Discussion

@julian@activitypub.space · 22 hours ago

⁂ Article

Bonfire shared inbox usage

Hi @mayel@sunbeam.city, does Bonfire utilise the sharedInbox value?

I noticed this come through my nginx logs today:

128.140.127.206 - - [21/Jan/2026:19:58:04 +0000] "POST /uid/1/inbox HTTP/1.1" 500 128 "-" "https://btfree.social - Bonfire ActivityPub federation" "-"

Hi @mayel@sunbeam.city, does Bonfire utilise the sharedInbox value?

I noticed this come through my nginx logs today:

128.140.127.206 - - [21/Jan/2026:19:58:04 +0000] "POST /uid/1/inbox HTTP/1.1" 500 128 "-" "https://btfree.social - Bonfire ActivityPub federation" "-"

/uid/1/inbox is an endpoint specified in my user's inbox, but that actor also sends "endpoints":{"sharedInbox":"https://activitypub.space/inbox"}, so wanted to double-check that Bonfire uses it. It should, it helps reduce the number of requests to send if multiple users belong to the same server

Mayel

@mayel replied · 19 hours ago

@julian@activitypub.space Hi yes we send to sharedInbox when there's more than one recipient on that instance, otherwise direct to to the user's inbox.

@mayel@sunbeam.city

julian

@julian@activitypub.space replied · 19 hours ago

Re: Bonfire shared inbox usage

@mayel@bonfire.cafe oh that is an interesting choice. I suppose that makes sense, I never really thought about it. NodeBB just sends to shared inbox if available.

infinite love ⴳ

@trwnh@mastodon.social replied · 17 hours ago

@julian @mayel subtle difference: sharedInbox is not delivering to the individual inboxes, and it is not strictly delivering to the addressed actors either. what it *actually* means is "make the shared inbox decide who gets it, using the addressing as a *hint*". in theory, the shared inbox is supposed to distribute the activity to the appropriate inboxes internally. this, of course, leads to Problems when the shared inbox doesn't understand a specific recipient (like with private collections)

julian

@julian@activitypub.space replied · 17 hours ago

Re: Bonfire shared inbox usage

@trwnh@mastodon.social that sounds like a them problem not a my problem 😝

cc @mayel@bonfire.cafe

infinite love ⴳ

@trwnh@mastodon.social replied · 17 hours ago

@julian @mayel well, that's exactly it! you never said which inboxes to deliver to, so my shared inbox has to *guess*...

https://w3id.org/fep/0499/multibox tries to avoid this by using an Add activity targeting the specific inboxes, iirc. (probably should revisit that FEP...)

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