Support audioStreamEnd in send_realtime for realtimeInput

src/google/adk/agents/live_request_queue.py

@@ -53,6 +53,14 @@ class LiveRequest(BaseModel):
  activity_end: Optional[types.ActivityEnd] = None
  """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. state_delta, if set, is always
+ applied regardless of the other fields.
+ """
+ audio_stream_end: Optional[bool] = None
+ """If set, signal the end of the audio stream to force flush buffered audio
+ when VAD (voice activity detection) is enabled.
+
  When multiple fields are set, they are processed by priority (highest first):
  activity_start > activity_end > blob > content. state_delta, if set, is always
  applied regardless of the other fields.
@@ -92,6 +100,14 @@ def send_activity_end(self) -> None:
  """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 buffered audio.
+
+ Use this to signal the end of an audio stream when VAD is enabled,
+ which causes the model to process any buffered audio immediately.
+ """
+ self._queue.put_nowait(LiveRequest(audio_stream_end=True))
+
  def send(self, req: LiveRequest) -> None:
  self._queue.put_nowait(req)
 

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

@@ -827,6 +827,8 @@ 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(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 +29,7 @@
 
 logger = logging.getLogger('google_adk.' + __name__)
 
-RealtimeInput = Union[types.Blob, types.ActivityStart, types.ActivityEnd]
+RealtimeInput = Union[types.Blob, types.ActivityStart, types.ActivityEnd, bool]
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
@@ -173,6 +173,9 @@ async def send_realtime(self, input: RealtimeInput) -> None:
  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, bool) and input:
+ logger.debug('Sending LLM audio stream end signal.')
+ await self._gemini_session.send_realtime_input(audio_stream_end=True)
  else:
  raise ValueError('Unsupported input type: %s' % type(input))
 

tests/unittests/models/test_gemini_llm_connection.py

@@ -89,6 +89,18 @@ async def test_send_realtime_audio_uses_audio_channel_for_live_translate(
  )
 
 
+@pytest.mark.asyncio
+async def test_send_realtime_audio_stream_end(
+ gemini_connection, mock_gemini_session
+):
+ """Test send_realtime with audio_stream_end=True sends the flush signal."""
+ await gemini_connection.send_realtime(True)
+
+ mock_gemini_session.send_realtime_input.assert_called_once_with(
+ audio_stream_end=True
+ )
+
+
 @pytest.mark.asyncio
 async def test_send_history(gemini_connection, mock_gemini_session):
  """Test send_history method."""