Federated private groups (Announce vs Add)

[julian@activitypub.space]

@sk@utsukta.org mentioned in another thread that the way Hubzilla and threadiverse software handle group discussions is incompatible.

It got me thinking about whether that is true. At its core both FEPs (171b and 1b12, respectively) rely on a central "distributor" node to send activities to recipients.

@silverpill@mitra.social did further comparisons in thr text of 171b itself:

> Announce activity is used instead of Add. Conversation and related activities are synchronized between participants, but conversation backfilling mechanism is not specified.

The questions here are:

1. If threadiverse software federated out an Add in addition to Announce, would that satisfy basic synchronization (not backfill) requirements laid out by 171b?
2. Is there any reason why Announce could not be used to facilitate private federated group discussions as well? Assuming visibility maintains scoped to addresses, I don't see any immediate reason why not...

[mario@hub.somaton.com]

@silverpill imo using Announce instead of Add does not make any sense for conversation containers. You add/remove items to a collection right?

@julian @z6MkhPXNfiHDh2qSNjFzZ9yY27C1iHnHVbb1eaxuoiEe4tjk/actor" rel="nofollow noopener">Mike Macgirvin

[julian@activitypub.space]

> @silverpill@mitra.social said:
>
> Your personal inbox still 404s but maybe the group inbox will work.

Unrelated to the topic at hand there was a regression in the codebase for the past month that caused the inbox to return a 404 even with a valid content type header.

I think that was the cause of the inbox 404

[julian@activitypub.space]

> @silverpill@mitra.social said:
>
> Alternatively, they can start using Add instead of Announce, like we do. @julian Does that sound feasible?

I personally have no problem with it (after all, I advocated in OP to just send both activities)

But I know @nutomic@lemmy.ml will absolutely veto the discussion because it is a breaking change for the entire threadiverse, and he is not wrong.

There is a third option... and that is to send a single multi-typed activity maybe this is the turning point for adoption of multi type activities! (Of course I'm only half joking because I'm sure that'll be ruled breaking and unfeasible too.)

cc @mario@hub.somaton.com

[nutomic@lemmy.ml]

Is there any reason why Announce could not be used to facilitate private federated group discussions as well? Assuming visibility maintains scoped to addresses, I don’t see any immediate reason why not…

Private communities are already implemented in Lemmy 1.0 using Announce. Here is the RFC with details, and you can test it on voyager.lemmy.ml.