Also very difficult because: - direct connections are really hard (Tailscale built a whole company on solving this one problem) - even Tailscale can't establi

Also very difficult because: - direct connections are really hard (Tailscale built a whole company on solving this one problem) - even Tailscale can't establish direct connections without a coordination server - even if you can reliably, and always, establish direct connections, it doesn't matter if someone is offline - push notifications don't work without a server, on Android or iOS, so even if you're online, you're out of luck (won't ever get a new message because there's no push notification to tell the client to connect, and you can't just leave a TCP connection open forever on a mobile phone) My take is that it's fine to have a server in the middle with E2EE. That's the whole point of E2EE.