Merge https://github.com/google/adk-python/pull/1130
This enables the use of the `model-optimizer-*` family of models in vertex, as per the [documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/vertex-ai-model-optimizer#using-vertex-ai-model-optimizer).
To use this, ensure your location is set to `global` and pass a model optimizer model to an agent:
```python
root_agent = Agent(
model="model-optimizer-exp-04-09",
name="fast_and_slow_agent",
instruction="Answer any question the user gives you - easy or hard.",
generate_content_config=types.GenerateContentConfig(
temperature=0.01,
model_selection_config=ModelSelectionConfig(
feature_selection_preference=FeatureSelectionPreference.BALANCED
# Options: PRIORITIZE_QUALITY, BALANCED, PRIORITIZE_COST
)
),
)
```
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/1130 from calvingiles:feat-model-optimizer 1a76bfa22420edb07d83415dcea6dd0114084e8e
PiperOrigin-RevId: 784921913
Now the LangchainTool can wrap:
* Langchain StructuredTool (sync and async).
* Langchain @Tool (sync and async).
This enhance the flexibility for user and enables async functionalities.
PiperOrigin-RevId: 784728061
**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
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
This is to support model path like :
projects/265104255505/locations/us-central1/publishers/google/models/gemini-2.0-flash-001"
PiperOrigin-RevId: 783413351
