langchain-ai/langgraph · error · RuntimeError

thread.run.respond: ambiguous — {len(outstanding)} outstandi

Error message

thread.run.respond: ambiguous — {len(outstanding)} outstanding interrupts ({ids!r}). Provide an explicit `interrupt_id`.

What it means

Error "thread.run.respond: ambiguous — {len(outstanding)} outstanding interrupts ({ids!r}). Provide an explicit `interrupt_id`." thrown in langchain-ai/langgraph.

Source

Thrown at libs/sdk-py/langgraph_sdk/_async/stream.py:244

            RuntimeError: no outstanding interrupts; `interrupt_id` is None but
                multiple interrupts are outstanding; or the explicit
                `interrupt_id` doesn't match any outstanding interrupt.
        """
        # Why: take the `interrupts` snapshot AND dispatch the command under
        # `_interrupts_lock`, so the lifecycle watcher's terminal-clear path
        # cannot wipe `interrupts` between the snapshot and the wire send.
        async with self._owner._interrupts_lock:
            outstanding = list(self._owner.interrupts)
            if interrupt_id is None:
                if len(outstanding) == 0:
                    raise RuntimeError(
                        "thread.run.respond: no outstanding interrupt. Provide "
                        "an explicit `interrupt_id` or wait for "
                        "`thread.interrupted`."
                    )
                if len(outstanding) > 1:
                    ids = [p["interrupt_id"] for p in outstanding]
                    raise RuntimeError(
                        f"thread.run.respond: ambiguous — {len(outstanding)} "
                        f"outstanding interrupts ({ids!r}). Provide an explicit "
                        "`interrupt_id`."
                    )
                match = outstanding[0]
            else:
                match = next(
                    (p for p in outstanding if p["interrupt_id"] == interrupt_id),
                    None,
                )
                if match is None:
                    raise RuntimeError(
                        f"thread.run.respond: interrupt_id {interrupt_id!r} does "
                        "not match any outstanding interrupt in "
                        "`thread.interrupts`."
                    )
            params = {
                "interrupt_id": match["interrupt_id"],

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/sdk-py/langgraph_sdk/_async/stream.py:244 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of langchain-ai/langgraph@38031739e5 (2026-08-26). Data as JSON: /api/errors/c723c67299d9d9d2. Report an issue: GitHub.