MSC3391: API to delete account data

[ShadowJonathan]

Rendered

Implementations;

• Synapse
  • PR: Add experimental support for MSC3391: deleting account data synapse#14714 (design: Implement MSC3391: Removing account data synapse#14244) + Add an unstable feature flag for MSC3391 to the /versions endpoint synapse#15562 (add an unstable features flag)
• Ruma
  • #TBD
• JS SDK
  • matrix-org/matrix-js-sdk@b2a10e6
• Element iOS
  • Delete old account data (PSG-635) element-hq/element-ios#7164

Fixes matrix-org/matrix-spec#190

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>

FCP tickyboxes for closure: #3391 (comment)

[anoadragon453]

lgtm, have left a few clarifications below.

[turt2live]

This is currently in need of a shepherd to get the MSC to the next steps. It's been proposed for FCP at least once already and got quite a bit of feedback: working through that feedback and sending it back to the SCT to send through FCP is what's required.

As the branch is on a contributor's fork, the shepherd would either need to be a member of the matrix-org github to push to the PR branch, ask the original author for access, or failing all of that open a new MSC so we can mark this one obsolete.

Unfortunately there is no bandwidth within the SCT to do the shepherding required here.

If folks are interested in taking this on, please speak up and do so :)

[richvdh]

This seems to be bitrotting, with no real interest from a maintainer. I also think it's overreaching somewhat: we have basically the same semantics in the ecosystem today, with clients explicitly setting account data to {} to effectively mean "deleted".

I'd like to propose this for closure.

@mscbot fcp close

[mscbot]

Team member @richvdh has proposed to close this. The next step is review by the rest of the tagged people:

• @clokep
• @dbkr
• @uhoreg
• @turt2live
• @ara4n
• @anoadragon453
• @richvdh
• @tulir
• @erikjohnston
• @KitsuneRal

Once at least 75% of reviewers approve (and there are no outstanding concerns), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for information about what commands tagged team members can give me.

[Johennes]

Nullifying account data events by setting the content to {} definitely works. It does feel like a bit of a band-aid though. For instance, you technically cannot nullify m.marked_unread because it contains a required field. While the lack of a proper deletion API does not annoy me terribly, it does feel a bit annoying that we're going from fcp merge to fcp close. 🫤

[clokep]

This seems to be bitrotting, with no real interest from a maintainer. I also think it's overreaching somewhat: we have basically the same semantics in the ecosystem today, with clients explicitly setting account data to {} to effectively mean "deleted".

This seems to conflict with just having merged MSC4133, which explicitly included a DELETE for profile fields. I see profile fields and account data as analogous, the first being public and the second private. It would be nice if these APIs would match.

I'm against on closing this on the merit it isn't useful. I can't speak to the bitrot or not though.

[richvdh]

Honestly, the main reason for wanting to close it is that it seems to have been abandoned by its author, and apparently wasn't ready to merge. As such, it feels like distracting noise. I'm not in favour of a pattern where MSCs get started, implemented in some places, then abandoned, and we have to carry the mental load forever.

If anybody would like to take on pushing this forward, that would certainly be a better outcome than closing it, but given github's permissions model, it's likely to require a new MSC in any case.

[clokep]

@richvdh and I discussed more out of band and I think we're fairly close in our thoughts. Having proposals open with no one driving them is not super useful. If someone does want to drive this in the future they can open a new MSC or reopen this one: i.e. the closure is due to abandonment and not due to an unwanted feature.

[TheArcaneBrony]

I'd like to note that I'd still like to see a way to "permanently" delete account data (ie, sync not returning events that have empty content)

[mscbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[mscbot]

The final comment period, with a disposition to close, as per the review above, is now complete.