# Ltx 2.3 Quality · Reference Video to Video API

> Prompt-gesteiert Generatioun op Basis vun engem Referenzvideo, mat optionalen éischten, mëttleren an leschte Schlësselframe-Biller

Erstellt en neie Video aus engem obligatoresche `prompt` an engem Referenz-`video_url`, deen d'Beweegung an d'Struktur liwwert. Optional `image_url`, `mid_image_url` an `end_image_url` fixéiere de Look um Ufank, an der Mëtt an um Enn. `video_strength` an `strength` (béid 0 to 1) steieren, wéi enk de Video der Quell follegt oder wéi vill se erhale bleift, an `control_video_url` kann e virberechent Kontrollsignal liwweren. `resolution` bitt automatesch oder fix Presets wéi quadratesch an 16:9 Portrait- oder Landschaftsformat.

- Model id: `ltx-2.3-quality/reference-video-to-video`
- Made by: Lightricks
- Category: Video to Video
- Output: video
- Price per megapixel of your output video: $0.00241 / megapixel of output video (cheapest run $0.003 (3 API credits))
- Run: `POST https://api.doitong.com/v1/run/ltx-2.3-quality/reference-video-to-video`
- Quote: `POST https://api.doitong.com/v1/quote/ltx-2.3-quality/reference-video-to-video`
- Docs page: https://doitong.com/lb/developers/models/ltx-2.3-quality/reference-video-to-video

## Pricing

Price: **$0.00241 / 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 $0.27 = 270 API credits (112 MP output video × $0.002408).

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-quality/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, deen d'Generatioun steiert. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL op e Referenzvideo, deen d'Beweegung an d'Struktur steiert. |
| `control_video_url` |  | string (video URL) \| null | no |  |  | Optional virbereete Kontrollvideo, dat amplaz vun der integréierter Kontrollschätzung benotzt gëtt, wann et zesumme mat `skip_control_preprocess` geliwwert gëtt. No der Neiskaléierung op d'Output-Dimensiounen an d'Framezuel gëtt et zum direkte Kontrollsignal. De Video kann zum Beispill eng scho gerenderte Kompositioun aus Déift, Kanten oder Pose enthalen. |
| `skip_control_preprocess` |  | boolean | no | `false` |  | Direkte Kontrollmodus mat `control_video_url` amplaz vun enger interner Schätzung vun Déift, Kanten oder Pose; ouni dës URL gëtt d'Astellung ignoréiert. D'Output-Gréisst an dësem Modus respektéiert explizit Dimensioune mat 64er-Ausrichtung, fir RGB- a Kontrollvideoen ofzestëmmen, wärend `auto` d'Quell-Dimensiounen an d'Aspektverhältnis bannent den LTX-Limite iwwerhëlt. |
| `preserve_original_video` |  | boolean | no | `false` |  | Modus fir d'Erhale vum Originalvideo, nëmme verfügbar mat `skip_control_preprocess`, `video_url` an `control_video_url`. Standardméisseg deaktivéiert, léisst en déi normal Kontrollveraarbechtung intakt; beim Aktivéiere fänkt d'Generatioun mat `video_url` un, wärend strukturell Guidance vu `control_video_url` erhale bleift. Denoising iwwer `strength` bestëmmt de preservéierte Montant, woubäi méi niddreg Astellunge méi originell Pixel behalen. |
| `image_url` | `image` | string (image URL) \| null | no |  |  | Optional Bildverankerungsstil oder Charakteridentitéit als Keyframe vum éischte Frame. |
| `mid_image_url` |  | string (image URL) \| null | no |  |  | Optional Bildverankerungsoptrieden no beim Mëttelpunkt vum Clips, als Ergänzung zum initialen `image_url`-Keyframe. Et hëlleft, datt d'Optriede der Kamerabeweegung follegt amplaz ofzedriften; erfuerdert `image_url`. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Optional Bildverankerungsoptrieden um leschte Frame vum Clips. Nëtzlech, wann d'Kamerabeweegung op enger anerer Positioun wéi d'Startbild ophält; erfuerdert `image_url`. |
| `video_strength` |  | number | no | `0.6` | 0 – 1 | D'Fräiheet, d'Beweegung an d'Struktur vum Referenzvideo z'änneren, gëtt duerch dës Conditioning-Stäerkt gesteiert: méi kleng Astellunge erlaben méi grouss Ännerungen. |
| `strength` |  | number | no | `1` | 0 – 1 | Denoising-Kontroll fir d'Referenzvideo-zu-Video-Sampling, där hiren Effekt vun `preserve_original_video` ofhänkt. Wann dëse Modus aus ass, verkierzt en nëmmen den Denoising-Zäitplang; wann en un ass, steiert en d'Transformatioun vun de Quellpixel, woubäi 1.0 alles nei generéiert a méi niddreg Astellunge méi erhalen (zum Beispill erhält 0.5 ongeféier 50%). |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Zuel vun den Output-Frames, ënnerleien engem IC-LoRA-Stabilitéitsbudget op Basis vun Opléisung multiplizéiert mat Frames. Eng 422-Äntwert bedeit, datt dëse Budget iwwerschratt gouf: reduzéiert d'Opléisung oder `num_frames`. De Budget erlaabt ongeféier 150 Frames bei 720p-Klass-Dimensiounen a méi bei méi klengen Dimensiounen. |
| `resolution` |  | object {width, height} \| enum (string) | no | `auto` | `auto`, `square_hd`, `square`, `portrait_4_3`, `portrait_16_9`, `landscape_4_3`, `landscape_16_9` | Output-Video-Dimensiounen, déi och d'stabil Dauer beaflossen: méi kleng Gréissten erlaben méi Frames, wärend méi grouss d'Maximum reduzéieren. Déi integréiert Kontrollschätzung hält d'Gréisst no um offiziellen Kontroll-Workflow; direkt Kontroll iwwer `skip_control_preprocess` an `control_video_url` respektéiert amplaz explizit Dimensioune mat 64px-Ausrichtung. Am Direkt-Kontrollmodus iwwerhëlt `auto` d'Quell-Dimensiounen an d'Aspektverhältnis bannent den LTX-Limiten. |
| `frames_per_second` |  | number | no | `24` | 1 – 60 | Output-Video-Frame-Rate, gemooss a Frames pro Sekonn. |
| `num_inference_steps` |  | integer | no | `15` | 8 – 30 | Setzt d'Zuel vun den Inference-Schrëtt op bis zu 30; wann onverännert, ginn 15 benotzt. |
| `guidance_scale` |  | number | no | `1` | 1 – 20 | Passt classifier-free guidance mat dëser Skala un; de Standard ass op héich Qualitéit a séier Generatioun ofgestëmmt. |
| `generate_audio` |  | boolean | no | `true` |  | Audio-Spur-Toggle fir den zeréckginnene MP4: ausgeschalt produzéiert eng Video-nëmmen-Datei, ageschalt enthält Audio. |
| `negative_prompt` |  | string | no | `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` |  | Negativen Prompt, deen ugëtt, wat d'Generatioun vermeide soll. |
| `seed` |  | integer \| null | no |  |  | Seed, deen d'Generatioun reproduzéierbar mécht. Wann et op None gesat gëtt, gëtt e Seed zoufälleg gewielt. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Steiert, ob d'Prompt-Erweiderung aktivéiert ass. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Steiert, ob d'Sécherheetskontroll aktivéiert ass. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Qualitéitsvirstellung, déi op den Output-Video applizéiert gëtt. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Schreifmodus vum resultéierende Video. |

File parameters (`video`, `control_video_url`, `image`, `mid_image_url`, `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-quality/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-quality/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-quality/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-quality/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-quality/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": 270,
    "usd": "0.27",
    "charged": 270,
    "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
    },
    "seed": 42,
    "prompt": "string"
  },
  "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} | Video, dee vum Modell produzéiert gëtt. |
| `seed` | integer | Tatsächlech Seed, deen wärend der Generatioun applizéiert gëtt. |
| `prompt` | string | Generatiouns-Prompt, inklusiv all Erweiderung, déi virun der Benotzung applizéiert gouf. |

## Related models

- [Ltx 2.3 Quality · Text to Video](https://doitong.com/developers/models/ltx-2.3-quality/text-to-video.md) (`ltx-2.3-quality/text-to-video`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Text to Video · LoRA](https://doitong.com/developers/models/ltx-2.3-quality/text-to-video/lora.md) (`ltx-2.3-quality/text-to-video/lora`): $0.00271 / megapixel of output video
- [Ltx 2.3 Quality · Image to Video](https://doitong.com/developers/models/ltx-2.3-quality/image-to-video.md) (`ltx-2.3-quality/image-to-video`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Image to Video · LoRA](https://doitong.com/developers/models/ltx-2.3-quality/image-to-video/lora.md) (`ltx-2.3-quality/image-to-video/lora`): $0.00271 / megapixel of output video
- [Ltx 2.3 Quality · Ingredient](https://doitong.com/developers/models/ltx-2.3-quality/ingredient.md) (`ltx-2.3-quality/ingredient`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Clean Plate](https://doitong.com/developers/models/ltx-2.3-quality/clean-plate.md) (`ltx-2.3-quality/clean-plate`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Colorization](https://doitong.com/developers/models/ltx-2.3-quality/colorization.md) (`ltx-2.3-quality/colorization`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Cross Eyed](https://doitong.com/developers/models/ltx-2.3-quality/cross-eyed.md) (`ltx-2.3-quality/cross-eyed`): $0.00241 / megapixel of output video

## Links

- HTML page: https://doitong.com/developers/models/ltx-2.3-quality/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-quality/reference-video-to-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ltx-2.3-quality/reference-video-to-video