Recently, there was a discussion about generic #ActivityPub servers.
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> But then you want to introduce context collection. And then 50 other extensions. How to do that without special-casing every one of them?
You don't! An extension is an extension. A Generic server only needs to support the base protocol. Extensions are optional, not a requirement.
@raphael @silverpill @julian @mariusor
I agree. Aboveall we need to know where protocol ends and 'app' begins. And be generally more deliberate in terminology use, and no longer talk in overloaded that has different unclear meanings to different people in different settings (to avoid saying 'contexts' one of such overloaded words

I've noticed for instance people having a very different notion of what a 'generic server' is, in definitions that are almost diametrical opposites.
My definition of generic is 'not specific' i.e. a generic server is a pure #ActivityPub protocol implementation (which is something to agree upon, what that exactly entails), having no knowledge of *any* app / solution built on top of it or 'passing through' its messaging architecture.
In the other meaning a generic server 'knows/does/has it all' i.e. it understands everything we comprise to be 'the fediverse' in a kind of hard-wired fashion based on the functionalities that (marginally) interoperate today.
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@raphael @silverpill @julian @mariusor
I agree. Aboveall we need to know where protocol ends and 'app' begins. And be generally more deliberate in terminology use, and no longer talk in overloaded that has different unclear meanings to different people in different settings (to avoid saying 'contexts' one of such overloaded words

I've noticed for instance people having a very different notion of what a 'generic server' is, in definitions that are almost diametrical opposites.
My definition of generic is 'not specific' i.e. a generic server is a pure #ActivityPub protocol implementation (which is something to agree upon, what that exactly entails), having no knowledge of *any* app / solution built on top of it or 'passing through' its messaging architecture.
In the other meaning a generic server 'knows/does/has it all' i.e. it understands everything we comprise to be 'the fediverse' in a kind of hard-wired fashion based on the functionalities that (marginally) interoperate today.
Another example of the need for careful terminology use is in the post that @silverpill quoted above:
> prevent actors on the same server from deleting each other posts
"post"? There is no post in #ActivityPub, not as a verb and neither as a noun. While I am not worried that silverpill used the word in a wrong meaning here, the terminology easily leads to confusion where someone who interprets AS/AP to be equivalent to the fediverse we have today, pictures in their mind as Mastodon posts or toots in fedi slang, or elsewhere called statuses.
That is app terminology. AP only knows Actor, Activities, Objects, and perhaps Collections. Period. The rest is solution design.
Where they are transferred they can be said to be messages, and messaging happens.
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@silverpill @raphael @julian @mariusor
Yes, I see you working hard in that quest.
But in the chaotic fediverse that evolved by post-facto interoperability that is a wicked challenge. Post-facto interop means "if I am first I can become law, and drag fediverse sideways in my image".
In another branch of this thread, there's another confusing thing. "how can a mastodon client ask the server .." and you respond with a possible URL pattern that may be defined.
> Maybe something like `/api/v1/timelines/tag/{tag}?only_media=true` ?
Perhaps Mastodon's non-generic server may have that, but not a generic server, but it is unclear which one is referred to.
Since microblogging nowhere aggregates comprehensive overview it is an echo chamber for confusion.
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@silverpill @raphael @julian @mariusor
Yes, I see you working hard in that quest.
But in the chaotic fediverse that evolved by post-facto interoperability that is a wicked challenge. Post-facto interop means "if I am first I can become law, and drag fediverse sideways in my image".
In another branch of this thread, there's another confusing thing. "how can a mastodon client ask the server .." and you respond with a possible URL pattern that may be defined.
> Maybe something like `/api/v1/timelines/tag/{tag}?only_media=true` ?
Perhaps Mastodon's non-generic server may have that, but not a generic server, but it is unclear which one is referred to.
Since microblogging nowhere aggregates comprehensive overview it is an echo chamber for confusion.
@silverpill @raphael @julian @mariusor
I sometimes picture fediverse as one of these old horseracing toys from the 50s, where the horses represent all the various perspectives and expectations people have of the fediverse. There is no horse to bet on, positions change all the time, horses change tracks randomly. And furthermore there no finish line, the race is an endless slog. The prize of a robust #ActivityPub protocol forever out of reach, getting more elusive as time progresses.
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@raphael Nevermind, side effects wouldn't be a problem. However, it still doesn't seem to be compatible with ActivityPub... Because
Announceactivity is not defined in C2S context
https://www.w3.org/TR/activitypub/#client-to-server-interactions
@silverpill @raphael @julian @mariusor
In my book if a side effect is part of the protocol specification, then it constitutes a protocol capability. If not, then it is part of some app's / solution's business logic.
The definition of "ActivityPub extension" by itself is unclear. With overloaded use causing confusion. It may refer to:
- Protocol extension
- App / solution built on top of the protocolTo deal with protocol capabilities they must have water-tight specs, well-defined behavior and strict consistent use across the fediverse.
To deal with side effects that are part of solution designs for a particular application or business domain things go from simple to very complex in the amount of introspection and machine-readability that the #ActivityPub Actor abstraction offers.
Simplest is finding the URL where the docs of the extension / solution design sit. Most complex is full introspection and handshaking. The latter is the Solid route.
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Recently, there was a discussion about generic #ActivityPub servers. Several people claimed that they were working on one, but it turned out that their "generic" servers only support activities defined in the ActivityPub specification. Such a server shouldn't be called generic. It is not difficult to build, neither it is an interesting concept because competing protocols (e.g. Nostr) already offer much more.
I've been writing a #FEP that describes how to build a real generic server. It is not finished yet, but I feel like now is a good time to publish it:
FEP-fc48: Generic ActivityPub server
This kind of server:
- Can process any object type, and can process non-standard activities like
EmojiReact.
- Compatible with FEP-ae97 clients.
- Does not require JSON-LD.I attempted to implement it when I was researching security properties of FEP-ae97 API: https://codeberg.org/silverpill/fep-ae97-server. Back then I didn't know what to do with side effects, but now I think that we can simply force clients to specify them.
I e*love* this idea- especially in principle. I say that because I’m having a hard time wrapping my head around this and how it would be used in practice.
Do you think you could post an example workflow (or three) to demonstrate how this would work?
I get that objects could be added to client-defined collections (very cool) but if object/collection IDs don’t have predefined semantics, how will I know where to look to get the data I need?
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@silverpill @raphael @julian @mariusor
Yes, I agree. Though I would rather see a generic server having much less functionality than a Mastodon API exposes, since much of that is app-specific, Microblogging domain already. The generic server should make Mastodon possible as a solution design modeled on top of its #ActivityPub networking layer.
In such a way where we can finally consider the protocol layer to be robust, and are able to treat it as a black box, and are not confronted with all its implementation details when we are doing a solution design.
I think we are probably on the same page, but..
> If you want to go beyond Mastodon API capabilities, you need a truly generic server. Something akin to Nostr relay.
This I would reformulate as:
"If you want to go beyond an app-centric fediverse bound to a Microblogging domain, then you need a generic server conformant to the ActivityPub specification."
Which also indicates I think we need to aggregate puzzle pieces into an AP 2.0
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what Vocata did
This project is often brought up as an example of a generic server, but it never reached production stage. The last commit was in 2023.
It is one thing to have an idea and build a prototype, and a completely different thing to build an application that is secure and interoperates with the rest of the network.
@silverpill @raphael @mariusor
> neither is it an interesting concept
> interoperates with the rest of the network
look, we clearly have different goals here. your goal is to interoperate with the mastodon network. my goal is to publish activities to my website. mastodon doesn't even support all the activities defined in AS2-Vocab. a generic server supports *any* activity, even those not defined by AS2. the network i want to interoperate with isn't mastodon, it's the web.
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@silverpill @raphael @julian @mariusor
Yes, I agree. Though I would rather see a generic server having much less functionality than a Mastodon API exposes, since much of that is app-specific, Microblogging domain already. The generic server should make Mastodon possible as a solution design modeled on top of its #ActivityPub networking layer.
In such a way where we can finally consider the protocol layer to be robust, and are able to treat it as a black box, and are not confronted with all its implementation details when we are doing a solution design.
I think we are probably on the same page, but..
> If you want to go beyond Mastodon API capabilities, you need a truly generic server. Something akin to Nostr relay.
This I would reformulate as:
"If you want to go beyond an app-centric fediverse bound to a Microblogging domain, then you need a generic server conformant to the ActivityPub specification."
Which also indicates I think we need to aggregate puzzle pieces into an AP 2.0
@silverpill @raphael @julian @mariusor
Btw, damn we should've caused this entire discussion thread to somehow flow to #SocialHub to have it in the archives. Instead of on "now you see me, now you don't" channel. Peekaboo. 🫣
https://social.coop/@smallcircles/116141469199837056
Here today, gone tomorrow, who made notes? The post-facto interoperability leaders did. Those who happened to be around at the right time to hear things being said on the grapevine.
We need a proper Grassroots standardization process, and a Grassroots open standard that is able to healthily evolve. The good organization of this is just as important as the technical robustness of the protocol, which is the solution artifact at the end of the open standards cocreation pipeline.
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I e*love* this idea- especially in principle. I say that because I’m having a hard time wrapping my head around this and how it would be used in practice.
Do you think you could post an example workflow (or three) to demonstrate how this would work?
I get that objects could be added to client-defined collections (very cool) but if object/collection IDs don’t have predefined semantics, how will I know where to look to get the data I need?
@benpate @silverpill @mariusor none of the IDs should have any semantics; from the outside, there is no distinction between a client managed or server managed collection. likes/shares/etc could be managed by a "client" like mastodon, or even a "default" one. it's not any more complex unless you want to vary the collection responses based on the request headers. for that you need a minimal dynamic layer with an access control policy of some sort. (WAC is the simplest, but ACP is more powerful)
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@benpate @silverpill @mariusor none of the IDs should have any semantics; from the outside, there is no distinction between a client managed or server managed collection. likes/shares/etc could be managed by a "client" like mastodon, or even a "default" one. it's not any more complex unless you want to vary the collection responses based on the request headers. for that you need a minimal dynamic layer with an access control policy of some sort. (WAC is the simplest, but ACP is more powerful)
@benpate @silverpill in a client managed followers collection i would Add you to my followers just like fedi instances currently do silently. "but how can you prove--" yes exactly, how can current fedi prove anyone is a follower either? you need the Follow+Accept pair to both be live without an Undo on either, right? and that's what leads to the "follow state machine" on fedi that drifts out of sync and leads to private posts being leaked to removed followers (which you can't officially do!)
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I e*love* this idea- especially in principle. I say that because I’m having a hard time wrapping my head around this and how it would be used in practice.
Do you think you could post an example workflow (or three) to demonstrate how this would work?
I get that objects could be added to client-defined collections (very cool) but if object/collection IDs don’t have predefined semantics, how will I know where to look to get the data I need?
@benpate Let's assume that my client is a music player. It publishes a
Listenactivity whereobjectis anAudio. This activity should increaseplayCounton theAudioobject.One way to support this on the server side is to teach it about
Listen,Audioand how to updateplayCount. This is how most existing servers are built.But a server described in my FEP would work differently:
- It doesn't know anything about
Listen,AudioorplayCount.
- Upon receivingListen, it will recognize it as an activity, and embeddedAudioas an object.
- Since this is not a CRUD operation, it will not check permissions.
- IfListenactivity has aresultproperty, the server will process that activity as well.
- Ifresultis anUpdateactivity, the server will recognize it as a CRUD operation and will check permissions:Update.actorandAudio.attributedTomust be the same.
- The server will save both activities,ListenandUpdate.
- Then it will deliver them to intended recipients (toandcc).Effects are client's responsibility now, it must provide an
Updateactivity if it wants to updateplayCount. There are other requirements too, for example all objects should have anattributedToproperty, which is needed for permission checks.But in this setup a single server can work with any kind of client.
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@benpate Let's assume that my client is a music player. It publishes a
Listenactivity whereobjectis anAudio. This activity should increaseplayCounton theAudioobject.One way to support this on the server side is to teach it about
Listen,Audioand how to updateplayCount. This is how most existing servers are built.But a server described in my FEP would work differently:
- It doesn't know anything about
Listen,AudioorplayCount.
- Upon receivingListen, it will recognize it as an activity, and embeddedAudioas an object.
- Since this is not a CRUD operation, it will not check permissions.
- IfListenactivity has aresultproperty, the server will process that activity as well.
- Ifresultis anUpdateactivity, the server will recognize it as a CRUD operation and will check permissions:Update.actorandAudio.attributedTomust be the same.
- The server will save both activities,ListenandUpdate.
- Then it will deliver them to intended recipients (toandcc).Effects are client's responsibility now, it must provide an
Updateactivity if it wants to updateplayCount. There are other requirements too, for example all objects should have anattributedToproperty, which is needed for permission checks.But in this setup a single server can work with any kind of client.
Yes, I think I like the idea of clients being able to store data on the server however they like. It reminds me of this description of ATProto that I found recently: https://overreacted.io/a-social-filesystem/
I guess my question is: once I store my custom stuff in custom places on my server, how do I publish this so other people can find?
And, object IDs are usually defined by the server. So how would it work to say "create a collection named XYZ and add this object to it"?
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