Model
bytedance/seedance-1.0-pro-fast
Request types
| Request type | Required inputs | Optional inputs | Notes |
|---|---|---|---|
| Text-to-video | prompt | aspect_ratio, duration, resolution, camera_fixed, seed | No frame URLs |
| Image-to-video | first_frame_url | prompt, duration, resolution, camera_fixed, seed | prompt optional. Does not support last_frame_url |
Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
prompt | string | Conditional | "" | Text prompt (max 5000 chars). Required for text-to-video. Optional for image-to-video when first_frame_url is set |
aspect_ratio | string | No | "16:9" | 1:1, 3:4, 4:3, 9:16, 16:9, 21:9 |
duration | integer | No | 4 | Output duration in seconds (4–12). Sent to provider as frames = 24 × seconds + 1 |
resolution | string | No | "480p" | 480p, 720p, 1080p |
seed | integer | No | — | Seed for reproducibility. Omit for a random seed. |
camera_fixed | boolean | No | false | When true, keeps the virtual camera stationary throughout the clip |
first_frame_url | string | No | null | Start frame image URL for image-to-video. Formats: png, webp, jpeg, gif. Max 30 MB. Dimensions: 300–6000 px (short side). Aspect ratio: 0.4–2.5 |
Example - Text-to-Video
curl -X POST https://api.unifically.com/v1/tasks \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "bytedance/seedance-1.0-pro-fast",
"input": {
"prompt": "A person breakdancing in an urban setting",
"aspect_ratio": "9:16",
"duration": 10,
"resolution": "1080p"
}
}'
Example - Image-to-Video
curl -X POST https://api.unifically.com/v1/tasks \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY" \
-d '{
"model": "bytedance/seedance-1.0-pro-fast",
"input": {
"prompt": "The subject begins to walk forward slowly",
"first_frame_url": "https://example.com/standing.jpg",
"duration": 5,
"resolution": "720p"
}
}'
Response
{
"code": 200,
"success": true,
"data": {
"task_id": "abc123def456",
"status": "processing"
}
}