Merge pull request 'The mesh's own verbs are the mesh-controller seat's tools' (#166) from feat/the-mesh-answers-for-itself into main

Reviewed-on: #166

cmd/mesh-controller/push.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"log"
 	"os"
 	"sort"
 	"strings"
@@ -124,6 +125,22 @@ func serve(ctx context.Context) error {
 		return err
 	}
 
+	// And the mesh's own verbs, as the seat this control plane holds (novox/hq ADR 0154). Served
+	// from the store's row, so what the seat declares is what is answered.
+	handlers, err := seatToolHandlers()
+	if err != nil {
+		return err
+	}
+	bus, isNATS := server.Bus().(link.OverNATS)
+	if !isNATS {
+		return errors.New("the mesh's verbs are served over the bus, and this control plane is not on it")
+	}
+	stopServing, err := bus.ServeSeatTools(catalogue.ControllerSeatName, handlers, log.New(os.Stdout, "", log.LstdFlags))
+	if err != nil {
+		return err
+	}
+	defer stopServing()
+
 	return server.Serve(ctx)
 }
 

cmd/mesh-controller/seatverbs.go

@@ -0,0 +1,190 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// The mesh's own verbs, served as the mesh-controller seat's tools (novox/hq ADR 0154, design 33).
+//
+// **Each tool runs the command it names, in this same binary, and answers what it printed.** That is
+// ADR 0035 taken literally: the logic lives once, in the command, and a surface is an adapter with no
+// decisions in it. Running a fresh process rather than calling the function keeps two things true
+// that calling it would not — every command opens and closes its own stores the way it does from a
+// shell, and nothing a command prints to the process's standard output can leak into another call's
+// answer. It also means a refusal is the same refusal in the same words, because it is the same
+// output.
+
+// verbAnswer is what a verb answers: what the command printed, whether it succeeded, and — where the
+// command speaks JSON — the same as data.
+type verbAnswer struct {
+	Output string `json:"output"`
+	OK     bool   `json:"ok"`
+	Answer any    `json:"answer,omitempty"`
+}
+
+// argvFor is the command line a verb and its arguments become. Only the verbs the seat declares, and
+// only the arguments each declares: a caller cannot reach a flag the schema did not name.
+func argvFor(verb string, args map[string]any) ([]string, error) {
+	str := func(key string) string {
+		v, _ := args[key].(string)
+		return strings.TrimSpace(v)
+	}
+	need := func(keys ...string) error {
+		for _, k := range keys {
+			if str(k) == "" {
+				return fmt.Errorf("%s needs %q", verb, k)
+			}
+		}
+		return nil
+	}
+	switch verb {
+	case "status":
+		return []string{"status", "--json"}, nil
+	case "nodes":
+		return []string{"node", "list"}, nil
+	case "node":
+		if err := need("node"); err != nil {
+			return nil, err
+		}
+		return []string{"node", "show", str("node")}, nil
+	case "modules":
+		return []string{"module", "list"}, nil
+	case "seats":
+		return []string{"seats", "--json"}, nil
+	case "builds":
+		if m := str("module"); m != "" {
+			return []string{"builds", m}, nil
+		}
+		return []string{"builds"}, nil
+	case "plan":
+		if err := need("node"); err != nil {
+			return nil, err
+		}
+		return []string{"plan", str("node"), "--json"}, nil
+	case "assign", "unassign":
+		if err := need("node", "module"); err != nil {
+			return nil, err
+		}
+		return []string{verb, str("node"), str("module")}, nil
+	case "push":
+		// Sent and not waited for: the asker reads `status` for what the machine did, which is
+		// what a person at a shell does too. A tool call that blocked for a push's whole apply would
+		// time out on every machine that takes a minute, and say nothing about the ones that did not.
+		if n := str("node"); n != "" {
+			return []string{"push", n, "--wait", "0"}, nil
+		}
+		return []string{"push", "--behind", "--wait", "0"}, nil
+	case "build":
+		if err := need("repository"); err != nil {
+			return nil, err
+		}
+		argv := []string{"build", str("repository"), "--wait", "0"}
+		if p := str("path"); p != "" {
+			argv = append(argv, "--path", p)
+		}
+		if r := str("ref"); r != "" {
+			argv = append(argv, "--ref", r)
+		}
+		return argv, nil
+	}
+	return nil, fmt.Errorf("%q is not a verb the %s seat serves", verb, catalogue.ControllerSeatName)
+}
+
+// jsonVerbs are the verbs whose command speaks JSON, so the answer carries it as data as well.
+var jsonVerbs = map[string]bool{"status": true, "seats": true, "plan": true}
+
+// runVerb runs this binary with the given command line and gathers what it said.
+func runVerb(ctx context.Context, argv []string) (verbAnswer, error) {
+	self, err := os.Executable()
+	if err != nil {
+		return verbAnswer{}, err
+	}
+	cmd := exec.CommandContext(ctx, self, argv...)
+	// The same environment: the stores' credentials, the bus, the broker — everything a command run
+	// from a shell in this container would have, because it is that.
+	cmd.Env = os.Environ()
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &out
+	runErr := cmd.Run()
+	answer := verbAnswer{Output: out.String(), OK: runErr == nil}
+	if jsonVerbs[argv[0]] && runErr == nil {
+		var parsed any
+		if json.Unmarshal(bytes.TrimSpace(out.Bytes()), &parsed) == nil {
+			answer.Answer = parsed
+		}
+	}
+	var exit *exec.ExitError
+	if runErr != nil && !errors.As(runErr, &exit) {
+		// Not the command refusing — the command not running at all, which is this process's fault.
+		return answer, fmt.Errorf("could not run %s: %w", strings.Join(argv, " "), runErr)
+	}
+	return answer, nil
+}
+
+// seatToolHandlers are the handlers for every verb the mesh-controller seat declares, from the
+// store's row, so a verb the row does not carry is not served and a verb it carries that this binary
+// cannot run is said at start rather than at the first call.
+func seatToolHandlers() (map[string]link.ToolHandler, error) {
+	seat, known := catalogue.SeatNamed(catalogue.ControllerSeatName)
+	if !known {
+		return nil, fmt.Errorf("this mesh defines no %s seat", catalogue.ControllerSeatName)
+	}
+	handlers := map[string]link.ToolHandler{}
+	for _, v := range seat.Serves {
+		verb := v.Name
+		if verb == "tools" {
+			handlers[verb] = func(ctx context.Context, _ json.RawMessage) (any, error) {
+				return seatTools(), nil
+			}
+			continue
+		}
+		if _, err := argvFor(verb, map[string]any{"node": "x", "module": "x", "repository": "x"}); err != nil {
+			return nil, fmt.Errorf("the %s seat's row declares %q, which this control plane cannot run: %w",
+				catalogue.ControllerSeatName, verb, err)
+		}
+		handlers[verb] = func(ctx context.Context, raw json.RawMessage) (any, error) {
+			args := map[string]any{}
+			if len(raw) > 0 {
+				if err := json.Unmarshal(raw, &args); err != nil {
+					return nil, fmt.Errorf("the arguments are not a JSON object: %w", err)
+				}
+			}
+			argv, err := argvFor(verb, args)
+			if err != nil {
+				return nil, err
+			}
+			return runVerb(ctx, argv)
+		}
+	}
+	return handlers, nil
+}
+
+// seatTools is what `tools` answers: every seat with a protocol, and the tools each serves, from the
+// mesh's own records — no holder in the path, so it is true while a holder restarts (design 33 §5).
+func seatTools() map[string]any {
+	var seats []map[string]any
+	for _, s := range catalogue.SeatsWithAProtocol() {
+		if len(s.Serves) == 0 {
+			continue
+		}
+		var tools []map[string]any
+		for _, v := range s.Serves {
+			tools = append(tools, map[string]any{
+				"name": v.Name, "description": v.Description, "input": v.Input, "output": v.Output,
+			})
+		}
+		seats = append(seats, map[string]any{"seat": s.Name, "scope": s.Scope, "tools": tools})
+	}
+	return map[string]any{"seats": seats}
+}

cmd/mesh-controller/seatverbs_test.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// Every verb the mesh-controller seat declares is one this binary can run, with the arguments the
+// schema names and no other (novox/hq ADR 0154, ADR 0035).
+func TestEveryDeclaredVerbHasACommandLine(t *testing.T) {
+	for _, v := range catalogue.ControllerVerbs {
+		if v.Name == "tools" {
+			continue
+		}
+		args := map[string]any{}
+		props, _ := v.Input["properties"].(map[string]any)
+		for name := range props {
+			args[name] = "x"
+		}
+		argv, err := argvFor(v.Name, args)
+		if err != nil {
+			t.Errorf("%s: %v", v.Name, err)
+			continue
+		}
+		if argv[0] == "" {
+			t.Errorf("%s: empty command", v.Name)
+		}
+	}
+}
+
+// A required argument missing is refused in the verb's own words, before anything runs.
+func TestAVerbMissingWhatItNeedsIsRefused(t *testing.T) {
+	if _, err := argvFor("node", map[string]any{}); err == nil || !strings.Contains(err.Error(), `node needs "node"`) {
+		t.Fatalf("node without a machine was accepted: %v", err)
+	}
+	if _, err := argvFor("upgrade", map[string]any{}); err == nil {
+		t.Fatal("a verb the seat does not serve was accepted")
+	}
+}
+
+// A push and a build are sent, not waited for: the asker reads status for what happened.
+func TestActsDoNotBlockTheCall(t *testing.T) {
+	argv, _ := argvFor("push", map[string]any{"node": "one"})
+	if strings.Join(argv, " ") != "push one --wait 0" {
+		t.Fatalf("push waits: %v", argv)
+	}
+	argv, _ = argvFor("build", map[string]any{"repository": "novox/x", "path": "modules/x"})
+	if strings.Join(argv, " ") != "build novox/x --wait 0 --path modules/x" {
+		t.Fatalf("build: %v", argv)
+	}
+}
+
+// What `tools` answers is the seats' records, with each verb's schema.
+func TestToolsAnswersTheSeatsRecords(t *testing.T) {
+	handlers, err := seatToolHandlers()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(handlers) != len(catalogue.ControllerVerbs) {
+		t.Fatalf("%d handlers for %d verbs", len(handlers), len(catalogue.ControllerVerbs))
+	}
+	answer := seatTools()
+	seats, _ := answer["seats"].([]map[string]any)
+	var found bool
+	for _, s := range seats {
+		if s["seat"] == catalogue.ControllerSeatName {
+			found = true
+			tools, _ := s["tools"].([]map[string]any)
+			if len(tools) != len(catalogue.ControllerVerbs) || tools[0]["input"] == nil {
+				t.Fatalf("the controller seat's tools are not listed in full: %v", tools)
+			}
+		}
+	}
+	if !found {
+		t.Fatal("the mesh-controller seat is not in the listing")
+	}
+}

internal/broker/invokes_test.go

@@ -42,7 +42,8 @@ func TestInvokingGrantsNothingButTheCall(t *testing.T) {
 		if strings.Contains(p, ".event.") {
 			t.Errorf("a module that only invokes may publish %q, an event it never declared", p)
 		}
-		if strings.HasPrefix(p, "mesh.seat.") {
+		// A role's tools are tools (ADR 0132); a role's work queue and events are not.
+		if strings.HasPrefix(p, "mesh.seat.") && !strings.Contains(p, ".tool.") {
 			t.Errorf("a module that only invokes may publish %q, a seat it neither holds nor uses", p)
 		}
 	}

internal/broker/nats.go

@@ -39,7 +39,11 @@ const (
 // Seat is a role on the bus as a principal relates to it: the subjects it accepts, and those it
 // emits (novox/hq ADR 0118, design 29 §5).
 type Seat struct {
-	Name     string
+	Name string
+	// Scope is where the seat has one holder. A node-scoped seat's tool carries the node in its
+	// subject, because one subject reaching six machines' holders is not an address
+	// (novox/hq ADR 0132, design 33 §4). Empty reads as mesh.
+	Scope    string
 	Accepts  []string
 	Emits    []string
 	Serves   []string
@@ -197,6 +201,13 @@ func PermissionsFor(p Principal) (Permissions, error) {
 		// the new bus was refused the publish (2026-09-28).
 		pub = append(pub, "mesh.mod.*.tool.>")
 
+		// **And the mesh's own verbs, as the seat it holds** (novox/hq ADR 0132, ADR 0154):
+		// `status`, `push`, `assign` are the mesh-controller seat's tools, served by its holder. The
+		// whole verb namespace of its own seat rather than a list: the list is the seat's protocol,
+		// which this package mirrors rather than reads, and a verb the seat does not declare is a
+		// subject nothing publishes.
+		sub = append(sub, "mesh.seat."+ControllerSeat+".tool.>")
+
 		// The two events it reacts to, and its ack subject on the stream they arrive from
 		// (streams.go). **Each named, not a pattern**: `mesh.mod.*.event.>` would make the
 		// controller a subscriber to every event in the mesh, and its permission list would stop
@@ -343,7 +354,7 @@ func PermissionsFor(p Principal) (Permissions, error) {
 				pub = append(pub, seatSubject(s, "event", e))
 			}
 			for _, t := range s.Serves {
-				sub = append(sub, seatSubject(s, "tool", t))
+				sub = append(sub, seatToolSubject(s, t, p.Node))
 			}
 		}
 
@@ -355,7 +366,7 @@ func PermissionsFor(p Principal) (Permissions, error) {
 				pub = append(pub, seatSubject(s, "accept", a))
 			}
 			for _, t := range s.Serves {
-				pub = append(pub, seatSubject(s, "tool", t))
+				pub = append(pub, seatToolSubject(s, t, "*"))
 			}
 		}
 	}
@@ -405,6 +416,18 @@ func seatSubject(s Seat, kind, verb string) string {
 	return "mesh.seat." + s.Name + "." + kind + "." + verb
 }
 
+// seatToolSubject is where a role's tool is asked. Mesh-wide for a mesh-scoped seat; a node-scoped
+// seat carries the node it is asked of, because a flat subject would reach every machine's holder
+// and the queue group would silently pick a winner (novox/hq ADR 0132, design 33 §4). A holder
+// subscribes its own node's; a user publishes any node's (`*`) and names the machine in the subject.
+func seatToolSubject(s Seat, verb, node string) string {
+	base := seatSubject(s, "tool", verb)
+	if s.Scope == "node" && node != "" {
+		return base + "." + node
+	}
+	return base
+}
+
 // consumerStream and consumerDurable are the two halves of a consumer's identity, and they are
 // two functions because conflating them was a real bug.
 //
@@ -615,13 +638,27 @@ func invokedSubjects(invokes []string) ([]string, error) {
 	var out []string
 	for _, t := range invokes {
 		if t == "*" {
-			out = append(out, "mesh.mod.*.tool.>")
+			// Every module's tools and every role's (novox/hq ADR 0132): a role's verb is a tool
+			// like any other, addressed to the seat instead of a module.
+			out = append(out, "mesh.mod.*.tool.>", "mesh.seat.*.tool.>")
+			continue
+		}
+		if rest, isSeat := strings.CutPrefix(t, "seat:"); isSeat {
+			// A role's tool, `seat:<seat>.<verb>`. Both address shapes, because the grant is
+			// written without knowing the seat's scope: a mesh seat's verb is flat and a node
+			// seat's carries the machine (design 33 §4).
+			seat, verb, ok := strings.Cut(rest, ".")
+			if !ok || seat == "" || verb == "" {
+				return nil, fmt.Errorf(
+					"%q does not name a role's tool: one invokes seat:<seat>.<verb>", t)
+			}
+			out = append(out, "mesh.seat."+seat+".tool."+verb, "mesh.seat."+seat+".tool."+verb+".*")
 			continue
 		}
 		module, tool, ok := strings.Cut(t, ".")
 		if !ok || module == "" || tool == "" {
 			return nil, fmt.Errorf(
-				"%q does not name a tool: one invokes <module>.<tool>, or * for every one", t)
+				"%q does not name a tool: one invokes <module>.<tool>, seat:<seat>.<verb>, or * for every one", t)
 		}
 		out = append(out, "mesh.mod."+module+".tool."+tool)
 	}

internal/broker/seattools_test.go

@@ -0,0 +1,57 @@
+package broker
+
+import "testing"
+
+// A node-scoped seat's tool carries the node (novox/hq ADR 0132, design 33 §4): two nodes holding one
+// node-scoped seat derive two addresses, and a user of the seat may publish any node's.
+func TestTwoNodesHoldingOneNodeSeatDeriveTwoToolAddresses(t *testing.T) {
+	seat := Seat{Name: "node-dns-resolver", Scope: "node", Serves: []string{"lookup"}}
+	one, _ := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "dnsmasq", Holds: []Seat{seat}, PasswordHash: "x"})
+	two, _ := PermissionsFor(Principal{Kind: KindModule, Node: "two", Module: "dnsmasq", Holds: []Seat{seat}, PasswordHash: "x"})
+	has(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.one")
+	has(t, two.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.two")
+	hasNot(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup")
+	hasNot(t, one.Subscribe, "mesh.seat.node-dns-resolver.tool.lookup.two")
+
+	user, _ := PermissionsFor(Principal{Kind: KindModule, Node: "three", Module: "asker", Uses: []Seat{seat}, PasswordHash: "x"})
+	has(t, user.Publish, "mesh.seat.node-dns-resolver.tool.lookup.*")
+}
+
+// A mesh-scoped seat's tool stays flat: nothing about it changes.
+func TestAMeshSeatsToolIsAddressedToTheSeatAlone(t *testing.T) {
+	seat := Seat{Name: "git", Scope: "mesh", Serves: []string{"list_repos"}}
+	holder, _ := PermissionsFor(Principal{Kind: KindModule, Node: "one", Module: "gitea", Holds: []Seat{seat}, PasswordHash: "x"})
+	has(t, holder.Subscribe, "mesh.seat.git.tool.list_repos")
+	user, _ := PermissionsFor(Principal{Kind: KindModule, Node: "two", Module: "asker", Uses: []Seat{seat}, PasswordHash: "x"})
+	has(t, user.Publish, "mesh.seat.git.tool.list_repos")
+}
+
+// The controller serves its own seat's verbs and may answer them (novox/hq ADR 0154).
+func TestTheControllerServesItsSeatsToolsAndMayAnswer(t *testing.T) {
+	perms, err := PermissionsFor(Principal{Kind: KindController, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, perms.Subscribe, "mesh.seat.mesh-controller.tool.>")
+	if !perms.AllowResponses {
+		t.Fatal("the controller serves tools and may not answer one")
+	}
+}
+
+// A grant to every tool reaches a role's tools too, and a role's tool is granted by name.
+func TestAGrantReachesARolesTools(t *testing.T) {
+	all, _ := PermissionsFor(Principal{Kind: KindModule, Node: "desk", Module: "mesh-console", Invokes: []string{"*"}, PasswordHash: "x"})
+	has(t, all.Publish, "mesh.seat.*.tool.>")
+
+	one, err := PermissionsFor(Principal{Kind: KindPerson, Module: "jo", Invokes: []string{"seat:mesh-controller.status"}, PasswordHash: "x"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	has(t, one.Publish, "mesh.seat.mesh-controller.tool.status")
+	hasNot(t, one.Publish, "mesh.seat.mesh-controller.tool.push")
+	hasNot(t, one.Publish, "mesh.mod.*.tool.>")
+
+	if _, err := PermissionsFor(Principal{Kind: KindPerson, Module: "jo", Invokes: []string{"seat:mesh-controller"}, PasswordHash: "x"}); err == nil {
+		t.Fatal("a role grant naming no verb was accepted")
+	}
+}

internal/broker/testdata/composed.conf

@@ -25,7 +25,7 @@ accounts {
     users = [
       { user: "controller", password: "$2a$11$cccccccccccccccccccccc", permissions: {
         publish: { allow: ["$JS.ACK.CONTROL.controller.>", "$JS.ACK.EVENTS.controller.>", "$JS.API.>", "_INBOX.enrol.>", "mesh.control.>", "mesh.mod.*.tool.>", "mesh.node.>", "mesh.seat.mesh-build-machine.accept.>", "mesh.seat.mesh-controller.event.applied", "mesh.seat.mesh-controller.event.built-before", "mesh.seat.mesh-controller.event.refused"] }
-        subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built"] }
+        subscribe: { allow: ["$JS.API.>", "_DELIVER.controller", "_DELIVER.controller.>", "_INBOX.controller.>", "mesh.control.>", "mesh.mod.gitea.event.pull.merged", "mesh.mod.mesh-catalog.event.catching-up", "mesh.mod.mesh-catalog.event.upgraded", "mesh.seat.mesh-build-machine.event.built", "mesh.seat.mesh-controller.tool.>"] }
         allow_responses: { max: 1, ttl: "1m" }
       } }
       { user: "enrol.one", password: "$2a$11$eeeeeeeeeeeeeeeeeeeeee", permissions: {

internal/catalogue/manifest.go

@@ -252,8 +252,8 @@ type Manifest struct {
 	// module claiming a seat answers what that seat's protocol promises (novox/hq ADR 0118).
 	Tools []string `json:"tools,omitempty"`
 
-	// Invokes are the tools this module calls, each `<module>.<tool>`, or the single entry `*` for
-	// every tool on the mesh (novox/hq ADR 0152).
+	// Invokes are the tools this module calls, each `<module>.<tool>` or a role's `seat:<seat>.<verb>`,
+	// or the single entry `*` for every tool on the mesh (novox/hq ADR 0152, ADR 0154).
 	//
 	// **A grant, and only a grant.** The bus lets this module publish exactly those tool subjects
 	// and nothing beside them — no event, no subscription, no seat. A module that declares none
@@ -1795,6 +1795,7 @@ func invokeProblems(m Manifest) []string {
 		if t == "*" {
 			continue
 		}
+		t = strings.TrimPrefix(t, "seat:")
 		module, tool, named := strings.Cut(t, ".")
 		if !named || !name.MatchString(module) || !toolName.MatchString(tool) {
 			problems = append(problems, fmt.Sprintf(

internal/catalogue/seats.go

@@ -37,7 +37,9 @@ type Seat struct {
 	// today — which the bus refuses, because a namespace belongs to who it is named for.
 	Accepts []string
 	Emits   []string
-	Serves  []string
+	// Serves carries each verb in full — name, description, schema — because a role's tools are the
+	// mesh's to define and an agent's to call (novox/hq ADR 0132, design 33 §2).
+	Serves []Verb
 	// Decision is the record that made it a seat.
 	Decision string
 }
@@ -51,8 +53,12 @@ var defaultSeats = []Seat{
 	// The control plane states what it did under the seat it holds (novox/hq ADR 0134): a role's
 	// events belong to the role, so they keep their address while the holder is replaced. No accepts,
 	// so no work queue is raised for it — only what its holder may say.
-	{Name: "mesh-controller", Scope: ScopeMesh, Decision: "novox/hq ADR 0079",
-		Emits: []string{"applied", "refused", "built-before"}},
+	// And it serves the mesh's own verbs as the seat's tools (novox/hq ADR 0154): `status`, `push`,
+	// `assign` and the rest are a role's interface, not a container's, and stay addressable while
+	// the control plane is replaced.
+	{Name: ControllerSeatName, Scope: ScopeMesh, Decision: "novox/hq ADR 0079",
+		Emits:  []string{"applied", "refused", "built-before"},
+		Serves: ControllerVerbs},
 	{Name: "mesh-store", Scope: ScopeMesh, Delivers: "postgres-database", Decision: "novox/hq ADR 0079"},
 	// **Delivers the mesh's own bus, not `amqp`.** Those were the same word until
 	// ADR 0127 separated them: `amqp` is a backing service a module may require, and this seat is
@@ -269,6 +275,14 @@ func CanHold(m Manifest, seat Seat) error {
 		return fmt.Errorf("%s claims %s, whose holder answers for %q, and %s does not provide %q at %s scope",
 			m.Module, seat.Name, seat.Delivers, m.Module, seat.Delivers, seat.Scope)
 	}
+	// **Serving the seat's tools is a condition of holding it** (novox/hq ADR 0132). A holder that
+	// does not answer what the role promises is every caller's timeout, found at registration and
+	// at handover instead, naming the verbs rather than the fact that something is missing.
+	if missing := unservedVerbs(m.Tools, seat.Serves); len(missing) > 0 {
+		return fmt.Errorf("%s claims %s but does not serve %s, which that seat's protocol promises "+
+			"(novox/hq ADR 0132) — a holder lists every verb its seat declares under tools",
+			m.Module, seat.Name, strings.Join(missing, ", "))
+	}
 	return nil
 }
 

internal/catalogue/seats_declared.go

@@ -38,8 +38,9 @@ type SeatDeclaration struct {
 	Accepts []string `json:"accepts,omitempty"`
 	// Emits are the verbs the holder publishes: 1:many, nobody obliged to act.
 	Emits []string `json:"emits,omitempty"`
-	// Serves are the verbs the holder answers: request and reply, awaited.
-	Serves []string `json:"serves,omitempty"`
+	// Serves are the verbs the holder answers: request and reply, awaited. A bare name, or the
+	// verb in full with its schema (novox/hq ADR 0132).
+	Serves []Verb `json:"serves,omitempty"`
 
 	// RetainSeconds is how long the inbound backlog survives with no holder, zero for the
 	// mesh's default. Retention belongs to whoever owns the namespace (design 29 §3) — a seat
@@ -62,7 +63,7 @@ func (s SeatDeclaration) At() string {
 func (s SeatDeclaration) verbs() []string {
 	out := append([]string{}, s.Accepts...)
 	out = append(out, s.Emits...)
-	return append(out, s.Serves...)
+	return append(out, VerbNames(s.Serves)...)
 }
 
 // declaredSeatProblems is what one manifest can be judged on alone.
@@ -228,8 +229,8 @@ func unserved(m Manifest, s SeatDeclaration) []string {
 	}
 	var missing []string
 	for _, t := range s.Serves {
-		if !has[t] {
-			missing = append(missing, t)
+		if !has[t.Name] {
+			missing = append(missing, t.Name)
 		}
 	}
 	return missing

internal/catalogue/seats_declared_test.go

@@ -13,7 +13,7 @@ func problemsFor(t *testing.T, shelf Shelf) string {
 func telegram() Manifest {
 	return Manifest{Module: "telegram", Tools: []string{"status"}, DefinesSeats: []SeatDeclaration{{
 		Name: "telegram-sender", Scope: ScopeMesh,
-		Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}, Serves: []string{"status"},
+		Accepts: []string{"send"}, Emits: []string{"delivered", "failed"}, Serves: []Verb{{Name: "status"}},
 	}}, Claims: []Claim{{Name: "telegram-sender", Scope: ScopeMesh}}}
 }
 

internal/catalogue/verbs.go

@@ -0,0 +1,133 @@
+package catalogue
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+)
+
+// A Verb is one tool a role serves: its name, what it does, and the schema of its arguments and of
+// its answer (novox/hq ADR 0132, design 33 §2).
+//
+// **A name alone is not callable by something that has never seen the mesh before**, which is the
+// whole population a tool surface exists for. So a seat's protocol carries the definition, in the
+// form an agent protocol already uses — a JSON schema for the input — so nothing translates between
+// a seat's idea of an argument and the caller's.
+//
+// A manifest may still write a bare verb name (`"serves": ["price"]`); that is a Verb with only a
+// name, and the module's runtime answers `tools` with the rest. The two forms read into one type so
+// nothing downstream cares which was written.
+type Verb struct {
+	Name        string         `json:"name"`
+	Description string         `json:"description,omitempty"`
+	Input       map[string]any `json:"input,omitempty"`
+	Output      map[string]any `json:"output,omitempty"`
+}
+
+func (v *Verb) UnmarshalJSON(raw []byte) error {
+	trimmed := bytes.TrimSpace(raw)
+	if len(trimmed) > 0 && trimmed[0] == '"' {
+		var name string
+		if err := json.Unmarshal(trimmed, &name); err != nil {
+			return err
+		}
+		*v = Verb{Name: name}
+		return nil
+	}
+	// Strictly, like the manifest around it: a misspelt key in a tool's definition would otherwise
+	// describe a tool nobody can call and refuse nothing.
+	type plain Verb
+	var p plain
+	decoder := json.NewDecoder(bytes.NewReader(trimmed))
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&p); err != nil {
+		return fmt.Errorf("a served verb is a name or {name, description, input, output}: %w", err)
+	}
+	if p.Name == "" {
+		return fmt.Errorf("a served verb has no name: %s", trimmed)
+	}
+	*v = Verb(p)
+	return nil
+}
+
+// VerbNames are the names alone, for the grants and the checks that care about nothing else.
+func VerbNames(verbs []Verb) []string {
+	out := make([]string, 0, len(verbs))
+	for _, v := range verbs {
+		out = append(out, v.Name)
+	}
+	return out
+}
+
+// ControllerSeatName is the seat the control plane holds, whose tools are the mesh's own verbs.
+const ControllerSeatName = "mesh-controller"
+
+// ControllerVerbs are the mesh's own verbs, as the `mesh-controller` seat's tools (novox/hq ADR 0154).
+//
+// **The same function the command line calls, and nothing the tool adds** (ADR 0035): each of these
+// is a command the controller's binary already answers, run by the holder of the seat with the
+// arguments below and answered with what the command printed. A verb here is a contract every future
+// holder must implement, which is why the list is short and made of what an operator asks weekly.
+// Additive within a version (design 33 §7); a verb that would break a caller takes a new version.
+var ControllerVerbs = []Verb{
+	{Name: "tools", Description: "Every seat's tools, from the mesh's own records: what each role " +
+		"answers, whether or not its holder is up. The mesh's own verbs are the mesh-controller seat's.",
+		Input: schema(nil, nil)},
+	{Name: "status", Description: "What is wrong, what is quiet, what is out of date, and which " +
+		"machines are behind what the mesh would send them.",
+		Input: schema(nil, nil)},
+	{Name: "nodes", Description: "Every machine the mesh knows, with whether it is converged or adopted.",
+		Input: schema(nil, nil)},
+	{Name: "node", Description: "What one machine reported it can do, what it is assigned, and why.",
+		Input: schema(map[string]string{"node": "the machine's name"}, []string{"node"})},
+	{Name: "modules", Description: "Every module the mesh holds: version, the commit it was built from, " +
+		"and which machines run it.",
+		Input: schema(nil, nil)},
+	{Name: "seats", Description: "Every seat the mesh defines, what it delivers, and who holds it.",
+		Input: schema(nil, nil)},
+	{Name: "builds", Description: "What has been built lately and what came of it, for every module or for one.",
+		Input: schema(map[string]string{"module": "one module's name; every module when absent"}, nil)},
+	{Name: "plan", Description: "What one machine would run, and why: the declaration the mesh would send it.",
+		Input: schema(map[string]string{"node": "the machine's name"}, []string{"node"})},
+	{Name: "assign", Description: "Put a module on a machine. Refused with the mesh's own words when it cannot resolve there.",
+		Input: schema(map[string]string{"node": "the machine's name", "module": "the module's name"}, []string{"node", "module"})},
+	{Name: "unassign", Description: "Take a module off a machine.",
+		Input: schema(map[string]string{"node": "the machine's name", "module": "the module's name"}, []string{"node", "module"})},
+	{Name: "push", Description: "Send a machine everything it should be — or every machine that is behind, when no machine is named.",
+		Input: schema(map[string]string{"node": "the machine's name; every machine behind when absent"}, nil)},
+	{Name: "build", Description: "Have the build machine build a repository and record what came out.",
+		Input: schema(map[string]string{
+			"repository": "the repository's URL, or its path on the forge holding the git seat",
+			"path":       "the module's directory inside it (optional)",
+			"ref":        "the branch, tag or commit to build (optional)",
+		}, []string{"repository"})},
+}
+
+// schema is a JSON schema for an object of string properties, which is every argument the verbs
+// above take. Kept small on purpose: a schema an agent cannot read is a tool it cannot call.
+func schema(properties map[string]string, required []string) map[string]any {
+	props := map[string]any{}
+	for name, description := range properties {
+		props[name] = map[string]any{"type": "string", "description": description}
+	}
+	out := map[string]any{"type": "object", "properties": props}
+	if len(required) > 0 {
+		out["required"] = required
+	}
+	return out
+}
+
+// unservedVerbs is what a seat promises and a claimant's `tools` does not answer.
+func unservedVerbs(tools []string, promised []Verb) []string {
+	has := map[string]bool{}
+	for _, t := range tools {
+		has[t] = true
+	}
+	var missing []string
+	for _, v := range promised {
+		if !has[v.Name] {
+			missing = append(missing, v.Name)
+		}
+	}
+	return missing
+}

internal/catalogue/verbs_test.go

@@ -0,0 +1,72 @@
+package catalogue
+
+import (
+	"strings"
+	"testing"
+)
+
+// A served verb is written as a bare name or in full, and both read into one type (novox/hq ADR 0132).
+func TestAServedVerbIsANameOrADefinition(t *testing.T) {
+	m, err := ParseManifest([]byte(`{"module":"till","version":"1","tools":["price","refund"],` +
+		`"seats":[{"name":"shop-till","serves":["price",{"name":"refund","description":"give it back",` +
+		`"input":{"type":"object","properties":{"order":{"type":"string"}}}}]}],` +
+		`"claims":[{"name":"shop-till","scope":"mesh"}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := m.DefinesSeats[0].Serves
+	if len(got) != 2 || got[0].Name != "price" || got[1].Name != "refund" || got[1].Description != "give it back" {
+		t.Fatalf("verbs not read: %+v", got)
+	}
+	if got[1].Input["type"] != "object" {
+		t.Fatalf("the schema did not travel with the verb: %+v", got[1].Input)
+	}
+}
+
+// A misspelt key inside a verb's definition is refused, like one anywhere else in the manifest.
+func TestAVerbWithAnUnknownKeyIsRefused(t *testing.T) {
+	_, err := ParseManifest([]byte(`{"module":"till","version":"1",` +
+		`"seats":[{"name":"shop-till","serves":[{"name":"price","descripton":"typo"}]}]}`))
+	if err == nil || !strings.Contains(err.Error(), "descripton") {
+		t.Fatalf("a verb with a misspelt key was accepted: %v", err)
+	}
+}
+
+// Holding a mesh seat that serves verbs requires serving them, and the refusal names the verbs.
+func TestHoldingAMeshSeatRequiresServingItsVerbs(t *testing.T) {
+	was := Seats()
+	t.Cleanup(func() { UseSeats(was) })
+	UseSeats([]Seat{{Name: "mesh-controller", Scope: ScopeMesh, Decision: "test",
+		Serves: []Verb{{Name: "status"}, {Name: "push"}}}})
+	seat, _ := SeatNamed("mesh-controller")
+
+	partial := Manifest{Module: "a-controller", Tools: []string{"status"},
+		Claims: []Claim{{Name: "mesh-controller", Scope: ScopeMesh}}}
+	err := CanHold(partial, seat)
+	if err == nil || !strings.Contains(err.Error(), "does not serve push") {
+		t.Fatalf("a holder missing a verb was not refused by name: %v", err)
+	}
+	whole := Manifest{Module: "a-controller", Tools: []string{"status", "push"},
+		Claims: []Claim{{Name: "mesh-controller", Scope: ScopeMesh}}}
+	if err := CanHold(whole, seat); err != nil {
+		t.Fatalf("a holder serving every verb was refused: %v", err)
+	}
+}
+
+// The mesh's own verbs are declared in full: an agent cannot call a name without a schema.
+func TestEveryControllerVerbIsDescribedWithASchema(t *testing.T) {
+	seen := map[string]bool{}
+	for _, v := range ControllerVerbs {
+		if v.Description == "" || v.Input == nil || v.Input["type"] != "object" {
+			t.Errorf("%s: no description or no object schema", v.Name)
+		}
+		if seen[v.Name] {
+			t.Errorf("%s declared twice", v.Name)
+		}
+		seen[v.Name] = true
+	}
+	seat, _ := SeatNamed(ControllerSeatName)
+	if len(seat.Serves) != len(ControllerVerbs) {
+		t.Fatalf("the compiled mesh-controller seat serves %d verbs, the table has %d", len(seat.Serves), len(ControllerVerbs))
+	}
+}

internal/inventory/busrecords.go

@@ -137,7 +137,8 @@ func declaredFor(m catalogue.Manifest, seats map[string]catalogue.SeatDeclaratio
 }
 
 func asSeat(s catalogue.SeatDeclaration) broker.Seat {
-	return broker.Seat{Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: s.Serves}
+	return broker.Seat{Name: s.Name, Scope: s.Scope, Accepts: s.Accepts, Emits: s.Emits,
+		Serves: catalogue.VerbNames(s.Serves)}
 }
 
 // MeshSeats are the mesh's own seats that carry a protocol, as the bus needs them: what to make a work
@@ -146,7 +147,7 @@ func MeshSeats() []broker.DeclaredSeat {
 	var out []broker.DeclaredSeat
 	for _, s := range catalogue.SeatsWithAProtocol() {
 		out = append(out, broker.DeclaredSeat{
-			Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: s.Serves,
+			Name: s.Name, Accepts: s.Accepts, Emits: s.Emits, Serves: catalogue.VerbNames(s.Serves),
 		})
 	}
 	return out

internal/inventory/migrations/0047-a-seat-carries-its-tools.sql

@@ -0,0 +1,12 @@
+-- A seat's protocol lives in the store, not in the binary (novox/hq ADR 0129, ADR 0132, design 33 §2).
+--
+-- ADR 0122 moved the seat set into this table with name, scope, delivers and decision, and the
+-- protocol — what a role accepts, emits and serves — stayed compiled into the control plane and was
+-- merged in as a row was read. Discovery that reads a binary disagrees with the mesh the moment the
+-- two are on different versions, and a tool without a schema is not something an agent can call. So
+-- the three halves become columns: accepts and emits as lists of verbs, serves as the verbs in full
+-- ({name, description, input, output}). Seeded from the compiled defaults where a row has none,
+-- additively thereafter (a verb a release adds joins the row; nothing is taken away).
+alter table seat add column accepts jsonb not null default '[]'::jsonb;
+alter table seat add column emits   jsonb not null default '[]'::jsonb;
+alter table seat add column serves  jsonb not null default '[]'::jsonb;

internal/inventory/seats.go

@@ -2,6 +2,7 @@ package inventory
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 
 	"github.com/novox/mesh-controller/internal/catalogue"
@@ -17,7 +18,7 @@ import (
 // Seats is every seat the mesh defines, read from the store.
 func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
 	rows, err := i.store.Pool().Query(ctx,
-		`select name, scope, delivers, decided from seat order by name`)
+		`select name, scope, delivers, decided, accepts, emits, serves from seat order by name`)
 	if err != nil {
 		return nil, err
 	}
@@ -26,9 +27,21 @@ func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
 	var seats []catalogue.Seat
 	for rows.Next() {
 		var s catalogue.Seat
-		if err := rows.Scan(&s.Name, &s.Scope, &s.Delivers, &s.Decision); err != nil {
+		var accepts, emits, serves []byte
+		if err := rows.Scan(&s.Name, &s.Scope, &s.Delivers, &s.Decision, &accepts, &emits, &serves); err != nil {
 			return nil, err
 		}
+		// The protocol, from the row (novox/hq ADR 0132). A row that predates the columns has empty
+		// lists, and UseSeats keeps the compiled protocol for it until the next seeding fills them.
+		if err := json.Unmarshal(accepts, &s.Accepts); err != nil {
+			return nil, fmt.Errorf("seat %s: accepts: %w", s.Name, err)
+		}
+		if err := json.Unmarshal(emits, &s.Emits); err != nil {
+			return nil, fmt.Errorf("seat %s: emits: %w", s.Name, err)
+		}
+		if err := json.Unmarshal(serves, &s.Serves); err != nil {
+			return nil, fmt.Errorf("seat %s: serves: %w", s.Name, err)
+		}
 		seats = append(seats, s)
 	}
 	return seats, rows.Err()
@@ -41,21 +54,116 @@ func (i *Inventory) Seats(ctx context.Context) ([]catalogue.Seat, error) {
 // exactly as it is, so an operator's rename in the table is not undone by the next deploy putting
 // the old name back. What a release removes from the defaults is not deleted here either; retiring a
 // seat is its own decision, not a silent consequence of it dropping out of the binary.
+//
+// **The protocol is seeded additively** (novox/hq ADR 0132, design 33 §7). A row that has none takes
+// the compiled protocol whole — that is the compiled fallback becoming data, once. A row that has one
+// gains any verb the defaults name and it lacks, and loses nothing: a seat's tools are an interface,
+// additive within a version, and a verb an operator added to the row is theirs to keep.
 func (i *Inventory) SeedSeats(ctx context.Context, defaults []catalogue.Seat) (int, error) {
 	var added int
 	for _, s := range defaults {
-		tag, err := i.store.Pool().Exec(ctx,
-			`insert into seat (name, scope, delivers, decided) values ($1, $2, $3, $4)
-			 on conflict (name) do nothing`,
-			s.Name, s.Scope, s.Delivers, s.Decision)
+		accepts, emits, serves, err := protocolJSON(s)
 		if err != nil {
 			return added, err
 		}
-		added += int(tag.RowsAffected())
+		tag, err := i.store.Pool().Exec(ctx,
+			`insert into seat (name, scope, delivers, decided, accepts, emits, serves)
+			 values ($1, $2, $3, $4, $5, $6, $7)
+			 on conflict (name) do nothing`,
+			s.Name, s.Scope, s.Delivers, s.Decision, accepts, emits, serves)
+		if err != nil {
+			return added, err
+		}
+		if n := int(tag.RowsAffected()); n > 0 {
+			added += n
+			continue
+		}
+		if err := i.widenProtocol(ctx, s); err != nil {
+			return added, err
+		}
 	}
 	return added, nil
 }
 
+// widenProtocol adds to a seat's row whatever the defaults name and the row lacks, by verb name.
+func (i *Inventory) widenProtocol(ctx context.Context, s catalogue.Seat) error {
+	var accepts, emits, serves []byte
+	if err := i.store.Pool().QueryRow(ctx,
+		`select accepts, emits, serves from seat where name = $1`, s.Name).Scan(&accepts, &emits, &serves); err != nil {
+		return err
+	}
+	var row catalogue.Seat
+	if err := json.Unmarshal(accepts, &row.Accepts); err != nil {
+		return err
+	}
+	if err := json.Unmarshal(emits, &row.Emits); err != nil {
+		return err
+	}
+	if err := json.Unmarshal(serves, &row.Serves); err != nil {
+		return err
+	}
+	changed := false
+	row.Accepts, changed = union(row.Accepts, s.Accepts, changed)
+	row.Emits, changed = union(row.Emits, s.Emits, changed)
+	have := map[string]bool{}
+	for _, v := range row.Serves {
+		have[v.Name] = true
+	}
+	for _, v := range s.Serves {
+		if !have[v.Name] {
+			row.Serves = append(row.Serves, v)
+			changed = true
+		}
+	}
+	if !changed {
+		return nil
+	}
+	a, e, sv, err := protocolJSON(row)
+	if err != nil {
+		return err
+	}
+	_, err = i.store.Pool().Exec(ctx,
+		`update seat set accepts = $2, emits = $3, serves = $4 where name = $1`, s.Name, a, e, sv)
+	return err
+}
+
+func union(have, want []string, changed bool) ([]string, bool) {
+	seen := map[string]bool{}
+	for _, h := range have {
+		seen[h] = true
+	}
+	for _, w := range want {
+		if !seen[w] {
+			have = append(have, w)
+			seen[w] = true
+			changed = true
+		}
+	}
+	return have, changed
+}
+
+func protocolJSON(s catalogue.Seat) (accepts, emits, serves []byte, err error) {
+	if accepts, err = json.Marshal(orEmpty(s.Accepts)); err != nil {
+		return
+	}
+	if emits, err = json.Marshal(orEmpty(s.Emits)); err != nil {
+		return
+	}
+	verbs := s.Serves
+	if verbs == nil {
+		verbs = []catalogue.Verb{}
+	}
+	serves, err = json.Marshal(verbs)
+	return
+}
+
+func orEmpty(s []string) []string {
+	if s == nil {
+		return []string{}
+	}
+	return s
+}
+
 // Aliases is every former seat name and the seat it now resolves to (novox/hq ADR 0122).
 func (i *Inventory) Aliases(ctx context.Context) (map[string]string, error) {
 	rows, err := i.store.Pool().Query(ctx, `select alias, seat from seat_alias`)

internal/link/seattools.go

@@ -0,0 +1,76 @@
+package link
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/nats-io/nats.go"
+)
+
+// A role's tools, served by its holder (novox/hq ADR 0132, ADR 0154).
+//
+// The mesh's own verbs — `status`, `push`, `assign` — are the mesh-controller seat's tools, and the
+// control plane is that seat's holder. So it answers them here, on the seat's subjects, the way a
+// module's runtime answers a module's: one request, one reply on the asker's own inbox, `{result}` or
+// `{error}`. Nothing about the transport is the command's business; a handler is a function of its
+// arguments and gets the same answer the command line prints.
+
+// ToolHandler answers one call of a role's tool. What it returns is marshalled as the result; an
+// error is the tool answering with one, which is an answer and not a timeout.
+type ToolHandler func(ctx context.Context, args json.RawMessage) (any, error)
+
+// SeatToolSubject is where a mesh-scoped seat's tool is asked (design 33 §4).
+func SeatToolSubject(seat, verb string) string { return "mesh.seat." + seat + ".tool." + verb }
+
+// HandlerTimeout bounds one answer. A verb that runs a command — a push, a build with no wait —
+// answers in seconds; anything that has not in this long is said to have not answered.
+const HandlerTimeout = 5 * time.Minute
+
+// ServeSeatTools binds every handler on its seat's subject until stopped. A queue group per seat, so
+// a second holder during a handover shares the calls rather than both answering one.
+func (b OverNATS) ServeSeatTools(seat string, handlers map[string]ToolHandler, logger *log.Logger) (func(), error) {
+	var subs []*nats.Subscription
+	stop := func() {
+		for _, s := range subs {
+			_ = s.Unsubscribe()
+		}
+	}
+	for verb, handle := range handlers {
+		verb, handle := verb, handle
+		subject := SeatToolSubject(seat, verb)
+		sub, err := b.Conn.QueueSubscribe(subject, "seat."+seat, func(msg *nats.Msg) {
+			// Its own goroutine per call: a slow `push` must not hold up a `status` asked beside it,
+			// and the library would otherwise run handlers one after another.
+			go func() {
+				ctx, cancel := context.WithTimeout(context.Background(), HandlerTimeout)
+				defer cancel()
+				args := json.RawMessage(msg.Data)
+				if len(args) == 0 {
+					args = json.RawMessage(`{}`)
+				}
+				var reply []byte
+				result, err := handle(ctx, args)
+				if err != nil {
+					reply, _ = json.Marshal(map[string]any{"error": err.Error()})
+				} else if reply, err = json.Marshal(map[string]any{"result": result}); err != nil {
+					reply, _ = json.Marshal(map[string]any{"error": "the answer could not be written as JSON: " + err.Error()})
+				}
+				if err := msg.Respond(reply); err != nil && logger != nil {
+					logger.Printf("%s: could not answer: %v", subject, err)
+				}
+			}()
+		})
+		if err != nil {
+			stop()
+			return nil, fmt.Errorf("serving %s: %w", subject, err)
+		}
+		subs = append(subs, sub)
+	}
+	if logger != nil {
+		logger.Printf("serving %d tool(s) of the %s seat", len(handlers), seat)
+	}
+	return stop, nil
+}

module.json

@@ -28,6 +28,20 @@
   },
   "secrets-owner": "65534:65534",
   "prepares": true,
+  "tools": [
+    "tools",
+    "status",
+    "nodes",
+    "node",
+    "modules",
+    "seats",
+    "builds",
+    "plan",
+    "assign",
+    "unassign",
+    "push",
+    "build"
+  ],
   "resources": [
     {
       "id": "mesh-state",