Securing Microservices with YARP and Authentication (JWT or Basic Auth)

Introduction

In microservice architectures, YARP (Yet Another Reverse Proxy) serves as a flexible and performant gateway to route requests to backend services. But routing alone isn’t enough — securing your APIs is essential.

This guide walks you through implementing authentication in YARP, using JWT tokens (recommended for production) or Basic Authentication (for simpler or internal systems).

Goals

• Secure your microservices via the API Gateway.
• Centralize authentication in the YARP gateway.
• Support JWT and optionally Basic Authentication.

Architecture Overview

Option 1: JWT Authentication in YARP

Step 1: Add JWT Authentication in Program.cs

Step 2: Configure YARP Routes with Authorization

Step 3: Protect Routes in Middleware

Optional: Add policy

Option 2: Basic Authentication (for internal APIs or testing)

Note: Basic Auth should only be used over HTTPS and ideally for internal systems.

Step 1: Add custom BasicAuth middleware

Step 2: Register it in the pipeline

Best Practices

Conclusion

With YARP, you can easily implement centralized authentication using either JWT or Basic Auth depending on your system needs. JWT is recommended for scalability and security, while Basic Auth can serve for quick internal solutions.

YARP offers native integration with ASP.NET Core middleware, allowing you to apply policies per route, cluster, or globally giving you full control of how and when users authenticate.