langchain-ai/langgraph · error · NotImplementedError

RemoteGraph.stream_events(version='v3') does not support `{n

Error message

RemoteGraph.stream_events(version='v3') does not support `{name}=`.

What it means

Error "RemoteGraph.stream_events(version='v3') does not support `{name}=`." thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/pregel/remote.py:212

    def _reject_v3_unsupported(
        self,
        *,
        control: Any,
        transformers: Any,
        interrupt_before: Any,
        interrupt_after: Any,
        extra_kwargs: dict[str, Any],
    ) -> None:
        """Raise NotImplementedError for kwargs unsupported by the v3 streaming path."""
        for name, value in (
            ("control", control),
            ("transformers", transformers),
            ("interrupt_before", interrupt_before),
            ("interrupt_after", interrupt_after),
        ):
            if value:
                raise NotImplementedError(
                    f"RemoteGraph.stream_events(version='v3') does not support `{name}=`."
                )
        unknown = set(extra_kwargs) - _V3_SUPPORTED_KWARGS
        if unknown:
            raise NotImplementedError(
                f"RemoteGraph.stream_events(version='v3') does not support "
                f"the following kwargs: {sorted(unknown)!r}. "
                f"Supported: {sorted(_V3_SUPPORTED_KWARGS)!r}."
            )

    def copy(self, update: dict[str, Any]) -> Self:
        attrs = {**self.__dict__, **update}
        return self.__class__(attrs.pop("assistant_id"), **attrs)

    def with_config(self, config: RunnableConfig | None = None, **kwargs: Any) -> Self:
        return self.copy(
            {"config": merge_configs(self.config, config, cast(RunnableConfig, kwargs))}
        )

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/pregel/remote.py:212 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/a184a503c460b06a. Report an issue: GitHub.