MCP Gets Largest Update Yet, Sessions Abolished
The Model Context Protocol (MCP), the open standard for connecting AI applications with external tools and data, received its largest update since its debut on July 28, 2026. The new specification, designated '2026-07-28', shifts MCP from a stateful to a stateless design, abolishing the session-based communication that required initialization and sticky sessions. This change allows each request to be self-contained, enabling MCP servers to be deployed and scaled on general HTTP infrastructure like Kubernetes, serverless, and edge environments. The update also introduces Multi Round-Trip Requests (MRTR) for handling user confirmations in stateless communication, revamps HTTP headers and caching, and moves long-running processing and screen display features into a formal extension mechanism. Authentication has been enhanced with mandatory validation of the 'iss' information in OAuth 2.0 and OpenID Connect, and Dynamic Client Registration has been deprecated in favor of Client ID Metadata Documents. A 12-month transition period is provided for deprecated features, including Roots, Sampling, Logging, and the old HTTP and Server-Sent Events communication method. Major SDKs for TypeScript, Python, Go, and C# support the new specification, with Rust in beta. GitHub MCP Server has adopted the new spec, and Anthropic plans to gradually introduce support to Claude products.