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Synthesize speech for one text and return it as a WAV file. Runs the same session as a streaming client against this app's /v2/tts/ws WebSocket. This route is bounded for demos. Production integrations use the WebSocket endpoint, which streams the audio as it is generated, documented at https://fal.ai/models/kotoba-technologies/kotoba-tts/v2/tts/ws/api. This demo route may change or be removed without notice.
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("kotoba-technologies/kotoba-tts/v2/tts", {
input: {
text: "",
language: "ja",
speaker_id: "male-01"
},
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("kotoba-technologies/kotoba-tts/v2/tts", {
input: {
text: "",
language: "ja",
speaker_id: "male-01"
},
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("kotoba-technologies/kotoba-tts/v2/tts", {
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("kotoba-technologies/kotoba-tts/v2/tts", {
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.
text string* requiredJapanese text to speak, up to 400 characters.
language LanguageEnum* requiredLanguage of the text.
Possible enum values: ja
speaker_id SpeakerIdEnum* requiredVoice.
Possible enum values: male-01, female-01
{
"text": "",
"language": "ja",
"speaker_id": "male-01"
}Synthesized speech (WAV, 24 kHz mono, 16-bit) as a link to the file.
text string* requiredThe text that was synthesized.
audio_duration_secs float* requiredSeconds of synthesized speech.
{
"audio": {
"content_type": "",
"file_name": "",
"url": ""
},
"text": ""
}content_type string* requiredMIME type of the file.
file_name string* requiredSuggested file name.
url string* requiredWhere the file is: an https link (on fal, a file on its CDN that expires after 24 hours unless the request set its own lifecycle preference), or a data: URI on a deployment without a media store.
file_size integer* requiredSize of the file in bytes.