@panaudia/lasa-client

The TypeScript client for LASA, live spatial audio over Media over QUIC. It runs in the browser and speaks to a LASA space over WebTransport: it publishes object audio with pose, plays rendered sinks, follows the presence feed, and synchronises the space's distributed state store.

The protocol lives one directory up, in lasa-core.md and lasa-base-profile.md. This package is the browser half of it. The server half is Panaudia LASA.

Requirements

The client uses four browser platform features, and every one is mandatory:

• WebTransport, for the QUIC connection.
• WebCodecs, for Opus encode and decode (AudioEncoder and AudioDecoder).
• AudioWorklet, for capture and playout on the audio thread.
• SharedArrayBuffer, for the lock-free rings between the audio thread, the transport worker and the page.

SharedArrayBuffer needs cross-origin isolation. Your page MUST be served with these two headers, or capture and playout refuse to start:

Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp

Chromium is the engine the interop suite runs against. Other engines work as their WebTransport and WebCodecs support allows.

The package is ESM only and targets ES2022. There are no runtime dependencies.

Install

npm install @panaudia/lasa-client

The transport worker is inlined into the bundle as a Blob, so there is no worker file to copy and nothing for your bundler to resolve.

A first session

import { LasaClient } from '@panaudia/lasa-client';

const client = await LasaClient.connect({
  url: 'https://lasa.example.com:4443/lasa',
  spaceId: 'main',
  clientId: 'alice',
  entities: [{ id: 'alice-voice', name: 'Alice' }],
});

// Capture: the microphone into the entity, five-millisecond Opus
// frames, each stamped with the freshest pose.
const mic = await navigator.mediaDevices.getUserMedia({ audio: true });
const ctx = new AudioContext({ sampleRate: 48000 });
const source = ctx.createMediaStreamSource(mic);
const capture = await client.startCapture('alice-voice', { source });
capture.setPose({ x: 0, y: 0, z: 0, yaw: 0, pitch: 0, roll: 0 });

// Playout: the space renders a binaural mix for this entity, the
// client decodes it in the worker and plays it through a worklet.
const player = await client.playSink('alice-voice', 'binaural');
player.setVolume(0.8);

// Presence: who else is here, and where.
const roster = await client.subscribeRoster(() => {
  for (const entry of roster.snapshot()) {
    console.log(entry.id, entry.pose, entry.loudness);
  }
});

// Later.
await client.close();

playSink builds an AudioContext, so on browsers that gate audio behind a user gesture, call it from a click or key handler.

Guides

• Connecting covers tickets, entities and setups, certificate pinning for development servers, rejection codes, and the session lifecycle.
• Audio covers capture, playout, sink formats, quality and redundancy, microphone selection, and the raw packet API underneath.
• Presence covers the roster and the receive rules it applies.
• State covers the store, synchronisation, writes, reconnects and cursors.
• Base profile covers the typed helpers over the lasa. vocabulary: personal mutes and solos, moderation, channels, rendering parameters, and the entity view.
• Coordinate systems covers the LASA pose and the converters for Three.js, Babylon, A-Frame, PlayCanvas, Unity, Unreal and Pixi.

The API reference is generated from the source with TypeDoc, as markdown, and committed. npm run docs:api regenerates it after a change to the exported surface.

Working with Claude Code

The repository ships a skill, .claude/skills/lasa-client/SKILL.md, that points Claude at the verified examples and the details client code must get right. Copy that directory into your own project's .claude/skills/ to use it there.

Examples

• minimal is the starting point to copy: join a space, send the microphone, play the binaural render, list who is there. It depends on the built package the way a published dependency would.
• test-page is the development instrument: every subsystem on one page, consuming the SDK from source.

Both need a running space; each README says how to start one.

Development

npm install
npm run typecheck      # tsc
npm test               # vitest unit suite
npm run test:interop   # Playwright, against a server built from ../../panaudia-lasa
npm run build          # dist/index.js + declarations

The interop suite builds and launches the Go server itself, one instance in unticketed dev mode and one ticketed, and drives a real Chromium against both. npm run dev serves the same interop page with the isolation headers set.

PROVENANCE.md records what this package inherits from the earlier Panaudia SDK and what was pruned on the way.

Licence

MIT. See LICENSE.