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Outpaint audio using the ACE-Step 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/ace-step/audio-outpaint", {
input: {
audio_url: "https://storage.googleapis.com/falserverless/example_inputs/ace-step-audio-to-audio.wav",
tags: "lofi, hiphop, drum and bass, trap, chill"
},
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/ace-step/audio-outpaint", {
input: {
audio_url: "https://storage.googleapis.com/falserverless/example_inputs/ace-step-audio-to-audio.wav",
tags: "lofi, hiphop, drum and bass, trap, chill"
},
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/ace-step/audio-outpaint", {
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/ace-step/audio-outpaint", {
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.
audio_url string* requiredURL of the audio file to be outpainted.
extend_before_duration floatDuration in seconds to extend the audio from the start.
extend_after_duration floatDuration in seconds to extend the audio from the end. Default value: 30
tags string* requiredComma-separated list of genre tags to control the style of the generated audio. Can also be supplied as prompt.
lyrics stringLyrics to be sung in the audio. If not provided or if [inst] or [instrumental] is the content of this field, no lyrics will be sung. Use control structures like [verse], [chorus] and [bridge] to control the structure of the song. Default value: ""
number_of_steps integerNumber of steps to generate the audio. Default value: 27
seed integerRandom seed for reproducibility. If not provided, a random seed will be used.
scheduler SchedulerEnumScheduler to use for the generation process. Default value: "euler"
Possible enum values: euler, heun
guidance_type GuidanceTypeEnumType of CFG to use for the generation process. Default value: "apg"
Possible enum values: cfg, apg, cfg_star
granularity_scale integerGranularity scale for the generation process. Higher values can reduce artifacts. Default value: 10
guidance_interval floatGuidance interval for the generation. 0.5 means only apply guidance in the middle steps (0.25 * infer_steps to 0.75 * infer_steps) Default value: 0.5
guidance_interval_decay floatGuidance interval decay for the generation. Guidance scale will decay from guidance_scale to min_guidance_scale in the interval. 0.0 means no decay.
guidance_scale floatGuidance scale for the generation. Default value: 15
minimum_guidance_scale floatMinimum guidance scale for the generation after the decay. Default value: 3
tag_guidance_scale floatTag guidance scale for the generation. Default value: 5
lyric_guidance_scale floatLyric guidance scale for the generation. Default value: 1.5
{
"audio_url": "https://storage.googleapis.com/falserverless/example_inputs/ace-step-audio-to-audio.wav",
"extend_before_duration": 0,
"extend_after_duration": 30,
"tags": "lofi, hiphop, drum and bass, trap, chill",
"number_of_steps": 27,
"scheduler": "euler",
"guidance_type": "apg",
"granularity_scale": 10,
"guidance_interval": 0.5,
"guidance_interval_decay": 0,
"guidance_scale": 15,
"minimum_guidance_scale": 3,
"tag_guidance_scale": 5,
"lyric_guidance_scale": 1.5
}The generated audio file.
seed integer* requiredThe random seed used for the generation process.
tags string* requiredThe genre tags used in the generation process.
lyrics string* requiredThe lyrics used in the generation process.
{
"audio": {
"url": "https://storage.googleapis.com/falserverless/example_outputs/ace-step-text-to-audio.wav"
},
"seed": 42,
"tags": "lofi, hiphop, drum and bass, trap, chill",
"lyrics": "[inst]"
}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.