The 2026-07-28 Model Context Protocol (MCP) specification release candidate eliminates transport-level session management, replacing the stateful initialize/session-ID handshake with a fully stateless protocol core. Every request is now self-describing, carrying protocol version and client info inline via a `_meta` field. New HTTP headers (Mcp-Protocol-Version, Mcp-Method, Mcp-Name) enable proxies and load balancers to route and rate-limit traffic without inspecting request bodies. Multi Round-Trip Requests (SEP-2322) handle server-to-client elicitation prompts without holding open SSE connections, using a serialized `requestState` payload any server instance can resume. The Tasks Extension graduates to a first-class feature for long-running async tool calls. Security improvements include OAuth `iss` parameter support and stricter JSON Schema validation. All four Tier-1 SDKs (TypeScript, Python, Go, C#) have beta releases available, with migration codemods provided for TypeScript.
