MCP goes stateless in its July 2026 revision
The July 2026 MCP revision removes the initialize handshake and session IDs, lets clients cache tool lists, moves tasks into a new extensions framework and deprecates several older features.
The Model Context Protocol, now governed under the Agentic AI Foundation, published a new specification revision on July 28, 2026. It is the biggest structural change since MCP launched.
What changed
- Stateless core. The initialize handshake and session ID are gone. A new
server/discovercall replaces them. - Cacheable lists. Tool and resource lists can carry a time to live and a scope, so clients stop asking for the same list on every call.
- Extensions framework. Tasks move out of the core spec into a new extensions framework.
- Deprecations. Roots, Sampling and Logging are deprecated. Dynamic client registration is deprecated in favor of Client ID Metadata Documents.
Why it matters
Stateless servers are much easier to run at scale behind load balancers, which is what large companies need before they put MCP in front of production systems. This revision is aimed at operators, and it shows the protocol settling in for long-term use.
Cacheable tool lists also make a quiet point. What a server offers is now treated as something stable enough to cache. The meaning of the data behind those tools deserves the same treatment: written once, versioned, reviewed and shared, rather than worked out again by every agent on every call.