# LTX-2.3 22B · Extend Video API

> Tęsia esamą vaizdo įrašą pagal raginį, su generuojamu garsu ir pasirinktiniu pabaigos vaizdu

Priima `video_url` ir `prompt` bei sugeneruoja `num_frames` kadrų tęsinį (nuo 9 iki 481). Pasirinktinis `end_image_url` nustato, kur baigiasi tęsinys. `match_input_fps` išlaiko šaltinio kadrų dažnį, `generate_audio` prideda garsą, o `video_size` pagal numatytuosius nustatymus yra auto. Išvestis gali būti mp4, webm, mov arba GIF.

- Model id: `ltx-2.3-22b/extend-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/extend-video`
- Quote: `POST https://api.doitong.com/v1/quote/ltx-2.3-22b/extend-video`
- Docs page: https://doitong.com/lt/developers/models/ltx-2.3-22b/extend-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 $0.18 = 180 API credits (112 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/extend-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 |  |  | Raginys, naudojamas kaip vaizdo įrašo generavimo pagrindas. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL, nurodantis vaizdo įrašą, kuris bus pratęstas. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Pateikite baigiamojo kadro vaizdą URL formatu, kad apibrėžtumėte, kaip baigsis pratęstas vaizdo įrašas. |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Generuojamos išvesties kadrų skaičius. |
| `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` | Sugeneruoto vaizdo įrašo matmenys. |
| `generate_audio` |  | boolean | no | `true` |  | Nurodo, ar vaizdo įraše bus sugeneruotas garsas. |
| `use_multiscale` |  | boolean | no | `true` |  | Daugiamastelio generavimo perjungiklis, skirtas geresniam vientisumui ir detalumui. Kai reikšmė True, mažesnis preliminarus vaizdo įrašas nurodo antrojo generavimo dydį, kuris atitinka arba viršija prašomus matmenis. |
| `match_input_fps` |  | boolean | no | `true` |  | Išvesties kadrų dažnio perrašymas: įjungus numatytasis tikslinis FPS pakeičiamas šaltinio vaizdo įrašo FPS. |
| `fps` |  | number | no | `24` | 1 – 60 | Išvesties vaizdo įrašo kadrų dažnis, matuojamas kadrais per sekundę. |
| `num_inference_steps` |  | integer | no | `40` | 8 – 50 | Atliktų išvadų žingsnių skaičius. |
| `video_cfg_scale` |  | number | no | `3` | 1 – 20 | Vaizdo įrašo valdymo nustatymas: padidinkite jį, kad generuojamame turinyje būtų daugiau vientisumo ir dėmesio. Naudojamas classifier-free guidance (CFG). |
| `video_stg_scale` |  | number | no | `0` | 0 – 20 | Vaizdo įrašo vientisumo ir dėmesio valdymas naudojant Spatiotemporal Guidance (STG) skalę; padidinkite nustatymą, kad sustiprintumėte abi savybes. |
| `video_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Vaizdo įrašo mastelio keitimo koregavimas, skirtas classifier-free ir erdvėlaikio valdymui subalansuoti kaip santykis. |
| `video_modality_scale` |  | number | no | `3` | 0 – 10 | Vaizdo įrašo modalumo koregavimas, skirtas vaizdo įrašo ir garso indėliui subalansuoti kaip santykis. |
| `audio_cfg_scale` |  | number | no | `7` | 1 – 20 | Garso valdymo nustatymas: padidinkite jį, kad generuojamame turinyje būtų daugiau vientisumo ir dėmesio. Naudojamas classifier-free guidance (CFG). |
| `audio_stg_scale` |  | number | no | `0` | 0 – 20 | Garso vientisumo ir dėmesio valdymas naudojant Spatiotemporal Guidance (STG) skalę; padidinkite nustatymą, kad sustiprintumėte abi savybes. |
| `audio_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Garso mastelio keitimo koregavimas, skirtas classifier-free ir erdvėlaikio valdymui subalansuoti kaip santykis. |
| `audio_modality_scale` |  | number | no | `3` | 0 – 10 | Garso modalumo koregavimas, skirtas vaizdo įrašo ir garso indėliui subalansuoti kaip santykis. |
| `gradient_estimation_gamma` |  | number | no | `2` | 0 – 10 | Triukšmo šalinimo gradiento įvertinimo nustatymas: 0 išjungia įvertinimą, o kita reikšmė nurodo gamma. |
| `use_restart_sampling` |  | boolean | no | `false` |  | Pakartotinio semplinimo perjungiklis, galintis pagerinti vaizdo įrašo kokybę: jį įjungus, kiekviename triukšmo šalinimo žingsnyje pridedama šiek tiek triukšmo. |
| `scheduler` |  | enum (string) | no | `ltx2` | `ltx2`, `linear_quadratic`, `beta` | Planuoklio pasirinkimas. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular`, `high`, `full` | Apdorojimui taikomas spartinimo lygis. |
| `camera_lora` |  | enum (string) | no | `none` | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `none` | Kameros LoRA pasirinkimas, leidžiantis tiksliau valdyti judėjimą generuojamame vaizdo įraše nei vien kameros judesio raginiais. |
| `camera_lora_scale` |  | number | no | `1` | 0 – 1 | Kameros LoRA stiprumas, leidžiantis tiksliau valdyti judėjimą generuojamame vaizdo įraše nei vien kameros judesio raginiais. |
| `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` |  | Neigiamas raginys, naudojamas generuojant vaizdo įrašą. |
| `seed` |  | integer \| null | no |  |  | Atsitiktinių skaičių generavimą inicijuojanti pradinis reikšmė. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Valdo, ar įjungtas raginio išplėtimas. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Valdo, ar įjungtas saugos tikrinimas. |
| `video_output_type` |  | enum (string) | no | `X264 (.mp4)` | `X264 (.mp4)`, `VP9 (.webm)`, `PRORES4444 (.mov)`, `GIF (.gif)` | Gauto vaizdo įrašo išvesties tipas. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Gauto vaizdo įrašo kokybės lygis. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Gauto vaizdo įrašo įrašymo režimas. |
| `distill_lora_first_pass_scale` |  | number | no | `0.2` | 0 – 1 | Valdykite pirmojo praejimo distill LoRA mastelį; 0 jį išjungia. |
| `distill_lora_second_pass_scale` |  | number | no | `0.5` | 0 – 1 | Valdykite distill LoRA mastelį kiekviename praejime po pirmojo. |
| `extend_direction` |  | enum (string) | no | `forward` | `forward`, `backward` | Vaizdo įrašo pusė, kurią reikia pratęsti: pasirinkite 'backward', kad pridėtumėte turinį prieš pradžią, arba 'forward', kad pridėtumėte turinį po pabaigos. |
| `num_context_frames` |  | integer | no | `25` | 0 – 121 | Kadrų skaičius, naudojamas kontekstui pateikti pratęsiant vaizdo įrašą. |
| `video_strength` |  | number | no | `1` | 0 – 1 | Laisvę keisti vaizdo įrašo turinį valdo šis sąlygojimo stiprumas: mažesnės reikšmės suteikia modeliui daugiau laisvės. |
| `audio_strength` |  | number | no | `1` | 0 – 1 | Laisvę keisti garso turinį valdo šis sąlygojimo stiprumas: mažesnės reikšmės suteikia modeliui daugiau laisvės. |
| `end_image_strength` |  | number | no | `1` | 0 – 1 | Valdykite, kiek baigiamasis vaizdas veikia generuojamą vaizdo įrašą. |

File parameters (`video`, `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/extend-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/extend-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/extend-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/extend-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/extend-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": 180,
    "usd": "0.18",
    "charged": 180,
    "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": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence. City lights flicker and reflections shift across her denim jacket."
  },
  "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} | Modelio sukurtas vaizdo įrašas. |
| `seed` | integer | Pradinė reikšmė atsitiktinių skaičių generavimui. |
| `prompt` | string | Generavimui nukreipti naudojamas raginys. |

## 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 · 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 · Reference Video to Video](https://doitong.com/developers/models/ltx-2.3-22b/reference-video-to-video.md) (`ltx-2.3-22b/reference-video-to-video`): $0.00161 / 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/extend-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/extend-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ltx-2.3-22b/extend-video