# Ltx 2.3 Quality

> Inpaint high-quality video using LTX-2.3  with lora


## Overview

- **Endpoint**: `https://fal.run/fal-ai/ltx-2.3-quality/inpaint/lora`
- **Model ID**: `fal-ai/ltx-2.3-quality/inpaint/lora`
- **Category**: video-to-video
- **Kind**: inference
**Tags**: inpaint



## Pricing

fal-ai/ltx23-trainer-v2/inpaint
fal-ai/ltx23-v2v-trainer

For more details, see [fal.ai pricing](https://fal.ai/pricing).

## API Information

This model can be used via our HTTP API or more conveniently via our client libraries.
See the input and output schema below, as well as the usage examples.


### Input Schema

The API accepts the following input parameters:


- **`prompt`** (`string`, _required_):
  The prompt describing what to generate inside the masked area.
  - Examples: "Replace the masked region with matching cinematic background detail."

- **`video_url`** (`string`, _required_):
  The source video to inpaint.

- **`mask_video_url`** (`string`, _required_):
  The mask video. White regions are regenerated; black regions are preserved from the source video.

- **`video_strength`** (`float`, _optional_):
  Strength of the IC-LoRA video guide for the preserved content. Higher values keep the source video structure more strongly. Default value: `1`
  - Default: `1`
  - Range: `0` to `1`

- **`num_frames`** (`integer`, _optional_):
  The number of frames to generate. Default value: `121`
  - Default: `121`
  - Range: `9` to `481`

- **`frames_per_second`** (`float`, _optional_):
  Frames per second of the generated video. Default value: `24`
  - Default: `24`
  - Range: `1` to `60`

- **`num_inference_steps`** (`integer`, _optional_):
  Number of inference steps. Defaults to 15 and can be increased up to 30. Default value: `15`
  - Default: `15`
  - Range: `8` to `30`

- **`guidance_scale`** (`float`, _optional_):
  Classifier-free guidance scale. The default is tuned for fast, high-quality generation. Default value: `1`
  - Default: `1`
  - Range: `1` to `20`

- **`generate_audio`** (`boolean`, _optional_):
  Whether to include audio in the returned video. When disabled, the final MP4 is returned without an audio track. Default value: `true`
  - Default: `true`

- **`negative_prompt`** (`string`, _optional_):
  The negative prompt to steer generation away from. Default value: `"color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards"`
  - Default: `"color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards"`

- **`seed`** (`integer`, _optional_):
  Random seed for reproducibility. If None, a random seed is chosen.

- **`enable_prompt_expansion`** (`boolean`, _optional_):
  Whether to enable prompt expansion. Default value: `true`
  - Default: `true`

- **`enable_safety_checker`** (`boolean`, _optional_):
  Whether to enable the safety checker. Default value: `true`
  - Default: `true`

- **`video_quality`** (`VideoQualityEnum`, _optional_):
  The quality preset of the generated video. Default value: `"high"`
  - Default: `"high"`
  - Options: `"low"`, `"medium"`, `"high"`, `"maximum"`

- **`video_write_mode`** (`VideoWriteModeEnum`, _optional_):
  The write mode of the generated video. Default value: `"balanced"`
  - Default: `"balanced"`
  - Options: `"fast"`, `"balanced"`, `"small"`

- **`sync_mode`** (`boolean`, _optional_):
  If True, the media is returned as a data URI inline in the response. Useful for short-lived requests and tests.
  - Default: `false`

- **`loras`** (`list<LoRAInput>`, _required_):
  Up to 3 LoRAs to apply on top of LTX-2.3. Each path is downloaded through the registry SSRF-safe downloader before it is loaded. Max size: 3 GB per LoRA.
  - Array of LoRAInput



**Required Parameters Example**:

```json
{
  "prompt": "Replace the masked region with matching cinematic background detail.",
  "video_url": "",
  "mask_video_url": "",
  "loras": [
    {
      "path": "https://example.com/path/to/lora.safetensors",
      "scale": 1,
      "transformer": "both"
    }
  ]
}
```

**Full Example**:

```json
{
  "prompt": "Replace the masked region with matching cinematic background detail.",
  "video_url": "",
  "mask_video_url": "",
  "video_strength": 1,
  "num_frames": 121,
  "frames_per_second": 24,
  "num_inference_steps": 15,
  "guidance_scale": 1,
  "generate_audio": true,
  "negative_prompt": "color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards",
  "enable_prompt_expansion": true,
  "enable_safety_checker": true,
  "video_quality": "high",
  "video_write_mode": "balanced",
  "loras": [
    {
      "path": "https://example.com/path/to/lora.safetensors",
      "scale": 1,
      "transformer": "both"
    }
  ]
}
```


### Output Schema

The API returns the following output format:

- **`video`** (`File`, _required_):
  The generated video.

- **`seed`** (`integer`, _required_):
  The seed actually used for generation.

- **`prompt`** (`string`, _required_):
  The prompt used for generation (after any expansion).



**Example Response**:

```json
{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  },
  "prompt": ""
}
```


## Usage Examples

### cURL

```bash
curl --request POST \
  --url https://fal.run/fal-ai/ltx-2.3-quality/inpaint/lora \
  --header "Authorization: Key $FAL_KEY" \
  --header "Content-Type: application/json" \
  --data '{
     "prompt": "Replace the masked region with matching cinematic background detail.",
     "video_url": "",
     "mask_video_url": "",
     "loras": [
       {
         "path": "https://example.com/path/to/lora.safetensors",
         "scale": 1,
         "transformer": "both"
       }
     ]
   }'
```

### Python

Ensure you have the Python client installed:

```bash
pip install fal-client
```

Then use the API client to make requests:

```python
import fal_client

def on_queue_update(update):
    if isinstance(update, fal_client.InProgress):
        for log in update.logs:
           print(log["message"])

result = fal_client.subscribe(
    "fal-ai/ltx-2.3-quality/inpaint/lora",
    arguments={
        "prompt": "Replace the masked region with matching cinematic background detail.",
        "video_url": "",
        "mask_video_url": "",
        "loras": [{
            "path": "https://example.com/path/to/lora.safetensors",
            "scale": 1,
            "transformer": "both"
        }]
    },
    with_logs=True,
    on_queue_update=on_queue_update,
)
print(result)
```

### JavaScript

Ensure you have the JavaScript client installed:

```bash
npm install --save @fal-ai/client
```

Then use the API client to make requests:

```javascript
import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/ltx-2.3-quality/inpaint/lora", {
  input: {
    prompt: "Replace the masked region with matching cinematic background detail.",
    video_url: "",
    mask_video_url: "",
    loras: [{
      path: "https://example.com/path/to/lora.safetensors",
      scale: 1,
      transformer: "both"
    }]
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);
```


## Additional Resources

### Documentation

- [Model Playground](https://fal.ai/models/fal-ai/ltx-2.3-quality/inpaint/lora)
- [API Documentation](https://fal.ai/models/fal-ai/ltx-2.3-quality/inpaint/lora/api)
- [OpenAPI Schema](https://fal.ai/api/openapi/queue/openapi.json?endpoint_id=fal-ai/ltx-2.3-quality/inpaint/lora)

### fal.ai Platform

- [Platform Documentation](https://docs.fal.ai)
- [Python Client](https://docs.fal.ai/clients/python)
- [JavaScript Client](https://docs.fal.ai/clients/javascript)