feat: support audio_stream_end for realtime input

src/google/adk/agents/live_request_queue.py

@@ -24,35 +24,33 @@
 
 
 class LiveRequest(BaseModel):
- """Request send to live agents."""
+ """Request send to live agents.
+
+ When multiple fields are set, they are processed by priority (highest first):
+ activity_start > activity_end > audio_stream_end > blob > content.
+ state_delta, if set, is always applied regardless of the other fields.
+ """
 
  model_config = ConfigDict(ser_json_bytes='base64', val_json_bytes='base64')
  """The pydantic model config."""
 
  content: Optional[types.Content] = None
- """If set, send the content to the model in turn-by-turn mode.
+ """If set, send the content to the model in turn-by-turn mode."""
 
- When multiple fields are set, they are processed by priority (highest first):
- activity_start > activity_end > blob > content.
- """
  blob: Optional[types.Blob] = None
- """If set, send the blob to the model in realtime mode.
+ """If set, send the blob to the model in realtime mode."""
 
- When multiple fields are set, they are processed by priority (highest first):
- activity_start > activity_end > blob > content.
- """
  activity_start: Optional[types.ActivityStart] = None
- """If set, signal the start of user activity to the model.
+ """If set, signal the start of user activity to the model."""
 
- When multiple fields are set, they are processed by priority (highest first):
- activity_start > activity_end > blob > content.
- """
  activity_end: Optional[types.ActivityEnd] = None
- """If set, signal the end of user activity to the model.
+ """If set, signal the end of user activity to the model."""
 
- When multiple fields are set, they are processed by priority (highest first):
- activity_start > activity_end > blob > content.
+ audio_stream_end: bool = False
+ """If set, signal the end of the audio stream to the model. This is only used
+ when Voice Activity Detection is enabled.
  """
+
  close: bool = False
  """If set, close the queue. queue.shutdown() is only supported in Python 3.13+."""
 
@@ -80,6 +78,10 @@ def send_activity_end(self):
  """Sends an activity end signal to mark the end of user input."""
  self._queue.put_nowait(LiveRequest(activity_end=types.ActivityEnd()))
 
+ def send_audio_stream_end(self) -> None:
+ """Sends an audio stream end signal to force flush audio."""
+ self._queue.put_nowait(LiveRequest(audio_stream_end=True))
+
  def send(self, req: LiveRequest):
  self._queue.put_nowait(req)
 

src/google/adk/flows/llm_flows/base_llm_flow.py

@@ -768,6 +768,10 @@ async def _send_to_model(
  await llm_connection.send_realtime(types.ActivityStart())
  elif live_request.activity_end:
  await llm_connection.send_realtime(types.ActivityEnd())
+ elif live_request.audio_stream_end:
+ await llm_connection.send_realtime(
+ types.LiveClientRealtimeInput(audio_stream_end=True)
+ )
  elif live_request.blob:
  # Cache input audio chunks before flushing
  self.audio_cache_manager.cache_audio(

src/google/adk/models/gemini_llm_connection.py

@@ -29,7 +29,12 @@
 
 logger = logging.getLogger('google_adk.' + __name__)
 
-RealtimeInput = Union[types.Blob, types.ActivityStart, types.ActivityEnd]
+RealtimeInput = Union[
+ types.Blob,
+ types.ActivityStart,
+ types.ActivityEnd,
+ types.LiveClientRealtimeInput,
+]
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
@@ -157,6 +162,12 @@ async def send_realtime(self, input: RealtimeInput):
  elif isinstance(input, types.ActivityEnd):
  logger.debug('Sending LLM activity end signal.')
  await self._gemini_session.send_realtime_input(activity_end=input)
+ elif isinstance(input, types.LiveClientRealtimeInput):
+ if input.audio_stream_end:
+ logger.debug('Sending LLM audio stream end signal.')
+ await self._gemini_session.send_realtime_input(audio_stream_end=True)
+ else:
+ logger.warning('Unary LiveClientRealtimeInput not fully supported yet.')
  else:
  raise ValueError('Unsupported input type: %s' % type(input))
 

tests/unittests/models/test_gemini_llm_connection.py

@@ -71,6 +71,37 @@ async def test_send_realtime_default_behavior(
  mock_gemini_session.send.assert_not_called()
 
 
+@pytest.mark.asyncio
+async def test_send_realtime_audio_stream_end(
+ gemini_connection, mock_gemini_session
+):
+ """Test send_realtime with LiveClientRealtimeInput(audio_stream_end=True)."""
+ input_signal = types.LiveClientRealtimeInput(audio_stream_end=True)
+ await gemini_connection.send_realtime(input_signal)
+
+ # Should call send_realtime_input with audio_stream_end=True
+ mock_gemini_session.send_realtime_input.assert_called_once_with(
+ audio_stream_end=True
+ )
+
+
+@pytest.mark.asyncio
+async def test_send_realtime_unsupported_liveClientRealtimeInput(
+ gemini_connection, mock_gemini_session, caplog
+):
+ """Test send_realtime with unsupported LiveClientRealtimeInput."""
+ input_signal = types.LiveClientRealtimeInput()
+
+ with caplog.at_level('WARNING'):
+ await gemini_connection.send_realtime(input_signal)
+
+ # Should log a warning
+ assert 'Unary LiveClientRealtimeInput not fully supported yet.' in caplog.text
+ # Should not call send_realtime_input or send
+ mock_gemini_session.send_realtime_input.assert_not_called()
+ mock_gemini_session.send.assert_not_called()
+
+
 @pytest.mark.asyncio
 async def test_send_history(gemini_connection, mock_gemini_session):
  """Test send_history method."""