MCP's stateless spec ships SDK betas

The Model Context Protocol’s maintainers shipped beta Python, TypeScript, Go, and C# SDKs for the 2026-07-28 spec release candidate, the largest revision since MCP’s launch: it removes the protocol-level session handshake entirely so any request can hit any server instance, adds Extensions, MCP Apps, and Tasks as first-class, and formalizes a deprecation policy.