adk-callbacks-hitl

Human-in-the-loop approval gates in Google ADK are implemented by configuring callback workflows that block sensitive tool execution until human approval is granted via state management.

ADK agent callbacks fail silently due to incorrect parameter matching during injection. This skill prevents silent failures by providing exact signatures for before and after model and tool callbacks.

You manage persistent state across ADK multi-agent pipelines by applying the correct state_delta usage for BaseAgent subclasses, ensuring state synchronization persists across multiple agent turns.

The best way to enforce input guardrails in an ADK agent is to utilize lifecycle hooks that intercept inputs before model processing, ensuring technical compliance with keyword-based callback injection.

No specific external dependencies are required to manage ADK callbacks. This skill provides reference components that define exact callback signatures and state management patterns natively.

You should use tool execution gates when your ADK agent workflow requires blocking sensitive operations, ensuring defensive tool execution only proceeds after validating human-in-the-loop approval.