# LTX 2.3 Video Fast · Image to Video API

> Biến thể chuyển ảnh thành video nhanh, cho phép thời lượng tối đa 20 giây và có khung hình cuối tùy chọn

Tạo chuyển động cho hình ảnh bằng lời nhắc bắt buộc và `end_image_url` tùy chọn để chuyển tiếp. `duration` có thể từ 6 đến 20 giây với bước tăng 2, nhưng thời lượng trên 10 giây cần 25 fps và 1080p. `resolution` gồm 1080p, 1440p và 2160p, còn fps có thể là 24, 25, 48 hoặc 50. Có thể tạo âm thanh.

- Model id: `ltx-2.3/image-to-video/fast`
- Made by: Lightricks
- Category: Image to Video
- Output: video
- Price: from $0.06 / second (6 s ≈ $0.36) (cheapest run $0.36 (360 API credits))
- Run: `POST https://api.doitong.ru/v1/run/ltx-2.3/image-to-video/fast`
- Quote: `POST https://api.doitong.ru/v1/quote/ltx-2.3/image-to-video/fast`
- Docs page: https://doitong.com/vi/developers/models/ltx-2.3/image-to-video/fast

## Pricing

Price: **from $0.06 / second (6 s ≈ $0.36)** (the lowest tier; the quote prices your exact input). Billed per second of output (`duration`, default 20).

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

- When `resolution` = 1440p: $0.12 (120 API credits) / second
- When `resolution` = 2160p: $0.24 (240 API credits) / second

The full example input below costs $0.36 = 360 API credits (6 s × 60 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/ltx-2.3/image-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

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 |
|---|---|---|---|---|---|---|
| `image_url` | `image` | string (image URL) | yes |  |  | Hình ảnh bắt đầu cho quá trình tạo video, ở định dạng PNG, JPEG, WebP, AVIF hoặc HEIF. Cung cấp URI dữ liệu base64 hoặc URL công khai. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Đích chuyển tiếp tùy chọn, được cung cấp dưới dạng URL hình ảnh. Việc thêm tham số này khiến video được tạo chuyển tiếp từ khung hình bắt đầu đến hình ảnh cuối cùng này. |
| `prompt` |  | string | yes |  | 1 – 5000 characters | Lời nhắc mô tả video cần tạo. |
| `duration` |  | enum (integer) | no | `6` | `6`, `8`, `10`, `12`, `14`, `16`, `18`, `20` | Độ dài clip đầu ra tính bằng giây; chọn hơn 10 giây (12, 14, 16, 18, 20) yêu cầu độ phân giải 1080p cùng 25 FPS. Mô hình nhanh chấp nhận thời lượng từ 6 đến 20 giây. |
| `resolution` |  | enum (string) | no | `1080p` | `1080p`, `1440p`, `2160p` | Độ phân giải của video đầu ra. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `16:9`, `9:16` | Tỷ lệ khung hình của video đầu ra. |
| `fps` |  | enum (integer) | no | `25` | `24`, `25`, `48`, `50` | Tốc độ khung hình của video đầu ra, đo bằng khung hình mỗi giây. |
| `generate_audio` |  | boolean | no | `true` |  | Công tắc tạo sinh âm thanh cho video đầu ra. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Có thể nới lỏng việc kiểm duyệt bằng cách đặt thành false, nếu người gọi được cấp quyền. |

File parameters (`image`, `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",
  "image": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
}
```

## 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/ltx-2.3/image-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",
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  }'

# 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/ltx-2.3/image-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",
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  }),
});
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",
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ltx-2.3/image-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": "ltx-2.3/image-to-video/fast",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
      },
      "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/image-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": 360,
    "usd": "0.36",
    "charged": 360,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "image_url": "https://content.doitong.com/images/showcase/v3/gen_fox_cartoon.jpg"
  },
  "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} | Tệp video kết quả. |

## Related models

- [LTX 2.3 Video Fast · Text to Video](https://doitong.com/developers/models/ltx-2.3/text-to-video/fast.md) (`ltx-2.3/text-to-video/fast`): from $0.06 / second
- [LTX Video 2.3 Pro · Text to Video](https://doitong.com/developers/models/ltx-2.3/text-to-video.md) (`ltx-2.3/text-to-video`): from $0.08 / second
- [LTX 2.3 Video Pro · Image to Video](https://doitong.com/developers/models/ltx-2.3/image-to-video.md) (`ltx-2.3/image-to-video`): from $0.08 / second
- [Ltx 2.3](https://doitong.com/developers/models/ltx-2.3/reframe.md) (`ltx-2.3/reframe`): from $0.10 / second of input video
- [LTX Video 2.3 Pro · Extend Video](https://doitong.com/developers/models/ltx-2.3/extend-video.md) (`ltx-2.3/extend-video`): $0.10 / second
- [LTX Video 2.3 Pro · Retake Video](https://doitong.com/developers/models/ltx-2.3/retake-video.md) (`ltx-2.3/retake-video`): $0.10 / second
- [LTX 2.3 Video Pro · Audio to Video](https://doitong.com/developers/models/ltx-2.3/audio-to-video.md) (`ltx-2.3/audio-to-video`): $0.10 / second of input audio
- [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

## Links

- HTML page: https://doitong.com/developers/models/ltx-2.3/image-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=ltx-2.3/image-to-video/fast
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/ltx-2.3/image-to-video/fast