I have been enjoying espanso[1], which at first glance is just a text-expanding keystoke saver, but can run shell scripts when it's doing its thing. So I can type :extip anywhere and it will curl ipinfo.io then pipe the json response through jq -r and leave my current external IP in whatever app I was typing in.
Holy cow, espanso looks bonkers. Open source, completely cross-platform, fully extensible... it ticks all the boxes. Might just have to try it out tonight!
I had a similar reaction, although annoyingly it seems that on my Debian system it doesn't expand text inside gnome-terminal. Inside Emacs, Firefox, and similar it does work but if it's not "everywhere" I suspect I'll get frustrated.
1: https://espanso.org/