Upload reference images

Several generation routes take a publicly reachable image URL as input — Seedance first/last frame. If your image only exists locally, upload it here first and use the returned URL in those requests.

Upload an image

Endpoint

POST https://inference-api-pre-d80ca3.worldrouter.ai/v1/images/uploads

Send multipart/form-data with a single file field named image:

curl

curl -X POST "https://inference-api-pre-d80ca3.worldrouter.ai/v1/images/uploads" \
-H "Authorization: Bearer your_api_key" \
-F "image=@./first-frame.png"

Typical response:

200 OK

{
"object": "image.upload",
"id": "imgupl_5f3a1c2e9b8d4e7fa61b2c3d4e5f6a7b",
"url": "https://oss.example.com/images/uploads/20260612/imgupl_5f3a....png?X-Amz-Signature=...",
"content_type": "image/png",
"size_bytes": 482133,
"expires_at": "2026-06-19T10:00:00+00:00"
}

Pass url directly as the first_frame / last_frame field of a Seedance generation request.

Limits and behavior

Accepted types: PNG, JPEG, WebP, GIF. The file content is sniffed — mislabeled files are rejected with 400.
Maximum size: 10 MiB (the dashboard Playground uploader caps at 4 MB).
The returned URL is presigned and expires after 7 days; uploaded objects are deleted on the same schedule. Re-upload if you need a fresh URL.
Uploads are authenticated with your API key but are not billed.

Tip:

Seedance reference images (reference_image roles) still require the asset flow — register the uploaded URL via the asset-group routes to obtain an asset:// URI. First/last frame fields accept the uploaded URL directly.

Troubleshooting

Symptom	Likely cause	What to do
`400` unsupported type	The file is not PNG/JPEG/WebP/GIF	Convert the image, or check the file is not corrupt.
`413` too large	The file exceeds the upload limit	Compress or resize the image, or host it yourself.
`503` storage unavailable	Object storage is temporarily unreachable	Retry shortly; nothing was stored.

Upload reference images

Upload an image

Limits and behavior

Troubleshooting

See also