How to undelete?

[snarfed]

Is undeleting theoretically possible in AP? If so, I expect you'd do it with an Undo with object pointing to the original Delete activity's id, right?

I expect this support would be best effort and optional in implementations?

Apart from that, after a Delete, a Create or Update of the deleted object should have no effect, and should probably return an error, right?

OK if this is unspecified, just curious.

[evanp]

I think there is a clear pattern for how to manage undeletion. As you mention, using an Undo activity with the Delete activity as the object is the most natural and "ActivityPubish" way to do it. The fact that many implementations use the Tombstone type for deleted objects is also an indication that deleted things have some, probably limited, life after deletion.

I see two possible resolutions here: one is a Primer page that describes how this could work, which I believe would be the right solution if we think the specifications as they stand point to this solution, and we just need to connect the dots.

Another resolution, if we think there are open questions on how to implement this at the protocol level, is to create a FEP.

The more I think about it, the more I think this is a good topic for a primer page. I think the pieces are in place, but not put together.

If anyone thinks this mechanism is wider open, let's discuss.