"Decentralization" and erasure: Blacksky, Bluesky, and the ATmosphere

Part 3 of I for one welcome Bluesky, the ATmosphere, BTS ARMY, millions of Brazilians, Black Twitter, and sex worker Twitter to the fediverses. Originally written December 2024, epilogue added August 2025.

"As Black users, aka Black Twitter, flee X in unprecedented numbers, a grassroots developer is building what many see as the future of Black social media culture. His platform, Blacksky, gained over 750,000 users in months without venture funding or promotion, operating as an open-source project on the decentralized Bluesky social network."

– Tarik Moody, Could Blacksky emerge as Black Twitter’s spiritual successor on Bluesky?

In the original version of the first post in this series, I said I thought it was obvious that Bluesky and the ATmosphere are decentralized. Okay, fine, it clearly isn't obvious; I was wrong about that part! See the Appendix for a partial list of some of the dozens of interesting perspectives on whether or not the Bluesky social network and the broader ATmosphere (an ecosystem of services and apps built on top of Blueskys Autenticated Transfer Protocol, aka AT Proto).

That said, my conclusion hasn't changed. I still see Bluesky and the ATmosphere as clearly decentralized.

Rudy Fraser's Blacksky, for example, runs three feed generators, a moderation service, and a work-in-progress personal data store (PDS), and is considering implementing their own relay as well. And as Moody notes, the vision for Blacksky "extends beyond any single platform":

"Fraser envisions Blacksky’s open-source technology, as enabling other marginalized communities to build safe spaces online. Already, he’s hosting other communities on Blacksky’s infrastructure while letting them maintain their distinct identities.

“Every time the culture moves to a new app, there’s a Black Twitter, there’s Black TikTok, a Black People Reddit section,” Fraser notes. “What if you keep your community and the interface changes?”"

That sounds pretty darn decentralized to me!

Blacksky is an independent project.
Please join me in supporting them!

It's true that Blacksky also currently relies on some of Bluesky's services. As of December 2024, Bluesky currently runs the only network-wide Relay and the PDSs and AppViews used by 99%+ of the people in the ATmosphere; Bluesky also controls the identity provider, the protocol, and the official Bluesky software When Bluesky's Relay was down for a few hours last week, so was Blacksky (and almost everything in the ATmosphere).

Then again, Blacksky's already building their own PDS; once it's available, people will be able to store their data on a server not under Bluesky's control – and will be able to have an *.blacksky.app handle.

Update, September 2025: Blacksky PDS blacksky.app and hundreds of accounts are now hosted there (including my new primary account at @jdp23.blackcomra.de). The blacksky.community app uses the Blacksky moderation service and has the Blacksky: Trending as the feed for new users (which in turn leverages atproto.africa 🌍, which launched in May and Rudy accurately described as "One of (if not Thee 1st) from-scratch, full-network relays"). That sure looks decentralized about me.

In Fraser's December 2024 roadmap he talked about possibly doing their own Relay. As Isaiah Thompson notes in Building #Blacksky

"Part of the vision, too, for Blacksky is to become resilient enough to eventually live on its own servers—literally and otherwise."

If the Bluesky Relay and Appview went away (or put in unacceptable new policies), Blacksky could almost certainly get their own up and running – by themselves, or working with some of the communities Fraser is already hosting.

Update, March 2025: Fraser talks more about building "our own independent implementation of Bluesky's underlying technology" and the goal of "trying to create a home for Black users on the network that is safe and self-governable and self-sovereign" and in the TechPolicy.Press Podcast with Justin Hendrix. Blacksky's also working on Cypher, an Appview, with "local-only posts"

So while I agree that today's actually-existing Bluesky and ATmosphere are still largely centralized in some important ways, and that the combination of AT's architecture and Bluesky's initial dominance could well lead to de-facto centralization, my perspective is that focusing only on that ignores the ways that they already are meaningfully decentralized.

Your mileage may vary of course. "Decentralization" means different things to different people, and as Tolulope Oshinowo et al point out in Seeing the Politics of Decentralized Social Media Protocols, different protocols interpret "decentralization" in different ways. As the links in the Appendix highlight, people who are focusing on the (very real) concentration of power in the ATmosphere today, or the potentially-centralizing architecture of AT, find it more useful to describe Bluesky as centralized.

Blacksky has been erased from discussions of Bluesky's decentralization

Regardless of the conclusions people reach, though, what's especially interesting to me is that as far as I can tell, nobody else in the discussion is talking about Blacksky as an actually-existing example of decentralization. What's with that?

The erasure of Blacksky from this discussion is particularly striking because so many people writing about this talk about a goal of decentralization is to create a more equitable distribution of power. Hey wait a second, that's what Blacksky is actually doing! And you don't just take my word for it. Here's what Fraser says in Blacksky: Expressing the Black Everyday in a New Digital Space (Part 3)

"The power in the protocol is that other people (in this case people who aren't me) will be able to build job boards, dating apps, and video streaming(?) social apps and Blacksky will work across all of them on the same infrastructure.

To put it plainly, it will be someone else's job to come up with the next TikTok, the next Reddit, or the next LinkedIn. My only job will be to integrate it into Blacksky (which should be easy) and amplify, protect, and moderate Black content no matter where it is on the network....

Tools like Bluesky and AT Protocol have their own tradeoffs and considerations (what @ntnsndr.in describes as "implicit feudalism" for one) but personally my belief in self-determination extends to my technology use and development. And the opportunity to build out an extensible Black social network that can be controlled by community instead of corporations, that doesn't require being segregated from the broader social space, and reflects the many aspects of the diaspora (not just whatever is trendy at the time or what a corporation is pushing on me) is too important to pass up."

But no. Instead, all the discussions of power distributions are in a deracialized context. Watch whiteness write.

Pay attention, dammit!

"Seize this new technology, all the new technology. Deal with it! ‘Cause we’re not gonna unknow anything anyway. And make that technology act in a desired manner as both a tool and a weapon."

Sister Elaine Brown, quoted in Rudy Fraser's Blacksky: Expressing the Black Everyday in a New Digital Space (Part 3)

"[A]s Blacksky highlights, Bluesky and that ATmosphere are developing new organizations for strong communities and how they interact, complementing the Fediverse's instance-oriented structure. These aren't (yet) as place-oriented as Fediverse instances but it's still useful to think of them as part of the Social Archipelagos ... and new topologies may well emerge.

– me, in From the Fediverse to fediverses, communities, and Social Archipelagos

A lot of the pushback to the idea that Bluesky is decentralized has come from people comparing it to the ActivityPub-based Fediverse. And don't get me wrong: many of the concerns people bring up are worth paying attention to. Bluesky currently dominates the ATmosphere far more than any single entity dominates today's ActivityPub Fediverse. Even if that changes, the AT ecosystem could wind up resembling the web, where Google, Microsoft, and a few other search engines largely control visibility; or email, where Google, Microsoft, and a few other email providers host 95% of personal email accounts. AT Proto is an all-public architecture that's optimized for surveillance capitalism, and includes several choke points that are likely to lead to centralization. And there are plenty of other ways in which Bluesky is problematic as well.

Still, whether or not you're just focusing on decentralization, dismissing Bluesky without even considering Blacksky isn't just erasure, it's also missing out on something very important. Especially for people in and the ActivityPub Fediverse – with its long history of whiteness, anti-Blackness, and misogynoir – there's a lot to learn here. More positively, the ActivityPub Fediverse's focus on scoped-visibility complements Bluesky's panoptic all-public architecture, so there's a lot of opportunity for hybrids that combine the Fediverse model of smaller networked communities with Blacksky's innovative approach to community in Bluesky/AT Proto's "big world" flat networks.

But it's really hard to learn from Blacksky if you're pretending it doesn't exist.

So please stop doing that.

And please don't just learn from Blacksky.
Please also support Blacksky!

For more on Blacksky, here's Rudy Fraser's Tech Talk – good stuff!

Speaking of erasure ...

At least Blacksky is getting attention in the broader conversation about Bluesky, and Fraser's work is justifiably being credited as playing a huge role in leading to so much of Black Twitter moving to Bluesky. But even though Fraser deserves all the credit in the world for this, he's not the only one who deserves all the credit in the world.

Work by Aveta (aka @aliafonsy.bsky.social) – including their original Black Tech Twitter follow thread as well as inviting so many key Black tweeters to Bluesky in early 2023, and then speaking out strongly against the anti-Blackness on Bluesky – also provided a critical foundation for Black Twitter's move to Bluesky. And unsurprisingly, Aveta has been almost completely erased from the broader narrative. In fact, as far as I know, Bluesky hasn't ever even apologized to Aveta for the shitty stuff that happeend back then – let alone credited these contributions or looked for ways to help get compensation for Aveta and others for all the unpaid work they did to make Bluesky succesful.

What's with that?

Yeah, I know this might seem like a digression from the discussion of decentralization. But it certainly relates to discussions of equitable distribution of power on social networks, and that's what decentralization's supposedly about. Also, there's certainly a parallel between how Blacksky has been erased from discussions of decentralization and how Aveta's been eraased from the broader narrative. And since I mentioned the ActivityPub Fediverse in the previous section, there's also a parallel to how Marcia X's contributions with #Fediblock aren't generally acknolwedged. So maybe it's not really that much of a digression after all?

Epilogue-in-progress: nine months later ...

Parts of this were also published separately, in slightly different form, as Can we please stop arguing about whether Bluesky is decentralized?

"Whatever one thinks of Bluesky, *the* most innovative cultural and technical experimental space there right now is Blacksky; *and* it’s also the clearest example of decentralized possibility on the AT protocol. When people double down saying “AT isn’t decentralized”, they are denying that Blacksky exists."

– inquiline, in a thread on assemblag.es discussing the "long history of Black inventors' ingenuity being denied at a systemic level"

Blacksky has continued to progress by leaps and bounds in the months since I first wrote this article.

• Over the last few weeks hundreds of people have moved their accounts to the new blacksky.app PDS – including me!
• There's an early version of their app at blacksky.community (with Blacksky: Trending as the feed for new users instead of Bluesky's crappy Discover feed)
• The Blacksky Moderation service uses the relay at atproto.africa
• There's also a gorgeous Blacksky Algorithms website at blacksky.xyz.

Rudy Fraser's recent 🔭🖤🚀 Social media’s next evolution: decentralized, open-source, and scalable on New Public (with Josh Kramer), podcast with TechDirt founder (and Bluesky board member) Mike Masnick, and Infrastructure for Interdependence: Building technology in service of collective power are good late-August 2024 overviews.

Other ATmosphere projects are making great progress too, with Spark in Brazil also implementing its own complete stack, Northsky in focusing on the 2SLGBTQIA2S+ community, Gander (also in Canada) planning on launching this fall, there's a lot of energy behind Eurosky, and far too many other interesting things to list here. The ATmosphere developer ecosystem is thriving with a lot of collaboration and synergies, and Blacksky's trailblazing is helping everybody.

• dapurplesharpie's excellent short video demos how to use indepented Bailey Townsend's PDS Moover to migrate accounts to blacksky.app, and Clinton Bowen's also-excellent short video demos how to use Blacksky's Tektite migrator. Northsky's PDS migration can build on both of those.
• Blacksky can and does making different blocking decisions than Bluesky, which is hugely valuable to people like international humanitarian aid worker in the Balkans who couldn't get to their DMs because Bluesky thought they were in the United Kingdom (which like Mississippi has an age verification law).

So while Bluesky is still largely centralized in some important ways (99%+ of users are still on Bluesky infrastructure and most of them don't have backups, Bluesky still controls the PLC directory that most ATmosphere software depends on and the magic "rotation keys" ) it sure seems to me that's in the process of changing.

But as for the discourse about whether or not Bluesky is decentralized ... well, when it flared again in response to Bluesky's mid-August decision to block Mississippi and Blacksy's announcment that they weren't going to block Mississippi ... and guess what?

It was the same f—ing discourse.

People continue to focus on different aspects of decentralization. People who saw Bluesky as centralized nine months ago still see it as centralized. Mastodon founder Eugen Rochko's post "And this is why real decentralization matters" and the discussion thread, is one example. There were plenty of others as well – enough that I wound up doing a post Can we please stop arguing about whether Bluesky is decentralized?

It's all so unnecessary! The Statement on discourse about ActivityPub and AT Protocol organized by Emelia Smith and signed by many of her SWICG colleagues as well as Bluesky engineers and fediverse and ATmosphere developers, was a call to cool down the discourse.

"There does not have to be a “winning” protocol. We do not build a better open social web for everyone by fighting and arguing about protocol superiority.... There has already been cross-pollination of ideas between the people working on ActivityPub and AT Protocol."

As I said in a comment of on the statement.

"It's a great point about the cross-fertilization between the ecosystems (Blacksky's approach to private data is another example, building on the local-only posts pioneered by Glitch and Hometown and now adopted widely in fedi). And it's certainly true (and very under-appreciated) that ActivityPub is much richer and more flexible than is reflected in current implementations. Similarly, a lot of experimentation in the ATmosphere highlights that current implementations are only scratching the surface of what's possible. So there are likely to be even more opportunities for mutual learning going forward.

But the toxicity of the current protocol discourse on the ActivityPub side really interferes with the synergies and potential learning in both directions."

Of course not everybody agrees. Evan Prodromou of the Social Web Foundation, the so-called "father of the Fediverse", objected to the statement, arguing that "Competing protocols are not good for the space. They divide the community and prevent reaching critical mass." Sigh.

And it's especially frustrating (and sadly in keeping with Mastodon and the Fediverse's long history of anti-Blackness) that Blacksky continues to be erased so frequently – like one well-known fediverse influencer's post claim that "Communities built around interests are something #Twitter never offered, and #Bluesky still doesn’t. Blacksky begs to differ!

Even when Blacksky is acknowledged its importance is often dismissed. Sometimes its with variants of "yeah but other than Blacksky....". Sometimes it's because the numbers are still relatively small. Sometimes by people with career and emotional attachments to the ActivityPub protocol that powers Mastodon and today's Fediverse.

Sigh.

In terms of the decentralization debate, I get it that everybody has their own definition of decentralization. Still, at this point

• Blacksky is running its own PDS, feeds, moderation service, relay, and app – and on track for developing the rest of its tech stack.
• Blacksky made a different decision than Bluesky about whether to block Mississippi
• Bluesky users can use Blacksky's labelers and feeds, interact with blacksky.app users – and use blacksky.community to access their DMs even if Bluesky has blocked them from DM access.

So if you are picking one that ignores or minimizes all these very real and important aspects of decentralization, it's worth thinking about expanding your definition).

Whatever your definition of decentralization is, though ...

Please stop erasing Blacksky.

Appendix: links on Bluesky and decentralization that are worth reading even though they don't mention Blacksky

If you're interested in decentralized social networks, there's a lot to learn from various perspectives on Bluesky and decentralization. Alexia's Bluesky, and what Bluesky is not is a good introduction to Bluesky's approach and how it contrasts with ActivityPub. Laurens Hof's A conceptual model of ATProto and ActivityPub and Bluesky, decentralisation, and the distribution of power are two other good fairly-recent overviews.

Christine Lemmer-Webber's How decentralized is Bluesky really? and Bluesky engineer Bryan Newbold's Reply on Bluesky and Decentralization, and Lemmer-Webber's Re: Re: Bluesky and Decentralization are deeper dives on some of the key issues. Both agree that Bluesky's focus on "credible exit" is worthwhile, and highlight the difference between AT Proto's "shared heap" approach and the message-passing architecture of ActivityPub, XMPP, and email. However, they disagree on a lot of other topics, starting with the definition of "decentralization."

Newbold uses Mark Nottingham's definitinn in RFC 9518: Centralization, Decentralization, and Internet Standards (which in turn is based on Paul Baran's 1964 definition in "On Distributed Communications: I. Introduction to Distributed Communication Networks)

[Decentralization is when] "complete reliance upon a single point is not always required"

Lemmer-Webber views this definition as too weak ("decentralization washing"), and suggests that contemporary nomenclature positions "centralized" and "decentralized" as polar ends of a spectrum (in contrast with Baran's terminology, which positioned "centralized" and "distributed" at the ends). Accordingly, Lemmer-Webber's definition is

Decentralization is the result of a system that diffuses power throughout its structure, so that no node holds particular power at the center.

Lemmer-Webber and Newbold also discuss the natural centralizing tendency of search engines in big-world public networks. Even if alternative whole-network Relays do emerge, will the costs and liability of running one be so high that only a few large companies can afford to do so? As the email and XMPP examples highlight, this kind of near-total capture by a few entities is a risk of any decentralized protocol (see for example Embrace, Extend, and Exploit: Meta’s plan for ActivityPub, Mastodon and the Fediverse), so now's certainly a good time to be discussing how this applies to AT!

And those articles are only the tip of the iceberg.

Other perspectives arguing that Bluesky isn't really decentralized include

• Michał "rysiek" Woźniak's April 2023 BlueSky is cosplaying decentralization describes Bluesky as “ostensibly decentralized.” This was written in April 2023, before Blacksky existed, so gets a pass on the erasure front ... and even though s lot has changed since it was written, it's still worth reading!
• jonny (good kind) talks about the "mirage of decentralization in atproto", noting that "i am not concerned with decentralization for decentralization's sake, as a technological fetish, but the implications on the social, political, and economic structure of the system - specifically its capacity to be turned into an extractive chokepoint by those that control the center (the relay)," and has written that AT's relay system is "decentralized in the same sense as google alerts is decentralized"
• Possibly a Dog, in a thread that led to discussion on Hacker News, says "It's not decentralized. #BlueSky is a centralized corporate app, running a theoretically-decentralized network protocol that currently has only one (1) active node on the network: BlueSky."
• Oblomov's A credible threat to (and from) commercial social network silos/2 suggests that "the purported decentralization theoretically made possible by ATproto is largely performative"
• EFF's What You Should Know When Joining Bluesky states "the current Bluesky network is not decentralized," and suggests that even once "credible exit" is possible it still "falls short of the distributed power and decision making of decentralized networks."
• Mike Sass' Cloudy with a chance of not enshittifying says "I’ll say that Bluesky is in no meaningful way decentralized at the moment.... But can Bluesky be decentralized? This is up for debate it seems."

Then again, others argue that Bluesky and AT are decentralized.

• The Related Work sections of Bluesky and the AT Protocol: Usable Decentralized Social Media (and Jay Graber's the earlier 2021 Ecosystem Overview) sites AT and Bluesky in the context of other decentralized social networking technologies.
• In Decentralization or Noncentralization, Bluesky or the Fediverse?, Robert Gehl (author of the upcoming Move Slowly and Build Bridges, a book about the fediverse) argues that "Bluesky has started out centralized and is slowly spinning out parts of itself from the center to the edges," so is decentralized in the sense of de-centering (as opposed to the ActivityPub Fediverse which is non-centralized)
• Kye Fox' Nobody cares about decentralization until they do makes the case that "most people don't care about decentralization now. When they do, more will be happy with the recovery paths available if they choose a platform on the AT protocol."
• In Decentralisation, Michael Exon suggests that "By delegating control over labellers to independent communities, BlueSky has taken the most important step towards decentralisation in a political sense."

And in Hacker News, pxoe suggests it's actually Mastodon that isn't decentralized, a position Chris Hornberger also took in Mastodon isn’t ‘decentralized’ and won’t be the next big thing (2023) and I've heard similar points from more than one peer-to-peer network advocate in the past.

Power in the ActivityPub Fediverse has historically been somewhat centralized as well; Mastodon gGmbH (which controls the code base adn the mobile apps as running mastodon.social, historically by far the largest instance in the Fediverse) and the W3C SWICG (which controls the spec) together had enough power that they brought innovation to a crawl from 2018-2022 are are still major barriers to progress. As Hrefna points out, noting that users have very few remediations if the admin of mastodon.social goes to war with them,

"[W]hile in _theory_ ActivityPub is decentralized, in _practice_ the predominant system for this is _not_ decentralized as far as your median user is concerned."

Using Lemmer-Webber's definition, it seems to me that they both have "particular power" at the center of the network that isn't diffused. So does that mean that the ActivityPub Fediverse isn't decentralized? I'd still say that it is, although not completely ... but your mileage may vary.

So it's all messy and confusing. Welcome to the fediverses.

But as interesting as all these articles are, what's even more interesting to me is that none of them talk about Blacksky. Funny how that works!

Update log

Ongoing: minor fixes (typos, wording changes) and additional links

December 2: originally published

December 15-16: updated to reflect Lemmer-Webber's Re: Re: Bluesky and Decentralization

March 3, 2025: add update from TechPolicy podcast

July 8: add updates and links to Blacksky's Relay and AppView, and the Politics of Protocols draft. Also worth mentioning (although not yet sure where to put it): after a successful crowdfunding campaign, Blacksky is beginning development on an app as well.

August 28: start adding new epilogue-in-progress