Lucia

What is Lucia?

Lucia is an open source resource focused on teaching developers how to implement authentication systems using JavaScript and TypeScript. Rather than functioning as a ready-to-use authentication library, Lucia serves as an educational platform that guides developers through building authentication from scratch, making it particularly valuable for those who want to understand the underlying principles of secure authentication implementation. The project is designed for developers and teams who prefer to maintain control over their authentication logic rather than relying on third-party solutions. By providing comprehensive documentation and code examples, Lucia enables developers to create custom authentication systems tailored to their specific application needs while learning best practices along the way. As an open source project, Lucia benefits from community contributions and remains freely accessible. The platform covers various aspects of authentication implementation, including session management, password handling, and security considerations. Developers can access the project through its website at lucia-auth.com and its GitHub repository, where the source code and documentation are available for review and contribution. It should be noted that Lucia v3 is deprecated as of March 2025, and the project has transitioned to focus primarily on its educational mission. The source code for v3 remains available for those who need it, with a documented migration path for existing users.