Some reasons:

1. AP federation is basically broken: if your instance has not yet interacted with another one and you want to see the profile of a user you will never see his old posts but you will only receive new ones in the future if you click โ€œfollowโ€. The counters like followers, likes and boosts are different depending on how your instance is connected to the others.



With ActivityPub the information hardly spreads, with Matrix you have the assured consistency because Matrix is basically a decentralized database for real-time content.

2. Access Control Lists, they are not supported by ActivityPub so no stuff like private groups. When it comes to Matrix,they are built-in.

3. Matrix defines APIs for both server-to-server federation and client-server communication, while ActivityPub is currently only used for federation.



Client-server ActivityPub APIs have been discarded in favor of thin-client APIs such as Mastodonโ€™s.

4. Matrix specs continually add new features. ActivityPub is stopped and too generic, it could be expanded in many ways for different use cases but each group of people works on it separately and for now without big results (see ForgeFed).

So AP is good only for PUBLIC content and the final user experience with federation is a mess.


@alexl i still have the feeling that matrix and activitypub have different use cases. matrix has much more functionality, while AP is rather simple. i'd argue that AP is more like RSS and less than a chat protocol :) i also think that it is better to reuse existing stuff by bridging, that way everyone can use what he likes!



Nobody is prevented from implementing a social network where the servers federate using Matrix and also implement AP-S2S to also keep federating with Mastodon&Co ๐Ÿ˜‰

Matrix is not a chat protocol: it's a decentralized database where real-time information streams can be organized in arbitrary hierarchies, with decentralized Access Control Lists and End2End encryption built-it.

See: fosdem.org/2021/schedule/event

ยท ยท Husky ยท 2 ยท 1 ยท 2

@alexl i know about the matrix protocol, i think what i meant is that they set out to build a chat protocol :)

i'd maybe build a "social network" frontend for matrix and bridge the server with AP?


Yes, there are some experiments with social networks built on Matrix:

hummingbard.com (this has a very cool arbitrary (sub)-groups, like hummingbard.com/music/classica )

cerulean.matrix.org (this is an experiment by the developers of Matrix themselves)

@alexl ah, i didn't know of them.. i'm a big matrix proponent, but a bit out of the loop currently :)


No problem, this is new stuff and I have only recently known it too ๐Ÿ˜‰

My poll serves to demonstrate two things:

1. The federation in AP is a lie because depending on the instance you are in you will see different results in the poll

2. Most of the users here still don't know the potential of Matrix


1. i wouldn't call it a lie, but it is "best effort" but things can get lost kind of easy. that's what i mean by different scopes of the protocols, i'm not sure if a social media protocol has to have the same guarantees as matrix if it makes implementation much easier.

2. ๐Ÿ’ฏ though we really need custom emojis in matrix :ablobblewobble:


1. Users expect social networks to support private stuff, AP is best suited to federate the public articles on websites and their comments, but very few use it for that... (there is a very basic plugin for WordPress and Ghost may implement AP in the future)

2. Custom emoji are on their way to Matrix! Even mentioned in the talk I linked

@alexl "Matrix is not a chat protocol: it's a decentralized database" โ€” thank you for phrasing this so simply!

I'm poking around the #Matrix API to see if we can wrap it in a library that presents a more traditional database-like API, with Matrix twists like single-user rooms (if that's possible, for apps to store data that is not intended to be shared) and conflict resolution, etc.!

Sign in to participate in the conversation

The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!