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

# SeeDance 1.0 Pro Fast

> Fast text-to-video and image-to-video generation

Generate videos using ByteDance SeeDance 1.0 Pro Fast with text-to-video and image-to-video workflows. Does not support first/last frame. Supports 4–12 second durations at 480p, 720p, or 1080p.

## Model

```
bytedance/seedance-1.0-pro-fast
```

## Request types

| Request type   | Required inputs   | Optional inputs                                                  | Notes                                                |
| -------------- | ----------------- | ---------------------------------------------------------------- | ---------------------------------------------------- |
| Text-to-video  | `prompt`          | `aspect_ratio`, `duration`, `resolution`, `camera_fixed`, `seed` | No frame URLs                                        |
| Image-to-video | `first_frame_url` | `prompt`, `duration`, `resolution`, `camera_fixed`, `seed`       | `prompt` optional. Does not support `last_frame_url` |

## Parameters

| Parameter         | Type    | Required    | Default  | Description                                                                                                                                     |
| ----------------- | ------- | ----------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| `prompt`          | string  | Conditional | `""`     | Text prompt (max 5000 chars). **Required** for text-to-video. **Optional** for image-to-video when `first_frame_url` is set                     |
| `aspect_ratio`    | string  | No          | `"16:9"` | `1:1`, `3:4`, `4:3`, `9:16`, `16:9`, `21:9`                                                                                                     |
| `duration`        | integer | No          | `4`      | Output duration in seconds (4–12). Sent to provider as `frames = 24 × seconds + 1`                                                              |
| `resolution`      | string  | No          | `"480p"` | `480p`, `720p`, `1080p`                                                                                                                         |
| `seed`            | integer | No          | —        | Seed for reproducibility. Omit for a random seed.                                                                                               |
| `camera_fixed`    | boolean | No          | `false`  | When true, keeps the virtual camera stationary throughout the clip                                                                              |
| `first_frame_url` | string  | No          | `null`   | Start frame image URL for image-to-video. Formats: png, webp, jpeg, gif. Max 30 MB. Dimensions: 300–6000 px (short side). Aspect ratio: 0.4–2.5 |

## Example - Text-to-Video

```bash theme={null}
curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "bytedance/seedance-1.0-pro-fast",
    "input": {
      "prompt": "A person breakdancing in an urban setting",
      "aspect_ratio": "9:16",
      "duration": 10,
      "resolution": "1080p"
    }
  }'
```

## Example - Image-to-Video

```bash theme={null}
curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "bytedance/seedance-1.0-pro-fast",
    "input": {
      "prompt": "The subject begins to walk forward slowly",
      "first_frame_url": "https://example.com/standing.jpg",
      "duration": 5,
      "resolution": "720p"
    }
  }'
```

## Response

```json theme={null}
{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "pending"
  }
}
```