Keep the client filling secrets and reading the controller's assignments until the lease write; plans for held modules; warrant says yes

Review round 3 (issue 1954): the node-engine of today writes ${secret:} as given and the new one fills only
provision keys, so the client fills secrets this release; plans exist only for modules with a want, so a
module without a seat plan is read from the controller's assignment and never leaves for want of one, and
the holder composes held modules at the build they run; the SDK's provider lets go only on "yes".

checks/credentialform/go.mod

@@ -0,0 +1,5 @@
+module checks/credentialform
+
+go 1.26.0
+
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

checks/credentialform/go.sum

@@ -0,0 +1,2 @@
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=

checks/credentialform/main.go

@@ -0,0 +1,70 @@
+// Package credentialform refuses an offer that does not say the form of its credential: an own secret, an issuer, or
+// `form` pair or none (the lead, 2026-10-29). It reads every modules/*/module.json through mesh-sdk's
+// CredentialFormProblems.
+package credentialform
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// Problems is every offer of the manifests under root/modules that says no credential form, one line each.
+func Problems(root string) ([]string, error) {
+	files, err := filepath.Glob(filepath.Join(root, "modules", "*", "module.json"))
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(files)
+	var out []string
+	reads := map[string]bool{}
+	var binders []string
+	for _, f := range files {
+		raw, err := os.ReadFile(f)
+		if err != nil {
+			return nil, err
+		}
+		var m catalogue.Manifest
+		if err := json.Unmarshal(raw, &m); err != nil {
+			return nil, fmt.Errorf("%s: %w", f, err)
+		}
+		out = append(out, catalogue.CredentialFormProblems(m)...)
+		var kept struct {
+			Reads []string          `json:"reads"`
+			State []json.RawMessage `json:"state"`
+		}
+		_ = json.Unmarshal(raw, &kept) // reads may hold objects in another module; only the provisioner's are read
+		if m.Module == "mesh-provisioner" {
+			for _, r := range kept.Reads {
+				reads[r] = true
+			}
+		}
+		if len(m.Provides) > 0 && keepsBound(kept.State) {
+			binders = append(binders, m.Module)
+		}
+	}
+	for _, module := range binders {
+		if !reads[module+".bound"] {
+			out = append(out, fmt.Sprintf("%s provides and keeps a `bound` state, and mesh-provisioner's manifest does not read %s.bound", module, module))
+		}
+	}
+	return out, nil
+}
+
+// keepsBound says whether a manifest's `state` names `bound`, as a plain name or an object with a name.
+func keepsBound(state []json.RawMessage) bool {
+	for _, s := range state {
+		var name string
+		var obj struct {
+			Name string `json:"name"`
+		}
+		if json.Unmarshal(s, &name) == nil && name == "bound" || json.Unmarshal(s, &obj) == nil && obj.Name == "bound" {
+			return true
+		}
+	}
+	return false
+}

checks/credentialform/main_test.go

@@ -0,0 +1,49 @@
+package credentialform
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func aCatalogue(t *testing.T, manifests map[string]string) string {
+	t.Helper()
+	root := t.TempDir()
+	for module, body := range manifests {
+		dir := filepath.Join(root, "modules", module)
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(dir, "module.json"), []byte(body), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return root
+}
+
+// An offer that says no form is refused and named; one that says pair, none or an own secret passes; and the real
+// catalogue is clean.
+func TestEveryOfferSaysTheFormOfItsCredential(t *testing.T) {
+	root := aCatalogue(t, map[string]string{
+		"silent":           `{"module":"silent","provides":[{"name":"thing","scope":"mesh"}]}`,
+		"binder":           `{"module":"binder","provides":[{"name":"d","credential":{"form":"pair"}}],"state":["bound"]}`,
+		"mesh-provisioner": `{"module":"mesh-provisioner","reads":["other.bound"]}`,
+		"says":             `{"module":"says","provides":[{"name":"a","credential":{"form":"pair"}},{"name":"b","credential":{"form":"none"}},{"name":"c","credential":{"own":"jwt"}}]}`,
+	})
+	got, err := Problems(root)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got) != 2 || !strings.Contains(got[0], `silent provides "thing"`) ||
+		!strings.Contains(got[1], "binder") || !strings.Contains(got[1], "mesh-provisioner") {
+		t.Fatalf("refused %v, wanted the silent offer and the binder the provisioner does not read", got)
+	}
+	real, err := Problems(filepath.Join("..", ".."))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(real) != 0 {
+		t.Fatalf("the catalogue has offers with no credential form:\n%s", strings.Join(real, "\n"))
+	}
+}

checks/credentialform/reads-outside

@@ -0,0 +1,3 @@
+# What these tests read outside their package, as paths from the repository's root (issue 1936).
+# every manifest, for what each offer says of its credential's form.
+modules/*/module.json

checks/handacts/fallbacks

@@ -0,0 +1,8 @@
+# The calls of the controller's hand-act log a manifest of this catalogue may still invoke, each `<module> <verb> <why>`:
+# the fallback of a recorder (mesh-sdk handacts.Recorder) while the seat mesh-hand-acts has no holder that answers, until
+# the controller's lease is written to a holder that is no controller. The check of this directory (handacts) refuses any
+# other, and an entry whose module no longer invokes it: the list only shrinks, and it is empty before the lease write
+# (novox/hq ADR 0565 §11; issue 1953, issue 774).
+mesh-config   hand-act   fallback until the lease write: its sets, clears and held values record through mesh-hand-acts first
+mesh-config   warranted  fallback until the lease write: its warrants record through mesh-hand-acts first
+mesh-healers  drill      fallback until the lease write: a drill records through mesh-hand-acts first

checks/handacts/go.mod

@@ -0,0 +1,3 @@
+module git.novox.be/novox/mesh-catalog/checks/handacts
+
+go 1.22

checks/handacts/main.go

@@ -0,0 +1,109 @@
+// Command handacts refuses a manifest that records into the controller's hand-act log (novox/hq ADR 0565 §11): every
+// recorder records through the seat mesh-hand-acts from its delivery, so no manifest invokes
+// `seat:mesh-controller.hand-act`, `.warranted` or `.drill`. The recorders' fallbacks to the controller's log while the
+// seat has no holder are named in checks/handacts/fallbacks, each module and verb with why; that list only shrinks, and
+// an entry whose module no longer invokes the verb is refused too.
+//
+//	go run . <catalog root>
+//
+// Exits 1 on a finding.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// Verbs are the controller's hand-act verbs, as a manifest invokes them, and Allowed the list of named fallbacks.
+var Verbs = []string{"hand-act", "warranted", "drill"}
+
+const (
+	invokePrefix = "seat:mesh-controller."
+	Allowed      = "checks/handacts/fallbacks"
+)
+
+// Findings is every refusal in the catalog at root, sorted.
+func Findings(root string) ([]string, error) {
+	allowed := map[string]bool{}
+	raw, err := os.ReadFile(filepath.Join(root, Allowed))
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	for _, line := range strings.Split(string(raw), "\n") {
+		if f := strings.Fields(line); len(f) >= 3 && !strings.HasPrefix(f[0], "#") {
+			allowed[f[0]+" "+f[1]] = true
+		} else if len(f) > 0 && !strings.HasPrefix(f[0], "#") {
+			return nil, fmt.Errorf("%s: %q is not `<module> <verb> <why>`", Allowed, line)
+		}
+	}
+	manifests, err := filepath.Glob(filepath.Join(root, "modules", "*", "module.json"))
+	if err != nil {
+		return nil, err
+	}
+	var out []string
+	invoked := map[string]bool{}
+	for _, path := range manifests {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			return nil, err
+		}
+		var m struct {
+			Module  string   `json:"module"`
+			Invokes []string `json:"invokes"`
+		}
+		if json.Unmarshal(raw, &m) != nil || m.Module == "mesh-controller" {
+			continue
+		}
+		for _, inv := range m.Invokes {
+			verb, ok := strings.CutPrefix(strings.TrimSpace(inv), invokePrefix)
+			if !ok || !contains(Verbs, verb) {
+				continue
+			}
+			invoked[m.Module+" "+verb] = true
+			if !allowed[m.Module+" "+verb] {
+				out = append(out, fmt.Sprintf("%s invokes %s%s: record through seat:mesh-hand-acts.%s (novox/hq ADR 0565 §11), "+
+					"or name the fallback in %s", m.Module, invokePrefix, verb, verb, Allowed))
+			}
+		}
+	}
+	for entry := range allowed {
+		if !invoked[entry] {
+			out = append(out, fmt.Sprintf("%s names %q, which is no longer invoked: take it off the list, which only shrinks",
+				Allowed, entry))
+		}
+	}
+	sort.Strings(out)
+	return out, nil
+}
+
+func contains(list []string, s string) bool {
+	for _, x := range list {
+		if x == s {
+			return true
+		}
+	}
+	return false
+}
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Fprintln(os.Stderr, "usage: handacts <catalog root>")
+		os.Exit(2)
+	}
+	found, err := Findings(os.Args[1])
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	for _, f := range found {
+		fmt.Println(f)
+	}
+	if len(found) > 0 {
+		os.Exit(1)
+	}
+	fmt.Println("no manifest records into the controller's hand-act log but the fallbacks named")
+}

checks/handacts/main_test.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// No manifest invokes the controller's hand-act verbs but a named fallback; a named fallback no longer invoked is
+// refused (novox/hq ADR 0565 §11's catalog test).
+func TestFindings(t *testing.T) {
+	for _, row := range []struct {
+		name  string
+		files map[string]string
+		want  string // empty: clean
+	}{
+		{"clean", map[string]string{"modules/a/module.json": `{"module":"a","invokes":["seat:mesh-hand-acts.hand-act"]}`}, ""},
+		{"an unnamed call", map[string]string{"modules/a/module.json": `{"module":"a","invokes":["seat:mesh-controller.warranted"]}`},
+			"a invokes seat:mesh-controller.warranted"},
+		{"a named fallback, and the controller's own", map[string]string{
+			"modules/a/module.json":               `{"module":"a","invokes":["seat:mesh-controller.drill"]}`,
+			"modules/mesh-controller/module.json": `{"module":"mesh-controller","invokes":["seat:mesh-controller.hand-act"]}`,
+			Allowed:                               "# why\na drill fallback until the lease write\n"}, ""},
+		{"a fallback no longer invoked", map[string]string{Allowed: "gone hand-act fallback\n"}, `names "gone hand-act"`},
+		{"another verb of the controller", map[string]string{"modules/a/module.json": `{"module":"a","invokes":["seat:mesh-controller.conditions"]}`}, ""},
+	} {
+		t.Run(row.name, func(t *testing.T) {
+			root := t.TempDir()
+			for path, text := range row.files {
+				p := filepath.Join(root, path)
+				if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
+					t.Fatal(err)
+				}
+				if err := os.WriteFile(p, []byte(text), 0o644); err != nil {
+					t.Fatal(err)
+				}
+			}
+			got, err := Findings(root)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if all := strings.Join(got, "\n"); (row.want == "") != (all == "") || !strings.Contains(all, row.want) {
+				t.Fatalf("findings = %q, want one containing %q", all, row.want)
+			}
+		})
+	}
+}
+
+// The run of this check over the real tree.
+func TestTheCatalogRecordsOnlyThroughTheSeat(t *testing.T) {
+	got, err := Findings(filepath.Join("..", ".."))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range got {
+		t.Error(f)
+	}
+}

checks/handacts/reads-outside

@@ -0,0 +1,3 @@
+# What these tests read outside their package, as paths from the repository's root (issue 1936).
+# every manifest, for what it invokes.
+modules/*/module.json

checks/health/go.mod

@@ -2,4 +2,4 @@ module checks/health
 
 go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

checks/health/go.sum

@@ -1,2 +1,2 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468 h1:UcMee+IV2ii5E4dRZdQUaSaeh9IedTFYumuQbBiB0k0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=

checks/noplacement/assignments-readers

@@ -0,0 +1,4 @@
+# The modules of this catalogue that still read the controller's assignments (mesh-controller.assignments), each with
+# why. The check of this directory (noplacement) refuses any other module that reads them, and an entry here whose module no longer
+# does: the list only shrinks, and it is empty before the controller's lease is written to a holder that is no
+# controller (novox/hq ADR 0549 §3, §6; issue 774).

checks/noplacement/go.mod

@@ -1,3 +1,7 @@
 module git.novox.be/novox/mesh-catalog/checks/noplacement
 
 go 1.22
+
+require git.novox.be/novox/mesh-catalog/checks/trunk v0.0.0
+
+replace git.novox.be/novox/mesh-catalog/checks/trunk => ../trunk

checks/noplacement/main.go

@@ -8,7 +8,13 @@
 //  2. a `particulars` file at the root (the mesh's node names come from the checker's run, §16);
 //
 //  3. a manifest naming a state, stream, event or bucket of the indexer's placement (`mesh-delivery-indexer.placement…`
-//     or `mesh-delivery-indexer_placement…`) in any string value, such as `reads`.
+//     or `mesh-delivery-indexer_placement…`) in any string value, such as `reads`;
+//
+//  4. a manifest, other than mesh-controller's, that reads the controller's assignments (`mesh-controller.assignments`):
+//     every reader takes placement from the seat mesh-placement (novox/hq ADR 0549 §3, ADR 0567), and the lease write is
+//     refused while one still reads them (ADR 0549 §6; issue 774). The modules that still read them for what the
+//     placement does not carry are named in checks/noplacement/assignments-readers, each with why; that list only
+//     shrinks: an entry whose module no longer reads them is refused too.
 //
 //     go run . <catalogue root>
 //
@@ -55,9 +61,74 @@ func Findings(root string) ([]string, error) {
 			out = append(out, fmt.Sprintf("%s: names %q, which the indexer no longer keeps; placement is the seat mesh-placement's (novox/hq ADR 0567 §12)", module, s))
 		}
 	}
+	readers, err := assignmentsReaders(root)
+	if err != nil {
+		return nil, err
+	}
+	out = append(out, readers...)
+	sort.Strings(out)
 	return out, nil
 }
 
+// AssignmentsRead is the controller's assignments as a manifest reads them, and Allowed the file, relative to the
+// catalogue's root, that names the modules still reading them: `<module> <why>` per line, `#` a comment.
+const (
+	AssignmentsRead = "mesh-controller.assignments"
+	Allowed         = "checks/noplacement/assignments-readers"
+)
+
+// assignmentsReaders is every finding on the reads of the controller's assignments: a module other than the controller
+// reading them that Allowed does not name, and a module Allowed names that no longer reads them (issue 774).
+func assignmentsReaders(root string) ([]string, error) {
+	allowed := map[string]bool{}
+	raw, err := os.ReadFile(filepath.Join(root, Allowed))
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	for _, line := range strings.Split(string(raw), "\n") {
+		if f := strings.Fields(line); len(f) > 0 && !strings.HasPrefix(f[0], "#") {
+			allowed[f[0]] = true
+		}
+	}
+	manifests, err := filepath.Glob(filepath.Join(root, "modules", "*", "module.json"))
+	if err != nil {
+		return nil, err
+	}
+	var found []string
+	reads := map[string]bool{}
+	for _, path := range manifests {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			return nil, err
+		}
+		var m struct {
+			Module string   `json:"module"`
+			Reads  []string `json:"reads"`
+		}
+		if json.Unmarshal(raw, &m) != nil || m.Module == "mesh-controller" {
+			continue // a manifest that does not read is the manifest checks' to refuse
+		}
+		for _, r := range m.Reads {
+			if strings.TrimSpace(r) != AssignmentsRead {
+				continue
+			}
+			reads[m.Module] = true
+			if !allowed[m.Module] {
+				found = append(found, fmt.Sprintf("%s reads %s: read where modules run from mesh-delivery-assigner.placement, "+
+					"the seat mesh-placement's (novox/hq ADR 0549 §3, ADR 0567); the lease write is refused while a module reads "+
+					"the assignments (ADR 0549 §6)", m.Module, AssignmentsRead))
+			}
+		}
+	}
+	for module := range allowed {
+		if !reads[module] {
+			found = append(found, fmt.Sprintf("%s names %s, which no longer reads %s: take it off the list, which only shrinks",
+				Allowed, module, AssignmentsRead))
+		}
+	}
+	return found, nil
+}
+
 // named collects the strings of a decoded manifest that start with one of the Prefixes.
 func named(v any, into []string) []string {
 	switch v := v.(type) {
@@ -95,5 +166,5 @@ func main() {
 	if len(found) > 0 {
 		os.Exit(1)
 	}
-	fmt.Println("no placement directory, and no manifest reads the indexer's placement")
+	fmt.Println("no placement directory, no manifest reads the indexer's placement, and only the modules listed read the controller's assignments")
 }

checks/noplacement/main_test.go

@@ -5,6 +5,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"git.novox.be/novox/mesh-catalog/checks/trunk"
 )
 
 func TestFindingsRefuseWhatThePlacementPathLeft(t *testing.T) {
@@ -13,12 +15,18 @@ func TestFindingsRefuseWhatThePlacementPathLeft(t *testing.T) {
 		files map[string]string
 		want  string // empty: clean
 	}{
-		{"clean", map[string]string{"modules/a/module.json": `{"module":"a","reads":["mesh-controller.assignments"]}`}, ""},
+		{"clean", map[string]string{"modules/a/module.json": `{"module":"a","reads":["mesh-delivery-assigner.placement"]}`}, ""},
 		{"a placement directory", map[string]string{"placement/ace.json": `{}`}, "placement: the repository holds no placement"},
 		{"a particulars file", map[string]string{"particulars": "ace\n"}, "particulars: the repository lists no node names"},
 		{"a read of the indexer's placement", map[string]string{"modules/a/module.json": `{"module":"a","reads":["mesh-delivery-indexer.placement"]}`}, `a: names "mesh-delivery-indexer.placement"`},
 		{"a read of its candidates", map[string]string{"modules/b/module.json": `{"module":"b","reads":["mesh-delivery-indexer.placement-candidates"]}`}, "placement-candidates"},
 		{"its event", map[string]string{"modules/c/module.json": `{"module":"c","on":[{"event":"mesh-delivery-indexer.placement-changed"}]}`}, "placement-changed"},
+		// Issue 774 (ADR 0549 §3, §6): a reader of the controller's assignments is refused unless the list names it, the
+		// controller's own manifest is not judged, and a name on the list whose module no longer reads them is refused.
+		{"an unlisted reader of the assignments", map[string]string{"modules/r/module.json": `{"module":"r","reads":["mesh-controller.assignments"]}`}, "r reads mesh-controller.assignments"},
+		{"a listed reader and the controller", map[string]string{"modules/l/module.json": `{"module":"l","reads":["mesh-controller.assignments"]}`,
+			"modules/mesh-controller/module.json": `{"module":"mesh-controller","reads":["mesh-controller.assignments"]}`, Allowed: "# why\nl  its plan\n"}, ""},
+		{"a listed module that reads them no more", map[string]string{Allowed: "gone  no longer reads\n"}, "names gone, which no longer reads"},
 		{"the seat's own state is allowed", map[string]string{"modules/d/module.json": `{"module":"d","reads":["mesh-placement.placement"]}`}, ""},
 	} {
 		t.Run(row.name, func(t *testing.T) {
@@ -52,4 +60,29 @@ func TestTheCatalogueHoldsNoPlacementOfTheRepositoryPath(t *testing.T) {
 	for _, f := range got {
 		t.Error(f)
 	}
+	// Issue 774 (ADR 0549 §3, §6; the comparison of novox/hq ADR 0529 clause 2): the list of modules still reading the
+	// controller's assignments gains none the trunk's copy at the merge base does not hold. Its first copy gains nothing.
+	path, ok := trunk.Copy(t, Allowed)
+	if !ok {
+		return
+	}
+	names := func(path string) map[string]bool {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		out := map[string]bool{}
+		for _, line := range strings.Split(string(raw), "\n") {
+			if f := strings.Fields(line); len(f) > 0 && !strings.HasPrefix(f[0], "#") {
+				out[f[0]] = true
+			}
+		}
+		return out
+	}
+	base := names(path)
+	for module := range names(filepath.Join("..", "..", Allowed)) {
+		if !base[module] {
+			t.Errorf("%s gains %s, which the trunk's copy does not hold: the list only shrinks", Allowed, module)
+		}
+	}
 }

modules/artifact-store-tools/cmd/artifact-store-tools/door.go

@@ -0,0 +1,129 @@
+package main
+
+// The artifact store's door and the bus, as the holder reaches them through this module's runtime.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+
+	"artifactstoretools/internal/registry"
+)
+
+// door is registry.Store at the store's address as this machine reaches it.
+type door struct{ s registry.Store }
+
+func (d *door) Address() string                                  { return d.s.Address }
+func (d *door) Hold(ctx context.Context, r string) (bool, error) { return d.s.Hold(ctx, r) }
+func (d *door) Holds(ctx context.Context, r string) error        { return d.s.Holds(ctx, r) }
+func (d *door) IsIndex(ctx context.Context, r string) (bool, error) {
+	return d.s.IsIndex(ctx, r)
+}
+func (d *door) LetGo(ctx context.Context, r string) error { return d.s.LetGo(ctx, r) }
+func (d *door) SpareKept(ctx context.Context, keptImages, touching []string) error {
+	spare, err := d.s.SpareKeptIndexes(ctx, keptImages, touching)
+	if err == nil {
+		d.s.Spare = spare
+	}
+	return err
+}
+
+// DoorAt reads the store's address (host:port) from the file the manifest fills from the seat mesh-artifact-store's
+// reach, each time, so a store that moved is reached where it is now.
+func DoorAt(file string) func() (Door, error) {
+	return func() (Door, error) {
+		if file == "" {
+			return nil, fmt.Errorf("this bundle was given no file naming the artifact store's address")
+		}
+		raw, err := os.ReadFile(file)
+		if err != nil {
+			return nil, fmt.Errorf("the artifact store's address: %w", err)
+		}
+		address := strings.TrimSpace(string(raw))
+		if address == "" {
+			return nil, fmt.Errorf("the artifact store's address is empty in %s", file)
+		}
+		return &door{s: registry.Store{Address: address}}, nil
+	}
+}
+
+// runtimeBus is the holder's bus through the runtime: its reads, its findings and its seat's event.
+type runtimeBus struct{}
+
+func (runtimeBus) Keys(state string) ([]string, error) { return stdio.State(state).Keys() }
+func (runtimeBus) Get(state, key string) ([]byte, bool, error) {
+	e, err := stdio.State(state).Get(key)
+	if err != nil || e == nil {
+		return nil, false, err
+	}
+	return e.Value, true, nil
+}
+func (runtimeBus) History(state, key string) ([]stdio.StateRevision, error) {
+	return stdio.State(state).History(key)
+}
+func (runtimeBus) LogSince(read string, at time.Time) ([]stdio.LogEntry, error) {
+	var out []stdio.LogEntry
+	page, err := stdio.Log(read).Since(at, "", 0)
+	for err == nil {
+		out = append(out, page.Entries...)
+		if page.Next == 0 {
+			return out, nil
+		}
+		page, err = stdio.Log(read).Read(page.Next, "", 0)
+	}
+	return nil, err
+}
+
+func (runtimeBus) Put(state, key string, value any) error {
+	_, err := stdio.State(state).Put(key, value)
+	return err
+}
+func (runtimeBus) Delete(state, key string) error { return stdio.State(state).Delete(key) }
+func (runtimeBus) Publish(subject string, body any) error {
+	return stdio.SeatPublish(subject, body, "")
+}
+
+// follow watches the builder's done keys and the wants: a build's end sweeps (once the lease names no controller) and
+// observes again; a want changed observes again. Event-driven: nothing reads them on a timer.
+func follow(h *Holder) {
+	<-stdio.Served()
+	watch := func(state string, handle func(stdio.StateChange) error) {
+		for {
+			if err := stdio.State(state).Watch("", handle); err == nil {
+				return
+			} else {
+				h.logf("watching %s: %v; asked again in 10s", state, err)
+			}
+			time.Sleep(10 * time.Second)
+		}
+	}
+	observe := func() {
+		if err := h.Observe(context.Background()); err != nil {
+			h.logf("image-missing could not be observed: %v", err)
+		}
+	}
+	watch(BuildsRead, func(c stdio.StateChange) error {
+		if c.Current || c.Op != stdio.OpPut {
+			return nil
+		}
+		var b struct {
+			State string `json:"state"`
+		}
+		if json.Unmarshal(c.Value, &b) == nil && b.State == "done" {
+			go func() { h.AfterBuild(c.Key); observe() }()
+		}
+		return nil
+	})
+	watch(WantsRead, func(c stdio.StateChange) error {
+		if !c.Current {
+			go observe()
+		}
+		return nil
+	})
+	observe()
+}

modules/artifact-store-tools/cmd/artifact-store-tools/holder_integration_test.go

@@ -0,0 +1,260 @@
+//go:build integration
+
+package main
+
+// The seat mesh-artifact-sweep's holder whole against a real bus (novox/hq ADR 0571 clause 2, issue 1955): the builder's done
+// keys, the wants and the controller's lease in a real nats-server's key-value buckets, a build's end heard by a watch
+// of the builds as the runtime hands it over, each deletion recorded by a request to the seat mesh-hand-acts on the bus,
+// artifacts-gone said on the seat's subject, and S25's finding written to the holder's own bucket. Only the store's
+// door is in memory: its HTTP is the copied registry package's, tested there.
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nats.go/jetstream"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
+	"git.novox.be/novox/mesh-sdk/go/handacts"
+	"git.novox.be/novox/mesh-sdk/go/testbus"
+)
+
+// realBus is the holder's Bus over a real nats-server: each read state a bucket named as the runtime names it.
+type realBus struct {
+	ctx context.Context
+	nc  *nats.Conn
+	js  jetstream.JetStream
+	// log is the builder's log as the runtime's log verbs would read it (mesh-tools adds them; the sdk's own read of a
+	// log is tested in mesh-sdk's process package).
+	log []stdio.LogEntry
+}
+
+func (b realBus) LogSince(_ string, at time.Time) ([]stdio.LogEntry, error) {
+	var out []stdio.LogEntry
+	for _, e := range b.log {
+		if !e.At.Before(at) {
+			out = append(out, e)
+		}
+	}
+	return out, nil
+}
+
+func bucketOf(state string) string { return strings.Replace(state, ".", "_", 1) }
+
+func (b realBus) kv(state string) (jetstream.KeyValue, error) {
+	return b.js.KeyValue(b.ctx, bucketOf(state))
+}
+
+func (b realBus) Keys(state string) ([]string, error) {
+	kv, err := b.kv(state)
+	if err != nil {
+		return nil, err
+	}
+	keys, err := kv.Keys(b.ctx)
+	if err == jetstream.ErrNoKeysFound {
+		return nil, nil
+	}
+	return keys, err
+}
+
+func (b realBus) Get(state, key string) ([]byte, bool, error) {
+	kv, err := b.kv(state)
+	if err != nil {
+		return nil, false, err
+	}
+	e, err := kv.Get(b.ctx, key)
+	if err == jetstream.ErrKeyNotFound {
+		return nil, false, nil
+	}
+	if err != nil {
+		return nil, false, err
+	}
+	return e.Value(), true, nil
+}
+
+func (b realBus) History(state, key string) ([]stdio.StateRevision, error) {
+	kv, err := b.kv(state)
+	if err != nil {
+		return nil, err
+	}
+	h, err := kv.History(b.ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	var out []stdio.StateRevision
+	for _, e := range h {
+		out = append(out, stdio.StateRevision{Key: key, Value: e.Value(), Revision: e.Revision(), At: e.Created()})
+	}
+	return out, nil
+}
+
+func (b realBus) Put(state, key string, value any) error {
+	kv, err := b.kv(state)
+	if err != nil {
+		return err
+	}
+	raw, _ := json.Marshal(value)
+	_, err = kv.Put(b.ctx, key, raw)
+	return err
+}
+
+func (b realBus) Delete(state, key string) error {
+	kv, err := b.kv(state)
+	if err != nil {
+		return err
+	}
+	return kv.Delete(b.ctx, key)
+}
+
+func (b realBus) Publish(subject string, body any) error {
+	raw, _ := json.Marshal(body)
+	return b.nc.Publish(subject, raw)
+}
+
+func TestTheSeatSweepsAtABuildsEndOnARealBusOnceTheLeaseIsAway(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	nc, err := nats.Connect(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer nc.Close()
+	js, err := jetstream.New(nc)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, s := range []string{BuildsRead, WantsRead, HavesRead, LeaseRead, ManifestsRead, "artifact-store-tools." + FindingsState} {
+		if _, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: bucketOf(s), History: 5}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	bus := realBus{ctx: ctx, nc: nc, js: js}
+
+	// The mesh as aMesh lays it, copied onto the real buckets: letta's seven builds, a want, the store's listing.
+	mem, memb, door, _ := aMesh(t, &buscompose.LeaseHolder{Instance: "c1", Host: "novox", Epoch: 3})
+	bus.log = memb.log
+	for _, s := range []string{BuildsRead, WantsRead, LeaseRead, ManifestsRead} {
+		keys, _ := memb.Keys(s)
+		for _, k := range keys[:min(len(keys), 6)] { // the seventh build ends later, on the bus
+			raw, _, _ := memb.Get(s, k)
+			if err := bus.Put(s, k, json.RawMessage(raw)); err != nil {
+				t.Fatal(err)
+			}
+		}
+	}
+	time.Sleep(20 * time.Millisecond) // each build's end is its key's time on the bus: the seventh the newest
+
+	// The seat mesh-hand-acts, answering every act it records; artifacts-gone heard on the seat's subject.
+	var mu sync.Mutex
+	var acts, gone []string
+	if _, err := nc.Subscribe("mesh.seat."+handacts.Seat+".tool.hand-act", func(m *nats.Msg) {
+		mu.Lock()
+		acts = append(acts, string(m.Data))
+		mu.Unlock()
+		_ = m.Respond([]byte(`{"ok":true}`))
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := nc.Subscribe(GoneSubject, func(m *nats.Msg) {
+		mu.Lock()
+		gone = append(gone, string(m.Data))
+		mu.Unlock()
+	}); err != nil {
+		t.Fatal(err)
+	}
+	h := &Holder{Bus: findingsAt{realBus: bus}, Door: mem.Door, Listed: mem.Listed, Now: time.Now, Logf: t.Logf}
+	h.Acts = handacts.Recorder{LeaseAway: h.LeaseAway, Ask: func(key string, body any) (json.RawMessage, error) {
+		raw, _ := json.Marshal(body)
+		m, err := nc.Request("mesh.seat."+strings.TrimPrefix(strings.Replace(key, ".", ".tool.", 1), "seat:"), raw, 5*time.Second)
+		if err != nil {
+			return nil, err
+		}
+		return m.Data, nil
+	}}
+
+	// A build's end heard from the builds bucket, as follow hands it over.
+	kv, _ := bus.kv(BuildsRead)
+	w, err := kv.WatchAll(ctx, jetstream.UpdatesOnly())
+	if err != nil {
+		t.Fatal(err)
+	}
+	ended := func() {
+		keys, _ := memb.Keys(BuildsRead)
+		raw, _, _ := memb.Get(BuildsRead, keys[6])
+		if err := bus.Put(BuildsRead, keys[6], json.RawMessage(raw)); err != nil {
+			t.Fatal(err)
+		}
+		select {
+		case e := <-w.Updates():
+			h.AfterBuild(e.Key())
+		case <-ctx.Done():
+			t.Fatal("the build's end was not heard")
+		}
+	}
+
+	// While the lease names the controller, a build's end lets nothing go.
+	ended()
+	if len(door.asked) != 0 {
+		t.Fatalf("before the lease write the store was asked %v", door.asked)
+	}
+	// The lease handed away: the next build's end holds the kept archives and lets go of letta's 2nd, which the 7th moved
+	// past the five newest and no want names (the want keeps the 1st), recording each deletion.
+	if err := bus.Put(LeaseRead, buscompose.ControllerLeaseKey, buscompose.LeaseHolder{HandedTo: "mesh-grants", Why: "the lease write"}); err != nil {
+		t.Fatal(err)
+	}
+	ended()
+	deadline := time.Now().Add(5 * time.Second)
+	for {
+		mu.Lock()
+		n := len(gone)
+		mu.Unlock()
+		if n > 0 || time.Now().After(deadline) {
+			break
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	if len(acts) != 3 || !strings.Contains(acts[0], archiveRef("letta", 2)) || !strings.Contains(acts[1], imageRef("letta", 2)) ||
+		!strings.Contains(acts[2], mirror(1)) {
+		t.Fatalf("the hand acts recorded are %v; the store was asked %v", acts, door.asked)
+	}
+	if len(gone) != 1 || !strings.Contains(gone[0], `"fingerprint":"`+fp(2)+`"`) {
+		t.Fatalf("artifacts-gone said %v", gone)
+	}
+
+	// S25 through the real findings bucket: letta's wanted image missing from the store is a finding there.
+	view, _ := mem.Listed(ctx)
+	repo, digest, _ := splitReference(imageRef("letta", 1))
+	delete(view.L.Repos[repo].Revisions, digest)
+	if err := h.Observe(ctx); err != nil {
+		t.Fatal(err)
+	}
+	if keys, _ := bus.Keys("artifact-store-tools." + FindingsState); len(keys) != 1 || keys[0] != "module.letta.ace.image-missing" {
+		t.Fatalf("the findings are %v", keys)
+	}
+}
+
+// findingsAt reads and writes the holder's own findings in its bucket, artifact-store-tools_findings.
+type findingsAt struct{ realBus }
+
+func (f findingsAt) own(state string) string {
+	if state == FindingsState {
+		return Module + "." + state
+	}
+	return state
+}
+func (f findingsAt) Keys(state string) ([]string, error) { return f.realBus.Keys(f.own(state)) }
+func (f findingsAt) Get(state, key string) ([]byte, bool, error) {
+	return f.realBus.Get(f.own(state), key)
+}
+func (f findingsAt) Put(state, key string, value any) error {
+	return f.realBus.Put(f.own(state), key, value)
+}
+func (f findingsAt) Delete(state, key string) error { return f.realBus.Delete(f.own(state), key) }

modules/artifact-store-tools/cmd/artifact-store-tools/holder_test.go

@@ -0,0 +1,351 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"sort"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/handacts"
+	"git.novox.be/novox/mesh-sdk/go/health"
+
+	"artifactstoretools/internal/registry"
+)
+
+// memBus is the holder's bus in memory: states by name, each key's history, and what was published.
+type memBus struct {
+	mu        sync.Mutex
+	states    map[string]map[string][]byte
+	history   map[string][]stdio.StateRevision
+	log       []stdio.LogEntry
+	published []string
+}
+
+func (b *memBus) LogSince(read string, at time.Time) ([]stdio.LogEntry, error) {
+	var out []stdio.LogEntry
+	for _, e := range b.log {
+		if read == delivery.BuildLogRead && !e.At.Before(at) {
+			out = append(out, e)
+		}
+	}
+	return out, nil
+}
+
+func (b *memBus) Keys(state string) ([]string, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	var out []string
+	for k := range b.states[state] {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out, nil
+}
+
+func (b *memBus) Get(state, key string) ([]byte, bool, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	v, ok := b.states[state][key]
+	return v, ok, nil
+}
+
+func (b *memBus) History(state, key string) ([]stdio.StateRevision, error) {
+	return b.history[state+" "+key], nil
+}
+
+func (b *memBus) Put(state, key string, value any) error {
+	raw, _ := json.Marshal(value)
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.states[state] == nil {
+		b.states[state] = map[string][]byte{}
+	}
+	b.states[state][key] = raw
+	return nil
+}
+
+func (b *memBus) Delete(state, key string) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	delete(b.states[state], key)
+	return nil
+}
+
+func (b *memBus) Publish(subject string, body any) error {
+	raw, _ := json.Marshal(body)
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.published = append(b.published, subject+" "+string(raw))
+	return nil
+}
+
+// memDoor is the store's door in memory: what it holds, which references are indexes, and what was asked.
+type memDoor struct {
+	holds   map[string]bool
+	indexes map[string]bool
+	asked   []string
+}
+
+func (d *memDoor) Address() string { return "10.0.0.5:5000" }
+func (d *memDoor) Hold(_ context.Context, r string) (bool, error) {
+	d.asked = append(d.asked, "hold "+r)
+	if !d.holds[r] {
+		return false, registry.Gone
+	}
+	return false, nil
+}
+func (d *memDoor) Holds(_ context.Context, r string) error {
+	if !d.holds[r] {
+		return registry.Gone
+	}
+	return nil
+}
+func (d *memDoor) IsIndex(_ context.Context, r string) (bool, error) { return d.indexes[r], nil }
+func (d *memDoor) LetGo(_ context.Context, r string) error {
+	d.asked = append(d.asked, "let go "+r)
+	delete(d.holds, r)
+	return nil
+}
+func (d *memDoor) SpareKept(context.Context, []string, []string) error {
+	d.asked = append(d.asked, "spare")
+	return nil
+}
+
+// mirror is a copy of an upstream base in the store, the n-th.
+func mirror(n int) string {
+	return "artifact-store://upstream/docker.io/library/alpine@sha256:" + strings.Repeat(fmt.Sprintf("%x", n%16), 64)
+}
+
+// pinnedImage is the image letta's manifest names by itself, at the store's address.
+const pinnedImage = "10.0.0.5:5000/letta/pinned@sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc"
+
+func digestOf(ref string) string { _, d, _ := splitReference(ref); return d }
+
+func fp(n int) string { return "src2:" + strings.Repeat(fmt.Sprintf("%x", n%16), 64) }
+
+func imageRef(module string, n int) string {
+	return "artifact-store://" + module + "/image@sha256:" + strings.Repeat(fmt.Sprintf("%x", n%16), 64)
+}
+
+func archiveRef(module string, n int) string {
+	return "artifact-store://" + module + "/files/blobs/sha256:" + strings.Repeat(fmt.Sprintf("%x", (n+8)%16), 64)
+}
+
+// A mesh with seven done builds of letta, the n-th ending n hours after a day began, each with an image and an archive;
+// a want names the first on ace; the store lists them all and one image no build names; the lease as given.
+func aMesh(t *testing.T, lease *buscompose.LeaseHolder) (*Holder, *memBus, *memDoor, *[]string) {
+	t.Helper()
+	day := time.Date(2026, 10, 1, 0, 0, 0, 0, time.UTC)
+	b := &memBus{states: map[string]map[string][]byte{}, history: map[string][]stdio.StateRevision{}}
+	door := &memDoor{holds: map[string]bool{}, indexes: map[string]bool{}}
+	listing := &Listing{Blobs: map[string]int64{}, Repos: map[string]*Repo{}}
+	for n := 1; n <= 7; n++ {
+		key, _ := delivery.BuilderBuildKey("letta", fp(n))
+		raw, err := delivery.EncodeBuilderBuild(delivery.BuilderBuild{State: delivery.BuildDone, Manifest: strings.Repeat("d", 64), Artifacts: []delivery.BuiltArtifact{
+			{Name: "image", Kind: "image", Digest: digestOf(imageRef("letta", n)), Reference: imageRef("letta", n)},
+			{Name: "files", Kind: "archive", Digest: digestOf(archiveRef("letta", n)), Reference: archiveRef("letta", n)},
+			{Name: "pkg", Kind: "package", Digest: "sha256:" + strings.Repeat("f", 64), Reference: "letta@1.0." + fmt.Sprint(n)}}})
+		if err != nil {
+			t.Fatal(err)
+		}
+		_ = b.Put(BuildsRead, key, json.RawMessage(raw))
+		b.history[BuildsRead+" "+key] = []stdio.StateRevision{{Key: key, Value: raw, At: day.Add(time.Duration(n) * time.Hour)}}
+		for _, r := range []string{imageRef("letta", n), archiveRef("letta", n)} {
+			door.holds[r] = true
+			repo, digest, kind := splitReference(r)
+			if kind == "archive" {
+				listing.Blobs[digest] = 10
+			} else {
+				listing.repo(repo).Revisions[digest] = true
+			}
+		}
+	}
+	listing.repo("letta/image").Revisions["sha256:"+strings.Repeat("e", 64)] = true // no build names it
+	listing.repo("letta/pinned").Revisions["sha256:"+strings.Repeat("c", 64)] = true
+	// Three copies of a base: letta's 2nd stood on the first, its 7th on the second, and no build on the third.
+	for n := 1; n <= 3; n++ {
+		repo, digest, _ := splitReference(mirror(n))
+		listing.repo(repo).Revisions[digest] = true
+		door.holds[mirror(n)] = true
+	}
+	for n := 1; n <= 7; n++ {
+		e := delivery.BuildLogEntry{Event: delivery.BuildEndedEvent, Module: "letta", FP: fp(n), Repository: "novox/x", Commit: "c",
+			Node: "ace", At: day.Add(time.Duration(n) * time.Hour), Outcome: "done"}
+		switch n {
+		case 2:
+			e.Against = []string{mirror(1)}
+		case 7:
+			e.Against = []string{mirror(2)}
+		}
+		raw, _ := delivery.EncodeBuildLogEntry(e)
+		b.log = append(b.log, stdio.LogEntry{Sequence: uint64(n), Key: "letta", Value: raw, At: e.At})
+	}
+	manifest, _ := delivery.EncodeManifest(delivery.Manifest{Module: "letta",
+		JSON: `{"module":"letta","resources":[{"id":"app","type":"container","image":"` + pinnedImage + `"},` +
+			`{"id":"built","type":"container","image":"${artifact:image}"}]}`})
+	mk, _ := delivery.ManifestsKey(strings.Repeat("d", 64))
+	_ = b.Put(ManifestsRead, mk, json.RawMessage(manifest))
+	want, _ := json.Marshal(delivery.Want{V: delivery.Version, FP: fp(1), Self: true})
+	_ = b.Put(WantsRead, "want.ace.letta", json.RawMessage(want))
+	if lease != nil {
+		_ = b.Put(LeaseRead, buscompose.ControllerLeaseKey, lease)
+	}
+	var acts []string
+	h := &Holder{Bus: b, Door: func() (Door, error) { return door, nil },
+		Listed: func(context.Context) (*View, error) { return &View{L: listing}, nil },
+		Now:    func() time.Time { return day.Add(48 * time.Hour) },
+		Acts: handacts.Recorder{Ask: func(key string, body any) (json.RawMessage, error) {
+			raw, _ := json.Marshal(body)
+			acts = append(acts, key+" "+string(raw))
+			return json.RawMessage(`{}`), nil
+		}}}
+	h.Acts.LeaseAway = h.LeaseAway
+	return h, b, door, &acts
+}
+
+// ADR 0571 clause 2: the keep set from the store's listing, the wants and the five newest builds; nothing let go of while
+// the lease names a controller; once it names another holder, a build's end lets go of the eligible within the bound,
+// leaves an index for a confirmed collect, records each deletion and says artifacts-gone.
+func TestTheSeatKeepsTheFiveNewestAndTheWantedAndSweepsOnlyOnceTheLeaseIsAway(t *testing.T) {
+	controller := &buscompose.LeaseHolder{Instance: "c1", Host: "novox", Epoch: 3}
+	handed := &buscompose.LeaseHolder{HandedTo: "mesh-grants", HandedBy: "person.jochen", Why: "the lease write"}
+
+	h, _, _, _ := aMesh(t, controller)
+	r, err := h.Artifacts("")
+	if err != nil {
+		t.Fatal(err)
+	}
+	states := map[string]string{}
+	for _, x := range r.References {
+		states[x.Reference] = x.State
+	}
+	// letta's 3rd to 7th are the five newest; its 1st a want names on ace, however old; its 2nd is eligible; the package
+	// and the manifest no build names are no reference of the seat's.
+	for n, want := range map[int]string{1: "kept", 2: "eligible", 3: "kept", 7: "kept"} {
+		if states[imageRef("letta", n)] != want || states[archiveRef("letta", n)] != want {
+			t.Errorf("letta's build %d is %s and %s, not %s", n, states[imageRef("letta", n)], states[archiveRef("letta", n)], want)
+		}
+	}
+	// And the copies: the one letta's 2nd stood on is eligible with it, the 7th's kept; the third no build names.
+	if states[mirror(1)] != "eligible" || states[mirror(2)] != "kept" || states[mirror(3)] != "" {
+		t.Errorf("the copies are %s, %s and %q", states[mirror(1)], states[mirror(2)], states[mirror(3)])
+	}
+	if m, err := h.MirrorsNow(); err != nil || len(m.Copies) != 3 || m.Copies[2].State != "unrecorded" || m.Held != "" {
+		t.Errorf("mirrors answered %+v: %v", m, err)
+	}
+	if len(r.References) != 16 || r.Counts["kept"] != 13 || r.Counts["eligible"] != 3 || r.Store != "10.0.0.5:5000" {
+		t.Errorf("the references are %d, counted %v, at %q", len(r.References), r.Counts, r.Store)
+	}
+
+	for _, c := range []struct {
+		name    string
+		lease   *buscompose.LeaseHolder
+		index   bool
+		most    int
+		letGo   []string
+		left    int
+		skipped int
+		unlog   int
+	}{
+		{name: "the lease names a controller", lease: controller},
+		{name: "no lease key", lease: nil},
+		{name: "handed away", lease: handed, most: MostPerSweep, letGo: []string{archiveRef("letta", 2), imageRef("letta", 2), mirror(1)}},
+		{name: "an index waits", lease: handed, index: true, most: MostPerSweep, letGo: []string{archiveRef("letta", 2), mirror(1)}, skipped: 1},
+		{name: "bounded", lease: handed, most: 1, letGo: []string{archiveRef("letta", 2)}, left: 2},
+		// A kept build the log no longer holds: what it stood on is unknown, so no copy goes.
+		{name: "a kept build's bases unknown", lease: handed, most: MostPerSweep, letGo: []string{archiveRef("letta", 2), imageRef("letta", 2)}, unlog: 3},
+	} {
+		t.Run(c.name, func(t *testing.T) {
+			h, b, door, acts := aMesh(t, c.lease)
+			door.indexes[imageRef("letta", 2)] = c.index
+			if c.unlog > 0 {
+				b.log = append(b.log[:c.unlog-1:c.unlog-1], b.log[c.unlog:]...)
+			}
+			if c.most == 0 {
+				h.AfterBuild("letta.x")
+				if _, err := h.Collect("tidy", true, 0); err == nil {
+					t.Error("a confirmed collect was let through while the controller sweeps")
+				}
+				if len(door.asked) != 0 || len(*acts) != 0 || len(b.published) != 0 {
+					t.Fatalf("before the lease write the store was asked %v, acts %v, said %v", door.asked, *acts, b.published)
+				}
+				return
+			}
+			a, err := h.Sweep(context.Background(), Sweeping{Most: c.most, By: "after the build letta.x"})
+			if err != nil {
+				t.Fatal(err)
+			}
+			if fmt.Sprint(a.LetGo) != fmt.Sprint(c.letGo) || a.Left != c.left || a.Skipped != c.skipped || a.Held != 6 || a.Missing != 0 {
+				t.Fatalf("let go of %v (left %d, skipped %d, held %d, missing %d), want %v", a.LetGo, a.Left, a.Skipped, a.Held, a.Missing, c.letGo)
+			}
+			// Every kept archive held before the first deletion.
+			first := -1
+			for i, x := range door.asked {
+				if strings.HasPrefix(x, "let go ") && first < 0 {
+					first = i
+				}
+			}
+			if first != 6 {
+				t.Errorf("the store was asked %v: the six kept archives are held first", door.asked)
+			}
+			if len(*acts) != len(c.letGo) || !strings.HasPrefix((*acts)[0], "seat:mesh-hand-acts.hand-act ") ||
+				!strings.Contains((*acts)[0], c.letGo[0]) {
+				t.Errorf("the hand acts recorded are %v", *acts)
+			}
+			if len(b.published) != 1 || !strings.HasPrefix(b.published[0], GoneSubject+" ") ||
+				!strings.Contains(b.published[0], `"fingerprint":"`+fp(2)+`"`) {
+				t.Errorf("said %v", b.published)
+			}
+		})
+	}
+}
+
+// S25 (image-missing): a want whose build names an image the store does not hold is a finding in the seat's own state,
+// written once and deleted once the store holds it again; images names what a machine's wants and haves name.
+func TestAWantedImageTheStoreLacksIsAFindingAndImagesNamesWantsAndHaves(t *testing.T) {
+	h, b, _, _ := aMesh(t, nil)
+	view, _ := h.Listed(context.Background())
+	repo, digest, _ := splitReference(imageRef("letta", 1))
+	delete(view.L.Repos[repo].Revisions, digest)
+	h.Listed = func(context.Context) (*View, error) { return view, nil }
+	if err := h.Observe(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	key := health.FindingKey(health.ScopeModule, "letta.ace", ImageMissing)
+	raw, found, _ := b.Get(FindingsState, key)
+	f, err := health.DecodeFinding(raw)
+	if !found || err != nil || f.Subject.Machine != "ace" || f.Source != "S25" || !strings.Contains(f.Evidence[0].Said, imageRef("letta", 1)) {
+		t.Fatalf("the finding is %+v (%v, %v)", f, found, err)
+	}
+	view.L.Repos[repo].Revisions[digest] = true
+	if err := h.Observe(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if _, found, _ := b.Get(FindingsState, key); found {
+		t.Fatal("the finding stayed once the store held the image again")
+	}
+	// An image the manifest pins by itself, under the store's address, is judged as the controller judged it.
+	delete(view.L.Repos["letta/pinned"].Revisions, "sha256:"+strings.Repeat("c", 64))
+	if err := h.Observe(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if raw, found, _ := b.Get(FindingsState, key); !found || !strings.Contains(string(raw), "letta/pinned@sha256:") {
+		t.Fatalf("the pinnedImage image missing is %s", raw)
+	}
+
+	have, _ := json.Marshal(delivery.Have{V: delivery.Version, FP: fp(7), Phase: "running"})
+	_ = b.Put(HavesRead, "ace.letta", json.RawMessage(have))
+	images, err := h.ImagesOf("ace", "10.0.0.5:5000")
+	if err != nil || len(images.Images) != 3 || !images.SentKnown || images.Images[0].Image != "10.0.0.5:5000/letta/image@sha256:"+strings.Repeat("1", 64) ||
+		fmt.Sprint(images.Images[0].In) != "[declared]" || fmt.Sprint(images.Images[1].In) != "[sent]" ||
+		images.Images[2].Image != pinnedImage || fmt.Sprint(images.Images[2].In) != "[declared sent]" {
+		t.Fatalf("the images of ace are %+v: %v", images, err)
+	}
+}

modules/artifact-store-tools/cmd/artifact-store-tools/main.go

@@ -1,30 +1,38 @@
-// The artifact-store-tools module's Go bundle (novox/hq ADR 0251 §1–3, to-be 51): a process the node's
-// runtime launches and speaks MCP over stdio to. It says what the artifact store holds — its
-// repositories, its size, and what the controller's records say of each manifest — read from the
-// store's own files through the store's own container, and writing nothing. A collection is asked of
-// the controller, which decides and records what it lets go of (ADR 0189).
+// The artifact-store-tools module's Go bundle (novox/hq ADR 0251 §1–3, ADR 0571 clause 2, to-be 51): a process the
+// node's runtime launches and speaks MCP over stdio to. It says what the artifact store holds — its repositories, its
+// size, and what the mesh keeps of each manifest — read from the store's own files through the store's own container,
+// and it holds the seat mesh-artifact-sweep: the keep set, the sweep at each build's end once the controller's lease names
+// no controller, and S25's image-missing.
 //
-// **A module beside the store, not the store's own.** A module that provides the artifact store cannot
-// also build an artifact: building publishes to the store, so the store would be needed to create
-// itself, and the controller refuses that manifest. So these tools are a second module, assigned to the
-// machine that holds the store. stdout is the protocol; what this bundle says, it says on stderr.
+// **A module beside the store, not the store's own.** A module that provides the artifact store cannot also build an
+// artifact: building publishes to the store, so the store would be needed to create itself. So these tools are a
+// second module, assigned to the machine that holds the store. stdout is the protocol; what this bundle says, it says
+// on stderr.
 package main
 
 import (
 	"fmt"
 	"os"
+	"time"
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/handacts"
 )
 
+func logf(format string, a ...any) { fmt.Fprintf(os.Stderr, format+"\n", a...) }
+
 func main() {
 	s := &Store{
 		Container: os.Getenv("MESH_ARTIFACT_STORE_CONTAINER"),
 		Run:       ExecRunner,
 		UID:       os.Getuid(),
 	}
+	h := &Holder{Bus: runtimeBus{}, Door: DoorAt(os.Getenv("MESH_ARTIFACT_STORE_ADDRESS_FILE")), Listed: s.View,
+		Now: time.Now, Logf: logf}
+	h.Acts = handacts.Recorder{Ask: stdio.Ask, LeaseAway: h.LeaseAway}
+	go follow(h)
 	// An empty name serves as the module the runtime names (MESH_SERVED_MODULE): artifact-store-tools.
-	if err := stdio.Serve("", Tools(s, Controller{Ask: stdio.Ask}, &Catalogue{Ask: stdio.Ask})); err != nil {
+	if err := stdio.Serve("", append(Tools(s, h, &Catalogue{Ask: stdio.Ask}), SeatTools(h, s)...)); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}

modules/artifact-store-tools/cmd/artifact-store-tools/seat.go

@@ -0,0 +1,122 @@
+package main
+
+// The seat mesh-artifact-sweep's verbs (novox/hq ADR 0571 clause 2; catalogue.ArtifactSweepSeat), each a tool named
+// `artifact-store.<verb>` as the runtime serves a seat's verb, answering as the controller's verb answered: {output,
+// ok, answer}.
+
+import (
+	"fmt"
+	"strings"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// verbAnswer is the controller's verbs' answer shape, which the builder and docker read (answerOf).
+type verbAnswer struct {
+	Output string `json:"output"`
+	OK     bool   `json:"ok"`
+	Answer any    `json:"answer"`
+}
+
+// SeatTools are the seat's verbs over h; s reads the store's listing for mirrors.
+func SeatTools(h *Holder, s *Store) []stdio.Tool {
+	seat := catalogue.ArtifactSweepSeat + "."
+	return []stdio.Tool{
+		{Name: seat + "artifacts", Description: "Every artifact the mesh made that the store holds: kept and why, eligible, " +
+			"or with collected those it no longer holds.",
+			Run: func(args map[string]any) (any, error) {
+				r, err := h.Artifacts(text(args, "repository"))
+				if err != nil {
+					return nil, err
+				}
+				if text(args, "collected") != "true" {
+					refs := r.References[:0:0]
+					for _, x := range r.References {
+						if x.State != "collected" {
+							refs = append(refs, x)
+						}
+					}
+					r.References = refs
+				}
+				return verbAnswer{Output: fmt.Sprintf("%d kept, %d eligible, %d collected\n", r.Counts["kept"],
+					r.Counts["eligible"], r.Counts["collected"]), OK: true, Answer: r}, nil
+			}},
+		{Name: seat + "held", Description: "Whether the store holds each reference given: held, gone or unknown with why.",
+			Run: func(args map[string]any) (any, error) {
+				a, err := h.Held(listOf(args["references"]))
+				if err != nil {
+					return nil, err
+				}
+				return verbAnswer{Output: fmt.Sprintf("the artifact store at %s holds %d of the %d reference(s) asked\n",
+					a.Store, len(a.Held), len(a.Held)+len(a.Gone)+len(a.Unknown)), OK: true, Answer: a}, nil
+			}},
+		{Name: seat + "collect", Description: "The sweep now: a dry run without confirm; with confirm and why, every kept " +
+			"archive held, then each eligible artifact let go of, each recorded in the hand-act log.",
+			Run: func(args map[string]any) (any, error) {
+				most, err := count(args, "most", MostPerSweep, 1, MostAtAll)
+				if err != nil {
+					return nil, err
+				}
+				a, err := h.Collect(text(args, "why"), text(args, "confirm") == "true", most)
+				if err != nil {
+					return nil, err
+				}
+				return verbAnswer{Output: fmt.Sprintf("let go of %d, would let go of %d, %d left\n", len(a.LetGo),
+					len(a.WouldLetGo), a.Left), OK: true, Answer: a}, nil
+			}},
+		{Name: seat + "mirrors", Description: "The bases the mesh copied into its store, each kept (a kept build stood on " +
+			"it), eligible (only builds no longer kept stood on it) or unrecorded (no build the builder's log holds stood " +
+			"on it: never removed).",
+			Run: func(args map[string]any) (any, error) {
+				if text(args, "record") != "" {
+					return nil, fmt.Errorf("mirrors records nothing by hand on this seat: a copy is recorded by the builds the " +
+						"builder's log says stood on it (novox/hq ADR 0571 clause 1)")
+				}
+				m, err := h.MirrorsNow()
+				if err != nil {
+					return nil, err
+				}
+				return verbAnswer{Output: fmt.Sprintf("%d copies\n", len(m.Copies)), OK: true, Answer: m}, nil
+			}},
+		{Name: seat + "images", Description: "Every container image one machine's wants and haves name.",
+			Run: func(args map[string]any) (any, error) {
+				node := text(args, "node")
+				if node == "" {
+					return nil, fmt.Errorf("images names the machine")
+				}
+				address := ""
+				if d, err := h.Door(); err == nil {
+					address = d.Address()
+				}
+				a, err := h.ImagesOf(node, address)
+				if err != nil {
+					return nil, err
+				}
+				return verbAnswer{Output: fmt.Sprintf("%s: %d images\n", node, len(a.Images)), OK: true, Answer: a}, nil
+			}},
+	}
+}
+
+// listOf is a list argument: a list, or one text separated by commas.
+func listOf(v any) []string {
+	var out []string
+	add := func(s string) {
+		for _, p := range strings.Split(s, ",") {
+			if p = strings.TrimSpace(p); p != "" && !contains(out, p) {
+				out = append(out, p)
+			}
+		}
+	}
+	switch x := v.(type) {
+	case string:
+		add(x)
+	case []any:
+		for _, e := range x {
+			if s, ok := e.(string); ok {
+				add(s)
+			}
+		}
+	}
+	return out
+}

modules/artifact-store-tools/cmd/artifact-store-tools/store_test.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+
 	"context"
 	"encoding/json"
 	"fmt"
@@ -411,6 +413,11 @@ func TestTheToolsServedAreTheToolsTheManifestNames(t *testing.T) {
 	var m struct {
 		Tools   []string `json:"tools"`
 		Invokes []string `json:"invokes"`
+		Reads   []string `json:"reads"`
+		Claims  []struct {
+			Name   string   `json:"name"`
+			Serves []string `json:"serves"`
+		} `json:"claims"`
 	}
 	if err := json.Unmarshal(raw, &m); err != nil {
 		t.Fatal(err)
@@ -428,10 +435,30 @@ func TestTheToolsServedAreTheToolsTheManifestNames(t *testing.T) {
 	if !reflect.DeepEqual(served, listed) {
 		t.Fatalf("served %v, manifest %v", served, listed)
 	}
-	want := []string{"seat:mesh-controller.artifacts", "seat:mesh-controller.collect", CatalogueModules, CatalogueModule}
+	// ADR 0571 clause 2: it holds the seat mesh-artifact-sweep and serves its verbs, and calls no verb of the controller's;
+	// the lease is the one controller state it reads (clause 10's exemption).
+	want := []string{"seat:mesh-hand-acts.hand-act", CatalogueModules, CatalogueModule}
 	if !reflect.DeepEqual(m.Invokes, want) {
 		t.Errorf("invokes %v", m.Invokes)
 	}
+	var verbs []string
+	for _, tl := range SeatTools(&Holder{}, &Store{}) {
+		verbs = append(verbs, strings.TrimPrefix(tl.Name, catalogue.ArtifactSweepSeat+"."))
+	}
+	seat, _ := catalogue.SeatNamed(catalogue.ArtifactSweepSeat)
+	var contract []string
+	for _, v := range seat.Serves {
+		contract = append(contract, v.Name)
+	}
+	if len(m.Claims) != 1 || m.Claims[0].Name != catalogue.ArtifactSweepSeat || !reflect.DeepEqual(m.Claims[0].Serves, verbs) ||
+		!reflect.DeepEqual(verbs, contract) {
+		t.Errorf("claims %+v, serves %v, the seat's verbs %v", m.Claims, verbs, contract)
+	}
+	for _, r := range m.Reads {
+		if strings.HasPrefix(r, "mesh-controller.") && r != LeaseRead {
+			t.Errorf("reads the controller's %s", r)
+		}
+	}
 }
 
 func TestASocketRefusalIsAskedAgainThroughSudo(t *testing.T) {

modules/artifact-store-tools/cmd/artifact-store-tools/tools.go

@@ -11,9 +11,16 @@ import (
 	stdio "git.novox.be/novox/mesh-sdk/go"
 )
 
+// Recorded is what says which references the mesh keeps and lets go of them: the seat's holder (Holder, novox/hq ADR
+// 0571 clause 2), or before it the controller (Controller), each in the controller's answer's shape.
+type Recorded interface {
+	Artifacts(repository string) (*Records, error)
+	Collect(why string, confirm bool, most int) (*CollectAnswer, error)
+}
+
 // Tools are the artifact store's tools (novox/hq ADR 0251 §1). The first three only read; artifact_store_collect
-// only reads too, unless it is a real run, and then it asks the controller, which decides and deletes.
-func Tools(s *Store, c Controller, cat *Catalogue) []stdio.Tool {
+// only reads too, unless it is a real run, and then it asks the seat's sweep, which decides and deletes.
+func Tools(s *Store, c Recorded, cat *Catalogue) []stdio.Tool {
 	ctx := context.Background()
 	repoArg := map[string]any{"type": "string", "description": "one repository, as the store names it (<module>/<artifact>)"}
 	return []stdio.Tool{

modules/artifact-store-tools/files/store-address

@@ -0,0 +1 @@
+${seat:mesh-artifact-store:reach}

modules/artifact-store-tools/go.mod

@@ -1,5 +1,22 @@
 module artifactstoretools
 
-go 1.22
+go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.7
+require (
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde
+	github.com/nats-io/nats.go v1.54.0
+)
+
+require (
+	github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op // indirect
+	github.com/google/go-tpm v0.9.8 // indirect
+	github.com/klauspost/compress v1.20.0 // indirect
+	github.com/minio/highwayhash v1.0.4 // indirect
+	github.com/nats-io/jwt/v2 v2.8.1 // indirect
+	github.com/nats-io/nats-server/v2 v2.11.17 // indirect
+	github.com/nats-io/nkeys v0.4.16 // indirect
+	github.com/nats-io/nuid v1.0.1 // indirect
+	golang.org/x/crypto v0.57.0 // indirect
+	golang.org/x/sys v0.48.0 // indirect
+	golang.org/x/time v0.15.0 // indirect
+)

modules/artifact-store-tools/go.sum

@@ -1,2 +1,27 @@
-git.novox.be/novox/mesh-sdk/go v0.1.7 h1:C0sTQmtTiyYH7bnqZb7PusXnqA37gKuT7Nqjn9gG47w=
-git.novox.be/novox/mesh-sdk/go v0.1.7/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
+github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
+github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=
+github.com/google/go-tpm v0.9.8/go.mod h1:h9jEsEECg7gtLis0upRBQU+GhYVH6jMjrFxI8u6bVUY=
+github.com/klauspost/compress v1.20.0 h1:a3C1ke2ohxFymNlb2HWAHjDeKCI90scRskErZkR0ezA=
+github.com/klauspost/compress v1.20.0/go.mod h1:LUdAzn7YLVvxLpc7y3V1m40wESHTgc1422pwwBSKYuI=
+github.com/minio/highwayhash v1.0.4 h1:asJizugGgchQod2ja9NJlGOWq4s7KsAWr5XUc9Clgl4=
+github.com/minio/highwayhash v1.0.4/go.mod h1:GGYsuwP/fPD6Y9hMiXuapVvlIUEhFhMTh0rxU3ik1LQ=
+github.com/nats-io/jwt/v2 v2.8.1 h1:V0xpGuD/N8Mi+fQNDynXohVvp7ZztevW5io8CUWlPmU=
+github.com/nats-io/jwt/v2 v2.8.1/go.mod h1:nWnOEEiVMiKHQpnAy4eXlizVEtSfzacZ1Q43LIRavZg=
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+github.com/nats-io/nkeys v0.4.16 h1:rd5oAuLOb8mnAycB0xleuEBNS1pVVnN0fv/FF34Eypg=
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+github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
+golang.org/x/crypto v0.57.0 h1:3ZVCjf8Ggz7zneR/EHRVx68Ctf+2pmIMP2UFhh9cC6M=
+golang.org/x/crypto v0.57.0/go.mod h1:Fdz0i5U6CoizGwLda9DttjSk6qlZo25zYNtR+ycvuZA=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
+golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=

modules/artifact-store-tools/internal/registry/blob.go

@@ -0,0 +1,57 @@
+package registry
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+// blobBound is the most GetBlob reads: a templates archive is a few kilobytes; anything near this is no archive a
+// take-in reads text from.
+const blobBound = 64 << 20
+
+// GetBlob is the archive a recorded reference names (`artifact-store://<repository>/blobs/sha256:<hex>`), read whole
+// and checked against the digest it names: bytes that hash to another digest are refused, never read (R4e: the
+// controller reads a templates archive by the reference of a builder's done key). Gone when the store does not hold
+// it; ErrNotOurs for a reference outside the store or one that is not an archive.
+func (s Store) GetBlob(ctx context.Context, reference string) ([]byte, error) {
+	repository, digest, archive, err := s.archive(reference)
+	if err != nil {
+		return nil, err
+	}
+	if !archive {
+		return nil, fmt.Errorf("%w: %s is not an archive", ErrNotOurs, reference)
+	}
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, s.url(repository, "blobs", digest), nil)
+	if err != nil {
+		return nil, err
+	}
+	response, err := s.client().Do(request)
+	if err != nil {
+		return nil, fmt.Errorf("cannot reach the artifact store at %s: %w", s.Address, err)
+	}
+	defer response.Body.Close()
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusNotFound:
+		return nil, Gone
+	default:
+		return nil, fmt.Errorf("the artifact store answered %s for %s/blobs/%s", response.Status, repository, digest)
+	}
+	body, err := io.ReadAll(io.LimitReader(response.Body, blobBound+1))
+	if err != nil {
+		return nil, fmt.Errorf("reading %s/blobs/%s: %w", repository, digest, err)
+	}
+	if len(body) > blobBound {
+		return nil, fmt.Errorf("%s/blobs/%s is larger than %d bytes, which no archive read here is", repository, digest, blobBound)
+	}
+	sum := sha256.Sum256(body)
+	if got := "sha256:" + hex.EncodeToString(sum[:]); got != digest {
+		return nil, fmt.Errorf("the artifact store answered %s/blobs/%s with bytes of the digest %s: refused", repository,
+			digest, got)
+	}
+	return body, nil
+}

modules/artifact-store-tools/internal/registry/blob_test.go

@@ -0,0 +1,44 @@
+package registry
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+// A take-in reads a templates archive by its reference, and only bytes of the digest the reference names.
+func TestGetBlobReadsOnlyTheBytesOfItsDigest(t *testing.T) {
+	good := []byte("the archive")
+	sum := sha256.Sum256(good)
+	digest := "sha256:" + hex.EncodeToString(sum[:])
+	liar := "sha256:" + strings.Repeat("0", 64)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.HasSuffix(r.URL.Path, "/x/files/blobs/"+digest), strings.HasSuffix(r.URL.Path, "/x/files/blobs/"+liar):
+			_, _ = w.Write(good)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer server.Close()
+	s := Store{Address: strings.TrimPrefix(server.URL, "http://")}
+	ctx := context.Background()
+	body, err := s.GetBlob(ctx, "artifact-store://x/files/blobs/"+digest)
+	if err != nil || string(body) != string(good) {
+		t.Fatalf("the archive: %q %v", body, err)
+	}
+	if _, err := s.GetBlob(ctx, "artifact-store://x/files/blobs/"+liar); err == nil || !strings.Contains(err.Error(), "refused") {
+		t.Fatalf("bytes of another digest are read: %v", err)
+	}
+	if _, err := s.GetBlob(ctx, "artifact-store://x/other/blobs/"+digest); !errors.Is(err, Gone) {
+		t.Fatalf("a blob the store does not hold: %v", err)
+	}
+	if _, err := s.GetBlob(ctx, "registry.example/x@"+digest); !errors.Is(err, ErrNotOurs) {
+		t.Fatalf("a reference outside the store: %v", err)
+	}
+}

modules/artifact-store-tools/internal/registry/hold.go

@@ -0,0 +1,345 @@
+package registry
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// Every archive the store keeps is held by a manifest (novox/hq issue 253, ADR 0189).
+//
+// **The store's collector marks only from manifests.** The mesh's store is a stock registry, and
+// its nightly `registry garbage-collect` walks every manifest in every repository, marks the blobs
+// those manifests name, and deletes every blob it did not mark. An image is a manifest, so what
+// the mesh keeps of an image survives. An archive was not: the builder put it in the store as a
+// bare blob — upload, then `PUT ?digest=` — and nothing in the store names it. To the collector a
+// bare blob is unreferenced, so the first real collection would have deleted every archive the
+// mesh holds, kept or not, and every machine pinning a bundle would have found it gone. The
+// collector runs `--dry-run` until this is true.
+//
+// **So each archive gets a holder**: the smallest OCI image manifest that names it — the empty
+// config, one layer, nothing else — put in the archive's own repository, by digest, untagged. The
+// collector marks it and so keeps the archive; the sweep lets go of an archive by deleting its
+// holder first, which is what lets the bytes go at the next collection.
+//
+// **Nothing a machine reads changes.** The recorded reference stays
+// `artifact-store://<module>/<artifact>/blobs/sha256:…`, and machines fetch the blob exactly as
+// before. The holder is the store's bookkeeping, not a second way to reach anything.
+//
+// **Deterministic, so it never needs recording.** The holder is composed from the archive's digest
+// and size alone, in a fixed field order with no timestamps or annotations, so the sweep can
+// compute which manifest holds any archive from the reference it already has plus one HEAD for the
+// size. No schema change, no second record that could disagree with the store.
+
+const (
+	// mediaManifest is the type a holder is put and asked for as.
+	mediaManifest = "application/vnd.oci.image.manifest.v1+json"
+	// mediaEmpty is the OCI empty descriptor's type: a config that says nothing, for a manifest
+	// whose only purpose is to name its layer.
+	mediaEmpty = "application/vnd.oci.empty.v1+json"
+	// emptyDigest is the digest of `{}`, the empty config's content, fixed by the OCI spec.
+	emptyDigest = "sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a"
+	// mediaArchive is the layer type an archive is held as. Every archive the builder publishes is
+	// `pack`'s gzipped tar, so this is the true type and not a placeholder — and it is a constant,
+	// not read from anywhere, because the holder must be recomputable from the reference alone.
+	mediaArchive = "application/vnd.oci.image.layer.v1.tar+gzip"
+)
+
+// emptyConfig is the content emptyDigest names.
+var emptyConfig = []byte("{}")
+
+// manifestAccept is what a manifest is asked for as. A registry answers a manifest HEAD only in a
+// type the caller named, and answers 404 to a bare one for a manifest it holds perfectly well
+// (measured 2026-09-28; internal/builder/registry.go says how that was found).
+var manifestAccept = []string{
+	mediaManifest,
+	"application/vnd.docker.distribution.manifest.v2+json",
+}
+
+type descriptor struct {
+	MediaType string `json:"mediaType"`
+	Digest    string `json:"digest"`
+	Size      int64  `json:"size"`
+}
+
+type holderManifest struct {
+	SchemaVersion int          `json:"schemaVersion"`
+	MediaType     string       `json:"mediaType"`
+	Config        descriptor   `json:"config"`
+	Layers        []descriptor `json:"layers"`
+}
+
+// Holder is the manifest that holds an archive in the store, and its digest.
+//
+// A pure function of the archive's digest and size: the same two in give the same bytes out,
+// always, because `encoding/json` writes a struct's fields in their declared order and there is
+// nothing here that varies by when or where it was composed.
+func Holder(digest string, size int64) (body []byte, holder string) {
+	body, err := json.Marshal(holderManifest{
+		SchemaVersion: 2,
+		MediaType:     mediaManifest,
+		Config:        descriptor{MediaType: mediaEmpty, Digest: emptyDigest, Size: int64(len(emptyConfig))},
+		Layers:        []descriptor{{MediaType: mediaArchive, Digest: digest, Size: size}},
+	})
+	if err != nil {
+		// Marshalling a struct of strings and integers cannot fail.
+		panic(err)
+	}
+	sum := sha256.Sum256(body)
+	return body, "sha256:" + hex.EncodeToString(sum[:])
+}
+
+// Hold makes sure the store holds this archive by a manifest, and says whether it had to write one.
+//
+// Takes a reference as the mesh records it. An image is its own manifest and needs no holder, so
+// it answers false and nothing is asked. Idempotent: a holder already there is left alone, which
+// is what lets the sweep run it over every kept archive on every build and so backfill the bare
+// blobs published before holders existed (novox/hq issue 253).
+//
+// Gone when the store does not hold the archive at all: there is nothing to hold, and that is a
+// fact the caller reports rather than one this invents a remedy for.
+func (s Store) Hold(ctx context.Context, reference string) (bool, error) {
+	repository, digest, archive, err := s.archive(reference)
+	if err != nil || !archive {
+		return false, err
+	}
+	size, err := s.blobSize(ctx, repository, digest)
+	if err != nil {
+		return false, err
+	}
+	return s.HoldBlob(ctx, repository, digest, size)
+}
+
+// Held is whether the store holds this archive by its manifest. Asks and changes nothing — the
+// question an operator needs answered with "none unheld" before the collector is let loose.
+//
+// An image answers true: it is its own manifest. An archive the store does not have answers Gone.
+func (s Store) Held(ctx context.Context, reference string) (bool, error) {
+	repository, digest, archive, err := s.archive(reference)
+	if err != nil {
+		return false, err
+	}
+	if !archive {
+		return true, nil
+	}
+	size, err := s.blobSize(ctx, repository, digest)
+	if err != nil {
+		return false, err
+	}
+	_, holder := Holder(digest, size)
+	return s.has(ctx, s.url(repository, "manifests", holder), manifestAccept...)
+}
+
+// HoldBlob puts the holder for a blob of this digest and size into its repository, unless it is
+// there already. Answers whether it wrote one.
+//
+// The builder calls this with the size it has just uploaded; the sweep, through Hold, with the size
+// the store reports. Both arrive at the same holder, which is the point of composing it.
+func (s Store) HoldBlob(ctx context.Context, repository, digest string, size int64) (bool, error) {
+	if s.Address == "" {
+		return false, fmt.Errorf("this mesh has no artifact store on its network to hold %s/%s in", repository, digest)
+	}
+	body, holder := Holder(digest, size)
+	there, err := s.has(ctx, s.url(repository, "manifests", holder), manifestAccept...)
+	if err != nil {
+		return false, err
+	}
+	if there {
+		return false, nil
+	}
+
+	// The config must be in the repository before a manifest naming it is accepted: a registry
+	// refuses a manifest whose blobs it cannot find there, which is the property that makes a
+	// holder mean something.
+	if err := s.putBlob(ctx, repository, emptyDigest, emptyConfig); err != nil {
+		return false, err
+	}
+
+	// **By digest, never by tag.** A tag would be one more name to move and one more thing the
+	// collector's `--delete-untagged` would read as meaningful; the mesh names nothing by tag that
+	// it pins by digest, and an untagged manifest is kept by plain collection.
+	request, err := http.NewRequestWithContext(ctx, http.MethodPut,
+		s.url(repository, "manifests", holder), bytes.NewReader(body))
+	if err != nil {
+		return false, err
+	}
+	request.Header.Set("Content-Type", mediaManifest)
+	response, err := s.client().Do(request)
+	if err != nil {
+		return false, err
+	}
+	defer response.Body.Close()
+	if response.StatusCode != http.StatusCreated {
+		said, _ := io.ReadAll(io.LimitReader(response.Body, 4096))
+		return false, fmt.Errorf("the artifact store refused to hold %s/%s: %s %s",
+			repository, digest, response.Status, strings.TrimSpace(string(said)))
+	}
+	return true, nil
+}
+
+// letGoOfHolder deletes the manifest holding an archive, before the archive's own link goes.
+//
+// **Holder first.** Deleting the blob link alone leaves a manifest still naming the blob, and the
+// collector would keep its bytes for ever on the strength of it — the sweep would record the
+// archive collected while the disk said otherwise. Deleting the holder first and failing before
+// the link goes leaves an unheld archive that the next sweep still offers, which is safe.
+//
+// A store that no longer has the blob answers Gone: without its size the holder cannot be named,
+// and without the blob there is nothing left for a holder to keep. A store that never had a holder
+// for it — an archive published before holders, never backfilled — answers 404 to the delete, and
+// that is the outcome wanted.
+func (s Store) letGoOfHolder(ctx context.Context, repository, digest string) error {
+	size, err := s.blobSize(ctx, repository, digest)
+	if err != nil {
+		return err
+	}
+	_, holder := Holder(digest, size)
+	err = s.remove(ctx, s.url(repository, "manifests", holder), repository+"/manifests/"+holder)
+	if err == Gone {
+		return nil
+	}
+	return err
+}
+
+// archive reads a recorded reference into its repository and digest, and whether it is an archive
+// at all. Refuses as ErrNotOurs anything the mesh did not put in its own store.
+func (s Store) archive(reference string) (repository, digest string, archive bool, err error) {
+	path, kept := catalogue.InArtifactStore(reference)
+	if !kept {
+		return "", "", false, fmt.Errorf("%w: %s", ErrNotOurs, reference)
+	}
+	if s.Address == "" {
+		return "", "", false, fmt.Errorf("this mesh has no artifact store on its network to ask about %s", reference)
+	}
+	repository, kind, digest, err := split(path)
+	if err != nil {
+		return "", "", false, err
+	}
+	return repository, digest, kind == "blobs", nil
+}
+
+// blobSize is how large the store says a blob is; Gone when it does not have it.
+func (s Store) blobSize(ctx context.Context, repository, digest string) (int64, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodHead, s.url(repository, "blobs", digest), nil)
+	if err != nil {
+		return 0, err
+	}
+	response, err := s.client().Do(request)
+	if err != nil {
+		return 0, fmt.Errorf("cannot reach the artifact store at %s: %w", s.Address, err)
+	}
+	defer response.Body.Close()
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusNotFound:
+		return 0, Gone
+	default:
+		return 0, fmt.Errorf("the artifact store answered %s for %s/blobs/%s", response.Status, repository, digest)
+	}
+	// Read from the header rather than ContentLength: a HEAD's ContentLength is what the response
+	// says it would have sent, which Go reports faithfully, but a proxy in between is free to drop
+	// it, and the header is what the registry itself wrote.
+	if length := response.Header.Get("Content-Length"); length != "" {
+		if n, err := strconv.ParseInt(length, 10, 64); err == nil && n >= 0 {
+			return n, nil
+		}
+	}
+	if response.ContentLength >= 0 {
+		return response.ContentLength, nil
+	}
+	return 0, fmt.Errorf("the artifact store holds %s/blobs/%s and will not say how large it is", repository, digest)
+}
+
+// putBlob uploads a small blob unless the repository already has it: ask where, then put it there
+// naming the digest — the registry's own two steps, the same the builder takes for an archive.
+func (s Store) putBlob(ctx context.Context, repository, digest string, body []byte) error {
+	if there, err := s.has(ctx, s.url(repository, "blobs", digest)); err != nil {
+		return err
+	} else if there {
+		return nil
+	}
+	start, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		"http://"+s.Address+"/v2/"+repository+"/blobs/uploads/", nil)
+	if err != nil {
+		return err
+	}
+	begun, err := s.client().Do(start)
+	if err != nil {
+		return fmt.Errorf("cannot start an upload to %s: %w", repository, err)
+	}
+	begun.Body.Close()
+	if begun.StatusCode != http.StatusAccepted {
+		return fmt.Errorf("the artifact store answered %s when asked where to put a blob in %s", begun.Status, repository)
+	}
+	where := begun.Header.Get("Location")
+	if where == "" {
+		return fmt.Errorf("the artifact store accepted an upload to %s and said nowhere to put it", repository)
+	}
+	if strings.HasPrefix(where, "/") {
+		where = "http://" + s.Address + where
+	}
+	separator := "?"
+	if strings.Contains(where, "?") {
+		separator = "&"
+	}
+	put, err := http.NewRequestWithContext(ctx, http.MethodPut, where+separator+"digest="+digest, bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	put.Header.Set("Content-Type", "application/octet-stream")
+	done, err := s.client().Do(put)
+	if err != nil {
+		return err
+	}
+	defer done.Body.Close()
+	if done.StatusCode != http.StatusCreated {
+		said, _ := io.ReadAll(io.LimitReader(done.Body, 4096))
+		return fmt.Errorf("the artifact store refused a blob in %s: %s %s", repository, done.Status, strings.TrimSpace(string(said)))
+	}
+	return nil
+}
+
+// has is whether the store answers 200 for a HEAD at that URL.
+func (s Store) 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 := s.client().Do(request)
+	if err != nil {
+		return false, fmt.Errorf("cannot reach the artifact store at %s: %w", s.Address, err)
+	}
+	defer response.Body.Close()
+	switch response.StatusCode {
+	case http.StatusOK:
+		return true, nil
+	case http.StatusNotFound:
+		return false, nil
+	default:
+		return false, fmt.Errorf("the artifact store answered %s for %s", response.Status, url)
+	}
+}
+
+func (s Store) url(repository, kind, digest string) string {
+	return "http://" + s.Address + "/v2/" + repository + "/" + kind + "/" + digest
+}
+
+func (s Store) client() *http.Client {
+	if s.HTTP != nil {
+		return s.HTTP
+	}
+	return &http.Client{Timeout: 30 * time.Second}
+}

modules/artifact-store-tools/internal/registry/hold_test.go

@@ -0,0 +1,268 @@
+package registry
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"strings"
+	"sync"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// Every kept archive is held by a manifest (novox/hq issue 253, ADR 0189).
+//
+// Against an in-memory registry that keeps blobs and manifests per repository and refuses what a
+// registry refuses — a blob whose digest does not match, a manifest whose digest does not match
+// or whose blobs the repository does not have, a manifest asked for without an Accept naming its
+// type. What is asserted is this side's decisions; the live test below asserts the registry's.
+
+type memRegistry struct {
+	mu        sync.Mutex
+	blobs     map[string][]byte // repository + "@" + digest
+	manifests map[string][]byte // repository + "@" + digest
+	writes    []string          // every PUT and DELETE, as "METHOD path"
+}
+
+func digestOf(body []byte) string {
+	sum := sha256.Sum256(body)
+	return "sha256:" + hex.EncodeToString(sum[:])
+}
+
+func (m *memRegistry) serve(t *testing.T) Store {
+	t.Helper()
+	m.blobs = map[string][]byte{}
+	m.manifests = map[string][]byte{}
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		m.mu.Lock()
+		defer m.mu.Unlock()
+		path := strings.TrimPrefix(r.URL.Path, "/v2/")
+		if r.Method == http.MethodPut || r.Method == http.MethodDelete {
+			m.writes = append(m.writes, r.Method+" "+r.URL.Path)
+		}
+		switch {
+		case r.Method == http.MethodPost && strings.HasSuffix(path, "/blobs/uploads/"):
+			repository := strings.TrimSuffix(path, "/blobs/uploads/")
+			w.Header().Set("Location", "/upload/"+repository+"?state=x")
+			w.WriteHeader(http.StatusAccepted)
+		case r.Method == http.MethodPut && strings.HasPrefix(r.URL.Path, "/upload/"):
+			repository := strings.TrimPrefix(r.URL.Path, "/upload/")
+			body, _ := io.ReadAll(r.Body)
+			digest := r.URL.Query().Get("digest")
+			if digest != digestOf(body) {
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+			m.blobs[repository+"@"+digest] = body
+			w.WriteHeader(http.StatusCreated)
+		case strings.Contains(path, "/blobs/"):
+			repository, digest, _ := strings.Cut(path, "/blobs/")
+			key := repository + "@" + digest
+			body, ok := m.blobs[key]
+			if !ok {
+				w.WriteHeader(http.StatusNotFound)
+				return
+			}
+			switch r.Method {
+			case http.MethodHead:
+				w.Header().Set("Content-Length", strconv.Itoa(len(body)))
+				w.WriteHeader(http.StatusOK)
+			case http.MethodDelete:
+				delete(m.blobs, key)
+				w.WriteHeader(http.StatusAccepted)
+			default:
+				w.WriteHeader(http.StatusMethodNotAllowed)
+			}
+		case strings.Contains(path, "/manifests/"):
+			repository, digest, _ := strings.Cut(path, "/manifests/")
+			key := repository + "@" + digest
+			switch r.Method {
+			case http.MethodHead:
+				if _, ok := m.manifests[key]; !ok || !strings.Contains(r.Header.Get("Accept"), mediaManifest) {
+					w.WriteHeader(http.StatusNotFound)
+					return
+				}
+				w.WriteHeader(http.StatusOK)
+			case http.MethodPut:
+				body, _ := io.ReadAll(r.Body)
+				if digest != digestOf(body) {
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+				var named holderManifest
+				if err := json.Unmarshal(body, &named); err != nil {
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+				for _, d := range append([]descriptor{named.Config}, named.Layers...) {
+					if _, ok := m.blobs[repository+"@"+d.Digest]; !ok {
+						w.WriteHeader(http.StatusBadRequest)
+						fmt.Fprintf(w, "MANIFEST_BLOB_UNKNOWN %s", d.Digest)
+						return
+					}
+				}
+				m.manifests[key] = body
+				w.WriteHeader(http.StatusCreated)
+			case http.MethodDelete:
+				if _, ok := m.manifests[key]; !ok {
+					w.WriteHeader(http.StatusNotFound)
+					return
+				}
+				delete(m.manifests, key)
+				w.WriteHeader(http.StatusAccepted)
+			}
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	t.Cleanup(server.Close)
+	return Store{Address: strings.TrimPrefix(server.URL, "http://")}
+}
+
+// bare puts an archive in the store the way the builder did before holders: a blob, nothing more.
+func (m *memRegistry) bare(repository string, body []byte) string {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	digest := digestOf(body)
+	m.blobs[repository+"@"+digest] = body
+	return catalogue.ArtifactStoreScheme + repository + "/blobs/" + digest
+}
+
+func TestTheHolderIsComposedFromTheDigestAndSizeAlone(t *testing.T) {
+	// The sweep must arrive at the very manifest the builder wrote, with nothing recorded between
+	// them. Same inputs, same bytes — and a different size is a different holder, so a holder can
+	// never be mistaken for one of a different blob.
+	digest := "sha256:" + strings.Repeat("a", 64)
+	one, first := Holder(digest, 42)
+	two, second := Holder(digest, 42)
+	if !bytes.Equal(one, two) || first != second {
+		t.Fatalf("the same archive composed two holders:\n%s\n%s", one, two)
+	}
+	if _, other := Holder(digest, 43); other == first {
+		t.Fatal("a different size composed the same holder")
+	}
+	want := `{"schemaVersion":2,"mediaType":"application/vnd.oci.image.manifest.v1+json",` +
+		`"config":{"mediaType":"application/vnd.oci.empty.v1+json",` +
+		`"digest":"sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a","size":2},` +
+		`"layers":[{"mediaType":"application/vnd.oci.image.layer.v1.tar+gzip","digest":"` + digest + `","size":42}]}`
+	if string(one) != want {
+		t.Fatalf("the holder is\n%s\nwant\n%s", one, want)
+	}
+	if digestOf(emptyConfig) != emptyDigest {
+		t.Fatalf("the empty config's digest is %s, not %s", digestOf(emptyConfig), emptyDigest)
+	}
+}
+
+func TestHoldBackfillsABareArchiveAndIsIdempotent(t *testing.T) {
+	// The archives published before this have no holder. Hold, run over every kept archive on
+	// every sweep, writes one the first time and nothing after.
+	m := &memRegistry{}
+	store := m.serve(t)
+	ctx := context.Background()
+	body := []byte("a theme")
+	reference := m.bare("shell/config", body)
+
+	if held, err := store.Held(ctx, reference); err != nil || held {
+		t.Fatalf("a bare blob reads as held=%v (%v)", held, err)
+	}
+	wrote, err := store.Hold(ctx, reference)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !wrote {
+		t.Fatal("holding a bare archive wrote nothing")
+	}
+	_, holder := Holder(digestOf(body), int64(len(body)))
+	if _, ok := m.manifests["shell/config@"+holder]; !ok {
+		t.Fatalf("the store holds manifests %v; want %s", m.manifests, holder)
+	}
+	if held, err := store.Held(ctx, reference); err != nil || !held {
+		t.Fatalf("after holding, held=%v (%v)", held, err)
+	}
+
+	writes := len(m.writes)
+	wrote, err = store.Hold(ctx, reference)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if wrote || len(m.writes) != writes {
+		t.Fatalf("holding again wrote %v", m.writes[writes:])
+	}
+}
+
+func TestAnImageNeedsNoHolderAndAMissingArchiveIsGone(t *testing.T) {
+	m := &memRegistry{}
+	store := m.serve(t)
+	ctx := context.Background()
+
+	// An image is its own manifest: nothing is asked.
+	wrote, err := store.Hold(ctx, catalogue.ArtifactStoreScheme+"web/app@sha256:"+strings.Repeat("b", 64))
+	if err != nil || wrote || len(m.writes) != 0 {
+		t.Fatalf("holding an image wrote=%v err=%v writes=%v", wrote, err, m.writes)
+	}
+	// An archive the store does not have is a fact to report, not something to invent a holder for.
+	_, err = store.Hold(ctx, catalogue.ArtifactStoreScheme+"web/config/blobs/sha256:"+strings.Repeat("c", 64))
+	if !errors.Is(err, Gone) {
+		t.Fatalf("holding a missing archive answered %v, want Gone", err)
+	}
+	// And a reference that is not the mesh's is refused as such.
+	if _, err := store.Hold(ctx, "docker.io/library/registry@sha256:abc"); !errors.Is(err, ErrNotOurs) {
+		t.Fatalf("holding a vendor's image answered %v, want ErrNotOurs", err)
+	}
+}
+
+func TestLettingGoOfAnArchiveDeletesItsHolderFirst(t *testing.T) {
+	// A holder left behind would keep the bytes through every collection while the record said
+	// collected; the link deleted first and the holder failing after would be that exactly.
+	m := &memRegistry{}
+	store := m.serve(t)
+	ctx := context.Background()
+	body := []byte("an old theme")
+	reference := m.bare("shell/config", body)
+	if _, err := store.Hold(ctx, reference); err != nil {
+		t.Fatal(err)
+	}
+	m.writes = nil
+
+	if err := store.LetGo(ctx, reference); err != nil {
+		t.Fatal(err)
+	}
+	_, holder := Holder(digestOf(body), int64(len(body)))
+	want := []string{
+		"DELETE /v2/shell/config/manifests/" + holder,
+		"DELETE /v2/shell/config/blobs/" + digestOf(body),
+	}
+	if strings.Join(m.writes, "\n") != strings.Join(want, "\n") {
+		t.Fatalf("the store was asked\n%s\nwant\n%s", strings.Join(m.writes, "\n"), strings.Join(want, "\n"))
+	}
+	if len(m.manifests) != 0 {
+		t.Fatalf("a holder survived: %v", m.manifests)
+	}
+	// Asked again, the archive is already gone, which is the outcome wanted.
+	if err := store.LetGo(ctx, reference); !errors.Is(err, Gone) {
+		t.Fatalf("letting go twice answered %v, want Gone", err)
+	}
+}
+
+func TestLettingGoOfAnUnheldArchiveStillDeletesIt(t *testing.T) {
+	// An archive published before holders and let go of before any sweep held it: the holder's
+	// delete answers 404, which is the outcome wanted, and the blob still goes.
+	m := &memRegistry{}
+	store := m.serve(t)
+	reference := m.bare("shell/config", []byte("never held"))
+	if err := store.LetGo(context.Background(), reference); err != nil {
+		t.Fatal(err)
+	}
+	if len(m.blobs) != 0 {
+		t.Fatalf("the blob survived: %v", m.blobs)
+	}
+}

modules/artifact-store-tools/internal/registry/platforms_test.go

@@ -0,0 +1,176 @@
+package registry
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// An index is let go of with the platform manifests it names, except those a kept index of the same
+// repository names too (novox/hq ADR 0257). Each platform manifest is a manifest of the repository in
+// its own right, and the store's collector keeps every manifest a repository holds — so an index let go
+// of alone frees nothing of the images it names.
+
+func digestN(n int) string { return fmt.Sprintf("sha256:%064x", n) }
+
+// indexStore holds indexes and images in one repository, answers GETs with their documents, and records
+// every delete.
+type indexStore struct {
+	mu      sync.Mutex
+	indexes map[string][]string // digest → the platform manifests it names
+	images  map[string]bool
+	deleted []string
+}
+
+func (s *indexStore) serve(t *testing.T) Store {
+	t.Helper()
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		s.mu.Lock()
+		defer s.mu.Unlock()
+		digest := r.URL.Path[strings.LastIndex(r.URL.Path, "/")+1:]
+		switch r.Method {
+		case http.MethodGet:
+			if children, ok := s.indexes[digest]; ok {
+				var named []string
+				for _, c := range children {
+					named = append(named, `{"mediaType":"application/vnd.oci.image.manifest.v1+json","digest":"`+c+`","size":1}`)
+				}
+				w.Header().Set("Content-Type", "application/vnd.oci.image.index.v1+json")
+				_, _ = w.Write([]byte(`{"schemaVersion":2,"mediaType":"application/vnd.oci.image.index.v1+json","manifests":[` +
+					strings.Join(named, ",") + `]}`))
+				return
+			}
+			if s.images[digest] {
+				w.Header().Set("Content-Type", "application/vnd.oci.image.manifest.v1+json")
+				_, _ = w.Write([]byte(`{"schemaVersion":2,"mediaType":"application/vnd.oci.image.manifest.v1+json","layers":[]}`))
+				return
+			}
+			w.WriteHeader(http.StatusNotFound)
+		case http.MethodHead:
+			if _, ok := s.indexes[digest]; ok || s.images[digest] {
+				w.WriteHeader(http.StatusOK)
+				return
+			}
+			w.WriteHeader(http.StatusNotFound)
+		case http.MethodDelete:
+			if _, ok := s.indexes[digest]; !ok && !s.images[digest] {
+				w.WriteHeader(http.StatusNotFound)
+				return
+			}
+			s.deleted = append(s.deleted, digest)
+			delete(s.indexes, digest)
+			delete(s.images, digest)
+			w.WriteHeader(http.StatusAccepted)
+		default:
+			w.WriteHeader(http.StatusBadRequest)
+		}
+	}))
+	t.Cleanup(server.Close)
+	return Store{Address: strings.TrimPrefix(server.URL, "http://")}
+}
+
+func TestAnIndexGoesWithItsPlatformsAndAKeptIndexKeepsItsOwn(t *testing.T) {
+	// Two indexes of one image's repository: the old one names platforms 11 and 12, the kept one 12 and 13.
+	s := &indexStore{
+		indexes: map[string][]string{digestN(1): {digestN(11), digestN(12)}, digestN(2): {digestN(12), digestN(13)}},
+		images:  map[string]bool{digestN(11): true, digestN(12): true, digestN(13): true},
+	}
+	store := s.serve(t)
+	repository := "upstream/docker.io/library/golang"
+	old := catalogue.ArtifactStoreScheme + repository + "@" + digestN(1)
+	kept := catalogue.ArtifactStoreScheme + repository + "@" + digestN(2)
+	spare, err := store.SpareKeptIndexes(context.Background(), []string{kept}, []string{old})
+	if err != nil {
+		t.Fatal(err)
+	}
+	store.Spare = spare
+
+	if err := store.LetGo(context.Background(), old); err != nil {
+		t.Fatal(err)
+	}
+	// Its own platform first, the index last; the platform the kept index names is left in place.
+	if !slices.Equal(s.deleted, []string{digestN(11), digestN(1)}) {
+		t.Fatalf("deleted %v; want the old index's own platform, then the index", s.deleted)
+	}
+	if !s.images[digestN(12)] || !s.images[digestN(13)] {
+		t.Fatal("a platform a kept index names was let go of")
+	}
+}
+
+func TestWithoutSparingAnIndexGoesAloneAndAnImageNamesNoPlatforms(t *testing.T) {
+	s := &indexStore{indexes: map[string][]string{digestN(1): {digestN(11)}}, images: map[string]bool{digestN(11): true, digestN(5): true}}
+	store := s.serve(t)
+	// No Spare: as before ADR 0257, the index alone.
+	if err := store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/base@"+digestN(1)); err != nil {
+		t.Fatal(err)
+	}
+	if !slices.Equal(s.deleted, []string{digestN(1)}) {
+		t.Fatalf("without a Spare, deleted %v", s.deleted)
+	}
+	// An image is one delete, with a Spare or without.
+	s.deleted = nil
+	spare, err := store.SpareKeptIndexes(context.Background(), nil, []string{catalogue.ArtifactStoreScheme + "web/app@" + digestN(5)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	store.Spare = spare
+	if err := store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/app@"+digestN(5)); err != nil {
+		t.Fatal(err)
+	}
+	if !slices.Equal(s.deleted, []string{digestN(5)}) {
+		t.Fatalf("an image was let go of as %v", s.deleted)
+	}
+	// An index the store no longer holds is Gone, and nothing is deleted on its account.
+	s.deleted = nil
+	err = store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/base@"+digestN(9))
+	if !errors.Is(err, Gone) || len(s.deleted) != 0 {
+		t.Fatalf("an index the store does not hold: %v, deleted %v", err, s.deleted)
+	}
+}
+
+func TestASpareThatCannotBeReadKeepsTheIndex(t *testing.T) {
+	s := &indexStore{indexes: map[string][]string{digestN(1): {digestN(11)}}, images: map[string]bool{digestN(11): true}}
+	store := s.serve(t)
+	store.Spare = func(context.Context, string) (map[string]bool, error) { return nil, fmt.Errorf("the store went away") }
+	err := store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/base@"+digestN(1))
+	if err == nil || !strings.Contains(err.Error(), "was kept") {
+		t.Fatalf("a spare that could not be read: %v", err)
+	}
+	if len(s.deleted) != 0 {
+		t.Fatalf("deleted %v without knowing what a kept index names", s.deleted)
+	}
+}
+
+// The spare list is read whole before the sweep: a kept index that cannot be read is an error before
+// anything is deleted, and a repository not read before keeps its index.
+func TestASpareListIsReadWholeBeforeAnythingGoes(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	t.Cleanup(server.Close)
+	store := Store{Address: strings.TrimPrefix(server.URL, "http://")}
+	kept := catalogue.ArtifactStoreScheme + "web/base@" + digestN(2)
+	old := catalogue.ArtifactStoreScheme + "web/base@" + digestN(1)
+	if _, err := store.SpareKeptIndexes(context.Background(), []string{kept}, []string{old}); err == nil {
+		t.Fatal("a kept index the store would not answer for was taken as naming nothing")
+	}
+
+	s := &indexStore{indexes: map[string][]string{digestN(1): {digestN(11)}}, images: map[string]bool{digestN(11): true}}
+	good := s.serve(t)
+	spare, err := good.SpareKeptIndexes(context.Background(), nil, []string{catalogue.ArtifactStoreScheme + "other/repo@" + digestN(3)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	good.Spare = spare
+	if err := good.LetGo(context.Background(), old); err == nil || len(s.deleted) != 0 {
+		t.Fatalf("an index in a repository not read before the sweep was let go of: %v, deleted %v", err, s.deleted)
+	}
+}

modules/artifact-store-tools/internal/registry/store.go

@@ -0,0 +1,325 @@
+// Package registry speaks to the mesh's artifact store over its own door.
+//
+// Only what the mesh needs that nothing else does: letting go of something it put there
+// (novox/hq ADR 0189, issue 108), and holding every archive it keeps by a manifest so the store's
+// own collector does not take it (novox/hq issue 253). Pushing is the builder's, through the container runtime; reading
+// is every machine's, through its runtime. This is the one operation that belongs to the thing
+// holding the records, because it is the only one that is a decision rather than a transfer.
+//
+// Copied from mesh-controller internal/artifacts at e04846e9 (novox/hq ADR 0571 clause 2): the seat mesh-artifact-sweep lets
+// go of what it no longer keeps exactly as the controller's sweep did; the controller's copy goes with its lease.
+package registry
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// Store is the artifact store at an address, as this machine reaches it.
+type Store struct {
+	// Address is `host:port` — the store as the caller reaches it now, composed and never
+	// recorded (novox/hq 04-ISSUES/102).
+	Address string
+	// HTTP is the client used; nil is a client with a modest timeout.
+	HTTP *http.Client
+	// Spare says, for one repository, which manifests a kept index there names: the platform
+	// manifests an index being let go of must leave in place (novox/hq ADR 0257). Nil spares every
+	// platform manifest — an index is then let go of alone, as it was before.
+	Spare func(ctx context.Context, repository string) (map[string]bool, error)
+}
+
+// Gone is the answer when the store does not hold it: the outcome wanted, already true.
+var Gone = errors.New("the store does not hold it")
+
+// ErrNotOurs is a reference this sweep will not address: not the mesh's own, or naming nothing
+// the store holds by digest.
+//
+// **A fact about the record, not about the store** (novox/hq issue 226). The two deserve opposite
+// responses — skip one and go on, abandon the sweep for the other — and collapsing them into "an
+// error" is how a cautious loop became one that did nothing while reporting the right number.
+var ErrNotOurs = errors.New("not a reference into the mesh's artifact store")
+
+// LetGo asks the store to drop one artifact the mesh recorded making.
+//
+// Takes a reference as the mesh records it — `artifact-store://<module>/<artifact>@sha256:…` for
+// an image, `…/blobs/sha256:…` for an archive — because that is the identity every record uses,
+// and composes the address here at the moment of use.
+//
+// An archive is let go of in two deletes, its holder manifest and then the blob's link (novox/hq
+// issue 253); an image in one.
+//
+// Returns Gone when the store answers that it does not have it. That is not a failure: the sweep
+// wants the artifact absent, and it is. It is distinguished from success only so a caller can say
+// which of the two happened.
+func (s Store) LetGo(ctx context.Context, reference string) error {
+	// **Strict, and deliberately** (novox/hq issue 226). Only a reference the mesh keeps in its
+	// own vocabulary is addressed here. `Recorded` would read `docker.io/library/registry@sha256:…`
+	// as the mesh's too — it cannot tell one registry host from another — so normalising belongs
+	// where the provenance is known, which is the sweep reading its own build records, not here
+	// where the only job is to refuse anything that is not plainly ours.
+	path, kept := catalogue.InArtifactStore(reference)
+	if !kept {
+		// Nothing the mesh put in its own store. Refused rather than attempted: composing a
+		// delete for a reference of unknown shape is how a sweep reaches something that is not
+		// the mesh's. Distinguished from a store that refuses, so a sweep skips this and goes on.
+		return fmt.Errorf("%w: %s", ErrNotOurs, reference)
+	}
+	if s.Address == "" {
+		return fmt.Errorf("this mesh has no artifact store on its network to ask about %s", reference)
+	}
+	repository, kind, digest, err := split(path)
+	if err != nil {
+		return err
+	}
+	if kind == "blobs" {
+		// **An archive's holder goes before the archive** (novox/hq issue 253): a manifest left
+		// naming the blob would keep its bytes through every collection while the record said
+		// collected. Gone here means the store has no such blob, so there is nothing to let go.
+		if err := s.letGoOfHolder(ctx, repository, digest); err != nil {
+			return err
+		}
+	}
+	if kind == "manifests" && s.Spare != nil {
+		// **An index's platform manifests go before the index** (novox/hq ADR 0257). Each was put
+		// under its own digest, so each is a manifest of the repository in its own right, and the
+		// store's collector keeps every manifest a repository holds: an index let go of alone frees
+		// no byte of the images it names. Before, not after, so a sweep cut short leaves the index
+		// to be asked about again, and with it the list of what is still to go.
+		if err := s.letGoOfPlatforms(ctx, repository, digest, reference); err != nil {
+			return err
+		}
+	}
+	return s.remove(ctx, s.url(repository, kind, digest), reference)
+}
+
+// letGoOfPlatforms deletes the manifests an index names, except those a kept index of the same
+// repository also names. A manifest that is not an index names none.
+func (s Store) letGoOfPlatforms(ctx context.Context, repository, digest, reference string) error {
+	children, err := s.Platforms(ctx, repository, digest)
+	if err != nil || len(children) == 0 {
+		// Gone: there is no index to read, and the delete that follows says so.
+		if errors.Is(err, Gone) {
+			return nil
+		}
+		return err
+	}
+	spared, err := s.Spare(ctx, repository)
+	if err != nil {
+		return fmt.Errorf("cannot say which platform manifests of %s a kept index names, so %s was kept: %w",
+			repository, reference, err)
+	}
+	for _, child := range children {
+		if spared[child] {
+			continue
+		}
+		if err := s.remove(ctx, s.url(repository, "manifests", child), reference+" (its "+child+")"); err != nil && !errors.Is(err, Gone) {
+			return err
+		}
+	}
+	return nil
+}
+
+// anyManifest is every manifest the store may hold, indexes included, so it answers with the
+// document as it is.
+var anyManifest = []string{
+	"application/vnd.oci.image.index.v1+json",
+	"application/vnd.docker.distribution.manifest.list.v2+json",
+	"application/vnd.oci.image.manifest.v1+json",
+	"application/vnd.docker.distribution.manifest.v2+json",
+}
+
+// Platforms is the manifests an index names, by digest; none for a manifest that is not an index.
+// Gone when the store does not hold it.
+func (s Store) Platforms(ctx context.Context, repository, digest string) ([]string, error) {
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, s.url(repository, "manifests", digest), nil)
+	if err != nil {
+		return nil, err
+	}
+	request.Header.Set("Accept", strings.Join(anyManifest, ", "))
+	response, err := s.client().Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer response.Body.Close()
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusNotFound:
+		return nil, Gone
+	default:
+		return nil, fmt.Errorf("the artifact store answered %s when asked for %s@%s", response.Status, repository, digest)
+	}
+	var document struct {
+		Manifests []struct {
+			Digest string `json:"digest"`
+		} `json:"manifests"`
+	}
+	if err := json.NewDecoder(io.LimitReader(response.Body, 4<<20)).Decode(&document); err != nil {
+		return nil, fmt.Errorf("%s@%s is not a manifest: %w", repository, digest, err)
+	}
+	var out []string
+	for _, m := range document.Manifests {
+		if strings.HasPrefix(m.Digest, "sha256:") {
+			out = append(out, m.Digest)
+		}
+	}
+	return out, nil
+}
+
+// SpareKeptIndexes is a Spare for a sweep, read whole before it starts: for every repository an
+// image reference of `touching` is in, each kept manifest there and every platform manifest a kept
+// index there names. Any read that fails is an error, and the sweep lets nothing go. A repository not
+// read here is answered with an error, so an index in it is kept. A kept index the store no longer
+// holds names nothing.
+func (s Store) SpareKeptIndexes(ctx context.Context, kept, touching []string) (func(context.Context, string) (map[string]bool, error), error) {
+	imageIn := func(reference string) (repository, digest string, ok bool) {
+		path, ours := catalogue.InArtifactStore(reference)
+		if !ours {
+			return "", "", false
+		}
+		repository, kind, digest, err := split(path)
+		if err != nil || kind != "manifests" {
+			return "", "", false
+		}
+		return repository, digest, true
+	}
+	read := map[string]map[string]bool{}
+	for _, reference := range touching {
+		if repository, _, ok := imageIn(reference); ok {
+			read[repository] = map[string]bool{}
+		}
+	}
+	for _, reference := range kept {
+		repository, digest, ok := imageIn(reference)
+		spared, touched := read[repository]
+		if !ok || !touched {
+			continue
+		}
+		spared[digest] = true
+		children, err := s.Platforms(ctx, repository, digest)
+		if errors.Is(err, Gone) {
+			continue
+		}
+		if err != nil {
+			return nil, fmt.Errorf("reading the kept %s@%s: %w", repository, digest, err)
+		}
+		for _, c := range children {
+			spared[c] = true
+		}
+	}
+	return func(_ context.Context, repository string) (map[string]bool, error) {
+		spared, done := read[repository]
+		if !done {
+			return nil, fmt.Errorf("%s was not read before the sweep began", repository)
+		}
+		return spared, nil
+	}, nil
+}
+
+// remove asks the store to delete what is at url. Gone when it has no such thing.
+func (s Store) remove(ctx context.Context, url, what string) error {
+	request, err := http.NewRequestWithContext(ctx, http.MethodDelete, url, nil)
+	if err != nil {
+		return err
+	}
+	response, err := s.client().Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	switch response.StatusCode {
+	case http.StatusAccepted, http.StatusOK, http.StatusNoContent:
+		return nil
+	case http.StatusNotFound:
+		return Gone
+	case http.StatusMethodNotAllowed:
+		// The registry was started without deletion enabled. Said plainly, because the remedy is
+		// a setting on the store's module and not anything about this artifact.
+		return fmt.Errorf(
+			"the artifact store refuses deletion: its server was started without it enabled "+
+				"(REGISTRY_STORAGE_DELETE_ENABLED), so nothing can be collected until the store "+
+				"module is applied again (novox/hq ADR 0189). Asking about %s", what)
+	default:
+		return fmt.Errorf("the artifact store answered %s for %s", response.Status, what)
+	}
+}
+
+// split reads a recorded path into the repository, which endpoint names the thing, and the digest.
+//
+// Two shapes, which are the two the mesh records: `<repository>@sha256:<hex>` is a manifest, and
+// `<repository>/blobs/sha256:<hex>` is a blob.
+func split(path string) (repository, kind, digest string, err error) {
+	if before, after, ok := strings.Cut(path, "@sha256:"); ok {
+		return before, "manifests", "sha256:" + after, nil
+	}
+	if before, after, ok := strings.Cut(path, "/blobs/sha256:"); ok {
+		return before, "blobs", "sha256:" + after, nil
+	}
+	return "", "", "", fmt.Errorf("%w: %q names nothing the store holds by digest", ErrNotOurs, path)
+}
+
+// IsIndex is whether a recorded reference is an index the store holds: one that names manifests. A
+// blob, or a manifest that names none, is not. Gone when the store does not hold it.
+func (s Store) IsIndex(ctx context.Context, reference string) (bool, error) {
+	path, ours := catalogue.InArtifactStore(reference)
+	if !ours {
+		return false, fmt.Errorf("%w: %s", ErrNotOurs, reference)
+	}
+	repository, kind, digest, err := split(path)
+	if err != nil || kind != "manifests" {
+		return false, err
+	}
+	children, err := s.Platforms(ctx, repository, digest)
+	return len(children) > 0, err
+}
+
+// HoldsManifest is whether the store holds the manifest a recorded image reference names.
+func (s Store) HoldsManifest(ctx context.Context, reference string) (bool, error) {
+	path, ours := catalogue.InArtifactStore(reference)
+	if !ours {
+		return false, fmt.Errorf("%w: %s", ErrNotOurs, reference)
+	}
+	repository, kind, digest, err := split(path)
+	if err != nil {
+		return false, err
+	}
+	if kind != "manifests" {
+		return false, fmt.Errorf("%w: %s names a blob, not a manifest", ErrNotOurs, reference)
+	}
+	return s.has(ctx, s.url(repository, kind, digest), anyManifest...)
+}
+
+// Holds is whether the store holds what a recorded reference names: the blob of an archive, the manifest of an image.
+// Gone when it does not; asks and changes nothing (ADR 0526 clause 3: a registration by hand is refused at bytes that
+// are not there).
+func (s Store) Holds(ctx context.Context, reference string) error {
+	path, ours := catalogue.InArtifactStore(reference)
+	if !ours {
+		return fmt.Errorf("%w: %s", ErrNotOurs, reference)
+	}
+	repository, kind, digest, err := split(path)
+	if err != nil {
+		return err
+	}
+	if s.Address == "" {
+		return fmt.Errorf("this mesh has no artifact store on its network to ask about %s", reference)
+	}
+	if kind == "blobs" {
+		_, err := s.blobSize(ctx, repository, digest)
+		return err
+	}
+	held, err := s.has(ctx, s.url(repository, kind, digest), anyManifest...)
+	if err != nil {
+		return err
+	}
+	if !held {
+		return Gone
+	}
+	return nil
+}

modules/artifact-store-tools/internal/registry/store_test.go

@@ -0,0 +1,134 @@
+package registry
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// Asking the store to let go of what the mesh no longer keeps (novox/hq ADR 0189, issue 108).
+//
+// A fake store records what it was asked to delete, so what is asserted is the mesh's decision
+// and the shape of the request — not the registry's behaviour, which is the registry's to test.
+
+func fakeStore(t *testing.T, answer int) (Store, *[]string) {
+	t.Helper()
+	var asked []string
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method == http.MethodHead && strings.Contains(r.URL.Path, "/blobs/") {
+			// An archive's size, asked so its holder can be named (novox/hq issue 253). A store
+			// that does not have the thing does not have its blob either.
+			if answer == http.StatusNotFound {
+				w.WriteHeader(http.StatusNotFound)
+				return
+			}
+			w.Header().Set("Content-Length", "7")
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+		if r.Method != http.MethodDelete {
+			t.Errorf("the store was asked %s %s; collecting is a delete", r.Method, r.URL.Path)
+		}
+		asked = append(asked, r.URL.Path)
+		w.WriteHeader(answer)
+	}))
+	t.Cleanup(server.Close)
+	return Store{Address: strings.TrimPrefix(server.URL, "http://")}, &asked
+}
+
+func TestAnImageAndAnArchiveAreAskedForAtTheirOwnEndpoints(t *testing.T) {
+	// The two shapes the mesh records: a manifest by digest, and a blob by digest. They are
+	// different endpoints, and asking at the wrong one answers 404 — which this would then
+	// record as collected, leaving the bytes on disk for ever while the record says otherwise.
+	store, asked := fakeStore(t, http.StatusAccepted)
+	ctx := context.Background()
+
+	image := catalogue.ArtifactStoreScheme + "web/app@sha256:abc123"
+	archive := catalogue.ArtifactStoreScheme + "web/config/blobs/sha256:def456"
+	if err := store.LetGo(ctx, image); err != nil {
+		t.Fatal(err)
+	}
+	if err := store.LetGo(ctx, archive); err != nil {
+		t.Fatal(err)
+	}
+	// The archive's holder goes first, then the archive (novox/hq issue 253).
+	_, holder := Holder("sha256:def456", 7)
+	want := []string{
+		"/v2/web/app/manifests/sha256:abc123",
+		"/v2/web/config/manifests/" + holder,
+		"/v2/web/config/blobs/sha256:def456",
+	}
+	if strings.Join(*asked, " ") != strings.Join(want, " ") {
+		t.Fatalf("the store was asked %v; want %v", *asked, want)
+	}
+}
+
+func TestAStoreThatDoesNotHaveItAnswersGone(t *testing.T) {
+	// The outcome wanted, already true. Told apart from success only so the sweep can say which
+	// happened; both are recorded, because retrying for ever is the thing to avoid.
+	store, _ := fakeStore(t, http.StatusNotFound)
+	err := store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/app@sha256:abc123")
+	if !errors.Is(err, Gone) {
+		t.Fatalf("a store that does not hold it answered %v, want Gone", err)
+	}
+}
+
+func TestAStoreWithDeletionOffSaysSoAndNamesTheRemedy(t *testing.T) {
+	// The registry answers 405 when it was started without deletion enabled. The remedy is a
+	// setting on the store's module, and saying "405" would send somebody to the wrong place.
+	store, _ := fakeStore(t, http.StatusMethodNotAllowed)
+	err := store.LetGo(context.Background(), catalogue.ArtifactStoreScheme+"web/app@sha256:abc123")
+	if err == nil {
+		t.Fatal("a store that refuses deletion was read as success")
+	}
+	if !strings.Contains(err.Error(), "REGISTRY_STORAGE_DELETE_ENABLED") {
+		t.Fatalf("the refusal does not name the remedy: %v", err)
+	}
+}
+
+func TestAReferenceThatIsNotTheMeshsOwnIsNeverAsked(t *testing.T) {
+	// The whole safety of the sweep is that it names only what the mesh recorded putting there.
+	// A reference of another shape — a vendor's image, a package version — is refused rather
+	// than composed into a delete somewhere that is not the mesh's store.
+	store, asked := fakeStore(t, http.StatusAccepted)
+	for _, reference := range []string{
+		"docker.io/library/registry@sha256:abc123",
+		"registry@sha256:abc123",
+		"1.4.2",
+	} {
+		if err := store.LetGo(context.Background(), reference); err == nil {
+			t.Errorf("%s was asked about; it is not a reference into the mesh's store", reference)
+		}
+	}
+	if len(*asked) != 0 {
+		t.Fatalf("the store was asked about %v", *asked)
+	}
+}
+
+// A reference this sweep will not address says so as ErrNotOurs, which is a fact about the
+// record and not about the store (novox/hq issue 226).
+//
+// The sweep skips one and abandons itself for the other, so they cannot be the same error. The
+// first live run met a reference recorded with the store's old address, read the refusal as "the
+// store refuses everything", and collected none of the 1681 it had found.
+func TestAReferenceThisSweepWillNotAddressIsToldApartFromAStoreRefusing(t *testing.T) {
+	store, asked := fakeStore(t, http.StatusAccepted)
+	for _, reference := range []string{
+		"docker.io/library/registry@sha256:abc123",
+		"127.0.0.1:5100/mesh-tools/build@sha256:abc123",
+		"1.4.2",
+	} {
+		err := store.LetGo(context.Background(), reference)
+		if !errors.Is(err, ErrNotOurs) {
+			t.Errorf("%s answered %v; a sweep must be able to skip it and go on", reference, err)
+		}
+	}
+	if len(*asked) != 0 {
+		t.Fatalf("the store was asked about %v", *asked)
+	}
+}

modules/artifact-store-tools/module.json

@@ -1,26 +1,52 @@
 {
   "module": "artifact-store-tools",
   "version": "1",
+  "claims": [
+    {
+      "name": "mesh-artifact-sweep",
+      "scope": "mesh",
+      "serves": [
+        "artifacts",
+        "held",
+        "collect",
+        "mirrors",
+        "images"
+      ]
+    }
+  ],
+  "requires": [
+    "artifact-store"
+  ],
   "invokes": [
-    "seat:mesh-controller.artifacts",
-    "seat:mesh-controller.collect",
+    "seat:mesh-hand-acts.hand-act",
     "mesh-catalog.catalog_modules",
     "mesh-catalog.catalog_module"
   ],
+  "reads": [
+    "mesh-delivery-assigner.wants",
+    "mesh-delivery-builder.builds",
+    "mesh-delivery-builder.build-log",
+    "mesh-delivery-indexer.manifests",
+    "node-engine.have",
+    "mesh-controller.lease"
+  ],
+  "state": [
+    "findings"
+  ],
   "tools": [
     "artifact_store_repositories",
     "artifact_store_usage",
     "artifact_store_references",
     "artifact_store_collect"
   ],
-    "config": {
-      "older-store-names": {
-        "type": "string",
-        "description": "The names the artifact store had before, as host names or host:port separated by spaces, or none when it had no other. artifact_store_references reads every definition under these as well as under the store's current name, so an image a definition pins under one is said to be named by a definition (novox/hq issue 323).",
-        "pattern": "none|[A-Za-z0-9.:-]+( [A-Za-z0-9.:-]+)*",
-        "default": "none"
-      }
-    },
+  "config": {
+    "older-store-names": {
+      "type": "string",
+      "description": "The names the artifact store had before, as host names or host:port separated by spaces, or none when it had no other. artifact_store_references reads every definition under these as well as under the store's current name, so an image a definition pins under one is said to be named by a definition (novox/hq issue 323).",
+      "pattern": "none|[A-Za-z0-9.:-]+( [A-Za-z0-9.:-]+)*",
+      "default": "none"
+    }
+  },
   "resources": [
     {
       "id": "state",
@@ -36,6 +62,14 @@
       "mode": "0600",
       "trusted": false,
       "template": "files/store-names"
+    },
+    {
+      "id": "store-address",
+      "type": "file",
+      "path": "${dir:state}/store-address",
+      "mode": "0600",
+      "trusted": false,
+      "template": "files/store-address"
     }
   ],
   "build": {
@@ -52,7 +86,8 @@
         ],
         "env": {
           "MESH_ARTIFACT_STORE_CONTAINER": "mesh-registry",
-          "MESH_ARTIFACT_STORE_NAMES_FILE": "${dir:state}/store-names"
+          "MESH_ARTIFACT_STORE_NAMES_FILE": "${dir:state}/store-names",
+          "MESH_ARTIFACT_STORE_ADDRESS_FILE": "${dir:state}/store-address"
         }
       },
       {

modules/buildah/module.json

@@ -8,7 +8,10 @@
   "provides": [
     {
       "name": "rootless-image-build",
-      "reach": "machine"
+      "reach": "machine",
+      "credential": {
+        "form": "none"
+      }
     }
   ],
   "resources": [

modules/disk-load/.gitignore

@@ -0,0 +1 @@
+disk-load

modules/disk-load/cmd/disk-load/keeper.go

@@ -0,0 +1,248 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/health"
+	"os"
+	"os/exec"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+)
+
+// Store is the state `readings` as the keeper uses it.
+type Store interface {
+	Get(key string) (json.RawMessage, error)
+	Put(key string, value any) error
+	Keys() ([]string, error)
+}
+
+// busStore is the state through the runtime.
+type busStore struct{}
+
+func (busStore) Get(key string) (json.RawMessage, error) {
+	e, err := stdio.State(StateReadings).Get(key)
+	if err != nil || e == nil {
+		return nil, err
+	}
+	return e.Value, nil
+}
+func (busStore) Put(key string, v any) error {
+	_, err := stdio.State(StateReadings).Put(key, v)
+	return err
+}
+func (busStore) Keys() ([]string, error) { return stdio.State(StateReadings).Keys() }
+
+// Keeper measures the items of its node and keeps the readings.
+type Keeper struct {
+	Node string
+	// Items is every data item the modules placed on this node declare, composed from the bus (frombus.DataItems).
+	Items    func(ctx context.Context) (map[string][]catalogue.PlacedDataItem, error)
+	Measurer Measurer
+	Store    Store
+	Say      func(string, ...any)
+
+	mu sync.Mutex // one round at a time
+}
+
+// Round measures every item that is not a cache, one at a time, and writes the readings that changed. An item
+// measured by a walk is walked only when walks is true or its last walk is older than WalkEvery: the hourly round
+// reads counters, and a walk runs at most once a day (ADR 0233 §22).
+func (k *Keeper) Round(ctx context.Context, walks bool) (written, kept int, err error) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	items, err := k.Items(ctx)
+	if err != nil {
+		return 0, 0, err
+	}
+	modules := make([]string, 0, len(items))
+	for m := range items {
+		modules = append(modules, m)
+	}
+	sort.Strings(modules)
+	var failed []string
+	for _, module := range modules {
+		for _, it := range items[module] {
+			if it.Class == ClassCache {
+				continue
+			}
+			w, err := k.measureOne(ctx, it, walks)
+			if err != nil {
+				failed = append(failed, fmt.Sprintf("%s.%s: %v", module, it.ID, err))
+				continue
+			}
+			if w {
+				written++
+			} else {
+				kept++
+			}
+		}
+	}
+	retired, err := k.retireGone(items)
+	written += retired
+	if err != nil {
+		failed = append(failed, err.Error())
+	}
+	if len(failed) > 0 {
+		return written, kept, errors.New("readings not kept: " + strings.Join(failed, "; "))
+	}
+	return written, kept, nil
+}
+
+// retireGone marks retired every reading of this node whose item the node no longer declares — its module was unassigned
+// there, or is no longer pulled in — with when and why, and keeps it: the record of what the module left behind, until a
+// person deletes it (ADR 0233). It is cleared when the item is declared again (measureOne).
+func (k *Keeper) retireGone(declared map[string][]catalogue.PlacedDataItem) (int, error) {
+	keys, err := k.Store.Keys()
+	if err != nil {
+		return 0, err
+	}
+	declaredNow := map[string]bool{}
+	for module, its := range declared {
+		for _, it := range its {
+			declaredNow[health.ReadingKey(k.Node, module, it.ID)] = true
+		}
+	}
+	now := k.Measurer.Now().UTC()
+	n := 0
+	for _, key := range keys {
+		if !strings.HasPrefix(key, k.Node+".") || declaredNow[key] {
+			continue
+		}
+		raw, err := k.Store.Get(key)
+		if err != nil || len(raw) == 0 {
+			continue
+		}
+		r, err := health.DecodeReading(raw)
+		if err != nil || r.Node != k.Node || !r.RetiredAt.IsZero() {
+			continue
+		}
+		r.RetiredAt = now
+		r.RetiredWhy = fmt.Sprintf("no longer declared on %s: its module was unassigned there, or is no longer pulled in", k.Node)
+		if err := k.Store.Put(key, r); err != nil {
+			return n, err
+		}
+		n++
+	}
+	return n, nil
+}
+
+func (k *Keeper) measureOne(ctx context.Context, it catalogue.PlacedDataItem, walks bool) (bool, error) {
+	key := health.ReadingKey(k.Node, it.Module, it.ID)
+	var prev *health.Reading
+	raw, err := k.Store.Get(key)
+	if err != nil {
+		return false, err
+	}
+	if len(raw) > 0 {
+		if p, err := health.DecodeReading(raw); err == nil {
+			prev = &p
+		}
+	}
+	now := k.Measurer.Now()
+	if prev != nil && prev.RetiredAt.IsZero() && it.Measure == catalogue.MeasureWalk && !walks && prev.MeasuredAt != nil && now.Sub(*prev.MeasuredAt) < WalkEvery {
+		return false, nil
+	}
+	m := k.Measurer.Measure(ctx, it)
+	next, changed := health.NextReading(prev, k.Node, it, m, now)
+	if prev != nil && !prev.RetiredAt.IsZero() {
+		// Declared again: it is no longer retired.
+		next.RetiredAt, next.RetiredWhy, changed = time.Time{}, "", true
+	}
+	if !changed {
+		return false, nil
+	}
+	return true, k.Store.Put(key, next)
+}
+
+// MeasureNow measures one item now, walk or not, and writes its reading when it changed.
+func (k *Keeper) MeasureNow(ctx context.Context, module, item string) (health.Reading, bool, error) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	items, err := k.Items(ctx)
+	if err != nil {
+		return health.Reading{}, false, err
+	}
+	for _, it := range items[module] {
+		if it.ID != item {
+			continue
+		}
+		if it.Class == ClassCache {
+			return health.Reading{}, false, fmt.Errorf("%s.%s is a cache, which is listed and never measured", module, item)
+		}
+		w, err := k.measureOne(ctx, it, true)
+		if err != nil {
+			return health.Reading{}, false, err
+		}
+		raw, err := k.Store.Get(health.ReadingKey(k.Node, module, item))
+		if err != nil {
+			return health.Reading{}, w, err
+		}
+		r, err := health.DecodeReading(raw)
+		return r, w, err
+	}
+	return health.Reading{}, false, fmt.Errorf("%s declares no data item %q on this machine", module, item)
+}
+
+// Loop runs a round after a few minutes and then every `every`, with the walks of the night's round when it is the
+// hour after the night; ctx ends it.
+func (k *Keeper) Loop(ctx context.Context, every time.Duration, first time.Duration) {
+	select {
+	case <-ctx.Done():
+		return
+	case <-time.After(first):
+	}
+	for {
+		w, kept, err := k.Round(ctx, false)
+		if err != nil {
+			k.Say("measuring the data declared here: %v", err)
+		} else {
+			k.Say("measured the data declared here: %d readings changed, %d unchanged", w, kept)
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(every):
+		}
+	}
+}
+
+// RootRunner runs a command as root, through sudo without a prompt when this process is not root. A walk is bounded
+// by WalkFor itself; the runner's own bound is a little longer.
+func RootRunner(ctx context.Context, name string, args ...string) (string, error) {
+	ctx, cancel := context.WithTimeout(ctx, WalkFor+time.Minute)
+	defer cancel()
+	program, argv := name, args
+	if os.Getuid() != 0 {
+		program, argv = "sudo", append([]string{"-n", name}, args...)
+	}
+	var stdout, stderr bytes.Buffer
+	cmd := exec.CommandContext(ctx, program, argv...)
+	cmd.Stdout, cmd.Stderr = &stdout, &stderr
+	if err := cmd.Run(); err != nil {
+		said := strings.TrimSpace(stderr.String())
+		if said == "" {
+			said = strings.TrimSpace(stdout.String())
+		}
+		if program == "sudo" && strings.HasPrefix(said, "sudo:") {
+			return "", fmt.Errorf("%s needs root and the runtime's account may not run it without a prompt: %s", name, said)
+		}
+		lines := strings.Split(said, "\n")
+		if len(lines) > 3 {
+			lines = lines[len(lines)-3:]
+		}
+		if said == "" {
+			return "", fmt.Errorf("%s: %w", name, err)
+		}
+		return "", errors.New(strings.Join(lines, " / "))
+	}
+	return stdout.String(), nil
+}

modules/disk-load/cmd/disk-load/main.go

@@ -1,20 +1,61 @@
 // The disk-load module's Go bundle (novox/hq ADR 0188, ADR 0193, issue 312): a process the node's
 // runtime launches and speaks MCP over stdio to. It reads the machine's storage load from /proc and
 // /sys — iowait, pressure stall, each disk's busy share, throughput, IOPS, wait and queue depth, the
-// filesystems' space and the processes doing the I/O — and changes nothing.
+// filesystems' space and the processes doing the I/O — and changes nothing of the machine.
+//
+// It also measures the data items the modules of its node declare (ADR 0233) and keeps each reading and the item's
+// seven-day peak as its own state `readings` (ADR 0571 clause 3), composed from the bus (no file).
 package main
 
 import (
+	"context"
 	"fmt"
 	"os"
+	"strings"
+	"time"
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/announce"
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/compose/frombus"
+	"git.novox.be/novox/mesh-sdk/go/compose/fromruntime"
 )
 
+func logf(format string, args ...any) { fmt.Fprintf(os.Stderr, "[disk-load] "+format+"\n", args...) }
+
 func main() {
+	if err := stdio.Keeps(announce.State{Name: StateReadings}); err != nil {
+		logf("%v", err)
+		os.Exit(1)
+	}
+	node := os.Getenv("MESH_NODE")
+	k := &Keeper{Node: node, Store: busStore{}, Say: logf, Measurer: Measurer{Run: RootRunner, Now: time.Now},
+		Items: func(ctx context.Context) (map[string][]catalogue.PlacedDataItem, error) {
+			return placedItems(ctx, node)
+		}}
+	if node != "" {
+		every := time.Hour
+		if d, err := time.ParseDuration(os.Getenv("MESH_DISK_MEASURE_EVERY")); err == nil && d >= time.Minute {
+			every = d
+		}
+		go k.Loop(context.Background(), every, 3*time.Minute)
+	}
+	tools := append(Tools(Here()), ReadingTools(k)...)
 	// An empty name serves as the module the runtime names (MESH_SERVED_MODULE): disk-load.
-	if err := stdio.Serve("", Tools(Here())); err != nil {
+	if err := stdio.Serve("", tools); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
 }
+
+// placedItems is every data item the modules placed on node declare, composed from the bus as the node composes itself.
+func placedItems(ctx context.Context, node string) (map[string][]catalogue.PlacedDataItem, error) {
+	items, unplaced, err := frombus.DataItems(ctx, fromruntime.Reader(), frombus.Mesh{}, frombus.Scope{Node: node})
+	if err != nil {
+		return nil, err
+	}
+	if len(unplaced) > 0 {
+		logf("data items left out as not placeable: %s", strings.Join(unplaced, "; "))
+	}
+	return items, nil
+}

modules/disk-load/cmd/disk-load/measure.go

@@ -0,0 +1,215 @@
+package main
+
+// How an item is measured (novox/hq ADR 0233 §22 to §25), moved here from the backup holder, which only reads the
+// readings now (ADR 0571 clause 3). Never an unbounded walk of something large.
+
+import (
+	"context"
+	"fmt"
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/health"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// The bounds on a walk: a walk is for small items, and one that meets a large one stops and says so.
+var (
+	WalkFor   = 10 * time.Minute
+	WalkFiles = 2_000_000
+	WalkEvery = 23 * time.Hour
+)
+
+// walkCommand sums the files under a path and finds its newest change, in one walk, bounded by time and by files.
+// One line out: "<bytes> <epoch seconds> <files>", then the status of find.
+func walkCommand(path string) string {
+	return fmt.Sprintf("timeout %d find '%s' -xdev -printf '%%y %%s %%T@\\n' 2>/dev/null | head -n %d | "+
+		"awk 'BEGIN{s=0;m=0;n=0} {n++; if ($1==\"f\") s+=$2; if ($3>m) m=$3} END {printf \"%%d %%.0f %%d\\n\", s, m, n}'; "+
+		"echo \"${PIPESTATUS[0]:-0}\"", int(WalkFor.Seconds()), path, WalkFiles)
+}
+
+// topCommand is the newest change among a path and its top-level entries, and how many there are.
+func topCommand(path string) string {
+	return "timeout 60 find '" + path + "' -maxdepth 1 -printf '%T@\\n' 2>/dev/null | " +
+		"awk 'BEGIN{m=0;n=0} {n++; if ($1>m) m=$1} END {printf \"%.0f %d\\n\", m, n-1}'"
+}
+
+func epochTime(s string) *time.Time {
+	epoch, err := strconv.ParseInt(s, 10, 64)
+	if err != nil || epoch <= 0 {
+		return nil
+	}
+	t := time.Unix(epoch, 0).UTC()
+	return &t
+}
+
+// Measurer measures items through a runner that has the root the walks need.
+type Measurer struct {
+	Run Runner
+	Now func() time.Time
+}
+
+func (b Measurer) exists(ctx context.Context, path string) bool {
+	_, err := b.Run(ctx, "test", "-e", path)
+	return err == nil
+}
+
+// Measure is one item, measured now, by its own method.
+func (b Measurer) Measure(ctx context.Context, it catalogue.PlacedDataItem) health.Measured {
+	at := b.Now().UTC()
+	m := health.Measured{MeasuredAt: &at}
+	if !b.exists(ctx, it.Path) {
+		m.Error = it.Path + " does not exist"
+		zero := int64(0)
+		m.SizeBytes, m.Precision = &zero, "exact"
+		return m
+	}
+	m.Redundancy = b.redundancyOf(ctx, it.Path)
+	switch it.Measure {
+	case catalogue.MeasureDataset, catalogue.MeasureShallow:
+		out, err := b.Run(ctx, "bash", "-c", topCommand(it.Path))
+		if f := strings.Fields(out); err == nil && len(f) == 2 {
+			m.LastWrite = epochTime(f[0])
+		} else if err != nil {
+			m.Error = err.Error()
+		}
+		m.Precision = "no size: the newest change among its top-level entries only"
+		if it.Measure == catalogue.MeasureShallow {
+			return m
+		}
+		out, err = b.Run(ctx, "zfs", "list", "-Hp", "-o", "name,used", it.Path)
+		f := strings.Fields(out)
+		if err != nil || len(f) != 2 {
+			m.Precision = "no size: it is on no ZFS dataset to read one from; the newest change among its top-level entries only"
+			return m
+		}
+		used, err := strconv.ParseInt(f[1], 10, 64)
+		if err != nil {
+			return m
+		}
+		m.SizeBytes = &used
+		m.Precision = "dataset " + f[0] + ": its whole size, from the filesystem's counters; the newest change among the top-level entries"
+		return m
+	}
+	out, err := b.Run(ctx, "bash", "-c", walkCommand(it.Path))
+	if err != nil {
+		m.Error = err.Error()
+		return m
+	}
+	lines := strings.Split(strings.TrimSpace(out), "\n")
+	f := strings.Fields(lines[0])
+	if len(f) != 3 || len(lines) < 2 {
+		m.Error = "the measurement said " + strings.TrimSpace(out)
+		return m
+	}
+	size, err1 := strconv.ParseInt(f[0], 10, 64)
+	files, err2 := strconv.Atoi(f[2])
+	if err1 != nil || err2 != nil {
+		m.Error = "the measurement said " + strings.TrimSpace(out)
+		return m
+	}
+	m.SizeBytes, m.LastWrite = &size, epochTime(f[1])
+	m.Precision = "exact"
+	if status := strings.TrimSpace(lines[len(lines)-1]); status == "124" || files >= WalkFiles {
+		m.Precision = fmt.Sprintf("partial: measured partially — stopped after %s or %d files; the size is a lower bound, "+
+			"and this item wants measure: dataset or shallow", WalkFor, WalkFiles)
+	}
+	return m
+}
+
+// redundancyOf is the redundant storage a path is on: a ZFS pool's health, an md array's members, a btrfs
+// filesystem's error counters. Nil for storage with no redundancy it knows how to read.
+func (b Measurer) redundancyOf(ctx context.Context, path string) *health.Redundancy {
+	out, err := b.Run(ctx, "findmnt", "-no", "SOURCE,FSTYPE", "--target", path)
+	if err != nil {
+		return nil
+	}
+	f := strings.Fields(out)
+	if len(f) < 2 {
+		return nil
+	}
+	source, fstype := f[0], f[1]
+	yes, no := true, false
+	switch {
+	case fstype == "zfs":
+		pool, _, _ := strings.Cut(source, "/")
+		r := &health.Redundancy{Kind: "zfs", Where: pool}
+		health, err := b.Run(ctx, "zpool", "list", "-H", "-o", "health", pool)
+		if err != nil {
+			r.Said = "zpool list: " + err.Error()
+			return r
+		}
+		status, err := b.Run(ctx, "zpool", "status", "-x", pool)
+		if err != nil {
+			r.Said = "zpool status: " + err.Error()
+			return r
+		}
+		health, status = strings.TrimSpace(health), strings.TrimSpace(status)
+		r.Said = "health " + health + "; " + firstLineOf(status)
+		if health == "ONLINE" && strings.Contains(status, "is healthy") {
+			r.Healthy = &yes
+		} else {
+			r.Healthy = &no
+			r.Said = "health " + health + "; " + oneLineOf(status)
+		}
+		return r
+	case strings.HasPrefix(source, "/dev/md"):
+		device := strings.TrimPrefix(source, "/dev/")
+		r := &health.Redundancy{Kind: "md", Where: device}
+		mdstat, err := b.Run(ctx, "cat", "/proc/mdstat")
+		if err != nil {
+			r.Said = err.Error()
+			return r
+		}
+		healthy, said, found := mdHealth(mdstat, device)
+		if !found {
+			r.Said = device + " is not in /proc/mdstat"
+			return r
+		}
+		r.Said = said
+		if healthy {
+			r.Healthy = &yes
+		} else {
+			r.Healthy = &no
+		}
+		return r
+	case fstype == "btrfs":
+		r := &health.Redundancy{Kind: "btrfs", Where: source}
+		stats, err := b.Run(ctx, "btrfs", "device", "stats", "--check", path)
+		if err != nil {
+			r.Healthy, r.Said = &no, "device errors: "+oneLineOf(err.Error())
+			return r
+		}
+		r.Healthy, r.Said = &yes, firstLineOf(stats)
+		return r
+	}
+	return nil
+}
+
+var mdMembers = regexp.MustCompile(`\[([U_]+)\]`)
+
+// mdHealth reads one array's block of /proc/mdstat: healthy when every member is up and it is not recovering.
+func mdHealth(mdstat, device string) (bool, string, bool) {
+	lines := strings.Split(mdstat, "\n")
+	for i, l := range lines {
+		if !strings.HasPrefix(l, device+" ") {
+			continue
+		}
+		block := l
+		for j := i + 1; j < len(lines) && strings.HasPrefix(lines[j], " "); j++ {
+			block += " " + strings.TrimSpace(lines[j])
+		}
+		members := mdMembers.FindStringSubmatch(block)
+		healthy := members != nil && !strings.Contains(members[1], "_") && !strings.Contains(block, "recovery")
+		return healthy, oneLineOf(block), true
+	}
+	return false, "", false
+}
+
+func firstLineOf(s string) string {
+	line, _, _ := strings.Cut(strings.TrimSpace(s), "\n")
+	return line
+}
+
+func oneLineOf(s string) string { return strings.Join(strings.Fields(s), " ") }

modules/disk-load/cmd/disk-load/readings.go

@@ -0,0 +1,12 @@
+package main
+
+// The readings layout, their key and the peak are mesh-sdk's (health.Reading, health.NextReading; novox/hq ADR 0571
+// clause 3): disk-load measures each placed data item of its node and keeps the readings as its own state.
+
+import "git.novox.be/novox/mesh-sdk/go/health"
+
+// StateReadings is the state disk-load keeps.
+const StateReadings = health.ReadingsState
+
+// ClassCache is the class of an item that is listed and never measured.
+const ClassCache = "cache"

modules/disk-load/cmd/disk-load/readings_test.go

@@ -0,0 +1,144 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/health"
+)
+
+type memStore struct{ m map[string]json.RawMessage }
+
+func (s *memStore) Get(k string) (json.RawMessage, error) { return s.m[k], nil }
+func (s *memStore) Put(k string, v any) error {
+	raw, _ := json.Marshal(v)
+	s.m[k] = raw
+	return nil
+}
+func (s *memStore) Keys() ([]string, error) {
+	var out []string
+	for k := range s.m {
+		out = append(out, k)
+	}
+	return out, nil
+}
+
+// A round measures what the data file declares but caches, keeps the readings, writes nothing the second time, and a
+// walk is not repeated within a day unless asked.
+func TestARoundMeasuresTheDeclaredItemsAndWritesWhatChanged(t *testing.T) {
+	text := "# pg\nitem data valuable /srv/pg /srv/pg backup walk\nitem tmp cache /srv/tmp - none\n# bad-line-module\nitem logs rebuildable /srv/logs - none shallow\n"
+	placed, err := catalogue.ParseDataItems(text)
+	if err != nil {
+		t.Fatal(err)
+	}
+	walks := 0
+	run := func(_ context.Context, name string, args ...string) (string, error) {
+		switch {
+		case name == "test":
+			return "", nil
+		case name == "findmnt":
+			return "", os.ErrNotExist
+		case name == "bash" && strings.Contains(args[1], "-maxdepth 1"):
+			return "1760000000 2\n", nil
+		case name == "bash":
+			walks++
+			return "4096 1760000000 3\n0\n", nil
+		}
+		return "", os.ErrNotExist
+	}
+	now := time.Date(2026, 10, 29, 12, 0, 0, 0, time.UTC)
+	store := &memStore{m: map[string]json.RawMessage{}}
+	k := &Keeper{Node: "ace", Items: func(context.Context) (map[string][]catalogue.PlacedDataItem, error) { return placed, nil }, Store: store, Say: func(string, ...any) {},
+		Measurer: Measurer{Run: run, Now: func() time.Time { return now }}}
+	w, kept, err := k.Round(context.Background(), false)
+	if err != nil || w != 2 || kept != 0 || len(store.m) != 2 {
+		t.Fatalf("first round: %d written %d kept %v, keys %d", w, kept, err, len(store.m))
+	}
+	now = now.Add(time.Hour)
+	if w, kept, _ := k.Round(context.Background(), false); w != 0 || kept != 2 || walks != 1 {
+		t.Fatalf("second round: %d written, %d kept, %d walks; wanted none written and the walk not repeated", w, kept, walks)
+	}
+	if _, _, err := k.MeasureNow(context.Background(), "pg", "data"); err != nil || walks != 2 {
+		t.Fatalf("measure now: %v, %d walks", err, walks)
+	}
+	// An item no longer declared is kept, retired with when and why; declared again, it is not retired any more.
+	delete(placed, "pg")
+	if _, _, err := k.Round(context.Background(), false); err != nil {
+		t.Fatal(err)
+	}
+	gone, _ := health.DecodeReading(store.m["ace.pg.data"])
+	if gone.RetiredAt.IsZero() || !strings.Contains(gone.RetiredWhy, "no longer declared on ace") || gone.FirstSeen.IsZero() {
+		t.Fatalf("a reading of an item no longer declared: %+v", gone)
+	}
+	placed["pg"] = []catalogue.PlacedDataItem{{Module: "pg", ID: "data", Class: "valuable", Path: "/srv/pg", Measure: catalogue.MeasureWalk}}
+	if _, _, err := k.Round(context.Background(), false); err != nil {
+		t.Fatal(err)
+	}
+	if back, _ := health.DecodeReading(store.m["ace.pg.data"]); !back.RetiredAt.IsZero() {
+		t.Fatalf("a reading declared again is still retired: %+v", back)
+	}
+	if _, _, err := k.MeasureNow(context.Background(), "pg", "tmp"); err == nil {
+		t.Fatal("a cache was measured")
+	}
+}
+
+// The redundant storage under an item is read: a ZFS pool healthy, then degraded; an md array with a member missing; and
+// plain storage, which is no redundancy at all. A dataset is measured from the filesystem's counters and a shallow item
+// from its top-level entries only; a walk that meets more than its bound stops and says so.
+func TestTheStorageUnderAnItemAndTheLargeMethodsAreRead(t *testing.T) {
+	poolHealth, statusX, fs := "ONLINE\n", "pool 'storage' is healthy\n", "storage/media zfs\n"
+	run := func(_ context.Context, name string, args ...string) (string, error) {
+		line := name + " " + strings.Join(args, " ")
+		switch {
+		case name == "test":
+			return "", nil
+		case name == "findmnt":
+			return fs, nil
+		case name == "zpool" && args[0] == "list":
+			return poolHealth, nil
+		case name == "zpool":
+			return statusX, nil
+		case name == "cat":
+			return "Personalities : [raid1]\nmd127 : active raid1 sdb1[1] sda1[0]\n      976630464 blocks super 1.2 [2/1] [U_]\n\nunused devices: <none>\n", nil
+		case name == "zfs" && args[len(args)-1] == "/storage/media/movies":
+			return "storage/media\t97067690722560\n", nil
+		case name == "zfs":
+			return "", os.ErrNotExist
+		case name == "bash" && strings.Contains(line, "-maxdepth 1"):
+			return "1759744800 12673\n", nil
+		case name == "bash":
+			return "123 1759700000 2000000\n141\n", nil
+		}
+		return "", nil
+	}
+	m := Measurer{Run: run, Now: time.Now}
+	ctx := context.Background()
+	got := m.Measure(ctx, catalogue.PlacedDataItem{Module: "media", ID: "movies", Path: "/storage/media/movies", Measure: catalogue.MeasureDataset})
+	if got.SizeBytes == nil || *got.SizeBytes != 97067690722560 || !strings.HasPrefix(got.Precision, "dataset storage/media") ||
+		got.LastWrite == nil || got.Redundancy == nil || got.Redundancy.Kind != "zfs" || got.Redundancy.Healthy == nil || !*got.Redundancy.Healthy {
+		t.Fatalf("the library from its dataset: %+v", got)
+	}
+	poolHealth, statusX = "DEGRADED\n", "  pool: storage\n state: DEGRADED\nstatus: One or more devices has been removed\n"
+	if r := m.redundancyOf(ctx, "/storage/media/movies"); r.Healthy == nil || *r.Healthy || !strings.Contains(r.Said, "DEGRADED") {
+		t.Fatalf("a degraded pool: %+v", r)
+	}
+	fs = "/dev/md127 ext4\n"
+	if r := m.redundancyOf(ctx, "/srv/x"); r == nil || r.Kind != "md" || r.Healthy == nil || *r.Healthy {
+		t.Fatalf("an array missing a member: %+v", r)
+	}
+	fs = "/dev/nvme0n1p3 ext4\n"
+	if r := m.redundancyOf(ctx, "/var/lib/x"); r != nil {
+		t.Fatalf("plain storage read as redundant: %+v", r)
+	}
+	if s := m.Measure(ctx, catalogue.PlacedDataItem{Path: "/mnt/plex/config", Measure: catalogue.MeasureShallow}); s.SizeBytes != nil || !strings.HasPrefix(s.Precision, "no size") {
+		t.Fatalf("a shallow item: %+v", s)
+	}
+	if w := m.Measure(ctx, catalogue.PlacedDataItem{Path: "/srv/big", Measure: catalogue.MeasureWalk}); !strings.HasPrefix(w.Precision, "partial") {
+		t.Fatalf("a walk stopped at its bound: %+v", w)
+	}
+}

modules/disk-load/cmd/disk-load/readings_tools.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/health"
+)
+
+// ReadingTools are the tools over the state `readings`: every key, one key, how full the state is, and one item
+// measured now (a module's tools are its command line).
+func ReadingTools(k *Keeper) []stdio.Tool {
+	return []stdio.Tool{
+		{
+			Name: "disk_readings",
+			Description: "The data readings disk-load keeps for this machine's data items (ADR 0233, ADR 0571 clause 3): every key " +
+				"`<node>.<module>.<item>` with its size, newest write, measured-at, precision and seven-day peak, or one key with " +
+				"all it holds when `key` is given; and how full the state is: keys kept, their bytes, and the cap the bus puts on " +
+				"a state (none declared). Filter by `module`. (r)",
+			Input: map[string]any{
+				"key":    map[string]any{"type": "string", "description": "one key, <node>.<module>.<item>, with everything it holds"},
+				"module": map[string]any{"type": "string", "description": "only this module's items"},
+			},
+			Run: func(args map[string]any) (any, error) {
+				if key := text(args, "key"); key != "" {
+					raw, err := k.Store.Get(key)
+					if err != nil {
+						return nil, err
+					}
+					if len(raw) == 0 {
+						return nil, fmt.Errorf("no reading is kept at %q", key)
+					}
+					r, err := health.DecodeReading(raw)
+					return r, err
+				}
+				keys, err := k.Store.Keys()
+				if err != nil {
+					return nil, err
+				}
+				sort.Strings(keys)
+				module := text(args, "module")
+				type line struct {
+					Key       string         `json:"key"`
+					SizeBytes *int64         `json:"size_bytes,omitempty"`
+					PeakBytes *int64         `json:"peak_bytes,omitempty"`
+					Precision string         `json:"precision,omitempty"`
+					Error     string         `json:"error,omitempty"`
+					Reading   health.Reading `json:"-"`
+				}
+				var lines []line
+				total := 0
+				for _, key := range keys {
+					raw, err := k.Store.Get(key)
+					if err != nil {
+						return nil, err
+					}
+					total += len(raw)
+					r, err := health.DecodeReading(raw)
+					if err != nil || (module != "" && r.Module != module) {
+						continue
+					}
+					lines = append(lines, line{Key: key, SizeBytes: r.SizeBytes, PeakBytes: r.Peak, Precision: r.Precision, Error: r.Error})
+				}
+				return map[string]any{"readings": lines, "fill": map[string]any{"keys": len(keys), "bytes": total,
+					"cap": "none declared: the bus's own limit on a state applies"}}, nil
+			},
+		},
+		{
+			Name: "disk_measure",
+			Description: "Measure one data item of this machine now, whatever its method (a walk too), and write its reading when it " +
+				"changed. Reads the disks as root: a walk is bounded by time and files and says when it was partial.",
+			Input: map[string]any{
+				"module": map[string]any{"type": "string", "description": "the module that declares the item"},
+				"item":   map[string]any{"type": "string", "description": "the item's id"},
+			},
+			Run: func(args map[string]any) (any, error) {
+				module, item := text(args, "module"), text(args, "item")
+				if module == "" || item == "" {
+					return nil, fmt.Errorf("module and item are required")
+				}
+				r, written, err := k.MeasureNow(context.Background(), module, item)
+				if err != nil {
+					return nil, err
+				}
+				return map[string]any{"written": written, "reading": r, "key": health.ReadingKey(k.Node, module, item),
+					"note": strings.TrimSpace(map[bool]string{true: "the reading changed and was written", false: "the reading had not changed"}[written])}, nil
+			},
+		},
+	}
+}

modules/disk-load/cmd/disk-load/tools_test.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"os"
+	"regexp"
 	"sort"
 	"strings"
 	"testing"
@@ -35,9 +36,11 @@ func TestTheManifestNamesExactlyTheToolsTheBundleServesAndNoMachine(t *testing.T
 		t.Fatal(err)
 	}
 	var served []string
-	for _, tl := range Tools(newFake(t).machine()) {
+	k := &Keeper{Store: &memStore{m: map[string]json.RawMessage{}}}
+	for _, tl := range append(Tools(newFake(t).machine()), ReadingTools(k)...) {
 		served = append(served, tl.Name)
-		if !strings.HasSuffix(tl.Description, "(r)") {
+		// disk_measure writes the module's own state of readings and nothing else of the machine.
+		if !strings.HasSuffix(tl.Description, "(r)") && tl.Name != "disk_measure" {
 			t.Errorf("%s only reads and does not say so", tl.Name)
 		}
 	}
@@ -50,7 +53,7 @@ func TestTheManifestNamesExactlyTheToolsTheBundleServesAndNoMachine(t *testing.T
 		t.Errorf("the module only reads, and declares %d resources", len(m.Resources))
 	}
 	for _, banned := range []string{"g14", "novox", "ace", "shanks", "jochen", "/home/"} {
-		if strings.Contains(string(raw), banned) {
+		if regexp.MustCompile(`(^|[^a-z0-9-])` + regexp.QuoteMeta(banned) + `($|[^a-z0-9-])`).Match(raw) {
 			t.Errorf("the manifest says %q", banned)
 		}
 	}

modules/disk-load/go.mod

@@ -1,5 +1,5 @@
 module diskload
 
-go 1.22
+go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.6
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

modules/disk-load/go.sum

@@ -1,2 +1,14 @@
-git.novox.be/novox/mesh-sdk/go v0.1.6 h1:9qzdYONYbJdWcu6sxQcq9v1LI0JxcfkiKYkMUzJSkVQ=
-git.novox.be/novox/mesh-sdk/go v0.1.6/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+github.com/klauspost/compress v1.20.0 h1:a3C1ke2ohxFymNlb2HWAHjDeKCI90scRskErZkR0ezA=
+github.com/klauspost/compress v1.20.0/go.mod h1:LUdAzn7YLVvxLpc7y3V1m40wESHTgc1422pwwBSKYuI=
+github.com/nats-io/nats.go v1.54.0 h1:vsXoOxjHp/GmPUN+EcI7uOf/uB+iAP+kEsAFNQN0yzA=
+github.com/nats-io/nats.go v1.54.0/go.mod h1:y+DZoD1oBOYfZTU681eTUiUjI0vbqYGixNVFHcjHJ0k=
+github.com/nats-io/nkeys v0.4.16 h1:rd5oAuLOb8mnAycB0xleuEBNS1pVVnN0fv/FF34Eypg=
+github.com/nats-io/nkeys v0.4.16/go.mod h1:llLgWoI0o4z/Q57q2R1kHfmocyhGV6VG/U18Glg1Afs=
+github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
+github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
+golang.org/x/crypto v0.57.0 h1:3ZVCjf8Ggz7zneR/EHRVx68Ctf+2pmIMP2UFhh9cC6M=
+golang.org/x/crypto v0.57.0/go.mod h1:Fdz0i5U6CoizGwLda9DttjSk6qlZo25zYNtR+ycvuZA=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=

modules/disk-load/module.json

@@ -7,7 +7,9 @@
     "disk_filesystems",
     "disk_folders",
     "disk_devices",
-    "cpu_top"
+    "cpu_top",
+    "disk_readings",
+    "disk_measure"
   ],
   "build": {
     "artifacts": [
@@ -23,5 +25,16 @@
         ]
       }
     ]
-  }
+  },
+  "state": [
+    "readings"
+  ],
+  "reads": [
+    "mesh-config.resolved",
+    "mesh-delivery-assigner.placement",
+    "mesh-delivery-builder.builds",
+    "mesh-delivery-indexer.manifests",
+    "mesh-delivery-indexer.modules",
+    "node-engine.have"
+  ]
 }

modules/distribution/module.json

@@ -4,7 +4,10 @@
   "provides": [
     {
       "name": "artifact-store",
-      "scope": "mesh"
+      "scope": "mesh",
+      "credential": {
+        "form": "none"
+      }
     }
   ],
   "claims": [

modules/dnsmasq/go.mod

@@ -1,5 +1,5 @@
 module dnsmasq
 
-go 1.25.0
+go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.7
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

modules/dnsmasq/go.sum

@@ -1,2 +1,2 @@
-git.novox.be/novox/mesh-sdk/go v0.1.7 h1:C0sTQmtTiyYH7bnqZb7PusXnqA37gKuT7Nqjn9gG47w=
-git.novox.be/novox/mesh-sdk/go v0.1.7/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=

modules/dnsmasq/module.json

@@ -9,7 +9,10 @@
     {
       "name": "wildcard-resolution",
       "scope": "mesh",
-      "identity": false
+      "identity": false,
+      "credential": {
+        "form": "none"
+      }
     }
   ],
   "requires": [

modules/docker/cmd/docker-tools/prune_images.go

@@ -9,7 +9,7 @@ package main
 //
 //   - every image a container on this machine uses, in any state;
 //   - every image this machine's declaration names — what the mesh would send it now and what it was
-//     last sent — as the controller's `images` verb answers. **No answer, no removal**: what the
+//     last sent — as the mesh-artifact-sweep seat's `images` verb answers. **No answer, no removal**: what the
 //     declaration names is the one thing that cannot be guessed;
 //   - every image younger than the floor (seven days, the weekly prune's week);
 //   - in each line of images holding one of those, the newest image besides them: the previous
@@ -43,7 +43,7 @@ type PruneImagesAsk struct {
 	Limit         int
 }
 
-// declaredImages is the controller's `images` answer (novox/hq ADR 0251 §5).
+// declaredImages is the mesh-artifact-sweep seat's `images` answer (novox/hq ADR 0251 §5).
 type declaredImages struct {
 	Node   string `json:"node"`
 	Images []struct {
@@ -129,7 +129,7 @@ func digestOf(ref string) string {
 	return ""
 }
 
-// askDeclared asks the controller what this machine's declarations name. An error means unknown.
+// askDeclared asks the mesh-artifact-sweep seat what this machine's declarations name. An error means unknown.
 func (c *Client) askDeclared() (*declaredImages, error) {
 	if c.Node == "" {
 		return nil, errors.New("the runtime did not say which machine this is (MESH_NODE is empty)")
@@ -137,20 +137,20 @@ func (c *Client) askDeclared() (*declaredImages, error) {
 	if c.Ask == nil {
 		return nil, errors.New("this bundle cannot ask the mesh")
 	}
-	raw, err := c.Ask("seat:mesh-controller.images", map[string]any{"node": c.Node})
+	raw, err := c.Ask("seat:mesh-artifact-sweep.images", map[string]any{"node": c.Node})
 	if err != nil {
-		return nil, fmt.Errorf("the controller's images verb did not answer: %w", err)
+		return nil, fmt.Errorf("the mesh-artifact-sweep seat's images verb did not answer: %w", err)
 	}
 	answer, output, ok := answerOf(raw)
 	if !ok {
-		return nil, fmt.Errorf("the controller refused images: %s", firstLine(output))
+		return nil, fmt.Errorf("the mesh-artifact-sweep seat refused images: %s", firstLine(output))
 	}
 	var d declaredImages
 	if err := json.Unmarshal(answer, &d); err != nil {
-		return nil, fmt.Errorf("the controller's images answer is not readable: %v", err)
+		return nil, fmt.Errorf("the mesh-artifact-sweep seat's images answer is not readable: %v", err)
 	}
 	if d.Node != "" && d.Node != c.Node {
-		return nil, fmt.Errorf("the controller answered for %q, not for this machine %q", d.Node, c.Node)
+		return nil, fmt.Errorf("the mesh-artifact-sweep seat answered for %q, not for this machine %q", d.Node, c.Node)
 	}
 	return &d, nil
 }

modules/docker/cmd/docker-tools/prune_images_test.go

@@ -43,7 +43,7 @@ func imagesMachine() *fake {
 
 func declaring(t *testing.T, answer string) Asker {
 	return func(key string, body any) (json.RawMessage, error) {
-		if key != "seat:mesh-controller.images" {
+		if key != "seat:mesh-artifact-sweep.images" {
 			t.Errorf("asked %s", key)
 		}
 		if b, _ := body.(map[string]any); b["node"] != "laptop" {

modules/docker/go.mod

@@ -1,5 +1,5 @@
 module docker
 
-go 1.22
+go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.6
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

modules/docker/go.sum

@@ -1,2 +1,2 @@
-git.novox.be/novox/mesh-sdk/go v0.1.6 h1:9qzdYONYbJdWcu6sxQcq9v1LI0JxcfkiKYkMUzJSkVQ=
-git.novox.be/novox/mesh-sdk/go v0.1.6/go.mod h1:GFuZUElBZ9A++mxgIKo97aXXo+kV0uJ/UkbhQPPIbrY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=

modules/docker/module.json

@@ -7,7 +7,7 @@
     "privileged"
   ],
   "invokes": [
-    "seat:mesh-controller.images"
+    "seat:mesh-artifact-sweep.images"
   ],
   "claims": [
     {

modules/gitea/cmd/forge-account-provider/builder_test.go

@@ -192,17 +192,14 @@ func (r *teamRig) pass() []provider.Outcome {
 	return out
 }
 
-// bind makes module on node bind gitea's forge-account in the assignments mirror.
+// bind makes module on node bind gitea's forge-account in the seat mesh-provisioner's plans.
 func (r *teamRig) bind(node, module string) {
-	r.bus.set(provider.AssignmentsBucket, node+"."+module, []byte(fmt.Sprintf(
-		`{"node":%q,"module":%q,"provisioning":{"provisions":[{"provision":"forge-account","provider":"novox","provider-module":"gitea","as":"mesh_%s"}]}}`,
-		node, module, strings.ReplaceAll(node+"_"+module, "-", "_"))))
+	r.bus.bindPlan(node, module, "mesh_"+strings.ReplaceAll(node+"_"+module, "-", "_"))
 }
 
+// unbind is the operator's yes to retiring module's forge-account on node (ADR 0570 clause 5).
 func (r *teamRig) unbind(node, module string) {
-	r.bus.mu.Lock()
-	delete(r.bus.buckets[provider.AssignmentsBucket], node+"."+module)
-	r.bus.mu.Unlock()
+	r.bus.retire(node, module)
 }
 
 // key reports a key in module's state keys, of the kind and for the account given.

modules/gitea/cmd/forge-account-provider/bus_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/nats-io/nats.go/jetstream"
 
 	"git.novox.be/novox/mesh-sdk/go/provider"
+	"git.novox.be/novox/mesh-sdk/go/provisions"
 )
 
 const bundleVar = "MESH_FORGE_ACCOUNT_TEST_BUNDLE"
@@ -80,7 +81,7 @@ func startBus(t *testing.T) (*runtime, context.CancelFunc) {
 	rt := &runtime{t: t, js: js, kvs: map[string]jetstream.KeyValue{}, ctx: ctx, wait: map[string]chan json.RawMessage{}}
 	// The controller's job: a bucket per state the module declares (bound) or reads (the others).
 	for state, bucket := range map[string]string{"bound": "gitea_bound", "ssh-client.keys": "ssh-client_keys",
-		"mesh-controller.assignments": "mesh-controller_assignments"} {
+		"mesh-provisioner.plans": "mesh-provisioner_plans", "mesh-provisioner.provisions": "mesh-provisioner_provisions"} {
 		kv, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: bucket, History: 1})
 		if err != nil {
 			t.Fatal(err)
@@ -296,9 +297,11 @@ func TestTheProviderWholeAnswersAMachineThatReportedItsKey(t *testing.T) {
 	}
 	rt, cancel := startBus(t)
 	t.Cleanup(cancel)
-	rt.put("mesh-controller.assignments", "g14.ssh-client", map[string]any{"node": "g14", "module": "ssh-client",
-		"provisioning": map[string]any{"provisions": []map[string]any{{"provision": "forge-account", "provider": "novox",
+	rt.put("mesh-provisioner.plans", "g14.ssh-client", map[string]any{"v": 1, "node": "g14", "module": "ssh-client",
+		"plan": map[string]any{"provisions": []map[string]any{{"provision": "forge-account", "provider": "novox",
 			"provider-module": "gitea", "as": "mesh_g14_ssh_client"}}}})
+	rt.put("mesh-provisioner.provisions", "g14.ssh-client.forge-account",
+		json.RawMessage(provisionKey("g14", "ssh-client", provisions.Asked, nil)))
 	rt.put("ssh-client.keys", "g14.nox", map[string]string{"node": "g14", "account": "nox", "kind": "machine",
 		"public": pubA + " nox@g14 (mesh)", "fingerprint": "SHA256:x", "at": "2026-10-16T10:00:00Z"})
 	rt.start([]string{"MESH_NODE=novox", "MESH_MODULE=gitea", "MESH_SERVED_MODULE=gitea",

modules/gitea/cmd/forge-account-provider/main_test.go

@@ -25,7 +25,7 @@ func TestConfigFromEnvNamesWhatIsMissing(t *testing.T) {
 }
 
 // Issue 955: the runtime grants a module only the states its manifest `reads`, and the provider watches the machines'
-// keys and, through the SDK's provider, the controller's assignments (where it learns its consumers). Run as the
+// keys and, through the SDK's provider, the seat mesh-provisioner's plans and provisions (where it learns its consumers, ADR 0570). Run as the
 // bus test does, with every bucket made, a missing grant passes unseen; the manifest is read here instead.
 func TestTheManifestReadsEveryStateTheProviderWatches(t *testing.T) {
 	raw, err := os.ReadFile("../../module.json")
@@ -38,7 +38,7 @@ func TestTheManifestReadsEveryStateTheProviderWatches(t *testing.T) {
 	if err := json.Unmarshal(raw, &m); err != nil {
 		t.Fatal(err)
 	}
-	for _, state := range []string{"mesh-controller.assignments", "ssh-client.keys"} {
+	for _, state := range []string{"mesh-provisioner.plans", "mesh-provisioner.provisions", "ssh-client.keys"} {
 		if !slices.Contains(m.Reads, state) {
 			t.Errorf("gitea's reads %v lack %q, so the runtime refuses its watch", m.Reads, state)
 		}

modules/gitea/cmd/forge-account-provider/service.go

@@ -184,7 +184,9 @@ func (s *Service) Make(ctx context.Context, c provider.Consumer) error {
 	s.mu.Unlock()
 	if !loaded {
 		// After a restart the first pass can come before the keys arrive: nothing is removed or deleted on that.
-		return fmt.Errorf("the keys of %s are not read yet, so nothing is made, removed or deleted", source)
+		// Not ready, not failed: the entry waits and keeps serving what it served (provider.ErrNotReady).
+		return fmt.Errorf("the keys of %s are not read yet, so nothing is made, removed or deleted: %w", source,
+			provider.ErrNotReady)
 	}
 	have := s.keysFrom(source, node, kind)
 	if len(have) == 0 {

modules/gitea/cmd/forge-account-provider/service_test.go

@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"git.novox.be/novox/mesh-sdk/go/provider"
+	"git.novox.be/novox/mesh-sdk/go/provisions"
 
 	"gitea/internal/forgehttp"
 )
@@ -78,6 +79,22 @@ func (b *fakeBus) entry(t *testing.T, key string) provider.Entry {
 	}
 	return e
 }
+
+// serves is whether gitea's entry under key serves its consumer: there, in state (provided when none is given) and with
+// values (ADR 0570 clause 3: an entry the provider could not make is kept, failed, serving nothing; one it is not
+// ready to make waits and keeps serving).
+func (b *fakeBus) serves(key string, state ...string) bool {
+	want := provisions.Provided
+	if len(state) > 0 {
+		want = state[0]
+	}
+	b.mu.Lock()
+	raw, ok := b.buckets[provider.BucketOf("gitea")][key]
+	b.mu.Unlock()
+	var e provider.Entry
+	return ok && json.Unmarshal(raw, &e) == nil && e.State == want && len(e.Values) > 0
+}
+
 func (b *fakeBus) has(key string) bool {
 	b.mu.Lock()
 	defer b.mu.Unlock()
@@ -85,11 +102,41 @@ func (b *fakeBus) has(key string) bool {
 	return ok
 }
 
-// bindClient makes ssh-client on node bind gitea's forge-account in the assignments mirror.
+// bindClient makes ssh-client on node bind gitea's forge-account in the seat mesh-provisioner's plans.
 func (b *fakeBus) bindClient(node string) {
-	b.set(provider.AssignmentsBucket, node+".ssh-client", []byte(fmt.Sprintf(
-		`{"node":%q,"module":"ssh-client","provisioning":{"provisions":[{"provision":"forge-account","provider":"novox","provider-module":"gitea","as":"mesh_%s_ssh_client"}]}}`,
-		node, node)))
+	b.bindPlan(node, "ssh-client", "mesh_"+node+"_ssh_client")
+}
+
+// bindPlan makes module on node bind gitea's forge-account as the seat mesh-provisioner keeps it: its plan, and the
+// provision key asked of gitea on novox (novox/hq ADR 0570 clauses 1 to 3).
+func (b *fakeBus) bindPlan(node, module, as string) {
+	b.set(provisions.PlansBucket, node+"."+module, []byte(fmt.Sprintf(
+		`{"v":1,"node":%q,"module":%q,"plan":{"provisions":[{"provision":"forge-account","provider":"novox","provider-module":"gitea","as":%q}]}}`,
+		node, module, as)))
+	b.set(provisions.ProvisionsBucket, node+"."+module+".forge-account", provisionKey(node, module, provisions.Asked, nil))
+}
+
+// retire is the operator's yes to the retiring of module's forge-account on node: its plan gone, its key retiring
+// with the warrant (ADR 0570 clause 5), the only way the provider lets an entry go.
+func (b *fakeBus) retire(node, module string) {
+	b.mu.Lock()
+	delete(b.buckets[provisions.PlansBucket], node+"."+module)
+	b.mu.Unlock()
+	b.set(provisions.ProvisionsBucket, node+"."+module+".forge-account", provisionKey(node, module, provisions.Retiring,
+		&provisions.Warrant{Ask: "ask-1", Option: "yes", By: "operator", At: time.Date(2026, 10, 29, 12, 0, 0, 0, time.UTC)}))
+}
+
+func provisionKey(node, module, state string, w *provisions.Warrant) []byte {
+	pr := provisions.Provision{Provision: "forge-account", State: state, Warrant: w,
+		Consumer: provisions.End{Node: node, Module: module}, Provider: provisions.End{Node: "novox", Module: "gitea"}}
+	if state == provisions.Retiring {
+		pr.Why = "no want needs it"
+	}
+	raw, err := provisions.Encode(pr)
+	if err != nil {
+		panic(err)
+	}
+	return raw
 }
 
 // fakeForge is gitea's API as far as the provider uses it.
@@ -343,9 +390,7 @@ func TestAConsumerThatNoLongerBindsLosesItsMeshKeysAndKeepsItsAccount(t *testing
 	r.forge.mu.Lock()
 	r.forge.held["nox-agent"] = append(r.forge.held["nox-agent"], map[string]any{"id": int64(99), "title": "my own", "key": pubB})
 	r.forge.mu.Unlock()
-	r.bus.mu.Lock()
-	delete(r.bus.buckets[provider.AssignmentsBucket], "g14.ssh-client")
-	r.bus.mu.Unlock()
+	r.bus.retire("g14", "ssh-client")
 	r.pass()
 	if r.bus.has("g14.ssh-client.forge-account") {
 		t.Fatal("the entry stayed")
@@ -460,7 +505,7 @@ func TestADeletedKeyEntryRemovesTheMeshKeyAndTheBoundEntryButNotTheOperatorsKey(
 	if got := r.forge.titles("nox-agent"); len(got) != 1 || got[0] != "my own" {
 		t.Fatalf("keys = %v", got)
 	}
-	if r.bus.has("g14.ssh-client.forge-account") {
+	if r.bus.serves("g14.ssh-client.forge-account") {
 		t.Fatal("the entry still serves a machine whose key is gone")
 	}
 }
@@ -482,8 +527,8 @@ func TestAPassBeforeTheKeysAreLoadedRemovesAndDeletesNothing(t *testing.T) {
 	if got := strings.Join(r.forge.titles("nox-agent"), ","); got != "mesh:g14.nox,my own" {
 		t.Fatalf("keys = %s", got)
 	}
-	if !r.bus.has("g14.ssh-client.forge-account") {
-		t.Fatal("the entry was deleted before the keys were read")
+	if !r.bus.serves("g14.ssh-client.forge-account", provisions.Waits) {
+		t.Fatal("the entry stopped serving before the keys were read; it waits and keeps serving")
 	}
 	if len(out) != 1 || !strings.Contains(out[0].Why, "not read yet") {
 		t.Fatalf("the wait should be said: %+v", out)
@@ -493,7 +538,7 @@ func TestAPassBeforeTheKeysAreLoadedRemovesAndDeletesNothing(t *testing.T) {
 	r.svc.loaded = true
 	r.svc.mu.Unlock()
 	r.pass()
-	if got := strings.Join(r.forge.titles("nox-agent"), ","); got != "my own" || r.bus.has("g14.ssh-client.forge-account") {
+	if got := strings.Join(r.forge.titles("nox-agent"), ","); got != "my own" || r.bus.serves("g14.ssh-client.forge-account") {
 		t.Fatalf("keys = %s", got)
 	}
 }
@@ -515,7 +560,7 @@ func TestKeepRunningStartsTheProviderAgainAfterARefusedWatch(t *testing.T) {
 		r.svc.KeepRunning(ctx, func(ctx context.Context) error {
 			calls++
 			if calls <= 2 {
-				return errors.New(`watching mesh-controller_assignments: gitea reads no state called "mesh-controller.assignments"`)
+				return errors.New(`watching mesh-provisioner_plans: gitea reads no state called "mesh-provisioner.plans"`)
 			}
 			close(serving)
 			<-ctx.Done()
@@ -535,7 +580,7 @@ func TestKeepRunningStartsTheProviderAgainAfterARefusedWatch(t *testing.T) {
 	if len(pauses) != 2 || pauses[0] != 5*time.Second || pauses[1] != 10*time.Second {
 		t.Fatalf("the backoff is %v", pauses)
 	}
-	if len(said) == 0 || !strings.Contains(said[0], "mesh-controller.assignments") {
+	if len(said) == 0 || !strings.Contains(said[0], "mesh-provisioner.plans") {
 		t.Fatalf("a refusal is said loudly: %v", said)
 	}
 	loud := 0

modules/gitea/cmd/forge-account-provider/watch_test.go

@@ -142,7 +142,7 @@ func TestABuildModulesStateThatNeverAnswersHoldsBackOnlyItsOwnEntries(t *testing
 }
 
 // 1482/AC4 (the provider's half): the manifest reads the states of both build modules beside ssh-client's and the
-// controller's assignments; the provider watches exactly the modules the code names as builders.
+// seat mesh-provisioner's plans; the provider watches exactly the modules the code names as builders.
 func TestTheManifestReadsTheBuildModulesKeys(t *testing.T) {
 	raw, err := os.ReadFile("../../module.json")
 	if err != nil {
@@ -154,7 +154,7 @@ func TestTheManifestReadsTheBuildModulesKeys(t *testing.T) {
 	if err := json.Unmarshal(raw, &m); err != nil {
 		t.Fatal(err)
 	}
-	for _, state := range []string{"mesh-controller.assignments", "ssh-client.keys", "mesh-build-go.keys", "mesh-build-node.keys", "mesh-build-image.keys"} {
+	for _, state := range []string{"mesh-provisioner.plans", "mesh-provisioner.provisions", "ssh-client.keys", "mesh-build-go.keys", "mesh-build-node.keys", "mesh-build-image.keys"} {
 		if !slices.Contains(m.Reads, state) {
 			t.Errorf("gitea's reads %v lack %q", m.Reads, state)
 		}

modules/gitea/go.mod

@@ -3,7 +3,7 @@ module gitea
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 	golang.org/x/crypto v0.57.0

modules/gitea/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468 h1:UcMee+IV2ii5E4dRZdQUaSaeh9IedTFYumuQbBiB0k0=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261023150321-a2c813a6b468/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/gitea/module.json

@@ -399,6 +399,7 @@
   "provides": [
     {
       "name": "npm-package-registry",
+      "credential": {"form": "pair"},
       "scope": "mesh",
       "identity": {
         "max": 40,
@@ -407,6 +408,7 @@
     },
     {
       "name": "git",
+      "credential": {"form": "none"},
       "scope": "mesh"
     },
     {
@@ -419,6 +421,7 @@
     },
     {
       "name": "forge-account",
+      "credential": {"form": "none"},
       "scope": "mesh"
     }
   ],
@@ -563,7 +566,8 @@
     "announced"
   ],
   "reads": [
-    "mesh-controller.assignments",
+    "mesh-provisioner.plans",
+    "mesh-provisioner.provisions",
     "ssh-client.keys",
     "mesh-build-go.keys",
     "mesh-build-node.keys",

modules/go/module.json

@@ -7,7 +7,10 @@
   "provides": [
     {
       "name": "go-toolchain",
-      "reach": "machine"
+      "reach": "machine",
+      "credential": {
+        "form": "none"
+      }
     }
   ],
   "resources": [

modules/influxdb/module.json

@@ -7,6 +7,9 @@
       "scope": "mesh",
       "identity": {
         "in": "an InfluxDB v1 authorization"
+      },
+      "credential": {
+        "form": "pair"
       }
     }
   ],

modules/keycloak/cmd/keycloak-provider/grant_moved_test.go

@@ -15,6 +15,7 @@ import (
 
 	"git.novox.be/novox/mesh-sdk/go/provider"
 	"git.novox.be/novox/mesh-sdk/go/provider/harness"
+	"git.novox.be/novox/mesh-sdk/go/provisions"
 )
 
 // grantGives writes a grant file (MESH_RECEIVES) naming consumers the plans do not move (issue 937): each one's
@@ -38,11 +39,33 @@ func grantGives(t *testing.T, given ...map[string]any) string {
 	return at
 }
 
-// noOpPlan puts one assignment the bus can read that binds nothing of keycloak's, so the moved path has plans it
+// noOpPlan puts one plan the bus can read that binds nothing of keycloak's, so the moved path has plans it
 // could read (m.asked answers "read", issue 241) even when nothing is moved.
 func noOpPlan(bus *bucketBus, node, module string) {
-	raw, _ := json.Marshal(map[string]any{"node": node, "module": module})
-	_ = bus.Put(ctx, provider.AssignmentsBucket, node+"."+module, raw)
+	seatPlan(bus, node, module, map[string]any{})
+}
+
+// seatPlan puts a module's plan as the seat mesh-provisioner keeps it, and for each of its provisions served by
+// keycloak on novox the key the seat composes, asked (novox/hq ADR 0570 clauses 1 to 3).
+func seatPlan(bus *bucketBus, node, module string, plan map[string]any) {
+	raw, _ := json.Marshal(map[string]any{"v": 1, "node": node, "module": module, "plan": plan})
+	_ = bus.Put(ctx, provisions.PlansBucket, node+"."+module, raw)
+	list, _ := plan["provisions"].([]any)
+	for _, e := range list {
+		entry := e.(map[string]any)
+		name, _ := entry["provision"].(string)
+		local, _ := entry["local"].(string)
+		key, err := provisions.Key(node, module, name, local)
+		if err != nil {
+			panic(err)
+		}
+		asked, err := provisions.Encode(provisions.Provision{Provision: name, Local: local, State: provisions.Asked,
+			Consumer: provisions.End{Node: node, Module: module}, Provider: provisions.End{Node: "novox", Module: "keycloak"}})
+		if err != nil {
+			panic(err)
+		}
+		_ = bus.Put(ctx, provisions.ProvisionsBucket, key, asked)
+	}
 }
 
 // waitUntil polls cond until it is true or the timeout passes.

modules/keycloak/cmd/keycloak-provider/live_retire_test.go

@@ -62,6 +62,14 @@ func TestLiveRetirement(t *testing.T) {
 	if code := authorize(); code == 200 {
 		t.Fatal("a retired client is still served")
 	}
+	// Its secret is removed (ADR 0570 clause 5): the mesh's no longer authenticates.
+	if found, err := o.KC.FindClient(ctx, o.Realm, p.As); err != nil || found == nil {
+		t.Fatal(found, err)
+	} else if id, _ := found["id"].(string); true {
+		if secret, err := o.KC.ClientSecretByID(ctx, o.Realm, id); err != nil || secret == p.Password {
+			t.Fatal("a retired client keeps the mesh's secret", err)
+		}
+	}
 	// Retired, so a person may delete it.
 	if err := o.Delete(ctx, p.As); err != nil {
 		t.Fatal(err)

modules/keycloak/cmd/keycloak-provider/moved_test.go

@@ -155,10 +155,9 @@ func TestBothPathsLeaveTheSameClientInKeycloak(t *testing.T) {
 			t.Fatal(err)
 		}
 		bus := &bucketBus{buckets: map[string]map[string][]byte{}}
-		plan, _ := json.Marshal(map[string]any{"node": "home", "module": "grafana", "provisioning": map[string]any{
+		seatPlan(bus, "home", "grafana", map[string]any{
 			"provisions": []any{map[string]any{"provision": ProvisionName, "provider": "novox",
-				"provider-module": "keycloak", "contributes": grafanaContributes, "names": grafanaNames}}}})
-		_ = bus.Put(ctx, provider.AssignmentsBucket, "home.grafana", plan)
+				"provider-module": "keycloak", "contributes": grafanaContributes, "names": grafanaNames}}})
 		pr := provider.New(provider.Options{Node: "novox", Module: "keycloak", Bus: bus,
 			Vault: provider.ConsumersFile{Paths: []string{file}},
 			Offers: map[string]provider.Offer{ProvisionName: {Credential: provider.PerConsumer,

modules/keycloak/cmd/keycloak-provider/oidc.go

@@ -24,15 +24,18 @@ package main
 
 import (
 	"context"
+	"crypto/rand"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"git.novox.be/novox/mesh-sdk/go/provider/harness"
 	"net/url"
 	"regexp"
 	"sort"
 	"strings"
 	"time"
+
+	"git.novox.be/novox/mesh-sdk/go/provider/harness"
 )
 
 // Mark is the attribute marking a client as the mesh's own work.
@@ -307,8 +310,10 @@ func (o OidcClients) Holds(ctx context.Context, p harness.Provision) (bool, erro
 	return secret == p.Password, nil
 }
 
-// Retire disables a consumer's client — only one the mesh made — and marks it with when and why.
-// Answers what happened: "retired", "absent" or "not ours".
+// Retire, on the operator's yes (novox/hq ADR 0570 clause 5), removes the client's secret — replaced by one nobody
+// is given, so the mesh's credential no longer authenticates — and disables and marks the client with when and why.
+// The client and its settings are kept; asked for again, Ensure sets the mesh's secret and enables it. Only a client
+// the mesh made. Answers what happened: "retired", "absent" or "not ours".
 func (o OidcClients) Retire(ctx context.Context, as, why string, at time.Time) (string, error) {
 	found, err := o.KC.FindClient(ctx, o.Realm, as)
 	if err != nil {
@@ -332,6 +337,11 @@ func (o OidcClients) Retire(ctx context.Context, as, why string, at time.Time) (
 	attrs[MarkRetiredWhy] = why
 	merged["attributes"] = attrs
 	merged["enabled"] = false
+	unknown := make([]byte, 32)
+	if _, err := rand.Read(unknown); err != nil {
+		return "", err
+	}
+	merged["secret"] = hex.EncodeToString(unknown) // never kept, never said
 	id, _ := found["id"].(string)
 	return "retired", o.KC.UpdateClient(ctx, o.Realm, id, merged)
 }

modules/keycloak/cmd/keycloak-provider/oidc_test.go

@@ -186,7 +186,7 @@ func TestAClientTheMeshDidNotMakeIsRefusedAndLeftAlone(t *testing.T) {
 	}
 }
 
-// Retired is disabled and marked, everything else kept; asked for again it is enabled as it was; only
+// Retired is its secret removed, disabled and marked, everything else kept (ADR 0570 clause 5); asked for again it is enabled as it was; only
 // a deletion removes it, and never while enabled (novox/hq ADR 0230).
 func TestARetiredClientIsDisabledKeptAndEnabledAgainAsItWas(t *testing.T) {
 	f, o := oidcWorld(t)
@@ -204,7 +204,7 @@ func TestARetiredClientIsDisabledKeptAndEnabledAgainAsItWas(t *testing.T) {
 		t.Fatal(done, err)
 	}
 	c := f.clients[id]
-	if c["enabled"] != false || c["secret"] != "s" || attributes(c)[MarkRetired] != "2026-10-06T12:00:00Z" ||
+	if c["enabled"] != false || c["secret"] == "s" || c["secret"] == "" || attributes(c)[MarkRetired] != "2026-10-06T12:00:00Z" ||
 		attributes(c)[MarkRetiredWhy] != "the mesh stopped asking for it" || c["description2"] == nil {
 		t.Fatalf("%v", c)
 	}
@@ -219,7 +219,7 @@ func TestARetiredClientIsDisabledKeptAndEnabledAgainAsItWas(t *testing.T) {
 		t.Fatal(err)
 	}
 	c = f.clients[id]
-	if c["enabled"] != true || attributes(c)[MarkRetired] != nil || attributes(c)[MarkRetiredWhy] != nil || c["description2"] == nil {
+	if c["enabled"] != true || c["secret"] != "s" || attributes(c)[MarkRetired] != nil || attributes(c)[MarkRetiredWhy] != nil || c["description2"] == nil {
 		t.Fatalf("%v", c)
 	}
 	mustHold(t, o, p, true)

modules/keycloak/cmd/keycloak-provider/provisioner.go

@@ -62,7 +62,8 @@ func (a provisioner) Create(ctx context.Context, p harness.Provision) error {
 	return nil
 }
 
-// Retire disables the consumer's client and marks it, never deletes it (novox/hq ADR 0230).
+// Retire removes the consumer's client secret and disables and marks the client, never deletes it (novox/hq ADR 0570
+// clause 5, ADR 0230).
 func (a provisioner) Retire(ctx context.Context, as string, _ map[string]any, why string, at time.Time) error {
 	if err := a.refused(); err != nil {
 		return err
@@ -75,7 +76,7 @@ func (a provisioner) Retire(ctx context.Context, as string, _ map[string]any, wh
 	case "not ours":
 		a.log("[provisioner:oidc-client] %s: a client of that id exists that the mesh did not make — left alone", as)
 	case "retired":
-		a.log("[provisioner:oidc-client] retired client %s in realm %s: disabled, kept, marked to delete", as, a.clients.Realm)
+		a.log("[provisioner:oidc-client] retired client %s in realm %s: its secret removed, disabled, kept, marked to delete", as, a.clients.Realm)
 		a.announce("client.retired", map[string]any{"realm": a.clients.Realm, "clientId": as})
 	}
 	return nil

modules/keycloak/go.mod

@@ -2,4 +2,4 @@ module keycloak
 
 go 1.26.0
 
-require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021114014-66e8fdaa62e2
+require git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde

modules/keycloak/go.sum

@@ -1,2 +1,2 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021114014-66e8fdaa62e2 h1:Cdl5N56QPfmFBoLHrDfvvyc5Q+PUnTjf3fgYD7imcco=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021114014-66e8fdaa62e2/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=

modules/keycloak/module.json

@@ -9,6 +9,7 @@
   "provides": [
     {
       "name": "oidc-client",
+      "credential": {"form": "pair"},
       "scope": "mesh",
       "identity": {
         "max": 255,
@@ -240,6 +241,7 @@
     "bound"
   ],
   "reads": [
-    "mesh-controller.assignments"
+    "mesh-provisioner.plans",
+    "mesh-provisioner.provisions"
   ]
 }

modules/mailu/module.json

@@ -665,7 +665,14 @@
       "path": "${dir:mesh-state}/config.json",
       "mode": "0600",
       "template": "files/config.json",
-      "takes-config": ["domain", "proxy-address", "sitename", "website", "url", "container"],
+      "takes-config": [
+        "domain",
+        "proxy-address",
+        "sitename",
+        "website",
+        "url",
+        "container"
+      ],
       "merge": "json"
     },
     {
@@ -758,6 +765,9 @@
       "identity": {
         "max": 64,
         "in": "a mailbox's local part"
+      },
+      "credential": {
+        "form": "pair"
       }
     }
   ],

modules/mesh-build-go/cmd/mesh-build-go/fetch.go

@@ -296,7 +296,6 @@ func (m *Module) goEnv() []string {
 		modcache = m.GoModCache
 	}
 	return append([]string{
-		"CGO_ENABLED=0", // as a production build compiles (build.go), so a check tests what ships and the warm cache matches (ADR 0542 §1)
 		"GOTOOLCHAIN=local",
 		"GOFLAGS=-mod=mod",
 		"GOMODCACHE=" + modcache,

modules/mesh-build-go/cmd/mesh-build-go/integration.go

@@ -12,7 +12,6 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
 	"git.novox.be/novox/mesh-sdk/go/buildstep"
@@ -63,73 +62,30 @@ func (m *Module) integrationHere(ctx context.Context, workspace, tree string, pa
 	if err != nil {
 		return nil, err
 	}
+	postgres, stopStore, err := m.startStore(ctx, run)
+	if err != nil {
+		return nil, fmt.Errorf("the integration level's store: %w", err)
+	}
+	defer stopStore()
+	nats, stopBus, err := m.startBus(ctx, filepath.Join(run, "nats"))
+	if err != nil {
+		return nil, fmt.Errorf("the integration level's bus: %w", err)
+	}
+	defer stopBus()
+	env := append([]string{"MESH_TEST_POSTGRES=" + postgres, "MESH_TEST_NATS=" + nats}, m.checkEnv(workspace, nil)...)
+	// Compiling counts as setup: the tests are built once, here, with the addresses a TestMain may read, and the run
+	// below finds them built. Whether they compile is for the run to say; its failure is not read here.
 	// Only the directories the selected packages lie in compile (ADR 0536 §3); no selection is every directory.
 	byDir, err := packagesByDir(tree, dirs, packages)
 	if err != nil {
 		return nil, err
 	}
-	// The store, the bus and the compile start together, and the directories compile side by side up to the bound
-	// (issue 1921, try speed S5): the setup is the longest of them, not their sum. The compile runs no test binary
-	// (-exec true), so it needs neither server and is given nothing a test reads; whether the tests compile is for the
-	// run to say, its failure is not read here, and the run below finds them built.
-	var (
-		wg                 sync.WaitGroup
-		postgres, nats     string
-		stopStore, stopBus func()
-		storeErr, busErr   error
-		crash              any
-		crashMu            sync.Mutex
-	)
-	guard := func() {
-		if p := recover(); p != nil {
-			crashMu.Lock()
-			crash = p
-			crashMu.Unlock()
-		}
-	}
-	wg.Add(2)
-	go func() {
-		defer wg.Done()
-		defer guard()
-		postgres, stopStore, storeErr = m.startStore(ctx, run)
-	}()
-	go func() {
-		defer wg.Done()
-		defer guard()
-		nats, stopBus, busErr = m.startBus(ctx, filepath.Join(run, "nats"))
-	}()
-	slots := make(chan struct{}, m.parallel())
 	for _, d := range dirs {
 		if len(byDir[d]) == 0 {
 			continue
 		}
-		wg.Add(1)
-		slots <- struct{}{}
-		go func() {
-			defer wg.Done()
-			defer func() { <-slots }()
-			defer guard()
-			m.Run(ctx, m.goEnvFor(filepath.Join(tree, d)), "go", append([]string{"-C", filepath.Join(tree, d), "test", "-tags", strings.Join(integrationTags, ","), "-exec", "true", "-count=1"}, byDir[d]...)...)
-		}()
+		m.Run(ctx, append(m.goEnvFor(filepath.Join(tree, d)), env...), "go", append([]string{"-C", filepath.Join(tree, d), "test", "-tags", strings.Join(integrationTags, ","), "-run", "^$", "-count=1"}, byDir[d]...)...)
 	}
-	wg.Wait()
-	// Whatever started is stopped however the level ends, a half-started store included.
-	if stopStore != nil {
-		defer stopStore()
-	}
-	if stopBus != nil {
-		defer stopBus()
-	}
-	if crash != nil {
-		panic(crash)
-	}
-	if storeErr != nil {
-		return nil, fmt.Errorf("the integration level's store: %w", storeErr)
-	}
-	if busErr != nil {
-		return nil, fmt.Errorf("the integration level's bus: %w", busErr)
-	}
-	env := append([]string{"MESH_TEST_POSTGRES=" + postgres, "MESH_TEST_NATS=" + nats}, m.checkEnv(workspace, nil)...)
 	setup := m.clock().Sub(began)
 
 	return m.runLevel(ctx, tree, levelOpts{

modules/mesh-build-go/cmd/mesh-build-go/integration_level_test.go

@@ -35,9 +35,6 @@ type integFake struct {
 	// command runs, with its line.
 	gomods string
 	onTest func(line string)
-	// onCompile is called, unlocked, as each compile of the setup runs, and onStart as the store starts (issue 1921, S5).
-	onCompile func(line string, env []string)
-	onStart   func()
 }
 
 func newIntegFake(t *testing.T, captured string) *integFake {
@@ -74,10 +71,7 @@ func (f *integFake) run(ctx context.Context, env []string, name string, args ...
 			return forgekey.Ran{Stdout: f.gomods}
 		}
 		return forgekey.Ran{Stdout: "go.mod\n"}
-	case name == "go" && strings.Contains(line, "-exec true"):
-		if f.onCompile != nil {
-			f.onCompile(line, env)
-		}
+	case name == "go" && strings.Contains(line, "-run ^$"):
 		f.tick("compile")
 	case name == "go":
 		if f.onTest != nil {
@@ -90,9 +84,6 @@ func (f *integFake) run(ctx context.Context, env []string, name string, args ...
 		}
 		return forgekey.Ran{Stdout: f.captured, Status: status}
 	case name == "pg_ctl" && strings.HasSuffix(line, " start"):
-		if f.onStart != nil {
-			f.onStart()
-		}
 		f.tick("start")
 		for i, a := range args {
 			if a == "-D" {
@@ -323,8 +314,8 @@ func TestAStoreThatDoesNotStartEndsTheStepFailedAndLeavesNothing(t *testing.T) {
 	if !strings.Contains(f.lines(), " stop") {
 		t.Errorf("the half-started store was not stopped:\n%s", f.lines())
 	}
-	if f.busDir != "" && !f.busDown {
-		t.Errorf("the bus, started beside the store, was not stopped after the store failed")
+	if f.busDir != "" {
+		t.Errorf("the bus was started after the store failed")
 	}
 	if entries, _ := os.ReadDir(filepath.Join(m.Work, "ws1")); len(entries) != 1 || entries[0].Name() != "tree" {
 		t.Errorf("the workspace holds %v, want only its tree", entries)

modules/mesh-build-go/cmd/mesh-build-go/isolate.go

@@ -29,32 +29,23 @@ func (m *Module) caches() []string {
 }
 
 // isolation is how a run step of the workspace is shut off: the workspace (its tree, its siblings, its run directories,
-// its packed artifacts) read-write, the caches beneath the ask's own layer unless write, and an environment of a PATH and
+// its packed artifacts) read-write, the caches beneath a throwaway layer unless write, and an environment of a PATH and
 // a locale alone (the step's HOME is its own, inside its /tmp).
 func (m *Module) isolation(workspace string, write bool) buildstep.Isolation {
 	path := os.Getenv("PATH")
 	if path == "" {
 		path = defaultPath
 	}
-	iso := buildstep.Isolation{
+	return buildstep.Isolation{
 		Workspace:   filepath.Join(m.Work, workspace),
 		Caches:      m.caches(),
 		WriteCaches: write,
 		Env:         append([]string{"PATH=" + path, "LC_ALL=C"}, m.threadEnv()...),
 	}
-	if !write {
-		// What one command of the ask compiles is kept for its later commands (the vet, the unit tests, the integration
-		// level's compile), in the workspace and gone with it (issue 1921, try speed S2).
-		iso.CacheLayer = filepath.Join(iso.Workspace, cacheLayerDir)
-	}
-	return iso
 }
 
-// cacheLayerDir is the directory in a workspace's root where an ask keeps what its commands wrote into the caches.
-const cacheLayerDir = "cachelayer"
-
 // stepRunner is the runner of a run step of the workspace: buildstep.Isolated over m.Run, so every command it runs is
-// shut off; write is true for a trunk build and for a check's go vet, compile steps that run nothing of the change (ADR 0541 §2). Inside is the
+// shut off; write is true for a trunk build alone (the shared caches are written by trunk builds only). Inside is the
 // integration level's own process, already running shut off (level.go): it runs its commands as they are.
 func (m *Module) stepRunner(workspace string, write bool) (forgekey.Runner, error) {
 	if m.Inside {

modules/mesh-build-go/cmd/mesh-build-go/isolate_test.go

@@ -20,7 +20,6 @@ import (
 type shutOff struct {
 	flags                    []string
 	binds, roBinds, overlays []string
-	uppers                   map[string]string // the writable layer each --overlay gives a cache: cache -> upper
 	env                      []string
 	command                  string
 	chdir                    string
@@ -28,7 +27,7 @@ type shutOff struct {
 
 // bwrapArity is how many words each bubblewrap option the SDK writes takes.
 var bwrapArity = map[string]int{"--unshare-all": 0, "--die-with-parent": 0, "--new-session": 0, "--clearenv": 0,
-	"--proc": 1, "--dev": 1, "--tmpfs": 1, "--dir": 1, "--chdir": 1, "--overlay-src": 1, "--tmp-overlay": 1, "--overlay": 3,
+	"--proc": 1, "--dev": 1, "--tmpfs": 1, "--dir": 1, "--chdir": 1, "--overlay-src": 1, "--tmp-overlay": 1,
 	"--ro-bind": 2, "--ro-bind-try": 2, "--bind": 2, "--symlink": 2, "--setenv": 2}
 
 // throughBubblewrap is the fake runner of a step's tests: a bubblewrap command is read back (recorded in seen) and its
@@ -57,11 +56,6 @@ func throughBubblewrap(t *testing.T, run forgekey.Runner, seen *[]shutOff) forge
 				s.roBinds = append(s.roBinds, args[i+1])
 			case "--overlay-src":
 				s.overlays = append(s.overlays, args[i+1])
-			case "--overlay":
-				if s.uppers == nil {
-					s.uppers = map[string]string{}
-				}
-				s.uppers[args[i+3]] = args[i+1]
 			case "--setenv":
 				s.env = append(s.env, args[i+1]+"="+args[i+2])
 			case "--chdir":
@@ -111,9 +105,6 @@ func checkShutOff(t *testing.T, m *Module, s shutOff, write bool) {
 			t.Errorf("a trunk build's %s does not write the shared cache %s (bound %v, layered %v)", s.command, c, bound, layered)
 		case !write && (bound || !layered):
 			t.Errorf("%s may write the shared cache %s (bound %v, layered %v): only a trunk build does", s.command, c, bound, layered)
-		case !write && !strings.HasPrefix(s.uppers[c], filepath.Join(m.Work, "ws1", "cachelayer")+"/"):
-			// 1921/S2: what one command of the ask compiles is kept for its later commands, in the workspace
-			t.Errorf("%s writes the cache %s into %q, not the ask's cache layer in its workspace", s.command, c, s.uppers[c])
 		}
 	}
 	if want := filepath.Join(m.Work, "ws1"); !slices.Contains(s.binds, want) {
@@ -139,23 +130,8 @@ func TestTheUnitLevelRunsEveryGoTestShutOff(t *testing.T) {
 	if ran == 0 || len(seen) != ran {
 		t.Fatalf("%d go commands ran, %d of them shut off: %v", ran, len(seen), *calls)
 	}
-	// A check compiles with cgo off as a build does (ADR 0542 §1), and the lint's go vet, a compile that runs nothing
-	// of the change, writes the shared caches; every other command reads them beneath its own layer (ADR 0541 §2).
-	for _, c := range *calls {
-		if strings.HasPrefix(c.line, "go ") && !slices.Contains(c.env, "CGO_ENABLED=0") {
-			t.Errorf("%s ran without CGO_ENABLED=0: %v", c.line, c.env)
-		}
-	}
-	vets := 0
 	for _, s := range seen {
-		vet := strings.Contains(s.command, " vet ")
-		if vet {
-			vets++
-		}
-		checkShutOff(t, m, s, vet)
-	}
-	if vets == 0 {
-		t.Error("no go vet ran shut off")
+		checkShutOff(t, m, s, false)
 	}
 }
 

modules/mesh-build-go/cmd/mesh-build-go/lint.go

@@ -13,7 +13,6 @@ import (
 	"sort"
 	"strings"
 	"sync"
-	"time"
 
 	"git.novox.be/novox/mesh-sdk/go/buildstep"
 	"git.novox.be/novox/mesh-sdk/go/forgekey"
@@ -145,18 +144,6 @@ func (m *Module) lintAll(ctx context.Context, run forgekey.Runner, tree string,
 	var wg sync.WaitGroup
 	var crash any // a panic of a lint goes on in the caller, as a panic of a test run does
 	var crashMu sync.Mutex
-	// Each directory's end is said as a phase, so a long lint is readable while it runs (issue 1921): which directories
-	// are done and how long the last one took.
-	var doneMu sync.Mutex
-	done := 0
-	said := func(d string, began time.Time) {
-		doneMu.Lock()
-		defer doneMu.Unlock()
-		done++
-		if done < len(dirs) {
-			buildstep.Phase(ctx, fmt.Sprintf("unit: lint of %d directories, %d done (%s in %s)", len(dirs), done, d, m.clock().Sub(began).Round(time.Second)))
-		}
-	}
 	for i, d := range dirs {
 		wg.Add(1)
 		slots <- struct{}{}
@@ -170,9 +157,7 @@ func (m *Module) lintAll(ctx context.Context, run forgekey.Runner, tree string,
 					crashMu.Unlock()
 				}
 			}()
-			began := m.clock()
 			answers[i].failed, answers[i].err = m.lint(ctx, run, tree, d, env(d))
-			said(d, began)
 		}()
 	}
 	wg.Wait()

modules/mesh-build-go/cmd/mesh-build-go/preview_test.go

@@ -290,8 +290,8 @@ func TestTheIntegrationLevelIsGivenTheBesideDirectoryOnlyWhenSiblingsWerePlaced(
 		}
 		tested := 0
 		for _, c := range f.calls {
-			if !strings.HasPrefix(c.line, "go ") || !strings.Contains(c.line, "-tags integration") || strings.Contains(c.line, "-exec true") {
-				continue // the setup's compile runs no test binary, so it is given nothing a test reads (issue 1921, S5)
+			if !strings.HasPrefix(c.line, "go ") || !strings.Contains(c.line, "-tags integration") {
+				continue
 			}
 			tested++
 			got := ""

modules/mesh-build-go/cmd/mesh-build-go/selected_dirs_test.go

@@ -72,7 +72,7 @@ func TestOnlyTheSelectedDirectoryCompilesAndRuns(t *testing.T) {
 		if !strings.HasPrefix(l, "go -C "+filepath.Join(tree, "b")+" test ") {
 			t.Errorf("go test ran outside the selected directory: %s", l)
 		}
-		if strings.Contains(l, "-exec true") {
+		if strings.Contains(l, "-run ^$") {
 			compiled++
 		} else {
 			ran++
@@ -91,7 +91,7 @@ func TestWithoutASelectionEveryDirectoryCompilesAndRuns(t *testing.T) {
 	compiled, ran := 0, 0
 	for _, l := range strings.Split(f.lines(), "\n") {
 		if strings.HasPrefix(l, "go ") && strings.Contains(l, " test ") {
-			if strings.Contains(l, "-exec true") {
+			if strings.Contains(l, "-run ^$") {
 				compiled++
 			} else {
 				ran++
@@ -146,85 +146,27 @@ func TestSelectedDirectoriesRunAtOnceAndAnswerInDirectoryOrder(t *testing.T) {
 	}
 }
 
-// The bound holds for the setup's compiles and for the tests: no more of them run at once than the bound, and with a
-// bound of 3 the three directories compile at once, beside the store's start, given nothing a test reads, since the
-// compile runs no test binary (issue 1921, try speed S5).
+// The bound holds: with one directory at a time, no two go test commands run at once.
 func TestTheDirectoriesAtOnceNeverPassTheBound(t *testing.T) {
-	for _, tc := range []struct {
-		name    string
-		compile bool // the setup's compiles are counted, not the tests
-		bound   int
-		want    int // how many must run at once (at most the bound always)
-	}{
-		{"tests one at a time", false, 1, 1},
-		{"compiles one at a time", true, 1, 1},
-		{"compiles at once beside the store", true, 3, 3},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			f := newIntegFake(t, "slow")
-			var mu sync.Mutex
-			running, most := 0, 0
-			reached := make(chan struct{})
-			storeStarting, beside := false, false
-			count := func() {
-				mu.Lock()
-				running++
-				most = max(most, running)
-				if running == tc.want && tc.want > 1 {
-					close(reached)
-				}
-				mu.Unlock()
-				if tc.want > 1 {
-					select { // held until all of them run, so "at once" does not hang on timing
-					case <-reached:
-					case <-time.After(2 * time.Second):
-					}
-				} else {
-					time.Sleep(20 * time.Millisecond)
-				}
-				mu.Lock()
-				running--
-				mu.Unlock()
-			}
-			if tc.compile {
-				f.onCompile = func(_ string, env []string) {
-					for _, e := range env {
-						if strings.HasPrefix(e, "MESH_TEST_") {
-							t.Errorf("the compile was given %s: it runs no test binary", e)
-						}
-					}
-					mu.Lock()
-					beside = beside || storeStarting
-					mu.Unlock()
-					count()
-				}
-				if tc.want > 1 {
-					f.onStart = func() { // the store starts until the compiles have all run at once, or 2 s pass
-						mu.Lock()
-						storeStarting = true
-						mu.Unlock()
-						select {
-						case <-reached:
-						case <-time.After(2 * time.Second):
-						}
-					}
-				}
-			} else {
-				f.onTest = func(string) { count() }
-			}
-			m, states := threeModules(t, f)
-			m.Parallel = tc.bound
-			if _, st := runIntegrationOf(t, m, states); st.State != delivery.StepPassed {
-				t.Fatalf("the step ended %s: %s", st.State, st.Reason)
-			}
-			mu.Lock()
-			defer mu.Unlock()
-			if most > tc.bound || most < tc.want {
-				t.Errorf("%d ran at once with a bound of %d, want %d", most, tc.bound, tc.want)
-			}
-			if tc.compile && tc.want > 1 && !beside {
-				t.Errorf("no compile ran while the store was starting:\n%s", f.lines())
-			}
-		})
+	f := newIntegFake(t, "slow")
+	var mu sync.Mutex
+	running, most := 0, 0
+	f.onTest = func(string) {
+		mu.Lock()
+		running++
+		if running > most {
+			most = running
+		}
+		mu.Unlock()
+		time.Sleep(20 * time.Millisecond)
+		mu.Lock()
+		running--
+		mu.Unlock()
+	}
+	m, states := threeModules(t, f)
+	m.Parallel = 1
+	runIntegrationOf(t, m, states)
+	if most != 1 {
+		t.Errorf("%d go test commands ran at once with a bound of 1", most)
 	}
 }

modules/mesh-build-go/cmd/mesh-build-go/test.go

@@ -251,15 +251,8 @@ func (m *Module) runLevel(ctx context.Context, tree string, o levelOpts) (*TestR
 	if o.level == LevelUnit {
 		// gofmt and go vet of each directory the level runs come before its tests (ADR 0529 §1; issue 1887 D7-go): a
 		// directory that fails them fails the level at once, and their time is the result's Lint.
-		// go vet compiles and runs nothing of the change, with cgo off (goEnv), so it writes the shared cache and warms it
-		// for every later check, a pull request's head included (ADR 0541 §2, ADR 0542 §1); the tests run beneath their
-		// own throwaway layer.
-		compile, err := m.stepRunner(o.workspace, true)
-		if err != nil {
-			return nil, err
-		}
 		linted := m.clock()
-		failed, err := m.lintAll(ctx, compile, tree, todo, func(d string) []string {
+		failed, err := m.lintAll(ctx, run, tree, todo, func(d string) []string {
 			return append(m.goEnvFor(filepath.Join(tree, d)), o.env...)
 		})
 		if err != nil {

modules/mesh-build-go/go.mod

@@ -3,7 +3,7 @@ module meshbuildgo
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028235126-2a8670189188
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5
 	github.com/distribution/distribution/v3 v3.1.2
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0

modules/mesh-build-go/go.sum

@@ -1,7 +1,5 @@
 git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5 h1:L7EJbCPZfJRCYHyco5Ck3ui+pWc//sp+h5nnPqSarng=
 git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028235126-2a8670189188 h1:0ZJZmp4wqiJlBlVHAdGonVIRaLf0Z79Ql4DFR2k8E8c=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028235126-2a8670189188/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/alicebob/miniredis/v2 v2.35.0 h1:QwLphYqCEAo1eu1TqPRN2jgVMPBweeQcR21jeqDCONI=
 github.com/alicebob/miniredis/v2 v2.35.0/go.mod h1:TcL7YfarKPGDAthEtl5NBeHZfeUQj6OXMm/+iu5cLMM=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=

modules/mesh-build-image/.gitignore

@@ -0,0 +1 @@
+mesh-build-image

modules/mesh-build-image/go.mod

@@ -3,7 +3,7 @@ module meshbuildimage
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-build-image/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5 h1:L7EJbCPZfJRCYHyco5Ck3ui+pWc//sp+h5nnPqSarng=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/google/go-tpm v0.9.8 h1:slArAR9Ft+1ybZu0lBwpSmpwhRXaa85hWtMinMyRAWo=

modules/mesh-build-node/.gitignore

@@ -0,0 +1 @@
+mesh-build-node

modules/mesh-build-node/go.mod

@@ -3,7 +3,7 @@ module meshbuildnode
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde
 	github.com/distribution/distribution/v3 v3.1.2
 	github.com/nats-io/nats.go v1.54.0
 )

modules/mesh-build-node/go.sum

@@ -1,5 +1,5 @@
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5 h1:L7EJbCPZfJRCYHyco5Ck3ui+pWc//sp+h5nnPqSarng=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261028190821-9e5666b4d6f5/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde h1:ddf/jKI9c87sQKDmZLoG6PMnvXwsNH16ByVveyuFME4=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261029231453-6e4a3014cbde/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/alicebob/miniredis/v2 v2.35.0 h1:QwLphYqCEAo1eu1TqPRN2jgVMPBweeQcR21jeqDCONI=
 github.com/alicebob/miniredis/v2 v2.35.0/go.mod h1:TcL7YfarKPGDAthEtl5NBeHZfeUQj6OXMm/+iu5cLMM=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=

modules/mesh-catalog/heard.ts

@@ -45,13 +45,72 @@ export interface Built {
   branches?: string[];
 }
 
-/** The events a build outcome reaches this module on: the build seat's, as it happens, and the control plane's replay. */
-export const BUILD_EVENTS = [
-  // The build seat node-build-agent and the retired mesh-build-machine went with build-agent (novox/hq ADR 0524 §5,
-  // ADR 0525 §10): no build seat says `built` since R4g, so what the mesh holds is asked when this module starts.
-  // What the mesh already held, when this module asks what it missed (novox/hq ADR 0134).
-  "mesh-controller.built-before",
-] as const;
+/**
+ * Where a build outcome comes from now: the builder's log (novox/hq ADR 0571 clauses 1 and 9). The module asks the
+ * builder's tool for the builds that ended since a time, and again whenever the builder's state of done keys changes.
+ */
+export const BUILDER = "mesh-delivery-builder";
+export const BUILDS_SINCE_TOOL = "builder_builds_since";
+export const BUILDS_STATE = "mesh-delivery-builder.builds";
+export const MANIFESTS_STATE = "mesh-delivery-indexer.manifests";
+
+/** One entry of the builder's log, an ended build (mesh-sdk delivery.BuildLogEntry). */
+export interface LogEntry {
+  event: string;
+  module: string;
+  fp: string;
+  repository: string;
+  directory: string;
+  commit: string;
+  ref?: string;
+  node?: string;
+  at: string;
+  /** done, failed or queued. */
+  outcome?: string;
+  /** The digest of the manifest built, read from the indexer's state of manifests. */
+  manifest?: string;
+  against?: string[];
+  made?: Made[];
+}
+
+/** The answer of the builder's tool: every ended build since a time, oldest first, and whether the log held more. */
+export interface BuildsSince {
+  since: string;
+  builds: LogEntry[];
+  more?: boolean;
+}
+
+/**
+ * What a tool answers, whether bare or wrapped as the runtime wraps a tool's reply ({output} or {content:[{text}]}).
+ */
+export function answerOf<T>(raw: unknown): T {
+  const r = raw as { output?: unknown; content?: { text?: string }[] } | null;
+  if (r && typeof r.output === "string") return JSON.parse(r.output) as T;
+  if (r && Array.isArray(r.content) && typeof r.content[0]?.text === "string") return JSON.parse(r.content[0].text) as T;
+  if (typeof raw === "string") return JSON.parse(raw) as T;
+  return raw as T;
+}
+
+/**
+ * A log entry as the build outcome the catalogue places: a build that is done is placed with its manifest, what it
+ * made and what it was built against; one that failed is passed over (placeable says so); one still queued has not
+ * ended and is not taken in. `replay` is set by the caller for history.
+ */
+export function builtFrom(e: LogEntry, manifest: unknown, replay: boolean): Built | undefined {
+  if (e.outcome === "queued") return undefined;
+  return {
+    module: e.module,
+    commit: e.commit,
+    repository: e.repository,
+    path: e.directory,
+    ref: e.ref ?? "",
+    manifest,
+    made: e.made ?? [],
+    against: e.against ?? [],
+    replay,
+    ...(e.outcome === "failed" ? { failed: "the builder's log says the build failed" } : {}),
+  };
+}
 
 /**
  * Whether a build outcome is a module-version to place in the graph, and why not when it is not.

modules/mesh-catalog/index.ts

@@ -9,9 +9,15 @@
 // and appear the next time round, once whatever they were waiting for is registered. A chain and a
 // diamond need no special handling, and nothing holds a plan.
 
-import { on, emit } from "@novox/mesh-sdk/events";
+import { emit } from "@novox/mesh-sdk/events";
+import { broker } from "@novox/mesh-sdk/messaging";
+import { invokeTool } from "@novox/mesh-sdk/tools";
+import { state } from "@novox/mesh-sdk/state";
 import { Graph } from "./store.js";
-import { BUILD_EVENTS, placeable, type Built } from "./heard.js";
+import {
+  answerOf, builtFrom, placeable, BUILDER, BUILDS_SINCE_TOOL, BUILDS_STATE, MANIFESTS_STATE,
+  type Built, type BuildsSince, type LogEntry,
+} from "./heard.js";
 
 const graph = Graph.fromEnv();
 
@@ -77,18 +83,74 @@ const placeTheBuild = async (event: { body: unknown }): Promise<void> => {
   }
 };
 
-// As it happens — from the build seat that builds now, and the retired one while it still answers — and
-// what the mesh already held when this module asked what it missed (novox/hq issue 712).
-for (const heard of BUILD_EVENTS) await on(heard, placeTheBuild);
+// **From the builder's log** (novox/hq ADR 0571 clauses 1 and 9). The builder keeps every build's end in a log of its
+// own and answers the builds that ended since a time by its tool. This module asks at its start for what it missed (all
+// the log holds, taken in as history: registered, announced to nobody), and again whenever the builder's state of done
+// keys changes, for what ended since the last build it took in. Registering a build already held changes nothing, and a
+// build is taken in once per run of this module.
+const taken = new Set<string>();
+let since = new Date(0).toISOString();
+let caughtUp = false;
+let asking: Promise<void> | undefined;
+let askAgain = false;
 
-// **And ask for what was built before this catalogue existed** (novox/hq 04-ISSUES/050).
-//
-// The queue above is durable, so nothing is missed once this is running. What it cannot have is
-// what was announced before it first ran — and on a fresh mesh that is never arbitrary: the shared
-// base, the store this runs on, and this module itself are each necessarily built BEFORE a
-// catalogue exists to hear about them. The graph's foundation is the part it never sees.
-//
-// Asked on every start, not only the first. A catalogue cannot tell whether it has a gap, and the
-// answer is idempotent: registering a build already held changes nothing and announces nothing.
-// Asked AFTER subscribing, so a build arriving during the replay is not lost between the two.
+const manifestOf = async (digest: string | undefined): Promise<unknown> => {
+  if (!digest) return {};
+  const held = await state<{ manifest?: string }>(MANIFESTS_STATE).get(digest);
+  if (!held?.value.manifest) return {};
+  return JSON.parse(held.value.manifest);
+};
+
+const takeIn = async (e: LogEntry, replay: boolean): Promise<void> => {
+  const key = `${e.module}/${e.fp}`;
+  if (taken.has(key)) return;
+  const built = builtFrom(e, await manifestOf(e.manifest), replay);
+  if (!built) return;
+  await placeTheBuild({ body: built });
+  taken.add(key);
+};
+
+const catchUp = async (): Promise<void> => {
+  for (;;) {
+    const answer = answerOf<BuildsSince>(
+      await invokeTool(broker(), BUILDER, BUILDS_SINCE_TOOL, { since }),
+    );
+    for (const e of answer.builds ?? []) {
+      await takeIn(e, !caughtUp);
+      if (e.at > since) since = e.at;
+    }
+    if (!answer.more) break;
+  }
+  caughtUp = true;
+};
+
+/** One ask at a time; a change heard while asking is asked for again once, so none is missed. */
+const ask = (): Promise<void> => {
+  if (asking) {
+    askAgain = true;
+    return asking;
+  }
+  asking = (async () => {
+    try {
+      do {
+        askAgain = false;
+        await catchUp();
+      } while (askAgain);
+    } catch (err) {
+      console.error("mesh-catalog: the builder's builds since", since, "could not be taken in:", err);
+    } finally {
+      asking = undefined;
+    }
+  })();
+  return asking;
+};
+
+// Asked AFTER watching begins, so a build ending while the first ask runs asks again rather than being missed: the watch
+// hands every current key first (the start's ask), then every change.
+await state(BUILDS_STATE).watch(async (change) => {
+  if (!change.current) await ask();
+});
+await ask();
+
+// **And say that this catalogue has caught up** (novox/hq 04-ISSUES/050).
 await emit("catching-up", {});

modules/mesh-catalog/module.json

@@ -25,9 +25,7 @@
   "secrets": {
     "postgres-database": "${dir:state}/database.secret"
   },
-  "consumes": [
-    "mesh-controller.built-before"
-  ],
+  "consumes": [],
   "emits": [
     "registered",
     "upgraded",
@@ -92,5 +90,12 @@
         "from": "files"
       }
     ]
-  }
+  },
+  "invokes": [
+    "mesh-delivery-builder.builder_builds_since"
+  ],
+  "reads": [
+    "mesh-delivery-builder.builds",
+    "mesh-delivery-indexer.manifests"
+  ]
 }

modules/mesh-catalog/test/heard.test.ts

@@ -2,7 +2,7 @@ import { test } from "node:test";
 import assert from "node:assert/strict";
 import { readFile } from "node:fs/promises";
 
-import { BUILD_EVENTS, placeable } from "../heard.js";
+import { answerOf, builtFrom, placeable, BUILDER, BUILDS_SINCE_TOOL, BUILDS_STATE, MANIFESTS_STATE } from "../heard.js";
 
 // A walk's build as the build seat says it (mesh-controller's link.BuildResult), here mailu's of novox/hq issue 712.
 const walkBuild = {
@@ -20,14 +20,25 @@ const walkBuild = {
   made: [{ name: "code", kind: "bundle", reference: "artifact-store://mailu/code/blobs/sha256:d041" }],
 };
 
-test("the catalogue hears no retired build seat, and what the mesh held (issue 712, issue 1887 E2)", async () => {
-  for (const retired of ["node-build-agent.built", "mesh-build-machine.built"]) {
-    assert.ok(!(BUILD_EVENTS as readonly string[]).includes(retired), `${retired} is still heard`);
-  }
-  assert.ok(BUILD_EVENTS.includes("mesh-controller.built-before"));
-  // Subscribing is not enough: the mesh grants and routes only what the manifest consumes.
+test("the catalogue takes builds from the builder's log, and hears no controller event (ADR 0571 clause 9)", async () => {
   const manifest = JSON.parse(await readFile(new URL("../module.json", import.meta.url), "utf8"));
-  for (const heard of BUILD_EVENTS) assert.ok(manifest.consumes.includes(heard), `${heard} is not consumed`);
+  assert.deepEqual(manifest.consumes, []);
+  assert.ok(manifest.invokes.includes(`${BUILDER}.${BUILDS_SINCE_TOOL}`), "the builder's tool is not invoked");
+  for (const read of [BUILDS_STATE, MANIFESTS_STATE]) assert.ok(manifest.reads.includes(read), `${read} is not read`);
+  // A log entry is placed as a build: done with its manifest, made and against; failed passed over; queued not taken in.
+  const entry = { event: "build.ended", module: "mailu", fp: "fp1", repository: walkBuild.repository, directory: "modules/mailu",
+    commit: walkBuild.commit, ref: "main", at: "2026-10-29T20:00:00Z", outcome: "done", manifest: "ab", against: ["img@sha256:1"],
+    made: walkBuild.made };
+  const done = builtFrom(entry, walkBuild.manifest, false);
+  assert.deepEqual(placeable(done!), { placed: "yes", module: "mailu", commit: walkBuild.commit });
+  assert.deepEqual([done!.path, done!.against, done!.replay], ["modules/mailu", ["img@sha256:1"], false]);
+  assert.equal(placeable(builtFrom({ ...entry, outcome: "failed" }, {}, true)!).placed, "no");
+  assert.equal(builtFrom({ ...entry, outcome: "queued" }, {}, true), undefined);
+  // The tool's answer is read bare or as the runtime wraps it.
+  const bare = { since: "x", builds: [entry] };
+  for (const raw of [bare, { output: JSON.stringify(bare) }, { content: [{ text: JSON.stringify(bare) }] }]) {
+    assert.equal(answerOf<typeof bare>(raw).builds[0].module, "mailu");
+  }
 });
 
 test("a walk's build is placed, under its module and commit", () => {

modules/mesh-conditions/cmd/mesh-conditions/compare.go

@@ -0,0 +1,221 @@
+package main
+
+// **Built dark, compared, then switched by the operator** (novox/hq ADR 0564 clause 9; issue 1952 C5, C8): `compare`
+// lists the open keys of the keeper and of the controller, each difference with its reason; the kinds that end with the
+// controller, the kinds only the keeper raises and the keys held while their module is delivered are listed apart and
+// not counted. `take-over` raises an approve ask under the keeper's own name (ADR 0259), refused while compare shows a
+// difference, and on the warrant writes the take-over key naming the keeper. `hand-back` writes it back to the
+// controller until the lease write, and is refused after it.
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/asks"
+	"git.novox.be/novox/mesh-sdk/go/health"
+)
+
+// Difference is one key the two sides do not agree on, or one listed apart.
+type Difference struct {
+	Key    string `json:"key"`
+	Kind   string `json:"kind"`
+	Reason string `json:"reason"`
+}
+
+// Comparison is compare's answer.
+type Comparison struct {
+	Differences []Difference `json:"differences"`
+	// Apart are the keys not counted: of kinds that end with the controller, raised only by the keeper, or held.
+	Apart []Difference `json:"apart"`
+	Same  int          `json:"same"`
+	At    time.Time    `json:"at"`
+}
+
+// Empty says nothing differs.
+func (c Comparison) Empty() bool { return len(c.Differences) == 0 }
+
+// Compare is the keeper's open conditions against the controller's.
+func (k *Keeper) Compare() (Comparison, error) {
+	mine, err := k.Open()
+	if err != nil {
+		return Comparison{}, err
+	}
+	k.mu.Lock()
+	k.init()
+	theirs := map[string]health.Condition{}
+	for key, c := range k.ctrl {
+		theirs[key] = c
+	}
+	heldNow := map[string]held{}
+	for key, h := range k.held {
+		heldNow[key] = h
+	}
+	k.mu.Unlock()
+	out := Comparison{Differences: []Difference{}, Apart: []Difference{}, At: k.Now().UTC()}
+	open := map[string]health.Condition{}
+	for _, c := range mine {
+		open[c.Key] = c
+	}
+	keys := map[string]bool{}
+	for key := range open {
+		keys[key] = true
+	}
+	for key := range theirs {
+		keys[key] = true
+	}
+	for key := range heldNow {
+		keys[key] = true
+	}
+	sorted := make([]string, 0, len(keys))
+	for key := range keys {
+		sorted = append(sorted, key)
+	}
+	sort.Strings(sorted)
+	for _, key := range sorted {
+		c, inMine := open[key]
+		t, inTheirs := theirs[key]
+		kind := c.Kind
+		if !inMine {
+			kind = t.Kind
+		}
+		home, homed := k.homeOf(kind)
+		if h, ok := heldNow[key]; ok {
+			out.Apart = append(out.Apart, Difference{Key: key, Kind: kind,
+				Reason: fmt.Sprintf("held while %s is delivered on %s (version %s)", h.Module, h.Node, short(h.Version))})
+			continue
+		}
+		switch {
+		case homed && (home.Carried || home.Replaced):
+			why := "ends with the controller: carried from its bucket until the lease write"
+			if home.Replaced {
+				why = "ends with the controller: its fault is observed otherwise"
+			}
+			if home.Why != "" {
+				why += " (" + home.Why + ")"
+			}
+			out.Apart = append(out.Apart, Difference{Key: key, Kind: kind, Reason: why})
+		case inMine && !inTheirs && (!homed || !home.Controller):
+			out.Apart = append(out.Apart, Difference{Key: key, Kind: kind, Reason: "keeper only: the controller never raises this kind"})
+		case inMine && !inTheirs:
+			out.Differences = append(out.Differences, Difference{Key: key, Kind: kind,
+				Reason: "open at the keeper, not at the controller"})
+		case !inMine && !homed:
+			out.Differences = append(out.Differences, Difference{Key: key, Kind: kind,
+				Reason: fmt.Sprintf("open at the controller; no home is decided for the kind %s (ADR 0564's gap)", kind)})
+		case !inMine:
+			out.Differences = append(out.Differences, Difference{Key: key, Kind: kind,
+				Reason: fmt.Sprintf("open at the controller; %s has not written its finding", home.Observer)})
+		case c.Severity != t.Severity:
+			out.Differences = append(out.Differences, Difference{Key: key, Kind: kind,
+				Reason: fmt.Sprintf("%s at the keeper, %s at the controller", c.Severity, t.Severity)})
+		default:
+			out.Same++
+		}
+	}
+	return out, nil
+}
+
+// Asks is the operator channel as the keeper asks it: an approve ask under its own name, and where one stands.
+type Asks interface {
+	Ask(a asks.Ask) error
+}
+
+// TakeOver raises the approve ask of a switch to the keeper, refused while compare differs or after the lease write.
+func (k *Keeper) TakeOver(a Asks, by, why string) (map[string]any, error) {
+	if strings.TrimSpace(why) == "" {
+		return nil, errors.New("a take-over says why")
+	}
+	if k.LeaseAway() {
+		return nil, errors.New("the controller's lease is handed away: the keeper is the one source already")
+	}
+	cmp, err := k.Compare()
+	if err != nil {
+		return nil, err
+	}
+	if !cmp.Empty() {
+		return nil, fmt.Errorf("refused: compare shows %d difference(s), the first %s (%s); the take-over waits for none",
+			len(cmp.Differences), cmp.Differences[0].Key, cmp.Differences[0].Reason)
+	}
+	now := k.Now().UTC()
+	id := fmt.Sprintf("take-over-%d", now.UnixNano())
+	act := asks.Act{"verb": Seat + ".take-over", "module": Module, "ask": id}
+	bind, err := asks.ActDigest(act)
+	if err != nil {
+		return nil, err
+	}
+	ask := asks.Ask{ID: id, Headline: "Switch the mesh's alarms to the new keeper?", Who: asks.Operator,
+		Explanation: fmt.Sprintf("The new condition keeper holds the same %d open alarms as the controller. Your yes makes "+
+			"the alarm messages come from the keeper, with the same words. It can be handed back until the controller "+
+			"gives up its lease.", cmp.Same),
+		Options: []asks.Option{{ID: "yes", Label: "Yes, switch", Does: "Alarms come from the keeper.", Level: asks.Approve, Binds: bind},
+			{ID: "no", Label: "No, leave it", Does: "Alarms keep coming from the controller.", Level: asks.Acknowledge}},
+		Expires: now.Add(asks.ApproveLasts - time.Minute), OnExpiry: "Alarms keep coming from the controller.",
+		About: Module + "-take-over", Details: "Asked by " + by + ": " + why}
+	if err := a.Ask(ask); err != nil {
+		return nil, err
+	}
+	return map[string]any{"asked": id, "same": cmp.Same, "apart": len(cmp.Apart)}, nil
+}
+
+// Warranted is the act on the operator's answer: a yes, compare still empty, writes the take-over key naming the keeper.
+func (k *Keeper) Warranted(o asks.Option, w asks.Warrant) error {
+	if o.ID != "yes" {
+		k.Logf("the take-over %s was answered %s: alarms stay with the controller", w.Ask, o.ID)
+		return nil
+	}
+	cmp, err := k.Compare()
+	if err != nil {
+		return err
+	}
+	if !cmp.Empty() {
+		return fmt.Errorf("the take-over %s was approved, and compare now shows %d difference(s): not switched", w.Ask,
+			len(cmp.Differences))
+	}
+	return k.writeTakeover(health.Takeover{Follow: health.FollowKeeper, At: k.Now().UTC(), By: w.Says(), Ask: w.Ask})
+}
+
+// HandBack switches the readers back to the controller, until the lease write.
+func (k *Keeper) HandBack(by, why string) (map[string]any, error) {
+	if strings.TrimSpace(why) == "" {
+		return nil, errors.New("a hand-back says why")
+	}
+	if k.LeaseAway() {
+		return nil, errors.New("refused: the controller's lease is handed away, so there is no controller to hand back to")
+	}
+	t := health.Takeover{Follow: health.FollowController, At: k.Now().UTC(), By: by, Why: why}
+	if err := k.writeTakeover(t); err != nil {
+		return nil, err
+	}
+	return map[string]any{"follow": t.Follow, "at": t.At}, nil
+}
+
+// writeTakeover writes the take-over key, and keeps it in history as the record of the switch.
+func (k *Keeper) writeTakeover(t health.Takeover) error {
+	raw, err := health.EncodeTakeover(t)
+	if err != nil {
+		return err
+	}
+	_, rev, found, err := k.Store.Get(TakeoverState, health.TakeoverKey)
+	if err != nil {
+		return err
+	}
+	if found {
+		_, err = k.Store.Update(TakeoverState, health.TakeoverKey, json.RawMessage(raw), rev)
+	} else {
+		_, err = k.Store.Create(TakeoverState, health.TakeoverKey, json.RawMessage(raw))
+	}
+	if errors.Is(err, stdio.ErrChanged) {
+		return fmt.Errorf("the take-over key moved under this write: read it again and ask again")
+	}
+	if err != nil {
+		return err
+	}
+	k.Takeover(t)
+	k.Logf("the readers of conditions follow the %s from now (%s)", t.Follow, t.By)
+	return nil
+}

modules/mesh-conditions/cmd/mesh-conditions/hold.go

@@ -0,0 +1,340 @@
+package main
+
+// **A module being delivered raises no condition until its delivery ends** (novox/hq ADR 0564 clause 13 and Limits 12;
+// issue 1952 C7, C8). The keeper reads the assigner's wants and the nodes' haves, and judges a module's delivery on a
+// node with mesh-sdk's delivery.MotionOf, as the view does. While it is delivered there, a finding about it there, or
+// about what it serves, and a condition carried from the controller's bucket on those subjects, is kept in the state
+// `held` and raises nothing. When the delivery ends, healthy at the want or failed, what still stands is raised once,
+// saying it happened during the delivery; what went is dropped with a log line. The hold lasts at most the delivery's
+// bound, a key of the state `bounds` whose time to live is the bound: its expiry raises what is held, saying the delivery
+// did not end. A finding about another module or about the machine itself is never held. A condition already open is
+// not held: it is no news.
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	stdio "git.novox.be/novox/mesh-sdk/go"
+	"git.novox.be/novox/mesh-sdk/go/delivery"
+	"git.novox.be/novox/mesh-sdk/go/health"
+)
+
+// The modules whose delivery holds what they serve beyond their own findings (Limits 12).
+const (
+	controllerModule = "mesh-controller"
+	runtimeModule    = "node-tools"
+)
+
+// controllerServes are the sources of what the controller serves while it is delivered: its listening, its lease, its
+// writes and its facts (ADR 0505 §2 (a)), matched to mesh-controller whatever its key names.
+var controllerServes = map[string]bool{"S4": true, "S7": true, "S12": true, "S13": true, "S14": true, "S25": true}
+
+// about is a node and a module a finding or a condition is about, for the hold.
+type about struct{ Node, Module string }
+
+// aboutOf are the modules on nodes a condition's subject is about (Limits 12): a module on a machine, a provider on its
+// node, a seat of the same name as its module on a machine, the controller's own work wherever mesh-controller is
+// delivered, and every module's tools on a machine whose tool runner is delivered. Never the machine itself.
+func (k *Keeper) aboutOf(kind, source string, s health.Subject) []about {
+	var out []about
+	parts := strings.Split(s.ID, ".")
+	switch s.Scope {
+	case health.ScopeModule:
+		if len(parts) >= 2 {
+			out = append(out, about{Node: parts[len(parts)-1], Module: strings.Join(parts[:len(parts)-1], ".")})
+		}
+	case health.ScopeProvider:
+		if len(parts) >= 2 {
+			out = append(out, about{Node: parts[1], Module: parts[0]})
+		}
+	case health.ScopeSeat:
+		// The module the placement says holds the seat on that node, or the seat's own name where none is read.
+		if len(parts) >= 2 {
+			node, seat := parts[len(parts)-1], strings.Join(parts[:len(parts)-1], ".")
+			module := k.holders[node+"."+seat]
+			if module == "" {
+				module = seat
+			}
+			out = append(out, about{Node: node, Module: module})
+		}
+	case health.ScopeMachine:
+		// The machine itself (presence, network, resolver, disk) is never held; its tools are, while its tool runner is
+		// delivered.
+		if source == "S11" || kind == "tools-silent" {
+			out = append(out, about{Node: s.Machine, Module: runtimeModule})
+			if s.Machine == "" && len(parts) > 0 {
+				out[len(out)-1].Node = parts[0]
+			}
+		}
+		return out
+	}
+	if controllerServes[source] || (s.Scope == health.ScopeCore && strings.HasPrefix(s.ID, "controller")) {
+		for hk := range k.wants {
+			if node, module := splitNodeModule(hk); module == controllerModule {
+				out = append(out, about{Node: node, Module: module})
+			}
+		}
+	}
+	if s.Machine != "" && s.Scope != health.ScopeMachine {
+		out = append(out, about{Node: s.Machine, Module: runtimeModule})
+	}
+	return out
+}
+
+func splitNodeModule(hk string) (string, string) {
+	node, module, _ := strings.Cut(hk, ".")
+	return node, module
+}
+
+// motion is the delivery of module on node, from its want and have.
+func (k *Keeper) motion(node, module string) (delivery.Motion, delivery.Want) {
+	w, wanted := k.wants[node+"."+module]
+	h, has := k.haves[node+"."+module]
+	return delivery.MotionOf(w, wanted, h, has, "", false), w
+}
+
+// holdFor says whether key is held now, and as what. Called with mu held.
+func (k *Keeper) holdFor(key string, f *health.Finding, carried *health.Condition, open bool) (held, bool) {
+	if open || (f == nil && carried == nil) {
+		return held{}, false
+	}
+	var kind, source string
+	var subject health.Subject
+	if f != nil {
+		kind, source, subject = f.Kind, f.Source, f.Subject
+	} else {
+		kind, source, subject = carried.Kind, carried.Source, carried.Subject
+	}
+	if _, raisedOut := k.outOfHold[key]; raisedOut {
+		return held{}, false
+	}
+	for _, a := range k.aboutOf(kind, source, subject) {
+		m, w := k.motion(a.Node, a.Module)
+		if !m.Delivering || m.Ended() || k.passed[a.Node+"."+a.Module] == w.FP {
+			continue
+		}
+		since := k.Now().UTC()
+		if was, ok := k.held[key]; ok {
+			since = was.Since
+		}
+		return held{Key: key, Node: a.Node, Module: a.Module, Since: since, Version: w.FP}, true
+	}
+	return held{}, false
+}
+
+// keepHeld keeps a held key in the state `held`, and starts its delivery's bound once.
+func (k *Keeper) keepHeld(h held) error {
+	k.mu.Lock()
+	_, was := k.held[h.Key]
+	k.held[h.Key] = h
+	bound := k.bound(h.Module)
+	k.mu.Unlock()
+	if was {
+		return nil
+	}
+	if _, err := k.Store.Create(HeldState, h.Key, h); err != nil && !errors.Is(err, stdio.ErrChanged) {
+		return fmt.Errorf("keeping %s held: %w", h.Key, err)
+	}
+	b := boundKey(h.Node, h.Module)
+	err := k.Store.CreateTTL(BoundsState, b, map[string]any{"node": h.Node, "module": h.Module, "version": h.Version,
+		"bound-seconds": int(bound / time.Second)}, bound)
+	if err != nil && !errors.Is(err, stdio.ErrChanged) {
+		return fmt.Errorf("starting the bound of %s's delivery on %s: %w", h.Module, h.Node, err)
+	}
+	k.Logf("held %s while %s is delivered on %s (version %s), at most %s", h.Key, h.Module, h.Node, h.Version, bound)
+	return nil
+}
+
+// bound is a module's delivery bound: its manifest names none yet, so the default (clause 13 (d)). Each key of the state
+// `bounds` is written with it as its own time to live, and its expiry is the bound passing.
+func (k *Keeper) bound(string) time.Duration {
+	if k.Bound > 0 {
+		return k.Bound
+	}
+	return delivery.DefaultDeliveryBound
+}
+
+func boundKey(node, module string) string { return node + "." + module }
+
+// dropHeld lets a held key go: raised, or gone with why said.
+func (k *Keeper) dropHeld(key, why string) {
+	k.mu.Lock()
+	h, ok := k.held[key]
+	delete(k.held, key)
+	k.mu.Unlock()
+	if !ok {
+		return
+	}
+	if err := k.Store.Delete(HeldState, key); err != nil {
+		k.Logf("the held %s could not be removed from held: %v", key, err)
+	}
+	if why != "" {
+		k.Logf("dropped %s, held while %s was delivered on %s: %s", key, h.Module, h.Node, why)
+	}
+}
+
+// Want takes one change of the assigner's wants; Have one of the nodes' haves. Each may end a delivery, which raises or
+// drops what it held.
+func (k *Keeper) Want(key string, value []byte, deleted bool) error {
+	node, module, err := delivery.ParseWantKey(key)
+	if err != nil {
+		return nil // not a want of a module on a node (a held fingerprint's key)
+	}
+	k.mu.Lock()
+	k.init()
+	if deleted {
+		delete(k.wants, node+"."+module)
+	} else if w, err := delivery.DecodeWant(value); err == nil {
+		k.wants[node+"."+module] = w
+	} else {
+		k.Logf("the want %s is not readable: %v", key, err)
+	}
+	k.mu.Unlock()
+	return k.judge(node, module, "")
+}
+
+// Have takes one change of a node's have.
+func (k *Keeper) Have(key string, value []byte, deleted bool) error {
+	node, module, isNode, err := delivery.ParseHaveKey(key)
+	if err != nil || isNode {
+		return nil
+	}
+	k.mu.Lock()
+	k.init()
+	if deleted {
+		delete(k.haves, node+"."+module)
+	} else if h, err := delivery.DecodeHave(value); err == nil {
+		k.haves[node+"."+module] = h
+	} else {
+		k.Logf("the have %s is not readable: %v", key, err)
+	}
+	k.mu.Unlock()
+	return k.judge(node, module, "")
+}
+
+// Placement takes one change of the placement: which module holds which seat on a node.
+func (k *Keeper) Placement(key string, value []byte, deleted bool) {
+	node, err := delivery.ParsePlacementKey(key)
+	if err != nil {
+		return
+	}
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	k.init()
+	for hk := range k.holders {
+		if strings.HasPrefix(hk, node+".") {
+			delete(k.holders, hk)
+		}
+	}
+	if deleted {
+		return
+	}
+	p, err := delivery.DecodePlacement(value)
+	if err != nil {
+		k.Logf("the placement of %s is not readable, so its seats' holders are not known: %v", node, err)
+		return
+	}
+	for _, h := range p.Holds {
+		k.holders[node+"."+h.Claim] = h.Module
+	}
+}
+
+// BoundPassed is a delivery's bound key expiring: what it holds is raised, saying the delivery did not end.
+func (k *Keeper) BoundPassed(key string) error {
+	node, module := splitNodeModule(key)
+	k.mu.Lock()
+	k.init()
+	_, w := k.motion(node, module)
+	holding := false
+	for _, h := range k.held {
+		holding = holding || (h.Node == node && h.Module == module)
+	}
+	if !holding {
+		k.mu.Unlock()
+		return nil
+	}
+	k.passed[key] = w.FP
+	k.mu.Unlock()
+	return k.judge(node, module, fmt.Sprintf("Its delivery of version %s on %s did not end within %s.", short(w.FP), node,
+		k.bound(module)))
+}
+
+// judge raises or drops what node and module hold when their delivery ended, or with line past its bound.
+func (k *Keeper) judge(node, module, line string) error {
+	k.mu.Lock()
+	m, w := k.motion(node, module)
+	var keys []string
+	for key, h := range k.held {
+		if h.Node == node && h.Module == module {
+			keys = append(keys, key)
+		}
+	}
+	if line == "" && !m.Ended() && m.Delivering {
+		k.mu.Unlock()
+		return nil
+	}
+	if line == "" {
+		line = fmt.Sprintf("It happened during the delivery of version %s of %s on %s.", short(w.FP), module, node)
+		if m.Failed {
+			line = fmt.Sprintf("It happened as the delivery of version %s of %s on %s failed.", short(w.FP), module, node)
+		}
+		delete(k.passed, node+"."+module)
+	}
+	for _, key := range keys {
+		k.outOfHold[key] = line
+	}
+	k.mu.Unlock()
+	sort.Strings(keys)
+	var problems []string
+	for _, key := range keys {
+		k.dropHeld(key, "")
+		if err := k.Settle(key); err != nil {
+			problems = append(problems, err.Error())
+		}
+		k.mu.Lock()
+		delete(k.outOfHold, key)
+		k.mu.Unlock()
+	}
+	if len(problems) > 0 {
+		return errors.New(strings.Join(problems, "; "))
+	}
+	return nil
+}
+
+func short(fp string) string {
+	if _, rest, ok := strings.Cut(fp, ":"); ok {
+		fp = rest
+	}
+	if len(fp) > 12 {
+		return fp[:12]
+	}
+	return fp
+}
+
+// Held is every key held now, for the read tool and compare.
+func (k *Keeper) Held() []held {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	out := make([]held, 0, len(k.held))
+	for _, h := range k.held {
+		out = append(out, h)
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Key < out[j].Key })
+	return out
+}
+
+// restoreHeld takes the state `held` as read at the start.
+func (k *Keeper) restoreHeld(key string, value []byte) {
+	var h held
+	if json.Unmarshal(value, &h) != nil {
+		return
+	}
+	k.mu.Lock()
+	k.init()
+	k.held[key] = h
+	k.mu.Unlock()
+}