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Index TTS 2.0 Text to Speech

fal-ai/index-tts-2/text-to-speech
Generate natural, clear speeches using Index TTS 2.0 from IndexTeam
Inference
Commercial use
PlaygroundAPI

About

Generate

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

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/index-tts-2/text-to-speech", {
  input: {
    audio_url: "https://storage.googleapis.com/falserverless/example_inputs/index-tts-2/tts_in.mp3",
    prompt: "Hide! He's coming! He's coming to get us!"
  },
  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"
});

3. Queue#

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/index-tts-2/text-to-speech", {
  input: {
    audio_url: "https://storage.googleapis.com/falserverless/example_inputs/index-tts-2/tts_in.mp3",
    prompt: "Hide! He's coming! He's coming to get us!"
  },
  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/index-tts-2/text-to-speech", {
  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/index-tts-2/text-to-speech", {
  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);

Read more about file handling in our file upload guide.

5. Schema#

Input#

audio_url string* required

The audio file to generate the speech from.

prompt string* required

The speech prompt to generate

emotional_audio_url string

The emotional reference audio file to extract the style from.

strength float

The strength of the emotional style transfer. Higher values result in stronger emotional influence. Default value: 1

emotional_strengths EmotionalStrengths

The strengths of individual emotions for fine-grained control.

should_use_prompt_for_emotion boolean

Whether to use the prompt to calculate emotional strengths, if enabled it will overwrite the emotional_strengths values. If emotion_prompt is provided, it will be used to instead of prompt to extract the emotional style.

emotion_prompt string

The emotional prompt to influence the emotional style. Must be used together with should_use_prompt_for_emotion.

{
  "audio_url": "https://storage.googleapis.com/falserverless/example_inputs/index-tts-2/tts_in.mp3",
  "prompt": "Hide! He's coming! He's coming to get us!",
  "strength": 1,
  "emotional_strengths": null,
  "should_use_prompt_for_emotion": true,
  "emotion_prompt": "You scared me to death! What are you, a ghost?"
}

Output#

audio File* required

The generated audio file in base64 format.

{
  "audio": "https://storage.googleapis.com/falserverless/example_outputs/index-tts-2/tts_out.mp3"
}

Other types#

EmotionalStrengths#

happy float

Strength of happiness emotion

angry float

Strength of anger emotion

sad float

Strength of sadness emotion

afraid float

Strength of fear emotion

disgusted float

Strength of disgust emotion

melancholic float

Strength of melancholic emotion

surprised float

Strength of surprise emotion

calm float

Strength of calm emotion

File#

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.