We use the Doorkeeper gem for OAuth, so you can refer to their docs on specifics of the end-points.
The API is divided up into access scopes:
read: Read datawrite: Post statuses and upload media for statusesfollow: Follow, unfollow, block, unblock
Multiple scopes can be requested during the authorization phase with the scope query param (space-separate the scopes). If you do not specify a scope in your authorization request, the resulting access token will default to read access.