Seedance 2.0 Video Generation API

Access Notice Seedance 2.0 currently has very limited upstream concurrency. To avoid long queues and failed tasks, we are not opening new access at this time. This page is for users who already have access and developers preparing an integration. Availability and concurrency updates will be posted in the TG announcement channel @laozhang_ai.

Base URL: https://api.laozhang.ai/seedance/api/v3Endpoints:

POST /contents/generations/tasks: create a video generation task
GET /contents/generations/tasks/{id}: query task status and result

Video generation is asynchronous. The create endpoint may return only the task id; poll the query endpoint and read the final video URL from content.video_url.

Route Setup

The LaoZhang API creation URL is:

https://api.laozhang.ai/seedance/api/v3/contents/generations/tasks

If you are configuring the upstream channel in the admin panel, use:

Setting	Value
Upstream API URL	`https://ark.cn-beijing.volces.com`
Secret key	Volcengine Ark API key
Custom prefix	`/seedance`
Prefix to remove	Empty
Available models	Use only the plain model IDs in the model table below

Token Setup

When creating a token for Seedance 2.0 in Token management, use:

Setting	Value
Billing mode	`Volume priority` / pay-as-you-go
Group	`SeeDance2`
Recommendation	Create a dedicated Seedance 2.0 token for easier log and billing review

Seedance 2.0 requests must use a token assigned to the SeeDance2 group. Tokens in the default group or other video groups may produce no-channel, model mismatch, or billing-group errors.

Do not directly append the official path /api/v3/contents/generations/tasks to https://api.laozhang.ai. Use the Base URL with the /seedance/api/v3 prefix.

Under the current relay path, GET /contents/generations/tasks without a task ID returns the site HTML instead of API JSON. Do not use the list endpoint in client integrations. Use create task plus query by task ID.

API Flow

Create task

Call POST /contents/generations/tasks, put the plain model ID in model, and provide the prompt plus optional assets in the content array.

Poll status

Call GET /contents/generations/tasks/{id} until status reaches a terminal state.

Download result

When status=succeeded, download the video from content.video_url. If return_last_frame=true was set, read content.last_frame_url as well.

Status values:

Status	Meaning
`queued`	The task is queued
`running`	The task is generating
`succeeded`	The task succeeded and result data is in `content`
`failed`	The task failed; check `error`
`expired`	The task expired

Do not wait for completed and do not read a top-level video_url. The LaoZhang relay keeps the official Ark response shape: success status is succeeded, and the video URL is content.video_url.

Models

model must be a plain model ID. Do not use console endpoint IDs, and do not append human-readable labels to the model name.

Model ID	Description	Recommended use
`doubao-seedance-2-0-fast-260128`	Seedance 2.0 fast	Fast generation, text-to-video, image reference, video reference, audio reference, multimodal reference, video extension, track completion
`doubao-seedance-2-0-260128`	Seedance 2.0 standard	Standard quality, first/last frames, video editing, and workflows that need more stable output

Do not pass an ep-... endpoint ID in client requests. The LaoZhang relay matches channels by plain model ID.

Create Task

/contents/generations/tasks

Create a Seedance 2.0 video generation task.

Headers

Header	Required	Description
`Authorization`	Yes	`Bearer $API_KEY`, using a LaoZhang API token assigned to the `SeeDance2` group
`Content-Type`	Yes	`application/json`
`Accept`	Recommended	`application/json`
`Accept-Encoding`	Recommended for debugging	`identity`, which avoids compression decoding noise in some clients

Request Parameters

Parameter	Type	Required	Description
`model`	string	Yes	Plain model ID, for example `doubao-seedance-2-0-fast-260128`
`content`	array	Yes	Multimodal content array; text prompts also go here
`ratio`	string	No	`16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, or `adaptive`
`duration`	integer	No	Seedance 2.0 supports `4` to `15` seconds, or `-1` for adaptive duration
`frames`	integer	No	Control output by frame count; takes priority over `duration`
`resolution`	string	No	Common value: `720p`. Seedance 2.0 fast does not support `1080p`
`watermark`	boolean	No	Whether to add a watermark
`generate_audio`	boolean	No	Whether to generate or use audio
`return_last_frame`	boolean	No	Whether to return the final frame image URL

`content` Items

Field	Type	Required	Description
`type`	string	Yes	`text`, `image_url`, `video_url`, or `audio_url`
`text`	string	Required when `type=text`	Prompt text
`image_url.url`	string	Required when `type=image_url`	Image URL
`video_url.url`	string	Required when `type=video_url`	Video URL
`audio_url.url`	string	Required when `type=audio_url`	Audio URL
`role`	string	Recommended for assets	Asset purpose

Common role values:

role	Purpose
`first_frame`	First-frame image
`last_frame`	Last-frame image
`reference_image`	Multimodal image reference
`reference_video`	Multimodal video reference
`reference_audio`	Multimodal audio reference

Audio cannot be the only reference asset. When using audio_url, include at least one image or video asset in the same request.

Text-to-Video

curl -X POST "https://api.laozhang.ai/seedance/api/v3/contents/generations/tasks" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "Authorization: Bearer $API_KEY" \
  --data-raw '{
    "model": "doubao-seedance-2-0-fast-260128",
    "content": [
      {
        "type": "text",
        "text": "First-person apple fruit tea ad, 4 seconds, fast-paced edit, show apple tea preparation and finished product, fresh bright style"
      }
    ],
    "ratio": "16:9",
    "duration": 4,
    "resolution": "720p",
    "watermark": false,
    "generate_audio": false,
    "return_last_frame": true
  }'

The create response usually contains only the task ID:

{
  "id": "cgt-example-task-id"
}

First and Last Frame

curl -X POST "https://api.laozhang.ai/seedance/api/v3/contents/generations/tasks" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $API_KEY" \
  --data-raw '{
    "model": "doubao-seedance-2-0-260128",
    "content": [
      {
        "type": "text",
        "text": "The first frame is image 1 and the final frame is image 2. Create a smooth commercial transition from a red apple product close-up to a finished apple fruit tea cup. Keep product appearance consistent and avoid people."
      },
      {
        "type": "image_url",
        "image_url": {
          "url": "https://ark-project.tos-cn-beijing.volces.com/doc_image/r2v_tea_pic1.jpg"
        },
        "role": "first_frame"
      },
      {
        "type": "image_url",
        "image_url": {
          "url": "https://ark-project.tos-cn-beijing.volces.com/doc_image/r2v_tea_pic2.jpg"
        },
        "role": "last_frame"
      }
    ],
    "ratio": "adaptive",
    "duration": 4,
    "resolution": "720p",
    "watermark": false,
    "generate_audio": false,
    "return_last_frame": true
  }'

Image, Video, and Audio References

curl -X POST "https://api.laozhang.ai/seedance/api/v3/contents/generations/tasks" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $API_KEY" \
  --data-raw '{
    "model": "doubao-seedance-2-0-fast-260128",
    "content": [
      {
        "type": "text",
        "text": "Use image 1 for the apple product details, video 1 for first-person camera motion, and audio 1 as the background music. Generate a concise apple fruit tea commercial with quick ingredient cuts and a clean finished cup close-up."
      },
      {
        "type": "image_url",
        "image_url": {
          "url": "https://ark-project.tos-cn-beijing.volces.com/doc_image/r2v_tea_pic1.jpg"
        },
        "role": "reference_image"
      },
      {
        "type": "video_url",
        "video_url": {
          "url": "https://ark-project.tos-cn-beijing.volces.com/doc_video/r2v_tea_video1.mp4"
        },
        "role": "reference_video"
      },
      {
        "type": "audio_url",
        "audio_url": {
          "url": "https://ark-project.tos-cn-beijing.volces.com/doc_audio/r2v_tea_audio1.mp3"
        },
        "role": "reference_audio"
      }
    ],
    "ratio": "16:9",
    "duration": 4,
    "resolution": "720p",
    "watermark": false,
    "generate_audio": true
  }'

Query Task

/contents/generations/tasks/{id}

Query the status of a video generation task.

curl "https://api.laozhang.ai/seedance/api/v3/contents/generations/tasks/cgt-example-task-id" \
  -H "Authorization: Bearer $API_KEY"

Successful response example:

{
  "id": "cgt-example-task-id",
  "model": "doubao-seedance-2-0-fast-260128",
  "status": "succeeded",
  "ratio": "16:9",
  "duration": 4,
  "resolution": "720p",
  "content": {
    "video_url": "https://example.com/generated-video.mp4",
    "last_frame_url": "https://example.com/last-frame.jpeg"
  },
  "usage": {
    "completion_tokens": 87300,
    "total_tokens": 87300
  }
}

Result URLs are temporary signed URLs, usually valid for 24 hours. In production, download successful results immediately and copy them to your own object storage.

Full Python Example

import os
import time
import requests

API_KEY = os.environ["API_KEY"]
BASE_URL = "https://api.laozhang.ai/seedance/api/v3"

headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/json",
    "Accept": "application/json",
}

payload = {
    "model": "doubao-seedance-2-0-fast-260128",
    "content": [
        {
            "type": "text",
            "text": "First-person apple fruit tea ad, 4 seconds, fast-paced edit, fresh bright style",
        }
    ],
    "ratio": "16:9",
    "duration": 4,
    "resolution": "720p",
    "watermark": False,
    "generate_audio": False,
    "return_last_frame": True,
}

create_resp = requests.post(
    f"{BASE_URL}/contents/generations/tasks",
    headers=headers,
    json=payload,
    timeout=60,
)
create_resp.raise_for_status()
task_id = create_resp.json()["id"]

while True:
    query_resp = requests.get(
        f"{BASE_URL}/contents/generations/tasks/{task_id}",
        headers={"Authorization": f"Bearer {API_KEY}", "Accept": "application/json"},
        timeout=60,
    )
    query_resp.raise_for_status()
    task = query_resp.json()
    status = task.get("status")

    if status == "succeeded":
        video_url = task["content"]["video_url"]
        video_resp = requests.get(video_url, timeout=180)
        video_resp.raise_for_status()
        with open(f"{task_id}.mp4", "wb") as output:
            output.write(video_resp.content)
        break

    if status in {"failed", "expired"}:
        raise RuntimeError(task)

    time.sleep(15)

Common Integration Questions

Why does /seedance/v3/contents/generations/tasks return HTML?

The current path is /seedance/api/v3/contents/generations/tasks. Do not remove /api from the official path.

Can I add a Chinese label after the model name?

No. The request model must be the plain model ID, such as doubao-seedance-2-0-260128. Do not send doubao-seedance-2-0-260128 (2.0-audio-video).

Can I pass an ep endpoint ID?

Not recommended. The LaoZhang relay matches channels by plain model ID, so do not pass ep-....

Where is the final video URL?

The final video URL is content.video_url. If return_last_frame=true was set when creating the task, the final frame image URL is content.last_frame_url.

Can audio be the only reference asset?

No. Audio references must be sent with at least one image or video asset, otherwise the official API rejects the request.

Documentation Index

​Route Setup

​Token Setup

​API Flow

​Models

​Create Task

​Headers

​Request Parameters

​content Items

​Text-to-Video

​First and Last Frame

​Image, Video, and Audio References

​Query Task

​Full Python Example

​Common Integration Questions

Route Setup

Token Setup

API Flow

Models

Create Task

Headers

Request Parameters

`content` Items

Text-to-Video

First and Last Frame

Image, Video, and Audio References

Query Task

Full Python Example

Common Integration Questions