RC2 is a small release with a bugfix and a breaking change (that should have been in RC1): fastmcp dev is now a subcommand group, with the inspector moving to fastmcp dev inspector. We're planning to add new dev tools — mock servers, apps testing — that the Inspector alone can't handle, and this is the right time to claim the CLI namespace.

What's Changed

Fixes 🐞

• Fix include_tags/exclude_tags ignored without tools in MCPConfig by @jlowin in https://github.com/jlowin/fastmcp/pull/3186

Breaking Changes 🛫

• Move fastmcp dev to fastmcp dev inspector by @jlowin in https://github.com/jlowin/fastmcp/pull/3188

Dependencies 📦

• chore(deps): bump cryptography from 46.0.4 to 46.0.5 in the uv group across 1 directory by @dependabot[bot] in https://github.com/jlowin/fastmcp/pull/3147

Full Changelog: https://github.com/jlowin/fastmcp/compare/v3.0.0rc1...v3.0.0rc2