fix(codex): keep delegated child-agent output out of parent chats

apps/server/src/provider/Layers/CodexAdapter.test.ts

@@ -555,6 +555,41 @@ lifecycleLayer("CodexAdapterLive lifecycle", (it) => {
     }),
   );
 
+  it.effect("renames an agent without overwriting its existing identity metadata", () =>
+    Effect.gen(function* () {
+      const { adapter, runtime } = yield* startLifecycleRuntime();
+      const firstEventFiber = yield* Stream.runHead(adapter.streamEvents).pipe(Effect.forkChild);
+
+      yield* runtime.emit({
+        id: asEventId("evt-agent-renamed"),
+        kind: "notification",
+        provider: ProviderDriverKind.make("codex"),
+        createdAt: "2026-01-01T00:00:00.000Z",
+        method: "collabAgent/renamed",
+        threadId: asThreadId("thread-1"),
+        payload: {
+          agentThreadId: "child-rename",
+          nickname: "Alpha",
+        },
+      } satisfies ProviderEvent);
+
+      const firstEvent = yield* Fiber.join(firstEventFiber);
+      NodeAssert.equal(firstEvent._tag, "Some");
+      if (firstEvent._tag !== "Some") {
+        return;
+      }
+      NodeAssert.equal(firstEvent.value.type, "task.updated");
+      if (firstEvent.value.type !== "task.updated") {
+        return;
+      }
+      NodeAssert.deepStrictEqual(firstEvent.value.payload, {
+        taskId: "child-rename",
+        title: "Alpha",
+        timelineBypass: true,
+      });
+    }),
+  );
+
   it.effect("labels MCP lifecycle entries with server and tool names", () =>
     Effect.gen(function* () {
       const { adapter, runtime } = yield* startLifecycleRuntime();

apps/server/src/provider/Layers/CodexAdapter.ts

@@ -605,6 +605,18 @@ function mapCollabAgentEvent(
           payload: { taskId, status: "running", ...statusLinkage },
         },
       ];
+    case "collabAgent/renamed":
+      return [
+        {
+          ...base,
+          type: "task.updated",
+          payload: {
+            taskId,
+            ...(nickname ? { title: nickname } : {}),
+            timelineBypass: true,
+          },
+        },
+      ];
     case "collabAgent/turnCompleted": {
       // Idle, not terminal: the identity is resumable via sendInput/resume.
       const turn =

apps/server/src/provider/Layers/CodexCollabRuntime.integration.test.ts

@@ -70,10 +70,254 @@ function buildScript() {
   };
 }
 
+function buildDirectChildScript() {
+  const rootTurnId = "019fcfd6-1806-7de1-8564-de69fd55bffb";
+  const childTurnId = `${CHILD_A}-direct-turn`;
+  const childItemId = `${CHILD_A}-direct-message`;
+  return {
+    rootThreadId: ROOT,
+    notifications: [
+      {
+        method: "item/completed",
+        params: {
+          threadId: ROOT,
+          turnId: rootTurnId,
+          item: {
+            type: "collabAgentToolCall",
+            id: "call_direct_spawn",
+            tool: "spawnAgent",
+            status: "completed",
+            senderThreadId: ROOT,
+            receiverThreadIds: [CHILD_A],
+            prompt: "Return one concise result.",
+            agentsStates: {
+              [CHILD_A]: { status: "pendingInit", message: null },
+            },
+          },
+          completedAtMs: 1785898350000,
+        },
+      },
+      {
+        method: "item/started",
+        params: {
+          threadId: CHILD_A,
+          turnId: childTurnId,
+          item: { type: "agentMessage", id: childItemId, text: "" },
+        },
+      },
+      {
+        method: "item/agentMessage/delta",
+        params: {
+          threadId: CHILD_A,
+          turnId: childTurnId,
+          itemId: childItemId,
+          delta: "child narration must not enter the parent transcript",
+        },
+      },
+      {
+        method: "item/completed",
+        params: {
+          threadId: CHILD_A,
+          turnId: childTurnId,
+          completedAtMs: 1785898350000,
+          item: {
+            type: "agentMessage",
+            id: childItemId,
+            phase: "final_answer",
+            text: "child result is consumed by the parent model",
+          },
+        },
+      },
+      {
+        method: "item/completed",
+        params: {
+          threadId: ROOT,
+          turnId: rootTurnId,
+          item: {
+            type: "agentMessage",
+            id: "root-summary",
+            phase: "final_answer",
+            text: "The agent completed:\n- Direct Child Researcher: returned one concise result.",
+          },
+          completedAtMs: 1785898350000,
+        },
+      },
+    ],
+  };
+}
+
+function buildOutOfOrderNamingScript() {
+  const rootTurnId = "019fcfd6-1806-7de1-8564-de69fd55bffb";
+  return {
+    rootThreadId: ROOT,
+    notifications: [
+      // Child B speaks before the parent-side fan-out arrives. This makes
+      // provisional registration order differ from receiverThreadIds order.
+      {
+        method: "turn/started",
+        params: {
+          threadId: CHILD_B,
+          turn: {
+            id: `${CHILD_B}-early-turn`,
+            items: [],
+            itemsView: "notLoaded",
+            status: "inProgress",
+            error: null,
+            startedAt: 1785898342,
+            completedAt: null,
+            durationMs: null,
+          },
+        },
+      },
+      {
+        method: "item/completed",
+        params: {
+          threadId: ROOT,
+          turnId: rootTurnId,
+          item: {
+            type: "collabAgentToolCall",
+            id: "call_direct_spawn_ordered",
+            tool: "spawnAgent",
+            status: "completed",
+            senderThreadId: ROOT,
+            receiverThreadIds: [CHILD_A, CHILD_B],
+            prompt: "Return one concise result.",
+            agentsStates: {
+              [CHILD_A]: { status: "pendingInit", message: null },
+              [CHILD_B]: { status: "pendingInit", message: null },
+            },
+          },
+          completedAtMs: 1785898350000,
+        },
+      },
+      {
+        method: "item/completed",
+        params: {
+          threadId: ROOT,
+          turnId: rootTurnId,
+          item: {
+            type: "agentMessage",
+            id: "root-order-summary",
+            phase: "final_answer",
+            text: "Agents:\n- Alpha\n- Beta",
+          },
+          completedAtMs: 1785898350000,
+        },
+      },
+    ],
+  };
+}
+
 const scriptPath = NodePath.join(import.meta.dirname, "../testFixtures/.collab-script.json");
 const peerPath = NodePath.join(import.meta.dirname, "../testFixtures/codexCollabMockPeer.sh");
 
 describe("CodexSessionRuntime collab integration", () => {
+  it.effect("registers receiver ids and keeps child narration out of the parent stream", () =>
+    Effect.gen(function* () {
+      // @effect-diagnostics-next-line preferSchemaOverJson:off
+      NodeFS.writeFileSync(scriptPath, JSON.stringify(buildDirectChildScript()), "utf8");
+      yield* Effect.addFinalizer(() =>
+        Effect.sync(() => NodeFS.rmSync(scriptPath, { force: true })),
+      );
+
+      const runtime = yield* makeCodexSessionRuntime({
+        threadId: ThreadId.make("thread-collab-direct-child"),
+        binaryPath: peerPath,
+        cwd: "/tmp",
+        runtimeMode: "full-access",
+        environment: { ...process.env, T3_CODEX_COLLAB_SCRIPT: scriptPath },
+      });
+
+      const eventsFiber = yield* runtime.events.pipe(
+        Stream.takeUntil((event) => event.method === "turn/completed"),
+        Stream.runCollect,
+        Effect.forkScoped,
+      );
+
+      yield* runtime.start();
+      yield* runtime.sendTurn({ input: "direct child" });
+
+      const events = Array.from(yield* Fiber.join(eventsFiber));
+      const methods = events.map((event) => event.method);
+      assert.include(methods, "collabAgent/started");
+      assert.include(methods, "collabAgent/item");
+      assert.include(methods, "collabAgent/statusChanged");
+      assert.include(methods, "collabAgent/renamed");
+      assert.include(methods, "turn/completed");
+      assert.notInclude(methods, "item/agentMessage/delta");
+      const started = events.find((event) => event.method === "collabAgent/started");
+      assert.isUndefined((started?.payload as { nickname?: string } | undefined)?.nickname);
+      const renamed = events.find((event) => event.method === "collabAgent/renamed");
+      assert.equal(
+        (renamed?.payload as { nickname?: string } | undefined)?.nickname,
+        "Direct Child Researcher",
+      );
+      const statusChanged = events.find(
+        (event) =>
+          event.method === "collabAgent/statusChanged" &&
+          (event.payload as { status?: { type?: string } } | undefined)?.status?.type === "idle",
+      );
+      assert.deepEqual((statusChanged?.payload as { status?: unknown } | undefined)?.status, {
+        type: "idle",
+      });
+
+      const leakedChildEvents = events.filter((event) => {
+        if (event.method === "item/agentMessage/delta") return true;
+        const payload = event.payload as { threadId?: string } | undefined;
+        return payload?.threadId === CHILD_A;
+      });
+      assert.deepEqual(
+        leakedChildEvents.map((event) => event.method),
+        [],
+        "child notifications must not be emitted as parent-timeline events",
+      );
+
+      yield* runtime.close;
+    }).pipe(Effect.scoped, Effect.provide(NodeServices.layer)),
+  );
+
+  it.effect("assigns coordinator names in receiver order after child-first registration", () =>
+    Effect.gen(function* () {
+      // @effect-diagnostics-next-line preferSchemaOverJson:off
+      NodeFS.writeFileSync(scriptPath, JSON.stringify(buildOutOfOrderNamingScript()), "utf8");
+      yield* Effect.addFinalizer(() =>
+        Effect.sync(() => NodeFS.rmSync(scriptPath, { force: true })),
+      );
+
+      const runtime = yield* makeCodexSessionRuntime({
+        threadId: ThreadId.make("thread-collab-name-order"),
+        binaryPath: peerPath,
+        cwd: "/tmp",
+        runtimeMode: "full-access",
+        environment: { ...process.env, T3_CODEX_COLLAB_SCRIPT: scriptPath },
+      });
+
+      const eventsFiber = yield* runtime.events.pipe(
+        Stream.takeUntil((event) => event.method === "turn/completed"),
+        Stream.runCollect,
+        Effect.forkScoped,
+      );
+
+      yield* runtime.start();
+      yield* runtime.sendTurn({ input: "name the children" });
+
+      const events = Array.from(yield* Fiber.join(eventsFiber));
+      const renamed = events.filter((event) => event.method === "collabAgent/renamed");
+      assert.deepEqual(
+        renamed.map((event) => {
+          const payload = event.payload as { agentThreadId?: string; nickname?: string };
+          return [payload.agentThreadId, payload.nickname];
+        }),
+        [
+          [CHILD_A, "Alpha"],
+          [CHILD_B, "Beta"],
+        ],
+      );
+
+      yield* runtime.close;
+    }).pipe(Effect.scoped, Effect.provide(NodeServices.layer)),
+  );
+
   it.effect("replays the captured fan-out into synthetic agent events without child leaks", () =>
     Effect.gen(function* () {
       // @effect-diagnostics-next-line preferSchemaOverJson:off

apps/server/src/provider/Layers/CodexCollabWire.test.ts

@@ -15,7 +15,7 @@
 import { assert, describe, it } from "vite-plus/test";
 
 import fixture from "../testFixtures/codexMultiAgentWire.json" with { type: "json" };
-import { routeCodexChildNotification } from "./CodexSessionRuntime.ts";
+import { readCoordinatorAgentNames, routeCodexChildNotification } from "./CodexSessionRuntime.ts";
 
 interface WireNotification {
   readonly method: string;
@@ -61,8 +61,8 @@ describe("codex multi-agent wire capture", () => {
   it("emits child traffic BEFORE the item that registers the child", () => {
     // Ordering hazard: the child's own thread/status/changed arrives before
     // the parent-side subAgentActivity naming it. Registration must tolerate
-    // child-first arrival, so unregistered child traffic passes through
-    // rather than being eaten (no regression vs. pre-feature behavior).
+    // child-first arrival without leaking the child's conversation into the
+    // parent timeline.
     const firstChildTraffic = notifications.findIndex((entry) => {
       const threadId = notificationThreadId(entry);
       return threadId !== undefined && childThreadIds.has(threadId);
@@ -128,11 +128,35 @@ describe("routeCodexChildNotification", () => {
     }
   });
 
+  it("reads coordinator-assigned names from fleet summaries", () => {
+    assert.deepEqual(
+      readCoordinatorAgentNames(
+        "Three agents are running in parallel: Halley, Banach, and Parfit.",
+      ),
+      ["Halley", "Banach", "Parfit"],
+    );
+    assert.deepEqual(
+      readCoordinatorAgentNames(
+        "All three agents completed successfully:\n\n- Halley: generated names\n- Banach: wrote a riddle\n- Parfit: sorted terms",
+      ),
+      ["Halley", "Banach", "Parfit"],
+    );
+    assert.deepEqual(
+      readCoordinatorAgentNames(
+        "Started 3 Luna medium sub-agents:\n\n- Planck\n- Parfit\n- Avicenna",
+      ),
+      ["Planck", "Parfit", "Avicenna"],
+    );
+    assert.deepEqual(readCoordinatorAgentNames("Summary:\n\n- Tests: passed\n- Build: passed"), []);
+  });
+
   it("drops only enumerated child chatter", () => {
     for (const method of [
       "item/agentMessage/delta",
       "item/reasoning/textDelta",
       "item/commandExecution/outputDelta",
+      "item/commandExecution/terminalInteraction",
+      "item/mcpToolCall/progress",
       "turn/plan/updated",
       "thread/name/updated",
     ]) {