I would like to give an update on "federation" on Bluesky

[jdp23@neuromatch.social]

@mcc yeah have a look at Rudy's thread there, he makes that very clear. And similarly Northsky is saying well, our original plan was do PDS as Phase 1, Relay as Phase 2, and AppView as Phase 3, but now we're acceslerating Relay and AppView up and treating it all as Phase 1. My take is that everybody always took the approach of treating Bluesky PBC as a potential adversary but didn't expect them to be this adversarialy this quickly.

(If this is all an N-dimensional chess play to blow up the company to speed up the decentralization ... well as shitposting goes, that's pretty darned epic. But it's probably just horrbile comms accelerating and magnifying the tensions that were always inherent. Time will tell I guess.)

@by_caballero it's true that's a huge hole in the composable moderation model (and Rudy and others had been looking at it even before this -- https://discourse.atprotocol.community/t/how-should-we-fairly-split-the-costs-of-commons-moderation-across-producer-and-consumer-apps/122 is interesting thinking from the Eurosky perspective although doesn't yet point to any conclusions). But for this particular case they just need an appeal method for community members that allows themm to override the Bluesky mod service's app-level takedowns in their own AppView. On the deeper issue though I feel pretty vindicated because I've always said that composable moderation is interesting and valuable in some important use cases but doesn't actually solve the moderation scalability issue.

[thisismissem@hachyderm.io]

@anna @adrienne @eniko @mcc all the records in your PDS contain references to your identity (DID document), it's theoretically possible to modify the data to change that but requires rewriting your entire PDS for that account, so not particularly practical.

It's the DID that is moderated against in the higher layers, not your handle.

So it doesn't matter if you're @fred.example or @jason.example, if the DID used for one becomes the DID used for another handle.

It's kinda like how on ActivityPub, software has often encoded your username into the identifier for all your posts, meaning you can't change it without breaking everything.

(Though Mastodon is starting to fix this long-standing issue, there's fix only applies on new accounts, there's no protocol level way to fix it yet — it's kinda a weakness in JSON-LD)

[mcc@mastodon.social]

Follow up, 2025-12-27: Rudy here confirms the Blacksky appview is still being worked on (eg: blacksky uses bluesky's appview still)

https://bsky.app/profile/rude1.blacksky.team/post/3maykethsbk24

The sticking point, as he describes it, is "backfill". This alludes to the issue that makes me compare ATProto to blockchain: to get the features users expect, every node on the network must mirror the network's entire history. This is impractical, which is why bluesky is as of this moment a federated network with effectively only one node.

[emaytch@mastodon.social]

@mcc its really weird for it to be controversial to compare ATProto to blockchain when it was an explicit selling point of the protocol before blockchains became embarrassing to develop for!!

[whitequark@mastodon.social]

@mcc it's such a confusing aspect of the protocol. why does everything need the firehose? how do they expect it to scale/?

[mcc@mastodon.social]

@whitequark If hypothetically, just hypothetically, we imagine that a core design requirement of the protocol was "regardless of what happens in future, it must continue to be necessary that the company Bluesky LLC exists"… the decision becomes a lot less confusing.

[mcc@mastodon.social]

@whitequark (More charitably: If one considered fast, full-text search to be a highest priority feature, and it was merely *unimportant* to the designer whether a second full-service node could ever function… then one might make the decisions bluesky made here.

As for scaling, I assume when the day comes they need it to actually scale they'll either discontinue or break the externally-published linear event stream?)

[mcc@mastodon.social]

:frogsiren: BLUESKY HAS OFFICIALLY NETSPLIT :frogsiren:

There has always been more than one Fediverse. Different instances make different moderation decisions so some instances can't see posts by some users.

There has only ever been one Bluesky because every ATProto frontend uses the same Appview.

It is January 2026 and that's no longer true; Blacksky's Appview is available for beta use and there is at least 1 user banned on Bluesky but not Blacksky. And vice versa.

https://bsky.app/profile/did:plc:w4xbfzo7kqfes5zb7r6qv3rw/post/3mcozwdhjos2b

[mayintoronto@beige.party]

@mcc Would this mean that there'd be a new bridgy specifically to Blacksky?

[quillmatiq@mastodon.social]

@mayintoronto No - Bridgy Fed supports any ATProto PDS, including the ones run by Blacksky

@mcc

[coracinho@sunbeam.city]

@mcc for us tech noobies in the audience, could you explain what does this mean?

[mcc@mastodon.social]

The "portable identity" elements of Bluesky/ATProto make the netsplit just a tad odd. My account is hosted on a PDS server I run, so I'm beholden to no frontend. If I log in through the main Blacksky frontend (Bluesky appview) one user I'm following shows only an error message. Via the Staging Blacksky frontend (atproto.africa), I can see I'm following him and see his posts. I'm SO curious about the edge cases. I assume if I boost him it's hidden from the Bluesky appview. What if I reply to him?

[fabrice@fosstodon.org]

@mcc When you are suspended by bluesky corp, is the ban at the app view or PDS level?

[martinvermeer@fediscience.org]

@quillmatiq @mayintoronto @mcc But what if I want to cancel the bridge, but only to the Nazi one? Can I do that, and advise my correspondents to migrate to BlackSky? How hard would that be?

[quillmatiq@mastodon.social]

@martinvermeer Not today, but stay tuned for next week 🙂

@mayintoronto @mcc

[mcc@mastodon.social]

Oh and I can't get staging.blacksky on my phone app. So imagine if you were using Mastodon, but you saw a slightly different list of posters, *and potentially a different set of your own posts*, depending on whether you were using your PC or your phone. This is great if there's a banned user you want to follow— you get an *option* to follow them. Mastodon.social can deny me the *option* to follow someone, on Fediverse. But except in this edge case that *might* not be a fantastic user experience!

[mcc@mastodon.social]

@coracinho Does this help? https://mastodon.social/@mcc/115918101156654032

[mcc@mastodon.social]

@fabrice This is a VERY interesting question, as the answer appears to be "all of them". And when Link got banned, *that answer appeared to be surprising even to Bluesky employees*. The original messaging from Bluesky suggested you'd get banned only by the "labeler"— a third thing altogether. But there's obvious problems with that answer, it's never what Bluesky implemented. After Link got banned Bluesky said they were reviewing this, but I don't think *changed* anything.

[mcc@mastodon.social]

Oh, and let's consider, for a moment, the downsides of an individual user being able to "opt out" of moderation decisions. The problem with misbehavior on social media is force multipliers. One person harassing you is no problem; one person and their 3000 friends is a big problem. Imagine Bluesky and Blacksky ban user X but Trumpsky lets X keep posting. Now their 3000 friends— still in Bluesky's good graces— can see their posts calling to harass you, AND can zero-friction zip over to yell at you

[ratsnakegames@mastodon.social]

@mcc is

is Trumpsky a real thing