About

Lean libraries are easy to publish and hard to size up. A README can look complete while the toolchain is unpinned, the build is broken, or the sources are full of sorry.

Cloning and building every candidate is slow. Reading a Lake manifest is incomplete. Lean Report Card is a public index of coarse, explained scores for Lean 4 GitHub repositories, so maintainers, users, and reviewers can compare the same signals: does it build, is Lean pinned, and what shows up in source, tests, and project files.

The grade is a heuristic from 0 to 100, not a kernel proof of correctness or security. Compare scores only for the same analyzer version. If you maintain a public repository, you can submit it for analysis and, if you allow publication, keep the result on the index and as a README badge.