ungualdoriane@post.lurk.org
Aug 20, 2026, 2:20 PMcan someone explain to me the "problems" that ATProtocol people tried to "solve" in comparison to ActivityPub like if i'm 12 years old
Replies
- ungualdoriane@post.lurk.orgAug 20, 2026, 2:37 PM
the "fediverse", the "atmosphere", ok baby have you ever went to the "parc" to "touch some grass" ? it's also social and local and interoperable (you can be there for walk, or party, or sport and still gossip with each others).
ok im being a cynical brat i know but i wanna understand why sometimes protocol battles matters and also who's winning by providing the most computationally-abstracted model of freedom lol and why it's not escapism through problem-solving instead of looking at stuff that always made community with actual human like idk situatedness and in-groups with shared values, exciting subcultures, gossiping and intimacy, trust over privacy, and most importantly where are the funny & cool people and all those bangers
- ungualdoriane@post.lurk.orgAug 20, 2026, 9:31 PM
@gwil i want you to girlsplain me every edgy opinions you have about this
Aug 20, 2026, 3:21 PM@doriane Two possible theories; only one is true.
Theory 1. ActivityPub has no "center"; each server handles only its own traffic. This means that if a startup wanted to start an ActivityPub startup, it cannot justify its own existence. Users could simply not use the startup's products, meaning you can't move from the "expand" to "cash in" phases. Forcing everything through the funnel of the relay makes the startup "necessary". You can only replace the startup with ops resources equal to it.
- Aug 20, 2026, 3:24 PM
@doriane Theory 2. Entire-network full text search. Ex-Twitter users expect this; in practice you cannot implement it with high quality user experience unless every "node" in your decentralized network has access to every message in the network. If this is a "must have", the rest of Bluesky's architecture (scrape PDSes->relay funnel->AppView) falls out naturally. The relay means every AppView sees everything that happens and can build its index accordingly
fedward :omya:fedward@distraction.partyAug 20, 2026, 3:53 PM@mcc @doriane I may be missing something but I don't think those two theories are mutually exclusive. If the path from expansion to profit extraction has to go through a single point for which there's no commercially viable competitor, then you kind of need both the unique protocol (so somebody else can't easily stand up a competitive service provider on "your" network) and the (perceived) competitive advantage (in this case, a "single" network with easier onboarding that also, coincidentally, offers functional indexing and search).- Aug 21, 2026, 2:56 PM
@fedward @doriane What I'd consider the synthesis theory:
Bluesky started as an attempt by Jack Dorsey to neutralize the Fediverse as a threat to Twitter.
Then it got handed off to some protocol designers who were earnestly thinking about free, decentralized networks, but sketching within Dorsey's lines.
Then it got handed off to this company of ex-Twitter engineers, who don't necessarily care about (and haven't been trying to preserve—features like DMs, bookmarks go around it) centralization
- Aug 21, 2026, 3:07 PM
…then this group of ex-Twitter engineers are trying to operate a website for this group of ex-Twitter users. And the ex-Twitter users may or may not care about *either* the things the things the decentralized-protocol designer cared about (which may not be the same *kind* of decentralization Mastodon users care about), *or* the things the ex-Twitter engineers care about (like garnering investment rounds and stock options).
And then to all this, you add "vibecoding".
- ungualdoriane@post.lurk.orgAug 20, 2026, 9:18 PM
@mcc oh so it's really like activitypub is a lot of little islands and well you can't see a faraway island from your island if you never went there and that's it that's the nature of knowing and not knowing
while atp is more a babel-tower/panopticon in the center of the islands and whenever you want to know if an island exist you ask mr. know-it-all the big source of truth, and all the islands must conform to effectively know everything otherwise they are bad islands?
is it an anarchist ideologies versus humanist ideologies type of situation?
- ungualdoriane@post.lurk.orgAug 20, 2026, 9:28 PM
@mcc if anyone else is reading this thread with my level of knowledge, PDS means Personal Data Server (took me 5 links with PDS used until i reached the acronynim unfolding), which is like when you copy the big index on your own server, like your island that's a copy of other islands?
also the thing that send all the synching data so that the PDS stay in synch (to be sure you have eyes everywhere) is called a "firehose" like big data pipelines?
- ungualdoriane@post.lurk.orgAug 20, 2026, 9:35 PM
@mcc is ATProtocol interoperability for people who believe in democracy and is the answer yes?
Aug 21, 2026, 9:31 AM- Aug 21, 2026, 3:33 PM
You can imagine that if this has happened to you multiple times— livejournal enshittified, twitter enshittified— you just kind of expect everything enshittifies, and instead of going "I want a site that will never enshittify on me!" you go "guess I'm switching sites every four years for the rest of my life. here's the new one. let's see how long this one lasts"
- Aug 21, 2026, 3:19 PM
PDS (all user posts are stored here. anyone can connect to a PDS endpoint and get a live feed of a user's posts. or a combined feed of all user's posts)
⬇️
Relay (connects to every PDS's combined feed. you can connect to an endpoint and get a giant combined combined feed)
⬇️
AppView (Connects to a relay. Puts every post in a big database.)
⬇️
Client (Web page or phone app that shows posts from an AppView)I'm happy to explain terms but ATP is so complicated, I can't fit it all in one pos
- Aug 21, 2026, 9:32 AM
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:35 AM
@Aedius @mcc like when a team of intellectual think they will do something for the good of humanity, a new form of utopia, the right model for knowledge, etc etc, but of course by doing so they end up not making space for difference, wilderness, contamination, and lowkey imposing stuff in the name of rational thinking or something because they way they did is "better"
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:38 AM
- Aug 21, 2026, 9:38 AM
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:41 AM
- Aug 21, 2026, 9:46 AM
Well it's a for profit corporation, not a non profit organization.
They want to finance the network with premium feature so they need to keep users in their net.
How do they sell premium feature if anyone can run an interoperable system for free with this feature ? They can't and they will close their api, like twitter did long before Musk.
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:50 AM
@Aedius @mcc for bluesky access sure, and i globally agree. but i think i understood you could make your own PDS with your own identity handlers things, and that people are making ATP communities that are entirely independent, but i must say i don't really get if there is any strong infrastructure dependencies between the two.
- Aug 21, 2026, 10:00 AM
Well their is blacksky https://en.wikipedia.org/wiki/Blacksky
That is interoperable but I dont know how far it goes and I read that it was hard and costly to keep up.
Eurosky ( mu.social ) is following the same path.
- Aug 21, 2026, 2:51 PM
@Aedius @doriane Yes, I use it. It is very nice. Except that notifications are partially broken, and the support folks are helpful but they can't fix the notifications issue, because I'm not using Bluesky PDS. Which is reasonable, but sort of pulls the decentralized thing into question.
And I wonder, as the Bluesky network gets larger and people start doing things other than posting microblogs on it, how hard or easy it will be for Blacksky and Eurosky to keep up with *literally all content*.
Oblomovoblomov@sociale.networkAug 22, 2026, 3:41 PM@mcc @Aedius @doriane OTOH, the Fediverse support for alternative forms of content is severely crippled by Mastodon's dominance (which is e.g. the reason why WordPress blogs when federating often prefer to use the Note object rather than the more appropriate Article object, or why Pixelfed publishes its images as Notes too, IIRC). Of course this could theoretically solved by more type-agnostic servers, but we still don't have them 8-(
- Aug 21, 2026, 3:39 PM
@doriane @Aedius A thing to remember about ATProto *enthusiasts*— as distinct from *people who are being paid by Bluesky*— is they're interested in a particular *kind* of openness. ATProto makes it very hard to reproduce the stack, where Mastodon makes it easy. But ATProto's super-fragmented design makes it easy to make add-on apps and tools, much easier than Mastodon. The enthusiasts are enthusiastic because ATProto lets them *do things* that they wouldn't be able to do without ATProto.
- Aug 21, 2026, 3:41 PM
@doriane @Aedius And I think they are fools, because their interoperability and communities are entirely dependent on Bluesky continuing to be nice and not (as Aedius brought up) closing their API like Twitter did, because bluesky pbllc has too much power in the governance model.
But maybe everything will turn out okay and bluesky pbllc will never go full evil and will continue providing infrastructure for free indefinitely. Maybe I will be wrong!
- Aug 21, 2026, 4:07 PM
Aug 22, 2026, 3:08 PM@mcc I expect them to run out of money before they have a chance to go full evil, but who knows!
https://stefanbohacek.online/@stefan/116697583448447818
It will definitely be interesting to see the impact of this when it happens.
Aug 20, 2026, 3:39 PM@doriane Someone else will have said this by now, but it does feel kinda like the primary motivation for ATProto (as deployed in BSky) is to offload a significant chunk of infra running costs whilst retaining control over the horizontal and the vertical. Being able to claim to be somehow (waves hands) "de-centralised" ends up as a side-effect. You actually want to run your own PDS? How convenient!
Aug 20, 2026, 3:49 PM@doriane the generous answer: data portability. it decouples user identity and user data from the service you use. it also (by virtue of only being theoretically decentralised, not actually) makes it so there's no upfront choice as to which server you're on, which eases the signup process for any particular service.
- ungualdoriane@post.lurk.orgAug 20, 2026, 9:03 PM
@v oh interesting i see! so instead of having an account on an instance of some fediverse server like i'm @doriane (in lurk), i can only have one atp id/account that's the same on bluesky and whatever other stuff and that's "me" like just doriane, then my content can be different per server, app, service whatver.
but then i guess the registry of those identity must follow some synching process through atp instances right that eventually converge or some shit? bc in fedi every instances will have a registry of their users, but atp is one big list of identities that propagate? (if at some point it actually decentralize yes)
- Oblomovoblomov@sociale.networkAug 21, 2026, 1:33 AM
@doriane @v the thing is, there have been Fediverse-adjacent platforms with protocol support for nomadic identities and content portability (most famously Hubzilla and the Zot labs projects that ultimately confluenced in (streams) https://codeberg.org/streams/streams) even before ATproto was developed. There are also FEPs to support portable objects and nomadic identities in ActivityPub directly (e.g. https://codeberg.org/fediverse/fep/src/branch/main/fep/ef61/fep-ef61.md) so that's not the reason for AT existence.
- Aug 21, 2026, 6:51 AM
@oblomov @doriane well okay, the reason for AT's existence is that there were a load of nerds that were really into decentralised system design and they got talking about how they'd like to design a system, and then they got some money from Twitter to do that as a job for a bit, and they had a good time reinventing everything, but Right this time.
(but mostly they were reinventing SSB, not AP)
- Aug 21, 2026, 6:46 AM
@doriane there's two identity systems - one that's backed by having a file on your web site, and one that's a central registry - you can use either. but it's a (cryptographically signed) pointer to a data store which is the canonical source of truth for your posts and profile and any other information you've generated. and then there are lots of relays/caches that propagate that out elsewhere to the actual services (which can listen to a subset of that data). and you can trust the relays because stuff is, again, signed.
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:03 AM
@v thanks for your very generous answers, it helps a lot to draw a mind pictures :))) but so the whole ATProto thing does rely on a central registry ok well that's a super big difference wow... where is that central registry that is the canonical source of truth and who owns it, is it the bluesky team? and when you say you can use either, that means i could make my PDS or instance of the ATProto and decide to not use the big central registry but have my own, but then i loose the nomadic/portable identity thing?
- Aug 21, 2026, 8:24 PM
@doriane mm, so. account identity comes in two forms: a domain or a "plc" address, which is a registry Bluesky is spinning off into an independent org. that then points to the PDS (the source of truth for account data), which is portable.
so you can set up your account with a did:web pointing at your domain, host your PDS yourself (which is not too hard to do), and then tell Bluesky to index your PDS. or you can stand up your own version of Bluesky and index every single user of the service. (yes, hosting your own version of Bluesky and ingesting every event that happens on Bluesky is complicated and expensive. but it is just about possible)
Aug 21, 2026, 1:00 PM@doriane wow looks like you may have had your fill of ‘splaining for today
Aug 22, 2026, 3:16 PM
Aug 20, 2026, 11:55 PM@doriane I hope @thisismissem answers this one :mochi002:
- ungualdoriane@post.lurk.orgAug 21, 2026, 9:44 AM
@liaizon @thisismissem hello! i would greatly appreciate too :) i heard there was a sex worker mastodon instance project that failed because of weakness in activity pub security and other stuffs (https://switter.at/). i see that Emelia you work on tech for sex worker, anything to do with ATProto linked to this? i'd love to learn how in certain social use case we need stuff from ATProto and where ActivityPub failed if that's the case. love
Emelia 👸🏻thisismissem@hachyderm.ioAug 21, 2026, 12:54 PM@doriane @liaizon I'd suggest re-reading switter.at's website since it clearly states what happened.
Yes, as an early moderator on switter.at, the Fediverse did not have appropriate tools to allow our community to co-exist. We got a lot of reports that were enabled by unsafe design and user behaviours.
That's how mastodon gained a lot of the tools in the moderator UI — we (primarily me) added them to be able to effectively moderate.
Aug 21, 2026, 3:51 AM@doriane hi. I'm an author and current editor of ActivityPub.
There's a good FAQ here:
https://atproto.com/guides/faq
Roughly:
- Data portability between instances
- Scalability for small instances
- Global view of content and people, such as search
- Data format
- Domain handles instead of email-like handles
- Algorithmic feeds- Aug 21, 2026, 3:54 AM
@doriane another is governance. Bluesky started as a project at Twitter to provide a backplane for federation between commercial social networks. They were going to spin out as an independent company that would provide that backplane as a service. Using an open protocol would defeat that business model, since the other networks could just interoperate without paying Bluesky. So, they built their own.
- Aug 21, 2026, 3:54 AM
@doriane Even though Bluesky is not that company any more, the protocol still meets those original design constraints.
- Aug 21, 2026, 4:09 AM
@doriane the original announcement of Bluesky by Jack Dorsey gives some idea of where they were heading.
- Aug 22, 2026, 3:12 PM
@doriane You already got some pretty insightful replies here, I would maybe just add, and feel free to call me cynical, but all (most of?) the problems ATProto solves can be solved within the fediverse.
Eg. account portability with https://swicg.github.io/activitypub-data-portability/lola, discoverability with https://www.fediscovery.org, etc.
To me, what ATProto *really* solves is: coopting a grassroots movement with crypto VC funding and vibecoding. That's it.
Kennykbruen@procial.tchncs.deAug 23, 2026, 8:33 PM@stefan@stefanbohacek.online @doriane@post.lurk.org I really hate posts like these.
Sure, ATProto's funding, governance, coding all suck. But this post makes improving ActivityPub hard, as it delegitimises any discussion about things AP could improve.
The account portability, as an example, is nowhere near what ATProto does and I don't count it as a solution. It requires the source server to be online and cooperating. Someone fucking up their server and not having a backup is out of luck, and so is anyone using Pixelfed (where people on the main instance can't migrate followers right now).
They can maybe be solved (even if they aren't now and the proposed solutions aren't good solutions), but this doesn't change that, right now, ATProto does some stuff better, and ActivityPub should strive to actually improve rather than going "lalalalala everything is perfect here actually".- Aug 23, 2026, 9:51 PM
Sorry, not sure where you're getting "everything is perfect here actually".
And yeah, nomadic identity and perfect account migration across all of the fediverse would be great, I would very much love that!
Alas, I don't have the time and expertise to help implement it, nor enough money to fund the necessary work, sorry.
- ungualdoriane@post.lurk.orgAug 23, 2026, 11:52 PM
@kbruen @stefan i'm sorry i asked in the initial post exactly with this intention: knowing not everything is perfect here and that they are other things. i know ActivityPub failed multiple social situations or movements. ATProto is more recent and they are enthusiast, so as a fediverse user i wanna understand the bigger picture!!! i also know a lot of people are going to give me their crispy hot takes opinions and tbh that's what i am asking for :)
for example thanks to your post i learned this thing about account migration in ActivityPub that the source server need to be online and cooperating, which i agree is big constraint and a difference worth noting, and exactly the type of answer i was looking for. thank youu
- Aug 23, 2026, 11:58 PM
@doriane Sure, but looking at https://www.da.vidbuchanan.co.uk/blog/adversarial-pds-migration.html, I am getting a sense that this is not perfect with ATProto either?
Yes, relays might have your public content, but now with Spaces and private data, I'm guessing that stuff won't show up in relays, since it's private. So how would that work, if your PDS goes down or goes rogue?
@kbruen@procial.tchncs.de