@memberjunction/livekit-room-core

Framework-agnostic, pure-TypeScript core for the MJ-native realtime room UX. It wraps livekit-client into a single observable room controller with a deep, cancelable event model — consumable from any framework (Angular, React, Vue) or plain TS.

This is Layer A’s engine in the LiveKit room stack:

@memberjunction/livekit-room-core   ← you are here (pure TS, no UI)
        ▲
@memberjunction/ng-livekit-room      (portable Angular UI)
        ▲
@memberjunction/ng-mj-livekit-room   (MJ binding → realtime bridge)

Why a core package?

The room logic — connect/disconnect, participant + track tracking, active speakers, audio metering, device control, data-channel messages, cloud effects, E2EE — has nothing to do with Angular. Keeping it here means the Angular widget (and any future React binding) is a thin view over a tested engine, and the logic unit-tests with no WebRTC, no browser, no network via an injectable Room factory seam.

Install

npm install @memberjunction/livekit-room-core livekit-client
# optional cloud effects:
npm install @livekit/krisp-noise-filter @livekit/track-processors

Quick start

import { LiveKitRoomController } from '@memberjunction/livekit-room-core';

const room = new LiveKitRoomController();

// Render from the observable snapshot
room.State$.subscribe((state) => renderParticipants(state.Remote));

// Cancelable Before-events (veto an action)
room.Events.On('beforeDisconnect', (e) => {
    if (!confirm('Leave the call?')) e.Cancel = true;
});

// Transform an outgoing chat message
room.Events.On('beforeSendData', (e) => { e.Text = e.Text.trim(); });

await room.Connect('wss://livekit.myorg.com', signedToken, { DisplayName: 'Amith' });
await room.ToggleCamera();
await room.SendData('hello', 'lk-chat');

What it gives you

Capability	API
Connect / leave	`Connect(url, token, options)`, `Disconnect()`
Local media	`ToggleMicrophone()` / `ToggleCamera()` / `ToggleScreenShare()`, `Set*Enabled()`
Devices	`ListDevices(kind)`, `SwitchDevice(kind, id)`
Data channel	`SendData(text, topic?)`
Audio autoplay unblock	`StartAudio()` + `State.AudioPlaybackBlocked`
Krisp noise filter (Cloud)	`SetNoiseFilterEnabled(bool)`
Background blur / virtual bg	`SetBackgroundEffect({ Kind: 'blur' \| 'image' \| 'none' })`
End-to-end encryption	`Connect(..., { E2EE: { Passphrase, Worker } })`
PreJoin preview (room-free)	`LiveKitMediaPreview`
Audio visualizer math	`LiveKitAudioMeter`

The cancelable event architecture

controller.Events is a typed LiveKitRoomEventBus. Before-events run synchronously and may be vetoed (event.Cancel = true) or mutated; notification events report what happened.

Cancelable: beforeConnect, beforeDisconnect, beforeMediaToggle, beforeSendData, beforeDeviceSwitch
Notifications: connected, disconnected, reconnecting, reconnected, participantJoined, participantLeft, activeSpeakersChanged, dataReceived, localMediaChanged, stateChanged, audioPlaybackChanged, noiseFilterChanged, backgroundEffectChanged, error

Testability

Inject a fake Room via the factory seam — no WebRTC needed:

const controller = new LiveKitRoomController({ RoomFactory: () => fakeRoom as unknown as Room });

See src/__tests__/ for the in-memory fake used by the package’s own 22-test suite.