[1] https://git-scm.com/docs/git-http-backend
I discovered this by tabbing git ?TAB in a zsh shell and going through the alphabet.
FYI - no commands starting with e, j, k, o, w, x, y or z using this method. Is there a definitive list of all git commands I wonder?
(My hobby workflow is to just start writing in a directory, and then after a little bit do a "git init"... and then once I have enough to pick a name, I have a "git save-project projectname" script that goes off and does a git init --bare on a homelab server and git push --set-upstream so it's now a remote. Just gradually escalating how "seriously" I'm treating it and therefore how much plumbing I bother with.)
git help -a
It's important to note that the git binaries are (usually) both client and server - by design what with the hole "decentralised" thing.
So the default package will let you run server functionality such as the http-backend (which allows the machine you run it on to serve http(s):// schema repositories)