Fatalf("the object a send relies on is gone: %v %v", have, err)
+	}
+	// And the mark still on it is honoured: marked again and deleted by that mark, it goes.
+	if err := b.MarkUnnamed(ctx, name, judged); err != nil {
+		t.Fatal(err)
+	}
+	if gone, err := b.Delete(ctx, name, judged); err != nil || !gone {
+		t.Fatalf("an object still carrying the mark it was judged by is kept: gone %v, %v", gone, err)
+	}
+}
+
+// 1696/AC9 on a real bus: the sweep of a node's bucket takes the node's lock first, so it waits for a send that has put its objects
+// and not yet published the declaration that names them.
+func TestTheSweepOfANodesBucketHoldsTheNodesLock(t *testing.T) { // 1696/AC9
+	s := testbus.Start(t)
+	conn, err := nats.Connect(s.ClientURL())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	const node = "sweep-lock-node"
+	if _, err := openBucket(ctx, conn, node); err != nil { // the bucket exists, or the sweep would return before the lock
+		t.Fatal(err)
+	}
+	release := lockFilesOf(node) // a send is between its put and its publication
+	done := make(chan struct{})
+	go func() {
+		_, _ = sweepNode(ctx, conn, node)
+		close(done)
+	}()
+	select {
+	case <-done:
+		t.Fatal("the sweep judged the node's bucket while a send held it")
+	case <-time.After(300 * time.Millisecond):
+	}
+	release()
+	select {
+	case <-done:
+	case <-time.After(20 * time.Second):
+		t.Fatal("the sweep did not go on once the send let go")
+	}
+}

cmd/mesh-controller/declaration_files_test.go

@@ -0,0 +1,534 @@
+package main
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+
+	sdkdecl "git.novox.be/novox/mesh-sdk/go/declaration"
+
+	"github.com/novox/mesh-controller/internal/conditions"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// contentOf is a deterministic content of n bytes that does not compress to nothing and holds no character JSON escapes.
+func contentOf(seed string, n int) string {
+	var b strings.Builder
+	for i := 0; b.Len() < n; i++ {
+		fmt.Fprintf(&b, "%s-%07d-%x;", seed, i, i*2654435761%1000003)
+	}
+	return b.String()[:n]
+}
+
+func aFileResource(id, content string) map[string]any {
+	return map[string]any{"id": id, "type": "file", "path": "/etc/" + id, "mode": "0644", "content": content}
+}
+
+// controlNodeShape is a declaration shaped like the control node's on 2026-10-21 (issue 1689), the sizes measured then: a bus users
+// file of 252,678 bytes, the vault's export of 138,475 bytes (compact), the tool runtime 21 KB, the packet filter 19 KB, the launcher
+// 14 KB, and about 600 small resources for the rest (about 286 KB). `more` scales the count of small ones: 1 is the shape, 1.4 forty
+// percent more of them.
+func controlNodeShape(more float64) []map[string]any {
+	res := []map[string]any{
+		aFileResource("nats.bus-users", contentOf("users", 252678)),
+		aFileResource("mesh-vault.kept", contentOf("kept", 138475)),
+		aFileResource("node-tools.runtime", contentOf("runtime", 21<<10)),
+		aFileResource("nftables.filtering", contentOf("filter", 19<<10)),
+		aFileResource("mesh-host.launcher", contentOf("launcher", 14<<10)),
+	}
+	for i := 0; i < int(600*more); i++ {
+		res = append(res, aFileResource(fmt.Sprintf("module-%03d.config", i), contentOf(fmt.Sprintf("small%d", i), 380)))
+	}
+	return res
+}
+
+func wireSizeOf(t *testing.T, s sendable) int {
+	t.Helper()
+	body, err := s.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The signature the controller's key makes is 64 bytes.
+	msg, err := link.Envelope(body, make([]byte, 64))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return len(msg)
+}
+
+// 1696/AC1: for a node that reports the capability, the two big files of a control-node-shaped declaration carry their digest and size
+// and no content, and the declaration is far under the bus's 1 MiB.
+func TestAFileOver64KiBTravelsByDigestToANodeThatReadsOne(t *testing.T) { // 1696/AC1
+	users, kept := contentOf("users", 252678), contentOf("kept", 138475)
+	s := sendable{fileReferences: true, Resources: []map[string]any{
+		aFileResource("nats.bus-users", users), aFileResource("mesh-vault.kept", kept),
+		aFileResource("small", "tiny\n"),
+	}}
+	body, err := s.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got struct {
+		Resources []map[string]any `json:"resources"`
+	}
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatal(err)
+	}
+	for i, want := range []string{users, kept} {
+		r := got.Resources[i]
+		digest := sdkdecl.DigestOf([]byte(want))
+		if _, has := r["content"]; has || r["digest"] != digest || r["size"] != float64(len(want)) {
+			t.Errorf("%v goes with content %v, digest %v, size %v; want no content, %s and %d", r["id"], r["content"] != nil,
+				r["digest"], r["size"], digest, len(want))
+		}
+		if r["path"] == nil || r["mode"] != "0644" {
+			t.Errorf("%v lost its path or mode: %v", r["id"], r)
+		}
+	}
+	if got.Resources[2]["content"] != "tiny\n" || got.Resources[2]["digest"] != nil {
+		t.Errorf("a small file is not inline: %v", got.Resources[2])
+	}
+	if strings.Contains(string(body), users[:200]) || strings.Contains(string(body), kept[:200]) {
+		t.Error("the content of a file that went by digest is in the body")
+	}
+	if n := wireSizeOf(t, s); n > 100<<10 {
+		t.Errorf("the declaration is %d bytes on the wire, want under 100 KB", n)
+	}
+	// The objects to put are the contents, each under the hex of its digest, and a reference verifies against its object.
+	objects, err := s.objects()
+	if err != nil || len(objects) != 2 {
+		t.Fatalf("objects: %v %v", objects, err)
+	}
+	for _, want := range []string{users, kept} {
+		name, _ := sdkdecl.ObjectName(sdkdecl.DigestOf([]byte(want)))
+		if string(objects[name]) != want {
+			t.Errorf("the object %s does not hold the content", name[:12])
+		}
+	}
+	named, err := namedObjects(body)
+	if err != nil || len(named) != 2 {
+		t.Fatalf("the objects the body names: %v %v", named, err)
+	}
+	for name := range objects {
+		if _, ok := named[name]; !ok {
+			t.Errorf("the body does not name the object %s it was sent with", name[:12])
+		}
+		if _, err := hex.DecodeString(name); err != nil || len(name) != 64 {
+			t.Errorf("the object name %q is not 64 hex characters", name)
+		}
+	}
+}
+
+// 1696/AC2: a node that does not report the capability is sent every content inline, as before, and has no object put.
+func TestANodeWithoutTheCapabilityIsSentEveryContentInline(t *testing.T) { // 1696/AC2
+	users := contentOf("users", 252678)
+	s := sendable{Resources: []map[string]any{aFileResource("nats.bus-users", users)}}
+	body, err := s.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got struct {
+		Resources []map[string]any `json:"resources"`
+	}
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatal(err)
+	}
+	if got.Resources[0]["content"] != users || got.Resources[0]["digest"] != nil || got.Resources[0]["size"] != nil {
+		t.Fatalf("a node that reads no references is not sent the content inline: %v", got.Resources[0]["digest"])
+	}
+	if objects, err := s.objects(); err != nil || len(objects) != 0 {
+		t.Fatalf("objects for a node that reads none: %v %v", len(objects), err)
+	}
+}
+
+// 1696/AC3: only a file that may travel by digest does: one of exactly 64 KiB, a sealed one, one filled with secrets, one written
+// into another file, and a directory stay inline, whatever the node reads.
+func TestOnlyAFileThatMayTravelByDigestDoes(t *testing.T) { // 1696/AC3
+	exact := contentOf("exact", 64<<10)
+	big := contentOf("big", 64<<10+1)
+	sealed := aFileResource("sealed", big)
+	sealed["sealed"], sealed["content"] = "box", ""
+	sealed["content"] = big // a sealed file's content is none; the body must pass it as it is, whatever it holds
+	secret := aFileResource("secret", big)
+	secret["secrets"] = map[string]any{"token": "x"}
+	into := aFileResource("into", big)
+	into["into"] = "/etc/other"
+	s := sendable{fileReferences: true, Resources: []map[string]any{
+		aFileResource("exact", exact), sealed, secret, into,
+		{"id": "dir", "type": "directory", "path": "/etc/d", "content": big},
+		aFileResource("big", big),
+	}}
+	body, err := s.Body()
+	if err != nil {
+		t.Fatal(err)
+	}
+	var got struct {
+		Resources []map[string]any `json:"resources"`
+	}
+	if err := json.Unmarshal(body, &got); err != nil {
+		t.Fatal(err)
+	}
+	for i, id := range []string{"exact", "sealed", "secret", "into", "dir"} {
+		if got.Resources[i]["id"] != id || got.Resources[i]["digest"] != nil || got.Resources[i]["content"] == nil {
+			t.Errorf("%s went by digest or lost its content: %v", id, got.Resources[i]["digest"])
+		}
+	}
+	if big := got.Resources[5]; big["id"] != "big" || big["digest"] == nil || big["content"] != nil {
+		t.Errorf("a plain file of 64 KiB and a byte did not go by digest: %v", big["digest"])
+	}
+}
+
+// A file given as bytes goes by digest on its decoded length, with the decoded bytes in the object.
+func TestAFileOfBytesTravelsByDigestOnItsDecodedLength(t *testing.T) {
+	raw := []byte(contentOf("png", 70<<10))
+	r := map[string]any{"id": "icon", "type": "file", "path": "/usr/share/icon.png", "bytes": stdBase64(raw)}
+	s := sendable{fileReferences: true, Resources: []map[string]any{r}}
+	objects, err := s.objects()
+	if err != nil || len(objects) != 1 {
+		t.Fatalf("%v %v", len(objects), err)
+	}
+	name, _ := sdkdecl.ObjectName(sdkdecl.DigestOf(raw))
+	if string(objects[name]) != string(raw) {
+		t.Fatal("the object is not the decoded bytes")
+	}
+	if r["bytes"] == nil {
+		t.Fatal("the composed resource was changed in place")
+	}
+}
+
+type memObjects struct {
+	have   map[string][]byte
+	marked map[string]bool
+	puts   []string
+	fail   map[string]error
+}
+
+func (m *memObjects) Has(_ context.Context, name string) (bool, bool, error) {
+	_, ok := m.have[name]
+	return ok, m.marked[name], nil
+}
+func (m *memObjects) Put(_ context.Context, name string, c []byte) error {
+	if err := m.fail[name]; err != nil {
+		return err
+	}
+	m.puts = append(m.puts, name)
+	m.have[name] = c
+	delete(m.marked, name)
+	return nil
+}
+
+// 1696/AC4: an object already in the bucket is not put again, one absent is, and a put that fails stops the send, naming the object.
+func TestObjectsAreInTheBucketBeforeTheDeclarationIsSent(t *testing.T) { // 1696/AC4
+	objects := map[string][]byte{strings.Repeat("a", 64): []byte("one"), strings.Repeat("b", 64): []byte("two")}
+	b := &memObjects{have: map[string][]byte{strings.Repeat("a", 64): []byte("one")}}
+	if err := putObjects(t.Context(), b, objects); err != nil || len(b.puts) != 1 || b.puts[0] != strings.Repeat("b", 64) {
+		t.Fatalf("put %v (%v), want the one absent", b.puts, err)
+	}
+	// An object the sweep marked unnamed is put again, which erases the mark: a send relies on it.
+	b = &memObjects{have: map[string][]byte{strings.Repeat("a", 64): []byte("one"), strings.Repeat("b", 64): []byte("two")},
+		marked: map[string]bool{strings.Repeat("a", 64): true}}
+	if err := putObjects(t.Context(), b, objects); err != nil || len(b.puts) != 1 || b.puts[0] != strings.Repeat("a", 64) || b.marked[strings.Repeat("a", 64)] {
+		t.Fatalf("a marked object: put %v (%v) marked %v, want it put again and the mark gone", b.puts, err, b.marked)
+	}
+	b = &memObjects{have: map[string][]byte{}, fail: map[string]error{strings.Repeat("a", 64): errors.New("permissions violation")}}
+	err := putObjects(t.Context(), b, objects)
+	if err == nil || !strings.Contains(err.Error(), "aaaaaaaaaaaa") || !strings.Contains(err.Error(), "permissions violation") {
+		t.Fatalf("a failed put: %v", err)
+	}
+}
+
+// fallbackDelivery refuses the first declaration it is sent with the bucket's failure, as a bus that has not yet been given the
+// controller's grant does, and takes the second.
+type fallbackDelivery struct {
+	bodies [][]byte
+	first  error
+}
+
+func (f *fallbackDelivery) grant(context.Context, []readyNode) error { return nil }
+func (f *fallbackDelivery) declare(_ context.Context, _ readyNode, body []byte) (string, error) {
+	f.bodies = append(f.bodies, body)
+	if len(f.bodies) == 1 && f.first != nil {
+		return "", fmt.Errorf("x: %w: %w", errFilesNotPut, f.first)
+	}
+	return "digest", nil
+}
+
+// 1696/AC5: when the bucket cannot be written yet (the grant travels in the declaration of the machine holding the bus), that send goes
+// with every content inline and is made; a send that fails for another reason is not retried inline.
+func TestASendWhoseFilesCannotBePutGoesInlineOnce(t *testing.T) { // 1696/AC5
+	users := contentOf("users", 100<<10)
+	s := readyNode{node: "novox", declared: sendable{fileReferences: true, Resources: []map[string]any{aFileResource("nats.bus-users", users)}}}
+	f := &fallbackDelivery{first: errors.New("timeout")}
+	digests, err := deliver(t.Context(), f, "novox", []readyNode{s})
+	if err != nil || digests["novox"] != "digest" || len(f.bodies) != 2 {
+		t.Fatalf("%v %v %d", digests, err, len(f.bodies))
+	}
+	if strings.Contains(string(f.bodies[0]), users[:100]) || !strings.Contains(string(f.bodies[1]), users[:100]) {
+		t.Error("the first body should name the file by digest and the second carry it inline")
+	}
+	other := &fallbackDelivery{}
+	other.first = nil
+	failing := &failingDelivery{err: errors.New("the bus is down")}
+	if _, err := deliver(t.Context(), failing, "novox", []readyNode{s}); err == nil || failing.calls != 1 {
+		t.Fatalf("a failure of another kind: %v after %d send(s)", err, failing.calls)
+	}
+}
+
+type failingDelivery struct {
+	err   error
+	calls int
+}
+
+func (f *failingDelivery) grant(context.Context, []readyNode) error { return nil }
+func (f *failingDelivery) declare(context.Context, readyNode, []byte) (string, error) {
+	f.calls++
+	return "", f.err
+}
+
+// A bucket for the sweep.
+type sweepBucketFake struct {
+	objects map[string]time.Time // zero: named at the last look
+	deleted []string
+}
+
+func (b *sweepBucketFake) Objects(context.Context) ([]bucketObject, error) {
+	var out []bucketObject
+	for n, at := range b.objects {
+		out = append(out, bucketObject{Name: n, UnnamedSince: at})
+	}
+	return out, nil
+}
+func (b *sweepBucketFake) MarkUnnamed(_ context.Context, n string, at time.Time) error {
+	b.objects[n] = at
+	return nil
+}
+func (b *sweepBucketFake) ClearUnnamed(_ context.Context, n string) error {
+	b.objects[n] = time.Time{}
+	return nil
+}
+func (b *sweepBucketFake) Delete(_ context.Context, n string, markedAt time.Time) (bool, error) {
+	if at, ok := b.objects[n]; !ok || !at.Equal(markedAt) {
+		return false, nil // put again since it was judged: its mark is gone
+	}
+	delete(b.objects, n)
+	b.deleted = append(b.deleted, n)
+	return true, nil
+}
+
+// 1696/AC6: an object a latest declaration still names is not removed, however long; one unnamed is marked at the first look and removed
+// only when the mark is 24 hours old; one named again loses its mark.
+func TestAnObjectIsRemovedADayAfterNoLatestDeclarationNamesIt(t *testing.T) { // 1696/AC6
+	named, unnamed, back := strings.Repeat("1", 64), strings.Repeat("2", 64), strings.Repeat("3", 64)
+	t0 := time.Date(2026, 10, 21, 12, 0, 0, 0, time.UTC)
+	b := &sweepBucketFake{objects: map[string]time.Time{named: t0.Add(-100 * time.Hour), unnamed: {}, back: t0.Add(-5 * time.Hour)}}
+	named3 := map[string]bool{named: true, back: true}
+	r, err := sweepDeclarationFiles(t.Context(), b, named3, t0)
+	if err != nil || r.Marked != 1 || r.Cleared != 2 || r.Removed != 0 || len(b.deleted) != 0 {
+		t.Fatalf("first look: %+v %v %v", r, err, b.deleted)
+	}
+	if !b.objects[named].IsZero() || !b.objects[back].IsZero() || !b.objects[unnamed].Equal(t0) {
+		t.Fatalf("marks after the first look: %v", b.objects)
+	}
+	// Still unnamed 23 hours 59 minutes later: kept. A day after the mark: removed. The named ones stay for ever.
+	if r, err = sweepDeclarationFiles(t.Context(), b, map[string]bool{named: true, back: true}, t0.Add(24*time.Hour-time.Minute)); err != nil ||
+		r.Removed != 0 || len(b.deleted) != 0 {
+		t.Fatalf("a minute short of a day: %+v %v %v", r, err, b.deleted)
+	}
+	if r, err = sweepDeclarationFiles(t.Context(), b, map[string]bool{named: true, back: true}, t0.Add(24*time.Hour)); err != nil ||
+		r.Removed != 1 || len(b.deleted) != 1 || b.deleted[0] != unnamed {
+		t.Fatalf("a day after: %+v %v %v", r, err, b.deleted)
+	}
+	if _, ok := b.objects[named]; !ok {
+		t.Fatal("an object a latest declaration names was removed")
+	}
+	// An object named again before the day is up loses its mark and is not removed.
+	b = &sweepBucketFake{objects: map[string]time.Time{unnamed: t0}}
+	if _, err := sweepDeclarationFiles(t.Context(), b, map[string]bool{unnamed: true}, t0.Add(23*time.Hour)); err != nil || !b.objects[unnamed].IsZero() {
+		t.Fatalf("named again: %v %v", b.objects, err)
+	}
+}
+
+// What a node's latest declaration names is read from the signed envelope as stored on the bus; an unreadable one is an error and
+// never "names none", which would mark an object a node needs.
+func TestTheObjectsALatestDeclarationNamesAreReadFromTheBus(t *testing.T) {
+	s := sendable{fileReferences: true, Resources: []map[string]any{aFileResource("a", contentOf("a", 70<<10))}}
+	body, _ := s.Body()
+	msg, _ := link.Envelope(body, []byte("sig"))
+	named, err := namedByLatest("novox", msg)
+	name, _ := sdkdecl.ObjectName(sdkdecl.DigestOf([]byte(contentOf("a", 70<<10))))
+	if err != nil || len(named) != 1 || !named[name] {
+		t.Fatalf("%v %v", named, err)
+	}
+	if none, err := namedByLatest("ace", []byte(`{"declaration":"e30=","signature":""}`)); err != nil || len(none) != 0 {
+		t.Fatalf("a declaration naming none: %v %v", none, err)
+	}
+	if _, err := namedByLatest("novox", []byte("not json")); err == nil {
+		t.Fatal("an unreadable latest declaration was read as naming none")
+	}
+}
+
+// 1698/AC2 (ADR 0486 §9): a declaration shaped like the control node's, for a node that reads references, stays under half of the
+// bus's largest message on the wire; the inline form of the same does not fit at all; and the same shape with 40 percent more resources
+// fails the test's own limit, so a change that eats the room fails in a pull request and not on the live mesh.
+func TestTheControlNodesDeclarationInTheReferenceFormStaysUnderHalfTheBusLimit(t *testing.T) { // 1698/AC2
+	const limit = 1048576
+	shape := sendable{fileReferences: true, Resources: controlNodeShape(1)}
+	n := wireSizeOf(t, shape)
+	t.Logf("the control node's shape in the reference form: %d bytes on the wire, %.1f%% of %d", n, 100*float64(n)/limit, limit)
+	if n > limit/2 {
+		t.Errorf("the reference form is %d bytes on the wire, over half (%d) of the bus's largest message", n, limit/2)
+	}
+	if inline := wireSizeOf(t, sendable{Resources: controlNodeShape(1)}); inline < limit*3/4 {
+		t.Errorf("the inline form is %d bytes, which is not the shape that was over the limit", inline)
+	}
+	grown := wireSizeOf(t, sendable{fileReferences: true, Resources: controlNodeShape(1.4)})
+	if grown <= limit/2 {
+		t.Errorf("the shape with 40%% more resources is %d bytes, which the test would let pass", grown)
+	}
+}
+
+func stdBase64(b []byte) string { return base64.StdEncoding.EncodeToString(b) }
+
+// A sweep that read an object's mark before a send put it again must not remove it: the object, now without the mark, is left.
+func TestASweepDoesNotRemoveAnObjectASendPutAgainAfterItWasJudged(t *testing.T) { // 1696/AC8
+	n := strings.Repeat("4", 64)
+	t0 := time.Date(2026, 10, 21, 12, 0, 0, 0, time.UTC)
+	b := &sweepBucketFake{objects: map[string]time.Time{n: t0}}
+	judged := bucketObject{Name: n, UnnamedSince: t0}
+	b.objects[n] = time.Time{} // the send put it again: no mark
+	if gone, err := b.Delete(t.Context(), judged.Name, judged.UnnamedSince); err != nil || gone || len(b.deleted) != 0 {
+		t.Fatalf("an object put again was removed: %v %v %v", gone, err, b.deleted)
+	}
+}
+
+// One node's bucket is held by one act at a time in this process: the sweep waits for a send that has put its objects and not yet
+// published the declaration that names them (1696/AC9).
+func TestTheSweepOfANodesBucketWaitsForASendThatHasPutItsObjects(t *testing.T) { // 1696/AC9
+	unlock := lockFilesOf("lock-test-node")
+	got := make(chan struct{})
+	go func() {
+		defer lockFilesOf("lock-test-node")()
+		close(got)
+	}()
+	select {
+	case <-got:
+		t.Fatal("the sweep took the node's bucket while a send held it")
+	case <-time.After(50 * time.Millisecond):
+	}
+	other := lockFilesOf("lock-test-other-node") // another node's bucket is not held
+	other()
+	unlock()
+	select {
+	case <-got:
+	case <-time.After(2 * time.Second):
+		t.Fatal("the sweep did not take the node's bucket once the send was done")
+	}
+}
+
+// A put that fails send after send raises a condition; the first failure does not (the grant it waits for travels in that very
+// declaration), and a put that works clears it (1696/AC10).
+func TestAPutThatFailsSendAfterSendRaisesAConditionAndClearsWhenItWorks(t *testing.T) { // 1696/AC10
+	store := conditions.NewInMemory()
+	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
+		Teller: &conditions.Told{}, Now: func() time.Time { return time.Date(2026, 10, 21, 14, 0, 0, 0, time.UTC) }})
+	t.Cleanup(func() { k.Close(t.Context()) })
+	was := conditionsFrom
+	conditionsFrom = k
+	t.Cleanup(func() { conditionsFrom = was })
+	key := filesNotPutObservation("cond-node", "").Key()
+	open := func() bool {
+		_, found, err := conditions.ReadOne(t.Context(), store, key)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return found
+	}
+	boom := errors.New("permissions violation")
+	notePut(t.Context(), "cond-node", boom)
+	if open() {
+		t.Fatal("the first failure raised the condition")
+	}
+	notePut(t.Context(), "cond-node", boom)
+	if !open() {
+		t.Fatal("the second failure in a row did not raise the condition")
+	}
+	notePut(t.Context(), "cond-node", nil)
+	if open() {
+		t.Fatal("a put that worked did not clear the condition")
+	}
+	notePut(t.Context(), "cond-node", boom)
+	if open() {
+		t.Fatal("the count did not start again after a put that worked")
+	}
+}
+
+// aBusThatSays is a bus that keeps the declarations published to it and, at each, asks whether the node's bucket is held.
+type aBusThatSays struct {
+	link.Bus
+	published     chan string
+	heldAtPublish func() bool
+}
+
+func (b *aBusThatSays) PublishDeclaration(_ context.Context, node string, _ []byte) error {
+	if b.heldAtPublish != nil && !b.heldAtPublish() {
+		return errors.New("published while the node's bucket was not held")
+	}
+	b.published <- node
+	return errors.New("stop here: nothing is recorded")
+}
+
+type aSignerOfZeros struct{}
+
+func (aSignerOfZeros) Sign(context.Context, []byte) ([]byte, error) { return make([]byte, 64), nil }
+
+// whileHeld says whether the node's lock is held by someone right now, without keeping it.
+func whileHeld(node string) bool {
+	got := make(chan struct{})
+	go func() {
+		defer lockFilesOf(node)()
+		close(got)
+	}()
+	select {
+	case <-got:
+		return false
+	case <-time.After(100 * time.Millisecond):
+		// held: the goroutine stays waiting and takes and releases the lock once it is let go.
+		return true
+	}
+}
+
+// 1696/AC9: a send holds the node's lock from the put to the publication, so the sweep never removes an object between them. The
+// test goes through overTheBus.declare: while another holds the lock the declaration is not published, and at the publication the
+// lock is held.
+func TestASendHoldsTheNodesLockFromThePutToThePublication(t *testing.T) { // 1696/AC9
+	const node = "lock-send-node"
+	bus := &aBusThatSays{published: make(chan string, 1)}
+	bus.heldAtPublish = func() bool { return whileHeld(node) }
+	send := overTheBus{server: link.SendingOn(bus), signer: aSignerOfZeros{}}
+	release := lockFilesOf(node) // a sweep is judging this node's bucket
+	done := make(chan error, 1)
+	go func() {
+		_, err := send.declare(t.Context(), readyNode{node: node}, []byte(`{}`))
+		done <- err
+	}()
+	select {
+	case n := <-bus.published:
+		t.Fatalf("%s was sent its declaration while the sweep held the node's bucket", n)
+	case <-time.After(150 * time.Millisecond):
+	}
+	release()
+	select {
+	case <-bus.published:
+	case <-time.After(5 * time.Second):
+		t.Fatal("the send did not go on once the sweep let go")
+	}
+	if err := <-done; err == nil || !strings.Contains(err.Error(), "nothing is recorded") {
+		t.Fatalf("the send did not reach the publication (a lock held at it): %v", err)
+	}
+}

cmd/mesh-controller/declaration_room.go

@@ -13,8 +13,8 @@ import (
 
 // **A declaration is one bus message, and the bus's largest message is a cliff** (novox/hq issue 1689). On 2026-10-21
 // the control node's declaration passed it by 2 KB and nothing reached that node until two assignments were undone.
-// So the size is measured at every send: a warning condition from 90% of the limit, urgent over it, cleared when
-// the declaration is back under 90%. The limit is the connection's own, not a constant.
+// So the size is measured at every send: a warning condition from 75% of the limit (ADR 0486 §8, issue 1698: it was 90% while every file travelled inline), urgent over it, cleared when
+// the declaration is back under 75%. The limit is the connection's own, not a constant.
 
 // kindDeclarationNearLimit is a declaration at or near the bus's largest message.
 const kindDeclarationNearLimit = "declaration-near-limit"

cmd/mesh-controller/declaration_room_test.go

@@ -33,7 +33,7 @@ func TestTheVaultsExportIsSentCompactAndNothingElseIsTouched(t *testing.T) {
 	}
 }
 
-// From 90% of the bus's largest message the declaration is a warning; over it, urgent; back under 90%, cleared.
+// From 75% of the bus's largest message (ADR 0486 §8, issue 1698) the declaration is a warning; over it, urgent; back under 75%, cleared.
 func TestADeclarationNearTheBusLimitRaisesAConditionAndClearsWhenSmaller(t *testing.T) {
 	store := conditions.NewInMemory()
 	k := conditions.NewKeeper(t.Context(), conditions.Options{Store: store, History: store,
@@ -50,22 +50,22 @@ func TestADeclarationNearTheBusLimitRaisesAConditionAndClearsWhenSmaller(t *test
 		return c, found
 	}
 
-	settleDeclarationRoom(t.Context(), k, "novox", 899, limit)
+	settleDeclarationRoom(t.Context(), k, "novox", 749, limit)
 	if _, found := read(); found {
-		t.Fatal("a declaration at 89.9% raised a condition")
+		t.Fatal("a declaration at 74.9% raised a condition")
 	}
-	settleDeclarationRoom(t.Context(), k, "novox", 900, limit)
+	settleDeclarationRoom(t.Context(), k, "novox", 750, limit)
 	c, found := read()
-	if !found || c.Severity != conditions.Warning || !strings.Contains(c.Summary, "900 bytes") ||
+	if !found || c.Severity != conditions.Warning || !strings.Contains(c.Summary, "750 bytes") ||
 		!strings.Contains(c.Summary, "1000") || c.Subject.Machine != "novox" {
-		t.Fatalf("at 90%% the condition is %v %+v", found, c)
+		t.Fatalf("at 75%% the condition is %v %+v", found, c)
 	}
 	settleDeclarationRoom(t.Context(), k, "novox", 1001, limit)
 	if c, _ := read(); c.Severity != conditions.Urgent {
 		t.Fatalf("over the limit the condition is %q, expected urgent", c.Severity)
 	}
-	settleDeclarationRoom(t.Context(), k, "novox", 850, limit)
+	settleDeclarationRoom(t.Context(), k, "novox", 700, limit)
 	if _, found := read(); found {
-		t.Fatal("the condition stayed after the declaration fell under 90%")
+		t.Fatal("the condition stayed after the declaration fell under 75%")
 	}
 }

cmd/mesh-controller/declaration_sweep.go

@@ -0,0 +1,273 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **An object is removed a day after no node's latest declaration names it** (novox/hq ADR 0486 §3, issue 1696), so a node that is
+// asleep and receives its latest declaration later still finds every object that declaration names. What each node's latest
+// declaration names is read from the bus itself, the last message of that node's subject of the stream NODES: nothing else
+// is kept of it. When an object is first found named by none, the time is written in its own metadata (declarationUnnamed);
+// found named again, that is erased; found unnamed for a day, it is removed. Each node has a bucket of its own, judged against that
+// node's latest declaration alone. Objects are immutable and regenerable from the
+// controller's state, so a removal loses nothing.
+
+// declarationUnnamed is the key of an object's metadata holding when it was first found named by no node's latest declaration.
+const declarationUnnamed = "unnamed-since"
+
+// sweepEvery is how often the bucket is judged: the removal is exact to within this.
+const sweepEvery = time.Hour
+
+// bucketObject is one object of the bucket as the sweep sees it.
+type bucketObject struct {
+	Name string
+	// UnnamedSince is when it was first found named by none, zero when it was named at the last look.
+	UnnamedSince time.Time
+}
+
+// sweptBucket is what the sweep needs of the bucket.
+type sweptBucket interface {
+	Objects(ctx context.Context) ([]bucketObject, error)
+	MarkUnnamed(ctx context.Context, name string, since time.Time) error
+	ClearUnnamed(ctx context.Context, name string) error
+	// Delete removes the object if it still carries the mark it was judged by, and says whether it did: a send that put it again
+	// since has erased the mark, and the object is left.
+	Delete(ctx context.Context, name string, markedAt time.Time) (bool, error)
+}
+
+// filesSweep says what a sweep did.
+type filesSweep struct{ Kept, Marked, Cleared, Removed int }
+
+// sweepDeclarationFiles judges every object against the names of the latest declarations: named ones are kept (and a
+// mark of being unnamed is erased), unnamed ones are marked at the first look and removed once the mark is a day old.
+func sweepDeclarationFiles(ctx context.Context, bucket sweptBucket, named map[string]bool, now time.Time) (filesSweep, error) {
+	var r filesSweep
+	objects, err := bucket.Objects(ctx)
+	if err != nil {
+		return r, err
+	}
+	sort.Slice(objects, func(i, j int) bool { return objects[i].Name < objects[j].Name })
+	for _, o := range objects {
+		switch {
+		case named[o.Name]:
+			r.Kept++
+			if !o.UnnamedSince.IsZero() {
+				if err := bucket.ClearUnnamed(ctx, o.Name); err != nil {
+					return r, fmt.Errorf("the object %s: %w", o.Name[:12], err)
+				}
+				r.Cleared++
+			}
+		case o.UnnamedSince.IsZero():
+			if err := bucket.MarkUnnamed(ctx, o.Name, now); err != nil {
+				return r, fmt.Errorf("the object %s: %w", o.Name[:12], err)
+			}
+			r.Marked++
+		case now.Sub(o.UnnamedSince) >= broker.DeclarationFilesKeptFor:
+			gone, err := bucket.Delete(ctx, o.Name, o.UnnamedSince)
+			if err != nil {
+				return r, fmt.Errorf("the object %s: %w", o.Name[:12], err)
+			}
+			if gone {
+				r.Removed++
+			} else {
+				r.Kept++
+			}
+		default:
+			r.Kept++
+		}
+	}
+	return r, nil
+}
+
+// namedByLatest is the name of every object this latest declaration of a node names. A body that cannot be read is an error, never
+// "names none": an object the node still needs would be marked for removal.
+func namedByLatest(node string, signed []byte) (map[string]bool, error) {
+	var s link.Signed
+	if err := json.Unmarshal(signed, &s); err != nil {
+		return nil, fmt.Errorf("%s's latest declaration is not readable: %w", node, err)
+	}
+	names, err := namedObjects(s.Declaration)
+	if err != nil {
+		return nil, fmt.Errorf("%s's latest declaration is not readable: %w", node, err)
+	}
+	named := make(map[string]bool, len(names))
+	for name := range names {
+		named[name] = true
+	}
+	return named, nil
+}
+
+// latestDeclarations are the last signed declarations of the nodes, by node, as the stream NODES holds them. A node with none has
+// no entry.
+func latestDeclarations(ctx context.Context, conn *nats.Conn, nodes []string) (map[string][]byte, error) {
+	js, err := conn.JetStream(nats.Context(ctx))
+	if err != nil {
+		return nil, err
+	}
+	out := map[string][]byte{}
+	for _, node := range nodes {
+		msg, err := js.GetLastMsg("NODES", link.DeclareSubject(node), nats.Context(ctx))
+		if errors.Is(err, nats.ErrMsgNotFound) {
+			continue
+		}
+		if err != nil {
+			return nil, fmt.Errorf("the latest declaration of %s: %w", node, err)
+		}
+		out[node] = msg.Data
+	}
+	return out, nil
+}
+
+// busSweptBucket is the bucket on the controller's connection.
+type busSweptBucket struct{ store jetstream.ObjectStore }
+
+func (b busSweptBucket) Objects(ctx context.Context) ([]bucketObject, error) {
+	infos, err := b.store.List(ctx)
+	if errors.Is(err, jetstream.ErrNoObjectsFound) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	out := make([]bucketObject, 0, len(infos))
+	for _, info := range infos {
+		o := bucketObject{Name: info.Name}
+		if at, err := time.Parse(time.RFC3339, info.Metadata[declarationUnnamed]); err == nil {
+			o.UnnamedSince = at
+		}
+		out = append(out, o)
+	}
+	return out, nil
+}
+
+func (b busSweptBucket) meta(ctx context.Context, name string, change func(map[string]string)) error {
+	info, err := b.store.GetInfo(ctx, name)
+	if err != nil {
+		return err
+	}
+	meta := info.ObjectMeta
+	kept := map[string]string{}
+	for k, v := range meta.Metadata {
+		kept[k] = v
+	}
+	change(kept)
+	meta.Metadata = kept
+	return b.store.UpdateMeta(ctx, name, meta)
+}
+
+func (b busSweptBucket) MarkUnnamed(ctx context.Context, name string, since time.Time) error {
+	return b.meta(ctx, name, func(m map[string]string) { m[declarationUnnamed] = since.UTC().Format(time.RFC3339) })
+}
+
+func (b busSweptBucket) ClearUnnamed(ctx context.Context, name string) error {
+	return b.meta(ctx, name, func(m map[string]string) { delete(m, declarationUnnamed) })
+}
+
+func (b busSweptBucket) Delete(ctx context.Context, name string, markedAt time.Time) (bool, error) {
+	info, err := b.store.GetInfo(ctx, name)
+	if errors.Is(err, jetstream.ErrObjectNotFound) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	if at, perr := time.Parse(time.RFC3339, info.Metadata[declarationUnnamed]); perr != nil || !at.Equal(markedAt) {
+		return false, nil
+	}
+	return true, b.store.Delete(ctx, name)
+}
+
+// sweepingDeclarationFiles judges the bucket every sweepEvery for as long as this controller serves and holds the lease.
+func sweepingDeclarationFiles(ctx context.Context, inv *inventory.Inventory, conn *nats.Conn) {
+	tick := time.NewTicker(sweepEvery)
+	defer tick.Stop()
+	failing := ""
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-tick.C:
+		}
+		if epoch, err := theLease.epoch(ctx); err != nil || epoch == 0 {
+			continue
+		}
+		why := sweepOnce(ctx, inv, conn)
+		if why != failing {
+			if why != "" {
+				fmt.Printf("the bucket of declaration files cannot be swept: %s\n", why)
+			} else {
+				fmt.Printf("the bucket of declaration files is swept again\n")
+			}
+			failing = why
+		}
+	}
+}
+
+// sweepOnce judges the bucket of every node against that node's latest declaration, one bucket at a time under the node's lock, with
+// the declaration read again under it: a send that put an object and published its declaration is seen, and one that has not yet
+// is waiting for the lock.
+func sweepOnce(ctx context.Context, inv *inventory.Inventory, conn *nats.Conn) string {
+	nodes, err := inv.Nodes(ctx)
+	if err != nil {
+		return fmt.Sprintf("the nodes cannot be read: %v", err)
+	}
+	var problems []string
+	var total filesSweep
+	for _, n := range nodes {
+		r, err := sweepNode(ctx, conn, n.Name)
+		total.Kept, total.Marked, total.Cleared, total.Removed = total.Kept+r.Kept, total.Marked+r.Marked, total.Cleared+r.Cleared, total.Removed+r.Removed
+		if err != nil {
+			problems = append(problems, fmt.Sprintf("%s: %v", n.Name, err))
+		}
+	}
+	if total.Removed+total.Marked+total.Cleared > 0 {
+		fmt.Printf("the buckets of declaration files: %d object(s) kept, %d found unnamed, %d named again, %d removed\n",
+			total.Kept, total.Marked, total.Cleared, total.Removed)
+	}
+	return strings.Join(problems, "; ")
+}
+
+func sweepNode(ctx context.Context, conn *nats.Conn, node string) (filesSweep, error) {
+	working, cancel := context.WithTimeout(ctx, 2*time.Minute)
+	defer cancel()
+	js, err := jetstream.New(conn)
+	if err != nil {
+		return filesSweep{}, err
+	}
+	bucket, err := broker.DeclarationFilesBucketOf(node)
+	if err != nil {
+		return filesSweep{}, fmt.Errorf("the bucket of node %q: %w", node, err)
+	}
+	store, err := js.ObjectStore(working, bucket)
+	if errors.Is(err, jetstream.ErrBucketNotFound) {
+		return filesSweep{}, nil // a node never sent a reference has no bucket yet
+	}
+	if err != nil {
+		return filesSweep{}, fmt.Errorf("the bucket cannot be read: %w", err)
+	}
+	defer lockFilesOf(node)()
+	latest, err := latestDeclarations(working, conn, []string{node})
+	if err != nil {
+		return filesSweep{}, err
+	}
+	named := map[string]bool{}
+	if body, ok := latest[node]; ok {
+		if named, err = namedByLatest(node, body); err != nil {
+			return filesSweep{}, err
+		}
+	}
+	return sweepDeclarationFiles(working, busSweptBucket{store}, named, time.Now())
+}

cmd/mesh-controller/plain_words.go

@@ -195,6 +195,14 @@ var plainWordings = map[string]func(conditions.Observation) words{
 				"there yet is sealed by the controller until the vault holds it.", m, m),
 			Resolved: "Resolved: the vault gave " + m + " the core's credentials"}
 	}),
+	kindFilesNotPut: worded(func(o conditions.Observation) words {
+		m := machineOr(o, "a machine")
+		return words{Headline: "The big files for " + m + " cannot be put on the bus",
+			Needs: "look at the bus's permissions for the controller; the details give the reason.",
+			Explanation: fmt.Sprintf("The mesh could not put the large files of %s's instructions in their place on the bus, "+
+				"send after send, so %s is sent them inside the instructions instead, which may make them too big.", m, m),
+			Resolved: "Resolved: the big files for " + m + " reach the bus again"}
+	}),
 	kindDeclarationNearLimit: worded(func(o conditions.Observation) words {
 		m := machineOr(o, "a machine")
 		if o.Severity == conditions.Urgent {

cmd/mesh-controller/push.go

@@ -282,6 +282,8 @@ func serve(ctx context.Context) (err error) {
 	// assignment.
 	inv.SetProvisioningPlans(inv.SentProvisioningPlans)
 	go mirroringRecords(ctx, inv, bus.Conn, bus)
+	// And the bucket of the files that travel by digest, judged against what each machine's latest declaration names (ADR 0486 §3).
+	go sweepingDeclarationFiles(ctx, inv, bus.Conn)
 	// Every call carries the lease's epoch, and its record is written only under the lease (novox/hq
 	// to-be 45 §6).
 	link.Calls.UnderLease(func() (uint64, error) { return theLease.epoch(ctx) })
@@ -979,6 +981,18 @@ func deliver(ctx context.Context, d delivery, holder string, sending []readyNode
 			return err
 		}
 		digest, err := d.declare(ctx, s, body)
+		if errors.Is(err, errFilesNotPut) && s.declared.fileReferences {
+			// **The grant that lets the controller write the bucket travels in the very declaration of the machine holding the
+			// bus** (novox/hq ADR 0486 §2): until the bus has it, a put is refused, and the declaration that would deliver the
+			// grant would wait for it. So that send, and only that, goes with every content inline, as to a node that reads no
+			// references, and says so; the next one tries the bucket again.
+			fmt.Printf("%s: the files that travel by digest could not be put in the bucket (%v): sending them inline\n", s.node, err)
+			s.declared.fileReferences = false
+			if body, err = s.declared.Body(); err != nil {
+				return err
+			}
+			digest, err = d.declare(ctx, s, body)
+		}
 		if err != nil {
 			return err
 		}
@@ -1040,6 +1054,35 @@ type overTheBus struct {
 	indent string
 }
 
+// putFiles puts the contents s names by digest in the bucket.
+func (b overTheBus) putFiles(ctx context.Context, s readyNode) error {
+	objects, err := s.declared.objects()
+	if err != nil {
+		return fmt.Errorf("%s: the files that travel by digest cannot be read: %w", s.node, err)
+	}
+	if len(objects) == 0 {
+		return nil
+	}
+	bus, ok := b.server.Bus().(link.OverNATS)
+	if !ok {
+		return fmt.Errorf("%s: the declaration names files by digest and this bus has no object bucket", s.node)
+	}
+	putting, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+	store, err := openBucket(putting, bus.Conn, s.node)
+	if err == nil {
+		err = putObjects(putting, store, objects)
+	}
+	notePut(ctx, s.node, err)
+	if err != nil {
+		return fmt.Errorf("%s was not sent its declaration: %w: %w", s.node, errFilesNotPut, err)
+	}
+	return nil
+}
+
+// errFilesNotPut marks a send that stopped because the files it names by digest could not be put in the bucket.
+var errFilesNotPut = errors.New("the files it names by digest are not in the bucket")
+
 func (b overTheBus) grant(ctx context.Context, sending []readyNode) error {
 	// The bus's objects first, which every declaration implies (novox/hq issue 208): said and raised
 	// when they cannot be, and never what holds the send back (assertOnSend).
@@ -1052,9 +1095,20 @@ func (b overTheBus) grant(ctx context.Context, sending []readyNode) error {
 }
 
 func (b overTheBus) declare(ctx context.Context, s readyNode, body []byte) (string, error) {
-	if err := link.Declare(ctx, b.server.Bus(), b.signer, s.node, body, 15*time.Second); err != nil {
+	// The contents the declaration names by digest are in the bucket before it is sent (novox/hq ADR 0486 §1, issue 1696): a node
+	// that applies it finds every one. A node reading no references has none.
+	// **Under the node's lock** from the put to the publication, so the sweep of its bucket cannot remove an object between them.
+	unlock := lockFilesOf(s.node)
+	err := b.putFiles(ctx, s)
+	if err != nil {
+		unlock()
 		return "", err
 	}
+	declared := link.Declare(ctx, b.server.Bus(), b.signer, s.node, body, 15*time.Second)
+	unlock()
+	if declared != nil {
+		return "", declared
+	}
 	// After it is away, not before. A digest recorded for something that failed to send would make
 	// the machine look current for a declaration it never received.
 	digest, err := recordSent(ctx, b.open.inventory, s.node, body, s.declared.Builds, s.declared.Epoch,

cmd/mesh-controller/sendable.go

@@ -39,6 +39,10 @@ type sendable struct {
 	// ReadsModules says the machine's node-engine reads a module per resource and a build per module (novox/hq issue
 	// 1145): only then are they sent, because an older node-engine refuses a key it does not know, whole.
 	ReadsModules bool
+	// fileReferences says the machine's node-engine reports the capability of reading a file given as a digest and a size
+	// (declaration.FileReferencesCapability, novox/hq ADR 0486 §5): then every file over 64 KiB that may travel so does (Body,
+	// objects). Not on the wire as a field; the bodies differ.
+	fileReferences bool
 	// moduleOf is the composer's owner of each resource id, and buildIDs the build each module carries (its id):
 	// kept beside the resources, and on the wire only to a machine that reads them.
 	moduleOf map[string]string
@@ -115,12 +119,16 @@ type adoptionEnvelope struct {
 
 // Body is the declaration's bytes, as sent and as digested.
 func (s sendable) Body() ([]byte, error) {
-	envelope := map[string]any{"declaration": 1, "resources": s.Resources}
+	resources, _, err := s.byReference()
+	if err != nil {
+		return nil, err
+	}
+	envelope := map[string]any{"declaration": 1, "resources": resources}
 	if s.ReadsModules {
 		// The module of each resource the composer owns (what the mesh adds of its own has none), and the build of each
 		// module (novox/hq issue 1145): to a machine that said it reads them, and no other.
-		named := make([]map[string]any, len(s.Resources))
-		for n, r := range s.Resources {
+		named := make([]map[string]any, len(resources))
+		for n, r := range resources {
 			module, owned := s.moduleOf[fmt.Sprint(r["id"])]
 			if !owned {
 				named[n] = r
@@ -165,3 +173,19 @@ func (s sendable) Body() ([]byte, error) {
 	}
 	return json.Marshal(envelope)
 }
+
+// byReference is the resources as the machine is sent them: with the contents of its large files replaced by their digests when
+// it reports it reads them (issue 1696), and the contents it replaced, by the name of the object that holds each.
+func (s sendable) byReference() ([]map[string]any, map[string][]byte, error) {
+	if !s.fileReferences {
+		return s.Resources, nil, nil
+	}
+	return referencing(s.Resources)
+}
+
+// objects are the contents the body names by digest, by the name of each one's object: what is put in the bucket before the
+// body is sent. Empty for a machine that is sent every content inline.
+func (s sendable) objects() (map[string][]byte, error) {
+	_, objects, err := s.byReference()
+	return objects, err
+}

go.mod

@@ -3,7 +3,7 @@ module github.com/novox/mesh-controller
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021153908-725590e06e75
 	github.com/jackc/pgx/v5 v5.10.0
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0

go.sum

@@ -1,7 +1,7 @@
 git.novox.be/novox/mesh-host v0.0.0-20261018171808-9d9e3a46c4f5 h1:E5stfIeCN6uYgA9TCv+4K8JgaURg3zQppvUgJLaDMP4=
 git.novox.be/novox/mesh-host v0.0.0-20261018171808-9d9e3a46c4f5/go.mod h1:4wyoCr6IIIIarEUuROThWDj7DAvJvIidqMjWcpSnOwE=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b h1:5UlQ8ytlHNgqlm5AbwJEnZwuf1EWUiNyXX2hcOV9Yro=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021153908-725590e06e75 h1:AcYfyJpYaUufhI93VG76+b001msXY4XX7kuRjnf33HY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021153908-725590e06e75/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/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

internal/broker/declaration_files.go

@@ -0,0 +1,123 @@
+package broker
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// The object buckets a declaration's large files travel in (novox/hq ADR 0486, issues 1696 and 1697): **one bucket for each
+// node**, `declaration-files-<node>`.
+//
+// **The controller alone writes them, and a node-engine reads an object by its name from its own bucket** (ADR 0486 §2): its
+// account may neither list the bucket nor write it, no account may touch another node's, and no other account has any access.
+// Why a bucket each: a subject pattern cannot tell a name from a wildcard. A grant of `...M.*` matches a publish to the literal
+// subject `...M.*` too (probed on nats-server 2.11.17 by the review of this issue: a node created a consumer filtered on
+// `$O.<bucket>.C.*` and read every object of the bucket), so in one shared bucket a node could read every other node's files.
+// With a bucket each, the same trick reads only the node's own files, which are the files of its own declaration.
+//
+// A bucket of the bus's object store is a stream, OBJ_<bucket>, whose messages are the objects' metadata
+// (`$O.<bucket>.M.<base64 of the name>`) and chunks (`$O.<bucket>.C.<nuid>`).
+
+// DeclarationFilesBucket is the prefix of the buckets' names, which mesh-sdk fixes for the node-engine and the controller alike.
+const DeclarationFilesBucket = declaration.FileBucketPrefix
+
+// DeclarationFilesBucketOf is the bucket a node's files are in: mesh-sdk's FileBucketFor, the one place the name is composed. A
+// node name it refuses (one that could carry a subject wildcard or separator into a grant) is an error, never a bucket.
+func DeclarationFilesBucketOf(node string) (string, error) { return declaration.FileBucketFor(node) }
+
+// DeclarationFilesStreamOf is the stream under a node's bucket: mesh-sdk's FileStreamFor.
+func DeclarationFilesStreamOf(node string) (string, error) { return declaration.FileStreamFor(node) }
+
+// DeclarationFilesMaxBytes is a bucket's size: the objects are immutable and regenerable, and one node's hold well under a hundred
+// megabytes.
+const DeclarationFilesMaxBytes = 1 << 30
+
+// DeclarationFilesKeptFor is how long an object stays after no node's latest declaration names it (ADR 0486 §3).
+const DeclarationFilesKeptFor = 24 * time.Hour
+
+// DeclarationFilesWrites is the one pattern the controller may publish to write a node's bucket: every object's metadata and
+// chunks. The server's API for the stream is the controller's `$JS.API.>`.
+func DeclarationFilesWrites(node string) (string, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return "", err
+	}
+	return "$O." + bucket + ".>", nil
+}
+
+// DeclarationFilesReads is what a node-engine's account may publish to read an object of its own bucket by its name, and nothing
+// more. The set is the one node-engine's own call (mesh-host internal/link FileObject) makes, for B the node's bucket and S its
+// stream (issue 1697, notes 4 and 5):
+//
+//   - the object's metadata, by a direct get of the last message of the one subject that names it. **Only the suffixed
+//     form**: the bare `$JS.API.DIRECT.GET.S` takes a sequence number and would read any message of the stream.
+//   - the ordered consumer on that object's chunks: `$JS.API.CONSUMER.CREATE.S.<name>.$O.B.C.<nuid>`. **Not `S.>`**:
+//     a consumer filtered on `$O.B.M.>` would read every object's name.
+//   - the flow-control replies of that consumer, without which a large object stalls at the flow-control window.
+//   - the consumer's deletion, best effort: the consumer's inactivity threshold removes it if this is refused.
+//
+// **Never granted:** STREAM.INFO (a `subjects_filter` of `>` lists every name), STREAM.MSG.GET (any message by its sequence), a
+// publish to `$O.B.>` (a write), and any subject of another node's stream. A literal `*` in a subject matches the grant's `*`: it
+// reaches the objects of this node's own bucket and no other (above).
+func DeclarationFilesReads(node string) ([]string, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return nil, err
+	}
+	stream, err := DeclarationFilesStreamOf(node)
+	if err != nil {
+		return nil, err
+	}
+	return []string{
+		"$JS.API.DIRECT.GET." + stream + ".$O." + bucket + ".M.*",
+		"$JS.API.CONSUMER.CREATE." + stream + ".*.$O." + bucket + ".C.*",
+		"$JS.API.CONSUMER.DELETE." + stream + ".*",
+		"$JS.FC." + stream + ".>",
+	}, nil
+}
+
+// EnsureDeclarationFiles creates the buckets of these nodes if absent and brings their options to match. A bucket exists whenever the
+// bus does, so a node that is starting finds it (ADR 0486 §4). An update, never a delete.
+func (j *JetStream) EnsureDeclarationFiles(nodes []string) error {
+	js, err := jetstream.New(j.conn)
+	if err != nil {
+		return err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	return EnsureDeclarationFiles(ctx, js, nodes...)
+}
+
+// EnsureDeclarationFiles is the same on a JetStream the caller holds.
+func EnsureDeclarationFiles(ctx context.Context, js jetstream.JetStream, nodes ...string) error {
+	for _, node := range nodes {
+		cfg, err := DeclarationFilesConfig(node)
+		if err != nil {
+			return err
+		}
+		if _, err := js.CreateOrUpdateObjectStore(ctx, cfg); err != nil {
+			return fmt.Errorf("asserting the object bucket %s: %w", cfg.Bucket, err)
+		}
+	}
+	return nil
+}
+
+// DeclarationFilesConfig is a node's bucket as the controller asserts it.
+func DeclarationFilesConfig(node string) (jetstream.ObjectStoreConfig, error) {
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return jetstream.ObjectStoreConfig{}, err
+	}
+	return jetstream.ObjectStoreConfig{
+		Bucket: bucket,
+		Description: "the contents of the files over 64 KiB of the declaration of " + node + ", each under the hex of its sha256 " +
+			"digest (novox/hq ADR 0486): written by the controller alone, read by the node-engine of that node by name, removed " +
+			"a day after the node's latest declaration no longer names it",
+		MaxBytes: DeclarationFilesMaxBytes,
+		Storage:  jetstream.FileStorage,
+	}, nil
+}

internal/broker/declaration_files_live_test.go

@@ -0,0 +1,316 @@
+//go:build integration
+
+package broker
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats-server/v2/server"
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+	"golang.org/x/crypto/bcrypt"
+)
+
+// nodeEnginesFileObject is the node-engine's own call (mesh-host internal/link files.go, OverNATS.FileObject), as the
+// engine makes it: the object's metadata by a direct get of one subject, then its chunks through an ordered consumer
+// bound to the stream. It is copied here so the grants are judged by the call that has to work, and its subjects are the
+// ones the grant names (issue 1697, notes 4 and 5); the node-engine's own integration test holds the other copy.
+func nodeEnginesFileObject(ctx context.Context, nc *nats.Conn, node, name string) ([]byte, error) {
+	js, err := nc.JetStream(nats.MaxWait(10 * time.Second))
+	if err != nil {
+		return nil, err
+	}
+	stream, err := DeclarationFilesStreamOf(node)
+	if err != nil {
+		return nil, err
+	}
+	bucket, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		return nil, err
+	}
+	meta, err := js.GetLastMsg(stream, "$O."+bucket+".M."+base64.URLEncoding.EncodeToString([]byte(name)),
+		nats.DirectGet(), nats.Context(ctx))
+	if err != nil {
+		return nil, err
+	}
+	var info struct {
+		NUID string `json:"nuid"`
+		Size uint64 `json:"size"`
+	}
+	if err := json.Unmarshal(meta.Data, &info); err != nil {
+		return nil, err
+	}
+	sub, err := js.SubscribeSync("$O."+bucket+".C."+info.NUID, nats.OrderedConsumer(), nats.BindStream(stream))
+	if err != nil {
+		return nil, err
+	}
+	defer sub.Unsubscribe()
+	body := make([]byte, 0, info.Size)
+	for uint64(len(body)) < info.Size {
+		msg, err := sub.NextMsgWithContext(ctx)
+		if err != nil {
+			return nil, err
+		}
+		body = append(body, msg.Data...)
+	}
+	return body, nil
+}
+
+// **The buckets' grants on a real server, judged by the node-engine's own call** (novox/hq ADR 0486 §2, issue 1697, 1697/AC2): the
+// controller's account writes an object into each node's bucket, a node-engine's account reads one of its own bucket by its name,
+// a large object included, and is refused a list of the bucket (a stream info asking for every subject), a message get by
+// sequence, a direct get by sequence, a consumer on the names, and a write; it is refused every one of those and the read by name on
+// another node's bucket, **the literal-`*` forms included** (a published subject `...M.*` or `...C.*` matches the grant's `*`: on
+// its own bucket that reaches its own files, on another's it is refused); another module's account is refused all of them.
+func TestNatsANodeEngineReadsAnObjectOfItsOwnBucketByNameAndNothingElse(t *testing.T) { // 1697/AC2
+	hash, err := bcrypt.GenerateFromPassword([]byte("pw"), bcrypt.MinCost)
+	if err != nil {
+		t.Fatal(err)
+	}
+	users, err := Users(Records{Nodes: []string{"alpha", "beta"}, Assigned: map[string][]Declared{
+		"alpha": {{Module: RuntimeModule}, {Module: "other-module"}},
+	}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for i := range users {
+		users[i].PasswordHash = string(hash)
+	}
+	accounts, err := ComposeAccounts(users)
+	if err != nil {
+		t.Fatal(err)
+	}
+	conf := filepath.Join(t.TempDir(), "bus.conf")
+	if err := os.WriteFile(conf, []byte("listen: 127.0.0.1:-1\njetstream { store_dir: "+
+		`"`+t.TempDir()+`"`+" }\n"+accounts), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	opts, err := server.ProcessConfigFile(conf)
+	if err != nil {
+		t.Fatalf("the composed accounts do not parse: %v", err)
+	}
+	opts.NoLog, opts.NoSigs = true, true
+	s, err := server.NewServer(opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	go s.Start()
+	if !s.ReadyForConnections(10 * time.Second) {
+		t.Fatal("the bus did not come up")
+	}
+	t.Cleanup(s.Shutdown)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 90*time.Second)
+	defer cancel()
+	connect := func(user string) (*nats.Conn, chan error) {
+		t.Helper()
+		refused := make(chan error, 16)
+		nc, err := nats.Connect(s.ClientURL(), nats.UserInfo(user, "pw"), nats.CustomInboxPrefix("_INBOX."+user),
+			nats.ErrorHandler(func(_ *nats.Conn, _ *nats.Subscription, err error) { refused <- err }))
+		if err != nil {
+			t.Fatalf("%s cannot connect: %v", user, err)
+		}
+		t.Cleanup(nc.Close)
+		return nc, refused
+	}
+
+	// The controller makes the buckets (as it does at its start) and writes into each: for alpha a small object and one of
+	// several chunks, which needs the consumer's flow control; for beta one that holds a marker alpha must never read.
+	controller, _ := connect(ControllerName)
+	cjs, err := jetstream.New(controller)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := EnsureDeclarationFiles(ctx, cjs, "alpha", "beta"); err != nil {
+		t.Fatalf("the controller cannot make the buckets: %v", err)
+	}
+	if err := EnsureDeclarationFiles(ctx, cjs, "alpha", "beta"); err != nil {
+		t.Fatalf("asserting them again: %v", err)
+	}
+	put := func(node string, content []byte) string {
+		t.Helper()
+		store, err := cjs.ObjectStore(ctx, mustBucket(t, node))
+		if err != nil {
+			t.Fatal(err)
+		}
+		sum := sha256.Sum256(content)
+		name := hex.EncodeToString(sum[:])
+		if _, err := store.PutBytes(ctx, name, content); err != nil {
+			t.Fatalf("the controller cannot write the object %s of %s: %v", name[:8], node, err)
+		}
+		return name
+	}
+	small := bytes.Repeat([]byte("small file\n"), 100)
+	large := make([]byte, 900<<10)
+	for i := range large {
+		large[i] = byte(i*7 + i>>8)
+	}
+	secret := bytes.Repeat([]byte("BETA-SECRET "), 50)
+	smallName, largeName, betaName := put("alpha", small), put("alpha", large), put("beta", secret)
+
+	alpha, alphaRefused := connect("node.alpha")
+	for name, want := range map[string][]byte{smallName: small, largeName: large} {
+		got, err := nodeEnginesFileObject(ctx, alpha, "alpha", name)
+		if err != nil {
+			t.Fatalf("a node-engine cannot read the object %s of its own bucket by its name: %v", name[:8], err)
+		}
+		if !bytes.Equal(got, want) {
+			t.Fatalf("the node-engine read %d bytes of the object %s, want %d", len(got), name[:8], len(want))
+		}
+	}
+	beta, _ := connect("node.beta")
+	if got, err := nodeEnginesFileObject(ctx, beta, "beta", betaName); err != nil || !bytes.Equal(got, secret) {
+		t.Fatalf("beta's node-engine reads its own object: %v", err)
+	}
+	select {
+	case err := <-alphaRefused:
+		t.Fatalf("a node-engine's own read was refused something: %v", err)
+	default:
+	}
+
+	// What each account is refused, judged by the server.
+	alphaStream, alphaBucket := mustStream(t, "alpha"), mustBucket(t, "alpha")
+	betaStream, betaBucket := mustStream(t, "beta"), mustBucket(t, "beta")
+	listing := []byte(`{"subjects_filter":">"}`)
+	bySeq := []byte(`{"seq":1}`)
+	type refusal struct {
+		what string
+		do   func(nc *nats.Conn)
+	}
+	onBucket := func(stream, bucket, which string) []refusal {
+		return []refusal{
+			{which + ": a list of the bucket (stream info asking for every subject)", func(nc *nats.Conn) {
+				_, _ = nc.Request("$JS.API.STREAM.INFO."+stream, listing, 300*time.Millisecond)
+			}},
+			{which + ": a message get by sequence", func(nc *nats.Conn) {
+				_, _ = nc.Request("$JS.API.STREAM.MSG.GET."+stream, bySeq, 300*time.Millisecond)
+			}},
+			{which + ": a direct get by sequence", func(nc *nats.Conn) {
+				_, _ = nc.Request("$JS.API.DIRECT.GET."+stream, bySeq, 300*time.Millisecond)
+			}},
+			{which + ": a consumer on every object's name", func(nc *nats.Conn) {
+				js, _ := nc.JetStream(nats.MaxWait(500 * time.Millisecond))
+				if sub, err := js.SubscribeSync("$O."+bucket+".M.>", nats.OrderedConsumer(), nats.BindStream(stream)); err == nil {
+					sub.Unsubscribe()
+				}
+			}},
+			{which + ": a write of an object's metadata", func(nc *nats.Conn) {
+				_ = nc.Publish("$O."+bucket+".M.abc", []byte(`{}`))
+				_ = nc.Flush()
+			}},
+			{which + ": a write of a chunk", func(nc *nats.Conn) {
+				_ = nc.Publish("$O."+bucket+".C.abc", []byte("x"))
+				_ = nc.Flush()
+			}},
+		}
+	}
+	refusedWith := func(who string, nc *nats.Conn, ch chan error, r refusal) {
+		t.Helper()
+		for len(ch) > 0 {
+			<-ch
+		}
+		r.do(nc)
+		_ = nc.Flush()
+		deadline := time.After(3 * time.Second)
+		for {
+			select {
+			case err := <-ch:
+				if errors.Is(err, nats.ErrPermissionViolation) {
+					return
+				}
+			case <-deadline:
+				t.Errorf("the server did not refuse %s %s", who, r.what)
+				return
+			}
+		}
+	}
+	// Alpha's account on its own bucket (list, sequence reads, names, writes) and on beta's (all of that, and the read by name,
+	// and the literal-`*` probes of the review).
+	reachBeta := []refusal{
+		{"beta's bucket: a read of one object by its name", func(nc *nats.Conn) {
+			_, _ = nc.Request("$JS.API.DIRECT.GET."+betaStream+".$O."+betaBucket+".M."+
+				base64.URLEncoding.EncodeToString([]byte(betaName)), nil, 300*time.Millisecond)
+		}},
+		{"beta's bucket: a direct get with a literal `*` for the name", func(nc *nats.Conn) {
+			_, _ = nc.Request("$JS.API.DIRECT.GET."+betaStream+".$O."+betaBucket+".M.*", nil, 300*time.Millisecond)
+		}},
+		{"beta's bucket: a consumer with a literal `*` for the chunks", func(nc *nats.Conn) {
+			js, _ := nc.JetStream(nats.MaxWait(500 * time.Millisecond))
+			if sub, err := js.SubscribeSync("$O."+betaBucket+".C.*", nats.OrderedConsumer(), nats.BindStream(betaStream)); err == nil {
+				sub.Unsubscribe()
+			}
+		}},
+	}
+	all := append(append(onBucket(alphaStream, alphaBucket, "its own bucket"), onBucket(betaStream, betaBucket, "beta's bucket")...), reachBeta...)
+	for _, r := range all {
+		nodeNC, nodeCh := connect("node.alpha")
+		refusedWith("a node-engine", nodeNC, nodeCh, r)
+	}
+	// Another module is refused all of that on both buckets, and the reads by name on both.
+	for _, r := range append(append(onBucket(alphaStream, alphaBucket, "alpha's bucket"), reachBeta...),
+		refusal{"alpha's bucket: a read of one object by its name", func(nc *nats.Conn) {
+			_, _ = nc.Request("$JS.API.DIRECT.GET."+alphaStream+".$O."+alphaBucket+".M."+
+				base64.URLEncoding.EncodeToString([]byte(smallName)), nil, 300*time.Millisecond)
+		}}) {
+		otherNC, otherCh := connect("alpha.other-module")
+		refusedWith("another module", otherNC, otherCh, r)
+	}
+
+	// The literal `*` on alpha's own bucket reaches alpha's own files and never beta's: the chunks it is given hold no marker of beta's.
+	js, err := alpha.JetStream(nats.MaxWait(2 * time.Second))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sub, err := js.SubscribeSync("$O."+alphaBucket+".C.*", nats.OrderedConsumer(), nats.BindStream(alphaStream)); err == nil {
+		for i := 0; i < 20; i++ {
+			msg, err := sub.NextMsg(300 * time.Millisecond)
+			if err != nil {
+				break
+			}
+			if bytes.Contains(msg.Data, []byte("BETA-SECRET")) {
+				t.Fatal("a literal `*` on alpha's bucket gave it a chunk of beta's file")
+			}
+		}
+		sub.Unsubscribe()
+	}
+
+	// Nothing was written by the refused: each bucket holds what the controller wrote.
+	for node, want := range map[string]int{"alpha": 2, "beta": 1} {
+		store, err := cjs.ObjectStore(ctx, mustBucket(t, node))
+		if err != nil {
+			t.Fatal(err)
+		}
+		infos, err := store.List(ctx)
+		if err != nil || len(infos) != want {
+			t.Errorf("the bucket of %s holds %d objects (%v), want the %d the controller wrote", node, len(infos), err, want)
+		}
+	}
+}
+
+func mustBucket(t *testing.T, node string) string {
+	t.Helper()
+	b, err := DeclarationFilesBucketOf(node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return b
+}
+
+func mustStream(t *testing.T, node string) string {
+	t.Helper()
+	b, err := DeclarationFilesStreamOf(node)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return b
+}

internal/broker/declaration_files_test.go

@@ -0,0 +1,131 @@
+package broker
+
+import (
+	"slices"
+	"strings"
+	"testing"
+)
+
+// 1697/AC1: the composed accounts give a node-engine exactly the four reads of one object by its name, on its own node's bucket and
+// no other's; the controller the write of every node's bucket; and no other principal anything of any bucket.
+func TestEachNodesBucketIsWrittenByTheControllerAndReadByNameByThatNodesEngine(t *testing.T) { // 1697/AC1
+	node, err := PermissionsFor(Principal{Kind: KindNode, Node: "alpha", PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var mine []string
+	for _, s := range node.Publish {
+		if strings.Contains(s, "declaration-files") {
+			mine = append(mine, s)
+		}
+	}
+	want := []string{
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-alpha.*.$O.declaration-files-alpha.C.*",
+		"$JS.API.CONSUMER.DELETE.OBJ_declaration-files-alpha.*",
+		"$JS.API.DIRECT.GET.OBJ_declaration-files-alpha.$O.declaration-files-alpha.M.*",
+		"$JS.FC.OBJ_declaration-files-alpha.>",
+	}
+	if !slices.Equal(mine, want) {
+		t.Fatalf("a node-engine may publish %q of the buckets, want exactly %q", mine, want)
+	}
+	// What would make a list, a write, or a read of another node's files: none of it, in any pattern a node holds. (The real
+	// server's judgement of the wildcard forms is the live test's.)
+	for _, refused := range []string{
+		"$JS.API.STREAM.INFO.OBJ_declaration-files-alpha",
+		"$JS.API.STREAM.MSG.GET.OBJ_declaration-files-alpha",
+		"$JS.API.DIRECT.GET.OBJ_declaration-files-alpha",
+		"$JS.API.DIRECT.GET.OBJ_declaration-files-alpha.$O.declaration-files-alpha.M.abc.def",
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-alpha.x.$O.declaration-files-alpha.M.YWJj",
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-alpha.x.$O.declaration-files-alpha.M.YWJj.more",
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-alpha",
+		"$O.declaration-files-alpha.M.abc",
+		"$O.declaration-files-alpha.C.abc",
+		// another node's bucket, however it is named
+		"$JS.API.DIRECT.GET.OBJ_declaration-files-beta.$O.declaration-files-beta.M.YWJj",
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-beta.h4sh.$O.declaration-files-beta.C.NUID",
+		"$JS.API.CONSUMER.DELETE.OBJ_declaration-files-beta.h4sh",
+		"$JS.FC.OBJ_declaration-files-beta.x",
+		// and the old shared bucket
+		"$JS.API.DIRECT.GET.OBJ_declaration-files.$O.declaration-files.M.YWJj",
+	} {
+		if MayPublish(node, refused) {
+			t.Errorf("a node-engine may publish %s, which lists or writes a bucket or reads another node's", refused)
+		}
+	}
+	for _, kept := range []string{
+		"$JS.API.DIRECT.GET.OBJ_declaration-files-alpha.$O.declaration-files-alpha.M.YWJj",
+		"$JS.API.CONSUMER.CREATE.OBJ_declaration-files-alpha.h4sh.$O.declaration-files-alpha.C.NUID",
+	} {
+		if !MayPublish(node, kept) {
+			t.Errorf("a node-engine may not publish %s, which reads one object of its own bucket by its name", kept)
+		}
+	}
+
+	controller, err := PermissionsFor(Principal{Kind: KindController, PasswordHash: "x", FilesFor: []string{"alpha", "beta"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, s := range []string{"$O.declaration-files-alpha.M.abc", "$O.declaration-files-beta.C.nuid"} {
+		if !MayPublish(controller, s) {
+			t.Errorf("the controller may not write %s", s)
+		}
+	}
+	if MayPublish(controller, "$O.declaration-files-gamma.M.abc") {
+		t.Error("the controller may write the bucket of a node it was not given")
+	}
+
+	for _, p := range []Principal{
+		{Kind: KindModule, Module: "mesh-vault", PasswordHash: "x"},
+		{Kind: KindNodeTools, Node: "alpha", PasswordHash: "x"},
+		{Kind: KindPerson, Module: "jochen", Invokes: []string{"*"}, PasswordHash: "x"},
+	} {
+		perms, err := PermissionsFor(p)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for _, s := range append(append([]string(nil), perms.Publish...), perms.Subscribe...) {
+			if strings.Contains(s, "declaration-files") {
+				t.Errorf("%s holds %s, and no account but the controller's and the node-engines' has any access", p.Username(), s)
+			}
+		}
+	}
+}
+
+// The users the controller composes carry each node's bucket to the controller and to that node alone.
+func TestTheComposedUsersGiveEachNodeItsOwnBucketAndTheControllerAll(t *testing.T) {
+	users, err := Users(Records{Nodes: []string{"alpha", "beta"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var controller Principal
+	for _, u := range users {
+		if u.Kind == KindController {
+			controller = u
+		}
+	}
+	if !slices.Equal(controller.FilesFor, []string{"alpha", "beta"}) {
+		t.Fatalf("the controller writes the buckets of %v", controller.FilesFor)
+	}
+}
+
+// A node name that could carry a subject wildcard or separator into a grant is refused with an error, never composed into a bucket
+// (ADR 0488): the grants of such a name would reach another node's bucket.
+func TestANodeNameThatCarriesAWildcardGetsNoBucketAndNoGrant(t *testing.T) {
+	for _, node := range []string{"", "*", ">", "a.b", "a b", "a*"} {
+		if b, err := DeclarationFilesBucketOf(node); err == nil {
+			t.Errorf("node %q got the bucket %q", node, b)
+		}
+		if _, err := DeclarationFilesReads(node); err == nil {
+			t.Errorf("node %q got read grants", node)
+		}
+		if _, err := DeclarationFilesWrites(node); err == nil {
+			t.Errorf("node %q got write grants", node)
+		}
+		if _, err := DeclarationFilesConfig(node); err == nil {
+			t.Errorf("node %q got a bucket config", node)
+		}
+	}
+	if b, err := DeclarationFilesBucketOf("g14"); err != nil || b != "declaration-files-g14" {
+		t.Errorf("g14: %q %v", b, err)
+	}
+}

internal/broker/nats.go

@@ -104,6 +104,10 @@ type Principal struct {
 	// Username and inbox are <node>.<module>.<process id>.
 	Process string
 
+	// FilesFor are the nodes whose declaration-file buckets this principal writes, for the controller alone (novox/hq ADR 0486 §2):
+	// every node of the mesh, one bucket each.
+	FilesFor []string
+
 	Emits    []string
 	Consumes []string
 	Serves   []string
@@ -736,6 +740,15 @@ func PermissionsFor(p Principal) (Permissions, error) {
 			}
 			pub = append(pub, "$KV."+bucket+".>")
 		}
+		// **And the object bucket a declaration's large files travel in** (novox/hq ADR 0486 §2, issue 1697): the
+		// controller alone writes it, as a publish to the bucket's own subjects, which `$JS.API.>` does not cover.
+		for _, node := range p.FilesFor {
+			writes, err := DeclarationFilesWrites(node)
+			if err != nil {
+				return Permissions{}, err
+			}
+			pub = append(pub, writes)
+		}
 		// **And what the bus says about itself, read-only** (novox/hq to-be 45 §3, S9): a durable
 		// consumer that gave up on a message, or one that was deleted. The server already publishes
 		// both in the mesh's own account; the controller says each as a condition in the mesh's words.
@@ -835,6 +848,13 @@ func PermissionsFor(p Principal) (Permissions, error) {
 			return Permissions{}, err
 		}
 		pub = append(pub, haveKeys...)
+		// And an object of the declaration bucket by its name, and nothing of the bucket's list or writing
+		// (novox/hq ADR 0486 §2, issue 1697).
+		fileReads, err := DeclarationFilesReads(p.Node)
+		if err != nil {
+			return Permissions{}, err
+		}
+		pub = append(pub, fileReads...)
 		// And, while the vault serves it, the vault's move-in in its own name and nobody else's (issue 676): the
 		// values sealed to this machine, which only it opens, handed in sealed to the vault's key for the call.
 		if p.MovesIntoTheVault {

internal/broker/testdata/composed.conf

@@ -38,7 +38,7 @@ accounts {
         subscribe: { allow: ["_INBOX.enrol.one.>"] }
       } }
       { user: "node.one", password: "$2a$11$nnnnnnnnnnnnnnnnnnnnnn", permissions: {
-        publish: { allow: ["$JS.ACK.NODES.one.>", "$JS.API.CONSUMER.CREATE.KV_node-engine_have.*.$KV.node-engine_have.one.>", "$JS.API.CONSUMER.DELETE.KV_node-engine_have.>", "$JS.API.CONSUMER.INFO.NODES.one", "$JS.API.DIRECT.GET.KV_node-engine_have.$KV.node-engine_have.one.>", "$JS.API.STREAM.INFO.KV_node-engine_have", "$JS.FC.KV_node-engine_have.>", "$KV.node-engine_have.one.>", "$SRV.PING.node-tools.one", "mesh.control.one.>"] }
+        publish: { allow: ["$JS.ACK.NODES.one.>", "$JS.API.CONSUMER.CREATE.KV_node-engine_have.*.$KV.node-engine_have.one.>", "$JS.API.CONSUMER.CREATE.OBJ_declaration-files-one.*.$O.declaration-files-one.C.*", "$JS.API.CONSUMER.DELETE.KV_node-engine_have.>", "$JS.API.CONSUMER.DELETE.OBJ_declaration-files-one.*", "$JS.API.CONSUMER.INFO.NODES.one", "$JS.API.DIRECT.GET.KV_node-engine_have.$KV.node-engine_have.one.>", "$JS.API.DIRECT.GET.OBJ_declaration-files-one.$O.declaration-files-one.M.*", "$JS.API.STREAM.INFO.KV_node-engine_have", "$JS.FC.KV_node-engine_have.>", "$JS.FC.OBJ_declaration-files-one.>", "$KV.node-engine_have.one.>", "$SRV.PING.node-tools.one", "mesh.control.one.>"] }
         subscribe: { allow: ["_DELIVER.one", "_DELIVER.one.>", "_INBOX.node.one.>", "mesh.node.one.ask.hand-over", "mesh.node.one.ask.judge-directories", "mesh.node.one.ask.move-secret", "mesh.node.one.ask.report", "mesh.node.one.ask.setuid-search", "mesh.node.one.declare"] }
         allow_responses: { max: 1, ttl: "1m" }
       } }

internal/broker/users.go

@@ -135,7 +135,7 @@ type Records struct {
 // correct.
 func Users(r Records) ([]Principal, error) {
 	out := []Principal{{Kind: KindController, Uses: asksSeatOf(r), AsksIssued: issuedOf(r), AsksTheVault: vaultVerbsOf(r),
-		AsksTheConfig: servedOf(r, VerbsTheControllerAsksTheConfig)}}
+		AsksTheConfig: servedOf(r, VerbsTheControllerAsksTheConfig), FilesFor: sortedCopy(r.Nodes)}}
 
 	for _, node := range sortedCopy(r.Nodes) {
 		witness := false

internal/broker/writers.go

@@ -219,6 +219,13 @@ var WritersTable = []WriterRow{
 	{State: "a machine's have", Writer: "the node-engine of the machine, under its own keys `<node>.>`",
 		KeptIn: "key-value " + delivery.HaveBucket + ", twenty revisions of each key",
 		Others: "read through `reads` as node-engine.have", Subjects: kvOf(delivery.HaveBucket), Writes: ownNodeKeys},
+	// The contents of a declaration's files over 64 KiB (novox/hq ADR 0486 §2): the controller alone writes the bucket, each
+	// object under the digest of its content; a node-engine reads one by its name, with no list and no write.
+	{State: "a declaration's large files", Writer: "controller, each object under the sha256 digest of its content",
+		KeptIn: "the object bucket " + DeclarationFilesBucket + "-<node> of each node, an object removed a day after the " +
+			"node's latest declaration no longer names it",
+		Others:   "a node-engine reads an object of its own bucket by its name and may neither list the bucket nor write it",
+		Subjects: []string{"$O.*.>"}, Writes: isController},
 	{State: "the declared-config mirror", Writer: "controller (lease holder), from its store, only on a change",
 		KeptIn: "key-value " + DeclaredConfigBucket, Others: "read through `reads` as mesh-controller." + MirrorDeclaredConfig,
 		Subjects: kvOf(DeclaredConfigBucket), Writes: isController},

internal/broker/writers_test.go

@@ -43,6 +43,8 @@ var designRows = []string{
 	"the rollouts of the chain",
 	// What each machine has of each module, written by its node-engine under its own keys (ADR 0429 §1, issue 1136).
 	"a machine's have",
+	// The contents of a declaration's large files, in the bus's object bucket (ADR 0486 §2, issue 1697).
+	"a declaration's large files",
 	"the declared-config mirror",
 	"the predefined-keys mirror",
 	// The provisioner client's word on what it placed (novox/hq ADR 0349 §4, design 57 P6).

internal/link/builds_nats.go

@@ -362,6 +362,14 @@ func (m *natsMachine) Take(ctx context.Context, do func(context.Context, Build))
 			_ = msg.Nak()
 			continue
 		}
+		// **A duplicate of a check another builder is running is dropped** (issue 1649): an ask redelivered to this machine
+		// because its first holder did not say, in time, that it had it. The running key names that builder and this same
+		// ask; running it a second time would spend a second place on one check.
+		if why := m.runningElsewhere(ctx, request); why != "" {
+			fmt.Fprintf(os.Stderr, "%s is handed out again while another builder runs it and is dropped: %s\n", request.ID, why)
+			_ = msg.Ack()
+			continue
+		}
 		// A build outlives the acknowledgement window many times over; said while it runs,
 		// as the controller says it for its own long handlers, so the server neither hands
 		// the ask to a second machine nor counts the wait against its deliveries.
@@ -376,6 +384,35 @@ func (m *natsMachine) Take(ctx context.Context, do func(context.Context, Build))
 	}
 }
 
+// runningElsewhere says why an ask need not run here, or nothing: the bucket of the checks running says another builder
+// runs this very ask (its id, its head and its trunk commit). A key that cannot be read runs the check.
+func (m *natsMachine) runningElsewhere(ctx context.Context, r BuildRequest) string {
+	if r.Check == nil {
+		return ""
+	}
+	running, ok, err := ReadRunning(ctx, m.js.Conn(), r)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "could not read whether %s is running elsewhere, so it runs: %v\n", r.ID, err)
+		return ""
+	}
+	return duplicateOf(running, ok, r, m.on)
+}
+
+// runningFreshFor is how recent a running key's last heartbeat must be for its builder to be taken as alive: two missed
+// heartbeats of ten seconds are not yet a dead builder, and a redelivery after a crash comes a minute after the last one.
+const runningFreshFor = 25 * time.Second
+
+// duplicateOf says why an ask is a second hand-out of one another builder is running, or nothing.
+func duplicateOf(running CheckRunning, found bool, r BuildRequest, me string) string {
+	// Seen is the server's time and runningFreshFor is judged against this builder's clock: a skew over about 35 s would matter.
+	// A key not renewed for runningFreshFor is a builder that has gone: its ask is redelivered after the ack wait, and
+	// that is the recovery, not a duplicate (the key itself lives two minutes).
+	if found && running.Build == r.ID && running.Builder != me && running.Same(r) && time.Since(running.Seen) < runningFreshFor {
+		return fmt.Sprintf("%s is running it as %s since %s", running.Builder, running.Build, running.Started.Local().Format("15:04:05"))
+	}
+	return ""
+}
+
 // bind binds a queue's worker, which exists and is not created here.
 //
 // **The consumer's own filter, not the one subject this machine cares about.** The client checks what is asked for

internal/link/bus_nats.go

@@ -24,3 +24,6 @@ func ConnectNats(js *broker.JetStream, enroller Enroller, listener Listener) *Se
 // Bus is the controller's outbound, whichever transport it connected over. Callers that send a
 // declaration or ask a tool use this rather than the channel, which one transport does not have.
 func (s *Server) Bus() Bus { return s.bus }
+
+// SendingOn is a server that only sends, over the bus given: for a test of a sender with a bus it holds in its hand.
+func SendingOn(bus Bus) *Server { return &Server{bus: bus} }

internal/link/checks_nats.go

@@ -253,11 +253,25 @@ func watchPullIn(ctx context.Context, buckets []string, open func(ctx context.Co
 
 // checkTakeWait is how long a taking loop waits on one queue for an ask that is not there, and takeIdleWait how long it
 // waits on the first when all three are empty.
+//
+// **A fetch's pull request must end before the fetch does** (issue 1649). nats.go gives the server-side request an expiry a tenth
+// shorter than the fetch's wait (fetchExpiryOf), and the server then answers with a status message at the expiry; a wait so
+// short that the answer can land after the fetch gave up left a status message in the pull's buffer, and anything a request
+// could still deliver would be held by a machine that is busy. Each wait leaves at least minFetchMargin between the two.
 const (
-	checkTakeWait = 30 * time.Millisecond
+	checkTakeWait = 100 * time.Millisecond
 	takeIdleWait  = time.Second
 )
 
+// minFetchMargin is the least time between a fetch's server-side expiry and the end of its wait.
+const minFetchMargin = 10 * time.Millisecond
+
+// fetchExpiryOf is the expiry nats.go gives the pull request of a fetch that waits this long: the wait less a tenth of it, or
+// less five seconds.
+func fetchExpiryOf(wait time.Duration) time.Duration {
+	return wait - min(wait/10, 5*time.Second)
+}
+
 // CheckRunning is what a builder says of the check it is running, in the bucket of the checks running (novox/hq ADR 0406
 // §3): the head and trunk commit it checks, the builder and its build. The key is the pull request's (RunningKeyOf).
 type CheckRunning struct {
@@ -268,6 +282,8 @@ type CheckRunning struct {
 	// Started is when the check started, kept on every heartbeat: the entry's own time is the last heartbeat's, and a
 	// reader that asks how long a check has run reads this (novox/hq ADR 0433 §6).
 	Started time.Time `json:"started"`
+	// Seen is when the key was last put, which is the last heartbeat: read from the entry, never written (issue 1649).
+	Seen time.Time `json:"-"`
 }
 
 // RunningKeyOf is the key a check is said running under: its pull request's tokens, or `group.<name>` for a group's
@@ -319,6 +335,7 @@ func ReadRunning(ctx context.Context, conn *nats.Conn, r BuildRequest) (CheckRun
 	if err := json.Unmarshal(e.Value(), &running); err != nil {
 		return CheckRunning{}, false, nil // a key of a builder from before this means no match
 	}
+	running.Seen = e.Created()
 	return running, true, nil
 }
 

internal/link/checks_nats_integration_test.go

@@ -6,6 +6,7 @@ import (
 	"context"
 	"encoding/json"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
@@ -510,3 +511,122 @@ func TestAnUnacknowledgedCheckGoesToASecondBuilder(t *testing.T) {
 		stop()
 	}
 }
+
+// An ask handed out a second time to another builder while the first still runs it is acknowledged and not run: the
+// running key names the other builder and this same ask (issue 1649).
+func TestAnAskHandedOutAgainWhileAnotherBuilderRunsItIsNotRunTwice(t *testing.T) {
+	js := aBusWithTheBuildRole(t)
+	aKeyBucket(t, js)
+	aRunningBucket(t, js, 2*time.Minute)
+	ctx, stop := context.WithCancel(t.Context())
+	defer stop()
+	asks := BuildsOn(js, TheBuildMachine)
+	running := make(chan string, 4)
+	release := make(chan struct{})
+	a := MachineOverNATS(js, "builder-a")
+	defer a.Close()
+	go func() {
+		_ = a.Take(ctx, func(ctx context.Context, work Build) {
+			running <- work.Request().ID
+			<-release
+			_ = work.Announce(ctx, BuildResult{ID: work.Request().ID, On: "builder-a", Failed: "no"})
+			_ = work.Done()
+		})
+	}()
+	check := aPullCheck("build-twice", 7, "head-7-000000000", "trunk-1-000000", false)
+	if err := asks.Ask(ctx, check); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case <-running:
+	case <-time.After(10 * time.Second):
+		t.Fatal("builder a took nothing")
+	}
+	// The bus's redelivery, as it reaches the other machine: the same ask, the same id.
+	if err := asks.Ask(ctx, check); err != nil {
+		t.Fatal(err)
+	}
+	b := MachineOverNATS(js, "builder-b")
+	defer b.Close()
+	took := make(chan string, 4)
+	go func() {
+		_ = b.Take(ctx, func(ctx context.Context, work Build) {
+			took <- work.Request().ID
+			_ = work.Done()
+		})
+	}()
+	select {
+	case id := <-took:
+		t.Fatalf("builder b ran %s, which builder a is running", id)
+	case <-time.After(3 * time.Second):
+	}
+	if n := len(queueOf(t, js).Of(AskWaiting)); n != 0 {
+		t.Errorf("%d request(s) still wait; builder b was to acknowledge the duplicate", n)
+	}
+	close(release)
+}
+
+// A busy machine fetches nothing, so no ask waiting in the queue is taken by it, whatever status message sits in its pulls
+// (issue 1649). A pull request of our own that expires at once leaves such a message in the other checks' pull.
+func TestABusyMachineTakesNoWaitingAskWhateverItsPullsHold(t *testing.T) {
+	js := aBusWithTheBuildRole(t)
+	aKeyBucket(t, js)
+	aRunningBucket(t, js, 2*time.Minute)
+	ctx, stop := context.WithCancel(t.Context())
+	defer stop()
+	asks := BuildsOn(js, TheBuildMachine)
+	busy := make(chan string, 4)
+	release := make(chan struct{})
+	a := MachineOverNATS(js, "builder-a").(*natsMachine)
+	defer a.Close()
+	go func() {
+		_ = a.Take(ctx, func(ctx context.Context, work Build) {
+			busy <- work.Request().ID
+			<-release
+			_ = work.Announce(ctx, BuildResult{ID: work.Request().ID, On: "builder-a", Failed: "no"})
+			_ = work.Done()
+		})
+	}()
+	if err := asks.Ask(ctx, BuildRequest{ID: "busy", Repository: "/d"}); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case <-busy:
+	case <-time.After(10 * time.Second):
+		t.Fatal("builder a took nothing")
+	}
+	var other *takeQueue
+	for _, q := range a.subs {
+		if q.kind == queueOther && q.bound {
+			other = q
+		}
+	}
+	if other == nil {
+		t.Fatal("builder a has no pull on the other checks")
+	}
+	// The queue is empty, so this request is answered at its expiry with a status message that lands in the pull.
+	reply := strings.TrimSuffix(other.sub.Subject, "*") + "late"
+	if err := js.Conn().PublishRequest("$JS.API.CONSUMER.MSG.NEXT."+other.worker.Stream+"."+other.worker.Name, reply,
+		[]byte(`{"batch":1,"expires":1000000}`)); err != nil {
+		t.Fatal(err)
+	}
+	time.Sleep(500 * time.Millisecond)
+	for i, id := range []string{"wait-1", "wait-2"} {
+		if err := asks.Ask(ctx, aPullCheck(id, 20+i, "head-x-000000000", "trunk-1-000000", false)); err != nil {
+			t.Fatal(err)
+		}
+	}
+	time.Sleep(5 * time.Second)
+	info, err := js.Context().ConsumerInfo(other.worker.Stream, other.worker.Name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.NumAckPending != 0 || info.NumRedelivered != 0 || info.Delivered.Consumer != 0 {
+		t.Fatalf("a busy machine took from the queue: %d delivered, %d pending, %d redelivered", info.Delivered.Consumer,
+			info.NumAckPending, info.NumRedelivered)
+	}
+	if n := len(queueOf(t, js).Of(AskWaiting)); n != 2 {
+		t.Fatalf("%d asks wait; want the 2 nobody took", n)
+	}
+	close(release)
+}

internal/link/declare.go

@@ -41,7 +41,7 @@ func Declare(ctx context.Context, bus Bus, signer Signer, node string,
 		return fmt.Errorf("cannot sign a declaration for %s: %w", node, err)
 	}
 
-	body, err := json.Marshal(Signed{Declaration: declaration, Signature: signature})
+	body, err := Envelope(declaration, signature)
 	if err != nil {
 		return err
 	}
@@ -66,8 +66,16 @@ func Declare(ctx context.Context, bus Bus, signer Signer, node string,
 	return bus.PublishDeclaration(publish, node, body)
 }
 
-// NearTheLimit is the share of the bus's largest message at which a declaration is said to be near it.
-const NearTheLimit = 0.9
+// Envelope is the message a declaration goes on the bus as: the declaration and its signature, each as base64 in one JSON
+// document. Its length is what the bus's largest message bounds.
+func Envelope(declaration, signature []byte) ([]byte, error) {
+	return json.Marshal(Signed{Declaration: declaration, Signature: signature})
+}
+
+// NearTheLimit is the share of the bus's largest message at which a declaration is said to be near it: three quarters, so that
+// a declaration which should stay far from the limit raises the condition while there is still room to act (novox/hq ADR 0486
+// §8; the first fix of issue 1689 warned at nine tenths while every file was still inline).
+const NearTheLimit = 0.75
 
 // DeclarationMeasured is told, at every send of a declaration, its size on the wire and the bus's largest message,
 // so the controller raises a condition when it nears the limit and clears it when it is back under (issue 1689).

internal/link/held_asks_test.go

@@ -0,0 +1,43 @@
+package link
+
+import (
+	"testing"
+	"time"
+)
+
+// An ask a machine holds but does not start gets no heartbeat, and the bus hands it to another machine after the ack
+// wait, so two machines run one check (issue 1649).
+
+// A fetch's server-side pull request ends clearly before the fetch does, so the server's answer and any message it could still
+// deliver come inside the fetch and never into a buffer nobody reads while the machine builds.
+func TestAFetchsPullRequestEndsClearlyBeforeTheFetchDoes(t *testing.T) {
+	for name, wait := range map[string]time.Duration{"a check queue": checkTakeWait, "the idle wait": takeIdleWait} {
+		if margin := wait - fetchExpiryOf(wait); margin < minFetchMargin {
+			t.Errorf("%s: the pull request ends %v before a fetch of %v does; want at least %v", name, margin, wait, minFetchMargin)
+		}
+	}
+}
+
+func TestAnAskAnotherBuilderIsRunningIsADuplicateAndYoursIsNot(t *testing.T) {
+	r := aPullCheck("build-1", 423, "head-4771ee53aa", "trunk-0123456789", false)
+	run := CheckRunning{Head: r.Ref, Trunk: "trunk-0123456789", Builder: "shanks", Build: "build-1", Started: time.Now().Add(-time.Minute), Seen: time.Now().Add(-4 * time.Second)}
+	dead := run
+	dead.Seen = time.Now().Add(-60 * time.Second)
+	for name, c := range map[string]struct {
+		running CheckRunning
+		found   bool
+		me      string
+		dup     bool
+	}{
+		"another builder runs this very ask":                {run, true, "ace", true},
+		"its builder stopped renewing the key a minute ago": {dead, true, "ace", false},
+		"this builder runs it itself":                       {run, true, "shanks", false},
+		"nobody runs it":                                    {CheckRunning{}, false, "ace", false},
+		"another ask of the same head":                      {CheckRunning{Head: r.Ref, Trunk: "trunk-0123456789", Builder: "shanks", Build: "build-0"}, true, "ace", false},
+		"the same ask at another head":                      {CheckRunning{Head: "head-other-0000", Trunk: "trunk-0123456789", Builder: "shanks", Build: "build-1"}, true, "ace", false},
+	} {
+		if got := duplicateOf(c.running, c.found, r, c.me) != ""; got != c.dup {
+			t.Errorf("%s: duplicate = %v; want %v", name, got, c.dup)
+		}
+	}
+}

testdata/beside/CAPTURED

@@ -9,7 +9,7 @@ a second place to clean besides the catalogue itself.
 
 mesh-catalog  e0bc919d4945bb5f13f971f74643a0b714cf45da  modules/*/module.json, modules/nats/Dockerfile
 mesh-host     9d9e3a46c4f5943cfffb413d962ce48b75e2fd39  examples/foundation-first-node.lock
-mesh-sdk      d4deecdb380b69358aae2fdaedcfcc06e1571d42  conformance/events/module-event.json
+mesh-sdk      725590e06e75c67b96ce58d015b3056c2d261249  conformance/events/module-event.json
 
 To move them, from this repository's root, with the two repositories checked out beside it:
 

vendor/git.novox.be/novox/mesh-sdk/go/declaration/declaration.go

@@ -326,7 +326,7 @@ type File struct {
 
 	// Digest and Size say the content is not carried but fetched: a file over FileReferenceThreshold travels as
 	// the sha256 digest of its content, "sha256:<64 hex>", and its size in bytes, in place of Content or Bytes
-	// (novox/hq ADR 0486 §1). The node-engine fetches the object of that name from FileBucket, checks what it
+	// (novox/hq ADR 0486 §1). The node-engine fetches the object of that name from FileBucketFor(node), checks what it
 	// received against Digest and Size, and only then writes the file. Exclusive with Content, Sealed, Bytes,
 	// VaultSealed and Secrets; sent only to an engine that reports FileReferencesCapability, as an older engine
 	// refuses a field it does not know, whole.

vendor/git.novox.be/novox/mesh-sdk/go/declaration/filereference.go

@@ -14,13 +14,38 @@ const (
 	// FileReferenceThreshold is the size above which a file travels by digest: a file of this many bytes or fewer
 	// stays in the declaration as it is.
 	FileReferenceThreshold = 64 * 1024
-	// FileBucket is the object bucket of the bus that holds the contents, each under the hex of its sha256 digest
-	// (ObjectName). The controller alone writes it; a node-engine reads an object by name.
-	FileBucket = "declaration-files"
+	// FileBucketPrefix starts the name of a node's object bucket, FileBucketFor(node), which holds the contents of the
+	// files of that node's declaration, each under the hex of its sha256 digest (ObjectName). One bucket per node,
+	// so a grant names it and a literal `*` is never needed (ADR 0486 §2, changed by ADR 0488 §1 and §2). The controller alone writes it; the
+	// node's engine reads an object by name.
+	FileBucketPrefix = "declaration-files-"
+	// FileStreamPrefix starts the name of the stream behind such a bucket, which the bus's grants name.
+	FileStreamPrefix = "OBJ_"
 	// FileReferencesCapability is what a node-engine reports when it reads a file given as a digest and size.
 	FileReferencesCapability = "file-references"
 )
 
+var nodeToken = regexp.MustCompile(`^[A-Za-z0-9_-]+$`)
+
+// FileBucketFor is the name of the object bucket of a node's files, "declaration-files-<node>" (novox/hq ADR 0488
+// §4, which replaces the single bucket constant of issue 1694). The node name must be a name the bus accepts in a
+// bucket and in a subject token: letters, digits, '_' and '-', so no '.', '*', '>' or space.
+func FileBucketFor(node string) (string, error) {
+	if !nodeToken.MatchString(node) {
+		return "", fmt.Errorf("node %q; a node's bucket is named by letters, digits, '_' and '-' only", node)
+	}
+	return FileBucketPrefix + node, nil
+}
+
+// FileStreamFor is the name of the stream behind a node's bucket, "OBJ_" and the bucket's name.
+func FileStreamFor(node string) (string, error) {
+	b, err := FileBucketFor(node)
+	if err != nil {
+		return "", err
+	}
+	return FileStreamPrefix + b, nil
+}
+
 var digestForm = regexp.MustCompile(`^sha256:[0-9a-f]{64}$`)
 
 // DigestOf is the digest a reference names for a content: "sha256:<64 lower-case hex>".

vendor/modules.txt

@@ -1,4 +1,4 @@
-# git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b
+# git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021153908-725590e06e75
 ## explicit; go 1.26.0
 git.novox.be/novox/mesh-sdk/go/asks
 git.novox.be/novox/mesh-sdk/go/catalogue