Fix mobile agent timeline catch-up

packages/server/src/server/client-activity.e2e.test.ts

@@ -96,6 +96,31 @@ describe("client activity tracking", () => {
     });
   }
 
+  function waitForAssistantTimeline(
+    client: DaemonClient,
+    agentId: string,
+    timeout = 60000,
+  ): Promise<string> {
+    return new Promise((resolve, reject) => {
+      const timer = setTimeout(() => {
+        cleanup();
+        reject(new Error(`Timeout waiting for assistant timeline (${timeout}ms)`));
+      }, timeout);
+
+      const cleanup = client.on("agent_stream", (msg) => {
+        if (msg.type !== "agent_stream") return;
+        if (msg.payload.agentId !== agentId) return;
+        if (msg.payload.event.type !== "timeline") return;
+        const item = msg.payload.event.item;
+        if (item.type !== "assistant_message") return;
+
+        clearTimeout(timer);
+        cleanup();
+        resolve(item.text);
+      });
+    });
+  }
+
   // ===========================================================================
   // SINGLE CLIENT SCENARIOS
   // ===========================================================================
@@ -355,6 +380,31 @@ describe("client activity tracking", () => {
   // ===========================================================================
 
   describe("web and mobile clients", () => {
+    test("mobile stream delivery does not depend on heartbeat focus", async () => {
+      client1 = await createClient(); // web
+      client2 = await createClient(); // mobile
+
+      const agent = await createAgent({
+        client: client1,
+        title: "Mobile Stale Focus Stream Test",
+      });
+
+      client2.sendHeartbeat({
+        deviceType: "mobile",
+        focusedAgentId: null,
+        lastActivityAt: new Date(Date.now() - PRESENCE_THRESHOLD_MS - 60_000).toISOString(),
+        appVisible: false,
+        appVisibilityChangedAt: new Date(Date.now() - 120_000).toISOString(),
+      });
+
+      await new Promise((r) => setTimeout(r, 100));
+
+      const mobileStream = waitForAssistantTimeline(client2, agent.id);
+      await client1.sendMessage(agent.id, "Say 'hello' and nothing else");
+
+      await expect(mobileStream).resolves.toMatch(/hello/i);
+    }, 120000);
+
     test("no notification to either when user actively on agent (web)", async () => {
       client1 = await createClient(); // web
       client2 = await createClient(); // mobile

packages/server/src/server/session.ts

@@ -783,7 +783,6 @@ export class Session {
     appVisible: boolean;
     appVisibilityChangedAt: Date;
   } | null = null;
-  private readonly MOBILE_BACKGROUND_STREAM_GRACE_MS = 60_000;
   private readonly terminalManager: TerminalManager | null;
   private readonly providerSnapshotManager: ProviderSnapshotManager;
   private unsubscribeProviderSnapshotEvents: (() => void) | null = null;
@@ -1302,13 +1301,6 @@ export class Session {
             });
         }
 
-        // Reduce bandwidth/CPU on mobile: only forward high-frequency agent stream events
-        // for the focused agent, with a short grace window while backgrounded.
-        // History catch-up is handled via pull-based `fetch_agent_timeline_request`.
-        if (this.shouldSkipAgentStreamForward(event.agentId)) {
-          return;
-        }
-
         const serializedEvent = serializeAgentStreamEvent(event.event);
         if (!serializedEvent) {
           return;
@@ -1355,21 +1347,6 @@ export class Session {
     );
   }
 
-  private shouldSkipAgentStreamForward(agentId: string): boolean {
-    const activity = this.clientActivity;
-    if (activity?.deviceType !== "mobile") {
-      return false;
-    }
-    if (!activity.focusedAgentId || activity.focusedAgentId !== agentId) {
-      return true;
-    }
-    if (activity.appVisible) {
-      return false;
-    }
-    const hiddenForMs = Date.now() - activity.appVisibilityChangedAt.getTime();
-    return hiddenForMs >= this.MOBILE_BACKGROUND_STREAM_GRACE_MS;
-  }
-
   private buildAgentStreamPayload(
     event: Extract<AgentManagerEvent, { type: "agent_stream" }>,
     serializedEvent: Extract<SessionOutboundMessage, { type: "agent_stream" }>["payload"]["event"],