# Kling Video · O3 · 4k · Reference to Video API

> Video iz referenc v 4K z večkadrovnimi pozivi, začetnimi/končnimi kadri, elementi in neobveznim izvornim zvokom

Ustvari videoposnetek iz `prompt` z največ 2500 znaki ali iz `multi_prompt` za več kadrov, vendar ne iz obojega. Usmerjajo ga `start_image_url`, `end_image_url`, referenčni `image_urls` in `elements`, v pozivu navedeni kot @Image1 ali @Element1, skupaj največ 7. Trajanje je od 3 do 15 sekund, razmerje stranic 16:9, 9:16 ali 1:1, `generate_audio` pa doda zvok.

- Model id: `kling-video/o3/4k/reference-to-video`
- Made by: Kling
- Category: Reference to Video
- Output: video
- Price: $0.42 / second (5 s ≈ $2.10) (cheapest run $2.10 (2100 API credits))
- Run: `POST https://api.doitong.ru/v1/run/kling-video/o3/4k/reference-to-video`
- Quote: `POST https://api.doitong.ru/v1/quote/kling-video/o3/4k/reference-to-video`
- Docs page: https://doitong.com/sl/developers/models/kling-video/o3/4k/reference-to-video

## Pricing

Price: **$0.42 / second (5 s ≈ $2.10)**. Billed per second of output (`duration`, default 15).

The full example input below costs $2.10 = 2100 API credits (5 s × 420 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/o3/4k/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 |
|---|---|---|---|---|---|---|
| `enable_safety_checker` |  | boolean | no | `true` |  | Varnostna preverjanja je mogoče onemogočiti samo z avtorizacijo računa; zahteve brez avtorizacije so vedno preverjene. |
| `prompt` |  | string \| null | no |  | ≤ 2500 characters | Besedilna navodila za ustvarjanje videa. Podajte natanko enega od parametrov poziv ali multi_prompt. |
| `multi_prompt` |  | array of object {prompt, duration} \| null | no |  |  | Seznam pozivov za generiranje videa z več kadri. |
| `multi_prompt[].prompt` |  | string | yes |  |  | Besedilna navodila za trenutni kader. |
| `multi_prompt[].duration` |  | enum (string) | no | `5` | `1`, `2`, `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15` | Dolžina trenutnega kadra, merjena v sekundah. |
| `start_image_url` | `image` | string (image URL) \| null | no |  |  | Slika, uporabljena za začetno sličico videa. Velikost datoteke ne sme presegati 50 MB; širina in višina morata biti dolgi najmanj 300px, razmerje stranic pa mora biti med 0.40 in 2.50. |
| `end_image_url` | `end_image` | string (image URL) \| null | no |  |  | Slika, ki določa končno sličico videa, omejena na 50 MB. Širina in višina morata biti dolgi najmanj 300 px, razmerje stranic pa mora biti med 0.40 in 2.50. |
| `image_urls` | `images` | array of image URL \| null | no |  |  | Slike z referencami sloga ali videza, v pozivu naslovljene z @Image1, @Image2 in tako naprej. Elementov in referenčnih slik skupaj ne sme biti več kot 7. Vsaka datoteka je lahko velika največ 50 MB, širina in višina pa morata biti dolgi najmanj 300px, z razmerjem stranic med 0.40 in 2.50. |
| `elements` |  | array of object {frontal_image_url, reference_image_urls, video_url, voice_id} \| null | no |  |  | Liki ali predmeti, ki jih želite vključiti in so v pozivu naslovljeni z @Element1 in @Element2. |
| `elements[].frontal_image_url` |  | string (image URL) \| null | no |  |  | Čelna slika glavnega pogleda elementa. Velikost datoteke ne sme presegati 50 MB; širina in višina morata biti dolgi najmanj 300px, razmerje stranic pa mora biti med 0.40 in 2.50. |
| `elements[].reference_image_urls` |  | array of image URL \| null | no |  |  | Posredujte 1–3 dodatne referenčne slike z različnimi koti. Vsaka slika mora imeti razmerje stranic med 0.40 in 2.50, obe dimenziji dolgi najmanj 300px in velikost največ 50.0MB. |
| `elements[].video_url` |  | string (video URL) \| null | no |  |  | URL videa elementa; samo en element v zahtevi lahko vključuje video. Datoteka je lahko velika največ 200 MB, širina in višina pa morata biti med 720px in 2160px. Trajanje mora biti med 3 in 10.05 sekundami, FPS pa med 24.0 in 60.0. |
| `elements[].voice_id` |  | string \| null | no |  |  | Voice ID, dodeljen elementu. Sklici na ta element uporabljajo njegov dodeljeni glas. |
| `generate_audio` |  | boolean | no | `false` |  | Določa, ali se skupaj z videom generira izvorni zvok. |
| `duration` |  | enum (string) | no | `5` | `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15` | Dolžina videa od 3 do 15 sekund. |
| `shot_type` |  | enum (string) | no | `customize` | `customize`, `intelligent` | Izberite, kako generiranje z več kadri načrtuje kadre; z izbiro 'intelligent' strukturo kadrov določite modelu. |
| `aspect_ratio` |  | enum (string) | no | `16:9` | `16:9`, `9:16`, `1:1` | Razmerje med širino in višino sličic v ustvarjenem videu. |

File parameters (`image`, `end_image`, `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
{}
```

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/kling-video/o3/4k/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.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/o3/4k/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.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/kling-video/o3/4k/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.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/o3/4k/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-video/o3/4k/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": 2100,
    "usd": "2.10",
    "charged": 2100,
    "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.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} | Video, ki ga ustvari model. |

## 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/o3/4k/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-video/o3/4k/reference-to-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/kling-video/o3/4k/reference-to-video