Late to this thread, but since it keeps coming up for anyone searching "SE-0292 registry", figured I'd add another data point. The original question here was about a registry for proxying open source dependencies, which Perchly doesn't really do (that's genuinely a different problem, closer to what Artifactory/JFrog are for). But if anyone lands here looking for a way to host your own team's private Swift packages behind a real SE-0292 registry instead of git-subtree hacks or one-repo-per-package, I built Perchly for exactly that: https://perchly.dev. It's SE-0292 native, so swift package resolve just works with no plugins. Still early and solo-built, so happy to hear if anyone runs into rough edges.