[Release] google/adk-python v1.20.0: 1.20.0

Google ADK Python v1.20.0 introduces multi-provider LLM support (Claude, LiteLLM), streaming function call arguments, and a new APIRegistryToolset for Cloud API integration. The release includes numerous bug fixes for agent validation, response processing, path handling, and LLM compatibility improvements.

Key Points

• •Add enum constraint validation to `agent_name` parameter in `transfer_to_agent` function for stricter type safety
• •Implement validation for unique sub-agent names to prevent naming conflicts in multi-agent architectures
• •Support streaming function call arguments in progressive SSE streaming for improved real-time response handling
• •Enable multi-provider LLM support for Claude and LiteLLM models to increase flexibility in model selection
• •Create APIRegistryToolset to seamlessly integrate Cloud API registry tools into agents without manual configuration
• •Add option to control runner plugin propagation in AgentTool to prevent unintended plugin inheritance
• •Implement new endpoint to list apps with detailed information for improved app management and visibility
• •Fix double response processing issue in bi-directional streaming mode that caused duplicated responses in multi-agent setups
• •Resolve quota errors by optimizing Stale Agent with GraphQL and Search API integration
• •Improve cross-platform compatibility with Windows path handling normalization in AgentLoader

Workflow Diagram

Concepts