langgraph-human-in-the-loop

To pause a LangGraph workflow for human review, use the interrupt function to suspend execution and surface data for human inspection. This enables reliable human-in-the-loop control before safely resuming the graph.

The best way to resume a LangGraph graph after an interrupt is using Command(resume=...) with your human-provided input. This restarts execution with validated decisions and supports both single and multi-interrupt coordination.

Yes, you need a checkpointer to use human-in-the-loop patterns in LangGraph. A checkpointer, along with a thread_id and JSON-serializable payload, is required to persist state across interrupt pauses and resume execution reliably.

Yes, LangGraph handles multiple interrupts and subgraph re-execution. It coordinates multi-interrupt flows and includes safeguards against duplicative side effects and lost state when re-executing subgraphs with human input.

Interrupt-based error handling in LangGraph workflows works by pausing execution upon errors using interrupt, routing to validation or approval loops, and resuming with Command(resume=...) to apply human-provided corrections safely.