NousResearch/hermes-agent · error · ValueError

invalid_content_part

invalid_content_part

Error message

invalid_content_part:Image detail must be a non-empty string when provided.

What it means

Error "invalid_content_part:Image detail must be a non-empty string when provided." thrown in NousResearch/hermes-agent.

Source

Thrown at gateway/platforms/api_server.py:639

                url_value = image_ref
            if not isinstance(url_value, str) or not url_value.strip():
                raise ValueError("invalid_image_url:Image parts must include a non-empty image URL.")
            url_value = url_value.strip()
            lowered = url_value.lower()
            if lowered.startswith("data:"):
                if not lowered.startswith("data:image/") or "," not in url_value:
                    raise ValueError(
                        "unsupported_content_type:Only image data URLs are supported. "
                        "Non-image data payloads are not supported."
                    )
            elif not (lowered.startswith("http://") or lowered.startswith("https://")):
                raise ValueError(
                    "invalid_image_url:Image inputs must use http(s) URLs or data:image/... URLs."
                )
            image_part: Dict[str, Any] = {"type": "image_url", "image_url": {"url": url_value}}
            if detail is not None:
                if not isinstance(detail, str) or not detail.strip():
                    raise ValueError("invalid_content_part:Image detail must be a non-empty string when provided.")
                image_part["image_url"]["detail"] = detail.strip()
            normalized_parts.append(image_part)
            continue

        if part_type in _FILE_PART_TYPES:
            raise ValueError(
                "unsupported_content_type:Inline image inputs are supported, "
                "but uploaded files and document inputs are not supported on this endpoint."
            )

        # Unknown part type — reject explicitly so clients get a clear error
        # instead of a silently dropped turn.
        raise ValueError(
            f"unsupported_content_type:Unsupported content part type {raw_type!r}. "
            "Only text and image_url/input_image parts are supported."
        )

    if not normalized_parts:

View on GitHub (pinned to c896c09c42)

Solutions

1. Provide a non-empty detail string on image parts, or omit the detail field.

When it happens

Trigger: Thrown at gateway/platforms/api_server.py:639 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of NousResearch/hermes-agent@c896c09c42 (2026-08-14). Data as JSON: /api/errors/8f1783427cfa8ab3. Report an issue: GitHub.