Loading API documentation
Frontier image editing model.
Loading API documentation
FLUX.1 Kontext [dev] -- Frontier image editing model.
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/flux-kontext/dev", {
input: {
prompt: "Change the setting to a day time, add a lot of people walking the sidewalk while maintaining the same style of the painting",
image_url: "https://storage.googleapis.com/falserverless/example_inputs/kontext_example_input.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);This model supports streaming requests. You can stream data directly to the model and get the result in real-time.
import { fal } from "@fal-ai/client";
const stream = await fal.stream("fal-ai/flux-kontext/dev", {
input: {
prompt: "Change the setting to a day time, add a lot of people walking the sidewalk while maintaining the same style of the painting",
image_url: "https://storage.googleapis.com/falserverless/example_inputs/kontext_example_input.webp"
}
});
for await (const event of stream) {
console.log(event);
}
const result = await stream.done();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/flux-kontext/dev", {
input: {
prompt: "Change the setting to a day time, add a lot of people walking the sidewalk while maintaining the same style of the painting",
image_url: "https://storage.googleapis.com/falserverless/example_inputs/kontext_example_input.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/flux-kontext/dev", {
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/flux-kontext/dev", {
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 string* requiredThe prompt to edit the image.
image_url string* requiredThe URL of the image to edit.
Max width: 14142px, Max height: 14142px, Timeout: 20s
num_inference_steps integerThe number of inference steps to perform. Default value: 28
seed integerThe same seed and the same prompt given to the same version of the model will output the same image every time.
guidance_scale floatThe CFG (Classifier Free Guidance) scale is a measure of how close you want
the model to stick to your prompt when looking for a related image to show you. Default value: 2.5
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.
num_images integerThe number of images to generate. Default value: 1
enable_safety_checker booleanIf set to true, the safety checker will be enabled. Disabling it requires account authorization; unauthorized requests are always checked, and images flagged as unsafe are returned as black images. Default value: true
output_format OutputFormatEnumOutput format Default value: "jpeg"
Possible enum values: jpeg, png
acceleration AccelerationEnumThe speed of the generation. The higher the speed, the faster the generation. Default value: "none"
Possible enum values: none, regular, high
resolution_mode ResolutionModeEnumDetermines how the output resolution is set for image editing.
auto: The model selects an optimal resolution from a predefined set that best matches the input image's aspect ratio. This is the recommended setting for most use cases as it's what the model was trained on.match_input: The model will attempt to use the same resolution as the input image. The resolution will be adjusted to be compatible with the model's requirements (e.g. dimensions must be multiples of 16 and within supported limits).
Apart from these, a few aspect ratios are also supported. Default value: "match_input"Possible enum values: auto, match_input, 1:1, 16:9, 21:9, 3:2, 2:3, 4:5, 5:4, 3:4, 4:3, 9:16, 9:21
{
"prompt": "Change the setting to a day time, add a lot of people walking the sidewalk while maintaining the same style of the painting",
"image_url": "https://storage.googleapis.com/falserverless/example_inputs/kontext_example_input.webp",
"num_inference_steps": 28,
"guidance_scale": 2.5,
"num_images": 1,
"enable_safety_checker": true,
"output_format": "jpeg",
"acceleration": "none",
"resolution_mode": "match_input"
}The generated image files info.
seed integer* requiredSeed of the generated Image. It will be the same value of the one passed in the input or the randomly generated that was used in case none was passed.
Whether the generated images contain NSFW concepts.
prompt string* requiredThe prompt used for generating the image.
{
"images": [
{
"height": 768,
"width": 1024,
"content_type": "image/jpeg",
"url": "https://storage.googleapis.com/falserverless/example_outputs/kontext_example_output.jpeg"
}
],
"prompt": ""
}url string* requiredwidth integer* requiredheight integer* requiredcontent_type stringDefault value: "image/jpeg"