Now that we have proved that the user authentication service is working, we can set up the Notes application to support user logins. We'll be using Passport to support login/logout, and the authentication server to store the required data.

Among the available packages, Passport stands out for simplicity and flexibility. It integrates directly with the Express middleware chain, and the Passport community has developed hundreds of so-called Strategy modules to handle authentication against a long list of third-party services. See http://www.passportjs.org/ for information and documentation.