# H3 Max Extend Video API

> Fortsetter en eksisterende video fra en tekstprompt og returnerer enten hele det forlengede klippet eller bare det nye materialet

Tar imot en kildevideo (1.625 til 60 s, opptil 50 MB) og en `prompt` som beskriver hva som skjer videre. `duration` angir 0.71 til 15 sekunder med nytt videomateriale, og `resolution` går fra 480P til 2K. Opptil 3 `reference_audio_urls` kan styre fortsettelsen, og `output` velger mellom den kombinerte «extended»-videoen og et «continuation»-klipp.

- 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/se/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 | Gáldovideo URL guhkideapmái; fiila ii sáhte leat badjel 50 MB. Dohkkehuvvon videoin lea oasselohku 0.4–2.5 ja guhkkodat 1.625 s–60 s. |
| `prompt` |  | string | yes |  | 1 – 50000 characters | Dáhpáhusaid čilgehus mat galget čuovvut, iige gáldomateriála čilgehus. |
| `reference_audio_urls` |  | array of audio URL | no |  | ≤ 3 items | Eaktodáhtolaš klippat mat stivrejit guhkideami ođđa jiena gáldočuovusbeaivvi sadjái; meroštit sin rollaid bivddas, ovdamearkka dihte 'Audio 1 for the voice' ja 'Audio 2 for background music'. Juohkehaš ferte bistit 2–15 sekunda, ja buot klippaid oktasaš guhkkodat ii sáhte leat badjel 15 sekunda. Ollislaš guhkkiduvvon video bisuha gáldočuovusbeaivvi, man loahppa ain stivre molsašumi. |
| `enable_prompt_expansion` |  | boolean | no | `true` |  | Gáldostivrejuvvon bivdda-buorideapmi eanet čuovvovaš guhkideami várás. Aktiveren diktá vuogádahkii ođđasit heivehit bivdda automáhtalaččat, muhto sáhttá guhkit dahkat gieđahallama. |
| `duration` |  | number | no | `5` | 0.71 – 15 | Bivdojuvvon ođđa videomateriála meari, sekundain iige guhkideami ollislaš guhkkodagain. Klippa ožžo maiddái gáldo loahpa maŋemus 1.625 sekunda, ja rámma-geahpedeapmi sáhttá lasihit velá áiggi. |
| `resolution` |  | enum (string) | no | `768P` | `480P`, `768P`, `1080P`, `2K` | Boađusvideo resolušuvdna. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16` | Boađusgorri: gorri válljemus čáhppesbuhttejuvvo dan heiveheapmái, go fas 'auto' geavaha gáldovideo oasselogu. |
| `seed` |  | integer \| null | no |  |  | Guhkideami ráhkadeami sjiehtadus; jus guđđe meroštakeahttá, geavahuvvo random árvu. |
| `output` |  | enum (string) | no | `extended` | `extended`, `continuation` | Boađusláhki: 'continuation' fállá ođđa videomateriála, man ovddabealde lea gáldoloahpa 1.625-sekundosaš geardduheapmi. Ovtta videos gáldu ja ođđa materiála ovttastahttimii vállje 'extended'. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Sisaaddi video ja bivdda modereren. |

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} | Boađusvideo, mas lea álggus 1.625-sekundosaš geardduheapmi go geavahuvvo 'continuation'-láhki. |
| `seed` | integer | Sjiehtadus mii geavahuvvo guhkideami ráhkadeamis. |
| `duration` | number | Máhcaheaddji video guhkkodat sekundain. |
| `source` | object | Gáldomateriála metadata mas leat dimenšuvnnat (govdo ja allodat), rámma-leaktu, guhkkodat ja jietna. |
| `expanded_prompt` | string \| null | Viiddiduvvon bivdda-teaksta, dahje null jus rievdadusat eai dahkkojuvvon. |
| `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