I think the #ActivityPub client-to-server API is extremely important and underrated.
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@smallcircles@social.coop I feel personally called out for this
No need to, I didn't call you out
I think the fediverse-we-have has become a very different one than the fediverse-promised based on the initial specs when there weren't implementations and an installed base making numerous design decisions in a very ad-hoc pragmatic fashion. Which is in itself fine, and a very good approach to get an ecosystem off the ground. But having the app-centric, app-first evolution be the primary evolution process, brought us to a different space than the ubiquitous, heterogeneous social networking environment we might all be working in, focused on exciting solution designs and less in all the plumbing and impl details.
No one is really to blame I guess. This is where laissez-faire in grassroots environments leads us, following the social dynamics that exist.
We can do better, but it is very hard in our individualist, FOSS-project-oriented herding of cats chaotic environment. The challenges are social in nature..
Major challenges for the Fediverse
Various forum topics highlights big challenges for the Fediverse to overcome. Below there is a list of those, and all of them are within scope of Social Coding #foundations to contribute to solutions. Challenge Descβ¦
Discuss Social Coding (discuss.coding.social)
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I haven't seen anyone use Add and Remove activities to notify updates to the `outbox`. I don't think it would work; it's too recursive.
I've done it for other feeds, like `replies` or `followers`, and it works pretty well.
@evan @julian@activitypub.space @smallcircles Mind if I butt in here with a question about management of the `replies` collection? I'm looking at this for the interaction controls FEP draft.
GoToSocial currently broadcasts an `Accept(Note)` to let followers know a reply has been accepted (see https://docs.gotosocial.org/en/latest/federation/interaction_controls/#broadcasting-accepts-for-the-benefit-of-third-servers). We'd want to add an inverse for revocation, which would be `Undo(Accept(Note))` imo.
I feel `Add` and `Remove` on the `replies` collection may be more idiomatic and, in a sense, easier. Opinions?
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@evan @julian@activitypub.space @smallcircles Mind if I butt in here with a question about management of the `replies` collection? I'm looking at this for the interaction controls FEP draft.
GoToSocial currently broadcasts an `Accept(Note)` to let followers know a reply has been accepted (see https://docs.gotosocial.org/en/latest/federation/interaction_controls/#broadcasting-accepts-for-the-benefit-of-third-servers). We'd want to add an inverse for revocation, which would be `Undo(Accept(Note))` imo.
I feel `Add` and `Remove` on the `replies` collection may be more idiomatic and, in a sense, easier. Opinions?
@julian@fietkau.social @julian@activitypub.space @smallcircles I like Accept and Reject but @trwnh is pretty insistent on Add and Remove so I defer to them.
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No need to, I didn't call you out
I think the fediverse-we-have has become a very different one than the fediverse-promised based on the initial specs when there weren't implementations and an installed base making numerous design decisions in a very ad-hoc pragmatic fashion. Which is in itself fine, and a very good approach to get an ecosystem off the ground. But having the app-centric, app-first evolution be the primary evolution process, brought us to a different space than the ubiquitous, heterogeneous social networking environment we might all be working in, focused on exciting solution designs and less in all the plumbing and impl details.
No one is really to blame I guess. This is where laissez-faire in grassroots environments leads us, following the social dynamics that exist.
We can do better, but it is very hard in our individualist, FOSS-project-oriented herding of cats chaotic environment. The challenges are social in nature..
Major challenges for the Fediverse
Various forum topics highlights big challenges for the Fediverse to overcome. Below there is a list of those, and all of them are within scope of Social Coding #foundations to contribute to solutions. Challenge Descβ¦
Discuss Social Coding (discuss.coding.social)
Btw, some time ago in a matrix discussion I sketched how I'd like to conceptually 'see' the social network. Not Mastodon-compliant per se (though it might be via a Profile or Bridge) but back to "promised land". Where the protocol is expressed in familiar architecture patterns and borrows concepts from message queuing, actor model, event-driven architecture, etc.
Then as a "Solution designer" I am a stakeholder that wants to be completely shielded from all that jazz. That should all be encapsulated by the protocol libraries and SDK's that are offered in language variants across the ecosystem. #ActivityPub et al is a black box. I can directly start modeling what should be exchanged on the bus, and I can apply domain driven design here. And if I have a semantic web part of my app I'd use linked data modeling best-practices.
I would have power tools like #EventCatalog and methods like #EventModeling.
Visualize Your Architecture - EventCatalog
See how your services connect, how data flows, and how messages move through your system. Generated from your docs, always accurate.
EventCatalog (www.eventcatalog.dev)
Event Modeling Introduction
Event Modeling can be applied in designing systems that will store state in traditional databases. By providing a more thorough design, the solution can be implemented with a lot less waste that usually comes in the form of having to re-visit finished items as the solution is built up.
(eventmodeling.org)
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@julian@fietkau.social @julian@activitypub.space @smallcircles I like Accept and Reject but @trwnh is pretty insistent on Add and Remove so I defer to them.
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles personally i think three things happen generally, which could each be described by their own activity in succession:
1) the original Activity is posted.
2) you can Accept or Reject the Activity.
3) as a result, you can Add or Remove the Activity to the corresponding AP collection.this holds for Like and Announce 1:1. Follow we currently Add the Follow.object instead, but i think we ought to store the actual Follow activity in a follows collection.
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles personally i think three things happen generally, which could each be described by their own activity in succession:
1) the original Activity is posted.
2) you can Accept or Reject the Activity.
3) as a result, you can Add or Remove the Activity to the corresponding AP collection.this holds for Like and Announce 1:1. Follow we currently Add the Follow.object instead, but i think we ought to store the actual Follow activity in a follows collection.
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles of course follows are a bit more stateful and complex, so it can be argued that we should actually allow for richer subscription management, similar to when you open a dashboard and manage which email notifications you want to receive. the subscription could be reified as a Follow activity, but the side effects and semantics are not exactly the same with what's in AP right now. (AP doesn't have a way to remove a follower; masto uses Reject without Undo Accept)
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles of course follows are a bit more stateful and complex, so it can be argued that we should actually allow for richer subscription management, similar to when you open a dashboard and manage which email notifications you want to receive. the subscription could be reified as a Follow activity, but the side effects and semantics are not exactly the same with what's in AP right now. (AP doesn't have a way to remove a follower; masto uses Reject without Undo Accept)
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles and then there are replies, which in fedi currently require deep introspection of a Create.object.inReplyTo, which is information that may not be immediately available to you. so it leads to the unfortunately complicated situation where you don't actually know when you received a reply, because there is no Reply activity to be used as a notification -- you have the side effect without the activity.
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles and then there are replies, which in fedi currently require deep introspection of a Create.object.inReplyTo, which is information that may not be immediately available to you. so it leads to the unfortunately complicated situation where you don't actually know when you received a reply, because there is no Reply activity to be used as a notification -- you have the side effect without the activity.
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles re: the Undo Accept thing vs Reject thing, using a Reject is prone to issues with out-of-order deliveries. if you send a Follow and get back an Accept and a Reject with the same published datetime, then are you currently a follower? what if the Reject came first but then you receive a later Accept? it makes it incredibly hard to reason about the distributed state machine, and leads to terrible desyncs when one side thinks you follow them and the other doesn't.
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles re: the Undo Accept thing vs Reject thing, using a Reject is prone to issues with out-of-order deliveries. if you send a Follow and get back an Accept and a Reject with the same published datetime, then are you currently a follower? what if the Reject came first but then you receive a later Accept? it makes it incredibly hard to reason about the distributed state machine, and leads to terrible desyncs when one side thinks you follow them and the other doesn't.
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles i think there needs to be a way to get a consistent event log in-order from the canonical/authoritative source. failing that, though, the least you could do is have your activities refer to each other in an obvious way. Undo(Accept(Follow)) lets you reverse-reconstruct what happened because all 3 activities are right there (hopefully fetchable!). so maybe Undo(Add) makes more sense than Remove; perhaps we say that the Remove is the result of the Undo?
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles i think there needs to be a way to get a consistent event log in-order from the canonical/authoritative source. failing that, though, the least you could do is have your activities refer to each other in an obvious way. Undo(Accept(Follow)) lets you reverse-reconstruct what happened because all 3 activities are right there (hopefully fetchable!). so maybe Undo(Add) makes more sense than Remove; perhaps we say that the Remove is the result of the Undo?
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles i guess you could hack it with inReplyTo on the Activity, if you assume responses always come after the thing they are responding to (although i could make a famous joke here about answering a question before it is asked).
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles i guess you could hack it with inReplyTo on the Activity, if you assume responses always come after the thing they are responding to (although i could make a famous joke here about answering a question before it is asked).
@evan @julian@fietkau.social @julian@activitypub.space @smallcircles anyway, to address julian (not lam)'s question: what does Accept(Note) even mean? what does it entail? can you always assume it has to do something with a replies collection that may or may not be there?
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#ActivityPub builds on top of #ActivityStreams in the sense that it adopted a number of its 'social primitives' defined in its vocabulary, and Collection being among those. These particular uses become 'protocol space', but other than that AS from the perspective of AP solution development is purely a set of social primitives, granular building blocks that one *may* use in a solution. AS is a utility library of sorts then. Or is that a wrong perception?
A 'feed' is something that lives in solution space, and I would only choose Collection to model it, if it offers a perfect fit in functionality. And aboveall.. does not assign some new app-specific use along the way.
I tooted today that I feel the biggest folly of the fedi is that everyone tries to cram their domain into the AS namespace. The AS primitives should not be Swiss army knives and have only singular well-defined meaning and purpose, yet they have become that along the way.
𫧠socialcoding.. (@smallcircles@social.coop)
@thisismissem@hachyderm.io @eyeinthesky@mastodon.social The biggest folly imho is this idea of "let's cram every domain into #ActivityStreams somehow". Flatten everything and project it onto this small set of social primitives that AS defines. It is once more a choice of pragmatism: "Hey, I've seen it working with Mastodon, so I copied that. And #LinkedData extension mechanism is a handwaved horror show". So understandable perhaps that we did it. But now we must overcome this trend which has taken stubborn root and drags the ecosystem down.
social.coop (social.coop)
@smallcircles @evan @julian if only the application domain of activitystreams was activities and streams...
i do think it causes a lot of confusion to stray away from activities as content, instead using them as vehicles for state changes (which will never be consistent, not even eventually consistent).
back when atompub and atom+as1 were a thing, the "feed entry" was atom semantics and the "activity stream" was as1 semantics. they coexisted in the same xml file. it worked well enough.
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@smallcircles @evan @julian if only the application domain of activitystreams was activities and streams...
i do think it causes a lot of confusion to stray away from activities as content, instead using them as vehicles for state changes (which will never be consistent, not even eventually consistent).
back when atompub and atom+as1 were a thing, the "feed entry" was atom semantics and the "activity stream" was as1 semantics. they coexisted in the same xml file. it worked well enough.
Yes, for the ideation on Protosocial as an #ActivityPub compliant extension (going back to the roots with blank slate W3C specs) I imagined mapping the AS primitives to consistent protocol capabilities and thereby define a set of normative architecture patterns, like "this is how we do CRUD, this is Publish/Subscribe, this is an Event stream and this a Collection", etc.
Then Protosocial library and SDK implementers would need to deal with #ActivityStreams at a low-level plumbing impl detail, while solution developers would have a higher-level API to invoke these patterns. And other than that would not need to touch #ActivityStreams which is now entirely reserved to making AP work on the wire.
A combination of linked data practices and schema-based design would be used for both open-world and closed-world extension modeling. But here too the solution developer should be shield from the nitty gritty internal mechanics.
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@evan @julian@fietkau.social @julian@activitypub.space @smallcircles anyway, to address julian (not lam)'s question: what does Accept(Note) even mean? what does it entail? can you always assume it has to do something with a replies collection that may or may not be there?
@trwnh That's kinda what I'm getting at, yeah. The goal is to express that the owner of the replied-to object has accepted a reply, i.e. that the reply is added to the post's replies collection and shown under it in the web view. Followers and other observers are made aware this reply is accepted and can be shown similarly in other places that want to honor the poster's reply filters, so observers don't need to iterate over the replies collection all the time.
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@trwnh That's kinda what I'm getting at, yeah. The goal is to express that the owner of the replied-to object has accepted a reply, i.e. that the reply is added to the post's replies collection and shown under it in the web view. Followers and other observers are made aware this reply is accepted and can be shown similarly in other places that want to honor the poster's reply filters, so observers don't need to iterate over the replies collection all the time.
@trwnh The GTS interaction controls docs mention the replies collection, but only tangentially. For the purpose of conversation backfilling (which GTS doesn't do yet) I'm wanting to emphasize that the replies collection is the source of truth for replies curated by the object owner.
The Accept(Note) is essentially a hack to allow interactions from servers that don't implement GTS's ReplyRequest activity. I'll discuss with them how best to signal reply acceptance.
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@trwnh The GTS interaction controls docs mention the replies collection, but only tangentially. For the purpose of conversation backfilling (which GTS doesn't do yet) I'm wanting to emphasize that the replies collection is the source of truth for replies curated by the object owner.
The Accept(Note) is essentially a hack to allow interactions from servers that don't implement GTS's ReplyRequest activity. I'll discuss with them how best to signal reply acceptance.
@julian@fietkau.social @evan @julian@activitypub.space @smallcircles
> express that the owner of the replied-to object has accepted a reply, i.e. that the reply is added to the post's replies collection and shown under it in the web view
i get that, but the question is whether you can claim this understanding universally for all peers. as it stands, Accept is very vague wrt this. Accept(Note) meaning "Add to replies collection" might be a thing gts does, but that's their interpretation of Accept, not the definition.
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@julian@fietkau.social @evan @julian@activitypub.space @smallcircles
> express that the owner of the replied-to object has accepted a reply, i.e. that the reply is added to the post's replies collection and shown under it in the web view
i get that, but the question is whether you can claim this understanding universally for all peers. as it stands, Accept is very vague wrt this. Accept(Note) meaning "Add to replies collection" might be a thing gts does, but that's their interpretation of Accept, not the definition.
@julian@fietkau.social @evan @julian@activitypub.space @smallcircles
> replies collection is the source of truth for replies curated by the object owner.
this is fine i think, but the way to do this usually is HTTP GET. you could notify of changes to the replies collection, or you could reify the Reply and then Accept that?
the Reply has an instrument which is the Note. it has clear side effects to Add the instrument to the object.replies. the side effects can be gated behind Accept/Reject like following currently works.
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@julian@fietkau.social @evan @julian@activitypub.space @smallcircles
> replies collection is the source of truth for replies curated by the object owner.
this is fine i think, but the way to do this usually is HTTP GET. you could notify of changes to the replies collection, or you could reify the Reply and then Accept that?
the Reply has an instrument which is the Note. it has clear side effects to Add the instrument to the object.replies. the side effects can be gated behind Accept/Reject like following currently works.
@julian@fietkau.social @evan @julian@activitypub.space @smallcircles alternatively add the Reply itself, parallel to likes/shares collections. it depends on whether you think the replies collection should always contain a specific type of object, which i don't think is something you can guarantee because publishers can do anything with it. similar to how some publishers include activities in threads and some include notes.
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@julian@fietkau.social @evan @julian@activitypub.space @smallcircles alternatively add the Reply itself, parallel to likes/shares collections. it depends on whether you think the replies collection should always contain a specific type of object, which i don't think is something you can guarantee because publishers can do anything with it. similar to how some publishers include activities in threads and some include notes.
@julian@fietkau.social @evan @julian@activitypub.space @smallcircles i think the issue here is that projects are doing things that may or may not get widely adopted, then if the proposals ever change, they have to deal with older software only understanding the old thing they tried. (this is where i would say something about protocol capability negotiation)
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@julian@fietkau.social @evan @julian@activitypub.space @smallcircles
> express that the owner of the replied-to object has accepted a reply, i.e. that the reply is added to the post's replies collection and shown under it in the web view
i get that, but the question is whether you can claim this understanding universally for all peers. as it stands, Accept is very vague wrt this. Accept(Note) meaning "Add to replies collection" might be a thing gts does, but that's their interpretation of Accept, not the definition.
@trwnh This is in the context of a FEP draft which prescribes a meaning (including desired side effects) for compliant implementations.
Hence my fidgeting with the vocabulary. The effects are the goal, the question is how they should be expressed and broadcasted. (Principle of least surprise, potential compatibility with existing implementations that look at the replies collection, concerns around server traffic...)
