Building Secure APIs with Express: Authentication and Authorization Best Practices for JavaScript Apps is a comprehensive guide for developers aiming to create robust, secure, and scalable RESTful APIs using Express.js. This book demystifies the complexities of authentication and authorization, providing clear explanations of essential security concepts and hands-on implementation strategies. Readers will learn how to safeguard their applications from common threats such as injection attacks, cross-site scripting (XSS), and data breaches by leveraging proven middleware solutions like Passport.js and express-jwt.

The book covers the full authentication lifecycle, including password management, token-based authentication with JWT, multi-factor authentication, and integration with third-party identity providers such as Auth067. Detailed chapters walk through best practices for structuring Express apps, managing user roles and permissions, and implementing fine-grained access control. Real-world examples and code snippets help readers apply security measures effectively, ensuring their APIs are resilient against evolving threats. Whether you are new to Express.js or an experienced developer looking to enhance your security expertise, this book equips you with the knowledge and tools needed to build and maintain secure JavaScript APIs that protect both your users and your data.