fix: realtime agent handoff race conditions

livekit-agents/livekit/agents/voice/agent_activity.py

@@ -2690,6 +2690,10 @@ def _create_assistant_message(
             if fnc_executed_ev._handoff_required and new_agent_task and not ignore_task_switch:
                 self._session.update_agent(new_agent_task)
                 draining = True
+                # Skip chat context update and reply creation - the new agent will handle this.
+                # The old realtime session is being closed by update_agent(), so we cannot
+                # continue using self._rt_session after this point.
+                return
 
             if len(new_fnc_outputs) > 0:
                 # wait all speeches played before updating the tool output and generating the response

livekit-agents/livekit/agents/voice/agent_session.py

@@ -1108,7 +1108,12 @@ async def _update_activity_task(
         if old_task is not None:
             await old_task
 
-        await self._update_activity(agent)
+        # If the target agent has an existing activity (was paused), resume it
+        # Otherwise, start a new activity
+        if agent._activity is not None:
+            await self._update_activity(agent, new_activity="resume")
+        else:
+            await self._update_activity(agent)
 
     def _on_error(
         self,

livekit-plugins/livekit-plugins-cambai/livekit/plugins/cambai/version.py

@@ -1,2 +1 @@
 __version__ = "1.4.1"
-

livekit-plugins/livekit-plugins-google/livekit/plugins/google/realtime/realtime_api.py

@@ -282,7 +282,7 @@ def __init__(
                 user_transcription=input_audio_transcription is not None,
                 auto_tool_reply_generation=True,
                 audio_output=types.Modality.AUDIO in modalities,
-                manual_function_calls=False,
+                manual_function_calls=True,
             )
         )