A common requirement when building a web app is to implement a login system, so that users can authenticate themselves before gaining access to protected views or resources. Luckily for those building Node apps, there’s a middleware called Passport that can be dropped into any Express-based web application to provide authentication mechanisms in only a few commands. Prerequisites To follow along with this tutorial, you’ll need to have Node and MongoDB installed on your machine. You can install Node by heading to the official Node download page and grabbing the correct binaries for your system. Alternatively, you can use a version manager — a program that allows you to install multiple versions of Node and switch between them at will. If you fancy going this route, please consult our quick tip, “Install Multiple Versions of Node.js Using nvm”. MongoDB comes in various editions. The one we’re interested in is the MongoDB Community Edition. The project’s home page has excellent documentation and I won’t try to replicate that here. Rather, I’ll offer you links to instructions for each of the main operating systems: