node-tools/src/broker-nats.ts

@@ -277,6 +277,12 @@ export async function connectNats(
     const sub = conn.subscribe(subject, queue ? { queue } : {});
     subs.push(sub);
     void (async () => {
+      // **A refused subscription is said, never fatal** (novox/hq 04-ISSUES/218, as 217 for the
+      // announcements). The grants are the mesh's word on what this account may answer; a subject
+      // they leave out — a seat claimed here and held elsewhere — costs that subject, never the
+      // module's other tools, its handlers and its provisioning. Unhandled, the refusal ended the
+      // process and a module's runtime crash-looped on 2026-10-04.
+      try {
         for await (const msg of sub) {
           let reply: { result?: Res; error?: string; node?: string };
           try {
@@ -289,6 +295,10 @@ export async function connectNats(
           if (node) reply.node = node;
           msg.respond(sc.encode(JSON.stringify(reply)));
         }
+      } catch (err) {
+        console.log(`[mesh-tools] the bus refused ${subject}: ${err instanceof Error ? err.message : String(err)}; ` +
+          "not served here, and the rest serves on");
+      }
     })();
     return () => sub.unsubscribe();
   };

node-tools/test/fixtures/refusing-nats.conf

@@ -3,7 +3,7 @@ authorization {
   users = [
     { user: "runtime", password: "runtime", permissions: {
         publish: { allow: [">"] }
-        subscribe: { allow: [">"], deny: ["$SRV.PING.>"] }
+        subscribe: { allow: [">"], deny: ["$SRV.PING.>", "mesh.seat.held-elsewhere.>"] }
     } }
   ]
 }

node-tools/test/refused.test.ts

@@ -9,6 +9,7 @@
 import assert from "node:assert/strict";
 import { test } from "node:test";
 import { connectNats } from "../dist/broker-nats.js";
+import { callTool } from "../dist/client.js";
 
 const url = process.env.MESH_TEST_REFUSING_NATS;
 
@@ -35,3 +36,33 @@ test("a refused discovery subscription is logged and the runtime serves on", asy
     await bus.close();
   }
 });
+
+// novox/hq issue 218: a tool subject the grants leave out — a seat claimed here and held elsewhere —
+// is refused, said, and the module's other tools still answer.
+test("a refused tool subscription is logged and the module's other tools answer", async (t) => {
+  if (!url) return t.skip("MESH_TEST_REFUSING_NATS unset");
+  const bus = await connectNats({ url, user: "runtime", password: "runtime", module: "alpha", node: "anchor" });
+  const asker = await connectNats({ url, user: "runtime", password: "runtime", module: "console", node: "workstation" });
+  const said: string[] = [];
+  const log = console.log;
+  console.log = (...a: unknown[]) => said.push(a.join(" "));
+  const crashed: unknown[] = [];
+  const onRejection = (e: unknown) => crashed.push(e);
+  process.on("unhandledRejection", onRejection);
+  try {
+    const refused = await bus.handleSubject!("mesh.seat.held-elsewhere.tool.databases", async () => ({ seat: true }));
+    const stop = await bus.handle("alpha.ping", async () => ({ pong: true }));
+    for (let i = 0; i < 50 && !said.some((s) => s.includes("the bus refused mesh.seat.held-elsewhere")); i++) await new Promise((r) => setTimeout(r, 50));
+    console.log = log;
+    assert.ok(said.some((s) => /the bus refused mesh\.seat\.held-elsewhere\.tool\.databases.*serves on/.test(s)), said.join("\n"));
+    assert.equal(crashed.length, 0, `the refusal escaped: ${String(crashed[0])}`);
+    assert.deepEqual((await callTool(asker, "alpha.ping@anchor", {})).result, { pong: true });
+    stop();
+    refused();
+  } finally {
+    console.log = log;
+    process.off("unhandledRejection", onRejection);
+    await asker.close();
+    await bus.close();
+  }
+});