Services can be thought of as libraries which contain functions that you might want to use
in many places of your application. For example, you might have an Email service which
wraps some default email message boilerplate code that you would want to use in many parts
of your application.
Simply create a JavaScript file containing a function or an object into your ./api/services
directory. Services are exposed at strapi.services.
module.exports = {
functionName: function (options) {
// ...
}
};