# LTX-2.3 22B · Extend Video API

> Nadaljuje obstoječi video na podlagi poziva, z ustvarjenim zvokom in neobvezno končno sliko

Sprejme `video_url` in `prompt` ter ustvari nadaljevanje z `num_frames` sličicami (od 9 do 481). Neobvezni `end_image_url` določa, kje se razširitev konča. `match_input_fps` ohrani hitrost sličic vira, `generate_audio` doda zvok, `video_size` pa je privzeto nastavljen na auto. Izhod je lahko mp4, webm, mov ali 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/sl/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 |  |  | Poziv, uporabljen kot osnova za generiranje videa. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL videa, ki bo podaljšan. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Z URL-jem posredujte sliko končne sličice, da določite konec podaljšanega videa. |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Število sličic ustvarjenega izhoda. |
| `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` | Mere ustvarjenega videa. |
| `generate_audio` |  | boolean | no | `true` |  | Določa, ali video vključuje ustvarjeni zvok. |
| `use_multiscale` |  | boolean | no | `true` |  | Preklop več-razsežnostnega generiranja za boljšo skladnost in podrobnosti. Pri True predhodni manjši video usmerja drugo generiranje, katerega velikost dosega ali presega zahtevane mere. |
| `match_input_fps` |  | boolean | no | `true` |  | Preglasitev izhodne hitrosti sličic, ki ob omogočitvi privzeti ciljni FPS nadomesti s FPS izvornega videa. |
| `fps` |  | number | no | `24` | 1 – 60 | Hitrost sličic izhodnega videa, izmerjena v sličicah na sekundo. |
| `num_inference_steps` |  | integer | no | `40` | 8 – 50 | Število izvedenih korakov inference. |
| `video_cfg_scale` |  | number | no | `3` | 1 – 20 | Nastavitev usmerjanja videa: povečajte jo za večjo skladnost in osredotočenost ustvarjene vsebine. Uporablja usmerjanje brez klasifikatorja (CFG). |
| `video_stg_scale` |  | number | no | `0` | 0 – 20 | Nadzor skladnosti in osredotočenosti videa prek lestvice Spatiotemporal Guidance (STG); povečajte nastavitev za okrepitev obeh lastnosti. |
| `video_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Prilagoditev ponovnega skaliranja videa za uravnoteženje usmerjanja brez klasifikatorja in prostorsko-časovnega usmerjanja kot razmerja. |
| `video_modality_scale` |  | number | no | `3` | 0 – 10 | Prilagoditev modalnosti videa za uravnoteženje prispevkov videa in zvoka kot razmerja. |
| `audio_cfg_scale` |  | number | no | `7` | 1 – 20 | Nastavitev usmerjanja zvoka: povečajte jo za večjo skladnost in osredotočenost ustvarjene vsebine. Uporablja usmerjanje brez klasifikatorja (CFG). |
| `audio_stg_scale` |  | number | no | `0` | 0 – 20 | Nadzor skladnosti in osredotočenosti zvoka prek lestvice Spatiotemporal Guidance (STG); povečajte nastavitev za okrepitev obeh lastnosti. |
| `audio_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Prilagoditev ponovnega skaliranja zvoka za uravnoteženje usmerjanja brez klasifikatorja in prostorsko-časovnega usmerjanja kot razmerja. |
| `audio_modality_scale` |  | number | no | `3` | 0 – 10 | Prilagoditev modalnosti zvoka za uravnoteženje prispevkov videa in zvoka kot razmerja. |
| `gradient_estimation_gamma` |  | number | no | `2` | 0 – 10 | Nastavitev ocenjevanja gradienta odstranjevanja šuma: 0 izklopi ocenjevanje, sicer vrednost določa gamo. |
| `use_restart_sampling` |  | boolean | no | `false` |  | Preklop ponovnega vzorčenja za morebitno boljšo kakovost videa: če ga omogočite, se pri vsakem koraku odstranjevanja šuma doda malo šuma. |
| `scheduler` |  | enum (string) | no | `ltx2` | `ltx2`, `linear_quadratic`, `beta` | Izbira razporejevalnika. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular`, `high`, `full` | Raven pospeševanja, uporabljena pri obdelavi. |
| `camera_lora` |  | enum (string) | no | `none` | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `none` | Izbira Camera LoRA za natančnejši nadzor gibanja v ustvarjenem videu kot samo s pozivi za gibanje kamere. |
| `camera_lora_scale` |  | number | no | `1` | 0 – 1 | Moč Camera LoRA za natančnejši nadzor gibanja v ustvarjenem videu kot samo s pozivi za gibanje kamere. |
| `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` |  | Negativni poziv, uporabljen pri generiranju videa. |
| `seed` |  | integer \| null | no |  |  | Vrednost semena, ki inicializira generiranje naključnih števil. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Določa, ali je razširjanje poziva omogočeno. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Določa, ali je preverjanje varnosti omogočeno. |
| `video_output_type` |  | enum (string) | no | `X264 (.mp4)` | `X264 (.mp4)`, `VP9 (.webm)`, `PRORES4444 (.mov)`, `GIF (.gif)` | Vrsta izhoda za nastali video. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Raven kakovosti nastalega videa. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Način zapisovanja nastalega videa. |
| `distill_lora_first_pass_scale` |  | number | no | `0.2` | 0 – 1 | Nadzor skaliranja distill LoRA v prvem prehodu; z vrednostjo 0 ga izklopite. |
| `distill_lora_second_pass_scale` |  | number | no | `0.5` | 0 – 1 | Nadzor skaliranja distill LoRA pri vsakem prehodu po prvem. |
| `extend_direction` |  | enum (string) | no | `forward` | `forward`, `backward` | Stran videa za podaljšanje: izberite 'backward' za dodajanje vsebine pred njegovim začetkom ali 'forward' za dodajanje vsebine za njegovim koncem. |
| `num_context_frames` |  | integer | no | `25` | 0 – 121 | Število sličic, uporabljeno za zagotovitev konteksta pri podaljševanju videa. |
| `video_strength` |  | number | no | `1` | 0 – 1 | Svobodo spreminjanja vsebine videa določa ta moč pogojevanja: nižje nastavitve modelu omogočajo več svobode. |
| `audio_strength` |  | number | no | `1` | 0 – 1 | Svobodo spreminjanja vsebine zvoka določa ta moč pogojevanja: nižje nastavitve modelu omogočajo več svobode. |
| `end_image_strength` |  | number | no | `1` | 0 – 1 | Nadzira, koliko končna slika vpliva na ustvarjeni video. |

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} | Video, ki ga ustvari model. |
| `seed` | integer | Vrednost semena, uporabljena za inicializacijo generiranja naključnih števil. |
| `prompt` | string | Poziv, uporabljen za usmerjanje generiranja. |

## 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