Generate Image
The client provides a convenient way to interact with the model API.
npm install --save @fal-ai/clientThe @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.
Set FAL_KEY as an environment variable in your runtime.
export FAL_KEY="YOUR_API_KEY"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);The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.
import { fal } from "@fal-ai/client";
fal.config({
credentials: "YOUR_FAL_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.
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",
});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,
});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);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.
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.
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.
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);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.
prompt stringText prompt for generation. Can be empty for pure style transfer. Default value: ""
List of image URLs in order: [content_image, style_image, extra_style_image].
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 stringWhat you don't want in the image. Use it to exclude unwanted elements, styles, or artifacts. Default value: ""
num_inference_steps integerNumber of denoising steps. More steps can improve quality but increase generation time. Default value: 28
guidance_scale floatHow closely to follow the prompt. Higher values stick closer to the prompt. Default value: 4
keep_size booleanPreserve the layout and dimensions of the input content image. Useful for style transfer.
num_images integerNumber of images to generate in parallel. Default value: 1
seed integerRandom seed for reproducible generation. Use same seed for consistent results.
sync_mode booleanIf True, the media will be returned as a data URI and the output data won't be available in the request history.
enable_safety_checker booleanEnable NSFW content detection and filtering. Default value: true
output_format OutputFormatEnumOutput 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"
}The generated images with applied style and/or subject customization
seed integer* requiredSeed used for generation
NSFW detection results for each generated image
prompt string* requiredThe prompt used for generation
Performance timings for different stages
{
"images": [
{
"url": "https://storage.googleapis.com/falserverless/USO/G6n97WN0goYpXPeiHaBnP.png",
"width": 1024,
"height": 1024,
"content_type": "image/png"
}
],
"prompt": ""
}width integerThe width of the generated image. Default value: 512
height integerThe height of the generated image. Default value: 512
url string* requiredThe URL where the file can be downloaded from.
content_type stringThe mime type of the file.
file_name stringThe name of the file. It will be auto-generated if not provided.
file_size integerThe size of the file in bytes.
width integerThe width of the image in pixels.
height integerThe height of the image in pixels.