Bookmarked https://jackjamieson.net/yarns-microsub-server-getting-started-guide/. “Yarns is a Microsub server that runs on your WordPress site. This means it can help you follow feeds from blogs, websites, and social media all in place, running on your own server. You tell Yarns which feeds you want to follow, and it will collect new posts in the background. It can understand feeds in several different formats (Microformats, RSS, Atom, JSONFeed).”