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

[mcc@mastodon.social]

@mattsheffield I do not think, in the context of the post you have made here, shatteredsky is "a PDS". I think we are using terminology differently and this is making it difficult for me to follow the conversation.

[mattsheffield@mastodon.social]

@mcc It is both a PDS and an app view. I'll be publishing a piece about this later today after getting more info. Nothing from Rudy though

[nicolas17@social.treehouse.systems]

@Bigshellevent @mcc Dorsey quit Bluesky in May 2024.

[ellyxir@humanwords.cc]

@mcc@mastodon.social amazing thread. so clear even explaining what you’re not clear about. but it does make me feel like it shouldn’t be this complicated. i haven’t looked at atproto but everything i read makes me not want to.

[mcc@mastodon.social]

@ellyxir I honestly don't think their architecture is very good

[mattsheffield@mastodon.social]

@mcc I filed my report.

Got quotes from Link and Bluesky about the federation situation and why Blacksky was affected. It was their use of Bluesky's appview (aka appserver) which forced them to be affected by Bluesky's moderation decisions.

It appears there are not any independent, full stack implementations of ATProto, but a company is trying to build a system to make appview deployment much easier: https://plus.flux.community/p/banning-controversy-reveals-blueskys

[jdp23@neuromatch.social]

@mcc mmmmkay it looks like Rudy is now in the process of "standing up an app.bsky.* API server" (aka appview) which "Is different from our community.blacksky.* API which is going on hold". So, my best guess is that his answer to you reflected the architecture (where the ommunity.blacksky,* API server is conceptually part of blacksky,.community) rather than the currently-available public implementation at the time.

(And no idea whether he's standing up an early implementation of their Rust appview or doing the off-the-shelf Bluesky appview or something else.)

[mcc@mastodon.social]

@jdp23 What's interesting to me here is, the bluesky line is "ha ha it's super good everyone is angry at us because it accelerates federation", but you're making it sound like Rudy is having to upend his software engineering schedule to do stuff he otherwise wouldn't have had to do at all early, because of this incident forcing him to protect his users

[adrienne@social.treehouse.systems]

@eniko @mcc if you're on your own PDS, you at least don't lose all your existing posts if bsky decides to permaban you. (If you're on one of their mushroom PDSes, they'll nuke all your content along with a permaban.)

[anna@hexile.witches.live]

@adrienne @eniko @mcc one thing i was never clear on, if you have your own pds and get permad, can you migrate and get around the perma, or is it some kind of cryptographic seed/hash of your pds data that's perma'd so you're fucked?

[by_caballero@mastodon.social]

@mcc @jdp23 here guys this might help clarify why Rudy has to rearrange his epics in jira:
https://whtwnd.com/bnewbold.net/3m2j6ccx2bs2t
moderation can only be additive until/unless you pony up the CSAM/hashmatch API key money plus roll and run yr own mod sys at scale. thats the real Achilles heel of composable moderation-- replacing the bottom layer is incredibly expensive

[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)

[mpjgregoire@cosocial.ca]

@mcc It's a damned shame that the Fediverse didn't succeed in keeping the Black developer community around.

[swetland@chaos.social]

@feld @aeva @mcc I think mastodon.social's chunk of the fedi network isn't anywhere near as large as the bsky operated service is relative to its network. And there's plenty of (mostly?) healthy skepticism about and pushback against "too-big" servers.

That does need to be tempered with the reality that tiny personal or community servers have issues too (time/money to operate, migration not being truly seamless -- can't take your identity or posts with you, what server is right for me?, etc)

[bitpickup@troet.cafe]

@mcc
@msh

In general, the bottleneck of social media is moderation. Big servers get that problem, a lot of small community servers don't. At the same time, that's when the resilience of decentralization really kicks in. By default the dominant idea of the internet and VC for the last 25 years is and was "big is beautiful" and the more followers I have the more important and valuable I am.

The fedi should and actually wants to be something different.

@swetland @gbargoud

[by_caballero@mastodon.social]

@jdp23 @mcc not adversary (directly), just forced to be less cooperative by being a US entity under meddling FCC and congress! I would also note that how bsky.app shows content to bsky users NOT applying their own blocklist/mod service is uncharted and unspecified territory. they never promised they even would and reserve the right to just not. its a hard problem! I refer to it as "federated moderation" and its totally fair they never even promised to try doing it

[by_caballero@mastodon.social]

@jdp23 @mcc also note: there is a weird migration corner-case where the "blob store" of high-activity/high-attachment-volume accounts seems to glitch out when people move between PDS implementations. fascinating from the POV of someone who's been studying migration corner-cases in both protocols for years 🤯
https://bsky.app/profile/matthewcort.land/post/3m2nvkpx5tc2d

[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!!