Commit Graph
1041 Commits
Author SHA1 Message Date
Erik JohnstonandClaude Opus 5.5 32448196cc Drop the rust_sync gate on an unshared event cache
`rust_sync: on` was refused unless `rust_sync_allow_unshared_event_cache`
was set, because the Rust sync handler held a second copy of every event
it served. Python and Rust now share one event cache, so the gate and its
option go.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VpBQxvqZTUvHCMm3u6CR7J
2026-10-15 12:14:54 +00:00
Erik JohnstonandClaude Opus 5.5 47367a14a2 Make the Rust event cache EventsWorkerStore's event cache
`EventsWorkerStore._get_event_cache` is now the Rust `EventCache` that the
sync handler and state resolution read, so each event is held once.

The cache keeps Rust `CachedEvent` values. Python gets them through
`RustEventCache`, a `RustCache` subclass with the `AsyncLruCache` names the
rest of Synapse uses, and each hit wraps the cached event in a new `Event`
object. The wrapper shares the cached event's internal metadata, unsigned
data and signatures, so a change Python makes, such as adding
`prev_content` or flipping `outlier`, lands in the one copy the Rust
readers see. Python's `_event_ref` weak map is checked before the cache,
so while anything holds an event, a lookup returns that same object, as
before. A hit there marks the cache entry as read, and puts the event back
if it was evicted.

- The cache is sized from `caches.event_cache_size` and named
  `*getEvent*`, so its metrics and `per_cache_factors` keep their names.
  The Rust loader now counts its misses too.
- Invalidating an event drops its chain position as well, and a room
  purge drops the room's events through the room index, plus the chain
  cover and state group caches, as `RustStore.invalidate_event` and
  `clear_event_cache` did. Those two calls are gone.
- `EventsWorkerStore` and `RustWorkerStore` run their `__init__` bodies
  in a different order in `DataStore` and `GenericWorkerStore`, as they
  sit differently in each MRO. So whichever runs first builds the
  `RustStore`. A datastore without `RustWorkerStore`, such as the port
  script's, gets a standalone `RustEventCache`.
- The external cache stubs (`get_external`, `set_external`,
  `_invalidate_async_get_event_cache` and its room variant) are dropped.
  They were documented no-ops.
- The sync shadow diff still ignores `prev_content` on state events.
  Python keeps the objects it holds after the cache evicts them, so a Rust
  reader can still load a second copy without it. Trial's cache of one
  event makes that routine.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VpBQxvqZTUvHCMm3u6CR7J
2026-10-15 12:14:54 +00:00
Erik JohnstonandClaude Opus 5.5 6c7b4975bc Dispatch the rooms section of sync to Rust
With `rust_sync: on`, Python hands the rooms section to the Rust handler in
two calls, fetching the sticky events of newly joined rooms between them.
Python computes the rooms the Rust handler leaves to it. If the Rust
handler fails to work out the room changes, Python computes the whole
section.

Shadow mode runs the Python and Rust sections at once. It compares the room
changes (newly joined and left rooms, invites and knocks) as well as each
room's entry.

Python still computes what feeds the steps before the rooms: the joined
rooms of `get_sync_result_builder`, ephemeral events, room account data,
tags and sticky events. It also drops the invites of ignored users and those
the invite rules ignore.

The unknown room version test also clears the Rust event cache, as the
restart it stands for would.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R5b7Ruy4cgt27Mjq6Ptxbb
2026-10-15 09:45:45 +00:00
Erik JohnstonandClaude Opus 5.5 a28082a499 Dispatch sync rooms to Rust in rust_sync shadow and on modes
`on` serves each joined or archived room from the Rust handler. A room the
Rust handler cannot compute, or fails on, is computed by Python. Python's
fallback rooms share the Rust handler's lazy-loaded members caches, so a
room that moves between the two does not resend members.

`shadow` serves Python's entry and compares the Rust one with it, counting
the outcome in synapse_sync_rust_shadow_total. The two run at once, so the
response waits for the slower. Cancellation stops both.

Config parsing refuses `on` while the Rust and Python event caches are
separate, unless `rust_sync_allow_unshared_event_cache` is set. Under trial,
a Rust error or a shadow mismatch fails the test.

The call invite test now builds its events for the room's own version. An
event of another version is stored, but the Rust event loader cannot read
it back.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0194eNQP5weBtVMg8NKtc6VU
2026-10-14 23:14:41 +00:00
Erik JohnstonandClaude Fable 5.1 1abc57e826 Add the Rust sync handler skeleton behind experimental_features.rust_sync
`rust_sync` takes `off`, `shadow` or `on`, as `rust_state_res` does, and
`RustHandlers.sync` is built when the main database uses the native Rust
driver. The Python `SyncHandler` reads the option and takes the Rust
handler, warning and keeping the Python path when the driver is not the
Rust one. Nothing is served by Rust yet: the per-room entry points come
with the ports that follow.

Trial gets the same plumbing the state resolution has: `SYNAPSE_TEST_
RUST_SYNC` sets the option on every test homeserver, and the Rust handler
is wrapped so that each entry point's `_blocking` twin answers under the
fake reactor.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0194eNQP5weBtVMg8NKtc6VU
2026-10-14 13:35:25 +00:00
Erik JohnstonandClaude Opus 5.5 34fdef7a9d Use the Rust auth rules from Python
check_state_dependent_auth_rules and auth_types_for_event now call the
Rust implementation, so every caller (federation, sticky events, state
res v1 and v2) uses it. The Python helpers that only they used are gone.
The ed25519 check for third-party invites stays in Python, as a helper
the Rust rule calls.

auth_types_for_event returns its pairs in the order the Python added
them. Event creation lists the auth events in the set's iteration
order, so a Rust HashSet's random order changed event IDs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ULdieJyQoHNzeHq42H2M1p
2026-10-13 10:49:24 +00:00
694ad6bfa7 Fix leave event missing from state_after on incremental sync (#18793) (#20081)
Fixes https://github.com/element-hq/synapse/issues/18793


When the last local user leaves a room, Synapse clears
`current_state_events` and writes `null` `event_id` entries into the
`current_state_delta_stream`. The incremental sync code for MSC4222's
state_after skipped those `null` deltas entirely, and
`get_current_state_ids` also returned nothing (table already cleared).
Result: clients using `state_after` never learned about the leave.

Fix by falling back to state groups (which are preserved) to look up the
actual state at `end_token` for any cleared state keys.

### 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).
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: Paul Chobert <paul@chobert.fr>
Co-authored-by: Quentin Gliech <quenting@element.io>
Co-authored-by: Eric Eastwood <madlittlemods@gmail.com>
2026-10-08 15:11:22 +02:00
Jason RobinsonandEric Eastwood e36ce7df9b Filter out MSC4426 User Status profile fields for remote users (#20328)
Several clients, including Element Web/Desktop and Element X, have
already implemented
[MSC4426](https://github.com/matrix-org/matrix-spec-proposals/pull/4426)
User Status profile fields. However, we have only implemented sending
profile fields down sync for local users
([MSC4429](https://github.com/matrix-org/matrix-spec-proposals/pull/4429)/[MSC4262](https://github.com/matrix-org/matrix-spec-proposals/pull/4262)),
since federation support for pushing profile field updates from server
to server has not yet been implemented
([MSC4259](https://github.com/matrix-org/matrix-spec-proposals/pull/4259)).

This has created user confusion. The before mentioned clients use the
profile and/or profile field fetch endpoints to fetch missing profile
information, regardless of the user being local or remote. Since the
sync response isn't delivering these profiles, the client does a
fallback fetch, causing a one time update of the profile information
over federation.

This causes stale data to be cached in the client for the remote user,
which in the case of EW for example is never cleared.

This filtering should be temporary until MSC4259 is implemented and the
remote profile data also syncs via the profile update stream to clients.

I suggest making this not configurable so we don't have to maintain a
configuration property, as hopefully this would only be a case for a few
months at most.

### 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 10:29:33 +00:00
Paul Chobert a93175ccb5 Skip application services with url: null when notifying them of events (#20273)
ESS deployments of MatrixRTC are going to run `lk-jwt-service` as an
application service so that it can manage delayed events. However,
setting up an application service is particularly inefficient, as
Synapse iterates through all the events of the rooms it covers since
their creation.

When an application service is configured with `url: null`, there is no
need to traverse all the events for it, so we can set up such
application services much faster without having to decide what to do for
other application services. Discussions about those are still open:
element-hq/synapse#11629 (see also matrix-org/synapse#1834).


### 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 07:35:37 +00:00
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
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
Paul ChobertandOlivier 'reivilibre db618e276d Fix appservice ephemeral read receipts being permanently skipped on large receipt bursts (#20108)
Fixes https://github.com/element-hq/synapse/issues/20096.

Part of https://github.com/element-hq/synapse/issues/18118

The spec requires read receipts to be delivered to interested
application services ([Pushing ephemeral
data](https://spec.matrix.org/v1.19/application-service-api/#pushing-ephemeral-data)):

> If the `receive_ephemeral` settings is enabled in the registration
file, homeservers MUST send ephemeral data that is relevant to the
application service via the transaction API, using the `ephemeral`
property of the request's body.
>
> `m.receipt`: MUST be sent to the application service under the same
rules as regular events, meaning that the application service must have
registered interest in the room itself, or in a user that is in the
room.

Ephemeral data delivery to application services was added in Matrix
v1.13 from
[MSC2409](https://github.com/matrix-org/matrix-spec-proposals/pull/2409)
(see the [v1.13
changelog](https://spec.matrix.org/v1.19/changelog/v1.13/#application-service-api)).

## Problem

When more than 100 read receipts are covered by a single receipt stream
update, only the last 100 are sent to appservices. The rest is
permanently skipped.


## Proposed Fix

- Looping over the receipts in batches of 100 items and updating the
cursor on every iteration
- Keep the fast-forward behavior for new appservices as intended in
https://github.com/matrix-org/synapse/pull/8744

---------

Co-authored-by: Olivier 'reivilibre <oliverw@element.io>
2026-09-29 12:06:15 +01:00
Ankit Jha 929e3524d1 fix: reject user creation via the admin API when delegating to MAS (#20241)
Signed-off-by: Ankit Jha <jhaankit373@gmail.com>
Signed-off-by: Ankit Jha <ankit.jha@tradomate.one>
2026-09-28 10:17:37 +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
Eric Eastwood 625b331768 MSC4311: Use full PDU's in stripped state (like invite_room_state) over federation and always include m.room.create event (#19723)
### Background

This PR was originally just trying to remove the flawed [MSC4311](https://github.com/matrix-org/matrix-spec-proposals/pull/4311) partial implementation as client side API's like `/sync` should still use stripped events. But it turns out we were just re-using the client logic for the federation side and things might break if we didn't include the full `m.room.create` event so this PR now introduces MSC4311 support to use full PDU's in the `invite_room_state`/`knock_room_state` in the federation API's.

The flawed implementation was originally introduced in https://github.com/element-hq/synapse/commit/0eb7252a230811e59679cc7e55b92dac26532efc (no PR I assume because part of Hydra security fix) which was part of [Synapse v1.136.0](https://github.com/element-hq/synapse/blob/7530874a1250d6ad975b39582a784c594d29a505/CHANGES.md#synapse-11360-2025-08-12).

Spawning from reviewing https://github.com/element-hq/synapse/pull/19722 and noticing that we have [`TestMSC4311FullCreateEventOnStrippedState`](https://github.com/matrix-org/complement/blob/1e2e12eebc1edb27bbf12108ec849a8254b6ddcd/tests/v12_test.go#L1341-L1376) in Complement which already passes even though that test looks [flawed](https://github.com/matrix-org/complement/pull/791#discussion_r3132468346):

> I think this test is mixing up what [MSC4311](https://github.com/matrix-org/matrix-spec-proposals/pull/4311) proposes. Perhaps these were changes to the MSC that came after?
> 
> For the client API's like `/sync`, it only proposes that `m.room.create` is a required *stripped* state event.
> 
> For the federation API's, alongside requiring `m.room.create`, it also mandates using the full event PDU format for all events in the `invite_room_state`/`knock_room_state` on `m.room.member` events (in `unsigned`)

### What does this PR do?

 1. Always use stripped state for client API's
    1. Remove flawed [MSC4311](https://github.com/matrix-org/matrix-spec-proposals/pull/4311) partial implementation (as explained above)
    1. Sanitize stripped state when we receive events over federation
 1. Use full PDU's when sending `invite_room_state`/`knock_room_state` over federation
 1. Validate PDU's and warn when receiving `invite_room_state`/`knock_room_state` over federation
     1. In the future, we will strictly validate and reject

Complement tests: https://github.com/matrix-org/complement/pull/796

---

Part of https://github.com/element-hq/synapse/issues/19414
2026-09-22 11:57:54 -05:00
Erik JohnstonandClaude Opus 5 9b5697d378 Move per-homeserver Rust state into a RustRuntime object on the HomeServer (#20011)
Previously the tokio runtime was stashed in a hidden attribute on the
reactor object, installed lazily by whichever Rust code first needed it,
and started via `callWhenRunning`.

Instead, we create a `RustRuntime` (accessible via
`HomeServer.get_rust_runtime()`) that holds any per-reactor Rust state,
such as the tokio runtime. It is constructed lazily on use. Rust
consumers (`HttpClient`, `VersionsHandler`, the Python DB pool wrapper)
now receive the runtime or reactor handle explicitly, and the
`reactor.run()` / manual-startup workarounds in tests are no longer
needed.

We also add helper wrappers in Rust for `Reactor` and `HomeServer` that
exposes the needed functionality.

The aim is to allow us to have a Rust-side clock (mainly to get the
current time), that respects the unit test per-reactor time management.

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-09-21 18:48:37 +01:00
Erik Johnston 26e46786b3 Port LogContext to Rust (#19979)
Ports the logcontext classes to Rust, and gives tokio tasks a captured
logcontext so that work running in (or spawned from) Rust is attributed
to the request that caused it.

1. **Add characterization tests for logcontext error messages and the
filter** — pins the exact `logcontext_error` message shapes, the
abuse-detection code paths and `LoggingContextFilter`'s observable
behaviour, *against the existing Python implementation* (this commit is
green on its own). These are the behavioural contract the port has to
satisfy.
2. **Port `ContextResourceUsage` to a Rust pyclass** — self-contained:
the new `synapse_rust.logcontext` module, the class, its stub and the
re-export.
3. **Move the logcontext storage and `LoggingContext` to Rust** — the
core change; the commit message carries detailed design notes.
Highlights:
- The slot is typed `Option<Py<LoggingContext>>`, with `None`
representing the sentinel. `_Sentinel`/`SENTINEL_CONTEXT` stay pure
Python (unchanged); thin wrappers on
`current_context`/`set_current_context` convert at the boundary, and
pyo3's extraction enforces the type (`TypeError` otherwise).
- The accounting is native: one `getrusage(RUSAGE_THREAD)` read per
switch via libc, inline `stop`/`start` bookkeeping for base
`LoggingContext`s, Python dispatch only for subclasses
(`BackgroundProcessLoggingContext`) so their overrides run. The thread
id comes from `PyThread_get_thread_ident` (the exact
`threading.get_ident()`
     value) without calling into Python.
- The hot paths avoid per-operation allocation: names are `Py<PyString>`
(the per-log-record `str(context)`/`server_name` reads are INCREF-only),
error branches materialise strings only when hit.
4. **Attribute Rust-spawned work to the caller's logcontext** —
`create_deferred` captures the caller's context and scopes it onto the
spawned task via a tokio task-local (`LogContextHandle`);
`current_context()` gives the task-local read precedence, so
`LoggingContextFilter`/`pyo3-log` resolve the right context on worker
threads with no per-record stamping. `run_python_awaitable` restores the
captured context (via a `with_logcontext` helper, the Rust
`PreserveLoggingContext`) around Python called back from Rust, so e.g.
`runInteraction` from the Rust `/versions` handler accounts its DB usage
against the right request. Integration tests exercise both guarantees
through real production code paths.

Follow-up work on top of this (separate PR): porting
`BackgroundProcessLoggingContext` natively and removing further `Py<_>`
indirections. The fact that `BackgroundProcessLoggingContext` is a
subclass is what forces some of the warts in this PR: e.g. having to use
`Py<LoggingContext>` everywhere, etc.

We don't try (yet) to make this pure Rust, instead we see this as simply
maintaining the Python logcontext machinery when crossing, rather than
trying to make a Rust equivalent that can be used by pure Rust
dependencies. We probably do want to do that in future, as well as wire
up e.g. CPU recording on Rust side, but that is unnecessary for now.
2026-09-21 10:00:53 +01:00
Jason LittleandPaul Chobert 7530874a12 Raise default room version to "12" (#20130)
Requires
* #19768 
* #19782 
* https://github.com/matrix-org/complement/pull/915

To meet the requirements for bumping Synapse to support [Matrix spec to
1.16](https://github.com/element-hq/synapse/issues/19414) the default
room version should be incremented to "12".

Other than the two separate Synapse PRs above(which are included here
but marked as "[diverted]" and should be removed prior to review) there
is only [one other real
change](https://github.com/element-hq/synapse/commit/c005e96c665b5a098a9b95d10f33faf224564be9)
to the code base itself to fix a `KeyError` during logging for a `/sync`
test against unknown room versions. Everything else should be on the
unit tests themselves.

Standard unit test running applies, should be nothing special to test
this outright.
`poetry run trial -jN tests` and similar for Postgresql.

Probably ok to review commit-by-commit

I took the liberty of writing a [room creating
helper](https://github.com/element-hq/synapse/commit/5ba81ad5d4a0a6787b7626bdb3293f633ea4097a)
for the two test series that try and test the sharding of the
`event_persister` workers. I'm not certain it stands up to scrutiny, but
at least does not do any funny mocking when producing room v12
appropriate room IDs.

I also took the liberty of writing an [assertion
helper](https://github.com/element-hq/synapse/pull/20130/commits/e408cef241d1b9c6a88f069eb5832de053790f9b)
for comparing lists of dicts for a select subset of keys/values. This is
used to compare stripped state selections while waiting on
https://github.com/element-hq/synapse/pull/19723 to be completed.

### 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: Paul Chobert <paul@chobert.fr>
2026-09-17 18:32:51 +00:00
Paul Chobert d553b05e45 Return allowed_room_ids in the client /hierarchy response (#20154)
Part of #18731 (Support Matrix 1.15).

Since Matrix 1.15, the
[spec](https://spec.matrix.org/v1.19/client-server-api/#get_matrixclientv1roomsroomidhierarchy)
defines `allowed_room_ids` on the room summaries returned by `GET
/_matrix/client/v1/rooms/{roomId}/hierarchy`, so that clients can tell
whether a restricted room can be joined or only knocked at:

> **`allowed_room_ids`** — `[Room ID]` — If the room is a [restricted
room](https://spec.matrix.org/v1.19/client-server-api/#restricted-rooms),
these are the room IDs which are specified by the join rules. Empty or
omitted otherwise. Added in `v1.15`
>
> — [Matrix
Spec](https://spec.matrix.org/v1.19/client-server-api/#get_matrixclientv1roomsroomidhierarchy)

Synapse currently strips the field from the client `/hierarchy` response
before returning it — a guard added in matrix-org/synapse#12175 (2022),
correct at the time, when the spec defined the field for federation only
and it was leaking into client responses. The other two surfaces that
define the field (`/room_summary` and the federation `/hierarchy`)
already return it.

This PR removes the strip in `_RoomEntry.as_json` (and the now-unused
`for_client` parameter), so client hierarchy entries include
`allowed_room_ids` for restricted rooms, both local and received over
federation. The first commit adds the failing test coverage, the second
removes the strip.


---

### Pull Request Checklist

<!-- Please read
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before submitting your pull request -->

* [x] Pull request is based on the develop branch
* [x] Pull request includes a [changelog
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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))
2026-09-17 10:16:25 +00:00
Olivier 'reivilibre cd2c84b5a5 Stop treating unset display names and avatar URLs as profile fields with a null value. (#20145)
Instead, treat them as absent fields as they feel like they should be.

The database implementation detail that these fields have a dedicated
column with `NULL`
when unset is kept to the storage layer.

The goal here is to reduce the amount of special casing needed for these
two original profile fields and treat them a little bit more like
regular profile fields.

Follows: #20003

Follows: #20147 (needed as a bugfix to continue sending them down
oldschool sync when they get deleted. Without #20147, this PR would
break that — which matches how custom profile fields were broken too.)

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-09-15 15:49:51 +01:00
Skye ElliotandAndrew Morgan 8c8138d572 Reject OTK uploads if clients exceed 500 server-side keys (#20162)
Co-authored-by: Andrew Morgan <andrew@amorgan.xyz>
Signed-off-by: Skye Elliot <actuallyori@gmail.com>
2026-09-14 15:05:23 +00:00
Paul Chobert 470b941895 Fix private read receipts of other users being leaked to application services (#20114)
Application services that opt in to receiving ephemeral events
(`receive_ephemeral: true` in the
[registration](https://spec.matrix.org/v1.19/application-service-api/#registration),
added in Matrix v1.13 from
[MSC2409](https://github.com/matrix-org/matrix-spec-proposals/pull/2409))
are sent the private read receipts (`m.read.private`) of **every** user
in the rooms they are interested in — not just their own users.

The [Application Service
API](https://spec.matrix.org/v1.19/application-service-api/#pushing-ephemeral-data)
is explicit about this (*Pushing ephemeral data*, `m.receipt`):

> Private read receipts MUST only be sent for users matching one of the
application service's namespaces. Normal read receipts and threaded read
receipts are always sent.

This matches the [Client-Server
API](https://spec.matrix.org/v1.19/client-server-api/#private-read-receipts):
"Servers MUST NOT send the `m.read.private` receipt to any other user
than the one which originally sent it."

The restriction to namespaced users is safe because the appservice could
learn those receipts anyway by syncing as the user. For everyone else,
`m.read.private` exists precisely so that nobody — including bridges and
bots in the room — can observe it.

For example, take an appservice registered with:

```yaml
namespaces:
  users:
    - regex: "@_bridge_.*:example\\.org"
      exclusive: true
```

When `@alice:example.org` (a regular user, not one of the appservice's)
and `@_bridge_bob:example.org` (a namespaced user) each send read
receipts in a bridged room, the appservice receives:

```json
{
    "type": "m.receipt",
    "room_id": "!room:example.org",
    "content": {
        "$event": {
            "m.read": { "@alice:example.org": { "ts": 1436451550453 } },
            "m.read.private": {
                "@_bridge_bob:example.org": { "ts": 1436451550453 },
                "@alice:example.org": { "ts": 1436451550453 }
            }
        }
    }
}
```

- `m.read` from `@alice` — correct, public read receipts are always
sent.
- `m.read.private` from `@_bridge_bob` — correct, the user is within the
appservice's namespaces.
- `m.read.private` from `@alice` — **the leak**: their private read
receipt must not be sent to the appservice.

## History

- matrix-org/synapse#8437 (Oct 2020, Synapse 1.22.0) implemented MSC2409
ephemeral event delivery to appservices. No leak at that point: private
read receipts did not exist yet.
- matrix-org/synapse#10413 (Jul 2021, Synapse 1.40.0) added the initial,
experimental-flag-gated implementation of MSC2285 ("hidden" read
receipts) and filtered them out of the `/sync` path
(`filter_out_hidden`) — but not out of the appservice path in the same
file. This is where the leak originates, for servers with
`msc2285_enabled`.
- matrix-org/synapse#12168 (May 2022, Synapse 1.59.0) reworked this into
the `m.read.private` receipt type and `filter_out_private_receipts`; the
appservice path was again left unfiltered.
- matrix-org/synapse#13273 (Aug 2022, Synapse 1.65.0) moved to the
stable `m.read.private` identifier; the appservice path has leaked it
ever since.

---

### 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))
2026-09-07 10:35:03 +02:00
Kegan Dougal 0088e43da7 MSC4242: State DAGs (fed client) (#20127)
Split out from https://github.com/element-hq/synapse/pull/19425

- Add federation support for MSC4242 fields in `/send_join` and
`/get_missing_events`
- Move the gate preventing joining MSC4242 rooms higher in the call
stack


Part of a series of 5x PRs to land the federation part of MSC4242
(storage, fedclient, serving, inbound-joins, inbound-pulls).


### 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))
2026-09-04 08:08:38 +00:00
Paul Chobert 207f6560ce Stabilize the M_APPSERVICE_LOGIN_UNSUPPORTED error code (#20180)
Part of: https://github.com/element-hq/synapse/issues/19415

Return `M_APPSERVICE_LOGIN_UNSUPPORTED` error code instead of the
unstable `IO.ELEMENT.MSC4190.M_APPSERVICE_LOGIN_UNSUPPORTED` identifier.

> Servers MUST still allow application services to use the `/register`
endpoint with a login type of `m.login.application_service` even if they
don't support the Legacy Authentication API. In that case application
services MUST set the `"inhibit_login": true` parameter as they cannot
use it to log in as users. If the `inhibit_login` parameter is not set
to `true`, the server MUST return a 400 HTTP status code with an
`M_APPSERVICE_LOGIN_UNSUPPORTED` error code.
>
> [...]
>
> Application services MUST NOT use the `/login` endpoint if the server
doesn't support the Legacy authentication API. If `/login` is called
with the `m.login.application_service` login type the server MUST return
a 400 HTTP status code with an `M_APPSERVICE_LOGIN_UNSUPPORTED` error
code.
>
> — [Matrix v1.19, Application Service
API](https://spec.matrix.org/v1.19/application-service-api/#registration)

Synapse returns the correct 400 on both endpoints, but with the unstable
identifier.

Before:

```
POST /_matrix/client/v3/login    {"type": "m.login.application_service", ...}  # appservice with MSC4190 device management
POST /_matrix/client/v3/register {"type": "m.login.application_service", ...}  # without "inhibit_login": true
  400 {"errcode": "IO.ELEMENT.MSC4190.M_APPSERVICE_LOGIN_UNSUPPORTED"}
```

After:

```
POST /_matrix/client/v3/login    {"type": "m.login.application_service", ...}  # appservice with MSC4190 device management
POST /_matrix/client/v3/register {"type": "m.login.application_service", ...}  # without "inhibit_login": true
  400 {"errcode": "M_APPSERVICE_LOGIN_UNSUPPORTED"}
```

A Sister PR exists in MAS:
https://github.com/element-hq/matrix-authentication-service/pull/5961 ;
when delegation is enabled, `/login` reaches MAS instead of Synapse, and
MAS currently answers `m.login.application_service` with `M_UNKNOWN`.
2026-09-03 15:07:51 +01:00
Paul Chobert d4de2ae1c5 Fix state_after for left rooms including post-leave lazy-loaded memberships (#20169)
## The bug

With the experimental
[MSC4222](https://github.com/matrix-org/matrix-spec-proposals/pull/4222)
implementation enabled (`use_state_after`) and lazy-loading of room
members, an incremental `/sync` could disclose state from **after** the
user's leave in a left room's `state_after`.

1. Alice syncs with `lazy_load_members: true` and
`use_state_after=true`.
2. Bob sends a message in a room they share.
3. Alice leaves the room.
4. Bob updates his per-room displayname
5. Alice does an incremental sync covering steps 2–3. Alice's
`state_after` contains Bob's post-leave membership event from step 4

Alice should not see the new per-room display name of Bob.


## The fix

Copy what has been done for `_compute_state_delta_for_full_sync`: pass
`joined` down and, for rooms the user is no longer joined to, fetch the
memberships as of `end_token` via state groups (`get_state_ids_at`)
instead of current state.
2026-09-03 11:58:56 +01:00
FrenchGithubUser c40ab6e3b9 Fix sending duplicate m.room.encryption events on room creation (#20106)
On room creation when the client already supplies one in the initial
state and `encryption_enabled_by_default_for_room_type` is enabled.
2026-09-02 15:52:41 +01:00
Paul Chobert f94abb6924 Return 403 instead of 400 when profile changes are disabled (#20173)
With `enable_set_displayname: false` (or `enable_set_avatar_url:
false`), refusing a profile change returned the right errcode with the
wrong status:

```
PUT /_matrix/client/v3/profile/@alice:example.com/displayname   (displayname already set)
→ 400 {"errcode": "M_FORBIDDEN", "error": "Changing display name is disabled on this server"}

DELETE /_matrix/client/v3/profile/@alice:example.com/displayname
→ 400 {"errcode": "M_FORBIDDEN", "error": "Changing display name is disabled on this server"}
```

With this fix:

```
PUT /_matrix/client/v3/profile/@alice:example.com/displayname   (displayname already set)
→ 403 {"errcode": "M_FORBIDDEN", "error": "Changing display name is disabled on this server"}

DELETE /_matrix/client/v3/profile/@alice:example.com/displayname
→ 403 {"errcode": "M_FORBIDDEN", "error": "Changing display name is disabled on this server"}
```

The spec defines the [403 response of `PUT
/_matrix/client/v3/profile/{userId}/{keyName}`](https://spec.matrix.org/v1.19/client-server-api/#put_matrixclientv3profileuseridkeyname)
as "The server is unwilling to perform the operation, either due to
insufficient permissions or **because profile modifications are
disabled**", while 400 is reserved for malformed input (`M_BAD_JSON`,
`M_MISSING_PARAM`, …).

Clients seem to rely on `errcode` field more than the HTTP Status Code,
that change seems safe.
2026-09-02 14:29:08 +01:00
Hubert ChathiandAndrew Morgan 89363f45d2 Relax validation of signature upload for master keys, and allow updates (#19915)
Co-authored-by: Andrew Morgan <andrew@amorgan.xyz>
2026-09-01 09:13:56 +00:00
Jason Robinson 4245bdc6f0 Fix sending down removed custom profile fields in legacy sync (#20147)
When a client (correctly) calls the `DELETE` endpoint to remove a custom
profile field (like Element X does with `m.status`), we incorrectly
don't include it in the sync response in legacy sync. This was due to
the fact that we cleaned up the sent fields down to what fields the
profile currently has.

Always ensure any fields in `ProfileUpdateAction.UPDATE` are sent down,
as `null` values for profile fields which have been deleted.

Fixes an issue where clearing a user status from Element X does not
reflect in the user status being cleared on Element Web.

Note, target is the v1.160.0 release branch due to customer commitments,
and this fixes web and mobile clients not working together correctly.

### 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
* [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))
2026-08-27 06:29:50 +00:00
Jason Robinson d59856b9a7 Fix sync stream not being woken up when a user updates a profile field without belonging to any rooms (#20135)
Fix sync stream not being woken up when a user updates a profile field
without belonging to any rooms.

Fixes https://github.com/element-hq/synapse/issues/20110
2026-08-25 17:14:17 +01:00
4bb07152c8 Support for profile updates over Sliding Sync (MSC4262) (#20003)
This PR implements support for profile updates over Sliding Sync:
https://github.com/matrix-org/matrix-spec-proposals/pull/4262. This pr
may be easier to review as a whole than commit by commit.

This builds on the legacy sync profile updates feature
https://github.com/element-hq/synapse/pull/19556, specifically the
profile updates stream it added.

Submitting for early review to get consensus on implementation. There
are some things we would like to add still, from spec, mainly:

* > Homeservers should only consider a profile field update "accepted"
by a client
> once the client returns with a new /sync request with the next /sync
token,
> NOT just after sending down the profile update. The client may never
receive
> response due to network conditions, or a bug in the client
implementation.
* > When a room enters this subset in this connection for the first
time, all requested
> fields from profiles of users in that room MAY be sent down. This
gives the client
> a base set of information for which future field updates can be
applied on top of.
> The homeserver MAY omit some fields and profiles if it believes that
the client has
> already received them, likewise repeat profiles MAY be sent down based
on homeserver
  > implementation.
* > Finally, if the list of fields expands to cover a new field ID,
those fields should
> be sent down for all users that are within the current room subset.
Future incremental
  > updates will then include changes to this field.
* Additionally, we would need to implement a lazy loading cache similar
to the legacy sync. (not part of MSC as such)

Depending on review these could either be added to this pr, or to keep
this pr from not growing too much, be added in a follow-up pr, as they
are more enhancement to this base sliding sync profile updates
functionality than a part of the core functionality.

### Pull Request Checklist

<!-- Please read
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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: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Olivier 'reivilibre' <olivier@librepush.net>
Co-authored-by: Olivier 'reivilibre <oliverw@element.io>
2026-08-25 14:37:03 +00:00
c5f02a9313 Introduce support for MSC4429: Profile Updates for Legacy Sync (#19556)
Implements support for [MSC4429: Profile Updates for Legacy
Sync](https://github.com/matrix-org/matrix-spec-proposals/pull/4429).

Paired with https://github.com/matrix-org/complement/pull/849 and
https://github.com/matrix-org/sytest/tree/anoa/msc4429

Tracking issue for removing unstable identifiers in Synapse:
https://github.com/element-hq/synapse/issues/19891
Further improvements tracked in:
https://github.com/element-hq/synapse/issues/19981

---------

Co-authored-by: Half-Shot <will@half-shot.uk>
Co-authored-by: Jason Robinson <jasonr@element.io>
Co-authored-by: Olivier 'reivilibre' <oliverw@element.io>
2026-08-06 15:35:07 +01:00
Olivier 'reivilibre 9761f9bc42 Merge branch 'master' into develop 2026-07-28 14:39:05 +01:00
Olivier 'reivilibre c3adee3509 Restrict what errors we forward to clients from federation and policy servers
Fixes: https://github.com/element-hq/synapse/security/advisories/GHSA-95fh-hv8c-chvq
Fixes: https://github.com/matrix-org/internal-config/issues/1721

https://github.com/element-hq/synapse-private/pull/158 is the end goal, I think

-----

Reviewed-on: https://github.com/element-hq/synapse-private/pull/159
2026-07-28 13:58:06 +01:00
FrenchGithubUserandAndrew Morgan 343581a1a0 fixes related to room v12 and sytest (#19898)
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-07-23 11:13:21 +00:00
Erik Johnston be511b22a2 Send offline presence for stale states when presence is disabled (#19948)
If presence is disabled after having been enabled, the presence states
in the database (and hence on clients) are frozen at whatever they were
when presence was last enabled: nothing writes to the presence stream
any more and /sync omits the presence section entirely, so clients show
the old presence states forever.

Fix this in two parts:

1. At startup, if presence is disabled but the database still contains
non-offline presence states, the presence writer sends out one final
round of updates marking those users as offline.

2. /sync no longer unconditionally omits presence when presence is
disabled: incremental syncs whose since token is behind the presence
stream still get the straggling updates. As the stream doesn't advance
while presence is disabled, clients catch up once and the check then
short-circuits to a token comparison.

Remote servers already handle this themselves by timing out our users
([`FEDERATION_TIMEOUT`](https://github.com/element-hq/synapse/blob/4d8905a15a417ed0054ec2533d243932d890bbbd/synapse/handlers/presence.py#L194-L198)),
so no federation changes are needed.

Note that this only fixes the issue if presence is fully disabled. If
set to `untracked` we still have the same issue, however since modules
would still write to presence we can't just clobber everything like we
do in this patch.
2026-07-13 10:08:57 +01:00
Erik JohnstonandClaude Fable 5 0bd28389b1 Improve caching for presence (#19939)
This does two things, first it adds a config flag to ignore rooms for
the purposes of presence routing.

Secondly, it changes the caching behaviour to try and improve the cache
hit ratio. Previously, the size of the `do_users_share_a_room` cache
(which stores pairs of users) needs to `O(n²)` for the number of online
users, which is infeasible for large servers.

Instead, we call `get_users_in_room` for both the syncing and updated
users. This sounds more expensive, but a) we will already have cached
the syncing user's rooms, and b) we will only calculate the updated
user's rooms once (rather than once per syncing user).

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-13 09:34:07 +01:00
4d8905a15a Throttle sync-driven presence updates relayed to the presence writer (#19941)
Sync workers proxied a full `ReplicationPresenceSetState` call to the
presence writer on every sync request with `affect_presence=True` (via
`user_syncing`), and a `ReplicationBumpPresenceActiveTime` call on every
user action, even though the writer's presence timers only need feeding
every `SYNC_ONLINE_TIMEOUT` / `LAST_ACTIVE_GRANULARITY`. On busy clients
this amounts to tens of no-op replication calls per user per minute, and
the resulting per-update work is the dominant CPU cost on saturated
presence writers.

Track the last relayed `(state, timestamp)` per `(user, device)` on the
worker and suppress unchanged sync-driven repeats within a 25s relay
interval - deliberately below `SYNC_ONLINE_TIMEOUT` (30s) so the
writer's device `last_sync_ts`/`last_active_ts` timers stay fed and
users neither flap offline nor bounce `currently_active`. Genuine state
changes are relayed immediately, explicit (non-sync) set_state calls
always go through and reset the throttle, bumps that might un-idle a
device bypass it, and entries are evicted when a `USER_SYNC` stop is
sent so reconnecting devices are relayed afresh.

This gives the writer-CPU benefit that deployments currently obtain by
tightening `rc_presence` to ~1/29s, without dropping real presence
transitions.

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: Quentin Gliech <quenting@element.io>
2026-07-10 14:05:10 +01:00
Erik JohnstonandClaude Fable 5 3f3edaf029 Make the presence state-machine timers configurable (#19942)
Adds `last_active_granularity`, `sync_online_timeout` and `idle_timeout`
options to the `presence` config section, controlling the previously
hard-coded `LAST_ACTIVE_GRANULARITY`, `SYNC_ONLINE_TIMEOUT` and
`IDLE_TIMER` constants (which remain as the defaults).

This is mainly useful on deployments that ratelimit how often syncs can
affect presence (`rc_presence`): the sync timeout must exceed the
ratelimit interval or users flap offline between syncs, so tuning down
presence traffic currently requires squeezing under the fixed 30s limit.

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-09 17:21:50 +01:00
Erik JohnstonandClaude Fable 5 b4deb24be6 Use a CPU-time budget for test_lock_contention to fix postgres flakiness (#19929)
`test_lock_contention` is a performance-regression canary (#16840): the
pathological behaviour it guards against spent ~30s spinning the CPU, vs
~0.5s when healthy. The 5s wall-clock alarm it used was calibrated on
SQLite, but against PostgreSQL a healthy run already takes 3-4s of
wall-clock time (500 sequential acquire/release cycles, each a real
database round-trip), so any CI load pushed it over the limit.

Add a `cpu_time` mode to `tests/utils.py`'s test_timeout, implemented
with
[`setitimer(ITIMER_PROF)`](https://docs.python.org/3/library/signal.html#signal.setitimer),
which budgets process CPU time instead of wall-clock time. Time spent
blocked on the database or lost to a loaded CI runner no longer counts,
while a regression to CPU-spinning still trips the alarm mid-spin. A
healthy run costs <1s of CPU on either database engine; the budget is
10s.

This also subsumes the RISC-V wall-clock carve-out from #18430, which is
removed.

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-09 10:40:53 +01:00
Lukas JungandAndrew Morgan 963e486a70 Recreate user profile on account reactivation (#19902)
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2026-07-06 12:38:24 +00:00
807795e5ee Change the MSC3814 dehydrated device /events endpoint paging to match spec conventions (#19897)
To match [the spec requirements for
pagination](https://spec.matrix.org/v1.9/appendices/#pagination):

* rename the query parameter of
`/org.matrix.msc3814.v1/dehydrated_device/[device_id]/events` to `from`,
and
* omit `next_batch` from the response content if there are no more
events to fetch

This matches [the changes that are coming in
MSC3814](https://github.com/matrix-org/matrix-spec-proposals/pull/3814/files#r1540896531).

The previous change https://github.com/element-hq/synapse/pull/19896
kept the old POST API to support old clients. This preserves that
compatibility, so the POST API still works how it used to.

Depends on https://github.com/element-hq/synapse/pull/19896
Part of https://github.com/element-hq/element-meta/issues/2799


### 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).
The entry should:
* [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: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Co-authored-by: Quentin Gliech <quenting@element.io>
2026-07-03 14:48:43 +02:00
Eric Eastwood 7da21a715d Update HomeserverTestCase.get_success(...) and friends to drive async Rust (Tokio runtime/thread pool) (#19871)
This means you can use `get_success(...)` anywhere regardless
of what kind of work needs to be done.

Spawning from adding some more async Rust things in
https://github.com/element-hq/synapse/pull/19846 and wanting something
more standard instead of the custom `till_deferred_has_result(...)` that
has crept in to a few files.

Alternative to https://github.com/element-hq/synapse/pull/19867 spurred
on by [this
comment](https://github.com/element-hq/synapse/pull/19867#discussion_r3441774685)
from @erikjohnston


### How does this work?

Previously, `get_success(...)` just ran in a hot-loop advancing the
Twisted reactor clock which didn't give any time for other threads to do
some work or acquire the GIL if necessary (whenever there is a hand-off
from Rust to Python, we need the GIL).

Now, `get_success(...)` loops until we see a result (until we hit the
~0.1s real-time timeout). In the loop, we call
[`time.sleep(0)`](https://docs.python.org/3/library/time.html#time.sleep)
which will "Suspend execution of the calling thread [...]" (CPU and GIL)
to allow other threads to do some work. Then like before, we advance the
Twisted reactor clock to run any scheduled callbacks which includes
anything the other threads may have scheduled.


### Does this slow down the entire test suite?

Seems just as fast as before. There is minutes variance in what we had
before and after but both are within the same range of each other.

(see PR for actual before/after timings)
2026-07-02 15:20:38 -05:00
Olivier 'reivilibre 5df6d1be65 Remove legacy MSC3861 auth delegation support (#19895)
Modern 'MAS integration' (as we call it now) is, of course, preserved.

Fixes: #19549

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
2026-07-02 12:25:11 +01:00
FrenchGithubUser 75ee23a16b feat: Include allowed_room_ids in the /summary client-server API response for rooms with restricted join rules, as required by Matrix 1.15. (#19762)
Currently the `/summary` endpoint on the client and federation APIs does
not include the allowed_room_ids field, that is present on the
/hierarchy API. This is required by the 1.15 spec and this is what this
PR does.

Complement test: https://github.com/matrix-org/complement/pull/873

Part of https://github.com/element-hq/synapse/issues/18731
2026-06-18 14:12:51 +01:00
Eric Eastwood d11b012a81 Force keyword-args for clear default_config(server_name="test") usage (#19849)
I.e. `default_config("test")` and `default_config("test", False)` are so
opaque and hard to connect the dots with.

Spawning from trying to figure out what the `server_name` is set as for
our `HomeserverTestCase` in order to reference it in
https://github.com/element-hq/synapse/pull/19848#discussion_r3397455309
2026-06-12 09:45:22 -05:00
Erik Johnston e8e5a42180 Fix parsing events that have large integers (#19819)
Follow on from https://github.com/element-hq/synapse/pull/19701.

Unfortunately serde has a bug when using `#[serde(flatten)]` with
`arbitrary-precision` feature when handling integers that fit in a i128
when doing `serde_json::from_value`. See
https://github.com/serde-rs/serde/issues/2230.

The `depythonize` hits the same issue. To fix this we make it so we only
parse events from strings and not values.
2026-06-03 14:52:05 +01:00
5bf825c016 Limit to-device EDU sizes (#19617)
This is based on https://github.com/element-hq/synapse/pull/18416, which
got reverted (#19614) due to it incorrectly rejecting to-device messages
to users with many devices (and thus breaking message sending).

Fix https://github.com/element-hq/synapse/issues/17035

A to-device message content looks like:

```jsonc
{
  "@user:domain": {"device1": {...}, "device2": {...}},
  ...
}
```

The previous PR would split up into multiple EDUs, each with a subset of
the users. However, if one user's entry was too large it would not
further split it up and then error out.

The main change in this PR is to allow splitting up a single user into
multiple EDUs.

Other changes:
1. Rename to `SOFT_MAX_EDU_SIZE` to indicate that we sometimes send EDUs
with larger size than that, and its more a target than a hard limit.
2. Check early if any to-device message (to a specific device) is too
large to send, even if we're not going to send it over federation. This
ensures that we catch issues where clients try to send too large
to-device.

This still means that if a client send a large individual to-device
message it will fail, but I don't believe we ever send such large
to-device messages (normally they're in the range of a few KB).

---

I ended up changing the implementation a bunch to make it easy to reuse
the code to split up dictionaries. Instead of repeatedly splitting up
the EDU until each bit fits into the size, we instead record the size of
each entry in the dict and instead split up based on cumulative size.
This means we call `encode_canonical_json` on each entry rather than
once on the entire struct, but its not significantly slower to do so.

--

cc @MatMaul @MadLittleMods

---------

Co-authored-by: Mathieu Velten <matmaul@gmail.com>
Co-authored-by: mcalinghee <mcalinghee.dev@gmail.com>
Co-authored-by: Eric Eastwood <madlittlemods@gmail.com>
2026-06-02 15:57:55 +00:00
Erik JohnstonandEric Eastwood 9e2a076144 Port Event class to Rust (#19701)
Ports the event class to Rust.

The main difference here are:
1. There is now a single event class
2. We now validate a lot more at event construction time than we
previously did (we basically checked nothing before). This required some
changes to the tests, including
https://github.com/matrix-org/sytest/pull/1423

Reviewable commit-by-commit.

### Overview of Event Rust structure

The format of the event struct in Rust is quite different than that in
Python.

The top-level looks like:

```rust
pub struct Event {
    /// The parsed event JSON.
    fields: FormattedEvent,

    /// The event ID. For format v1 this is read directly from the JSON;
    /// for v2+ it is computed from the canonical-JSON hash at
    /// construction time and cached here.
    event_id: Arc<str>,

    /// Synapse-internal per-event state that lives outside the federated
    /// JSON (e.g. outlier flag, soft-failure, stream positions).
    #[pyo3(get)]
    internal_metadata: EventInternalMetadata,

    /// The room version this event was parsed for.
    #[pyo3(get)]
    room_version: &'static RoomVersion,

    /// `None` for accepted events; otherwise a short reason set by auth
    /// when the event was rejected.
    rejected_reason: Option<Box<str>>,
}
```

which includes the actual parsed event in `FormattedEvent`, plus the
rest of the event metadata.

```rust
pub struct FormattedEvent<E = Arc<EventFormatEnum>> {
    #[serde(default)]
    pub signatures: Signatures,

    #[serde(default)]
    pub unsigned: Unsigned,

    #[serde(flatten)]
    pub specific_fields: E,

    #[serde(flatten)]
    pub common_fields: Arc<EventCommonFields>,
}
```

The struct is further split into the common fields, format specific
fields, plus the signatures and unsigned. We split out the signature and
unsigned fields as they are mutable, so when we clone the event we can
still share the common and specific fields and only copy signature and
unsigned.

The `specific_fields` are the fields that depend on the format version.
They can either be a specific format (e.g. `E = EventFormatV1`) or a
type-erased enum `EventFormatEnum` that is across all room versions:

```rust
pub enum EventFormatEnum {
    V1(EventFormatV1),
    V2V3(EventFormatV2V3),
    V4(EventFormatV4),
    VMSC4242(EventFormatVMSC4242),
}
```

For example:

```rust
/// Shared flat-list encoding of `auth_events` and `prev_events`, reused
/// by every format from v2/v3 onwards.
#[derive(Serialize, Deserialize)]
pub struct SimpleAuthPrevEvents {
    pub auth_events: Vec<String>,
    pub prev_events: Vec<String>,
}

/// Version-specific fields for room versions 3-10.
#[derive(Serialize, Deserialize)]
pub struct EventFormatV2V3 {
    pub room_id: Box<str>,
    #[serde(flatten)]
    pub auth_prev_events: SimpleAuthPrevEvents,
}
```


### Dev notes

As discussed in
[`#element-backend-internal:matrix.org`](https://matrix.to/#/!SGNQGPGUwtcPBUotTL:matrix.org/$3gTjDO440GbAz57cXcCawwiyFLiD0crrarvS1uhzKOY?via=jki.re&via=element.io&via=matrix.org)

---------

Co-authored-by: Eric Eastwood <erice@element.io>
2026-06-02 11:05:38 +01:00