Ask an AI assistant about .NET and it will happily generate some code for you. Ask it which customer owns ticket 1234, or whether that deployment can go out today, and suddenly it has no clue. The answer exists; it is just stuck inside systems the assistant cannot reach.

That gap is what this session is about. I'll build an MCP server in C# and .NET, connect it to an existing system, and expose a few useful operations as tools. Then we'll plug it into an AI assistant and see the whole thing work end to end.

The existing system doesn't need to be .NET. It can be whatever you already run. .NET is just what we're using to build the MCP server.

Getting a tool to show up is easy. Getting the model to use it correctly is where things get interesting. We'll get into naming and shaping tools, authentication, and access control. We'll also stop and ask the slightly uncomfortable question: should an AI be allowed to do this at all?

At the end, you should have a good idea of how MCP fits into your existing systems and enough code to try it yourself. Should you connect everything? Probably not.