NousResearch/hermes-agent · error · ValueError
unsupported_content_type
unsupported_content_type
Error message
unsupported_content_type:Only image data URLs are supported. Non-image data payloads are not supported.
What it means
Error "unsupported_content_type:Only image data URLs are supported. Non-image data payloads are not supported." thrown in NousResearch/hermes-agent.
Source
Thrown at gateway/platforms/api_server.py:628
if part_type in _IMAGE_PART_TYPES:
detail = part.get("detail")
image_ref = part.get("image_url")
# OpenAI Responses sends ``input_image`` with a top-level
# ``image_url`` string; Chat Completions sends ``image_url`` as
# ``{"url": "...", "detail": "..."}``. Support both.
if isinstance(image_ref, dict):
url_value = image_ref.get("url")
detail = image_ref.get("detail", detail)
else:
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, "View on GitHub (pinned to c896c09c42)
Solutions
- Send image parts as image data URLs only; remove non-image data payloads from content parts.
When it happens
Trigger: Thrown at gateway/platforms/api_server.py:628 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/36e6e11b633456bd.
Report an issue: GitHub.