@peter - WireGuard is great and it's getting the job done, but it's not the same as having a client that can chose best server, where you can easily specify countries or cities, configure netshield options, killswitch and port-forwarding without going neck deep into iptables. The "router" part in the original request is confusing me too - but requiring X to run CLI on Linux is absurd and completely defeats the purpose IMHO.

This is already possible by downloading a WireGuard configuration; you can use any WireGuard client on the router to connect, not just ProtonVPN. https://protonvpn.com/support/wireguard-configurations

I desperately want this as I am having innumerable issues with Gluetun, and I also find it very odd that they developed a CLI that requires a GUI. it seem counterintuitive.

"Please also note that the CLI doesn’t currently work on headless setups."

I mean... this has got to be one of the dumbest things I've ever seen. Think about it... in a meeting somewhere somebody said "let's do a CLI version of the client, but require a running X session to use it" and somebody else (probably a group of somebody elses) actually said "Sure! That makes sense. Let's do it!"