ActivityPub: the new standard for decentralized networks

Originally published at:

Today, the World Wide Web gained a new standard: ActivityPub. The recommendation has been published by the responsible W3C workgroup after 3 years of work, started in no small part by Christopher Lemmer Webber, founder of the Mediagoblin project. Nextcloud uses ActivityPub, implementing it to handle Activity federation between servers, crucial for our Global Scale architecture.

And indeed, you may already be using ActivityPub now without realizing it.
--Christopher Lemmer Webber

Nextcloud and ActivityPub

Nextcloud implements ActivityPub to inform users about changes to their files, new calendar and so on between users on different Nextcloud servers since Nextcloud 12. This makes ActivityPub part of what makes Nextcloud Global Scale work!

The Activity app which implements ActivityPub will continue to be improved, as its role has expanded over the years to inform users about a lot of things beyond file changes. Its core developer, Joas, blogged earlier about his todo list for the year, including changes to the Activity App.

[caption id=“attachment_3536” align=“alignright” width=“300”] Illustration of how ActivityPub works from[/caption]

What is ActivityPub

The origins of ActivityPub trace back to microblogging technology StatusNet, the former Laconia which was first widely implemented at has since migrated to, the successor to OStatus and the protocol it implements is essentially the base of ActivityPub. Evan Prodromou, the original author of Laconia and, designed the new protocol to use Activity Streams for commands and transfer data via a simple REST inbox API. The best place to get started to learn more about the protocol is on the website.

Christopher Lemmer Webber wrote a guest post on the Free Software Foundation blog explaining some history and features of the protocol. It provides a server-server protocol for federation and a client-server protocol for users to connect to a server. The core idea of ActivityPub is to bring together decentralized social networks, gaining critical user mass while keeping data on separate servers.

The popular Twitter alternative Mastodon is a prominent user, same goes for Mediagoblin which aims more at sharing photos and videos. And, then, Nextcloud of course!

1 Like

Too bad Nextcloud is only using it to federate between different Nextcloud instances, instead of thinking out of the box and actually investigation potential cross federation between different web services such as Mastodon or PeerTube that also use activity pub :stuck_out_tongue:

See previous discussion here:

I’ve installed social plugin, and even posted something on global wall. Too bad it’s totally empty

could you put some instructions how to configure this thing on selfhosted instance with domain and certificate to actually see the people?