This PEP proposes a mechanism by which projects hosted on pypi.org can safely host wheel artifacts on external sites other than PyPI. This PEP explicitly does not propose external hosting of projects, packages, or their metadata. That functionality is already available by externally hosting independent package indexes. Because this PEP only provides a mechanism for projects to customize the download URL for specific released wheel artifacts, dependency resolution as already implemented by common installer tools such as pip and uv does not need to change.