Secure a C# MCP Server with Auth0

As the Model Context Protocol (MCP) gains traction, the transition from "localhost" experimentation to enterprise integration introduces a critical challenge: security. For developers building sophisticated integrations, treating every LLM request as an "admin" action is a significant risk. Luckily, the MCP specification supports authorization based on OAuth 2.1. So, basically, to protect your MCP server, you have to treat it as a resource server with some extra challenges in case you want to share it publicly to a wide audience. The .NET ecosystem can leverage the C# SDK for MCP to easily expose tools and resources to an AI-powered application. The SDK reached maturity recently supporting all the features defined by the specification , including security. This article explores a practical implementation of a secured MCP server. You will walk through a sample project and learn how to: Implement three distinct tools: one available for public consumption and two gated behind specific per