This document lists changes made to the Model Context Protocol (MCP) specification since the previous revision, 2025-03-26.
Major changes
Other schema changes
Add _meta field to additional interface types (PR #710), and specify proper usage. Add context field to CompletionRequest , providing for completion requests to include previously-resolved variables (PR #598). Add title field for human-friendly display names, so that name can be used as a programmatic identifier (PR #663)
Full changelog
For a complete list of all changes that have been made since the last protocol revision, see GitHub.