Post #3967328

2026-07-20 18:36 UTC

I have acquired opinions on #ActivityPub vs #ATProto in strong favor of ActivityPub. Basically for ATProto to work you need one big entity (called the relay) to sift through all updates published on all servers and provide that to users as their feed. It also provides search and so on. Nobody wants to run these relays since they're really resource-heavy and you don't get any money for running them so if you are a relay operator you can censor all you like because it's not like your users can leave. ActivityPub doesn't have this problem because it has instances which do the feed aggregation. Relays are just one big point of failure for ATProto and thus ATmosphere is not really decentralized.

Replies (2)

@silverpill@mitra.social 2026-07-20 19:08

@katzenmann@c3d2.social The best part is that we have relays too. They can even be big, like in ATProto world - but they are not indispensable, just additional services that improve discovery.

Open ##3967327
@baileytownsend@hachyderm.io 2026-07-20 19:27

@katzenmann@c3d2.social Hey! Been checking out #activitypub today, but I come from #atproto land. Relays have gotten pretty cheap to run now, thankfully. They used to keep a mirror of the whole network, but now only keep a couple of days. Can squeeze by with less than $40 on them nowadays, or even cheaper. https://whtwnd.com/bnewbold.net/3lo7a2a4qxg2l. We also have a bunch of community ran ones, a few listed at this beautiful URL lol https://compare.hose.cam. Relay's also don't directly do feed aggregation, but they do feed the feed with the posts. But that can also be swapped out between relay's or even something called JetStream, which is a diet relay. Feeds listen to this firehose and filter out posts on how it wants, like which content it wants to show. For instance, here's a feed URL for posts about cornbread lol https://api.graze.social/xrpc/app.bsky.feed.getFeedSkeleton?feed=at://did:plc:rnpkyqnmsw4ipey6eotbdnnf/app.bsky.feed.generator/Cornbread The feed just returns the at-uri's which can be used to hydrate the feed from getting posts from an AppView or connecting directly to the user's PDSs

Open ##4310339