Bytedance Seedance 2.0 Fast

Endpoint

POST /videos/generations

Full URL: https://modelfold.ai/v1/videos/generations

Authentication: every request must include the Authorization: Bearer <API_KEY> header.

Send model parameters directly in the JSON body. Do not wrap them in input. This request waits for generation to finish and returns data[].url; supported media models also offer async jobs, polling and callbacks. Replace example media URLs with your own publicly accessible files. See API gateway for billing and errors.

Input parameters for the generation task

Request Parameters

Body (application/json)

Parameter	Type	Required	Description
model	string	Yes	The model name to use for generation. Required field. - Must be bytedance/seedance-2-fast for this endpoint Default："bytedance/seedance-2-fast"。 Allowed values：bytedance/seedance-2-fast。 Example：bytedance/seedance-2-fast。
prompt	string	Yes	Prompt required by the ModelFold gateway; at most 2000 characters. The text prompt used to generate the video. Required field. (Min length: 3, Max length: 20000 characters) minLength: 3. maxLength: 2000. Example：A serene beach at sunset with waves gently crashing on the shore, palm trees swaying in the breeze, and seagulls flying across the orange sky。
first_frame_url	string	No	First frame image url or asset://{assetId} (for example: asset://asset-20260404242101-76djj)
last_frame_url	string	No	End frame image url or asset://{assetId} (for example: asset://asset-20260404242101-76djj)
reference_image_urls	array<string>	No	Enter a list of image URLs or asset://{assetId} (for example: asset://asset-20260404242101-76djj). Single image requirements: Format: jpeg, png, webp, bmp, tiff, gif. Aspect ratio (width/height): (0.4, 2.5) Width and height (px): (300, 6000) Size: Single image less than 30 MB. Up to 9 images. maxItems: 9.
reference_video_urls	array<string>	No	Enter a list of video URLs or asset://{assetId} (for example: asset://asset-20260404242101-76djj). Single video requirements: Video format: mp4, mov. Resolution: 480p, 720p Duration: Single video duration [2, 15] s, maximum 3 reference videos, total duration of all videos not exceeding 15 seconds. Dimensions: Aspect ratio (width/height): [0.4, 2.5] Width/height (px): [300, 6000] Total pixels: [640×640=409600, 834×1112=927408], i.e., the product of width and height must meet the range requirement of [409600, 927408]. Size: Single video not exceeding 50 MB. Frame rate (FPS): [24, 60] maxItems: 3.
reference_audio_urls	array<string>	No	Enter a list of audio URLs or asset://{assetId} (for example: asset://asset-20260404242101-76djj). Single audio requirements: Format: wav, mp3 Duration: Single audio duration [2, 15] s, maximum 3 reference audios, total duration of all audios not exceeding 15 s. Size: Single audio file size not exceeding 15 MB. maxItems: 3.
return_last_frame	boolean	No	Whether to return the last frame of the video as an image. Default：false。 Example：false。
generate_audio	boolean	No	Whether to generate audio for the video. - true: Generate with audio - false: Generate without audio Default：true。 Example：false。
resolution	string	No	Video resolution - 480p for faster generation, 720p for balance Default："720p"。 Allowed values：480p / 720p。 Example：720p。
aspect_ratio	string	No	Video aspect ratio configuration. Required field. Default："16:9"。 Allowed values：1:1 / 4:3 / 3:4 / 16:9 / 9:16 / 21:9 / adaptive。 Example：16:9。
duration	integer	No	Video duration in 4-15 seconds or -1. ModelFold minimum: 4 seconds; -1 is not supported. Default：5。 Example：5。
web_search	boolean	No	Use online search. Text-to-video only.
nsfw_checker	boolean	No	Defaults to false. When false, no additional content filtering is applied and results are returned directly by the model.

Request Example

curl -X POST "https://modelfold.ai/v1/videos/generations" \
  -H "Authorization: Bearer $MODELFOLD_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "bytedance/seedance-2-fast",
  "prompt": "A serene beach at sunset with waves gently crashing on the shore, palm trees swaying in the breeze, and seagulls flying across the orange sky",
  "return_last_frame": false,
  "generate_audio": true,
  "resolution": "720p",
  "aspect_ratio": "16:9",
  "duration": 5
}'

{
  "model": "bytedance/seedance-2-fast",
  "prompt": "A serene beach at sunset with waves gently crashing on the shore, palm trees swaying in the breeze, and seagulls flying across the orange sky",
  "return_last_frame": false,
  "generate_audio": true,
  "resolution": "720p",
  "aspect_ratio": "16:9",
  "duration": 5
}

Response

200 — Generation completed. usage contains actual billing details; result URLs are illustrative.

{
  "ok": true,
  "created": 1792134000,
  "data": [
    {
      "url": "https://modelfold.ai/uploads/outputs/result.mp4"
    }
  ],
  "usage": {}
}