Bluesky opens up federation, letting anyone run their own server that connects to Bluesky's network, which uses the AT Protocol; Mastodon uses ActivityPub
> Initially to join the network you'll need to join the AT Protocol PDS Admins Discord and register the hostname of your PDS. — https://github.com/... [image] @isagalaev@mastodon.social : It looks like BlueSky blog authors were compelled to make the difference from Mastodon to look more drastic than it actually is: — https://bsky.social/... They made it seem like on Mastodon you're locked inside your server and accessing global content is somehow more difficult, which isn't true. … @mackuba@martianbase.net : Ok Fediverse, time to move the goalposts from “#Bluesky will never open the federation!” to “it's not a *real* federation” 😎 Andy / @pixel@desu.social : yeah, I see how Bluesky is not like Mastodon. — At least for Mastodon I don't need to ask Eugen about being able to federate with other instances. @Obdurodon@hachyderm.io : I kind of hate to say anything positive about anything associated with Jack Dorsey, and I'll probably be pilloried for doing so, but I have to say that the Bluesky “Personal Data Server” idea looks interesting. Even if it fails or is abandoned, there might be some interesting lessons we all can learn about different models of federation. … @fenarinarsa@shelter.moe : Bluesky federation is opening. — In addition to federating feeds, you can now self-host your account. — The main relay is still hosted by Bluesky but you can make your own if you want (unlike personal data servers, it needs a lot of resources though). — https://bsky.social/... @fediversereport@mastodon.social : Bluesky has announced that today they have started with federation, allowing anyone to host their own data on the #bluesky network. — In a blog post they announced that anyone can now host their own PDS, framing it as a way to control your own data, and also explaining how it differs from Mastodon. … Bluesky: @bsky.app : We just crossed 5M people total on the network! 🎉 [image] Dave Lee / @davelee.bsky.social : Big moment. BlueSky may have been well behind the curve when it comes to opening up to the public, but it's flying ahead of Meta by bringing in federation. Interesting race! [embedded post] @bsky.app : Today, we're excited to announce that the Bluesky network is federating, or opening up in a way that allows you to host your own data! — Read more here for how this will affect your experience on Bluesky (in short: it won't) and why this matters. — bsky.social/about/blog/0... X: Alex Van de Sande / @avsa : Bluesky is federating the right way. Mastodon is basically little social sites reading each others rss feed, while Bluesky is lead by a badass former zcash engineer. If you care about decentralized social, you should be integrating with At Protocol https://bsky.social/... @bluesky : Today, we're excited to announce that the Bluesky network is federating and opening up in a way that allows you to host your own data! Read more here for how this will affect your experience on Bluesky (in short: it won't) and why this matters. https://bsky.social/... @bluesky : With traditional social media, your data is stored by a single company. If you ever want to stop using that company's services, you can do that—but you would have to leave that social network and lose your existing connections. We think social media should be as open as the web... @bluesky : While Bluesky shares the term “federation” with other networks, there are some key differences. On Bluesky, server choice doesn't affect what content you see. The experience will continue to be straightforward and intuitive. [image] Forums: Hacker News : Bluesky announces data federation for self hosters r/Mastodon : Bluesky federation goes live r/BlueskySocial : Bluesky federation goes live Jaz / Lobsters : Bluesky announces data federation for self hosters BeauHD / Slashdot : Bluesky Now Open To Federation
Context & Ripple Effects
Bluesky's move from an early Twitter-like federated network toward user-controlled infrastructure follows its earlier work on account portability, which framed leaving a host as a core user protection. It also builds on community-driven moderation proposals, extending the network's architecture beyond a single operator.
The distinction from Mastodon's ActivityPub model matters because Bluesky is opening server operation while retaining a shared relay and a consistent content experience across servers. That makes federation an operational change as much as a user-facing one.
First-order effects
- Independent operators can host Personal Data Servers for Bluesky accounts, though initial participation requires hostname registration through the AT Protocol PDS Admins Discord.
- Users gain a choice of data host without a stated change in the content they can access; Bluesky continues to run the network's main relay.
Second-order effects
- Hosting providers and community operators can begin testing AT Protocol server operations, while Bluesky must support a broader set of independently run data stores.
- The design puts pressure on federated-social comparisons to distinguish between portable data hosting and server-specific discovery or audience experiences; the recent Mastodon–Threads ActivityPub discussion makes that protocol competition more salient.
Third-order effects
- If third-party hosting becomes practical at scale, social networks can separate account-data custody from the shared indexing and discovery layer rather than treating each server as a self-contained social destination.
- That split could make protocol governance, relay operation, and moderation interoperability the key control points in federated social networking, even where users can move their data.
The trend: Federated social platforms are moving toward portable identity and data hosting while competing over who controls the shared discovery, moderation, and relay layers.