HunyuanCustom revolutionizes video generation with unmatched identity consistency across multiple input types. Its innovative fusion modules and alignment networks outperform competitors, maintaining subject integrity while responding flexibly to text, image, audio, and video conditions.

fal-ai/hunyuan-custom

Inference

Commercial use

This endpoint is deprecated

This model is no longer supported.

Schema

LLMs

Playground API

SandboxOpen in Sandbox

1. Calling the API

2. Authentication

API Key

3. Queue

4. Files

5. Schema

This endpoint is deprecated

This model is no longer supported.

About

Generate Video

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("fal-ai/hunyuan-custom", {
  input: {
    prompt: "Realistic, High-quality. A woman is playing a violin.",
    image_url: "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png"
  },
  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("fal-ai/hunyuan-custom", {
  input: {
    prompt: "Realistic, High-quality. A woman is playing a violin.",
    image_url: "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png"
  },
  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("fal-ai/hunyuan-custom", {
  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("fal-ai/hunyuan-custom", {
  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#

prompt string* required

Text prompt for video generation (max 500 characters).

negative_prompt string

Negative prompt for video generation. Default value: "Aerial view, aerial view, overexposed, low quality, deformation, a poor composition, bad hands, bad teeth, bad eyes, bad limbs, distortion, blurring, text, subtitles, static, picture, black border."

image_url string* required

URL of the image input.

num_inference_steps integer

The number of inference steps to run. Lower gets faster results, higher gets better results. Default value: 30

seed integer

The seed to use for generating the video.

aspect_ratio AspectRatio(W:H)Enum

The aspect ratio of the video to generate. Default value: "16:9"

Possible enum values: 16:9, 9:16

resolution ResolutionEnum

The resolution of the video to generate. 720p generations cost 1.5x more than 480p generations. Default value: "512p"

Possible enum values: 512p, 720p

fps integer

The frames per second of the generated video. Default value: 25

cfg_scale float

Classifier-Free Guidance scale for the generation. Default value: 7.5

num_frames integer

The number of frames to generate. Default value: 129

enable_prompt_expansion boolean

Whether to enable prompt expansion. Default value: true

enable_safety_checker boolean

If set to true, the safety checker will be enabled. Disabling it requires account authorization; unauthorized requests are always checked. Default value: true

{
  "prompt": "Realistic, High-quality. A woman is playing a violin.",
  "negative_prompt": "Ugly, blurry.",
  "image_url": "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png",
  "num_inference_steps": 30,
  "aspect_ratio": "16:9",
  "resolution": "512p",
  "fps": 25,
  "cfg_scale": 7.5,
  "num_frames": 129,
  "enable_prompt_expansion": true,
  "enable_safety_checker": true
}

Output#

video File* required

seed integer* required

The seed used for generating the video.

{
  "video": {
    "url": "https://storage.googleapis.com/falserverless/example_outputs/test/p1/uQ4ddGyJ9U6cymnns0l6o_input-image-1747117169.mp4"
  }
}

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.

1. Calling the API

2. Authentication

API Key

3. Queue

4. Files

5. Schema

This endpoint is deprecated

This model is no longer supported.

About

Generate Video

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("fal-ai/hunyuan-custom", {
  input: {
    prompt: "Realistic, High-quality. A woman is playing a violin.",
    image_url: "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png"
  },
  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("fal-ai/hunyuan-custom", {
  input: {
    prompt: "Realistic, High-quality. A woman is playing a violin.",
    image_url: "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png"
  },
  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("fal-ai/hunyuan-custom", {
  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("fal-ai/hunyuan-custom", {
  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#

prompt string* required

Text prompt for video generation (max 500 characters).

negative_prompt string

image_url string* required

URL of the image input.

num_inference_steps integer

The number of inference steps to run. Lower gets faster results, higher gets better results. Default value: 30

seed integer

The seed to use for generating the video.

aspect_ratio AspectRatio(W:H)Enum

The aspect ratio of the video to generate. Default value: "16:9"

Possible enum values: 16:9, 9:16

resolution ResolutionEnum

The resolution of the video to generate. 720p generations cost 1.5x more than 480p generations. Default value: "512p"

Possible enum values: 512p, 720p

fps integer

The frames per second of the generated video. Default value: 25

cfg_scale float

Classifier-Free Guidance scale for the generation. Default value: 7.5

num_frames integer

The number of frames to generate. Default value: 129

enable_prompt_expansion boolean

Whether to enable prompt expansion. Default value: true

enable_safety_checker boolean

If set to true, the safety checker will be enabled. Disabling it requires account authorization; unauthorized requests are always checked. Default value: true

{
  "prompt": "Realistic, High-quality. A woman is playing a violin.",
  "negative_prompt": "Ugly, blurry.",
  "image_url": "https://storage.googleapis.com/falserverless/model_tests/hidream/woman.png",
  "num_inference_steps": 30,
  "aspect_ratio": "16:9",
  "resolution": "512p",
  "fps": 25,
  "cfg_scale": 7.5,
  "num_frames": 129,
  "enable_prompt_expansion": true,
  "enable_safety_checker": true
}

Output#

video File* required

seed integer* required

The seed used for generating the video.

{
  "video": {
    "url": "https://storage.googleapis.com/falserverless/example_outputs/test/p1/uQ4ddGyJ9U6cymnns0l6o_input-image-1747117169.mp4"
  }
}

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.

Hunyuan Custom Image to Video API Docs | fal

fal-ai/hunyuan-custom

This endpoint is deprecated

Table of contents

Table of contents

fal-ai/hunyuan-custom

This endpoint is deprecated

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

This endpoint is deprecated

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#

Table of contents

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

This endpoint is deprecated

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#