This is completely self-hosted (beside GitHub) and does not require an external signalling server to establish the WebRTC p2p connection.

Signalling is done manually on GitHub issue comments, guided by a comment bot.

All transmission of data is done P2P over WebRTC, there is no web service / HTTP server involved. The only HTTP service involved is GitHub - which is used to host the static client chat page and facilitate the manual signalling over issue comments.

The additional signalling latency of manual signalling normally causes problems but we use a modified SimplePeer library to provide more time for ICE to reconnect, and we also call restartIce^0

Even then, you can't guarantee WebRTC is foolproof. But as deployed here, it works in a variety of networking and client configurations that I tested.

0: https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConn...