This tutorial by Osmar Pérez, part of the Write for the Community program, provides a comprehensive guide on implementing a local authentication system using Strapi, Next.js, and NextAuth.js. It begins with setting up a project structure, creating a PostgreSQL database, and installing Strapi using a custom configuration. The guide then explains the use of JSON Web Tokens (JWT) for secure authentication and the different methods of token storage, emphasizing the advantages of using cookies to mitigate security risks such as XSS and CSRF attacks. By integrating NextAuth, the tutorial provides a streamlined approach to authentication, using hooks to manage user sessions and JWTs. It covers creating a login interface, a protected page, and configuring the NextAuth provider for session management, all while emphasizing security best practices. The tutorial concludes by guiding users on testing the setup and accessing JWT tokens via a Strapi endpoint, with the complete code accessible on GitHub.