Standard peer-to-peer WebRTC connection via Minecraft Bedrock's signalling channel

BedrockP2P.js

const WebSocket = require('ws');
const { RTCPeerConnection } = require('werift');

const token = ""

const networkId = "";

const randomID = () => Math.floor(Math.random() * 10000000000000000000)

const sessionId = randomID()

const offerId = randomID()

const main = async () => {
  const ws = new WebSocket('wss://signal.franchise.minecraft-services.net/ws/v1.0/signaling/9806856835729287287', {
    headers: { Authorization: token }
  });

  let resolve;
  const promise = new Promise((res) => {
    resolve = res;
  });

  ws.on('message', (data) => {
    const message = JSON.parse(String(data));

    switch (message.Type) {
      case 1: {
        const [type, id, ...rest] = message.Message.split(' ');

        if (type === 'CONNECTRESPONSE') {
          console.log(`Client <- Peer SDP answer`);
          peer.setRemoteDescription({ type: 'answer', sdp: rest.join(' ') })
        }

        if (type === 'CANDIDATEADD') {
          console.log(`Client <- Peer ICE candidate: ${rest.join(' ')}`);
          peer.addIceCandidate({ candidate: rest.join(' ') })
            .catch((error) => console.error('Error adding ICE candidate:', error));
        }

        break;

      }
      case 2: {
        const payload = JSON.parse(message.Message);
        resolve(payload);
        break;
      }
    }

  });

  const data = await promise;

  const peer = new RTCPeerConnection({
    iceServers: [
      {
        urls: 'stun:relay.communication.microsoft.com:3478',
        credential: data.Password,
        username: data.Username
      },
      {
        urls: 'turn:relay.communication.microsoft.com:3478',
        credential: data.Password,
        username: data.Username
      },
    ]
  });

  peer.createDataChannel('test')

  peer.onnegotiationneeded = async () => {
    const offer = await peer.createOffer()
      
    const pattern = /o=- \d+ 0 IN IP4 0\.0\.0\.0/;

    const newOLine = `o=- ${offerId} 2 IN IP4 127.0.0.1`;

    offer.sdp = offer.sdp.replace(pattern, newOLine);

    console.log(`Client -> Peer SDP offer`);

    await peer.setLocalDescription(offer)

    const message = `{"Message": "CONNECTREQUEST ${sessionId} ${offer.sdp}","To":"${networkId}","Type":1}`

    ws.send(message)
  }

  peer.onicecandidate = function (evt) {
    if (evt.candidate) {

      console.log(`Client -> Peer ICE candidate: ${evt.candidate.candidate}`);

      const message = `{"Message":"CANDIDATEADD ${sessionId} ${evt.candidate.candidate}","To":${networkId},"Type":1}`
      
      ws.send(message)
    }
  };

};

main();