diff --git a/apps/mobile/src/features/threads/threadPresentation.ts b/apps/mobile/src/features/threads/threadPresentation.ts
index b5f286937e0c..88d28407f54b 100644
--- a/apps/mobile/src/features/threads/threadPresentation.ts
+++ b/apps/mobile/src/features/threads/threadPresentation.ts
@@ -98,5 +98,15 @@ export function resolveThreadStatus(
     };
   }
 
+  if (thread.backgroundLiveness === "working") {
+    return {
+      kind: "working",
+      label: "Working",
+      pillClassName: "bg-adaptive-sky-500-a12-a16",
+      textClassName: "text-adaptive-sky-600-400",
+      pulse: true,
+    };
+  }
+
   return null;
 }
diff --git a/apps/web/src/components/Sidebar.logic.test.ts b/apps/web/src/components/Sidebar.logic.test.ts
index 76960f3f533b..89c981a158f8 100644
--- a/apps/web/src/components/Sidebar.logic.test.ts
+++ b/apps/web/src/components/Sidebar.logic.test.ts
@@ -334,6 +334,7 @@ describe("hasUnseenCompletion", () => {
         interactionMode: "default",
         latestTurn: makeLatestTurn(),
         lastVisitedAt: "2026-03-09T10:04:00.000Z",
+        backgroundLiveness: null,
         session: null,
       }),
     ).toBe(true);
@@ -348,10 +349,52 @@ describe("hasUnseenCompletion", () => {
         interactionMode: "default",
         latestTurn: makeLatestTurn(),
         lastVisitedAt: undefined,
+        backgroundLiveness: null,
         session: null,
       }),
     ).toBe(false);
   });
+
+  it.each(["working", "monitoring"] as const)(
+    "does not mark a thread unread while background work is %s",
+    (backgroundLiveness) => {
+      expect(
+        hasUnseenCompletion({
+          hasActionableProposedPlan: false,
+          hasPendingApprovals: false,
+          hasPendingUserInput: false,
+          interactionMode: "default",
+          latestTurn: makeLatestTurn(),
+          lastVisitedAt: "2026-03-09T10:04:00.000Z",
+          backgroundLiveness,
+          session: null,
+        }),
+      ).toBe(false);
+    },
+  );
+
+  it("does not mark an active provider session unread", () => {
+    expect(
+      hasUnseenCompletion({
+        hasActionableProposedPlan: false,
+        hasPendingApprovals: false,
+        hasPendingUserInput: false,
+        interactionMode: "default",
+        latestTurn: makeLatestTurn(),
+        lastVisitedAt: "2026-03-09T10:04:00.000Z",
+        backgroundLiveness: null,
+        session: {
+          threadId: "thread-1" as never,
+          status: "running",
+          providerName: "Codex",
+          runtimeMode: "full-access",
+          activeTurnId: "turn-1" as never,
+          lastError: null,
+          updatedAt: "2026-03-09T10:05:00.000Z",
+        },
+      }),
+    ).toBe(false);
+  });
 });
 
 describe("shouldRecedeSidebarThread", () => {
diff --git a/apps/web/src/components/Sidebar.logic.ts b/apps/web/src/components/Sidebar.logic.ts
index fcedf46ce507..310135d7899f 100644
--- a/apps/web/src/components/Sidebar.logic.ts
+++ b/apps/web/src/components/Sidebar.logic.ts
@@ -633,6 +633,13 @@ export function useThreadJumpHintVisibility(): {
 }
 
 export function hasUnseenCompletion(thread: ThreadStatusInput): boolean {
+  if (
+    thread.session?.status === "running" ||
+    thread.session?.status === "starting" ||
+    thread.backgroundLiveness != null
+  ) {
+    return false;
+  }
   if (!thread.latestTurn?.completedAt) return false;
   const completedAt = Date.parse(thread.latestTurn.completedAt);
   if (Number.isNaN(completedAt)) return false;
diff --git a/apps/web/src/components/ThreadNotificationCoordinator.test.tsx b/apps/web/src/components/ThreadNotificationCoordinator.test.tsx
index 860b6389dc12..e94a02a31115 100644
--- a/apps/web/src/components/ThreadNotificationCoordinator.test.tsx
+++ b/apps/web/src/components/ThreadNotificationCoordinator.test.tsx
@@ -12,6 +12,7 @@ const state = vi.hoisted(() => ({
   visible: "visible",
   live: true,
   completedAt: null as string | null,
+  backgroundLiveness: null as "working" | "monitoring" | null,
   archivedAt: null as string | null,
   input: false,
   approval: false,
@@ -38,6 +39,7 @@ vi.mock("@effect/atom-react", () => ({
           id: "thread-1",
           title: "Fix the login form",
           archivedAt: state.archivedAt,
+          backgroundLiveness: state.backgroundLiveness,
           hasPendingUserInput: state.input,
           hasPendingApprovals: state.approval,
           session: state.sessionError ? { status: "error" } : null,
@@ -104,6 +106,7 @@ beforeEach(() => {
     visible: "visible",
     live: true,
     completedAt: null,
+    backgroundLiveness: null,
     archivedAt: null,
     input: false,
     approval: false,
@@ -239,6 +242,22 @@ describe("thread notifications", () => {
     expect(state.notification).not.toHaveBeenCalled();
   });
 
+  it("waits for background subagents to settle before reporting completion", async () => {
+    await render();
+    state.backgroundLiveness = "working";
+    await complete();
+    expect(state.add).not.toHaveBeenCalled();
+    expect(state.sound).not.toHaveBeenCalled();
+    expect(state.notification).not.toHaveBeenCalled();
+
+    state.backgroundLiveness = null;
+    await render();
+    expect(state.add).toHaveBeenCalledTimes(1);
+    expect(state.add).toHaveBeenLastCalledWith(
+      expect.objectContaining({ title: "Thread completed" }),
+    );
+  });
+
   it("keeps system alerts when the app is in the background", async () => {
     state.mode = "notifications";
     state.focused = false;
diff --git a/packages/shared/src/agentAwareness.test.ts b/packages/shared/src/agentAwareness.test.ts
index 28e07c04e6f3..4eee4f7ac936 100644
--- a/packages/shared/src/agentAwareness.test.ts
+++ b/packages/shared/src/agentAwareness.test.ts
@@ -26,6 +26,7 @@ function thread(
   | "modelSelection"
   | "session"
   | "latestTurn"
+  | "backgroundLiveness"
   | "updatedAt"
   | "hasPendingApprovals"
   | "hasPendingUserInput"
@@ -36,6 +37,7 @@ function thread(
     modelSelection: { instanceId: ProviderInstanceId.make("codex"), model: "gpt-5.4" },
     session: null,
     latestTurn: null,
+    backgroundLiveness: null,
     updatedAt: NOW,
     hasPendingApprovals: false,
     hasPendingUserInput: false,
@@ -102,6 +104,27 @@ describe("projectThreadAwareness", () => {
     });
   });
 
+  it("keeps completed parent turns running while subagents are active", () => {
+    const state = projectThreadAwareness({
+      environmentId: "env-1" as EnvironmentId,
+      project,
+      thread: thread({
+        backgroundLiveness: "working",
+        latestTurn: {
+          turnId: "turn-1" as TurnId,
+          state: "completed",
+          requestedAt: NOW,
+          startedAt: NOW,
+          completedAt: NOW,
+          assistantMessageId: null,
+        },
+      }),
+    });
+
+    expect(state?.phase).toBe("running");
+    expect(state?.headline).toBe("Agent is working");
+  });
+
   it("projects completed turns as completed even when teardown settled them as interrupted", () => {
     const finishedTurn = {
       turnId: "turn-1" as TurnId,
diff --git a/packages/shared/src/agentAwareness.ts b/packages/shared/src/agentAwareness.ts
index 77c7c845db31..9b3854ed0ff1 100644
--- a/packages/shared/src/agentAwareness.ts
+++ b/packages/shared/src/agentAwareness.ts
@@ -37,6 +37,7 @@ export interface ProjectThreadAwarenessInput {
     | "modelSelection"
     | "session"
     | "latestTurn"
+    | "backgroundLiveness"
     | "updatedAt"
     | "hasPendingApprovals"
     | "hasPendingUserInput"
@@ -92,6 +93,9 @@ function resolveThreadAwarenessPhase(
   if (thread.session?.status === "running" || thread.latestTurn?.state === "running") {
     return "running";
   }
+  if (thread.backgroundLiveness != null) {
+    return "running";
+  }
   if (thread.latestTurn?.state === "completed") {
     return "completed";
   }