Answer: Yes. WishList Member includes an API and a set of WordPress-style functions you can use to work with WishList Member code. The API lets you connect to and interact with WishList Member using an external (outside of WordPress) script that you write. The available WordPress-style functions allow you to connect to and interact with WishList Member inside of plugins and themes you write (that will be installed in the same WordPress install as WishList Member). More details: https://codex.wishlistproducts.com