# H3 Max Extend Video API

> Ipinagpapatuloy ang umiiral na video mula sa teksto prompt, at nagbabalik ng buong pinalawak na clip o bagong footage lamang

Tumatanggap ng source video (1.625 hanggang 60 s, hanggang 50 MB) at `prompt` na naglalarawan sa susunod na mangyayari. Itinatakda ng `duration` ang 0.71 hanggang 15 segundo ng bagong footage, at ang `resolution` ay mula 480P hanggang 2K. Hanggang 3 `reference_audio_urls` ang maaaring gumabay sa continuation, at pinipili ng `output` ang pinagsamang 'extended' video o 'continuation' clip.

- Model id: `minimax/h3-max/extend-video`
- Made by: MiniMax
- Category: Video to Video
- Output: video
- Price per second of your output video: from $0.05 / second of output video (cheapest run $0.05 (50 API credits))
- Run: `POST https://api.doitong.ru/v1/run/minimax/h3-max/extend-video`
- Quote: `POST https://api.doitong.ru/v1/quote/minimax/h3-max/extend-video`
- Docs page: https://doitong.com/fil/developers/models/minimax/h3-max/extend-video

## Pricing

Price: **from $0.05 / 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:

- 480P: $0.05 / second of output video
- 768P: $0.08 / second of output video
- 1080P: $0.16 / second of output video
- 2K: $0.32 / second of output video

The full example input below costs $0.40 = 400 API credits (5 s output video × $0.08 (768P)).

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/minimax/h3-max/extend-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 |
|---|---|---|---|---|---|---|
| `video_url` | `video` | string (video URL) | yes |  | ≥ 1 characters | Source video URL para sa extension; hindi dapat lumampas sa 50 MB ang file. Ang mga tinatanggap na video ay may aspect ratio na 0.4–2.5 at tagal na 1.625 s–60 s. |
| `prompt` |  | string | yes |  | 1 – 50000 characters | Paglalarawan ng mga event na dapat sumunod, sa halip na paglalarawan ng source footage. |
| `reference_audio_urls` |  | array of audio URL | no |  | ≤ 3 items | Mga opsyonal na clip na gumagabay sa bagong audio ng continuation bilang kapalit ng source soundtrack; tukuyin ang mga tungkulin ng mga ito sa prompt, halimbawa 'Audio 1 for the voice' at 'Audio 2 for background music'. Dapat 2–15 segundo ang bawat isa, at hindi lalampas sa 15 segundo ang kabuuan ng lahat ng clip. Pinananatili ng kumpletong extended video ang orihinal na source soundtrack, na gumagabay pa rin sa transition. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Source-guided prompt enhancement para sa mas consistent na continuation. Kapag in-enable, awtomatikong maaaring baguhin ng system ang prompt ngunit maaaring pahabain nito ang processing. |
| `duration` |  | number | no | `5` | 0.71 – 15 | Hinihinging dami ng bagong footage, sinusukat sa segundo sa halip na buong haba ng continuation clip. Isinasama rin ng clip na iyon ang huling 1.625 segundo ng source, at maaaring madagdagan pa ang oras dahil sa pag-round ng frame. |
| `resolution` |  | enum (string) | no | `768P` | `480P`, `768P`, `1080P`, `2K` | Resolution ng resultang video. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16` | Mga proporsyon ng output: ang pagpili ng ratio ay naglalapat ng cropping upang tumugma rito, samantalang ginagamit ng 'auto' ang aspect ratio ng source video. |
| `seed` |  | integer \| null | no |  |  | Seed para sa continuation pagbuo; kapag hindi tinukoy, random na value ang ginagamit. |
| `output` |  | enum (string) | no | `extended` | `extended`, `continuation` | Output mode: ibinibigay ng 'continuation' ang bagong footage na sinusundan ng 1.625-segundong replay ng dulo ng source. Upang matanggap ang source na pinagsama sa bagong footage sa iisang video, piliin ang 'extended'. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Moderation ng input video at prompt. |

File parameters (`video`, `reference_audio_urls`) 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
{
  "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field"
}
```

A fuller example:

```json
{
  "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
  "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/minimax/h3-max/extend-video?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
    "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/minimax/h3-max/extend-video?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
    "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 = {
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
    "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/minimax/h3-max/extend-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": "minimax/h3-max/extend-video",
      "input": {
        "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
        "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": "minimax/h3-max/extend-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": 400,
    "usd": "0.40",
    "charged": 400,
    "refunded": 0
  },
  "input": {
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
    "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
    },
    "seed": 42,
    "duration": 5,
    "source": {},
    "expanded_prompt": "string",
    "timings": {}
  },
  "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} | Resultang video, na may pambungad na 1.625-segundong ulit kapag ginagamit ang 'continuation' mode. |
| `seed` | integer | Seed na ginagamit kapag binubuo ang continuation. |
| `duration` | number | Tagal ng ibinalik na video sa segundo. |
| `source` | object | Metadata ng source footage na sumasaklaw sa mga dimensyon (width at height), frame rate, haba, at audio. |
| `expanded_prompt` | string \| null | Pinalawak na prompt text, o null kung walang binago. |
| `timings` | object |  |

## Related models

- [MiniMax H3 Max Text to Video](https://doitong.com/developers/models/minimax/h3-max/text-to-video.md) (`minimax/h3-max/text-to-video`): from $0.0325 / second of output video
- [H3 Max Camera Controls](https://doitong.com/developers/models/minimax/h3-max/camera-controls.md) (`minimax/h3-max/camera-controls`): from $0.0325 / second
- [H3 Max Image to Video](https://doitong.com/developers/models/minimax/h3-max/image-to-video.md) (`minimax/h3-max/image-to-video`): from $0.0325 / second of output video
- [H3 Max Reference to Video](https://doitong.com/developers/models/minimax/h3-max/reference-to-video.md) (`minimax/h3-max/reference-to-video`): from $0.05 / second of output video
- [H3 Max](https://doitong.com/developers/models/minimax/h3-max/insert-video.md) (`minimax/h3-max/insert-video`): from $0.05 / second
- [H3 Max Recast](https://doitong.com/developers/models/minimax/h3-max/recast.md) (`minimax/h3-max/recast`): from $0.30 / second of input video
- [H3 Max Reframe](https://doitong.com/developers/models/minimax/h3-max/reframe-video.md) (`minimax/h3-max/reframe-video`): from $0.05 / second of input video
- [H3 Max Relight](https://doitong.com/developers/models/minimax/h3-max/relight.md) (`minimax/h3-max/relight`): from $0.05 / second of input video

## Links

- HTML page: https://doitong.com/developers/models/minimax/h3-max/extend-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=minimax/h3-max/extend-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/minimax/h3-max/extend-video