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MCP

MCP Went Stateless on July 28. Here Is Where State Lives Now.

The 2026-07-28 MCP spec removed the session handshake, deprecated Roots, Sampling and Logging, and tightened OAuth. What changed, what it means for servers, and where memory fits.

Jose R. Gonzalez, CPA

Jose R. Gonzalez, CPA · Founder of ContxOS

Updated · 2 min read

In short

The Model Context Protocol revision released on July 28, 2026 is its biggest change since launch. The initialize handshake and the session header are gone. Every request carries its own version, identity and capabilities, so any server instance can answer it. Multi round-trip requests replace server-initiated calls. Roots, Sampling and Logging move out of the core. OAuth tightens, with issuer validation required and Client ID Metadata Documents preferred over dynamic registration. The protocol now carries no memory of its own, which makes the question of where an agent’s state lives an application-layer one.

What changed

  • Stateless by default: no initialize handshake and no session header. Requests carry protocol version, client identity and capabilities, so a load balancer can send any request to any instance.
  • Multi round-trip requests: a server can answer "input required" and the client retries with the input. This replaces server-initiated requests that needed a persistent stream.
  • Gateway-friendly: new method and name headers let gateways route and authorize without parsing the body. List results can say how long they may be cached.
  • Slimmer core: Roots, Sampling and Logging are deprecated to non-core, with at least 12 months of support and a formal deprecation policy.
  • Auth: issuer validation (RFC 9207) is required, dynamic client registration is deprecated in favor of Client ID Metadata Documents, and credentials are bound to the authorization server that issued them.
  • Extensions: Tasks, MCP Apps and enterprise-managed authorization are now extensions.

The context around it

MCP has been governed by the Linux Foundation’s Agentic AI Foundation since December 2025, alongside AGENTS.md and goose. The official registry is still labeled preview. Its August roadmap puts agent-to-agent messaging, one HTTP-native transport, agent identity and progressive discovery for large tool catalogs at the top of the list.

Security is still the area that needs the most care. A Cloud Security Alliance research note in July measured an average tool-poisoning success rate of 36.5% across 20 models, and found that several coding tools auto-execute project-defined MCP servers with full privileges. Its advice: allowlist servers, and review MCP configuration changes like code.

Where state lives now

A stateless protocol is easier to scale and secure. It also makes explicit what was always true: MCP moves requests, it does not remember. Anything an agent needs next week, such as decisions, progress or procedures, has to live in a service behind the protocol that is built to keep it.

What it means in practice

For people using remote MCP servers, little changes day to day. Clients and servers negotiate versions, and the Tier-1 SDKs already support the new spec. For choosing servers, the security guidance matters more than ever. Prefer remote servers with OAuth sign-in over local servers that execute with your full privileges, and connect only servers you trust. ContxOS is a remote MCP server with OAuth sign-in, and it keeps its state in the knowledge base, not in the connection.

Sources

  1. The 2026-07-28 MCP specification — Model Context Protocol blog, July 28, 2026
  2. MCP roadmap — Model Context Protocol blog, August 22, 2026
  3. MCP Registry: about — Model Context Protocol
  4. MCP joins the Agentic AI Foundation — Model Context Protocol blog, December 9, 2025
  5. Security best practices — Model Context Protocol
  6. MCP tool poisoning and auto-execution — Cloud Security Alliance, July 1, 2026
  7. Model Context Protocol prepares to break with its stateful past — The Register, July 23, 2026

Frequently asked questions

Do I need to change anything as a user?

Usually not. Keep your clients updated. The main change for users is stricter sign-in behavior on remote servers.

Is the MCP registry production-ready?

Not yet. It is still labeled preview, and it holds metadata only; security scanning is left to package registries and aggregators.

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