pip supports a download cache (off by default) that stores packages as their urlname. It works similar to how you describe. It will see it needs the package at

pip supports a download cache (off by default) that stores packages as their urlname. It works similar to how you describe. It will see it needs the package at url xyz.com/package.tar.gz, it'll check it's download cache and if it doesn't exist there it will download the file from the url and save it to the cache. The cacheable urls stem from the fact that currently on PyPI you can delete an existing file you've uploaded, and reupload a file of the same name. Pip (and any other cache like varnish etc) isn't notified of the fact that what used to be at url xyz.com/packages.tar.gz is gone and now something else is at xyz.com/packages.tar.gz. This can cause issues with installing packages, especially on remote deployment infrastructures. With crate I place the sha256 of the file in the url, so if someone deletes + uploads the same name, it should still (unless you get (un)lucky and get a collision somehow) have a completely different url, so pip and other caches will see it as a different file. As a side effect it would allow a simple caching proxy to be installed at someones office, or wherever that easily does the behavior you describe as well. It could function similarly to pip but be shared amongst multiple people.