PyPI rolls out new security tab and clearer warnings about package provenance

PyPI, the official package repository for the Python programming language, has finished rolling out a redesigned interface that presents security signals more clearly. The PyPI team announced the planned changes in July, shaping them with user research among members of the Python community. The aim is to help users judge whether the files they download came from a project's maintainers, as the repository has become an increasingly attractive target for malicious actors.

The new security tab

Project pages now include a dedicated security tab showing a release's provenance state and per-file digital attestations. PyPI introduced attestations in 2024 as a verifiable record of where a release file came from. Two types are supported: "PyPI Publish" attestations confirm that a file was published by a PyPI Trusted Publisher, while "SLSA Build Provenance" attestations link a file to its exact source commit, build platform and build instructions.

A release is typically in one of two states. "Full provenance" means every file in the release has an attestation. "No provenance" means none does, which is common for older releases or projects that have not yet set up Trusted Publishing. It does not mean a file is malicious, only that its origin cannot be cryptographically verified.

Warnings

PyPI shows a prominent warning when provenance data looks unusual:

• incomplete provenance: only some files have attestations;
• inconsistent provenance: files come from different build systems or source repositories;
• change of provenance: files come from a different repository or workflow than a previous release;
• loss of provenance: a project that previously published with attestations now uploads without them.

These can point to a compromised account or pipeline, but often have legitimate explanations, so users are advised to check release notes before installing.

Other improvements

The project page, release files tab and release history have also been redesigned. The file list can be searched and filtered, each file's provenance state is visible, and late-uploaded files are marked with a warning icon. The work was funded by the Open Source Security Foundation and implemented by Kabu Creative.