[eric] fix browser agent stop: cancel mid-flight API calls, stop children before parent, guard frontend state

backend/apps/agents/agent_manager.py

@@ -1353,23 +1353,25 @@ class AgentManager:
 
     async def stop_agent(self, session_id: str):
         """Stop a running agent and all its browser-agent children."""
-        task = self.tasks.get(session_id)
-        if task and not task.done():
-            task.cancel()
-            try:
-                await task
-            except asyncio.CancelledError:
-                pass
-        
+        # Stop children first so browser agents get cancelled before parent
+        children = [
+            s for s in self.sessions.values()
+            if s.parent_session_id == session_id and s.mode == "browser-agent"
+        ]
+        for child in children:
+            await self.stop_agent(child.id)
+
         session = self.sessions.get(session_id)
         if session:
+            # Set cancel event BEFORE cancelling the task so in-flight
+            # browser agent loops see it immediately
+            if hasattr(session, '_cancel_event'):
+                session._cancel_event.set()
+
             for req in list(session.pending_approvals):
                 ws_manager.resolve_approval(req.id, {"behavior": "deny", "message": "Agent stopped"})
             session.pending_approvals = []
 
-            if hasattr(session, '_cancel_event'):
-                session._cancel_event.set()
-
             session.status = "stopped"
             if not session.closed_at:
                 session.closed_at = datetime.now()
@@ -1379,12 +1381,13 @@ class AgentManager:
                 "session": session.model_dump(mode="json"),
             })
 
-        children = [
-            s for s in self.sessions.values()
-            if s.parent_session_id == session_id and s.mode == "browser-agent"
-        ]
-        for child in children:
-            await self.stop_agent(child.id)
+        task = self.tasks.get(session_id)
+        if task and not task.done():
+            task.cancel()
+            try:
+                await task
+            except asyncio.CancelledError:
+                pass
 
     def handle_approval(self, request_id: str, decision: dict):
         """Resolve a pending HITL approval."""

backend/apps/agents/browser_agent.py

@@ -337,18 +337,33 @@ async def run_browser_agent(
         "message": user_msg.model_dump(mode="json"),
     })
 
+    async def _cancellable(coro):
+        """Race any awaitable against the cancel event. Returns None if cancelled."""
+        task = asyncio.ensure_future(coro)
+        cancel_wait = asyncio.ensure_future(cancel_event.wait())
+        done, pending = await asyncio.wait(
+            [task, cancel_wait], return_when=asyncio.FIRST_COMPLETED,
+        )
+        for p in pending:
+            p.cancel()
+        if cancel_event.is_set():
+            return None
+        return task.result()
+
     try:
         for turn in range(MAX_TURNS):
             if cancel_event.is_set():
                 break
 
-            response = await client.messages.create(
+            response = await _cancellable(client.messages.create(
                 model=api_model,
                 max_tokens=4096,
                 system=SYSTEM_PROMPT,
                 tools=BROWSER_TOOLS_SCHEMA,
                 messages=messages,
-            )
+            ))
+            if response is None:
+                break
 
             assistant_content = []
             text_parts = []
@@ -444,9 +459,12 @@ async def run_browser_agent(
                         continue
 
                 start = time.time()
-                result = await execute_browser_tool(
+                result = await _cancellable(execute_browser_tool(
                     tu.name, tu.input, browser_id, tab_id,
-                )
+                ))
+                if result is None:
+                    cancelled = True
+                    break
                 elapsed_ms = int((time.time() - start) * 1000)
 
                 action_log.append({

electron/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "openswarm",
-  "version": "1.0.18",
+  "version": "1.0.19",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "openswarm",
-      "version": "1.0.18",
+      "version": "1.0.19",
       "hasInstallScript": true,
       "dependencies": {
         "electron-updater": "^6.3.0",

frontend/src/shared/state/agentsSlice.ts

@@ -536,6 +536,11 @@ const agentsSlice = createSlice({
         }
       }
       const existing = state.sessions[action.payload.id];
+      // Don't let a stale "running" message overwrite a terminal status
+      const terminal = ['stopped', 'error'] as const;
+      if (existing && terminal.includes(existing.status as any) && action.payload.status === 'running') {
+        return;
+      }
       // Preserve local pending_approvals if the server payload has none but
       // the frontend has some (avoids race where backend clears approvals
       // before the frontend processes the removal).
@@ -559,6 +564,10 @@ const agentsSlice = createSlice({
     ) {
       const session = state.sessions[action.payload.sessionId];
       if (session) {
+        const terminal = ['stopped', 'error'] as const;
+        if (terminal.includes(session.status as any) && action.payload.status === 'running') {
+          return;
+        }
         session.status = action.payload.status;
       }
       if (action.payload.status === 'running' && !state.trackedNotificationIds.includes(action.payload.sessionId)) {