Comment by danabramov
Comment by danabramov a day ago
>What do you mean by this?
RSS is a way to aggregate data from many sites into one place. AT lets you do the same, but with bells and whistles (the data is signed and typed, and there's a realtime stream in addition to pulling on demand). If you're forced to describe AT via existing technologies, AT is basically like RSS for typed JSON in Git over HTTP or WebSockets that scales to millions of users.
It is completely up to you what you decide to index. If you want to build an app that listens to records of "Bluesky post" type that are created only by people you follow, you absolutely can.
See https://bsky.app/profile/why.bsky.team/post/3m2fjnh5hpc2f (which runs locally and indexes posts relevant to you) and https://reddwarf.whey.party/ (which doesn't have a database at all and pulls data from original servers on demand + using https://constellation.microcosm.blue/ for some queries).
The reason you don't see more of these is because an isolated experience is... well, isolated. So people are less interested in running something like this compared to, say, a whole new AT app. But AT can scale down to Mastodon-like use cases too.
>ATProto requires a giant indexing database that has access to every post in the network.
Only if you want to index every post, i.e. if you want to run a full-scale social app for millions of users. As an app builder, you get to choose what you index.
For a start, you probably only want to store the records relevant to your app. For example, I doubt that Tangled (https://tangled.org/), which is an AT app, has a database with every Bluesky post. That seems absurd because Tangled is focused on a completely different use case — a social layer around Git. So Tangled only indexes records like "Tangled repo", "Tangled follow", "Tangled star", and so on.
Naturally, Tangled wants to index all posts related to Tangled — that's just how apps work. If you wanted to build a centralized app, you'd also want it to contain the whole database of what you want the app to show. This isn't specific to AT, that's just common sense—to be able to show every possible post on demand with aggregated information (such as like counts), you have to index that information, hit someone else's index, or fetch posts from the source (but then you won't know the aggregated like counts).
That said — if you want to build a copy of a specific app (like Bluesky) but filtered down to just the people you follow (with no global search, algorithmic feeds, etc), you absolutely can, as I've linked earlier. Or you can build something hybrid relying on global caches, or some other subset of the network (say, last 2 weeks of posts). How you do indexing is up to you. You're the developer here.
This would make sense if there weren't so many features—like Blocks, DMs, followers-only posts, etc—that were reliant on the AppView enforcing a single global view of the world. I agree that I do think the AT model does have good properties but right now too much of it is reliant on this single shared global app view
But thanks for the link to Konbini! That looks really exciting and promising and I would love to start using it if I can run it completely decoupled from Bluesky infrastructure.