README

Signal Fire Connect

Signal-Fire Connect is a low-level WebRTC signaling client for Signal Fire Server, a WebRTC signaling server for node.js.

A WebRTC signaling server communicates between peers to set up peer-to-peer audio/video and/or data channels. This allows your clients to communicate directly with each other.

Install

> npm i @signal-fire/connect

Features

Works seamlessly with Signal Fire Server
Connect uses vanilla WebSockets and a JSON protocol
Automatically reconnect on close or error
Buffers outgoing requests until the connection has been established
Dispatches description events on incoming session descriptions
Dispatches icecandidate events on incoming ICE candidates
Send session descriptions and ICE candidates to a remote peer

Example

import Connect, {
  ConnectSessionDescriptionEvent,
  ConnectIceCandidateEvent
} from '@signal-fire/connect'

const connect = new Connect({
  /** Whether or not to reconnect after a normal close. */
  reconnectOnClose: false,
  /** Whether to reconnect after an error close. */
  reconnectOnError: true,
  /** Interval to wait between reconnect attempts. */
  reconnectInterval: 2500,
  /** Maximum number of reconnect attempts. */
  reconnectAttempts: 5,
  /** Function to transform the URL upon reconnecting. */
  urlTransform: previousUrl => previousUrl
})

// Connect to the signalling server
await connect.connect('wss://webrtc.example.com')

// Create a new connection
const target = '<target id>'
const connection = new RTCPeerConnection()

connection.addEventListener('negotiationneeded', async () => {
  const offer = await connection.createOffer()
  await connection.setLocalDescription(offer)

  // Send the session description to the remote peer
  await connect.sendDescription(target, connection.localDescription)
})

connection.addEventListener('icecandidate', async (ev: RTCIceCandidateEvent) => {
  if (ev.candidate) {
    // Send the ICE candidate to the remote peer
    await connect.sendIceCandidate(target, ev.candidate)
  }
})

// Listen for incoming session descriptions
connect.addEventListener('description', async (ev: ConnectSessionDescriptionEvent) => {
  const { origin, description } = ev

  if (origin !== target) {
    return
  }

  if (description.type === 'offer') {
    await connection.setRemoteDescription(description)
    const answer = await connection.createAnswer()
    await connection.setLocalDescription(answer)

    // Send the session description to the remote peer
    await connect.sendDescription(target, connection.localDescription)
  } else if (description.type === 'answer') {
    await connection.setRemoteDescription(description)
  }
})

// Listen for incoming ICE candidates
connect.addEventListener('icecandidate', async (ev: ConnectIceCandidateEvent) => {
  const { origin, candidate } = ev

  if (origin !== target) {
    return
  }

  await connection.addIceCandidate(ev.candidate)
})

Questions

I'm getting the following error

You may get the following (or similar) error:

Argument of type '(event: ConnectSessionDescriptionEvent) => void' is not assignable to parameter of type 'EventListenerOrEventListenerObject'

This is an open issue with TypeScript, see Microsoft/TypeScript#28357. See the issue thread for possible temporary solutions.

License

This software is licensed under the MIT License.

Usage no npm install needed!