langchain-ai/langgraph · error · EmptyChannelError

EmptyChannelError

Error message

EmptyChannelError

What it means

Error "EmptyChannelError" thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/channels/any_value.py:65

        empty = self.__class__(self.typ, self.key)
        if checkpoint is not MISSING:
            empty.value = checkpoint
        return empty

    def update(self, values: Sequence[Value]) -> bool:
        if len(values) == 0:
            if self.value is MISSING:
                return False
            else:
                self.value = MISSING
                return True

        self.value = values[-1]
        return True

    def get(self) -> Value:
        if self.value is MISSING:
            raise EmptyChannelError()
        return self.value

    def is_available(self) -> bool:
        return self.value is not MISSING

    def checkpoint(self) -> Value:
        return self.value

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/channels/any_value.py:65 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/3228b45da1216d04. Report an issue: GitHub.