AssemblyAI JavaScript SDK

The AssemblyAI JavaScript SDK provides an easy-to-use interface for interacting with the AssemblyAI API, which supports async and real-time transcription, as well as the latest LeMUR models. It is written primarily for Node.js in TypeScript with all types exported, but also compatible with other runtimes.

Documentation

Visit the AssemblyAI documentation for step-by-step instructions and a lot more details about our AI models and API. Explore the SDK API reference for more details on the SDK types, functions, and classes.

Quickstart

Install the AssemblyAI SDK using your preferred package manager:

npm install assemblyai

yarn add assemblyai

pnpm add assemblyai

bun add assemblyai

Then, import the assemblyai module and create an AssemblyAI object with your API key:

import { AssemblyAI } from "assemblyai";

const client = new AssemblyAI({
  apiKey: process.env.ASSEMBLYAI_API_KEY,
});

You can now use the client object to interact with the AssemblyAI API.

Using a CDN

You can use automatic CDNs like UNPKG to load the library from a script tag.

• Replace :version with the desired version or latest.
• Remove .min to load the non-minified version.
• Remove .streaming to load the entire SDK. Keep .streaming to load the Streaming STT specific version.

<!-- Unminified full SDK -->
<script src="https://www.unpkg.com/assemblyai@:version/dist/assemblyai.umd.js"></script>
<!-- Minified full SDK -->
<script src="https://www.unpkg.com/assemblyai@:version/dist/assemblyai.umd.min.js"></script>
<!-- Unminified Streaming STT only -->
<script src="https://www.unpkg.com/assemblyai@:version/dist/assemblyai.streaming.umd.js"></script>
<!-- Minified Streaming STT only -->
<script src="https://www.unpkg.com/assemblyai@:version/dist/assemblyai.streaming.umd.min.js"></script>

The script creates a global assemblyai variable containing all the services. Here's how you create a RealtimeTranscriber object.

const { RealtimeTranscriber } = assemblyai;
const transcriber = new RealtimeTranscriber({
  token: "[GENERATE TEMPORARY AUTH TOKEN IN YOUR API]",
  ...
});

For type support in your IDE, see Reference types from JavaScript.

Speech-To-Text

Transcribe audio and video files

Transcribe in real-time

Create the real-time transcriber.

const rt = client.realtime.transcriber();

You can also pass in the following options.

const rt = client.realtime.transcriber({
  realtimeUrl: 'wss://localhost/override',
  apiKey: process.env.ASSEMBLYAI_API_KEY // The API key passed to `AssemblyAI` will be used by default,
  sampleRate: 16_000,
  wordBoost: ['foo', 'bar']
});

[!WARNING] Storing your API key in client-facing applications exposes your API key. Generate a temporary auth token on the server and pass it to your client. Server code:

const token = await client.realtime.createTemporaryToken({ expires_in = 60 });
// TODO: return token to client

Client code:

import { RealtimeTranscriber } from "assemblyai"; // or "assemblyai/streaming"
// TODO: implement getToken to retrieve token from server
const token = await getToken();
const rt = new RealtimeTranscriber({
  token,
});

You can configure the following events.

rt.on("open", ({ sessionId, expiresAt }) => console.log('Session ID:', sessionId, 'Expires at:', expiresAt));
rt.on("close", (code: number, reason: string) => console.log('Closed', code, reason));
rt.on("transcript", (transcript: TranscriptMessage) => console.log('Transcript:', transcript));
rt.on("transcript.partial", (transcript: PartialTranscriptMessage) => console.log('Partial transcript:', transcript));
rt.on("transcript.final", (transcript: FinalTranscriptMessage) => console.log('Final transcript:', transcript));
rt.on("error", (error: Error) => console.error('Error', error));

After configuring your events, connect to the server.

await rt.connect();

Send audio data via chunks.

// Pseudo code for getting audio
getAudio((chunk) => {
  rt.sendAudio(chunk);
});

Or send audio data via a stream by piping to the real-time stream.

audioStream.pipeTo(rt.stream());

Close the connection when you're finished.

await rt.close();

Apply LLMs to your audio with LeMUR

Call LeMUR endpoints to apply LLMs to your transcript.

Contributing

If you want to contribute to the JavaScript SDK, follow the guidelines in CONTRIBUTING.md.