The Model Context Protocol (MCP) is undergoing a wire-level redesign that replaces session-based connections and initialization handshakes with a stateless, request-centric model aimed at simplifying deployment and horizontal scaling. Under the release candidate, protocol version, client capabilities, and client identity move into per-request metadata, while routable transport headers, deterministic caching behavior, and a new server/discover method are intended to make remote MCP servers easier to run behind standard cloud load balancers without session affinity, shared session stores, or MCP-specific routing logic.
The update also adds Multi Round-Trip Requests, interactive MCP Apps, and an authorization framework built on OAuth 2.1 and OpenID Connect, while deprecating legacy features including Sampling, Roots, Logging, the older HTTP+SSE transport, Dynamic Client Registration, Tasks, and some server-initiated request patterns. Developers face potentially significant migration work, particularly where servers relied on Sampling or persistent session machinery, but updated SDKs for Python, TypeScript, Go, and C# support both old and new protocol versions during a transition period that includes beta tooling, validation, and minimum deprecation windows.

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The Model Context Protocol is reported to be moving from a session-based design to a stateless, request-centric architecture in a release candidate scheduled for July 28, 2026. The update also introduces features such as Multi Round-Trip Requests, routable transport headers, OAuth 2.1/OpenID Connect-based authorization, interactive MCP Apps, and caching improvements while deprecating several legacy features.
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