AGENT DESIGN · PROTOCOL INFRASTRUCTURE
The Model Context Protocol shipped its final 2026-07-28 specification today, its largest revision since launch. The old core required an initialize handshake that pinned a client to whichever server instance held its Mcp-Session-Id. The new core drops that entirely, every request now carries its own protocol version and client info, so a remote MCP server can sit behind a plain round-robin load balancer with no sticky routing and no shared session store. This is a small working demo of exactly that difference.
Same 5 requests, three-node round robin
A plain load balancer hands each request to the next node in sequence, A, B, C, A, B. No sticky routing, no shared session store. Run the same request sequence against the old core and the new one.
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WHY THIS MATTERS FOR CLIENT WORK
Every Claude Code session I run for client work, this routine included, connects a stack of MCP servers. The stateful handshake was always the thing that made hosting a custom MCP server for a client feel like standing up real infrastructure: sticky sessions, a session store, a single point of failure. Stateless means a client's MCP server can now be a few boring pods behind a load balancer, the same shape as any other stateless API. Two official Extensions ship alongside it, MCP Apps and a redesigned Tasks extension, both governed under a new reverse-DNS framework, and a 10-week window lets SDK maintainers catch up.
Built 28 July 2026 · pattern sourced from the MCP 2026-07-28 specification