Pyre-check
lastmod 2026-11-10created 2020-12-142 edits
Pyre is a static type checker for Python developed by Meta (Facebook). Written in OCaml, it aims to run fast even on large codebases; it finds errors based on type hints and supports incremental checking and editor integration (LSP). The same repository also includes Pysa, which finds security vulnerabilities through data flow analysis. It is compared with mypy, which serves as a reference implementation, and Microsoft's pyright as one of the main choices among Python type checkers.