langgraph-human-in-the-loop

To pause LangGraph execution for human approval, use the interrupt() function to halt the graph and surface data to the user, then resume execution with Command(resume=...). This workflow ensures safe and controlled AI actions.

Maintaining state across LangGraph interruptions requires a configured checkpointer and a thread identifier. These components capture the graph's state during the pause and enable it to resume correctly after human validation.

Command(resume=...) works by continuing LangGraph execution with the provided user response. It can handle approval workflows, validation loops, and multiple parallel interrupts to manage complex human-in-the-loop decision gating.

Use human-in-the-loop interrupt boundaries in AI agent workflows when user validation, error handling, or decision gating is necessary. This prevents unsafe actions by ensuring human oversight before an agent executes sensitive operations.

Handling idempotent side effects and subgraph re-execution during a LangGraph pause involves configuring the interrupt to safely manage state. This ensures reliable human-in-the-loop implementations without duplicating actions upon graph resumption.