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Seedance 2.0 Ultra is ByteDance’s latest video generation model, available through the Starrise AI API. It supports text-to-video, image-to-video, multimodal reference input, video editing, video extension, and synchronized audio generation.

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Key Capabilities

FeatureDescription
Text-to-videoGenerate video from a text description
Image-to-video (first frame)Use one image as the first frame
Image-to-video (first and last frame)Use two images as the first and last frames respectively
Multimodal referenceCombine images, video, and audio as references (1–9 images, up to 3 videos, up to 3 audio clips)
Video editingModify elements in an existing video using a reference image
Video extensionExtend and concatenate reference videos
Audio generationAutomatically generate synchronized voice, sound effects, and background music
Web search enhancementEnhance generation with real-time internet content (text-to-video only)
Return last frameRetrieve the last frame of the generated video

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Output Specifications

PropertyValue
Resolution720p, 1080p, 2k
Aspect ratio16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive
Duration4–15 seconds
Formatmp4

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Workflow

1. POST /v1/video/generations  →  task_id
2. Poll GET /v1/video/generations/{task_id}  →  status
3. When status = "succeeded"  →  download video URL (valid for 24 hours)

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Examples

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Text-to-Video

curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "A cat playing piano in a sunlit room, cinematic lighting"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 8
  }'

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Multimodal Reference (Image + Video + Audio)

In the prompt you can reference content array items using @image1, @video1, @audio1, numbered by media type starting from 1.
Important: Assets must be passed in strict order: text, image_url, video_url, audio_url. Do not reorder them, as this may cause errors; when including multiple assets, also ensure no other asset types are mixed in.
cURL
curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "The character from @image1 dances in the scene from @video1, with @audio1 as background music, festive New Year atmosphere"
      },
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/character.jpg"},
        "role": "reference_image"
      },
      {
        "type": "video_url",
        "video_url": {"url": "https://example.com/clip.mp4"},
        "role": "reference_video"
      },
      {
        "type": "audio_url",
        "audio_url": {"url": "https://example.com/bgm.mp3"},
        "role": "reference_audio"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 11
  }'

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Video Editing

cURL
curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "Replace the water in @video1 with the perfume from @image1, keep the same camera motion"
      },
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/perfume.jpg"},
        "role": "reference_image"
      },
      {
        "type": "video_url",
        "video_url": {"url": "https://example.com/original.mp4"},
        "role": "reference_video"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 5
  }'

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Web Search Enhancement (Text-to-Video Only)

cURL
curl https://ai.alad.com/v1/video/generations \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-ultra",
    "content": [
      {
        "type": "text",
        "text": "Macro shot of vivid flower petals on a tree, gradually zooming in"
      }
    ],
    "generate_audio": true,
    "ratio": "16:9",
    "duration": 11,
    "tools": [{"type": "web_search"}]
  }'

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Request Parameters

ParameterTypeRequiredDescription
modelstringYesseedance-2.0-ultra
contentarrayYesInput content array (text, image_url, video_url, audio_url)
content[].typestringYestext, image_url, video_url, or audio_url
content[].textstringFor text typeText prompt (recommended ≤500 Chinese chars or ≤1000 English words)
content[].image_url.urlstringFor image typeImage URL, Base64, or asset://<ID>
content[].video_url.urlstringFor video typeVideo URL or asset://<ID> (mp4/mov, ≤50 MB, 2–15 seconds)
content[].audio_url.urlstringFor audio typeAudio URL, Base64, or asset://<ID> (wav/mp3, ≤15 MB)
content[].rolestringConditionallyfirst_frame, last_frame, reference_image, reference_video, reference_audio
generate_audiobooleanNoGenerate synchronized audio, default true
resolutionstringYes720p, 1080p, or 2k. Required for Ultra.
ratiostringNo16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive, default adaptive
durationintegerNo4–15 seconds, default 5
toolsarrayNo[{"type": "web_search"}] enables web search (text-to-video only)
watermarkbooleanNoWhether to add a watermark, default false

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Input Modes

ModeContent itemsrole values
Text-to-video1× text—
Image-to-video (first frame)text (optional) + 1× image_urlfirst_frame or omitted
Image-to-video (first and last frame)text (optional) + 2× image_urlfirst_frame + last_frame
Multimodal referencetext (optional) + images/videos/audioreference_image, reference_video, reference_audio
Video editingtext + image_url + video_urlreference_image + reference_video
Video extensiontext + video_url(s)reference_video
Note: First frame, first-and-last-frame, and multimodal reference are three mutually exclusive modes that cannot be combined.

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Referencing Assets in Prompts

In the text prompt you can use @<type><N> placeholders to reference media items in the content array, numbered in order of appearance within each media type:
PlaceholderReferenced item
@image1, @image2, …1st, 2nd, … image_url item
@video1, @video2, …1st, 2nd, … video_url item
@audio1, @audio2, …1st, 2nd, … audio_url item
Example: "The character from @image1 walks through the scene in @video1, with @audio1 as background music".
Note: Assets must be passed in strict order: text, image_url, video_url, audio_url. Do not reorder them, as this may cause errors; when including multiple assets, also ensure no other asset types are mixed in.

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Resolution and Pixel Values by Aspect Ratio

Resolution16:94:31:13:49:1621:9
720p1280x7201112x834960x960834x1112720x12801470x630
1080p1920x10801664x12481440x14401248x16641080x19202208x944
2k2560x14402224x16681920x19201668x22241440x25602944x1260

API Reference

View the interactive API documentation for Seedance 2.0 Ultra.