Generate video between first and last frames

Prepare the frames

1. 01Host two imagesUpload both frames to publicly reachable HTTPS URLs.
2. 02Reference them in orderUse @图片1 and @图片2 in the same order as references.
3. 03Assign the rolesThe first item is first_frame and the second is last_frame.
4. 04Submit and pollWait for completed, then read metadata.url.

{
  "model": "seedance2.0",
  "prompt": "The person moves naturally from @图片1 to @图片2 while the camera stays stable",
  "seconds": 5,
  "resolution": "720p",
  "aspect_ratio": "16:9",
  "references": [
    {
      "type": "image",
      "role": "first_frame",
      "source": "https://cdn.example.com/first-frame.png"
    },
    {
      "type": "image",
      "role": "last_frame",
      "source": "https://cdn.example.com/last-frame.png"
    }
  ]
}

Common causes of failure

• Only one of the two frames is submitted.
• A first or last frame is not an image.
• First/last frames are mixed with reference video or audio.
• The prompt omits a submitted material or uses a different order.
• A localhost, private IP, HTTP, hotlink-protected, or signed temporary URL is used.