What is an Actor, anyway...
from julian@community.nodebb.org to swicg-threadiverse-wg@community.nodebb.org on 06 Jun 2024 20:17
https://community.nodebb.org/post/99944

This is a spin-off discussion from today's ForumWG meeting

During today's ForumWG meeting an interesting side discussion cropped up regarding what constitutes an Actor, and whether other object types could be considered Actor-like.

ActivityStreams defines an Actor as being one of five types:

However, a looser definition of an Actor could simply be "if the resolved object contains an inbox and an outbox".

Such a definition opens up the possibility of having lots of things be followable, perhaps without direct user interaction. This was one possibility outlined by @cpmoser@mastodon.social

@trwnh@mastodon.social also mentioned that Mastodon does not consider an object as being an actor unless it is one of those five types.

@dmitri@social.coop noted that this was a topic brought up at a previous AP issue triage meeting. Could you provide a summary?

Also cc @evan@cosocial.ca for his thoughts.

#activitypub #forumwg #socialcg #swicg-threadiverse-wg

threaded - newest

[deleted] on 06 Jun 2024 20:37 next collapse

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silverpill@mitra.social on 06 Jun 2024 22:38 next collapse

@julian From ActivityPub spec:

>ActivityPub actors are generally one of the ActivityStreams Actor Types, but they don't have to be.

The looser definition is correct.

smallcircles@social.coop on 07 Jun 2024 04:52 next collapse

@silverpill @julian

Though they are different beasts I continue to be intrigued by alignments in codebase and architecture of actor model with the actor-based nature of AP.

https://socialhub.activitypub.rocks/t/thoughts-on-actor-model-versus-fediverse/3572

[deleted] on 07 Jun 2024 04:53 collapse

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hrefna@hachyderm.io on 07 Jun 2024 06:26 collapse

@smallcircles

To answer the question: The standard that I have been told is that "anything can be an actor without declaring it, it just needs an inbox and outbox."

I think this is a terrible pattern, personally, but that's the standard.

@silverpill @julian

evan@cosocial.ca on 07 Jun 2024 00:15 next collapse

@julian @cpmoser @trwnh @dmitri absolutely. The ActivityPub spec says anything can be an actor. It just has to have the required properties.

evan@cosocial.ca on 07 Jun 2024 00:17 collapse

@julian @cpmoser @trwnh @dmitri HOWEVER, Mastodon currently only allows the big five. There should probably be a ticket for that somewhere.

trwnh@mastodon.social on 07 Jun 2024 08:04 collapse

@evan @julian @cpmoser @dmitri

https://github.com/mastodon/mastodon/issues/22322

What would work for Mastodon is to multi-type the actor as one of the five types, so you could do [Group, Collection] or [Service, Collection] but not just [Collection]

But yeah, I think the restriction should be dropped.

evan@cosocial.ca on 07 Jun 2024 00:15 collapse

@julian @cpmoser @trwnh @dmitri also, sorry I missed the call!