# H3 Max Extend Video API

> פֿירט ווײַטער אַן עקזיסטירנדן ווידעאָ פֿון אַ טעקסט־פּראָמפּט און גיט צוריק דעם גאַנצן פֿאַרלענגערטן קליפּ אָדער בלויז נײַעם פֿוטאַזש

נעמט אַ מקור־ווידעאָ (1.625 ביז 60 s, ביז 50 MB) און אַ `prompt` וואָס באַשרײַבט וואָס פּאַסירט ווײַטער. `duration` שטעלט 0.71 ביז 15 סעקונדעס נײַעם פֿוטאַזש, און `resolution` לויפֿט פֿון 480P ביז 2K. ביז 3 `reference_audio_urls` קענען פירן די פֿאָרזעצונג, און `output` קלייבט צווישן דעם צונויפֿגעשטעלטן 'extended' ווידעאָ און אַ 'continuation' קליפּ.

- 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.com/v1/run/minimax/h3-max/extend-video`
- Quote: `POST https://api.doitong.com/v1/quote/minimax/h3-max/extend-video`
- Docs page: https://doitong.com/yi/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.com/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 | מקור־ווידעא־URL פֿאַר פֿאַרלענגערונג; די פֿײַל טאָר נישט איבערגיין 50 MB. אנגענומענע ווידעאָס האָבן אַ בילד־פּראָפּאָרץ־פאַרהעלטעניש פון 0.4–2.5 און אַ געדויער פון 1.625 s–60 s. |
| `prompt` |  | string | yes |  | 1 – 50000 characters | באַשרײַבונג פון די געשעענישן וואָס זאָלן נאָכפאָלגן, נישט אַ באַשרײַבונג פונעם מקור־מאַטעריאַל. |
| `reference_audio_urls` |  | array of audio URL | no |  | ≤ 3 items | אָפּציאָנעלע קליפּס וואָס פירן דעם נײַעם אַודיאָ פון דער ווײַטערפֿירונג אַנשטאָט פונעם מקור־סאַונדטרעק; ספּעציפֿיציר זייערע ראָלעס אינעם פּראָמפּט, למשל 'Audio 1 for the voice' און 'Audio 2 for background music'. יעדער מוז געדויערן 2–15 סעקונדעס, מיט נישט מער ווי 15 סעקונדעס איבער אַלע קליפּס. דער גאַנצער פֿאַרלענגערטער ווידעא האַלט דעם אָריגינעלן מקור־סאַונדטרעק, וועמענס סוף פֿירט נאָך אַלץ די איבערגאַנג. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | מקור־געפירטע פּראָמפּט־פֿאַרבעסערונג פֿאַר אַ מער קאָנסיסטענטער ווײַטערפֿירונג. אַקטיווירן עס לאָזט דעם סיסטעם אויטאָמאַטיש איבעראַרבעטן דעם פּראָמפּט, אָבער פּראַסעסינג קען דויערן לענגער. |
| `duration` |  | number | no | `5` | 0.71 – 15 | געבעטן סומע נײַער ווידעאָ־מאַטעריאַל, געמאסטן אין סעקונדעס אַנשטאָט פונעם גאַנצן לענג פונעם ווײַטערפֿירונג־קליפּ. דער קליפּ נעמט אויך איבער די לעצטע 1.625 סעקונדעס פונעם מקור, און ראַם־ראָונדינג קען צוגעבן נאָך צײַט. |
| `resolution` |  | enum (string) | no | `768P` | `480P`, `768P`, `1080P`, `2K` | רעזאָלוציע פונעם רעזולטירנדיקן ווידעא. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16` | רעזולטאַט־פּראָפּאָרציעס: אויסקלייבן אַ פאַרהעלטעניש ברענגט צו קראַפּן כּדי עס צו פּאַסן, בשעת 'auto' ניצט דעם מקור־ווידעאָס בילד־פּראָפּאָרץ־פאַרהעלטעניש. |
| `seed` |  | integer \| null | no |  |  | סיד פֿאַר ווײַטערפֿירונג־גענערירונג; אויב מען לאָזט אים אויס, ווערט גענוצט אַ צופֿעליקער ווערט. |
| `output` |  | enum (string) | no | `extended` | `extended`, `continuation` | רעזולטאַט־מאָדע: 'continuation' גיט דעם נײַעם מאַטעריאַל מיט אַ פֿריִערדיקן 1.625־סעקונדעסדיקן איבערשפּיל פונעם מקור־סוף. כּדי צו באַקומען דעם מקור צוזאַמענגעלייגט מיטן נײַעם מאַטעריאַל אין איין ווידעא, קלײַב 'extended'. |
| `enable_safety_checker` |  | boolean | no | `true` |  | מאָדעראַציע פון ביידע, דעם אַרײַנגעגעבענעם ווידעא און דעם פּראָמפּט. |

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.com/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.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/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.com/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.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": "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.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} | רעזולטירנדיקער ווידעא, מיט אַן עפֿענונגס־איבערשפּיל פון 1.625 סעקונדעס ווען מען ניצט 'continuation' מאָדע. |
| `seed` | integer | סיד געווענדט בײַם גענערירן די ווײַטערפֿירונג. |
| `duration` | number | געדויער פונעם אומגעקערטן ווידעא אין סעקונדעס. |
| `source` | object | מעטאַדאַטן פון מקור־מאַטעריאַל מיט דימענסיעס (ברייט און הייך), ראַם־קורס, לענג און אַודיאָ. |
| `expanded_prompt` | string \| null | אויסגעברייטערטער פּראָמפּט־טעקסט, אָדער null אויב קיין ענדערונגען זענען נישט געמאַכט געוואָרן. |
| `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.com/v1/models/minimax/h3-max/extend-video