# LTX-2.3 22B · Extend Video API

> Džal angle jekh egzistirime video katar jekh prompto, generirime audioha thaj opcionalno agorutne kipoha

Lel `video_url` thaj jekh `prompt` thaj kerel jekh pokračuvani katar `num_frames` kadra (9 to 481). Opcionalno `end_image_url` phenel kaj o lungavipen agoril. `match_input_fps` rakhel o kadro-rato e sursosko, `generate_audio` thovel zvuko, thaj `video_size` si standardno auto. O rezultato šaj te avel mp4, webm, mov vaj 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/rom/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 |  |  | Prompto upotreblomo sar baza e videoske keripnaske. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL kaj sikavel o video savo si te avel lungeder. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Den jekh final-kadro kipo URL-esa te sikaven sar o lungardo video agorarel. |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Kadronge gin vaš o kerdo rezultato. |
| `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` | Dimenzije e kerde videoske. |
| `generate_audio` |  | boolean | no | `true` |  | Kontrolinel, či o video lel kerdo audio. |
| `use_multiscale` |  | boolean | no | `true` |  | Multi-scale keripesko toggle vaš feder coherence thaj detail. Le True, jekh cikno video angluno keripe sikavel jekh dujto keripe, savo si bare vaj jekhbaro le mangle dimensiasa. |
| `match_input_fps` |  | boolean | no | `true` |  | Rezultato frame-rate override savo paruvdel standardno target FPS le source video FPS-esa kana si kerdo. |
| `fps` |  | number | no | `24` | 1 – 60 | Kadro rate e rezultatoske videosko, merime ande kadronge per sekunda. |
| `num_inference_steps` |  | integer | no | `40` | 8 – 50 | Gendo e kerde inference steps-ongo. |
| `video_cfg_scale` |  | number | no | `3` | 1 – 20 | Video guidance settingo: vazdel les vaš feder consistency thaj focus ande o kerdo contento. Labarel classifier-free guidance (CFG). |
| `video_stg_scale` |  | number | no | `0` | 0 – 20 | Video consistency thaj focus kontrolime le Spatiotemporal Guidance (STG) scale-sa; vazden o settingo te zoraren duje kvaliteta. |
| `video_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Video rescaling adjustment vaš balansos maškar classifier-free thaj spatiotemporal guidance sar ratio. |
| `video_modality_scale` |  | number | no | `3` | 0 – 10 | Video modality adjustment vaš balansos maškar video thaj audio contribution sar ratio. |
| `audio_cfg_scale` |  | number | no | `7` | 1 – 20 | Audio guidance settingo: vazden les vaš feder consistency thaj focus ande o kerdo contento. Labarel classifier-free guidance (CFG). |
| `audio_stg_scale` |  | number | no | `0` | 0 – 20 | Audio consistency thaj focus kontrolime le Spatiotemporal Guidance (STG) scale-sa; vazden o settingo te zoraren duje kvaliteta. |
| `audio_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Audio rescaling adjustment vaš balansos maškar classifier-free thaj spatiotemporal guidance sar ratio. |
| `audio_modality_scale` |  | number | no | `3` | 0 – 10 | Audio modality adjustment vaš balansos maškar video thaj audio contribution sar ratio. |
| `gradient_estimation_gamma` |  | number | no | `2` | 0 – 10 | Denoising gradient-estimation settingo: 0 phagel la estimation; aver value sikavel gamma. |
| `use_restart_sampling` |  | boolean | no | `false` |  | Restart sampling toggle vaš potencialno feder video quality: te kerdo, del cikno noise ande sako denoising step. |
| `scheduler` |  | enum (string) | no | `ltx2` | `ltx2`, `linear_quadratic`, `beta` | Scheduler alosaripen. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular`, `high`, `full` | Acceleration level aplicado ko processing. |
| `camera_lora` |  | enum (string) | no | `none` | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `none` | Camera LoRA alosaripen vaš buteder precizno kontrola le movementosko ande o kerdo video, sar numa camera-motion promptura. |
| `camera_lora_scale` |  | number | no | `1` | 0 – 1 | Camera LoRA zor vaš buteder precizno kontrola le movementosko ande o kerdo video, sar numa camera-motion promptura. |
| `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 prompto labardo kana kerel pes video. |
| `seed` |  | integer \| null | no |  |  | Seed value savo startarel randomone ginengo keripe. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Kontrolisarel te si aktivno prompto barvalipen. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Kontrolinel, si li aktivno o bezbednostno proveripe. |
| `video_output_type` |  | enum (string) | no | `X264 (.mp4)` | `X264 (.mp4)`, `VP9 (.webm)`, `PRORES4444 (.mov)`, `GIF (.gif)` | Tiposko rezultato-videosko. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Kvalitoski úroveň e rezultato-videoski. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Pisimen modo vaš o rezultato-video. |
| `distill_lora_first_pass_scale` |  | number | no | `0.2` | 0 – 1 | Kontrolinel o first-pass distill LoRA scaling; labaren 0 te phagaren les. |
| `distill_lora_second_pass_scale` |  | number | no | `0.5` | 0 – 1 | Kontrolinel o distill LoRA scaling vaš sako pass pala o angluno. |
| `extend_direction` |  | enum (string) | no | `forward` | `forward`, `backward` | Video rig kaj si te lungarel: alosar 'backward' te thaven contento angluno startoske vaj 'forward' te thaven contento pala o agor. |
| `num_context_frames` |  | integer | no | `25` | 0 – 121 | Kadro count labardo te del contexto kana lungaren o video. |
| `video_strength` |  | number | no | `1` | 0 – 1 | Kadava conditioning strength kontrolinel sloboda te paruven o video contento: ciklone value den le modelos buter sloboda. |
| `audio_strength` |  | number | no | `1` | 0 – 1 | Kadava conditioning strength kontrolinel sloboda te paruven o audio contento: ciklone value den le modelos buter sloboda. |
| `end_image_strength` |  | number | no | `1` | 0 – 1 | Kontrolinel keci o end kipo influencerel o kerdo 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 kerdo le modelostar. |
| `seed` | integer | Seed value labardo te startinel o random numero keripe. |
| `prompt` | string | Prompto labardo te sikavel o keripe. |

## 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