langchain-ai/langgraph · error · ValueError

Invalid managed channels detected in {schema_name}: {names}.

Error message

Invalid managed channels detected in {schema_name}: {names}. Managed channels are not permitted in Input/Output schema.

What it means

Error "Invalid managed channels detected in {schema_name}: {names}. Managed channels are not permitted in Input/Output schema." thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/graph/state.py:350

            defaults.error_handler = error_handler
        if timeout is not None:
            defaults.timeout = coerce_timeout_policy(timeout)
        return self

    @property
    def _all_edges(self) -> set[tuple[str, str]]:
        return self.edges | {
            (start, end) for starts, end in self.waiting_edges for start in starts
        }

    def _add_schema(self, schema: type[Any], /, allow_managed: bool = True) -> None:
        if schema not in self.schemas:
            _warn_invalid_state_schema(schema)
            channels, managed, type_hints = _get_channels(schema)
            if managed and not allow_managed:
                names = ", ".join(managed)
                schema_name = getattr(schema, "__name__", "")
                raise ValueError(
                    f"Invalid managed channels detected in {schema_name}: {names}."
                    " Managed channels are not permitted in Input/Output schema."
                )
            self.schemas[schema] = {**channels, **managed}
            for key, channel in channels.items():
                if key in self.channels:
                    if self.channels[key] != channel:
                        if isinstance(channel, LastValue):
                            pass
                        else:
                            raise ValueError(
                                f"Channel '{key}' already exists with a different type"
                            )
                else:
                    self.channels[key] = channel
            for key, managed in managed.items():
                if key in self.managed:
                    if self.managed[key] != managed:

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/graph/state.py:350 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/05aa299928fcad14. Report an issue: GitHub.