Full-Stack React Projects - Second Edition

How JWT works

Before diving into the implementation of authentication with JWT in the MERN stack, we will look at how this mechanism generally works across a client-server application, as outlined in the following diagram:

Initially, when a user signs in using their credentials, the server-side generates a JWT signed with a secret key and a unique user detail. Then, this token is returned to the requesting client to be saved locally either in localStorage, sessionStorage or a cookie in the browser, essentially handing over the responsibility for maintaining user state to the client-side.

For HTTP requests that are made following a successful ...