# MiniMax H3 Max Extend

> Continue an existing video with newly generated footage — describe what happens next and get 5-15 more seconds, either appended to the source or on its own. Up to 2K.

## Overview

- **Model ID**: `minimax-h3-max-extend`
- **Workflow**: `minimax/h3-max/extend-video`
- **Provider**: MiniMax
- **Category**: Video → Video (video)
- **Output**: A video URL.
- **Tags**: video input, extend, 2k, 5-15 sec
- **Unified endpoint**: `POST https://api.picsart.com/workflows/v1/models/execute` (model id in the body)
- **Compatibility endpoint**: `POST https://api.picsart.com/workflows/minimax/h3-max/extend-video/execute` (vendor's own parameters)
- **Execution**: long-running — use the async submit/poll pair or the SDK, which polls for you
- **Model page**: https://picsart.com/api-platform/models/minimax-h3-max-extend

## Pricing

Rates are in USD. Every row below is an exact rate for the settings it names — the columns are the settings that change the price for this model. Every response reports what was actually charged in `response.usage.credits`.

| Tier | Rate |
| --- | --- |
| 480p | $0.055 / sec |
| 768p | $0.088 / sec |
| 1080p | $0.176 / sec |
| 2K | $0.352 / sec |

Published rates. Volume pricing, invoicing and annual agreements: https://picsart.com/api-platform/contact-sales

## Authentication

The SDK and the REST API authenticate with a Picsart API key sent as a bearer token. Create a key in the console at https://picsart.com/api-platform/dashboard/api-keys, keep it in a server-side environment variable, and never ship it in browser code or commit it.

```bash
export PICSART_API_KEY="YOUR_KEY"
```

```http
Authorization: Bearer $PICSART_API_KEY
```

The CLI and the MCP server do not use an API key: `gen-ai login` signs in through the browser once per machine and stores a token locally.

## Interfaces

- **SDK** — `@picsart/ai-sdk` (TypeScript, Node 20+, ESM). Type-safe `ai.generate()` / `ai.generateText()` with per-model parameter types; polls long jobs for you.
- **REST** — the API gateway at `https://api.picsart.com`. Sync `/execute`, or async `/submit` + `/{taskId}/result`.
- **CLI** — `@picsart/gen-ai` (`gen-ai`). Generate from a terminal, quote cost before spending, emit JSON for pipelines.
- **MCP** — the same models inside Claude Code, Cursor, Windsurf and other MCP hosts. Setup: https://picsart.com/gen-ai-mcp/

```bash
npm install @picsart/ai-sdk      # SDK
npm install -g @picsart/gen-ai   # CLI (also drives the MCP server)
```

## Unified API (recommended)

One parameter set, used by the SDK and by REST alike: the names below are what `ai.generate('minimax-h3-max-extend', …)` takes, and what goes inside the inner `params` of a REST call. Over REST the model id travels in the body, not the path — one workflow, `v1/models`, fronts the whole catalogue.

### Execution modes

- **Sync** — `POST /workflows/v1/models/execute` returns the result in one call. Only for jobs that finish within ~20 seconds; otherwise it times out.
- **Async** — `POST /workflows/v1/models/submit` returns a task id; poll `GET /workflows/v1/models/{taskId}/result` until `response.status` is `COMPLETED` or `FAILED`. Task statuses: `ACCEPTED` · `IN_PROGRESS` · `COMPLETED` · `FAILED`.
- **SDK** — `ai.generate()` always awaits the finished result; polling is hidden.

Video jobs routinely outrun the sync limit: use async over REST, or the SDK, which polls for you.

### Input parameters

- **`prompt`** (`string`, _required_): Prompt
  - e.g. "What happens next"
- **`videoUrl`** (`string`, _required_): Source Video
  - Accepts: video URL, up to 60s
- **`duration`** (`number`, _optional_)
  - Default: `5`
  - Range: 5–15 (step 1)
- **`output`** (`string`, _optional_): Output
  - Default: `"extended"`
  - Options: `extended`, `continuation`
- **`aspectRatio`** (`string`, _optional_)
  - Default: `"auto"`
  - Options: `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`
- **`resolution`** (`string`, _optional_)
  - Default: `"768p"`
  - Options: `480p`, `768p`, `1080p`, `2k`
- **`enhancePrompt`** (`boolean`, _optional_)
  - Default: `true`
- **`enableSafetyChecker`** (`boolean`, _optional_): Safety Checker
  - Default: `true`
- **`seed`** (`number`, _optional_): Seed
  - Range: 0–2147483647 (step 1)

### Input JSON Schema

The inner `params` object. Over REST it is wrapped as `{ "params": { "model": "<id>", "params": <this> } }`; the SDK takes it directly.

```json
{
  "type": "object",
  "required": [
    "prompt",
    "videoUrl"
  ],
  "properties": {
    "prompt": {
      "type": "string",
      "description": "Prompt"
    },
    "videoUrl": {
      "type": "string",
      "format": "uri",
      "description": "Source Video"
    },
    "duration": {
      "type": "number",
      "minimum": 5,
      "maximum": 15,
      "multipleOf": 1,
      "default": 5
    },
    "output": {
      "type": "string",
      "enum": [
        "extended",
        "continuation"
      ],
      "default": "extended",
      "description": "Output"
    },
    "aspectRatio": {
      "type": "string",
      "enum": [
        "auto",
        "21:9",
        "16:9",
        "4:3",
        "1:1",
        "3:4",
        "9:16"
      ],
      "default": "auto"
    },
    "resolution": {
      "type": "string",
      "enum": [
        "480p",
        "768p",
        "1080p",
        "2k"
      ],
      "default": "768p"
    },
    "enhancePrompt": {
      "type": "boolean",
      "default": true
    },
    "enableSafetyChecker": {
      "type": "boolean",
      "default": true,
      "description": "Safety Checker"
    },
    "seed": {
      "type": "number",
      "minimum": 0,
      "maximum": 2147483647,
      "multipleOf": 1,
      "description": "Seed"
    }
  },
  "additionalProperties": false
}
```

### Required parameters example

The required parameters plus the defaults that shape the output, as a REST body:

```json
{
  "params": {
    "model": "minimax-h3-max-extend",
    "params": {
      "prompt": "A serene mountain lake at golden hour, ultra detailed",
      "videoUrl": "https://cdn.example.com/input.mp4",
      "duration": 5,
      "aspectRatio": "auto",
      "resolution": "768p"
    }
  }
}
```

### Response

The body is the gateway's status envelope: the output is at `response.result`, next to the task id, its status and the credits charged. Asset models return `url` plus an `items` array of results.

```json
{
  "status": "success",
  "response": {
    "id": "task_abc123",
    "status": "COMPLETED",
    "result": {
      "url": "https://cdn.picsart.com/…/result",
      "items": [
        {
          "url": "https://cdn.picsart.com/…/result"
        }
      ],
      "model": "minimax-h3-max-extend"
    }
  }
}
```

What `ai.generate()` / `ai.generateText()` resolve to (the envelope already unwrapped):

```json
{
  "items": [
    {
      "url": "https://cdn.picsart.com/…/result"
    }
  ],
  "model": "minimax-h3-max-extend"
}
```

### Usage examples

#### TypeScript (SDK)

```typescript
import { createClient } from '@picsart/ai-sdk';

const ai = createClient({
  apiKey: process.env.PICSART_API_KEY,
  apiUrl: 'https://api.picsart.com',
});

const result = await ai.generate('minimax-h3-max-extend', {
  prompt: "A serene mountain lake at golden hour, ultra detailed",
  videoUrl: "https://cdn.example.com/input.mp4",
  duration: 5,
  aspectRatio: "auto",
  resolution: "768p"
});

console.log(result.url); // video URL
```

#### cURL (sync)

```bash
curl -X POST 'https://api.picsart.com/workflows/v1/models/execute' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "model": "minimax-h3-max-extend",
    "params": {
      "prompt": "A serene mountain lake at golden hour, ultra detailed",
      "videoUrl": "https://cdn.example.com/input.mp4",
      "duration": 5,
      "aspectRatio": "auto",
      "resolution": "768p"
    }
  }
}'
```

#### cURL (async: submit, then poll)

```bash
# 1. Submit the job
curl -X POST 'https://api.picsart.com/workflows/v1/models/submit' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "model": "minimax-h3-max-extend",
    "params": {
      "prompt": "A serene mountain lake at golden hour, ultra detailed",
      "videoUrl": "https://cdn.example.com/input.mp4",
      "duration": 5,
      "aspectRatio": "auto",
      "resolution": "768p"
    }
  }
}'
# → { "status": "success", "response": { "id": "task_abc123" } }

# 2. Poll until response.status is COMPLETED
curl 'https://api.picsart.com/workflows/v1/models/task_abc123/result' \
  -H 'Authorization: Bearer $PICSART_API_KEY'
```

#### CLI

```bash
gen-ai login  # once per machine
gen-ai models info minimax-h3-max-extend  # this model's parameters
gen-ai pricing minimax-h3-max-extend  # quote before spending credits
gen-ai generate -m minimax-h3-max-extend \
  -p "A serene mountain lake at golden hour" \
  -d 5 \
  --ar auto
```

## Compatibility API (vendor parameters)

Alongside the unified API, the `minimax/h3-max/extend-video` workflow takes MiniMax's own parameters exactly as the vendor defines them — nothing renamed or reshaped. It is the shortest path onto Picsart for request bodies already written against the vendor; the trade is that a request is written for one vendor, and the result comes back in the vendor's own shape. Same authentication.

- **Endpoint**: `POST https://api.picsart.com/workflows/minimax/h3-max/extend-video/execute` (sync) · `POST …/submit` + `GET …/{taskId}/result` (async)
- **SDK**: `ai.apis.run('minimax/h3-max/extend-video', params, { mode })` — params forwarded verbatim

### Vendor parameters

| Parameter | Type | Required | Default | Details |
| --- | --- | --- | --- | --- |
| `seed` | `integer` | no | — | Seed for the continuation. Random when omitted. |
| `video_url` | `string` | yes | — | URL of the video to extend. Must be 1.625 s to 60 s long, up to 50 MB, aspect ratio between 0.4 and 2.5. · min 1 chars · e.g. `https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4` |
| `output` | `string` | no | `extended` | 'extended' returns the source and new footage as one video. 'continuation' returns a clip that starts with a 1.625-second repeat of the source's ending, then shows the new footage. · Options: `extended`, `continuation` |
| `enable_safety_checker` | `boolean` | no | `true` | Moderate the source video and the prompt. |
| `enable_prompt_expansion` | `boolean` | no | `true` | Automatically enhance the prompt using the source video to help keep the continuation consistent. May increase processing time. |
| `resolution` | `string` | no | `768P` | Output video resolution. · Options: `480P`, `768P`, `1080P`, `2K` |
| `reference_audio_urls` | `string[]` | no | — | Optional audio references for the continuation (2–15 seconds each, 15 seconds combined). The full extended video retains its original source soundtrack, and its ending still conditions the transition. These clips guide the newly generated audio instead of using that soundtrack as an audio reference. Assign each clip a role in the prompt, such as 'Audio 1 for the voice' and 'Audio 2 for background music'. · max 3 items |
| `prompt` | `string` | yes | — | What happens next. Describe the continuation, not the source. · 1–50000 chars · e.g. `The red panda keeps walking along the log, then looks up at a bird.` |
| `aspect_ratio` | `string` | no | `auto` | Output aspect ratio. 'auto' follows the source video. Other values crop the video to fit the selected ratio. · Options: `auto`, `21:9`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16` |
| `duration` | `number` | no | `5` | Seconds of new footage to add. The continuation clip also includes 1.625 seconds from the source's ending and may be longer because of frame rounding. · 0.71–15 |
| `options` | `object` | no | — | Platform-specific options for safety checks and Picsart Drive integration. |
| └ `safety_checks` | `object` | no | — | Safety check configuration. |
| └   `enabled` | `boolean` | no | `true` | Enable or disable text safety checks. Defaults to true. |
| └ `drive` | `object` | no | — | Picsart Drive storage options. When provided, the result will be saved to the user's Drive. |
| └   `name` | `string` | yes | — | Filename to save the result as in Picsart Drive. |
| └   `attributes` | `object` | no | — | Additional file metadata attributes. |
| └   `folder` | `object` | no | — | Destination folder in Picsart Drive. |

### Example request body

```json
{
  "params": {
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4",
    "prompt": "The red panda keeps walking along the log, then looks up at a bird."
  }
}
```

### Usage examples

#### TypeScript (`ai.apis.run`)

```typescript
import { createClient, ApiRunMode } from '@picsart/ai-sdk';

const ai = createClient({
  apiKey: process.env.PICSART_API_KEY,
  apiUrl: 'https://api.picsart.com',
});

// Calls the 'minimax/h3-max/extend-video' workflow directly — params are sent as-is.
const { result, usage } = await ai.apis.run('minimax/h3-max/extend-video', {
  video_url: "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4",
  prompt: "The red panda keeps walking along the log, then looks up at a bird."
}, {
  mode: ApiRunMode.SYNC,
});

console.log(result); // workflow-specific output
console.log(usage?.credits); // amount charged, in $
```

#### cURL (sync)

```bash
curl -X POST 'https://api.picsart.com/workflows/minimax/h3-max/extend-video/execute' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4",
    "prompt": "The red panda keeps walking along the log, then looks up at a bird."
  }
}'
```

#### cURL (async: submit, then poll)

```bash
# 1. Submit the job
curl -X POST 'https://api.picsart.com/workflows/minimax/h3-max/extend-video/submit' \
  -H 'Authorization: Bearer $PICSART_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
  "params": {
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4",
    "prompt": "The red panda keeps walking along the log, then looks up at a bird."
  }
}'
# → { "status": "success", "response": { "id": "wf_abc123" } }

# 2. Poll until response.status is COMPLETED
curl 'https://api.picsart.com/workflows/minimax/h3-max/extend-video/wf_abc123/result' \
  -H 'Authorization: Bearer $PICSART_API_KEY'
```

### Response

Over HTTP the vendor-shaped result arrives inside the gateway envelope at `response.result`:

```json
{
  "status": "success",
  "response": {
    "id": "wf_abc123",
    "status": "COMPLETED",
    "result": {
      "timings": {},
      "seed": 0,
      "video": {
        "file_name": "z9RV14K95DvU.png",
        "url": "https://cdn.picsart.com/…/result.mp4",
        "content_type": "image/png",
        "file_size": 4404019
      },
      "source": {},
      "expanded_prompt": "…",
      "duration": 0
    }
  }
}
```

`ai.apis.run()` unwraps that envelope and resolves to `{ result, usage }`:

```json
{
  "result": {
    "timings": {},
    "seed": 0,
    "video": {
      "file_name": "z9RV14K95DvU.png",
      "url": "https://cdn.picsart.com/…/result.mp4",
      "content_type": "image/png",
      "file_size": 4404019
    },
    "source": {},
    "expanded_prompt": "…",
    "duration": 0
  }
}
```

## Additional resources

- Model page: https://picsart.com/api-platform/models/minimax-h3-max-extend
- Try it: https://picsart.com/api-platform/models/minimax-h3-max-extend/playground
- SDK: https://picsart.com/api-platform/models/minimax-h3-max-extend/sdk
- REST API (unified): https://picsart.com/api-platform/models/minimax-h3-max-extend/api
- Compatibility API (vendor parameters): https://picsart.com/api-platform/models/minimax-h3-max-extend/advanced
- Pricing: https://picsart.com/api-platform/models/minimax-h3-max-extend/pricing
- This document: https://picsart.com/api-platform/models/minimax-h3-max-extend/llms.txt
- All models: https://picsart.com/api-platform/models
- Docs — quickstart https://picsart.com/api-platform/docs/quickstart, authentication https://picsart.com/api-platform/docs/authentication, SDK https://picsart.com/api-platform/docs/sdk, REST https://picsart.com/api-platform/docs/api-reference, CLI https://picsart.com/api-platform/docs/cli, MCP https://picsart.com/api-platform/docs/mcp
- CLI reference: https://picsart.github.io/picsart-mcp-cli-docs/guide/introduction