1070 Commits
Author SHA1 Message Date
Erik Johnston 3bbbbf5d04 Run homeserver shutdown handlers at the end of each test (#20509)
This fixes the test `ThreadedMemoryReactorClock` to support
`removeSystemEventTrigger`, which in turn allows the shutdown triggers
to run when `HomeServer.shutdown()` is called in the tests. Previously,
`ThreadedMemoryReactorClock.removeSystemEventTrigger` raised a
`NotImplementedError`,

`cleanup_test_reactor_system_event_triggers` cleared the triggers by
hand so that a homeserver could be garbage collected. `shutdown()` now
removes them itself, so the helper goes.

We can also remove all the `tearDown` implementations that tried to
manually trigger the shutdown as its not longer necessary to do so
manually. They also didn't work, as they indexed `reactor.triggers` as
`[eventType][phase]` when the keys are `[phase][eventType]`
2026-11-13 10:09:16 +00:00
Ayesha Waseem 9d8354419c Report a user in device_lists.changed when they join after being invited (#20487)
`DeviceHandler.get_user_ids_changed`, which the sliding sync e2ee
extension and `GET /keys/changes` use, adds a member to
`newly_joined_or_invited_or_knocked_users` only when the previous
membership was none of join, invite or knock. A user going from invite
to join is skipped, so other members are never told to refresh the
devices of a user whose device list changed while they were only
invited. Classic sync does report them.

A change to join from any membership other than join is now counted.
join -> join (a profile change) is still ignored.
`test_extension_e2ee.py` covers invite -> join, invite -> join -> leave
in one window and a profile change, `test_keys.py` covers invite -> join
through `/keys/changes`. Not covered: device list changes made while a
user is only invited (#3504), which are still not announced until the
user joins.

Fixes #20486
2026-11-10 14:11:31 +00:00
Erik Johnston 4e43a3f710 Fix sync lazy-loaded membership cache to correctly handle concurrent requests (#20435)
Follows on from #20289 and #20433. Properly fixes handling of concurrent
requests (on single workers).

This tries to fix two cases:
1. We are *computing* responses for multiple syncs at the same time,
which currently causes the cache to get cross-contaminated.
2. Two syncs concurrent syncs on the wire (but don't overlap during
processing). When the second request is processed we correctly forget
any entries from the first request, however we currently still update
the cache with members returned on the second request. However, there is
no guarantee that the second request is what the client actually reads.

We use three rules to handle concurrent requests:
1. A response only uses cached members recorded at or before the
request's `since`. Members recorded after it cannot be from an ancestor
sync response.
2. Once a response has been built, we forget all already cached members
recorded after its `since`. This handles the client reusing an older
`since` token. Doing it at the end of the build rather than the start
also forgets members recorded by responses built at the same time.
3. We track the highest position seen for the device (`_newest`), from
the `since` of each request and the `next_batch` of each built response.
A response only records its members if its `next_batch` is after that
position. This handles responses that end at the same position, or that
finish out of order.

With these rules, when concurrent requests happen we throw away all
existing cached members and don't record any further members until one
sync has advanced sufficiently such that there are no longer any
concurrent sync requests.


Note that ideally we'd have some sort of per-connection identity so that
we can track this properly (like in sliding sync). However, that is a
bigger change. Instead, we note that we just need to detect concurrent
requests, and not update the cache in those cases.

Also note, can only detect concurrent requests that go to the same
worker.
2026-11-10 13:15:03 +00:00
Hugh Nimmo-Smith 8e1e7dc0af Rate limiting, configurable TTL and correct auth responses for MSC4388 (sign-in with QR code) (#20404)
This PR should be reviewable on a commit-by-commit basis. If you would
prefer that it is broken down into multiple PRs then I can do so.

Fixes to match latest MSC4388:

- Return `200` with `create_available=false` for `GET` when configured
in `authenticated` mode and no access token presented
- Return `401` for a `GET` where an invalid/expired token is presented
- Return `404` for `DELETE` where session has expired but not yet
evicted

Features:

- Rate limiting which is configurable via
`experimental_features.msc4388_rc_create` (for `POST` and is per
requester for authenticated requests or per client IP for
unauthenticated requests) and
`experimental_features.msc4388_rc_requests` (for `GET`/`PUT`/`DELETE`).
- Allow the session TTL to be configured via the
`experimental_features.msc4388_session_ttl`. As per spec this is between
2 and 5 minutes.
- Concurrent sessions are unlimited for authenticated requesters
(subject to the rate limits).
- Unauthenticated requesters have a maximum concurrent sessions limit
(default 1,000) which is configurable by
`experimental_features.msc4388_max_unauthenticated_sessions`.

Misc:

- Code and comment cleanup

The experimental feature is tracked by
https://github.com/element-hq/synapse/issues/19433 and I will update it
with the new config options when this PR merges.
2026-11-05 15:00:12 +00:00
2e81f0785a Handle read receipts in Server Announcement rooms (#20427)
Co-authored-by: Quentin Gliech <quenting@element.io>
Co-authored-by: Andrew Morgan <andrew@amorgan.xyz>
2026-11-04 18:32:44 +00:00
Paul ChobertandQuentin Gliech 7593add0c5 Server Announcement Room Tags (#20448)
> [!NOTE]
> **Epic**: [Efficient Server
Announcements](https://github.com/element-hq/synapse/issues/20240)

In the previous PR, @anoadragon453 noted that we should sync account
data, see
https://github.com/element-hq/synapse/pull/20412#discussion_r4404823625.
Unfortunately, tagging required another change in the authorization
check.

This PR:
- [x] Allows synthetic members to set tags (eg: `m.favorite`)
- [x] Return tags of announcement rooms in Sync
  - [x] Legacy Sync
  - [ ] Sliding Sync
_Should merge the branch `barodeur/srv-announcements-sync-sliding` &
change the PR base branch_.
- [x] Always returns the tag `m.server_notice`
- [x] Prevent from removing the tag `m.server_notice`

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [ ] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Quentin Gliech <quenting@element.io>
2026-11-04 15:44:33 +01:00
Andrew Morgan e2661d692b Correctly invalidate announcement room ID mapping in unit tests (#20469) 2026-11-04 12:39:53 +00:00
Quentin GliechandAndrew Morgan 4902d34f93 [Server Announcements] Don't deliver announcement rooms to excluded users in legacy sync (#20465)
Follow-up to https://github.com/element-hq/synapse/pull/20407, which
added the `excluded_user_ids` option without enforcing it. This makes
legacy `/sync` respect it: users listed in a room's `excluded_user_ids`
no longer get that room through the synthetic join. They can still read
it, as it is world-readable.

The cached lookup now maps room ID to config ID, so the per-user filter
runs in memory and adds no database query to `/sync`.
`get_server_announcement_room_ids()` is kept as a wrapper, so the
stacked PRs are unaffected.

Known limitation, documented in the config docs: changing the list does
not update rooms that clients already have. A newly excluded user keeps
the room, which stops updating. A user removed from the list gets new
events without the room's state until their next initial sync. I think
that's an okay limitation for now, as we don't really expect this list
to be used for real users

---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-11-04 11:55:07 +01:00
bf9a68b017 Allow reading Server Announcement history outside of sync (#20423)
> [!NOTE]
> Epic: [Efficient Server
Announcements](https://github.com/element-hq/synapse/issues/20240)
> Follows: https://github.com/element-hq/synapse/pull/20372

This PR first tests that every user can read the server announcements
through the "history" endpoints like

- [x] `GET /rooms/{roomId}/messages`
- [x] `GET /rooms/{roomId}/context/{eventId}`
- [x] `GET /rooms/{roomId}/event/{eventId}`
- [x] `GET /rooms/{roomId}/relations/{eventId}`
- [x] `GET /rooms/{roomId}/threads`
- [x] `GET /rooms/{roomId}/initialSync`

This already works for users who have never been in the room, because
announcement rooms are world-readable.

It doesn't for a sender who was removed from the room's config: Synapse
still uses their `leave` membership and shows them the room as it was
when they left.
This PR then treats a user who left a configured announcement room like
a user who has never been in it.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
Co-authored-by: Quentin Gliech <quenting@element.io>
2026-11-03 19:04:28 +01:00
JimKnoxxandClaude Opus 5.5 dec679de1c Do not read media from disk when answering a HEAD request (#20368)
Fixes #20367

HEAD requests are routed to the GET handlers, so the media download
endpoints read the whole file and stream it to Twisted, which then
discards the body. Stop after writing the headers instead.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-03 15:06:03 +00:00
Paul ChobertandQuentin Gliech ab8f060746 Deliver Server Announcement over Legacy Sync (#20412)
> [!NOTE]
> **Epic**: [Efficient Server
Announcements](https://github.com/element-hq/synapse/issues/20240)
> Follows: https://github.com/element-hq/synapse/pull/20372

When a new announcement is sent in the announcement room, this PR will
ensure that the announcement and the room state are shared with the
client over Legacy Sync.

If you reviewed the PoC before, please note that there are several
differences:
- We intentionally don't wake all sync
- We don't want typing and receipts
- We don't need device lists

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Quentin Gliech <quenting@element.io>
2026-11-03 13:14:08 +01:00
Andrew Ferrazzutti 241dc05caa MSC4140 + MSC4354: Update sticky delayed event arg (#20378)
- For the dedicated delayed event scheduling endpoint, drop support for
setting the sticky duration in a query parameter, as MSC4354 is slated
to use only a body parameter for that
- Restrict the sticky duration for delayed events to being strictly
positive, analogously to #20350
2026-11-02 21:46:57 +00:00
Eric Eastwood 33aa953879 Merge branch 'master' into develop 2026-11-02 10:21:32 -06:00
Quentin Gliech e3e847083e [v1.164] Restore the unstable MSC2965 /auth_metadata endpoint (#20460)
This is a partial revert of
https://github.com/element-hq/synapse/pull/20143 to restore the unstable
`/auth_metadata` C-S API endpoint.

The details on why are in #20459 

Since this is affecting live clients (Rust SDK-based clients including
Element X iOS and Android), this PR is against the 1.164 release branch
as we plan to release 1.164.2 with this fix.

The CI failures are unrelated and were already fixed on `develop` in
https://github.com/element-hq/synapse/pull/20386. Please look at
`develop` counterpart of this PR
https://github.com/element-hq/synapse/pull/20461 for the green CI
2026-11-02 16:55:22 +01:00
Olivier 'reivilibre 0a88b4287e Fix MSC4354 Sticky Events that expired during sync processing being returned as expired events in the sticky section of the sync response. (#20349)
Part of: MSC4354 (Experimental Feature tracking issue #19409)

This is a bit of an edge case, but nonetheless good to handle.

The included regression tests failed before the fix.

- Fix sticky events that expired during sync processing being returned

  See discussion:

https://github.com/matrix-org/matrix-spec-proposals/pull/4354#discussion_r4209309068

  See MSC cautionary note:

https://github.com/matrix-org/matrix-spec-proposals/commit/9915d50437ac494efdd91244451f46fd1934168c

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-10-30 17:29:14 +00:00
Johannes Marbach 25492acda3 Stabilise MSC4143 (#20425)
This stabilizes the implementation of
https://github.com/matrix-org/matrix-spec-proposals/pull/4143 which
includes the following:

- Stable `/rtc/transports` as per
https://github.com/matrix-org/matrix-spec-proposals/pull/4143 and
https://github.com/matrix-org/matrix-spec-proposals/pull/4195. The
unstable endpoint is retained for backwards compatibility.
- Adding `m.rtc.slot` events to the state events retained during room
upgrades.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
2026-10-30 15:47:01 +00:00
Raphael Fakhri 56acc229a5 Return identity server errors from third-party invites instead of a 500 (#20401)
Fixes #19257.

When an identity server returns a non-2xx response to
`/_matrix/identity/v2/store-invite` during a third-party invite,
`ask_id_server_for_third_party_invite` lets the `HttpResponseException`
escape. The client receives a 500 `M_UNKNOWN` error and the real cause
(for example, `M_THREEPID_IN_USE`) is lost.

This change catches `HttpResponseException` and converts it with
`to_synapse_error()`, which matches how the other identity server calls
in `IdentityHandler` (bind, `requestToken`) already handle error
responses.

A new test in `ThreepidInviteTestCase` makes the identity server return
a 400 `M_THREEPID_IN_USE` error and checks that the client receives the
same code and errcode. The test fails on `develop` with `500 != 400` and
passes with this change.
2026-10-29 18:43:27 +00:00
Erik Johnston eca9a4acd3 Fix regression with lazy membership and concurrenet syncs (#20433)
Broke by #20289. Hopefully fixes element-hq/element-web#35567.

One subtle change in #20289 was that we started to filter rooms with
`full_state` set through the cache. This *should* be safe since none of
the membership events should have been previously sent down the sync.

However, there is a bug with the lazy-loaded member cache when two
concurrent syncs for the same device happens. The updates to the cache
from the handling of one request are immediately seen by the other
request, polluting the cache.

This is a relatively common scenario in Element Web when a user reloads
the page. The sync from before the reload is still being processed when
Synapse receives the initial sync from after the reload.

The full fix to correctly handle overlapping requests is a separate PR,
but this is a stop-gap measure that should help Element Web.
2026-10-29 16:06:13 +00:00
Jason Robinson 2ff51d3c7f Partially revert "Reject setting null profile field values" (#20422)
As per https://github.com/element-hq/synapse/issues/20419 this change
broke Element Web clearing user status, which basically means the client
is stuck with any status, and users cannot set a new one.

EW should move to use DELETE to clear user status, but until then we
should ensure the feature is not broken on existing clients in the wild.

Should we set a clear deprecation time for rejecting nulls? There might
be other clients using profile fields and doing PUT to clear the field.


Discussed in
[`#element-backend-internal:matrix.org`](https://matrix.to/#/!SGNQGPGUwtcPBUotTL:matrix.org/$b7zid3lLGdFDC8pwy1IvSPv3zl9y1fXEpnnBte9vcQU?via=jki.re&via=element.io&via=matrix.org)
[[1]](https://matrix.to/#/!SGNQGPGUwtcPBUotTL:matrix.org/$jTEcHlDBIvKRAKtV-ESXabkPkLia9B7C4JQVkoOxzj0?via=jki.re&via=element.io&via=matrix.org)

Reverts a part of https://github.com/element-hq/synapse/pull/20153 by
only rejecting null fields when the profile update stream is configured
(ie user status requirement).

Future work to unrevert tracked by
https://github.com/element-hq/synapse/issues/20424
2026-10-28 12:56:29 -05:00
Jason Robinson ee3fc37345 Partially revert "Reject setting null profile field values" (#20422)
As per https://github.com/element-hq/synapse/issues/20419 this change
broke Element Web clearing user status, which basically means the client
is stuck with any status, and users cannot set a new one.

EW should move to use DELETE to clear user status, but until then we
should ensure the feature is not broken on existing clients in the wild.

Should we set a clear deprecation time for rejecting nulls? There might
be other clients using profile fields and doing PUT to clear the field.


Discussed in
[`#element-backend-internal:matrix.org`](https://matrix.to/#/!SGNQGPGUwtcPBUotTL:matrix.org/$b7zid3lLGdFDC8pwy1IvSPv3zl9y1fXEpnnBte9vcQU?via=jki.re&via=element.io&via=matrix.org)
[[1]](https://matrix.to/#/!SGNQGPGUwtcPBUotTL:matrix.org/$jTEcHlDBIvKRAKtV-ESXabkPkLia9B7C4JQVkoOxzj0?via=jki.re&via=element.io&via=matrix.org)

Reverts a part of https://github.com/element-hq/synapse/pull/20153 by
only rejecting null fields when the profile update stream is configured
(ie user status requirement).

Future work to unrevert tracked by
https://github.com/element-hq/synapse/issues/20424
2026-10-28 11:34:02 -05:00
Johannes MarbachandOlivier 'reivilibre 0d28e93a7a Move the sticky events sliding sync extension to the global pos and MSC4508 scoping (#20363)
This includes the following:
    
- Implements ['Implicit Forward
Pagination'](https://github.com/matrix-org/matrix-spec/issues/2378).
Remove the extension's `since` and `next_batch` fields. The position is
now tracked via the global `pos`, with per-room connection state
recording how far each room has been sent so that `limit` paginates
without holding `pos` back and lost responses are re-delivered.
- Discussed in
https://github.com/matrix-org/matrix-spec-proposals/pull/4480#discussion_r4165887827
- Honour the `lists` and `rooms` fields.
- Send all unexpired sticky events when a room enters scope for the
first time or is newly joined, and catch up on events sent while a room
was out of scope when it re-enters.
- Enabling the extension partway through a connection returns all
unexpired sticky events for in-scope rooms, and re-enabling it after
disabling it returns the unexpired sticky events sent in the meantime.

I tried to split this up into standalone commits though the bulk of the
change is in the third commit.

---------

Co-authored-by: Olivier 'reivilibre <git.oo@emunest.net>
2026-10-26 14:02:22 +00:00
Hugh Nimmo-Smith d99e5fe783 Implement transaction IDs for MSC4388 and other updates (sign-in with QR code) (#19906) 2026-10-26 11:56:06 +00:00
Paul Chobert 26a92c7111 MSC4140: Reject scheduling a delayed event that the sender could not send at that time (#20266)
## What the MSC says

From MSC4140's [Auth rule
evaluation](https://github.com/matrix-org/matrix-spec-proposals/blob/b7cb09664fed684388ba656459d08cfaf786c1d1/proposals/4140-delayed-events-futures.md#auth-rule-evaluation):

> The server SHOULD also check the event could be sent when it is
scheduled and reject the request if not. In particular, servers SHOULD
check the sender is in the room (or otherwise authorized to send the
event) to avoid storing events for rooms the user is not in.

## This PR

- Checks the event against the room's auth rules as if it were sent now,
and returns the same 403 `M_FORBIDDEN` that `/send` and `/state` would.
- Changes to the sender's own membership are exempt: a join or knock can
be sent from outside the room, which is how this PR reads the MSC's "or
otherwise authorized". They are checked by the auth rules when they are
sent.

Here are a few examples:

| Delayed event | Before | After |
| ----------------------------------------------------------------- |
--------------------------------------- |
---------------------------------------- |
| `m.room.message` from outside the room | 200 `delay_id`, fails at send
time | 403 `M_FORBIDDEN` |
| Kick of another member from outside the room | 200 `delay_id`, fails
at send time | 403 `M_FORBIDDEN` |
| `m.room.name` from a member whose power level is too low | 200
`delay_id`, fails at send time | 403 `M_FORBIDDEN` |
| **Exception**: join of a public room from outside it | 200 `delay_id`,
joins at send time | unchanged |
| Join from outside the room, then a message due after it | both
accepted, message sent once joined | join accepted, message 403
`M_FORBIDDEN` |
2026-10-16 14:38:12 +01:00
Olivier 'reivilibre 4785f06e0e In legacy sync, lazy-load the memberships of the senders of MSC4354 Sticky Events. (#20362)
Part of: MSC4354 (Sticky Events, Experimental Feature tracking issue
#19409)

When a user is the sender of a sticky event that comes down sync, that
user is now in scope for having their lazy-loaded membership sent down
in sync.

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-10-15 20:26:51 +01:00
Andrew Morgan 98735bc6db Remove remaining references to lxml python dependency, which is no longer required (#20356) 2026-10-15 12:54:54 +00:00
Olivier 'reivilibreandAndrew Morgan 1423a29f93 Reject null profile field values (following an optional clause in the specification), in order to avoid clients accidentally harming interoperability. (#20153)
Depends on: https://github.com/matrix-org/complement/pull/914

`displayname` and `avatar_url` already did not permit nulls, seemingly
from #8223.

The specification at v1.15 does not permit `null` for those fields
either, so this seems consistent with historical specification.

This only changes behaviour for 'custom' fields.

---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-10-15 09:52:28 +01:00
Olivier 'reivilibre e86eb378af Require a strictly positive stickiness duration for MSC4354 Sticky Events. (#20350)
Part of: MSC4354 (Sticky Events, Experimental Feature tracking issue
#19409)

Since a zero value would be meaningless, don't accept it.

Spawns from
https://github.com/matrix-org/matrix-spec-proposals/pull/4354#discussion_r4211703962

- MSC4354 Sticky Events: only strictly positive durations are valid

  MSC clarified in

https://github.com/matrix-org/matrix-spec-proposals/commit/2d1c3d646aae3738680f8a9a0ccb38b2d941a45f
  to require strict positivity!

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-10-15 09:51:56 +01:00
Paul Chobert d773067277 MSC4140: authenticate the delayed event management endpoints and allow guests (#20257) 2026-10-13 16:24:30 +00:00
Paul Chobert 766f057305 Stop forwarding non compliant user ids (#20338)
Closes #20116

> [!NOTE]
> This PR Follows #20115 which already implemented this for
`m.device_list_update`

> User IDs with localparts containing characters outside the range
U+0021 to U+007E, or with
> an empty localpart, are considered non-compliant. For current room
versions, servers must
> still accept events using such user IDs over federation; however they
SHOULD NOT forward
> such user IDs to clients when referenced outside the context of an
event. For example,
> device list updates from non-compliant user IDs would be dropped by
the receiving server.
>
> — [Spec
1.19](https://spec.matrix.org/v1.19/appendices/#historical-user-ids)

This PR prevents from forwarding non compliant user ids for the
following events:

- `m.signing_key_update` 8c3c35e95d
- `m.presence` 26a8dfe862
- `m.typing` 1110cf2d73
- `m.receipt` 9e2da8b0a6
- `m.direct_to_device` 9541232a30
2026-10-13 11:10:48 +01:00
Richard van der Hoff 52f053abef Remove support for unstable MSC2965 (#20143)
These things are not needed now that MSC2965 has stabilised. In any
case, they
should never have been exposed without a config flag in the first place.
2026-10-12 16:43:38 +00:00
Will Hunt c52121d4b4 Add m.preview_url capability (Stabilise MSC4452) (#20298)
For https://github.com/element-hq/synapse/issues/19719

MSC4452 is now merged, so the stable capability can be made visible.
I've kept in the unstable flag in order to transition away at a later
date.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [ ] Pull request is based on the develop branch
* [ ] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [ ] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
2026-10-12 14:40:44 +01:00
Will Hunt 91020a9518 Short-circuit push rule evaluation when only one user is in a room (#20315)
This speeds up the /createRoom calls a tiny bit by not checking the
senders push rules.

This helps speed up a lot of test runs in Element Web which 
runs a lot of tests in one-person rooms (and creates a heck of a lot of rooms)
2026-10-12 11:56:27 +01:00
40acb97022 MSC4140: drop delayed state interference (#19495)
No longer cancel a user's delayed state events by a more recent state
event sent from a different user. This behaviour has been delegated to
an "alternative" in the delayed event MSC for some time now, and is not
known to be used by any module other than experimental iterations of
MatrixRTC.

See also: https://github.com/matrix-org/complement/pull/845

Opens: https://github.com/element-hq/synapse/issues/20311

---------

Co-authored-by: Olivier 'reivilibre' <olivier@librepush.net>
Co-authored-by: Paul Chobert <paul@chobert.fr>
2026-10-12 10:33:13 +01:00
MANI K 5e78aad7d7 Default request token errors to privacy-preserving responses (#20243)
## Summary

- default `request_token_inhibit_3pid_errors` to `true` to prevent
account enumeration
- document the new default and the explicit opt-out
- add an upgrade note and regression coverage for the default

Fixes #18415.
2026-10-09 13:26:31 +01:00
Olivier 'reivilibre 36f3e1df4b Apply the MSC4354 Sticky Events history visibility exemptions on all client-server endpoints. (#20295)
Part of: MSC4354 (Experimental Feature tracking issue:
https://github.com/element-hq/synapse/issues/19409)

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-10-09 11:15:36 +01:00
Paul ChobertandEric Eastwood 3c46a10955 Stabilise MSC4222: support the stable use_state_after identifiers on /sync (#20170)
Part of #19414 (Support Matrix 1.16).

⚠️ Before merging, wait for the following PRs to be merged first:
- https://github.com/element-hq/synapse/pull/20081
- https://github.com/element-hq/synapse/pull/20169
- https://github.com/element-hq/synapse/pull/20171

---

Since Matrix 1.16, the
[spec](https://spec.matrix.org/v1.19/client-server-api/#get_matrixclientv3sync)
defines the stable identifiers for
[MSC4222](https://github.com/matrix-org/matrix-spec-proposals/pull/4222):
the `use_state_after` query parameter on `GET /_matrix/client/v3/sync`,
and the `state_after` room response field:

> **`use_state_after`** — `boolean` — Controls whether to receive state
changes between the previous sync and the start of the timeline, or
between the previous sync and the end of the timeline. If this is set to
`true`, servers MUST respond with the state between the previous sync
and the end of the timeline in `state_after` and MUST omit `state`. […]
>
> **`state_after`** — […] Required if `use_state_after` was set to true
in the request, even if it is empty. Added in `v1.16`
>
> — [Matrix
Spec](https://spec.matrix.org/v1.19/client-server-api/#get_matrixclientv3sync)

Synapse so far only implemented the unstable identifiers
(`org.matrix.msc4222.use_state_after` /
`org.matrix.msc4222.state_after`), gated behind the `msc4222_enabled`
experimental flag and the per-user experimental features admin API.

This PR:

- accepts the stable `use_state_after` query parameter, unconditionally,
and responds with the stable `state_after` field. The unstable query
parameter is kept for a transition period; clients opting in with it get
the unstable response field name back, so unstable-era clients see an
unchanged wire format. If both parameters are set, the stable one wins.
- removes the `msc4222_enabled` experimental flag and the `msc4222`
per-user feature from the experimental features admin API, since the
behaviour is no longer gated.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Eric Eastwood <madlittlemods@gmail.com>
2026-10-08 15:14:23 +02:00
Olivier 'reivilibre 815d2e0c7d Remove the stickiness of MSC4354 Sticky Events when they are redacted after persistence. (#20323)
Part of: MSC4354
Part of: #19641
Follows: #20232 (redacted before persistence), #20322 (redacted during
persistence)

Original commit schedule, with full messages:

- Add tests for redaction of Sticky Events

- Add `delete_sticky_events_txn`

- Remove stickiness from validly redacted events at persistence


### Dev notes

Overview:

- [`#20232`](https://github.com/element-hq/synapse/pull/20232) (redacted
before persistence)
- [`#20322`](https://github.com/element-hq/synapse/pull/20322) (redacted
during persistence)
- [`#20323`](https://github.com/element-hq/synapse/pull/20323) (redacted
after persistence)

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-10-08 10:04:08 +01:00
Paul Chobert 42ddc70ea7 Remove the legacy mention push rules by default (#20220)
Part of #19415 (Support Matrix 1.17).

Companion test PRs:
- Complement: https://github.com/matrix-org/complement/pull/920
- Sytest: https://github.com/matrix-org/sytest/pull/1430

**What this does:** `experimental_features.msc4210_enabled` default
value changed `true`
([MSC4210](https://github.com/matrix-org/matrix-spec-proposals/pull/4210)).
The rest of the changes is fixing the tests, making sure test relying en
mentions sends the proper `m.mentions` attribute.

## Migration plan

Element Web has been writing both rule sets together since September
2023
([matrix-react-sdk#11667](https://github.com/matrix-org/matrix-react-sdk/pull/11667),
[element-web@0d367a7c7e](https://github.com/element-hq/element-web/commit/0d367a7c7e)),
so for its users `.m.rule.is_user_mention` and `.m.rule.is_room_mention`
already carry the same customisations as the legacy rules.

<strike>For everyone else, #20215 adds a background update that migrates
the overrides on the legacy rules to the intentional ones.</strike>

## Opt-out

```yaml
experimental_features:
  msc4210_enabled: false
```

---

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
2026-10-08 11:03:30 +02:00
Paul Chobert 46ff03f93a Reject modifying server-default push rules that are not served (#20202)
TLDR: `PUT` on a server-default push rule now applies the same existence
check that `GET` already does. A rule that is not served cannot be
modified.

Synapse ships some server-default push rules behind experimental feature
flags, so the set of server-default rules a user has depends on the
server's configuration. Most flags add rules that only exist while the
flag is on.
[MSC4210](https://github.com/matrix-org/matrix-spec-proposals/pull/4210)
works the other way: it removes the three legacy mention rules while its
flag is on. The flags that change the set are:

- `msc1767_enabled`:
[MSC1767](https://github.com/matrix-org/matrix-spec-proposals/pull/1767)
extensible events rules
- `msc3381_polls_enabled`:
[MSC3381](https://github.com/matrix-org/matrix-spec-proposals/pull/3381)
poll rules
- `msc3664_enabled`:
[MSC3664](https://github.com/matrix-org/matrix-spec-proposals/pull/3664)
reply rule
- `msc4028_push_encrypted_events`:
[MSC4028](https://github.com/matrix-org/matrix-spec-proposals/pull/4028)
encrypted event rule
- `msc4306_enabled`:
[MSC4306](https://github.com/matrix-org/matrix-spec-proposals/pull/4306)
thread subscription rules
- `msc4210_enabled`: removes `.m.rule.contains_display_name`,
`.m.rule.contains_user_name` and `.m.rule.roomnotif`

`GET /pushrules/` only lists the rules that exist for that
configuration. `GET` on a single rule that is not in the set returns
`404 M_NOT_FOUND`. The same set is used to evaluate notifications, and
to build the `m.push_rules` account data in `/sync`.

`PUT .../enabled` and `PUT .../actions` did not use that set. They
accepted any rule ID that Synapse knows about, whether or not the server
currently serves it. Clients could modify a rule the server had just
said did not exist. The request returned `200`, the change was stored,
and it was then ignored. Both endpoints now return `404 M_NOT_FOUND` for
such a rule, as [the spec
requires](https://spec.matrix.org/v1.19/client-server-api/#put_matrixclientv3pushrulesglobalkindruleidenabled)
for a rule that does not exist.

Before (`msc4210_enabled: true`):

```
GET /_matrix/client/v3/pushrules/global/override/.m.rule.roomnotif
  404 {"errcode": "M_NOT_FOUND", "error": "..."}

PUT /_matrix/client/v3/pushrules/global/override/.m.rule.roomnotif/enabled
  {"enabled": false}
  200 {}
```

After:

```
GET /_matrix/client/v3/pushrules/global/override/.m.rule.roomnotif
  404 {"errcode": "M_NOT_FOUND", "error": "..."}

PUT /_matrix/client/v3/pushrules/global/override/.m.rule.roomnotif/enabled
  {"enabled": false}
  404 {"errcode": "M_NOT_FOUND", "error": "Unknown rule"}
```

This is a no-op for default configurations. All of these flags are off
by default, and rules that are served are still modifiable as before.
2026-10-08 08:57:58 +01:00
dc1291aa65 MSC4140: add dedicated endpoint for delayed events (#19354)
Use a new, dedicated endpoint for scheduling delayed events. This should
deprecate the `delay` query parameter on the `/send` and `/state`
endpoints.

Co-authored-by: Paul Chobert <paul@chobert.fr>
Co-authored-by: Eric Eastwood <erice@element.io>
2026-10-08 05:02:12 +00:00
Will Hunt 63bade4325 Skip running delayed event background job if the room event stream has not advanced. (#20316)
In a similar vein to #20315, this attempts to speed up Synapse when
delayed events aren't in use. Here we skip doing any work if the room
event stream has not advanced.
2026-10-07 14:57:56 +01:00
Hugh Nimmo-SmithandAndrew Morgan 52835fc397 Don't store file on disk after media upload limit failure (#20006)
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-10-07 12:05:01 +00:00
Olivier 'reivilibreandEric Eastwood 7773f05596 Use sharded tokens in MSC4354: Sticky Events sync and sliding sync, preventing events appearing in multiple sync responses. (#20186)
Fixes: #19661
Part of: MSC4354

First introduced some helpers for querying a sharded stream, which were moved to
https://github.com/element-hq/synapse/pull/20108.

- SQL builder for 'give me rows between two sharded tokens'
- a function to return the 'new' from_token after a limited read


Then make the sticky events portions of both oldschool and sliding sync use
sharded tokens.

This prevents a 'torn sync' problem where, because the events and sticky
events streams are both sharded with the same writers:

1. persisting a sticky event leads to an event row and a `sticky_events`
row being created for event `e` (on writer `W`).
2. Suppose another writer is still persisting, so the position of the
stream for writer W advances, but the global
['linear'](https://element-hq.github.io/synapse/latest/development/synapse_architecture/streams.html?highlight=%E2%80%9Clinear%E2%80%9D#current-stream-id)
(I have been calling this 'baseline') position does not advance yet.
3. sync is sharding-aware for the regular events stream, so `e` appears
as a real-time timeline event, thus coming down sync
4. since sticky events were not sharding-aware, `e` is not detected as a
sticky event in this sync response. The sticky event position doesn't
advance in the sync token, either.
5. (assume the position advances because other writers have finished
writing and so the 'linear' position advances for the sticky events
stream)
6. the client then syncs again, using the new sync token. This time, `e`
appears in the sticky event section.

If we make sticky events sharding-aware in sync, then `e` would appear
for consideration in both the timeline section **and** the sticky event
section in the first sync.
It then gets deduplicated out of the sticky section since it is
appearing in the timeline section in the same sync.

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
Co-authored-by: Eric Eastwood <erice@element.io>
2026-10-05 12:40:55 +01:00
4f5524043c Use beautifulsoup4 instead of lxml for URL previews (#19301)
Use `beautifulsoup4` instead of `lxml` for URL previews. This offers
some nicer APIs when parsing HTML and avoids using `libxml`, [which is
unmaintained](https://gitlab.gnome.org/GNOME/libxml2/-/commit/9c80a89af2fdf4f853892f84e46580f4902658ba).

I haven’t done a full regression against commonly previewed sites, but I
expect this will give similar (or better) results.

beautiulsoup also handles decoding the charset for us, which is less
custom code.

---------

Co-authored-by: Andrew Morgan <andrew@amorgan.xyz>
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-10-02 15:46:34 +01:00
Erik Johnston 5a8c4b3990 Fix bug where /sync would not return membership changes due to lazy-loaded membership cache (#20289)
In `/sync` there is a mode called lazy loaded (LL) members. In this mode
`/sync` does not return all memberships in the room, instead it only
returns a) membership changes, and b) the memberships of senders of
events in the timeline (if not previously sent).

Synapse implements a lazy-loaded member cache to avoid repeatedly
sending down the same memberships when a single user sends multiple
events. It does this by storing for each user/device the memberships it
has previously returned in an LRU cache. Note that it is fine for the
server to return the same membership, clients handle that fine, but it
is a waste of bandwidth.

The current lazy-loaded membership cache has three intertwined flaws:
1. It does not handle retries or clients re-using old tokens.
2. It incorrectly applies the membership cache to membership changes,
not just memberships added by lazy-loading.
3. It does not correctly handle multiple "sync streams" from the same
device.

In this PR we explicitly fix the first two issues in two commits, and
the third issue is mitigated:

1. Alongside each membership in the LL cache we store the `next_batch`
position of the response that carried it. A client that processed a
response syncs from its `next_batch` next. When a request arrives with a
`since` token, we delete every membership recorded after that token, as
they were sent in responses the client never processed. Memberships
recorded at or before `since` are kept.
2. We always return memberships that have changed, even if they appear
in the LL member cache.

These changes also half mitigate the issue of running multiple `/sync`
loops per-device (though we do not see this in the wild), as we'd at
least always return the changed membership states.

Fixes #19978 and #20278, supersedes #20279
2026-10-02 09:48:14 +01:00
Andrew Morgan b3c67110a5 Bump Twisted in poetry.lock from 25.5.0 to 26.4.0 (#20259) 2026-09-29 17:50:55 +00:00
Ankit Jha 18c10b8075 Fix 500 error when user-interactive auth requests send a null or non-object auth (#20274)
Fixes #15871

### What was broken

Sending `{"auth": null}` to any endpoint that requires user-interactive
auth (for example `POST /keys/device_signing/upload`, `DELETE
/devices/{deviceId}` or `POST /register`) returned a 500 instead of the
usual 401 with the available flows. A non-object `auth` on endpoints
that do not validate the body with a model (such as `/register`) could
also 500, e.g. `{"auth": ["session"]}`.

### Root cause

`AuthHandler.check_ui_auth` did `clientdict.pop("auth", {})`, so the
`{}` default only applies when the key is missing. An explicit `null`
came through as `None` and the following `"session" in authdict` raised
`TypeError`. `get_session_id` had the same assumption that `auth` is a
dict.

### Pull Request Checklist

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Signed-off-by: Ankit Jha <ankit.jha@tradomate.one>
2026-09-28 18:36:39 +00:00
Jason Robinson b0d44f9352 Fixes to the profile update stream when a user leaves a room (#20203)
This pull request fixes a few issues with the profile update stream,
when a user leaves a room. This is basically just mimicking what we
already had for when someone leaves a room, and they no longer share any
rooms, but in reverse - ie when we leave a room, and no longer share
rooms with some users. This was missed in the implementation when adding
the profile update stream for legacy and sliding sync.

[Fix missing profile update stream rows on user leaving
room](https://github.com/element-hq/synapse/commit/e953322226731a99718ebe13139b9c5f05ae4b62)

When a user leaves a room, profile update stream rows are generated with
the `LEFT_ROOM` action for each user in the room that no longer shares a
room with the user who left the room.

This also needs to happen in reverse. The user who left the room needs
to have a profile update stream row for each user they no longer share a
room with.

If we don't do this, clients may keep stale data around even after they
don't share a room with a user, which may mean they don't know when to
refetch profiles after re-joining a room with the stale profile data
user.

[Clear out old profile update stream rows when leaving a
room](https://github.com/element-hq/synapse/commit/e7642bf141b098c1eefaf74655e5e7e18415500b)

When we leave a room, ensure profile update stream rows are cleared out
for every user we no longer share a room with. This is the same as what
happens when someone else leaves a room, but in reverse. The only
remaining profile update stream row should be the `LEFT_ROOM` action.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))
2026-09-24 21:22:08 +00:00
Olivier 'reivilibre 62cb420a0e Send all of a room's MSC4354 Sticky Events down oldschool /sync when a user joins it. (#20233)
Part of: MSC4354 whose experimental feature tracking issue is
https://github.com/element-hq/synapse/issues/19409
Part of: #19662

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-09-24 15:28:06 +01:00
64f0590705 MSC4140: cancel a user's delayed events when their account is deactivated (#20247)
[MSC4140](https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/4140-delayed-events-futures.md),
"Account deactivation":

> when an account is deactivated, the homeserver MUST cancel that
account's delayed events which have not yet been added to a room's event
DAG. These cancelled records MAY be removed immediately, including their
stored event content, as an exception to the usual finalised-record
retention policy.

Deactivation currently leaves the user's scheduled delayed events,
including their content, in place, and they are still attempted at their
scheduled time:

| Delayed event scheduled by the user | What happens after deactivation
today |
| --- | --- |
| Message or state event, fires after deactivation has made the user
leave the room | The send fails with a 403 (user not in room) and the
record is dropped |
| Message or state event, fires before deactivation has made the user
leave the room (leaving happens room by room in the background) | The
event is sent |
| `m.room.member` join for themselves in a public room | The deactivated
user re-joins the room |

### What changes

- Deactivating an account (client or admin API) removes the user's
unsent delayed events as its first step, and re-arms the send timer for
whatever is scheduled next.
- Deactivation can run on a worker, while the send timer lives on the
main process, so the cancellation goes through a new replication
request.
- A delayed event whose send has already started is left alone, as with
a normal cancel: it is already on its way into the DAG, and the send
path removes its record itself.

Suspension and locking are unchanged.

### After #19038

Today a cancelled delayed event is simply deleted, so this PR deletes
the user's records too. #19038 changes cancellation to keep the record
and mark it as cancelled ("finalised"), so that clients can look up what
happened to a delayed event. Once it has landed, deactivation should
probably finalise the user's records as cancelled the same way, rather
than delete them. The MSC allows either: it permits removing the records
immediately, content included, as an exception to the usual retention of
finalised records, which is worth doing at least when the user asks to
be erased.

### Pull Request Checklist

<!-- Please read
https://element-hq.github.io/synapse/latest/development/contributing_guide.html
before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
file](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#changelog).
The entry should:
- Be a short description of your change which makes sense to users.
"Fixed a bug that prevented receiving messages from other servers."
instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
  - Use markdown where necessary, mostly for `code blocks`.
  - End with either a period (.) or an exclamation mark (!).
  - Start with a capital letter.
- Feel free to credit yourself, by adding a sentence "Contributed by
@github_username." or "Contributed by [Your Name]." to the end of the
entry.
* [x] [Code
style](https://element-hq.github.io/synapse/latest/code_style.html) is
correct (run the
[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

---------

Co-authored-by: Andrew Ferrazzutti <af_0_af@hotmail.com>
Co-authored-by: Andrew Ferrazzutti <andrewf@element.io>
2026-09-24 10:05:33 +02:00