Layercode JavaScript SDK

A JavaScript SDK for integrating Layercode voice agents into web applications.

Installation

npm install @layercode/js-sdk

Or load it another way:

• Module import from your own hosted ESM (current project): const { default: LayercodeClient, listAudioInputDevices, watchAudioInputDevices } = await import("/static/layercode-js-sdk.esm.js");
• Module import from npm inside a bundler: import LayercodeClient, { listAudioInputDevices, watchAudioInputDevices } from "@layercode/js-sdk";
• Module import from CDN ESM: import LayercodeClient, { listAudioInputDevices, watchAudioInputDevices } from "https://cdn.jsdelivr.net/npm/@layercode/js-sdk/dist/layercode-js-sdk.esm.js";
• Global access via UMD <script> (no modules):

  <script src="https://cdn.jsdelivr.net/npm/@layercode/js-sdk/dist/layercode-js-sdk.umd.js"></script>
  <script>
    const { LayercodeClient, listAudioInputDevices, watchAudioInputDevices } = window.Layercode;
  </script>

Device helpers require a secure context (https/localhost).

Device helpers

The SDK now exposes microphone helpers so you can build device pickers or react to hot-swaps without reimplementing the tricky parts:

import {
  LayercodeClient,
  listAudioInputDevices,
  watchAudioInputDevices,
  type LayercodeAudioInputDevice,
} from '@layercode/js-sdk';

async function main() {
  const devices: LayercodeAudioInputDevice[] = await listAudioInputDevices();
  console.log('Default mic:', devices.find((d) => d.default));

  const stopWatching = watchAudioInputDevices((nextDevices) => {
    console.log('Devices changed', nextDevices);
  });

  const client = new LayercodeClient({ /* ... */ });
  await client.setPreferredInputDevice('abcdef123'); // persists your pick even before connecting
  await client.connect();

  // Later, when you need to follow the system default again:
  await client.setPreferredInputDevice('default');

  // Stop watching once the page/component unmounts
  stopWatching();
}

main().catch(console.error);

• listAudioInputDevices() triggers a permission prompt (once) and returns labeled devices with a default flag.
• watchAudioInputDevices(cb) re-emits whenever the browser fires devicechange, de-duping noisy events for you.
• client.setPreferredInputDevice(deviceId | 'default' | null) pins recording to a concrete device ID, or passes 'default'/null to follow the operating system’s default input.

All helpers guard against stale media streams and ensure tracks are stopped whenever we only need labels, which avoids the “mic busy” bugs that browsers frequently hit.

Documentation

Full API reference lives in the docs: https://docs.layercode.com/sdk-reference/vanilla-js-sdk