Runtime

User provided context

Run-scoped control plane for cooperative draining.

Populated automatically during graph runs. Nodes can read runtime.control.drainRequested / drainReason, or call runtime.control.requestDrain() to ask the graph to stop at the next superstep boundary. Undefined outside an active graph runtime.

Read-only execution information/metadata for the current node run. Undefined before task preparation.

Manually signal that the node is still making progress, resetting the idleTimeout of the node's TimeoutPolicy (if configured).

This is a no-op when the node has no idleTimeout configured. It is the only progress signal when refreshOn is "heartbeat", and is useful for long-running work that doesn't otherwise emit writes, stream events, child tasks, or callback events.

Interrupts the execution of a graph node.

This function can be used to pause execution of a node, and return the value of the resume input when the graph is re-invoked using Command. Multiple interrupts can be called within a single node, and each will be handled sequentially.

When an interrupt is called:

1. If there's a resume value available (from a previous Command), it returns that value.
2. Otherwise, it throws a GraphInterrupt with the provided value
3. The graph can be resumed by passing a Command with a resume value

Because the interrupt function propagates by throwing a special GraphInterrupt error, you should avoid using try/catch blocks around the interrupt function, or if you do, ensure that the GraphInterrupt error is thrown again within your catch block.

Metadata injected by LangGraph Server. Undefined when running open-source LangGraph without LangSmith deployments.

Abort signal to cancel the run.

Persistent key-value store

Callback to send custom data chunks via the custom stream mode