Creating an API check-in and check-out for a woocoomerce shop

We want to build up a self-hosted online shop with [login to view URL] The currency are points, s no payment getaway is necessary- The Login link will be external, therefore we need an API check-in and check-out. For authentication it is necessary that we can use our own user database. To access our user database we have an API that provides user login with standard functionality (REST). The login link is external, so woocommerce can just link to another site. The API returns the user session as a cookie on a domain, therefore you can check if the user is logged in via a simple API (REST) call, where all the user credentials are (if logged in) or not (if not logged in). So it’s important that you can add every database entries in woocommerce with our user ID (you can just duplicate the user from the API, our API delivers unique ID for every user) While checking out, there is no money transaction needed. There is just one secure API endpoint to transmit how much points to remove on the user Every other data can be saved in normal woocommerce database. Please start the convesation with the word "shop".