The Miniflux protocol is a fairly well-designed protocol supporting a wide variety of operations on newsfeeds, folders (termed "categories"), and articles; it also allows for user administration, and native OPML importing and exporting. Architecturally it is similar to the Nextcloud News protocol, but has more capabilities.
Miniflux version 2.0.29 is emulated, though not all features are implemented
Miniflux version 2.0.28 is emulated, though not all features are implemented