Soniox
SDKs

Web SDK

Build speech-to-text workflows in browser with real-time API.

Soniox Web SDK is the official JavaScript/TypeScript SDK for using the Soniox Real-time API directly in the browser. It lets you:

  • Capture audio from the user's microphone
  • Stream audio to Soniox in real time
  • Receive transcription and translation results instantly

Quickstart

Install

Install via your preferred package manager:

npm install @soniox/client
yarn add @soniox/client
pnpm add @soniox/client
bun add @soniox/client

Set up your temporary API key endpoint

In client enviroment (browser, mobile app, React Native, etc.), you don't want to expose your API key to the client. For this reason, you can create a temporary API key endpoint on your server and use it to issue temporary API keys for the client.

For example, you can use our Node SDK to create a temporary API key endpoint.

import express from 'express';
import { SonioxNodeClient } from '@soniox/node';

const app = express();
const client = new SonioxNodeClient(); // reads SONIOX_API_KEY from env

// Create a temporary API key endpoint
app.get('/tmp-key', async (_req, res) => {
try {
    const { api_key, expires_at } = await client.auth.createTemporaryKey({
    usage_type: 'transcribe_websocket',
    expires_in_seconds: 300, // 1..3600
    });

    res.json({ api_key, expires_at });
} catch (err) {
    res.status(500).json({ error: err instanceof Error ? err.message : 'Failed to create temporary key' });
}
});

app.listen(3000, () => {
  console.log('Server listening on http://localhost:3000');
});

Read more about our Node SDK and Temporary API keys

Create your first real-time session

import { SonioxClient } from "@soniox/client";

// Create a Soniox client
const client = new SonioxClient({
  // Pass a function that fetches a temporary API key from your server
  api_key: async () => {
    const res = await fetch("/tmp-key", { method: "POST" });
    const { api_key } = await res.json();
    return api_key;
  },
});

// Create a recording session
const recording = client.realtime.record({ model: "stt-rt-v4" });

// Listen for transcription results
recording.on("result", (result) => {
  const text = result.tokens.map((t) => t.text).join("");
  if (text) console.log(text);
});

// Listen for errors
recording.on("error", (err) => console.error("Error:", err));

// Later, stop gracefully (waits for final results):
// await recording.stop();

Learn more about Real-time transcription

Minimal JavaScript example

Simple transcription example in vanilla JavaScript.

Next steps

Types

Soniox Node SDK — Types Reference

Real-time transcription

Create and manage real-time speech-to-text sessions with the Soniox Web SDK