> I think the python community, and really all package managers, need to promote standard cache servers as first class citizens as a broader solution to supply chain issues. What I want is a server that presents pypi with safeguards I choose. For instance, add packages to the local index that are no less than xxx days old (this uv feature), but also freeze that unless an update is requested or required by a security concern, scan security blacklists to remove/block packages and versions that have been found to have issues. Update the cache to allow a specific version bump. That kind of thing.

FWIW, https://pypi.org/project/bandersnatch/ is the standard tool for setting up a PyPI mirror, and https://github.com/pypi/warehouse is the codebase for PyPI itself (including the actual website, account management etc.).

If "my own curated pypi" extends as far as a whitelist of build artifacts, you can just make a local "wheelhouse" directory of those, and pass `--no-index` and `--find-links /path/to/wheelhouse` in your `pip install` commands (I'm sure uv has something analogous).