The mesh's interface takes over the found tunnel's MTU

Carries MTU from the reported tunnel (mesh-host#28) through inventory,
the overlay graph's TakeOver, into the generated config's [Interface].
A tuned path keeps its MTU across the takeover instead of regressing to
1420 and hanging transfers no ping would reveal. Two emit tests; a
tunnel with no MTU writes no line.

cmd/mesh-builder/main.go

@@ -24,6 +24,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net/url"
 	"os"
 	"os/signal"
 	"strings"
@@ -202,6 +203,7 @@ func answer(ctx context.Context, channel *amqp.Channel, publisher builder.Publis
 		// not after a clone that then fails at npm ci.
 		built, err = builder.Build(ctx, builder.Command, publisher,
 			request.Repository, request.Path, request.Ref, workspace, request.Held, npmrc,
+			forgeFrom(),
 			func(step, message string) {
 				fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message)
 			})
@@ -367,6 +369,53 @@ func packagesFrom() (builder.Npmrc, error) {
 	return builder.Npmrc{Scope: scope, Registry: registry, Token: secret}, nil
 }
 
+// forgeFrom is the git credential this builder may offer a clone, composed from the same binding
+// and sealed secret its package-registry half already reads: the forge that answers npm is the
+// forge that hosts the repositories, and its provisioner applies one password to one user for
+// both. Anything missing means no credential, and every clone stays anonymous — which is all a
+// mesh of public repositories ever needs.
+//
+// The URL names the binding's own address — the machine the mesh says the forge is on — so a
+// private repository is registered and built by that address, and a clone of anything else is
+// never shown this credential (git's credential store matches the whole origin).
+func forgeFrom() builder.GitCredential {
+	path := strings.TrimSpace(os.Getenv("MESH_PACKAGE_BINDING"))
+	if path == "" {
+		return builder.GitCredential{}
+	}
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return builder.GitCredential{}
+	}
+	var told struct {
+		At     string         `json:"at"`
+		As     string         `json:"as"`
+		Serves map[string]any `json:"serves"`
+	}
+	if err := json.Unmarshal(raw, &told); err != nil || told.At == "" || told.As == "" {
+		return builder.GitCredential{}
+	}
+	secret := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN"))
+	if file := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN_FILE")); file != "" {
+		if raw, err := os.ReadFile(file); err == nil {
+			secret = strings.TrimSpace(string(raw))
+		}
+	}
+	if secret == "" {
+		return builder.GitCredential{}
+	}
+	scheme := "https"
+	if s, ok := told.Serves["scheme"]; ok {
+		scheme = fmt.Sprintf("%v", s)
+	}
+	host := told.At
+	if port, ok := told.Serves["port"]; ok {
+		host = fmt.Sprintf("%s:%v", told.At, port)
+	}
+	made := url.URL{Scheme: scheme, User: url.UserPassword(told.As, secret), Host: host}
+	return builder.GitCredential{URL: made.String()}
+}
+
 func short(commit string) string {
 	if len(commit) > 8 {
 		return commit[:8]

cmd/mesh-builder/once.go

@@ -89,6 +89,7 @@ func buildOnce(ctx context.Context, args []string) error {
 		return err
 	}
 	built, buildErr := builder.Build(ctx, builder.Command, publisher, repository, *path, *ref, where, bases, npmrc,
+		forgeFrom(),
 		func(step, message string) { fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message) })
 	if buildErr != nil {
 		return buildErr

cmd/mesh-controller/acts.go

@@ -46,9 +46,16 @@ func assign(ctx context.Context, open *stores, node, module string) (string, err
 		return "", err
 	}
 	defer release()
-	if err := open.inventory.Assign(ctx, node, module); err != nil {
+	fresh, err := open.inventory.Assign(ctx, node, module)
+	if err != nil {
 		return "", err
 	}
+	if !fresh {
+		// Nothing changed, and saying "is assigned" would read as an action. One node runs one
+		// of each — the module's name is the assignment's identity (novox/hq ADR 0115).
+		return fmt.Sprintf("%s already runs %s — one node runs one of each (ADR 0115); nothing changed",
+			node, module), nil
+	}
 	said := fmt.Sprintf("%s is assigned %s", node, module)
 	plan, _, err := planFor(ctx, open, node)
 	if err != nil {

cmd/mesh-controller/adoption.go

@@ -355,7 +355,7 @@ func converge(ctx context.Context, open *stores, node string, yes bool, digest s
 			strings.Join(assigned, ", "))
 	}
 	if !slices.Contains(assigned, filter) {
-		if err := inv.Assign(ctx, node, filter); err != nil {
+		if _, err := inv.Assign(ctx, node, filter); err != nil {
 			return "", err
 		}
 		if _, _, err := planFor(ctx, open, node); err != nil {

cmd/mesh-controller/build.go

@@ -46,25 +46,35 @@ func buildCommand(ctx context.Context, args []string) error {
 	// retype each repository is asking them to be the loop. Naming a repository and asking which
 	// ones need building are different requests, so they are not combined.
 	behind := set.Bool("behind", false, "every module the mesh holds older than its source has")
+	// A repository on the mesh's own forge, named by its path there (novox/hq ADR 0111). Without it
+	// the repository is external, cloned exactly as given — see source.go.
+	self := set.Bool("self", false, "the repository is a path on the forge holding the git seat")
 	positionals, err := parseAround(set, args)
 	if err != nil {
 		return err
 	}
 	if *behind {
-		if len(positionals) != 0 {
+		if len(positionals) != 0 || *self {
 			return errors.New("build <repository> or build --behind, not both: one names a " +
 				"repository and the other asks which need building")
 		}
 		return buildBehind(ctx, *wait)
 	}
 	if len(positionals) != 1 {
-		return errors.New("build <repository> [--ref R] [--wait D] [--dry-run]")
+		return errors.New("build <repository> [--self] [--path P] [--ref R] [--wait D] [--dry-run]")
+	}
+	source := buildSource{Repository: positionals[0]}
+	if *self {
+		if err := onASeat(source.Repository); err != nil {
+			return err
+		}
+		source.Seat = gitSeat
 	}
 
 	if *dryRun {
-		return buildAndShow(ctx, positionals[0], *path, *ref, *wait)
+		return buildAndShow(ctx, source, *path, *ref, *wait)
 	}
-	return buildOne(ctx, positionals[0], *path, *ref, *wait)
+	return buildOne(ctx, source, *path, *ref, *wait)
 }
 
 // buildFrom turns what a builder said into what the mesh keeps.
@@ -325,7 +335,8 @@ func buildBehind(ctx context.Context, wait time.Duration) error {
 		// Its own recorded ref, not its head commit: a module tracking a branch should be built
 		// from that branch, and pinning to the commit the mesh happened to notice would quietly
 		// turn a tracked branch into a pin.
-		if err := buildOne(ctx, e.Source.Repository, e.Source.Path, e.Source.Ref, wait); err != nil {
+		source := buildSource{Repository: e.Source.Repository, Seat: e.Source.Seat}
+		if err := buildOne(ctx, source, e.Source.Path, e.Source.Ref, wait); err != nil {
 			fmt.Printf("  %v\n", err)
 			failed = append(failed, e.Manifest.Module)
 		}
@@ -343,7 +354,14 @@ func buildBehind(ctx context.Context, wait time.Duration) error {
 // buildOne asks a build machine for one repository and records everything that came back.
 //
 // Separated from the command so `--behind` can walk a list without a second path to the same act.
-func buildOne(ctx context.Context, repository, path, ref string, wait time.Duration) error {
+func buildOne(ctx context.Context, source buildSource, path, ref string, wait time.Duration) error {
+	// Before anything is asked of a builder: a source on a seat nobody holds is refused here, with
+	// the reason, rather than sent to a machine to fail at `git clone`.
+	repository, err := cloneFrom(ctx, source)
+	if err != nil {
+		return err
+	}
+
 	ident, err := openIdentity(ctx)
 	if err != nil {
 		return err
@@ -365,7 +383,10 @@ func buildOne(ctx context.Context, repository, path, ref string, wait time.Durat
 		Ref:        ref,
 		Held:       heldBy(ctx),
 	}
-	fmt.Printf("asked for %s", request.Repository)
+	fmt.Printf("asked for %s", source)
+	if source.Seat != "" {
+		fmt.Printf(" (%s)", repository)
+	}
 	if path != "" {
 		fmt.Printf(" at %s", path)
 	}
@@ -414,11 +435,18 @@ func buildOne(ctx context.Context, repository, path, ref string, wait time.Durat
 	}
 
 	// Recorded with where it came from, so "is this current?" is answerable without building it
-	// again (novox/hq ADR 0009).
-	if err := inv.RegisterModule(ctx, manifest, inventory.Source{
+	// again (novox/hq ADR 0009). **For a source on a seat, as the path and the seat, never the URL
+	// just cloned** (ADR 0111): the URL is where the forge runs today, and recording it would put
+	// the forge's address back into every module built from it. The build log above keeps the URL,
+	// because that is what was cloned.
+	recorded := inventory.Source{
 		Repository: result.Repository, Path: result.Path, Ref: result.Ref,
 		BuiltFrom: result.Commit, Head: result.Commit,
-	}); err != nil {
+	}
+	if source.Seat != "" {
+		recorded.Repository, recorded.Seat = source.Repository, source.Seat
+	}
+	if err := inv.RegisterModule(ctx, manifest, recorded); err != nil {
 		return err
 	}
 	fmt.Printf("\n%s %s, built on %s from %s\n",
@@ -428,7 +456,11 @@ func buildOne(ctx context.Context, repository, path, ref string, wait time.Durat
 }
 
 // buildAndShow builds and prints the manifest without recording anything.
-func buildAndShow(ctx context.Context, repository, path, ref string, wait time.Duration) error {
+func buildAndShow(ctx context.Context, source buildSource, path, ref string, wait time.Duration) error {
+	repository, err := cloneFrom(ctx, source)
+	if err != nil {
+		return err
+	}
 	ident, err := openIdentity(ctx)
 	if err != nil {
 		return err

cmd/mesh-controller/foundation_scope_test.go

@@ -0,0 +1,33 @@
+package main
+
+// The broker opening belongs only on the node that listens on it (novox/hq: it leaked onto
+// every enrolled node's declaration, opening a from-anywhere hole for a port nothing there
+// serves). foundationPortsFor is the scope.
+
+import (
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+func TestTheBrokerHostGetsTheFoundationOpening(t *testing.T) {
+	broker := catalogue.Manifest{Module: "lavinmq", Listens: []catalogue.Listening{
+		{Port: 5671, Protocol: "tcp", From: "mesh"},
+		{Port: 5672, Protocol: "tcp", From: "mesh"},
+	}}
+	got := foundationPortsFor(5671, []catalogue.Manifest{broker})
+	if len(got) != 1 || got[0] != 5671 {
+		t.Fatalf("the node that listens on the broker port keeps it; got %v", got)
+	}
+}
+
+func TestANodeThatOnlyDialsTheBrokerGetsNoOpening(t *testing.T) {
+	// ace's set: things that reach the broker as a client, none listening on 5671.
+	ace := []catalogue.Manifest{
+		{Module: "plex", Listens: []catalogue.Listening{{Port: 32400, Protocol: "tcp", From: "anywhere"}}},
+		{Module: "postgres", Listens: []catalogue.Listening{{Port: 5432, Protocol: "tcp", From: "mesh"}}},
+	}
+	if got := foundationPortsFor(5671, ace); got != nil {
+		t.Fatalf("a node that only dials out opens nothing for the broker; got %v", got)
+	}
+}

cmd/mesh-controller/main.go

@@ -114,6 +114,8 @@ func run() error {
 		return planCommand(ctx, args[1:])
 	case "push":
 		return pushCommand(ctx, args[1:])
+	case "seats":
+		return seatsCommand(ctx, args[1:])
 	case "status":
 		return statusCommand(ctx, args[1:])
 	case "version":
@@ -157,6 +159,7 @@ func usage() {
   upgrade <name> roll-out [--together]   ...send it to the machines running it
   upgrade <name> record          ...record that they are behind, and send nothing
   status [--json]                what is wrong, what is quiet, and what is out of date
+  seats [--json]                 every seat this mesh defines, what it delivers, and who holds it
   board [--listen ADDR]          the same three questions, as a page that holds nothing
   api --issuer URL [--listen A]  assign and unassign over http, for a surface that is not here
   assign <node> <module>         put a module on a node

cmd/mesh-controller/mesh_for_test.go

@@ -73,7 +73,7 @@ func aMesh(t *testing.T) *stores {
 		if err := open.inventory.RecordOverlayKey(t.Context(), record.ID, aPublicKey(t)); err != nil {
 			t.Fatal(err)
 		}
-		if err := open.inventory.Assign(t.Context(), name, overlay.Name); err != nil {
+		if _, err := open.inventory.Assign(t.Context(), name, overlay.Name); err != nil {
 			t.Fatal(err)
 		}
 	}

cmd/mesh-controller/network.go

@@ -48,7 +48,7 @@ func overlayRange(ctx context.Context, inv *inventory.Inventory) (string, error)
 
 func overlayCommand(ctx context.Context, args []string) error {
 	if len(args) == 0 {
-		return errors.New("overlay place <node> [flags], or overlay show")
+		return errors.New("overlay place <node> [flags], overlay name <address> <name>, or overlay show")
 	}
 	// Answered before anything is opened. A message about which command to use should not need a
 	// database to say so, and needing one turns a redirect into a connection error.
@@ -69,12 +69,29 @@ func overlayCommand(ctx context.Context, args []string) error {
 		return overlayPlace(ctx, inv, args[1:])
 	case "show":
 		return overlayShow(ctx, open)
+	case "name":
+		return overlayName(ctx, inv, args[1:])
 
 	default:
-		return fmt.Errorf("overlay has no %q; it has place and show", args[0])
+		return fmt.Errorf("overlay has no %q; it has place, name and show", args[0])
 	}
 }
 
+// overlayName is the operator saying which machine a carried address is (novox/hq issue 112),
+// so the mesh answers for its name until the machine enrols and verifies it.
+func overlayName(ctx context.Context, inv *inventory.Inventory, args []string) error {
+	if len(args) != 2 {
+		return errors.New("overlay name <carried-address> <node-name>")
+	}
+	address, name := args[0], args[1]
+	if err := inv.NamePeer(ctx, address, name); err != nil {
+		return err
+	}
+	fmt.Printf("the peer at %s is %s until it enrols — the mesh answers for %s.<suffix> from the "+
+		"operator's word, and enrolment under this key must use this name\n", address, name, name)
+	return nil
+}
+
 func overlayPlace(ctx context.Context, inv *inventory.Inventory, args []string) error {
 	if len(args) == 0 {
 		return errors.New(
@@ -239,7 +256,7 @@ func network(ctx context.Context, inv *inventory.Inventory, on map[string]bool,
 					"Re-place it — `overlay place %s --hub --endpoint <host>:%d …` — and push again; "+
 					"nothing was composed", p.Name, t.Interface, wrong, p.Name, t.Port)
 			}
-			n.TakesOver = &overlay.TakeOver{Interface: t.Interface, Unit: t.Unit, Config: t.Config}
+			n.TakesOver = &overlay.TakeOver{Interface: t.Interface, Unit: t.Unit, Config: t.Config, Port: t.Port, MTU: t.MTU}
 		}
 		if p.Hub {
 			for _, c := range carried {
@@ -588,6 +605,24 @@ func namesInTheMesh(ctx context.Context, inv *inventory.Inventory,
 	for _, p := range places {
 		out[overlay.InternalName(p.Name)] = p.Address
 	}
+	// And the carried peers the operator has named (novox/hq issue 112): machines the
+	// predecessor's resolver answers for and the mesh routes to, known by name on the operator's
+	// word until they enrol — at which point enrolment verifies the name and the node's own
+	// entry takes over above. A name the predecessor answers for must keep resolving until the
+	// machine behind it is a node; without these, taking the resolver silences three machines.
+	carried, err := inv.CarriedPeers(ctx)
+	if err != nil {
+		return nil, err
+	}
+	for _, p := range carried {
+		if p.Named == "" || p.EnrolledAs != "" {
+			continue
+		}
+		if _, taken := out[overlay.InternalName(p.Named)]; taken {
+			continue // a node of the mesh owns the name; the stale statement loses
+		}
+		out[overlay.InternalName(p.Named)] = p.Address
+	}
 	return out, nil
 }
 

cmd/mesh-controller/plan.go

@@ -217,6 +217,7 @@ func theRestOfTheMesh(ctx context.Context, inv *inventory.Inventory,
 	}
 
 	offered := map[string][]catalogue.Provider{}
+	var firstHeld []catalogue.Held
 	for _, o := range others {
 		got, err := catalogue.Resolve(shelf, o.assigned, o.node, catalogue.World{Unchecked: true})
 		if err != nil {
@@ -224,6 +225,7 @@ func theRestOfTheMesh(ctx context.Context, inv *inventory.Inventory,
 			// report, and nothing of theirs is running, so it offers nothing.
 			continue
 		}
+		firstHeld = append(firstHeld, got.Claims...)
 		for _, m := range got.Modules {
 			for _, name := range m.OffersAt(catalogue.ScopeMesh) {
 				// What that module says a consumer needs to know, with that node's settings on
@@ -234,7 +236,7 @@ func theRestOfTheMesh(ctx context.Context, inv *inventory.Inventory,
 					return catalogue.World{}, err
 				}
 				offered[name] = append(offered[name], catalogue.Provider{
-					Node: o.node.Name, At: o.node.At, Serves: serves})
+					Node: o.node.Name, At: o.node.At, Serves: serves, Module: m.Module})
 			}
 		}
 	}
@@ -244,14 +246,20 @@ func theRestOfTheMesh(ctx context.Context, inv *inventory.Inventory,
 		})
 	}
 
-	world := catalogue.World{Offered: offered}
+	// **The second pass is given the first pass's holdings.** A seat's holder answers a requirement
+	// with several providers (novox/hq ADR 0110), so a node consuming one resolves only once the
+	// holder is known. Without them its set is refused here, and a refused node's own claims drop
+	// out of what the mesh holds — so a second holder of one of its seats would pass unrefused.
+	world := catalogue.World{Offered: offered, Held: firstHeld}
+	var held []catalogue.Held
 	for _, o := range others {
 		got, err := catalogue.Resolve(shelf, o.assigned, o.node, world)
 		if err != nil {
 			continue
 		}
-		world.Held = append(world.Held, got.Claims...)
+		held = append(held, got.Claims...)
 	}
+	world.Held = held
 	return world, nil
 }
 
@@ -509,6 +517,12 @@ func renderingFor(ctx context.Context, open *stores, node string,
 	// `<node>.internal` names above, so a container — or an internal ACME validator — resolves a
 	// routed name to the proxy that serves it, mesh-wide. The mesh publishes the names it was told
 	// to serve and knows nothing about what they mean.
+	// Kept apart from the machines, because a fact about the machines must not be handed the names
+	// the mesh merely serves (novox/hq 04-ISSUES/111).
+	machines := make(map[string]string, len(names))
+	for name, at := range names {
+		machines[name] = at
+	}
 	routes, err := routeNamesInTheMesh(ctx, open)
 	if err != nil {
 		return catalogue.Rendering{}, inventory.Node{}, err
@@ -520,11 +534,19 @@ func renderingFor(ctx context.Context, open *stores, node string,
 	// The ports the mesh itself needs open, which no module declares. Read from the broker this
 	// control plane was told about rather than written down twice: the address a node is handed in
 	// its token and the port its machine must accept on are the same fact.
+	//
+	// **Only on the node that listens on it** (novox/hq issue: the broker opening leaked onto
+	// every node). The opening exists to WIDEN the broker's port to from-anywhere — a machine
+	// enrolling is not on the mesh yet, so the broker's own `from: mesh` listen would refuse its
+	// first dial. That widening belongs on the broker's host and nowhere else: a node that only
+	// dials out needs no incoming rule, and an opening for a port nothing here listens on is a
+	// from-anywhere hole for a dead port. So the foundation port is kept only when a module
+	// resolved onto THIS node actually listens on it.
 	var foundation []int
 	if b, err := broker.FromEnvironment(); err == nil {
 		if _, port, err := net.SplitHostPort(b.Address); err == nil {
 			if n, err := strconv.Atoi(port); err == nil {
-				foundation = append(foundation, n)
+				foundation = foundationPortsFor(n, plan.Modules)
 			}
 		}
 	}
@@ -574,7 +596,8 @@ func renderingFor(ctx context.Context, open *stores, node string,
 	return catalogue.Rendering{
 		Settings: settings, Generators: gens, Grants: grants, Needed: needed, Ports: ports,
 		Certificate: certificate, Authority: authority, Mesh: private, Names: names,
-		Suffix: overlay.Suffix(), Foundation: foundation, Kept: kept, Adopted: record.Adopted,
+		Machines: machines,
+		Suffix:   overlay.Suffix(), Foundation: foundation, Kept: kept, Adopted: record.Adopted,
 		Given: given, Taken: taken, Seats: seats, ArtifactStore: artifactStore, Built: built,
 	}, record, nil
 }
@@ -793,6 +816,22 @@ func grantsFor(ctx context.Context, open *stores, node string) ([]catalogue.Gran
 	return out, nil
 }
 
+// listensLines is what a person is told about what this module would open, and why — the same
+// `why` every listens entry already carries for the firewall it also feeds (novox/hq ADR 0007), so
+// deciding whether to assign a module can see what it would open before it opens it, not only
+// after. A module with nothing to listen on prints nothing extra, same as today.
+func listensLines(m catalogue.Manifest) []string {
+	var out []string
+	for _, l := range m.Listens {
+		if l.Why == "" {
+			out = append(out, fmt.Sprintf("    listens %d/%s from %s", l.Port, l.At(), l.From))
+			continue
+		}
+		out = append(out, fmt.Sprintf("    listens %d/%s from %s — %s", l.Port, l.At(), l.From, l.Why))
+	}
+	return out
+}
+
 func planCommand(ctx context.Context, args []string) error {
 	set := flag.NewFlagSet("plan", flag.ContinueOnError)
 	// Because "one resource" does not tell you whether the settings landed. Being able to read
@@ -846,6 +885,9 @@ func planCommand(ctx context.Context, args []string) error {
 	fmt.Printf("%s would run:\n", args[0])
 	for _, m := range plan.Modules {
 		fmt.Printf("  %-20s %s\n", m.Module, plan.Because[m.Module])
+		for _, line := range listensLines(m) {
+			fmt.Println(line)
+		}
 	}
 	// What was assigned here and cannot run here. Said with the rest rather than as a refusal: it is
 	// one module on the wrong machine, the others still run, and the remedy is to move this one.
@@ -1101,3 +1143,20 @@ func portsOn(
 	}
 	return out, nil
 }
+
+// foundationPortsFor is the broker port, kept only when a module resolved onto this node listens
+// on it (novox/hq issue: the broker opening leaked onto every node). The foundation opening
+// exists to WIDEN the broker's `from: mesh` port to from-anywhere, because a machine enrolling is
+// not on the mesh yet and its first dial would be refused. That widening belongs on the broker's
+// host alone: a node that only dials out needs no incoming rule, and an opening for a port
+// nothing here listens on is a from-anywhere hole for a dead port.
+func foundationPortsFor(brokerPort int, modules []catalogue.Manifest) []int {
+	for _, m := range modules {
+		for _, l := range m.Listens {
+			if l.Port == brokerPort {
+				return []int{brokerPort}
+			}
+		}
+	}
+	return nil
+}

cmd/mesh-controller/plan_test.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// `plan` tells a person what a module would open and why, from the same `why` every listens
+// entry already carries for the firewall (novox/hq ADR 0007) — so deciding whether to assign a
+// module does not need reading its manifest first.
+func TestListensLinesShowWhatAModuleWouldOpenAndWhy(t *testing.T) {
+	m := catalogue.Manifest{Module: "minio", Listens: []catalogue.Listening{
+		{Port: 9000, From: catalogue.FromMesh, Why: "the S3 endpoint"},
+		{Port: 9001, From: catalogue.FromMesh},
+	}}
+	got := listensLines(m)
+	if len(got) != 2 {
+		t.Fatalf("two listens entries, got %d: %v", len(got), got)
+	}
+	if !strings.Contains(got[0], "9000/tcp") || !strings.Contains(got[0], "the S3 endpoint") {
+		t.Errorf("the port and its why did not both appear: %q", got[0])
+	}
+	if strings.Contains(got[1], "—") {
+		t.Errorf("a listens entry with no why should not print a dash: %q", got[1])
+	}
+	if !strings.Contains(got[1], "9001/tcp") {
+		t.Errorf("the port still appears without a why: %q", got[1])
+	}
+}
+
+func TestListensLinesAreEmptyForAModuleWithNothingToListenOn(t *testing.T) {
+	if got := listensLines(catalogue.Manifest{Module: "board"}); len(got) != 0 {
+		t.Errorf("a module with no listens should print nothing, got %v", got)
+	}
+}

cmd/mesh-controller/seats.go

@@ -0,0 +1,150 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// What this mesh can have one of, and who fills each (novox/hq ADR 0110).
+//
+// **Derived every time, never stored.** A seat is held by a module assignment, so the answer is
+// computed from assignments by the same resolution that decides what every machine runs. A table
+// of holders kept beside the assignments would be a second copy of one fact, and the first thing
+// to be wrong about it.
+
+// seatHolder is one assignment holding a seat.
+type seatHolder struct {
+	Node   string `json:"node"`
+	Module string `json:"module"`
+}
+
+// seatRow is one seat and who holds it. Unheld is an answer — "this mesh has no X" — not a fault.
+type seatRow struct {
+	Seat     string       `json:"seat"`
+	Scope    string       `json:"scope"`
+	Delivers string       `json:"delivers,omitempty"`
+	Decision string       `json:"decision"`
+	Holders  []seatHolder `json:"holders"`
+}
+
+// seatsHeld is every seat the mesh defines with its holders, and every claim held that names no
+// seat in the set.
+//
+// **The second list is not empty by construction.** Manifests are held to the set when they are
+// registered, and a mesh can hold one registered before the set closed. Leaving its claim out of the
+// overview would make the one thing the overview is for — what does this mesh have — quietly
+// incomplete.
+func seatsHeld(seats []catalogue.Seat, held []catalogue.Held) ([]seatRow, []catalogue.Held) {
+	defined := map[string]bool{}
+	rows := make([]seatRow, 0, len(seats))
+	for _, s := range seats {
+		defined[s.Name] = true
+		row := seatRow{Seat: s.Name, Scope: s.Scope, Delivers: s.Delivers, Decision: s.Decision,
+			Holders: []seatHolder{}}
+		seen := map[seatHolder]bool{}
+		for _, h := range held {
+			if h.Claim != s.Name || h.Scope != s.Scope {
+				continue
+			}
+			holder := seatHolder{Node: h.Node, Module: h.Module}
+			if !seen[holder] {
+				seen[holder] = true
+				row.Holders = append(row.Holders, holder)
+			}
+		}
+		sort.Slice(row.Holders, func(i, j int) bool {
+			if row.Holders[i].Node != row.Holders[j].Node {
+				return row.Holders[i].Node < row.Holders[j].Node
+			}
+			return row.Holders[i].Module < row.Holders[j].Module
+		})
+		rows = append(rows, row)
+	}
+	var outside []catalogue.Held
+	for _, h := range held {
+		if !defined[h.Claim] {
+			outside = append(outside, h)
+		}
+	}
+	sort.Slice(outside, func(i, j int) bool {
+		if outside[i].Claim != outside[j].Claim {
+			return outside[i].Claim < outside[j].Claim
+		}
+		return outside[i].Node < outside[j].Node
+	})
+	return rows, outside
+}
+
+func seatsCommand(ctx context.Context, args []string) error {
+	set := flag.NewFlagSet("seats", flag.ContinueOnError)
+	asJSON := set.Bool("json", false, "the same, as JSON")
+	if err := set.Parse(args); err != nil {
+		return err
+	}
+
+	open, err := openStores(ctx)
+	if err != nil {
+		return err
+	}
+	defer open.Close()
+	inv := open.inventory
+	shelf, err := inv.Catalogue(ctx)
+	if err != nil {
+		return err
+	}
+	// Every node, none excluded: the same view of what each machine holds that planning uses.
+	world, err := theRestOfTheMesh(ctx, inv, shelf, "")
+	if err != nil {
+		return err
+	}
+	rows, outside := seatsHeld(catalogue.Seats(), world.Held)
+
+	if *asJSON {
+		out := struct {
+			Seats   []seatRow        `json:"seats"`
+			Outside []catalogue.Held `json:"outside,omitempty"`
+		}{rows, outside}
+		body, err := json.MarshalIndent(out, "", "  ")
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(body))
+		return nil
+	}
+
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	fmt.Fprintln(w, "SEAT\tSCOPE\tDELIVERS\tHELD BY")
+	for _, r := range rows {
+		delivers := r.Delivers
+		if delivers == "" {
+			delivers = "—"
+		}
+		holders := "unheld"
+		if len(r.Holders) > 0 {
+			parts := make([]string, 0, len(r.Holders))
+			for _, h := range r.Holders {
+				parts = append(parts, h.Module+" on "+h.Node)
+			}
+			holders = strings.Join(parts, ", ")
+		}
+		fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", r.Seat, r.Scope, delivers, holders)
+	}
+	if err := w.Flush(); err != nil {
+		return err
+	}
+	if len(outside) > 0 {
+		fmt.Println("\nheld, and not a seat this mesh defines (registered before the set closed — novox/hq ADR 0110):")
+		for _, h := range outside {
+			fmt.Printf("  %s  %s on %s\n", h.Claim, h.Module, h.Node)
+		}
+	}
+	return nil
+}

cmd/mesh-controller/seats_test.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// The overview of what a mesh has (novox/hq ADR 0110).
+
+func TestEverySeatIsListedIncludingTheOnesNobodyHolds(t *testing.T) {
+	// An unheld seat is an answer — "this mesh has no forge" — so it is listed rather than omitted.
+	rows, _ := seatsHeld(catalogue.Seats(), []catalogue.Held{
+		{Claim: "mesh-store", Scope: catalogue.ScopeMesh, Node: "anchor", Module: "postgres"},
+	})
+	if len(rows) != len(catalogue.Seats()) {
+		t.Fatalf("%d seats listed of %d", len(rows), len(catalogue.Seats()))
+	}
+	for _, r := range rows {
+		switch r.Seat {
+		case "mesh-store":
+			if len(r.Holders) != 1 || r.Holders[0].Module != "postgres" || r.Holders[0].Node != "anchor" {
+				t.Errorf("mesh-store is held by %+v", r.Holders)
+			}
+			if r.Delivers != "postgres-database" {
+				t.Errorf("mesh-store does not say what it delivers: %q", r.Delivers)
+			}
+		case "git":
+			if len(r.Holders) != 0 {
+				t.Errorf("git is held by %+v in a mesh with no forge", r.Holders)
+			}
+		}
+	}
+}
+
+func TestANodeSeatListsEveryMachineHoldingIt(t *testing.T) {
+	rows, _ := seatsHeld(catalogue.Seats(), []catalogue.Held{
+		{Claim: "the-packet-filter", Scope: catalogue.ScopeNode, Node: "node2", Module: "nftables"},
+		{Claim: "the-packet-filter", Scope: catalogue.ScopeNode, Node: "anchor", Module: "nftables"},
+		// Resolved twice, reported once: a machine is one holder however many passes saw it.
+		{Claim: "the-packet-filter", Scope: catalogue.ScopeNode, Node: "anchor", Module: "nftables"},
+	})
+	for _, r := range rows {
+		if r.Seat != "the-packet-filter" {
+			continue
+		}
+		if len(r.Holders) != 2 || r.Holders[0].Node != "anchor" || r.Holders[1].Node != "node2" {
+			t.Fatalf("the packet filter is held by %+v", r.Holders)
+		}
+		return
+	}
+	t.Fatal("the packet filter is not listed")
+}
+
+func TestAClaimOutsideTheSetIsShownNotHidden(t *testing.T) {
+	// A manifest registered before the set closed can still hold one. Leaving it out would make
+	// the overview quietly incomplete, which is the one thing it may not be.
+	_, outside := seatsHeld(catalogue.Seats(), []catalogue.Held{
+		{Claim: "the-controller", Scope: catalogue.ScopeMesh, Node: "anchor", Module: "mesh-controller"},
+	})
+	if len(outside) != 1 || outside[0].Claim != "the-controller" {
+		t.Fatalf("a claim outside the set was not shown: %+v", outside)
+	}
+}

cmd/mesh-controller/source.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// where a build's repository is (novox/hq ADR 0111).
+//
+// A repository is on the mesh's own forge, or it is anywhere else. The first is recorded as its path
+// on the forge holding the git seat, and cloned from wherever that forge runs at the moment of
+// building; the second is a URL, recorded and cloned exactly as given. The build machine is not told
+// the difference — it is handed a URL either way — because only the control plane knows where the
+// seat's holder runs.
+
+// gitSeat is the seat a self-hosted repository lives on.
+const gitSeat = "git"
+
+// buildSource is where a build's repository is: a URL, or a path on a seat's holder.
+type buildSource struct {
+	Repository string
+	Seat       string
+}
+
+// String is the source as a person reads it, which for one on a seat is not the URL: the URL is a
+// fact about where the forge happens to run today.
+func (s buildSource) String() string {
+	if s.Seat == "" {
+		return s.Repository
+	}
+	return fmt.Sprintf("%s on the %s seat", s.Repository, s.Seat)
+}
+
+// onASeat refuses an address given as a path on the forge.
+//
+// **A URL here would be recorded as a path**, and then composed onto the forge's address as one —
+// cloning `http://forge:3000/https://github.com/…`. Refused by what an address plainly looks like,
+// not repaired: `--self` promises a path, and something that is not one is a mistake to name.
+func onASeat(repository string) error {
+	if strings.Contains(repository, ":") || strings.HasPrefix(repository, "/") ||
+		strings.Trim(repository, "/") == "" {
+		return fmt.Errorf("--self takes the repository's path on the forge, such as novox/mesh-catalog, "+
+			"and %q is not one — without --self it is built from exactly what is given", repository)
+	}
+	return nil
+}
+
+// cloneFrom is the URL a build machine clones for a source.
+//
+// A URL is itself. A path on a seat is composed from the seat's holder as the mesh sees it now —
+// the same view planning takes of every machine, so the forge a build clones from is the forge the
+// mesh says holds the seat.
+func cloneFrom(ctx context.Context, source buildSource) (string, error) {
+	if source.Seat == "" {
+		return source.Repository, nil
+	}
+	open, err := openStores(ctx)
+	if err != nil {
+		return "", err
+	}
+	defer open.Close()
+	shelf, err := open.inventory.Catalogue(ctx)
+	if err != nil {
+		return "", err
+	}
+	world, err := theRestOfTheMesh(ctx, open.inventory, shelf, "")
+	if err != nil {
+		return "", err
+	}
+	return clonedFromSeat(world, source.Seat, source.Repository)
+}
+
+// clonedFromSeat composes the clone URL for a repository on a seat's holder.
+//
+// **Refused, never defaulted, at every step that has no answer.** Nobody holding the seat is a mesh
+// without a forge of its own: it builds from external repositories and must say so rather than fail
+// to clone. A holder off the private network cannot be reached by any build machine. A holder that
+// serves no scheme or port has nothing to compose from — a default port here would be the forge's
+// address guessed, which is the thing this exists to stop.
+func clonedFromSeat(world catalogue.World, seatName, repository string) (string, error) {
+	seat, known := catalogue.SeatNamed(seatName)
+	if !known || seat.Delivers == "" {
+		return "", fmt.Errorf("%q is not a seat a repository can live on", seatName)
+	}
+	var holder *catalogue.Held
+	for i, h := range world.Held {
+		if h.Claim == seat.Name && h.Scope == seat.Scope {
+			holder = &world.Held[i]
+			break
+		}
+	}
+	if holder == nil {
+		return "", fmt.Errorf("nobody holds the %s seat, so %s cannot be cloned from this mesh's "+
+			"forge — assign a module that claims it, or build from the repository's URL without --self",
+			seat.Name, repository)
+	}
+	var provider *catalogue.Provider
+	for i, p := range world.Offered[seat.Delivers] {
+		if p.Node == holder.Node && p.Module == holder.Module {
+			provider = &world.Offered[seat.Delivers][i]
+		}
+	}
+	if provider == nil {
+		return "", fmt.Errorf("%s on %s holds the %s seat and offers no %q to clone from",
+			holder.Module, holder.Node, seat.Name, seat.Delivers)
+	}
+	if provider.At == "" {
+		return "", fmt.Errorf("%s on %s holds the %s seat and is not on the private network, so no "+
+			"build machine can reach it", holder.Module, holder.Node, seat.Name)
+	}
+	scheme, _ := provider.Serves["scheme"].(string)
+	port := servedPort(provider.Serves["port"])
+	if scheme == "" || port == "" {
+		return "", fmt.Errorf("%s on %s holds the %s seat and does not serve a scheme and a port for %q",
+			holder.Module, holder.Node, seat.Name, seat.Delivers)
+	}
+	path := strings.TrimSuffix(strings.Trim(repository, "/"), ".git")
+	return fmt.Sprintf("%s://%s:%s/%s.git", scheme, provider.At, port, path), nil
+}
+
+// servedPort is a served port as text, however the manifest and the node's settings carried it.
+func servedPort(v any) string {
+	switch p := v.(type) {
+	case float64:
+		return strconv.Itoa(int(p))
+	case int:
+		return strconv.Itoa(p)
+	case string:
+		return p
+	}
+	return ""
+}

cmd/mesh-controller/source_test.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// Defends novox/hq ADR 0111: a build source is on the git seat, or it is external.
+
+func forgeHolding(port any) catalogue.World {
+	return catalogue.World{
+		Held: []catalogue.Held{{Claim: "git", Scope: catalogue.ScopeMesh, Node: "anchor", Module: "gitea"}},
+		Offered: map[string][]catalogue.Provider{"git": {
+			// A second forge that does not hold the seat, so taking the first one found would be wrong.
+			{Node: "archive", At: "archive.internal", Module: "gitea-mirror",
+				Serves: map[string]any{"scheme": "http", "port": float64(3000)}},
+			{Node: "anchor", At: "anchor.internal", Module: "gitea",
+				Serves: map[string]any{"scheme": "http", "port": port}},
+		}},
+	}
+}
+
+func TestARepositoryOnTheSeatIsClonedFromItsHolder(t *testing.T) {
+	got, err := clonedFromSeat(forgeHolding(float64(3000)), "git", "novox/mesh-catalog")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "http://anchor.internal:3000/novox/mesh-catalog.git" {
+		t.Fatalf("cloned from %s", got)
+	}
+}
+
+func TestAMovedForgeIsFollowedWithoutRewritingAnything(t *testing.T) {
+	// The whole point: the node gave the forge another port, and the same recorded path clones
+	// from the new one. Nothing recorded contained the old one to be wrong.
+	got, err := clonedFromSeat(forgeHolding(float64(3100)), "git", "novox/mesh-catalog")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(got, ":3100/") {
+		t.Fatalf("the moved port was not followed: %s", got)
+	}
+}
+
+func TestWithNobodyHoldingTheSeatASelfHostedBuildIsRefusedAndSaysWhy(t *testing.T) {
+	_, err := clonedFromSeat(catalogue.World{}, "git", "novox/mesh-catalog")
+	if err == nil {
+		t.Fatal("a repository was cloned from a forge the mesh does not have")
+	}
+	for _, want := range []string{"nobody holds the git seat", "without --self"} {
+		if !strings.Contains(err.Error(), want) {
+			t.Fatalf("the refusal does not say %q: %v", want, err)
+		}
+	}
+}
+
+func TestAnExternalRepositoryIsClonedExactlyAsGiven(t *testing.T) {
+	// Unaffected by the seat, held or not: GitHub and GitLab are the ordinary cases.
+	given := "https://github.com/someone/something.git"
+	got, err := cloneFrom(t.Context(), buildSource{Repository: given})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != given {
+		t.Fatalf("an external repository became %s", got)
+	}
+}
+
+func TestAHolderOffThePrivateNetworkIsRefused(t *testing.T) {
+	world := forgeHolding(float64(3000))
+	world.Offered["git"][1].At = ""
+	if _, err := clonedFromSeat(world, "git", "novox/mesh-catalog"); err == nil ||
+		!strings.Contains(err.Error(), "private network") {
+		t.Fatalf("a forge nothing can reach was cloned from: %v", err)
+	}
+}
+
+func TestAHolderServingNoPortIsRefusedRatherThanGuessed(t *testing.T) {
+	// A default port would be the forge's address guessed, which is what this exists to stop.
+	if _, err := clonedFromSeat(forgeHolding(nil), "git", "novox/mesh-catalog"); err == nil {
+		t.Fatal("a port was guessed for a forge that serves none")
+	}
+}
+
+func TestAnAddressGivenAsAPathOnTheForgeIsRefused(t *testing.T) {
+	for _, bad := range []string{
+		"https://github.com/someone/something.git",
+		"git@anchor:novox/mesh-catalog.git",
+		"/srv/git/mesh-catalog",
+		"",
+	} {
+		if err := onASeat(bad); err == nil {
+			t.Errorf("--self accepted %q as a path on the forge", bad)
+		}
+	}
+	if err := onASeat("novox/mesh-catalog"); err != nil {
+		t.Errorf("a path on the forge was refused: %v", err)
+	}
+}
+
+func TestASourceOnTheSeatReadsAsAPathNotAnAddress(t *testing.T) {
+	s := buildSource{Repository: "novox/mesh-catalog", Seat: "git"}
+	if got := s.String(); got != "novox/mesh-catalog on the git seat" {
+		t.Fatalf("read as %q", got)
+	}
+}

examples/route-proxy/challenge_test.go

@@ -0,0 +1,109 @@
+package main
+
+// The challenge path falls through for real. autocert's own HTTPHandler answers 404 itself for a
+// token it does not hold and never consults its fallback on the challenge path — the
+// predecessor's fault, the edge owning /.well-known/acme-challenge outright, rediscovered live
+// when Mailu's renewal died behind this proxy on cutover day (2026-09-26). These tests pin the
+// three behaviours tokenOrRoute exists for.
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/crypto/acme/autocert"
+)
+
+func routedTo(t *testing.T, marker string) http.Handler {
+	t.Helper()
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		if _, err := w.Write([]byte(marker)); err != nil {
+			t.Fatal(err)
+		}
+	})
+}
+
+func TestATokenNoAuthorityHoldsIsRoutedNot404d(t *testing.T) {
+	m := &autocert.Manager{Prompt: autocert.AcceptTOS, Cache: autocert.DirCache(t.TempDir())}
+	h := tokenOrRoute(routedTo(t, "the workload answered"), m)
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "http://mail.example/.well-known/acme-challenge/somebody-elses-token", nil))
+
+	if rec.Code != http.StatusOK || rec.Body.String() != "the workload answered" {
+		t.Fatalf("a token no authority holds must reach plain routing; got %d %q", rec.Code, rec.Body.String())
+	}
+}
+
+func TestATokenAManagerHoldsIsAnsweredByIt(t *testing.T) {
+	// autocert reads a token it does not have in memory from its cache, under "<token>+http-01" —
+	// which is also how a token would survive the manager restarting mid-issuance.
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "held-token+http-01"), []byte("the-key-authorization"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	m := &autocert.Manager{Prompt: autocert.AcceptTOS, Cache: autocert.DirCache(dir)}
+	h := tokenOrRoute(routedTo(t, "must not be reached"), m)
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "http://mail.example/.well-known/acme-challenge/held-token", nil))
+
+	if rec.Code != http.StatusOK || rec.Body.String() != "the-key-authorization" {
+		t.Fatalf("the manager holding a token answers it; got %d %q", rec.Code, rec.Body.String())
+	}
+}
+
+func TestASecondAuthorityIsProbedBeforeRouting(t *testing.T) {
+	first := &autocert.Manager{Prompt: autocert.AcceptTOS, Cache: autocert.DirCache(t.TempDir())}
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "internal-token+http-01"), []byte("internal-key"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	second := &autocert.Manager{Prompt: autocert.AcceptTOS, Cache: autocert.DirCache(dir)}
+	h := tokenOrRoute(routedTo(t, "must not be reached"), first, second)
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "http://git.internal/.well-known/acme-challenge/internal-token", nil))
+
+	if rec.Code != http.StatusOK || rec.Body.String() != "internal-key" {
+		t.Fatalf("the second authority's token is found by probing past the first; got %d %q", rec.Code, rec.Body.String())
+	}
+}
+
+func TestAnAuthorityWhosePolicyRefusesTheNameIsProbedPast(t *testing.T) {
+	// autocert checks the host policy before the token and answers 403 — the internal authority
+	// does this for every public name. A policy refusal is as much "not mine" as a missing token:
+	// the request must still reach plain routing, where the workload's own ACME client answers.
+	refusing := &autocert.Manager{
+		Prompt: autocert.AcceptTOS,
+		Cache:  autocert.DirCache(t.TempDir()),
+		HostPolicy: func(ctx context.Context, host string) error {
+			return fmt.Errorf("no internal-only route for %q in this mesh", host)
+		},
+	}
+	h := tokenOrRoute(routedTo(t, "the workload answered"), refusing)
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "http://mail.example/.well-known/acme-challenge/mailus-token", nil))
+
+	if rec.Code != http.StatusOK || rec.Body.String() != "the workload answered" {
+		t.Fatalf("a policy refusal must fall through to routing; got %d %q", rec.Code, rec.Body.String())
+	}
+}
+
+func TestAnOrdinaryPathNeverTouchesTheChallengeMachinery(t *testing.T) {
+	m := &autocert.Manager{Prompt: autocert.AcceptTOS, Cache: autocert.DirCache(t.TempDir())}
+	h := tokenOrRoute(routedTo(t, "routed"), m)
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "http://site.example/index.html", nil))
+
+	if rec.Code != http.StatusOK || rec.Body.String() != "routed" {
+		t.Fatalf("an ordinary path goes straight to routing; got %d %q", rec.Code, rec.Body.String())
+	}
+}

examples/route-proxy/main.go

@@ -10,10 +10,31 @@
 // program. What lives here is that contract, written as something that runs so it can be read
 // rather than described.
 //
+// **A route also carries what a request arriving at it may do** (novox/hq ADR 0108). The grant used
+// to say only where to send traffic, so this proxy applied nothing; the four things the ingress it
+// replaces actually relies on are now part of the contribution. The set is closed at four, because
+// an open middleware surface recreates the thing being replaced and is far harder to narrow later
+// than a closed one is to widen.
+//
 // What it is given, written by the host from an ordinary declaration:
 //
 //	$ROUTES    every consumer, the name it asked for, and where the mesh says that machine is
 //
+// Each contribution's values carry the name and port as before, and optionally:
+//
+//	path       the path prefix this rule is scoped to; absent means every path
+//	priority   which rule wins where two match; higher first, and the order is total
+//	deny       refuse the request outright — the shape an incident mitigation needs
+//	redirect   answer with a permanent redirect to this name, keeping the path and query
+//	auth       the *path of a secret* holding `user:hash` lines, never the credential itself
+//
+// A host may appear more than once, which is what path scoping means: one rule refusing a path
+// while another serves everything else on the same name.
+//
+// **`auth` names a secret and never holds one.** A declaration carrying a credential is refused
+// outright rather than served unprotected, and a secret that cannot be read makes the route refuse
+// rather than open — a gate that cannot check is not a gate that opens.
+//
 // It re-reads on change rather than being restarted, for the same reason the provisioner does:
 // a route arriving or leaving is an ordinary event and must not drop the connections of every
 // other workload.
@@ -23,6 +44,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha256"
+	"crypto/subtle"
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/hex"
@@ -42,6 +64,7 @@ import (
 
 	"golang.org/x/crypto/acme"
 	"golang.org/x/crypto/acme/autocert"
+	"golang.org/x/crypto/bcrypt"
 )
 
 // Where public certificates come from when nothing says otherwise.
@@ -74,10 +97,23 @@ func issuer() string {
 // to what it may serve.
 func onlyWhatTheMeshSaid(held *table) autocert.HostPolicy {
 	return func(_ context.Context, host string) error {
-		if _, known := held.find(host); known {
+		if held.eligibleForACME(host) {
 			return nil
 		}
-		return fmt.Errorf("no route for %q in this mesh, so no certificate is asked for", host)
+		return fmt.Errorf("no public route for %q in this mesh, so no certificate is asked for", host)
+	}
+}
+
+// onlyInternalNamesTheMeshSaid is onlyWhatTheMeshSaid's mirror for the internal authority — the
+// same quota-spending concern applies even to an authority with no rate limit of its own, because
+// an order for a name this proxy does not actually route is a bug worth refusing rather than
+// serving.
+func onlyInternalNamesTheMeshSaid(held *table) autocert.HostPolicy {
+	return func(_ context.Context, host string) error {
+		if held.eligibleForInternalACME(host) {
+			return nil
+		}
+		return fmt.Errorf("no internal-only route for %q in this mesh, so no certificate is asked for", host)
 	}
 }
 
@@ -95,48 +131,194 @@ type contribution struct {
 	Values map[string]any `json:"values"`
 }
 
+// policy is what a rule does with a request that matched it.
+//
+// **Decided by the mesh, not here** (novox/hq ADR 0108). A route grant used to hand back a name and
+// say nothing about what the name admitted, so this proxy admitted everything. The set is closed at
+// four — authentication, refusal, path scoping, redirect — because an open middleware surface
+// recreates the thing being replaced and is far harder to narrow later than a closed one is to widen.
+type policy struct {
+	// deny refuses the request outright, whatever it is.
+	deny bool
+	// redirectTo answers with a permanent redirect instead of proxying. The request's own path and
+	// query are carried across, which is what canonicalising one public name onto another means.
+	redirectTo string
+	// users is what a request must present, read at load time from the secret the declaration
+	// *named*. A declaration never carries the credential itself.
+	users map[string]string
+	// sealed is set when authentication was declared and the secret could not be read. The rule then
+	// refuses everything and says why.
+	//
+	// **Fail closed.** The alternative — serve the route unauthenticated because the gate is
+	// missing — turns an unreadable file into a silently public admin surface, which is the exact
+	// outcome ADR 0108 exists to prevent. A gate that cannot check is not a gate that opens.
+	sealed string
+}
+
+// rule is one way a host may be routed. A host may have several, which is what path scoping means.
+type rule struct {
+	path     string // "" matches every path
+	priority int
+	policy   policy
+	to       *httputil.ReverseProxy
+	target   string
+	// insecure skips certificate verification when target is reached over https. For a backend
+	// that terminates TLS with its own certificate this proxy has no reason to trust — Mailu's
+	// webmail front is the first of these — never for anything reached over plain http, where
+	// there is nothing to verify in the first place.
+	insecure bool
+	// maxRequestBody is the largest body, in bytes, this route carries. Zero is no limit, which is
+	// what every route gets by saying nothing: this proxy has never limited a body, and a default
+	// arriving with the field would change every route that never asked for one.
+	//
+	// **Configuration, not a policy** (novox/hq ADR 0108 closed that set at four). It belongs beside
+	// `insecure` for the same reason `insecure` is not a policy: both tune how this proxy carries a
+	// request to a backend, rather than deciding what the name admits or who may reach it. A
+	// registry is the case that needs it — image layers arrive as single requests of gigabytes, and
+	// a proxy's own default refuses them long before the workload is reached.
+	maxRequestBody int64
+}
+
 // table is what the proxy is currently serving, replaced whole whenever the file changes.
 //
 // Replaced rather than merged: the file is the whole truth about who has a route, so merging
 // would keep serving a name whose module was unassigned — which is the stale-route fault
 // 08-connectivity lists as open, reintroduced one level down.
+//
+// Keyed by host to an *ordered* list rather than to one target, because two of the four policies
+// need a single host routed more than one way: a refusal on a path the ordinary route also matches,
+// and a certificate-challenge path on a host that otherwise serves a workload.
 type table struct {
-	mu      sync.RWMutex
-	to      map[string]*httputil.ReverseProxy
-	targets map[string]string
+	mu sync.RWMutex
+	to map[string][]rule
+	// public is which routed hosts are eligible for a real certificate — every host reached as a
+	// route's own `name`, never one reached only as its `internal-name`. A private alias can never
+	// pass ACME's own validation (it has no public DNS to prove it against), so asking for it is
+	// not merely pointless but the failing order onlyWhatTheMeshSaid exists to prevent.
+	public map[string]bool
 }
 
-func (t *table) set(routes map[string]string) {
-	made := map[string]*httputil.ReverseProxy{}
-	for name, target := range routes {
-		where, err := url.Parse(target)
-		if err != nil {
-			log.Printf("route %s points at %q, which is not a URL: %v", name, target, err)
+func (t *table) set(routes map[string][]rule, public map[string]bool) {
+	made := map[string][]rule{}
+	for host, rules := range routes {
+		kept := make([]rule, 0, len(rules))
+		for _, r := range rules {
+			// A rule that only refuses or only redirects has nowhere to send anything, and needs
+			// nowhere: it answers by itself.
+			if r.policy.deny || r.policy.redirectTo != "" {
+				kept = append(kept, r)
+				continue
+			}
+			where, err := url.Parse(r.target)
+			if err != nil {
+				log.Printf("route %s points at %q, which is not a URL: %v", host, r.target, err)
+				continue
+			}
+			r.to = httputil.NewSingleHostReverseProxy(where)
+			if r.insecure {
+				r.to.Transport = &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}}
+			}
+			kept = append(kept, r)
+		}
+		if len(kept) == 0 {
 			continue
 		}
-		made[name] = httputil.NewSingleHostReverseProxy(where)
+		inOrder(kept)
+		made[host] = kept
 	}
 	t.mu.Lock()
-	t.to, t.targets = made, routes
+	t.to = made
+	t.public = public
 	t.mu.Unlock()
 }
 
-func (t *table) find(host string) (*httputil.ReverseProxy, bool) {
-	// The port is not part of the name. A request to app.example:8080 is for app.example.
+// inOrder puts the rules for one host into the order they are matched in, and does so totally.
+//
+// **Equal priorities must resolve identically every time** (ADR 0108). Sorting only by priority
+// leaves rules that share one in whatever order the map produced, so the same declaration would
+// serve differently between restarts — a proxy that is not reproducible. Longest path first within a
+// priority is also the intuitive reading: the more specific rule wins. The last two keys exist only
+// to make the order total.
+func inOrder(rules []rule) {
+	sort.SliceStable(rules, func(i, j int) bool {
+		a, b := rules[i], rules[j]
+		if a.priority != b.priority {
+			return a.priority > b.priority
+		}
+		if len(a.path) != len(b.path) {
+			return len(a.path) > len(b.path)
+		}
+		if a.path != b.path {
+			return a.path < b.path
+		}
+		return a.target < b.target
+	})
+}
+
+// find is the rule that answers this request, or nothing if the host is not routed here at all.
+func (t *table) find(host, path string) (rule, bool) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	for _, r := range t.to[bareHost(host)] {
+		if r.path == "" || strings.HasPrefix(path, r.path) {
+			return r, true
+		}
+	}
+	return rule{}, false
+}
+
+// routed says whether this proxy serves the name at all, whatever the path.
+//
+// Separate from find because certificate issuance is a question about the *name*: a host whose only
+// rules are path-scoped is still a name this proxy answers to, and still needs a certificate.
+// eligibleForACME says whether this proxy may ask a certificate authority for this name — every
+// host reached as a route's own public `name`, never one reached only as its `internal-name`
+// alias, which no public CA can ever validate.
+func (t *table) eligibleForACME(host string) bool {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	bare := bareHost(host)
+	return len(t.to[bare]) > 0 && t.public[bare]
+}
+
+func (t *table) routed(host string) bool {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	return len(t.to[bareHost(host)]) > 0
+}
+
+// eligibleForInternalACME says whether this proxy may ask its *internal* authority for a
+// certificate for this name — every host it routes that is not also a route's public `name`.
+//
+// **The mesh has two name spaces and two authorities** (novox/hq 03-DESIGN/01-to-be/08-connectivity
+// §2): a public name is certified by a public CA, an internal one by the mesh's own. This is
+// composed only from `to` and `public`, which routesFrom already builds correctly — a host never
+// lands in both a route's own `name` and only its `internal-name`, so nothing new has to be
+// tracked to tell the two apart.
+func (t *table) eligibleForInternalACME(host string) bool {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	bare := bareHost(host)
+	return len(t.to[bare]) > 0 && !t.public[bare]
+}
+
+// bareHost is the name without the port, lower-cased.
+//
+// The port is not part of the name: a request to app.example:8080 is for app.example. Lower-cased
+// because a Host header is not case-sensitive, and a route that only answers the spelling in the
+// manifest answers half the requests made to it.
+func bareHost(host string) string {
 	if h, _, err := net.SplitHostPort(host); err == nil {
 		host = h
 	}
-	t.mu.RLock()
-	defer t.mu.RUnlock()
-	p, ok := t.to[strings.ToLower(host)]
-	return p, ok
+	return strings.ToLower(host)
 }
 
 func (t *table) names() []string {
 	t.mu.RLock()
 	defer t.mu.RUnlock()
-	out := make([]string, 0, len(t.targets))
-	for name := range t.targets {
+	out := make([]string, 0, len(t.to))
+	for name := range t.to {
 		out = append(out, name)
 	}
 	sort.Strings(out)
@@ -162,7 +344,7 @@ func run() error {
 
 	held := newTable()
 	read := func() {
-		routes, err := routesFrom(path)
+		routes, public, err := routesFrom(path)
 		if err != nil {
 			// Kept serving what it had. A file being rewritten is momentarily unreadable, and
 			// dropping every route because one read landed mid-write would turn an ordinary
@@ -170,7 +352,7 @@ func run() error {
 			log.Printf("cannot read %s, keeping what is already served: %v", path, err)
 			return
 		}
-		held.set(routes)
+		held.set(routes, public)
 		log.Printf("serving %d route(s): %s", len(routes), strings.Join(held.names(), ", "))
 	}
 	read()
@@ -197,16 +379,158 @@ func run() error {
 		return fmt.Errorf("TLS_LISTEN is set and ACME_CACHE is not: certificates need somewhere " +
 			"to persist, or every restart orders them again")
 	}
-	client := &acme.Client{DirectoryURL: issuer()}
-	// An issuer that is not one of the public ones serves its own API over TLS with a certificate
-	// nothing trusts yet — the lab's, or an internal step-ca. Trusting it is a deliberate act and
-	// names a file, rather than the client being told to skip verification: *skip* would also
-	// apply on the day this points at a public issuer, and nothing would say so.
+	publicManager, err := newManager(cache, issuer(), strings.TrimSpace(os.Getenv("ACME_CA_BUNDLE")),
+		onlyWhatTheMeshSaid(held))
+	if err != nil {
+		return err
+	}
+	log.Printf("issuing public certificates from %s, for whatever the mesh routes here", issuer())
+
+	// The internal authority is optional: unset means this proxy serves internal-only aliases over
+	// plain HTTP exactly as it always has, which is the standalone-binary default and a safe one —
+	// it asks nothing of an authority it was not told about.
+	var internalManager *autocert.Manager
+	if directory := strings.TrimSpace(os.Getenv("INTERNAL_ACME_DIRECTORY")); directory != "" {
+		internalManager, err = newManager(cache, directory, strings.TrimSpace(os.Getenv("INTERNAL_ACME_CA_BUNDLE")),
+			onlyInternalNamesTheMeshSaid(held))
+		if err != nil {
+			return fmt.Errorf("internal certificate authority: %w", err)
+		}
+		log.Printf("issuing internal certificates from %s, for every internal-only alias this routes",
+			directory)
+	}
+
+	// Port 80 answers the HTTP-01 challenge and goes on proxying everything else. The challenge
+	// must be answered *at the name being certified*, which is why issuance happens on the node
+	// that is publicly reachable rather than wherever the workload runs.
+	//
+	// **autocert's own HTTPHandler does not fall through on the challenge path.** For a token it
+	// does not hold it answers 404 itself; its fallback only ever sees non-challenge paths — which
+	// is exactly the predecessor's fault, the edge owning `/.well-known/acme-challenge` outright,
+	// rediscovered live when Mailu's renewal died behind this proxy on cutover day. tokenOrRoute
+	// probes each manager and hands a token neither authority recognises to plain routing, which
+	// is what lets a consumer's own ACME client — Mailu's, certifying its own name for a protocol
+	// this proxy never proxies — answer its own challenge through an ordinary path-scoped route.
+	port80 := tokenOrRoute(handler(held), publicManager)
+	if internalManager != nil {
+		port80 = tokenOrRoute(handler(held), publicManager, internalManager)
+	}
+	go func() {
+		if err := http.ListenAndServe(listen, port80); err != nil {
+			log.Printf("plain HTTP stopped: %v", err)
+		}
+	}()
+
+	tlsConfig := publicManager.TLSConfig()
+	if internalManager != nil {
+		// Dispatched by which authority may certify this name at all — the same question
+		// eligibleForInternalACME already answers, asked once more at handshake time rather than
+		// only when an order is placed, since a cached certificate is served here on every request
+		// and never goes through HostPolicy again.
+		fromPublic, fromInternal := tlsConfig.GetCertificate, internalManager.TLSConfig().GetCertificate
+		tlsConfig.GetCertificate = func(hello *tls.ClientHelloInfo) (*tls.Certificate, error) {
+			if held.eligibleForInternalACME(hello.ServerName) {
+				return fromInternal(hello)
+			}
+			return fromPublic(hello)
+		}
+	}
+
+	server := &http.Server{
+		Addr:      secure,
+		Handler:   handler(held),
+		TLSConfig: tlsConfig,
+	}
+	return server.ListenAndServeTLS("", "")
+}
+
+// tokenOrRoute serves port 80: each manager answers the challenge tokens it is itself holding,
+// and a token none of them holds is routed like any other request instead of being 404'd at the
+// edge.
+//
+// autocert gives no way to ask "is this your token?" — its HTTPHandler both answers and refuses —
+// so each manager is probed against a buffered writer and its refusal (404 on the challenge path)
+// is discarded in favour of the next candidate. The probe is cheap: the handler answers from
+// memory, and the path only carries traffic while an issuance is actually running.
+func tokenOrRoute(routes http.Handler, managers ...*autocert.Manager) http.Handler {
+	const challengePrefix = "/.well-known/acme-challenge/"
+	// Non-challenge paths never reach a manager at all; autocert's tryHTTP01 switch still has to
+	// be armed, which HTTPHandler is the only exported way to do.
+	probes := make([]http.Handler, len(managers))
+	for i, m := range managers {
+		probes[i] = m.HTTPHandler(routes)
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !strings.HasPrefix(r.URL.Path, challengePrefix) {
+			routes.ServeHTTP(w, r)
+			return
+		}
+		for _, probe := range probes {
+			buffered := &probedResponse{header: make(http.Header)}
+			probe.ServeHTTP(buffered, r)
+			// Two shapes of "not mine": 404, a token this manager is not holding — and 403, a
+			// name its host policy would never certify at all (autocert checks the policy before
+			// the token, so the internal authority answers 403 for every public name).
+			if buffered.status == http.StatusNotFound || buffered.status == http.StatusForbidden {
+				continue
+			}
+			buffered.replayTo(w)
+			return
+		}
+		routes.ServeHTTP(w, r) // no authority holds it: the workload behind a routed path may
+	})
+}
+
+// probedResponse buffers one handler's answer so a refusal can be discarded unseen.
+type probedResponse struct {
+	header http.Header
+	status int
+	body   bytes.Buffer
+}
+
+func (p *probedResponse) Header() http.Header { return p.header }
+
+func (p *probedResponse) WriteHeader(status int) {
+	if p.status == 0 {
+		p.status = status
+	}
+}
+
+func (p *probedResponse) Write(b []byte) (int, error) {
+	if p.status == 0 {
+		p.status = http.StatusOK
+	}
+	return p.body.Write(b)
+}
+
+func (p *probedResponse) replayTo(w http.ResponseWriter) {
+	for k, vs := range p.header {
+		for _, v := range vs {
+			w.Header().Add(k, v)
+		}
+	}
+	status := p.status
+	if status == 0 {
+		status = http.StatusOK
+	}
+	w.WriteHeader(status)
+	_, _ = w.Write(p.body.Bytes())
+}
+
+// newManager is one ACME authority's autocert manager: where to ask, what to trust it with, and
+// which names it may be asked to certify.
+//
+// **Trusting an authority names a file rather than skipping verification.** An issuer that is not
+// one of the public ones — the lab's, or the mesh's own step-ca — serves its own ACME API over TLS
+// with a certificate nothing trusts yet. *Skip* would also apply the day this points at a public
+// issuer, and nothing would say so; naming a bundle is a deliberate, visible act instead.
+func newManager(cache, directory, bundle string, policy autocert.HostPolicy) (*autocert.Manager, error) {
+	client := &acme.Client{DirectoryURL: directory}
 	var root []byte
-	if bundle := strings.TrimSpace(os.Getenv("ACME_CA_BUNDLE")); bundle != "" {
+	if bundle != "" {
 		read, err := os.ReadFile(bundle)
 		if err != nil {
-			return fmt.Errorf("ACME_CA_BUNDLE names %s and it cannot be read: %w", bundle, err)
+			return nil, fmt.Errorf("the CA bundle names %s and it cannot be read: %w", bundle, err)
 		}
 		root = read
 		// An empty bundle means the issuer's root is already in the system trust store — a public
@@ -218,7 +542,7 @@ func run() error {
 		if strings.TrimSpace(string(root)) != "" {
 			pool := x509.NewCertPool()
 			if !pool.AppendCertsFromPEM(root) {
-				return fmt.Errorf("%s holds no certificate this can trust", bundle)
+				return nil, fmt.Errorf("%s holds no certificate this can trust", bundle)
 			}
 			client.HTTPClient = &http.Client{
 				Timeout:   30 * time.Second,
@@ -227,31 +551,16 @@ func run() error {
 		}
 	}
 	// Where this authority's account and certificates are kept. Per authority, not per proxy — see
-	// forThisAuthority, which is what makes a re-initialised CA heal itself.
-	mine := forThisAuthority(cache, issuer(), root)
-	manager := &autocert.Manager{
+	// forThisAuthority, which is what makes a re-initialised CA heal itself, and what lets the
+	// public and internal authorities share one ACME_CACHE without colliding: they hash to
+	// different names because their directories differ.
+	mine := forThisAuthority(cache, directory, root)
+	return &autocert.Manager{
 		Cache:      autocert.DirCache(mine),
 		Prompt:     autocert.AcceptTOS,
-		HostPolicy: onlyWhatTheMeshSaid(held),
+		HostPolicy: policy,
 		Client:     client,
-	}
-	log.Printf("issuing from %s into %s, for whatever the mesh routes here", issuer(), mine)
-
-	// Port 80 answers the HTTP-01 challenge and goes on proxying everything else. The challenge
-	// must be answered *at the name being certified*, which is why issuance happens on the node
-	// that is publicly reachable rather than wherever the workload runs.
-	go func() {
-		if err := http.ListenAndServe(listen, manager.HTTPHandler(handler(held))); err != nil {
-			log.Printf("plain HTTP stopped: %v", err)
-		}
-	}()
-
-	server := &http.Server{
-		Addr:      secure,
-		Handler:   handler(held),
-		TLSConfig: manager.TLSConfig(),
-	}
-	return server.ListenAndServeTLS("", "")
+	}, nil
 }
 
 // forThisAuthority is where one ACME authority's account and certificates are kept.
@@ -285,61 +594,303 @@ func forThisAuthority(cache, directory string, root []byte) string {
 
 // newTable is an empty routing table.
 func newTable() *table {
-	return &table{to: map[string]*httputil.ReverseProxy{}, targets: map[string]string{}}
+	return &table{to: map[string][]rule{}}
 }
 
 // handler is the proxy itself, separated so it can be driven by a test without a listener.
 func handler(held *table) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		proxy, known := held.find(r.Host)
+		matched, known := held.find(r.Host, r.URL.Path)
 		if !known {
 			// **Named, not a bare 404.** A route that was withdrawn and a name that never existed
 			// are different things, and a proxy that says only "not found" makes an operator go
 			// and read the mesh to tell them apart. What it is serving is the answer to both.
+			//
+			// And since a host may now be routed only on some paths, those are a third thing:
+			// saying "no route for this name" while listing that very name as served is a
+			// contradiction an operator would have to disbelieve the proxy to get past.
 			w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 			w.WriteHeader(http.StatusNotFound)
+			if held.routed(r.Host) {
+				fmt.Fprintf(w, "%s is served here, but no route covers %q.\n",
+					bareHost(r.Host), r.URL.Path)
+				return
+			}
 			fmt.Fprintf(w, "no route for %q in this mesh.\nserving: %s\n",
 				r.Host, strings.Join(held.names(), ", "))
 			return
 		}
-		proxy.ServeHTTP(w, r)
+
+		switch {
+		case matched.policy.sealed != "":
+			// Declared a gate, cannot check it. Refused, and says why — an operator reading this
+			// learns the secret is missing, rather than wondering why a protected name is 503.
+			w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+			w.WriteHeader(http.StatusServiceUnavailable)
+			fmt.Fprintf(w, "this route requires authentication and its credentials cannot be read: %s\n",
+				matched.policy.sealed)
+			return
+
+		case matched.policy.deny:
+			http.Error(w, "this path is not served to you", http.StatusForbidden)
+			return
+
+		case matched.policy.redirectTo != "":
+			http.Redirect(w, r, canonical(matched.policy.redirectTo, r.URL), http.StatusMovedPermanently)
+			return
+
+		case len(matched.policy.users) > 0 && !allowed(matched.policy.users, r):
+			// The realm is the name asked for, so a browser's prompt says which route it is for.
+			w.Header().Set("WWW-Authenticate", fmt.Sprintf("Basic realm=%q, charset=\"UTF-8\"", bareHost(r.Host)))
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		if matched.maxRequestBody > 0 {
+			// Refused on the declared length where there is one, so an upload that cannot succeed
+			// is answered before it is carried; and capped while reading for a chunked body, which
+			// declares no length at all. Without the second, a limit is advice.
+			if r.ContentLength > matched.maxRequestBody {
+				http.Error(w, fmt.Sprintf("request body too large for this route: %d bytes is the most it carries",
+					matched.maxRequestBody), http.StatusRequestEntityTooLarge)
+				return
+			}
+			r.Body = http.MaxBytesReader(w, r.Body, matched.maxRequestBody)
+		}
+
+		matched.to.ServeHTTP(w, r)
 	})
 }
 
-// routesFrom reads what the mesh wrote and turns it into name → target.
-func routesFrom(path string) (map[string]string, error) {
+// canonical is where a redirect sends this request.
+//
+// The declaration names the destination *name*; the request keeps its own path and query. That is
+// what canonicalising one public name onto another means — a link to a page under the old name has
+// to arrive at the same page under the new one, or the redirect silently loses every deep link.
+func canonical(to string, from *url.URL) string {
+	where, err := url.Parse(to)
+	if err != nil {
+		return to
+	}
+	if where.Path == "" || where.Path == "/" {
+		where.Path = from.Path
+	}
+	if where.RawQuery == "" {
+		where.RawQuery = from.RawQuery
+	}
+	return where.String()
+}
+
+// allowed says whether the request presented credentials this route accepts.
+//
+// **Every path costs one bcrypt comparison**, including an unknown user, which is why the miss
+// compares against a fixed hash rather than returning early. Returning early would make an unknown
+// user measurably faster than a known one with a wrong password, and that difference is a way to
+// enumerate the users of a route from outside it.
+func allowed(users map[string]string, r *http.Request) bool {
+	// A hash of nothing anybody knows. Its only job is to cost what a real comparison costs.
+	const absent = "$2a$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy"
+	user, password, ok := r.BasicAuth()
+	if !ok {
+		return false
+	}
+	want, known := users[user]
+	if !known {
+		want = absent
+	}
+	if err := bcrypt.CompareHashAndPassword([]byte(want), []byte(password)); err != nil {
+		return false
+	}
+	// `known` is checked after the comparison, not instead of it, so the timing is the same either
+	// way. subtle.ConstantTimeByteEq keeps the branch from being the thing that differs.
+	return subtle.ConstantTimeByteEq(boolByte(known), 1) == 1
+}
+
+func boolByte(b bool) byte {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+// routesFrom reads what the mesh wrote and turns it into host → the rules for that host, and
+// which of those hosts is a public name — the second is `name`, ACME-eligible; a host reached
+// only through `internal-name` never appears there.
+func routesFrom(path string) (map[string][]rule, map[string]bool, error) {
 	raw, err := os.ReadFile(path)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	var said given
 	if err := json.Unmarshal(raw, &said); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
-	out := map[string]string{}
+	out := map[string][]rule{}
+	public := map[string]bool{}
 	for _, c := range said.Given {
 		name, _ := c.Values["name"].(string)
 		if name == "" {
 			log.Printf("%s on %s asked for a route and named nothing; skipped", c.From, c.Node)
 			continue
 		}
-		port, ok := asPort(c.Values["port"])
-		if !ok {
-			log.Printf("%s on %s asked for route %q and gave no usable port; skipped",
-				c.From, c.Node, name)
+		host := strings.ToLower(name)
+		public[host] = true
+
+		made := rule{path: asPath(c.Values["path"])}
+		if p, ok := asWhole(c.Values["priority"]); ok {
+			made.priority = p
+		}
+		made.policy.deny, _ = c.Values["deny"].(bool)
+		made.policy.redirectTo, _ = c.Values["redirect"].(string)
+
+		if named, carried := c.Values["auth"].(string); carried && strings.TrimSpace(named) != "" {
+			// **A declaration names a secret; it never holds one** (ADR 0108). Refused rather than
+			// tolerated, and the whole rule is dropped rather than served unprotected — the
+			// rejected option cannot come back by accident, which is the failure this check exists
+			// to make impossible.
+			if looksLikeACredential(named) {
+				log.Printf("%s on %s declared route %q with a credential in the declaration rather "+
+					"than the name of a secret; the whole route is refused (novox/hq ADR 0108)",
+					c.From, c.Node, name)
+				continue
+			}
+			users, err := usersFrom(named)
+			if err != nil {
+				// Fail closed: the rule is kept so the name stays routed and answers, and it
+				// answers by refusing. Dropping it instead would make the name 404 and read as a
+				// withdrawn route rather than an unreadable secret.
+				made.policy.sealed = err.Error()
+			}
+			made.policy.users = users
+		}
+
+		// Only a rule that actually proxies needs somewhere to send the request.
+		if !made.policy.deny && made.policy.redirectTo == "" {
+			port, ok := asPort(c.Values["port"])
+			if !ok {
+				log.Printf("%s on %s asked for route %q and gave no usable port; skipped",
+					c.From, c.Node, name)
+				continue
+			}
+			// Where the mesh says that machine is. Empty means it is this one — a workload beside
+			// the proxy is ordinary, and reaching it over loopback is both correct and the only
+			// thing that works when there is no private network.
+			at := c.At
+			if at == "" {
+				at = "127.0.0.1"
+			}
+			// http unless the contribution says otherwise. A backend that terminates its own TLS
+			// with a certificate this proxy has no reason to trust — Mailu's webmail front is the
+			// first of these — is the reason `insecure` exists, and it stays the exception: every
+			// other target the mesh hands this proxy is a plain workload on the private network.
+			scheme, _ := c.Values["scheme"].(string)
+			scheme = strings.ToLower(strings.TrimSpace(scheme))
+			if scheme == "" {
+				scheme = "http"
+			}
+			if scheme != "http" && scheme != "https" {
+				log.Printf("%s on %s asked for route %q with scheme %q, which is neither http "+
+					"nor https; skipped", c.From, c.Node, name, scheme)
+				continue
+			}
+			made.insecure, _ = c.Values["insecure"].(bool)
+			// A limit this proxy cannot read is a route it does not serve, named like a port that
+			// is not a port. Serving it without the limit would carry exactly what the module said
+			// not to carry, and report success doing it.
+			if asked, said := c.Values["max-request-body"]; said {
+				bytes, whole := asWhole(asked)
+				if !whole || bytes <= 0 {
+					log.Printf("%s on %s asked for route %q with a max-request-body of %v, which is "+
+						"not a whole positive number of bytes; skipped", c.From, c.Node, name, asked)
+					continue
+				}
+				made.maxRequestBody = int64(bytes)
+			}
+			made.target = fmt.Sprintf("%s://%s:%d", scheme, at, port)
+		}
+
+		out[host] = append(out[host], made)
+
+		// The internal-network alias, the same rule under a second host — a predecessor proxy
+		// answered both for one route, as a convenience (reaching a service over the VPN without a
+		// public TLS round trip), not as an access boundary; composing it here restores exactly
+		// that, nothing more. Absent whenever the node composed no internal name (novox/hq ADR
+		// 0056's internalDomain half) — the same "nothing to join a label to" case the public name
+		// already has.
+		if internal, _ := c.Values["internal-name"].(string); strings.TrimSpace(internal) != "" {
+			out[strings.ToLower(internal)] = append(out[strings.ToLower(internal)], made)
+		}
+	}
+	return out, public, nil
+}
+
+// asWhole is any whole number the mesh wrote, whatever its magnitude.
+//
+// **Not asPort.** Priority was read with the port reader first, which caps at 65535 — so a rule
+// declared at a priority above that silently became priority 0 and stopped shadowing the route it
+// exists to shadow. The one real rule this has to reproduce is declared at 100000, so the bug was
+// exactly load-bearing. A priority is an ordering, not a port: it has no range.
+func asWhole(v any) (int, bool) {
+	switch n := v.(type) {
+	case float64:
+		// JSON makes a float of every number, so a non-integral one was not meant as a priority.
+		if n != float64(int(n)) {
+			return 0, false
+		}
+		return int(n), true
+	case int:
+		return n, true
+	}
+	return 0, false
+}
+
+// asPath is the path prefix a rule is scoped to, or "" for every path.
+func asPath(v any) string {
+	p, _ := v.(string)
+	p = strings.TrimSpace(p)
+	if p == "" {
+		return ""
+	}
+	if !strings.HasPrefix(p, "/") {
+		p = "/" + p
+	}
+	return p
+}
+
+// looksLikeACredential is the check that keeps a secret out of a declaration.
+//
+// It errs towards refusing: a value holding a `:` (the htpasswd separator) or opening with a bcrypt
+// identifier is a credential, not a path, and no filesystem path the mesh writes needs either. A
+// false refusal is a loud log and a route that does not serve; a false accept is a credential
+// committed to a declaration, which is the thing being prevented.
+func looksLikeACredential(v string) bool {
+	v = strings.TrimSpace(v)
+	return strings.Contains(v, ":") || strings.HasPrefix(v, "$2")
+}
+
+// usersFrom reads the credentials the mesh mounted, in the one format every htpasswd already is.
+func usersFrom(path string) (map[string]string, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("cannot read the secret named for this route: %w", err)
+	}
+	users := map[string]string{}
+	for _, line := range strings.Split(string(raw), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
 			continue
 		}
-		// Where the mesh says that machine is. Empty means it is this one — a workload beside the
-		// proxy is ordinary, and reaching it over loopback is both correct and the only thing
-		// that works when there is no private network.
-		at := c.At
-		if at == "" {
-			at = "127.0.0.1"
+		user, hash, ok := strings.Cut(line, ":")
+		if !ok || user == "" || hash == "" {
+			continue
 		}
-		out[strings.ToLower(name)] = fmt.Sprintf("http://%s:%d", at, port)
+		users[user] = hash
 	}
-	return out, nil
+	if len(users) == 0 {
+		return nil, fmt.Errorf("the secret named for this route holds no usable credentials")
+	}
+	return users, nil
 }
 
 // asPort accepts what JSON makes of a number, which is a float even when it was written 8080.

examples/route-proxy/policy_test.go

@@ -0,0 +1,273 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+// What a route carries about the requests arriving at it — novox/hq ADR 0108.
+//
+// Each test here is one of the four capabilities that record closed the set at, plus the negative
+// case it promised would be refused. The negative case is the one that rots quietly: nothing fails
+// if it stops working, so nothing tells you it has.
+
+// served starts a workload and gives back the host and port the mesh would have recorded for it.
+func served(t *testing.T, body string) (string, int) {
+	t.Helper()
+	workload := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = w.Write([]byte(body))
+	}))
+	t.Cleanup(workload.Close)
+	host, port, _ := strings.Cut(strings.TrimPrefix(workload.URL, "http://"), ":")
+	n, err := strconv.Atoi(port)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return host, n
+}
+
+// ask makes one request through the proxy for a given name and path, without following redirects.
+func ask(t *testing.T, proxy, name, path string, auth [2]string) *http.Response {
+	t.Helper()
+	req, err := http.NewRequest(http.MethodGet, proxy+path, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Host = name
+	if auth[0] != "" {
+		req.SetBasicAuth(auth[0], auth[1])
+	}
+	client := &http.Client{CheckRedirect: func(*http.Request, []*http.Request) error {
+		return http.ErrUseLastResponse
+	}}
+	answer, err := client.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = answer.Body.Close() })
+	return answer
+}
+
+func proxyFor(t *testing.T, routesJSON string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "routes.json")
+	if err := os.WriteFile(path, []byte(routesJSON), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	routes, public, err := routesFrom(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	held := newTable()
+	held.set(routes, public)
+	server := httptest.NewServer(handler(held))
+	t.Cleanup(server.Close)
+	return server.URL
+}
+
+// A refusal on a path shadows the ordinary route for that path and leaves every other path alone.
+//
+// **This is why path scoping is a prerequisite and not a sibling capability.** The rule being
+// reproduced matches a path on a host that is already routed to a workload, so a table mapping a
+// host to one target cannot express it at all — no amount of authentication or source filtering
+// would have helped.
+func TestARefusedPathShadowsTheRouteAndLeavesTheRestServed(t *testing.T) {
+	at, port := served(t, "the workload")
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"forge","node":"anchor","at":"`+at+`","values":{"name":"forge.example","port":`+strconv.Itoa(port)+`}},
+	  {"from":"forge","node":"anchor","values":{"name":"forge.example","path":"/api/internal","priority":100,"deny":true}}
+	]}`)
+
+	if got := ask(t, proxy, "forge.example", "/api/internal/hook", [2]string{}).StatusCode; got != http.StatusForbidden {
+		t.Fatalf("the refused path answered %d, so the block that was put in front of it during an "+
+			"incident is not in front of it any more", got)
+	}
+	if got := ask(t, proxy, "forge.example", "/", [2]string{}).StatusCode; got != http.StatusOK {
+		t.Fatalf("refusing one path took the whole route with it: %d", got)
+	}
+}
+
+// A redirect answers with the redirect, and the request keeps its own path and query.
+//
+// Losing the path would turn canonicalising one name onto another into "every deep link now lands
+// on the front page", which is the kind of breakage that produces no error anywhere.
+func TestARedirectKeepsThePathAndQuery(t *testing.T) {
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"site","node":"anchor","values":{"name":"www.example","redirect":"https://example/"}}
+	]}`)
+
+	answer := ask(t, proxy, "www.example", "/deep/page?ref=1", [2]string{})
+	if answer.StatusCode != http.StatusMovedPermanently {
+		t.Fatalf("a declared redirect answered %d", answer.StatusCode)
+	}
+	where := answer.Header.Get("Location")
+	if !strings.Contains(where, "/deep/page") || !strings.Contains(where, "ref=1") {
+		t.Fatalf("the redirect dropped the path or the query: %q", where)
+	}
+}
+
+// Authentication refuses a request with no credentials, admits one with the right ones, and refuses
+// the wrong ones — with the credentials read from the secret the declaration *named*.
+func TestAuthenticationAdmitsOnlyWhatTheSecretSays(t *testing.T) {
+	at, port := served(t, "the console")
+	hash, err := bcrypt.GenerateFromPassword([]byte("correct horse"), bcrypt.MinCost)
+	if err != nil {
+		t.Fatal(err)
+	}
+	secret := filepath.Join(t.TempDir(), "console-auth")
+	if err := os.WriteFile(secret, []byte("# a comment\nadmin:"+string(hash)+"\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"console","node":"anchor","at":"`+at+`","values":{"name":"console.example","port":`+strconv.Itoa(port)+`,"auth":"`+secret+`"}}
+	]}`)
+
+	if got := ask(t, proxy, "console.example", "/", [2]string{}).StatusCode; got != http.StatusUnauthorized {
+		t.Fatalf("an admin surface with no login of its own answered %d without credentials", got)
+	}
+	if got := ask(t, proxy, "console.example", "/", [2]string{"admin", "wrong"}).StatusCode; got != http.StatusUnauthorized {
+		t.Fatalf("the wrong password answered %d", got)
+	}
+	if got := ask(t, proxy, "console.example", "/", [2]string{"admin", "correct horse"}).StatusCode; got != http.StatusOK {
+		t.Fatalf("the right password answered %d", got)
+	}
+}
+
+// The negative case ADR 0108 promised would be refused: a credential in the declaration.
+//
+// **Refused whole, not tolerated and not served unprotected.** A hash carried in a declaration was
+// the rejected option; nothing in the running system should quietly accept it later, because the
+// precedent is far easier to set than to withdraw. If this test is deleted the option returns and
+// nothing else notices.
+func TestACredentialInTheDeclarationIsRefusedRatherThanServed(t *testing.T) {
+	inline := []string{
+		`{"given":[{"from":"c","node":"n","at":"127.0.0.1","values":{"name":"c.example","port":8080,"auth":"admin:$2a$10$abcdefghijklmnopqrstuv"}}]}`,
+		`{"given":[{"from":"c","node":"n","at":"127.0.0.1","values":{"name":"c.example","port":8080,"auth":"$2a$10$abcdefghijklmnopqrstuv"}}]}`,
+	}
+	for _, body := range inline {
+		path := filepath.Join(t.TempDir(), "routes.json")
+		if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
+			t.Fatal(err)
+		}
+		routes, _, err := routesFrom(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(routes) != 0 {
+			t.Fatalf("a declaration carrying a credential was served anyway: %v", routes)
+		}
+	}
+}
+
+// Authentication declared, secret unreadable: the route refuses. It does not serve unprotected.
+//
+// **Fail closed.** The alternative turns a missing file into a silently public admin surface, which
+// is the outcome the whole record exists to prevent. It answers rather than 404s, so an operator
+// sees "cannot read the credentials" instead of concluding the route was withdrawn.
+func TestAnUnreadableSecretFailsClosed(t *testing.T) {
+	at, port := served(t, "the console")
+	missing := filepath.Join(t.TempDir(), "not-mounted")
+
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"console","node":"anchor","at":"`+at+`","values":{"name":"console.example","port":`+strconv.Itoa(port)+`,"auth":"`+missing+`"}}
+	]}`)
+
+	answer := ask(t, proxy, "console.example", "/", [2]string{})
+	if answer.StatusCode == http.StatusOK {
+		t.Fatal("a route whose credentials could not be read served the workload unprotected")
+	}
+	if answer.StatusCode != http.StatusServiceUnavailable {
+		t.Fatalf("expected the route to say it cannot check, got %d", answer.StatusCode)
+	}
+}
+
+// Equal priorities resolve the same way every time, so the same declaration serves the same way
+// after a restart.
+//
+// Sorting only by priority leaves rules that share one in whatever order the map produced. The
+// proxy would still work, and would work differently between restarts — which is the hardest kind
+// of fault to believe when it is reported.
+func TestRulesThatShareAPriorityAreStillTotallyOrdered(t *testing.T) {
+	first := []rule{
+		{path: "/a", priority: 10, target: "http://x:1"},
+		{path: "/bb", priority: 10, target: "http://y:2"},
+		{path: "", priority: 10, target: "http://z:3"},
+	}
+	second := []rule{
+		{path: "", priority: 10, target: "http://z:3"},
+		{path: "/bb", priority: 10, target: "http://y:2"},
+		{path: "/a", priority: 10, target: "http://x:1"},
+	}
+	inOrder(first)
+	inOrder(second)
+	for i := range first {
+		if first[i].path != second[i].path || first[i].target != second[i].target {
+			t.Fatalf("two orderings of the same rules disagree at %d: %q vs %q",
+				i, first[i].path, second[i].path)
+		}
+	}
+	// And the more specific rule is matched first, which is the intuitive reading.
+	if first[0].path != "/bb" {
+		t.Fatalf("the longest path is not matched first: %q", first[0].path)
+	}
+}
+
+// Priority decides before path length does, so a rule can be made to win regardless of specificity.
+func TestPriorityOutranksPathLength(t *testing.T) {
+	rules := []rule{
+		{path: "/very/long/path", priority: 1, target: "http://x:1"},
+		{path: "", priority: 100, target: "http://y:2"},
+	}
+	inOrder(rules)
+	if rules[0].priority != 100 {
+		t.Fatalf("a higher priority did not win: %+v", rules[0])
+	}
+}
+
+// A priority above a port number survives, because a priority is an ordering and not a port.
+//
+// **Found by review, and it was load-bearing.** Priority was first read with the port reader, which
+// caps at 65535 — so a rule declared above that silently became priority 0 and stopped shadowing the
+// route it exists to shadow. The one real rule this has to reproduce is declared at 100000, so the
+// capability would have shipped looking complete and doing nothing.
+func TestAPriorityAboveAPortNumberSurvives(t *testing.T) {
+	at, port := served(t, "the workload")
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"forge","node":"anchor","at":"`+at+`","values":{"name":"forge.example","port":`+strconv.Itoa(port)+`}},
+	  {"from":"forge","node":"anchor","values":{"name":"forge.example","path":"/api/internal","priority":100000,"deny":true}}
+	]}`)
+
+	if got := ask(t, proxy, "forge.example", "/api/internal/hook", [2]string{}).StatusCode; got != http.StatusForbidden {
+		t.Fatalf("a rule declared at priority 100000 answered %d instead of refusing", got)
+	}
+}
+
+// A host routed only on some paths says so, rather than claiming the name is not served here.
+//
+// Saying "no route for this name" while listing that very name as served is a contradiction an
+// operator has to disbelieve the proxy to get past — and path scoping makes it reachable, because a
+// host can now have rules that none of this request's paths match.
+func TestAHostRoutedOnlyOnSomePathsSaysSo(t *testing.T) {
+	proxy := proxyFor(t, `{"given":[
+	  {"from":"forge","node":"anchor","values":{"name":"forge.example","path":"/api/internal","deny":true}}
+	]}`)
+
+	answer := ask(t, proxy, "forge.example", "/elsewhere", [2]string{})
+	if answer.StatusCode != http.StatusNotFound {
+		t.Fatalf("an uncovered path answered %d", answer.StatusCode)
+	}
+	body := make([]byte, 256)
+	n, _ := answer.Body.Read(body)
+	said := string(body[:n])
+	if !strings.Contains(said, "is served here") || !strings.Contains(said, "/elsewhere") {
+		t.Fatalf("the refusal does not distinguish an uncovered path from an unserved name: %q", said)
+	}
+}

examples/route-proxy/routes_test.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"context"
+	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -19,10 +21,37 @@ func write(t *testing.T, body string) string {
 	return path
 }
 
+// plain is the table an ordinary set of routes makes: one host, one target, no policy.
+func plain(routes map[string]string) map[string][]rule {
+	out := map[string][]rule{}
+	for host, target := range routes {
+		out[host] = []rule{{target: target}}
+	}
+	return out
+}
+
+// allPublic is every host in a routes map, ACME-eligible — the ordinary case for a test with no
+// internal-name alias of its own to distinguish.
+func allPublic(routes map[string][]rule) map[string]bool {
+	out := map[string]bool{}
+	for host := range routes {
+		out[host] = true
+	}
+	return out
+}
+
+// targetOf is where a host's first matching rule sends a request.
+func targetOf(routes map[string][]rule, host string) string {
+	if rules := routes[host]; len(rules) > 0 {
+		return rules[0].target
+	}
+	return ""
+}
+
 // A route is a grant: the consumer supplies a target, and where that machine is comes from the
 // mesh rather than from a naming convention the proxy has to know.
 func TestARouteGoesToWhereTheMeshSaysTheConsumerIs(t *testing.T) {
-	routes, err := routesFrom(write(t, `{"contributions":1,"requirement":"route","given":[
+	routes, _, err := routesFrom(write(t, `{"contributions":1,"requirement":"route","given":[
 	  {"from":"app","node":"laptop","at":"laptop.internal","values":{"name":"App.Example","port":8080}}
 	]}`))
 	if err != nil {
@@ -30,28 +59,67 @@ func TestARouteGoesToWhereTheMeshSaysTheConsumerIs(t *testing.T) {
 	}
 	// Lower-cased, because a Host header is not case-sensitive and a route that only answers the
 	// spelling in the manifest answers half the requests made to it.
-	if routes["app.example"] != "http://laptop.internal:8080" {
+	if targetOf(routes, "app.example") != "http://laptop.internal:8080" {
 		t.Fatalf("the route does not point at the consumer: %v", routes)
 	}
 }
 
+// A route with an internal-name alias is reachable under both hostnames, pointed at the same
+// target — the same convenience a predecessor proxy gave for reaching a service over the VPN
+// without a public TLS round trip.
+func TestARouteWithAnInternalNameIsReachableUnderBoth(t *testing.T) {
+	routes, public, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal",
+	   "values":{"name":"app.example","internal-name":"app.anchor.internal","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if targetOf(routes, "app.example") != "http://anchor.internal:8080" {
+		t.Fatalf("the public name does not point at the consumer: %v", routes)
+	}
+	if targetOf(routes, "app.anchor.internal") != "http://anchor.internal:8080" {
+		t.Fatalf("the internal alias does not point at the same consumer: %v", routes)
+	}
+	if !public["app.example"] {
+		t.Errorf("the public name is not eligible for a certificate: %v", public)
+	}
+	if public["app.anchor.internal"] {
+		t.Errorf("the internal alias is eligible for a certificate no public CA could ever issue: %v",
+			public)
+	}
+}
+
+// A route with no internal-name composed gets no second host — the ordinary case, unchanged.
+func TestARouteWithNoInternalNameGetsNoAlias(t *testing.T) {
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","values":{"name":"app.example","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(routes) != 1 {
+		t.Fatalf("a route with no internal-name grew a second host: %v", routes)
+	}
+}
+
 // A workload beside the proxy is ordinary, and reaching it over loopback is both correct and the
 // only thing that works when there is no private network.
 func TestAConsumerOnTheProxysOwnMachineIsReachedOverLoopback(t *testing.T) {
-	routes, err := routesFrom(write(t, `{"given":[
+	routes, _, err := routesFrom(write(t, `{"given":[
 	  {"from":"app","node":"anchor","values":{"name":"app.example","port":9000}}
 	]}`))
 	if err != nil {
 		t.Fatal(err)
 	}
-	if routes["app.example"] != "http://127.0.0.1:9000" {
+	if targetOf(routes, "app.example") != "http://127.0.0.1:9000" {
 		t.Fatalf("a workload on this machine was not reachable: %v", routes)
 	}
 }
 
 // Skipped rather than served wrongly. A route with no port would proxy to :0.
 func TestAContributionMissingWhatARouteNeedsIsSkipped(t *testing.T) {
-	routes, err := routesFrom(write(t, `{"given":[
+	routes, _, err := routesFrom(write(t, `{"given":[
 	  {"from":"a","node":"n","at":"n.internal","values":{"name":"no-port.example"}},
 	  {"from":"b","node":"n","at":"n.internal","values":{"port":8080}},
 	  {"from":"c","node":"n","at":"n.internal","values":{"name":"fine.example","port":8080}}
@@ -59,11 +127,73 @@ func TestAContributionMissingWhatARouteNeedsIsSkipped(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(routes) != 1 || routes["fine.example"] == "" {
+	if len(routes) != 1 || targetOf(routes, "fine.example") == "" {
 		t.Fatalf("an unusable contribution was served: %v", routes)
 	}
 }
 
+// A route may name a target reached over https, for a backend that terminates its own TLS — the
+// shape Mailu's webmail front needs, which this proxy reaches as a plain workload otherwise.
+func TestARouteMayTargetHttps(t *testing.T) {
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"mail","node":"anchor","at":"anchor.internal",
+	   "values":{"name":"mail.example","port":7443,"scheme":"https","insecure":true}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if targetOf(routes, "mail.example") != "https://anchor.internal:7443" {
+		t.Fatalf("an https target was not built as one: %v", routes)
+	}
+	if !routes["mail.example"][0].insecure {
+		t.Fatal("insecure was declared and not carried onto the rule")
+	}
+}
+
+// A scheme that is neither http nor https is refused rather than guessed at.
+func TestARouteWithAnUnknownSchemeIsSkipped(t *testing.T) {
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"a","node":"n","at":"n.internal","values":{"name":"bad.example","port":80,"scheme":"ftp"}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(routes) != 0 {
+		t.Fatalf("a route with an unusable scheme was served: %v", routes)
+	}
+}
+
+// End to end: a backend terminating TLS with a certificate nothing would ordinarily trust is still
+// reached when the route declared `insecure`, and the response comes back through unmodified.
+func TestTheProxyReachesAnInsecureHttpsBackend(t *testing.T) {
+	workload := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = w.Write([]byte("the workload, over its own TLS"))
+	}))
+	defer workload.Close()
+	target := strings.TrimPrefix(workload.URL, "https://")
+
+	held := newTable()
+	routes := map[string][]rule{"mail.example": {{target: "https://" + target, insecure: true}}}
+	held.set(routes, allPublic(routes))
+
+	proxy := httptest.NewServer(handler(held))
+	defer proxy.Close()
+
+	asked, err := http.NewRequest(http.MethodGet, proxy.URL, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	asked.Host = "mail.example"
+	answer, err := http.DefaultClient.Do(asked)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer answer.Body.Close()
+	if answer.StatusCode != http.StatusOK {
+		t.Fatalf("an insecure https backend was not reached: %d", answer.StatusCode)
+	}
+}
+
 // End to end through the proxy itself: a request for the name reaches the workload, and a name
 // nobody asked for is refused in a way that says what IS served.
 func TestTheProxyReachesTheWorkloadAndNamesWhatItServes(t *testing.T) {
@@ -75,7 +205,7 @@ func TestTheProxyReachesTheWorkloadAndNamesWhatItServes(t *testing.T) {
 	host, port, _ := strings.Cut(target, ":")
 
 	held := newTable()
-	held.set(map[string]string{"app.example": "http://" + host + ":" + port})
+	held.set(plain(map[string]string{"app.example": "http://" + host + ":" + port}), allPublic(plain(map[string]string{"app.example": "http://" + host + ":" + port})))
 
 	proxy := httptest.NewServer(handler(held))
 	defer proxy.Close()
@@ -120,16 +250,17 @@ func TestTheProxyReachesTheWorkloadAndNamesWhatItServes(t *testing.T) {
 // nothing fails more visibly than a stale grant, which is exactly why it must not survive.
 func TestWithdrawingARouteStopsServingIt(t *testing.T) {
 	held := newTable()
-	held.set(map[string]string{
+	initial := plain(map[string]string{
 		"going.example":   "http://a.internal:80",
 		"staying.example": "http://b.internal:80",
 	})
-	held.set(map[string]string{"staying.example": "http://b.internal:80"})
+	held.set(initial, allPublic(initial))
+	held.set(plain(map[string]string{"staying.example": "http://b.internal:80"}), allPublic(plain(map[string]string{"staying.example": "http://b.internal:80"})))
 
-	if _, still := held.find("going.example"); still {
+	if _, still := held.find("going.example", "/"); still {
 		t.Fatal("a route whose module was unassigned is still served")
 	}
-	if _, kept := held.find("staying.example"); !kept {
+	if _, kept := held.find("staying.example", "/"); !kept {
 		t.Fatal("withdrawing one route took another with it")
 	}
 }
@@ -137,8 +268,8 @@ func TestWithdrawingARouteStopsServingIt(t *testing.T) {
 // A Host header carries a port and the name does not.
 func TestARequestNamingAPortStillFindsItsRoute(t *testing.T) {
 	held := newTable()
-	held.set(map[string]string{"app.example": "http://a.internal:8080"})
-	if _, found := held.find("app.example:8080"); !found {
+	held.set(plain(map[string]string{"app.example": "http://a.internal:8080"}), allPublic(plain(map[string]string{"app.example": "http://a.internal:8080"})))
+	if _, found := held.find("app.example:8080", "/"); !found {
 		t.Fatal("a request to app.example:8080 did not find the route for app.example")
 	}
 }
@@ -168,7 +299,7 @@ func TestTheIssuerIsStagingUnlessNamed(t *testing.T) {
 // rate limit — and the proxy would look healthy throughout.
 func TestNoCertificateIsAskedForOnAnUnroutedName(t *testing.T) {
 	held := newTable()
-	held.set(map[string]string{"photos.example": "http://127.0.0.1:8080"})
+	held.set(plain(map[string]string{"photos.example": "http://127.0.0.1:8080"}), allPublic(plain(map[string]string{"photos.example": "http://127.0.0.1:8080"})))
 	policy := onlyWhatTheMeshSaid(held)
 
 	if err := policy(context.Background(), "photos.example"); err != nil {
@@ -181,18 +312,179 @@ func TestNoCertificateIsAskedForOnAnUnroutedName(t *testing.T) {
 	}
 }
 
+// A certificate is asked for on a route's public name, never on its internal-network alias — no
+// public CA can validate a private name, and asking anyway would only spend the account's rate
+// limit on an order that can never succeed.
+func TestNoCertificateIsAskedForOnAnInternalAlias(t *testing.T) {
+	routes, public, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal",
+	   "values":{"name":"app.example","internal-name":"app.anchor.internal","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	held := newTable()
+	held.set(routes, public)
+	policy := onlyWhatTheMeshSaid(held)
+
+	if err := policy(context.Background(), "app.example"); err != nil {
+		t.Errorf("the route's public name was refused a certificate: %v", err)
+	}
+	if err := policy(context.Background(), "app.anchor.internal"); err == nil {
+		t.Error("a certificate was ordered for the internal alias, which no public CA can validate")
+	}
+}
+
+// A certificate is asked of the *internal* authority only for a name that is routed here and is
+// not a route's own public name — the internal-network alias, never the route it accompanies.
+func TestTheInternalAuthorityOnlyCertifiesInternalOnlyAliases(t *testing.T) {
+	routes, public, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal",
+	   "values":{"name":"app.example","internal-name":"app.anchor.internal","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	held := newTable()
+	held.set(routes, public)
+	policy := onlyInternalNamesTheMeshSaid(held)
+
+	if err := policy(context.Background(), "app.anchor.internal"); err != nil {
+		t.Errorf("the internal alias was refused by its own authority: %v", err)
+	}
+	if err := policy(context.Background(), "app.example"); err == nil {
+		t.Error("the internal authority certified a route's public name, which the public authority already covers")
+	}
+	if err := policy(context.Background(), "unrouted.internal"); err == nil {
+		t.Error("the internal authority certified a name nobody routed here")
+	}
+}
+
 // A route withdrawn stops being certifiable, without the proxy restarting.
 func TestWithdrawingARouteWithdrawsItsCertificate(t *testing.T) {
 	held := newTable()
-	held.set(map[string]string{"photos.example": "http://127.0.0.1:8080"})
+	held.set(plain(map[string]string{"photos.example": "http://127.0.0.1:8080"}), allPublic(plain(map[string]string{"photos.example": "http://127.0.0.1:8080"})))
 	policy := onlyWhatTheMeshSaid(held)
 	if err := policy(context.Background(), "photos.example"); err != nil {
 		t.Fatal(err)
 	}
 
-	held.set(nil)
+	held.set(nil, nil)
 	if err := policy(context.Background(), "photos.example"); err == nil {
 		t.Fatal("a withdrawn route can still order certificates, so the policy read a copy taken " +
 			"once rather than what is served now")
 	}
 }
+
+// A route may say the largest body it carries, and the proxy holds requests to it.
+//
+// The registry is why: image layers arrive as single requests of gigabytes, and a proxy's own
+// default refuses them long before the workload is reached. It is configuration beside `insecure`,
+// not a fifth policy — novox/hq ADR 0108 closed that set at four.
+func TestARouteMayLimitTheBodyItCarries(t *testing.T) {
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"registry","node":"anchor","at":"anchor.internal",
+	   "values":{"name":"images.example","port":5000,"max-request-body":21474836480}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	rules := routes["images.example"]
+	if len(rules) != 1 {
+		t.Fatalf("the route is not served once: %v", routes)
+	}
+	if rules[0].maxRequestBody != 21474836480 {
+		t.Fatalf("the limit did not survive the contribution: %d", rules[0].maxRequestBody)
+	}
+}
+
+// Saying nothing leaves the route unlimited, which is what every route already got.
+func TestARouteThatSaysNothingCarriesAnySize(t *testing.T) {
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"app","node":"anchor","at":"anchor.internal","values":{"name":"app.example","port":8080}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := routes["app.example"][0].maxRequestBody; got != 0 {
+		t.Fatalf("a route that asked for no limit got one: %d", got)
+	}
+}
+
+// A limit that is not a whole positive number of bytes takes the route with it. Serving it without
+// the limit would carry exactly what the module said not to carry, and report success doing it.
+func TestARouteWithAnUnusableLimitIsSkipped(t *testing.T) {
+	for _, asked := range []string{`"lots"`, `-1`, `0`, `1.5`} {
+		routes, _, err := routesFrom(write(t, `{"given":[
+		  {"from":"registry","node":"anchor","at":"anchor.internal",
+		   "values":{"name":"images.example","port":5000,"max-request-body":`+asked+`}}
+		]}`))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(routes["images.example"]) != 0 {
+			t.Errorf("a route asking for a max-request-body of %s was served anyway: %v", asked, routes)
+		}
+	}
+}
+
+// A request larger than the route carries is refused by the proxy, with the limit named, and the
+// workload never sees it. A request within it is proxied normally.
+func TestABodyOverTheLimitIsRefusedAndOneUnderItIsCarried(t *testing.T) {
+	var reached int
+	workload := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, _ := io.ReadAll(r.Body)
+		reached++
+		fmt.Fprintf(w, "carried %d bytes", len(body))
+	}))
+	defer workload.Close()
+
+	at := strings.TrimPrefix(workload.URL, "http://")
+	host, port, _ := strings.Cut(at, ":")
+	routes, _, err := routesFrom(write(t, `{"given":[
+	  {"from":"registry","node":"anchor","at":"`+host+`",
+	   "values":{"name":"images.example","port":`+port+`,"max-request-body":8}}
+	]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	held := newTable()
+	held.set(routes, map[string]bool{})
+	proxy := httptest.NewServer(handler(held))
+	defer proxy.Close()
+
+	over, err := post(proxy.URL, "images.example", "123456789")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer over.Body.Close()
+	if over.StatusCode != http.StatusRequestEntityTooLarge {
+		t.Fatalf("a body over the limit answered %d, not 413", over.StatusCode)
+	}
+	if reached != 0 {
+		t.Fatalf("the workload was reached by a request the route said it would not carry")
+	}
+
+	under, err := post(proxy.URL, "images.example", "1234")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer under.Body.Close()
+	if under.StatusCode != http.StatusOK {
+		t.Fatalf("a body within the limit answered %d, not 200", under.StatusCode)
+	}
+	if reached != 1 {
+		t.Fatalf("the workload was not reached by a request within the limit")
+	}
+}
+
+// post sends a body to the proxy as the named route, since a route is found by the Host header.
+func post(url, host, body string) (*http.Response, error) {
+	asked, err := http.NewRequest(http.MethodPost, url, strings.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	asked.Host = host
+	asked.Header.Set("Content-Type", "application/octet-stream")
+	return http.DefaultClient.Do(asked)
+}

internal/builder/builder.go

@@ -63,6 +63,19 @@ type Result struct {
 	Built []catalogue.Built
 }
 
+// GitCredential is the forge credential a clone may present when the server asks for one.
+//
+// **Offered, never pushed.** It is written as a git credential-store file and named to git with
+// `-c credential.helper=store`, so git itself decides when it applies: only on an authentication
+// challenge, and only for the URL it was written for — scheme, host and port included. A public
+// repository clones exactly as before, and a repository on any other host is never shown it.
+type GitCredential struct {
+	// URL is the credential-store line — scheme://user:password@host[:port] — naming the one
+	// server this credential belongs to. Empty means the builder holds none and every clone is
+	// anonymous, as it always was.
+	URL string
+}
+
 // Build clones a repository at a ref, reads its manifest, produces what it declares, publishes
 // each, and returns the manifest the mesh should hold.
 //
@@ -70,7 +83,8 @@ type Result struct {
 // archive failed would otherwise leave half of itself in the store under a digest the mesh never
 // records — reachable, unreferenced, and indistinguishable from something in use.
 func Build(ctx context.Context, run Runner, publish Publisher,
-	repository, path, ref, workspace string, held map[string]string, npmrc Npmrc, log Log) (Result, error) {
+	repository, path, ref, workspace string, held map[string]string, npmrc Npmrc,
+	forge GitCredential, log Log) (Result, error) {
 
 	say := logging(log)
 	say("clone", "%s%s at %s", repository, describePath(path), refOrHead(ref))
@@ -80,6 +94,15 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 	if err := os.MkdirAll(workspace, 0o755); err != nil {
 		return Result{}, err
 	}
+	// The credential is a file git reads, never an argument: a URL carrying a password in argv
+	// would be readable by anything that can list processes for as long as a clone runs.
+	credentials := ""
+	if forge.URL != "" {
+		credentials = filepath.Join(workspace, "git-credentials")
+		if err := os.WriteFile(credentials, []byte(forge.URL+"\n"), 0o600); err != nil {
+			return Result{}, err
+		}
+	}
 	tree := filepath.Join(workspace, "source")
 	if err := os.RemoveAll(tree); err != nil {
 		return Result{}, err
@@ -87,7 +110,7 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 	// A fresh clone every time rather than a fetch into a tree that is already there. A build
 	// that reuses a working tree can succeed because of something a previous build left behind,
 	// and that is a build nobody can reproduce.
-	if _, err := run(ctx, workspace, "git", "clone", "--quiet", repository, tree); err != nil {
+	if _, err := run(ctx, workspace, "git", cloneWith(credentials, "clone", "--quiet", repository, tree)...); err != nil {
 		say("clone", "FAILED: %v", err)
 		return Result{}, fmt.Errorf("cannot clone %s: %w", repository, err)
 	}
@@ -177,7 +200,7 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 		sort.Slice(artifacts, func(i, j int) bool { return artifacts[i].Name < artifacts[j].Name })
 		for _, a := range artifacts {
 			say("artifact", "%s (%s%s) — starting", a.Name, a.Kind, langSuffix(a))
-			made, err := one(ctx, run, publish, manifest.Module, within, commit, a, args, held, npmrcPath, say)
+			made, err := one(ctx, run, publish, manifest.Module, within, workspace, commit, credentials, a, args, held, npmrcPath, say)
 			if err != nil {
 				say("artifact", "%s FAILED: %v", a.Name, err)
 				return Result{}, err
@@ -210,6 +233,43 @@ func logging(log Log) func(step, format string, args ...any) {
 	}
 }
 
+// contextFrom clones an image artifact's own build context, when it names one apart from this
+// module's own repository — a fresh tree, the same way the module's own is, keyed by artifact
+// name so two artifacts of one module naming different contexts do not collide.
+func contextFrom(ctx context.Context, run Runner, workspace, artifact, credentials string,
+	from catalogue.ArtifactContext, say func(step, format string, args ...any)) (string, error) {
+	say("context", "cloning %s at %s for %s", from.Repository, refOrHead(from.Ref), artifact)
+	dir := filepath.Join(workspace, "context-"+artifact)
+	if err := os.RemoveAll(dir); err != nil {
+		return "", err
+	}
+	if _, err := run(ctx, workspace, "git", cloneWith(credentials, "clone", "--quiet", from.Repository, dir)...); err != nil {
+		return "", fmt.Errorf("cannot clone %s: %w", from.Repository, err)
+	}
+	if from.Ref != "" {
+		if _, err := run(ctx, dir, "git", "checkout", "--quiet", from.Ref); err != nil {
+			return "", fmt.Errorf("%s has no %s: %w", from.Repository, from.Ref, err)
+		}
+	}
+	say("context", "done")
+	return dir, nil
+}
+
+// cloneWith is a git invocation that may offer a stored credential.
+//
+// The first `-c credential.helper=` clears every helper the environment might carry, so exactly
+// one place answers an authentication challenge: the file the builder wrote. Without a file, the
+// invocation is exactly what it always was.
+func cloneWith(credentials string, rest ...string) []string {
+	if credentials == "" {
+		return rest
+	}
+	return append([]string{
+		"-c", "credential.helper=",
+		"-c", "credential.helper=store --file=" + credentials,
+	}, rest...)
+}
+
 func describePath(path string) string {
 	if path == "" {
 		return ""
@@ -333,7 +393,7 @@ func wantsPackages(manifest catalogue.Manifest, within string) bool {
 }
 
 func one(ctx context.Context, run Runner, publish Publisher,
-	module, tree, commit string, a catalogue.Artifact, args []string,
+	module, tree, workspace, commit, credentials string, a catalogue.Artifact, args []string,
 	held map[string]string, npmrc string, say func(step, format string, args ...any)) (catalogue.Built, error) {
 
 	switch a.Kind {
@@ -405,7 +465,27 @@ func one(ctx context.Context, run Runner, publish Publisher,
 					"and start FROM ${<NAME>} (novox/hq ADR 0097)",
 				module, a.From, strings.Join(bases, ", "))
 		}
-		invocation := append([]string{"build", "-f", a.From, "-t", local}, args...)
+		// The recipe is always read from this module's own tree, at this module's own commit — only
+		// the context docker build's final argument names can come from somewhere else, when the
+		// artifact says so.
+		recipePath := a.From
+		buildDir := tree
+		if a.Context != nil {
+			cloned, err := contextFrom(ctx, run, workspace, a.Name, credentials, *a.Context, say)
+			if err != nil {
+				return catalogue.Built{}, fmt.Errorf("%s: %s's context: %w", module, a.Name, err)
+			}
+			// docker build accepts -f outside the context it is given; the recipe stays exactly
+			// where it was read from and validated against, absolute so the working directory
+			// switching to the cloned context does not change which file that is.
+			absRecipe, err := filepath.Abs(filepath.Join(tree, a.From))
+			if err != nil {
+				return catalogue.Built{}, fmt.Errorf("%s: %s's recipe: %w", module, a.Name, err)
+			}
+			recipePath = absRecipe
+			buildDir = cloned
+		}
+		invocation := append([]string{"build", "-f", recipePath, "-t", local}, args...)
 		if a.Target != "" {
 			invocation = append(invocation, "--target", a.Target)
 		}
@@ -417,8 +497,8 @@ func one(ctx context.Context, run Runner, publish Publisher,
 			invocation = append(invocation, "--network", "host")
 		}
 		invocation = append(invocation, ".")
-		say("image", "docker build -f %s", a.From)
-		if _, err := run(ctx, tree, "docker", invocation...); err != nil {
+		say("image", "docker build -f %s", recipePath)
+		if _, err := run(ctx, buildDir, "docker", invocation...); err != nil {
 			return catalogue.Built{}, fmt.Errorf("%s: building %s failed: %w", module, a.Name, err)
 		}
 		say("image", "built, publishing")

internal/builder/builder_test.go

@@ -18,13 +18,19 @@ import (
 // tree, that two builds of one commit produce one digest. Running docker here would test docker.
 
 type recorded struct {
-	ran      []string
+	ran []string
+	// dirs is the directory each entry in ran was run from, same index — so a test can ask not
+	// only what ran but where.
+	dirs     []string
 	images   map[string]string
 	archives map[string]string
 	failPush bool
 	// contents is what a clone of this repository lands, so the fake clone can restore the tree
 	// Build deliberately removes first.
 	contents map[string]string
+	// secondary is what a clone of a repository OTHER than the one under test lands, keyed by
+	// that repository's URL — an artifact's own build context, cloned apart from the module.
+	secondary map[string]map[string]string
 	// stamped is the modification time the clone gives every file. Set differently between two
 	// builds of one commit, because otherwise both land in the same second and a packer that
 	// carried timestamps would still produce one digest — which is a test that passes for a
@@ -35,13 +41,28 @@ type recorded struct {
 func (r *recorded) run(_ context.Context, dir, name string, args ...string) (string, error) {
 	line := name + " " + strings.Join(args, " ")
 	r.ran = append(r.ran, line)
+	r.dirs = append(r.dirs, dir)
+	// A clone may carry `-c` configuration in front of the verb — the credential store — so the
+	// verb is found rather than assumed first.
+	isClone := false
+	for _, a := range args {
+		if a == "clone" {
+			isClone = true
+			break
+		}
+	}
 	switch {
-	case name == "git" && len(args) > 0 && args[0] == "clone":
+	case name == "git" && isClone:
+		repository := args[len(args)-2]
 		tree := args[len(args)-1]
 		if err := os.MkdirAll(tree, 0o755); err != nil {
 			return "", err
 		}
-		for path, body := range r.contents {
+		lands := r.contents
+		if by, is := r.secondary[repository]; is {
+			lands = by
+		}
+		for path, body := range lands {
 			full := filepath.Join(tree, path)
 			if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
 				return "", err
@@ -59,7 +80,6 @@ func (r *recorded) run(_ context.Context, dir, name string, args ...string) (str
 	case name == "git" && len(args) > 0 && args[0] == "rev-parse":
 		return "c0ffeec0ffeec0ffeec0ffeec0ffeec0ffeec0ff\n", nil
 	}
-	_ = dir
 	return "", nil
 }
 
@@ -108,7 +128,7 @@ func TestABuildProducesAManifestThePinsAreIn(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{
 		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
 	})
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -134,7 +154,7 @@ func TestTwoBuildsOfOneCommitProduceOneDigest(t *testing.T) {
 		})
 		// A year apart, so a packer carrying timestamps cannot accidentally agree.
 		r.stamped = time.Date(2020+i, time.March, 3, 4, 5, 6, 0, time.UTC)
-		got, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+		got, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -154,7 +174,7 @@ func TestNothingIsPublishedUntilEverythingIsBuilt(t *testing.T) {
 	// unreferenced, and indistinguishable from something in use.
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch"})
 	// `files` is missing, so packing the archive fails — after the image would have been pushed.
-	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a build with a missing input succeeded")
 	}
@@ -166,7 +186,7 @@ func TestNothingIsPublishedUntilEverythingIsBuilt(t *testing.T) {
 func TestARepositoryWithNoManifestSaysSo(t *testing.T) {
 	workspace := t.TempDir()
 	r := &recorded{contents: map[string]string{"README.md": "nothing to see"}}
-	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a repository with nothing saying what it is was built")
 	}
@@ -179,7 +199,7 @@ func TestAModuleThatBuildsNothingStillProducesAManifest(t *testing.T) {
 	// Most of what a person installs is configuration.
 	r, workspace := aRepository(t, `{"module":"shell","version":"1","resources":[
 		{"id":"rc","type":"file","path":"/etc/zsh/zshrc","content":"setopt"}]}`, nil)
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/shell.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/shell.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -209,7 +229,7 @@ func TestTheTreeIsFreshEveryTime(t *testing.T) {
 	if err := os.WriteFile(leftover, []byte("stale"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil); err != nil {
+	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := os.Stat(leftover); err == nil {
@@ -222,7 +242,7 @@ func TestABuildThatCannotPushFails(t *testing.T) {
 		"Dockerfile": "FROM scratch", "files/a": "b",
 	})
 	r.failPush = true
-	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil); err == nil {
+	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err == nil {
 		t.Fatal("a build that could publish nothing reported success")
 	}
 }
@@ -236,7 +256,7 @@ func TestAnUpstreamImageIsMirroredRatherThanBuilt(t *testing.T) {
 	  "resources":[{"id":"db","type":"container","name":"mesh-postgres","artifact":"store"}]}`
 
 	r, workspace := aRepository(t, mirrors, nil)
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/postgres.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/postgres.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -302,7 +322,7 @@ func TestAModuleIsBuiltFromItsPathWithinTheRepository(t *testing.T) {
 		"modules/other/" + ManifestName: `{"module":"other","version":"1"}`,
 	}}
 	got, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/catalogue.git", "modules/shell", "", t.TempDir(), nil, Npmrc{}, nil)
+		"https://forge.invalid/catalogue.git", "modules/shell", "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -321,7 +341,7 @@ func TestAPathThatLeavesTheRepositoryIsRefused(t *testing.T) {
 	for _, escaping := range []string{"../../etc", "/etc"} {
 		r := &recorded{contents: map[string]string{ManifestName: withBoth}}
 		_, err := Build(context.Background(), r.run, r,
-			"https://forge.invalid/x.git", escaping, "", t.TempDir(), nil, Npmrc{}, nil)
+			"https://forge.invalid/x.git", escaping, "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
 		if err == nil {
 			t.Fatalf("%q was accepted as a module's path", escaping)
 		}
@@ -331,3 +351,168 @@ func TestAPathThatLeavesTheRepositoryIsRefused(t *testing.T) {
 		}
 	}
 }
+
+// **Packaging and source are allowed to live apart** — a module that ships only the recipe for
+// source that lives in a second repository (the reference route-proxy, packaged in the catalogue
+// but built from mesh-controller's own repository) names where that source actually is, rather
+// than vendoring a second copy the two could drift from.
+func TestAnArtifactWithItsOwnContextIsBuiltFromThere(t *testing.T) {
+	const withContext = `{"module":"route-proxy","version":"1",
+	  "build":{"artifacts":[
+	    {"name":"server","kind":"image","from":"Dockerfile",
+	     "context":{"repository":"https://forge.invalid/source.git","ref":"main"}}]}}`
+	r := &recorded{
+		contents: map[string]string{
+			ManifestName: withContext,
+			// The recipe lives with the packaging, not the source — read from here regardless of
+			// where the build context comes from. FROM scratch declares no base, so what is under
+			// test — where the context comes from — is not entangled with ADR 0097's own checks.
+			"Dockerfile": "FROM scratch\nCOPY go.mod ./\n",
+		},
+		secondary: map[string]map[string]string{
+			// go.mod exists only in the second repository. A build context taken from the wrong
+			// place would never find it, which a real docker build would refuse on — the fake
+			// does not read files, so what is checked below is that the build was even pointed
+			// at the right place, not that COPY would have succeeded.
+			"https://forge.invalid/source.git": {"go.mod": "module route-proxy\n"},
+		},
+	}
+	_, err := Build(context.Background(), r.run, r,
+		"https://forge.invalid/catalogue.git", "", "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var clonedSource bool
+	for _, line := range r.ran {
+		if strings.HasPrefix(line, "git clone") && strings.Contains(line, "https://forge.invalid/source.git") {
+			clonedSource = true
+		}
+	}
+	if !clonedSource {
+		t.Fatalf("the artifact's own context was never cloned: %v", r.ran)
+	}
+
+	buildIndex := -1
+	for i, line := range r.ran {
+		if strings.HasPrefix(line, "docker build ") {
+			buildIndex = i
+		}
+	}
+	if buildIndex == -1 {
+		t.Fatal("no docker build was run")
+	}
+	build := r.ran[buildIndex]
+	buildDir := r.dirs[buildIndex]
+
+	if !strings.Contains(buildDir, "context-server") {
+		t.Errorf("docker build ran from %q, not the artifact's own cloned context", buildDir)
+	}
+	recipe := strings.SplitN(strings.SplitN(build, "-f ", 2)[1], " ", 2)[0]
+	if !filepath.IsAbs(recipe) {
+		t.Errorf("the recipe %q is not an absolute path, so it is read relative to whatever "+
+			"directory the build context moved to rather than where it actually is", recipe)
+	}
+	if !strings.HasSuffix(recipe, string(filepath.Separator)+"Dockerfile") {
+		t.Errorf("the recipe is not the module's own Dockerfile: %q", recipe)
+	}
+	if !strings.HasSuffix(build, " .") {
+		t.Errorf("the build was not given a context: %s", build)
+	}
+}
+
+// The forge credential is offered through git's own credential store — a file, never argv — and
+// git decides when it applies. What is checked: the clone names the store, the secret never
+// appears in a command line, and the file holds exactly the URL at 0600.
+func TestABuildOffersTheForgesCredentialThroughGitsOwnStore(t *testing.T) {
+	r, workspace := aRepository(t, withBoth, map[string]string{
+		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
+	})
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "",
+		workspace, nil, Npmrc{},
+		GitCredential{URL: "http://mesh_novox_builder:sw0rdfi5h@forge.invalid:20000"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stored := filepath.Join(workspace, "git-credentials")
+	clone := r.ran[0]
+	if !strings.Contains(clone, "credential.helper=store --file="+stored) {
+		t.Fatalf("the clone does not name the credential store: %s", clone)
+	}
+	for _, line := range r.ran {
+		if strings.Contains(line, "sw0rdfi5h") {
+			t.Fatalf("the secret is in a command line, readable by anything that can list processes: %s", line)
+		}
+	}
+	raw, err := os.ReadFile(stored)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.TrimSpace(string(raw)) != "http://mesh_novox_builder:sw0rdfi5h@forge.invalid:20000" {
+		t.Fatalf("the store does not hold the credential as given: %q", raw)
+	}
+	info, err := os.Stat(stored)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.Mode().Perm() != 0o600 {
+		t.Fatalf("the credential file is readable beyond its owner: %v", info.Mode())
+	}
+}
+
+// Without a credential, a clone is exactly the invocation it always was, and no credential file
+// appears — the builder a mesh of public repositories runs is unchanged.
+func TestABuildWithNoCredentialClonesExactlyAsBefore(t *testing.T) {
+	r, workspace := aRepository(t, withBoth, map[string]string{
+		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
+	})
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "",
+		workspace, nil, Npmrc{}, GitCredential{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(r.ran[0], "git clone --quiet ") {
+		t.Fatalf("a credential-less clone grew flags: %s", r.ran[0])
+	}
+	if _, err := os.Stat(filepath.Join(workspace, "git-credentials")); !os.IsNotExist(err) {
+		t.Fatal("a credential file was written with no credential to put in it")
+	}
+}
+
+// An artifact's own context is cloned with the same offer: a private module whose context is a
+// second private repository on the same forge builds, and the secret still never reaches argv.
+func TestAContextCloneCarriesTheSameCredentialStore(t *testing.T) {
+	const withContext = `{"module":"route-proxy","version":"1",
+	  "build":{"artifacts":[
+	    {"name":"server","kind":"image","from":"Dockerfile",
+	     "context":{"repository":"https://forge.invalid/source.git","ref":"main"}}]}}`
+	r := &recorded{
+		contents: map[string]string{
+			ManifestName: withContext,
+			"Dockerfile": "FROM scratch\nCOPY go.mod ./\n",
+		},
+		secondary: map[string]map[string]string{
+			"https://forge.invalid/source.git": {"go.mod": "module route-proxy\n"},
+		},
+	}
+	workspace := t.TempDir()
+	_, err := Build(context.Background(), r.run, r,
+		"https://forge.invalid/catalogue.git", "", "", workspace, nil, Npmrc{},
+		GitCredential{URL: "https://builder:s3cret@forge.invalid"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stored := filepath.Join(workspace, "git-credentials")
+	var contextClone string
+	for _, line := range r.ran {
+		if strings.Contains(line, "clone") && strings.Contains(line, "source.git") {
+			contextClone = line
+		}
+	}
+	if contextClone == "" {
+		t.Fatalf("the context was never cloned: %v", r.ran)
+	}
+	if !strings.Contains(contextClone, "credential.helper=store --file="+stored) {
+		t.Fatalf("the context clone does not name the credential store: %s", contextClone)
+	}
+}

internal/builder/bundle_test.go

@@ -54,7 +54,7 @@ func TestABundleIsCompiledAndPackedWithNoDockerfile(t *testing.T) {
 	held := map[string]string{"mesh-tools/build": "registry.invalid/mesh-tools/build@sha256:" + strings.Repeat("b", 64)}
 
 	got, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("a module with a language and no Dockerfile did not build: %v", err)
 	}
@@ -91,7 +91,7 @@ func TestABundleWhoseToolchainIsNotHeldIsRefusedFirst(t *testing.T) {
 	r, workspace := aRepository(t, aBundle, map[string]string{"index.ts": "console.log(1)"})
 
 	_, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, nil, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a bundle was built with no toolchain to compile it in")
 	}
@@ -112,7 +112,7 @@ func TestABundleInAnUnknownLanguageIsRefused(t *testing.T) {
 
 	_, err := Build(context.Background(), compiling{r}.run, r,
 		"https://forge.invalid/greeter.git", "", "", workspace,
-		map[string]string{"mesh-tools/build": "registry.invalid/x@sha256:" + strings.Repeat("c", 64)}, Npmrc{}, nil)
+		map[string]string{"mesh-tools/build": "registry.invalid/x@sha256:" + strings.Repeat("c", 64)}, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a language nothing can compile was accepted")
 	}
@@ -140,7 +140,7 @@ func TestTwoBundlesInOneModuleArePackedSeparately(t *testing.T) {
 	held := map[string]string{"mesh-tools/build": "registry.invalid/mesh-tools/build@sha256:" + strings.Repeat("b", 64)}
 
 	got, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("a module with two bundles did not build: %v", err)
 	}

internal/builder/packages_test.go

@@ -71,7 +71,7 @@ func TestAnImageBuildGetsTheCredentialInTheContextAndHostNetwork(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch\nCOPY .npmrc ./", "files/x": "y"})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 
@@ -101,7 +101,7 @@ func TestAnImageBuildGetsTheCredentialInTheContextAndHostNetwork(t *testing.T) {
 func TestAnImageBuildWithoutACredentialGetsNoHostNetwork(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch", "files/x": "y"})
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 	for _, line := range r.ran {
@@ -127,7 +127,7 @@ func TestAPackageIsBuiltOnAPublicBaseAndPublishedByVersion(t *testing.T) {
 	})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	got, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, n, nil)
+		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, n, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("the package did not build: %v", err)
 	}
@@ -159,7 +159,7 @@ func TestAPackageWithNoRegistryIsRefused(t *testing.T) {
 		"package.json": `{"name":"@novox/mesh-sdk","version":"0.1.0"}`,
 	})
 	_, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, Npmrc{}, nil)
+		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a package built with no registry to publish to, silently")
 	}
@@ -206,7 +206,7 @@ func TestAnImageThatDoesNotAskForTheCredentialDoesNotGetIt(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch\nCOPY . .", "files/x": "y"})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 	for _, line := range r.ran {

internal/catalogue/declaration.go

@@ -114,6 +114,14 @@ type Rendering struct {
 	// because which machines exist is a fact about the mesh.
 	Names map[string]string
 
+	// Machines is only the machines, by the same internal name — the subset of Names that is a
+	// node of this mesh rather than a name it was told to serve. Both matter and they are not the
+	// same set: a container's hosts wants every name, so a routed name resolves to the proxy that
+	// serves it, while a resolver told the mesh's suffix is authoritative for it answers from what
+	// it is given and forwards nothing — so a routed name written there is a name nobody asks for,
+	// standing beside the machines and looking as real as they do.
+	Machines map[string]string
+
 	Settings   SettingsBy
 	Generators map[string]Generator
 	// Grants are the credentials this node must create, for the provisions it offers. Passed in
@@ -160,6 +168,13 @@ type Rendering struct {
 	// with an address — before references were kept without one — from an image a module runs
 	// straight from a public registry.
 	Built map[string]bool
+
+	// DataRoot is where this node keeps the directories the mesh places for its modules
+	// (novox/hq ADR 0112, to-be 27): a directory resource that states no path resolves to
+	// <DataRoot>/<module>/<id>, and ${dir:<id>} names that place from the module's own files,
+	// mounts and environment. A node setting fixed at installation; empty means the default,
+	// /var/lib — see dir_into.go.
+	DataRoot string
 }
 
 // machinePort is where a module's port lives on this machine, or the port itself when the mesh has
@@ -209,6 +224,21 @@ func (r Resolution) Compose(with Rendering) (Composed, error) {
 }
 
 func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[string]any, error) {
+	// Every manifest is placed first (novox/hq ADR 0112): the maps naming where its bindings,
+	// credentials and contributions land are resolved against this node's directories, so every
+	// reader below — the binding files, the sealed secrets, the grant paths a contribution
+	// names — sees a concrete place and none learns the vocabulary.
+	// Into a fresh slice, never the caller's: one resolution may compose for many nodes, and a
+	// slice element written in place would carry the first node's places into the second's.
+	placed := make([]Manifest, len(r.Modules))
+	for i, m := range r.Modules {
+		var err error
+		if placed[i], err = placedManifest(m, with); err != nil {
+			return nil, err
+		}
+	}
+	r.Modules = placed
+
 	// Where each provision's credentials land, so a contribution can name the file rather than
 	// carry a value the mesh does not have.
 	directories := map[string]string{}
@@ -511,6 +541,9 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		}
 		// And what its bindings say, for the half of a connection that is not secret.
 		known := knownFor(m, r.Needs, r.Node)
+		// And where this node places the directories the module declared without a path
+		// (novox/hq ADR 0112) — resolved once per module, named by ${dir:…} from any resource.
+		dirs := dirsFor(m, with)
 		// And the machine underneath, which no binding of its own can tell it.
 		thisMachine := machineFacts(r, with.Names)
 
@@ -533,6 +566,13 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 			// Said in the catalogue, not on the machine: the host parses strictly and knows no
 			// such field, and the reason is for a reader of the manifest.
 			delete(copied, SecretsInEnvironment)
+			// **Placed before anything reads a path.** A pathless directory receives the path
+			// this node resolves for it, and every ${dir:…} — in paths, mounts, content and
+			// environment — becomes that path, so what follows sees only concrete places
+			// (novox/hq ADR 0112). The host receives paths exactly as it always has.
+			if err := dirInto(copied, dirs, m.Module); err != nil {
+				return nil, err
+			}
 			// **After settings, and that is the whole reason it is here.** A module's file
 			// content is where a setting lands, so a placeholder may only exist once the setting
 			// has been put in — filling secrets first would look at content that is not yet what
@@ -604,7 +644,7 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		// plane's; making a name resolve is the module's software. Emitted as ordinary files under
 		// this module's name, so they are applied, reported and removed exactly as anything else
 		// it declares.
-		given, err := FactsInto(m, r, with.Names, with.Suffix)
+		given, err := FactsInto(m, r, with.Names, with.Machines, with.Suffix)
 		if err != nil {
 			return nil, err
 		}
@@ -903,30 +943,53 @@ func (r Resolution) contributions(settings SettingsBy, grants []Grant,
 			if err != nil {
 				return nil, fmt.Errorf("%s contributing to %s: %w", m.Module, to, err)
 			}
-			composeName(values, r.PublicDomain)
+			composeName(values, r.PublicDomain, r.At)
 			out[to] = append(out[to], Contribution{From: m.Module, Values: values})
 		}
+		// Several contributions to one requirement (ADR 0094's sibling for `contributes`): an
+		// object store's data API and its console are two different public names from one module,
+		// not one. Never in `granted` — a route names a host, not a credential — so every local
+		// name always reaches the provider from here.
+		for _, to := range sortedKeys(m.ContributesMany) {
+			for _, local := range sortedKeys(m.ContributesMany[to]) {
+				values, err := settle(m.ContributesMany[to][local], settings[m.Module], nil,
+					m.Module+" contributing "+local+" to "+to)
+				if err != nil {
+					return nil, fmt.Errorf("%s contributing %s to %s: %w", m.Module, local, to, err)
+				}
+				composeName(values, r.PublicDomain, r.At)
+				out[to] = append(out[to], Contribution{From: m.Module, Values: values})
+			}
+		}
 	}
 	return out, nil
 }
 
-// composeName joins a contribution's label with a node's public domain, in place (novox/hq ADR
-// 0056).
+// composeName joins a contribution's label with a node's public domain, and separately with its
+// private one, in place (novox/hq ADR 0056).
 //
-// **The whole of what the mesh does with a route's name: join two given strings.** A contribution
-// carries a `label` — the subdomain its operator chose — and the node carries its public domain;
-// the granted name is `<label>.<public-domain>` and the mesh interprets neither half. It runs on
-// any contribution carrying a label, not only a route's, because the mesh does not know what a
+// **The whole of what the mesh does with a route's name: join two given strings — twice.** A
+// contribution carries a `label` — the subdomain its operator chose — and the node carries its
+// public domain and its own private-network address; the granted names are `<label>.<public-domain>`
+// and `<label>.<internal-domain>`, and the mesh interprets none of the halves. It runs on any
+// contribution carrying a label, not only a route's, because the mesh does not know what a
 // provision means — a name it can compose from parts it was given is the point, whatever the
 // provision is called.
 //
+// **The internal name is not a security boundary.** A predecessor proxy that answered both a
+// public and a private-network hostname for the same route did so as a convenience — reaching a
+// service over the VPN without a public TLS round trip — not as an access control, and composing
+// the same alias here restores that convenience rather than adding one. A route with no internal
+// domain to compose against (a node not on the private network) gets no internal name, the same as
+// it gets no public one with no public domain.
+//
 // **Additive, so an unmigrated catalogue still works.** A contribution that already carries a full
 // `name` and no `label` is left exactly as it is: the catalogue can migrate module by module while
 // the running mesh keeps serving the full names it has. And a labelled contribution on a node with
 // no public domain composes nothing — there is nothing to join it to — which reads downstream as a
 // route that named no host, the same as it would have before this existed.
-func composeName(values map[string]any, publicDomain string) {
-	if values == nil || publicDomain == "" {
+func composeName(values map[string]any, publicDomain, internalDomain string) {
+	if values == nil {
 		return
 	}
 	if _, already := values["name"]; already {
@@ -939,14 +1002,25 @@ func composeName(values map[string]any, publicDomain string) {
 	if !ok || strings.TrimSpace(label) == "" {
 		return
 	}
-	if strings.TrimSpace(label) == "@" {
-		// The apex: a module served at the bare public domain, no subdomain — the zone-file
-		// convention `@`. Composes to the domain itself, so a node's own site is a label like any
-		// other rather than the one route that must still carry a full name.
-		values["name"] = publicDomain
+	trimmed := strings.TrimSpace(label)
+	if trimmed == "@" {
+		// The apex: a module served at the bare domain, no subdomain — the zone-file convention
+		// `@`. Composes to the domain itself, so a node's own site is a label like any other rather
+		// than the one route that must still carry a full name.
+		if publicDomain != "" {
+			values["name"] = publicDomain
+		}
+		if internalDomain != "" {
+			values["internal-name"] = internalDomain
+		}
 		return
 	}
-	values["name"] = strings.TrimSpace(label) + "." + publicDomain
+	if publicDomain != "" {
+		values["name"] = trimmed + "." + publicDomain
+	}
+	if internalDomain != "" {
+		values["internal-name"] = trimmed + "." + internalDomain
+	}
 }
 
 // receivedFile is the file a provider is given its consumers' contributions in.
@@ -1097,17 +1171,34 @@ func boundFile(n Needed, path, as string) (map[string]any, error) {
 // arrangement refused is the ordinary one. A node running eight services against one database is
 // not an edge case; it is what a machine looks like. Now each consumer has its own credential and
 // there is nothing left to refuse.
+//
+// **One credential, even where a module contributes several times.** A module may answer one
+// requirement more than once (ADR 0094's sibling for `contributes`) — an object store's data API
+// and its console are two different names, not one. There is still only one `Needed` for it, one
+// credential minted, one grant to settle: a pair credential is not a place to put a label or a
+// port. So where several of this module's contributions reach the same requirement, none of them
+// is "the" value — settling to the first, arbitrarily, would hand the grant one contribution's
+// values under a credential the OTHER contribution's consumer never sees, and would collide with
+// that contribution's own entry from contributions() besides. Empty values, still granted: the
+// module asked, gets its credential, and each named contribution reaches the provider on its own.
 func (r Resolution) ContributionsFrom(requirement, module string, settings SettingsBy) (
 	map[string]any, bool, error) {
 	all, err := r.contributions(settings, nil, nil)
 	if err != nil {
 		return nil, false, err
 	}
+	var mine []map[string]any
 	for _, g := range all[requirement] {
 		if g.From == module {
-			return g.Values, true, nil
+			mine = append(mine, g.Values)
 		}
 	}
+	if len(mine) == 1 {
+		return mine[0], true, nil
+	}
+	if len(mine) > 1 {
+		return map[string]any{}, true, nil
+	}
 	// It contributes no payload — but a require-only consumer of a parameterless provision (one whose
 	// `serves` names no consumer-supplied key: `redis-cache`, `amqp`) still ASKS for it and must be
 	// granted a credential. Keying "asks" on contributions alone marked those grants withdrawn

internal/catalogue/dir_into.go

@@ -0,0 +1,322 @@
+package catalogue
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// A directory the mesh places (novox/hq ADR 0112, to-be 27, issue 119).
+//
+// **A module definition names no host path.** A directory resource may omit `path`; the mesh
+// resolves where it lands when the declaration is composed — `<root>/<module>/<id>`, the root a
+// node's own setting with /var/lib as the default. From then on the module's own files, mounts
+// and environment name the place as `${dir:<id>}`, the same shape as `${bound:…}` and
+// `${secret:…}`: a fact the module asks for by name and never states.
+//
+// **A directory that states a path keeps it, and still answers `${dir:<id>}`.** That is the
+// placement for an adopted machine: data that must sit where the predecessor already put it is
+// declared with the path as the exception it is, and everything else in the module names it by
+// id — so moving it later is one line, not a search.
+//
+// **Resolved here, not on the machine.** The host receives concrete paths exactly as it always
+// has; nothing new reaches it and it learns no field. Which also means a resolved path changing
+// is a spec change like any other — and the spec comparison must see it (novox/hq issue 126).
+
+// defaultDataRoot is where module data lands when a node states no root of its own.
+const defaultDataRoot = "/var/lib"
+
+// dirRef is how a module names one of its placed directories: ${dir:<id>}.
+var dirRef = regexp.MustCompile(`\$\{dir:([a-z0-9][a-z0-9-]*)\}`)
+
+// dataRoot is the root this node keeps placed directories under.
+func dataRoot(with Rendering) string {
+	if root := strings.TrimRight(strings.TrimSpace(with.DataRoot), "/"); root != "" {
+		return root
+	}
+	return defaultDataRoot
+}
+
+// dirsFor is every placed directory of a module, id → the path it resolves to on this node.
+//
+// A pathless directory saying `"place": "."` is the assignment's own root, <root>/<module> —
+// to-be 27's one directory per assignment, which every other placed thing sits beneath. At most
+// one makes sense; nothing enforces one, because two ids resolving to one path is a mistake the
+// module's own files make visible immediately.
+func dirsFor(m Manifest, with Rendering) map[string]string {
+	dirs := map[string]string{}
+	for _, r := range m.Resources {
+		if fmt.Sprint(r["type"]) != "directory" {
+			continue
+		}
+		id := fmt.Sprint(r["id"])
+		if path, stated := r["path"].(string); stated && path != "" {
+			dirs[id] = strings.TrimRight(path, "/")
+			continue
+		}
+		if place, said := r["place"].(string); said && place == "." {
+			dirs[id] = dataRoot(with) + "/" + m.Module
+			continue
+		}
+		dirs[id] = dataRoot(with) + "/" + m.Module + "/" + id
+	}
+	return dirs
+}
+
+// placedOrAbsolute says a path is usable where the mesh needs one: absolute already, or
+// beginning with a placed reference — resolution makes it absolute before anything reads it.
+// (unknownDirRefs is what checks the reference names a real directory.)
+func placedOrAbsolute(path string) bool {
+	return strings.HasPrefix(path, "/") ||
+		(strings.HasPrefix(path, "${dir:") && dirRef.MatchString(path))
+}
+
+// dirFill resolves every ${dir:…} in one string, or refuses a reference naming no directory.
+func dirFill(s string, dirs map[string]string, module string) (string, error) {
+	var missing error
+	out := dirRef.ReplaceAllStringFunc(s, func(ref string) string {
+		id := dirRef.FindStringSubmatch(ref)[1]
+		path, has := dirs[id]
+		if !has {
+			missing = fmt.Errorf(
+				"%s says ${dir:%s}, and %s declares no directory %q. It declares %s",
+				module, id, module, id, orNothing(namesOfDirs(dirs)))
+			return ref
+		}
+		return path
+	})
+	return out, missing
+}
+
+// placedManifest is the manifest with every path the mesh resolves already resolved: the maps
+// naming where bindings, credentials and contributions land are filled against this node's
+// placed directories, so everything downstream — the generated binding files, the sealed
+// secrets, the grant directories — reads a concrete place and learns nothing new.
+func placedManifest(m Manifest, with Rendering) (Manifest, error) {
+	dirs := dirsFor(m, with)
+	fillMap := func(in map[string]string) (map[string]string, error) {
+		if len(in) == 0 {
+			return in, nil
+		}
+		out := make(map[string]string, len(in))
+		for key, value := range in {
+			filled, err := dirFill(value, dirs, m.Module)
+			if err != nil {
+				return nil, err
+			}
+			out[key] = filled
+		}
+		return out, nil
+	}
+	var err error
+	if m.Receives, err = fillMap(m.Receives); err != nil {
+		return m, err
+	}
+	if m.Binds, err = fillMap(m.Binds); err != nil {
+		return m, err
+	}
+	if m.Secrets, err = fillMap(m.Secrets); err != nil {
+		return m, err
+	}
+	if m.OwnSecrets, err = fillMap(m.OwnSecrets); err != nil {
+		return m, err
+	}
+	if m.Grants, err = fillMap(m.Grants); err != nil {
+		return m, err
+	}
+	if len(m.SecretsMany) > 0 {
+		many := make(map[string]map[string]string, len(m.SecretsMany))
+		for to, locals := range m.SecretsMany {
+			if many[to], err = fillMap(locals); err != nil {
+				return m, err
+			}
+		}
+		m.SecretsMany = many
+	}
+	return m, nil
+}
+
+// dirInto places a resource: a pathless directory is given the path the mesh resolved for it,
+// and every ${dir:…} the resource carries — in its path, its content, its mounts, its
+// environment and its env-files — becomes that path.
+//
+// A reference naming no directory of this module is refused. Left as written, the literal
+// `${dir:x}` would reach the machine as a path, and the runtime would create and mount a
+// directory called `${dir:x}` — real, wrong, and named after the mistake.
+func dirInto(resource map[string]any, dirs map[string]string, module string) error {
+	fill := func(s string) (string, error) { return dirFill(s, dirs, module) }
+
+	if fmt.Sprint(resource["type"]) == "directory" {
+		id := fmt.Sprint(resource["id"])
+		if path, stated := resource["path"].(string); !stated || path == "" {
+			resource["path"] = dirs[id]
+		}
+		// Said in the catalogue, not on the machine: the host parses strictly and knows no
+		// such field — resolved, the place IS the path.
+		delete(resource, "place")
+	}
+
+	var err error
+	if path, ok := resource["path"].(string); ok {
+		if resource["path"], err = fill(path); err != nil {
+			return err
+		}
+	}
+	if content, ok := resource["content"].(string); ok {
+		if resource["content"], err = fill(content); err != nil {
+			return err
+		}
+	}
+	// Nested values are rebuilt, never written into: the resource is a shallow copy of the
+	// manifest's own map, and the manifest is composed once per node — a fill written in place
+	// would leave the first node's paths inside every later composition.
+	if volumes, ok := resource["volumes"].([]any); ok {
+		filled := make([]any, len(volumes))
+		for i, v := range volumes {
+			filled[i] = v
+			if mount, ok := v.(string); ok {
+				if filled[i], err = fill(mount); err != nil {
+					return err
+				}
+			}
+		}
+		resource["volumes"] = filled
+	}
+	if env, ok := resource["env"].(map[string]any); ok {
+		filled := make(map[string]any, len(env))
+		for key, v := range env {
+			filled[key] = v
+			if value, ok := v.(string); ok {
+				if filled[key], err = fill(value); err != nil {
+					return err
+				}
+			}
+		}
+		resource["env"] = filled
+	}
+	if files, ok := resource["env-file"].([]any); ok {
+		filled := make([]any, len(files))
+		for i, v := range files {
+			filled[i] = v
+			if path, ok := v.(string); ok {
+				if filled[i], err = fill(path); err != nil {
+					return err
+				}
+			}
+		}
+		resource["env-file"] = filled
+	}
+	return nil
+}
+
+// unknownDirRefs is every ${dir:…} in the definition that names no directory the definition
+// declares — refused where the author is, not at composition on some later day (the same
+// near-versus-far reasoning as the host's strict parse).
+func (m Manifest) unknownDirRefs() []string {
+	declared := map[string]bool{}
+	for _, r := range m.Resources {
+		if fmt.Sprint(r["type"]) == "directory" {
+			declared[fmt.Sprint(r["id"])] = true
+		}
+	}
+	referenced := func(s string) []string {
+		var ids []string
+		for _, match := range dirRef.FindAllStringSubmatch(s, -1) {
+			ids = append(ids, match[1])
+		}
+		return ids
+	}
+	var problems []string
+	for _, r := range m.Resources {
+		place, said := r["place"].(string)
+		if !said {
+			continue
+		}
+		if fmt.Sprint(r["type"]) != "directory" {
+			problems = append(problems, fmt.Sprintf(
+				"%s says place on %v, which is not a directory — only a directory is placed",
+				m.Module, r["id"]))
+			continue
+		}
+		if path, stated := r["path"].(string); stated && path != "" {
+			problems = append(problems, fmt.Sprintf(
+				"%s states both path and place on %v — a stated path IS the placement",
+				m.Module, r["id"]))
+		}
+		if place != "." {
+			problems = append(problems, fmt.Sprintf(
+				"%s says place %q on %v, and the only place is %q — the assignment's own root",
+				m.Module, place, r["id"], "."))
+		}
+	}
+	seen := map[string]bool{}
+	refuse := func(id string, where any) {
+		if declared[id] || seen[id] {
+			return
+		}
+		seen[id] = true
+		problems = append(problems, fmt.Sprintf(
+			"%s says ${dir:%s} in %v, and declares no directory %q — a reference the mesh "+
+				"cannot place would reach the machine as a literal path",
+			m.Module, id, where, id))
+	}
+	for _, r := range m.Resources {
+		for _, field := range []string{"path", "content"} {
+			if s, ok := r[field].(string); ok {
+				for _, id := range referenced(s) {
+					refuse(id, r["id"])
+				}
+			}
+		}
+		for _, field := range []string{"volumes", "env-file"} {
+			if list, ok := r[field].([]any); ok {
+				for _, v := range list {
+					if s, ok := v.(string); ok {
+						for _, id := range referenced(s) {
+							refuse(id, r["id"])
+						}
+					}
+				}
+			}
+		}
+		if env, ok := r["env"].(map[string]any); ok {
+			for _, v := range env {
+				if s, ok := v.(string); ok {
+					for _, id := range referenced(s) {
+						refuse(id, r["id"])
+					}
+				}
+			}
+		}
+	}
+	maps := map[string]map[string]string{
+		"receives": m.Receives, "binds": m.Binds, "secrets": m.Secrets,
+		"own-secrets": m.OwnSecrets, "grants": m.Grants,
+	}
+	for field, entries := range maps {
+		for _, value := range entries {
+			for _, id := range referenced(value) {
+				refuse(id, field)
+			}
+		}
+	}
+	for to, locals := range m.SecretsMany {
+		for _, value := range locals {
+			for _, id := range referenced(value) {
+				refuse(id, "secrets."+to)
+			}
+		}
+	}
+	sort.Strings(problems)
+	return problems
+}
+
+func namesOfDirs(dirs map[string]string) []string {
+	var names []string
+	for id := range dirs {
+		names = append(names, fmt.Sprintf("%q", id))
+	}
+	sort.Strings(names)
+	return names
+}

internal/catalogue/dir_into_test.go

@@ -0,0 +1,252 @@
+package catalogue
+
+// A directory the mesh places (novox/hq ADR 0112). These tests pin the contract: a pathless
+// directory resolves under the node's root, ${dir:…} names it from every field a host path can
+// live in, a stated path is the adopted-data placement and wins, an unknown reference refuses at
+// the manifest, and filling for one node never leaks into the next composition.
+
+import (
+	"strings"
+	"testing"
+)
+
+func placedModule() Manifest {
+	return Manifest{
+		Module: "photos",
+		Resources: []map[string]any{
+			{"id": "data", "type": "directory", "mode": "0700"},
+			{"id": "server-env", "type": "file", "path": "${dir:data}/server.env",
+				"content": "STORE=${dir:data}/objects\n"},
+			{"id": "server", "type": "container", "name": "photos-server",
+				"volumes":  []any{"${dir:data}:/data"},
+				"env":      map[string]any{"DATA": "${dir:data}/objects"},
+				"env-file": []any{"${dir:data}/server.env"}},
+		},
+	}
+}
+
+func TestAPathlessDirectoryResolvesUnderTheNodesRoot(t *testing.T) {
+	m := placedModule()
+	dirs := dirsFor(m, Rendering{})
+	if dirs["data"] != "/var/lib/photos/data" {
+		t.Fatalf("the default root is /var/lib and the shape is <root>/<module>/<id>; got %q", dirs["data"])
+	}
+	dirs = dirsFor(m, Rendering{DataRoot: "/tank/nox/"})
+	if dirs["data"] != "/tank/nox/photos/data" {
+		t.Fatalf("a node's own root is honoured, trailing slash and all; got %q", dirs["data"])
+	}
+}
+
+func TestDirReferencesBecomeThePlaceInEveryField(t *testing.T) {
+	m := placedModule()
+	dirs := dirsFor(m, Rendering{})
+
+	directory := shallowCopy(m.Resources[0])
+	if err := dirInto(directory, dirs, m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if directory["path"] != "/var/lib/photos/data" {
+		t.Fatalf("a pathless directory receives its resolved path; got %v", directory["path"])
+	}
+
+	file := shallowCopy(m.Resources[1])
+	if err := dirInto(file, dirs, m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if file["path"] != "/var/lib/photos/data/server.env" {
+		t.Fatalf("a file's path names the place; got %v", file["path"])
+	}
+	if file["content"] != "STORE=/var/lib/photos/data/objects\n" {
+		t.Fatalf("a file's content names the place; got %v", file["content"])
+	}
+
+	container := shallowCopy(m.Resources[2])
+	if err := dirInto(container, dirs, m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if container["volumes"].([]any)[0] != "/var/lib/photos/data:/data" {
+		t.Fatalf("a mount names the place; got %v", container["volumes"])
+	}
+	if container["env"].(map[string]any)["DATA"] != "/var/lib/photos/data/objects" {
+		t.Fatalf("an environment value names the place; got %v", container["env"])
+	}
+	if container["env-file"].([]any)[0] != "/var/lib/photos/data/server.env" {
+		t.Fatalf("an env-file names the place; got %v", container["env-file"])
+	}
+}
+
+func TestAStatedPathIsThePlacementAndStillAnswersByName(t *testing.T) {
+	m := placedModule()
+	// The adopted-machine case: data that must sit where the predecessor already put it.
+	m.Resources[0]["path"] = "/services/mssql/data/"
+	dirs := dirsFor(m, Rendering{})
+	if dirs["data"] != "/services/mssql/data" {
+		t.Fatalf("a stated path wins over the root, trimmed; got %q", dirs["data"])
+	}
+	container := shallowCopy(m.Resources[2])
+	if err := dirInto(container, dirs, m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if container["volumes"].([]any)[0] != "/services/mssql/data:/data" {
+		t.Fatalf("references follow the placement; got %v", container["volumes"])
+	}
+}
+
+func TestFillingForOneNodeLeaksIntoNoOther(t *testing.T) {
+	m := placedModule()
+	first := shallowCopy(m.Resources[2])
+	if err := dirInto(first, dirsFor(m, Rendering{DataRoot: "/first"}), m.Module); err != nil {
+		t.Fatal(err)
+	}
+	second := shallowCopy(m.Resources[2])
+	if err := dirInto(second, dirsFor(m, Rendering{DataRoot: "/second"}), m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if got := second["volumes"].([]any)[0]; got != "/second/photos/data:/data" {
+		t.Fatalf("the second composition must see the manifest, not the first fill; got %v", got)
+	}
+	if m.Resources[2]["volumes"].([]any)[0] != "${dir:data}:/data" {
+		t.Fatalf("the manifest itself stays a template; got %v", m.Resources[2]["volumes"])
+	}
+}
+
+func TestAReferenceToNoDirectoryRefusesAtTheManifest(t *testing.T) {
+	m := placedModule()
+	m.Resources[2]["volumes"] = []any{"${dir:date}:/data"} // a typo, the likely shape
+	problems := m.unknownDirRefs()
+	if len(problems) != 1 || !strings.Contains(problems[0], `${dir:date}`) {
+		t.Fatalf("a reference naming no directory is a manifest problem; got %v", problems)
+	}
+	if got := placedModule().unknownDirRefs(); len(got) != 0 {
+		t.Fatalf("a correct definition has none; got %v", got)
+	}
+}
+
+func TestAReferenceToNoDirectoryRefusesAtCompositionToo(t *testing.T) {
+	m := placedModule()
+	container := shallowCopy(m.Resources[2])
+	container["env"] = map[string]any{"DATA": "${dir:date}"}
+	err := dirInto(container, dirsFor(m, Rendering{}), m.Module)
+	if err == nil || !strings.Contains(err.Error(), `"date"`) || !strings.Contains(err.Error(), `"data"`) {
+		t.Fatalf("the refusal names the mistake and what exists; got %v", err)
+	}
+}
+
+func TestTheAssignmentsOwnRootIsAPlace(t *testing.T) {
+	m := Manifest{Module: "mailu", Resources: []map[string]any{
+		{"id": "state", "type": "directory", "place": ".", "mode": "0700"},
+		{"id": "data-mail", "type": "directory"},
+	}}
+	dirs := dirsFor(m, Rendering{})
+	if dirs["state"] != "/var/lib/mailu" {
+		t.Fatalf("place %q is the assignment's root; got %q", ".", dirs["state"])
+	}
+	if dirs["data-mail"] != "/var/lib/mailu/data-mail" {
+		t.Fatalf("everything else sits beneath it; got %q", dirs["data-mail"])
+	}
+	root := shallowCopy(m.Resources[0])
+	if err := dirInto(root, dirs, m.Module); err != nil {
+		t.Fatal(err)
+	}
+	if root["path"] != "/var/lib/mailu" {
+		t.Fatalf("the root receives its path; got %v", root["path"])
+	}
+	if _, still := root["place"]; still {
+		t.Fatal("place must never reach the host, which parses strictly")
+	}
+}
+
+func TestTheManifestsMapsArePlaced(t *testing.T) {
+	m := Manifest{
+		Module: "photos",
+		Resources: []map[string]any{
+			{"id": "state", "type": "directory", "place": "."},
+		},
+		Binds:      map[string]string{"route": "${dir:state}/route.json"},
+		Secrets:    map[string]string{"mongodb-database": "${dir:state}/database.secret"},
+		OwnSecrets: map[string]string{"admin-key": "${dir:state}/admin-key.secret"},
+		Receives:   map[string]string{"route": "${dir:state}/grants/mesh.json"},
+	}
+	placed, err := placedManifest(m, Rendering{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if placed.Binds["route"] != "/var/lib/photos/route.json" {
+		t.Fatalf("binds are placed; got %v", placed.Binds)
+	}
+	if placed.Secrets["mongodb-database"] != "/var/lib/photos/database.secret" {
+		t.Fatalf("secrets are placed; got %v", placed.Secrets)
+	}
+	if placed.OwnSecrets["admin-key"] != "/var/lib/photos/admin-key.secret" {
+		t.Fatalf("own-secrets are placed; got %v", placed.OwnSecrets)
+	}
+	if placed.Receives["route"] != "/var/lib/photos/grants/mesh.json" {
+		t.Fatalf("receives are placed; got %v", placed.Receives)
+	}
+	if m.Binds["route"] != "${dir:state}/route.json" {
+		t.Fatalf("the manifest itself stays a template; got %v", m.Binds)
+	}
+}
+
+func TestAMapReferenceToNoDirectoryRefusesAtTheManifest(t *testing.T) {
+	m := Manifest{
+		Module:    "photos",
+		Resources: []map[string]any{{"id": "state", "type": "directory", "place": "."}},
+		Binds:     map[string]string{"route": "${dir:stat}/route.json"},
+	}
+	problems := m.unknownDirRefs()
+	if len(problems) != 1 || !strings.Contains(problems[0], `${dir:stat}`) {
+		t.Fatalf("a map naming no directory is a manifest problem; got %v", problems)
+	}
+}
+
+func TestPlaceIsValidatedAtTheManifest(t *testing.T) {
+	both := Manifest{Module: "x", Resources: []map[string]any{
+		{"id": "d", "type": "directory", "place": ".", "path": "/somewhere"},
+	}}
+	if got := both.unknownDirRefs(); len(got) != 1 || !strings.Contains(got[0], "both path and place") {
+		t.Fatalf("path beside place refuses; got %v", got)
+	}
+	elsewhere := Manifest{Module: "x", Resources: []map[string]any{
+		{"id": "f", "type": "file", "place": ".", "path": "/somewhere", "content": ""},
+	}}
+	if got := elsewhere.unknownDirRefs(); len(got) != 1 || !strings.Contains(got[0], "not a directory") {
+		t.Fatalf("place on a file refuses; got %v", got)
+	}
+	wrong := Manifest{Module: "x", Resources: []map[string]any{
+		{"id": "d", "type": "directory", "place": "sub/dir"},
+	}}
+	if got := wrong.unknownDirRefs(); len(got) != 1 || !strings.Contains(got[0], `the only place is "."`) {
+		t.Fatalf("a place that is not the root refuses; got %v", got)
+	}
+}
+
+func TestTwoModulesPlacedRootsAreNoCollision(t *testing.T) {
+	a := Manifest{Module: "gitea", Resources: []map[string]any{
+		{"id": "state", "type": "directory", "place": "."},
+		{"id": "env", "type": "file", "path": "${dir:state}/server.env", "content": ""},
+	}}
+	b := Manifest{Module: "nextcloud", Resources: []map[string]any{
+		{"id": "state", "type": "directory", "place": "."},
+		{"id": "env", "type": "file", "path": "${dir:state}/server.env", "content": ""},
+	}}
+	if got := checkResources([]Manifest{a, b}); len(got) != 0 {
+		t.Fatalf("alike templates are different places; got %v", got)
+	}
+	// And the real collision is still caught: a module stating another's placed root.
+	c := Manifest{Module: "squatter", Resources: []map[string]any{
+		{"id": "nest", "type": "directory", "path": "/var/lib/gitea"},
+	}}
+	got := checkResources([]Manifest{a, c})
+	if len(got) != 1 || !strings.Contains(got[0], `"/var/lib/gitea"`) {
+		t.Fatalf("a stated path on a placed root collides; got %v", got)
+	}
+}
+
+func shallowCopy(resource map[string]any) map[string]any {
+	copied := map[string]any{}
+	for k, v := range resource {
+		copied[k] = v
+	}
+	return copied
+}

internal/catalogue/facts.go

@@ -36,16 +36,23 @@ const (
 // **A closed list.** A module asking for a fact the mesh does not have is asking for a file nobody
 // will write, and finding that out on a machine — as a daemon that starts, reads nothing, and
 // answers no queries — is worse than being told where the manifest is.
-var facts = map[string]func(Resolution, map[string]string, string) string{
-	FactNodeNames: nodeNames,
-	FactNodeZones: nodeZones,
+// A fact is written from the names it is about. `every` is every name the mesh serves — machines
+// and the names it was told to route; `machines` is only the machines. A fact takes the set it is
+// true of, and the two must not be confused (novox/hq 04-ISSUES/111).
+var facts = map[string]func(r Resolution, every, machines map[string]string, suffix string) string{
+	FactNodeNames: func(r Resolution, every, _ map[string]string, suffix string) string {
+		return nodeNames(r, every, suffix)
+	},
+	FactNodeZones: func(r Resolution, _, machines map[string]string, suffix string) string {
+		return nodeZones(r, machines, suffix)
+	},
 }
 
 // FactsInto renders the facts a module asked for, as files it will be given.
 //
 // The module owns everything after the file exists: loading it, restarting on it, what a resolver
 // does with it. This only puts it there.
-func FactsInto(m Manifest, r Resolution, addresses map[string]string, suffix string) ([]map[string]any, error) {
+func FactsInto(m Manifest, r Resolution, addresses, machines map[string]string, suffix string) ([]map[string]any, error) {
 	if len(m.Facts) == 0 {
 		return nil, nil
 	}
@@ -70,7 +77,7 @@ func FactsInto(m Manifest, r Resolution, addresses map[string]string, suffix str
 		}
 		out = append(out, map[string]any{
 			"id": "fact-" + name, "type": "file", "path": path, "mode": "0644",
-			"content": write(r, addresses, suffix),
+			"content": write(r, addresses, machines, suffix),
 		})
 	}
 	return out, nil

internal/catalogue/facts_test.go

@@ -63,7 +63,7 @@ func TestAMachinesOwnNameIsItsMeshAddress(t *testing.T) {
 // A module says where it wants a fact, and is given a file.
 func TestAModuleIsGivenTheFactsItAskedFor(t *testing.T) {
 	m := Manifest{Module: "dnsmasq", Facts: map[string]string{FactNodeZones: "/etc/mesh/zones.conf"}}
-	given, err := FactsInto(m, Resolution{Node: "homer"}, threeMachines, "")
+	given, err := FactsInto(m, Resolution{Node: "homer"}, threeMachines, threeMachines, "")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -82,7 +82,7 @@ func TestAModuleIsGivenTheFactsItAskedFor(t *testing.T) {
 // starts, reads a file nobody wrote, and answers no queries is a much worse way to find out.
 func TestAskingForAFactTheMeshDoesNotHaveIsRefused(t *testing.T) {
 	m := Manifest{Module: "dnsmasq", Facts: map[string]string{"the-weather": "/etc/weather"}}
-	_, err := FactsInto(m, Resolution{}, nil, "")
+	_, err := FactsInto(m, Resolution{}, nil, nil, "")
 	if err == nil {
 		t.Fatal("a module asked for something nobody computes and was given nothing, silently")
 	}
@@ -96,7 +96,7 @@ func TestAskingForAFactTheMeshDoesNotHaveIsRefused(t *testing.T) {
 // And a relative path is refused, or a module decides where the mesh writes on a machine.
 func TestAFactMustBeAskedForAtAnAbsolutePath(t *testing.T) {
 	m := Manifest{Module: "dnsmasq", Facts: map[string]string{FactNodeNames: "etc/hosts"}}
-	if _, err := FactsInto(m, Resolution{}, nil, ""); err == nil {
+	if _, err := FactsInto(m, Resolution{}, nil, nil, ""); err == nil {
 		t.Fatal("a relative path was accepted")
 	}
 }
@@ -140,3 +140,49 @@ func TestTheFactsWriteTheSuffixTheNamesWereComposedWith(t *testing.T) {
 		t.Fatalf("the hosts line does not carry the operator's suffix as given:\n%s", hosts)
 	}
 }
+
+// novox/hq 04-ISSUES/111: the map the control plane hands a resolution holds every name the mesh
+// serves — the machines, and the names it was told to route to whichever machine serves them. A
+// container's hosts wants all of it. A resolver's zones want only the machines: told the mesh's
+// suffix is its own, it answers authoritatively for everything under it and forwards nothing, so a
+// routed name written there with the suffix appended is a name nobody will ever ask for, standing
+// beside the machines and looking as real.
+func TestTheResolverIsToldTheMachinesAndNotTheNamesTheMeshMerelyServes(t *testing.T) {
+	machines := map[string]string{"homer.internal": "10.42.0.1", "marge.internal": "10.42.0.2"}
+	every := map[string]string{
+		"homer.internal": "10.42.0.1", "marge.internal": "10.42.0.2",
+		"drive.example.test": "10.42.0.1", "git.example.test": "10.42.0.2",
+	}
+	m := Manifest{Module: "resolver", Facts: map[string]string{
+		FactNodeZones: "/etc/zones.conf", FactNodeNames: "/etc/hosts",
+	}}
+	given, err := FactsInto(m, Resolution{Node: "homer"}, every, machines, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	by := map[string]string{}
+	for _, f := range given {
+		by[f["path"].(string)] = f["content"].(string)
+	}
+
+	zones := by["/etc/zones.conf"]
+	for _, machine := range []string{"address=/homer.internal/10.42.0.1", "address=/marge.internal/10.42.0.2"} {
+		if !strings.Contains(zones, machine) {
+			t.Fatalf("the resolver was not told %q:\n%s", machine, zones)
+		}
+	}
+	for _, served := range []string{"drive.example.test", "git.example.test"} {
+		if strings.Contains(zones, served) {
+			t.Fatalf("the resolver was told %q, a name the mesh serves rather than a machine:\n%s", served, zones)
+		}
+	}
+
+	// And the hosts file is the other way about: every name, so a container reaching a routed name
+	// finds the machine serving it.
+	hosts := by["/etc/hosts"]
+	for _, name := range []string{"homer.internal", "drive.example.test", "git.example.test"} {
+		if !strings.Contains(hosts, name) {
+			t.Fatalf("a container would not resolve %q from its hosts:\n%s", name, hosts)
+		}
+	}
+}

internal/catalogue/foundation_manifests_test.go

@@ -1,7 +1,6 @@
 package catalogue
 
 import (
-	"encoding/json"
 	"fmt"
 	"os"
 	"reflect"
@@ -85,9 +84,8 @@ func TestTheFilterModuleNeverFlushesTheRuleset(t *testing.T) {
 }
 
 // The package registry's port is the node's, like every other foundation port (novox/hq
-// 04-ISSUES/085, ADR 0100). Two halves, because the forge is reached two ways: through what the
-// module that serves it says it serves, and — for the genesis window, before any module provides
-// `package-registry` at all — through the one binding the builder carries instead of resolving.
+// 04-ISSUES/085, ADR 0100). The forge is reached through what it says it serves, and consumers —
+// the builder among them — are told that, rather than carrying a number of their own.
 
 func TestTheForgesPortIsGivenLikeAnyOtherProvidersPort(t *testing.T) {
 	forge := catalogueManifest(t, "gitea")
@@ -104,97 +102,67 @@ func TestTheForgesPortIsGivenLikeAnyOtherProvidersPort(t *testing.T) {
 
 	// And every consumer of the package registry is told where the machine actually put it,
 	// because that is read from what the forge serves rather than written in the consumer.
-	if got := ServedOn(forge, "package-registry", given)["port"]; got != 3100 {
+	if got := ServedOn(forge, "npm-package-registry", given)["port"]; got != 3100 {
 		t.Errorf("the package registry is served on %v, not the port this node gave it", got)
 	}
-	if got := ServedOn(forge, "package-registry", nil)["port"]; got != float64(3000) {
+	if got := ServedOn(forge, "npm-package-registry", nil)["port"]; got != float64(3000) {
 		t.Errorf("without a setting the forge serves %v, not the catalogue's port", got)
 	}
-}
-
-// bindingIn is the package binding the builder carries, as the machine would receive it.
-func bindingIn(t *testing.T, m Manifest, layers []Layer) map[string]any {
-	t.Helper()
-	for _, r := range m.Resources {
-		if fmt.Sprint(r["id"]) != "package-binding" {
-			continue
-		}
-		settled, err := ApplySettings(r, layers)
-		if err != nil {
-			t.Fatalf("the builder's package binding refused %v: %v", layers, err)
-		}
-		if settled["merge"] != nil || settled["protected"] != nil {
-			t.Fatal("the host would be sent fields it does not know")
-		}
-		var out map[string]any
-		if err := json.Unmarshal([]byte(fmt.Sprint(settled["content"])), &out); err != nil {
-			t.Fatalf("the builder's package binding is not a binding: %v", err)
-		}
-		return out
+	// And so is where a repository on it is cloned from (novox/hq ADR 0111), for the same reason:
+	// a build composes the URL from what the forge serves, so a given port is a followed port.
+	if got := ServedOn(forge, "git", given)["port"]; got != 3100 {
+		t.Errorf("git is served on %v, not the port this node gave the forge", got)
 	}
-	t.Fatal("the builder carries no package binding")
-	return nil
 }
 
-func TestTheBuildersCarriedPackageBindingTakesThePortFromTheNode(t *testing.T) {
+// **The builder requires the registry the npm seat delivers, and carries no binding of its own.**
+//
+// It used to carry a hand-written binding because nothing provided a package registry to resolve
+// one from at genesis. The catalogue now requires it like any consumer, and ADR 0110 makes the
+// seat's holder the answer when more than one module provides it — so a carried copy would be a
+// second answer to the same question, free to drift from the first. Asserted gone, not merely
+// unused.
+func TestTheBuilderRequiresTheRegistryTheNpmSeatDelivers(t *testing.T) {
 	builder := catalogueManifest(t, "builder")
-
-	// Nothing set: the catalogue's own number, which is what a mesh raised on the defaults uses.
-	serves := bindingIn(t, builder, nil)["serves"].(map[string]any)
-	if serves["port"] != float64(3000) {
-		t.Fatalf("the builder's binding defaults to %v", serves["port"])
+	seat, _ := SeatNamed("npm-package-registry")
+	var requires bool
+	for _, r := range builder.Requires {
+		requires = requires || r == seat.Delivers
 	}
-
-	// Given a port, the binding dials it — and the rest of what the forge serves survives, because
-	// a setting is merged into the module's own values rather than replacing them.
-	moved := bindingIn(t, builder, []Layer{{From: "anchor",
-		Values: map[string]any{"serves": map[string]any{"port": float64(3100)}}}})
-	got := moved["serves"].(map[string]any)
-	if got["port"] != float64(3100) {
-		t.Errorf("the builder dials %v, not the port this node gave the package registry", got["port"])
+	if !requires {
+		t.Fatalf("the builder does not require %q: %v", seat.Delivers, builder.Requires)
 	}
-	if got["scheme"] != "http" || got["npm-path"] != "/api/packages/novox/npm/" {
-		t.Errorf("setting the port lost the rest of what the forge serves: %v", got)
+	if builder.Binds[seat.Delivers] == "" {
+		t.Errorf("the builder is not told where the registry is: binds %v", builder.Binds)
 	}
-	if moved["as"] != "mesh-builder" || moved["from"] != "gitea" {
-		t.Errorf("setting the port changed who the binding is with: %v", moved)
-	}
-}
-
-// The two halves are one number. The builder carries a binding because at genesis nothing provides
-// `package-registry` to resolve one from; the day the forge is a module, the same consumer is told
-// what the forge serves. They have to start from the same port, or a mesh raised on the defaults
-// dials one number before the forge is assigned and another after.
-func TestTheBuildersCarriedBindingStartsWhereTheForgeServes(t *testing.T) {
-	forge := ServedOn(catalogueManifest(t, "gitea"), "package-registry", nil)
-	carried := bindingIn(t, catalogueManifest(t, "builder"), nil)["serves"].(map[string]any)
-	for _, key := range []string{"port", "scheme", "npm-path"} {
-		if fmt.Sprint(forge[key]) != fmt.Sprint(carried[key]) {
-			t.Errorf("the forge serves %s %v and the builder's carried binding says %v — the two "+
-				"halves of the same registry have drifted apart in the catalogue",
-				key, forge[key], carried[key])
+	for _, r := range builder.Resources {
+		if fmt.Sprint(r["id"]) == "package-binding" {
+			t.Fatal("the builder carries its own package binding beside the one the mesh resolves")
 		}
 	}
 }
 
-func TestTheBuildersPackageBindingKeepsItsIdentity(t *testing.T) {
-	builder := catalogueManifest(t, "builder")
-	// `at` above all: a setting that moves it points the builder, and the registry password it
-	// sends as basic auth, at a host somebody else chose.
-	for _, key := range []string{"provision", "from", "at", "as"} {
-		var refused error
-		for _, r := range builder.Resources {
-			if fmt.Sprint(r["id"]) != "package-binding" {
-				continue
-			}
-			_, refused = ApplySettings(r, []Layer{{From: "anchor",
-				Values: map[string]any{key: "something else"}}})
-		}
-		if refused == nil {
-			t.Errorf("%q can be set on the builder's package binding, which is not a port but who "+
-				"the binding is with", key)
+// The forge holds the seats it answers for (novox/hq ADR 0110, 0111), parsed by the real parser —
+// which refuses a delivering seat claimed by a module that does not provide what it delivers.
+func TestTheForgeHoldsTheNpmAndGitSeats(t *testing.T) {
+	forge := catalogueManifest(t, "gitea")
+	holds := map[string]bool{}
+	for _, c := range forge.Claims {
+		holds[c.Name] = true
+	}
+	for _, seat := range []string{"npm-package-registry", "git"} {
+		if !holds[seat] {
+			t.Errorf("gitea does not claim the %s seat: %+v", seat, forge.Claims)
 		}
 	}
+	git := ServedOn(forge, "git", nil)
+	if git["scheme"] != "http" || git["port"] != float64(3000) {
+		t.Errorf("gitea serves nothing a clone URL can be composed from: %v", git)
+	}
+	npm := ServedOn(forge, "npm-package-registry", nil)
+	if npm["npm-path"] != "/api/packages/novox/npm/" {
+		t.Errorf("gitea no longer says where its npm registry is: %v", npm)
+	}
 }
 
 // **And the forge's own address follows it**, composed from the manifest in the catalogue beside
@@ -251,27 +219,13 @@ func TestTheForgesOwnAddressFollowsThePortTheNodeGaveIt(t *testing.T) {
 	}
 }
 
-// **And the port the forge publishes the long way is the node's too** (novox/hq ADR 0100).
-//
-// The forge's ssh port is written `2222:22` — the machine's own daemon holds 22, so the module
-// takes 2222 and says so in `listens`. A node whose predecessor served git on another number
-// cannot be told to leave it there unless the setting may name the machine side of that mapping,
-// which is the number the manifest itself uses everywhere else. Composed from the manifest in the
-// catalogue beside this checkout, because what the mesh can move is a fact about what the module
-// actually writes.
-func TestTheForgesSshPortIsGivenByTheNumberTheForgeCallsIt(t *testing.T) {
+// gitea's own sshd is unmodified — the module's own internal port is 22, the number in
+// `listens`, the same convention every other module in the catalogue uses (its internal port,
+// not an invented identity). Composed from the manifest in the catalogue beside this checkout,
+// because what the mesh publishes is a fact about what the module actually writes.
+func declaredGiteaSsh(t *testing.T, given map[int]int) map[string]any {
+	t.Helper()
 	forge := catalogueManifest(t, "gitea")
-	given, err := GivenPorts(forge, []Layer{{From: "anchor",
-		Values: map[string]any{PortsSetting: map[string]any{"2222": float64(222)}}}})
-	if err != nil {
-		t.Fatalf("the forge's ssh port cannot be given on a node: %v", err)
-	}
-	// Under the number the module listens on — 2222, the machine side of its mapping — which is
-	// the number the plan, the filter, the openings and the consumer all ask for. One entry.
-	if want := map[int]int{2222: 222}; !reflect.DeepEqual(given, want) {
-		t.Fatalf("the forge was given %v, and it names its ssh port %v", given, want)
-	}
-
 	resolved, err := forge.Resolve([]Built{{
 		Name: "runtime", Kind: ArtifactImage,
 		Reference: "registry.example/gitea-runtime@sha256:" + strings.Repeat("a", 64),
@@ -286,9 +240,13 @@ func TestTheForgesSshPortIsGivenByTheNumberTheForgeCallsIt(t *testing.T) {
 		{Name: "secret", For: "gitea", From: "anchor", Local: "internal-token", Sealed: "sealed-token"},
 		{Name: "secret", For: "gitea", From: "anchor", Local: "admin", Sealed: "sealed-admin"},
 	}}
+	givenPorts := map[int]int{3000: 3000}
+	for k, v := range given {
+		givenPorts[k] = v
+	}
 	out, err := r.Declaration(Rendering{
 		Needed: map[string]map[string]string{"gitea": {"broker": "sealed-broker"}},
-		Ports:  map[string]map[int]int{"gitea": {3000: 3000, 2222: 222}},
+		Ports:  map[string]map[int]int{"gitea": givenPorts},
 		Given:  map[string]map[int]int{"gitea": given},
 	})
 	if err != nil {
@@ -298,8 +256,48 @@ func TestTheForgesSshPortIsGivenByTheNumberTheForgeCallsIt(t *testing.T) {
 	if server == nil {
 		t.Fatalf("the forge's own container is not in the declaration: %v", out)
 	}
-	if published := fmt.Sprint(server["ports"]); !strings.Contains(published, "222:22") ||
-		strings.Contains(published, "2222:22") {
+	return server
+}
+
+// **The forge publishes ssh at the mesh's own fixed convention by default** (novox/hq ADR 0100).
+//
+// `222` is the mesh's own public convention for the forge's ssh, written directly in the
+// manifest's `ports` — every node the forge has run on used the same number, so it needs no
+// per-node setting to reach it.
+func TestTheForgesSshPortIsTheMeshsFixedConventionByDefault(t *testing.T) {
+	forge := catalogueManifest(t, "gitea")
+	// Nothing was given — no node moved this port — which is the ordinary answer: the mesh only
+	// reports what a setting moved, and the manifest's own `222:22` needs no move to be reached.
+	given, err := GivenPorts(forge, nil)
+	if err != nil {
+		t.Fatalf("the forge's ssh port cannot be given on a node: %v", err)
+	}
+	if len(given) != 0 {
+		t.Fatalf("nothing moved the forge's ssh port, yet it was given %v", given)
+	}
+	server := declaredGiteaSsh(t, given)
+	if published := fmt.Sprint(server["ports"]); !strings.Contains(published, "222:22") {
+		t.Fatalf("the forge is published on %v, not its own fixed convention", server["ports"])
+	}
+}
+
+// **A node whose predecessor served git on a different number can still be told to leave it
+// there.** The setting names the port the module itself listens on — 22, gitea's own sshd, the
+// same number `listens` uses — not the mesh's own default machine-side number, so moving it does
+// not require guessing what the manifest happens to default to.
+func TestANodeMayGiveTheForgesSshPortADifferentNumber(t *testing.T) {
+	forge := catalogueManifest(t, "gitea")
+	given, err := GivenPorts(forge, []Layer{{From: "anchor",
+		Values: map[string]any{PortsSetting: map[string]any{"22": float64(9022)}}}})
+	if err != nil {
+		t.Fatalf("the forge's ssh port cannot be moved on a node: %v", err)
+	}
+	if want := map[int]int{22: 9022}; !reflect.DeepEqual(given, want) {
+		t.Fatalf("the forge was given %v, and the setting named %v", given, want)
+	}
+	server := declaredGiteaSsh(t, given)
+	if published := fmt.Sprint(server["ports"]); !strings.Contains(published, "9022:22") ||
+		strings.Contains(published, "222:22") {
 		t.Fatalf("the forge is published on %v, not the port this node gave it", server["ports"])
 	}
 }

internal/catalogue/manifest.go

@@ -233,6 +233,18 @@ type Manifest struct {
 	// module that had to say both would eventually say one.
 	Contributes map[string]map[string]any `json:"contributes,omitempty"`
 
+	// ContributesMany is the same key, `contributes`, where a module tells one provider several
+	// things under local names — `"route": {"api": {"label": "files-api", "port": 9000}, "console":
+	// {"label": "files", "port": 9001}}` — because a module may answer one requirement more than
+	// once: an object store with a data API and a console are two different public names, not one
+	// (novox/hq ADR 0094's sibling for `contributes` rather than `secrets` — "a module may need more
+	// than one value from a provider that gives one per pair" applies exactly as well to what a
+	// module gives a provider as to what it keeps from one). Each local name is a contribution of
+	// its own, reaching the provider as its own entry in the file it receives.
+	//
+	// Filled from the manifest's `contributes` object by UnmarshalJSON; never written by hand.
+	ContributesMany map[string]map[string]map[string]any `json:"-"`
+
 	// Receives is where this module wants its consumers' contributions written, per requirement
 	// it provides.
 	//
@@ -435,6 +447,18 @@ type BuildsOn struct {
 	Image string `json:"image,omitempty"`
 }
 
+// ArtifactContext names the repository an image artifact's build context is cloned from, when
+// that is not this module's own repository.
+type ArtifactContext struct {
+	// Repository is cloned fresh, the same way the module's own repository is — a working tree
+	// nothing has touched, so what was built is reproducible from the two commits named rather
+	// than from whatever a previous build happened to leave behind.
+	Repository string `json:"repository"`
+	// Ref is the branch, tag or commit of that repository to build. Empty means its own default
+	// branch — the same meaning an empty module ref already has.
+	Ref string `json:"ref,omitempty"`
+}
+
 // Artifact is one thing built from a module's source.
 type Artifact struct {
 	// Name is how resources refer to it. Local to the module.
@@ -454,6 +478,17 @@ type Artifact struct {
 	// Empty means the whole recipe, which is what a module with one image says by saying nothing.
 	Target string `json:"target,omitempty"`
 
+	// Context names a second repository this image's build reaches into for its own source — the
+	// recipe itself is still read from this module's own directory, at this module's own commit;
+	// only the build context `docker build`'s final argument names comes from here instead.
+	//
+	// **Packaging and source are allowed to live apart.** A module that only ships the recipe for
+	// source that lives elsewhere — the reference route-proxy in mesh-controller's own repository,
+	// packaged as a module in the catalogue rather than vendored a second time the two copies
+	// could drift from — names where that source actually is. Empty means the ordinary case: an
+	// image built from this same module's own repository, the same as every other artifact.
+	Context *ArtifactContext `json:"context,omitempty"`
+
 	// Language is what this module's code is written in, for a bundle.
 	//
 	// **Declared, never guessed.** Inferring it from what files happen to be present makes a
@@ -615,16 +650,24 @@ func AccessID(path string) string { return "access-" + strings.TrimPrefix(path,
 // it contributes to.
 func (m Manifest) Wants() []string {
 	out := append([]string{}, m.Requires...)
-	for to := range m.Contributes {
-		var already bool
+	add := func(to string) {
 		for _, r := range m.Requires {
 			if r == to {
-				already = true
+				return
 			}
 		}
-		if !already {
-			out = append(out, to)
+		for _, already := range out {
+			if already == to {
+				return
+			}
 		}
+		out = append(out, to)
+	}
+	for to := range m.Contributes {
+		add(to)
+	}
+	for to := range m.ContributesMany {
+		add(to)
 	}
 	sort.Strings(out)
 	return out
@@ -679,6 +722,47 @@ func (m *Manifest) UnmarshalJSON(raw []byte) error {
 		}
 		delete(keys, "secrets")
 	}
+	contributesPlain := map[string]map[string]any{}
+	contributesMany := map[string]map[string]map[string]any{}
+	if contributes, ok := keys["contributes"]; ok && string(contributes) != "null" {
+		var byTo map[string]json.RawMessage
+		if err := json.Unmarshal(contributes, &byTo); err != nil {
+			return fmt.Errorf("contributes: an object of requirement to values, or to {local name: values}: %w", err)
+		}
+		for to, v := range byTo {
+			// Both shapes are JSON objects, unlike secrets' path-vs-object split, so the shapes are
+			// told apart by what is INSIDE: an ordinary contribution's fields are scalars (a label,
+			// a port); the several-instance shape is an object of local names, each itself an
+			// object of fields. Confirmed against the whole catalogue before relying on it — no
+			// contribution anywhere has an object-valued field.
+			var fields map[string]json.RawMessage
+			if err := json.Unmarshal(v, &fields); err != nil {
+				return fmt.Errorf("contributes.%s: an object of values, or of local name to values: %w", to, err)
+			}
+			many := len(fields) > 0
+			for _, field := range fields {
+				trimmed := bytes.TrimSpace(field)
+				if len(trimmed) == 0 || trimmed[0] != '{' {
+					many = false
+					break
+				}
+			}
+			if many {
+				var locals map[string]map[string]any
+				if err := json.Unmarshal(v, &locals); err != nil {
+					return fmt.Errorf("contributes.%s: an object of local name to values: %w", to, err)
+				}
+				contributesMany[to] = locals
+				continue
+			}
+			var values map[string]any
+			if err := json.Unmarshal(v, &values); err != nil {
+				return fmt.Errorf("contributes.%s: an object of values: %w", to, err)
+			}
+			contributesPlain[to] = values
+		}
+		delete(keys, "contributes")
+	}
 	rest, err := json.Marshal(keys)
 	if err != nil {
 		return err
@@ -696,22 +780,46 @@ func (m *Manifest) UnmarshalJSON(raw []byte) error {
 	if len(many) > 0 {
 		m.SecretsMany = many
 	}
+	if len(contributesPlain) > 0 {
+		m.Contributes = contributesPlain
+	}
+	if len(contributesMany) > 0 {
+		m.ContributesMany = contributesMany
+	}
 	return nil
 }
 
-// MarshalJSON writes `secrets` back in the shape it was read: paths, and objects of local names.
+// MarshalJSON writes `secrets` and `contributes` back in the shape they were read: single values,
+// and objects of local names.
 func (m Manifest) MarshalJSON() ([]byte, error) {
 	raw, err := json.Marshal(manifestFields(m))
 	if err != nil {
 		return nil, err
 	}
-	if len(m.SecretsMany) == 0 {
+	if len(m.SecretsMany) == 0 && len(m.ContributesMany) == 0 {
 		return raw, nil
 	}
 	var keys map[string]json.RawMessage
 	if err := json.Unmarshal(raw, &keys); err != nil {
 		return nil, err
 	}
+	if len(m.ContributesMany) > 0 {
+		mergedContributes := map[string]any{}
+		for to, values := range m.Contributes {
+			mergedContributes[to] = values
+		}
+		for to, locals := range m.ContributesMany {
+			mergedContributes[to] = locals
+		}
+		contributes, err := json.Marshal(mergedContributes)
+		if err != nil {
+			return nil, err
+		}
+		keys["contributes"] = contributes
+	}
+	if len(m.SecretsMany) == 0 {
+		return json.Marshal(keys)
+	}
 	merged := map[string]any{}
 	for to, path := range m.Secrets {
 		merged[to] = path
@@ -842,9 +950,11 @@ func ParseManifest(raw []byte) (Manifest, error) {
 			problems = append(problems, fmt.Sprintf("%s requires itself", m.Module))
 		}
 	}
+	wellFormed := true
 	for _, c := range m.Claims {
 		if !name.MatchString(c.Name) {
 			problems = append(problems, fmt.Sprintf("%q is not a usable claim name", c.Name))
+			wellFormed = false
 		}
 		switch c.At() {
 		case ScopeNode, ScopeSite, ScopeMesh:
@@ -852,8 +962,14 @@ func ParseManifest(raw []byte) (Manifest, error) {
 			problems = append(problems, fmt.Sprintf(
 				"%s claims %s at scope %q; a claim is held per node, per site or per mesh",
 				m.Module, c.Name, c.Scope))
+			wellFormed = false
 		}
 	}
+	// Against the seats the mesh defines (novox/hq ADR 0110), once every claim is at least a name
+	// and a scope — a malformed claim is refused for that, not a second time for being unknown.
+	if wellFormed {
+		problems = append(problems, claimProblems(m)...)
+	}
 	if m.Computed != "" && len(m.Resources) > 0 {
 		// One or the other. A module that both ships files and has them computed would leave
 		// nobody able to say where a given file came from.
@@ -872,6 +988,25 @@ func ParseManifest(raw []byte) (Manifest, error) {
 				"%s contributes nothing to %q; if it only needs one, require it", m.Module, to))
 		}
 	}
+	for to, locals := range m.ContributesMany {
+		if !name.MatchString(to) {
+			problems = append(problems, fmt.Sprintf("%q is not a usable name to contribute to", to))
+		}
+		if len(locals) == 0 {
+			problems = append(problems, fmt.Sprintf(
+				"%s contributes nothing to %q; if it only needs one, require it", m.Module, to))
+		}
+		for local, values := range locals {
+			if !name.MatchString(local) {
+				problems = append(problems, fmt.Sprintf(
+					"%s contributes to %q under %q, which is not a usable name", m.Module, to, local))
+			}
+			if len(values) == 0 {
+				problems = append(problems, fmt.Sprintf(
+					"%s contributes nothing to %q under %q", m.Module, to, local))
+			}
+		}
+	}
 	problems = append(problems, m.Build.problems(m.Module)...)
 	// **What provides the artifact store cannot be delivered through it** (novox/hq 04-ISSUES/029).
 	//
@@ -914,9 +1049,9 @@ func ParseManifest(raw []byte) (Manifest, error) {
 		}
 	}
 	for to, where := range m.Binds {
-		if !strings.HasPrefix(where, "/") {
+		if !placedOrAbsolute(where) {
 			problems = append(problems, fmt.Sprintf(
-				"%s binds %q at %q, which is not an absolute path", m.Module, to, where))
+				"%s binds %q at %q, which is neither an absolute path nor a placed one", m.Module, to, where))
 		}
 		var wanted bool
 		for _, w := range m.Wants() {
@@ -1048,9 +1183,9 @@ func ParseManifest(raw []byte) (Manifest, error) {
 		}
 	}
 	for name, where := range m.OwnSecrets {
-		if !strings.HasPrefix(where, "/") {
+		if !placedOrAbsolute(where) {
 			problems = append(problems, fmt.Sprintf(
-				"%s needs %q at %q, which is not an absolute path", m.Module, name, where))
+				"%s needs %q at %q, which is neither an absolute path nor a placed one", m.Module, name, where))
 		}
 		if name == "" {
 			problems = append(problems, m.Module+" needs a secret with no name")
@@ -1065,9 +1200,9 @@ func ParseManifest(raw []byte) (Manifest, error) {
 			}
 		}
 		for _, f := range m.SecretFiles(to) {
-			if !strings.HasPrefix(f.Path, "/") {
+			if !placedOrAbsolute(f.Path) {
 				problems = append(problems, fmt.Sprintf(
-					"%s keeps the credential for %q at %q, which is not an absolute path",
+					"%s keeps the credential for %q at %q, which is neither an absolute path nor a placed one",
 					m.Module, SecretLocal(to, f.Local), f.Path))
 			}
 			if f.Local != "" && !name.MatchString(f.Local) {
@@ -1117,9 +1252,9 @@ func ParseManifest(raw []byte) (Manifest, error) {
 		}
 	}
 	for to, where := range m.Grants {
-		if !strings.HasPrefix(where, "/") {
+		if !placedOrAbsolute(where) {
 			problems = append(problems, fmt.Sprintf(
-				"%s grants %q into %q, which is not an absolute path", m.Module, to, where))
+				"%s grants %q into %q, which is neither an absolute path nor a placed one", m.Module, to, where))
 		}
 		var offered bool
 		for _, o := range m.Offers() {
@@ -1140,9 +1275,9 @@ func ParseManifest(raw []byte) (Manifest, error) {
 		if !name.MatchString(to) {
 			problems = append(problems, fmt.Sprintf("%q is not a usable name to receive", to))
 		}
-		if !strings.HasPrefix(where, "/") {
+		if !placedOrAbsolute(where) {
 			problems = append(problems, fmt.Sprintf(
-				"%s receives %q at %q, which is not an absolute path", m.Module, to, where))
+				"%s receives %q at %q, which is neither an absolute path nor a placed one", m.Module, to, where))
 		}
 		var offered bool
 		for _, o := range m.Offers() {
@@ -1189,6 +1324,7 @@ func ParseManifest(raw []byte) (Manifest, error) {
 	// Checked here rather than on the machine because the machine cannot tell the difference: by
 	// the time it sees the mount it is being asked to create the directory, which it can do.
 	problems = append(problems, m.undeclaredMounts()...)
+	problems = append(problems, m.unknownDirRefs()...)
 
 	for i, r := range m.Resources {
 		id, _ := r["id"].(string)

internal/catalogue/resolve.go

@@ -87,6 +87,10 @@ type Provider struct {
 	At string
 	// Serves is what the providing module said a consumer needs to know, settled.
 	Serves map[string]any
+	// Module is which module on that node provides it. A provider is a (node, module) pair
+	// (novox/hq to-be 23), and the pair is what tells the holder of a seat apart from another module
+	// providing the same thing (ADR 0110).
+	Module string
 }
 
 // Held is a claim somebody already has, used for the scopes wider than one node.
@@ -381,6 +385,15 @@ func Resolve(catalogue map[string]Manifest, assigned []string, node Node, world
 			default:
 				chosenNode, pinned := world.Pinned[want]
 				if !pinned {
+					// **The seat's holder answers, when a seat delivers this** (novox/hq ADR 0110).
+					// Not a guess, which ADR 0009 refuses: the choice was made once, mesh-wide, by
+					// assigning the holder, where a pin makes it again on every consumer's node. A
+					// pin still wins — it is a consumer coupled to one provider's contents, and has
+					// said so.
+					if holder, held := HolderAmong(want, where, world.Held); held {
+						take(holder)
+						break
+					}
 					problems = append(problems, fmt.Sprintf(
 						"%d nodes provide %q, wanted by %s — say which with `pin %s %s <node>`: %s",
 						len(where), want, because[want], node.Name, want,
@@ -692,11 +705,30 @@ func checkResources(modules []Manifest) []string {
 	ownedPath := map[string]string{} // path → owning module, for the access check below
 
 	for _, m := range modules {
+		// Compared placed, not as written (novox/hq ADR 0112): ${dir:state} is the same six
+		// characters in every module and a different directory in each — two modules' templates
+		// being spelled alike is not two modules owning one path. The default root serves the
+		// comparison: a collision is within one node, and any one root keeps distinct modules'
+		// places distinct. A reference that cannot be placed is left as written — naming what
+		// does not exist is the manifest's own problem, refused where it was made.
+		dirs := dirsFor(m, Rendering{})
 		for _, r := range m.Resources {
 			for _, field := range []string{"path", "unit", "name", "package"} {
 				value, ok := r[field].(string)
 				if !ok || value == "" {
-					continue
+					if field == "path" && fmt.Sprint(r["type"]) == "directory" {
+						// A pathless directory owns its placed path — a module stating that
+						// very path is exactly the collision this exists to catch.
+						value = dirs[fmt.Sprint(r["id"])]
+					}
+					if value == "" {
+						continue
+					}
+				}
+				if field == "path" {
+					if placed, err := dirFill(value, dirs, m.Module); err == nil {
+						value = placed
+					}
 				}
 				key := field + " " + value
 				if other, taken := owner[key]; taken && other != m.Module {

internal/catalogue/resolver_manifests_test.go

@@ -101,7 +101,10 @@ func TestTheResolverAndWhatAsksItComposeOnOneMachine(t *testing.T) {
 		t.Fatalf("the resolver's data is the mesh's addresses, and nothing answering them was taken: %v", named(got))
 	}
 	out, err := got.Declaration(Rendering{
-		Names: twoMachines, Suffix: "internal",
+		// Names is every name the mesh serves; Machines is the subset that is a node (novox/hq
+		// issue 111) — the resolver's zones read only the second, and in this scenario the two
+		// happen to be the same map, since nothing routed is part of it.
+		Names: twoMachines, Machines: twoMachines, Suffix: "internal",
 		Needed: map[string]map[string]string{"dnsmasq": {"broker": "sealed"}},
 	})
 	if err != nil {

internal/catalogue/routing_test.go

@@ -132,6 +132,72 @@ func TestALabelWithNoPublicDomainComposesNothing(t *testing.T) {
 	}
 }
 
+// withPrivateAddress is a workstation on the private network, at the given internal name — the
+// same fact a route's own consumers already receive as `${bound:...:at}`.
+func withPrivateAddress(at string) Node {
+	n := workstation()
+	n.At = at
+	return n
+}
+
+func TestALabelComposesWithTheNodesPrivateAddressToo(t *testing.T) {
+	// A predecessor proxy answered a route on both a public and a private-network hostname for the
+	// same convenience the mesh restores here: reaching a service over the VPN without a public TLS
+	// round trip. Composed independently of the public name, from the node's own `At`.
+	got, err := Resolve(shelf(proxy(), labelled("board", "git", 8080)),
+		[]string{"board"}, withPrivateAddress("anchor.internal"), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	given := received(t, mustDeclare(t, got))
+	if given[0].Values["internal-name"] != "git.anchor.internal" {
+		t.Fatalf("the label did not compose with the private address: %v", given[0].Values)
+	}
+}
+
+func TestThePublicAndInternalNamesComposeIndependently(t *testing.T) {
+	// A node with both a public domain and a private address gets both names from one label; a
+	// node with only one of the two gets only the matching one — neither composition depends on
+	// the other being possible.
+	both := withPrivateAddress("anchor.internal")
+	both.PublicDomain = "example.tld"
+	got, err := Resolve(shelf(proxy(), labelled("board", "git", 8080)),
+		[]string{"board"}, both, World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	given := received(t, mustDeclare(t, got))
+	if given[0].Values["name"] != "git.example.tld" {
+		t.Fatalf("the public name did not compose alongside the internal one: %v", given[0].Values)
+	}
+	if given[0].Values["internal-name"] != "git.anchor.internal" {
+		t.Fatalf("the internal name did not compose alongside the public one: %v", given[0].Values)
+	}
+
+	publicOnly, err := Resolve(shelf(proxy(), labelled("board", "git", 8080)),
+		[]string{"board"}, withDomain("example.tld"), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	givenPublicOnly := received(t, mustDeclare(t, publicOnly))
+	if _, has := givenPublicOnly[0].Values["internal-name"]; has {
+		t.Fatalf("an internal name was composed with no private address to compose it from: %v",
+			givenPublicOnly[0].Values)
+	}
+}
+
+func TestTheApexLabelComposesToTheBarePrivateAddress(t *testing.T) {
+	got, err := Resolve(shelf(proxy(), labelled("board", "@", 4000)),
+		[]string{"board"}, withPrivateAddress("anchor.internal"), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	given := received(t, mustDeclare(t, got))
+	if given[0].Values["internal-name"] != "anchor.internal" {
+		t.Fatalf("the apex label did not compose to the bare private address: %v", given[0].Values)
+	}
+}
+
 func TestARoutedNameResolvesToTheServingNode(t *testing.T) {
 	// novox/hq ADR 0066 propagate: a granted route name is published into internal resolution,
 	// mapped to the node that serves it, alongside the `<node>.internal` names — so every

internal/catalogue/seats.go

@@ -0,0 +1,149 @@
+package catalogue
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// The seats a mesh can have (novox/hq ADR 0110).
+//
+// **A closed set, defined here rather than by whoever claims one.** Until this, a well-formed name
+// became a seat by being claimed, so nothing could say which seats a mesh has or who fills them:
+// `the-showcase` and `the-build-machine` were each invented by the module claiming it. The set is
+// what a person reads to learn what a mesh can have, so an entry nobody argued for is an entry
+// nobody can explain — the same reason every shape in the host's vocabulary names its decision.
+//
+// A seat is held by a module assignment. What the mesh knows about a holder is what it knows about
+// that assignment; nothing about holders is kept here or anywhere else.
+
+// Seat is one role the mesh defines.
+type Seat struct {
+	// Name is what a manifest claims.
+	Name string
+	// Scope is where there may be only one holder.
+	Scope string
+	// Delivers is the provision the seat's holder answers for, or empty. A seat that delivers a
+	// provision may only be held by a module providing it at the seat's scope, and its holder is
+	// what a requirement for that provision resolves to when several modules provide it.
+	Delivers string
+	// Decision is the record that made it a seat.
+	Decision string
+}
+
+// seats is the whole set, in the order a person reads it: the mesh's own, then a node's.
+var seats = []Seat{
+	{Name: "mesh-controller", Scope: ScopeMesh, Decision: "novox/hq ADR 0079"},
+	{Name: "mesh-store", Scope: ScopeMesh, Delivers: "postgres-database", Decision: "novox/hq ADR 0079"},
+	{Name: "mesh-broker", Scope: ScopeMesh, Delivers: "amqp", Decision: "novox/hq ADR 0079"},
+	{Name: "the-artifact-store", Scope: ScopeMesh, Delivers: "artifact-store", Decision: "novox/hq ADR 0075"},
+	{Name: "the-catalogue", Scope: ScopeMesh, Decision: "novox/hq ADR 0110"},
+	{Name: "npm-package-registry", Scope: ScopeMesh, Delivers: "npm-package-registry", Decision: "novox/hq ADR 0109"},
+	{Name: "git", Scope: ScopeMesh, Delivers: "git", Decision: "novox/hq ADR 0111"},
+	{Name: "the-build-machine", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-dns-port", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-intrusion-prevention", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-packet-filter", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-private-network", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-resolver-configuration", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+	{Name: "the-showcase", Scope: ScopeNode, Decision: "novox/hq ADR 0110"},
+}
+
+// Seats is every seat the mesh defines, in reading order.
+func Seats() []Seat {
+	return append([]Seat(nil), seats...)
+}
+
+// SeatNamed is the seat a claim names, if the mesh defines one.
+func SeatNamed(name string) (Seat, bool) {
+	for _, s := range seats {
+		if s.Name == name {
+			return s, true
+		}
+	}
+	return Seat{}, false
+}
+
+// SeatDelivering is the seat whose holder answers for a provision, if there is one.
+func SeatDelivering(provision string) (Seat, bool) {
+	if provision == "" {
+		return Seat{}, false
+	}
+	for _, s := range seats {
+		if s.Delivers == provision {
+			return s, true
+		}
+	}
+	return Seat{}, false
+}
+
+// claimProblems is what is wrong with a manifest's claims against the set.
+//
+// Three refusals, each naming the seat: a seat the mesh does not define, a seat claimed at another
+// scope, and a seat that delivers a provision claimed by a module that does not provide it — which
+// would make the module the mesh's answer for something it cannot answer.
+func claimProblems(m Manifest) []string {
+	var problems []string
+	for _, c := range m.Claims {
+		seat, known := SeatNamed(c.Name)
+		if !known {
+			problems = append(problems, fmt.Sprintf(
+				"%s claims %q, which is not a seat this mesh defines (novox/hq ADR 0110) — "+
+					"the seats are: %s", m.Module, c.Name, seatNames()))
+			continue
+		}
+		if c.At() != seat.Scope {
+			problems = append(problems, fmt.Sprintf(
+				"%s claims %s at scope %q, and %s is a %s seat",
+				m.Module, c.Name, c.At(), c.Name, seat.Scope))
+		}
+		if seat.Delivers != "" && !providesAt(m, seat.Delivers, seat.Scope) {
+			problems = append(problems, fmt.Sprintf(
+				"%s claims %s, whose holder answers for %q, and %s does not provide %q at %s scope",
+				m.Module, c.Name, seat.Delivers, m.Module, seat.Delivers, seat.Scope))
+		}
+	}
+	return problems
+}
+
+func providesAt(m Manifest, provision, scope string) bool {
+	for _, o := range m.Provides {
+		if o.Name == provision && o.At() == scope {
+			return true
+		}
+	}
+	return false
+}
+
+func seatNames() string {
+	names := make([]string, 0, len(seats))
+	for _, s := range seats {
+		names = append(names, s.Name)
+	}
+	sort.Strings(names)
+	return strings.Join(names, ", ")
+}
+
+// HolderAmong is which of several providers of a provision holds the seat that delivers it.
+//
+// Found by the (node, module) pair, because a provider is identified by both (novox/hq to-be 23):
+// two modules on one node could both provide a provision, and only the one holding the seat
+// answers for it. Nothing when no seat delivers the provision, when nobody holds
+// it, or when the holder is not among the providers offered.
+func HolderAmong(provision string, providers []Provider, held []Held) (Provider, bool) {
+	seat, delivered := SeatDelivering(provision)
+	if !delivered {
+		return Provider{}, false
+	}
+	for _, h := range held {
+		if h.Claim != seat.Name || h.Scope != seat.Scope {
+			continue
+		}
+		for _, p := range providers {
+			if p.Node == h.Node && p.Module == h.Module {
+				return p, true
+			}
+		}
+	}
+	return Provider{}, false
+}

internal/catalogue/seats_test.go

@@ -0,0 +1,208 @@
+package catalogue
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+// Defends novox/hq ADR 0110: a seat is a module assignment from a closed set.
+
+// The set is closed, and changing it is a decision.
+//
+// **The count is asserted, and every entry names the record that made it a seat**, so the next
+// person changing the set finds the argument rather than a number to edit — the pattern the host's
+// vocabulary test follows. If this fails because a seat was added, the fix is a record in novox/hq
+// and a row in to-be 26, not a new number here.
+func TestTheSeatsAreAClosedSetAndEachNamesItsDecision(t *testing.T) {
+	record := regexp.MustCompile(`^novox/hq ADR \d{4}$`)
+	seen := map[string]bool{}
+	delivered := map[string]string{}
+	for _, s := range Seats() {
+		if seen[s.Name] {
+			t.Errorf("%s is in the set twice", s.Name)
+		}
+		seen[s.Name] = true
+		if !record.MatchString(s.Decision) {
+			t.Errorf("%s names %q as its decision; every seat names the record that made it one",
+				s.Name, s.Decision)
+		}
+		switch s.Scope {
+		case ScopeNode, ScopeSite, ScopeMesh:
+		default:
+			t.Errorf("%s is held per %q, which is not a scope", s.Name, s.Scope)
+		}
+		if s.Delivers != "" {
+			// Two seats answering for one provision would put the question "which one?" back,
+			// which is the question a seat exists to answer.
+			if other, twice := delivered[s.Delivers]; twice {
+				t.Errorf("%s and %s both deliver %q", other, s.Name, s.Delivers)
+			}
+			delivered[s.Delivers] = s.Name
+		}
+	}
+	if len(Seats()) != 14 {
+		t.Errorf("the mesh defines %d seats rather than 14; the set is closed, so a change here is "+
+			"a decision (novox/hq ADR 0110): %s", len(Seats()), seatNames())
+	}
+}
+
+func claimed(claims string) []byte {
+	return []byte(`{"module":"thing","version":"1","provides":[{"name":"npm-package-registry","scope":"mesh"}],"claims":` + claims + `}`)
+}
+
+func TestAClaimOnASeatTheMeshDoesNotDefineIsRefused(t *testing.T) {
+	_, err := ParseManifest(claimed(`[{"name":"the-anything","scope":"node"}]`))
+	if err == nil {
+		t.Fatal("a module invented a seat by claiming it")
+	}
+	if !strings.Contains(err.Error(), "the-anything") || !strings.Contains(err.Error(), "not a seat") {
+		t.Fatalf("the refusal does not say the seat is unknown: %v", err)
+	}
+	// And it says what the seats are, because "no" without the list sends somebody reading code.
+	if !strings.Contains(err.Error(), "the-packet-filter") {
+		t.Fatalf("the refusal does not list the seats: %v", err)
+	}
+}
+
+func TestASeatClaimedAtAnotherScopeIsRefused(t *testing.T) {
+	_, err := ParseManifest(claimed(`[{"name":"npm-package-registry","scope":"node"}]`))
+	if err == nil {
+		t.Fatal("a mesh seat was held per node")
+	}
+	if !strings.Contains(err.Error(), "mesh seat") {
+		t.Fatalf("the refusal does not say which scope the seat is: %v", err)
+	}
+}
+
+func TestADeliveringSeatIsOnlyHeldByAModuleThatProvides(t *testing.T) {
+	// Holding it makes the module the mesh's answer for the provision. A module that cannot answer
+	// would be the answer anyway, and every consumer would be sent to it.
+	raw := []byte(`{"module":"thing","version":"1","claims":[{"name":"git","scope":"mesh"}]}`)
+	_, err := ParseManifest(raw)
+	if err == nil {
+		t.Fatal("a module holding the git seat need not provide git")
+	}
+	if !strings.Contains(err.Error(), `does not provide "git"`) {
+		t.Fatalf("the refusal does not say what is missing: %v", err)
+	}
+}
+
+func TestAClaimThatIsMalformedIsRefusedOnceForThat(t *testing.T) {
+	// Not a second time for being unknown: one mistake, one line.
+	_, err := ParseManifest(claimed(`[{"name":"Not A Name","scope":"node"}]`))
+	if err == nil {
+		t.Fatal("a malformed claim was accepted")
+	}
+	if strings.Contains(err.Error(), "not a seat") {
+		t.Fatalf("a malformed claim was also called unknown: %v", err)
+	}
+}
+
+// Every module in use claims a seat in the set, so closing it refuses nothing that runs.
+//
+// Read from the catalogue beside this checkout and from this repository's own manifest, the two
+// places a manifest lives (ADR 0069). The private-network module's manifest is composed in code,
+// and its claim is checked where it is composed.
+func TestEveryManifestInUseClaimsASeatTheMeshDefines(t *testing.T) {
+	paths, _ := filepath.Glob("../../../mesh-catalog/modules/*/module.json")
+	if len(paths) == 0 {
+		t.Skip("the catalogue is not beside this checkout")
+	}
+	paths = append(paths, "../../module.json")
+	var checked int
+	for _, path := range paths {
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		// Leniently, so a manifest refused for something unrelated is not reported as a seat
+		// problem, and the seat check below is the only thing this test holds a module to.
+		var m Manifest
+		if err := json.Unmarshal(raw, &m); err != nil {
+			t.Fatalf("%s: %v", path, err)
+		}
+		for _, problem := range claimProblems(m) {
+			t.Errorf("%s: %s", path, problem)
+		}
+		checked += len(m.Claims)
+	}
+	if checked == 0 {
+		t.Fatal("no claims were checked, so this proved nothing")
+	}
+}
+
+// The holder of a seat answers among several providers.
+
+func registryShelf() map[string]Manifest {
+	return shelf(
+		Manifest{Module: "gitea", Version: "1", Provides: FromAnywhere("npm-package-registry"),
+			Claims: []Claim{{Name: "npm-package-registry", Scope: ScopeMesh}}},
+		Manifest{Module: "verdaccio", Version: "1", Provides: FromAnywhere("npm-package-registry")},
+		Manifest{Module: "builder", Version: "1", Requires: []string{"npm-package-registry"}},
+	)
+}
+
+func twoRegistries() map[string][]Provider {
+	return map[string][]Provider{"npm-package-registry": {
+		{Node: "anchor", At: "anchor.internal", Module: "gitea"},
+		{Node: "archive", At: "archive.internal", Module: "verdaccio"},
+	}}
+}
+
+func giteaHoldsTheSeat() []Held {
+	return []Held{{Claim: "npm-package-registry", Scope: ScopeMesh, Node: "anchor", Module: "gitea"}}
+}
+
+func TestTheSeatsHolderAnswersWhenSeveralProvide(t *testing.T) {
+	// The whole point: a second registry beside the holder harms nothing, and nobody pins.
+	got, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
+		World{Offered: twoRegistries(), Held: giteaHoldsTheSeat()})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got.Needs) != 1 || got.Needs[0].From != "anchor" {
+		t.Fatalf("the seat's holder did not answer: %v", got.Needs)
+	}
+}
+
+func TestAPinStillWinsOverTheSeat(t *testing.T) {
+	// A consumer coupled to one provider's contents has said so, and the seat does not overrule it.
+	got, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
+		World{Offered: twoRegistries(), Held: giteaHoldsTheSeat(),
+			Pinned: map[string]string{"npm-package-registry": "archive"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(got.Needs) != 1 || got.Needs[0].From != "archive" {
+		t.Fatalf("the pin was overruled by the seat: %v", got.Needs)
+	}
+}
+
+func TestWithTheSeatUnheldSeveralProvidersAreStillRefused(t *testing.T) {
+	// No seat held is no choice made, and ADR 0009's rule stands: never guessed.
+	_, err := Resolve(registryShelf(), []string{"builder"}, reachable(),
+		World{Offered: twoRegistries()})
+	if err == nil {
+		t.Fatal("one of two registries was picked with nobody holding the seat")
+	}
+	if !strings.Contains(err.Error(), "pin") {
+		t.Fatalf("the refusal does not say how to choose: %v", err)
+	}
+}
+
+func TestTheHolderIsTheModuleNotTheMachine(t *testing.T) {
+	// Two modules on one machine could provide the same thing; only the one holding the seat
+	// answers. A holder matched by node alone would send consumers to whichever came first.
+	providers := []Provider{
+		{Node: "anchor", At: "anchor.internal", Module: "verdaccio"},
+		{Node: "anchor", At: "anchor.internal", Module: "gitea"},
+	}
+	holder, held := HolderAmong("npm-package-registry", providers, giteaHoldsTheSeat())
+	if !held || holder.Module != "gitea" {
+		t.Fatalf("the holder was not told apart from a neighbour: %+v", holder)
+	}
+}

internal/catalogue/several_contributions_test.go

@@ -0,0 +1,167 @@
+package catalogue
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+// A module may answer one requirement more than once, the sibling of ADR 0094 for `contributes`
+// rather than `secrets`: an object store's data API and its console are two different public
+// names, not one. `contributes` maps a requirement to several sets of values under local names,
+// each reaching the provider as its own entry — the same "several from one" shape ADR 0094 gave
+// `secrets`, applied to the other half of an edge.
+
+const twoRoutes = `{"module":"minio","version":"1","requires":["route"],
+  "contributes":{"route":{"api":{"label":"files-api","port":9000},"console":{"label":"files","port":9001}}}}`
+
+func TestContributesReadsBothShapesAndWritesThemBack(t *testing.T) {
+	m, err := ParseManifest([]byte(twoRoutes))
+	if err != nil {
+		t.Fatal(err)
+	}
+	locals := m.ContributesMany["route"]
+	if len(locals) != 2 || locals["api"]["label"] != "files-api" || locals["console"]["port"] != float64(9001) {
+		t.Fatalf("two contributions under local names: %+v", locals)
+	}
+	plain, err := ParseManifest([]byte(`{"module":"board","version":"1","requires":["route"],
+	  "contributes":{"route":{"label":"board","port":8080}}}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := plain.Contributes["route"]; got["label"] != "board" || len(plain.ContributesMany) != 0 {
+		t.Fatalf("the plain shape is one contribution with no local names: %+v / %+v", got, plain.ContributesMany)
+	}
+	// Written back in the shape it was read, so a built manifest keeps its local names.
+	raw, err := json.Marshal(m)
+	if err != nil {
+		t.Fatal(err)
+	}
+	again, err := ParseManifest(raw)
+	if err != nil {
+		t.Fatalf("what was written does not read: %v\n%s", err, raw)
+	}
+	if len(again.ContributesMany["route"]) != 2 {
+		t.Fatalf("the local names did not survive a round trip:\n%s", raw)
+	}
+}
+
+func TestAContributionLocalNameMustBeUsable(t *testing.T) {
+	for _, bad := range []string{
+		// Not a usable name.
+		`{"module":"minio","version":"1","requires":["route"],
+		  "contributes":{"route":{"Not OK":{"label":"files","port":9000}}}}`,
+		// A local contribution with nothing in it.
+		`{"module":"minio","version":"1","requires":["route"],
+		  "contributes":{"route":{"api":{}}}}`,
+	} {
+		if _, err := ParseManifest([]byte(bad)); err == nil {
+			t.Errorf("accepted:\n%s", bad)
+		}
+	}
+}
+
+func minimalRouteProxy() Manifest {
+	return Manifest{Module: "route-proxy", Version: "1",
+		Provides: FromAnywhere("route"),
+		Receives: map[string]string{"route": "/var/lib/route-proxy/routes/mesh.json"},
+	}
+}
+
+func TestAModuleWithTwoRoutesGivesTheProviderTwoContributions(t *testing.T) {
+	minio, err := ParseManifest([]byte(twoRoutes))
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := Resolve(shelf(minimalRouteProxy(), minio), []string{"route-proxy", "minio"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := got.Declaration(Rendering{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	var given []Contribution
+	for _, r := range out {
+		if r["path"] != "/var/lib/route-proxy/routes/mesh.json" {
+			continue
+		}
+		var parsed struct {
+			Given []Contribution `json:"given"`
+		}
+		if err := json.Unmarshal([]byte(r["content"].(string)), &parsed); err != nil {
+			t.Fatal(err)
+		}
+		given = parsed.Given
+	}
+	if len(given) != 2 {
+		t.Fatalf("two named routes from one module are two contributions: %+v", given)
+	}
+	byPort := map[float64]string{}
+	for _, g := range given {
+		if g.From != "minio" {
+			t.Fatalf("both contributions are minio's: %+v", g)
+		}
+		port, _ := g.Values["port"].(float64)
+		label, _ := g.Values["label"].(string)
+		byPort[port] = label
+	}
+	if byPort[9000] != "files-api" || byPort[9001] != "files" {
+		t.Fatalf("the two routes did not both survive: %+v", given)
+	}
+}
+
+// A module with the ordinary, single-contribution shape resolves exactly as it did before —
+// ContributesMany being empty must change nothing about it.
+func TestASingleRouteStillResolvesTheOrdinaryWay(t *testing.T) {
+	got, err := Resolve(shelf(proxy(), published("board", "board", 8080)), []string{"board"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	given := received(t, mustDeclare(t, got))
+	if len(given) != 1 || given[0].From != "board" {
+		t.Fatalf("the plain shape regressed: %+v", given)
+	}
+}
+
+// ContributionsFrom is what mints the ONE pair credential a requiring module is granted
+// (cmd/mesh-controller/plan.go's grantsFor) — a separate path from Declaration()'s raw file, and
+// the one the two-routes test above never exercised. Where a module contributes several times,
+// there is no single "the" value: settling to whichever sorts first would both misrepresent the
+// grant and collide with that same contribution's own entry from contributions(), which is
+// exactly the duplicate a live plan against minio surfaced (files-api appearing once with a
+// credential, once without, while files got neither).
+func TestContributionsFromHasNoSingleValueWhenAModuleContributesSeveralTimes(t *testing.T) {
+	minio, err := ParseManifest([]byte(twoRoutes))
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := Resolve(shelf(minimalRouteProxy(), minio), []string{"route-proxy", "minio"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	values, asks, err := got.ContributionsFrom("route", "minio", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !asks {
+		t.Fatal("minio still requires route, so it still asks")
+	}
+	if len(values) != 0 {
+		t.Fatalf("no single value represents two contributions, got %+v", values)
+	}
+}
+
+// The ordinary, single-contribution case is unchanged: exactly one match still settles to it.
+func TestContributionsFromReturnsTheOneValueForAnOrdinaryContribution(t *testing.T) {
+	got, err := Resolve(shelf(proxy(), published("board", "board", 8080)), []string{"board"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	values, asks, err := got.ContributionsFrom("reverse-proxy", "board", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !asks || values["host"] != "board" {
+		t.Fatalf("the ordinary single contribution should still settle to its own value: %+v", values)
+	}
+}

internal/inventory/addresses.go

@@ -69,6 +69,17 @@ func (i *Inventory) AssignAddress(ctx context.Context, node, cidr string) (strin
 		if key != nil && p.PublicKey == *key {
 			// The tunnel already routes to this key: the node keeps that address, and the peer
 			// notices nothing when its machine enrols.
+			//
+			// **Unless the operator named it something else** (novox/hq issue 112). The name is
+			// what the mesh has been answering for this address in the meantime; a machine
+			// enrolling under a different one would silently split the two — the name resolving
+			// here, the node known as that — so it is refused where the operator can read it.
+			if p.Named != "" && p.Named != name {
+				return "", fmt.Errorf(
+					"the carried peer at %s was named %q, and %q is enrolling under its key — "+
+						"enrol it as %q, or rename the peer first (`overlay name`)",
+					p.Address, p.Named, name, p.Named)
+			}
 			return i.place(ctx, node, p.Address)
 		}
 		taken[p.Address] = true

internal/inventory/adoption_test.go

@@ -65,7 +65,7 @@ func TestTakingIsRefusedOnAConvergedNodeAndForAnUnassignedModule(t *testing.T) {
 	if _, err := inv.AddNode(t.Context(), "converged"); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(t.Context(), "converged", "hello-web"); err != nil {
+	if _, err := inv.Assign(t.Context(), "converged", "hello-web"); err != nil {
 		t.Fatal(err)
 	}
 	if err := inv.Take(t.Context(), "converged", "hello-web"); !errors.Is(err, ErrNotAdopted) {
@@ -91,7 +91,7 @@ func TestATakenModuleOutlivesItsAssignmentAndReturningToAdopted(t *testing.T) {
 		t.Fatal(err)
 	}
 	for _, m := range []string{"hello-web", "postgres"} {
-		if err := inv.Assign(t.Context(), "anchor", m); err != nil {
+		if _, err := inv.Assign(t.Context(), "anchor", m); err != nil {
 			t.Fatal(err)
 		}
 	}

internal/inventory/catalogue.go

@@ -24,7 +24,12 @@ var ErrStillAssigned = errors.New("that module is still assigned to nodes")
 
 // Source is where a module comes from and what has been built from it.
 type Source struct {
+	// Repository is a URL, cloned exactly as given, unless Seat is set — then it is the
+	// repository's path on that seat's holder, and never an address (novox/hq ADR 0111).
 	Repository string
+	// Seat is the seat the repository lives on: `git` for the mesh's own forge, empty for a
+	// repository anywhere else.
+	Seat string
 	// Path is the module's directory inside that repository (novox/hq ADR 0069). Empty is the
 	// repository's root, which is a real answer rather than a missing one.
 	Path string
@@ -62,8 +67,8 @@ func (i *Inventory) RegisterModule(ctx context.Context, m catalogue.Manifest, fr
 	// record of where the module normally comes from — which is the only thing that would say,
 	// afterwards, that the machine is running something nobody can rebuild.
 	_, err = i.store.Pool().Exec(ctx,
-		`insert into module (name, manifest, version, source, source_path, ref, built_from, source_head)
-		 values ($1, $2, nullif($3,''), nullif($4,''), $7, nullif($5,''), nullif($6,''), nullif($6,''))
+		`insert into module (name, manifest, version, source, source_path, source_seat, ref, built_from, source_head)
+		 values ($1, $2, nullif($3,''), nullif($4,''), $7, $8, nullif($5,''), nullif($6,''), nullif($6,''))
 		 on conflict (name) do update set
 		     manifest   = excluded.manifest,
 		     version    = excluded.version,
@@ -71,10 +76,12 @@ func (i *Inventory) RegisterModule(ctx context.Context, m catalogue.Manifest, fr
 		     source     = coalesce(excluded.source, module.source),
 		     source_path = case when excluded.source is null then module.source_path
 		                        else excluded.source_path end,
+		     source_seat = case when excluded.source is null then module.source_seat
+		                        else excluded.source_seat end,
 		     ref        = coalesce(excluded.ref, module.ref),
 		     built_from = coalesce(excluded.built_from, module.built_from),
 		     source_head = coalesce(excluded.built_from, module.source_head)`,
-		m.Module, raw, m.Version, from.Repository, from.Ref, from.BuiltFrom, from.Path)
+		m.Module, raw, m.Version, from.Repository, from.Ref, from.BuiltFrom, from.Path, from.Seat)
 	return err
 }
 
@@ -99,10 +106,10 @@ func (i *Inventory) SourceMoved(ctx context.Context, module, head string) error
 func (i *Inventory) SourceOf(ctx context.Context, module string) (Source, error) {
 	var s Source
 	var repo, ref, built, head *string
-	var path string
+	var path, seat string
 	err := i.store.Pool().QueryRow(ctx,
-		`select source, source_path, ref, built_from, source_head from module where name = $1`,
-		module).Scan(&repo, &path, &ref, &built, &head)
+		`select source, source_path, source_seat, ref, built_from, source_head from module where name = $1`,
+		module).Scan(&repo, &path, &seat, &ref, &built, &head)
 	if errors.Is(err, pgx.ErrNoRows) {
 		return Source{}, fmt.Errorf("%w: %s", ErrNoSuchModule, module)
 	}
@@ -117,9 +124,10 @@ func (i *Inventory) SourceOf(ctx context.Context, module string) (Source, error)
 			*pair.to = *pair.from
 		}
 	}
-	// Not in the loop above: the path is never null, because "the repository's root" is an answer
-	// rather than an absence.
+	// Not in the loop above: the path and the seat are never null, because "the repository's root"
+	// and "not on a seat" are answers rather than absences.
 	s.Path = path
+	s.Seat = seat
 	return s, nil
 }
 
@@ -422,27 +430,36 @@ func (i *Inventory) discard(ctx context.Context, name string) error {
 	return nil
 }
 
-// Assign puts a module on a node.
+// Assign puts a module on a node, and says whether that is new.
 //
 // Records the intention and checks nothing. Whether the set of assignments can actually become a
 // declaration is resolution's question, asked over the whole set at once — and asking it here,
 // one module at a time, would let an assignment look accepted and then refuse when a second
 // arrives.
-func (i *Inventory) Assign(ctx context.Context, nodeName, module string) error {
+//
+// **One assignment of a module per node is the rule, not a race lost** (novox/hq ADR 0115). The
+// module's name is the assignment's identity — its database user, its broker account, its
+// containers and its placed directory are all named by it — so the schema's (node, module) key
+// is the decision, and a repeat is absorbed rather than refused. Absorbed audibly: the caller is
+// told nothing changed, because "is assigned" printed for a no-op reads as an action.
+func (i *Inventory) Assign(ctx context.Context, nodeName, module string) (bool, error) {
 	node, err := i.NodeByName(ctx, nodeName)
 	if err != nil {
-		return err
+		return false, err
 	}
 	if err := i.runsSomewhere(ctx, module); err != nil {
-		return err
+		return false, err
 	}
-	_, err = i.store.Pool().Exec(ctx,
+	tag, err := i.store.Pool().Exec(ctx,
 		`insert into assignment (node, module) values ($1, $2) on conflict do nothing`,
 		node.ID, module)
 	if err != nil && strings.Contains(err.Error(), "assignment_module_fkey") {
-		return fmt.Errorf("%w: %s", ErrNoSuchModule, module)
+		return false, fmt.Errorf("%w: %s", ErrNoSuchModule, module)
 	}
-	return err
+	if err != nil {
+		return false, err
+	}
+	return tag.RowsAffected() > 0, nil
 }
 
 // Unassign takes a module off a node.
@@ -917,13 +934,14 @@ type Entry struct {
 func (i *Inventory) Catalogued(ctx context.Context) ([]Entry, error) {
 	rows, err := i.store.Pool().Query(ctx,
 		`select m.name, m.manifest,
-		        coalesce(m.source, ''), m.source_path, coalesce(m.ref, ''),
+		        coalesce(m.source, ''), m.source_path, m.source_seat, coalesce(m.ref, ''),
 		        coalesce(m.built_from, ''), coalesce(m.source_head, ''),
 		        coalesce(array_agg(n.name order by n.name) filter (where n.name is not null), '{}')
 		 from module m
 		 left join assignment a on a.module = m.name
 		 left join node n on n.id = a.node
-		 group by m.name, m.manifest, m.source, m.source_path, m.ref, m.built_from, m.source_head
+		 group by m.name, m.manifest, m.source, m.source_path, m.source_seat, m.ref, m.built_from,
+		          m.source_head
 		 order by m.name`)
 	if err != nil {
 		return nil, err
@@ -936,7 +954,7 @@ func (i *Inventory) Catalogued(ctx context.Context) ([]Entry, error) {
 		var name string
 		var source Source
 		var on []string
-		if err := rows.Scan(&name, &raw, &source.Repository, &source.Path, &source.Ref,
+		if err := rows.Scan(&name, &raw, &source.Repository, &source.Path, &source.Seat, &source.Ref,
 			&source.BuiltFrom, &source.Head, &on); err != nil {
 			return nil, err
 		}

internal/inventory/catalogue_test.go

@@ -77,7 +77,7 @@ func TestAModuleAMachineIsRunningCannotBeForgotten(t *testing.T) {
 	if err := inv.RegisterModule(t.Context(), manifest("thing", nil, nil), Source{}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(t.Context(), "laptop", "thing"); err != nil {
+	if _, err := inv.Assign(t.Context(), "laptop", "thing"); err != nil {
 		t.Fatal(err)
 	}
 
@@ -104,7 +104,7 @@ func TestRemovingANodeTakesItsAssignments(t *testing.T) {
 	if err := inv.RegisterModule(t.Context(), manifest("thing", nil, nil), Source{}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(t.Context(), "laptop", "thing"); err != nil {
+	if _, err := inv.Assign(t.Context(), "laptop", "thing"); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := inv.store.Pool().Exec(t.Context(), `delete from node where id = $1`, node.ID); err != nil {
@@ -136,14 +136,16 @@ func TestAssigningAModuleTheMeshDoesNotKnowIsRefused(t *testing.T) {
 	if _, err := inv.AddNode(t.Context(), "laptop"); err != nil {
 		t.Fatal(err)
 	}
-	err := inv.Assign(t.Context(), "laptop", "not-a-module")
+	_, err := inv.Assign(t.Context(), "laptop", "not-a-module")
 	if !errors.Is(err, ErrNoSuchModule) {
 		t.Fatalf("assigning an unknown module gave %v", err)
 	}
 }
 
-func TestAssigningTwiceIsNotAnError(t *testing.T) {
-	// It is a statement of what should be true, and it already is.
+func TestAssigningTwiceIsNotAnErrorAndSaysSo(t *testing.T) {
+	// It is a statement of what should be true, and it already is — one assignment of a module
+	// per node is the rule (novox/hq ADR 0115), so a repeat is absorbed, audibly: the caller is
+	// told nothing was new.
 	inv := fresh(t)
 	if _, err := inv.AddNode(t.Context(), "laptop"); err != nil {
 		t.Fatal(err)
@@ -151,10 +153,18 @@ func TestAssigningTwiceIsNotAnError(t *testing.T) {
 	if err := inv.RegisterModule(t.Context(), manifest("thing", nil, nil), Source{}); err != nil {
 		t.Fatal(err)
 	}
-	for i := 0; i < 3; i++ {
-		if err := inv.Assign(t.Context(), "laptop", "thing"); err != nil {
+	first, err := inv.Assign(t.Context(), "laptop", "thing")
+	if err != nil || !first {
+		t.Fatalf("the first assignment is the new one; got fresh=%v err=%v", first, err)
+	}
+	for i := 0; i < 2; i++ {
+		again, err := inv.Assign(t.Context(), "laptop", "thing")
+		if err != nil {
 			t.Fatalf("assigning again failed: %v", err)
 		}
+		if again {
+			t.Fatal("a repeat must say nothing was new")
+		}
 	}
 	assigned, err := inv.Assigned(t.Context(), "laptop")
 	if err != nil {
@@ -277,7 +287,7 @@ func TestBeingBehindNamesTheMachinesRunningTheOldOne(t *testing.T) {
 		t.Fatal(err)
 	}
 	for _, n := range []string{"laptop", "workstation"} {
-		if err := inv.Assign(t.Context(), n, "thing"); err != nil {
+		if _, err := inv.Assign(t.Context(), n, "thing"); err != nil {
 			t.Fatal(err)
 		}
 	}
@@ -451,7 +461,7 @@ func TestTheCatalogueSaysWhereEachModuleCameFromAndWhoRunsIt(t *testing.T) {
 		t.Fatal(err)
 	}
 	for _, n := range []string{"workstation", "laptop"} {
-		if err := inv.Assign(ctx, n, "shell"); err != nil {
+		if _, err := inv.Assign(ctx, n, "shell"); err != nil {
 			t.Fatal(err)
 		}
 	}
@@ -604,3 +614,74 @@ func TestNeverReportedAndReportedNothingAreDifferentProfiles(t *testing.T) {
 		t.Fatal("a machine that reported nothing looks like one that never reported")
 	}
 }
+
+// Defends novox/hq ADR 0111: a source on a seat is recorded as a path and the seat, never an
+// address, and a module recorded before the column existed keeps meaning a URL.
+func TestASourceOnASeatIsRecordedAsItsPathAndTheSeat(t *testing.T) {
+	inv := fresh(t)
+	ctx := t.Context()
+	if err := inv.RegisterModule(ctx, manifest("gitea-built", nil, nil), Source{
+		Repository: "novox/mesh-catalog", Seat: "git", Path: "modules/gitea", Ref: "main",
+		BuiltFrom: "aaaa1111",
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RegisterModule(ctx, manifest("external", nil, nil), Source{
+		Repository: "https://example.invalid/someone/something.git", BuiltFrom: "bbbb2222",
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	own, err := inv.SourceOf(ctx, "gitea-built")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if own.Seat != "git" || own.Repository != "novox/mesh-catalog" || own.Path != "modules/gitea" {
+		t.Fatalf("recorded as %+v", own)
+	}
+	if strings.Contains(own.Repository, "://") {
+		t.Fatalf("an address was recorded for a source on a seat: %s", own.Repository)
+	}
+
+	elsewhere, err := inv.SourceOf(ctx, "external")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if elsewhere.Seat != "" {
+		t.Fatalf("an external repository was put on a seat: %+v", elsewhere)
+	}
+
+	// And the list every rebuild walks carries the seat, or `build --behind` would clone the path
+	// as though it were a URL.
+	all, err := inv.Catalogued(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, e := range all {
+		if e.Manifest.Module == "gitea-built" && e.Source.Seat != "git" {
+			t.Fatalf("the rebuild list lost the seat: %+v", e.Source)
+		}
+	}
+}
+
+func TestRegisteringWithoutProvenanceKeepsTheSeat(t *testing.T) {
+	// A manifest handed over by hand keeps the record of where the module normally comes from —
+	// the seat included, or the next rebuild would treat a path as a URL.
+	inv := fresh(t)
+	ctx := t.Context()
+	if err := inv.RegisterModule(ctx, manifest("thing", nil, nil), Source{
+		Repository: "novox/thing", Seat: "git", BuiltFrom: "aaaa1111",
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RegisterModule(ctx, manifest("thing", []string{"a-thing"}, nil), Source{}); err != nil {
+		t.Fatal(err)
+	}
+	got, err := inv.SourceOf(ctx, "thing")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got.Seat != "git" || got.Repository != "novox/thing" {
+		t.Fatalf("a hand-registered manifest erased where the module comes from: %+v", got)
+	}
+}

internal/inventory/forget_test.go

@@ -212,7 +212,7 @@ func TestAModuleStillAssignedRefusesBeforeAnythingAboutWhatItHolds(t *testing.T)
 	if err := inv.SetSettings(ctx, "anchor", "step-ca", map[string]any{"a": 1}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(ctx, "anchor", "step-ca"); err != nil {
+	if _, err := inv.Assign(ctx, "anchor", "step-ca"); err != nil {
 		t.Fatal(err)
 	}
 	for _, forget := range []func() error{

internal/inventory/migrations/0032-a-source-may-live-on-a-seat.sql

@@ -0,0 +1,12 @@
+-- Which seat a module's source lives on, when it lives on one.
+--
+-- novox/hq ADR 0111. A module's repository was recorded exactly as a person typed it, so a
+-- self-hosted forge's scheme, host and port were written into every module built from it — and
+-- moving the forge made every one of those records stale at once, noticed only when a rebuild
+-- failed to clone. A source on the `git` seat is now recorded as its path on the seat's holder, and
+-- the clone URL is composed from wherever the holder runs at the moment of building.
+--
+-- Empty rather than null, and defaulted, because "not on a seat" is a real answer: the repository
+-- column is then a URL, cloned exactly as given, which is what every module recorded before this
+-- already is. So every existing row keeps exactly the meaning it had.
+alter table module add column source_seat text not null default '';

internal/inventory/migrations/0033-a-carried-peer-is-nameable.sql

@@ -0,0 +1,10 @@
+-- A carried peer may be named before it enrols (novox/hq issue 112).
+--
+-- The tunnel the hub took over routes to machines the predecessor knows by name and the mesh
+-- knows only by address. A name the predecessor answers for must keep resolving until the
+-- machine behind it is a node — so the operator may state which machine a carried address is,
+-- and everything derived from "the machines the mesh knows" (a container's hosts, the hosts
+-- fact, the resolver) answers for it in the meantime. The mesh records the statement as the
+-- operator's, unverified: enrolment is what verifies it, and enrolling under a different name
+-- than the one stated is refused rather than silently renamed.
+alter table tunnel_peer add column named text;

internal/inventory/named_peer_test.go

@@ -0,0 +1,92 @@
+package inventory
+
+// A carried peer is nameable (novox/hq issue 112): the operator states which machine a carried
+// address is, the mesh answers for the name until the machine enrols, and enrolment verifies the
+// statement rather than silently renaming it.
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestACarriedPeerIsNamedAndTheRegistrySaysSo(t *testing.T) {
+	inv := fresh(t)
+	anAdoptedHub(t, inv)
+
+	if err := inv.NamePeer(t.Context(), "192.0.2.2", "home-server"); err != nil {
+		t.Fatal(err)
+	}
+	carried, err := inv.CarriedPeers(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	byKey := map[string]CarriedPeer{}
+	for _, c := range carried {
+		byKey[c.PublicKey] = c
+	}
+	if byKey[peerTwo].Named != "home-server" || byKey[peerThree].Named != "" {
+		t.Fatalf("the statement was not recorded where it was made: %+v", carried)
+	}
+}
+
+func TestNamingRefusesWhatWouldCollide(t *testing.T) {
+	inv := fresh(t)
+	anAdoptedHub(t, inv)
+
+	if err := inv.NamePeer(t.Context(), "192.0.2.9", "ghost"); err == nil ||
+		!strings.Contains(err.Error(), "no carried peer") {
+		t.Fatalf("naming an address nothing carries must refuse; got %v", err)
+	}
+	if err := inv.NamePeer(t.Context(), "192.0.2.2", "anchor"); err == nil ||
+		!strings.Contains(err.Error(), "node of this mesh") {
+		t.Fatalf("naming a peer after a node must refuse; got %v", err)
+	}
+	if err := inv.NamePeer(t.Context(), "192.0.2.2", "home-server"); err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.NamePeer(t.Context(), "192.0.2.3", "home-server"); err == nil ||
+		!strings.Contains(err.Error(), "already named") {
+		t.Fatalf("one machine per name; got %v", err)
+	}
+}
+
+func TestEnrolmentUnderANamedKeyMustUseTheName(t *testing.T) {
+	inv := fresh(t)
+	anAdoptedHub(t, inv)
+	if err := inv.NamePeer(t.Context(), "192.0.2.3", "home-server"); err != nil {
+		t.Fatal(err)
+	}
+
+	// The wrong name is refused where the operator can read it…
+	imposter, err := inv.AddNode(t.Context(), "some-other-name")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RecordOverlayKey(t.Context(), imposter.ID, peerThree); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := inv.AssignAddress(t.Context(), imposter.ID, "192.0.2.0/24"); err == nil ||
+		!strings.Contains(err.Error(), `named "home-server"`) {
+		t.Fatalf("enrolling a named peer under another name must refuse; got %v", err)
+	}
+
+	// …and the stated name enrols cleanly, keeping the carried address.
+	named, err := inv.AddNode(t.Context(), "home-server")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := inv.RecordOverlayKey(t.Context(), named.ID, peerThree); err != nil {
+		t.Fatal(err)
+	}
+	address, err := inv.AssignAddress(t.Context(), named.ID, "192.0.2.0/24")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if address != "192.0.2.3" {
+		t.Fatalf("the named peer keeps its carried address; got %s", address)
+	}
+	if err := inv.NamePeer(t.Context(), "192.0.2.3", "renamed"); err == nil ||
+		!strings.Contains(err.Error(), "enrolled as") {
+		t.Fatalf("an enrolled peer's name is the node's; got %v", err)
+	}
+}

internal/inventory/ports_test.go

@@ -221,7 +221,7 @@ func TestWhatAMachineNoLongerHoldsIsAvailableAgain(t *testing.T) {
 func TestUnassigningReleasesTheModulesPorts(t *testing.T) {
 	inv, node := aNodeWithModules(t, "mailu", "other-mail")
 	ctx := t.Context()
-	if err := inv.Assign(ctx, node, "mailu"); err != nil {
+	if _, err := inv.Assign(ctx, node, "mailu"); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := inv.PortFor(ctx, node, "mailu", 25, true); err != nil {
@@ -230,7 +230,7 @@ func TestUnassigningReleasesTheModulesPorts(t *testing.T) {
 	if err := inv.Unassign(ctx, node, "mailu"); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(ctx, node, "other-mail"); err != nil {
+	if _, err := inv.Assign(ctx, node, "other-mail"); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := inv.PortFor(ctx, node, "other-mail", 25, true); err != nil {

internal/inventory/secrets_test.go

@@ -350,7 +350,7 @@ func TestACredentialGoesWhenTheConsumerStopsAskingForIt(t *testing.T) {
 	}, Source{}); err != nil {
 		t.Fatal(err)
 	}
-	if err := inv.Assign(ctx, "consumer", "meshboard"); err != nil {
+	if _, err := inv.Assign(ctx, "consumer", "meshboard"); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := inv.SecretFor(ctx, "postgres-database", "consumer", "gitea", "provider", ""); err != nil {

internal/inventory/tunnel.go

@@ -33,6 +33,9 @@ type Tunnel struct {
 	// Port is the port the found interface listened on — one the hosting provider already lets
 	// through, which is why it is worth taking.
 	Port int `json:"port"`
+	// MTU is the found interface's, when it set one; the mesh's interface takes it over so a
+	// tuned path does not silently regress to the default (novox/hq: a taken tunnel carries its MTU).
+	MTU int `json:"mtu,omitempty"`
 	// Address is the interface's own address with its prefix length, 192.0.2.1/24; Range is the
 	// network that prefix names, 192.0.2.0/24.
 	Address string `json:"address"`
@@ -85,6 +88,9 @@ type CarriedPeer struct {
 	Address   string
 	// EnrolledAs names the node that enrolled with this key, or is empty while none has.
 	EnrolledAs string
+	// Named is what the operator said this peer is, before it enrolled (novox/hq issue 112) —
+	// a statement the mesh records and cannot verify, which is why enrolment checks it.
+	Named string
 }
 
 // ErrNoTunnel is asking about a tunnel on a node that presented none.
@@ -247,7 +253,7 @@ func (i *Inventory) AdoptedTunnel(ctx context.Context) (Tunnel, string, bool, er
 // adopted no tunnel.
 func (i *Inventory) CarriedPeers(ctx context.Context) ([]CarriedPeer, error) {
 	rows, err := i.store.Pool().Query(ctx,
-		`select p.public_key, host(p.address), coalesce(n.name, '')
+		`select p.public_key, host(p.address), coalesce(n.name, ''), coalesce(p.named, '')
 		   from tunnel_peer p
 		   join node hub on hub.id = p.node and hub.is_hub
 		        and hub.tunnel is not null and hub.overlay_key = hub.tunnel->>'public_key'
@@ -260,7 +266,7 @@ func (i *Inventory) CarriedPeers(ctx context.Context) ([]CarriedPeer, error) {
 	var out []CarriedPeer
 	for rows.Next() {
 		var p CarriedPeer
-		if err := rows.Scan(&p.PublicKey, &p.Address, &p.EnrolledAs); err != nil {
+		if err := rows.Scan(&p.PublicKey, &p.Address, &p.EnrolledAs, &p.Named); err != nil {
 			return nil, err
 		}
 		out = append(out, p)
@@ -268,6 +274,46 @@ func (i *Inventory) CarriedPeers(ctx context.Context) ([]CarriedPeer, error) {
 	return out, rows.Err()
 }
 
+// NamePeer records the operator's statement that a carried address is a particular machine
+// (novox/hq issue 112). Refused when nothing carried has that address, when a node of the mesh
+// already has the name — the statement would collide with something verified — and when another
+// peer was already named it. Naming an enrolled peer is refused too: its name is the node's now.
+func (i *Inventory) NamePeer(ctx context.Context, address, name string) error {
+	peers, err := i.CarriedPeers(ctx)
+	if err != nil {
+		return err
+	}
+	var at *CarriedPeer
+	for idx := range peers {
+		if peers[idx].Address == address {
+			at = &peers[idx]
+			continue
+		}
+		if peers[idx].Named == name {
+			return fmt.Errorf("the carried peer at %s is already named %q — one machine per name",
+				peers[idx].Address, name)
+		}
+	}
+	if at == nil {
+		return fmt.Errorf("no carried peer has the address %s — `overlay show` lists them", address)
+	}
+	if at.EnrolledAs != "" {
+		return fmt.Errorf("the peer at %s enrolled as %q — its name is the node's now", address, at.EnrolledAs)
+	}
+	if _, err := i.NodeByName(ctx, name); err == nil {
+		return fmt.Errorf("%q is a node of this mesh — a carried peer cannot be named after one", name)
+	}
+	tag, err := i.store.Pool().Exec(ctx,
+		`update tunnel_peer set named = $2 where host(address) = $1`, address, name)
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("no carried peer has the address %s", address)
+	}
+	return nil
+}
+
 // FoundTunnel is a node's found tunnel with the node's mode, for composing: the takeover is
 // declared to an adopted node only, since only there is a found unit kept to be stopped.
 type FoundTunnel struct {

internal/link/enrolment.go

@@ -140,7 +140,7 @@ func (e Enrolment) Enrol(ctx context.Context, request EnrolRequest) (reply Enrol
 		}
 		if err := e.Inventory.RecordTunnel(ctx, node.ID, inventory.Tunnel{
 			Interface: request.Tunnel.Interface, Unit: request.Tunnel.Unit,
-			Config: request.Tunnel.Config, Port: request.Tunnel.Port,
+			Config: request.Tunnel.Config, Port: request.Tunnel.Port, MTU: request.Tunnel.MTU,
 			Address: request.Tunnel.Address, Range: request.Tunnel.Range,
 			PublicKey: request.Tunnel.PublicKey, Peers: peers,
 		}); err != nil {
@@ -199,7 +199,7 @@ func (e Enrolment) rekey(ctx context.Context, node inventory.Node, r Rekey) erro
 		peers = append(peers, inventory.TunnelPeer{PublicKey: p.PublicKey, Address: p.Address})
 	}
 	err := e.Inventory.Rekey(ctx, node.ID, r.Previous, r.OverlayKey, inventory.Tunnel{
-		Interface: r.Tunnel.Interface, Unit: r.Tunnel.Unit, Config: r.Tunnel.Config, Port: r.Tunnel.Port,
+		Interface: r.Tunnel.Interface, Unit: r.Tunnel.Unit, Config: r.Tunnel.Config, Port: r.Tunnel.Port, MTU: r.Tunnel.MTU,
 		Address: r.Tunnel.Address, Range: r.Tunnel.Range, PublicKey: r.Tunnel.PublicKey, Peers: peers,
 	})
 	if err != nil {

internal/link/protocol.go

@@ -93,6 +93,7 @@ type Tunnel struct {
 	Unit      string       `json:"unit"`
 	Config    string       `json:"config"`
 	Port      int          `json:"port"`
+	MTU       int          `json:"mtu,omitempty"`
 	Address   string       `json:"address"`
 	Range     string       `json:"range"`
 	PublicKey string       `json:"public_key"`

internal/overlay/declaration.go

@@ -123,6 +123,18 @@ func config(node Node, peers []Peer, keyPath string) string {
 		if port := portOf(node.Endpoint); port != "" {
 			fmt.Fprintf(&b, "ListenPort = %s\n", port)
 		}
+	} else if node.TakesOver != nil && node.TakesOver.Port != 0 {
+		// Not dialable from the hub, but a LAN peer dials this node on the tunnel it took over,
+		// so the mesh's interface must listen on that same port (novox/hq: a taken tunnel brings
+		// its port). Without this the takeover guard refuses overlay-up, and re-placing the node
+		// with an endpoint — the guard's suggested remedy — breaks a NAT'd node's path.
+		fmt.Fprintf(&b, "ListenPort = %d\n", node.TakesOver.Port)
+	}
+	// The MTU the found tunnel carried, when it set one: a path tuned to 1380 (say) stalls TLS
+	// and hangs transfers if the mesh's interface comes up at the 1420 default, and no ping shows
+	// it (novox/hq: a taken tunnel carries its MTU).
+	if node.TakesOver != nil && node.TakesOver.MTU != 0 {
+		fmt.Fprintf(&b, "MTU = %d\n", node.TakesOver.MTU)
 	}
 	// The private key is set from a file the node wrote, so it never appears here and never
 	// travelled. Everything else in this file came from the mesh; this one line is the node's.

internal/overlay/declaration_test.go

@@ -260,3 +260,52 @@ func TestTakingOverAFoundTunnelIsSaidOnTheInterfacesService(t *testing.T) {
 		}
 	}
 }
+
+func TestATakenTunnelBringsItsListenPortEvenWhenNotDialable(t *testing.T) {
+	// A home node behind NAT (no Endpoint, so not Reachable) that took over a tunnel must still
+	// listen on that tunnel's port, because its LAN peers dial it there (novox/hq: a taken tunnel
+	// brings its port). Without this the takeover guard refuses overlay-up.
+	config, _ := declarationFor(t, Node{
+		Name: "shanks", Key: "SPOKE", Address: "10.10.0.3",
+		TakesOver: &TakeOver{Interface: "wg0", Unit: "wg-quick@wg0", Port: 51820},
+	}, nil)
+
+	if !strings.Contains(config, "ListenPort = 51820") {
+		t.Fatalf("a taken tunnel's port must be the mesh interface's ListenPort:\n%s", config)
+	}
+	if strings.Contains(config, "Endpoint =") {
+		t.Error("a node that only listens for LAN peers must not advertise an endpoint")
+	}
+}
+
+func TestANodeWithNoTunnelAndNoEndpointStillListensOnNothing(t *testing.T) {
+	// The guard against over-emitting: a plain spoke with neither an endpoint nor a taken tunnel
+	// writes no ListenPort — it purely dials out.
+	config, _ := declarationFor(t, Node{Name: "laptop", Key: "K", Address: "10.10.0.9"}, nil)
+	if strings.Contains(config, "ListenPort") {
+		t.Fatalf("a dial-only node needs no ListenPort:\n%s", config)
+	}
+}
+
+func TestATakenTunnelCarriesItsMTU(t *testing.T) {
+	// A path tuned to a smaller MTU (1380 here) must survive the takeover — the mesh interface
+	// comes up with the same MTU, or transfers hang silently (novox/hq: a taken tunnel carries
+	// its MTU).
+	config, _ := declarationFor(t, Node{
+		Name: "shanks", Key: "SPOKE", Address: "10.10.0.3",
+		TakesOver: &TakeOver{Interface: "wg0", Port: 51820, MTU: 1380},
+	}, nil)
+	if !strings.Contains(config, "MTU = 1380") {
+		t.Fatalf("the tuned MTU was dropped:\n%s", config)
+	}
+}
+
+func TestNoMTULineWhenTheTunnelSetNone(t *testing.T) {
+	config, _ := declarationFor(t, Node{
+		Name: "shanks", Key: "SPOKE", Address: "10.10.0.3",
+		TakesOver: &TakeOver{Interface: "wg0", Port: 51820},
+	}, nil)
+	if strings.Contains(config, "MTU") {
+		t.Fatalf("no MTU was found, so none should be written:\n%s", config)
+	}
+}

internal/overlay/graph.go

@@ -50,6 +50,13 @@ type TakeOver struct {
 	Interface string
 	Unit      string
 	Config    string
+	// MTU is the found tunnel's, when it set one — emitted so a tuned path keeps its MTU.
+	MTU int
+	// Port is the port the found tunnel listened on. The mesh's interface must listen on it too,
+	// even on a node that is not dialable from the hub: a home node's LAN peers dial it there
+	// (novox/hq: a taken tunnel brings its port). Listening is "a peer dials me here"; it is not
+	// "the hub can dial me", which is Reachable — the two were conflated.
+	Port int
 }
 
 // HostPrefix is one address as a route: /32 for IPv4, /128 for IPv6.

internal/overlay/seat_test.go

@@ -0,0 +1,29 @@
+package overlay
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// The private network's claim is a seat the mesh defines (novox/hq ADR 0110).
+//
+// Checked here because this is where the manifest is composed: it ships with the control plane and
+// has no module.json for a test reading the catalogue to find. Parsed with the real parser, so a
+// set that forgot this seat refuses the control plane's own module here rather than on a machine.
+func TestThePrivateNetworksClaimIsASeatTheMeshDefines(t *testing.T) {
+	for _, composed := range []map[string]any{Manifest(), DomainManifest()} {
+		raw, err := json.Marshal(composed)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := catalogue.ParseManifest(raw); err != nil {
+			t.Errorf("%s, composed by the control plane, is refused: %v", composed["module"], err)
+		}
+	}
+	seat, defined := catalogue.SeatNamed(TheNetwork)
+	if !defined || seat.Scope != catalogue.ScopeNode {
+		t.Fatalf("%s is not a node seat the mesh defines: %+v", TheNetwork, seat)
+	}
+}

module.json

@@ -11,6 +11,12 @@
       "scope": "mesh"
     }
   ],
+  "accesses": [
+    {
+      "path": "/var/lib/mesh-broker-tls",
+      "mode": "read"
+    }
+  ],
   "own-secrets": {
     "inventory": "/var/lib/mesh/mesh-controller/inventory",
     "identity": "/var/lib/mesh/mesh-controller/identity",
@@ -51,7 +57,7 @@
         "MESH_BROKER_ADDRESS_PORT": "${seat:mesh-broker:5671}"
       },
       "volumes": [
-        "mesh-broker-tls:/broker-tls:ro",
+        "/var/lib/mesh-broker-tls:/broker-tls:ro",
         "/var/lib/mesh/mesh-controller/inventory:/run/secrets/inventory:ro",
         "/var/lib/mesh/mesh-controller/identity:/run/secrets/identity:ro",
         "/var/lib/mesh/mesh-controller/licences:/run/secrets/licences:ro",