SA LUA scripting allows you to run commands through an internal API and make changes to SA while it's connected. The LUA scripting is run in a sandbox mode with restrictions on what can be done on your computer. This makes it safe to import other scripts because the only thing that can be impacted negatively is your Stream Avatars data and the application's performance.
If you are looking for an API that allows another application to interact with your SA, you will have to write your own communications.
Want to start making a script from scratch? Find more information and tricks with the link below.