irelephant

There is a lot bluesky gets right, and a lot it gets wrong, the same is true with Activitypub.

(Some) strengths of Atproto

Atproto is content-addressed, and portable. This means that posts can exist independantly of their original server.
Instead of giving posts a https uri, which will stop working if a user moves servers or their server disappears, they give them at uris.
For example, this post on bsky.app: https://bsky.app/profile/ponder.ooo/post/3lk4yrmyugc2f
Has the at:// link is: at://did:plc:i4bfh2tyxihe2ksplmtcoopk/app.bsky.feed.post/3lk4yrmyugc2f.
The post does exist over https at https://porcini.us-east.host.bsky.network/xrpc/com.atproto.repo.getRecord?repo=did:plc:i4bfh2tyxihe2ksplmtcoopk&collection=app.bsky.feed.post&rkey=3lk4yrmyugc2f.

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Atproto is very easy to build apps on. For example, tangled.sh, frontpage.fyi and flushes.app are all apps built on atproto.
Atproto allows more flexibility in what an app can do, as opposed to lemmy or mastodon's api.

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Atproto is better documented. The ActivityPub spec leaves a lot up to the reader.

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Atproto has some really good moderation tools for users. People can make public blocklists of users, and people can subscribe to labellers, people or services which give users/posts a label.

Weaknesses of Atproto

almost everyone is on bluesky's PDSes. I thought mastodon.social and lemmy.world were bad, but the people on alternate PDSes altogether adds up to only a few thousand.

Its decentralised identifiers are actually completely centralised! DID:PLC, their DID method, originally stood for placeholder, but they renamed it to Public Ledger of Credentials.
To use it, you have to use plc.directory.
You can use a DID:WEB DID, but if your website linked to it goes down you lose your identity.
(I find it extremely funny that its not actually a requirement for a decentralised identifier to be decentralised. )

Everything on the network has to be public to work.
since relays have to be able to collect all the information on the network for Appviews to be able to make use of that information, anyone can find out who's blocking someone, or who is on a list, or who's following who, with no way of hiding that information.
Private accounts and posts are impossible to do on atproto.

Since everything is public, DMs (for now) are centralised. They do seem like they want to change that though.

Strengths of ActivityPub

AP (ActivityPub) is better distributed. While it has large servers (like mastodon.social or lemmy.world (and threads, but we don't talk about threads)) the majority of users are not on those servers. There is no single point of failure. If bluesky disappeared tomorrow, atproto would still exist, it would just have a negligable amount of users.

One node in the network lets you do everything, as opposed to bluesky which has three parts (You can do stuff without a relay though). This means you can trust a lot less of the network.

ActivityPub scales better than ATProto. Atproto scales quadratically, meaning that having a lot of nodes in the network harms performance.
AP scales horizontally, meaning it works better with a lot of small servers.

ActivityPub can keep stuff private, like blocks and posts.
Though, a lot of implementations can leak posts.

Weaknesses of ActivityPub

The spec leaves so much out. They didn't propose a way to make sure requests between servers are validated, so mastodon chose HTTP signatures.
They didn't add any way of looking up handles, so mastodon chose webfinger.

A posts's id is its https uri, this means thatif a server goes down, stuff can't be fetched. A user can't move their followers if their server goes down (you can on ATproto). There is a standard to fix this, FEP-ef61, but it breaks compatibility with a lot of implementations.

Missing information is a problem. Its not really a problem on lemmy, but on mastodon likes and replies from other servers may not make it to your server at all (you can fetch replies in newer versions of mastodon though).

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All this aside, I do think the two can coexist. I don't see anything like lemmy working on atproto. ActivityPub seems closer to social networking, as opposed to social media.
Something like facebook would be impossible to make on atproto, because not everything is made to be public.

I am hoping for a bridge, but good (bridgy is opt-in, making it useless).

Transcript

A picture of a person with their hand on their head and eyes closed, to imply a ear-ache. Next to it is a diagram of an ear with a part that looks like a snail highlighted in red, to imply the pain is coming from there. The person has text saying "Me (listening to the snail". The ear has text saying "Snail in my ear, telliing me what to do."

I see a lot of misinformation about bluesky here, so I want to address a lot of the talking points against atproto/bluesky.

This is partially inspired by accounts like mastodon migration and feditips being really annoying about bluesky.

How Bluesky Works

I see a lot of people misunderstanding how it works.
The network has three main parts:

1. A PDS -- This stands for Personal Data Server. These store information in records, like who you are following, your posts, who you are blocking and your images.
2. A relay -- These crawl PDSes and keep a copy of all the records on them. They give a "Firehose" of all the data on the network (that they crawled).
3. An AppView -- These index and work through the data from the firehose. All interactions are handled through these, meaning if someone follows me on bluesky, that app.bsky.graph.follow record will be crawled by the relay, and recieved by the AppView. https://bsky.app/ is an Appview. Appviews don't always have to use the relays, https://whtwnd.com/ connects to PDSes directly.

This is different to ActivityPub, where if I follow someone, my server sends that information directly to the other person's server.

Common misconceptions

An atproto relay is too expensive to run.

https://atproto.africa/ is a second full-network relay run by the blacksky team. We already have a second relay, and they're not even that expensive to run anymore, a lot of people run non-archival (meaning it doesn't backfill every post) relays for less than $40 a month.

There is no instances available except for bsky.social

bsky.social isn't actually an instance, its just the domain name assigned to users by default. This is explained here: https://app.wafrn.net/fediverse/post/f8fc8da8-cd7e-4fae-a895-ac59dc28088f

Wafrn has (opt-in) bluesky support, they act as a PDS and AppView, so if bluesky disappears tomorrow they can switch to the atproto.africa relay. (There is DID:PLC which is a problem, but I'll get to that later.)

You can't defederate bsky.social, this proves atproto is centralised!

https://app.wafrn.net/fediverse/post/f8fc8da8-cd7e-4fae-a895-ac59dc28088f also explains this, bsky.social is just the name assigned to users, each PDS has names like https://brittlegill.us-west.host.bsky.network/ (where my account is).

While you could ignore records from a specific PDS on the App layer, its pretty pointless, since atproto is portable/content addressed, meaning a user could seamlessly move to another PDS. (AP does support moving, but its pretty seamful.)

(While I was writing this someone posted a pretty good blogpost about this: https://blog.cyrneko.eu/there-is-no-bsky-social-instance)

Bluesky can censor people in turkey, this proves they're centralised!

Those posts weren't removed, people on third party bluesky apps in turkey could still see them.
People in Turkey are automatically subscribed to a Moderation Service which hides those posts, as the government requires it.
If a person unsubscribes, or uses a third party app/server the posts are still there.

Bluesky isn't decentralised as someone was banned for pointing out the head of T&S liked jailbait porn.

That person came back on a different PDS. They literally are still on bluesky because they joined a different server.

Bluesky went down due to a DDoS, this proves they are centralised!

The DDoS only crashed the Bluesky PDSes. People self hosting were fine.

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Wafrn

Wafrn is a federated tumblr alternative. It started off as a tumblr clone, the dev added AP support, and eventually, Atproto support.
Its a great example of how bluesky can be built on.
If bluesky disappeared tomorrow, Wafrn could switch relays to atproto.africa, and still interact with people on other PDSes.

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AppViewLite

appviewlite is a cool project I forgot to mention in the original post. It lets you self host an extremely lightweight Appview.
You can crawl PDSes yourself, eliminating the need for a relay.
https://github.com/alnkesq/AppViewLite

The main reason I made this post is because so many people are blindly anti-atproto, without fully understanding how it works and how it can be improved.

There is obviously problems with it, but it does a lot right. (There's a lot ActivityPub should do, like content addressing, DIDs and composable moderation).

I also think we could do with a better bridge. bridgy isn't really cutting it right now.

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Note on did:plc, its the only centralised part of the network as of now, its essentially the underlying ID every account has. It is possible to use a did:web id instead, which is tied to a website name.

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Transcript

A picture of a minecraft dog on a blue/purple background. It says "bedroom cup check! Do you have any cups or plates in your bedroom? take a moment to take them to the kitchen."

I've seen a lot of people say the piefed API is similar to the lemmy api.

Will it become more distinct as time goes on, or do you plan on keeping them similar?

Which version of the lemmy API is it similar to? v3 or v4?

I keep writing "much" as "mutch" for some reason.

I haven't really been following this closely anymore, but ryujinx, yuzu and a few of its forks have all stopped development, what still exists?