MCP C# SDK 2.0 Makes HTTP Stateless by Default and Adds Multi Round-Trip Requests

Microsoft announced version 2.0 of the official MCP C# SDK, which implements the 2026-07-28 revision of the Model Context Protocol with stateless HTTP servers by default, standardised routing headers and Multi Round-Trip Requests. Releases 2.1 to 2.3 have since added hybrid session serving, a subscriptions/listen handler and a series of discovery, OAuth and shutdown fixes.

By Edin Kapić