diff --git a/server/__tests__/task-orchestrator.test.ts b/server/__tests__/task-orchestrator.test.ts
index 6bee3465..a3e026f4 100644
--- a/server/__tests__/task-orchestrator.test.ts
+++ b/server/__tests__/task-orchestrator.test.ts
@@ -839,6 +839,49 @@ describe('TaskOrchestrator', () => {
       expect(deps.setTaskContext).not.toHaveBeenCalled();
     });
 
+    it('does not call setTaskContext (pinned) for spawned sessions', async () => {
+      const spawnSession = vi.fn().mockResolvedValue('spawned-client-1');
+      const deps = createTestDeps(store);
+      deps.spawnSession = spawnSession;
+      const orch = new TaskOrchestrator(deps);
+
+      const goal = store.create({ title: 'Goal' });
+      store.create({
+        title: 'Spawn task',
+        parentId: goal.id,
+        sessionPolicy: 'spawn',
+      });
+
+      orch.start(goal.id);
+
+      await vi.waitFor(() => {
+        expect(spawnSession).toHaveBeenCalled();
+      });
+
+      // Spawned sessions get taskContext via startChat options, not setTaskContext
+      expect(deps.setTaskContext).not.toHaveBeenCalled();
+    });
+
+    it('falls back to setTaskContext (pinned) when spawn returns null', async () => {
+      const spawnSession = vi.fn().mockResolvedValue(null);
+      const deps = createTestDeps(store);
+      deps.spawnSession = spawnSession;
+      const orch = new TaskOrchestrator(deps);
+
+      const goal = store.create({ title: 'Goal' });
+      const task = store.create({
+        title: 'Spawn task',
+        parentId: goal.id,
+        sessionPolicy: 'spawn',
+      });
+
+      orch.start(goal.id);
+
+      await vi.waitFor(() => {
+        expect(deps.setTaskContext).toHaveBeenCalledWith(task.id, goal.id);
+      });
+    });
+
     it('reuse policy tasks use pinned session as before', () => {
       const spawnSession = vi.fn().mockResolvedValue('spawned-client-1');
       const deps = createTestDeps(store);
diff --git a/server/chat.ts b/server/chat.ts
index 50579b77..0a8e681b 100644
--- a/server/chat.ts
+++ b/server/chat.ts
@@ -745,6 +745,7 @@ export async function startChat(
     onSessionResolved?: (sessionId: string) => void;
     telosTaskId?: string;
     agentName?: string;
+    taskContext?: { currentTaskId: string; goalId: string };
   },
 ) {
   return withSpanAsync(
@@ -775,6 +776,7 @@ async function _startChatInner(
     onSessionResolved?: (sessionId: string) => void;
     telosTaskId?: string;
     agentName?: string;
+    taskContext?: { currentTaskId: string; goalId: string };
   },
 ) {
   const abortController = new AbortController();
@@ -862,6 +864,9 @@ async function _startChatInner(
   const session = registry.get(clientId)!;
   session.model = options.model ?? session.model;
   session.inputQueue = inputQueue as { push: (msg: unknown) => void; close: () => void };
+  if (options.taskContext) {
+    session.taskContext = options.taskContext;
+  }
   _onSessionChange?.(clientId, 'start');
 
   // Session state machine: mark CREATED (Phase 1 — write only, no behavior change)
diff --git a/server/index.ts b/server/index.ts
index 8cb4640d..77d0bc7e 100644
--- a/server/index.ts
+++ b/server/index.ts
@@ -255,6 +255,7 @@ const orchestrator = new TaskOrchestrator({
         mode: 'agent',
         isolation: true,
         telosTaskId: goalId,
+        taskContext: { currentTaskId: taskId, goalId },
         onSessionResolved: (sessionId) => {
           log.info('spawned headless session resolved', { taskId, sessionId, clientId });
           sseRegistry.broadcast('sessions_changed', {});