Recently, there was a discussion about generic #ActivityPub servers.
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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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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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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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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.
@silverpill @mariusor @trwnh In principle, I like the general idea, but I think it's misleading to call this an "ActivityPub" server FEP since it doesn't conform to the ActivityPub specifications. You also recommend (require?) using the `result` property to describe server side-effects, but you don't describe *how*. I don't know how you expect to "force clients to specify them".
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@silverpill @mariusor @trwnh In principle, I like the general idea, but I think it's misleading to call this an "ActivityPub" server FEP since it doesn't conform to the ActivityPub specifications. You also recommend (require?) using the `result` property to describe server side-effects, but you don't describe *how*. I don't know how you expect to "force clients to specify them".
This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?
In any case, I think calling it an ActivityPub server is appropriate.
Side-effects are activities, I will clarify that in the FEP. The value of
resultproperty can be an embedded activity, or an array of activities.Clients either specify them, or they don't get any side effects.
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This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?
In any case, I think calling it an ActivityPub server is appropriate.
Side-effects are activities, I will clarify that in the FEP. The value of
resultproperty can be an embedded activity, or an array of activities.Clients either specify them, or they don't get any side effects.
@silverpill @mariusor @trwnh
> This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?Not at all. I was referring to the `Add` without an `object` to create a collection (instead of Create/Collection, I assume).
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This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?
In any case, I think calling it an ActivityPub server is appropriate.
Side-effects are activities, I will clarify that in the FEP. The value of
resultproperty can be an embedded activity, or an array of activities.Clients either specify them, or they don't get any side effects.
@silverpill @steve this actually raises an interesting question about "side effects" and where they live. in the AP spec it's rather muddled and i've talked before about the issue of "activities as content/notifications vs activities as procedure calls". i personally err toward having no side effects, which i think were kind of a mistake for the reason you bring up (generic servers can never be aware of extended side effects).
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@silverpill @steve this actually raises an interesting question about "side effects" and where they live. in the AP spec it's rather muddled and i've talked before about the issue of "activities as content/notifications vs activities as procedure calls". i personally err toward having no side effects, which i think were kind of a mistake for the reason you bring up (generic servers can never be aware of extended side effects).
@silverpill @steve typically i've taken a view similar to IFTTT -- the activities describe things that happen, probably already happened. one or more listeners can do whatever they want with that information. CRUD is boring to me and i would rather do that with HTTP (POST/GET/PUT/DELETE); the more interesting activities are things like Listen (scrobbles) or Arrive (checkins) or Question (stackoverflow) or so on.
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@silverpill @steve typically i've taken a view similar to IFTTT -- the activities describe things that happen, probably already happened. one or more listeners can do whatever they want with that information. CRUD is boring to me and i would rather do that with HTTP (POST/GET/PUT/DELETE); the more interesting activities are things like Listen (scrobbles) or Arrive (checkins) or Question (stackoverflow) or so on.
@silverpill @steve it sounds like you're describing an "AP server" whose primary functionality is not "publish activities" but rather "manage CRUD for objects and Add/Remove for collections", by taking the AP "side effects" for Create/Update/Delete/Add/Remove and and saying the outbox should also check as:result.
which is cool but should probably be disambiguated.
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@silverpill @steve it sounds like you're describing an "AP server" whose primary functionality is not "publish activities" but rather "manage CRUD for objects and Add/Remove for collections", by taking the AP "side effects" for Create/Update/Delete/Add/Remove and and saying the outbox should also check as:result.
which is cool but should probably be disambiguated.
@silverpill @steve so maybe instead of "generic activitypub server" the FEP should be called something like "explicitly specifying side effects with the result property". it seems to me like the references to 2277 and fe34 are not strictly necessary to the core idea and a separate FEP could bundle them together into a profile, like "a profile for using outbox activities to manage objects and collections". not sure what the best name is because naming things is the hardest
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@silverpill @steve so maybe instead of "generic activitypub server" the FEP should be called something like "explicitly specifying side effects with the result property". it seems to me like the references to 2277 and fe34 are not strictly necessary to the core idea and a separate FEP could bundle them together into a profile, like "a profile for using outbox activities to manage objects and collections". not sure what the best name is because naming things is the hardest
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@silverpill @steve it sounds like you're describing an "AP server" whose primary functionality is not "publish activities" but rather "manage CRUD for objects and Add/Remove for collections", by taking the AP "side effects" for Create/Update/Delete/Add/Remove and and saying the outbox should also check as:result.
which is cool but should probably be disambiguated.
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@silverpill @steve typically i've taken a view similar to IFTTT -- the activities describe things that happen, probably already happened. one or more listeners can do whatever they want with that information. CRUD is boring to me and i would rather do that with HTTP (POST/GET/PUT/DELETE); the more interesting activities are things like Listen (scrobbles) or Arrive (checkins) or Question (stackoverflow) or so on.
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@silverpill @steve this actually raises an interesting question about "side effects" and where they live. in the AP spec it's rather muddled and i've talked before about the issue of "activities as content/notifications vs activities as procedure calls". i personally err toward having no side effects, which i think were kind of a mistake for the reason you bring up (generic servers can never be aware of extended side effects).
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@silverpill @mariusor @trwnh
> This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?Not at all. I was referring to the `Add` without an `object` to create a collection (instead of Create/Collection, I assume).
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This FEP introduces new requirements to ActivityPub, and I will probably add more in the future. Does that make it non conformant?
In any case, I think calling it an ActivityPub server is appropriate.
Side-effects are activities, I will clarify that in the FEP. The value of result property can be an embedded activity, or an array of activities.
Clients either specify them, or they don't get any side effects.
-
@silverpill @mariusor @trwnh In principle, I like the general idea, but I think it's misleading to call this an "ActivityPub" server FEP since it doesn't conform to the ActivityPub specifications. You also recommend (require?) using the `result` property to describe server side-effects, but you don't describe *how*. I don't know how you expect to "force clients to specify them".
-
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"?
