# Kling 4.0 Reference to Video API

> 10 adede referans görselinin, 5 referans videosunun ve 7 öğenin görünümünü koruyan 3-30 saniyelik videolar oluşturur

Metin `prompt`u ile referans görselleri, referans videoları ve karakter veya nesne öğelerinden video oluşturur; bunlar istemde @Image1, @Video1 veya @Element1 olarak belirtilir. Süre 3-30 saniye (varsayılan 5), çıktı 720p veya 1080p ve en-boy oranları auto, 16:9, 9:16, 1:1 veya 21:9'dur. Çekim başına istemler için `multi_prompt` kullanın; bu durumda toplam uzunluk çekim sürelerinin toplamıdır. Sınırlar 10 görsel, her biri 3-30 saniyelik 5 video ve 7 öğedir; bunların en fazla 3'ü ses taşıyabilir.

- Model id: `kling/v4/reference-to-video`
- Made by: Kling
- Category: Reference to Video
- Output: video
- Price per second of your output video: from $0.157 / second of output video (cheapest run $0.157 (157 API credits))
- Run: `POST https://api.doitong.com/v1/run/kling/v4/reference-to-video`
- Quote: `POST https://api.doitong.com/v1/quote/kling/v4/reference-to-video`
- Docs page: https://doitong.com/tr/developers/models/kling/v4/reference-to-video

## Pricing

Price: **from $0.157 / second of output video** (the lowest tier; the quote prices your exact input). Price per second 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.

Price by tier:

- 720p: $0.157 / second of output video
- 1080p: $0.235 / second of output video

The full example input below costs $1.175 = 1175 API credits (5 s output video × $0.235 (1080p)).

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/kling/v4/reference-to-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 \| null | no |  | ≤ 2500 characters | `prompt` veya `multi_prompt` değerlerinden birinin sağlanması gereksinimini karşılayan üretim talimatları. Sağlanan girdilere başvurmak için @Image1, @Video1, @Element1 ve devamını kullanın. |
| `multi_prompt` |  | array of object {prompt, duration} \| null | no |  | ≥ 1 items | Çekim çekim üretim talimatları; her istem, süresi videonun toplam uzunluğuna katkıda bulunan bir çekim tanımlar. |
| `multi_prompt[].prompt` |  | string | yes |  | 1 – 512 characters | Geçerli çekim için metin talimatları. |
| `multi_prompt[].duration` |  | integer | no | `5` | 1 – 30 | Saniye cinsinden ölçülen tek bir çekimin süresi. |
| `duration` |  | integer | no | `5` | 3 – 30 | 3 ile 30 arasında saniye cinsinden video uzunluğu. |
| `start_image_url` | `image` | string (image URL) \| null | no |  |  | Görsel referans sınırına dahil edilen isteğe bağlı ilk kare görseli. Maksimum dosya boyutu 30.0 MB; genişlik ve yükseklik en az 300 px olmalı, en-boy oranı 0.40 ile 2.50 arasında bulunmalıdır. |
| `image_urls` | `images` | array of image URL \| null | no |  | ≤ 10 items | En fazla 10 görsel içeren ve @Image1, @Image2 ve devamı ile belirtilen görsel referansları. Her dosya 30.0 MB ile sınırlıdır, her iki boyutta en az 300 px gerektirir ve en-boy oranı 0.40 ile 2.50 arasında olmalıdır. |
| `video_urls` | `videos` | array of video URL \| null | no |  | ≤ 5 items | @Video1, @Video2 ve devamı ile belirtilen en fazla 5 referans video; her biri 3–30 saniye (en fazla 30.05 saniye) sürer ve öğe videolarıyla birlikte toplam süre 30 saniyeyi aşamaz. Her dosya 300 MB'tan büyük olmamalı, genişlik ve yükseklik 700 px ile 4553 px arasında bulunmalıdır. En-boy oranı 0.40 ile 2.50, kare hızı 23.9 ile 60.05 FPS arasında olmalıdır. |
| `elements` |  | array of object {frontal_image_url, reference_image_urls, video_url, voice_id} \| null | no |  | ≤ 7 items | En fazla 7 karakter veya nesneden oluşan koleksiyon; bunların en fazla 3'ü `voice_id` içerebilir ve en fazla 3'ü video kullanabilir. Bu öğelere @Element1, @Element2 ve devamı ile başvurun. |
| `elements[].frontal_image_url` |  | string (image URL) \| null | no |  |  | Öğenin ana görünümünü gösteren önden görsel. Maksimum dosya boyutu 30.0 MB; her iki boyut en az 300 px olmalı, en-boy oranı 0.40 ile 2.50 arasında bulunmalıdır. |
| `elements[].reference_image_urls` |  | array of image URL \| null | no |  | ≤ 3 items | Öğenin farklı açılarını gösteren, 1 ile 3 görünüm içeren ek görseller. Her dosya en fazla 30.0 MB olabilir, her iki boyutta en az 300 px ölçmeli ve en-boy oranı 0.40 ile 2.50 arasında olmalıdır. |
| `elements[].video_url` |  | string (video URL) \| null | no |  |  | Görseller yerine kullanılan, 3–30 saniye (en fazla 30.05 saniye) süren öğe video temsili. Dosya 300 MB'ı aşmamalı; genişlik ve yükseklik 700–4553 px arasında olmalıdır. Desteklenen en-boy oranları 0.40–2.50, kare hızları 23.9–60.05 FPS aralığındadır. |
| `elements[].voice_id` |  | string \| null | no |  |  | Öğeye atanan ses. |
| `resolution` |  | enum (string) | no | `1080p` | `720p`, `1080p` | Çıktının çözünürlüğü. |
| `aspect_ratio` |  | enum (string) | no | `16:9` | `auto`, `16:9`, `9:16`, `1:1`, `21:9` | Açıkça seçilen veya 'auto' seçilerek referanslardan türetilen video oranları. |

File parameters (`image`, `images`, `videos`) 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
{}
```

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.com/v1/run/kling/v4/reference-to-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"
  }'

# 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/kling/v4/reference-to-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"
  }),
});
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",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/kling/v4/reference-to-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": "kling/v4/reference-to-video",
      "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": "kling/v4/reference-to-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": 1175,
    "usd": "1.175",
    "charged": 1175,
    "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
    }
  },
  "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} | Model tarafından üretilen video. |

## Related models

- [Kling 4.0 Text to Video](https://doitong.com/developers/models/kling/v4/text-to-video.md) (`kling/v4/text-to-video`): from $0.157 / second of output video
- [Seedance 2.0 Fast Reference to Video](https://doitong.com/developers/models/bytedance/seedance-2.0/fast/reference-to-video.md) (`bytedance/seedance-2.0/fast/reference-to-video`): from $0.113 / second
- [Seedance 2.0 Reference to Video](https://doitong.com/developers/models/bytedance/seedance-2.0/reference-to-video.md) (`bytedance/seedance-2.0/reference-to-video`): from $0.141 / second
- [Wan 3.0 Reference to Video](https://doitong.com/developers/models/alibaba/wan-3.0/reference-to-video.md) (`alibaba/wan-3.0/reference-to-video`): from $0.05 / second
- [Kling O1 Reference Image to Video \[Pro\]](https://doitong.com/developers/models/kling-video/o1/reference-to-video.md) (`kling-video/o1/reference-to-video`): $0.112 / second
- [Kling O1 Reference Image to Video \[Standard\]](https://doitong.com/developers/models/kling-video/o1/standard/reference-to-video.md) (`kling-video/o1/standard/reference-to-video`): $0.084 / 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/v4/reference-to-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=kling/v4/reference-to-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/kling/v4/reference-to-video