free4.chat is an instant audio conferencing service.

It is designed by the local first and privacy first principle, and is very easy to use.

⚠️ This project is just using for technical test purpose, use at all your risk!

⚠️ There is freedom of speech, but I cannot guarantee freedom after speech. (- Idi Amin)

Features

• Common
  • Use WebSocket to replace http protocol of JSON-RPC
  • Compatibility
    • Make Safari(WebKit) compatibility better
• Room
  • Text chat, can sent text or emoji
    • Persist text messages to browser localStorage
  • Can send arbitrary data by WebRTC datachannel 🚩
  • Room permission setting, like public/private type setting
    • private room can't been seen on room discovery, and it needs password to enter. The password is End-to-End Encryption, server only need check the answer which given by the client like the PoW in blockchain.
    • Public rooms discovery, like hot room list or filter rooms by type/tag
• User
  • User real-time collaboration, like whiteboard, you draw I guess, etc.
    • Use CRDT to impelement real-time collaboration
      • https://github.com/liveblocks/liveblocks
      • https://github.com/derekkraan/delta_crdt_ex
    • Whiteboard
      • https://github.com/tldraw/tldraw
  • Robot user, like game robot who can play or facilitate game
    • robot use Web Speech API to play with user in room
    • robot can play some voice games like language learning, technical interview, etc.
      • Gartic Phone - The Telephone Game
      • ESL Game - Not only practicing English speaking
      • Gartic.io - Draw, Guess, WIN

Architecture

• Tech Stack
  • Use Elixir/Phoenix to rewrite the backend code
  • Use Recat/Next.js to rewrite the frontend code
• Infra
  • Use docker to deploy to PaaS platform like Railway or Fly
  • Use GitHub Actions + AWS Lightsail to deploy backend server
  • Backend service cluster, auto scaling, load balancing, etc.
    • Backend service use Elixir libcluster to build cluster
    • Frontend app use the client load balance strategy
    • TURN cluster scale
      • Fix by start turn before the libcluster, still wait the upstream library to fix it normally
  • Security enhancement, like coturn TLS setup, end-to-end encryption, etc.
    • TURN enable TLS
  • Privacy enhancement.
  • IPV6 support.

Contribution

If you are interested in webRTC, peer-to-peer(P2P), real-time collaboration(CRDT), distributed system or robot design, you can join this project and contact with me by twitter.

Thanks

• free4.chat Elixir version is build on the top of Membrane Framework, thanks for their heart of open source.
• free4.chat Golang version is build on the top of Kraken, Mornin, coturn and Pion, thanks for their heart of open source.
• These websites also inspired me:
  • Random voice and text chat rooms that you’ll love. | Speakrandom
  • Practice Speaking English Online Free - Language Practice Community
  • Agora Real-Time Voice and Video Engagement