CSharp-Coder

Learn ASP.NET Core JWT authentication step by step with runnable C# code, best practices, and common pitfalls. Start securing your API today! If you are building a modern web API, ASP.NET Core JWT authentication is one of the most important skills you can learn. JSON Web Tokens (JWT) let you secure your endpoints in a stateless, scalable way that works perfectly with single-page apps, mobile clients, and microservices. In this step-by-step tutorial, you will learn exactly how to implement JWT token authentication in C# with runnable code, understand why each piece matters, and avoid the security pitfalls that trip up most developers. By the end, you will have a working ASP.NET Core Web API that issues bearer tokens on login, validates them on protected routes, and follows production-grade best practices. What Is JWT and Why Use It in ASP.NET Core? A JSON Web Token is a compact, URL-safe string made of three Base64Url-encoded parts separated by dots: header.payload.signature ...