Major Revision to MCP Specification: Protocol Layer Fully Switches to Stateless HTTP

On July 28, 2026, the official MCP team released the largest revision since the protocol was launched: the `initialize` handshake and `Mcp-Session-Id` have been removed, and the core of the protocol has been changed to a stateless request/response model. Remote MCP Servers can be deployed behind load balancers like ordinary HTTP services for horizontal scaling; MRTR now supports elicitation interactions in stateless scenarios; gateway-level routing is implemented via the `Mcp-Method`/`Mcp-Name` headers. This article sorts out the changed mechanism, request comparisons, and key points for developer migration.