fix(channels): suppress nested subagent output

packages/channels/base/src/AcpBridge.test.ts

@@ -289,6 +289,41 @@ describe('AcpBridge', () => {
     );
   });
 
+  it('excludes nested subagent text from the final response', async () => {
+    const bridge = new AcpBridge({
+      cliEntryPath: '/tmp/qwen',
+      cwd: '/tmp',
+    }) as unknown as TestableAcpBridge;
+    bridge.child = { killed: false, exitCode: null };
+    bridge.connection = {
+      extMethod: vi.fn(),
+      prompt: vi.fn(async () => {
+        bridge.handleSessionUpdate({
+          sessionId: 's-1',
+          update: {
+            sessionUpdate: 'agent_message_chunk',
+            content: { type: 'text', text: 'Nested research report.' },
+            _meta: {
+              parentToolCallId: 'agent-call-1',
+              subagentType: 'Explore',
+            },
+          },
+        });
+        bridge.handleSessionUpdate({
+          sessionId: 's-1',
+          update: {
+            sessionUpdate: 'agent_message_chunk',
+            content: { type: 'text', text: 'Final answer.' },
+          },
+        });
+      }),
+    };
+
+    await expect(bridge.prompt('s-1', 'question')).resolves.toBe(
+      'Final answer.',
+    );
+  });
+
   it('returns only the final turn text after auto-approved tool calls', async () => {
     const bridge = new AcpBridge({
       cliEntryPath: '/tmp/qwen',

packages/channels/base/src/AcpBridge.ts

@@ -304,6 +304,10 @@ export class AcpBridge extends EventEmitter implements ChannelAgentBridge {
 
     switch (type) {
       case 'agent_message_chunk': {
+        const meta = update['_meta'] as Record<string, unknown> | undefined;
+        if (typeof meta?.['parentToolCallId'] === 'string') {
+          break;
+        }
         const content = update['content'] as
           | { type?: string; text?: string }
           | undefined;

packages/channels/base/src/DaemonChannelBridge.test.ts

@@ -313,6 +313,57 @@ describe('DaemonChannelBridge', () => {
     bridge.stop();
   });
 
+  it('excludes nested subagent text from the daemon response', async () => {
+    const events = new EventQueue();
+    const session = createFakeSession(events);
+    session.prompt.mockImplementation(async () => {
+      events.push({
+        id: 1,
+        v: 1,
+        type: 'session_update',
+        data: {
+          sessionId: 'session-1',
+          update: {
+            sessionUpdate: 'agent_message_chunk',
+            content: { type: 'text', text: 'Nested research report.' },
+            _meta: {
+              parentToolCallId: 'agent-call-1',
+              subagentType: 'Explore',
+            },
+          },
+        },
+      });
+      events.push({
+        id: 2,
+        v: 1,
+        type: 'session_update',
+        data: {
+          sessionId: 'session-1',
+          update: {
+            sessionUpdate: 'agent_message_chunk',
+            content: { type: 'text', text: 'Final answer.' },
+          },
+        },
+      });
+      events.push(turnCompleteEvent());
+      return { stopReason: 'end_turn' };
+    });
+    const bridge = new DaemonChannelBridge({
+      cwd: '/repo',
+      sessionFactory: vi.fn().mockResolvedValue(session),
+    });
+
+    await bridge.start();
+    await bridge.newSession('/repo');
+
+    await expect(bridge.prompt('session-1', 'summarize')).resolves.toBe(
+      'Final answer.',
+    );
+
+    events.close();
+    bridge.stop();
+  });
+
   it('returns only the final turn text after daemon auto-approved tool calls', async () => {
     const events = new EventQueue();
     const session = createFakeSession(events);

packages/channels/base/src/DaemonChannelBridge.ts

@@ -560,6 +560,10 @@ export class DaemonChannelBridge
     const type = getString(update['sessionUpdate']);
     switch (type) {
       case 'agent_message_chunk': {
+        const meta = isRecord(update['_meta']) ? update['_meta'] : undefined;
+        if (typeof meta?.['parentToolCallId'] === 'string') {
+          break;
+        }
         const text = getTextContent(update['content']);
         if (text) {
           this.emit('textChunk', sessionId, text);