Spec guide
The specification is the source of truth. These pages explain what it says and what changed, and link to the exact section.
- MCP 2026-07-28 in plain language: every method, notification and error code of the current revision, with links to the original.
- Spec diff: 2025-11-25 → 2026-07-28: every method, type and field that changed, generated from the official schema files.
/en/spec/latest/ always leads to the guide for the current revision, so you can bookmark or link it without updating the date later.
Pages elsewhere on this site follow the current revision. A page written for an older one says so at the top and links to the migration guides.
The official specification is published in English only, at modelcontextprotocol.io/specification.
MCPDev is community documentation. It is not affiliated with the Model Context Protocol project or with the vendors of the clients it covers.