langchain-ai/langgraph · error · ValueError

No cache is set for this graph. Cannot clear cache.

Error message

No cache is set for this graph. Cannot clear cache.

What it means

Error "No cache is set for this graph. Cannot clear cache." thrown in langchain-ai/langgraph.

Source

Thrown at libs/langgraph/langgraph/pregel/main.py:4139

                    chunks.append(chunk)

        if stream_mode == "values":
            if version == "v2":
                return GraphOutput(value=latest, interrupts=tuple(interrupts))
            if interrupts:
                return (
                    {**latest, INTERRUPT: interrupts}
                    if isinstance(latest, dict)
                    else {INTERRUPT: interrupts}
                )
            return latest
        else:
            return chunks

    def clear_cache(self, nodes: Sequence[str] | None = None) -> None:
        """Clear the cache for the given nodes."""
        if not self.cache:
            raise ValueError("No cache is set for this graph. Cannot clear cache.")
        nodes = nodes or self.nodes.keys()
        # collect namespaces to clear
        namespaces: list[tuple[str, ...]] = []
        for node in nodes:
            if node in self.nodes:
                namespaces.append(
                    (
                        CACHE_NS_WRITES,
                        (identifier(self.nodes[node]) or "__dynamic__"),
                        node,
                    ),
                )
        # clear cache
        self.cache.clear(namespaces)

    async def aclear_cache(self, nodes: Sequence[str] | None = None) -> None:
        """Asynchronously clear the cache for the given nodes."""
        if not self.cache:

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/langgraph/langgraph/pregel/main.py:4139 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/f6c46164c45e5893. Report an issue: GitHub.