PEP 639 – Improving License Clarity with Better Package Metadata | peps.python.org

The 2026 Packaging Summit convenes in Long Beach on May 15. Here's what's on the table based on the last two years of notes.

pyproject.toml is the standard configuration file for modern Python projects. It holds project metadata, dependencies, build-system requirements, and tool settings in one TOML file.

https://peps.python.org/pep-0639/ https://packaging.python.org/en/latest/specifications/core-metadata/ https://discuss.python.org/t/pep-639-round-3-improving-license-clarity-with-better-package-met...

https://peps.python.org/pep-0639/ https://packaging.python.org/en/latest/specifications/core-metadata/ https://discuss.python.org/t/pep-639-round-3-improving-license-clarity-with-better-package-met...

In late March, version 78.0.1 of Setuptools — an important Python packaging tool — was released [...]

In late March, version 78.0.1 of Setuptools — an important Python packaging tool — was released [...]

How to update your Python project for PEP 639

Pip 25.0 has been out for a bit over a month now; and we now also have an official blog post about the release, as well as a 25.0.1 patch for a regression. Pip 25.0 has what I consider a very serious

pip 25.0 adds support for SPDX License Expressions (PEP 639), build environment bugfixes, and further optimizations among other changes.