Fellow HN folks,

Many of us who build macOS apps use Sparkle to keep our apps up to date, which uses a published appcast.xml file to track current releases & metadata. If you push out a bad file you could break your updates, but there wasn't a way to validate an appcast.xml before deploying it. So I built one.

It's an NPM module, open source & MIT licensed. Also a web service that can take URLs, files, or pastes and validate as errors, warnings, or informational items. It's also a GitHub Action that's on the marketplace so you can integrate it into your CI/CD pipeline in about three lines. I also put together an XSD validator and plain .md docs as you (or your agent) are authoring.

Feedback welcome!