Meta’s launch of Threads has brought new interest in ActivityPub and how the social network protocol and the associated fediverse – including the Twitter-like Mastodon – work.

The new Twitter-like social media service from Mark Zuckerberg’s Meta, Threads, was released in July 2023 and quickly racked up tens of millions of downloads. At launch, it was, like Twitter before it, a walled garden; a Threads account only allows for posting and reading content on Threads. But, Meta promises, it won’t be that way forever. Threads customers will eventually be able to interact with other platforms in the so-called fediverse like Mastodon (an open-source Twitter replacement) and vice versa.

A protocol called ActivityPub is what will enable this, Meta says. While Twitter runs on a private and proprietary technology platform, ActivityPub promises a decentralized future for social media that, in theory, gives users much greater freedom to flee a service they don’t like (a position many Twitter users currently desire as they disagree with the direction Elon Musk is taking the company).

So what exactly is ActivityPub, how does it work and what do you need to know about it? We’ve got you covered

What is ActivityPub?

ActivityPub is a standard established by the World Wide Web Consortium (W3C), the group responsible for technologies that provide the basic plumbing of the internet. It does two big things:

1. Different services can speak to each other (like, in the future, Threads and Mastodon),
2. Users can take their data (the list of accounts they follow, etc.) with them from service to service.

With an ActivityPub-powered service, users control their data, content and audience, letting them take that information with them wherever they decide to go. Instead of having to rebuild followers and find out who to follow on each new platform, you can take all that with you to any new social media platform supporting ActivityPub.

This data portability is a large shift from the social media status quo driven by incumbents like Facebook (which, like Threads, is run by Meta), Twitter, YouTube and TikTok, which are run by centralized companies that harvest user data and control the content users provide.

Open social networking means that the social apps built on it are interoperable, so instead of having to re-upload a different version of a post for each platform, you can post once and it can be seen, shared and read across any app or program built on or that supports ActivityPub throughout the fediverse (the term used to describe the family of interconnected ActivityPub-powered services).  We’ll get more into that next.

So what is the fediverse?

If you go to any Threads user’s profile page, you’ll see a gray button with the words “threads.net” next to their username. If you tap on the button, you’ll receive this pop-up:

“Soon, you’ll be able to follow and interact with people on other fediverse platforms, like Mastodon. They can also find people on Threads using full usernames, like @[username]@threads.net.”

If you were one of the people who tested out or migrated to Mastodon after Musk’s 2022 acquisition of Twitter, the term fediverse may be familiar even if it’s meaning remains murky.

Fediverse is a portmanteau combining federated + universe. So, essentially, the “fediverse” is the universe of server-to-server social networks, which is described as a federated system. For those in the U.S., it’s the same way states make up the whole of the country; each state is independent but unite in important ways to make up a country. In a federated social network like Mastodon, each server is independent but they can share posts, information, users and together all the servers make up the whole network we call Mastodon.

In an interview with The Verge, the head of Meta’s Instagram, Adam Mosseri, spoke of the benefits of open social networks for creators, calling out the ability to “own your audience” and that if someone wanted to leave Threads, they could take that audience (and content) with them.

The other benefit is allowing the content within social networks to leave their walled garden – right now to view content on Facebook, Instagram and, most recently, Twitter, you need an account to even see the posts, let alone share them. Federated systems allow any compatible system to view content from one another – just the way you can see a website on any browser from Chrome to Edge to Brave or read an email from Gmail in your Yahoo or Microsoft outlook account.

Will supporting ActivityPub mean Threads is decentralized?

While ActivityPub is a decentralized, open social networking protocol, Threads itself is an app created and controlled by Meta. As CoinDesk’s David Z. Morris notes, “decentralization on the back-end doesn’t seem like it’s going to stop Meta from doing its very favorite thing: gathering data about users of the front-end Threads app.”

So while ActivityPub Protocol is a decentralized protocol, Threads is an app or interface built separately and controlled by a centralized company, Meta, and while you may be able to take your audience with you, Meta is also still going to be gathering and using your data every time you use Threads.

When will Threads integrate ActivityPub?

No timeline has been given as of writing.