> ## Documentation Index
> Fetch the complete documentation index at: https://apixo.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Seedance 2.0 API: Multimodal Video Generation

> ByteDance multimodal video generation API with text-to-video, first-and-last-frames, and omni-reference workflows, including 4k support

## Overview

Seedance 2.0 is a ByteDance video generation model for prompt-only video, first-and-last-frame animation, and multimodal reference workflows. Use this page when you are ready to call the API after trying the model in the APIXO playground.

| Capability | Value |
| - | - |
| Model ID | `seedance-2-0` |
| Modes | `text-to-video`, `first_and_last_frames`, `omni_reference` |
| Prompt | Required non-empty string |
| Resolutions | `480p`, `720p`, `1080p`, `4k` |
| Durations | Any integer from `4` through `15` seconds |
| Aspect ratios | `auto`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9` |
| Reference images | 1-2 URLs for `first_and_last_frames`; 1-9 URLs for `omni_reference` |
| Reference video/audio | 1-3 URLs each for `omni_reference`; each file 2-15 seconds, total max 15 seconds per media type |
| Output | MP4 video URL array in `resultJson.resultUrls` |

## Endpoint and authentication

Base URL:

```text theme={null}
https://api.apixo.ai/api/v1
```

| Method | Endpoint | Purpose |
| - | - | - |
| `POST` | `/generateTask/seedance-2-0` | Submit a generation task |
| `GET` | `/statusTask/seedance-2-0?taskId={taskId}` | Poll task status and retrieve results |

All requests require your APIXO API key:

```http theme={null}
Authorization: Bearer YOUR_API_KEY
```

Submit requests also require:

```http theme={null}
Content-Type: application/json
```

## Copy-paste async quickstart

This minimal request submits a text-to-video task and returns a `taskId`.

```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/seedance-2-0" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "async",
    "input": {
      "mode": "text-to-video",
      "prompt": "a cinematic tracking shot through a rainy neon street",
      "resolution": "4k",
      "duration": 5,
      "aspect_ratio": "16:9",
      "sound": true,
      "web_search": false
    }
  }'
```

Successful response:

```json theme={null}
{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678"
  }
}
```

Save the `taskId`; you need it to poll for the final result.

## Poll for result

```bash theme={null}
curl -X GET "https://api.apixo.ai/api/v1/statusTask/seedance-2-0?taskId=task_12345678" \
  -H "Authorization: Bearer YOUR_API_KEY"
```

Processing response:

```json theme={null}
{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "processing",
    "createTime": 1767965610929
  }
}
```

Success response:

```json theme={null}
{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "success",
    "resultJson": "{\"resultUrls\":[\"https://file.apixo.ai/video.mp4\"]}",
    "createTime": 1767965610929,
    "completeTime": 1767965890929,
    "costTime": 280000
  }
}
```

Failed response:

```json theme={null}
{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "UPSTREAM_ERROR",
    "failMsg": "Upstream error",
    "createTime": 1767965610929,
    "completeTime": 1767965620132
  }
}
```

Parse `resultJson` after `state` becomes `success`:

```javascript theme={null}
const payload = JSON.parse(data.resultJson);
const videoUrls = payload.resultUrls;
```

## Request body

### Text-to-video

```json theme={null}
{
  "request_type": "async",
  "input": {
    "mode": "text-to-video",
    "prompt": "a slow tracking shot through a foggy pine forest at dawn",
    "resolution": "4k",
    "duration": 10,
    "aspect_ratio": "16:9",
    "sound": true,
    "web_search": false
  }
}
```

### First-and-last-frames

```json theme={null}
{
  "request_type": "async",
  "input": {
    "mode": "first_and_last_frames",
    "prompt": "turn the still frames into a smooth cinematic camera move",
    "image_urls": [
      "https://example.com/frame-start.png",
      "https://example.com/frame-end.png"
    ],
    "resolution": "720p",
    "duration": 5,
    "aspect_ratio": "9:16",
    "sound": true,
    "web_search": false
  }
}
```

### Omni-reference

```json theme={null}
{
  "request_type": "async",
  "input": {
    "mode": "omni_reference",
    "prompt": "create a stylish product ad using the visual references and voice rhythm",
    "image_urls": [
      "https://example.com/product-shot.png"
    ],
    "video_urls": [
      "https://example.com/ref-motion.mp4"
    ],
    "audio_urls": [
      "https://example.com/ref-audio.mp3"
    ],
    "resolution": "720p",
    "duration": 6,
    "aspect_ratio": "auto",
    "sound": true,
    "web_search": false
  }
}
```

## Parameters

<ParamField body="request_type" type="string" default="async">
  Result delivery mode. Omit this field or use `async` for polling with `statusTask`, or use `callback` for webhook delivery.
</ParamField>

<ParamField body="callback_url" type="string">
  Required when `request_type` is `callback`. Must be a public HTTPS URL that can receive the final task payload. See [Webhooks](/docs/api-reference/webhooks).
</ParamField>

<ParamField body="input" type="object" required>
  Seedance 2.0 input parameters.

  <Expandable title="properties">
    <ParamField body="mode" type="string" required>
      Generation mode. Supported values: `text-to-video`, `first_and_last_frames`, `omni_reference`.
    </ParamField>

    <ParamField body="prompt" type="string" required>
      Text prompt describing the desired video. The backend trims whitespace and rejects empty prompts. Maximum length: 10000 characters.
    </ParamField>

    <ParamField body="resolution" type="string" default="720p">
      Output resolution. Supported values: `480p`, `720p`, `1080p`, `4k`. Values are trimmed and normalized to lowercase, so `4K` and `4k` are treated the same.
    </ParamField>

    <ParamField body="duration" type="integer|string" default="5">
      Output duration in seconds. Supports integers from `4` through `15`, including numeric strings such as `"10"`.
    </ParamField>

    <ParamField body="aspect_ratio" type="string" default="auto">
      Output aspect ratio. Supported values: `auto`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`.
    </ParamField>

    <ParamField body="sound" type="boolean" default="true">
      Whether to generate audio with the video. Must be a boolean when provided.
    </ParamField>

    <ParamField body="web_search" type="boolean" default="false">
      Whether to allow real-time web search during generation. Must be a boolean when provided.
    </ParamField>

    <ParamField body="nsfw_checker" type="boolean" default="false">
      Enables content safety filtering for this request. Defaults to `false`; must be a boolean when provided.
    </ParamField>

    <ParamField body="image_urls" type="string[]">
      Reference image URLs. Required for `first_and_last_frames` with 1-2 images. Optional for `omni_reference` with up to 9 images.
    </ParamField>

    <ParamField body="video_urls" type="string[]">
      Reference video URLs for `omni_reference`. Supports 1-3 URLs when provided. Each video must be 2-15 seconds, and total reference video duration cannot exceed 15 seconds.
    </ParamField>

    <ParamField body="audio_urls" type="string[]">
      Reference audio URLs for `omni_reference`. Supports 1-3 URLs when provided. Each audio file must be 2-15 seconds, and total reference audio duration cannot exceed 15 seconds.
    </ParamField>
  </Expandable>
</ParamField>

| Mode | Required media | Optional media | Billing note |
| - | - | - | - |
| `text-to-video` | None | None | Uses the no-video-reference rate. |
| `first_and_last_frames` | `image_urls` with 1-2 images | None | Uses the no-video-reference rate. |
| `omni_reference` | None by validation, unless `audio_urls` is supplied | `image_urls`, `video_urls`, `audio_urls` | Uses video-reference billing when `video_urls` is provided. |

<Tip>
  In `omni_reference`, audio-only requests are rejected. If you provide `audio_urls`, include at least one image or video reference as well.
</Tip>

<Tip>
  Use public, directly accessible URLs for all reference media. Video and audio durations are checked before the task is submitted.
</Tip>

<Tip>
  `image_urls` examples use URL strings. The backend also accepts object items with a non-empty `url` field and normalizes them to URL strings.
</Tip>

## Response format

### Submit task response

`POST /generateTask/seedance-2-0` returns a task ID when the task is accepted:

<ResponseField name="code" type="integer">
  API status code. `200` means the task was accepted.
</ResponseField>

<ResponseField name="message" type="string">
  Human-readable status message.
</ResponseField>

<ResponseField name="data.taskId" type="string">
  Unique task identifier used with the status endpoint.
</ResponseField>

### Status response fields

<ResponseField name="taskId" type="string">
  Unique task identifier.
</ResponseField>

<ResponseField name="state" type="string">
  Current task state: `pending`, `processing`, `success`, or `failed`.
</ResponseField>

<ResponseField name="resultJson" type="string">
  JSON string containing generated video URLs in `resultUrls`. Present when `state` is `success`.
</ResponseField>

<ResponseField name="failCode" type="string">
  Machine-readable failure code. Present when `state` is `failed`.
</ResponseField>

<ResponseField name="failMsg" type="string">
  Human-readable failure message. Present when `state` is `failed`.
</ResponseField>

<ResponseField name="createTime" type="integer">
  Task creation timestamp in Unix milliseconds.
</ResponseField>

<ResponseField name="completeTime" type="integer">
  Task completion timestamp in Unix milliseconds. Present after completion.
</ResponseField>

<ResponseField name="costTime" type="integer">
  Processing duration in milliseconds. Present after completion when timing data is available.
</ResponseField>

## Webhook callback mode

Use callback mode when your backend should receive the final result automatically instead of polling.

```bash theme={null}
curl -X POST "https://api.apixo.ai/api/v1/generateTask/seedance-2-0" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "callback",
    "callback_url": "https://your-server.com/webhooks/apixo",
    "input": {
      "mode": "first_and_last_frames",
      "prompt": "turn the still frames into a smooth cinematic camera move",
      "image_urls": [
        "https://example.com/frame-start.png",
        "https://example.com/frame-end.png"
      ],
      "resolution": "720p",
      "duration": 5,
      "aspect_ratio": "9:16",
      "sound": true,
      "web_search": false
    }
  }'
```

The callback payload uses the same top-level shape as status polling with `code`, `message`, and `data`. Successful callbacks include the final `state` and `resultJson`. See [Webhooks](/docs/api-reference/webhooks) for delivery requirements and retry behavior.

## Billing

Seedance 2.0 is billed per second. The selected `resolution` and whether `omni_reference` includes `video_urls` determine the per-second unit price.

| Configuration | APIXO price |
| - | - |
| `480p`, without video reference | `$0.0933 / second` |
| `480p`, with video reference | `$0.0573 / second` |
| `720p`, without video reference | `$0.20 / second` |
| `720p`, with video reference | `$0.124 / second` |
| `1080p`, without video reference | `$0.4933 / second` |
| `1080p`, with video reference | `$0.3047 / second` |
| `4k`, without video reference | `$1.04 / second` |
| `4k`, with video reference | `$0.622 / second` |

Formula without video reference:

```text theme={null}
total cost = output duration * unit price
```

Formula with video reference:

```text theme={null}
total cost = (output duration + total reference video duration) * unit price
```

`text-to-video` and `first_and_last_frames` always use the without-video-reference rate. `omni_reference` uses the with-video-reference rate only when `video_urls` is provided.

For current route and market comparison pricing, see [Pricing](https://apixo.ai/pricing).

## Latency and polling

Video generation is long-running. The user manual lists typical Seedance 2.0 generation time at about 4-8 minutes. Actual latency may vary by prompt complexity, duration, resolution, reference media accessibility, route queue load, and storage transfer time.

| Workload | Typical generation time | Recommended first poll | Poll interval |
| - | - | - | - |
| Text-to-video or first-and-last-frames | 4-8 minutes | 300s after task creation | 10s-20s |
| Omni-reference with image/video/audio inputs | 4-8 minutes or longer | 300s-400s after task creation | 10s-20s |

<Tip>
  For production workloads, use callback mode to avoid frequent polling while video tasks run.
</Tip>

Result URLs are temporary. Download and store important outputs promptly after task completion.

Rate limits and concurrency can vary by account, API key, and route. If you receive `429`, slow down requests and retry with backoff. For account-level details, see [System APIs](/docs/api-reference/system).

## Errors and troubleshooting

### HTTP errors

| Code | Meaning | What to do |
| - | - | - |
| `400` | Invalid request body, missing `input`, unsupported `mode`, missing `prompt`, invalid `resolution`, invalid `duration`, invalid `aspect_ratio`, invalid boolean value, or invalid media array | Fix the request before retrying |
| `401` | Missing or invalid API key | Check the `Authorization` header |
| `402` | Insufficient balance or quota | Add balance or switch account/key |
| `403` | Key or route cannot access the model | Check permissions and route strategy |
| `404` | Task not found when polling | Check the `taskId` |
| `429` | Rate limit or concurrency limit reached | Retry with exponential backoff |
| `500` | Server error or unknown task failure | Retry with backoff |
| `502` | Upstream error | Retry with backoff |
| `504` | Upstream timeout | Retry or use callback mode for long-running jobs |

### Validation notes

| Condition | Backend behavior |
| - | - |
| Missing `input` | Request fails before task creation. |
| Missing, non-string, or empty `prompt` | Request fails before task creation. |
| Missing `mode` | Request fails before task creation. |
| Unsupported `mode` | Request fails before task creation. Supported values are `text-to-video`, `first_and_last_frames`, and `omni_reference`. |
| Missing `resolution` | Defaults to `720p`. |
| Unsupported `resolution` | Request fails before task creation. Supported values are `480p`, `720p`, `1080p`, and `4k`. |
| Missing `duration` | Defaults to `5`. |
| `duration` outside `4` through `15` | Request fails before task creation. |
| Missing `aspect_ratio` | Defaults to `auto`. |
| Unsupported `aspect_ratio` | Request fails before task creation. |
| `sound` or `web_search` is not a boolean | Request fails before task creation. |
| `first_and_last_frames` without `image_urls` | Request fails before task creation. |
| `first_and_last_frames` with more than 2 images | Request fails before task creation. |
| `omni_reference` with more than 9 images, 3 videos, or 3 audio files | Request fails before task creation. |
| `omni_reference` with only `audio_urls` | Request fails before task creation. |
| Reference video or audio shorter than 2 seconds or longer than 15 seconds | Request fails before task creation. |
| Total reference video duration or total reference audio duration over 15 seconds | Request fails before task creation. |

### Task failure codes

`failCode` is generated from APIXO's mapped upstream error. Common values include:

| Fail code | Meaning | What to do |
| - | - | - |
| `SensitiveContent` | Prompt or input/output content was rejected by safety checks | Change the prompt or reference media |
| `PromptInvalid` | Prompt was invalid or rejected upstream | Rewrite the prompt and retry |
| `ImageFormatIncorrect` | Reference image format could not be processed | Use a public, direct image URL in a common image format |
| `RateLimited` | Upstream rate limit was reached | Retry with exponential backoff |
| `Timeout` | Upstream timeout | Retry later or use callback mode |
| `StreamError` | Upstream returned a `500`-class generation error | Retry with backoff |
| `Unknown error` | Upstream returned an unmapped failure | Retry with backoff or contact support with the `taskId` |

See [Error Codes](/docs/api-reference/errors) for the full error reference.

## Related links

* [Generation API Overview](/docs/models)
* [Video Models](/docs/models/video)
* [Generate Task](/docs/api-reference/generate-task)
* [Status Task](/docs/api-reference/status-task)
* [Webhooks](/docs/api-reference/webhooks)
* [Error Codes](/docs/api-reference/errors)
* [Parameter Specification](/docs/api-reference/parameters)
* [Routing Strategies](/docs/concepts/routing-strategies)
* [Try Seedance 2.0 in the APIXO Playground](https://apixo.ai/models/seedance-2-0)
* [Pricing](https://apixo.ai/pricing)


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.