# Veo 3.1 Fast

> Transforms static images into dynamic 1080p videos with synchronized audio and natural motion.


## Overview

- **Endpoint**: `https://api.segmind.com/v1/veo-3.1-fast`
- **Model ID**: `veo-3.1-fast`
- **Category**: Image-to-Video Generation
- **Type**: Synchronous (Direct response)

- **Average Cost**: $0.8602040816326532


## Pricing

| generate_audio | duration | cost |
| --- | --- | --- |
| false | 4 | 0.4 |
| true | 4 | 0.6 |
| false | 6 | 0.6 |
| true | 6 | 0.9 |
| false | 8 | 0.8 |
| true | 8 | 1.2 |

## API Information

This model uses a **synchronous response pattern**:
1. Make a POST request with your parameters
2. Receive the output directly in the response (binary for images/videos/audio, JSON for text)
3. No polling required - response is immediate


### Input Schema

The API accepts the following input parameters:

- **`seed`** (`integer | null`, _optional_):
  Seed
  Sets randomness for generations. Use fixed seed for consistency.
  - Default: `42`

- **`image`** (`File (URL)`, _optional_):
  Image
  Starting image for the video. For new designs, leave it empty.
  - Default: `"https://segmind-resources.s3.amazonaws.com/input/b130a60c-8ee2-4962-b5be-b8b87ece92b7-691b7010-c304-4c07-a9b8-5e03f5e5435a.jpeg"`

- **`prompt`** (`string`, _required_):
  Prompt
  Describe the video content. For abstract visuals, use 'Hypnotic fractal patterns'.
  - Default: `"A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos"`

- **`duration`** (`integer | null`, _optional_):
  Duration
  Length of video in seconds. Choose 4 for short intros.
  - Default: `8`
  - Options: "4" (4), "6" (6), "8" (8)

- **`last_frame`** (`File (URL)`, _optional_):
  Last frame
  Ending image for smooth transitions. Leave empty for standalone videos.
  - Default: `"https://segmind-resources.s3.amazonaws.com/input/0c6e38bc-ac47-4573-ace4-cf51c427962a-5af85fc2-bbbf-43ea-83b6-88cfd1e09374.jpeg"`

- **`resolution`** (`string | null`, _optional_):
  Resolution
  Video clarity setting. Use '720p' for faster processing.
  - Default: `"1080p"`
  - Options: "720p" (720p), "1080p" (1080p)

- **`aspect_ratio`** (`string | null`, _optional_):
  Aspect ratio
  Video's frame shape. Use '9:16' for vertical content.
  - Default: `"16:9"`
  - Options: "16:9" (16:9), "9:16" (9:16)

- **`generate_audio`** (`boolean | null`, _optional_):
  Generate audio
  Add sound to video. Set false for silent clips.
  - Default: `true`

- **`negative_prompt`** (`string | null`, _optional_):
  Negative prompt
  Exclude specific elements in video. Leave blank for freeform.


**Required Parameters Example**:

```json
{
  "prompt": "A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos"
}
```


**Full Example**:

```json
{
  "seed": 42,
  "image": "https://segmind-resources.s3.amazonaws.com/input/b130a60c-8ee2-4962-b5be-b8b87ece92b7-691b7010-c304-4c07-a9b8-5e03f5e5435a.jpeg",
  "prompt": "A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos",
  "duration": 8,
  "last_frame": "https://segmind-resources.s3.amazonaws.com/input/0c6e38bc-ac47-4573-ace4-cf51c427962a-5af85fc2-bbbf-43ea-83b6-88cfd1e09374.jpeg",
  "resolution": "1080p",
  "aspect_ratio": "16:9",
  "generate_audio": true,
  "negative_prompt": null
}
```


### Output Schema

The API returns a synchronous response based on the model type:

**For Image/Video/Audio Models**:
- Response contains binary data (image/png, video/mp4, audio/mp3)
- Content-Type header indicates the media type
- Save the response body directly to a file

**For Text Models**:
- Response is JSON with the generated text
- Structure varies by model

**HTTP Response Codes**:
- **200 - OK**: Request successful, output in response body
- **400 - Bad Request**: Invalid parameters
- **401 - Unauthorized**: Invalid or missing API key
- **404 - Not Found**: Model not found
- **406 - Not Acceptable**: Insufficient credits
- **429 - Too Many Requests**: Rate limit exceeded
- **500 - Server Error**: Internal server error


## Usage Examples

### cURL

```bash
curl -X POST "https://api.segmind.com/v1/veo-3.1-fast" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "seed": 42,
  "image": "https://segmind-resources.s3.amazonaws.com/input/b130a60c-8ee2-4962-b5be-b8b87ece92b7-691b7010-c304-4c07-a9b8-5e03f5e5435a.jpeg",
  "prompt": "A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos",
  "duration": 8,
  "last_frame": "https://segmind-resources.s3.amazonaws.com/input/0c6e38bc-ac47-4573-ace4-cf51c427962a-5af85fc2-bbbf-43ea-83b6-88cfd1e09374.jpeg",
  "resolution": "1080p",
  "aspect_ratio": "16:9",
  "generate_audio": true,
  "negative_prompt": null
}'
```

### Python

```python
import requests
import json

api_key = "YOUR_API_KEY"
url = "https://api.segmind.com/v1/veo-3.1-fast"

data = {
  "seed": 42,
  "image": "https://segmind-resources.s3.amazonaws.com/input/b130a60c-8ee2-4962-b5be-b8b87ece92b7-691b7010-c304-4c07-a9b8-5e03f5e5435a.jpeg",
  "prompt": "A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos",
  "duration": 8,
  "last_frame": "https://segmind-resources.s3.amazonaws.com/input/0c6e38bc-ac47-4573-ace4-cf51c427962a-5af85fc2-bbbf-43ea-83b6-88cfd1e09374.jpeg",
  "resolution": "1080p",
  "aspect_ratio": "16:9",
  "generate_audio": true,
  "negative_prompt": null
}

response = requests.post(
    url,
    json=data,
    headers={
        'x-api-key': api_key,
        'Content-Type': 'application/json'
    }
)

if response.status_code == 200:
    # For image/video/audio models, response.content contains the binary data
    with open('output.png', 'wb') as f:
        f.write(response.content)
    print('Generation complete, saved to output.png')
else:
    print(f"Error: {response.status_code}")
    print(response.text)
```

### JavaScript

```javascript
const apiKey = 'YOUR_API_KEY';
const url = 'https://api.segmind.com/v1/veo-3.1-fast';

const data = {
  "seed": 42,
  "image": "https://segmind-resources.s3.amazonaws.com/input/b130a60c-8ee2-4962-b5be-b8b87ece92b7-691b7010-c304-4c07-a9b8-5e03f5e5435a.jpeg",
  "prompt": "A hands-on workshop where participants are learning about Veo 3.1 Fast, presenter guiding them on laptops and tablets, modern classroom setup with projectors displaying reference images transforming into videos",
  "duration": 8,
  "last_frame": "https://segmind-resources.s3.amazonaws.com/input/0c6e38bc-ac47-4573-ace4-cf51c427962a-5af85fc2-bbbf-43ea-83b6-88cfd1e09374.jpeg",
  "resolution": "1080p",
  "aspect_ratio": "16:9",
  "generate_audio": true,
  "negative_prompt": null
};

const response = await fetch(url, {
  method: 'POST',
  headers: {
    'x-api-key': apiKey,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(data),
});

if (response.ok) {
  // For image/video/audio models, response contains binary data
  const blob = await response.blob();
  const downloadUrl = URL.createObjectURL(blob);

  // Create download link
  const a = document.createElement('a');
  a.href = downloadUrl;
  a.download = 'output.png';
  a.click();

  console.log('Generation complete');
}
```


## Additional Resources

### Documentation

- [Model Playground](https://www.segmind.com/models/veo-3.1-fast)
- [API Documentation](https://www.segmind.com/models/veo-3.1-fast/api)
- [Pricing Details](https://www.segmind.com/models/veo-3.1-fast/pricing)
- [Platform Documentation](https://docs.segmind.com/)

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