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

# Video Generation

> Video generation API reference for JavaScript SDK

## apiV1VideoDiffusionPost()

Generate a video from text prompt or animate an existing image.

```javascript theme={null}
const { Configuration, VideoApi } = require('@legnext-api/js-sdk');

const apiClient = new Configuration();
apiClient.basePath = 'https://api.legnext.ai';
const videoApi = new VideoApi(apiClient);

const apiKey = 'your-api-key-here';

// Text-to-video
const body = {
    prompt: 'a flowing river through mountains',
    videoType: 1, // 0=480p (faster), 1=720p (higher quality)
    callback: 'https://your-domain.com/webhook'
};

const response = await videoApi.apiV1VideoDiffusionPost(apiKey, body);
console.log('Job ID:', response.jobId);
```

**Image-to-video animation (from generated image):**

```javascript theme={null}
// Animate a specific image from a generation task
const body = {
    jobId: 'original-job-id',
    imageNo: 0, // Image number (0-3)
    prompt: 'flowing water animation',
    videoType: 1,
    callback: 'https://your-domain.com/webhook'
};

const response = await videoApi.apiV1VideoDiffusionPost(apiKey, body);
```

**Image-to-video animation (from image URL):**

```javascript theme={null}
// Animate an existing image by URL
const body = {
    prompt: 'https://example.com/image.png a flowing river through mountains',
    videoType: 1,
    callback: 'https://your-domain.com/webhook'
};

const response = await videoApi.apiV1VideoDiffusionPost(apiKey, body);
```

**Parameters:**

* `prompt` (String): Video prompt or "\[image\_url] prompt text" (1-8192 characters)
* `videoType` (Number): Quality (0=480p, 1=720p)
* `jobId` (String, optional): For animating from existing generation task
* `imageNo` (Number, optional): Image number (0-3) when using jobId
* `callback` (String): Webhook URL

**Returns:** Promise resolving to response with `job_id` and `status`

***

## apiV1ExtendVideoPost()

Extend an existing video.

```javascript theme={null}
const body = {
    jobId: 'original-video-job-id',
    videoNo: 0, // Video number (0-3)
    prompt: 'continue with dramatic lighting', // Optional
    callback: 'https://your-domain.com/webhook'
};

const response = await videoApi.apiV1ExtendVideoPost(apiKey, body);
console.log('Extended video Job ID:', response.jobId);
```

**Parameters:**

* `jobId` (String): Original video task ID
* `videoNo` (Number): Video number (0-3)
* `prompt` (String, optional): Extension prompt (1-8192 characters)
* `callback` (String): Webhook URL

***

## apiV1VideoUpscalePost()

Upscale video to higher resolution.

```javascript theme={null}
const body = {
    jobId: 'original-video-job-id',
    videoNo: 0, // Video number (0-3)
    callback: 'https://your-domain.com/webhook'
};

const response = await videoApi.apiV1VideoUpscalePost(apiKey, body);
console.log('Upscaled video Job ID:', response.jobId);
```

**Parameters:**

* `jobId` (String): Original video task ID
* `videoNo` (Number): Video number (0-3)
* `callback` (String): Webhook URL

***

## Complete Example

```javascript theme={null}
const { Configuration, VideoApi } = require('@legnext-api/js-sdk');

async function generateAndExtendVideo() {
    const apiClient = new Configuration();
    apiClient.basePath = 'https://api.legnext.ai';
    const videoApi = new VideoApi(apiClient);

    const apiKey = process.env.LEGNEXT_API_KEY;

    try {
        // Step 1: Generate initial video
        const body = {
            prompt: 'a sunset over ocean waves',
            videoType: 1
        };

        const initialResponse = await videoApi.apiV1VideoDiffusionPost(apiKey, body);
        const jobId = initialResponse.jobId;
        console.log('Initial video job:', jobId);

        // Wait for completion (see task-management.mdx)
        // await waitForCompletion(jobId);

        // Step 2: Extend the video
        const extendBody = {
            jobId: jobId,
            videoNo: 0,
            prompt: 'zoom in on the waves'
        };

        const extendResponse = await videoApi.apiV1ExtendVideoPost(apiKey, extendBody);
        console.log('Extended video job:', extendResponse.jobId);

    } catch (error) {
        console.error('Error:', error);
    }
}

generateAndExtendVideo();
```

***

## Next Steps

* [Image Generation](/sdk/javascript/image-generation)
* [Task Management](/sdk/javascript/task-management)
* [Quick Start](/sdk/javascript/quickstart)