Seedance Assets

The asset library stores and reviews reference media for video generation. Upload reference media (especially images and videos that contain people) to the asset library first, wait for review to pass, then reference it in a Seedance video task as asset://<asset ID>.

Endpoints

Mainland China and Global each have their own asset library, and they are not interchangeable: assets in the Mainland China library can only be used with Mainland China Seedance models, and assets in the Global library only with Global Seedance models. Referencing an asset from the other library is treated as "asset not found".

Every action is POST {endpoint}?Action={Action}&Version=2024-01-01 with a JSON body.

POST /ark/cn/?Action=CreateAsset&Version=2024-01-01
Authorization: Bearer $API_KEY
Content-Type: application/json

Authentication

Use either method with the same sk- platform key:

When signing:

• The service is ark; the signing region is cn-beijing for Mainland China and ap-southeast-1 for Global.
• Signed headers are content-type;host;x-content-sha256;x-date. X-Date must be within 5 minutes of server time, and X-Content-Sha256 must match the request body.
• The signed path is the actual request path (/ark/cn/ or /ark/global/). SDKs that can change only the host and not the path should use Bearer instead.

Response envelope

Success returns ResponseMetadata and Result:

{
  "ResponseMetadata": {
    "RequestId": "20261102161227a1b2c3d4e5f6a7b8c9",
    "Action": "CreateAsset",
    "Version": "2024-01-01",
    "Service": "ark",
    "Region": "cn-beijing"
  },
  "Result": {
    "Id": "asset-20261102161227-cj74s"
  }
}

Failures omit Result and put the error in ResponseMetadata.Error. HTTP status codes keep their standard meaning:

{
  "ResponseMetadata": {
    "RequestId": "20261102161227a1b2c3d4e5f6a7b8c9",
    "Action": "GetAsset",
    "Version": "2024-01-01",
    "Service": "ark",
    "Region": "cn-beijing",
    "Error": {
      "Code": "NotFound.Asset",
      "Message": "The specified Asset asset-20261102161227-cj74s is not found"
    }
  }
}

ID format

{prefix}-{yyyyMMddHHmmss}-{5 lowercase letters or digits}, with the time in UTC.

Supported actions

Every action accepts ProjectName (default default). It is the asset namespace: create, query, and delete calls must use the same value, and assets and groups under different ProjectName values are invisible to each other.

CreateAssetGroup

Returns Result.Id (the group ID).

CreateAsset

The call returns Result.Id immediately with status Processing. The asset is stored and reviewed in the background: poll GetAsset and use the asset in video tasks only after it becomes Active. Failed means review or processing failed; see Error for the reason.

GetAsset

Request fields: Id (required) and ProjectName. Returns:

{
  "ResponseMetadata": { "Action": "GetAsset", "Region": "cn-beijing" },
  "Result": {
    "Id": "asset-20261102161227-cj74s",
    "Name": "",
    "URL": "https://cdn.example.com/ark-assets/asset-20261102161227-cj74s.jpg",
    "AssetType": "Image",
    "GroupId": "group-20261102160629-smddt",
    "Status": "Active",
    "Moderation": { "Strategy": "Default" },
    "Error": { "Code": "", "Message": "" },
    "CreateTime": "2026-11-02T08:12:27Z",
    "UpdateTime": "2026-11-02T08:12:36Z",
    "ProjectName": "default"
  }
}

ListAssetGroups and ListAssets

Use one of two pagination styles; they cannot be mixed:

Page-number pagination requires PageNumber × PageSize to be at most 20,000 (10,000 for groups). Use cursor pagination for deeper results.

Update and delete

Use in video tasks

Once an asset is Active, put asset://<asset ID> in image_url.url, video_url.url, or audio_url.url; all other fields work as with ordinary reference media. Pair Mainland China assets with Mainland China models and Global assets with Global models.

curl "http://127.0.0.1:11113/v1/contents/generations/tasks" -H "Authorization: Bearer $API_KEY" -H "Content-Type: application/json" -d '{
  "model": "volcengine/seedance-2.0",
  "content": [
    {"type": "text", "text": "She turns around and smiles by the sea"},
    {
      "type": "image_url",
      "image_url": {"url": "asset://asset-20261102161227-cj74s"},
      "role": "reference_image"
    }
  ],
  "ratio": "16:9",
  "duration": 5
}'

• The creation response is the same as for any task and contains only the task ID. A task that references library assets may stay queued briefly while the assets are prepared before generation starts; query and callback behavior is unchanged.
• Preset asset IDs (such as preset virtual portraits) can also be referenced with asset://.
• One request can mix library assets, preset assets, and ordinary URLs.

Tasks that reference assets are rejected in these cases:

Media requirements

Accepted audio and video durations vary by model, so record media durations before uploading. See Seedance Video Tasks.

Notes

• Retention: assets are kept for 24 hours by default and then deleted automatically; afterwards queries return "not found". Re-upload assets you need beyond that window.
• URL: a temporary platform storage URL.
• ProjectName: echoed back as a platform namespace only.
• Real-person assets: liveness verification and real-person asset groups are not supported; GroupType accepts only AIGC.

Limits and error codes