# Kling O3 Reference Video to Video [Pro] API

> 참조 동영상의 움직임과 카메라 스타일을 바탕으로 새 장면을 생성하는 Pro 등급 O3 모델

참조 동영상(`video_url`, .mp4/.mov, 3-15 s, 720-3840px, 최대 200MB)과 프롬프트를 받아 참조에 따라 새 클립을 생성합니다. 출력 `duration`은 3~15초이고 `aspect_ratio`는 auto, 16:9, 9:16 또는 1:1입니다. 참조 이미지와 `elements`는 총 최대 4개까지 추가할 수 있으며 `keep_audio`가 원본 사운드를 제어합니다.

- Model id: `kling-video/o3/pro/video-to-video/reference`
- Made by: Kling
- Category: Video to Video
- Output: video
- Price: $0.168 / second (3 s ≈ $0.504) (cheapest run $0.504 (504 API credits))
- Run: `POST https://api.doitong.ru/v1/run/kling-video/o3/pro/video-to-video/reference`
- Quote: `POST https://api.doitong.ru/v1/quote/kling-video/o3/pro/video-to-video/reference`
- Docs page: https://doitong.com/ko/developers/models/kling-video/o3/pro/video-to-video/reference

## Pricing

Price: **$0.168 / second (3 s ≈ $0.504)**. Billed per second of output (`duration`, default 15).

The full example input below costs $2.52 = 2520 API credits (15 s × 168 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/kling-video/o3/pro/video-to-video/reference` 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 |
|---|---|---|---|---|---|---|
| `enable_safety_checker` |  | boolean | no | `true` |  | 안전 검사는 계정 인증이 있을 때만 비활성화할 수 있으며, 인증되지 않은 요청에는 항상 검사가 적용됩니다. |
| `prompt` |  | string | yes |  | ≤ 2500 characters | 동영상 생성용 텍스트 지침입니다. 참조 동영상은 @Video1로 지정합니다. |
| `video_url` | `video` | string (video URL) | yes |  |  | 참조 동영상을 가리키는 URL입니다. .mp4 또는 .mov 형식이며 200MB 이하여야 합니다. 두 치수는 720px~3840px, 프레임 속도는 23.0~60.0 FPS, 길이는 3~15초(최대 15.05초)여야 합니다. |
| `image_urls` | `images` | array of image URL \| null | no |  |  | 스타일이나 외관을 안내하는 이미지이며, 프롬프트에서 @Image1, @Image2 등으로 지정합니다. 동영상 입력을 사용하는 경우 요소와 참조 이미지를 합쳐 최대 4개까지 가능합니다. 각 파일은 50 MB로 제한되며 너비와 높이는 각각 300 px 이상, 가로세로 비율은 0.40~2.50이어야 합니다. |
| `keep_audio` |  | boolean | no | `true` |  | 참조 동영상의 원본 오디오를 유지할지 제어합니다. |
| `elements` |  | array of object {frontal_image_url, reference_image_urls} \| null | no |  |  | 포함할 캐릭터나 객체이며, 프롬프트에서 @Element1 및 @Element2로 지정합니다. |
| `elements[].frontal_image_url` |  | string (image URL) \| null | no |  |  | 요소의 주요 모습을 보여 주는 정면 이미지입니다. 파일 크기는 50 MB 이하여야 하며 너비와 높이는 각각 300px 이상, 가로세로 비율은 0.40~2.50이어야 합니다. |
| `elements[].reference_image_urls` |  | array of image URL \| null | no |  |  | 서로 다른 각도를 보여 주는 추가 참조 이미지 1~3개를 제공합니다. 각 이미지의 가로세로 비율은 0.40~2.50, 두 치수는 각각 300px 이상, 파일 크기는 50.0MB 이하여야 합니다. |
| `shot_type` |  | string | no | `customize` |  | 멀티 샷 동영상 생성에 사용할 모드입니다. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `16:9`, `9:16`, `1:1` | 너비와 높이의 비율입니다. |
| `duration` |  | enum (string) \| null | no |  | `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15` | 초 단위로 측정한 동영상 길이이며, 참조 동영상 범위는 3~15s입니다. |

File parameters (`video`, `images`) 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.ru/v1/run/kling-video/o3/pro/video-to-video/reference?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.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/kling-video/o3/pro/video-to-video/reference?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.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",
    "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/kling-video/o3/pro/video-to-video/reference", 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": "kling-video/o3/pro/video-to-video/reference",
      "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": "kling-video/o3/pro/video-to-video/reference",
  "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": 2520,
    "usd": "2.52",
    "charged": 2520,
    "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
    }
  },
  "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} | 모델이 생성한 동영상입니다. |

## Related models

- [Kling O3 Text to Video \[Pro\]](https://doitong.com/developers/models/kling-video/o3/pro/text-to-video.md) (`kling-video/o3/pro/text-to-video`): from $0.112 / second
- [Kling O3 Text to Video \[Standard\]](https://doitong.com/developers/models/kling-video/o3/standard/text-to-video.md) (`kling-video/o3/standard/text-to-video`): from $0.084 / second
- [Kling Video · O3 · 4k · Text to Video](https://doitong.com/developers/models/kling-video/o3/4k/text-to-video.md) (`kling-video/o3/4k/text-to-video`): $0.42 / second
- [Kling O3 Image to Video · Pro](https://doitong.com/developers/models/kling-video/o3/pro/image-to-video.md) (`kling-video/o3/pro/image-to-video`): from $0.112 / second
- [Kling O3 Image to Video · Standard](https://doitong.com/developers/models/kling-video/o3/standard/image-to-video.md) (`kling-video/o3/standard/image-to-video`): from $0.084 / second
- [Kling Video · O3 · 4k · Image to Video](https://doitong.com/developers/models/kling-video/o3/4k/image-to-video.md) (`kling-video/o3/4k/image-to-video`): $0.42 / second
- [Kling O3 Reference to Video \[Pro\]](https://doitong.com/developers/models/kling-video/o3/pro/reference-to-video.md) (`kling-video/o3/pro/reference-to-video`): from $0.112 / second
- [Kling O3 Reference to Video \[Standard\]](https://doitong.com/developers/models/kling-video/o3/standard/reference-to-video.md) (`kling-video/o3/standard/reference-to-video`): from $0.084 / second

## Links

- HTML page: https://doitong.com/developers/models/kling-video/o3/pro/video-to-video/reference
- 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=kling-video/o3/pro/video-to-video/reference
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/kling-video/o3/pro/video-to-video/reference