diff --git a/src/components/app-builder/project-manager/sessions/v2/streaming.ts b/src/components/app-builder/project-manager/sessions/v2/streaming.ts
index fdf327183..cca323c95 100644
--- a/src/components/app-builder/project-manager/sessions/v2/streaming.ts
+++ b/src/components/app-builder/project-manager/sessions/v2/streaming.ts
@@ -180,7 +180,7 @@ export function createV2StreamingCoordinator(config: V2StreamingConfig): V2Strea
         });
       },
 
-      onSessionStatusChanged: status => {
+      onSessionStatusChanged: (status, _sessionId) => {
         if (status.type === 'idle') {
           store.setState({ isStreaming: false });
           onStreamComplete?.();
diff --git a/src/components/cloud-agent-next/useCloudAgentStream.ts b/src/components/cloud-agent-next/useCloudAgentStream.ts
index 7ac88150f..6ab07dba0 100644
--- a/src/components/cloud-agent-next/useCloudAgentStream.ts
+++ b/src/components/cloud-agent-next/useCloudAgentStream.ts
@@ -239,7 +239,7 @@ export function useCloudAgentStream({
         }
       },
 
-      onSessionStatusChanged: status => {
+      onSessionStatusChanged: (status, _sessionId) => {
         setSessionStatus(status);
 
         // Handle streaming state based on status
diff --git a/src/lib/cloud-agent-next/processor/event-processor.ts b/src/lib/cloud-agent-next/processor/event-processor.ts
index b745ca8e2..e795e4102 100644
--- a/src/lib/cloud-agent-next/processor/event-processor.ts
+++ b/src/lib/cloud-agent-next/processor/event-processor.ts
@@ -309,9 +309,9 @@ export function createEventProcessor(config: EventProcessorConfig = {}): EventPr
    * Handle session.status events.
    */
   function handleSessionStatus(data: EventSessionStatus['properties']): void {
-    const { status } = data;
+    const { status, sessionID } = data;
 
-    callbacks.onSessionStatusChanged?.(status);
+    callbacks.onSessionStatusChanged?.(status, sessionID);
 
     // Update streaming state based on status
     if (status.type === 'idle') {
diff --git a/src/lib/cloud-agent-next/processor/types.ts b/src/lib/cloud-agent-next/processor/types.ts
index 7fd73e911..dc3e83121 100644
--- a/src/lib/cloud-agent-next/processor/types.ts
+++ b/src/lib/cloud-agent-next/processor/types.ts
@@ -70,7 +70,7 @@ export type EventProcessorCallbacks = {
   ) => void;
 
   /** Called when session status changes (idle/busy/retry) */
-  onSessionStatusChanged?: (status: SessionStatus) => void;
+  onSessionStatusChanged?: (status: SessionStatus, sessionId: string) => void;
 
   /** Called when a new session is created (session.created event) */
   onSessionCreated?: (sessionInfo: Session) => void;
diff --git a/src/lib/cloud-agent-next/run-session.ts b/src/lib/cloud-agent-next/run-session.ts
index 3fd979720..baa49d136 100644
--- a/src/lib/cloud-agent-next/run-session.ts
+++ b/src/lib/cloud-agent-next/run-session.ts
@@ -242,8 +242,9 @@ export async function runSessionToCompletion(input: RunSessionInput): Promise<Ru
           errorMessage = errData?.data?.message ?? 'Assistant message failed.';
         }
       },
-      onSessionStatusChanged: status => {
-        if (status.type === 'idle') resolveOnce();
+      onSessionStatusChanged: (status, eventSessionId) => {
+        // Only resolve when the root session goes idle, not subagent/child sessions.
+        if (status.type === 'idle' && eventSessionId === sessionId) resolveOnce();
       },
       onError: error => {
         hasError = true;