WireNix
WireNix is a Nix Flake designed to make creation of Wireguard mesh networks easier. The simplist and most likely layout is a full mesh network, but Wirenix can also support arbitrary graph topologies. Check out the WireNix wiki to get started. I consider WireNix to be cold-blooded software, so while there might not be recent commits, I assure you it's still maintained.