langgraph-human-in-the-loop

• interrupt(value) — pauses execution, surfaces a value to the caller
• Command(resume=value) — resumes execution, providing the value back to interrupt()
• Checkpointer — required to save state while paused
• Thread ID — required to identify which paused execution to resume

Requirements

Three things are required for interrupts to work:

1. Checkpointer — compile with checkpointer=InMemorySaver() (dev) or PostgresSaver (prod)
2. Thread ID — pass {"configurable": {"thread_id": "..."}} to every invoke/stream call
3. JSON-serializable payload — the value passed to interrupt() must be JSON-serializable