MCP 2026-07-28: Stateless, Production-Ready, and Not Replaced by Skills

The Model Context Protocol just shipped its biggest revision since launch. Spec 2026-07-28 deletes the two things every MCP implementation was built around: sessions and the initialize handshake.

That sounds brutal. It is also the change that finally makes MCP boring infrastructure — the kind you can run behind a load balancer without thinking about it. Here is the short version of what happened, what breaks, and why the "Skills vs. MCP" debate has the wrong premise.

The Headline: Stateless MCP

Until now, talking to a remote MCP server over HTTP meant a ritual: client and server exchanged capabilities, the server minted an Mcp-Session-Id, and every subsequent call had to land on the same process. In production that means sticky sessions, a shared Redis for session state, and gateways doing deep packet inspection to route correctly. Fun at a demo. Painful at scale.

Spec 2026-07-28 removes protocol-level sessions entirely. There is no Mcp-Session-Id header anymore, and no handshake. Every request now carries what it needs in _meta:

• io.modelcontextprotocol/protocolVersion — the version this request speaks
• io.modelcontextprotocol/clientCapabilities — what the client supports
• io.modelcontextprotocol/clientInfo — who is calling

Servers answer with their own identity in each result's _meta. A version mismatch returns UnsupportedProtocolVersionError instead of failing somewhere deep in the call. List endpoints (tools/list, , ) no longer vary per connection — the same request gets the same answer, no matter which replica handles it.