# LTX-2.3 22B · Reference Video to Video API

> Generates a new video guided by a reference video, with optional replacement audio and first and last frames

Takes a `prompt` and a reference `video_url`. An optional `audio_url` replaces the audio; if omitted, audio from the input video is used. `image_url` and `end_image_url` can fix first and last frames. With `match_video_length` on, the frame count follows the reference; otherwise `num_frames` (9 to 481) applies.

- Model id: `ltx-2.3-22b/reference-video-to-video`
- Made by: Lightricks
- Category: Video to Video
- Output: video
- Price per megapixel of your output video: $0.00161 / megapixel of output video (cheapest run $0.002 (2 API credits))
- Run: `POST https://api.doitong.com/v1/run/ltx-2.3-22b/reference-video-to-video`
- Quote: `POST https://api.doitong.com/v1/quote/ltx-2.3-22b/reference-video-to-video`
- Docs page: https://doitong.com/developers/models/ltx-2.3-22b/reference-video-to-video

## Pricing

Price: **$0.00161 / megapixel of output video**. Price per megapixel of your output video: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $0.453 = 453 API credits (282 MP output video × $0.001605).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/ltx-2.3-22b/reference-video-to-video` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  |  | Prompt used as the basis for video generation. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL identifying the reference video. |
| `audio_url` | `audio` | string (audio URL) \| null | no |  |  | Optional audio URL supplying the video's audio track. When omitted, audio from the source video is used if present. |
| `image_url` | `image` | string (image URL) \| null | no |  |  | Optional image URL defining the video's opening frame. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Image URL defining the video's ending frame. |
| `match_video_length` |  | boolean | no | `true` |  | Frame-count selection mode: disabled uses `num_frames`, while enabled computes the count using FPS and video duration. |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Frame count for the generated output. |
| `video_size` |  | object {width, height} \| enum (string) | no | `auto` | `auto`, `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | Dimensions of the generated video. |
| `generate_audio` |  | boolean | no | `true` |  | Controls whether the video includes generated audio. |
| `use_multiscale` |  | boolean | no | `true` |  | Multi-scale generation toggle for improved coherence and detail. With True, a preliminary smaller video guides a second generation whose size meets or exceeds the requested dimensions. |
| `match_input_fps` |  | boolean | no | `true` |  | Output frame-rate override that replaces the default target FPS with the source video's FPS when enabled. |
| `fps` |  | number | no | `24` | 1 – 60 | Output video frame rate, measured in frames per second. |
| `num_inference_steps` |  | integer | no | `40` | 8 – 50 | Count of inference steps performed. |
| `video_cfg_scale` |  | number | no | `3` | 1 – 20 | Video guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG). |
| `video_stg_scale` |  | number | no | `0` | 0 – 20 | Video consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities. |
| `video_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Video rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio. |
| `video_modality_scale` |  | number | no | `3` | 0 – 10 | Video modality adjustment for balancing the video and audio contributions as a ratio. |
| `audio_cfg_scale` |  | number | no | `7` | 1 – 20 | Audio guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG). |
| `audio_stg_scale` |  | number | no | `0` | 0 – 20 | Audio consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities. |
| `audio_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Audio rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio. |
| `audio_modality_scale` |  | number | no | `3` | 0 – 10 | Audio modality adjustment for balancing the video and audio contributions as a ratio. |
| `gradient_estimation_gamma` |  | number | no | `2` | 0 – 10 | Denoising gradient-estimation setting: 0 turns estimation off; otherwise, the value specifies gamma. |
| `use_restart_sampling` |  | boolean | no | `false` |  | Restart sampling toggle for potentially better video quality: enabling it introduces a little noise at every denoising step. |
| `scheduler` |  | enum (string) | no | `ltx2` | `ltx2`, `linear_quadratic`, `beta` | Scheduler selection. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular`, `high`, `full` | Acceleration level applied to processing. |
| `camera_lora` |  | enum (string) | no | `none` | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `none` | Camera LoRA selection for controlling movement in the generated video more precisely than camera-motion prompts alone. |
| `camera_lora_scale` |  | number | no | `1` | 0 – 1 | Camera LoRA strength for controlling movement in the generated video more precisely than camera-motion prompts alone. |
| `negative_prompt` |  | string | no | `news broadcast, 3d animation, computer graphics, pc game, console game, video game, cartoon, childish, watermark, logo, text, on screen text, subtitles, titles, signature, slowmo, static` |  | Negative prompt used during video generation. |
| `seed` |  | integer \| null | no |  |  | Seed value that initializes random-number generation. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Controls whether prompt expansion is enabled. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Controls whether safety checking is enabled. |
| `video_output_type` |  | enum (string) | no | `X264 (.mp4)` | `X264 (.mp4)`, `VP9 (.webm)`, `PRORES4444 (.mov)`, `GIF (.gif)` | Output type for the resulting video. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Quality level for the resulting video. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Write mode for the resulting video. |
| `distill_lora_first_pass_scale` |  | number | no | `0.2` | 0 – 1 | Control first-pass distill LoRA scaling, using 0 to turn it off. |
| `distill_lora_second_pass_scale` |  | number | no | `0.5` | 0 – 1 | Control distill LoRA scaling for every pass after the first. |
| `video_strength` |  | number | no | `1` | 0 – 1 | Freedom to alter video content is controlled by this conditioning strength: smaller settings allow the model greater latitude. |
| `audio_strength` |  | number | no | `1` | 0 – 1 | Freedom to alter audio content is controlled by this conditioning strength: smaller settings allow the model greater latitude. |
| `preprocessor` |  | enum (string) | no | `none` | `depth`, `canny`, `pose`, `none` | Preprocessor applied during generation. |
| `ic_lora_type` |  | enum (string) | no | `union` | `match_preprocessor`, `union`, `detailer`, `none` | IC LoRA variant applied during generation. |

File parameters (`video`, `audio`, `image`, `end_image`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/ltx-2.3-22b/reference-video-to-video?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/ltx-2.3-22b/reference-video-to-video?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ltx-2.3-22b/reference-video-to-video", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.com/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "ltx-2.3-22b/reference-video-to-video",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "ltx-2.3-22b/reference-video-to-video",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 453,
    "usd": "0.453",
    "charged": 453,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200,
      "width": 1024,
      "height": 768,
      "fps": 1.0,
      "duration": 5,
      "num_frames": 1
    },
    "seed": 42,
    "prompt": "black-and-white video, a cowboy walks through a dusty town, film grain"
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `video` | object {url, content_type, file_name, file_size, width, height, fps, duration, num_frames} | Video produced by the model. |
| `seed` | integer | Seed value used to initialize random number generation. |
| `prompt` | string | Prompt used to guide generation. |

## Related models

- [LTX-2.3 22B · Text to Video](https://doitong.com/developers/models/ltx-2.3-22b/text-to-video.md) (`ltx-2.3-22b/text-to-video`): $0.00161 / megapixel of output video
- [LTX-2.3 22B · Text to Video · LoRA](https://doitong.com/developers/models/ltx-2.3-22b/text-to-video/lora.md) (`ltx-2.3-22b/text-to-video/lora`): $0.00181 / megapixel of output video
- [LTX-2.3 22B · Image to Video](https://doitong.com/developers/models/ltx-2.3-22b/image-to-video.md) (`ltx-2.3-22b/image-to-video`): $0.00161 / megapixel of output video
- [LTX-2.3 22B · Image to Video · LoRA](https://doitong.com/developers/models/ltx-2.3-22b/image-to-video/lora.md) (`ltx-2.3-22b/image-to-video/lora`): $0.00181 / megapixel of output video
- [LTX 2.3 22B](https://doitong.com/developers/models/ltx-2.3-22b/reference-video-to-video/lora.md) (`ltx-2.3-22b/reference-video-to-video/lora`): $0.00181 / megapixel of output video
- [LTX-2.3 22B · Extend Video](https://doitong.com/developers/models/ltx-2.3-22b/extend-video.md) (`ltx-2.3-22b/extend-video`): $0.00161 / megapixel of output video
- [LTX-2.3 22B · Extend Video · LoRA](https://doitong.com/developers/models/ltx-2.3-22b/extend-video/lora.md) (`ltx-2.3-22b/extend-video/lora`): $0.00181 / megapixel of output video
- [LTX-2.3 22B · Video to Video](https://doitong.com/developers/models/ltx-2.3-22b/video-to-video.md) (`ltx-2.3-22b/video-to-video`): $0.00161 / megapixel of output video

## Links

- HTML page: https://doitong.com/developers/models/ltx-2.3-22b/reference-video-to-video
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=ltx-2.3-22b/reference-video-to-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ltx-2.3-22b/reference-video-to-video