# LTX-2.3 22B · Extend Video API

> Ipinagpapatuloy ang kasalukuyang video mula sa prompt, na may generated audio at opsyonal na end larawan

Tumatanggap ng `video_url` at `prompt` at gumagawa ng continuation na `num_frames` frame (9 hanggang 481). Itinatakda ng opsyonal na `end_image_url` kung saan magtatapos ang extension. Pinananatili ng `match_input_fps` ang source frame rate, nagdaragdag ng tunog ang `generate_audio`, at default na auto ang `video_size`. Maaaring mp4, webm, mov o GIF ang output.

- 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/fil/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 |  |  | Prompt na ginagamit bilang batayan sa pagbuo ng video. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL na tumutukoy sa video na palalawigin. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Magbigay ng final-frame larawan sa pamamagitan ng URL upang tukuyin kung paano magtatapos ang pinalawak na video. |
| `num_frames` |  | integer | no | `121` | 9 – 481 | Bilang ng frame para sa nabuong 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` | Mga dimension ng nabuong video. |
| `generate_audio` |  | boolean | no | `true` |  | Kinokontrol kung may nabuong audio ang video. |
| `use_multiscale` |  | boolean | no | `true` |  | Toggle ng multi-scale pagbuo para sa mas maayos na coherence at detalye. Kapag True, ginagabayan ng paunang mas maliit na video ang ikalawang pagbuo na ang laki ay katumbas o mas malaki sa hiniling na mga sukat. |
| `match_input_fps` |  | boolean | no | `true` |  | Override sa output frame rate na pinapalitan ang default na target FPS ng FPS ng source video kapag naka-enable. |
| `fps` |  | number | no | `24` | 1 – 60 | Frame rate ng output na video, na sinusukat sa frames per segundo. |
| `num_inference_steps` |  | integer | no | `40` | 8 – 50 | Bilang ng isinagawang inference step. |
| `video_cfg_scale` |  | number | no | `3` | 1 – 20 | Setting ng video guidance: itaas ito para sa mas malaking consistency at focus sa nabuong content. Gumagamit ito ng classifier-free guidance (CFG). |
| `video_stg_scale` |  | number | no | `0` | 0 – 20 | Kontrol sa consistency at focus ng video sa pamamagitan ng Spatiotemporal Guidance (STG) scale; itaas ang setting para palakasin ang dalawang ito. |
| `video_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Pagsasaayos ng video rescaling para balansehin bilang ratio ang classifier-free at spatiotemporal guidance. |
| `video_modality_scale` |  | number | no | `3` | 0 – 10 | Pagsasaayos ng video modality para balansehin bilang ratio ang ambag ng video at audio. |
| `audio_cfg_scale` |  | number | no | `7` | 1 – 20 | Setting ng audio guidance: itaas ito para sa mas malaking consistency at focus sa nabuong content. Gumagamit ito ng classifier-free guidance (CFG). |
| `audio_stg_scale` |  | number | no | `0` | 0 – 20 | Kontrol sa consistency at focus ng audio sa pamamagitan ng Spatiotemporal Guidance (STG) scale; itaas ang setting para palakasin ang dalawang ito. |
| `audio_rescaling_scale` |  | number | no | `0.7` | 0 – 1 | Pagsasaayos ng audio rescaling para balansehin bilang ratio ang classifier-free at spatiotemporal guidance. |
| `audio_modality_scale` |  | number | no | `3` | 0 – 10 | Pagsasaayos ng audio modality para balansehin bilang ratio ang ambag ng video at audio. |
| `gradient_estimation_gamma` |  | number | no | `2` | 0 – 10 | Setting ng denoising gradient estimation: pinapatay ng 0 ang estimation; kung hindi, tinutukoy ng value ang gamma. |
| `use_restart_sampling` |  | boolean | no | `false` |  | Toggle ng restart sampling para sa posibleng mas magandang kalidad ng video: kapag naka-enable, nagdaragdag ito ng kaunting noise sa bawat denoising step. |
| `scheduler` |  | enum (string) | no | `ltx2` | `ltx2`, `linear_quadratic`, `beta` | Pagpili ng scheduler. |
| `acceleration` |  | enum (string) | no | `regular` | `none`, `regular`, `high`, `full` | Antas ng acceleration na inilapat sa pagproseso. |
| `camera_lora` |  | enum (string) | no | `none` | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `none` | Pagpili ng Camera LoRA para mas tumpak na makontrol ang galaw sa nabuong video kaysa sa mga prompt lang para sa camera motion. |
| `camera_lora_scale` |  | number | no | `1` | 0 – 1 | Lakas ng Camera LoRA para mas tumpak na makontrol ang galaw sa nabuong video kaysa sa mga prompt lang para sa camera motion. |
| `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 na ginagamit habang bumubuo ng video. |
| `seed` |  | integer \| null | no |  |  | Seed value na nag-i-initialize sa pagbuo ng random number. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Kinokontrol kung naka-enable ang prompt expansion. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Kinokontrol kung pinapagana ang safety checking. |
| `video_output_type` |  | enum (string) | no | `X264 (.mp4)` | `X264 (.mp4)`, `VP9 (.webm)`, `PRORES4444 (.mov)`, `GIF (.gif)` | Uri ng output para sa resultang video. |
| `video_quality` |  | enum (string) | no | `high` | `low`, `medium`, `high`, `maximum` | Antas ng kalidad para sa resultang video. |
| `video_write_mode` |  | enum (string) | no | `balanced` | `fast`, `balanced`, `small` | Write mode para sa resultang video. |
| `distill_lora_first_pass_scale` |  | number | no | `0.2` | 0 – 1 | Kontrolin ang scaling ng first-pass distill LoRA; gamitin ang 0 para i-off ito. |
| `distill_lora_second_pass_scale` |  | number | no | `0.5` | 0 – 1 | Kontrolin ang scaling ng distill LoRA sa bawat pass pagkatapos ng una. |
| `extend_direction` |  | enum (string) | no | `forward` | `forward`, `backward` | Bahagi ng video na palalawigin: piliin ang 'backward' para magdagdag ng content bago ang simula nito o 'forward' para magdagdag ng content pagkatapos ng dulo nito. |
| `num_context_frames` |  | integer | no | `25` | 0 – 121 | Bilang ng frame na ginagamit upang magbigay ng context kapag pinapalawak ang video. |
| `video_strength` |  | number | no | `1` | 0 – 1 | Kinokontrol ng conditioning strength na ito ang laya sa pagbabago ng content ng video: nagbibigay ang mas mababang setting ng mas malaking kalayaan sa modelo. |
| `audio_strength` |  | number | no | `1` | 0 – 1 | Kinokontrol ng conditioning strength na ito ang laya sa pagbabago ng content ng audio: nagbibigay ang mas mababang setting ng mas malaking kalayaan sa modelo. |
| `end_image_strength` |  | number | no | `1` | 0 – 1 | Kontrolin kung gaano kalaki ang impluwensya ng end larawan sa nabuong 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} | Videong ginawa ng modelo. |
| `seed` | integer | Seed value na ginagamit upang simulan ang pagbuo ng random number. |
| `prompt` | string | Prompt na ginagamit upang gabayan ang pagbuo. |

## 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