Desired changes for a future revision of ActivityPub and ActivityStreams

ActivityPub
7

In no particular order:

  1. Any kind of mechanism to make it possible to migrate from one AP server implementation to another on the same domain without having to keep legacy IDs, see also this thread. This will likely not be backwards-compatible but I think it’s very important for the long-term success of the fediverse. Otherwise domains will be stuck with the same implementations (or maybe forks) forever. That seems bad.

  2. Eschew JSON-LD and just use JSON. To me, JSON-LD seems too complicated for its own good. Most (AFAIK) implementations don’t bother actually handling it as JSON-LD and just treats it as JSON. Personally I had never even heard of JSON-LD before I read about ActivityPub. This made understanding the spec majorly difficult as JSON-LD seemed very strange. I think using plain JSON would simplify things for almost no disadvantage. The argument that JSON-LD allows better extensibility falls kinda flat when most implementations do not even properly use JSON-LD. The different representations that JSON-LD has also makes treating it as plain JSON problematic, but AFAIK the spec doesn’t require using JSON-LD. It all seems very weird and again, plain JSON would just be simpler and I think simplicity should be prioritized a lot more than it has been. I believe extensibility could still be achieved quite painlessly with plain JSON. This is not backwards-compatible either.

  3. Support Dislike in the same fashion as Like, with a dislikes collection. The asymmetry here seems strange to me. Should be backwards-compatible.

  4. Support emoji reactions in the base spec. This is a very common thing on most social media so it is kind of strange that ActivityPub doesn’t support it natively. See also this thread. If added as a separate thing (which would seem fine to me), it should be backwards-compatible. It could also replace Likes/Dislikes and those could be modelled with :+1: and :-1: reactions, but that would not be backwards-compatible.

  5. Get rid of HTTP Signatures and instead provide a way to put signatures directly inside the JSON objects. This means that every object is fully self-describing and self-authenticating. The fact that the signature is associated with the request and not the object seems weird to me since it is the object that needs to be verified. In fact you need to cross-reference the HTTP Signature and the object anyway to properly verify the object, which should be a good hint that the signature should be on the object, not the request. Probably not backwards-compatible.

  6. Provide some way to send activities in bulk. I.e. instead of 1 request = 1 activity, allow 1 request = many activities. This just seems like a reasonable optimization as you can send a lot of activities to a shared inbox at once that way. If signatures are on the objects themselves, each object can also include a signature on its own and so the request doesn’t need the HTTP Signature (which would be difficult to provide for many activities at once). Probably not backwards-compatible.

  7. Provide better semantics for forums/reddit-like implementations in the base spec. As it is, ActivityPub is unfortunately quite focused on microblogging and the following of individual actors for content. However, social media like forums or reddit don’t work like that. You don’t follow actors, you follow “categories” or collections of posts. The way apps like Lemmy currently work around this is by modelling communities (subreddits) as Groups, where the group is a collection of all the people subscribed to the community. But this seems unnatural, as the more semantically accurate thing would be to follow a kind of category or collection, not an actor. It’s also slightly hacky as the community has to Announce (or boost in mastodon terms) every single piece of content (posts, comments, votes) to all the followers, even if that content comes from external users, which seems like a strange way to model it. Honestly don’t know if this could already be done more cleverly but long story short this use case seems poorly supported by ActivityPub right now. This could maybe be done backwards-compatibly?

  8. This could be very hard, but possibly provide some standard way to signify roles and permissions for actors. For instance, it is useful to know that a certain user is an admin of another instance and has certain permissions because of that. Currently Lemmy hardcodes a “moderator” role and assumes certain permissions based on that, but that seems rigid and not very flexible. Ideally roles and/or permissions could somehow be specified flexibly. Not sure if that is backwards-compatible.

3 Likes