Your Existing ASP.NET Core API is Already an MCP Server — You Just Don't Know It Yet

If you've been following the AI tooling space lately, you've probably heard about MCP — the Model Context Protocol. It's the standard that lets AI clients like Claude connect to external tools and APIs. And if you're a .NET developer, you've probably also had the thought: "How do I expose my existing API as MCP tools without rewriting everything?" The answer most tutorials give you looks something like this: [ McpServerToolType ] public class OrderTools { private readonly OrderService _orders ; public OrderTools ( OrderService orders ) => _orders = orders ; [ McpServerTool , Description ( "Retrieves a single order by ID." )] public async Task < Order > GetOrder ( int id ) => await _orders . GetByIdAsync ( id ); [ McpServerTool , Description ( "Creates a new order." )] public async Task < Order > CreateOrder ( string customerName , string product , int quantity ) => await _orders . CreateAsync ( customerName , product , quantity ); } You're duplicating your controller logic. Your auth f