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MSC4169: Backwards-compatible redaction sending using /send#4169

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MSC4169: Backwards-compatible redaction sending using /send#4169
turt2live merged 8 commits intomainfrom
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@tulir tulir commented Jul 7, 2024 •
edited by turt2live
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@tulir
Proposal for backwards-compatible redaction sending using /send
cc79f45 
Signed-off-by: Tulir Asokan <tulir@maunium.net>
@tulir tulir added proposal A matrix spec change proposal client-server Client-Server API needs-implementation This MSC does not have a qualifying implementation for the SCT to review. The MSC cannot enter FCP. kind:maintenance MSC which clarifies/updates existing spec labels Jul 7, 2024
@tulir
Clarify dependencies and add todo
d3ee606 
Signed-off-by: Tulir Asokan <tulir@maunium.net>
@tulir tulir mentioned this pull request Sep 8, 2025
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@tulir tulir removed the needs-implementation This MSC does not have a qualifying implementation for the SCT to review. The MSC cannot enter FCP. label Sep 8, 2025
@tulir tulir marked this pull request as ready for review September 8, 2025 15:59
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turt2live approved these changes Sep 8, 2025
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generally lgtm

@tulir
Undeprecate /redact
94ec653 
Signed-off-by: Tulir Asokan <tulir@maunium.net>
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tulir commented Sep 9, 2025 •
edited by KitsuneRal
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MSCs proposed for Final Comment Period (FCP) should meet the requirements outlined in the checklist prior to being accepted into the spec. This checklist is a bit long, but aims to reduce the number of follow-on MSCs after a feature lands.

SCT members: please check off things you check for, and raise a concern against FCP if the checklist is incomplete. If an item doesn't apply, prefer to check it rather than remove it. Unchecking items is encouraged where applicable.

Checklist:

  • Are appropriate implementation(s) specified in the MSC’s PR description?
  • Are all MSCs that this MSC depends on already accepted?
  • For each new endpoint that is introduced:
    • Have authentication requirements been specified?
    • Have rate-limiting requirements been specified?
    • Have guest access requirements been specified?
    • Are error responses specified?
      • Does each error case have a specified errcode (e.g. M_FORBIDDEN) and HTTP status code?
        • If a new errcode is introduced, is it clear that it is new?
  • Will the MSC require a new room version, and if so, has that been made clear?
    • Is the reason for a new room version clearly stated? For example, modifying the set of redacted fields changes how event IDs are calculated, thus requiring a new room version.
  • Are backwards-compatibility concerns appropriately addressed?
  • Are the endpoint conventions honoured?
    • Do HTTP endpoints use_underscores_like_this?
    • Will the endpoint return unbounded data? If so, has pagination been considered?
    • If the endpoint utilises pagination, is it consistent with the appendices?
  • An introduction exists and clearly outlines the problem being solved. Ideally, the first paragraph should be understandable by a non-technical audience.
  • All outstanding threads are resolved
    • All feedback is incorporated into the proposal text itself, either as a fix or noted as an alternative
  • While the exact sections do not need to be present, the details implied by the proposal template are covered. Namely:
    • Introduction
    • Proposal text
    • Potential issues
    • Alternatives
    • Dependencies
  • Stable identifiers are used throughout the proposal, except for the unstable prefix section
    • Unstable prefixes consider the awkward accepted-but-not-merged state
    • Chosen unstable prefixes do not pollute any global namespace (use “org.matrix.mscXXXX”, not “org.matrix”).
  • Changes have applicable Sign Off from all authors/editors/contributors
  • There is a dedicated "Security Considerations" section which detail any possible attacks/vulnerabilities this proposal may introduce, even if this is "None.". See RFC3552 for things to think about, but in particular pay attention to the OWASP Top Ten.

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tulir commented Sep 9, 2025

Probably no reason to delay this, it's very straightforward

@mscbot fcp merge

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mscbot commented Sep 9, 2025 •
edited by ara4n
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Team member @tulir has proposed to merge this. The next step is review by the rest of the tagged people:

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.

@mscbot mscbot added proposed-final-comment-period Currently awaiting signoff of a majority of team members in order to enter the final comment period. disposition-merge labels Sep 9, 2025
@github-project-automation github-project-automation bot moved this to Tracking for review in Spec Core Team Workflow Sep 9, 2025
@tulir tulir moved this from Tracking for review to Ready for FCP ticks in Spec Core Team Workflow Sep 9, 2025
@turt2live turt2live added the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Sep 9, 2025
anoadragon453
anoadragon453 reviewed Sep 9, 2025
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tulir and others added 2 commits September 9, 2025 20:32
@tulir @anoadragon453
Apply suggestions from code review
cbd5f10 
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
@tulir
Reword introduction
c4bc1f4
KitsuneRal
KitsuneRal reviewed Sep 9, 2025
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@tulir
Repeat why not /redact in alternatives section
b9ccea4 
Signed-off-by: Tulir Asokan <tulir@maunium.net>
@tulir tulir requested a review from anoadragon453 September 11, 2025 15:05
reivilibre pushed a commit to element-hq/synapse that referenced this pull request Sep 22, 2025
@SpiritCroc @tulir
Implement MSC4169: backwards-compatible redaction sending for rooms <…
83aca3f 
… v11 using the /send endpoint (#18898)

Implement
[MSC4169](matrix-org/matrix-spec-proposals#4169)

While there is a dedicated API endpoint for redactions, being able to
send redactions using the normal send endpoint is useful when using
[MSC4140](matrix-org/matrix-spec-proposals#4140)
for sending delayed redactions to replicate expiring messages. Currently
this would only work on rooms >= v11 but fail with an internal server
error on older room versions when setting the `redacts` field in the
content, since older rooms would require that field to be outside of
`content`. We can address this by copying it over if necessary.

Relevant spec at
https://spec.matrix.org/v1.8/rooms/v11/#moving-the-redacts-property-of-mroomredaction-events-to-a-content-property

---------

Co-authored-by: Tulir Asokan <tulir@maunium.net>
@turt2live turt2live removed the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Sep 30, 2025
netbsd-srcmastr pushed a commit to NetBSD/pkgsrc that referenced this pull request Oct 8, 2025
chat/matrix-synapse: Update to 1.139.0
762c0cd 
# Synapse 1.139.0 (2025-09-30)

## Features

- Add experimental support for [MSC4308: Thread Subscriptions extension to Sliding Sync](matrix-org/matrix-spec-proposals#4308) when [MSC4306: Thread Subscriptions](matrix-org/matrix-spec-proposals#4306) and [MSC4186: Simplified Sliding Sync](matrix-org/matrix-spec-proposals#4186) are enabled. ([\#18695](element-hq/synapse#18695))
- Update push rules for experimental [MSC4306: Thread Subscriptions](matrix-org/matrix-spec-proposals#4306) to follow a newer draft. ([\#18846](element-hq/synapse#18846))
- Add `get_media_upload_limits_for_user` and `on_media_upload_limit_exceeded` module API callbacks to the media repository. ([\#18848](element-hq/synapse#18848))
- Support [MSC4169](matrix-org/matrix-spec-proposals#4169) for backwards-compatible redaction sending using the `/send` endpoint. Contributed by @SpiritCroc @ Beeper. ([\#18898](element-hq/synapse#18898))
- Add an in-memory cache to `_get_e2e_cross_signing_signatures_for_devices` to reduce DB load. ([\#18899](element-hq/synapse#18899))
- Update [MSC4190](matrix-org/matrix-spec-proposals#4190) support to return correct errors and allow appservices to reset cross-signing keys without user-interactive authentication. Contributed by @tulir @ Beeper. ([\#18946](element-hq/synapse#18946))

## Deprecations and Removals

- Remove obsolete and experimental `/sync/e2ee` endpoint. ([\#18583](element-hq/synapse#18583))

# Synapse 1.138.0 (2025-09-09)

## Features

- Support for the stable endpoint and scopes of [MSC3861](matrix-org/matrix-spec-proposals#3861) & co. ([\#18549](element-hq/synapse#18549))
itsoyou pushed a commit to famedly/synapse that referenced this pull request Oct 13, 2025
@SpiritCroc @tulir @itsoyou
Implement MSC4169: backwards-compatible redaction sending for rooms <…
3fd5cd8 
… v11 using the /send endpoint (#18898)

Implement
[MSC4169](matrix-org/matrix-spec-proposals#4169)

While there is a dedicated API endpoint for redactions, being able to
send redactions using the normal send endpoint is useful when using
[MSC4140](matrix-org/matrix-spec-proposals#4140)
for sending delayed redactions to replicate expiring messages. Currently
this would only work on rooms >= v11 but fail with an internal server
error on older room versions when setting the `redacts` field in the
content, since older rooms would require that field to be outside of
`content`. We can address this by copying it over if necessary.

Relevant spec at
https://spec.matrix.org/v1.8/rooms/v11/#moving-the-redacts-property-of-mroomredaction-events-to-a-content-property

---------

Co-authored-by: Tulir Asokan <tulir@maunium.net>
@turt2live turt2live added the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Nov 18, 2025
dbkr
dbkr reviewed Dec 2, 2025
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mscbot commented Jan 6, 2026

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

@mscbot mscbot added final-comment-period This MSC has entered a final comment period in interest to approval, postpone, or delete in 5 days. and removed proposed-final-comment-period Currently awaiting signoff of a majority of team members in order to enter the final comment period. labels Jan 6, 2026
@turt2live turt2live moved this from Ready for FCP ticks to In FCP in Spec Core Team Workflow Jan 6, 2026
@turt2live turt2live removed the 00-weekly-pings Tracking for weekly pings in the SCT office. 00 to make it first in the labels list. label Jan 7, 2026
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mscbot commented Jan 11, 2026

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

@mscbot mscbot added finished-final-comment-period and removed disposition-merge final-comment-period This MSC has entered a final comment period in interest to approval, postpone, or delete in 5 days. labels Jan 11, 2026
@turt2live turt2live merged commit 1caeb8f into main Jan 12, 2026
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@turt2live turt2live added spec-pr-missing Proposal has been implemented and is being used in the wild but hasn't yet been added to the spec and removed finished-final-comment-period labels Jan 12, 2026
@turt2live turt2live moved this from In FCP to Requires spec writing in Spec Core Team Workflow Jan 12, 2026
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zecakeh commented Jan 26, 2026

Spec PR: matrix-org/matrix-spec#2298

@turt2live turt2live added spec-pr-in-review A proposal which has been PR'd against the spec and is in review and removed spec-pr-missing Proposal has been implemented and is being used in the wild but hasn't yet been added to the spec labels Jan 26, 2026
@turt2live turt2live moved this from Requires spec writing to Requires spec PR review in Spec Core Team Workflow Jan 26, 2026
@tulir tulir added merged A proposal whose PR has merged into the spec! and removed spec-pr-in-review A proposal which has been PR'd against the spec and is in review labels Jan 27, 2026
@tulir tulir moved this from Requires spec PR review to Merged/Done in Spec Core Team Workflow Jan 27, 2026
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tulir commented Jan 27, 2026

Merged 🎉

@zecakeh zecakeh mentioned this pull request Jan 29, 2026
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riastradh pushed a commit to riastradh/pkgsrc-test20250901 that referenced this pull request Feb 8, 2026
chat/matrix-synapse: Update to 1.139.0
a42a0dc 
# Synapse 1.139.0 (2025-09-30)

## Features

- Add experimental support for [MSC4308: Thread Subscriptions extension to Sliding Sync](matrix-org/matrix-spec-proposals#4308) when [MSC4306: Thread Subscriptions](matrix-org/matrix-spec-proposals#4306) and [MSC4186: Simplified Sliding Sync](matrix-org/matrix-spec-proposals#4186) are enabled. ([\#18695](element-hq/synapse#18695))
- Update push rules for experimental [MSC4306: Thread Subscriptions](matrix-org/matrix-spec-proposals#4306) to follow a newer draft. ([\#18846](element-hq/synapse#18846))
- Add `get_media_upload_limits_for_user` and `on_media_upload_limit_exceeded` module API callbacks to the media repository. ([\#18848](element-hq/synapse#18848))
- Support [MSC4169](matrix-org/matrix-spec-proposals#4169) for backwards-compatible redaction sending using the `/send` endpoint. Contributed by @SpiritCroc @ Beeper. ([\#18898](element-hq/synapse#18898))
- Add an in-memory cache to `_get_e2e_cross_signing_signatures_for_devices` to reduce DB load. ([\#18899](element-hq/synapse#18899))
- Update [MSC4190](matrix-org/matrix-spec-proposals#4190) support to return correct errors and allow appservices to reset cross-signing keys without user-interactive authentication. Contributed by @tulir @ Beeper. ([\#18946](element-hq/synapse#18946))

## Deprecations and Removals

- Remove obsolete and experimental `/sync/e2ee` endpoint. ([\#18583](element-hq/synapse#18583))

# Synapse 1.138.0 (2025-09-09)

## Features

- Support for the stable endpoint and scopes of [MSC3861](matrix-org/matrix-spec-proposals#3861) & co. ([\#18549](element-hq/synapse#18549))
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