Your existing .NET Web APIs have served you well—but what if they could do more with them in the era of AI? In this session, we’ll explore how to breathe new life into your existing ASP.NET Web API endpoints built with ASP.NET CORE by adding Model Creation Protocol (MCP) capabilities to them. We'll look at how the MCP C# SDK makes it simple to annotate your existing controllers, instantly transforming your REST endpoints into AI-powered services that can empower LLMs and agents. We’ll also compare this approach to a no-code approaches using Azure API Management. Finally we'll look at where both of these approaches fall short and are only a starting point for a good long-term MCP design. You can use then to jump start the process and then follow the path we outline together to evolve your APIs from technical plumbing to intelligent, task-focused tools that solve real problems using AI—all without starting from scratch.