ATH-MaaS/Pixelle-Video · error · HTTPException

str(e)

Error message

str(e)

What it means

The /image/generate endpoint wraps image generation in a broad except Exception and re-raises any unexpected failure as HTTP 500 with str(e) as the detail. HTTPExceptions (like the video-workflow 400 above) are re-raised unchanged. This 500 means the generation pipeline itself failed — workflow lookup, execution, or result handling — with the internal error text exposed to the client.

Source

Thrown at api/routers/image.py:69

            workflow=request.workflow
        )
        
        # For backward compatibility, only support image results in /image endpoint
        if media_result.is_video:
            raise HTTPException(
                status_code=400,
                detail="Video workflow used. Please use /media/generate endpoint for video generation."
            )
        
        return ImageGenerateResponse(
            image_path=media_result.url
        )
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Image generation error: {e}")
        raise HTTPException(status_code=500, detail=str(e))

View on GitHub (pinned to 848b054e4f)

Solutions

  1. Check server logs for 'Image generation error:' to identify the root cause
  2. Verify the generation backend (e.g. ComfyUI) is running and reachable
  3. Confirm the requested workflow exists and is an image workflow
  4. Retry the request if the failure was a transient timeout
  5. Server-side: return a generic detail instead of str(e) and log the stack trace

Example fix

// before
except Exception as e:
    logger.error(f"Image generation error: {e}")
    raise HTTPException(status_code=500, detail=str(e))
// after
except Exception:
    logger.exception("Image generation error")
    raise HTTPException(status_code=500, detail="Image generation failed; see server logs")
Defensive patterns

Strategy: try-catch

Validate before calling

// verify backend health and workflow validity before generating
const health = await fetch(`${base}/health`).then(r => r.ok);
const workflows = (await fetch(`${base}/workflows/image`).then(r => r.json())).workflows;
if (!health || !workflows.some(w => w.id === request.workflow)) throw new Error('Backend down or unknown workflow');

Type guard

function isImageResult(m) { return m != null && typeof m === 'object' && m.is_video === false && typeof m.url === 'string'; }

Try / catch

try {
  const res = await fetch('/image/generate', {method:'POST', body: JSON.stringify(req)});
  if (!res.ok) throw Object.assign(new Error((await res.json().catch(()=>({}))).detail ?? 'generation failed'), {status: res.status});
  return await res.json();
} catch (err) {
  if (err.status >= 500 && attempts < 3) return retryWithBackoff();
  throw err;
}

Prevention

When it happens

Trigger: POST /image/generate where the underlying media service call throws: ComfyUI/workflow engine unreachable, workflow JSON invalid, model missing, timeout, or unexpected response shape from media generation.

Common situations: Backend ComfyUI service down or restarting; workflow file removed or renamed after a version upgrade; GPU OOM during inference; network timeout between API and generation backend.

Related errors

AI-assisted analysis of ATH-MaaS/Pixelle-Video@848b054e4f (2026-08-30). Data as JSON: /api/errors/e7c455132d73299e. Report an issue: GitHub.