Model Context Protocol releases (2026-07-28 stable spec)

What it claims

The page lists eight releases. Each one notes only that a revision has shipped and links to its changelog. The actual protocol changes live in those linked changelogs, not on this page. The summary leaves out one revision: 2024-11-05. It was released in two parts:

• 2024-11-05, the initial release.
• 2024-11-05-final, which the page describes as "including all backwards compatible changes made since the initial 2024-11-05 release."

The full sequence is:

1. 2024-10-07
2. 2024-11-05
3. 2024-11-05-final
4. 2025-03-26
5. 2025-06-18
6. 2025-11-25-RC, then 2025-11-25
7. 2026-07-28 RC, then 2026-07-28 stable

Only the two most recent revisions went through a release-candidate stage. 2025-03-26 and 2025-06-18 shipped directly as "initial" revisions with no RC.

How to use it

The page makes several statements that affect adoption:

• Your SDK may not support 2026-07-28 yet. From 2025-03-26 onward, every release says "SDKs will adopt this version at their own pace." Check your SDK's own release notes before relying on 2026-07-28 features.
• Older revisions will stay in use. The page warns that the prior version "may remain in use for an undetermined amount of time." A server or client you deploy should expect peers on earlier revisions.
• Version negotiation is how mixed versions work. The page says the spec describes how clients and servers negotiate a version, "permitting backwards and forwards compatibility." Implement negotiation rather than pinning to one revision.
• Don't build on an RC. The RC notes say "this specification is not final. Changes may be introduced between the RC and the final release." Anything built against the 2026-07-28 RC should be re-checked against the stable 2026-07-28 changelog.

Limits

This page is an index only. It says nothing about:

• what changed between revisions,
• which changes are breaking,
• which SDKs support which revision,
• deprecation or end-of-support dates for older revisions.

To find out what 2026-07-28 changes, read the linked 2026-07-28 changelog. To see how older peers are handled, read the Version Negotiation documentation.