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Generate videos using ByteDance SeeDance 1.0 Pro Fast with text-to-video and image-to-video workflows. Does not support first/last frame. Supports 4–12 second durations at 480p, 720p, or 1080p.

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Model

bytedance/seedance-1.0-pro-fast

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Request types

Request typeRequired inputsOptional inputsNotes
Text-to-videopromptaspect_ratio, duration, resolution, camera_fixed, seedNo frame URLs
Image-to-videofirst_frame_urlprompt, duration, resolution, camera_fixed, seedprompt optional. Does not support last_frame_url

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Parameters

ParameterTypeRequiredDefaultDescription
promptstringConditional""Text prompt (max 5000 chars). Required for text-to-video. Optional for image-to-video when first_frame_url is set
aspect_ratiostringNo"16:9"1:1, 3:4, 4:3, 9:16, 16:9, 21:9
durationintegerNo4Output duration in seconds (4–12). Sent to provider as frames = 24 × seconds + 1
resolutionstringNo"480p"480p, 720p, 1080p
seedintegerNo—Seed for reproducibility. Omit for a random seed.
camera_fixedbooleanNofalseWhen true, keeps the virtual camera stationary throughout the clip
first_frame_urlstringNonullStart 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

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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"
    }
  }'

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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"
    }
  }'

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Response

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "pending"
  }
}