Seedance 2.5 Draft API

Draft mode lets you preview a 480p video before generating a 1080p final video from its task ID. The two steps create two independent task IDs, each queried and billed separately.

Models and endpoints

Item	Description
Model name	seedance-2.5 or doubao-seedance-2-5-260628; use the exact name enabled for your account
Create a draft or final video	POST /api/v3/contents/generations/tasks
Query a task	GET /api/v3/contents/generations/tasks/{id}
Production base URL used here	https://api.exchangetoken.ai
Authentication	Authorization: Bearer <YOUR_API_KEY>

Your account needs access to a Seedance 2.5 channel that supports draft mode. Use the same API key and exact model name for both steps.

These examples use seedance-2.5. If your account uses the versioned model name, replace model in both create requests.

Step 1: Create a draft

Set these environment variables:

export ET_BASE='https://api.exchangetoken.ai'
export ET_TOKEN='sk-xxxxxx'

Create request:

curl -sS "$ET_BASE/api/v3/contents/generations/tasks" \
  -H "Authorization: Bearer $ET_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.5",
    "content": [
      {"type": "text", "text": "A fox walks slowly through a forest as the camera follows steadily"}
    ],
    "duration": 5,
    "ratio": "16:9",
    "resolution": "480p",
    "output_format": "mp4",
    "draft": true
  }'

Example create response:

{"id": "sg_vid_draft_example"}

Save the actual returned id. This platform draft task ID is used for querying and creating the final video.

Field	Type	Description
model	string	Exact Seedance 2.5 model name enabled for your account
content	object[]	Prompt and any image, video, or audio inputs supported by the model
draft	boolean	Must be true
resolution	string	Only 480p; the platform supplies 480p if omitted
duration, ratio, generate_audio, seed	Depends on field	Set during draft creation; omit when creating the final video
output_format	string	mp4 or mov; the official default is mp4, subject to channel support

Step 2: Query and preview the draft

Replace the variable with the actual ID returned in Step 1:

export DRAFT_TASK_ID='sg_vid_draft_example'

curl -sS "$ET_BASE/api/v3/contents/generations/tasks/$DRAFT_TASK_ID" \
  -H "Authorization: Bearer $ET_TOKEN"

Continue polling while the status is queued or running, for example every 10 seconds. The draft must reach succeeded before you can use it to generate a final video.

Example success response:

{
  "id": "sg_vid_draft_example",
  "status": "succeeded",
  "content": {"video_url": "https://example.com/draft.mp4"},
  "resolution": "480p"
}

Preview or download the draft from the actual content.video_url. Result URLs expire, so save the video promptly. Stop polling on failed, cancelled, or expired, then inspect the failure or create a new draft.

Step 3: Generate a final video from the draft

Once you approve the draft, pass its platform ID in content.draft_task.id:

curl -sS "$ET_BASE/api/v3/contents/generations/tasks" \
  -H "Authorization: Bearer $ET_TOKEN" \
  -H "Content-Type: application/json" \
  -d "{
    \"model\": \"seedance-2.5\",
    \"content\": [
      {\"type\": \"draft_task\", \"draft_task\": {\"id\": \"$DRAFT_TASK_ID\"}}
    ],
    \"resolution\": \"1080p\",
    \"output_format\": \"mp4\"
  }"

The response returns a new final video task ID:

{"id": "sg_vid_final_example"}

Final video constraints:

• content must contain exactly one draft_task referencing a successful draft.
• Use the Exchange Token sg_vid_... ID, rather than a supplier task ID.
• resolution must be 1080p; the platform supplies 1080p if omitted.
• Omit draft or set it to false.
• Omit duration, ratio, seed, generate_audio, and omni_reference_task_type. Do not add text, images, video, or audio; the generation settings are reused from the draft.
• Output options such as output_format, return_last_frame, and watermark may be set again if supported by the channel. Omitted output options use model defaults rather than the draft's values.
• Draft tasks are valid for 7 days from creation. Create a new draft after expiry.
• The final video uses the draft's original channel and remains subject to account permissions, quota, and rate limits. Cross-channel fallback and fixchan / fallback routing overrides are unavailable for this workflow.

Output format

Both examples explicitly set output_format: "mp4". Use mov if needed, and specify the desired format again when generating the final video.

Step 4: Query the final video

Use the new ID returned in Step 3:

export FINAL_TASK_ID='sg_vid_final_example'

curl -sS "$ET_BASE/api/v3/contents/generations/tasks/$FINAL_TASK_ID" \
  -H "Authorization: Bearer $ET_TOKEN"

Wait for status=succeeded, then retrieve the final video from this response's content.video_url. The draft ID queries the draft; the final ID queries the final video.

Billing

The draft and final video are two generation tasks, billed independently using each task's billable token usage. Creating only a draft incurs only the draft charge. Creating the final video incurs an additional charge.

Original draft input	Draft pricing	Final video pricing
No reference video	No-video-input category, 480p output rate	No-video-input category, 1080p output rate
Includes reference video	Video-input category, 480p output rate	Video-input category, 1080p output rate

The final video inherits the draft's original input billing category. The draft video itself does not add input-video duration. Each task uses the account, model, and channel prices applicable when that task is submitted, together with its actual billable usage.

Querying the same task again does not incur another generation charge. Repeating a create request creates a new task; save the returned ID and use the query endpoint to track it.

Common errors

Errors use {"error":{"type":"...","message":"..."}}.

HTTP status	error.type	Action
400	invalid_request	Check resolution, forbidden parameters, draft success, exact model name, and the 7-day validity period
404	task_not_found	Check the platform task ID and use the API key that created the draft
409	draft_channel_changed	The original channel account, project, endpoint, or model mapping changed, or its identity cannot be verified; create a new draft
429	rate_limited	User or channel rate limit reached; retry later
503	no_channel / async_task_unavailable	Original channel or task service unavailable; retry later or contact support

Related documentation

• Seedance overview
• Seedance Video API
• Seedance Asset API
• Official Seedance 2.5 tutorial
• Official video task parameters