langchain-ai/langgraph · error · ValueError

snapshot_frequency must be a positive int, got {snapshot_fre

Error message

snapshot_frequency must be a positive int, got {snapshot_frequency}

What it means

Error "snapshot_frequency must be a positive int, got {snapshot_frequency}" thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/channels/delta.py:77

            and batching-invariant as described above.
        typ: The value type (e.g. `list`, `dict`). Inferred automatically
            from the outer type when used inside `Annotated[T, DeltaChannel(...)]`.
        snapshot_frequency: Every Nth update to this channel writes a snapshot
            blob (default `1000`). Must be a positive int.
    """

    __slots__ = ("value", "reducer", "snapshot_frequency")
    value: Value | Any

    def __init__(
        self,
        reducer: Callable[[Any, Sequence[Any]], Any],
        typ: type[Value] | None = None,
        *,
        snapshot_frequency: int = 1000,
    ) -> None:
        if snapshot_frequency <= 0:
            raise ValueError(
                f"snapshot_frequency must be a positive int, got {snapshot_frequency}"
            )
        if typ is None:
            typ = list  # type: ignore[assignment]  # placeholder; overridden by _is_field_channel
        super().__init__(typ)
        self.reducer = reducer
        self.snapshot_frequency = snapshot_frequency
        typ = _strip_extras(typ)
        if typ in (collections.abc.Sequence, collections.abc.MutableSequence):
            typ = list
        if typ in (collections.abc.Set, collections.abc.MutableSet):
            typ = set
        if typ in (collections.abc.Mapping, collections.abc.MutableMapping):
            typ = dict
        self.typ = typ
        self.value: Any = MISSING

    def __eq__(self, other: object) -> bool:

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/channels/delta.py:77 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/8d59f8aa5cb602e6. Report an issue: GitHub.