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  • 8 min read

Incident Report: File Hosting Errors

Executive summary

For about two weeks in August 2026, some PyPI users hit intermittent 502 and 503 errors downloading files from files.pythonhosted.org, triggering failures during installation from PyPI. Thanks to our users filing reports in the support tracker; one report in particular narrowed the problem to a single cache node.

Two separate problems were uncovered. A canary deployment inside Fastly's network had triggered a misconfiguration at one cache node, causing Fastly's routing layer to return 502 responses for traffic reaching the affected cache node. Separately, I found and fixed several bugs in our own Fastly configuration around origin fallback and range request behavior. Those had been there for a while, and only surfaced while digging into these reports.

Both intermittent problems are now fixed, and downloads are back to full function since August 28.

  • 6 min read

How AWS Powers PyPI and the PSF

Working on infrastructure at the Python Software Foundation (PSF) as the Director of Engineering is a broad job with many hats. Python turns up everywhere. It's in healthcare systems and government agencies, in research labs and classrooms, in one-person side projects and in infrastructure at companies with six-figure headcounts. Somebody is using it to analyze a genome right now and somebody else is using it to automate a spreadsheet they hate arranging by hand. That range has always been the interesting part of the PSF's work, and it's only broadened in the last couple of years as AI continues to pull people from many disciplines into writing Python.

  • 4 min read

The HTML representation of the index API is now frozen

PyPI has adopted PEP 833, which "freezes" the HTML representation of the index API, which is also sometimes called the "simple API" or the "simple repository API."

New packages and releases will continue to appear in the HTML representation, meaning this has no breaking implications for downstream index consumers.

However, future standardization and development efforts will focus on the JSON representation, and downstreams that consume only the HTML representation are strongly encouraged to transition to the JSON representation to ensure access to the latest and greatest index features.

  • 2 min read

Releases now reject new files after 14 days

The Python Package Index (PyPI) now rejects new files being uploaded to releases that are older than 14 days. This restriction was put in place to prevent old and long-stable releases from being poisoned in case publishing tokens or workflows of PyPI projects were compromised. As far as we are aware this has not yet been abused, but there is no technical reason beyond that attackers weren't aware it was possible.

  • 4 min read

Planned Updates to the PyPI User Interface

Over the next few months, we will be rolling out changes to the PyPI user interface, improving how we surface security signals and updating the pages where users view package details.

Updates will be staged to TestPyPI and deployed to production in phases. This approach allows our team to thoroughly test the UI with production-like data, while providing the community with an opportunity to share feedback.

The first phase of changes is now staged on TestPyPI and ready for users to review!

  • 6 min read

PyPI has completed its second audit

In 2023 PyPI completed its first security audit, and I am proud to announce that we have now completed our second external security audit.

This work was funded by the Sovereign Tech Agency, a supporter of Open Source security-related improvements, partnering with Trail of Bits to perform the audit. Thanks to ongoing support from Alpha-Omega, my role at the PSF enabled me to focus on rapid remediation of the findings.

This time around, there's no three-part series, as the scope was narrower, focused only on PyPI's codebase and behaviors. Read on for a summary of issues identified, their resolutions, and more details about the audit process.

  • 2 min read

Dispatch from PyPI Land: A Year (and a Half!) as the Inaugural PyPI Support Specialist

Hello there! I am Maria, the inaugural PyPI Support Specialist. I go by "Thespi-Brain" on GitHub. I wanted to provide a dispatch of how this past year (and a half!) has been regarding my role and PyPI. PyPI has now reached over a million users and has over 700,000 projects. It is, without a doubt, a critical part of the Python ecosystem. As the inaugural PyPI Support Specialist, there were numerous challenges that needed to be tackled regarding PyPI support, such as the ever growing backlog of account recovery and PEP 541 issues.

  • 5 min read

PyPI in 2025: A Year in Review

As 2025 comes to a close, it's time to look back at another busy year for the Python Package Index. This year, we've focused on delivering critical security enhancements, rolling out powerful new features for organizations, improving the overall user experience for the millions of developers who rely on PyPI every day, and responding to a number of security incidents with transparency.