Add audioStreamEnd support for realtimeInput in GeminiLlmConnection

src/google/adk/agents/live_request_queue.py

@@ -57,6 +57,14 @@ class LiveRequest(BaseModel):
  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 to True, signal that the audio stream has ended (e.g. microphone
+ turned off) to force flush buffered audio with VAD enabled.
+
+ 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.
+ """
  close: bool = False
  """If set, close the queue. queue.shutdown() is only supported in Python 3.13+."""
 
@@ -92,6 +100,10 @@ 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 with VAD."""
+ 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))