# Ltx 2.5 Text to Video Fast API

> 동기화된 오디오, 카메라 모션 프리셋 및 최대 2160p 해상도를 지원하는 고속 text-to-video

최대 5000 characters의 `prompt`로 영상을 생성합니다. `duration`은 6 to 20초 또는 auto, `resolution`은 720p to 2160p, `aspect_ratio`는 16:9 또는 9:16, `fps`는 24, 25, 48 또는 50입니다. 프레임 속도와 해상도가 높을수록 긴 클립이 제한됩니다. `camera_motion`과 `generate_audio`는 선택 사항입니다.

- Model id: `lightricks/ltx-2.5/text-to-video/fast`
- Made by: Lightricks
- Category: Text to Video
- Output: video
- Price: from $0.09 / second (6 s ≈ $0.54) (cheapest run $0.54 (540 API credits))
- Run: `POST https://api.doitong.ru/v1/run/lightricks/ltx-2.5/text-to-video/fast`
- Quote: `POST https://api.doitong.ru/v1/quote/lightricks/ltx-2.5/text-to-video/fast`
- Docs page: https://doitong.com/ko/developers/models/lightricks/ltx-2.5/text-to-video/fast

## Pricing

Price: **from $0.09 / second (6 s ≈ $0.54)** (the lowest tier; the quote prices your exact input). Billed per second of output (`duration`, default 6).

Price rules (the first rule that matches the input wins; a parameter you leave out counts as its default):

- When `resolution` = 1080p: $0.13 (130 API credits) / second
- When `resolution` = 1440p: $0.19 (190 API credits) / second
- When `resolution` = 2160p: $0.30 (300 API credits) / second

The full example input below costs $0.78 = 780 API credits (6 s × 130 API credits).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.ru/v1/quote/lightricks/ltx-2.5/text-to-video/fast` 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

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  | 1 – 5000 characters | 동영상 생성을 안내하는 프롬프트입니다. |
| `duration` |  | enum | no | `auto` | `6`, `8`, `10`, `12`, `14`, `16`, `18`, `20`, `auto` | 출력 동영상 길이(초)입니다. 'auto'는 모델에 길이 선택을 위임합니다. 720p 또는 1080p 출력의 경우 최대 길이는 24 또는 25 FPS에서 20초, 48 또는 50 FPS에서 10초입니다. 1440p 또는 2160p 출력은 프레임 속도와 관계없이 10초로 제한됩니다. |
| `resolution` |  | enum (string) | no | `1080p` | `720p`, `1080p`, `1440p`, `2160p` | 출력 동영상에 사용되는 해상도입니다. |
| `aspect_ratio` |  | enum (string) | no | `16:9` | `16:9`, `9:16` | 출력 동영상의 가로세로 비율입니다. |
| `fps` |  | enum (integer) | no | `25` | `24`, `25`, `48`, `50` | 초당 프레임 수로 측정되는 출력 동영상 프레임 속도입니다. |
| `generate_audio` |  | boolean | no | `true` |  | 출력 동영상의 오디오 생성 토글입니다. |
| `camera_motion` |  | enum (string) \| null | no |  | `dolly_in`, `dolly_out`, `dolly_left`, `dolly_right`, `jib_up`, `jib_down`, `static`, `focus_shift` | 출력 동영상의 선택적 카메라 움직임입니다. |

## Example input

Required parameters only:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
}
```

## 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.ru/v1/run/lightricks/ltx-2.5/text-to-video/fast?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"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.ru/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.ru/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/lightricks/ltx-2.5/text-to-video/fast?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"
  }),
});
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.ru/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",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/lightricks/ltx-2.5/text-to-video/fast", 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.ru/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": "lightricks/ltx-2.5/text-to-video/fast",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
      },
      "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": "lightricks/ltx-2.5/text-to-video/fast",
  "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": 780,
    "usd": "0.78",
    "charged": 780,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
  },
  "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
    }
  },
  "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.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.ru/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} | 결과 동영상 파일입니다. |

## Related models

- [LTX 2.5 Pro Text to Video](https://doitong.com/developers/models/lightricks/ltx-2.5/text-to-video/pro.md) (`lightricks/ltx-2.5/text-to-video/pro`): from $0.12 / second
- [LTX 2.5 Image to Video Fast](https://doitong.com/developers/models/lightricks/ltx-2.5/image-to-video/fast.md) (`lightricks/ltx-2.5/image-to-video/fast`): from $0.09 / second
- [LTX 2.5 Pro Image to Video](https://doitong.com/developers/models/lightricks/ltx-2.5/image-to-video/pro.md) (`lightricks/ltx-2.5/image-to-video/pro`): from $0.12 / second
- [Ltx 2.5 Audio to Video Fast](https://doitong.com/developers/models/lightricks/ltx-2.5/audio-to-video/fast.md) (`lightricks/ltx-2.5/audio-to-video/fast`): $0.13 / second of input audio
- [Ltx 2.5 Audio to Video Pro](https://doitong.com/developers/models/lightricks/ltx-2.5/audio-to-video/pro.md) (`lightricks/ltx-2.5/audio-to-video/pro`): $0.17 / second of input audio
- [FLUX 3 Max Text to Video](https://doitong.com/developers/models/blackforestlabs/flux-3-max/text-to-video.md) (`blackforestlabs/flux-3-max/text-to-video`): from $0.0425 / second of output video
- [Grok Imagine Video 1.5 Text to Video](https://doitong.com/developers/models/xai/grok-imagine-video/v1.5/text-to-video.md) (`xai/grok-imagine-video/v1.5/text-to-video`): from $0.08 / second
- [Kling 3.0 Pro Text to Video](https://doitong.com/developers/models/kling-video/v3/pro/text-to-video.md) (`kling-video/v3/pro/text-to-video`): from $0.112 / second

## Links

- HTML page: https://doitong.com/developers/models/lightricks/ltx-2.5/text-to-video/fast
- 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=lightricks/ltx-2.5/text-to-video/fast
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/lightricks/ltx-2.5/text-to-video/fast