2025-06-18
This release marks the initial 2025-06-18 revision of the Model Context Protocol.
For a detailed overview of changes, see 2025-06-18 changelog.
To users and implementors: note that SDKs will adopt this version at their own pace, and the prior version of the spec may remain in use for an undetermined amount of time. The spec describes how clients and servers perform version negotiation with one another, permitting backwards and forwards compatibility.