Yes. Please see the details below for a brief summary.

Building a Theme or Plugin that Works Together with s2Member Advanced

s2Member's API Functions are for developers (or advanced site owners) to use in projects of their own. These make it easy to integrate s2Member with themes and other plugins. Everything from permissions, to details about each user, and even a few utility methods.

We recommend using s2Member's API Functions, API Constants, or Hooks/Filters (over 1000 spread throughout all of s2Member's codebase) to complete an advanced integration. Note... please try to refrain from using other internal classes/methods/constants whenever possible; as those are subject to change from one release to the next. Conversely, the availability of API Functions, API Constants, and Hooks/Filters will remain from one version to another. Only in rare circumstances would we ever remove one of these key elements. If we do, backward compatibility would always remain when the previous version is deprecated for whatever reason.