Good morning Fediverse.

If one reads the ActivityPub specification, one might think that a headless server, i.e. not providing a HTML frontend, is a possibility. Sure it is!

BUT! Let's think about wanting to build a Recipe Sharing App. Well Mastodon cannot render recipes. You cannot expect everyone to switch to your new app. So if you want the Fediverse to see your recipes, you need to provide a HTML frontend.

Conclusion: headless ActivityPub is not Fediverse.