langchain-ai/langgraph · error · HostBackendError

{method} {path} failed with status {err.response.status_code

Error message

{method} {path} failed with status {err.response.status_code}: {detail}

What it means

Error "{method} {path} failed with status {err.response.status_code}: {detail}" thrown in langchain-ai/langgraph.

Source

Thrown at libs/cli/langgraph_cli/host_backend.py:57

            base_url=self._base_url,
            headers=headers,
            transport=transport,
            timeout=30,
        )

    def _request(
        self,
        method: str,
        path: str,
        payload: dict[str, Any] | None = None,
        params: dict[str, Any] | None = None,
    ) -> Any:
        try:
            resp = self._client.request(method, path, json=payload, params=params)
            resp.raise_for_status()
        except httpx.HTTPStatusError as err:
            detail = err.response.text or str(err.response.status_code)
            raise HostBackendError(
                f"{method} {path} failed with status {err.response.status_code}: {detail}",
                status_code=err.response.status_code,
            ) from None
        except httpx.TransportError as err:
            raise HostBackendError(str(err)) from None

        if not resp.content:
            return None
        try:
            return resp.json()
        except ValueError as err:
            raise HostBackendError(
                f"Failed to decode response from {path}: {err}"
            ) from None

    def create_deployment(
        self,
        name: str,

View on GitHub (pinned to 38031739e5)

When it happens

Trigger: Thrown at libs/cli/langgraph_cli/host_backend.py:57 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/076a86ed0b1ae70d. Report an issue: GitHub.