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

# LTX

> Fastest and cheapest video generation model — supports native audio and keyframe control

## Overview

LTX (Lightricks) is the most affordable video model available, and also one of the fastest. It supports unique features like native audio generation and first+last frame keyframe control.

| Model ID              | Credits | \~Cost |
| --------------------- | ------- | ------ |
| `ltx-2-19b-distilled` | 50      | \$0.50 |

<Note>
  The gateway model ID is `ltx-2-19b-distilled`. This is the distilled 19B parameter variant optimized for speed.
</Note>

## Quick start

<CodeGroup>
  ```typescript SDK theme={null}
  import { createVarg } from "vargai/ai"

  const varg = createVarg({ apiKey: process.env.VARG_API_KEY! })

  const result = await varg.videoModel("ltx-2-19b-distilled").generate({
    prompt: "a paper airplane flying through a sunlit room, slow motion",
    duration: 5,
    aspectRatio: "16:9",
  })

  console.log(result.video.url)
  ```

  ```bash cURL theme={null}
  curl -X POST https://api.varg.ai/v1/video \
    -H "Authorization: Bearer $VARG_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "model": "ltx-2-19b-distilled",
      "prompt": "a paper airplane flying through a sunlit room, slow motion",
      "duration": 5,
      "aspect_ratio": "16:9"
    }'
  ```
</CodeGroup>

## Special features

### Native audio generation

LTX can generate audio alongside the video. Enable it with provider options:

```bash cURL theme={null}
curl -X POST https://api.varg.ai/v1/video \
  -H "Authorization: Bearer $VARG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ltx-2-19b-distilled",
    "prompt": "rain falling on a tin roof, close up of droplets splashing",
    "duration": 5,
    "provider_options": { "varg": { "generate_audio": true } }
  }'
```

### Keyframe control (first + last frame)

Provide two images to control start and end frames:

```bash cURL theme={null}
curl -X POST https://api.varg.ai/v1/video \
  -H "Authorization: Bearer $VARG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "ltx-2-19b-distilled",
    "prompt": "smooth morphing transition",
    "duration": 5,
    "files": [
      { "url": "https://example.com/start.jpg" },
      { "url": "https://example.com/end.jpg" }
    ]
  }'
```

## Parameters

<ResponseField name="prompt" type="string" required>
  Text description of the video to generate.
</ResponseField>

<ResponseField name="duration" type="number" default="5">
  Video duration in seconds.
</ResponseField>

<ResponseField name="aspect_ratio" type="string" default="16:9">
  Output aspect ratio.
</ResponseField>

<ResponseField name="files" type="array">
  One image for image-to-video. Two images for first+last frame keyframe control.
</ResponseField>

<ResponseField name="provider_options" type="object">
  Set `{ "varg": { "generate_audio": true } }` to enable native audio generation.
</ResponseField>

<Note>
  LTX internally uses `num_frames` instead of `duration` and `video_size` instead of `aspect_ratio`. The gateway handles the conversion automatically.
</Note>

## Pricing

| Model                 | Credits | USD    |
| --------------------- | ------- | ------ |
| `ltx-2-19b-distilled` | 50      | \$0.50 |

The cheapest video model available. Ideal for prototyping and high-volume generation.

## Tips

* **Best for rapid iteration** — fast and cheap, great for testing prompts before upgrading to Kling or Seedance.
* **Native audio** is unique to LTX (and Grok Imagine / Kling V2.6). Useful for ambient sound effects.
* **Keyframe control** lets you define start and end frames for precise transitions.
* **Quality is lower** than Kling V3 or Seedance 2, but acceptable for social media and prototypes.

## Related models

<CardGroup cols={2}>
  <Card title="Wan 2.5" icon="wand-magic-sparkles" href="/models/video/wan-2">
    Slightly more expensive but better quality. Good upgrade path.
  </Card>

  <Card title="Kling V3" icon="film" href="/models/video/kling-v3">
    Premium quality. 3x the cost but significantly better output.
  </Card>
</CardGroup>