google/xb-netblocks
>- Add real-time multiplayer to an XR Blocks app with the netblocks addon — presence avatars (remote heads + hands), replicated `NetObject` transforms with cooperative ownership, typed pub/sub RPC events, and opt-in spatial WebRTC voice, over pluggable transports (BroadcastChannel for local dev, WebRTC/PeerJS for serverless P2P, WebSocket relay for scalable rooms). Use when building shared or co-located XR. Covers `enableNet()`, `joinRoom()`, `NetObject`, and `session.events`; the full reference (wire protocol, transports, threat model) is at src/addons/netblocks/.
npx skills add https://github.com/google/xrblocks --skill xb-netblocksA Transport moves bytes between peers; a NetSession layers presence, RPC, replicated
objects, and voice on top. Swap transports without changing app code.
> Full reference: ../../src/addons/netblocks/SKILL.md
> and ../../src/addons/netblocks/README.md.
Cooperative, trusted rooms (demos, classrooms, co-presence). It is prototype-grade — no peer
authentication, cooperative ownership, no rate limiting. For adversarial workloads, put a
server-authoritative arbiter on top.
import * as xb from 'xrblocks';
import {
enableNet,
BroadcastChannelTransport,
} from 'xrblocks/addons/netblocks/src/index.js';
class MyApp extends xb.Script {
async init() {
const net = enableNet(); // ticks on the standard xb frame loop
const session = await net.joinRoom('my-room', {
transport: new BroadcastChannelTransport(), // two tabs see each other instantly
displayName: 'Alice',
});
session.events.on('chat', (text, fromPeerId) =>
console.log(`${fromPeerId}: ${text}`)
);
}
}
xb.add(new MyApp());
xb.init();
import {
NetObject,
WebRTCTransport,
} from 'xrblocks/addons/netblocks/src/index.js';
const shared = new NetObject({id: 'cube', object: this.cube});
const net = enableNet();
await net.joinRoom('demo', {
transport: new WebRTCTransport(),
displayName: 'Alice',
});
net.session?.netObjects.add(shared);
// session.claim(obj) on grab, session.release(obj) on drop; owners broadcast, others interpolate.
BroadcastChannelTransport — local dev, two tabs, zero infra.WebRTCTransport — serverless P2P via PeerJS (≤ ~12 peers); pass iceServers/signalingUrl.WebSocketTransport — a small relay (server/relay.js) for scalable rooms.Enable voice with joinRoom({voice: true}) or session.voice.enable().
Take google/xb-netblocks from the repository into ~/.claude/skills for personal
use, or into .claude/skills inside a project.
The agent identifies a skill by the name field in its header. Two skills with the
same name cannot sit side by side — one of them will be ignored.