gRPC Basics

gRPC is a contract-first way for services to call each other over HTTP/2 using Protocol Buffers as the serialization format. Where REST and HttpClient make you stitch URLs, JSON shapes, and status codes together by hand, gRPC starts from a .proto file that describes the messages and the methods, and the tooling generates the C# classes for both the client and the server. This lesson covers what gRPC actually is, how the code generation pipeline works in .NET, how to build a server with ASP.NET Core, how to call it from a client, the four kinds of RPC the protocol supports, and how it compares to REST.