CinderX is a Python extension that improves the performance of the Python runtime.
CinderX is under active development. It is used in production at Meta for use-cases like the Instagram Django service. It is experimental for external users. New releases are published to PyPI on a weekly basis.
- JIT Compiler - Just-in-time compilation of Python bytecode to native machine code
- Static Python - A stricter form/subset of Python, for type safety and optimization
The codebase includes other features as well, such as a parallel garbage collector and a lighter weight implementation of Python interpreter frames. However these features are not compatible with the stock CPython runtime yet.
- Python 3.14 or later
- Linux (x86_64)
- GCC 13+ or Clang 18+
The extension should build and import on macOS but most features will be disabled at runtime. Windows is not yet supported at all.
pip install cinderxCinder was a fork of the CPython runtime developed at Meta. It included runtime optimizations (e.g. JIT) and was specifically targeted at the Instagram Django codebase. For Python 3.10, Meta decided to turn it into a Python extension to improve compatibility with newer Python versions. This extension is now known as CinderX ("the X" is for "extension").
For Python versions 3.10 through 3.12, CinderX still depends on patches to Meta's fork of the Python runtime. Python 3.14 is the first version of stock CPython that CinderX supports.
CinderX is MIT licensed, see the LICENSE file.
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