# Kling Video 4K Video to Video API

> Video-kwa-video ya 4K inayotumia klipu chanzo kama marejeo, ikiwa na mipangilio ya uwiano wa picha na muda

Huzalisha video mpya ikiongozwa na klipu ya marejeleo katika `video_url`, inayotajwa kwenye kidokezo kama @Video1. Chanzo lazima kiwe mp4 au mov, sekunde 3 hadi 15, 720 hadi 3840 px, na kisizidi 200MB. Tofauti na lahaja ya uhariri, inatoa `aspect_ratio` (auto, 16:9, 9:16, 1:1) na `duration` ya sekunde 3 hadi 15. Picha za marejeleo na vipengele vina kikomo cha 4 kwa pamoja, na `keep_audio` huwashwa kwa chaguomsingi.

- Model id: `kling-video/o3/4k/video-to-video/reference`
- Made by: Kling
- Category: Video to Video
- Output: video
- Price: $0.42 / second (3 s ≈ $1.26) (cheapest run $1.26 (1260 API credits))
- Run: `POST https://api.doitong.ru/v1/run/kling-video/o3/4k/video-to-video/reference`
- Quote: `POST https://api.doitong.ru/v1/quote/kling-video/o3/4k/video-to-video/reference`
- Docs page: https://doitong.com/sw/developers/models/kling-video/o3/4k/video-to-video/reference

## Pricing

Price: **$0.42 / second (3 s ≈ $1.26)**. Billed per second of output (`duration`, default 15).

The full example input below costs $6.30 = 6300 API credits (15 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/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` |  | Ukaguzi wa usalama unaweza kuzimwa tu kwa idhini ya akaunti; maombi yasiyo na idhini hukaguliwa kila wakati. |
| `prompt` |  | string | yes |  | ≤ 2500 characters | Maagizo ya maandishi ya kuzalisha video. Tumia @Video1 kurejelea video ya marejeleo. |
| `video_url` | `video` | string (video URL) | yes |  |  | URL inayoelekeza kwenye video ya marejeleo katika umbizo la .mp4 au .mov, isiyozidi 200MB. Vipimo vyote viwili lazima viwe kati ya 720px na 3840px, kwa kasi ya fremu ya 23.0–60.0 FPS na urefu wa sekunde 3–15 (sekunde 15.05 kwa kiwango cha juu). |
| `image_urls` | `images` | array of image URL \| null | no |  |  | Picha zinazoongoza mtindo au mwonekano, zinazorejelewa kwenye kidokezo kwa kutumia @Image1, @Image2, na kuendelea. Kwa ingizo la video, vipengele na picha za marejeleo kwa pamoja haviwezi kuzidi maingizo 4. Kila faili ina kikomo cha 50 MB, huku upana na urefu kila kimoja kikiwa angalau 300 px na uwiano wa pande ukiwa kutoka 0.40 hadi 2.50. |
| `keep_audio` |  | boolean | no | `true` |  | Hudhibiti uhifadhi wa sauti asilia ya video ya marejeleo. |
| `elements` |  | array of object {frontal_image_url, reference_image_urls} \| null | no |  |  | Wahusika au vitu vya kujumuisha, vinavyorejelewa kwenye kidokezo kwa kutumia @Element1 na @Element2. |
| `elements[].frontal_image_url` |  | string (image URL) \| null | no |  |  | Picha ya mbele inayoonyesha mwonekano mkuu wa kipengele. Ukubwa wa faili lazima usizidi 50 MB; upana na urefu lazima kila kimoja kiwe angalau 300px, na uwiano wa pande uwe kati ya 0.40 na 2.50. |
| `elements[].reference_image_urls` |  | array of image URL \| null | no |  |  | Toa picha 1–3 za ziada za marejeleo zinazoonyesha pembe tofauti. Kila picha lazima iwe na uwiano wa pande kati ya 0.40 na 2.50, iwe na angalau 300px katika vipimo vyote viwili, na isiwe kubwa kuliko 50.0MB. |
| `shot_type` |  | string | no | `customize` |  | Modi inayotumiwa kuzalisha video zenye picha nyingi. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `16:9`, `9:16`, `1:1` | Uwiano wa upana kwa urefu. |
| `duration` |  | enum (string) \| null | no |  | `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15` | Urefu wa video, unaopimwa kwa sekunde; masafa ya video ya marejeleo ni 3–15s. |

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/o3/4k/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/o3/4k/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/o3/4k/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/o3/4k/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/o3/4k/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": 6300,
    "usd": "6.30",
    "charged": 6300,
    "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} | Video iliyozalishwa na modeli. |

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