How do you manage default apps?

[mightyiam]

Would you mind sharing? For example, my xdg-open http://example.com opens Chromium, which I'd like it to open Firefox, instead.

[mightyiam]

Found an example here:
nix-community/home-manager#1028

[gvolpe]

I only use Firefox so that's set up for me without extra configuration but if you have multiple browsers then xdg is where you need to look at if you're running on Xorg.