Complete Access Token & Refresh Token Implementation in ASP.NET Core Web API 🔥 C# +SQL Server | 2026

🔥 **Build a secure Access Token and Refresh Token authentication system in ASP.NET Core Web API using C# and SQL Server!** In this practical 2026 tutorial, we walk through the complete JWT authentication flow, from login to token refresh and logout. **What you'll learn:** - Access Token vs Refresh Token - Create an ASP.NET Core Web API project - Configure JWT Bearer authentication - Generate JWT using claims and signing credentials - Generate cryptographically secure refresh tokens - Store refresh token hashes in SQL Server - Implement Login and Refresh API endpoints - Validate token expiry and revocation - Implement Refresh Token Rotation - Detect refresh token reuse - Secure refresh tokens using HttpOnly cookies - Revoke tokens during logout - Important production security practices **Real-world flow:** Login → Access Token → Protected API → Token Expired → Refresh API → New Access Token → Token Rotation → Logout 💡 **Important:** Never store raw refresh tokens in your database. Store their hashes, use HTTPS, protect cookie-based refresh endpoints against CSRF, and handle concurrent refresh requests safely. 💬 Comment **JWT CODE** if you want the complete copy-paste source code. 👍 Like, Share and Subscribe to **CODE X** for practical .NET, C#, ASP.NET Core, SQL Server, React, Azure and AWS tutorials. #dotnet #csharp #jwt #aspnetcore #webapi Access Token Refresh Token Implementation, JWT Authentication in ASP.NET Core, Refresh Token in C#, ASP.NET Core Web API Authentication, JWT Token C# Tutorial, JWT Refresh Token Rotation, Secure JWT Authentication, Refresh Token SQL Server, ASP.NET Core 8 Web API, C# Authentication Tutorial, JWT Bearer Authentication, Refresh Token Hashing, JWT Token Expiration, Token Revocation in ASP.NET Core, HttpOnly Cookie JWT, .NET Developer Tutorial 2026, ASP.NET Core Interview Questions, Senior .NET Developer, Full Stack Developer, CODE X