I have been working on an Android App quite a while now, starting from a simple idea.
A messenger where messages travel directly between phones with no servers in between. Using direct WebRTC encrypted connections (SRTP/DTLS), there are no servers that stores, reads, or relays content. Group chats use a gossip protocol where members relay to other members.
The only infrastructure the app touches is a signalling relay to set up the connection (no message content), a push notification to wake up a sleeping phone (also no content), and a TURN relay for restricted networks (encrypted packets only).
I wrote a detailed white paper explaining the full architecture: https://www.mindtheclub.com/white-paper.html
The app is in Open Testing on Google Play (1,000 tester cap): https://www.mindtheclub.com/beta-signup.html
I’m interested in this community’s perspective on whether the architecture holds up.
so it sounds like this is more for group chats, to ensure at least one member is online at all times. Otherwise, if it were just 1-1 messaging, and one person’s phone went offline, the other person would have to wait until it was back online to send a message, right?
That is correct, but it works well for 1 to 1 messages.
There’s no relay in between, but you don’t have to wait to send, you hit send normally and the message just queues locally on your device, then goes out automatically the moment a direct connection re-establishes. Nothing sits on a server in the meantime.