**Highlights:**
- **Callback Chaining:** Now supports a list of before and after callbacks, as in the non-live version. Callbacks are executed in order, stopping when one returns a response.
- **Unit Tests:** Added new unit tests for before and after callbacks, async and sync versions, callback chains and mixed callbacks.
- **Sample Agent:** Introduced a new example agent with multiple callbacks showing various behaviors: audit, security, validation, and enhancement. This provides practical usage examples.
PiperOrigin-RevId: 783884562
This change adds activity start and end signals to the LiveRequestQueue,
allowing clients to manually control the start and end of user input in
streaming sessions when automatic voice activity detection is disabled.
The LiveRequestQueue allows users to send messages to the model with the following semantics:
- `content`: sends turn-by-turn content.
- `blob`: sends a media blob for realtime streaming (e.g., audio).
- `activity_start`: indicates the beginning of an activity.
- `activity_end`: indicates the end of an activity.
- `close`: closes the connection.
GeminiLLMConnection has been updated to send the new activity signals to the backend.
This change is a necessary to support clients (e.g. voice assistants) that do not want to use automatic voice activity detection. In this case, the client will be responsible to send the `activity_start` signal when the user starts talking, and `activity_end` when the user finishes talking.
To test the change:
run_config = RunConfig(
realtime_input_config=types.RealtimeInputConfig(
automatic_activity_detection=types.AutomaticActivityDetection(
disabled=True,
),
)
)
import threading # Add this import
def thread_target():
# Define the async operations to run in the background.
async def background_task():
live_request_queue.send_activity_start()
# live_request_queue.send_content(
# content=types.Content(
# role='user',
# parts=[types.Part.from_text(text="hi, what's the time?")],
# )
# )
await asyncio.sleep(3)
live_request_queue.send_activity_end()
PiperOrigin-RevId: 783882447
1. credential service may be accessed by callbacks
2. plan to add load_credential and save_credential method in CallbackContext (see cl/782158513) given customer has requirement to access credential service themselves. (see https://github.com/google/adk-python/issues/1816)
It's backward compatible given CallbackContext is parent class of ToolContext
PiperOrigin-RevId: 783480378
