Uso | Image to Image

fal-ai/uso

Use USO to perform subject driven generations using reference image.

Inference

Commercial use

Schema

LLMs

Playground API

About

Generate Image

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. Please check the migration guide for more information.

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/uso", {
  input: {
    input_image_urls: ["https://storage.googleapis.com/falserverless/USO/style3.webp", "https://storage.googleapis.com/falserverless/USO/style4.webp"]
  },
  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 case your app is running in an environment where you cannot set environment variables, you can set the API Key manually as a client configuration.

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/uso", {
  input: {
    input_image_urls: ["https://storage.googleapis.com/falserverless/USO/style3.webp", "https://storage.googleapis.com/falserverless/USO/style4.webp"]
  },
  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/uso", {
  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/uso", {
  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

Text prompt for generation. Can be empty for pure style transfer. Default value: ""

input_image_urls list<string>* required

List of image URLs in order: [content_image, style_image, extra_style_image].

image_size ImageSize | Enum

The size of the generated image. Default value: square_hd

Possible enum values: square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9

Note: For custom image sizes, you can pass the width and height as an object:

"image_size": {
  "width": 1280,
  "height": 720
}

negative_prompt string

What you don't want in the image. Use it to exclude unwanted elements, styles, or artifacts. Default value: ""

num_inference_steps integer

Number of denoising steps. More steps can improve quality but increase generation time. Default value: 28

guidance_scale float

How closely to follow the prompt. Higher values stick closer to the prompt. Default value: 4

keep_size boolean

Preserve the layout and dimensions of the input content image. Useful for style transfer.

num_images integer

Number of images to generate in parallel. Default value: 1

seed integer

Random seed for reproducible generation. Use same seed for consistent results.

sync_mode boolean

If true, wait for generation and upload before returning. Increases latency but provides immediate access to images.

enable_safety_checker boolean

Enable NSFW content detection and filtering. Default value: true

output_format OutputFormatEnum

Output image format. PNG preserves transparency, JPEG is smaller. Default value: "png"

Possible enum values: jpeg, png

{
  "prompt": "A handsome man.",
  "input_image_urls": [
    "https://storage.googleapis.com/falserverless/USO/style3.webp",
    "https://storage.googleapis.com/falserverless/USO/style4.webp"
  ],
  "image_size": "square_hd",
  "negative_prompt": "blurry, low quality, distorted, ugly, bad anatomy",
  "num_inference_steps": 28,
  "guidance_scale": 4,
  "num_images": 1,
  "enable_safety_checker": true,
  "output_format": "png"
}

Output#

images list<Image>* required

The generated images with applied style and/or subject customization

seed integer* required

Seed used for generation

has_nsfw_concepts list<boolean>* required

NSFW detection results for each generated image

prompt string* required

The prompt used for generation

timings Timings* required

Performance timings for different stages

{
  "images": [
    {
      "height": 1024,
      "content_type": "image/png",
      "url": "https://storage.googleapis.com/falserverless/USO/G6n97WN0goYpXPeiHaBnP.png",
      "width": 1024
    }
  ],
  "prompt": ""
}

Other types#

Image#

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.

file_data string

File data

width integer

The width of the image in pixels.

height integer

The height of the image in pixels.

ImageSize#

width integer

The width of the generated image. Default value: 512

height integer

The height of the generated image. Default value: 512

Uso Image to Image

Table of contents

1. Calling the API

2. Authentication

3. Queue

4. Files

5. Schema

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#

Image#

ImageSize#