You can implement OAuth per repo if github wanted though, or alternatively can you grant access to a specific organisation? Not sure. The default should be per repo auth IMO.

I just looked at github OAuth scopes ( https://developer.github.com/apps/building-oauth-apps/unders... )

honest question, what's the point of using OAuth when the Authz is so coarse? Why not augment to have scopes per repo? Is it considered bad practice to have have a variable (repo name) as a scope?

IIRC the OAuth2-interfacing application needs to (or at least should) know beforehand exactly what to request access to, so if that's read/write access to all of the user's content, it's trivial. For the external application to know something specific like a particular resource is more complicated to deal with (especially with private/hidden content), so most OAuth providers don't provide that level of granularity. It can be done, it just requires more engineering than most (all?) off-the-shelf OAuth solutions provide, and it's more control than most users actually need.

Holy shit this is a crazy attack vector.