calesthio/OpenMontage · error · AtlasError

Atlas Cloud returned an unexpected 'data' field

Error message

Atlas Cloud returned an unexpected 'data' field: {str(data)[:500]}

What it means

Raised by _payload_of when the envelope has code 200 but its data field is not a JSON object (array, string, number, or boolean). This catches servers that acknowledge success yet attach a malformed data payload, breaking the downstream dict access (data.get('id'), data.get('status')). The offending value's first 500 characters are included.

Solutions

1. Log the included snippet to identify the actual shape, then compare with current Atlas API docs
2. If the shape is a legitimate new format, update the client handling for that endpoint instead of relying on the generic parser
3. Pin/request a stable API version header if Atlas exposes one
4. Report to Atlas support if HTTP 200 + code 200 + non-dict data appears on their standard endpoints

def has_dict_data(body: dict) -> bool:
    data = body.get("data")
    return data is None or isinstance(data, dict)

When it happens

Trigger: A poll returning data as a list of output URLs; a submit response with data as a bare prediction-id string; API version drift where data became a nested array per output format.

Common situations: Atlas API evolution changing the data shape; middleboxes rewriting responses; endpoints that legitimately return non-object data being routed through this generic client.

Related errors

• Atlas Cloud returned an unexpected payload
• Atlas Cloud did not return a prediction id
• Atlas Cloud upload returned no URL
• Ark query returned a non-object response
• Atlas Cloud returned a non-JSON response

AI-assisted analysis of calesthio/OpenMontage@95e1c3d0ab (2026-08-15). Data as JSON: /api/errors/ac8e01cac394ce12. Report an issue: GitHub.

Appendix: source

Thrown at tools/atlas_client.py:94

        body = response.json()
    except Exception as exc:  # noqa: BLE001 - surface the raw text, not a parse trace
        text = getattr(response, "text", "")
        raise AtlasError(f"Atlas Cloud returned a non-JSON response: {text[:500]}") from exc

    if not isinstance(body, dict):
        raise AtlasError(f"Atlas Cloud returned an unexpected payload: {str(body)[:500]}")

    code = body.get("code")
    if code is not None and int(code) != 200:
        message = body.get("message") or body.get("error") or str(body)[:500]
        raise AtlasError(f"Atlas Cloud error (code {code}): {message}")

    data = body.get("data")
    if data is None:
        # uploadMedia historically answered with a bare {"url": ...}.
        return body
    if not isinstance(data, dict):
        raise AtlasError(f"Atlas Cloud returned an unexpected 'data' field: {str(data)[:500]}")
    return data


def _raise_for_status(response: Any, context: str) -> None:
    status = getattr(response, "status_code", 200)
    if status >= 400:
        text = getattr(response, "text", "")
        raise AtlasError(f"{context} failed with HTTP {status}: {text[:500]}")


def submit(endpoint: str, payload: dict[str, Any], api_key: str, timeout: int = 60) -> str:
    """Submit a generation request and return its prediction id."""
    import requests

    try:
        response = requests.post(
            endpoint, headers=_headers(api_key), json=payload, timeout=timeout
        )

View on GitHub (pinned to 95e1c3d0ab)