modelcontextprotocol/python-sdk v2.0.0a2
Pre-releases are opt-in only; pip install mcp still resolves to the stable 1.x line.
Key points
- Full 2026-07-28 types added along with per-version protocol types and version-gated wire validation (#2849)
- mcp.types.v20251125 - generated verbatim from the 2025-11-25 schema (also serves earlier versions).
- The generated per-version packages are wired into both ServerRunner and ClientSession via mcp.types.methods, which maps each (method, version) pair to its request/result/notification types.
- User code keeps working with the monolith mcp.types; the per-version packages are an internal validation layer. 2026-07-28 is modeled but not yet negotiable - SUPPORTEDPROTOCOLVERSIONS is unchanged in this alpha.
Sources (1)
- [1]modelcontextprotocol/python-sdk v2.0.0a2GitHub: modelcontextprotocol/python-sdk · Jun 16, 09:55 PM
Pre-releases are opt-in only; `pip install mcp` still resolves to the stable 1.x line.
### Full 2026-07-28 types added along with per-version protocol types and version-gated wire validation (#2849)
Extractive summary: sentences quoted from the sources.