I assumed this was doing some LAN-based communication (multicast perhaps, or webRTC), but it looks like it's just a standard chat server that generates one room per IP address.
It'd be interesting to extend the idea to do literally local chat though. It'd be effectively serverless, super resilient, and impossible to externally access (nice for all sorts of compliance concerns). In theory it's all doable, but the initial bootstrapping to find other people on your network from within a web app is tricky...
Yes, for years I wanted what you're talking about, a fully offline, LAN-based communication tool, tried many times but was unable to do it in a way that didn't require the user to have a PhD in distributed systems.
In the end, I just want a tool that allows people to send things to each other easily when they're near. This tool achieves that and we can just ignore the fact that it isn't really LAN-based.
Also being just a chat room with an arbitrary name you can invite people from external places to join your "LAN" chat, which can be useful.
It'd be interesting to extend the idea to do literally local chat though. It'd be effectively serverless, super resilient, and impossible to externally access (nice for all sorts of compliance concerns). In theory it's all doable, but the initial bootstrapping to find other people on your network from within a web app is tricky...