ActivityPub 5.6.0 for WordPress just shipped! 
It’s a jam-packed release, led by a beta importer to bring your Mastodon posts into WordPress—plus improvements to make setup smoother when activating the plugin.
See the full changelog at:
ActivityPub
The ActivityPub protocol is a decentralized social networking protocol based upon the ActivityStreams 2.0 data format.
WordPress.org (wordpress.org)