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Select a single image from an image_urls array by 1-based index.
Returns the URL at the requested position without fetching or
re-uploading the image. The output exposes both an image object
and a single-element images array so downstream nodes can
reference image.url or images.0.url interchangeably.
When index exceeds the length of image_urls, the response falls
back to the image specified by fallback_index (default first-image)
instead of failing.
Validation: empty image_urls -> 422; index < 1 -> 422.
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/workflow-utilities/pick-image-by-index", {
input: {
image_urls: ["https://storage.googleapis.com/falserverless/example_inputs/ltxv-image-input.jpg", "https://storage.googleapis.com/falserverless/example_inputs/wan_s2v_cat.png"],
index: 1
},
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/workflow-utilities/pick-image-by-index", {
input: {
image_urls: ["https://storage.googleapis.com/falserverless/example_inputs/ltxv-image-input.jpg", "https://storage.googleapis.com/falserverless/example_inputs/wan_s2v_cat.png"],
index: 1
},
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/workflow-utilities/pick-image-by-index", {
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/workflow-utilities/pick-image-by-index", {
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.
Array of image URLs to select from
index integer* required1-based position of the image to return. Value 1 returns the first image, 2 returns the second, and so on.
fallback_index FallbackIndexEnumBehavior when index exceeds the length of image_urls. When first-image, returns the first image in the array. When last-image, returns the last image in the array. This input has no effect when index is within range, when index is below 1, or when image_urls is empty (the latter two cases still return validation errors). Default is first-image. Default value: "first-image"
Possible enum values: first-image, last-image
{
"image_urls": [
"https://storage.googleapis.com/falserverless/example_inputs/ltxv-image-input.jpg",
"https://storage.googleapis.com/falserverless/example_inputs/wan_s2v_cat.png"
],
"index": 1,
"fallback_index": "first-image"
}The image at the requested position
Single-element array containing the selected image. Included so downstream nodes that expect an images reference (matching merge and other utilities) work without changes.
{
"image": {
"url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-image-input.jpg"
},
"images": [
{
"url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-image-input.jpg"
}
]
}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.