The console: mesh serve on loopback, and every runtime answers tools

The runtime serves a tools verb per module with names, descriptions and schemas (design 34 §3), and
refuses a module naming its own tool tools. Discovery asks catalog_modules then each module, naming
what did not answer. One MCP handler over two transports: stdio (mesh mcp) and loopback HTTP (mesh
serve, the mesh-console module, novox/hq ADR 0152); serve refuses any bind but loopback. tools/call
may go through a running console with --console and no credential.

README.md

@@ -25,6 +25,20 @@ MESH_TOOL_MODULES   /a/tools/index.js,…   the assigned modules' compiled tool
 `node dist/main.js`, or the container (`Dockerfile`). On a node the host resolves both variables
 and starts it like any other supervised workload.
 
+## `mesh` — the tools for whoever is on a machine
+
+The same package carries the client (novox/hq design 25 §7, design 34): `mesh tools`, `mesh call
+<module>.<tool> [json]`, `mesh mcp` (an MCP server over stdio for a program a person starts) and
+`mesh serve` (the **console**: MCP over HTTP on a machine's loopback, started by the mesh as the
+`mesh-console` module on the credential in `MESH_BROKER_FILE` — novox/hq ADR 0152). `mesh serve`
+refuses to bind anything but loopback. With `--console <url>`, `tools` and `call` go through a console
+already on the machine and need no credential.
+
+Discovery asks the modules: every runtime answers a `tools` verb for each module it serves, with names,
+descriptions and schemas from the code that answers them, and the console asks the catalogue which
+modules the mesh holds and each module what it serves. A module that does not answer is named, never
+dropped. A module may not name a tool of its own `tools`; the runtime refuses it at load.
+
 ## Verified
 
 `npm test` stands up LavinMQ (the mesh's broker) and proves the whole path over real AMQP: the

src/client.ts

@@ -1,30 +1,32 @@
 /**
- * A person's client: the mesh's tools from a workstation (novox/hq design 25 §7).
+ * The mesh's tools, for whoever is on a machine (novox/hq design 25 §7, design 34).
  *
  * Two surfaces over one thing. A command line, for somebody at a terminal; an MCP server, for an
  * agent. Both are adapters over the same three calls — what tools are there, what does this one take,
  * call it — because a second way of reaching a tool is a second thing to keep correct.
  *
- * **It uses the same client a module's runtime uses.** Not a second protocol and not a bridge: a
- * person connects as their own bus user, publishes on the tool subjects their account permits, and the
- * server refuses anything else. So "what may this person do" is answered by the same permission list
- * that answers it for a module, and there is nothing here for an audit to read separately.
+ * **It uses the same client a module's runtime uses.** Not a second protocol and not a bridge: the
+ * caller connects as its own bus user — a person's, or the console's — publishes on the tool subjects
+ * that account permits, and the server refuses anything else. So "what may this ask" is answered by the
+ * same permission list that answers it for a module, and there is nothing here for an audit to read
+ * separately.
  *
- * What a person may NOT do is the more interesting half, and none of it is enforced here — it is the
- * account (design 25 §4): they cannot publish an event, so they cannot claim a module said something;
- * they have no consumer, so there is no delivery to acknowledge; and they cannot answer a request, so
- * they cannot impersonate a module on a bus where anyone may serve a tool.
+ * What the caller may NOT do is the more interesting half, and none of it is enforced here — it is the
+ * account (design 25 §4): it cannot publish an event, so it cannot claim a module said something; it
+ * has no consumer, so there is no delivery to acknowledge; and it cannot answer a request, so it cannot
+ * impersonate a module on a bus where anyone may serve a tool.
  */
 import { readFile } from "node:fs/promises";
 
 import type { Broker } from "@novox/mesh-sdk/messaging";
 
 import { connectNats, type Credential } from "./broker-nats.js";
+import { TOOLS_VERB, type ToolsAnswer } from "./runtime.js";
 
-/** Where the catalogue answers what tools the mesh has. */
-const CATALOGUE_TOOLS = "mesh-catalog.catalog_tools";
+/** Where the catalogue answers which modules the mesh holds. */
+const CATALOGUE_MODULES = "mesh-catalog.catalog_modules";
 
-/** A tool as the catalogue describes one. */
+/** A tool as its module describes it. */
 export interface Tool {
   module: string;
   name: string;
@@ -33,6 +35,20 @@ export interface Tool {
   input?: unknown;
 }
 
+/**
+ * What the mesh could say about its tools when asked (design 34 §3).
+ *
+ * **Silence is named, never dropped.** A module the catalogue holds and nothing answered for is in
+ * `notAnswering`, because a tool that is not offered looks exactly like a tool that does not exist,
+ * and those need different people to fix them.
+ */
+export interface Listing {
+  tools: Tool[];
+  /** Modules the catalogue holds whose runtime did not answer `tools`: not assigned, not up, or built
+   *  before the runtime answered it. Each may still be called by name. */
+  notAnswering: string[];
+}
+
 /**
  * A person's credential, as `operator issue` prints it.
  *
@@ -72,24 +88,63 @@ export async function connectAs(held: PersonCredential): Promise<Broker> {
 }
 
 /**
- * What tools the mesh has, asked of the catalogue.
- *
- * **Asked, not configured.** The catalogue is the only thing that knows what is installed, and a
- * client carrying its own list would be a list that goes stale the first time a module is assigned —
- * silently, because a tool that is not offered looks exactly like a tool that does not exist.
+ * Connect as the console: the module credential the mesh delivered (novox/hq ADR 0152), read from
+ * the same variable every runtime reads. It names the node and the module, so the account's inbox
+ * and subjects derive from what the mesh authorised and from nothing in this process's environment.
  */
-export async function toolsOn(bus: Broker): Promise<Tool[]> {
-  const answered = await bus.request<Record<string, never>, { tools?: Tool[] } | Tool[]>(
-    CATALOGUE_TOOLS,
-    {},
-  );
-  const tools = Array.isArray(answered) ? answered : (answered.tools ?? []);
-  return tools
-    .slice()
-    .sort((a: Tool, b: Tool) => `${a.module}.${a.name}`.localeCompare(`${b.module}.${b.name}`));
+export async function connectAsTheConsole(path: string): Promise<{ bus: Broker; who: string }> {
+  const raw = await readFile(path, "utf8");
+  let held: Credential;
+  try {
+    held = JSON.parse(raw) as Credential;
+  } catch (e) {
+    throw new Error(`${path} is not a broker credential: ${(e as Error).message}`);
+  }
+  if (!held.url || !held.module || !held.user) {
+    throw new Error(
+      `${path} names no bus, module or user: the console runs on the credential the mesh sealed to ` +
+        "this machine for it, and nothing else",
+    );
+  }
+  return { bus: await connectNats(held), who: `${held.node ?? "?"}.${held.module}` };
 }
 
-/** Call one tool. The key is `<module>.<tool>`, which is what a person types and what their account
+/**
+ * What tools the mesh has, asked of the modules (design 34 §3).
+ *
+ * The catalogue says which modules the mesh holds; each module says what it serves, through the one
+ * verb its runtime answers for it. **Asked, not configured**: a client carrying its own list would be a
+ * list that goes stale the first time a module is assigned. Every module is asked at once, and the bus
+ * refuses at once a request nothing serves, so the cost is bounded by the modules that are up.
+ */
+export async function toolsOn(bus: Broker): Promise<Listing> {
+  const answered = await bus.request<Record<string, never>, { modules?: { module: string }[] }>(
+    CATALOGUE_MODULES,
+    {},
+  );
+  const names = (answered.modules ?? []).map((m) => m.module).filter((m) => typeof m === "string");
+
+  const asked = await Promise.allSettled(
+    names.map((module) => bus.request<Record<string, never>, ToolsAnswer>(`${module}.${TOOLS_VERB}`, {})),
+  );
+  const tools: Tool[] = [];
+  const notAnswering: string[] = [];
+  asked.forEach((outcome, i) => {
+    const module = names[i]!;
+    if (outcome.status === "fulfilled" && Array.isArray(outcome.value?.tools)) {
+      for (const t of outcome.value.tools) {
+        tools.push({ module, name: t.name, description: t.description, input: t.input });
+      }
+    } else {
+      notAnswering.push(module);
+    }
+  });
+  tools.sort((a, b) => `${a.module}.${a.name}`.localeCompare(`${b.module}.${b.name}`));
+  notAnswering.sort();
+  return { tools, notAnswering };
+}
+
+/** Call one tool. The key is `<module>.<tool>`, which is what a person types and what the account
  *  permits — one vocabulary, so a refusal names the thing they asked for. */
 export async function callTool(bus: Broker, key: string, args: unknown): Promise<unknown> {
   if (!key.includes(".")) {
@@ -104,18 +159,18 @@ export async function callTool(bus: Broker, key: string, args: unknown): Promise
  * Why a call failed, said so that the remedy is in the words.
  *
  * Three answers a person actually gets, and they need different things done: nobody serves that tool,
- * the mesh refused this person, or the tool itself failed. Without this they are one timeout and a
+ * the mesh refused this account, or the tool itself failed. Without this they are one timeout and a
  * stack trace.
  */
 export function whyItFailed(key: string, err: unknown): string {
   const message = err instanceof Error ? err.message : String(err);
   if (/no responders|503/i.test(message)) {
     return `nothing serves ${key}. The module may not be assigned to any machine, or it is down — ` +
-      "`mesh tools` lists what the catalogue says is there.";
+      "`mesh tools` lists what answered.";
   }
   if (/permissions violation|authorization/i.test(message)) {
-    return `this credential may not call ${key}. What it may call was fixed when it was issued; ` +
-      "`operator issue` again with the tool named, or ask somebody who can.";
+    return `this account may not call ${key}. What it may call was fixed when it was issued — a ` +
+      "person's by `operator issue`, the console's by its manifest.";
   }
   if (/timeout/i.test(message)) {
     return `${key} did not answer in time. Something is serving it, so this is the tool being slow ` +

src/http.ts

@@ -0,0 +1,165 @@
+/**
+ * The console's endpoint: MCP over HTTP, on a machine's loopback (novox/hq ADR 0152, design 34 §2).
+ *
+ * **Loopback is the authority boundary.** Whoever can connect is on the machine, and whoever is on the
+ * machine is the account that owns the mesh there (ADR 0034, ADR 0144). So there is no token and no
+ * login here, and the one thing this file enforces is that it binds nothing else: a console reachable
+ * from another machine would be authority over the mesh handed to whoever finds the port.
+ *
+ * The transport is the streamable-HTTP shape an agent host speaks: `POST /mcp` with one JSON-RPC
+ * message, answered with one JSON body. No session, because the surface holds nothing per caller; no
+ * event stream, because nothing here has anything to say unasked.
+ */
+import { createServer, type IncomingMessage, type ServerResponse } from "node:http";
+
+import type { Broker } from "@novox/mesh-sdk/messaging";
+
+import { mcpSurface, type Reply, type Request } from "./mcp.js";
+
+/** The most a request body may be. A tool's arguments are small; a megabyte is somebody else's file. */
+const BODY_LIMIT = 1 << 20;
+
+export interface Listening {
+  /** Where it listens, as `host:port`, with the port the machine actually gave. */
+  address: string;
+  close(): Promise<void>;
+}
+
+/** Hosts that are this machine and no other. */
+const loopback = new Set(["127.0.0.1", "::1", "localhost", "[::1]"]);
+
+/**
+ * Listen on `host:port`. Refused unless the host is loopback — said before binding, so a manifest or
+ * a flag that would open the console to a network is a startup failure rather than something
+ * discovered by whoever finds it.
+ */
+export async function serveMcpHttp(bus: Broker, who: string, listen: string): Promise<Listening> {
+  const at = listen.lastIndexOf(":");
+  if (at < 0) {
+    throw new Error(`"${listen}" is not host:port`);
+  }
+  const host = listen.slice(0, at);
+  const port = Number(listen.slice(at + 1));
+  if (!loopback.has(host)) {
+    throw new Error(
+      `the console listens on loopback and nowhere else (novox/hq ADR 0152): "${host}" is not this ` +
+        "machine's own address — whoever is on the machine owns the mesh there, and nobody else may reach this",
+    );
+  }
+  if (!Number.isInteger(port) || port < 0 || port > 65535) {
+    throw new Error(`"${listen.slice(at + 1)}" is not a port`);
+  }
+
+  const surface = mcpSurface(bus, who);
+  const server = createServer((req, res) => {
+    void route(req, res, surface.handle).catch((e) => {
+      json(res, 500, { jsonrpc: "2.0", id: null, error: { code: -32603, message: String(e) } });
+    });
+  });
+
+  await new Promise<void>((resolve, reject) => {
+    server.once("error", reject);
+    server.listen(port, host.replace(/^\[|\]$/g, ""), () => resolve());
+  });
+  const bound = server.address();
+  const address = typeof bound === "object" && bound ? `${host}:${bound.port}` : listen;
+  return {
+    address,
+    close: () =>
+      new Promise<void>((resolve) => {
+        server.close(() => resolve());
+      }),
+  };
+}
+
+async function route(
+  req: IncomingMessage,
+  res: ServerResponse,
+  handle: (r: Request) => Promise<Reply | undefined>,
+): Promise<void> {
+  const path = (req.url ?? "/").split("?")[0];
+  if (path === "/") {
+    res.writeHead(200, { "content-type": "text/plain; charset=utf-8" });
+    res.end("the mesh's console: MCP over HTTP at POST /mcp (novox/hq design 34)\n");
+    return;
+  }
+  if (path !== "/mcp") {
+    json(res, 404, { error: "the console serves /mcp and nothing else" });
+    return;
+  }
+  switch (req.method) {
+    case "POST":
+      break;
+    case "DELETE":
+      // A host ending a session. There is no session to end; saying so is the truthful answer.
+      res.writeHead(204).end();
+      return;
+    case "GET":
+      // A host opening an event stream. The console has nothing to say unasked.
+      res.writeHead(405, { allow: "POST, DELETE" }).end();
+      return;
+    default:
+      res.writeHead(405, { allow: "POST, DELETE" }).end();
+      return;
+  }
+
+  let body: string;
+  try {
+    body = await read(req);
+  } catch (e) {
+    json(res, 413, { jsonrpc: "2.0", id: null, error: { code: -32600, message: String(e) } });
+    return;
+  }
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(body);
+  } catch {
+    json(res, 400, { jsonrpc: "2.0", id: null, error: { code: -32700, message: "the body is not JSON" } });
+    return;
+  }
+
+  // One message, or a batch of them; a batch is answered as a batch. A notification gets no reply
+  // and, alone, no body: 202 is how the transport says "heard".
+  if (Array.isArray(parsed)) {
+    const replies = (await Promise.all(parsed.map((r) => handle(r as Request)))).filter(Boolean);
+    if (replies.length === 0) {
+      res.writeHead(202).end();
+    } else {
+      json(res, 200, replies);
+    }
+    return;
+  }
+  const reply = await handle(parsed as Request);
+  if (!reply) {
+    res.writeHead(202).end();
+    return;
+  }
+  json(res, 200, reply);
+}
+
+function read(req: IncomingMessage): Promise<string> {
+  return new Promise((resolve, reject) => {
+    let size = 0;
+    const chunks: Buffer[] = [];
+    req.on("data", (chunk: Buffer) => {
+      size += chunk.length;
+      if (size > BODY_LIMIT) {
+        reject(new Error(`the request is larger than ${BODY_LIMIT} bytes`));
+        req.destroy();
+        return;
+      }
+      chunks.push(chunk);
+    });
+    req.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")));
+    req.on("error", reject);
+  });
+}
+
+function json(res: ServerResponse, status: number, body: unknown): void {
+  const text = JSON.stringify(body);
+  res.writeHead(status, {
+    "content-type": "application/json; charset=utf-8",
+    "content-length": Buffer.byteLength(text),
+  });
+  res.end(text);
+}

src/mcp.ts

@@ -1,47 +1,179 @@
 /**
- * The mesh's tools as an MCP server, over stdio (novox/hq design 25 §7).
+ * The mesh's tools as an MCP server (novox/hq design 25 §7, design 34).
  *
- * **A thin adapter and nothing more.** Every tool an agent sees is one the catalogue listed and one
- * this credential may call; the schema is the module's own; the answer is the module's own. Nothing
- * here decides anything, which is why it is short — an MCP surface that reshaped arguments or
- * summarised answers would be a second definition of what a tool is, and the module's manifest is the
- * first.
+ * **A thin adapter and nothing more.** Every tool an agent sees is one a module answered for and one
+ * this account may call; the schema is the module's own; the answer is the module's own. Nothing here
+ * decides anything, which is why it is short — an MCP surface that reshaped arguments or summarised
+ * answers would be a second definition of what a tool is, and the module's code is the first.
  *
  * Implemented against the protocol directly rather than through a library: the surface is three
- * methods and one framing, and a dependency here would be a dependency on every workstation.
+ * methods and one framing, and a dependency here would be a dependency on every machine.
+ *
+ * One handler, two transports. Over stdio for a program a person starts (`mesh mcp`), over HTTP on a
+ * machine's loopback for the console the mesh assigns there (`mesh serve`, http.ts). The handler does
+ * not know which asked.
  */
 import type { Broker } from "@novox/mesh-sdk/messaging";
 
-import { callTool, toolsOn, whyItFailed, type Tool } from "./client.js";
+import { callTool, toolsOn, whyItFailed, type Listing } from "./client.js";
 
 /** The protocol version this speaks. Stated, because a host that wants another should be told so
  *  rather than discovering it through a shape it did not expect. */
-const PROTOCOL = "2024-11-05";
+export const PROTOCOL = "2025-03-26";
 
-interface Request {
+export interface Request {
   jsonrpc: string;
   id?: number | string | null;
   method: string;
   params?: Record<string, unknown>;
 }
 
+export interface Reply {
+  jsonrpc: "2.0";
+  id: Request["id"];
+  result?: unknown;
+  error?: { code: number; message: string };
+}
+
+/** How long a fetched tool list is kept before the modules are asked again. An agent asks on every
+ *  turn; the mesh changes on the order of minutes. */
+export const LISTING_KEPT_MS = 30_000;
+
+export interface Surface {
+  /** Answer one request; undefined for a notification, which expects none. */
+  handle(request: Request): Promise<Reply | undefined>;
+}
+
 /**
- * Serve until stdin closes, which is how a host ends a session.
+ * The surface over one bus connection, as one account.
  *
- * The tool list is fetched once, on the first `tools/list`, and kept. An agent asks for it repeatedly
- * and the catalogue's answer does not change mid-session; refetching would make every turn cost a
- * round trip to a module for something nobody changed.
+ * The tool list is fetched when first asked and kept for a short while (design 34 §3): asking every
+ * module on every `tools/list` would fan out on every agent turn for something nobody changed, and
+ * never refreshing would hide a module assigned a moment ago.
+ */
+export function mcpSurface(bus: Broker, who: string): Surface {
+  let known: { listing: Listing; at: number } | undefined;
+
+  const answer = (id: Request["id"], result: unknown): Reply => ({ jsonrpc: "2.0", id, result });
+  const refuse = (id: Request["id"], code: number, message: string): Reply => ({
+    jsonrpc: "2.0",
+    id,
+    error: { code, message },
+  });
+
+  const listing = async (): Promise<Listing> => {
+    if (!known || Date.now() - known.at > LISTING_KEPT_MS) {
+      known = { listing: await toolsOn(bus), at: Date.now() };
+    }
+    return known.listing;
+  };
+
+  return {
+    async handle(request) {
+      // A notification has no id and expects no answer; `initialized` is the one every host sends.
+      const notification = request.id === undefined || request.id === null;
+
+      switch (request.method) {
+        case "initialize":
+          return answer(request.id, {
+            protocolVersion: PROTOCOL,
+            capabilities: { tools: {} },
+            serverInfo: { name: "mesh", version: "1" },
+            // Said in the handshake, because an agent that knows whose authority it is acting under
+            // can say so when a call is refused — and a refusal is the one thing here that is not
+            // the mesh's fault or the tool's.
+            instructions:
+              `These are the tools of a Novox mesh, reached as ${who}. Every call goes to the module ` +
+              `that serves it; what may be called was fixed when this account was issued, so a ` +
+              `refusal means the account, not the tool. The list is what the running modules ` +
+              `answered; a module that did not answer is named in the list's _meta and can still be ` +
+              `called by <module>.<tool>. The mesh's own verbs (status, push, assign) are not served ` +
+              `on the bus yet.`,
+          });
+
+        case "notifications/initialized":
+          return undefined;
+
+        case "ping":
+          return notification ? undefined : answer(request.id, {});
+
+        case "tools/list": {
+          let have: Listing;
+          try {
+            have = await listing();
+          } catch (e) {
+            return refuse(request.id, -32603, whyItFailed("mesh-catalog.catalog_modules", e));
+          }
+          return answer(request.id, {
+            tools: have.tools.map((t) => ({
+              name: `${t.module}.${t.name}`,
+              description: t.description ?? `${t.name}, served by ${t.module}`,
+              // The module's own schema, passed through. An empty object is a tool that takes
+              // nothing, which is a real answer and not a missing one.
+              inputSchema: asSchema(t.input),
+            })),
+            // Silence, named (design 34 §3): the modules the catalogue holds and nothing answered
+            // for. Not a tool, so not in `tools`; not dropped either.
+            _meta: { notAnswering: have.notAnswering },
+          });
+        }
+
+        case "tools/call": {
+          const name = String(request.params?.name ?? "");
+          const args = request.params?.arguments ?? {};
+          try {
+            const result = await callTool(bus, name, args);
+            // Text, because that is what every host renders. The content is the module's answer
+            // as JSON, unshaped: an adapter that flattened it would be deciding what matters in
+            // somebody else's answer.
+            return answer(request.id, {
+              content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
+            });
+          } catch (e) {
+            // **An error the agent can act on, not a stack.** isError rather than a protocol
+            // failure, because the call was well-formed and the mesh answered it — with a refusal,
+            // an absence or a fault, and the words say which.
+            return answer(request.id, {
+              content: [{ type: "text", text: whyItFailed(name, e) }],
+              isError: true,
+            });
+          }
+        }
+
+        default:
+          return notification ? undefined : refuse(request.id, -32601, `mesh's MCP surface has no ${request.method}`);
+      }
+    },
+  };
+}
+
+/**
+ * A module's declared input as a JSON schema an agent can read.
+ *
+ * The sdk keeps a tool's input opaque, and the catalogue's modules write it as a bare map of
+ * property to description — `{ module: { type, description } }` — which is the `properties` of a
+ * schema rather than a schema. Wrapped here when that is what arrived; passed through when a module
+ * already wrote a schema; an empty object when it declared nothing. The module's words are kept
+ * either way.
+ */
+export function asSchema(input: unknown): Record<string, unknown> {
+  if (!input || typeof input !== "object" || Array.isArray(input)) {
+    return { type: "object", properties: {} };
+  }
+  const given = input as Record<string, unknown>;
+  if (given.type === "object" || "properties" in given) return given;
+  if (Object.keys(given).length === 0) return { type: "object", properties: {} };
+  return { type: "object", properties: given };
+}
+
+/**
+ * Serve over stdio until stdin closes, which is how a host ends a session.
  */
 export async function serveMcp(bus: Broker, who: string): Promise<void> {
-  let known: Tool[] | undefined;
-
+  const surface = mcpSurface(bus, who);
   const say = (message: unknown) => {
     process.stdout.write(`${JSON.stringify(message)}\n`);
   };
-  const answer = (id: Request["id"], result: unknown) => say({ jsonrpc: "2.0", id, result });
-  const refuse = (id: Request["id"], code: number, message: string) =>
-    say({ jsonrpc: "2.0", id, error: { code, message } });
-
   for await (const line of lines()) {
     let request: Request;
     try {
@@ -51,75 +183,8 @@ export async function serveMcp(bus: Broker, who: string): Promise<void> {
       // reply to a request that was never framed is noise on the same channel.
       continue;
     }
-    // A notification has no id and expects no answer; `initialized` is the one every host sends.
-    const notification = request.id === undefined || request.id === null;
-
-    switch (request.method) {
-      case "initialize":
-        answer(request.id, {
-          protocolVersion: PROTOCOL,
-          capabilities: { tools: {} },
-          serverInfo: { name: "mesh", version: "1" },
-          // Said in the handshake, because an agent that knows whose authority it is acting under can
-          // say so when a call is refused — and a refusal is the one thing here that is not the
-          // mesh's fault or the tool's.
-          instructions:
-            `These are the tools of a Novox mesh, reached as ${who}. Every call goes to the module ` +
-            `that serves it; what may be called was fixed when this credential was issued, so a ` +
-            `refusal means the credential, not the tool.`,
-        });
-        break;
-
-      case "notifications/initialized":
-        break;
-
-      case "tools/list": {
-        try {
-          known ??= await toolsOn(bus);
-        } catch (e) {
-          refuse(request.id, -32603, whyItFailed("mesh-catalog.catalog_tools", e));
-          break;
-        }
-        answer(request.id, {
-          tools: known.map((t) => ({
-            name: `${t.module}.${t.name}`,
-            description: t.description ?? `${t.name}, served by ${t.module}`,
-            // The module's own schema, passed through. An empty object is a tool that takes nothing,
-            // which is a real answer and not a missing one.
-            inputSchema: t.input ?? { type: "object", properties: {} },
-          })),
-        });
-        break;
-      }
-
-      case "tools/call": {
-        const name = String(request.params?.name ?? "");
-        const args = request.params?.arguments ?? {};
-        try {
-          const result = await callTool(bus, name, args);
-          // Text, because that is what every host renders. The content is the module's answer as
-          // JSON, unshaped: an adapter that flattened it would be deciding what matters in somebody
-          // else's answer.
-          answer(request.id, {
-            content: [{ type: "text", text: JSON.stringify(result, null, 2) }],
-          });
-        } catch (e) {
-          // **An error the agent can act on, not a stack.** isError rather than a protocol failure,
-          // because the call was well-formed and the mesh answered it — with a refusal, an absence or
-          // a fault, and the words say which.
-          answer(request.id, {
-            content: [{ type: "text", text: whyItFailed(name, e) }],
-            isError: true,
-          });
-        }
-        break;
-      }
-
-      default:
-        if (!notification) {
-          refuse(request.id, -32601, `mesh's MCP surface has no ${request.method}`);
-        }
-    }
+    const reply = await surface.handle(request);
+    if (reply) say(reply);
   }
 }
 

src/mesh.ts

@@ -1,63 +1,100 @@
 #!/usr/bin/env node
 /**
- * `mesh` — the mesh's tools from a workstation, for a person (novox/hq design 25 §7).
+ * `mesh` — the mesh's tools, for whoever is on a machine (novox/hq design 25 §7, design 34).
  *
- * Three verbs and nothing else. What tools are there, call one, and serve the same two to an agent
- * over MCP. Deliberately thin: everything that could be a decision is one the mesh already made, and a
- * client that grew opinions would be a second place the mesh's behaviour is defined.
+ * Four verbs and nothing else. What tools are there, call one, serve the same two to an agent over
+ * stdio, and serve them on a machine's loopback as the console the mesh assigns. Deliberately thin:
+ * everything that could be a decision is one the mesh already made, and a client that grew opinions
+ * would be a second place the mesh's behaviour is defined.
  *
- *     mesh tools                        what this credential may call
+ *     mesh tools                        what the running modules answer
  *     mesh call <module>.<tool> [json]  call one, arguments as JSON on the command line or on stdin
- *     mesh mcp                          the same, as an MCP server over stdio
+ *     mesh mcp                          the same two, as an MCP server over stdio
+ *     mesh serve [--listen host:port]   the console: MCP over HTTP on this machine's loopback
  *
- * The credential comes from MESH_CREDENTIAL, or --credential. It is the JSON `operator issue` printed.
+ * Who it speaks as, in order of preference:
+ *   MESH_BROKER_FILE     the module credential the mesh delivered — the console's (ADR 0152)
+ *   MESH_CREDENTIAL / --credential <file>   a person's, as `operator issue` printed it (design 25 §7)
+ *   MESH_CONSOLE / --console <url>          no credential: `tools` and `call` go through a console
+ *                                           already running on this machine, over loopback HTTP
  */
 import { readFile } from "node:fs/promises";
 
-import { callTool, connectAs, credentialFrom, toolsOn, whyItFailed, type Tool } from "./client.js";
+import type { Broker } from "@novox/mesh-sdk/messaging";
+
+import {
+  callTool,
+  connectAs,
+  connectAsTheConsole,
+  credentialFrom,
+  toolsOn,
+  whyItFailed,
+  type Listing,
+} from "./client.js";
+import { serveMcpHttp } from "./http.js";
 import { serveMcp } from "./mcp.js";
 
 const usage = `mesh tools
 mesh call <module>.<tool> [json]
 mesh mcp
+mesh serve [--listen host:port]
 
-  --credential <file>   the JSON \`operator issue\` printed; default $MESH_CREDENTIAL`;
+  --credential <file>   a person's credential, the JSON \`operator issue\` printed; default $MESH_CREDENTIAL
+  --console <url>       a console on this machine to ask through instead; default $MESH_CONSOLE
+  --listen <host:port>  where \`serve\` listens; loopback only; default $MESH_CONSOLE_LISTEN or 127.0.0.1:4270
+  MESH_BROKER_FILE      the module credential the mesh delivered, which \`serve\` runs on`;
+
+/** What the console listens on when nothing says otherwise. */
+const DEFAULT_LISTEN = "127.0.0.1:4270";
 
 async function main(argv: string[]): Promise<number> {
   const args = [...argv];
   let credentialPath = process.env.MESH_CREDENTIAL ?? "";
+  let consoleUrl = process.env.MESH_CONSOLE ?? "";
+  let listen = process.env.MESH_CONSOLE_LISTEN ?? DEFAULT_LISTEN;
   for (let i = 0; i < args.length; i++) {
-    if (args[i] === "--credential") {
-      credentialPath = args[i + 1] ?? "";
+    const take = () => {
+      const v = args[i + 1] ?? "";
       args.splice(i, 2);
       i--;
-    }
+      return v;
+    };
+    if (args[i] === "--credential") credentialPath = take();
+    else if (args[i] === "--console") consoleUrl = take();
+    else if (args[i] === "--listen") listen = take();
   }
   const verb = args.shift();
   if (!verb || verb === "help" || verb === "--help") {
     console.log(usage);
     return verb ? 0 : 1;
   }
-  if (!credentialPath) {
-    console.error(
-      "no credential: set MESH_CREDENTIAL or pass --credential <file>. It is the JSON " +
-        "`operator issue` printed, saved verbatim.",
-    );
-    return 1;
+
+  // Through a console already on this machine: no credential to hold, which is the point of one.
+  if (consoleUrl && (verb === "tools" || verb === "call")) {
+    return verb === "tools" ? listingVia(consoleUrl) : callingVia(consoleUrl, args);
   }
 
-  const held = await credentialFrom(credentialPath);
-  const bus = await connectAs(held);
+  const { bus, who } = await connecting(credentialPath, verb);
   try {
     switch (verb) {
       case "tools":
-        return await listing(bus, held.person);
+        return await listing(bus, who);
       case "call":
         return await calling(bus, args);
       case "mcp":
         // Serves until stdin closes, which is how an MCP host ends a session.
-        await serveMcp(bus, held.person ?? held.user ?? "somebody");
+        await serveMcp(bus, who);
         return 0;
+      case "serve": {
+        const up = await serveMcpHttp(bus, who, listen);
+        console.log(`mesh console listening on http://${up.address}/mcp as ${who}`);
+        await new Promise<void>((resolve) => {
+          process.once("SIGTERM", () => resolve());
+          process.once("SIGINT", () => resolve());
+        });
+        await up.close();
+        return 0;
+      }
       default:
         console.error(`mesh has no "${verb}".\n\n${usage}`);
         return 1;
@@ -67,50 +104,70 @@ async function main(argv: string[]): Promise<number> {
   }
 }
 
-async function listing(bus: Awaited<ReturnType<typeof connectAs>>, who?: string): Promise<number> {
-  let tools: Tool[];
-  try {
-    tools = await toolsOn(bus);
-  } catch (e) {
-    console.error(whyItFailed("mesh-catalog.catalog_tools", e));
-    return 1;
+/**
+ * Who this process is on the bus. The module credential first: a console is started by the mesh with
+ * MESH_BROKER_FILE and nothing else, and must not fall back to a person's file lying around.
+ */
+async function connecting(credentialPath: string, verb: string): Promise<{ bus: Broker; who: string }> {
+  const delivered = process.env.MESH_BROKER_FILE;
+  if (delivered) {
+    return connectAsTheConsole(delivered);
   }
-  if (tools.length === 0) {
-    console.log("the catalogue lists no tools; nothing on this mesh serves any");
-    return 0;
+  if (!credentialPath) {
+    throw new Error(
+      verb === "serve"
+        ? "no credential: the console runs on MESH_BROKER_FILE, the module credential the mesh " +
+          "delivered; to run it by hand, pass --credential <file> with a person's credential"
+        : "no credential: set MESH_CREDENTIAL or pass --credential <file> (the JSON `operator issue` " +
+          "printed, saved verbatim), or --console <url> to ask through a console on this machine",
+    );
   }
-  // **What the catalogue has, not what this credential may call.** The two differ and the difference
-  // is the point: a person seeing only their own tools cannot tell "not installed" from "not yours",
-  // and those need different people to fix them.
-  for (const t of tools) {
+  const held = await credentialFrom(credentialPath);
+  return { bus: await connectAs(held), who: held.person ?? held.user ?? "somebody" };
+}
+
+function printListing(have: Listing, who?: string): void {
+  if (have.tools.length === 0) {
+    console.log("no running module answered with any tool");
+  }
+  // **What the modules answered, not what this account may call.** The two differ and the
+  // difference is the point: an account seeing only its own tools cannot tell "not installed" from
+  // "not yours", and those need different people to fix them.
+  for (const t of have.tools) {
     const name = `${t.module}.${t.name}`;
     console.log(t.description ? `${name.padEnd(36)} ${t.description}` : name);
   }
-  if (who) {
-    console.log(`\nthis is what the mesh has. What ${who} may call was fixed when the credential was issued.`);
+  if (have.notAnswering.length > 0) {
+    console.log(
+      `\nheld by the mesh and not answering: ${have.notAnswering.join(", ")} — not assigned, not up, ` +
+        "or built before the runtime answered `tools`; each can still be called by name",
+    );
   }
+  if (who) {
+    console.log(`\nasked as ${who}; what ${who} may call was fixed when the account was issued.`);
+  }
+}
+
+async function listing(bus: Broker, who?: string): Promise<number> {
+  let have: Listing;
+  try {
+    have = await toolsOn(bus);
+  } catch (e) {
+    console.error(whyItFailed("mesh-catalog.catalog_modules", e));
+    return 1;
+  }
+  printListing(have, who);
   return 0;
 }
 
-async function calling(
-  bus: Awaited<ReturnType<typeof connectAs>>,
-  args: string[],
-): Promise<number> {
+async function calling(bus: Broker, args: string[]): Promise<number> {
   const key = args.shift();
   if (!key) {
     console.error("mesh call <module>.<tool> [json]");
     return 1;
   }
-  const raw = args.length > 0 ? args.join(" ") : await maybeStdin();
-  let parsed: unknown = {};
-  if (raw.trim() !== "") {
-    try {
-      parsed = JSON.parse(raw);
-    } catch (e) {
-      console.error(`the arguments are not JSON: ${(e as Error).message}`);
-      return 1;
-    }
-  }
+  const parsed = await argumentsFrom(args);
+  if (parsed === undefined) return 1;
   try {
     const answer = await callTool(bus, key, parsed);
     console.log(JSON.stringify(answer, null, 2));
@@ -121,6 +178,76 @@ async function calling(
   }
 }
 
+/** The console's answer to one MCP request, over loopback HTTP. */
+async function viaConsole(consoleUrl: string, method: string, params?: unknown): Promise<any> {
+  const endpoint = consoleUrl.endsWith("/mcp") ? consoleUrl : `${consoleUrl.replace(/\/$/, "")}/mcp`;
+  const res = await fetch(endpoint, {
+    method: "POST",
+    headers: { "content-type": "application/json", accept: "application/json" },
+    body: JSON.stringify({ jsonrpc: "2.0", id: 1, method, params }),
+  });
+  if (!res.ok) {
+    throw new Error(`the console at ${endpoint} answered ${res.status}`);
+  }
+  const reply = (await res.json()) as { result?: any; error?: { message: string } };
+  if (reply.error) throw new Error(reply.error.message);
+  return reply.result;
+}
+
+async function listingVia(consoleUrl: string): Promise<number> {
+  try {
+    const result = await viaConsole(consoleUrl, "tools/list");
+    const have: Listing = {
+      tools: (result.tools ?? []).map((t: { name: string; description?: string; inputSchema?: unknown }) => {
+        const at = t.name.indexOf(".");
+        return { module: t.name.slice(0, at), name: t.name.slice(at + 1), description: t.description, input: t.inputSchema };
+      }),
+      notAnswering: result._meta?.notAnswering ?? [],
+    };
+    printListing(have);
+    return 0;
+  } catch (e) {
+    console.error(e instanceof Error ? e.message : String(e));
+    return 1;
+  }
+}
+
+async function callingVia(consoleUrl: string, args: string[]): Promise<number> {
+  const key = args.shift();
+  if (!key) {
+    console.error("mesh call <module>.<tool> [json]");
+    return 1;
+  }
+  const parsed = await argumentsFrom(args);
+  if (parsed === undefined) return 1;
+  try {
+    const result = await viaConsole(consoleUrl, "tools/call", { name: key, arguments: parsed });
+    const text = result?.content?.[0]?.text ?? JSON.stringify(result);
+    if (result?.isError) {
+      console.error(text);
+      return 1;
+    }
+    console.log(text);
+    return 0;
+  } catch (e) {
+    console.error(e instanceof Error ? e.message : String(e));
+    return 1;
+  }
+}
+
+/** A call's arguments: JSON on the command line, else on stdin, else nothing. Undefined when what
+ *  was given is not JSON, after saying so. */
+async function argumentsFrom(args: string[]): Promise<unknown> {
+  const raw = args.length > 0 ? args.join(" ") : await maybeStdin();
+  if (raw.trim() === "") return {};
+  try {
+    return JSON.parse(raw);
+  } catch (e) {
+    console.error(`the arguments are not JSON: ${(e as Error).message}`);
+    return undefined;
+  }
+}
+
 /** Arguments on stdin, for a call whose JSON is too long or too quoted to type. Empty when stdin is a
  *  terminal, so `mesh call x.y` with no arguments does not hang waiting for something nobody is
  *  typing. */

src/runtime.ts

@@ -6,9 +6,22 @@
 import { pathToFileURL } from "node:url";
 import { resolve } from "node:path";
 import { useBroker } from "@novox/mesh-sdk/messaging";
-import { serveTools, listTools } from "@novox/mesh-sdk/tools";
+import { collectTools, serveTools, listTools, toolKey } from "@novox/mesh-sdk/tools";
 import type { Broker } from "@novox/mesh-sdk/messaging";
 
+/**
+ * The one verb every module's runtime answers for it (novox/hq ADR 0152, design 34 §3): the
+ * module's tool names, descriptions and argument schemas, from the code that answers them and
+ * from nowhere else. Discovery asks the module, because a copy kept anywhere else drifts.
+ */
+export const TOOLS_VERB = "tools";
+
+/** What `tools` answers for one module. */
+export interface ToolsAnswer {
+  module: string;
+  tools: { name: string; description: string; input: Readonly<Record<string, unknown>> }[];
+}
+
 export interface RuntimeOptions {
   /** The mesh broker to serve over. */
   broker: Broker;
@@ -30,6 +43,29 @@ export async function runTools(opts: RuntimeOptions): Promise<() => void> {
   // runtime that always served would fail for exactly the modules that never needed it.
   const tools = listTools();
   const stop = tools.length > 0 ? await serveTools(opts.broker) : () => {};
+
+  // And, for every module that serves any, the verb that says what it serves. Refused before
+  // anything is bound if a module named a tool of its own `tools`: one name answering two things
+  // is the fault nobody can diagnose afterwards, and the runtime is the only place that sees both.
+  const stops: Array<() => void> = [stop];
+  for (const { module, tools: own } of collectTools()) {
+    if (own.length === 0) continue;
+    if (own.some((t) => t.name === TOOLS_VERB)) {
+      stop();
+      throw new Error(
+        `${module} names a tool "${TOOLS_VERB}", which is the verb the runtime answers for every ` +
+          "module with what it serves (novox/hq ADR 0152) — refused, rename it",
+      );
+    }
+    const answer: ToolsAnswer = {
+      module,
+      tools: own.map((t) => ({ name: t.name, description: t.description, input: t.input })),
+    };
+    stops.push(await opts.broker.handle(toolKey(module, TOOLS_VERB), async () => answer));
+  }
+
   console.log(`[mesh-tools] serving ${tools.length} tool(s): ${tools.map((t) => t.name).join(", ") || "(none)"}`);
-  return stop;
+  return () => {
+    for (const s of stops) s();
+  };
 }

test/client.test.ts

@@ -18,16 +18,22 @@ import { callTool, toolsOn, whyItFailed } from "../dist/client.js";
 
 const url = process.env.MESH_TEST_NATS;
 
-/** A module serving the catalogue's tool list and one tool of its own, so the client has a mesh to
- *  talk to. Two connections, because a person and a module are different users even in a test. */
+/** A mesh as discovery sees it (design 34 §3): the catalogue holding three modules, two of them up
+ *  and answering `tools`, one held and not running. Two connections, because a person and a module
+ *  are different users even in a test. */
 async function aMeshWithTools() {
   const catalogue = await connectNats({ url: url!, module: "mesh-catalog" });
   const shop = await connectNats({ url: url!, module: "shop" });
-  await catalogue.handle("catalog_tools", async () => ({
-    tools: [
-      { module: "shop", name: "price", description: "what something costs", input: { type: "object" } },
-      { module: "mesh-catalog", name: "catalog_tools", description: "what tools the mesh has" },
-    ],
+  await catalogue.handle("catalog_modules", async () => ({
+    modules: [{ module: "shop" }, { module: "mesh-catalog" }, { module: "ghost" }],
+  }));
+  await catalogue.handle("tools", async () => ({
+    module: "mesh-catalog",
+    tools: [{ name: "catalog_modules", description: "what modules the mesh has", input: {} }],
+  }));
+  await shop.handle("tools", async () => ({
+    module: "shop",
+    tools: [{ name: "price", description: "what something costs", input: { type: "object" } }],
   }));
   await shop.handle("price", async (body: { of?: string }) => ({ of: body.of ?? "nothing", cost: 12 }));
   return {
@@ -38,17 +44,22 @@ async function aMeshWithTools() {
   };
 }
 
-test("a person sees what the catalogue says the mesh has, sorted", async (t) => {
+test("a person sees what the running modules answer, sorted, and who did not answer", async (t) => {
   if (!url) return t.skip("MESH_TEST_NATS unset");
   const mesh = await aMeshWithTools();
   const person = await connectNats({ url, module: "person.ada" });
   try {
-    const tools = await toolsOn(person);
+    const began = Date.now();
+    const have = await toolsOn(person);
     assert.deepEqual(
-      tools.map((x) => `${x.module}.${x.name}`),
-      ["mesh-catalog.catalog_tools", "shop.price"],
-      "the list is what the catalogue answered, in a stable order",
+      have.tools.map((x) => `${x.module}.${x.name}`),
+      ["mesh-catalog.catalog_modules", "shop.price"],
+      "the list is what the modules answered, in a stable order",
     );
+    // Silence is named, never dropped: a module the catalogue holds and nothing answered for.
+    assert.deepEqual(have.notAnswering, ["ghost"]);
+    // And at once: a module that is not running costs nothing, or the list is unusable.
+    assert.ok(Date.now() - began < 5_000, "an absent module waited out the timeout");
   } finally {
     await person.close();
     await mesh.close();

test/fixtures/clash-tools.mjs

@@ -0,0 +1,6 @@
+// A module naming a tool after the verb the runtime answers for every module — refused at load.
+import { registerModuleTools } from "@novox/mesh-sdk/tools";
+
+registerModuleTools("clash", () => [
+  { name: "tools", description: "mine, not the runtime's", input: {}, run: async () => ({}) },
+]);

test/fixtures/shop-tools.mjs

@@ -0,0 +1,12 @@
+// A module's tool entrypoint, as the runtime imports one: registers and returns.
+import { registerModuleTools } from "@novox/mesh-sdk/tools";
+
+registerModuleTools("shop", () => [
+  {
+    name: "price",
+    description: "what something costs",
+    input: { of: { type: "string", description: "the thing" } },
+    run: async (args) => ({ of: args.of ?? "nothing", cost: 12 }),
+  },
+  { name: "refund", description: "give it back", input: {}, run: async () => ({ done: true }) },
+]);

test/http.test.ts

@@ -0,0 +1,113 @@
+/**
+ * The console: the same surface over HTTP on loopback, started the way the mesh starts it — on the
+ * module credential in MESH_BROKER_FILE (novox/hq ADR 0152, design 34 §2).
+ *
+ *   docker run -d --rm --name t -p 14232:4222 nats:2.10-alpine -js
+ *   MESH_TEST_NATS=nats://127.0.0.1:14232 node --test --experimental-strip-types test/http.test.ts
+ */
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { spawn, type ChildProcess } from "node:child_process";
+import { mkdtemp, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+
+import { connectNats } from "../dist/broker-nats.js";
+import { serveMcpHttp } from "../dist/http.js";
+
+const url = process.env.MESH_TEST_NATS;
+
+async function aMesh(t: { after: (fn: () => Promise<void> | void) => void }) {
+  const catalogue = await connectNats({ url: url!, module: "mesh-catalog" });
+  const shop = await connectNats({ url: url!, module: "shop" });
+  await catalogue.handle("catalog_modules", async () => ({ modules: [{ module: "shop" }] }));
+  await shop.handle("tools", async () => ({
+    module: "shop",
+    tools: [{ name: "price", description: "what something costs", input: {} }],
+  }));
+  await shop.handle("price", async (body: { of?: string }) => ({ of: body.of ?? "nothing", cost: 12 }));
+  t.after(async () => {
+    await catalogue.close();
+    await shop.close();
+  });
+}
+
+/** `mesh serve` as the mesh runs it: MESH_BROKER_FILE, a listen address, nothing else. */
+async function aConsole(t: { after: (fn: () => Promise<void> | void) => void }): Promise<string> {
+  const dir = await mkdtemp("/tmp/mesh-console-");
+  const credential = join(dir, "broker");
+  await writeFile(credential, JSON.stringify({ url, node: "desk", module: "mesh-console", user: "desk.mesh-console", password: "x" }));
+  const child: ChildProcess = spawn(process.execPath, ["dist/mesh.js", "serve", "--listen", "127.0.0.1:0"], {
+    env: { ...process.env, MESH_BROKER_FILE: credential, MESH_CREDENTIAL: "" },
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+  t.after(() => {
+    child.kill("SIGTERM");
+  });
+  return new Promise((resolve, reject) => {
+    let out = "";
+    let err = "";
+    child.stdout!.on("data", (d) => {
+      out += d.toString();
+      const m = /listening on (http:\/\/[^/]+\/mcp)/.exec(out);
+      if (m) resolve(m[1]!);
+    });
+    child.stderr!.on("data", (d) => (err += d.toString()));
+    child.on("exit", (code) => reject(new Error(`serve exited ${code}: ${err}`)));
+  });
+}
+
+async function post(endpoint: string, body: unknown): Promise<{ status: number; json?: any }> {
+  const res = await fetch(endpoint, {
+    method: "POST",
+    headers: { "content-type": "application/json", accept: "application/json" },
+    body: JSON.stringify(body),
+  });
+  const text = await res.text();
+  return { status: res.status, json: text ? JSON.parse(text) : undefined };
+}
+
+test("the console answers a host on loopback, as the account the mesh gave it", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  await aMesh(t);
+  const endpoint = await aConsole(t);
+
+  const hello = await post(endpoint, { jsonrpc: "2.0", id: 1, method: "initialize", params: {} });
+  assert.equal(hello.status, 200);
+  assert.match(hello.json.result.instructions, /desk\.mesh-console/, "the handshake names the console's account");
+
+  const heard = await post(endpoint, { jsonrpc: "2.0", method: "notifications/initialized" });
+  assert.equal(heard.status, 202, "a notification is heard and not answered");
+
+  const listed = await post(endpoint, { jsonrpc: "2.0", id: 2, method: "tools/list" });
+  assert.deepEqual(listed.json.result.tools.map((x: { name: string }) => x.name), ["shop.price"]);
+
+  const called = await post(endpoint, {
+    jsonrpc: "2.0", id: 3, method: "tools/call", params: { name: "shop.price", arguments: { of: "a hat" } },
+  });
+  assert.deepEqual(JSON.parse(called.json.result.content[0].text), { of: "a hat", cost: 12 });
+
+  // A person's client through the same endpoint, with no credential of its own.
+  const { main } = await import("../dist/mesh.js");
+  const logged: string[] = [];
+  const was = console.log;
+  console.log = (line: string) => logged.push(String(line));
+  try {
+    assert.equal(await main(["tools", "--console", endpoint]), 0);
+  } finally {
+    console.log = was;
+  }
+  assert.ok(logged.some((l) => l.startsWith("shop.price")), `the client did not list through the console: ${logged}`);
+});
+
+test("the console binds loopback and nowhere else", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  const bus = await connectNats({ url, module: "mesh-console", node: "desk" });
+  try {
+    await assert.rejects(() => serveMcpHttp(bus, "desk.mesh-console", "0.0.0.0:0"), /loopback and nowhere else/);
+    const up = await serveMcpHttp(bus, "desk.mesh-console", "127.0.0.1:0");
+    assert.match(up.address, /^127\.0\.0\.1:\d+$/);
+    await up.close();
+  } finally {
+    await bus.close();
+  }
+});

test/mcp.test.ts

@@ -20,8 +20,12 @@ const url = process.env.MESH_TEST_NATS;
 async function aMeshAndACredential(t: { after: (fn: () => Promise<void> | void) => void }) {
   const catalogue = await connectNats({ url: url!, module: "mesh-catalog" });
   const shop = await connectNats({ url: url!, module: "shop" });
-  await catalogue.handle("catalog_tools", async () => ({
-    tools: [{ module: "shop", name: "price", description: "what something costs" }],
+  await catalogue.handle("catalog_modules", async () => ({
+    modules: [{ module: "shop" }, { module: "ghost" }],
+  }));
+  await shop.handle("tools", async () => ({
+    module: "shop",
+    tools: [{ name: "price", description: "what something costs", input: { of: { type: "string" } } }],
   }));
   await shop.handle("price", async (body: { of?: string }) => ({ of: body.of ?? "nothing", cost: 12 }));
   t.after(async () => {
@@ -80,7 +84,7 @@ test("a host initialises, lists the mesh's tools and calls one", async (t) => {
   assert.equal(replies.length, 3, `expected three replies, got ${JSON.stringify(replies)}`);
 
   const hello = byId.get(1)!.result;
-  assert.equal(hello.protocolVersion, "2024-11-05");
+  assert.equal(hello.protocolVersion, "2025-03-26");
   assert.ok(hello.capabilities.tools, "a server offering no tools is not this one");
   assert.match(hello.instructions, /ada/, "the handshake says whose authority a call is made under");
 
@@ -88,6 +92,10 @@ test("a host initialises, lists the mesh's tools and calls one", async (t) => {
   assert.equal(listed.length, 1);
   assert.equal(listed[0].name, "shop.price", "a tool is named the way a person names it");
   assert.ok(listed[0].inputSchema, "a tool with no schema is one an agent cannot call");
+  // A module's bare property map arrives as a schema an agent can read, its words kept.
+  assert.deepEqual(listed[0].inputSchema, { type: "object", properties: { of: { type: "string" } } });
+  // Silence is named: the module the catalogue holds and nothing answered for.
+  assert.deepEqual(byId.get(2)!.result._meta.notAnswering, ["ghost"]);
 
   const called = byId.get(3)!.result;
   assert.ok(!called.isError, `the call failed: ${JSON.stringify(called)}`);

test/runtime-tools.test.ts

@@ -0,0 +1,60 @@
+/**
+ * Every module's runtime answers `tools` for it (novox/hq ADR 0152, design 34 §3): the names,
+ * descriptions and schemas from the code that answers them. Against a real bus, because the claim is
+ * what a second connection gets back.
+ *
+ *   docker run -d --rm --name t -p 14232:4222 nats:2.10-alpine -js
+ *   MESH_TEST_NATS=nats://127.0.0.1:14232 node --test --experimental-strip-types test/runtime-tools.test.ts
+ */
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { fileURLToPath } from "node:url";
+
+import { resetTools } from "@novox/mesh-sdk/tools";
+
+import { connectNats } from "../dist/broker-nats.js";
+import { runTools } from "../dist/runtime.js";
+
+const url = process.env.MESH_TEST_NATS;
+const fixture = (name: string) => fileURLToPath(new URL(`./fixtures/${name}`, import.meta.url));
+
+test("a module registering two tools answers three names, the third being what it serves", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  resetTools();
+  const shop = await connectNats({ url, node: "one", module: "shop" });
+  const asker = await connectNats({ url, module: "person.ada" });
+  const stop = await runTools({ broker: shop, moduleEntrypoints: [fixture("shop-tools.mjs")] });
+  try {
+    const answer = await asker.request<Record<string, never>, { module: string; tools: { name: string; input: unknown }[] }>(
+      "shop.tools",
+      {},
+    );
+    assert.equal(answer.module, "shop");
+    assert.deepEqual(answer.tools.map((x) => x.name), ["price", "refund"]);
+    // The schema travels with the name: a name alone is not callable by something that has never
+    // seen the mesh before.
+    assert.deepEqual(answer.tools[0].input, { of: { type: "string", description: "the thing" } });
+    // And the tools themselves still answer beside it.
+    const priced = await asker.request<{ of: string }, { cost: number }>("shop.price", { of: "a hat" });
+    assert.equal(priced.cost, 12);
+  } finally {
+    stop();
+    await asker.close();
+    await shop.close();
+  }
+});
+
+test("a module naming a tool of its own `tools` is refused at load", async (t) => {
+  if (!url) return t.skip("MESH_TEST_NATS unset");
+  resetTools();
+  const clash = await connectNats({ url, node: "one", module: "clash" });
+  try {
+    await assert.rejects(
+      () => runTools({ broker: clash, moduleEntrypoints: [fixture("clash-tools.mjs")] }),
+      /names a tool "tools"/,
+    );
+  } finally {
+    resetTools();
+    await clash.close();
+  }
+});