# Seedance 2.0 Fast API on TokenRa

Model ID: `seedance-2-0-fast`
Get an API key: https://tokenra.io/register?utm_source=llms-agent&utm_medium=model-llms
Updated: 2026-10-30

> Seedance 2.0 Fast is the lower-cost Fast model of ByteDance's Seedance 2.0 series. It takes the same requests as Seedance 2.0 Pro: create a task, then poll it until the video URL is ready.

- Provider: ByteDance
- Type: Video model
- Input: Text, images
- Output: Video with audio
- Mode: Async task

## Pricing

Rates in the TokenRa console when this file was last updated, in US dollars for the default group. The live price list is authoritative: https://tokenra.io/pricing (JSON: https://tokenra.io/api/pricing).

- `seedance-2-0-fast`: $5.15 per 1M tokens, input and output at the same rate (a video task is charged by the tokens it uses)

## Capabilities & endpoints

Video generation is asynchronous: create a task, then poll it. A 4-second 480p clip took 3.5 to 4 minutes in testing.

- `POST https://tokenra.io/v1/video/generations`: Create a task. Returns `task_id` immediately.
- `GET https://tokenra.io/v1/video/generations/{task_id}`: Query the task. The video link is in `data.result_url` when `data.status` is `SUCCESS`.

## Example

Set `TOKENRA_API_KEY` to your API key first. The docs page has the same example in Python, JavaScript and Java.

```bash
# 1. Create the task. The response contains task_id.
curl https://tokenra.io/v1/video/generations \
  -H "Authorization: Bearer $TOKENRA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2-0-fast",
    "prompt": "A paper boat drifting down a rainy neon street at night, cinematic close-up",
    "metadata": {
      "resolution": "720p",
      "ratio": "16:9",
      "duration": 5
    }
  }'

# 2. Poll every 10-15 s until data.status is SUCCESS or FAILURE.
curl https://tokenra.io/v1/video/generations/TASK_ID \
  -H "Authorization: Bearer $TOKENRA_API_KEY"
```

## Generation modes

All three request shapes produced a video on 2026-10-23.

### A. Text to video

Only a prompt. Output settings go in `metadata`.

**POST /v1/video/generations**

```json
{
  "model": "seedance-2-0-fast",
  "prompt": "A paper boat drifting down a rainy neon street at night, cinematic close-up",
  "metadata": {
    "resolution": "720p",
    "ratio": "16:9",
    "duration": 5
  }
}
```

### B. Image to video (first frame)

Put image URLs in `images`; one image is used as the first frame.

**POST /v1/video/generations**

```json
{
  "model": "seedance-2-0-fast",
  "prompt": "The girl in the picture turns around and smiles",
  "images": ["https://example.com/first-frame.png"],
  "metadata": {"resolution": "720p", "duration": 5}
}
```

### C. Reference images

To give images a role, send Volcengine Ark `content` items inside `metadata`. The prompt is added as the text item automatically.

**POST /v1/video/generations**

```json
{
  "model": "seedance-2-0-fast",
  "prompt": "The character from image 1 walks into the room from image 2",
  "metadata": {
    "resolution": "720p",
    "ratio": "16:9",
    "content": [
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/character.png"},
        "role": "reference_image"
      },
      {
        "type": "image_url",
        "image_url": {"url": "https://example.com/room.png"},
        "role": "reference_image"
      }
    ]
  }
}
```

## Request parameters

**Put output settings in metadata**

Top-level `resolution`, `ratio` and `duration` are ignored for Seedance 2.0. A test on 2026-10-23 with top-level `ratio: "9:16"` and `duration: 4` produced a 16:9, 5-second video, while `metadata.resolution` was applied. With the same values in `metadata`, the video was 9:16 and 4 seconds long.

### Top-level fields

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `model` | string | Yes | `seedance-2-0-fast`. `seedance-2-0-pro` and `seedance-2-0-mini` take the same parameters. |
| `prompt` | string | Yes | Describe the scene, the motion and the camera. |
| `images` | string[] | No | Image URLs. Plain strings only; use `metadata.content` when you need roles. |
| `metadata` | object | No | Output settings and Ark-native fields, see the next table. |

### metadata fields

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `resolution` | string | No | `480p`, `720p` or `1080p`; `480p` was tested. Also decides the price. |
| `ratio` | string | No | `16:9`, `9:16`, `4:3`, `3:4`, `1:1`, `21:9` or `adaptive`. `16:9` and `9:16` were tested. |
| `duration` | integer | No | Length in seconds, 4 to 15. Default 5; `4` was tested. |
| `generate_audio` | boolean | No | Generate a matching soundtrack. On by default: every test video had an audio track. |
| `seed` | integer | No | Random seed for repeatable results. |
| `camera_fixed` | boolean | No | Keep the camera still. |
| `watermark` | boolean | No | Add the upstream watermark. |
| `content` | array | No | Ark material items: `image_url` with `role` such as `first_frame`, `last_frame` or `reference_image`. |

## Response format

### Create response

**200 OK**

```json
{
  "id": "task_FUhA4FK80TV1p70mpHlyZXCxeHR0dPPa",
  "task_id": "task_FUhA4FK80TV1p70mpHlyZXCxeHR0dPPa",
  "object": "video",
  "model": "seedance-2-0-fast",
  "status": "queued",
  "progress": 0,
  "created_at": 1792766873
}
```

### Query response

**200 OK**

```json
{
  "code": "success",
  "message": "",
  "data": {
    "task_id": "task_FUhA4FK80TV1p70mpHlyZXCxeHR0dPPa",
    "action": "generate",
    "status": "SUCCESS",
    "fail_reason": "",
    "result_url": "https://example.com/output.mp4",
    "submit_time": 1792766873,
    "start_time": 1792766890,
    "finish_time": 1792767085,
    "progress": "100%",
    "data": {"resolution": "720p", "ratio": "16:9", "duration": 5, "...": "..."}
  }
}
```

`data.data` holds the raw upstream task, including the resolution, ratio and duration that were actually used.

| data.status | Meaning |
| --- | --- |
| `NOT_START` / `SUBMITTED` / `QUEUED` | Accepted, waiting to start. |
| `IN_PROGRESS` | Generating. |
| `SUCCESS` | Done. Download `result_url`. |
| `FAILURE` | Failed. The reason is in `fail_reason`; the pre-charged amount is refunded. |

## Errors & limits

### Common errors

| HTTP | error.code | Meaning | What to do |
| --- | --- | --- | --- |
| `401` | - | Missing, wrong or deleted API key. The message is `Invalid token`. | Check the `Authorization: Bearer` header and the key in the console. |
| `400` | - | The body is not valid JSON. | Fix the JSON and send `Content-Type: application/json`. |
| `500` | `invalid_request` | A required field is missing, for example `messages`. | Add the field named in the message. Retrying will not help. |
| `403` | `insufficient_user_quota` | Your balance or plan quota is used up. | Top up in the console, then retry. |
| `503` | `model_not_found` | Unknown model ID, or no channel serves it for your group. | Check the ID in the model list or with `GET /v1/models`. |
| `429` | - | Too many requests. | Back off exponentially and retry. |
| `5xx` | - | The upstream provider failed or timed out. | Retry a few times; keep the request id if it persists. |

### Limits and notes

- Poll every 10-15 seconds. Test tasks (4 s, 480p) finished in 3.5 to 4 minutes.
- `result_url` is a temporary link. Download and store the video yourself.
- The price depends on `metadata.resolution` and on whether a video reference is included. See the live rate in the Model Square.

## More

- [Seedance 2.0 Fast API docs page](https://tokenra.io/docs/seedance-2-0-fast.html): parameter tables and code samples in cURL, Python, JavaScript and Java
- [Seedance 2.0 Fast overview and pricing page](https://tokenra.io/models/seedance-2-0-api.html)
- [API basics](https://tokenra.io/docs/common.html): base URL, authentication, errors, retries
- [Quickstart](https://tokenra.io/docs/quickstart.html): create a key and send a first request
- [All models](https://tokenra.io/docs/models.html): every model ID
- [Chinese version of this guide](https://tokenra.io/zh/docs/seedance-2-0-fast/llms.txt)
- [Site index for agents](https://tokenra.io/llms.txt)

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Canonical version of this document: https://tokenra.io/docs/seedance-2-0-fast/llms.txt