Microsoft updates MCP C# SDK for stateless MCP

Microsoft has released MCP C# SDK v2.0 , a major update of the company’s official C# SDK for Model Context Protocol (MCP) servers and clients. Unveiled July 28 , MCP C# SDK v2.0 implements the 2026-07-28 revision of the MCP specification , which Microsoft described as the protocol’s largest revision since its launch. The 2026-07-28 revision makes the MCP protocol stateless by default, standardizes the HTTP surface to allow ordinary HTTP infrastructure to route MCP traffic, and introduces Multi R