Two faults found on review

A second Accept value would have overwritten the first, because the header was Set per value rather
than Added. One value is all any caller passes today, so nothing was wrong — but a helper that
quietly keeps only the last of what it was given is a trap for whoever passes two.

And a replayed announcement that could not be written was published as an empty body: a fact on the
mesh that says nothing, which the reader can only log and drop. It is now said and skipped, because a
body that cannot be marshalled is this program's fault rather than the bus's.

cmd/mesh-builder/main.go

@@ -194,6 +194,9 @@ func answer(ctx context.Context, publisher builder.Publisher, on, workspace stri
 				})
 			}
 			result.Against = built.Against
+			for _, r := range built.Read {
+				result.Read = append(result.Read, link.ReadRepository{Repository: r.Repository, Ref: r.Ref})
+			}
 			fmt.Fprintf(os.Stderr, "  built %s from %s\n", built.Manifest.Module, short(built.Commit))
 		}
 	}

cmd/mesh-builder/once.go

@@ -106,6 +106,9 @@ func buildOnce(ctx context.Context, args []string) error {
 		Manifest:   built.Manifest,
 		Against:    built.Against,
 	}
+	for _, r := range built.Read {
+		out.Read = append(out.Read, readRepository{Repository: r.Repository, Ref: r.Ref})
+	}
 	for _, made := range built.Built {
 		out.Made = append(out.Made, madeArtifact{Name: made.Name, Kind: made.Kind, Reference: made.Reference})
 	}
@@ -123,14 +126,21 @@ func buildOnce(ctx context.Context, args []string) error {
 // The same fields the mesh records for a build, so a reader comparing a genesis build against an
 // ordinary one is comparing the same thing said the same way.
 type onceResult struct {
-	Module     string         `json:"module"`
-	Commit     string         `json:"commit"`
-	Repository string         `json:"repository"`
-	Path       string         `json:"path,omitempty"`
-	Ref        string         `json:"ref,omitempty"`
-	Manifest   any            `json:"manifest"`
-	Made       []madeArtifact `json:"made"`
-	Against    []string       `json:"against,omitempty"`
+	Module     string           `json:"module"`
+	Commit     string           `json:"commit"`
+	Repository string           `json:"repository"`
+	Path       string           `json:"path,omitempty"`
+	Ref        string           `json:"ref,omitempty"`
+	Manifest   any              `json:"manifest"`
+	Made       []madeArtifact   `json:"made"`
+	Against    []string         `json:"against,omitempty"`
+	Read       []readRepository `json:"read,omitempty"`
+}
+
+// readRepository is a repository this build read source from besides the module's own.
+type readRepository struct {
+	Repository string `json:"repository"`
+	Ref        string `json:"ref,omitempty"`
 }
 
 type madeArtifact struct {

cmd/mesh-controller/adopting_test.go

@@ -88,7 +88,7 @@ func reportsReaching(t *testing.T, open *stores, reachable []link.Reach, held ..
 	if err := open.inventory.RecordSent(ctx, record.ID, digestOf(body)); err != nil {
 		t.Fatal(err)
 	}
-	if err := (link.Enrolment{Inventory: open.inventory}).Heard(ctx, link.Report{
+	if _, err := (link.Enrolment{Inventory: open.inventory}).Heard(ctx, link.Report{
 		Node: "anchor", Applied: []string{"hello-web.x"}, Declared: digestOf(body),
 		Firewall: "ufw", Held: held, Reachable: reachable,
 	}); err != nil {

cmd/mesh-controller/build.go

@@ -149,6 +149,9 @@ func buildFrom(result link.BuildResult) inventory.Build {
 	for _, ref := range result.Against {
 		kept.Against = append(kept.Against, catalogue.Recorded(ref))
 	}
+	for _, r := range result.Read {
+		kept.Read = append(kept.Read, inventory.ReadRepository{Repository: r.Repository, Ref: r.Ref})
+	}
 	var announced []inventory.Artifact
 	for _, made := range result.Made {
 		announced = append(announced, inventory.Artifact{

cmd/mesh-controller/main.go

@@ -76,7 +76,10 @@ func run() error {
 		return pinCommand(ctx, args[1:], true)
 	case "unpin":
 		return pinCommand(ctx, args[1:], false)
-	case "migrate":
+	// `prepare` is how the mesh asks any module to bring its state to the shape this version needs
+	// (novox/hq ADR 0135), and the control plane answers it the same way as everything else — its
+	// own schema is not a special case. `migrate` remains the word a person types.
+	case "prepare", "migrate":
 		return migrate(ctx)
 	case "node":
 		return nodeCommand(ctx, args[1:])
@@ -138,6 +141,7 @@ func usage() {
 	fmt.Fprint(os.Stderr, `mesh-controller — the control plane
 
   migrate                        bring each context's schema up to date
+  prepare                        the same, asked the way the mesh asks any module (ADR 0135)
   node add <name> [--adopted]    create a node record; --adopted: the machine is in use
   node list                      the nodes this mesh knows about
   node show <name>               what one machine reported it can do, and why

cmd/mesh-controller/modules.go

@@ -69,12 +69,20 @@ func moduleCommand(ctx context.Context, args []string) error {
 		repo := set.String("source", "", "where this module comes from")
 		ref := set.String("ref", "", "the branch followed there")
 		commit := set.String("commit", "", "the commit this manifest was read at")
+		// **Where inside the repository the module is** (novox/hq ADR 0069). A module is a
+		// repository *and* a directory, and a record that carries only the repository names a
+		// module.json at its root — so every later build of it looks in the wrong place and fails
+		// with "no module.json at its root". Nine modules on this mesh were registered that way
+		// and none of them could be rebuilt (2026-09-28).
+		path := set.String("path", "", "the module's directory inside that repository")
+		self := set.Bool("self", false, "the source is a path on the forge holding the git seat")
 		positionals, err := parseAround(set, args[1:])
 		if err != nil {
 			return err
 		}
 		if len(positionals) != 1 {
-			return errors.New("module add <manifest.json> [--source <repo> --ref <branch> --commit <sha>]")
+			return errors.New("module add <manifest.json> [--source <repo> [--self] [--path P] " +
+				"--ref <branch> --commit <sha>]")
 		}
 		raw, err := os.ReadFile(positionals[0])
 		if err != nil {
@@ -84,23 +92,24 @@ func moduleCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
-		// Provenance together or not at all. A source with no commit cannot be compared against
-		// anything, so it would record where the module came from and still never be able to say
-		// the mesh is behind it — which is the one thing recording it is for.
-		if (*repo == "") != (*commit == "") {
-			return errors.New("--source and --commit go together: a source with no commit " +
-				"cannot be compared against anything, and a commit with no source has nothing " +
-				"to be compared with")
+		from, err := whereItComesFrom(*repo, *ref, *commit, *path, *self)
+		if err != nil {
+			return err
 		}
-		if err := inv.RegisterModule(ctx, m, inventory.Source{
-			Repository: *repo, Ref: *ref, BuiltFrom: *commit,
-		}); err != nil {
+		if err := inv.RegisterModule(ctx, m, from); err != nil {
 			return err
 		}
 		fmt.Printf("%s registered", m.Module)
 		if *commit != "" {
 			fmt.Printf(" from %s", short(*commit))
 		}
+		if *repo != "" && *path == "" {
+			// Said, not refused: a module really at the root is the ordinary case for a repository
+			// of its own. But a repository holding many modules and a record naming none of them is
+			// a module nothing can rebuild, and the person adding it is the one who knows which.
+			fmt.Printf("\n  no directory inside %s, so it is built from that repository's root — "+
+				"`--path` if the module lives in a directory there", *repo)
+		}
 		if len(m.Provides) > 0 {
 			fmt.Printf(", providing %s", describeOffers(m.Provides))
 		}
@@ -602,3 +611,37 @@ func issueWith(ctx context.Context, inv *inventory.Inventory, m catalogue.Manife
 		"machine holding mesh-broker\n")
 	return nil
 }
+
+// whereItComesFrom is the provenance a module handed over by hand records, and what a record must
+// say to be worth anything later.
+//
+// **A module is a repository and a directory inside it** (novox/hq ADR 0069). A record carrying only
+// the repository names a module.json at its root, so every later build of it looks in the wrong
+// place — nine modules on this mesh were registered that way and none of them could be rebuilt
+// (2026-09-28). The directory cannot be checked from here, because the control plane does not clone;
+// what can be checked is that the record is whole.
+func whereItComesFrom(repository, ref, commit, path string, self bool) (inventory.Source, error) {
+	// Provenance together or not at all. A source with no commit cannot be compared against
+	// anything, so it would record where the module came from and still never be able to say the
+	// mesh is behind it — which is the one thing recording it is for.
+	if (repository == "") != (commit == "") {
+		return inventory.Source{}, errors.New("--source and --commit go together: a source with " +
+			"no commit cannot be compared against anything, and a commit with no source has " +
+			"nothing to be compared with")
+	}
+	// A directory or a forge with no repository is half a location, and the half it keeps is the
+	// half nothing can be found with.
+	if repository == "" && (path != "" || self) {
+		return inventory.Source{}, errors.New("--path and --self say where inside a source and " +
+			"which forge holds it, so they need --source: without one there is nothing for them " +
+			"to be part of")
+	}
+	from := inventory.Source{Repository: repository, Ref: ref, BuiltFrom: commit, Path: path}
+	if self {
+		if err := onASeat(repository); err != nil {
+			return inventory.Source{}, err
+		}
+		from.Seat = gitSeat
+	}
+	return from, nil
+}

cmd/mesh-controller/operator.go

@@ -189,13 +189,17 @@ func readPrivateKey(path string) (string, error) {
 func personIssue(ctx context.Context, args []string) error {
 	set := flag.NewFlagSet("operator issue", flag.ContinueOnError)
 	invokes := set.String("invokes", "", "the tools this person may call, comma-separated, or * for every one")
-	if err := set.Parse(args); err != nil {
+	// Flags on either side of the name, because the usage this command prints puts them after it —
+	// and the standard parser stops at the first thing that is not a flag, so the order the command
+	// documents was the one order it refused (2026-09-28).
+	positionals, err := parseAround(set, args)
+	if err != nil {
 		return err
 	}
-	if set.NArg() != 1 {
+	if len(positionals) != 1 {
 		return errors.New("operator issue <name> --invokes <tool,tool|*>")
 	}
-	name := set.Arg(0)
+	name := positionals[0]
 	if *invokes == "" {
 		return errors.New(
 			"say what this person may call: --invokes mesh-catalog.catalog_tools,gitea.repo_create, " +

cmd/mesh-controller/order_test.go

@@ -106,3 +106,107 @@ func TestAMergeOlderThanTheLastLookIsHistory(t *testing.T) {
 		t.Fatal("a merge or a source with no time on it was refused")
 	}
 }
+
+// A module as the catalogue holds it: built from a repository, at a directory inside it.
+func fromRepo(module, repository, path string) inventory.Entry {
+	return inventory.Entry{
+		Manifest: catalogue.Manifest{Module: module},
+		Source:   inventory.Source{Repository: repository, Path: path, Ref: "main"},
+	}
+}
+
+// A merge rebuilds the modules whose own directories it changed, and everything when what it changed
+// is shared. One repository holding many modules is the ordinary case here, and rebuilding all of
+// them for a change to one is what exhausted a registry's pull limit the first night this ran.
+func TestAMergeRebuildsTheModulesItChanged(t *testing.T) {
+	const repo = "http://forge.internal:20000/novox/mesh-catalog.git"
+	gitea := fromRepo("gitea", repo, "modules/gitea")
+	keycloak := fromRepo("keycloak", repo, "modules/keycloak")
+	known := []inventory.Entry{gitea, keycloak, fromRepo("plex", repo, "modules/plex")}
+	candidates := []inventory.Entry{gitea, keycloak}
+	merge := func(paths []string, truncated bool) link.SourceMoved {
+		return link.SourceMoved{Owner: "novox", Repo: "mesh-catalog", Base: "main",
+			Paths: paths, PathsTruncated: truncated}
+	}
+	named := func(entries []inventory.Entry) string {
+		var names []string
+		for _, e := range entries {
+			names = append(names, e.Manifest.Module)
+		}
+		return strings.Join(names, ",")
+	}
+	for _, c := range []struct {
+		what string
+		m    link.SourceMoved
+		want string
+	}{
+		{"one module's own files", merge([]string{"modules/gitea/index.ts", "modules/gitea/client.ts"}, false), "gitea"},
+		{"two modules' files", merge([]string{"modules/gitea/index.ts", "modules/keycloak/module.json"}, false), "gitea,keycloak"},
+		{"a file they share", merge([]string{"tsconfig.json"}, false), "gitea,keycloak"},
+		{"a module the mesh does not hold", merge([]string{"modules/plex/index.ts"}, false), ""},
+		{"nothing said about the files", merge(nil, false), "gitea,keycloak"},
+		{"more files than were listed", merge([]string{"modules/gitea/index.ts"}, true), "gitea,keycloak"},
+	} {
+		if got := named(whatTheMergeTouched(candidates, known, c.m)); got != c.want {
+			t.Errorf("%s: rebuilt %q, wanted %q", c.what, got, c.want)
+		}
+	}
+}
+
+// A module whose recipe packages source from another repository is affected when that repository
+// moves — the manifest the mesh keeps says nothing about it, so the record of what the build read is
+// the only thing that can say so.
+func TestAModuleIsAffectedByTheRepositoryItPackages(t *testing.T) {
+	m := link.SourceMoved{Owner: "novox", Repo: "mesh-controller", Base: "main",
+		CloneURL: "http://forge.internal:20000/novox/mesh-controller.git"}
+	for _, read := range [][]inventory.ReadRepository{
+		{{Repository: "http://forge.internal:20000/novox/mesh-controller.git", Ref: "main"}},
+		{{Repository: "novox/mesh-controller"}},
+		{{Repository: "https://elsewhere.example/novox/other"}, {Repository: "novox/mesh-controller.git", Ref: "main"}},
+	} {
+		if !readsFrom(read, m) {
+			t.Errorf("%+v was not matched by the merge", read)
+		}
+	}
+	for _, read := range [][]inventory.ReadRepository{
+		nil,
+		{{Repository: "novox/mesh-host", Ref: "main"}},
+		{{Repository: "novox/mesh-controller", Ref: "release"}},
+	} {
+		if readsFrom(read, m) {
+			t.Errorf("%+v was matched by a merge that is not its", read)
+		}
+	}
+}
+
+// What a module handed over by hand records about where it came from, and what is refused.
+func TestWhatAHandedOverModuleRecordsAboutItsSource(t *testing.T) {
+	// The whole location: a repository on the mesh's own forge, the directory inside it, the branch
+	// and the commit the manifest was read at.
+	from, err := whereItComesFrom("novox/mesh-catalog", "main", "c0ffee", "modules/gitea", true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if from.Path != "modules/gitea" || from.Seat != "git" || from.Repository != "novox/mesh-catalog" {
+		t.Fatalf("the source records as %+v", from)
+	}
+	// A manifest with no provenance at all is legitimate: fixing something in a hurry.
+	if from, err := whereItComesFrom("", "", "", "", false); err != nil || from != (inventory.Source{}) {
+		t.Fatalf("a manifest handed over with no provenance was refused: %+v, %v", from, err)
+	}
+	for _, c := range []struct {
+		what                          string
+		repository, ref, commit, path string
+		self                          bool
+	}{
+		{what: "a source with no commit", repository: "novox/mesh-catalog", commit: ""},
+		{what: "a commit with no source", commit: "c0ffee"},
+		{what: "a directory inside nothing", path: "modules/gitea"},
+		{what: "a forge holding nothing", self: true},
+		{what: "an address given as a path on the forge", repository: "http://forge.internal:20000/novox/x.git", commit: "c0ffee", self: true},
+	} {
+		if _, err := whereItComesFrom(c.repository, c.ref, c.commit, c.path, c.self); err == nil {
+			t.Errorf("%s was recorded as a source", c.what)
+		}
+	}
+}

cmd/mesh-controller/upgrades.go

@@ -232,29 +232,67 @@ func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
 	if err != nil {
 		return notNow(err)
 	}
-	var moved []inventory.Entry
+	read, err := inv.ReadRepositories(ctx)
+	if err != nil {
+		return notNow(err)
+	}
+
+	// Two kinds of module are affected by one merge, and they are affected differently.
+	//
+	// A module **built from** this repository and branch has moved: the mesh records the new commit
+	// as what its source now has, and only what the merge actually changed is rebuilt. A module that
+	// only **packages source from** it has not moved — its own source is somewhere else, at the
+	// commit it already records — so it is rebuilt and its record left alone. Writing this commit as
+	// its source would make it permanently behind a repository its manifest does not come from.
+	var from, packaging []inventory.Entry
+	already := 0
 	for _, e := range entries {
-		if !sourceIs(e.Source, m) {
-			continue
+		switch {
+		case sourceIs(e.Source, m):
+			if e.Source.BuiltFrom == m.Commit {
+				already++
+				continue
+			}
+			// **A merge older than the last look at the source is history, not a move.** The forge
+			// announces what it finds merged, and an old merge surfacing late would otherwise move
+			// the recorded head backwards and rebuild everything built from that repository, once
+			// per old merge (2026-09-28).
+			if isHistory(m.MergedAt, e.Source.Seen) {
+				continue
+			}
+			from = append(from, e)
+		case readsFrom(read[e.Manifest.Module], m):
+			packaging = append(packaging, e)
 		}
-		if e.Source.BuiltFrom == m.Commit {
-			continue
-		}
-		// **A merge older than the last look at the source is history, not a move.** The forge
-		// announces what it finds merged, and an old merge surfacing late would otherwise move the
-		// recorded head backwards and rebuild everything built from that repository, once per old
-		// merge (2026-09-28).
-		if isHistory(m.MergedAt, e.Source.Seen) {
-			continue
+	}
+	if len(from) == 0 && len(packaging) == 0 {
+		// "Already built from it" and "nothing reads it" are different facts, and reading the first
+		// as the second sends somebody looking for a broken trigger when the mesh is up to date.
+		if already > 0 {
+			fmt.Printf("%s/%s merged into %s (%.8s); %d module(s) the mesh holds are already built "+
+				"from it\n", m.Owner, m.Repo, m.Base, m.Commit, already)
+			return nil
 		}
+		fmt.Printf("%s/%s merged into %s (%.8s); nothing the mesh holds reads it\n",
+			m.Owner, m.Repo, m.Base, m.Commit)
+		return nil
+	}
+	// The same judgement for the packaging kind, against the newest look at that repository by
+	// anything built from it: they keep no record of it themselves, and a replayed old merge should
+	// not rebuild them either.
+	if isHistory(m.MergedAt, lastLookAt(entries, m)) {
+		packaging = nil
+	}
+	touched := whatTheMergeTouched(from, entries, m)
+	for _, e := range touched {
 		if err := inv.SourceMoved(ctx, e.Manifest.Module, m.Commit); err != nil {
 			return notNow(err)
 		}
-		moved = append(moved, e)
 	}
+	moved := append(append([]inventory.Entry{}, touched...), packaging...)
 	if len(moved) == 0 {
-		fmt.Printf("%s/%s merged into %s (%.8s); nothing the mesh holds is built from it\n",
-			m.Owner, m.Repo, m.Base, m.Commit)
+		fmt.Printf("%s/%s merged into %s (%.8s); it changed nothing any module the mesh holds is "+
+			"built from\n", m.Owner, m.Repo, m.Base, m.Commit)
 		return nil
 	}
 	against, err := inv.BuiltAgainst(ctx)
@@ -268,6 +306,14 @@ func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
 	}
 	fmt.Printf("%s/%s merged into %s (%.8s); building %s\n",
 		m.Owner, m.Repo, m.Base, m.Commit, strings.Join(names, ", "))
+	if len(packaging) > 0 {
+		var also []string
+		for _, e := range packaging {
+			also = append(also, e.Manifest.Module)
+		}
+		fmt.Printf("  %s package source from it, so they are rebuilt and their own source record "+
+			"is left where it is\n", strings.Join(also, ", "))
+	}
 	var failed []string
 	for _, e := range ordered {
 		source := buildSource{Repository: e.Source.Repository, Seat: e.Source.Seat}
@@ -293,16 +339,110 @@ func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
 // An empty recorded ref is the repository's default branch, which is what a merge into the base
 // branch of the forge's default means.
 func sourceIs(s inventory.Source, m link.SourceMoved) bool {
-	want := strings.ToLower(m.Owner + "/" + m.Repo)
-	repo := strings.ToLower(strings.TrimSuffix(s.Repository, ".git"))
-	matches := repo == want || strings.HasSuffix(repo, "/"+want) ||
-		(m.CloneURL != "" && strings.EqualFold(strings.TrimSuffix(s.Repository, ".git"), strings.TrimSuffix(m.CloneURL, ".git")))
-	if !matches {
+	if !sameRepository(s.Repository, m) {
 		return false
 	}
 	return s.Ref == "" || s.Ref == m.Base
 }
 
+// sameRepository is whether a recorded repository is the one a merge names, in either spelling it
+// may have been recorded in: a path on the git seat, or the URL it was cloned from.
+func sameRepository(repository string, m link.SourceMoved) bool {
+	want := strings.ToLower(m.Owner + "/" + m.Repo)
+	repo := strings.ToLower(strings.TrimSuffix(repository, ".git"))
+	return repo == want || strings.HasSuffix(repo, "/"+want) ||
+		(m.CloneURL != "" && repo == strings.ToLower(strings.TrimSuffix(m.CloneURL, ".git")))
+}
+
+// readsFrom is whether a module's build read the repository a merge names: the second repository its
+// recipe packages source from. Its ref must be the branch that moved, or unset — the same rule a
+// module's own source follows.
+func readsFrom(read []inventory.ReadRepository, m link.SourceMoved) bool {
+	for _, r := range read {
+		if sameRepository(r.Repository, m) && (r.Ref == "" || r.Ref == m.Base) {
+			return true
+		}
+	}
+	return false
+}
+
+// lastLookAt is the most recent look at this repository by anything built from it.
+func lastLookAt(entries []inventory.Entry, m link.SourceMoved) time.Time {
+	var newest time.Time
+	for _, e := range entries {
+		if sameRepository(e.Source.Repository, m) && e.Source.Seen.After(newest) {
+			newest = e.Source.Seen
+		}
+	}
+	return newest
+}
+
+// whatTheMergeTouched narrows the modules built from a repository to the ones the merge changed.
+//
+// **A change inside no module's own directory is a change to what they share.** The forge lists the
+// files a merge changed; a module is affected when one of them is inside its own directory, when it
+// is built from the repository's root — everything there is its source — or when some changed file
+// belongs to no module's directory at all, which is how a shared file, a build recipe or a
+// dependency at the root rebuilds everything built from that repository.
+//
+// A change inside *another* module's directory is that module's business and not this one's, even
+// when the mesh does not hold that module: `known` is every module this repository is known to hold,
+// whatever branch it was registered from. That is also the limit of this — a repository whose shared
+// code sits inside a directory the mesh has never seen a module in reads as shared, and everything
+// is rebuilt. Rebuilding too much is the safe direction: the fault this whole path exists for is a
+// mesh that believes it is current and is not (novox/hq 04-ISSUES/131).
+func whatTheMergeTouched(candidates, known []inventory.Entry, m link.SourceMoved) []inventory.Entry {
+	// Nothing said about the files, or not all of them said: everything built from it is affected.
+	if len(m.Paths) == 0 || m.PathsTruncated {
+		return candidates
+	}
+	var dirs []string
+	for _, e := range known {
+		if e.Source.Path != "" && sameRepository(e.Source.Repository, m) {
+			dirs = append(dirs, e.Source.Path)
+		}
+	}
+	for _, p := range m.Paths {
+		if !insideAny(p, dirs) {
+			return candidates
+		}
+	}
+	var out []inventory.Entry
+	for _, e := range candidates {
+		if e.Source.Path == "" || anyInside(m.Paths, e.Source.Path) {
+			out = append(out, e)
+		}
+	}
+	return out
+}
+
+// inside is whether a changed file is in a directory: that directory itself, or under it.
+func inside(path, dir string) bool {
+	dir = strings.Trim(dir, "/")
+	path = strings.TrimPrefix(path, "/")
+	return path == dir || strings.HasPrefix(path, dir+"/")
+}
+
+// insideAny is whether a changed file is in any of these directories.
+func insideAny(path string, dirs []string) bool {
+	for _, dir := range dirs {
+		if inside(path, dir) {
+			return true
+		}
+	}
+	return false
+}
+
+// anyInside is whether any of these changed files is in a directory.
+func anyInside(paths []string, dir string) bool {
+	for _, p := range paths {
+		if inside(p, dir) {
+			return true
+		}
+	}
+	return false
+}
+
 // orderByBases is the entries with every base before what stands on it: a module whose build stood
 // on another's artifact comes after that module. Entries outside the set are not waited for — they
 // are not being rebuilt. Stable for what has no order between it.

internal/broker/broker.go

@@ -66,6 +66,19 @@ func FromEnvironment() (Broker, error) {
 	if err != nil {
 		return Broker{}, err
 	}
+	// **One bus, one address** (novox/hq ADR 0131). Everything the mesh hands out — a token, a
+	// machine's membership, a person's credential — must name the bus the control plane itself is
+	// connected to; the setting above predates the move and, on a mesh that has moved, still names
+	// the broker it moved from. The first person issued after the move was handed the retired
+	// broker's port and could not connect to anything (2026-09-28).
+	//
+	// Read from the credential rather than from a second setting somebody keeps in step: the
+	// control plane cannot be wrong about where it is connected.
+	if bus, on, err := OnNATS(); err == nil && on {
+		if where := strings.TrimPrefix(BareAddress(bus), "nats://"); where != "" {
+			address = where
+		}
+	}
 	return Broker{Address: address, Fingerprint: fingerprint}, nil
 }
 

internal/broker/nats.go

@@ -181,6 +181,14 @@ func PermissionsFor(p Principal) (Permissions, error) {
 		for _, seat := range meshSeatsTheControllerUses {
 			pub = append(pub, "mesh.seat."+seat+".accept.>")
 		}
+		// **And what the mesh says it did** (novox/hq ADR 0134). The control plane states its own
+		// facts under the seat it holds, because a role's events belong to the role and keep their
+		// address while the holder is replaced. Named one by one rather than as a whole namespace:
+		// least authority, and a fact nothing states is authority nobody uses.
+		for _, event := range ControllerStates {
+			pub = append(pub, seatEventSubject(ControllerSeat, event))
+		}
+
 		// Every module's tools: **the control plane is the way in** (novox/hq ADR 0095). A person
 		// or an agent asks through it and every question passes one process where an audit
 		// belongs — so it, alone among principals, may call any tool by name. The first `ask` on

internal/broker/states_agreement_test.go

@@ -0,0 +1,30 @@
+package broker_test
+
+import (
+	"slices"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/broker"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The facts the control plane states are named twice — in the grant that permits them and in the code
+// that states them — because `link` imports `broker` and the dependency cannot go the other way. So a
+// test keeps them agreeing: a subject the grant omits is refused at the moment the mesh has something
+// to say, and one the grant adds that nothing states is authority nobody uses.
+//
+// An external test package, because it may import both while neither imports the other.
+func TestTheFactsTheGrantPermitsAreTheFactsTheMeshStates(t *testing.T) {
+	if broker.ControllerSeat != link.MeshControllerSeat {
+		t.Fatalf("the grant is written for the %q seat and the mesh states its facts under %q",
+			broker.ControllerSeat, link.MeshControllerSeat)
+	}
+	for _, event := range []string{link.KeyApplied, link.KeyRefused, link.KeyBuiltBefore} {
+		if !slices.Contains(broker.ControllerStates, event) {
+			t.Errorf("the mesh states %q and its account may not publish it", event)
+		}
+	}
+	if len(broker.ControllerStates) != 3 {
+		t.Errorf("the grant permits %v, which is more than the mesh states", broker.ControllerStates)
+	}
+}

internal/broker/streams.go

@@ -160,6 +160,17 @@ func Overlaps() []string {
 // ack subject is derived from (nats.go: `$JS.ACK.<stream>.controller.>`).
 const ControllerName = "controller"
 
+// ControllerSeat is the role the control plane holds, and ControllerStates are the facts it states
+// under it (novox/hq ADR 0134).
+//
+// **Written here as well as in `link`, and a test keeps them agreeing.** `link` imports `broker`, so
+// `broker` cannot import `link`; a grant naming a subject the controller never publishes is authority
+// nobody uses, and a controller publishing one the grant omits is refused at the moment it has
+// something to say.
+const ControllerSeat = "mesh-controller"
+
+var ControllerStates = []string{"applied", "refused", "built-before"}
+
 // ControllerFollows are the events the controller reacts to: the catalogue saying a module's
 // current version moved, and a catalogue that has just started saying it may have missed builds.
 //

internal/broker/testdata/composed.conf

@@ -24,7 +24,7 @@ accounts {
     jetstream: enabled
     users = [
       { user: "controller", password: "$2a$11$cccccccccccccccccccccc", permissions: {
-        publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>"] }
+        publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>", "mesh.seat.mesh-controller.event.applied", "mesh.seat.mesh-controller.event.built-before", "mesh.seat.mesh-controller.event.refused"] }
         subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built"] }
         allow_responses: { max: 1, ttl: "1m" }
       } }

internal/builder/builder.go

@@ -61,6 +61,12 @@ type Result struct {
 	Commit string
 	// Built is each artifact, for reporting.
 	Built []catalogue.Built
+
+	// Read is every repository this build read source from besides the module's own — the second
+	// repository an artifact's recipe names (ArtifactContext). Reported because the manifest the
+	// mesh keeps carries no build section, so nothing else could say that a merge there is a
+	// change to this module (novox/hq 04-ISSUES/131).
+	Read []catalogue.ArtifactContext
 }
 
 // GitCredential is the forge credential a clone may present when the server asks for one.
@@ -220,7 +226,7 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 	}
 	say("done", "%s at %s — %d artifact(s) pinned", manifest.Module, short(commit), len(built))
 	return Result{Manifest: resolved, Commit: commit, Built: built,
-		Against: against(within, manifest, stoodOn)}, nil
+		Against: against(within, manifest, stoodOn), Read: readBy(manifest)}, nil
 }
 
 // Log is where a build says what it is doing, step by step. Nil is silent — the tests pass none,
@@ -1016,3 +1022,31 @@ func instructions(recipe string) []string {
 	flush()
 	return out
 }
+
+// readBy is every repository other than the module's own that this build's recipes read source from,
+// each once and in a fixed order, so two builds of one commit report the same thing the same way.
+func readBy(manifest catalogue.Manifest) []catalogue.ArtifactContext {
+	if manifest.Build == nil {
+		return nil
+	}
+	seen := map[string]bool{}
+	var out []catalogue.ArtifactContext
+	for _, a := range manifest.Build.Artifacts {
+		if a.Context == nil || a.Context.Repository == "" {
+			continue
+		}
+		key := a.Context.Repository + "#" + a.Context.Ref
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		out = append(out, *a.Context)
+	}
+	sort.Slice(out, func(i, j int) bool {
+		if out[i].Repository != out[j].Repository {
+			return out[i].Repository < out[j].Repository
+		}
+		return out[i].Ref < out[j].Ref
+	})
+	return out
+}

internal/builder/mirror.go

@@ -180,6 +180,20 @@ func (r Registry) MirrorImage(ctx context.Context, from, repository string) (str
 	if err != nil {
 		return "", err
 	}
+	// **Already held is already mirrored.** A base is named by digest, and a digest this registry
+	// holds under the module's repository is the same bytes whatever upstream would say — so
+	// upstream is not asked. Asked every build, the public hub's anonymous pull limit was reached
+	// on the first merge that rebuilt a whole catalogue (2026-09-28), and every module whose base
+	// lives there failed on a copy it did not need.
+	if strings.HasPrefix(where.reference, "sha256:") {
+		held, err := r.has(ctx, "http://"+r.Address+"/v2/"+repository+"/manifests/"+where.reference, manifestAccept)
+		if err != nil {
+			return "", fmt.Errorf("asking %s whether it holds %s: %w", r.Address, from, err)
+		}
+		if held {
+			return r.Address + "/" + repository + "@" + where.reference, nil
+		}
+	}
 	src := &source{client: r.client()}
 	digest, err := r.copyManifest(ctx, src, where, where.reference, repository)
 	if err != nil {

internal/builder/mirror_test.go

@@ -103,6 +103,20 @@ func (m *theMeshsRegistry) handler() http.Handler {
 		m.mu.Lock()
 		defer m.mu.Unlock()
 		switch {
+		case r.Method == http.MethodHead && strings.Contains(r.URL.Path, "/manifests/"):
+			// **As strictly as a real registry.** A manifest is answered only in a media type the
+			// caller named; a request with no Accept is answered as if nothing were there. The fake
+			// used to answer regardless, which is why it could not catch a check that asked without
+			// one — and the mesh copied every base again (2026-09-28).
+			if !strings.Contains(r.Header.Get("Accept"), "manifest") && !strings.Contains(r.Header.Get("Accept"), "index") {
+				w.WriteHeader(http.StatusNotFound)
+				return
+			}
+			if _, ok := m.manifests[r.URL.Path[strings.LastIndex(r.URL.Path, "/")+1:]]; ok {
+				w.WriteHeader(http.StatusOK)
+			} else {
+				w.WriteHeader(http.StatusNotFound)
+			}
 		case r.Method == http.MethodHead && strings.Contains(r.URL.Path, "/blobs/"):
 			if _, ok := m.blobs[r.URL.Path[strings.LastIndex(r.URL.Path, "/")+1:]]; ok {
 				w.WriteHeader(http.StatusOK)
@@ -219,3 +233,27 @@ func TestATagBeforeTheDigestIsNotPartOfTheRepository(t *testing.T) {
 		t.Fatalf("got %+v", got)
 	}
 }
+
+// A base this registry already holds by digest is not asked of upstream at all: the public hub
+// limits anonymous pulls, and a catalogue rebuilt on one merge asked it once per module.
+func TestABaseAlreadyHeldIsNotAskedOfUpstream(t *testing.T) {
+	src, indexDigest, _ := anUpstreamRegistry(t)
+	dst := &theMeshsRegistry{blobs: map[string][]byte{}, manifests: map[string][]byte{}}
+	dstServer := httptest.NewServer(dst.handler())
+	defer dstServer.Close()
+	address := strings.TrimPrefix(dstServer.URL, "http://")
+	r := Registry{Address: address, HTTP: src.Client()}
+	host := strings.TrimPrefix(src.URL, "http://")
+	if _, err := r.MirrorImage(context.Background(), host+"/library/thing:latest", "hello-web/server"); err != nil {
+		t.Fatal(err)
+	}
+	// Upstream gone: the pinned base is answered from what the mesh holds.
+	src.Close()
+	reference, err := r.MirrorImage(context.Background(), host+"/library/thing@"+indexDigest, "hello-web/server")
+	if err != nil {
+		t.Fatalf("a base the registry holds was asked of an upstream that is gone: %v", err)
+	}
+	if reference != address+"/hello-web/server@"+indexDigest {
+		t.Fatalf("pinned as %q", reference)
+	}
+}

internal/builder/registry.go

@@ -122,11 +122,23 @@ func (r Registry) PublishArchive(ctx context.Context, repository string, body []
 	return final, nil
 }
 
-func (r Registry) has(ctx context.Context, url string) (bool, error) {
+// has is whether this registry already holds what is at that URL.
+//
+// **A manifest HEAD must say what it accepts.** A registry answers a manifest request only in a media
+// type the caller named, and a bare HEAD — no Accept at all — is answered 404 for a manifest it holds
+// perfectly well. Measured against the mesh's own registry (2026-09-28): the same digest answered 200
+// with the manifest media types and 404 without them, so a check written without them concluded the
+// registry held nothing, copied every base again, and exhausted the public hub's pull limit. A blob
+// needs no Accept, which is why this went unnoticed: the same helper was right for blobs and wrong
+// for manifests.
+func (r Registry) has(ctx context.Context, url string, accept ...string) (bool, error) {
 	request, err := http.NewRequestWithContext(ctx, http.MethodHead, url, nil)
 	if err != nil {
 		return false, err
 	}
+	for _, media := range accept {
+		request.Header.Add("Accept", media)
+	}
 	response, err := r.client().Do(request)
 	if err != nil {
 		return false, fmt.Errorf("cannot reach the registry at %s: %w", r.Address, err)

internal/builder/standing_on_test.go

@@ -179,3 +179,24 @@ func TestTheBasesABuildWasHandedAreWhatItStoodOn(t *testing.T) {
 		t.Fatalf("the bases the build was handed were not what it stood on: %v", got)
 	}
 }
+
+// What a build read besides its module's own repository is the second repository its recipes name,
+// each once: a module that packages source living elsewhere is affected when that source moves.
+func TestWhatABuildReadIsTheRepositoriesItsRecipesName(t *testing.T) {
+	elsewhere := catalogue.ArtifactContext{Repository: "http://forge.internal:20000/novox/mesh-controller.git", Ref: "main"}
+	manifest := catalogue.Manifest{
+		Module: "builder",
+		Build: &catalogue.Build{Artifacts: []catalogue.Artifact{
+			{Name: "server", Kind: catalogue.ArtifactImage, From: "Dockerfile", Context: &elsewhere},
+			{Name: "tools", Kind: catalogue.ArtifactImage, From: "Dockerfile", Context: &elsewhere},
+			{Name: "config", Kind: catalogue.ArtifactArchive, From: "etc"},
+		}},
+	}
+	read := readBy(manifest)
+	if len(read) != 1 || read[0] != elsewhere {
+		t.Fatalf("the repositories this build read are %+v", read)
+	}
+	if readBy(catalogue.Manifest{Module: "gitea", Build: &catalogue.Build{}}) != nil {
+		t.Fatal("a module whose recipes name no other repository read one")
+	}
+}

internal/catalogue/declaration.go

@@ -623,6 +623,9 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		// one of them as its environment without saying so (ADR 0086, issue 041).
 		secretFiles := secretFilesOf(resources)
 
+		// Which of this module's resources its preparation runs before, if it prepares anything.
+		prepareBefore := preparationTarget(m)
+
 		for _, unsettled := range resources {
 			resource, err := ApplySettings(unsettled, with.Settings[m.Module])
 			if err != nil {
@@ -708,6 +711,18 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 			if renamed := reflectsRenamed(m.Module, resource["reload-on"]); renamed != nil {
 				copied["reload-on"] = renamed
 			}
+			// **A version prepares its state before it runs** (novox/hq ADR 0135). Derived from the
+			// module's own resource rather than declared beside it: what prepares the state is the
+			// module's own code, so what it is given has to be what that code is given — and a
+			// second resource written by hand is a second copy to drift from the first. Placed
+			// immediately before it, because a run-once step stops everything the declaration
+			// places after it (ADR 0052), which is how a version whose preparation failed does not
+			// serve.
+			if prepareBefore != "" && fmt.Sprint(resource["id"]) == prepareBefore {
+				step := prepared(copied)
+				owner[fmt.Sprint(step["id"])] = m.Module
+				out = append(out, step)
+			}
 			owner[fmt.Sprint(copied["id"])] = m.Module
 			out = append(out, copied)
 		}
@@ -1610,3 +1625,76 @@ func atMachinePort(serves map[string]any, module string, ports map[string]map[in
 func AtPublishedPort(values map[string]any, module string, published map[int]int) map[string]any {
 	return atMachinePort(values, module, map[string]map[int]int{module: published})
 }
+
+// PreparationArgument is how the mesh asks a module to prepare its state: one word, to the module's
+// own program, whatever that program is (novox/hq ADR 0135).
+//
+// **One word for every kind of module.** A module built as a Go binary receives it as its argument;
+// one built as a bundle receives it through the runtime, whose entry takes the same word. So the
+// mesh has one way of asking and a module has one way of answering, and neither learns the other's
+// shape.
+const PreparationArgument = "prepare"
+
+// preparationTarget is the resource a module's preparation runs before: its own workload.
+//
+// The first container carrying an artifact this module built, and not itself a step — that is the
+// thing that runs the module's code, and therefore the thing whose state must be ready. Empty when
+// the module prepares nothing, or when nothing it declares could run its code.
+//
+// **A module with two own workloads gates the first of them.** Five modules in the catalogue declare
+// more than one container of their own, none of them preparing anything today. If one ever does and
+// its second workload shares the state, the gate is in front of the first — stated here because the
+// alternative is a field asking an author to restate what the mesh can see.
+func preparationTarget(m Manifest) string {
+	if !m.Prepares {
+		return ""
+	}
+	for _, r := range m.Resources {
+		if fmt.Sprint(r["type"]) != "container" || !ownArtifact(r, m.Module) {
+			continue
+		}
+		if once, _ := r["run-once"].(bool); once {
+			continue
+		}
+		return fmt.Sprint(r["id"])
+	}
+	return ""
+}
+
+// ownArtifact is whether a resource runs something this module built, in either spelling a manifest
+// may be in: naming the artifact, before a build resolved it, or carrying the reference a build
+// recorded — this mesh's own store, under this module's name.
+func ownArtifact(resource map[string]any, module string) bool {
+	if named, _ := resource["artifact"].(string); named != "" {
+		return true
+	}
+	image, _ := resource["image"].(string)
+	return strings.HasPrefix(image, ArtifactStoreScheme+module+"/")
+}
+
+// prepared is the module's own resource as the step that prepares its state: the same image, the same
+// context, run to completion with the mesh's preparation argument.
+//
+// Three things are taken away rather than copied, each because the step runs while the version it
+// prepares for is still running. A published port cannot be bound twice, and a step that tried would
+// fail for a reason that has nothing to do with the state. A fixed address cannot be held twice, for
+// the same reason. And a cadence is what a step is the opposite of: a container runs once and gates,
+// or on a schedule, or stays up, never two (ADR 0053).
+func prepared(from map[string]any) map[string]any {
+	step := map[string]any{}
+	for k, v := range from {
+		step[k] = v
+	}
+	// **A hyphen, not a dot.** A resource's id is `<module>.<its own id>`, and a module's name may
+	// itself contain a dot (`novox.be`), so the module is everything before the *last* dot — which
+	// only works if what the mesh derives adds no dot of its own.
+	step["id"] = fmt.Sprint(from["id"]) + "-prepare"
+	step["name"] = fmt.Sprint(from["name"]) + "-prepare"
+	step["run-once"] = true
+	step["args"] = []any{PreparationArgument}
+	delete(step, "ports")
+	delete(step, "ip")
+	delete(step, "schedule")
+	delete(step, "reload-on")
+	return step
+}

internal/catalogue/manifest.go

@@ -225,6 +225,19 @@ type Manifest struct {
 	// subscription to the queue it writes to (design 29 §2).
 	Uses []string `json:"uses,omitempty"`
 
+	// Prepares says this module has state that must be brought to the shape this version needs
+	// before this version runs, and that the module's own code does it (novox/hq ADR 0135).
+	//
+	// **A word, not an arrangement.** The mesh runs the module's own program in its preparation
+	// mode, in the module's own context — every binding, credential and setting its code receives,
+	// because it *is* its code. Nothing here names a container, a command, a mount or a variable:
+	// the module already said all of that once, and a second copy is a second thing to drift.
+	//
+	// **Declared, never inferred.** The control plane cannot read what is inside an artifact, so a
+	// module that ships a migration and does not say this breaks on its first upgrade. That is
+	// stated in the record rather than guarded here, because nothing mechanical can guard it.
+	Prepares bool `json:"prepares,omitempty"`
+
 	// Tools are the tools this module answers — request and reply, awaited.
 	//
 	// **New, and not `serves`**, which this manifest already uses for the facts a consumer needs
@@ -1276,6 +1289,17 @@ func ParseManifest(raw []byte) (Manifest, error) {
 				"program that reads what the mesh delivered and reconciles",
 			m.Module, r["id"]))
 	}
+	// **A module that prepares its state must have code the mesh can run** (novox/hq ADR 0135). The
+	// preparation is the module's own program in its preparation mode, so it is derived from the
+	// resource that runs that program — and a module declaring none has asked for something the mesh
+	// cannot compose. Said here, where the manifest is read, rather than by a declaration that
+	// quietly prepares nothing.
+	if m.Prepares && preparationTarget(m) == "" {
+		problems = append(problems, fmt.Sprintf(
+			"%s says it prepares its state, and declares no container running an artifact it built — "+
+				"the preparation is this module's own program, so there has to be one for the mesh to "+
+				"run it in", m.Module))
+	}
 	// **A run-once container is a step the host runs to completion** (novox/hq ADR 0052). It is a
 	// boolean modifier on the container shape — the host runs the container, requires it to exit 0,
 	// and starts whatever the declaration places after it only once it has. A value that is not a

internal/catalogue/prepares_test.go

@@ -0,0 +1,141 @@
+package catalogue
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"testing"
+)
+
+// A module version prepares its state before it runs (novox/hq ADR 0135).
+//
+// What the mesh derives is the module's own resource, run once with one word, placed immediately in
+// front of the thing it prepares for. What matters in these tests is that the derivation is a copy
+// rather than a second description: the failure it replaces was a hand-written step repeating six
+// fields of the resource it preceded, each free to drift from it.
+
+func aPreparingModule() Manifest {
+	return Manifest{
+		Module:   "gitea",
+		Prepares: true,
+		Resources: []map[string]any{
+			{"id": "state", "type": "directory", "path": "/var/lib/gitea", "mode": "0700"},
+			{"id": "server", "type": "container", "name": "mesh-gitea-server",
+				"image": "gitea/gitea@" + digest, "ports": []any{"3000:3000"}},
+			{"id": "runtime", "type": "container", "name": "mesh-gitea",
+				"image": ArtifactStoreScheme + "gitea/runtime@" + digest, "network": "host",
+				"env":     map[string]any{"MESH_GITEA_STATE_DIR": "/run/state"},
+				"volumes": []any{"/var/lib/gitea:/run/state:ro"},
+				"ports":   []any{"9000:9000"}},
+		},
+	}
+}
+
+func declaredFor(t *testing.T, m Manifest) []map[string]any {
+	t.Helper()
+	// The manifest as the mesh holds it: a build resolved the module's own artifact into the
+	// reference it recorded, which is also how the composition knows whose code a resource runs.
+	out, err := Resolution{Node: "anchor", Modules: []Manifest{m}}.Declaration(
+		Rendering{ArtifactStore: "anchor.internal:5100"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return out
+}
+
+func idsOf(resources []map[string]any) []string {
+	var ids []string
+	for _, r := range resources {
+		ids = append(ids, fmt.Sprint(r["id"]))
+	}
+	return ids
+}
+
+// The step runs the module's own code, and comes immediately before it — not before the upstream
+// server the module packages, which may be the very thing the state lives in.
+func TestThePreparationRunsTheModulesOwnCodeAndComesRightBeforeIt(t *testing.T) {
+	out := declaredFor(t, aPreparingModule())
+	ids := idsOf(out)
+	at := -1
+	for i, id := range ids {
+		if id == "gitea.runtime-prepare" {
+			at = i
+		}
+	}
+	if at < 0 {
+		t.Fatalf("nothing prepares this module's state: %v", ids)
+	}
+	// A module's name may contain a dot, so a resource's module is everything before the last one —
+	// which the derived id must not add to, or a machine reads the wrong owner from it.
+	if strings.Count("gitea.runtime-prepare", ".") != 1 {
+		t.Fatal("the derived id adds a dot, so what owns it cannot be read from it")
+	}
+	if ids[at+1] != "gitea.runtime" {
+		t.Fatalf("the preparation is not immediately before the module's own code: %v", ids)
+	}
+	for _, id := range ids[:at] {
+		if id == "gitea.runtime" {
+			t.Fatalf("the module's own code runs before its state is prepared: %v", ids)
+		}
+	}
+}
+
+// It is given exactly what the module's own code is given. Asserted field by field against the
+// resource it was derived from, because writing it twice is the fault this replaces.
+func TestThePreparationIsGivenWhatTheModuleIsGiven(t *testing.T) {
+	out := declaredFor(t, aPreparingModule())
+	declared := byID(out)
+	step, workload := declared["gitea.runtime-prepare"], declared["gitea.runtime"]
+	if step == nil || workload == nil {
+		t.Fatalf("expected both, got %v", idsOf(out))
+	}
+	for _, field := range []string{"image", "network", "env", "volumes", "type"} {
+		if fmt.Sprint(step[field]) != fmt.Sprint(workload[field]) {
+			t.Errorf("the preparation's %s is %v and the module's is %v", field, step[field], workload[field])
+		}
+	}
+	if once, _ := step["run-once"].(bool); !once {
+		t.Error("the preparation is not a step, so nothing waits for it and nothing is gated by it")
+	}
+	if fmt.Sprint(step["args"]) != fmt.Sprint([]any{PreparationArgument}) {
+		t.Errorf("the preparation is asked for as %v", step["args"])
+	}
+	if fmt.Sprint(step["name"]) == fmt.Sprint(workload["name"]) {
+		t.Error("the preparation and the workload have one name, so one removes the other")
+	}
+	// A published port cannot be bound twice, and the version being replaced is still running.
+	if _, published := step["ports"]; published {
+		t.Errorf("the preparation publishes a port the running version holds: %v", step["ports"])
+	}
+}
+
+// A module that says nothing about preparing gets nothing, which is most modules.
+func TestAModuleThatPreparesNothingGetsNoStep(t *testing.T) {
+	m := aPreparingModule()
+	m.Prepares = false
+	for _, id := range idsOf(declaredFor(t, m)) {
+		if id == "gitea.runtime-prepare" {
+			t.Fatal("a module that prepares nothing was given a preparation")
+		}
+	}
+}
+
+// A module whose own code the mesh cannot find has nothing to ask, and saying so where the manifest
+// is read beats a declaration that quietly prepares nothing.
+func TestAModuleThatPreparesAndRunsNoneOfItsOwnCodeIsRefused(t *testing.T) {
+	m := Manifest{
+		Module:   "gitea",
+		Prepares: true,
+		Resources: []map[string]any{
+			// Only the upstream server it packages: nothing here runs gitea's own code.
+			{"id": "server", "type": "container", "name": "mesh-gitea-server", "image": "gitea/gitea@" + digest},
+		},
+	}
+	raw, err := json.Marshal(m)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ParseManifest(raw); err == nil {
+		t.Fatal("a module that prepares its state with nothing of its own to run was accepted")
+	}
+}

internal/inventory/builds.go

@@ -36,12 +36,21 @@ type Build struct {
 	// Against is every artifact this build stood on, as references rather than module names —
 	// what makes a build edge derived rather than declared (ADR 0009).
 	Against []string
+	// Read is every repository this build read source from besides the module's own (novox/hq
+	// 04-ISSUES/131), at the ref it read.
+	Read []ReadRepository
 	// Failed is the builder's own words, empty when it worked.
 	Failed string
 	Made   []Artifact
 	At     time.Time
 }
 
+// ReadRepository is a repository a build read source from besides the module's own.
+type ReadRepository struct {
+	Repository string `json:"repository"`
+	Ref        string `json:"ref,omitempty"`
+}
+
 // Artifact is one thing a build published.
 type Artifact struct {
 	Name      string `json:"name"`
@@ -66,17 +75,21 @@ func (i *Inventory) RecordBuild(ctx context.Context, b Build) error {
 	if err != nil {
 		return err
 	}
+	read, err := json.Marshal(b.Read)
+	if err != nil {
+		return err
+	}
 	var module *string
 	if b.Module != "" {
 		module = &b.Module
 	}
 	_, err = i.store.Pool().Exec(ctx,
 		`insert into build (id, repository, ref, module, commit_hash, built_on, failed, made,
-		                    source_path, manifest, built_against)
-		 values ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
+		                    source_path, manifest, built_against, built_contexts)
+		 values ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
 		 on conflict (id) do nothing`,
 		b.ID, b.Repository, b.Ref, module, b.Commit, b.On, b.Failed, made,
-		b.Path, manifestOrNil(b.Manifest), against)
+		b.Path, manifestOrNil(b.Manifest), against, read)
 	return err
 }
 
@@ -199,6 +212,44 @@ func (i *Inventory) BuiltAgainst(ctx context.Context) (map[string][]string, erro
 	return against, rows.Err()
 }
 
+// ReadRepositories is what each module's newest successful build read source from besides its own
+// repository, by module name.
+//
+// The mirror of BuiltAgainst, and derived the same way and for the same reason: a merge into a
+// repository a module only packages is a change to that module, and the manifest the mesh keeps
+// carries nothing that would say so (novox/hq 04-ISSUES/131).
+func (i *Inventory) ReadRepositories(ctx context.Context) (map[string][]ReadRepository, error) {
+	rows, err := i.store.Pool().Query(ctx,
+		`select distinct on (module) module, built_contexts
+		   from build
+		  where module is not null and module <> '' and failed = ''
+		  order by module, at desc`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	read := map[string][]ReadRepository{}
+	for rows.Next() {
+		var module string
+		var raw []byte
+		if err := rows.Scan(&module, &raw); err != nil {
+			return nil, err
+		}
+		if len(raw) == 0 {
+			continue
+		}
+		var of []ReadRepository
+		if err := json.Unmarshal(raw, &of); err != nil {
+			continue
+		}
+		if len(of) > 0 {
+			read[module] = of
+		}
+	}
+	return read, rows.Err()
+}
+
 // manifestOrNil keeps the difference between "declared nothing" and "predates this being kept".
 //
 // A build recorded before the mesh kept manifests has no manifest, and that is not the same as one

internal/inventory/builds_test.go

@@ -136,3 +136,36 @@ func ids(builds []Build) []string {
 	}
 	return out
 }
+
+// What a build read besides its module's own repository comes back for the newest build of each
+// module, and only for builds that worked. Nothing recorded is absent rather than empty, which is how
+// a build made before the mesh kept this is told from one that read nothing (novox/hq 04-ISSUES/131).
+func TestWhatABuildReadComesBackForTheNewestBuildOfEachModule(t *testing.T) {
+	inv := fresh(t)
+	ctx := context.Background()
+	older := aBuild("older", "builder", "")
+	older.Read = []ReadRepository{{Repository: "novox/mesh-controller", Ref: "release"}}
+	newer := aBuild("newer", "builder", "")
+	newer.Read = []ReadRepository{{Repository: "novox/mesh-controller", Ref: "main"}}
+	plain := aBuild("plain", "gitea", "")
+	failed := aBuild("failed", "route-proxy", "cannot clone")
+	failed.Read = []ReadRepository{{Repository: "novox/mesh-controller", Ref: "main"}}
+	for _, b := range []Build{older, newer, plain, failed} {
+		if err := inv.RecordBuild(ctx, b); err != nil {
+			t.Fatal(err)
+		}
+	}
+	read, err := inv.ReadRepositories(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(read["builder"]) != 1 || read["builder"][0].Ref != "main" {
+		t.Fatalf("the newest build's reading is %+v", read["builder"])
+	}
+	if _, has := read["gitea"]; has {
+		t.Fatalf("a build that read nothing but its own repository reads as %+v", read["gitea"])
+	}
+	if _, has := read["route-proxy"]; has {
+		t.Fatal("a failed build's reading was kept as what that module reads")
+	}
+}

internal/inventory/doing_test.go

@@ -30,12 +30,12 @@ func TestRefusedAndFailedAreDifferentSituations(t *testing.T) {
 	refuser := nodeNamed(t, inv, "refuser")
 	failer := nodeNamed(t, inv, "failer")
 
-	if err := inv.RecordDoing(ctx, refuser, Doing{
+	if _, err := inv.RecordDoing(ctx, refuser, Doing{
 		Outcome: OutcomeRefused, Refused: "resource \"x\": a file needs a path",
 	}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.RecordDoing(ctx, failer, Doing{
+	if _, err := inv.RecordDoing(ctx, failer, Doing{
 		Outcome: OutcomeFailed,
 		Failed:  []FailedResource{{ID: "svc", Error: "unit not found"}},
 		Applied: 4,
@@ -70,7 +70,7 @@ func TestAMachineDoingWhatItWasToldIsNotOnTheList(t *testing.T) {
 	inv := fresh(t)
 	ctx := context.Background()
 	id := nodeNamed(t, inv, "fine")
-	if err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 6}); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 6}); err != nil {
 		t.Fatal(err)
 	}
 	wrong, err := inv.NotDoingWhatTheyWereTold(ctx)
@@ -97,12 +97,12 @@ func TestTheLastReportReplacesTheOneBefore(t *testing.T) {
 	inv := fresh(t)
 	ctx := context.Background()
 	id := nodeNamed(t, inv, "recovered")
-	if err := inv.RecordDoing(ctx, id, Doing{
+	if _, err := inv.RecordDoing(ctx, id, Doing{
 		Outcome: OutcomeFailed, Failed: []FailedResource{{ID: "a", Error: "no"}},
 	}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 3}); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 3}); err != nil {
 		t.Fatal(err)
 	}
 	wrong, err := inv.NotDoingWhatTheyWereTold(ctx)
@@ -141,7 +141,7 @@ func TestWhatANodeSaidGoesWhenTheNodeDoes(t *testing.T) {
 	inv := fresh(t)
 	ctx := context.Background()
 	id := nodeNamed(t, inv, "leaving")
-	if err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeFailed}); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeFailed}); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := inv.store.Pool().Exec(ctx, `delete from node where name = 'leaving'`); err != nil {
@@ -257,7 +257,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 	id := nodeNamed(t, inv, "looping")
 	same := Doing{Outcome: OutcomeFailed, Failed: []FailedResource{{ID: "img", Error: "no such image"}}}
 
-	if err := inv.RecordDoing(ctx, id, same); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, same); err != nil {
 		t.Fatal(err)
 	}
 	first, _, err := inv.DoingOf(ctx, "looping")
@@ -269,7 +269,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 	}
 
 	for range StuckAfter - 1 {
-		if err := inv.RecordDoing(ctx, id, same); err != nil {
+		if _, err := inv.RecordDoing(ctx, id, same); err != nil {
 			t.Fatal(err)
 		}
 	}
@@ -287,7 +287,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 	// The same resource failing with different words — a duration, a counter — is still the same
 	// failure: it is the resource that loops, not the sentence.
 	reworded := Doing{Outcome: OutcomeFailed, Failed: []FailedResource{{ID: "img", Error: "no such image (after 31s)"}}}
-	if err := inv.RecordDoing(ctx, id, reworded); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, reworded); err != nil {
 		t.Fatal(err)
 	}
 	still, _, err := inv.DoingOf(ctx, "looping")
@@ -300,7 +300,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 
 	// A different failure is a new situation, not a longer one.
 	other := Doing{Outcome: OutcomeFailed, Failed: []FailedResource{{ID: "svc", Error: "unit not found"}}}
-	if err := inv.RecordDoing(ctx, id, other); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, other); err != nil {
 		t.Fatal(err)
 	}
 	changed, _, err := inv.DoingOf(ctx, "looping")
@@ -312,7 +312,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 	}
 
 	// And a clean apply clears it: the machine is doing what it was told, since nothing.
-	if err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 2}); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, Doing{Outcome: OutcomeApplied, Applied: 2}); err != nil {
 		t.Fatal(err)
 	}
 	fine, _, err := inv.DoingOf(ctx, "looping")
@@ -324,7 +324,7 @@ func TestTheSameFailureReportedAgainIsCountedNotRestarted(t *testing.T) {
 	}
 
 	// The list of what is wrong carries the count, so `status` can say it.
-	if err := inv.RecordDoing(ctx, id, same); err != nil {
+	if _, err := inv.RecordDoing(ctx, id, same); err != nil {
 		t.Fatal(err)
 	}
 	wrong, err := inv.NotDoingWhatTheyWereTold(ctx)

internal/inventory/migrations/0042-a-build-says-which-repositories-it-read.sql

@@ -0,0 +1,13 @@
+-- A build says which repositories it read, so a merge can find everything it affects.
+--
+-- A module is built from the one repository the mesh records — where its module.json lives — and some
+-- modules' recipes reach into a second for the source they package: the packaging and the source are
+-- allowed to live apart (catalogue's ArtifactContext). That second repository is named in the manifest
+-- the build read, and the manifest the mesh *keeps* carries no build section, so nothing on the mesh
+-- could say that a merge into the other repository is a change to this module at all. Two modules are
+-- built from the control plane's own repository, and neither had ever been rebuilt when it moved
+-- (novox/hq 04-ISSUES/131).
+--
+-- Nullable, like the two derived columns beside it: null is a build recorded before the mesh kept
+-- this, which is not the same as a build that read nothing but its module's own repository.
+alter table build add column built_contexts jsonb;

internal/inventory/nodes.go

@@ -670,31 +670,39 @@ func sameFailure(a, b Doing) bool {
 // a clean apply clears both (novox/hq 04-ISSUES/065). The previous row is read first and the
 // comparison made here, so "the same" is a rule this package states rather than a jsonb equality
 // that would restart the count on a changed word in an error.
-func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) error {
+// **And whether this report was news**, which is what makes a fact about it worth stating (novox/hq
+// ADR 0134). A machine reconciles continuously and reports each time; the same outcome about the same
+// declaration is the same state said again, and a fact per report would be a fact per minute per
+// machine that tells nobody anything. Read here because the previous row is read here anyway.
+func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) (news bool, err error) {
 	failed, err := json.Marshal(d.Failed)
 	if err != nil {
-		return err
+		return false, err
+	}
+	var before Doing
+	var beforeFailed []byte
+	found := i.store.Pool().QueryRow(ctx,
+		`select outcome, refused, failed, failing_since, failures, coalesce(declared,'')
+		   from node_report where node = $1`,
+		node).Scan(&before.Outcome, &before.Refused, &beforeFailed, &before.Since, &before.Times,
+		&before.Declared)
+	switch {
+	case errors.Is(found, pgx.ErrNoRows):
+		news = true
+	case found != nil:
+		return false, found
+	default:
+		if err := json.Unmarshal(beforeFailed, &before.Failed); err != nil {
+			return false, err
+		}
+		news = before.Outcome != d.Outcome || before.Declared != d.Declared || !sameFailure(before, d)
 	}
 	var since *time.Time
 	times := 0
 	if d.Outcome != OutcomeApplied {
-		var before Doing
-		var beforeFailed []byte
-		err := i.store.Pool().QueryRow(ctx,
-			`select outcome, refused, failed, failing_since, failures from node_report where node = $1`,
-			node).Scan(&before.Outcome, &before.Refused, &beforeFailed, &before.Since, &before.Times)
-		switch {
-		case errors.Is(err, pgx.ErrNoRows):
-		case err != nil:
-			return err
-		default:
-			if err := json.Unmarshal(beforeFailed, &before.Failed); err != nil {
-				return err
-			}
-		}
 		now := time.Now()
 		since, times = &now, 1
-		if err == nil && sameFailure(before, d) && before.Since != nil {
+		if found == nil && sameFailure(before, d) && before.Since != nil {
 			since, times = before.Since, before.Times+1
 		}
 	}
@@ -707,7 +715,10 @@ func (i *Inventory) RecordDoing(ctx context.Context, node string, d Doing) error
 		   declared = excluded.declared,
 		   failing_since = excluded.failing_since, failures = excluded.failures`,
 		node, d.Outcome, d.Refused, failed, d.Applied, d.Declared, since, times)
-	return err
+	if err != nil {
+		return false, err
+	}
+	return news, nil
 }
 
 // NotDoingWhatTheyWereTold is every machine whose last report was not a clean apply.

internal/link/build.go

@@ -88,10 +88,23 @@ type BuildResult struct {
 	// (novox/hq ADR 0009). The catalogue turns these into edges; nothing else need care.
 	Against []string `json:"against,omitempty"`
 
+	// Read is every repository this build read source from besides the module's own. A module whose
+	// recipe packages source that lives elsewhere is affected when that repository moves, and the
+	// manifest the mesh keeps says nothing about it (novox/hq 04-ISSUES/131).
+	Read []ReadRepository `json:"read,omitempty"`
+
 	// Failed is why, when it did.
 	Failed string `json:"failed,omitempty"`
 }
 
+// ReadRepository is a repository a build read source from besides the module's own, at the branch,
+// tag or commit it read. Spelled here as well as in the catalogue and the inventory, for the reason
+// MadeArtifact is: one direction of dependency.
+type ReadRepository struct {
+	Repository string `json:"repository"`
+	Ref        string `json:"ref,omitempty"`
+}
+
 // MadeArtifact is one thing a build produced, as a person would want it reported.
 type MadeArtifact struct {
 	Name      string `json:"name"`

internal/link/bus.go

@@ -30,6 +30,11 @@ type Bus interface {
 	// (design 29 §4, the *state* shape).
 	PublishDeclaration(ctx context.Context, node string, body []byte) error
 
+	// PublishSeatEvent states a fact under a role's own name, for the holder of that role. A
+	// module's event is addressed to the module; a role's is addressed to the role, so it keeps
+	// meaning when the holder changes (novox/hq ADR 0121, ADR 0129).
+	PublishSeatEvent(ctx context.Context, seat, event string, body []byte) error
+
 	// AskTool sends one question to a module's tool and awaits one answer. A tool nobody serves
 	// must say so **at once** rather than after the whole wait: the difference between "that
 	// module is down" and "that tool is slow" is the first thing a person asking wants.
@@ -81,6 +86,13 @@ func EventSubject(source, key string) string {
 	return "mesh.mod." + source + ".event." + key
 }
 
+// SeatEventSubject is where a role's own event lands. Derived from the role, never from its holder:
+// a fact about the build machine or about the control plane keeps its address when the module holding
+// that role is replaced (novox/hq ADR 0121, ADR 0129).
+func SeatEventSubject(seat, event string) string {
+	return "mesh.seat." + seat + ".event." + event
+}
+
 // DeclareSubject is where one node's declaration lands. Last-per-subject on the NODES stream, so
 // a node that was away gets exactly the current one and a replayed older one is refused by
 // sequence — the wire-level answer to novox/hq issue 107.
@@ -112,6 +124,27 @@ func (b OverNATS) PublishEvent(ctx context.Context, key, source, node string, bo
 	return nil
 }
 
+// PublishSeatEvent states a role's own fact. Same envelope as a module's event and a different
+// address: the source header is the role, because that is what the fact is about.
+func (b OverNATS) PublishSeatEvent(ctx context.Context, seat, event string, body []byte) error {
+	id, err := eventID()
+	if err != nil {
+		return err
+	}
+	h := nats.Header{}
+	h.Set("x-event-id", id)
+	h.Set("x-source", seat)
+	_, err = b.JS.PublishMsg(&nats.Msg{
+		Subject: SeatEventSubject(seat, event),
+		Header:  h,
+		Data:    body,
+	}, nats.MsgId(id), nats.Context(ctx))
+	if err != nil {
+		return fmt.Errorf("stating %s of the %s seat: %w", event, seat, err)
+	}
+	return nil
+}
+
 func (b OverNATS) PublishDeclaration(ctx context.Context, node string, body []byte) error {
 	_, err := b.JS.Publish(DeclareSubject(node), body, nats.Context(ctx))
 	if err != nil {

internal/link/enrolment.go

@@ -265,7 +265,7 @@ func (e Enrolment) Outstanding(ctx context.Context, node string) (string, error)
 	return e.Inventory.Outstanding(ctx, node)
 }
 
-func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
+func (e Enrolment) Heard(ctx context.Context, report Report) (news bool, err error) {
 	// A store that could not be asked right now is said as such, so the report is kept for
 	// another attempt rather than acknowledged and lost (novox/hq issue 082).
 	defer func() {
@@ -274,11 +274,11 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 		}
 	}()
 	if report.Node == "" {
-		return errors.New("a report named no node")
+		return false, errors.New("a report named no node")
 	}
 	node, err := e.Inventory.NodeByName(ctx, report.Node)
 	if err != nil {
-		return err
+		return false, err
 	}
 
 	// What an adopted node holds, which firewall it found, and what is reachable on it (novox/hq
@@ -298,7 +298,7 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 				Port: r.Port, By: r.By, Published: r.Published, ContainerPort: r.ContainerPort})
 		}
 		if err := e.Inventory.RecordAdoption(ctx, node.ID, held, report.Firewall, reachable); err != nil {
-			return err
+			return false, err
 		}
 	}
 	// What it says about the tunnel it carried (novox/hq ADR 0105), whenever it says it.
@@ -308,7 +308,7 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 			Peers: report.Tunnel.Peers, State: report.Tunnel.State, Note: report.Tunnel.Note,
 			Kept: report.Tunnel.Kept,
 		}); err != nil {
-			return err
+			return false, err
 		}
 	}
 	// A node taking a found tunnel's key after enrolment (novox/hq ADR 0105). Verified against the
@@ -317,9 +317,9 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 	// does not verify or is stale — a refusal, not "not now", so the node hears why.
 	if report.Rekey != nil {
 		if err := e.rekey(ctx, node, *report.Rekey); err != nil {
-			return err
+			return false, err
 		}
-		return e.Inventory.Seen(ctx, node.ID)
+		return false, e.Inventory.Seen(ctx, node.ID)
 	}
 
 	// A bare word that a node is there is not an account of what the machine did or holds: it
@@ -334,7 +334,7 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 		if report.Superseded != "" {
 			log.Printf("%s set aside declaration %s for the newer %s", report.Node, report.Declared, report.Superseded)
 		}
-		return e.Inventory.Seen(ctx, node.ID)
+		return false, e.Inventory.Seen(ctx, node.ID)
 	}
 	// What it did is kept whichever way it went. Until this, a refusal or a failure moved
 	// last_seen and the reason went to a log line, so "which machine is not doing what it was
@@ -361,17 +361,20 @@ func (e Enrolment) Heard(ctx context.Context, report Report) (err error) {
 	// on top of it (novox/hq ADR 0038). Kept even when the declaration was refused: what the
 	// machine carries is true regardless of what it thought of the last thing it was sent.
 	if err := e.Inventory.RecordCarried(ctx, report.Node, report.Carried); err != nil {
-		return err
+		return false, err
 	}
-	if err := e.Inventory.RecordDoing(ctx, node.ID, doing); err != nil {
-		return err
+	// **Whether this is news** is the store's answer: it holds the previous report, and a machine
+	// that reconciles every minute says the same thing until something changes (novox/hq ADR 0134).
+	news, err = e.Inventory.RecordDoing(ctx, node.ID, doing)
+	if err != nil {
+		return false, err
 	}
 
 	// A refusal, a failure, or a bare word that the node is there — none of them is an account of
 	// what the machine holds, so each moves last_seen and nothing else. Recording a partial list
 	// as though it were the whole would tell a rebuilding node to remove what it still has.
 	if report.Refused != "" || len(report.Failed) > 0 || report.Applied == nil {
-		return e.Inventory.Seen(ctx, node.ID)
+		return news, e.Inventory.Seen(ctx, node.ID)
 	}
-	return e.Inventory.RecordOwned(ctx, node.ID, report.Applied)
+	return news, e.Inventory.RecordOwned(ctx, node.ID, report.Applied)
 }

internal/link/events.go

@@ -49,6 +49,39 @@ func eventID() (string, error) {
 	return hex.EncodeToString(raw), nil
 }
 
+// MeshControllerSeat is the role the control plane holds, and therefore where its own facts live: a
+// role's events belong to the role, not to whichever container is holding it today (novox/hq ADR 0121,
+// ADR 0129). It is what makes them addressable while the control plane itself is being replaced.
+const MeshControllerSeat = "mesh-controller"
+
+// The facts the mesh states about its own work (novox/hq ADR 0134).
+const (
+	// KeyApplied: a machine now runs what it was sent.
+	KeyApplied = "applied"
+	// KeyRefused: a machine did not take what it was sent, and why.
+	KeyRefused = "refused"
+	// KeyBuiltBefore: a build the mesh already held, for a catalogue that asked what it missed. Not
+	// `built` — that is the build machine's, said as it happens, and a replay is neither.
+	KeyBuiltBefore = "built-before"
+)
+
+// Applied is what a machine now runs, as the mesh states it.
+type Applied struct {
+	Node     string `json:"node"`
+	Declared string `json:"declared,omitempty"`
+	// Resources is how many the machine applied, not which: the list is the machine's own account
+	// of itself and belongs in the records, not in a fact every listener has to read past.
+	Resources int `json:"resources"`
+}
+
+// Refused is a machine that would not take what it was sent.
+type Refused struct {
+	Node     string            `json:"node"`
+	Declared string            `json:"declared,omitempty"`
+	Refused  string            `json:"refused,omitempty"`
+	Failed   map[string]string `json:"failed,omitempty"`
+}
+
 // KeyModuleBuilt is what the builder announces when it has built something. The catalogue places
 // it in the module graph; nothing else need care.
 const KeyModuleBuilt = "module.builder.built"
@@ -130,6 +163,16 @@ type SourceMoved struct {
 	HTMLURL  string `json:"html_url"`
 	// MergedAt is when the forge merged it, RFC 3339. What decides whether this is news.
 	MergedAt string `json:"merged_at"`
+
+	// Paths are the files the merge changed, from the repository's root. Empty means the forge said
+	// nothing about them, and every module built from the repository is treated as affected.
+	Paths []string `json:"paths,omitempty"`
+
+	// PathsTruncated says the merge changed more files than the forge was asked to list, so Paths is
+	// a beginning rather than the whole change — and again, everything is treated as affected. Said
+	// rather than inferred from a round number, because "this is all of it" and "this is as much as
+	// I asked for" are the difference between rebuilding a module and leaving it stale.
+	PathsTruncated bool `json:"paths_truncated,omitempty"`
 }
 
 type Upgraded struct {

internal/link/heard_test.go

@@ -22,7 +22,7 @@ func heardFrom(t *testing.T, report link.Report) (*inventory.Inventory, inventor
 	if _, err := inv.AddNode(ctx, report.Node); err != nil {
 		t.Fatal(err)
 	}
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, report); err != nil {
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, report); err != nil {
 		t.Fatal(err)
 	}
 	doing, said, err := inv.DoingOf(ctx, report.Node)
@@ -103,7 +103,7 @@ func TestABareAliveDoesNotWipeTheDeclarationThatSaysANodeIsCurrent(t *testing.T)
 	if err := inv.RecordSent(ctx, node.ID, digest); err != nil {
 		t.Fatal(err)
 	}
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{
 		Node: "anchor", Applied: []string{"a", "b"}, Declared: digest, Carried: []int{5432},
 	}); err != nil {
 		t.Fatal(err)
@@ -126,7 +126,7 @@ func TestABareAliveDoesNotWipeTheDeclarationThatSaysANodeIsCurrent(t *testing.T)
 	}
 
 	// Now the node says only that it is there, as it does every minute.
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor"}); err != nil {
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor"}); err != nil {
 		t.Fatal(err)
 	}
 	if !currentOf("anchor") {
@@ -162,7 +162,7 @@ func TestAFailureDoesNotBecomeTheAccountOfWhatTheMachineHolds(t *testing.T) {
 	if err := inv.RecordOwned(ctx, node.ID, []string{"one", "two", "three"}); err != nil {
 		t.Fatal(err)
 	}
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{
 		Node: "workstation", Applied: []string{"one"}, Failed: map[string]string{"two": "no"},
 	}); err != nil {
 		t.Fatal(err)
@@ -200,13 +200,13 @@ func TestWhatAnAdoptedNodeHoldsIsKeptAndAnAliveWordDoesNotWipeIt(t *testing.T) {
 	}
 	check("after the report")
 
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor"}); err != nil {
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor"}); err != nil {
 		t.Fatal(err)
 	}
 	check("after an alive word")
 
 	// A reconcile report carrying only adoption is recorded, though it applied nothing.
-	if err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor",
+	if _, err := (link.Enrolment{Inventory: inv}).Heard(ctx, link.Report{Node: "anchor",
 		Firewall: "ufw"}); err != nil {
 		t.Fatal(err)
 	}

internal/link/receive_nats.go

@@ -154,10 +154,47 @@ func (n *natsInbound) deliver(ctx context.Context, act func(context.Context, Con
 			m.seq = meta.Sequence.Stream
 			m.delivered = meta.NumDelivered
 		}
+		// **Work that outlives the acknowledgement window says so while it runs.**
+		//
+		// The bus waits a fixed time to be told a message was taken, and then hands it to whoever
+		// consumes next — which is right for a consumer that died and wrong for one that is busy.
+		// Acting on a merge builds every module the merge changed: minutes of work against a
+		// thirty-second window. So the same merge was handed over again while the first build was
+		// still running, and again after that — on 2026-09-28 one merge ran the mesh's whole
+		// catalogue five times over and exhausted a public registry's pull limit.
+		//
+		// Here rather than in each handler, because the window belongs to the transport and every
+		// handler would otherwise have to remember it. It changes nothing about a handler that
+		// dies: a message is kept alive only while this goroutine is, so a controller that stops
+		// stops saying so, and the bus redelivers exactly as it should.
+		working := make(chan struct{})
+		defer close(working)
+		go stillWorking(msg, working)
 	}
 	act(ctx, m)
 }
 
+// heartbeatWhileWorking is how often a handler still running tells the bus so — comfortably inside
+// the shortest acknowledgement window the mesh gives any of its consumers.
+const heartbeatWhileWorking = 10 * time.Second
+
+// stillWorking keeps one message alive until the work on it returns.
+//
+// An error is not worth reporting: what the bus does when it is not told is redeliver, which is
+// exactly what happens if this fails, and the handler's own outcome is the thing worth logging.
+func stillWorking(msg *nats.Msg, done <-chan struct{}) {
+	tick := time.NewTicker(heartbeatWhileWorking)
+	defer tick.Stop()
+	for {
+		select {
+		case <-done:
+			return
+		case <-tick.C:
+			_ = msg.InProgress()
+		}
+	}
+}
+
 // kindOfSubject is how this transport's addressing becomes what the mesh calls a message.
 //
 // By subject, which is the only thing the server enforces: a body claiming to be a report does not

internal/link/receive_nats_test.go

@@ -86,14 +86,15 @@ type counted struct {
 	heard []Report
 }
 
-func (c *counted) Heard(_ context.Context, r Report) error {
+func (c *counted) Heard(_ context.Context, r Report) (bool, error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.err != nil {
-		return c.err
+		return false, c.err
 	}
 	c.heard = append(c.heard, r)
-	return nil
+	// News, so what the mesh states about a report is exercised wherever a report is.
+	return true, nil
 }
 
 func (c *counted) refusing(err error) {
@@ -207,11 +208,11 @@ type sentAndHeardSafely struct {
 	heard []Report
 }
 
-func (s *sentAndHeardSafely) Heard(_ context.Context, r Report) error {
+func (s *sentAndHeardSafely) Heard(_ context.Context, r Report) (bool, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.heard = append(s.heard, r)
-	return nil
+	return true, nil
 }
 
 func (s *sentAndHeardSafely) Outstanding(context.Context, string) (string, error) {
@@ -395,3 +396,164 @@ func TestEverySubjectTheControllerFollowsDecodesToAKind(t *testing.T) {
 		t.Error("a subject nobody follows decoded to a kind")
 	}
 }
+
+// **A handler slower than the acknowledgement window is not handed its message again.**
+//
+// The bus waits a fixed time to be told a message was taken and then redelivers, which is right for
+// a consumer that died and wrong for one that is busy. Acting on a merge builds modules — minutes
+// against a thirty-second window — and the same merge was handed over five times while the first
+// build was still running (2026-09-28). Here the window is two seconds and the work takes six.
+func TestNatsWorkSlowerThanTheWindowIsNotHandedOverAgain(t *testing.T) {
+	js := aBus(t)
+	// The controller's own consumer, with a window short enough to outlive in a test.
+	if err := js.EnsureConsumer(broker.Consumer{
+		Name: broker.ControllerName, Stream: "CONTROL", Push: true, AckWaitSeconds: 2,
+		Why: "a window short enough to outlive in a test",
+	}); err != nil {
+		t.Fatal(err)
+	}
+	var mu sync.Mutex
+	handled := 0
+	slow := make(chan struct{})
+	s, stop := servingOn(t, js, nil)
+	defer stop()
+	s.listener = slowly{func() {
+		mu.Lock()
+		handled++
+		first := handled == 1
+		mu.Unlock()
+		if first {
+			time.Sleep(6 * time.Second)
+			close(slow)
+		}
+	}}
+
+	body, err := json.Marshal(Report{Node: "anchor", Declared: "d1", Applied: []string{"store"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := js.Context().Publish(ReportSubject("anchor"), body); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case <-slow:
+	case <-time.After(30 * time.Second):
+		t.Fatal("the slow work never finished")
+	}
+	// A moment for a redelivery to arrive, if the bus were going to send one.
+	time.Sleep(3 * time.Second)
+	mu.Lock()
+	defer mu.Unlock()
+	if handled != 1 {
+		t.Fatalf("one report was handled %d times, so slow work is run again while it is running", handled)
+	}
+}
+
+// slowly is a listener that runs whatever it was given.
+type slowly struct{ work func() }
+
+func (s slowly) Heard(context.Context, Report) (bool, error) { s.work(); return true, nil }
+
+// **The mesh says what it applied** (novox/hq ADR 0134), under the seat the control plane holds — and
+// says nothing when a report is the same state said again, which is what a machine reconciling every
+// minute sends.
+func TestNatsTheMeshSaysWhatAMachineApplied(t *testing.T) {
+	js := aBus(t)
+	heard := make(chan *nats.Msg, 4)
+	sub, err := js.Conn().Subscribe(SeatEventSubject(MeshControllerSeat, ">"), func(m *nats.Msg) {
+		heard <- m
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sub.Unsubscribe() //nolint:errcheck // the subscription dies with the connection
+
+	_, stop := servingOn(t, js, &counted{})
+	defer stop()
+
+	// A report that changed something: the store says it was news.
+	body, err := json.Marshal(Report{Node: "anchor", Declared: "d1", Applied: []string{"store", "broker"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := js.Context().Publish(ReportSubject("anchor"), body); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case m := <-heard:
+		if m.Subject != SeatEventSubject(MeshControllerSeat, KeyApplied) {
+			t.Fatalf("the mesh stated %q", m.Subject)
+		}
+		var said Applied
+		if err := json.Unmarshal(m.Data, &said); err != nil {
+			t.Fatal(err)
+		}
+		if said.Node != "anchor" || said.Declared != "d1" || said.Resources != 2 {
+			t.Fatalf("it said %+v", said)
+		}
+	case <-time.After(10 * time.Second):
+		t.Fatal("the mesh said nothing about a machine that now runs something else")
+	}
+
+	// A refusal is its own fact, with the reason in it rather than only in a log.
+	refusal, err := json.Marshal(Report{Node: "anchor", Declared: "d2",
+		Failed: map[string]string{"gitea.server": "no such image"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := js.Context().Publish(ReportSubject("anchor"), refusal); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case m := <-heard:
+		if m.Subject != SeatEventSubject(MeshControllerSeat, KeyRefused) {
+			t.Fatalf("a refusal was stated as %q", m.Subject)
+		}
+		var said Refused
+		if err := json.Unmarshal(m.Data, &said); err != nil {
+			t.Fatal(err)
+		}
+		if said.Failed["gitea.server"] == "" {
+			t.Fatalf("the refusal does not say which resource or why: %+v", said)
+		}
+	case <-time.After(10 * time.Second):
+		t.Fatal("the mesh said nothing about a machine that refused what it was sent")
+	}
+}
+
+// And a report that is not news is not a fact. A machine reconciles every minute; a fact per report
+// would be a fact per minute per machine, which is a stream nobody reads.
+func TestNatsAReportThatIsNotNewsIsNotStated(t *testing.T) {
+	js := aBus(t)
+	heard := make(chan *nats.Msg, 4)
+	sub, err := js.Conn().Subscribe(SeatEventSubject(MeshControllerSeat, ">"), func(m *nats.Msg) {
+		heard <- m
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sub.Unsubscribe() //nolint:errcheck // the subscription dies with the connection
+
+	// A store that records the report and says it was nothing new — which is what the mesh's own
+	// store says about a machine repeating itself.
+	_, stop := servingOn(t, js, sameAgain{})
+	defer stop()
+
+	body, err := json.Marshal(Report{Node: "anchor", Declared: "d1", Applied: []string{"store"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := js.Context().Publish(ReportSubject("anchor"), body); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case m := <-heard:
+		t.Fatalf("the mesh stated %q about a machine that changed nothing", m.Subject)
+	case <-time.After(3 * time.Second):
+	}
+}
+
+// sameAgain records a report and says it was the same state said again.
+type sameAgain struct{}
+
+func (sameAgain) Heard(context.Context, Report) (bool, error) { return false, nil }

internal/link/rekey_test.go

@@ -60,7 +60,7 @@ func TestASignedRekeyMovesTheHubOntoItsTunnel(t *testing.T) {
 	rekey := &link.Rekey{Previous: ownKey, OverlayKey: tunnelKey, Tunnel: theTunnel()}
 	rekey.Proof = ed25519.Sign(private, link.RekeyProof("anchor", ownKey, tunnelKey, theTunnel()))
 
-	if err := e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey}); err != nil {
+	if _, err := e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey}); err != nil {
 		t.Fatal(err)
 	}
 	placed, err := e.Inventory.Overlays(ctx)
@@ -77,7 +77,7 @@ func TestASignedRekeyMovesTheHubOntoItsTunnel(t *testing.T) {
 	_ = hub
 
 	// Replayed, it is stale: the previous key it names is no longer the node's.
-	err = e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey})
+	_, err = e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey})
 	if err == nil || !strings.Contains(err.Error(), "previous overlay key") {
 		t.Fatalf("a replayed rekey was accepted: %v", err)
 	}
@@ -93,7 +93,7 @@ func TestARekeySignedByAnotherKeyIsRefusedAndChangesNothing(t *testing.T) {
 	rekey := &link.Rekey{Previous: ownKey, OverlayKey: tunnelKey, Tunnel: theTunnel()}
 	rekey.Proof = ed25519.Sign(stranger, link.RekeyProof("anchor", ownKey, tunnelKey, theTunnel()))
 
-	err = e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey})
+	_, err = e.Heard(ctx, link.Report{Node: "anchor", Rekey: rekey})
 	if err == nil || !strings.Contains(err.Error(), "not signed by anchor's identity key") {
 		t.Fatalf("a rekey signed by a stranger was accepted: %v", err)
 	}
@@ -111,7 +111,7 @@ func TestARekeySignedByAnotherKeyIsRefusedAndChangesNothing(t *testing.T) {
 	other := theTunnel()
 	other.Port = 51820
 	moved.Proof = ed25519.Sign(mustPrivate(t, e, "anchor"), link.RekeyProof("anchor", ownKey, tunnelKey, other))
-	if err := e.Heard(ctx, link.Report{Node: "anchor", Rekey: moved}); err == nil {
+	if _, err := e.Heard(ctx, link.Report{Node: "anchor", Rekey: moved}); err == nil {
 		t.Fatal("a proof over another tunnel was accepted")
 	}
 }

internal/link/report_retry_test.go

@@ -9,12 +9,12 @@ import (
 
 type heardWith struct{ err error }
 
-func (h heardWith) Heard(context.Context, Report) error { return h.err }
+func (h heardWith) Heard(context.Context, Report) (bool, error) { return h.err == nil, h.err }
 
 // switchable answers with whatever it is set to — the store away, then back.
 type switchable struct{ err error }
 
-func (h *switchable) Heard(context.Context, Report) error { return h.err }
+func (h *switchable) Heard(context.Context, Report) (bool, error) { return h.err == nil, h.err }
 
 func aReport(node, declared string) Report {
 	return Report{Node: node, Declared: declared, Applied: []string{"store"}}

internal/link/serve.go

@@ -29,7 +29,12 @@ type Enroller interface {
 // Listener is what the controller does with a report. Separate from Enroller so the two can be
 // given independently, and so a server that only sends declarations needs neither.
 type Listener interface {
-	Heard(ctx context.Context, report Report) error
+	// Heard records what a node said, and says whether it was **news** — a machine that now runs
+	// something else, or refuses something it did not refuse before. A machine reconciles
+	// continuously and reports each time, so what is news is the store's answer rather than the
+	// bus's: only this side has the previous report to compare with. What the mesh states about it
+	// is the server's (novox/hq ADR 0134).
+	Heard(ctx context.Context, report Report) (news bool, err error)
 }
 
 // Recorder keeps what builders say.
@@ -257,7 +262,7 @@ func (s *Server) heartbeat(m Control) {
 		return
 	}
 	if s.listener != nil {
-		if err := s.listener.Heard(context.Background(), Report{Node: alive.Node}); err != nil {
+		if _, err := s.listener.Heard(context.Background(), Report{Node: alive.Node}); err != nil {
 			s.log.Printf("could not record that %s is here: %v", alive.Node, err)
 		}
 	}
@@ -291,7 +296,7 @@ func (s *Server) reported(ctx context.Context, m Control) {
 			return
 		}
 
-		err := s.listener.Heard(context.Background(), report)
+		news, err := s.listener.Heard(context.Background(), report)
 		switch s.decide(ctx, m, what, declaredIn, outstanding, err) {
 		case Hold:
 			// Held, not settled, while the store cannot take it: the node reports an apply once,
@@ -307,6 +312,13 @@ func (s *Server) reported(ctx context.Context, m Control) {
 			// node whose recovery copy is silently older than it looks.
 			s.log.Printf("could not record %s's report: %v", report.Node, err)
 		}
+		// **And the mesh says what it did** (novox/hq ADR 0134). Only when the report was news: a
+		// machine reports every convergence, and a fact per report would be a fact per minute per
+		// machine saying nothing. Stated after it is recorded, so nothing is announced that the
+		// mesh does not hold.
+		if err == nil && news {
+			s.saysWhatItDid(ctx, report)
+		}
 	}
 
 	switch {
@@ -460,7 +472,19 @@ func (s *Server) catchingUp(ctx context.Context, m Control) {
 	sent := 0
 	for _, a := range announcements {
 		a.Replay = true
-		if err := EmitEvent(ctx, s.bus, KeyModuleBuilt, "control-plane", "", a); err != nil {
+		// Under the control plane's own seat (novox/hq ADR 0134). It used to be published as a
+		// module's event from a module called "control-plane", which does not exist — so the
+		// controller's own account refused it, every catalogue that asked what it missed was
+		// answered with nothing, and its graph kept the gap (found 2026-09-28).
+		body, err := json.Marshal(a)
+		if err != nil {
+			// A body that cannot be written is this program's fault, not the bus's, and publishing
+			// an empty one would put a fact on the mesh that says nothing.
+			s.log.Printf("cannot re-announce %s at %s: %v", a.Module, short(a.Commit), err)
+			_ = m.Took()
+			return
+		}
+		if err := s.bus.PublishSeatEvent(ctx, MeshControllerSeat, KeyBuiltBefore, body); err != nil {
 			// Said and abandoned rather than retried: the catalogue asks again every time it
 			// starts, and half a graph delivered twice is no better than half delivered once.
 			s.log.Printf("replaying %s at %s failed, and the rest is abandoned: %v",
@@ -551,3 +575,37 @@ func (s *Server) sourceMoved(ctx context.Context, m Control) {
 	}
 	_ = m.Took()
 }
+
+// saysWhatItDid states what a machine now runs, or what it would not take, as a fact on the bus
+// (novox/hq ADR 0134).
+//
+// **The control plane speaks, as the holder of its seat.** A node's report is control traffic only
+// this process may read, so the chain from a merge to a machine went dark exactly where it touched
+// one: nothing said which version a machine runs, or that it refused to. The facts are second-hand
+// on purpose — one emitter, one ordering — and a machine that cannot reach the bus produces none, so
+// absence is not health.
+//
+// A failure to state a fact is logged and nothing else: the report is recorded, which is the part
+// that must not be lost, and the next change says the same thing again.
+func (s *Server) saysWhatItDid(ctx context.Context, report Report) {
+	if s.bus == nil {
+		return
+	}
+	event, body := KeyApplied, any(Applied{
+		Node: report.Node, Declared: report.Declared, Resources: len(report.Applied),
+	})
+	if report.Refused != "" || len(report.Failed) > 0 {
+		event, body = KeyRefused, Refused{
+			Node: report.Node, Declared: report.Declared,
+			Refused: report.Refused, Failed: report.Failed,
+		}
+	}
+	raw, err := json.Marshal(body)
+	if err != nil {
+		s.log.Printf("could not say what %s did: %v", report.Node, err)
+		return
+	}
+	if err := s.bus.PublishSeatEvent(ctx, MeshControllerSeat, event, raw); err != nil {
+		s.log.Printf("could not say that %s %s: %v", report.Node, event, err)
+	}
+}

internal/link/stale_report_test.go

@@ -23,12 +23,12 @@ type sentAndHeard struct {
 	err   error
 }
 
-func (s *sentAndHeard) Heard(_ context.Context, r Report) error {
+func (s *sentAndHeard) Heard(_ context.Context, r Report) (bool, error) {
 	if s.err != nil {
-		return s.err
+		return false, s.err
 	}
 	s.heard = append(s.heard, r)
-	return nil
+	return true, nil
 }
 
 func (s *sentAndHeard) Outstanding(context.Context, string) (string, error) { return s.sent, nil }

module.json

@@ -27,6 +27,7 @@
     "bus": "/var/lib/mesh/mesh-controller/bus"
   },
   "secrets-owner": "65534:65534",
+  "prepares": true,
   "resources": [
     {
       "id": "mesh-state",