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A performant type-checker for Python 3


Built from the ground up to support gradual typing and deliver responsive incremental checks. Performant on large codebases with millions of lines of Python.


Designed to help improve code quality and development speed by flagging type errors interactively in your terminal or live in your favorite editor.

Fully Featured

Follows the typing standards introduced in PEPs 484, 526, 612, and is being actively developed and constantly improved.

Built For Security

Pyre ships with Pysa, a security focused static analysis tool we've built to reason about data flows in Python applications at scale.