H3 Max Extend Video adds a text-guided continuation to an existing video. It supports prompt expansion, adjustable duration and aspect ratio, and output resolutions from 480p to 2K, returning either the full extended video or only the new footage.

minimax/h3-max/extend-video

Learn more about H3 Max

Inference

Commercial use

Schema

Playground API Examples

minimax/h3-max/extend-video

Schema

minimax/h3-max/extend-video

Learn more about H3 Max

Inference

Commercial use

Schema

Playground API Examples

About

Extend a video with new footage based on a prompt.

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("minimax/h3-max/extend-video", {
  input: {
    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."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.

3. Queue#

Long-running requests

For long-running requests, such as training jobs or models with slower inference times, it is recommended to check the Queue status and rely on Webhooks instead of blocking while waiting for the result.

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("minimax/h3-max/extend-video", {
  input: {
    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."
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("minimax/h3-max/extend-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("minimax/h3-max/extend-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).

Read more about file handling in our file upload guide.

5. Schema#

Input#

video_url string* required

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.

prompt string* required

What happens next. Describe the continuation, not the source.

reference_audio_urls list<string>

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'.

enable_prompt_expansion boolean

Automatically enhance the prompt using the source video to help keep the continuation consistent. May increase processing time. Default value: true

duration float

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. Default value: 5

resolution ResolutionEnum

Output video resolution. Default value: "768P"

Possible enum values: 480P, 768P, 1080P, 2K

aspect_ratio AspectRatioEnum

Output aspect ratio. 'auto' follows the source video. Other values crop the video to fit the selected ratio. Default value: "auto"

Possible enum values: auto, 21:9, 16:9, 4:3, 1:1, 3:4, 9:16

seed integer

Seed for the continuation. Random when omitted.

output OutputEnum

'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. Default value: "extended"

Possible enum values: extended, continuation

enable_safety_checker boolean

Moderate the source video and the prompt. Default value: true

{
  "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.",
  "enable_prompt_expansion": true,
  "duration": 5,
  "resolution": "768P",
  "aspect_ratio": "auto",
  "output": "extended",
  "enable_safety_checker": true
}

Output#

video File* required

The returned video. In 'continuation' mode, it includes the 1.625-second repeat at the start.

seed integer* required

Seed used for the continuation.

duration float* required

Seconds of returned video.

source Source* required

Source video information: width, height, frame rate, duration, and audio.

expanded_prompt string

The prompt used after expansion, or null when unchanged.

timings Timings

{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

Related Models

About

Extend a video with new footage based on a prompt.

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

Submit a request#

The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.

import { fal } from "@fal-ai/client";

const result = await fal.subscribe("minimax/h3-max/extend-video", {
  input: {
    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."
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

The client API provides a convenient way to submit requests to the model.

import { fal } from "@fal-ai/client";

const { request_id } = await fal.queue.submit("minimax/h3-max/extend-video", {
  input: {
    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."
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

You can fetch the status of a request to check if it is completed or still in progress.

import { fal } from "@fal-ai/client";

const status = await fal.queue.status("minimax/h3-max/extend-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.

import { fal } from "@fal-ai/client";

const result = await fal.queue.result("minimax/h3-max/extend-video", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. Files#

Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.

Data URI (base64)#

Hosted files (URL)#

You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.

Uploading files#

We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.

import { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).

Read more about file handling in our file upload guide.

5. Schema#

Input#

video_url string* required

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.

prompt string* required

What happens next. Describe the continuation, not the source.

reference_audio_urls list<string>

enable_prompt_expansion boolean

Automatically enhance the prompt using the source video to help keep the continuation consistent. May increase processing time. Default value: true

duration float

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. Default value: 5

resolution ResolutionEnum

Output video resolution. Default value: "768P"

Possible enum values: 480P, 768P, 1080P, 2K

aspect_ratio AspectRatioEnum

Output aspect ratio. 'auto' follows the source video. Other values crop the video to fit the selected ratio. Default value: "auto"

Possible enum values: auto, 21:9, 16:9, 4:3, 1:1, 3:4, 9:16

seed integer

Seed for the continuation. Random when omitted.

output OutputEnum

Possible enum values: extended, continuation

enable_safety_checker boolean

Moderate the source video and the prompt. Default value: true

{
  "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.",
  "enable_prompt_expansion": true,
  "duration": 5,
  "resolution": "768P",
  "aspect_ratio": "auto",
  "output": "extended",
  "enable_safety_checker": true
}

Output#

video File* required

The returned video. In 'continuation' mode, it includes the 1.625-second repeat at the start.

seed integer* required

Seed used for the continuation.

duration float* required

Seconds of returned video.

source Source* required

Source video information: width, height, frame rate, duration, and audio.

expanded_prompt string

The prompt used after expansion, or null when unchanged.

timings Timings

{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

Related Models

H3 Max Extend Video Video to Video API Docs | fal

minimax/h3-max/extend-video

Table of contents

Table of contents

minimax/h3-max/extend-video

About

1. Calling the API#

Install the client#

Migrate to @fal-ai/client

Setup your API Key#

Submit a request#

2. Authentication#

API Key#

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

Fetch request status#

Get the result#

4. Files#

Data URI (base64)#

Hosted files (URL)#

Uploading files#

Auto uploads

5. Schema#

Input#

Output#

Other types#

File#

Related Models

Table of contents

About

1. Calling the API#

Install the client#

Migrate to @fal-ai/client

Setup your API Key#

Submit a request#

2. Authentication#

API Key#

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

Fetch request status#

Get the result#

4. Files#

Data URI (base64)#

Hosted files (URL)#

Uploading files#

Auto uploads

5. Schema#

Input#

Output#

Other types#

File#

Related Models