- Add a flag to `/versions`, `org.matrix.simplified_msc3575`, to indicate whether experimental sliding sync support has been enabled. ([\#17571](https://github.com/element-hq/synapse/issues/17571))
- Handle changes in `timeline_limit` in experimental sliding sync. ([\#17579](https://github.com/element-hq/synapse/issues/17579))
- Correctly track read receipts that should be sent down in experimental sliding sync. ([\#17575](https://github.com/element-hq/synapse/issues/17575), [\#17589](https://github.com/element-hq/synapse/issues/17589), [\#17592](https://github.com/element-hq/synapse/issues/17592))
- Start handlers for new media endpoints when media resource configured. ([\#17483](https://github.com/element-hq/synapse/issues/17483))
- Fix timeline ordering (using `stream_ordering` instead of topological ordering) in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17510](https://github.com/element-hq/synapse/issues/17510))
- Fix experimental sliding sync implementation to remember any updates in rooms that were not sent down immediately. ([\#17535](https://github.com/element-hq/synapse/issues/17535))
- Better exclude partially stated rooms if we must await full state in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17538](https://github.com/element-hq/synapse/issues/17538))
- Handle lower-case http headers in `_Mulitpart_Parser_Protocol`. ([\#17545](https://github.com/element-hq/synapse/issues/17545))
- Fix fetching federation signing keys from servers that omit `old_verify_keys`. Contributed by @tulir @ Beeper. ([\#17568](https://github.com/element-hq/synapse/issues/17568))
- Fix bug where we would respond with an error when a remote server asked for media that had a length of 0, using the new multipart federation media endpoint. ([\#17570](https://github.com/element-hq/synapse/issues/17570))
- Improve docstrings for profile methods. ([\#17559](https://github.com/element-hq/synapse/issues/17559))
### Internal Changes
- Add more tracing to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17514](https://github.com/element-hq/synapse/issues/17514))
- Fixup comment in sliding sync implementation. ([\#17531](https://github.com/element-hq/synapse/issues/17531))
- Replace override of deprecated method `HTTPAdapter.get_connection` with `get_connection_with_tls_context`. ([\#17536](https://github.com/element-hq/synapse/issues/17536))
- Fix performance of device lists in `/key/changes` and sliding sync. ([\#17537](https://github.com/element-hq/synapse/issues/17537), [\#17548](https://github.com/element-hq/synapse/issues/17548))
- Bump setuptools from 67.6.0 to 72.1.0. ([\#17542](https://github.com/element-hq/synapse/issues/17542))
- Add a utility function for generating random event IDs. ([\#17557](https://github.com/element-hq/synapse/issues/17557))
- Speed up responding to media requests. ([\#17558](https://github.com/element-hq/synapse/issues/17558), [\#17561](https://github.com/element-hq/synapse/issues/17561), [\#17564](https://github.com/element-hq/synapse/issues/17564), [\#17566](https://github.com/element-hq/synapse/issues/17566), [\#17567](https://github.com/element-hq/synapse/issues/17567), [\#17569](https://github.com/element-hq/synapse/issues/17569))
- Test github token before running release script steps. ([\#17562](https://github.com/element-hq/synapse/issues/17562))
- Reduce log spam of multipart files. ([\#17563](https://github.com/element-hq/synapse/issues/17563))
- Refactor per-connection state in experimental sliding sync handler. ([\#17574](https://github.com/element-hq/synapse/issues/17574))
- Add histogram metrics for sliding sync processing time. ([\#17593](https://github.com/element-hq/synapse/issues/17593))
### Updates to locked dependencies
* Bump bytes from 1.6.1 to 1.7.1. ([\#17526](https://github.com/element-hq/synapse/issues/17526))
* Bump lxml from 5.2.2 to 5.3.0. ([\#17550](https://github.com/element-hq/synapse/issues/17550))
* Bump phonenumbers from 8.13.42 to 8.13.43. ([\#17551](https://github.com/element-hq/synapse/issues/17551))
* Bump regex from 1.10.5 to 1.10.6. ([\#17527](https://github.com/element-hq/synapse/issues/17527))
* Bump sentry-sdk from 2.10.0 to 2.12.0. ([\#17553](https://github.com/element-hq/synapse/issues/17553))
* Bump serde from 1.0.204 to 1.0.206. ([\#17556](https://github.com/element-hq/synapse/issues/17556))
* Bump serde_json from 1.0.122 to 1.0.124. ([\#17555](https://github.com/element-hq/synapse/issues/17555))
* Bump sigstore/cosign-installer from 3.5.0 to 3.6.0. ([\#17549](https://github.com/element-hq/synapse/issues/17549))
* Bump types-pyyaml from 6.0.12.20240311 to 6.0.12.20240808. ([\#17552](https://github.com/element-hq/synapse/issues/17552))
* Bump types-requests from 2.31.0.20240406 to 2.32.0.20240712. ([\#17524](https://github.com/element-hq/synapse/issues/17524))
- Track which rooms have been sent to clients in the experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17447](https://github.com/element-hq/synapse/issues/17447))
- Add Account Data extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17477](https://github.com/element-hq/synapse/issues/17477))
- Add receipts extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17489](https://github.com/element-hq/synapse/issues/17489))
- Add typing notification extension support to experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17505](https://github.com/element-hq/synapse/issues/17505))
### Bugfixes
- Update experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint to handle invite/knock rooms when filtering. ([\#17450](https://github.com/element-hq/synapse/issues/17450))
- Fix a bug introduced in v1.110.0 which caused `/keys/query` to return incomplete results, leading to high network activity and CPU usage on Matrix clients. ([\#17499](https://github.com/element-hq/synapse/issues/17499))
### Improved Documentation
- Update the [`allowed_local_3pids`](https://element-hq.github.io/synapse/v1.112/usage/configuration/config_documentation.html#allowed_local_3pids) config option's msisdn address to a working example. ([\#17476](https://github.com/element-hq/synapse/issues/17476))
### Internal Changes
- Change sliding sync to use their own token format in preparation for storing per-connection state. ([\#17452](https://github.com/element-hq/synapse/issues/17452))
- Ensure we don't send down negative `bump_stamp` in experimental sliding sync endpoint. ([\#17478](https://github.com/element-hq/synapse/issues/17478))
- Do not send down empty room entries down experimental sliding sync endpoint. ([\#17479](https://github.com/element-hq/synapse/issues/17479))
- Refactor Sliding Sync tests to better utilize the `SlidingSyncBase`. ([\#17481](https://github.com/element-hq/synapse/issues/17481), [\#17482](https://github.com/element-hq/synapse/issues/17482))
- Add some opentracing tags and logging to the experimental sliding sync implementation. ([\#17501](https://github.com/element-hq/synapse/issues/17501))
- Split and move Sliding Sync tests so we have some more sane test file sizes. ([\#17504](https://github.com/element-hq/synapse/issues/17504))
- Update the `limited` field description in the Sliding Sync response to accurately describe what it actually represents. ([\#17507](https://github.com/element-hq/synapse/issues/17507))
- Easier to understand `timeline` assertions in Sliding Sync tests. ([\#17511](https://github.com/element-hq/synapse/issues/17511))
- Reset the sliding sync connection if we don't recognize the per-connection state position. ([\#17529](https://github.com/element-hq/synapse/issues/17529))
### Updates to locked dependencies
* Bump bcrypt from 4.1.3 to 4.2.0. ([\#17495](https://github.com/element-hq/synapse/issues/17495))
* Bump black from 24.4.2 to 24.8.0. ([\#17522](https://github.com/element-hq/synapse/issues/17522))
* Bump phonenumbers from 8.13.39 to 8.13.42. ([\#17521](https://github.com/element-hq/synapse/issues/17521))
* Bump ruff from 0.5.4 to 0.5.5. ([\#17494](https://github.com/element-hq/synapse/issues/17494))
* Bump serde_json from 1.0.120 to 1.0.121. ([\#17493](https://github.com/element-hq/synapse/issues/17493))
* Bump serde_json from 1.0.121 to 1.0.122. ([\#17525](https://github.com/element-hq/synapse/issues/17525))
* Bump towncrier from 23.11.0 to 24.7.1. ([\#17523](https://github.com/element-hq/synapse/issues/17523))
* Bump types-pyopenssl from 24.1.0.20240425 to 24.1.0.20240722. ([\#17496](https://github.com/element-hq/synapse/issues/17496))
* Bump types-setuptools from 70.1.0.20240627 to 71.1.0.20240726. ([\#17497](https://github.com/element-hq/synapse/issues/17497))
This security release is to update our locked dependency on Twisted to 24.7.0rc1, which includes a security fix for [CVE-2024-41671 / GHSA-c8m8-j448-xjx7: Disordered HTTP pipeline response in twisted.web, again](https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7).
Note that this security fix is also available as **Synapse 1.111.1**, which does not include the rest of the changes in Synapse 1.112.0.
This issue means that, if multiple HTTP requests are pipelined in the same TCP connection, Synapse can send responses to the wrong HTTP request.
If a reverse proxy was configured to use HTTP pipelining, this could result in responses being sent to the wrong user, severely harming confidentiality.
With that said, despite being a high severity issue, **we consider it unlikely that Synapse installations will be affected**.
The use of HTTP pipelining in this fashion would cause worse performance for clients (request-response latencies would be increased as users' responses would be artificially blocked behind other users' slow requests). Further, Nginx and Haproxy, two common reverse proxies, do not appear to support configuring their upstreams to use HTTP pipelining and thus would not be affected. For both of these reasons, we consider it unlikely that a Synapse deployment would be set up in such a configuration.
Despite that, we cannot rule out that some installations may exist with this unusual setup and so we are releasing this security update today.
**pip users:** Note that by default, upgrading Synapse using pip will not automatically upgrade Twisted. **Please manually install the new version of Twisted** using `pip install Twisted==24.7.0rc1`. Note also that even the `--upgrade-strategy=eager` flag to `pip install -U matrix-synapse` will not upgrade Twisted to a patched version because it is only a release candidate at this time.
### Internal Changes
- Upgrade locked dependency on Twisted to 24.7.0rc1. ([\#17502](https://github.com/element-hq/synapse/issues/17502))
- Add configurable option to always include offline users in presence sync results. Contributed by @Michael-Hollister. ([\#17231](https://github.com/element-hq/synapse/issues/17231))
- Fix bug in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint when using room type filters and the user has one or more remote invites. ([\#17434](https://github.com/element-hq/synapse/issues/17434))
- Order `heroes` by `stream_ordering` as the Matrix specification states (applies to `/sync`). ([\#17435](https://github.com/element-hq/synapse/issues/17435))
- Fix rare bug where `/sync` would break for a user when using workers with multiple stream writers. ([\#17438](https://github.com/element-hq/synapse/issues/17438))
### Improved Documentation
- Update the readme image to have a white background, so that it is readable in dark mode. ([\#17387](https://github.com/element-hq/synapse/issues/17387))
- Add Red Hat Enterprise Linux and Rocky Linux 8 and 9 installation instructions. ([\#17423](https://github.com/element-hq/synapse/issues/17423))
- Improve documentation for the [`default_power_level_content_override`](https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#default_power_level_content_override) config option. ([\#17451](https://github.com/element-hq/synapse/issues/17451))
### Internal Changes
- Make sure we always use the right logic for enabling the media repo. ([\#17424](https://github.com/element-hq/synapse/issues/17424))
- Fix argument documentation for method `RateLimiter.record_action`. ([\#17426](https://github.com/element-hq/synapse/issues/17426))
- Reduce volume of 'Waiting for current token' logs, which were introduced in v1.109.0. ([\#17428](https://github.com/element-hq/synapse/issues/17428))
- Limit concurrent remote downloads to 6 per IP address, and decrement remote downloads without a content-length from the ratelimiter after the download is complete. ([\#17439](https://github.com/element-hq/synapse/issues/17439))
- Remove unnecessary call to resume producing in fake channel. ([\#17449](https://github.com/element-hq/synapse/issues/17449))
- Update experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint to bump room when it is created. ([\#17453](https://github.com/element-hq/synapse/issues/17453))
- Speed up generating sliding sync responses. ([\#17458](https://github.com/element-hq/synapse/issues/17458))
- Add cache to `get_rooms_for_local_user_where_membership_is` to speed up sliding sync. ([\#17460](https://github.com/element-hq/synapse/issues/17460))
- Speed up fetching room keys from backup. ([\#17461](https://github.com/element-hq/synapse/issues/17461))
- Speed up sorting of the room list in sliding sync. ([\#17468](https://github.com/element-hq/synapse/issues/17468))
- Implement handling of `$ME` as a state key in sliding sync. ([\#17469](https://github.com/element-hq/synapse/issues/17469))
### Updates to locked dependencies
* Bump bytes from 1.6.0 to 1.6.1. ([\#17441](https://github.com/element-hq/synapse/issues/17441))
* Bump hiredis from 2.3.2 to 3.0.0. ([\#17464](https://github.com/element-hq/synapse/issues/17464))
* Bump jsonschema from 4.22.0 to 4.23.0. ([\#17444](https://github.com/element-hq/synapse/issues/17444))
* Bump matrix-org/done-action from 2 to 3. ([\#17440](https://github.com/element-hq/synapse/issues/17440))
* Bump mypy from 1.9.0 to 1.10.1. ([\#17445](https://github.com/element-hq/synapse/issues/17445))
* Bump pyopenssl from 24.1.0 to 24.2.1. ([\#17465](https://github.com/element-hq/synapse/issues/17465))
* Bump ruff from 0.5.0 to 0.5.4. ([\#17466](https://github.com/element-hq/synapse/issues/17466))
* Bump sentry-sdk from 2.6.0 to 2.8.0. ([\#17456](https://github.com/element-hq/synapse/issues/17456))
* Bump sentry-sdk from 2.8.0 to 2.10.0. ([\#17467](https://github.com/element-hq/synapse/issues/17467))
* Bump setuptools from 67.6.0 to 70.0.0. ([\#17448](https://github.com/element-hq/synapse/issues/17448))
* Bump twine from 5.1.0 to 5.1.1. ([\#17443](https://github.com/element-hq/synapse/issues/17443))
* Bump types-jsonschema from 4.22.0.20240610 to 4.23.0.20240712. ([\#17446](https://github.com/element-hq/synapse/issues/17446))
* Bump ulid from 1.1.2 to 1.1.3. ([\#17442](https://github.com/element-hq/synapse/issues/17442))
* Bump zipp from 3.15.0 to 3.19.1. ([\#17427](https://github.com/element-hq/synapse/issues/17427))
This security release is to update our locked dependency on Twisted to 24.7.0rc1, which includes a security fix for [CVE-2024-41671 / GHSA-c8m8-j448-xjx7: Disordered HTTP pipeline response in twisted.web, again](https://github.com/twisted/twisted/security/advisories/GHSA-c8m8-j448-xjx7).
This issue means that, if multiple HTTP requests are pipelined in the same TCP connection, Synapse can send responses to the wrong HTTP request.
If a reverse proxy was configured to use HTTP pipelining, this could result in responses being sent to the wrong user, severely harming confidentiality.
The use of HTTP pipelining in this fashion would cause worse performance for clients (request-response latencies would be increased as users' responses would be artificially blocked behind other users' slow requests). Further, Nginx and Haproxy, two common reverse proxies, do not appear to support configuring their upstreams to use HTTP pipelining and thus would not be affected. For both of these reasons, we consider it unlikely that a Synapse deployment would be set up in such a configuration.
Despite that, we cannot rule out that some installations may exist with this unusual setup and so we are releasing this security update today.
**pip users:** Note that by default, upgrading Synapse using pip will not automatically upgrade Twisted. **Please manually install the new version of Twisted** using `pip install Twisted==24.7.0rc1`. Note also that even the `--upgrade-strategy=eager` flag to `pip install -U matrix-synapse` will not upgrade Twisted to a patched version because it is only a release candidate at this time.
- Fix bug where using `synapse.app.media_repository` worker configuration would break the new media endpoints. ([\#17420](https://github.com/element-hq/synapse/issues/17420))
### Improved Documentation
- Document the new federation media worker endpoints in the [upgrade notes](https://element-hq.github.io/synapse/v1.111/upgrade.html) and [worker docs](https://element-hq.github.io/synapse/v1.111/workers.html). ([\#17421](https://github.com/element-hq/synapse/issues/17421))
### Internal Changes
- Route authenticated federation media requests to media repository workers in Complement tests. ([\#17422](https://github.com/element-hq/synapse/issues/17422))
- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/3916-authentication-for-media.md) by adding [`_matrix/client/v1/media/download`](https://spec.matrix.org/v1.11/client-server-api/#get_matrixclientv1mediadownloadservernamemediaid) endpoint. ([\#17365](https://github.com/element-hq/synapse/issues/17365))
by adding [`_matrix/client/v1/media/thumbnail`](https://spec.matrix.org/v1.11/client-server-api/#get_matrixclientv1mediathumbnailservernamemediaid), [`_matrix/federation/v1/media/thumbnail`](https://spec.matrix.org/v1.11/server-server-api/#get_matrixfederationv1mediathumbnailmediaid) endpoints and stabilizing the
- Forget all of a user's rooms upon deactivation, preventing local room purges from being blocked on deactivated users. ([\#17400](https://github.com/element-hq/synapse/issues/17400))
- Declare support for [Matrix 1.11](https://matrix.org/blog/2024/06/20/matrix-v1.11-release/). ([\#17403](https://github.com/element-hq/synapse/issues/17403))
- [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861): allow overriding the introspection endpoint. ([\#17406](https://github.com/element-hq/synapse/issues/17406))
- Fix rare race which caused no new to-device messages to be received from remote server. ([\#17362](https://github.com/element-hq/synapse/issues/17362))
- Fix bug in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint when using an old database. ([\#17398](https://github.com/element-hq/synapse/issues/17398))
- Fix broken links in README. ([\#17379](https://github.com/element-hq/synapse/issues/17379))
- Clarify that changelog content *and file extension* need to match in order for entries to merge. ([\#17399](https://github.com/element-hq/synapse/issues/17399))
### Internal Changes
- Make the release script create a release branch for Complement as well. ([\#17318](https://github.com/element-hq/synapse/issues/17318))
- Fix uploading packages to PyPi. ([\#17363](https://github.com/element-hq/synapse/issues/17363))
- Add CI check for the README. ([\#17367](https://github.com/element-hq/synapse/issues/17367))
- Fix linting errors from new `ruff` version. ([\#17381](https://github.com/element-hq/synapse/issues/17381), [\#17411](https://github.com/element-hq/synapse/issues/17411))
- Fix building debian packages on non-clean checkouts. ([\#17390](https://github.com/element-hq/synapse/issues/17390))
- Finish up work to allow per-user feature flags. ([\#17392](https://github.com/element-hq/synapse/issues/17392), [\#17410](https://github.com/element-hq/synapse/issues/17410))
* Bump serde_json from 1.0.117 to 1.0.120. ([\#17385](https://github.com/element-hq/synapse/issues/17385), [\#17408](https://github.com/element-hq/synapse/issues/17408))
- Fix bug where `/sync` requests could get blocked indefinitely after an upgrade from Synapse versions before v1.109.0. ([\#17386](https://github.com/element-hq/synapse/issues/17386), [\#17391](https://github.com/element-hq/synapse/issues/17391))
### Internal Changes
- Limit size of presence EDUs to 50 entries. ([\#17371](https://github.com/element-hq/synapse/issues/17371))
- Fix building debian package for debian sid. ([\#17389](https://github.com/element-hq/synapse/issues/17389))
- Add experimental support for [MSC3823](https://github.com/matrix-org/matrix-spec-proposals/pull/3823) - Account suspension. ([\#17255](https://github.com/element-hq/synapse/issues/17255))
- Add support for the unstable [MSC4151](https://github.com/matrix-org/matrix-spec-proposals/pull/4151) report room API. ([\#17270](https://github.com/element-hq/synapse/issues/17270), [\#17296](https://github.com/element-hq/synapse/issues/17296))
- Filter for public and empty rooms added to Admin-API [List Room API](https://element-hq.github.io/synapse/latest/admin_api/rooms.html#list-room-api). ([\#17276](https://github.com/element-hq/synapse/issues/17276))
- Include user membership in events served to clients, per [MSC4115](https://github.com/matrix-org/matrix-spec-proposals/pull/4115). ([\#17282](https://github.com/element-hq/synapse/issues/17282))
- Do not require user-interactive authentication for uploading cross-signing keys for the first time, per [MSC3967](https://github.com/matrix-org/matrix-spec-proposals/pull/3967). ([\#17284](https://github.com/element-hq/synapse/issues/17284))
- Add support for via query parameter from [MSC4156](https://github.com/matrix-org/matrix-spec-proposals/pull/4156). ([\#17322](https://github.com/element-hq/synapse/issues/17322))
- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/blob/main/proposals/3916-authentication-for-media.md) by adding a federation /download endpoint. ([\#17350](https://github.com/element-hq/synapse/issues/17350))
- Fix searching for users with their exact localpart whose ID includes a hyphen. ([\#17254](https://github.com/element-hq/synapse/issues/17254))
- Fix wrong retention policy being used when filtering events. ([\#17272](https://github.com/element-hq/synapse/issues/17272))
- Fix bug where OTKs were not always included in `/sync` response when using workers. ([\#17275](https://github.com/element-hq/synapse/issues/17275))
- Fix a long-standing bug where an invalid 'from' parameter to [`/notifications`](https://spec.matrix.org/v1.10/client-server-api/#get_matrixclientv3notifications) would result in an Internal Server Error. ([\#17283](https://github.com/element-hq/synapse/issues/17283))
- Fix edge case in `/sync` returning the wrong the state when using sharded event persisters. ([\#17295](https://github.com/element-hq/synapse/issues/17295))
- Add initial implementation of an experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint. ([\#17301](https://github.com/element-hq/synapse/issues/17301))
- Fix email notification subject when invited to a space. ([\#17336](https://github.com/element-hq/synapse/issues/17336))
### Improved Documentation
- Add missing quotes for example for `exclude_rooms_from_sync`. ([\#17308](https://github.com/element-hq/synapse/issues/17308))
- Update header in the README to visually fix the the auto-generated table of contents. ([\#17329](https://github.com/element-hq/synapse/issues/17329))
- Fix stale references to the Foundation's Security Disclosure Policy. ([\#17341](https://github.com/element-hq/synapse/issues/17341))
- Add default values for `rc_invites.per_issuer` to docs. ([\#17347](https://github.com/element-hq/synapse/issues/17347))
- Fix an error in the docs for `search_all_users` parameter under `user_directory`. ([\#17348](https://github.com/element-hq/synapse/issues/17348))
### Internal Changes
- Remove unused `expire_access_token` option in the Synapse Docker config file. Contributed by @AaronDewes. ([\#17198](https://github.com/element-hq/synapse/issues/17198))
- Use fully-qualified `PersistedEventPosition` when returning `RoomsForUser` to facilitate proper comparisons and `RoomStreamToken` generation. ([\#17265](https://github.com/element-hq/synapse/issues/17265))
- Add debug logging for when room keys are uploaded, including whether they are replacing other room keys. ([\#17266](https://github.com/element-hq/synapse/issues/17266))
- Handle OTK uploads off master. ([\#17271](https://github.com/element-hq/synapse/issues/17271))
- Don't try and resync devices for remote users whose servers are marked as down. ([\#17273](https://github.com/element-hq/synapse/issues/17273))
- Re-organize Pydantic models and types used in handlers. ([\#17279](https://github.com/element-hq/synapse/issues/17279))
- Expose the worker instance that persisted the event on `event.internal_metadata.instance_name`. ([\#17300](https://github.com/element-hq/synapse/issues/17300))
- Update the README with Element branding, improve headers and fix the #synapse:matrix.org support room link rendering. ([\#17324](https://github.com/element-hq/synapse/issues/17324))
- Change path of the experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync implementation to `/org.matrix.simplified_msc3575/sync` since our simplified API is slightly incompatible with what's in the current MSC. ([\#17331](https://github.com/element-hq/synapse/issues/17331))
- Handle device lists notifications for large accounts more efficiently in worker mode. ([\#17333](https://github.com/element-hq/synapse/issues/17333), [\#17358](https://github.com/element-hq/synapse/issues/17358))
- Do not block event sending/receiving while calculating large event auth chains. ([\#17338](https://github.com/element-hq/synapse/issues/17338))
- Tidy up `parse_integer` docs and call sites to reflect the fact that they require non-negative integers by default, and bring `parse_integer_from_args` default in alignment. Contributed by Denis Kasak (@dkasak). ([\#17339](https://github.com/element-hq/synapse/issues/17339))
### Updates to locked dependencies
* Bump authlib from 1.3.0 to 1.3.1. ([\#17343](https://github.com/element-hq/synapse/issues/17343))
* Bump dawidd6/action-download-artifact from 3.1.4 to 5. ([\#17289](https://github.com/element-hq/synapse/issues/17289))
* Bump dawidd6/action-download-artifact from 5 to 6. ([\#17313](https://github.com/element-hq/synapse/issues/17313))
* Bump docker/build-push-action from 5 to 6. ([\#17312](https://github.com/element-hq/synapse/issues/17312))
* Bump jinja2 from 3.1.3 to 3.1.4. ([\#17287](https://github.com/element-hq/synapse/issues/17287))
* Bump lazy_static from 1.4.0 to 1.5.0. ([\#17355](https://github.com/element-hq/synapse/issues/17355))
* Bump msgpack from 1.0.7 to 1.0.8. ([\#17317](https://github.com/element-hq/synapse/issues/17317))
* Bump netaddr from 1.2.1 to 1.3.0. ([\#17353](https://github.com/element-hq/synapse/issues/17353))
* Bump packaging from 24.0 to 24.1. ([\#17352](https://github.com/element-hq/synapse/issues/17352))
* Bump phonenumbers from 8.13.37 to 8.13.39. ([\#17315](https://github.com/element-hq/synapse/issues/17315))
* Bump regex from 1.10.4 to 1.10.5. ([\#17290](https://github.com/element-hq/synapse/issues/17290))
* Bump requests from 2.31.0 to 2.32.2. ([\#17345](https://github.com/element-hq/synapse/issues/17345))
* Bump sentry-sdk from 2.1.1 to 2.3.1. ([\#17263](https://github.com/element-hq/synapse/issues/17263))
* Bump sentry-sdk from 2.3.1 to 2.6.0. ([\#17351](https://github.com/element-hq/synapse/issues/17351))
* Bump tornado from 6.4 to 6.4.1. ([\#17344](https://github.com/element-hq/synapse/issues/17344))
- When rolling back to a previous Synapse version and then forwards again to this release, don't require server operators to manually run SQL. ([\#17305](https://github.com/element-hq/synapse/issues/17305), [\#17309](https://github.com/element-hq/synapse/issues/17309))
### Internal Changes
- Use the release branch for sytest in release-branch PRs. ([\#17306](https://github.com/element-hq/synapse/issues/17306))
- Fix bug where one-time-keys were not always included in `/sync` response when using workers. Introduced in v1.109.0rc1. ([\#17275](https://github.com/element-hq/synapse/issues/17275))
- Fix bug where `/sync` could get stuck due to edge case in device lists handling. Introduced in v1.109.0rc1. ([\#17292](https://github.com/element-hq/synapse/issues/17292))
- Add the ability to auto-accept invites on the behalf of users. See the [`auto_accept_invites`](https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#auto-accept-invites) config option for details. ([\#17147](https://github.com/element-hq/synapse/issues/17147))
- Add experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync/e2ee` endpoint for to-device messages and device encryption info. ([\#17167](https://github.com/element-hq/synapse/issues/17167))
- Support [MSC3916](https://github.com/matrix-org/matrix-spec-proposals/issues/3916) by adding unstable media endpoints to `/_matrix/client`. ([\#17213](https://github.com/element-hq/synapse/issues/17213))
- Add logging to tasks managed by the task scheduler, showing CPU and database usage. ([\#17219](https://github.com/element-hq/synapse/issues/17219))
### Bugfixes
- Fix deduplicating of membership events to not create unused state groups. ([\#17164](https://github.com/element-hq/synapse/issues/17164))
- Fix bug where duplicate events could be sent down sync when using workers that are overloaded. ([\#17215](https://github.com/element-hq/synapse/issues/17215))
- Ignore attempts to send to-device messages to bad users, to avoid log spam when we try to connect to the bad server. ([\#17240](https://github.com/element-hq/synapse/issues/17240))
- Fix handling of duplicate concurrent uploading of device one-time-keys. ([\#17241](https://github.com/element-hq/synapse/issues/17241))
- Fix reporting of default tags to Sentry, such as worker name. Broke in v1.108.0. ([\#17251](https://github.com/element-hq/synapse/issues/17251))
- Fix bug where typing updates would not be sent when using workers after a restart. ([\#17252](https://github.com/element-hq/synapse/issues/17252))
### Improved Documentation
- Update the LemonLDAP documentation to say that claims should be explicitly included in the returned `id_token`, as Synapse won't request them. ([\#17204](https://github.com/element-hq/synapse/issues/17204))
### Internal Changes
- Improve DB usage when fetching related events. ([\#17083](https://github.com/element-hq/synapse/issues/17083))
- Log exceptions when failing to auto-join new user according to the `auto_join_rooms` option. ([\#17176](https://github.com/element-hq/synapse/issues/17176))
- Reduce work of calculating outbound device lists updates. ([\#17211](https://github.com/element-hq/synapse/issues/17211))
- Improve performance of calculating device lists changes in `/sync`. ([\#17216](https://github.com/element-hq/synapse/issues/17216))
- Move towards using `MultiWriterIdGenerator` everywhere. ([\#17226](https://github.com/element-hq/synapse/issues/17226))
- Replaces all usages of `StreamIdGenerator` with `MultiWriterIdGenerator`. ([\#17229](https://github.com/element-hq/synapse/issues/17229))
- Change the `allow_unsafe_locale` config option to also apply when setting up new databases. ([\#17238](https://github.com/element-hq/synapse/issues/17238))
- Fix errors in logs about closing incorrect logging contexts when media gets rejected by a module. ([\#17239](https://github.com/element-hq/synapse/issues/17239), [\#17246](https://github.com/element-hq/synapse/issues/17246))
- Clean out invalid destinations from `device_federation_outbox` table. ([\#17242](https://github.com/element-hq/synapse/issues/17242))
- Stop logging errors when receiving invalid User IDs in key querys requests. ([\#17250](https://github.com/element-hq/synapse/issues/17250))
### Updates to locked dependencies
* Bump anyhow from 1.0.83 to 1.0.86. ([\#17220](https://github.com/element-hq/synapse/issues/17220))
* Bump bcrypt from 4.1.2 to 4.1.3. ([\#17224](https://github.com/element-hq/synapse/issues/17224))
* Bump lxml from 5.2.1 to 5.2.2. ([\#17261](https://github.com/element-hq/synapse/issues/17261))
* Bump mypy-zope from 1.0.3 to 1.0.4. ([\#17262](https://github.com/element-hq/synapse/issues/17262))
* Bump phonenumbers from 8.13.35 to 8.13.37. ([\#17235](https://github.com/element-hq/synapse/issues/17235))
* Bump prometheus-client from 0.19.0 to 0.20.0. ([\#17233](https://github.com/element-hq/synapse/issues/17233))
* Bump pyasn1 from 0.5.1 to 0.6.0. ([\#17223](https://github.com/element-hq/synapse/issues/17223))
* Bump pyicu from 2.13 to 2.13.1. ([\#17236](https://github.com/element-hq/synapse/issues/17236))
* Bump pyopenssl from 24.0.0 to 24.1.0. ([\#17234](https://github.com/element-hq/synapse/issues/17234))
* Bump serde from 1.0.201 to 1.0.202. ([\#17221](https://github.com/element-hq/synapse/issues/17221))
* Bump serde from 1.0.202 to 1.0.203. ([\#17232](https://github.com/element-hq/synapse/issues/17232))
* Bump twine from 5.0.0 to 5.1.0. ([\#17225](https://github.com/element-hq/synapse/issues/17225))
* Bump types-psycopg2 from 2.9.21.20240311 to 2.9.21.20240417. ([\#17222](https://github.com/element-hq/synapse/issues/17222))
* Bump types-pyopenssl from 24.0.0.20240311 to 24.1.0.20240425. ([\#17260](https://github.com/element-hq/synapse/issues/17260))
- Add a feature that allows clients to query the configured federation whitelist. Disabled by default. ([\#16848](https://github.com/element-hq/synapse/issues/16848), [\#17199](https://github.com/element-hq/synapse/issues/17199))
- Add the ability to allow numeric user IDs with a specific prefix when in the CAS flow. Contributed by Aurélien Grimpard. ([\#17098](https://github.com/element-hq/synapse/issues/17098))
### Bugfixes
- Fix bug where push rules would be empty in `/sync` for some accounts. Introduced in v1.93.0. ([\#17142](https://github.com/element-hq/synapse/issues/17142))
- Add support for optional whitespace around the Federation API's `Authorization` header's parameter commas. ([\#17145](https://github.com/element-hq/synapse/issues/17145))
- Fix bug where disabling room publication prevented public rooms being created on workers. ([\#17177](https://github.com/element-hq/synapse/issues/17177), [\#17184](https://github.com/element-hq/synapse/issues/17184))
- Document [`/v1/make_knock`](https://spec.matrix.org/v1.10/server-server-api/#get_matrixfederationv1make_knockroomiduserid) and [`/v1/send_knock/`](https://spec.matrix.org/v1.10/server-server-api/#put_matrixfederationv1send_knockroomideventid) federation endpoints as worker-compatible. ([\#17058](https://github.com/element-hq/synapse/issues/17058))
- Update User Admin API with note about prefixing OIDC external_id providers. ([\#17139](https://github.com/element-hq/synapse/issues/17139))
- Clarify the state of the created room when using the `autocreate_auto_join_room_preset` config option. ([\#17150](https://github.com/element-hq/synapse/issues/17150))
- Update the Admin FAQ with the current libjemalloc version for latest Debian stable. Additionally update the name of the "push_rules" stream in the Workers documentation. ([\#17171](https://github.com/element-hq/synapse/issues/17171))
- Add note to reflect that [MSC3886](https://github.com/matrix-org/matrix-spec-proposals/pull/3886) is closed but will remain supported for some time. ([\#17151](https://github.com/element-hq/synapse/issues/17151))
- Update dependency PyO3 to 0.21. ([\#17162](https://github.com/element-hq/synapse/issues/17162))
- Fixes linter errors found in PR #17147. ([\#17166](https://github.com/element-hq/synapse/issues/17166))
- Bump black from 24.2.0 to 24.4.2. ([\#17170](https://github.com/element-hq/synapse/issues/17170))
- Cache literal sync filter validation for performance. ([\#17186](https://github.com/element-hq/synapse/issues/17186))
- Improve performance by fixing a reactor pause. ([\#17192](https://github.com/element-hq/synapse/issues/17192))
- Route `/make_knock` and `/send_knock` federation APIs to the federation reader worker in Complement test runs. ([\#17195](https://github.com/element-hq/synapse/issues/17195))
- Prepare sync handler to be able to return different sync responses (`SyncVersion`). ([\#17200](https://github.com/element-hq/synapse/issues/17200))
- Organize the sync cache key parameter outside of the sync config (separate concerns). ([\#17201](https://github.com/element-hq/synapse/issues/17201))
- Refactor `SyncResultBuilder` assembly to its own function. ([\#17202](https://github.com/element-hq/synapse/issues/17202))
- Rename to be obvious: `joined_rooms` -> `joined_room_ids`. ([\#17203](https://github.com/element-hq/synapse/issues/17203), [\#17208](https://github.com/element-hq/synapse/issues/17208))
- Add a short pause when rate-limiting a request. ([\#17210](https://github.com/element-hq/synapse/issues/17210))
### Updates to locked dependencies
* Bump cryptography from 42.0.5 to 42.0.7. ([\#17180](https://github.com/element-hq/synapse/issues/17180))
* Bump gitpython from 3.1.41 to 3.1.43. ([\#17181](https://github.com/element-hq/synapse/issues/17181))
* Bump immutabledict from 4.1.0 to 4.2.0. ([\#17179](https://github.com/element-hq/synapse/issues/17179))
* Bump sentry-sdk from 1.40.3 to 2.1.1. ([\#17178](https://github.com/element-hq/synapse/issues/17178))
* Bump serde from 1.0.200 to 1.0.201. ([\#17183](https://github.com/element-hq/synapse/issues/17183))
* Bump serde_json from 1.0.116 to 1.0.117. ([\#17182](https://github.com/element-hq/synapse/issues/17182))
- Add preliminary support for [MSC3823: Account Suspension](https://github.com/matrix-org/matrix-spec-proposals/pull/3823). ([\#17051](https://github.com/element-hq/synapse/issues/17051))
- Declare support for [Matrix v1.10](https://matrix.org/blog/2024/03/22/matrix-v1.10-release/). Contributed by @clokep. ([\#17082](https://github.com/element-hq/synapse/issues/17082))
- Add support for [MSC4115: membership metadata on events](https://github.com/matrix-org/matrix-spec-proposals/pull/4115). ([\#17104](https://github.com/element-hq/synapse/issues/17104), [\#17137](https://github.com/element-hq/synapse/issues/17137))
- Fixed search feature of Element Android on homesevers using SQLite by returning search terms as search highlights. ([\#17000](https://github.com/element-hq/synapse/issues/17000))
- Fixes a bug introduced in v1.52.0 where the `destination` query parameter for the [Destination Rooms Admin API](https://element-hq.github.io/synapse/v1.105/usage/administration/admin_api/federation.html#destination-rooms) failed to actually filter returned rooms. ([\#17077](https://github.com/element-hq/synapse/issues/17077))
- For MSC3266 room summaries, support queries at the recommended endpoint of `/_matrix/client/unstable/im.nheko.summary/summary/{roomIdOrAlias}`. The existing endpoint of `/_matrix/client/unstable/im.nheko.summary/rooms/{roomIdOrAlias}/summary` is deprecated. ([\#17078](https://github.com/element-hq/synapse/issues/17078))
- Apply user email & picture during OIDC registration if present & selected. ([\#17120](https://github.com/element-hq/synapse/issues/17120))
- Fix a bug which meant that to-device messages received over federation could be dropped when the server was under load or networking problems caused problems between Synapse processes or the database. ([\#17127](https://github.com/element-hq/synapse/issues/17127))
- Fix bug where `StreamChangeCache` would not respect configured cache factors. ([\#17152](https://github.com/element-hq/synapse/issues/17152))
### Updates to the Docker image
- Correct licensing metadata on Docker image. ([\#17141](https://github.com/element-hq/synapse/issues/17141))
### Improved Documentation
- Update the `event_cache_size` and `global_factor` configuration options' documentation. ([\#17071](https://github.com/element-hq/synapse/issues/17071))
- Update the Upgrade Notes with the latest minimum supported Rust version of 1.66.0. Contributed by @jahway603. ([\#17140](https://github.com/element-hq/synapse/issues/17140))
- Enable [MSC3266](https://github.com/matrix-org/matrix-spec-proposals/pull/3266) by default in the Synapse Complement image. ([\#17105](https://github.com/element-hq/synapse/issues/17105))
- Implement the rendezvous mechanism described by [MSC4108](https://github.com/matrix-org/matrix-spec-proposals/issues/4108). ([\#17056](https://github.com/element-hq/synapse/issues/17056))
- Support delegating the rendezvous mechanism described [MSC4108](https://github.com/matrix-org/matrix-spec-proposals/issues/4108) to an external implementation. ([\#17086](https://github.com/element-hq/synapse/issues/17086))
- Add validation to ensure that the `limit` parameter on `/publicRooms` is non-negative. ([\#16920](https://github.com/element-hq/synapse/issues/16920))
- Return `400 M_NOT_JSON` upon receiving invalid JSON in query parameters across various client and admin endpoints, rather than an internal server error. ([\#16923](https://github.com/element-hq/synapse/issues/16923))
- Make the CSAPI endpoint `/keys/device_signing/upload` idempotent. ([\#16943](https://github.com/element-hq/synapse/issues/16943))
- Redact membership events if the user requested erasure upon deactivating. ([\#17076](https://github.com/element-hq/synapse/issues/17076))
### Improved Documentation
- Add a prompt in the contributing guide to manually configure icu4c. ([\#17069](https://github.com/element-hq/synapse/issues/17069))
- Clarify what part of message retention is still experimental. ([\#17099](https://github.com/element-hq/synapse/issues/17099))
### Internal Changes
- Use new receipts column to optimise receipt and push action SQL queries. Contributed by Nick @ Beeper (@fizzadar). ([\#17032](https://github.com/element-hq/synapse/issues/17032), [\#17096](https://github.com/element-hq/synapse/issues/17096))
- Fix mypy with latest Twisted release. ([\#17036](https://github.com/element-hq/synapse/issues/17036))
- Bump minimum supported Rust version to 1.66.0. ([\#17079](https://github.com/element-hq/synapse/issues/17079))
- Add helpers to transform Twisted requests to Rust http Requests/Responses. ([\#17081](https://github.com/element-hq/synapse/issues/17081))
- Fix type annotation for `visited_chains` after `mypy` upgrade. ([\#17125](https://github.com/element-hq/synapse/issues/17125))
### Updates to locked dependencies
* Bump anyhow from 1.0.81 to 1.0.82. ([\#17095](https://github.com/element-hq/synapse/issues/17095))
* Bump peaceiris/actions-gh-pages from 3.9.3 to 4.0.0. ([\#17087](https://github.com/element-hq/synapse/issues/17087))
* Bump peaceiris/actions-mdbook from 1.2.0 to 2.0.0. ([\#17089](https://github.com/element-hq/synapse/issues/17089))
* Bump pyasn1-modules from 0.3.0 to 0.4.0. ([\#17093](https://github.com/element-hq/synapse/issues/17093))
* Bump pygithub from 2.2.0 to 2.3.0. ([\#17092](https://github.com/element-hq/synapse/issues/17092))
* Bump ruff from 0.3.5 to 0.3.7. ([\#17094](https://github.com/element-hq/synapse/issues/17094))
* Bump sigstore/cosign-installer from 3.4.0 to 3.5.0. ([\#17088](https://github.com/element-hq/synapse/issues/17088))
* Bump twine from 4.0.2 to 5.0.0. ([\#17091](https://github.com/element-hq/synapse/issues/17091))
* Bump types-pillow from 10.2.0.20240406 to 10.2.0.20240415. ([\#17090](https://github.com/element-hq/synapse/issues/17090))
- Stabilize support for [MSC4010](https://github.com/matrix-org/matrix-spec-proposals/pull/4010) which clarifies the interaction of push rules and account data. Contributed by @clokep. ([\#17022](https://github.com/element-hq/synapse/issues/17022))
- Stabilize support for [MSC3981](https://github.com/matrix-org/matrix-spec-proposals/pull/3981): `/relations` recursion. Contributed by @clokep. ([\#17023](https://github.com/element-hq/synapse/issues/17023))
- Add support for moving `/pushrules` off of main process. ([\#17037](https://github.com/element-hq/synapse/issues/17037), [\#17038](https://github.com/element-hq/synapse/issues/17038))
### Bugfixes
- Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations. ([\#16930](https://github.com/element-hq/synapse/issues/16930), [\#16932](https://github.com/element-hq/synapse/issues/16932), [\#16942](https://github.com/element-hq/synapse/issues/16942), [\#17064](https://github.com/element-hq/synapse/issues/17064), [\#17065](https://github.com/element-hq/synapse/issues/17065), [\#17066](https://github.com/element-hq/synapse/issues/17066))
- Fix server notice rooms not always being created as unencrypted rooms, even when `encryption_enabled_by_default_for_room_type` is in use (server notices are always unencrypted). ([\#17033](https://github.com/element-hq/synapse/issues/17033))
- Fix the `.m.rule.encrypted_room_one_to_one` and `.m.rule.room_one_to_one` default underride push rules being in the wrong order. Contributed by @Sumpy1. ([\#17043](https://github.com/element-hq/synapse/issues/17043))
### Internal Changes
- Refactor auth chain fetching to reduce duplication. ([\#17044](https://github.com/element-hq/synapse/issues/17044))
- Improve database performance by adding a missing index to `access_tokens.refresh_token_id`. ([\#17045](https://github.com/element-hq/synapse/issues/17045), [\#17054](https://github.com/element-hq/synapse/issues/17054))
- Improve database performance by reducing number of receipts fetched when sending push notifications. ([\#17049](https://github.com/element-hq/synapse/issues/17049))
### Updates to locked dependencies
* Bump packaging from 23.2 to 24.0. ([\#17027](https://github.com/element-hq/synapse/issues/17027))
* Bump regex from 1.10.3 to 1.10.4. ([\#17028](https://github.com/element-hq/synapse/issues/17028))
* Bump ruff from 0.3.2 to 0.3.5. ([\#17060](https://github.com/element-hq/synapse/issues/17060))
* Bump serde_json from 1.0.114 to 1.0.115. ([\#17041](https://github.com/element-hq/synapse/issues/17041))
* Bump types-pillow from 10.2.0.20240125 to 10.2.0.20240406. ([\#17061](https://github.com/element-hq/synapse/issues/17061))
* Bump types-requests from 2.31.0.20240125 to 2.31.0.20240406. ([\#17063](https://github.com/element-hq/synapse/issues/17063))
* Bump typing-extensions from 4.9.0 to 4.11.0. ([\#17062](https://github.com/element-hq/synapse/issues/17062))
- Add an OIDC config to specify extra parameters for the authorization grant URL. IT can be useful to pass an ACR value for example. ([\#16971](https://github.com/element-hq/synapse/issues/16971))
- Add support for OIDC provider returning JWT. ([\#16972](https://github.com/element-hq/synapse/issues/16972), [\#17031](https://github.com/element-hq/synapse/issues/17031))
- Fix a bug which meant that, under certain circumstances, we might never retry sending events or to-device messages over federation after a failure. ([\#16925](https://github.com/element-hq/synapse/issues/16925))
- Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations. ([\#16949](https://github.com/element-hq/synapse/issues/16949))
- Fix case in which `m.fully_read` marker would not get updated. Contributed by @SpiritCroc. ([\#16990](https://github.com/element-hq/synapse/issues/16990))
- Fix bug which did not retract a user's pending knocks at rooms when their account was deactivated. Contributed by @hanadi92. ([\#17010](https://github.com/element-hq/synapse/issues/17010))
- Updated `start.py` to generate config using the correct user ID when running as root (fixes [\#16824](https://github.com/element-hq/synapse/issues/16824), [\#15202](https://github.com/element-hq/synapse/issues/15202)). ([\#16978](https://github.com/element-hq/synapse/issues/16978))
- Add a query to force a refresh of a remote user's device list to the "Useful SQL for Admins" documentation page. ([\#16892](https://github.com/element-hq/synapse/issues/16892))
- Minor grammatical corrections to the upgrade documentation. ([\#16965](https://github.com/element-hq/synapse/issues/16965))
- Fix the sort order for the documentation version picker, so that newer releases appear above older ones. ([\#16966](https://github.com/element-hq/synapse/issues/16966))
- Remove recommendation for a specific poetry version from contributing guide. ([\#17002](https://github.com/element-hq/synapse/issues/17002))
### Internal Changes
- Improve lock performance when a lot of locks are all waiting for a single lock to be released. ([\#16840](https://github.com/element-hq/synapse/issues/16840))
- Refactor state delta calculation in `/sync` handler. ([\#16929](https://github.com/element-hq/synapse/issues/16929))
- Clarify docs for some room state functions. ([\#16950](https://github.com/element-hq/synapse/issues/16950))
- Specify IP subnets in canonical form. ([\#16953](https://github.com/element-hq/synapse/issues/16953))
- As done for SAML mapping provider, let's pass the module API to the OIDC one so the mapper can do more logic in its code. ([\#16974](https://github.com/element-hq/synapse/issues/16974))
- Allow containers building on top of Synapse's Complement container is use the included PostgreSQL cluster. ([\#16985](https://github.com/element-hq/synapse/issues/16985))
- Raise poetry-core version cap to 1.9.0. ([\#16986](https://github.com/element-hq/synapse/issues/16986))
- Patch the db conn pool sooner in tests. ([\#17017](https://github.com/element-hq/synapse/issues/17017))
### Updates to locked dependencies
* Bump anyhow from 1.0.80 to 1.0.81. ([\#17009](https://github.com/element-hq/synapse/issues/17009))
* Bump black from 23.10.1 to 24.2.0. ([\#16936](https://github.com/element-hq/synapse/issues/16936))
* Bump cryptography from 41.0.7 to 42.0.5. ([\#16958](https://github.com/element-hq/synapse/issues/16958))
* Bump dawidd6/action-download-artifact from 3.1.1 to 3.1.2. ([\#16960](https://github.com/element-hq/synapse/issues/16960))
* Bump dawidd6/action-download-artifact from 3.1.2 to 3.1.4. ([\#17008](https://github.com/element-hq/synapse/issues/17008))
* Bump jinja2 from 3.1.2 to 3.1.3. ([\#17005](https://github.com/element-hq/synapse/issues/17005))
* Bump log from 0.4.20 to 0.4.21. ([\#16977](https://github.com/element-hq/synapse/issues/16977))
* Bump mypy from 1.5.1 to 1.8.0. ([\#16901](https://github.com/element-hq/synapse/issues/16901))
* Bump netaddr from 0.9.0 to 1.2.1. ([\#17006](https://github.com/element-hq/synapse/issues/17006))
* Bump pydantic from 2.6.0 to 2.6.4. ([\#17004](https://github.com/element-hq/synapse/issues/17004))
* Bump pyo3 from 0.20.2 to 0.20.3. ([\#16962](https://github.com/element-hq/synapse/issues/16962))
* Bump ruff from 0.1.14 to 0.3.2. ([\#16994](https://github.com/element-hq/synapse/issues/16994))
* Bump serde from 1.0.196 to 1.0.197. ([\#16963](https://github.com/element-hq/synapse/issues/16963))
* Bump serde_json from 1.0.113 to 1.0.114. ([\#16961](https://github.com/element-hq/synapse/issues/16961))
* Bump types-jsonschema from 4.21.0.20240118 to 4.21.0.20240311. ([\#17007](https://github.com/element-hq/synapse/issues/17007))
* Bump types-psycopg2 from 2.9.21.16 to 2.9.21.20240311. ([\#16995](https://github.com/element-hq/synapse/issues/16995))
* Bump types-pyopenssl from 23.3.0.0 to 24.0.0.20240311. ([\#17003](https://github.com/element-hq/synapse/issues/17003))
- Add a new [List Accounts v3](https://element-hq.github.io/synapse/v1.103/admin_api/user_admin_api.html#list-accounts-v3) Admin API with improved deactivated user filtering capabilities. ([\#16874](https://github.com/element-hq/synapse/issues/16874))
- Include `Retry-After` header by default per [MSC4041](https://github.com/matrix-org/matrix-spec-proposals/pull/4041). Contributed by @clokep. ([\#16947](https://github.com/element-hq/synapse/issues/16947))
### Bugfixes
- Fix joining remote rooms when a module uses the `on_new_event` callback. This callback may now pass partial state events instead of the full state for remote rooms. Introduced in v1.76.0. ([\#16973](https://github.com/element-hq/synapse/issues/16973))
- Fix performance issue when joining very large rooms that can cause the server to lock up. Introduced in v1.100.0. Contributed by @ggogel. ([\#16968](https://github.com/element-hq/synapse/issues/16968))
- Add HAProxy example for single port operation to reverse proxy documentation. Contributed by Georg Pfuetzenreuter (@tacerus). ([\#16768](https://github.com/element-hq/synapse/issues/16768))
- Improve the documentation around running Complement tests with new configuration parameters. ([\#16946](https://github.com/element-hq/synapse/issues/16946))
- Add docs on upgrading from a very old version. ([\#16951](https://github.com/element-hq/synapse/issues/16951))
### Updates to locked dependencies
* Bump JasonEtco/create-an-issue from 2.9.1 to 2.9.2. ([\#16934](https://github.com/element-hq/synapse/issues/16934))
* Bump anyhow from 1.0.79 to 1.0.80. ([\#16935](https://github.com/element-hq/synapse/issues/16935))
* Bump dawidd6/action-download-artifact from 3.0.0 to 3.1.1. ([\#16933](https://github.com/element-hq/synapse/issues/16933))
* Bump furo from 2023.9.10 to 2024.1.29. ([\#16939](https://github.com/element-hq/synapse/issues/16939))
* Bump pyopenssl from 23.3.0 to 24.0.0. ([\#16937](https://github.com/element-hq/synapse/issues/16937))
* Bump types-netaddr from 0.10.0.20240106 to 1.2.0.20240219. ([\#16938](https://github.com/element-hq/synapse/issues/16938))
- Revert https://github.com/element-hq/synapse/pull/16756, which caused incorrect notification counts on mobile clients since v1.100.0. ([\#16979](https://github.com/element-hq/synapse/issues/16979))
- A metric was added for emails sent by Synapse, broken down by type: `synapse_emails_sent_total`. Contributed by Remi Rampin. ([\#16881](https://github.com/element-hq/synapse/issues/16881))
### Bugfixes
- Do not send multiple concurrent requests for keys for the same server. ([\#16894](https://github.com/element-hq/synapse/issues/16894))
- Fix performance issue when joining very large rooms that can cause the server to lock up. Introduced in v1.100.0. ([\#16903](https://github.com/element-hq/synapse/issues/16903))
- Always prefer unthreaded receipt when >1 exist ([MSC4102](https://github.com/matrix-org/matrix-spec-proposals/pull/4102)). ([\#16927](https://github.com/element-hq/synapse/issues/16927))
### Improved Documentation
- Fix a small typo in the Rooms section of the Admin API documentation. Contributed by @RainerZufall187. ([\#16857](https://github.com/element-hq/synapse/issues/16857))
### Internal Changes
- Don't invalidate the entire event cache when we purge history. ([\#16905](https://github.com/element-hq/synapse/issues/16905))
- Add experimental config option to not send device list updates for specific users. ([\#16909](https://github.com/element-hq/synapse/issues/16909))
- Fix incorrect docker hub link in release script. ([\#16910](https://github.com/element-hq/synapse/issues/16910))
### Updates to locked dependencies
* Bump attrs from 23.1.0 to 23.2.0. ([\#16899](https://github.com/element-hq/synapse/issues/16899))
* Bump bcrypt from 4.0.1 to 4.1.2. ([\#16900](https://github.com/element-hq/synapse/issues/16900))
* Bump pygithub from 2.1.1 to 2.2.0. ([\#16902](https://github.com/element-hq/synapse/issues/16902))
* Bump sentry-sdk from 1.40.0 to 1.40.3. ([\#16898](https://github.com/element-hq/synapse/issues/16898))
- Fix performance regression when fetching auth chains from the DB. Introduced in v1.100.0. ([\#16893](https://github.com/element-hq/synapse/issues/16893))
- Fix broken links in the documentation. ([\#16853](https://github.com/element-hq/synapse/issues/16853))
- Update MacOS installation instructions to mention that libicu is optional. ([\#16854](https://github.com/element-hq/synapse/issues/16854))
- The version picker now correctly lists versions after `v1.98.0`. ([\#16880](https://github.com/element-hq/synapse/issues/16880))
### Internal Changes
- Add support for stabilised [MSC3981](https://github.com/matrix-org/matrix-spec-proposals/pull/3981) that adds a `recurse` parameter on the `/relations` API. ([\#16842](https://github.com/element-hq/synapse/issues/16842))
### Updates to locked dependencies
* Bump dorny/paths-filter from 2 to 3. ([\#16869](https://github.com/element-hq/synapse/issues/16869))
* Bump gitpython from 3.1.40 to 3.1.41. ([\#16850](https://github.com/element-hq/synapse/issues/16850))
* Bump hiredis from 2.2.3 to 2.3.2. ([\#16862](https://github.com/element-hq/synapse/issues/16862))
* Bump jsonschema from 4.20.0 to 4.21.1. ([\#16887](https://github.com/element-hq/synapse/issues/16887))
* Bump lxml-stubs from 0.4.0 to 0.5.1. ([\#16885](https://github.com/element-hq/synapse/issues/16885))
* Bump mypy-zope from 1.0.1 to 1.0.3. ([\#16865](https://github.com/element-hq/synapse/issues/16865))
* Bump phonenumbers from 8.13.26 to 8.13.29. ([\#16868](https://github.com/element-hq/synapse/issues/16868))
* Bump pydantic from 2.5.3 to 2.6.0. ([\#16888](https://github.com/element-hq/synapse/issues/16888))
* Bump sentry-sdk from 1.39.1 to 1.40.0. ([\#16889](https://github.com/element-hq/synapse/issues/16889))
* Bump serde from 1.0.195 to 1.0.196. ([\#16867](https://github.com/element-hq/synapse/issues/16867))
* Bump serde_json from 1.0.111 to 1.0.113. ([\#16866](https://github.com/element-hq/synapse/issues/16866))
* Bump sigstore/cosign-installer from 3.3.0 to 3.4.0. ([\#16890](https://github.com/element-hq/synapse/issues/16890))
* Bump types-pillow from 10.1.0.2 to 10.2.0.20240125. ([\#16864](https://github.com/element-hq/synapse/issues/16864))
* Bump types-requests from 2.31.0.10 to 2.31.0.20240125. ([\#16886](https://github.com/element-hq/synapse/issues/16886))
* Bump types-setuptools from 69.0.0.0 to 69.0.0.20240125. ([\#16863](https://github.com/element-hq/synapse/issues/16863))
- Fix database performance regression due to changing Postgres table statistics. Introduced in v1.100.0rc1. ([\#16849](https://github.com/element-hq/synapse/issues/16849))
- Downgrade the `download-artifact` and `upload-artifact` actions to v3 due to breaking changes. ([\#16847](https://github.com/element-hq/synapse/issues/16847))
- Advertise experimental support for [MSC4028](https://github.com/matrix-org/matrix-spec-proposals/pull/4028) through `/_matrix/clients/versions` if enabled. Contributed by @hanadi92. ([\#16787](https://github.com/element-hq/synapse/issues/16787))
### Bugfixes
- Handle wildcard type filters properly for room messages endpoint. Contributed by Mo Balaa. ([\#14984](https://github.com/element-hq/synapse/issues/14984))
### Improved Documentation
- Add a link to the "Request log format" explainer on the "Logging sample config" documentation page. ([\#16778](https://github.com/element-hq/synapse/issues/16778))
- Fix broken links in issue templates and documentation. ([\#16810](https://github.com/element-hq/synapse/issues/16810))
- NGINX listen http2 deprecation in documentation template for reverse proxy. ([\#16831](https://github.com/element-hq/synapse/issues/16831))
### Internal Changes
- Faster partial join to room with complex auth graph. ([\#7](https://github.com/element-hq/synapse/issues/7))
- Improve DB performance of calculating badge counts for push. ([\#16756](https://github.com/element-hq/synapse/issues/16756))
- Split up deleting devices into batches. ([\#16766](https://github.com/element-hq/synapse/issues/16766))
- Remove CI check for sign-off as we require a CLA signature instead. ([\#16776](https://github.com/element-hq/synapse/issues/16776))
- Ensure CI fails when linting fails to make sure auto-merge does the correct thing. ([\#16781](https://github.com/element-hq/synapse/issues/16781))
- Faster load recents for sync by reducing amount of state pulled out. ([\#16783](https://github.com/element-hq/synapse/issues/16783))
- Reduce amount of state pulled out when querying federation hierachy. ([\#16785](https://github.com/element-hq/synapse/issues/16785))
- Pull less state out of the DB when we retry fetching old events during backfill. ([\#16788](https://github.com/element-hq/synapse/issues/16788))
- Optimize query for fetching to-device messages in `/sync`. ([\#16805](https://github.com/element-hq/synapse/issues/16805))
- Reject OIDC config when `client_secret` isn't specified, but the auth method requires one. ([\#16806](https://github.com/element-hq/synapse/issues/16806))
- Allow room creation but not publishing to continue if room publication rules are violated when creating
a new room. ([\#16811](https://github.com/element-hq/synapse/issues/16811))
- Fixup copyright lines in file headers after the licensing change. ([\#16820](https://github.com/element-hq/synapse/issues/16820))
- Add a `--generate-only` option to the internal configuration/launch script for Complement. ([\#16828](https://github.com/element-hq/synapse/issues/16828))
- Preparatory work for tweaking performance of auth chain lookups. ([\#16833](https://github.com/element-hq/synapse/issues/16833))
- Speed up e2e device keys queries for bot accounts. ([\#16841](https://github.com/element-hq/synapse/issues/16841))
### Updates to locked dependencies
* Bump actions/cache from 3 to 4. ([\#16832](https://github.com/element-hq/synapse/issues/16832))
* Bump actions/download-artifact from 3 to 4. ([\#16795](https://github.com/element-hq/synapse/issues/16795))
* Bump actions/upload-artifact from 3 to 4. ([\#16796](https://github.com/element-hq/synapse/issues/16796))
* Bump anyhow from 1.0.75 to 1.0.79. ([\#16789](https://github.com/element-hq/synapse/issues/16789))
* Bump authlib from 1.2.1 to 1.3.0. ([\#16801](https://github.com/element-hq/synapse/issues/16801))
* Bump dawidd6/action-download-artifact from 2.28.0 to 3.0.0. ([\#16794](https://github.com/element-hq/synapse/issues/16794))
* Bump immutabledict from 4.0.0 to 4.1.0. ([\#16812](https://github.com/element-hq/synapse/issues/16812))
* Bump isort from 5.13.1 to 5.13.2. ([\#16835](https://github.com/element-hq/synapse/issues/16835))
* Bump lxml from 4.9.3 to 5.1.0. ([\#16813](https://github.com/element-hq/synapse/issues/16813))
* Bump pillow from 10.1.0 to 10.2.0. ([\#16802](https://github.com/element-hq/synapse/issues/16802))
* Bump pydantic from 2.5.2 to 2.5.3. ([\#16836](https://github.com/element-hq/synapse/issues/16836))
* Bump pyo3 from 0.20.0 to 0.20.2. ([\#16791](https://github.com/element-hq/synapse/issues/16791))
* Bump regex from 1.9.6 to 1.10.3. ([\#16837](https://github.com/element-hq/synapse/issues/16837))
* Bump ruff from 0.1.13 to 0.1.14. ([\#16838](https://github.com/element-hq/synapse/issues/16838))
* Bump ruff from 0.1.7 to 0.1.13. ([\#16814](https://github.com/element-hq/synapse/issues/16814))
* Bump sentry-sdk from 1.35.0 to 1.39.1. ([\#16799](https://github.com/element-hq/synapse/issues/16799))
* Bump serde_json from 1.0.108 to 1.0.111. ([\#16792](https://github.com/element-hq/synapse/issues/16792))
* Bump service-identity from 23.1.0 to 24.1.0. ([\#16816](https://github.com/element-hq/synapse/issues/16816))
* Bump types-commonmark from 0.9.2.4 to 0.9.2.20240106. ([\#16797](https://github.com/element-hq/synapse/issues/16797))
* Bump types-jsonschema from 4.20.0.0 to 4.20.0.20240105. ([\#16800](https://github.com/element-hq/synapse/issues/16800))
* Bump types-jsonschema from 4.20.0.20240105 to 4.21.0.20240118. ([\#16834](https://github.com/element-hq/synapse/issues/16834))
* Bump types-netaddr from 0.9.0.1 to 0.10.0.20240106. ([\#16839](https://github.com/element-hq/synapse/issues/16839))
* Bump typing-extensions from 4.8.0 to 4.9.0. ([\#16815](https://github.com/element-hq/synapse/issues/16815))
- Add [config options](https://element-hq.github.io/synapse/v1.99/usage/configuration/config_documentation.html#server_notices) to set the avatar and the topic of the server notices room, as well as the avatar of the server notices user. ([\#16679](https://github.com/matrix-org/synapse/issues/16679))
- Add config option [`email.notif_delay_before_mail`](https://element-hq.github.io/synapse/v1.99/usage/configuration/config_documentation.html#email) to tweak the delay before an email is sent following a notification. ([\#16696](https://github.com/matrix-org/synapse/issues/16696))
- Add new configuration option [`sentry.environment`](https://element-hq.github.io/synapse/v1.99/usage/configuration/config_documentation.html#sentry) for improved system monitoring. Contributed by @zeeshanrafiqrana. ([\#16738](https://github.com/matrix-org/synapse/issues/16738))
- Filter out rooms from the room directory being served to other homeservers when those rooms block that homeserver by their Access Control Lists. ([\#16759](https://github.com/element-hq/synapse/issues/16759))
- Fix a long-standing bug where the signing keys generated by Synapse were world-readable. Contributed by Fabian Klemp. ([\#16740](https://github.com/matrix-org/synapse/issues/16740))
- Fix email verification redirection. Contributed by Fadhlan Ridhwanallah. ([\#16761](https://github.com/element-hq/synapse/issues/16761))
- Fixed a bug that prevented users from being queried by display name if it contains non-ASCII characters. ([\#16767](https://github.com/element-hq/synapse/issues/16767))
- Allow reactivate user without password with Admin API in some edge cases. ([\#16770](https://github.com/element-hq/synapse/issues/16770))
- Adds the `recursion_depth` parameter to the response of the /relations endpoint if MSC3981 recursion is being performed. ([\#16775](https://github.com/element-hq/synapse/issues/16775))
- Added version picker for Synapse documentation. Contributed by @Dmytro27Ind. ([\#16533](https://github.com/matrix-org/synapse/issues/16533))
- Clarify that `password_config.enabled: "only_for_reauth"` does not allow new logins to be created using password auth. ([\#16737](https://github.com/matrix-org/synapse/issues/16737))
- Remove value from header in configuration documentation for `refresh_token_lifetime`. ([\#16763](https://github.com/element-hq/synapse/issues/16763))
- Add another custom statistics collection server to the documentation. Contributed by @loelkes. ([\#16769](https://github.com/element-hq/synapse/issues/16769))
### Internal Changes
- Remove run-once workflow after adding the version picker to the documentation. ([\#9453](https://github.com/element-hq/synapse/issues/9453))
- Update the implementation of [MSC2965](https://github.com/matrix-org/matrix-spec-proposals/pull/2965) (OIDC Provider discovery). ([\#16726](https://github.com/matrix-org/synapse/issues/16726))
- Add `on_user_login` [module API](https://matrix-org.github.io/synapse/latest/modules/writing_a_module.html) callback for when a user logs in. ([\#15207](https://github.com/matrix-org/synapse/issues/15207))
- Support [MSC4069: Inhibit profile propagation](https://github.com/matrix-org/matrix-spec-proposals/pull/4069). ([\#16636](https://github.com/matrix-org/synapse/issues/16636))
- Restore tracking of requests and monthly active users when delegating authentication via [MSC3861](https://github.com/matrix-org/synapse/pull/16672) to an OIDC provider. ([\#16672](https://github.com/matrix-org/synapse/issues/16672))
- Add an autojoin setting for server notices rooms, so users may be joined directly instead of receiving an invite. ([\#16699](https://github.com/matrix-org/synapse/issues/16699))
- Follow redirects when downloading media over federation (per [MSC3860](https://github.com/matrix-org/matrix-spec-proposals/pull/3860)). ([\#16701](https://github.com/matrix-org/synapse/issues/16701))
### Bugfixes
- Enable refreshable tokens on the admin registration endpoint. ([\#16642](https://github.com/matrix-org/synapse/issues/16642))
- Consistently bypass rate limits when using the server notice admin API. ([\#16670](https://github.com/matrix-org/synapse/issues/16670))
- Fix a bug introduced in Synapse 1.7.2 where rooms whose power levels lacked an `events` field could not be upgraded. ([\#16725](https://github.com/matrix-org/synapse/issues/16725))
- Fix `GET /_synapse/admin/v1/federation/destinations` [admin API](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html) returning null (instead of 0) for `retry_last_ts` and `retry_interval`. ([\#16729](https://github.com/matrix-org/synapse/issues/16729))
### Improved Documentation
- Add schema rollback information to documentation. ([\#16661](https://github.com/matrix-org/synapse/issues/16661))
- Fix poetry version typo in the [contributors' guide](https://matrix-org.github.io/synapse/latest/development/contributing_guide.html). ([\#16695](https://github.com/matrix-org/synapse/issues/16695))
- Switch the example UNIX socket paths to `/run`. Add HAProxy example configuration for UNIX sockets. ([\#16700](https://github.com/matrix-org/synapse/issues/16700))
- Add documentation for how to validate the configuration file with `synapse.config` script. ([\#16714](https://github.com/matrix-org/synapse/issues/16714))
- Reduce a little database load while processing state auth chains. ([\#16552](https://github.com/matrix-org/synapse/issues/16552))
- Reduce database load of pruning old `user_ips`. ([\#16667](https://github.com/matrix-org/synapse/issues/16667))
- Reduce DB load when forget on leave setting is disabled. ([\#16668](https://github.com/matrix-org/synapse/issues/16668))
- Ignore `encryption_enabled_by_default_for_room_type` setting when creating server notices room, since the notices will be send unencrypted anyway. ([\#16677](https://github.com/matrix-org/synapse/issues/16677))
- Correctly read the to-device stream ID on startup using SQLite. ([\#16682](https://github.com/matrix-org/synapse/issues/16682))
- Reoranganise test files. ([\#16684](https://github.com/matrix-org/synapse/issues/16684))
- Remove old full schema dumps which are no longer used. ([\#16697](https://github.com/matrix-org/synapse/issues/16697))
- Raise poetry-core upper bound to <=1.8.1. This allows contributors to import Synapse after `poetry install`ing with Poetry 1.6 and above. Contributed by Mo Balaa. ([\#16702](https://github.com/matrix-org/synapse/issues/16702))
- Add a workflow to try and automatically fixup linting in a PR. ([\#16704](https://github.com/matrix-org/synapse/issues/16704))
### Updates to locked dependencies
* Bump cryptography from 41.0.5 to 41.0.6. ([\#16703](https://github.com/matrix-org/synapse/issues/16703))
* Bump cryptography from 41.0.6 to 41.0.7. ([\#16721](https://github.com/matrix-org/synapse/issues/16721))
* Bump idna from 3.4 to 3.6. ([\#16720](https://github.com/matrix-org/synapse/issues/16720))
* Bump jsonschema from 4.19.1 to 4.20.0. ([\#16692](https://github.com/matrix-org/synapse/issues/16692))
* Bump matrix-org/netlify-pr-preview from 2 to 3. ([\#16719](https://github.com/matrix-org/synapse/issues/16719))
* Bump phonenumbers from 8.13.23 to 8.13.26. ([\#16722](https://github.com/matrix-org/synapse/issues/16722))
* Bump prometheus-client from 0.18.0 to 0.19.0. ([\#16691](https://github.com/matrix-org/synapse/issues/16691))
* Bump pyasn1 from 0.5.0 to 0.5.1. ([\#16689](https://github.com/matrix-org/synapse/issues/16689))
* Bump pydantic from 2.4.2 to 2.5.1. ([\#16663](https://github.com/matrix-org/synapse/issues/16663))
- Add support for asynchronous uploads as defined by [MSC2246](https://github.com/matrix-org/matrix-spec-proposals/pull/2246). Contributed by @sumnerevans at @beeper. ([\#15503](https://github.com/matrix-org/synapse/issues/15503))
- Improve the performance of some operations in multi-worker deployments. ([\#16613](https://github.com/matrix-org/synapse/issues/16613), [\#16616](https://github.com/matrix-org/synapse/issues/16616))
### Bugfixes
- Fix a long-standing bug where some queries updated the same row twice. Introduced in Synapse 1.57.0. ([\#16609](https://github.com/matrix-org/synapse/issues/16609))
- Fix a long-standing bug where Synapse would not unbind third-party identifiers for Application Service users when deactivated and would not emit a compliant response. ([\#16617](https://github.com/matrix-org/synapse/issues/16617))
- Fix sending out of order `POSITION` over replication, causing additional database load. ([\#16639](https://github.com/matrix-org/synapse/issues/16639))
### Improved Documentation
- Note that the option [`outbound_federation_restricted_to`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#outbound_federation_restricted_to) was added in Synapse 1.89.0, and fix a nearby formatting error. ([\#16628](https://github.com/matrix-org/synapse/issues/16628))
- Update parameter information for the `/timestamp_to_event` admin API. ([\#16631](https://github.com/matrix-org/synapse/issues/16631))
- Provide an example for a common encrypted media response from the admin user media API and mention possible null values. ([\#16654](https://github.com/matrix-org/synapse/issues/16654))
### Internal Changes
- Remove whole table locks on push rule modifications. Contributed by Nick @ Beeper (@fizzadar). ([\#16051](https://github.com/matrix-org/synapse/issues/16051))
- Support reactor tick timings on more types of event loops. ([\#16532](https://github.com/matrix-org/synapse/issues/16532))
- Improve type hints. ([\#16564](https://github.com/matrix-org/synapse/issues/16564), [\#16611](https://github.com/matrix-org/synapse/issues/16611), [\#16612](https://github.com/matrix-org/synapse/issues/16612))
- Use standard SQL helpers in persistence code. ([\#16585](https://github.com/matrix-org/synapse/issues/16585))
- Avoid updating the stream cache unnecessarily. ([\#16586](https://github.com/matrix-org/synapse/issues/16586))
- Improve performance when using opentracing. ([\#16589](https://github.com/matrix-org/synapse/issues/16589))
- Run push rule evaluator setup in parallel. ([\#16590](https://github.com/matrix-org/synapse/issues/16590))
- Improve tests of the SQL generator. ([\#16596](https://github.com/matrix-org/synapse/issues/16596))
- Use more generic database methods. ([\#16615](https://github.com/matrix-org/synapse/issues/16615))
- Use `dbname` instead of the deprecated `database` connection parameter for psycopg2. ([\#16618](https://github.com/matrix-org/synapse/issues/16618))
- Add an internal [Admin API endpoint](https://matrix-org.github.io/synapse/v1.97/usage/configuration/config_documentation.html#allow-replacing-master-cross-signing-key-without-user-interactive-auth) to temporarily grant the ability to update an existing cross-signing key without UIA. ([\#16634](https://github.com/matrix-org/synapse/issues/16634))
- Improve references to GitHub issues. ([\#16637](https://github.com/matrix-org/synapse/issues/16637), [\#16638](https://github.com/matrix-org/synapse/issues/16638))
- More efficiently handle no-op `POSITION` over replication. ([\#16640](https://github.com/matrix-org/synapse/issues/16640), [\#16655](https://github.com/matrix-org/synapse/issues/16655))
- Speed up deleting of device messages when deleting a device. ([\#16643](https://github.com/matrix-org/synapse/issues/16643))
- Speed up persisting large number of outliers. ([\#16649](https://github.com/matrix-org/synapse/issues/16649))
- Reduce max concurrency of background tasks, reducing potential max DB load. ([\#16656](https://github.com/matrix-org/synapse/issues/16656), [\#16660](https://github.com/matrix-org/synapse/issues/16660))
- Speed up purge room by adding an index to `event_push_summary`. ([\#16657](https://github.com/matrix-org/synapse/issues/16657))
### Updates to locked dependencies
* Bump prometheus-client from 0.17.1 to 0.18.0. ([\#16626](https://github.com/matrix-org/synapse/issues/16626))
* Bump pyicu from 2.11 to 2.12. ([\#16603](https://github.com/matrix-org/synapse/issues/16603))
* Bump requests-toolbelt from 0.10.1 to 1.0.0. ([\#16659](https://github.com/matrix-org/synapse/issues/16659))
* Bump ruff from 0.0.292 to 0.1.4. ([\#16600](https://github.com/matrix-org/synapse/issues/16600))
* Bump serde from 1.0.190 to 1.0.192. ([\#16627](https://github.com/matrix-org/synapse/issues/16627))
* Bump serde_json from 1.0.107 to 1.0.108. ([\#16604](https://github.com/matrix-org/synapse/issues/16604))
* Bump setuptools-rust from 1.8.0 to 1.8.1. ([\#16601](https://github.com/matrix-org/synapse/issues/16601))
* Bump towncrier from 23.6.0 to 23.11.0. ([\#16622](https://github.com/matrix-org/synapse/issues/16622))
* Bump treq from 22.2.0 to 23.11.0. ([\#16623](https://github.com/matrix-org/synapse/issues/16623))
* Bump twisted from 23.8.0 to 23.10.0. ([\#16588](https://github.com/matrix-org/synapse/issues/16588))
* Bump types-bleach from 6.1.0.0 to 6.1.0.1. ([\#16624](https://github.com/matrix-org/synapse/issues/16624))
* Bump types-jsonschema from 4.19.0.3 to 4.19.0.4. ([\#16599](https://github.com/matrix-org/synapse/issues/16599))
* Bump types-pyopenssl from 23.2.0.2 to 23.3.0.0. ([\#16625](https://github.com/matrix-org/synapse/issues/16625))
* Bump types-pyyaml from 6.0.12.11 to 6.0.12.12. ([\#16602](https://github.com/matrix-org/synapse/issues/16602))
This minor release was needed only because of CI-related trouble on [v1.96.0](https://github.com/matrix-org/synapse/releases/tag/v1.96.0), which was never released.
### Internal Changes
- Fix building of wheels in CI. ([\#16653](https://github.com/matrix-org/synapse/issues/16653))
- Fix "'int' object is not iterable" error in `set_device_id_for_pushers` background update introduced in Synapse 1.95.0. ([\#16594](https://github.com/matrix-org/synapse/issues/16594))
- Add a new module API for controller presence. ([\#16544](https://github.com/matrix-org/synapse/issues/16544))
- Add a new module API callback that allows adding extra fields to events' unsigned section when sent down to clients. ([\#16549](https://github.com/matrix-org/synapse/issues/16549))
- Improve the performance of claiming encryption keys. ([\#16565](https://github.com/matrix-org/synapse/issues/16565), [\#16570](https://github.com/matrix-org/synapse/issues/16570))
- Fixed a bug in the example Grafana dashboard that prevents it from finding the correct datasource. Contributed by @MichaelSasser. ([\#16471](https://github.com/matrix-org/synapse/issues/16471))
- Fix a long-standing, exceedingly rare edge case where the first event persisted by a new event persister worker might not be sent down `/sync`. ([\#16473](https://github.com/matrix-org/synapse/issues/16473), [\#16557](https://github.com/matrix-org/synapse/issues/16557), [\#16561](https://github.com/matrix-org/synapse/issues/16561), [\#16578](https://github.com/matrix-org/synapse/issues/16578), [\#16580](https://github.com/matrix-org/synapse/issues/16580))
- Fix long-standing bug where `/sync` incorrectly did not mark a room as `limited` in a sync requests when there were missing remote events. ([\#16485](https://github.com/matrix-org/synapse/issues/16485))
- Fix a bug introduced in Synapse 1.41 where HTTP(S) forward proxy authorization would fail when using basic HTTP authentication with a long `username:password` string. ([\#16504](https://github.com/matrix-org/synapse/issues/16504))
- Force TLS certificate verification in user registration script. ([\#16530](https://github.com/matrix-org/synapse/issues/16530))
- Fix long-standing bug where `/sync` could tightloop after restart when using SQLite. ([\#16540](https://github.com/matrix-org/synapse/issues/16540))
- Fix ratelimiting of message sending when using workers, where the ratelimit would only be applied after most of the work has been done. ([\#16558](https://github.com/matrix-org/synapse/issues/16558))
- Fix a long-standing bug where invited/knocking users would not leave during a room purge. ([\#16559](https://github.com/matrix-org/synapse/issues/16559))
### Improved Documentation
- Improve documentation of presence router. ([\#16529](https://github.com/matrix-org/synapse/issues/16529))
- Add a sentence to the [opentracing docs](https://matrix-org.github.io/synapse/latest/opentracing.html) on how you can have jaeger in a different place than synapse. ([\#16531](https://github.com/matrix-org/synapse/issues/16531))
- Correctly describe the meaning of unspecified rule lists in the [`alias_creation_rules`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#alias_creation_rules) and [`room_list_publication_rules`](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#room_list_publication_rules) config options and improve their descriptions more generally. ([\#16541](https://github.com/matrix-org/synapse/issues/16541))
- Pin the recommended poetry version in [contributors' guide](https://matrix-org.github.io/synapse/latest/development/contributing_guide.html). ([\#16550](https://github.com/matrix-org/synapse/issues/16550))
- Fix a broken link to the [client breakdown](https://matrix.org/ecosystem/clients/) in the README. ([\#16569](https://github.com/matrix-org/synapse/issues/16569))
- Improve replication performance when purging rooms. ([\#16510](https://github.com/matrix-org/synapse/issues/16510))
- Run tests against Python 3.12. ([\#16511](https://github.com/matrix-org/synapse/issues/16511))
- Run trial & integration tests in continuous integration when `.ci` directory is modified. ([\#16512](https://github.com/matrix-org/synapse/issues/16512))
- Remove duplicate call to mark remote server 'awake' when using a federation sending worker. ([\#16515](https://github.com/matrix-org/synapse/issues/16515))
- Enable dirty runs on Complement CI, which is significantly faster. ([\#16520](https://github.com/matrix-org/synapse/issues/16520))
- Stop deleting from an unused table. ([\#16521](https://github.com/matrix-org/synapse/issues/16521))
- Improve type hints. ([\#16526](https://github.com/matrix-org/synapse/issues/16526), [\#16551](https://github.com/matrix-org/synapse/issues/16551))
- Fix running unit tests on Twisted trunk. ([\#16528](https://github.com/matrix-org/synapse/issues/16528))
- Reduce some spurious logging in worker mode. ([\#16555](https://github.com/matrix-org/synapse/issues/16555))
- Stop porting a table in port db that we're going to nuke and rebuild anyway. ([\#16563](https://github.com/matrix-org/synapse/issues/16563))
- Deal with warnings from running complement in CI. ([\#16567](https://github.com/matrix-org/synapse/issues/16567))
- Allow building with `setuptools_rust` 1.8.0. ([\#16574](https://github.com/matrix-org/synapse/issues/16574))
### Updates to locked dependencies
* Bump black from 23.10.0 to 23.10.1. ([\#16575](https://github.com/matrix-org/synapse/issues/16575))
* Bump black from 23.9.1 to 23.10.0. ([\#16538](https://github.com/matrix-org/synapse/issues/16538))
* Bump cryptography from 41.0.4 to 41.0.5. ([\#16572](https://github.com/matrix-org/synapse/issues/16572))
* Bump gitpython from 3.1.37 to 3.1.40. ([\#16534](https://github.com/matrix-org/synapse/issues/16534))
* Bump phonenumbers from 8.13.22 to 8.13.23. ([\#16576](https://github.com/matrix-org/synapse/issues/16576))
* Bump pygithub from 1.59.1 to 2.1.1. ([\#16535](https://github.com/matrix-org/synapse/issues/16535))
- Fix a bug introduced in Synapse 1.81.0 where an `AttributeError` would be raised when `_matrix/client/v3/account/whoami` is called over a unix socket. Contributed by @Sir-Photch. ([\#16404](https://github.com/matrix-org/synapse/issues/16404))
- Properly return inline media when content types have parameters. ([\#16440](https://github.com/matrix-org/synapse/issues/16440))
- Prevent the purging of large rooms from timing out when Postgres is in use. The timeout which causes this issue was introduced in Synapse 1.88.0. ([\#16455](https://github.com/matrix-org/synapse/issues/16455))
- Improve the performance of purging rooms, particularly encrypted rooms. ([\#16457](https://github.com/matrix-org/synapse/issues/16457))
- Fix a bug introduced in Synapse 1.59.0 where servers could be incorrectly marked as available after an error response was received. ([\#16506](https://github.com/matrix-org/synapse/issues/16506))
- Fix a typo in the sql for [useful SQL for admins document](https://matrix-org.github.io/synapse/latest/usage/administration/useful_sql_for_admins.html). ([\#16477](https://github.com/matrix-org/synapse/issues/16477))
### Internal Changes
- Bump pyo3 from 0.17.1 to 0.19.2. ([\#16162](https://github.com/matrix-org/synapse/issues/16162))
- Update registration of media repository URLs. ([\#16419](https://github.com/matrix-org/synapse/issues/16419))
- Improve type hints. ([\#16421](https://github.com/matrix-org/synapse/issues/16421), [\#16468](https://github.com/matrix-org/synapse/issues/16468), [\#16469](https://github.com/matrix-org/synapse/issues/16469), [\#16507](https://github.com/matrix-org/synapse/issues/16507))
- Refactor some code to simplify and better type receipts stream adjacent code. ([\#16426](https://github.com/matrix-org/synapse/issues/16426))
- Factor out `MultiWriter` token from `RoomStreamToken`. ([\#16427](https://github.com/matrix-org/synapse/issues/16427))
- Do not block running of CI behind the check for sign-off on PRs. ([\#16454](https://github.com/matrix-org/synapse/issues/16454))
- Update the release script to remind releaser to check for special release notes. ([\#16461](https://github.com/matrix-org/synapse/issues/16461))
- Update complement.sh to match new public API shape. ([\#16466](https://github.com/matrix-org/synapse/issues/16466))
- Clean up logging on event persister endpoints. ([\#16488](https://github.com/matrix-org/synapse/issues/16488))
- Remove useless async job to delete device messages on sync, since we only deliver (and hence delete) up to 100 device messages at a time. ([\#16491](https://github.com/matrix-org/synapse/issues/16491))
### Updates to locked dependencies
* Bump bleach from 6.0.0 to 6.1.0. ([\#16451](https://github.com/matrix-org/synapse/issues/16451))
* Bump jsonschema from 4.19.0 to 4.19.1. ([\#16500](https://github.com/matrix-org/synapse/issues/16500))
* Bump netaddr from 0.8.0 to 0.9.0. ([\#16453](https://github.com/matrix-org/synapse/issues/16453))
* Bump packaging from 23.1 to 23.2. ([\#16497](https://github.com/matrix-org/synapse/issues/16497))
* Bump pillow from 10.0.1 to 10.1.0. ([\#16498](https://github.com/matrix-org/synapse/issues/16498))
* Bump psycopg2 from 2.9.8 to 2.9.9. ([\#16452](https://github.com/matrix-org/synapse/issues/16452))
* Bump pyo3-log from 0.8.3 to 0.8.4. ([\#16495](https://github.com/matrix-org/synapse/issues/16495))
* Bump ruff from 0.0.290 to 0.0.292. ([\#16449](https://github.com/matrix-org/synapse/issues/16449))
* Bump sentry-sdk from 1.31.0 to 1.32.0. ([\#16496](https://github.com/matrix-org/synapse/issues/16496))
* Bump serde from 1.0.188 to 1.0.189. ([\#16494](https://github.com/matrix-org/synapse/issues/16494))
* Bump types-bleach from 6.0.0.4 to 6.1.0.0. ([\#16450](https://github.com/matrix-org/synapse/issues/16450))
* Bump types-jsonschema from 4.17.0.10 to 4.19.0.3. ([\#16499](https://github.com/matrix-org/synapse/issues/16499))
- Render plain, CSS, CSV, JSON and common image formats in the browser (inline) when requested through the /download endpoint. ([\#15988](https://github.com/matrix-org/synapse/issues/15988))
- Add experimental support for [MSC4028](https://github.com/matrix-org/matrix-spec-proposals/pull/4028) to push all encrypted events to clients. ([\#16361](https://github.com/matrix-org/synapse/issues/16361))
- Improve documentation of the user directory search algorithm. ([\#16320](https://github.com/matrix-org/synapse/issues/16320))
- Fix rendering of user admin API documentation around deactivation. This was broken in Synapse 1.91.0. ([\#16355](https://github.com/matrix-org/synapse/issues/16355))
- Update documentation around message retention policies. ([\#16382](https://github.com/matrix-org/synapse/issues/16382))
- Add note to `federation_domain_whitelist` config option to clarify its usage. ([\#16416](https://github.com/matrix-org/synapse/issues/16416))
- Remove Python version from `/_synapse/admin/v1/server_version`. ([\#16380](https://github.com/matrix-org/synapse/issues/16380))
### Internal Changes
- Avoid running CI steps when the files they check have not been changed. ([\#14745](https://github.com/matrix-org/synapse/issues/14745), [\#16387](https://github.com/matrix-org/synapse/issues/16387))
- Improve type hints. ([\#14911](https://github.com/matrix-org/synapse/issues/14911), [\#16350](https://github.com/matrix-org/synapse/issues/16350), [\#16356](https://github.com/matrix-org/synapse/issues/16356), [\#16395](https://github.com/matrix-org/synapse/issues/16395))
- Added support for pydantic v2 in addition to pydantic v1. Contributed by Maxwell G (@gotmax23). ([\#16332](https://github.com/matrix-org/synapse/issues/16332))
- Get CI to check PRs have been signed-off. ([\#16348](https://github.com/matrix-org/synapse/issues/16348))
- Support resolving homeservers using `matrix-fed` DNS SRV records from [MSC4040](https://github.com/matrix-org/matrix-spec-proposals/pull/4040). ([\#16137](https://github.com/matrix-org/synapse/issues/16137))
- Add the ability to use `G` (GiB) and `T` (TiB) suffixes in configuration options that refer to numbers of bytes. ([\#16219](https://github.com/matrix-org/synapse/issues/16219))
- Add span information to requests sent to appservices. Contributed by MTRNord. ([\#16227](https://github.com/matrix-org/synapse/issues/16227))
- Add the ability to enable/disable registrations when using CAS. Contributed by Aurélien Grimpard. ([\#16262](https://github.com/matrix-org/synapse/issues/16262))
- Enable users to easily unsubscribe to notifications emails via the `List-Unsubscribe` header. ([\#16274](https://github.com/matrix-org/synapse/issues/16274))
- Report whether a user is `locked` in the [List Accounts admin API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html#list-accounts), and exclude locked users by default. ([\#16328](https://github.com/matrix-org/synapse/issues/16328))
### Bugfixes
- Fix a long-standing bug where multi-device accounts could cause high load due to presence. ([\#16066](https://github.com/matrix-org/synapse/issues/16066), [\#16170](https://github.com/matrix-org/synapse/issues/16170), [\#16171](https://github.com/matrix-org/synapse/issues/16171), [\#16172](https://github.com/matrix-org/synapse/issues/16172), [\#16174](https://github.com/matrix-org/synapse/issues/16174))
- Fix a long-standing bug where appservices using [MSC2409](https://github.com/matrix-org/matrix-spec-proposals/pull/2409) to receive `to_device` messages would only get messages for one user. ([\#16251](https://github.com/matrix-org/synapse/issues/16251))
- Fix bug when using workers where Synapse could end up re-requesting the same remote device repeatedly. ([\#16252](https://github.com/matrix-org/synapse/issues/16252))
- Fix long-standing bug where we kept re-requesting a remote server's key repeatedly, potentially causing delays in receiving events over federation. ([\#16257](https://github.com/matrix-org/synapse/issues/16257))
- Avoid temporary storage of sensitive information. ([\#16272](https://github.com/matrix-org/synapse/issues/16272))
- Fix bug introduced in Synapse 1.49.0 when using dehydrated devices ([MSC2697](https://github.com/matrix-org/matrix-spec-proposals/pull/2697)) and refresh tokens. Contributed by Hanadi. ([\#16288](https://github.com/matrix-org/synapse/issues/16288))
- Fix a long-standing bug where invalid receipts would be accepted. ([\#16327](https://github.com/matrix-org/synapse/issues/16327))
- Use standard name for UTF-8 charset in emails. ([\#16329](https://github.com/matrix-org/synapse/issues/16329))
- Don't try refetching device lists for users on remote hosts that are marked as "down". ([\#16298](https://github.com/matrix-org/synapse/issues/16298))
- Use string for `federation_client_minimum_tls_version` documentation examples. Contributed by @jcgruenhage. ([\#16353](https://github.com/matrix-org/synapse/issues/16353))
- Allow modules to delete rooms. ([\#15997](https://github.com/matrix-org/synapse/issues/15997))
- Add GCC and GNU Make to the Nix flake development environment so that `ruff` can be compiled. ([\#16090](https://github.com/matrix-org/synapse/issues/16090), [\#16263](https://github.com/matrix-org/synapse/issues/16263))
- Fix type checking when using the new version of Twisted. ([\#16235](https://github.com/matrix-org/synapse/issues/16235))
- Delete device messages asynchronously and in staged batches using the task scheduler. ([\#16240](https://github.com/matrix-org/synapse/issues/16240), [\#16311](https://github.com/matrix-org/synapse/issues/16311), [\#16312](https://github.com/matrix-org/synapse/issues/16312), [\#16313](https://github.com/matrix-org/synapse/issues/16313))
- Bump minimum supported Rust version to 1.61.0. ([\#16248](https://github.com/matrix-org/synapse/issues/16248))
- Update rust to version 1.71.1 in the nix development environment. ([\#16260](https://github.com/matrix-org/synapse/issues/16260))
- Simplify server key storage. ([\#16261](https://github.com/matrix-org/synapse/issues/16261))
- Reduce CPU overhead of change password endpoint. ([\#16264](https://github.com/matrix-org/synapse/issues/16264))
- Stop purging from tables slated for removal. ([\#16273](https://github.com/matrix-org/synapse/issues/16273))
- Improve type hints. ([\#16276](https://github.com/matrix-org/synapse/issues/16276), [\#16301](https://github.com/matrix-org/synapse/issues/16301), [\#16325](https://github.com/matrix-org/synapse/issues/16325), [\#16326](https://github.com/matrix-org/synapse/issues/16326))
* Bump gitpython from 3.1.32 to 3.1.35. ([\#16267](https://github.com/matrix-org/synapse/issues/16267), [\#16279](https://github.com/matrix-org/synapse/issues/16279))
* Bump serde_json from 1.0.105 to 1.0.107. ([\#16296](https://github.com/matrix-org/synapse/issues/16296), [\#16345](https://github.com/matrix-org/synapse/issues/16345))
- Pillow 10.0.1 is now mandatory because of libwebp CVE-2023-4863, since Pillow provides libwebp in the wheels. ([\#16347](https://github.com/matrix-org/synapse/issues/16347))
### Updates to locked dependencies
* Bump pillow from 10.0.0 to 10.0.1. ([\#16344](https://github.com/matrix-org/synapse/issues/16344))
This is a Docker-only update to mitigate [CVE-2023-4863](https://cve.org/CVERecord?id=CVE-2023-4863), a critical vulnerability in `libwebp`. Server admins not using Docker should ensure that their `libwebp` is up to date (if installed). We encourage admins to upgrade as soon as possible.
This minor release was needed only because of CI-related trouble on [v1.92.0](https://github.com/matrix-org/synapse/releases/tag/v1.92.0), which was never released.
### Internal Changes
- Stop building Ubuntu Kinetic since it is EOL and repos seem to be dead.
- Add configuration setting for CAS protocol version. Contributed by Aurélien Grimpard. ([\#15816](https://github.com/matrix-org/synapse/issues/15816))
- Suppress notifications from message edits per [MSC3958](https://github.com/matrix-org/matrix-spec-proposals/pull/3958). ([\#16113](https://github.com/matrix-org/synapse/issues/16113))
- Experimental support for [MSC4041](https://github.com/matrix-org/matrix-spec-proposals/pull/4041): return a `Retry-After` header with `M_LIMIT_EXCEEDED` error responses. ([\#16136](https://github.com/matrix-org/synapse/issues/16136))
- Add `last_seen_ts` to the [admin users API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html). ([\#16218](https://github.com/matrix-org/synapse/issues/16218))
- Improve resource usage when sending data to a large number of remote hosts that are marked as "down". ([\#16223](https://github.com/matrix-org/synapse/issues/16223))
### Bugfixes
- Fix IPv6-related bugs on SMTP settings, adding groundwork to fix similar issues. Contributed by @evilham and @telmich (ungleich.ch). ([\#16155](https://github.com/matrix-org/synapse/issues/16155))
- Fix a spec compliance issue where requests to the `/publicRooms` federation API would specify `include_all_networks` as a string. ([\#16185](https://github.com/matrix-org/synapse/issues/16185))
- Fix inaccurate error message while attempting to ban or unban a user with the same or higher PL by spliting the conditional statements. Contributed by @leviosacz. ([\#16205](https://github.com/matrix-org/synapse/issues/16205))
- Fix a rare bug that broke looping calls, which could lead to e.g. linearly increasing memory usage. Introduced in v1.90.0. ([\#16210](https://github.com/matrix-org/synapse/issues/16210))
- Fix a long-standing bug where uploading images would fail if we could not generate thumbnails for them. ([\#16211](https://github.com/matrix-org/synapse/issues/16211))
- Fix a long-standing bug where we did not correctly back off from servers that had "gone" if they returned 4xx series error codes. ([\#16221](https://github.com/matrix-org/synapse/issues/16221))
- Update links to the [matrix.org blog](https://matrix.org/blog/). ([\#16008](https://github.com/matrix-org/synapse/issues/16008))
- Document which [admin APIs](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html) are disabled when experimental [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861) support is enabled. ([\#16168](https://github.com/matrix-org/synapse/issues/16168))
- Describe which rate limiter was hit in logs. ([\#16135](https://github.com/matrix-org/synapse/issues/16135))
- Simplify presence code when using workers. ([\#16170](https://github.com/matrix-org/synapse/issues/16170))
- Track per-device information in the presence code. ([\#16171](https://github.com/matrix-org/synapse/issues/16171), [\#16172](https://github.com/matrix-org/synapse/issues/16172))
- Stop using the `event_txn_id` table. ([\#16175](https://github.com/matrix-org/synapse/issues/16175))
- Use `AsyncMock` instead of custom code. ([\#16179](https://github.com/matrix-org/synapse/issues/16179), [\#16180](https://github.com/matrix-org/synapse/issues/16180))
- Improve error reporting of invalid data passed to `/_matrix/key/v2/query`. ([\#16183](https://github.com/matrix-org/synapse/issues/16183))
- Task scheduler: add replication notify for new task to launch ASAP. ([\#16184](https://github.com/matrix-org/synapse/issues/16184))
- Improve type hints. ([\#16186](https://github.com/matrix-org/synapse/issues/16186), [\#16188](https://github.com/matrix-org/synapse/issues/16188), [\#16201](https://github.com/matrix-org/synapse/issues/16201))
- Bump black version to 23.7.0. ([\#16187](https://github.com/matrix-org/synapse/issues/16187))
- Log the details of background update failures. ([\#16212](https://github.com/matrix-org/synapse/issues/16212))
- Cache device resync requests over replication. ([\#16241](https://github.com/matrix-org/synapse/issues/16241))
### Updates to locked dependencies
* Bump anyhow from 1.0.72 to 1.0.75. ([\#16141](https://github.com/matrix-org/synapse/issues/16141))
* Bump furo from 2023.7.26 to 2023.8.19. ([\#16238](https://github.com/matrix-org/synapse/issues/16238))
* Bump phonenumbers from 8.13.18 to 8.13.19. ([\#16237](https://github.com/matrix-org/synapse/issues/16237))
* Bump psycopg2 from 2.9.6 to 2.9.7. ([\#16196](https://github.com/matrix-org/synapse/issues/16196))
* Bump regex from 1.9.3 to 1.9.4. ([\#16195](https://github.com/matrix-org/synapse/issues/16195))
* Bump ruff from 0.0.277 to 0.0.286. ([\#16198](https://github.com/matrix-org/synapse/issues/16198))
* Bump sentry-sdk from 1.29.2 to 1.30.0. ([\#16236](https://github.com/matrix-org/synapse/issues/16236))
* Bump serde from 1.0.184 to 1.0.188. ([\#16194](https://github.com/matrix-org/synapse/issues/16194))
* Bump serde_json from 1.0.104 to 1.0.105. ([\#16140](https://github.com/matrix-org/synapse/issues/16140))
* Bump types-psycopg2 from 2.9.21.10 to 2.9.21.11. ([\#16200](https://github.com/matrix-org/synapse/issues/16200))
* Bump types-pyyaml from 6.0.12.10 to 6.0.12.11. ([\#16199](https://github.com/matrix-org/synapse/issues/16199))
- Fix a performance regression introduced in Synapse 1.91.0 where event persistence would cause an excessive linear growth in CPU usage. ([\#16220](https://github.com/matrix-org/synapse/issues/16220))
- Implements an admin API to lock an user without deactivating them. Based on [MSC3939](https://github.com/matrix-org/matrix-spec-proposals/pull/3939). ([\#15870](https://github.com/matrix-org/synapse/issues/15870))
- Implements a task scheduler for resumable potentially long running tasks. ([\#15891](https://github.com/matrix-org/synapse/issues/15891))
- Allow specifying `client_secret_path` as alternative to `client_secret` for OIDC providers. This avoids leaking the client secret in the homeserver config. Contributed by @Ma27. ([\#16030](https://github.com/matrix-org/synapse/issues/16030))
- Allow customising the IdP display name, icon, and brand for SAML and CAS providers (in addition to OIDC provider). ([\#16094](https://github.com/matrix-org/synapse/issues/16094))
- Add an `admins` query parameter to the [List Accounts](https://matrix-org.github.io/synapse/v1.91/admin_api/user_admin_api.html#list-accounts) [admin API](https://matrix-org.github.io/synapse/v1.91/usage/administration/admin_api/index.html), to include only admins or to exclude admins in user queries. ([\#16114](https://github.com/matrix-org/synapse/issues/16114))
### Bugfixes
- Fix long-standing bug where concurrent requests to change a user's push rules could cause a deadlock. Contributed by Nick @ Beeper (@fizzadar). ([\#16052](https://github.com/matrix-org/synapse/issues/16052))
- Fix a long-standing bu in `/sync` where timeout=0 does not skip caching, resulting in slow calls in cases where there are no new changes. Contributed by @PlasmaIntec. ([\#16080](https://github.com/matrix-org/synapse/issues/16080))
- Fix performance of state resolutions for large, old rooms that did not have the full auth chain persisted. ([\#16116](https://github.com/matrix-org/synapse/issues/16116))
- Filter out user agent references to the sliding sync proxy and rust-sdk from the user_daily_visits table to ensure that Element X can be represented fully. ([\#16124](https://github.com/matrix-org/synapse/issues/16124))
- User constent and 3-PID changes capability cannot be enabled when using experimental [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861) support. ([\#16127](https://github.com/matrix-org/synapse/issues/16127), [\#16134](https://github.com/matrix-org/synapse/issues/16134))
- Fix a rare race that could block new events from being sent for up to two minutes. Introduced in v1.90.0. ([\#16133](https://github.com/matrix-org/synapse/issues/16133), [\#16169](https://github.com/matrix-org/synapse/issues/16169))
- Fix performance degredation when there are a lot of in-flight replication requests. ([\#16148](https://github.com/matrix-org/synapse/issues/16148))
- Fix a bug introduced in 1.87 where synapse would send an excessive amount of federation requests to servers which have been offline for a long time. Contributed by Nico. ([\#16156](https://github.com/matrix-org/synapse/issues/16156), [\#16164](https://github.com/matrix-org/synapse/issues/16164))
### Improved Documentation
- Structured logging docs: add a link to explain the ELK stack ([\#16091](https://github.com/matrix-org/synapse/issues/16091))
- Fix database performance of read/write worker locks. ([\#16061](https://github.com/matrix-org/synapse/issues/16061))
- Fix building the nix development environment on MacOS systems. ([\#16063](https://github.com/matrix-org/synapse/issues/16063))
- Override global statement timeout when creating indexes in Postgres. ([\#16085](https://github.com/matrix-org/synapse/issues/16085))
- Fix the type annotation on `run_db_interaction` in the Module API. ([\#16089](https://github.com/matrix-org/synapse/issues/16089))
- Clean-up the presence code. ([\#16092](https://github.com/matrix-org/synapse/issues/16092))
- Run `pyupgrade` for Python 3.8+. ([\#16110](https://github.com/matrix-org/synapse/issues/16110))
- Rename pagination and purge locks and add comments to explain why they exist and how they work. ([\#16112](https://github.com/matrix-org/synapse/issues/16112))
- Attempt to fix the twisted trunk job. ([\#16115](https://github.com/matrix-org/synapse/issues/16115))
- Cache token introspection response from OIDC provider. ([\#16117](https://github.com/matrix-org/synapse/issues/16117))
- Add cache to `get_server_keys_json_for_remote`. ([\#16123](https://github.com/matrix-org/synapse/issues/16123))
- Add an admin endpoint to allow authorizing server to signal token revocations. ([\#16125](https://github.com/matrix-org/synapse/issues/16125))
- Add response time metrics for introspection requests for delegated auth. ([\#16131](https://github.com/matrix-org/synapse/issues/16131))
- MSC3861: allow impersonation by an admin user using `_oidc_admin_impersonate_user_id` query parameter. ([\#16132](https://github.com/matrix-org/synapse/issues/16132))
- Increase performance of read/write locks. ([\#16149](https://github.com/matrix-org/synapse/issues/16149))
- Raised the poetry-core version cap to 1.7.0. ([\#16152](https://github.com/matrix-org/synapse/issues/16152))
- Fix assertion in user directory unit tests. ([\#16157](https://github.com/matrix-org/synapse/issues/16157))
- Reduce scope of locks when paginating to alleviate DB contention. ([\#16159](https://github.com/matrix-org/synapse/issues/16159))
- Reduce DB contention on worker locks. ([\#16160](https://github.com/matrix-org/synapse/issues/16160))
- Task scheduler: mark task as active if we are scheduling as soon as possible. ([\#16165](https://github.com/matrix-org/synapse/issues/16165))
### Updates to locked dependencies
* Bump click from 8.1.6 to 8.1.7. ([\#16145](https://github.com/matrix-org/synapse/issues/16145))
* Bump gitpython from 3.1.31 to 3.1.32. ([\#16103](https://github.com/matrix-org/synapse/issues/16103))
* Bump ijson from 3.2.1 to 3.2.3. ([\#16143](https://github.com/matrix-org/synapse/issues/16143))
* Bump isort from 5.11.5 to 5.12.0. ([\#16108](https://github.com/matrix-org/synapse/issues/16108))
* Bump log from 0.4.19 to 0.4.20. ([\#16109](https://github.com/matrix-org/synapse/issues/16109))
* Bump pygithub from 1.59.0 to 1.59.1. ([\#16144](https://github.com/matrix-org/synapse/issues/16144))
* Bump sentry-sdk from 1.28.1 to 1.29.2. ([\#16142](https://github.com/matrix-org/synapse/issues/16142))
* Bump serde from 1.0.183 to 1.0.184. ([\#16139](https://github.com/matrix-org/synapse/issues/16139))
* Bump txredisapi from 1.4.9 to 1.4.10. ([\#16107](https://github.com/matrix-org/synapse/issues/16107))
* Bump types-bleach from 6.0.0.3 to 6.0.0.4. ([\#16106](https://github.com/matrix-org/synapse/issues/16106))
* Bump types-pillow from 10.0.0.1 to 10.0.0.2. ([\#16105](https://github.com/matrix-org/synapse/issues/16105))
* Bump types-pyopenssl from 23.2.0.1 to 23.2.0.2. ([\#16146](https://github.com/matrix-org/synapse/issues/16146))
# Synapse 1.91.0rc1 (2023-08-23)
### Features
- Implements an admin API to lock an user without deactivating them. Based on [MSC3939](https://github.com/matrix-org/matrix-spec-proposals/pull/3939). ([\#15870](https://github.com/matrix-org/synapse/issues/15870))
- Allow specifying `client_secret_path` as alternative to `client_secret` for OIDC providers. This avoids leaking the client secret in the homeserver config. Contributed by @Ma27. ([\#16030](https://github.com/matrix-org/synapse/issues/16030))
- Allow customising the IdP display name, icon, and brand for SAML and CAS providers (in addition to OIDC provider). ([\#16094](https://github.com/matrix-org/synapse/issues/16094))
- Add an `admins` query parameter to the [List Accounts](https://matrix-org.github.io/synapse/v1.91/admin_api/user_admin_api.html#list-accounts) [admin API](https://matrix-org.github.io/synapse/v1.91/usage/administration/admin_api/index.html), to include only admins or to exclude admins in user queries. ([\#16114](https://github.com/matrix-org/synapse/issues/16114))
### Bugfixes
- Fix long-standing bug where concurrent requests to change a user's push rules could cause a deadlock. Contributed by Nick @ Beeper (@fizzadar). ([\#16052](https://github.com/matrix-org/synapse/issues/16052))
- Fix a long-standing bug in `/sync` where timeout=0 does not skip caching, resulting in slow calls in cases where there are no new changes. Contributed by @PlasmaIntec. ([\#16080](https://github.com/matrix-org/synapse/issues/16080))
- Fix performance of state resolutions for large, old rooms that did not have the full auth chain persisted. ([\#16116](https://github.com/matrix-org/synapse/issues/16116))
- Filter out user agent references to the sliding sync proxy and rust-sdk from the `user_daily_visits` table to ensure that Element X can be represented fully. ([\#16124](https://github.com/matrix-org/synapse/issues/16124))
- User constent and third-party ID changes capability cannot be enabled when using experimental [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861) support. ([\#16127](https://github.com/matrix-org/synapse/issues/16127), [\#16134](https://github.com/matrix-org/synapse/issues/16134))
- Fix a rare race that could block new events from being sent for up to two minutes. Introduced in v1.90.0. ([\#16133](https://github.com/matrix-org/synapse/issues/16133), [\#16169](https://github.com/matrix-org/synapse/issues/16169))
- Fix performance degredation when there are a lot of in-flight replication requests. ([\#16148](https://github.com/matrix-org/synapse/issues/16148))
- Fix a bug introduced in 1.87 where synapse would send an excessive amount of federation requests to servers which have been offline for a long time. Contributed by Nico. ([\#16156](https://github.com/matrix-org/synapse/issues/16156), [\#16164](https://github.com/matrix-org/synapse/issues/16164))
### Improved Documentation
- Structured logging docs: add a link to explain the ELK stack ([\#16091](https://github.com/matrix-org/synapse/issues/16091))
- Fix database performance of read/write worker locks. ([\#16061](https://github.com/matrix-org/synapse/issues/16061))
- Fix building the nix development environment on MacOS systems. ([\#16063](https://github.com/matrix-org/synapse/issues/16063))
- Override global statement timeout when creating indexes in Postgres. ([\#16085](https://github.com/matrix-org/synapse/issues/16085))
- Fix the type annotation on `run_db_interaction` in the Module API. ([\#16089](https://github.com/matrix-org/synapse/issues/16089))
- Clean-up the presence code. ([\#16092](https://github.com/matrix-org/synapse/issues/16092))
- Run `pyupgrade` for Python 3.8+. ([\#16110](https://github.com/matrix-org/synapse/issues/16110))
- Rename pagination and purge locks and add comments to explain why they exist and how they work. ([\#16112](https://github.com/matrix-org/synapse/issues/16112))
- Attempt to fix the twisted trunk job. ([\#16115](https://github.com/matrix-org/synapse/issues/16115))
- Cache token introspection response from OIDC provider. ([\#16117](https://github.com/matrix-org/synapse/issues/16117))
- Add cache to `get_server_keys_json_for_remote`. ([\#16123](https://github.com/matrix-org/synapse/issues/16123))
- Add an admin endpoint to allow authorizing server to signal token revocations. ([\#16125](https://github.com/matrix-org/synapse/issues/16125))
- Add response time metrics for introspection requests for delegated auth. ([\#16131](https://github.com/matrix-org/synapse/issues/16131))
- [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861): allow impersonation by an admin user using `_oidc_admin_impersonate_user_id` query parameter. ([\#16132](https://github.com/matrix-org/synapse/issues/16132))
- Increase performance of read/write locks. ([\#16149](https://github.com/matrix-org/synapse/issues/16149))
- Scope transaction IDs to devices (implement [MSC3970](https://github.com/matrix-org/matrix-spec-proposals/pull/3970)). ([\#15629](https://github.com/matrix-org/synapse/issues/15629))
- Remove old rows from the `cache_invalidation_stream_by_instance` table automatically (this table is unused in SQLite). ([\#15868](https://github.com/matrix-org/synapse/issues/15868))
- Fix a long-standing bug where purging history and paginating simultaneously could lead to database corruption when using workers. ([\#15791](https://github.com/matrix-org/synapse/issues/15791))
- Fix a long-standing bug where profile endpoint returned a 404 when the user's display name was empty. ([\#16012](https://github.com/matrix-org/synapse/issues/16012))
- Fix a long-standing bug where the `synapse_port_db` failed to configure sequences for application services and partial stated rooms. ([\#16043](https://github.com/matrix-org/synapse/issues/16043))
- Add `org.opencontainers.image.version` labels to Docker containers [published by Matrix.org](https://hub.docker.com/r/matrixdotorg/synapse). Contributed by Mo Balaa. ([\#15972](https://github.com/matrix-org/synapse/issues/15972), [\#16009](https://github.com/matrix-org/synapse/issues/16009))
### Improved Documentation
- Add a internal documentation page describing the ["streams" used within Synapse](https://matrix-org.github.io/synapse/v1.90/development/synapse_architecture/streams.html). ([\#16015](https://github.com/matrix-org/synapse/issues/16015))
- Clarify comment on the keys/upload over replication enpoint. ([\#16016](https://github.com/matrix-org/synapse/issues/16016))
- Do not expose Admin API in caddy reverse proxy example. Contributed by @NilsIrl. ([\#16027](https://github.com/matrix-org/synapse/issues/16027))
### Deprecations and Removals
- Remove support for legacy application service paths. ([\#15964](https://github.com/matrix-org/synapse/issues/15964))
- Move support for application service query parameter authorization behind a configuration option. ([\#16017](https://github.com/matrix-org/synapse/issues/16017))
### Internal Changes
- Update SQL queries to inline boolean parameters as supported in SQLite 3.27. ([\#15525](https://github.com/matrix-org/synapse/issues/15525))
- Allow for the configuration of the backoff algorithm for federation destinations. ([\#15754](https://github.com/matrix-org/synapse/issues/15754))
- Allow modules to check whether the current worker is configured to run background tasks. ([\#15991](https://github.com/matrix-org/synapse/issues/15991))
- Update support for [MSC3958](https://github.com/matrix-org/matrix-spec-proposals/pull/3958) to match the latest revision of the MSC. ([\#15992](https://github.com/matrix-org/synapse/issues/15992))
- Allow modules to schedule delayed background calls. ([\#15993](https://github.com/matrix-org/synapse/issues/15993))
- Properly overwrite the `redacts` content-property for forwards-compatibility with room versions 1 through 10. ([\#16013](https://github.com/matrix-org/synapse/issues/16013))
- Fix building the nix development environment on MacOS systems. ([\#16019](https://github.com/matrix-org/synapse/issues/16019))
- Add Unix Socket support for HTTP Replication Listeners. [Document and provide usage instructions](https://matrix-org.github.io/synapse/v1.89/usage/configuration/config_documentation.html#listeners) for utilizing Unix sockets in Synapse. Contributed by Jason Little. ([\#15708](https://github.com/matrix-org/synapse/issues/15708), [\#15924](https://github.com/matrix-org/synapse/issues/15924))
- Allow `+` in Matrix IDs, per [MSC4009](https://github.com/matrix-org/matrix-spec-proposals/pull/4009). ([\#15911](https://github.com/matrix-org/synapse/issues/15911))
- Support room version 11 from [MSC3820](https://github.com/matrix-org/matrix-spec-proposals/pull/3820). ([\#15912](https://github.com/matrix-org/synapse/issues/15912))
- Allow configuring the set of workers to proxy outbound federation traffic through via `outbound_federation_restricted_to`. ([\#15913](https://github.com/matrix-org/synapse/issues/15913), [\#15969](https://github.com/matrix-org/synapse/issues/15969))
- Implement [MSC3814](https://github.com/matrix-org/matrix-spec-proposals/pull/3814), dehydrated devices v2/shrivelled sessions and move [MSC2697](https://github.com/matrix-org/matrix-spec-proposals/pull/2697) behind a config flag. Contributed by Nico from Famedly, H-Shay and poljar. ([\#15929](https://github.com/matrix-org/synapse/issues/15929))
- Fix a bug introduced in 1.86.0 where Synapse starting with an empty `experimental_features` configuration setting. ([\#15925](https://github.com/matrix-org/synapse/issues/15925))
- Fixed deploy annotations in the provided Grafana dashboard config, so that it shows for any homeserver and not just matrix.org. Contributed by @wrjlewis. ([\#15957](https://github.com/matrix-org/synapse/issues/15957))
- Fix a bug where resyncing stale device lists could block responding to federation transactions, and thus delay receiving new data from the remote server. ([\#15975](https://github.com/matrix-org/synapse/issues/15975))
- Improve [the documentation](https://matrix-org.github.io/synapse/v1.89/admin_api/user_admin_api.html#login-as-a-user) for the login as a user admin API. ([\#15938](https://github.com/matrix-org/synapse/issues/15938))
- Fix broken Arch Linux package link. Contributed by @SnipeXandrej. ([\#15981](https://github.com/matrix-org/synapse/issues/15981))
### Deprecations and Removals
- Remove support for calling the `/register` endpoint with an unspecced `user` property for application services. ([\#15928](https://github.com/matrix-org/synapse/issues/15928))
### Internal Changes
- Mark `get_user_in_directory` private since it is only used in tests. Also remove the cache from it. ([\#15884](https://github.com/matrix-org/synapse/issues/15884))
- Document which Python version runs on a given Linux distribution so we can more easily clean up later. ([\#15909](https://github.com/matrix-org/synapse/issues/15909))
- Add details to warning in log when we fail to fetch an alias. ([\#15922](https://github.com/matrix-org/synapse/issues/15922))
- Fix bug with read/write lock implementation. This is currently unused so has no observable effects. ([\#15933](https://github.com/matrix-org/synapse/issues/15933), [\#15958](https://github.com/matrix-org/synapse/issues/15958))
- Unbreak the nix development environment by pinning the Rust version to 1.70.0. ([\#15940](https://github.com/matrix-org/synapse/issues/15940))
- Update presence metrics to differentiate remote vs local users. ([\#15952](https://github.com/matrix-org/synapse/issues/15952))
- Stop reading from column `user_id` of table `profiles`. ([\#15955](https://github.com/matrix-org/synapse/issues/15955))
- Build packages for Debian Trixie. ([\#15961](https://github.com/matrix-org/synapse/issues/15961))
- Reduce the amount of state we pull out. ([\#15968](https://github.com/matrix-org/synapse/issues/15968))
- Speed up updating state in large rooms. ([\#15971](https://github.com/matrix-org/synapse/issues/15971))
### Updates to locked dependencies
* Bump anyhow from 1.0.71 to 1.0.72. ([\#15949](https://github.com/matrix-org/synapse/issues/15949))
* Bump click from 8.1.3 to 8.1.6. ([\#15984](https://github.com/matrix-org/synapse/issues/15984))
* Bump cryptography from 41.0.1 to 41.0.2. ([\#15943](https://github.com/matrix-org/synapse/issues/15943))
* Bump jsonschema from 4.17.3 to 4.18.3. ([\#15948](https://github.com/matrix-org/synapse/issues/15948))
* Bump pillow from 9.4.0 to 10.0.0. ([\#15986](https://github.com/matrix-org/synapse/issues/15986))
* Bump prometheus-client from 0.17.0 to 0.17.1. ([\#15945](https://github.com/matrix-org/synapse/issues/15945))
* Bump pydantic from 1.10.10 to 1.10.11. ([\#15946](https://github.com/matrix-org/synapse/issues/15946))
* Bump pygithub from 1.58.2 to 1.59.0. ([\#15834](https://github.com/matrix-org/synapse/issues/15834))
* Bump pyo3-log from 0.8.2 to 0.8.3. ([\#15951](https://github.com/matrix-org/synapse/issues/15951))
* Bump sentry-sdk from 1.26.0 to 1.28.1. ([\#15985](https://github.com/matrix-org/synapse/issues/15985))
* Bump serde_json from 1.0.100 to 1.0.103. ([\#15950](https://github.com/matrix-org/synapse/issues/15950))
* Bump types-pillow from 9.5.0.4 to 10.0.0.1. ([\#15932](https://github.com/matrix-org/synapse/issues/15932))
* Bump types-requests from 2.31.0.1 to 2.31.0.2. ([\#15983](https://github.com/matrix-org/synapse/issues/15983))
* Bump typing-extensions from 4.5.0 to 4.7.1. ([\#15947](https://github.com/matrix-org/synapse/issues/15947))
- Revert "Stop writing to column `user_id` of tables `profiles` and `user_filters`", which was introduced in Synapse 1.88.0rc1. ([\#15953](https://github.com/matrix-org/synapse/issues/15953))
- Add `not_user_type` param to the [list accounts admin API](https://matrix-org.github.io/synapse/v1.88/admin_api/user_admin_api.html#list-accounts). ([\#15844](https://github.com/matrix-org/synapse/issues/15844))
### Bugfixes
- Pin `pydantic` to `^=1.7.4` to avoid backwards-incompatible API changes from the 2.0.0 release.
Contributed by @PaarthShah. ([\#15862](https://github.com/matrix-org/synapse/issues/15862))
- Correctly resize thumbnails with pillow version >=10. ([\#15876](https://github.com/matrix-org/synapse/issues/15876))
### Improved Documentation
- Fixed header levels on the [Admin API "Users"](https://matrix-org.github.io/synapse/v1.87/admin_api/user_admin_api.html) documentation page. Contributed by @sumnerevans at @beeper. ([\#15852](https://github.com/matrix-org/synapse/issues/15852))
- Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options. ([\#15872](https://github.com/matrix-org/synapse/issues/15872))
- **Remove deprecated `worker_replication_host`, `worker_replication_http_port` and `worker_replication_http_tls` configuration options.** See the [upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.88/docs/upgrade.md#removal-of-worker_replication_-settings) for more details. ([\#15860](https://github.com/matrix-org/synapse/issues/15860))
- Remove support for Python 3.7 and hence for Debian Buster. ([\#15851](https://github.com/matrix-org/synapse/issues/15851), [\#15892](https://github.com/matrix-org/synapse/issues/15892), [\#15893](https://github.com/matrix-org/synapse/issues/15893), [\#15917](https://github.com/matrix-org/synapse/pull/15917))
- Stop writing to column `user_id` of tables `profiles` and `user_filters`. ([\#15787](https://github.com/matrix-org/synapse/issues/15787))
- Use lower isolation level when cleaning old presence stream data to avoid serialization errors. ([\#15826](https://github.com/matrix-org/synapse/issues/15826))
- Add tracing to media `/upload` code paths. ([\#15850](https://github.com/matrix-org/synapse/issues/15850), [\#15888](https://github.com/matrix-org/synapse/issues/15888))
- Add a timeout that aborts any Postgres statement taking more than 1 hour. ([\#15853](https://github.com/matrix-org/synapse/issues/15853))
- Fix the `devenv up` configuration which was ignoring the config overrides. ([\#15854](https://github.com/matrix-org/synapse/issues/15854))
- Optimised cleanup of old entries in `device_lists_stream`. ([\#15861](https://github.com/matrix-org/synapse/issues/15861))
- Update the Matrix clients link in the _It works! Synapse is running_ landing page. ([\#15874](https://github.com/matrix-org/synapse/issues/15874))
- Fix building Synapse with the nightly Rust compiler. ([\#15906](https://github.com/matrix-org/synapse/issues/15906))
- Add `Server` to Access-Control-Expose-Headers header. ([\#15908](https://github.com/matrix-org/synapse/issues/15908))
### Updates to locked dependencies
* Bump authlib from 1.2.0 to 1.2.1. ([\#15864](https://github.com/matrix-org/synapse/issues/15864))
* Bump importlib-metadata from 6.6.0 to 6.7.0. ([\#15865](https://github.com/matrix-org/synapse/issues/15865))
* Bump lxml from 4.9.2 to 4.9.3. ([\#15897](https://github.com/matrix-org/synapse/issues/15897))
* Bump regex from 1.8.4 to 1.9.1. ([\#15902](https://github.com/matrix-org/synapse/issues/15902))
* Bump ruff from 0.0.275 to 0.0.277. ([\#15900](https://github.com/matrix-org/synapse/issues/15900))
* Bump sentry-sdk from 1.25.1 to 1.26.0. ([\#15867](https://github.com/matrix-org/synapse/issues/15867))
* Bump serde_json from 1.0.99 to 1.0.100. ([\#15901](https://github.com/matrix-org/synapse/issues/15901))
* Bump types-pyopenssl from 23.2.0.0 to 23.2.0.1. ([\#15866](https://github.com/matrix-org/synapse/issues/15866))
This is due to Python 3.7 now having reached End of Life; see our [deprecation policy](https://matrix-org.github.io/synapse/v1.87/deprecation_policy.html)
Contributed by @PaarthShah. ([\#15862](https://github.com/matrix-org/synapse/issues/15862))
### Internal Changes
- Split out 2022 changes from the changelog so the rendered version in GitHub doesn't timeout as much. ([\#15846](https://github.com/matrix-org/synapse/issues/15846))
- Improve `/messages` response time by avoiding backfill when we already have messages to return. ([\#15737](https://github.com/matrix-org/synapse/issues/15737))
- Add spam checker module API for logins. ([\#15838](https://github.com/matrix-org/synapse/issues/15838))
### Bugfixes
- Fix a long-standing bug where media files were served in an unsafe manner. Contributed by @joshqou. ([\#15680](https://github.com/matrix-org/synapse/issues/15680))
- Avoid invalidating a cache that was just prefilled. ([\#15758](https://github.com/matrix-org/synapse/issues/15758))
- Fix requesting multiple keys at once over federation, related to [MSC3983](https://github.com/matrix-org/matrix-spec-proposals/pull/3983). ([\#15770](https://github.com/matrix-org/synapse/issues/15770))
- Fix joining rooms through aliases where the alias server isn't a real homeserver. Contributed by @tulir @ Beeper. ([\#15776](https://github.com/matrix-org/synapse/issues/15776))
- Fix a bug in push rules handling leading to an invalid (per spec) `is_user_mention` rule sent to clients. Also fix wrong rule names for `is_user_mention` and `is_room_mention`. ([\#15781](https://github.com/matrix-org/synapse/issues/15781))
- Fix a bug introduced in 1.57.0 where the wrong table would be locked on updating database rows when using SQLite as the database backend. ([\#15788](https://github.com/matrix-org/synapse/issues/15788))
- Fix Sytest environmental variable evaluation in CI. ([\#15804](https://github.com/matrix-org/synapse/issues/15804))
- Fix forgotten rooms missing from initial sync after rejoining them. Contributed by Nico from Famedly. ([\#15815](https://github.com/matrix-org/synapse/issues/15815))
- Fix sqlite `user_filters` upgrade introduced in v1.86.0. ([\#15817](https://github.com/matrix-org/synapse/issues/15817))
### Improved Documentation
- Document `looping_call()` functionality that will wait for the given function to finish before scheduling another. ([\#15772](https://github.com/matrix-org/synapse/issues/15772))
- Fix a typo in the [Admin API](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html). ([\#15805](https://github.com/matrix-org/synapse/issues/15805))
- Fix typo in MSC number in faster remote room join architecture doc. ([\#15812](https://github.com/matrix-org/synapse/issues/15812))
### Deprecations and Removals
- Remove experimental [MSC2716](https://github.com/matrix-org/matrix-spec-proposals/pull/2716) implementation to incrementally import history into existing rooms. ([\#15748](https://github.com/matrix-org/synapse/issues/15748))
### Internal Changes
- Replace `EventContext` fields `prev_group` and `delta_ids` with field `state_group_deltas`. ([\#15233](https://github.com/matrix-org/synapse/issues/15233))
- Regularly try to send transactions to other servers after they failed instead of waiting for a new event to be available before trying. ([\#15743](https://github.com/matrix-org/synapse/issues/15743))
- Fix requesting multiple keys at once over federation, related to [MSC3983](https://github.com/matrix-org/matrix-spec-proposals/pull/3983). ([\#15755](https://github.com/matrix-org/synapse/issues/15755))
- Allow for the configuration of max request retries and min/max retry delays in the matrix federation client. ([\#15783](https://github.com/matrix-org/synapse/issues/15783))
- Switch from `matrix://` to `matrix-federation://` scheme for internal Synapse routing of outbound federation traffic. ([\#15806](https://github.com/matrix-org/synapse/issues/15806))
- Fix harmless exceptions being printed when running the port DB script. ([\#15814](https://github.com/matrix-org/synapse/issues/15814))
### Updates to locked dependencies
* Bump attrs from 22.2.0 to 23.1.0. ([\#15801](https://github.com/matrix-org/synapse/issues/15801))
* Bump cryptography from 40.0.2 to 41.0.1. ([\#15800](https://github.com/matrix-org/synapse/issues/15800))
* Bump ijson from 3.2.0.post0 to 3.2.1. ([\#15802](https://github.com/matrix-org/synapse/issues/15802))
* Bump phonenumbers from 8.13.13 to 8.13.14. ([\#15798](https://github.com/matrix-org/synapse/issues/15798))
* Bump ruff from 0.0.265 to 0.0.272. ([\#15799](https://github.com/matrix-org/synapse/issues/15799))
* Bump ruff from 0.0.272 to 0.0.275. ([\#15833](https://github.com/matrix-org/synapse/issues/15833))
* Bump serde_json from 1.0.96 to 1.0.97. ([\#15797](https://github.com/matrix-org/synapse/issues/15797))
* Bump serde_json from 1.0.97 to 1.0.99. ([\#15832](https://github.com/matrix-org/synapse/issues/15832))
* Bump towncrier from 22.12.0 to 23.6.0. ([\#15831](https://github.com/matrix-org/synapse/issues/15831))
* Bump types-opentracing from 2.4.10.4 to 2.4.10.5. ([\#15830](https://github.com/matrix-org/synapse/issues/15830))
* Bump types-setuptools from 67.8.0.0 to 68.0.0.0. ([\#15835](https://github.com/matrix-org/synapse/issues/15835))
- Stable support for [MSC3882](https://github.com/matrix-org/matrix-spec-proposals/pull/3882) to allow an existing device/session to generate a login token for use on a new device/session. ([\#15388](https://github.com/matrix-org/synapse/issues/15388))
- Support resolving a room's [canonical alias](https://spec.matrix.org/v1.7/client-server-api/#mroomcanonical_alias) via the module API. ([\#15450](https://github.com/matrix-org/synapse/issues/15450))
- Enable support for [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952): intentional mentions. ([\#15520](https://github.com/matrix-org/synapse/issues/15520))
- Experimental [MSC3861](https://github.com/matrix-org/matrix-spec-proposals/pull/3861) support: delegate auth to an OIDC provider. ([\#15582](https://github.com/matrix-org/synapse/issues/15582))
- Add Synapse version deploy annotations to Grafana dashboard which enables easy correlation between behavior changes witnessed in a graph to a certain Synapse version and nail down regressions. ([\#15674](https://github.com/matrix-org/synapse/issues/15674))
- Add a catch-all * to the supported relation types when redacting an event and its related events. This is an update to [MSC3912](https://github.com/matrix-org/matrix-spec-proposals/pull/3861) implementation. ([\#15705](https://github.com/matrix-org/synapse/issues/15705))
- Speed up `/messages` by backfilling in the background when there are no backward extremities where we are directly paginating. ([\#15710](https://github.com/matrix-org/synapse/issues/15710))
- Expose a metric reporting the database background update status. ([\#15740](https://github.com/matrix-org/synapse/issues/15740))
Bugfixes
--------
- Correctly clear caches when we delete a room. ([\#15609](https://github.com/matrix-org/synapse/issues/15609))
- Check permissions for enabling encryption earlier during room creation to avoid creating broken rooms. ([\#15695](https://github.com/matrix-org/synapse/issues/15695))
Improved Documentation
----------------------
- Simplify query to find participating servers in a room. ([\#15732](https://github.com/matrix-org/synapse/issues/15732))
Internal Changes
----------------
- Log when events are (maybe unexpectedly) filtered out of responses in tests. ([\#14213](https://github.com/matrix-org/synapse/issues/14213))
- Read from column `full_user_id` rather than `user_id` of tables `profiles` and `user_filters`. ([\#15649](https://github.com/matrix-org/synapse/issues/15649))
- Add support for tracing functions which return `Awaitable`s. ([\#15650](https://github.com/matrix-org/synapse/issues/15650))
- Cache requests for user's devices over federation. ([\#15675](https://github.com/matrix-org/synapse/issues/15675))
- Add fully qualified docker image names to Dockerfiles. ([\#15689](https://github.com/matrix-org/synapse/issues/15689))
- Remove some unused code. ([\#15690](https://github.com/matrix-org/synapse/issues/15690))
- Improve type hints. ([\#15694](https://github.com/matrix-org/synapse/issues/15694), [\#15697](https://github.com/matrix-org/synapse/issues/15697))
- Update docstring and traces on `maybe_backfill()` functions. ([\#15709](https://github.com/matrix-org/synapse/issues/15709))
- Add context for when/why to use the `long_retries` option when sending Federation requests. ([\#15721](https://github.com/matrix-org/synapse/issues/15721))
- Removed some unused fields. ([\#15723](https://github.com/matrix-org/synapse/issues/15723))
- Update federation error to more plainly explain we can only authorize our own membership events. ([\#15725](https://github.com/matrix-org/synapse/issues/15725))
- Prevent the `latest_deps` and `twisted_trunk` daily GitHub Actions workflows from running on forks of the codebase. ([\#15726](https://github.com/matrix-org/synapse/issues/15726))
- Improve performance of user directory search. ([\#15729](https://github.com/matrix-org/synapse/issues/15729))
- Remove redundant table join with `room_memberships` when doing a `is_host_joined()`/`is_host_invited()` call (`membership` is already part of the `current_state_events`). ([\#15731](https://github.com/matrix-org/synapse/issues/15731))
- Remove superfluous `room_memberships` join from background update. ([\#15733](https://github.com/matrix-org/synapse/issues/15733))
- Speed up typechecking CI. ([\#15752](https://github.com/matrix-org/synapse/issues/15752))
- Bump minimum supported Rust version to 1.60.0. ([\#15768](https://github.com/matrix-org/synapse/issues/15768))
### Updates to locked dependencies
* Bump importlib-metadata from 6.1.0 to 6.6.0. ([\#15711](https://github.com/matrix-org/synapse/issues/15711))
* Bump library/redis from 6-bullseye to 7-bullseye in /docker. ([\#15712](https://github.com/matrix-org/synapse/issues/15712))
* Bump log from 0.4.18 to 0.4.19. ([\#15761](https://github.com/matrix-org/synapse/issues/15761))
* Bump phonenumbers from 8.13.11 to 8.13.13. ([\#15763](https://github.com/matrix-org/synapse/issues/15763))
* Bump pyasn1 from 0.4.8 to 0.5.0. ([\#15713](https://github.com/matrix-org/synapse/issues/15713))
* Bump pydantic from 1.10.8 to 1.10.9. ([\#15762](https://github.com/matrix-org/synapse/issues/15762))
* Bump pyo3-log from 0.8.1 to 0.8.2. ([\#15759](https://github.com/matrix-org/synapse/issues/15759))
* Bump pyopenssl from 23.1.1 to 23.2.0. ([\#15765](https://github.com/matrix-org/synapse/issues/15765))
* Bump regex from 1.7.3 to 1.8.4. ([\#15769](https://github.com/matrix-org/synapse/issues/15769))
* Bump sentry-sdk from 1.22.1 to 1.25.0. ([\#15714](https://github.com/matrix-org/synapse/issues/15714))
* Bump sentry-sdk from 1.25.0 to 1.25.1. ([\#15764](https://github.com/matrix-org/synapse/issues/15764))
* Bump serde from 1.0.163 to 1.0.164. ([\#15760](https://github.com/matrix-org/synapse/issues/15760))
* Bump types-jsonschema from 4.17.0.7 to 4.17.0.8. ([\#15716](https://github.com/matrix-org/synapse/issues/15716))
* Bump types-pyopenssl from 23.1.0.2 to 23.2.0.0. ([\#15766](https://github.com/matrix-org/synapse/issues/15766))
* Bump types-requests from 2.31.0.0 to 2.31.0.1. ([\#15715](https://github.com/matrix-org/synapse/issues/15715))
- Fix regression where using TLS for HTTP replication between workers did not work. Introduced in v1.85.0. ([\#15746](https://github.com/matrix-org/synapse/issues/15746))
Note: this release only fixes a bug that stopped some deployments from upgrading to v1.85.0. There is no need to upgrade to v1.85.1 if successfully running v1.85.0.
- Fix bug in schema delta that broke upgrades for some deployments. Introduced in v1.85.0. ([\#15738](https://github.com/matrix-org/synapse/issues/15738), [\#15739](https://github.com/matrix-org/synapse/issues/15739))
A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs).
See the advisories for more details. If you have any questions, email security@matrix.org.
- Fix a performance issue introduced in Synapse v1.83.0 which meant that purging rooms was very slow and database-intensive. ([\#15693](https://github.com/matrix-org/synapse/issues/15693))
Deprecations and Removals
-------------------------
- Deprecate calling the `/register` endpoint with an unspecced `user` property for application services. ([\#15703](https://github.com/matrix-org/synapse/issues/15703))
Internal Changes
----------------
- Speed up background jobs `populate_full_user_id_user_filters` and `populate_full_user_id_profiles`. ([\#15700](https://github.com/matrix-org/synapse/issues/15700))
- Improve performance of backfill requests by performing backfill of previously failed requests in the background. ([\#15585](https://github.com/matrix-org/synapse/issues/15585))
- Add a new [admin API](https://matrix-org.github.io/synapse/v1.85/usage/administration/admin_api/index.html) to [create a new device for a user](https://matrix-org.github.io/synapse/v1.85/admin_api/user_admin_api.html#create-a-device). ([\#15611](https://github.com/matrix-org/synapse/issues/15611))
- Add Unix socket support for Redis connections. Contributed by Jason Little. ([\#15644](https://github.com/matrix-org/synapse/issues/15644))
Bugfixes
--------
- Fix a long-standing bug where setting the read marker could fail when using message retention. Contributed by Nick @ Beeper (@fizzadar). ([\#15464](https://github.com/matrix-org/synapse/issues/15464))
- Fix a long-standing bug where the `url_preview_url_blacklist` configuration setting was not applied to oEmbed or image URLs found while previewing a URL. ([\#15601](https://github.com/matrix-org/synapse/issues/15601))
- Fix a long-standing bug where filters with multiple backslashes were rejected. ([\#15607](https://github.com/matrix-org/synapse/issues/15607))
- Fix a bug introduced in Synapse 1.82.0 where the error message displayed when validation of the `app_service_config_files` config option fails would be incorrectly formatted. ([\#15614](https://github.com/matrix-org/synapse/issues/15614))
- Fix a long-standing bug where deactivated users were still able to login using the custom `org.matrix.login.jwt` login type (if enabled). ([\#15624](https://github.com/matrix-org/synapse/issues/15624))
- Fix a long-standing bug where deactivated users were able to login in uncommon situations. ([\#15634](https://github.com/matrix-org/synapse/issues/15634))
Improved Documentation
----------------------
- Warn users that at least 3.75GB of space is needed for the nix Synapse development environment. ([\#15613](https://github.com/matrix-org/synapse/issues/15613))
- Remove outdated comment from the generated and sample homeserver log configs. ([\#15648](https://github.com/matrix-org/synapse/issues/15648))
- Improve contributor docs to make it more clear that Rust is a necessary prerequisite. Contributed by @grantm. ([\#15668](https://github.com/matrix-org/synapse/issues/15668))
Deprecations and Removals
-------------------------
- Remove the old version of the R30 (30-day retained users) phone-home metric. ([\#10428](https://github.com/matrix-org/synapse/issues/10428))
Internal Changes
----------------
- Create dependabot changelogs at release time. ([\#15481](https://github.com/matrix-org/synapse/issues/15481))
- Add not null constraint to column `full_user_id` of tables `profiles` and `user_filters`. ([\#15537](https://github.com/matrix-org/synapse/issues/15537))
- Allow connecting to HTTP Replication Endpoints by using `worker_name` when constructing the request. ([\#15578](https://github.com/matrix-org/synapse/issues/15578))
- Make the `thread_id` column on `event_push_actions`, `event_push_actions_staging`, and `event_push_summary` non-null. ([\#15597](https://github.com/matrix-org/synapse/issues/15597))
- Run mypy type checking with the minimum supported Python version to catch new usage that isn't backwards-compatible. ([\#15602](https://github.com/matrix-org/synapse/issues/15602))
- Fix subscriptable type usage in Python <3.9.([\#15604](https://github.com/matrix-org/synapse/issues/15604))
- Instrument `state` and `state_group` storage-related operations to better picture what's happening when tracing. ([\#15610](https://github.com/matrix-org/synapse/issues/15610), [\#15647](https://github.com/matrix-org/synapse/issues/15647))
- Trace how many new events from the backfill response we need to process. ([\#15633](https://github.com/matrix-org/synapse/issues/15633))
- Re-type config paths in `ConfigError`s to be `StrSequence`s instead of `Iterable[str]`s. ([\#15615](https://github.com/matrix-org/synapse/issues/15615))
- Update Mutual Rooms ([MSC2666](https://github.com/matrix-org/matrix-spec-proposals/pull/2666)) implementation to match new proposal text. ([\#15621](https://github.com/matrix-org/synapse/issues/15621))
- Remove the unstable identifiers from faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706)). ([\#15625](https://github.com/matrix-org/synapse/issues/15625))
If you have already upgraded to Synapse 1.84.0 and your homeserver is working normally, then there is no need to update to this patch release.
Bugfixes
--------
- Fix a bug introduced in Synapse v1.84.0 where workers do not start up when no `instance_map` was provided. ([\#15672](https://github.com/matrix-org/synapse/issues/15672))
Internal Changes
----------------
- Add `dch` and `notify-send` to the development Nix flake so that the release script can be used. ([\#15673](https://github.com/matrix-org/synapse/issues/15673))
The `worker_replication_*` configuration settings have been deprecated in favour of configuring the main process consistently with other instances in the `instance_map`. The deprecated settings will be removed in Synapse v1.88.0, but changing your configuration in advance is recommended. See the [upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.84/docs/upgrade.md#upgrading-to-v1840) for more information.
- Fix a bug introduced in Synapse 1.84.0rc1 where errors during startup were not reported correctly on Python <3.10.([\#15599](https://github.com/matrix-org/synapse/issues/15599))
- Add an option to prevent media downloads from configured domains. ([\#15197](https://github.com/matrix-org/synapse/issues/15197))
- Add `forget_rooms_on_leave` config option to automatically forget rooms when users leave them or are removed from them. ([\#15224](https://github.com/matrix-org/synapse/issues/15224))
- Add a config option to delay push notifications by a random amount, to discourage time-based profiling. ([\#15516](https://github.com/matrix-org/synapse/issues/15516))
- Stabilize support for [MSC2659](https://github.com/matrix-org/matrix-spec-proposals/pull/2659): application service ping endpoint. Contributed by Tulir @ Beeper. ([\#15528](https://github.com/matrix-org/synapse/issues/15528))
- Implement [MSC4009](https://github.com/matrix-org/matrix-spec-proposals/pull/4009) to expand the supported characters in Matrix IDs. ([\#15536](https://github.com/matrix-org/synapse/issues/15536))
- Advertise support for Matrix 1.6 on `/_matrix/client/versions`. ([\#15559](https://github.com/matrix-org/synapse/issues/15559))
- Print full error and stack-trace of any exception that occurs during startup/initialization. ([\#15569](https://github.com/matrix-org/synapse/issues/15569))
Bugfixes
--------
- Don't fail on federation over TOR where SRV queries are not supported. Contributed by Zdzichu. ([\#15523](https://github.com/matrix-org/synapse/issues/15523))
- Experimental support for [MSC4010](https://github.com/matrix-org/matrix-spec-proposals/pull/4010) which rejects setting the `"m.push_rules"` via account data. ([\#15554](https://github.com/matrix-org/synapse/issues/15554), [\#15555](https://github.com/matrix-org/synapse/issues/15555))
- Fix a long-standing bug where an invalid membership event could cause an internal server error. ([\#15564](https://github.com/matrix-org/synapse/issues/15564))
- Require at least poetry-core v1.1.0. ([\#15566](https://github.com/matrix-org/synapse/issues/15566), [\#15571](https://github.com/matrix-org/synapse/issues/15571))
- Remove need for `worker_replication_*` based settings in worker configuration yaml by placing this data directly on the `instance_map` instead. ([\#15491](https://github.com/matrix-org/synapse/issues/15491))
- Add pkg-config package to Stage 0 to be able to build Dockerfile on ppc64le architecture. ([\#15567](https://github.com/matrix-org/synapse/issues/15567))
Improved Documentation
----------------------
- Clarify documentation of the "Create or modify account" Admin API. ([\#15544](https://github.com/matrix-org/synapse/issues/15544))
- Fix path to the `statistics/database/rooms` admin API in documentation. ([\#15560](https://github.com/matrix-org/synapse/issues/15560))
- Update and improve Mastodon Single Sign-On documentation. ([\#15587](https://github.com/matrix-org/synapse/issues/15587))
Internal Changes
----------------
- Use oEmbed to generate URL previews for YouTube Shorts. ([\#15025](https://github.com/matrix-org/synapse/issues/15025))
- Create new `Client` for use with HTTP Replication between workers. Contributed by Jason Little. ([\#15470](https://github.com/matrix-org/synapse/issues/15470))
- Bump pyicu from 2.10.2 to 2.11. ([\#15509](https://github.com/matrix-org/synapse/issues/15509))
- Remove references to supporting per-user flag for [MSC2654](https://github.com/matrix-org/matrix-spec-proposals/pull/2654). ([\#15522](https://github.com/matrix-org/synapse/issues/15522))
- Don't use a trusted key server when running the demo scripts. ([\#15527](https://github.com/matrix-org/synapse/issues/15527))
- Speed up rebuilding of the user directory for local users. ([\#15529](https://github.com/matrix-org/synapse/issues/15529))
- Speed up deleting of old rows in `event_push_actions`. ([\#15531](https://github.com/matrix-org/synapse/issues/15531))
- Install the `xmlsec` and `mdbook` packages and switch back to the upstream [cachix/devenv](https://github.com/cachix/devenv) repo in the nix development environment. ([\#15532](https://github.com/matrix-org/synapse/issues/15532), [\#15533](https://github.com/matrix-org/synapse/issues/15533), [\#15545](https://github.com/matrix-org/synapse/issues/15545))
- Implement [MSC3987](https://github.com/matrix-org/matrix-spec-proposals/pull/3987) by removing `"dont_notify"` from the list of actions in default push rules. ([\#15534](https://github.com/matrix-org/synapse/issues/15534))
- Move various module API callback registration methods to a dedicated class. ([\#15535](https://github.com/matrix-org/synapse/issues/15535))
- Proxy `/user/devices` federation queries to application services for [MSC3984](https://github.com/matrix-org/matrix-spec-proposals/pull/3984). ([\#15539](https://github.com/matrix-org/synapse/issues/15539))
- Factor out an `is_mine_server_name` method. ([\#15542](https://github.com/matrix-org/synapse/issues/15542))
- Allow running Complement tests using [podman](https://podman.io/) by adding a `PODMAN` environment variable to `scripts-dev/complement.sh`. ([\#15543](https://github.com/matrix-org/synapse/issues/15543))
- Bump serde from 1.0.160 to 1.0.162. ([\#15548](https://github.com/matrix-org/synapse/issues/15548))
- Bump types-setuptools from 67.6.0.5 to 67.7.0.1. ([\#15549](https://github.com/matrix-org/synapse/issues/15549))
- Bump sentry-sdk from 1.19.1 to 1.22.1. ([\#15550](https://github.com/matrix-org/synapse/issues/15550))
- Bump ruff from 0.0.259 to 0.0.265. ([\#15551](https://github.com/matrix-org/synapse/issues/15551))
- Bump hiredis from 2.2.2 to 2.2.3. ([\#15552](https://github.com/matrix-org/synapse/issues/15552))
- Bump types-requests from 2.29.0.0 to 2.30.0.0. ([\#15553](https://github.com/matrix-org/synapse/issues/15553))
- Declare unstable support for [MSC3391](https://github.com/matrix-org/matrix-spec-proposals/pull/3391) under `/_matrix/client/versions` if the experimental implementation is enabled. ([\#15562](https://github.com/matrix-org/synapse/issues/15562))
- Implement [MSC3821](https://github.com/matrix-org/matrix-spec-proposals/pull/3821) to update the redaction rules. ([\#15563](https://github.com/matrix-org/synapse/issues/15563))
- Implement updated redaction rules from [MSC3389](https://github.com/matrix-org/matrix-spec-proposals/pull/3389). ([\#15565](https://github.com/matrix-org/synapse/issues/15565))
- Allow `pip install` to use setuptools_rust 1.6.0 when building Synapse. ([\#15570](https://github.com/matrix-org/synapse/issues/15570))
- Deal with upcoming Github Actions deprecations. ([\#15576](https://github.com/matrix-org/synapse/issues/15576))
- Export `run_as_background_process` from the module API. ([\#15577](https://github.com/matrix-org/synapse/issues/15577))
- Update build system requirements to allow building with poetry-core==1.6.0. ([\#15588](https://github.com/matrix-org/synapse/issues/15588))
- Bump serde from 1.0.162 to 1.0.163. ([\#15589](https://github.com/matrix-org/synapse/issues/15589))
- Bump phonenumbers from 8.13.7 to 8.13.11. ([\#15590](https://github.com/matrix-org/synapse/issues/15590))
- Bump types-psycopg2 from 2.9.21.9 to 2.9.21.10. ([\#15591](https://github.com/matrix-org/synapse/issues/15591))
- Bump types-commonmark from 0.9.2.2 to 0.9.2.3. ([\#15592](https://github.com/matrix-org/synapse/issues/15592))
- Bump types-setuptools from 67.7.0.1 to 67.7.0.2. ([\#15594](https://github.com/matrix-org/synapse/issues/15594))
- Experimental support to recursively provide relations per [MSC3981](https://github.com/matrix-org/matrix-spec-proposals/pull/3981). ([\#15315](https://github.com/matrix-org/synapse/issues/15315))
- Experimental support for [MSC3970](https://github.com/matrix-org/matrix-spec-proposals/pull/3970): Scope transaction IDs to devices. ([\#15318](https://github.com/matrix-org/synapse/issues/15318))
- Add an [admin API endpoint](https://matrix-org.github.io/synapse/v1.83/admin_api/experimental_features.html) to support per-user feature flags. ([\#15344](https://github.com/matrix-org/synapse/issues/15344))
- Add an [admin API endpoint](https://matrix-org.github.io/synapse/v1.83/admin_api/statistics.html#get-largest-rooms-by-size-in-database) to query the largest rooms by disk space used in the database. ([\#15482](https://github.com/matrix-org/synapse/issues/15482))
- Fix a long-standing bug where cached server key results which were directly fetched would not be properly re-used. ([\#15417](https://github.com/matrix-org/synapse/issues/15417))
- Fix a bug introduced in Synapse 1.73.0 where some experimental push rules were returned by default. ([\#15494](https://github.com/matrix-org/synapse/issues/15494))
- Update outdated development docs that mention restrictions in versions of SQLite that we no longer support. ([\#15498](https://github.com/matrix-org/synapse/issues/15498))
Internal Changes
----------------
- Speedup tests by caching HomeServerConfig instances. ([\#15284](https://github.com/matrix-org/synapse/issues/15284))
- Add denormalised event stream ordering column to membership state tables for future use. Contributed by Nick @ Beeper (@fizzadar). ([\#15356](https://github.com/matrix-org/synapse/issues/15356))
- Always use multi-user device resync replication endpoints. ([\#15418](https://github.com/matrix-org/synapse/issues/15418))
- Add column `full_user_id` to tables `profiles` and `user_filters`. ([\#15458](https://github.com/matrix-org/synapse/issues/15458))
- Update support for [MSC3983](https://github.com/matrix-org/matrix-spec-proposals/pull/3983) to allow always returning fallback-keys in a `/keys/claim` request. ([\#15462](https://github.com/matrix-org/synapse/issues/15462))
- Improve type hints. ([\#15465](https://github.com/matrix-org/synapse/issues/15465), [\#15496](https://github.com/matrix-org/synapse/issues/15496), [\#15497](https://github.com/matrix-org/synapse/issues/15497))
- Support claiming more than one OTK at a time. ([\#15468](https://github.com/matrix-org/synapse/issues/15468))
- Bump types-pyyaml from 6.0.12.8 to 6.0.12.9. ([\#15471](https://github.com/matrix-org/synapse/issues/15471))
- Bump pyasn1-modules from 0.2.8 to 0.3.0. ([\#15473](https://github.com/matrix-org/synapse/issues/15473))
- Bump cryptography from 40.0.1 to 40.0.2. ([\#15474](https://github.com/matrix-org/synapse/issues/15474))
- Bump types-netaddr from 0.8.0.7 to 0.8.0.8. ([\#15475](https://github.com/matrix-org/synapse/issues/15475))
- Bump types-jsonschema from 4.17.0.6 to 4.17.0.7. ([\#15476](https://github.com/matrix-org/synapse/issues/15476))
- Ask bug reporters to provide logs as text. ([\#15479](https://github.com/matrix-org/synapse/issues/15479))
- Add a Nix flake for use as a development environment. ([\#15495](https://github.com/matrix-org/synapse/issues/15495))
- Bump anyhow from 1.0.70 to 1.0.71. ([\#15507](https://github.com/matrix-org/synapse/issues/15507))
- Bump types-pillow from 9.4.0.19 to 9.5.0.2. ([\#15508](https://github.com/matrix-org/synapse/issues/15508))
- Bump packaging from 23.0 to 23.1. ([\#15510](https://github.com/matrix-org/synapse/issues/15510))
- Bump types-requests from 2.28.11.16 to 2.29.0.0. ([\#15511](https://github.com/matrix-org/synapse/issues/15511))
- Bump setuptools-rust from 1.5.2 to 1.6.0. ([\#15512](https://github.com/matrix-org/synapse/issues/15512))
- Update the check_schema_delta script to account for when the schema version has been bumped locally. ([\#15466](https://github.com/matrix-org/synapse/issues/15466))
- Allow loading the `/directory/room/{roomAlias}` endpoint on workers. ([\#15333](https://github.com/matrix-org/synapse/issues/15333))
- Add some validation to `instance_map` configuration loading. ([\#15431](https://github.com/matrix-org/synapse/issues/15431))
- Allow loading the `/capabilities` endpoint on workers. ([\#15436](https://github.com/matrix-org/synapse/issues/15436))
Bugfixes
--------
- Delete server-side backup keys when deactivating an account. ([\#15181](https://github.com/matrix-org/synapse/issues/15181))
- Fix and document untold assumption that `on_logged_out` module hooks will be called before the deletion of pushers. ([\#15410](https://github.com/matrix-org/synapse/issues/15410))
- Improve robustness when handling a perspective key response by deduplicating received server keys. ([\#15423](https://github.com/matrix-org/synapse/issues/15423))
- Synapse now correctly fails to start if the config option `app_service_config_files` is not a list. ([\#15425](https://github.com/matrix-org/synapse/issues/15425))
- Disable loading `RefreshTokenServlet` (`/_matrix/client/(r0|v3|unstable)/refresh`) on workers. ([\#15428](https://github.com/matrix-org/synapse/issues/15428))
Improved Documentation
----------------------
- Note that the `delete_stale_devices_after` background job always runs on the main process. ([\#15452](https://github.com/matrix-org/synapse/issues/15452))
Deprecations and Removals
-------------------------
- Remove the broken, unspecced registration fallback. Note that the *login* fallback is unaffected by this change. ([\#15405](https://github.com/matrix-org/synapse/issues/15405))
Internal Changes
----------------
- Bump black from 23.1.0 to 23.3.0. ([\#15372](https://github.com/matrix-org/synapse/issues/15372))
- Bump pyopenssl from 23.1.0 to 23.1.1. ([\#15373](https://github.com/matrix-org/synapse/issues/15373))
- Bump types-psycopg2 from 2.9.21.8 to 2.9.21.9. ([\#15374](https://github.com/matrix-org/synapse/issues/15374))
- Bump types-netaddr from 0.8.0.6 to 0.8.0.7. ([\#15375](https://github.com/matrix-org/synapse/issues/15375))
- Bump types-opentracing from 2.4.10.3 to 2.4.10.4. ([\#15376](https://github.com/matrix-org/synapse/issues/15376))
- Bump dawidd6/action-download-artifact from 2.26.0 to 2.26.1. ([\#15404](https://github.com/matrix-org/synapse/issues/15404))
- Bump parameterized from 0.8.1 to 0.9.0. ([\#15412](https://github.com/matrix-org/synapse/issues/15412))
- Bump types-pillow from 9.4.0.17 to 9.4.0.19. ([\#15413](https://github.com/matrix-org/synapse/issues/15413))
- Bump sentry-sdk from 1.17.0 to 1.19.1. ([\#15414](https://github.com/matrix-org/synapse/issues/15414))
- Bump immutabledict from 2.2.3 to 2.2.4. ([\#15415](https://github.com/matrix-org/synapse/issues/15415))
- Bump dawidd6/action-download-artifact from 2.26.1 to 2.27.0. ([\#15441](https://github.com/matrix-org/synapse/issues/15441))
- Bump serde_json from 1.0.95 to 1.0.96. ([\#15442](https://github.com/matrix-org/synapse/issues/15442))
- Bump serde from 1.0.159 to 1.0.160. ([\#15443](https://github.com/matrix-org/synapse/issues/15443))
- Bump pillow from 9.4.0 to 9.5.0. ([\#15444](https://github.com/matrix-org/synapse/issues/15444))
- Bump furo from 2023.3.23 to 2023.3.27. ([\#15445](https://github.com/matrix-org/synapse/issues/15445))
- Bump types-pyopenssl from 23.1.0.0 to 23.1.0.2. ([\#15446](https://github.com/matrix-org/synapse/issues/15446))
- Bump mypy from 1.0.0 to 1.0.1. ([\#15447](https://github.com/matrix-org/synapse/issues/15447))
- Bump psycopg2 from 2.9.5 to 2.9.6. ([\#15448](https://github.com/matrix-org/synapse/issues/15448))
- Improve DB performance of clearing out old data from `stream_ordering_to_exterm`. ([\#15382](https://github.com/matrix-org/synapse/issues/15382), [\#15429](https://github.com/matrix-org/synapse/issues/15429))
- Implement [MSC2175](https://github.com/matrix-org/matrix-doc/pull/2175) to stop adding `creator` to create events. ([\#15394](https://github.com/matrix-org/synapse/issues/15394))
- Implement [MSC2174](https://github.com/matrix-org/matrix-spec-proposals/pull/2174) to move the `redacts` key to a `content` property. ([\#15395](https://github.com/matrix-org/synapse/issues/15395))
- Trust dtonlay/rust-toolchain in CI. ([\#15406](https://github.com/matrix-org/synapse/issues/15406))
- Explicitly install Synapse during typechecking in CI. ([\#15409](https://github.com/matrix-org/synapse/issues/15409))
- Only load the SSO redirect servlet if SSO is enabled. ([\#15421](https://github.com/matrix-org/synapse/issues/15421))
- Refactor `SimpleHttpClient` to pull out a base class. ([\#15427](https://github.com/matrix-org/synapse/issues/15427))
- Improve type hints. ([\#15432](https://github.com/matrix-org/synapse/issues/15432))
- Convert async to normal tests in `TestSSOHandler`. ([\#15433](https://github.com/matrix-org/synapse/issues/15433))
- Speed up the user directory background update. ([\#15435](https://github.com/matrix-org/synapse/issues/15435))
- Disable directory listing for static resources in `/_matrix/static/`. ([\#15438](https://github.com/matrix-org/synapse/issues/15438))
- Move various module API callback registration methods to a dedicated class. ([\#15453](https://github.com/matrix-org/synapse/issues/15453))
- Add the ability to enable/disable registrations when in the OIDC flow. ([\#14978](https://github.com/matrix-org/synapse/issues/14978))
- Add a primitive helper script for listing worker endpoints. ([\#15243](https://github.com/matrix-org/synapse/issues/15243))
- Experimental support for passing One Time Key and device key requests to application services ([MSC3983](https://github.com/matrix-org/matrix-spec-proposals/pull/3983) and [MSC3984](https://github.com/matrix-org/matrix-spec-proposals/pull/3984)). ([\#15314](https://github.com/matrix-org/synapse/issues/15314), [\#15321](https://github.com/matrix-org/synapse/issues/15321))
- Allow loading `/password_policy` endpoint on workers. ([\#15331](https://github.com/matrix-org/synapse/issues/15331))
- Build Debian packages for Ubuntu 23.04 (Lunar Lobster). ([\#15381](https://github.com/matrix-org/synapse/issues/15381))
Bugfixes
--------
- Fix a long-standing bug where edits of non-`m.room.message` events would not be correctly bundled. ([\#15295](https://github.com/matrix-org/synapse/issues/15295))
- Fix a bug introduced in Synapse v1.55.0 which could delay remote homeservers being able to decrypt encrypted messages sent by local users. ([\#15297](https://github.com/matrix-org/synapse/issues/15297))
- Add a check to [SQLite port_db script](https://matrix-org.github.io/synapse/latest/postgres.html#porting-from-sqlite)
to ensure that the sqlite database passed to the script exists before trying to port from it. ([\#15306](https://github.com/matrix-org/synapse/issues/15306))
- Fix a bug introduced in Synapse 1.76.0 where responses from worker deployments could include an internal `_INT_STREAM_POS` key. ([\#15309](https://github.com/matrix-org/synapse/issues/15309))
- Fix a long-standing bug that Synpase only used the [legacy appservice routes](https://spec.matrix.org/v1.6/application-service-api/#legacy-routes). ([\#15317](https://github.com/matrix-org/synapse/issues/15317))
- Fix a long-standing bug preventing users from rejoining rooms after being banned and unbanned over federation. Contributed by Nico. ([\#15323](https://github.com/matrix-org/synapse/issues/15323))
- Fix bug in worker mode where on a rolling restart of workers the "typing" worker would consume 100% CPU until it got restarted. ([\#15332](https://github.com/matrix-org/synapse/issues/15332))
- Fix a long-standing bug where some to_device messages could be dropped when using workers. ([\#15349](https://github.com/matrix-org/synapse/issues/15349))
- Fix a bug introduced in Synapse 1.70.0 where the background sync from a faster join could spin for hours when one of the events involved had been marked for backoff. ([\#15351](https://github.com/matrix-org/synapse/issues/15351))
- Fix missing app variable in mail subject for password resets. Contributed by Cyberes. ([\#15352](https://github.com/matrix-org/synapse/issues/15352))
- Fix a rare bug introduced in Synapse 1.66.0 where initial syncs would fail when the user had been kicked from a faster joined room that had not finished syncing. ([\#15383](https://github.com/matrix-org/synapse/issues/15383))
Improved Documentation
----------------------
- Fix a typo in login requests ratelimit defaults. ([\#15341](https://github.com/matrix-org/synapse/issues/15341))
- Note that Synapse 1.74 queued a rebuild of the user directory tables. ([\#15386](https://github.com/matrix-org/synapse/issues/15386))
Internal Changes
----------------
- Use `immutabledict` instead of `frozendict`. ([\#15113](https://github.com/matrix-org/synapse/issues/15113))
- Add developer documentation for the Federation Sender and add a documentation mechanism using Sphinx. ([\#15265](https://github.com/matrix-org/synapse/issues/15265), [\#15336](https://github.com/matrix-org/synapse/issues/15336))
- Make the pushers rely on the `device_id` instead of the `access_token_id` for various operations. ([\#15280](https://github.com/matrix-org/synapse/issues/15280))
- Bump sentry-sdk from 1.15.0 to 1.17.0. ([\#15285](https://github.com/matrix-org/synapse/issues/15285))
- Allow running the Twisted trunk job against other branches. ([\#15302](https://github.com/matrix-org/synapse/issues/15302))
- Remind the releaser to ask for changelog feedback in [#synapse-dev](https://matrix.to/#/#synapse-dev:matrix.org). ([\#15303](https://github.com/matrix-org/synapse/issues/15303))
- Bump dtolnay/rust-toolchain from e12eda571dc9a5ee5d58eecf4738ec291c66f295 to fc3253060d0c959bea12a59f10f8391454a0b02d. ([\#15304](https://github.com/matrix-org/synapse/issues/15304))
- Reject events with an invalid "mentions" property per [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952). ([\#15311](https://github.com/matrix-org/synapse/issues/15311))
- As an optimisation, use `TRUNCATE` on Postgres when clearing the user directory tables. ([\#15316](https://github.com/matrix-org/synapse/issues/15316))
- Fix `.gitignore` rule for the Complement source tarball downloaded automatically by `complement.sh`. ([\#15319](https://github.com/matrix-org/synapse/issues/15319))
- Bump serde from 1.0.157 to 1.0.158. ([\#15324](https://github.com/matrix-org/synapse/issues/15324))
- Bump regex from 1.7.1 to 1.7.3. ([\#15325](https://github.com/matrix-org/synapse/issues/15325))
- Bump types-pyopenssl from 23.0.0.4 to 23.1.0.0. ([\#15326](https://github.com/matrix-org/synapse/issues/15326))
- Bump furo from 2022.12.7 to 2023.3.23. ([\#15327](https://github.com/matrix-org/synapse/issues/15327))
- Bump ruff from 0.0.252 to 0.0.259. ([\#15328](https://github.com/matrix-org/synapse/issues/15328))
- Bump cryptography from 40.0.0 to 40.0.1. ([\#15329](https://github.com/matrix-org/synapse/issues/15329))
- Bump mypy-zope from 0.9.0 to 0.9.1. ([\#15330](https://github.com/matrix-org/synapse/issues/15330))
- Speed up unit tests when using SQLite3. ([\#15334](https://github.com/matrix-org/synapse/issues/15334))
- Speed up pydantic CI job. ([\#15339](https://github.com/matrix-org/synapse/issues/15339))
- Speed up sample config CI job. ([\#15340](https://github.com/matrix-org/synapse/issues/15340))
- Fix copyright year in SSO footer template. ([\#15358](https://github.com/matrix-org/synapse/issues/15358))
- Bump peaceiris/actions-gh-pages from 3.9.2 to 3.9.3. ([\#15369](https://github.com/matrix-org/synapse/issues/15369))
- Bump serde from 1.0.158 to 1.0.159. ([\#15370](https://github.com/matrix-org/synapse/issues/15370))
- Bump serde_json from 1.0.94 to 1.0.95. ([\#15371](https://github.com/matrix-org/synapse/issues/15371))
- Speed up membership queries for users with forgotten rooms. ([\#15385](https://github.com/matrix-org/synapse/issues/15385))
- Fix a bug in which the [`POST /_matrix/client/v3/rooms/{roomId}/report/{eventId}`](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3roomsroomidreporteventid) endpoint would return the wrong error if the user did not have permission to view the event. This aligns Synapse's implementation with [MSC2249](https://github.com/matrix-org/matrix-spec-proposals/pull/2249). ([\#15298](https://github.com/matrix-org/synapse/issues/15298), [\#15300](https://github.com/matrix-org/synapse/issues/15300))
- Fix a bug introduced in Synapse 1.75.0rc1 where the [SQLite port_db script](https://matrix-org.github.io/synapse/latest/postgres.html#porting-from-sqlite)
would fail to open the SQLite database. ([\#15301](https://github.com/matrix-org/synapse/issues/15301))
- Stabilise support for [MSC3966](https://github.com/matrix-org/matrix-spec-proposals/pull/3966): `event_property_contains` push condition. ([\#15187](https://github.com/matrix-org/synapse/issues/15187))
- Implement [MSC2659](https://github.com/matrix-org/matrix-spec-proposals/pull/2659): application service ping endpoint. Contributed by Tulir @ Beeper. ([\#15249](https://github.com/matrix-org/synapse/issues/15249))
- Allow loading `/register/available` endpoint on workers. ([\#15268](https://github.com/matrix-org/synapse/issues/15268))
- Improve performance of creating and authenticating events. ([\#15195](https://github.com/matrix-org/synapse/issues/15195))
- Add topic and name events to group of events that are batch persisted when creating a room. ([\#15229](https://github.com/matrix-org/synapse/issues/15229))
- Fix a long-standing bug in which the user directory would assume any remote membership state events represent a profile change. ([\#14755](https://github.com/matrix-org/synapse/issues/14755), [\#14756](https://github.com/matrix-org/synapse/issues/14756))
- Implement [MSC3873](https://github.com/matrix-org/matrix-spec-proposals/pull/3873) to fix a long-standing bug where properties with dots were handled ambiguously in push rules. ([\#15190](https://github.com/matrix-org/synapse/issues/15190))
- Faster joins: Fix a bug introduced in Synapse 1.66 where spurious "Failed to find memberships ..." errors would be logged. ([\#15232](https://github.com/matrix-org/synapse/issues/15232))
- Ensure the Dockerfile builds on platforms that don't have a `cryptography` wheel. ([\#15239](https://github.com/matrix-org/synapse/issues/15239))
- Mirror images to the GitHub Container Registry (`ghcr.io/matrix-org/synapse`). ([\#15281](https://github.com/matrix-org/synapse/issues/15281), [\#15282](https://github.com/matrix-org/synapse/issues/15282))
Improved Documentation
----------------------
- Add a missing endpoint to the workers documentation. ([\#15223](https://github.com/matrix-org/synapse/issues/15223))
Internal Changes
----------------
- Add additional functionality to declaring worker types when starting Complement in worker mode. ([\#14921](https://github.com/matrix-org/synapse/issues/14921))
- Add `Synapse-Trace-Id` to `access-control-expose-headers` header. ([\#14974](https://github.com/matrix-org/synapse/issues/14974))
- Make the `HttpTransactionCache` use the `Requester` in addition of the just the `Request` to build the transaction key. ([\#15200](https://github.com/matrix-org/synapse/issues/15200))
- Improve log lines when purging rooms. ([\#15222](https://github.com/matrix-org/synapse/issues/15222))
- Improve type hints. ([\#15230](https://github.com/matrix-org/synapse/issues/15230), [\#15231](https://github.com/matrix-org/synapse/issues/15231), [\#15238](https://github.com/matrix-org/synapse/issues/15238))
- Move various module API callback registration methods to a dedicated class. ([\#15237](https://github.com/matrix-org/synapse/issues/15237))
- Configure GitHub Actions for merge queues. ([\#15244](https://github.com/matrix-org/synapse/issues/15244))
- Add schema comments about the `destinations` and `destination_rooms` tables. ([\#15247](https://github.com/matrix-org/synapse/issues/15247))
- Skip processing of auto-join room behaviour if there are no auto-join rooms configured. ([\#15262](https://github.com/matrix-org/synapse/issues/15262))
- Remove unused store method `_set_destination_retry_timings_emulated`. ([\#15266](https://github.com/matrix-org/synapse/issues/15266))
- Clean-up direct TCP replication code. ([\#15272](https://github.com/matrix-org/synapse/issues/15272), [\#15274](https://github.com/matrix-org/synapse/issues/15274))
- Make `configure_workers_and_start` script used in Complement tests compatible with older versions of Python. ([\#15275](https://github.com/matrix-org/synapse/issues/15275))
- Add a `/versions` flag for [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952). ([\#15293](https://github.com/matrix-org/synapse/issues/15293))
- Fix a bug introduced in Synapse 1.79.0rc1 where attempting to register a `on_remove_user_third_party_identifier` module API callback would be a no-op. ([\#15227](https://github.com/matrix-org/synapse/issues/15227))
- Fix a rare bug introduced in Synapse 1.73 where events could remain unsent to other homeservers after a faster-join to a room. ([\#15248](https://github.com/matrix-org/synapse/issues/15248))
- Add two new Third Party Rules module API callbacks: [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier) and [`on_remove_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_remove_user_third_party_identifier). ([\#15044](https://github.com/matrix-org/synapse/issues/15044))
- Experimental support for [MSC3967](https://github.com/matrix-org/matrix-spec-proposals/pull/3967) to not require UIA for setting up cross-signing on first use. ([\#15077](https://github.com/matrix-org/synapse/issues/15077))
- Add media information to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.79/usage/administration/admin_faq.html#how-can-i-export-user-data). ([\#15107](https://github.com/matrix-org/synapse/issues/15107))
- Add an [admin API](https://matrix-org.github.io/synapse/latest/usage/administration/admin_api/index.html) to delete a [specific event report](https://spec.matrix.org/v1.6/client-server-api/#reporting-content). ([\#15116](https://github.com/matrix-org/synapse/issues/15116))
- Add support for knocking to workers. ([\#15133](https://github.com/matrix-org/synapse/issues/15133))
- Allow use of the `/filter` Client-Server APIs on workers. ([\#15134](https://github.com/matrix-org/synapse/issues/15134))
- Update support for [MSC2677](https://github.com/matrix-org/matrix-spec-proposals/pull/2677): remove support for server-side aggregation of reactions. ([\#15172](https://github.com/matrix-org/synapse/issues/15172))
- Stabilise support for [MSC3758](https://github.com/matrix-org/matrix-spec-proposals/pull/3758): `event_property_is` push condition. ([\#15185](https://github.com/matrix-org/synapse/issues/15185))
Bugfixes
--------
- Fix a bug introduced in Synapse 1.75 that caused experimental support for deleting account data to raise an internal server error while using an account data writer worker. ([\#14869](https://github.com/matrix-org/synapse/issues/14869))
- Fix a long-standing bug where Synapse handled an unspecced field on push rules. ([\#15088](https://github.com/matrix-org/synapse/issues/15088))
- Fix a long-standing bug where a URL preview would break if the discovered oEmbed failed to download. ([\#15092](https://github.com/matrix-org/synapse/issues/15092))
- Fix a long-standing bug where an initial sync would not respond to changes to the list of ignored users if there was an initial sync cached. ([\#15163](https://github.com/matrix-org/synapse/issues/15163))
- Add the `transaction_id` in the events included in many endpoints' responses. ([\#15174](https://github.com/matrix-org/synapse/issues/15174))
- Fix a bug introduced in Synapse 1.78.0 where requests to claim dehydrated devices would fail with a `405` error. ([\#15180](https://github.com/matrix-org/synapse/issues/15180))
- Stop applying edits when bundling aggregations, per [MSC3925](https://github.com/matrix-org/matrix-spec-proposals/pull/3925). ([\#15193](https://github.com/matrix-org/synapse/issues/15193))
- Fix a long-standing bug where the user directory search was not case-insensitive for accented characters. ([\#15143](https://github.com/matrix-org/synapse/issues/15143))
Updates to the Docker image
---------------------------
- Improve startup logging in the with-workers Docker image. ([\#15186](https://github.com/matrix-org/synapse/issues/15186))
Improved Documentation
----------------------
- Document how to use caches in a module. ([\#14026](https://github.com/matrix-org/synapse/issues/14026))
- Clarify which worker processes the ThirdPartyRules' [`on_new_event`](https://matrix-org.github.io/synapse/v1.78/modules/third_party_rules_callbacks.html#on_new_event) module API callback runs on. ([\#15071](https://github.com/matrix-org/synapse/issues/15071))
- Document using [Shibboleth](https://www.shibboleth.net/) as an OpenID Provider. ([\#15112](https://github.com/matrix-org/synapse/issues/15112))
- Correct reference to `federation_verify_certificates` in configuration documentation. ([\#15139](https://github.com/matrix-org/synapse/issues/15139))
- Correct small documentation errors in some `MatrixFederationHttpClient` methods. ([\#15148](https://github.com/matrix-org/synapse/issues/15148))
- Correct the description of the behavior of `registration_shared_secret_path` on startup. ([\#15168](https://github.com/matrix-org/synapse/issues/15168))
- Deprecate the `on_threepid_bind` module callback, to be replaced by [`on_add_user_third_party_identifier`](https://matrix-org.github.io/synapse/v1.79/modules/third_party_rules_callbacks.html#on_add_user_third_party_identifier). See [upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.79/docs/upgrade.md#upgrading-to-v1790). ([\#15044](https://github.com/matrix-org/synapse/issues/15044))
- Remove the unspecced `room_alias` field from the [`/createRoom`](https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3createroom) response. ([\#15093](https://github.com/matrix-org/synapse/issues/15093))
- Remove the unspecced `PUT` on the `/knock/{roomIdOrAlias}` endpoint. ([\#15189](https://github.com/matrix-org/synapse/issues/15189))
- Remove unspecced and buggy `PUT` method on the unstable `/rooms/<room_id>/batch_send` endpoint. ([\#15199](https://github.com/matrix-org/synapse/issues/15199))
- Run the integration test suites with the asyncio reactor enabled in CI. ([\#14101](https://github.com/matrix-org/synapse/issues/14101))
- Batch up storing state groups when creating a new room. ([\#14918](https://github.com/matrix-org/synapse/issues/14918))
- Update [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952) support based on changes to the MSC. ([\#15051](https://github.com/matrix-org/synapse/issues/15051))
- Refactor writing json data in `FileExfiltrationWriter`. ([\#15095](https://github.com/matrix-org/synapse/issues/15095))
- Tighten the login ratelimit defaults. ([\#15135](https://github.com/matrix-org/synapse/issues/15135))
- Fix a typo in an experimental config setting. ([\#15138](https://github.com/matrix-org/synapse/issues/15138))
- Refactor the media modules. ([\#15146](https://github.com/matrix-org/synapse/issues/15146), [\#15175](https://github.com/matrix-org/synapse/issues/15175))
- Improve type hints. ([\#15164](https://github.com/matrix-org/synapse/issues/15164))
- Move `get_event_report` and `get_event_reports_paginate` from `RoomStore` to `RoomWorkerStore`. ([\#15165](https://github.com/matrix-org/synapse/issues/15165))
- Remove dangling reference to being a reference implementation in docstring. ([\#15167](https://github.com/matrix-org/synapse/issues/15167))
- Add an option to force a rebuild of the "editable" complement image. ([\#15184](https://github.com/matrix-org/synapse/issues/15184))
- Use nightly rustfmt in CI. ([\#15188](https://github.com/matrix-org/synapse/issues/15188))
- Add a `get_next_txn` method to `StreamIdGenerator` to match `MultiWriterIdGenerator`. ([\#15191](https://github.com/matrix-org/synapse/issues/15191))
- Combine `AbstractStreamIdTracker` and `AbstractStreamIdGenerator`. ([\#15192](https://github.com/matrix-org/synapse/issues/15192))
- Automatically fix errors with `ruff`. ([\#15194](https://github.com/matrix-org/synapse/issues/15194))
- Refactor database transaction for query users' devices to reduce database pool contention. ([\#15215](https://github.com/matrix-org/synapse/issues/15215))
- Correct `test_icu_word_boundary_punctuation` so that it passes with the ICU versions available in Alpine and macOS. ([\#15177](https://github.com/matrix-org/synapse/issues/15177))
- Fix a bug introduced in Synapse 1.76 where 5s delays would occasionally occur in deployments using workers. ([\#15150](https://github.com/matrix-org/synapse/issues/15150))
- Implement the experimental `exact_event_match` push rule condition from [MSC3758](https://github.com/matrix-org/matrix-spec-proposals/pull/3758). ([\#14964](https://github.com/matrix-org/synapse/issues/14964))
- Add account data to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.78/usage/administration/admin_faq.html#how-can-i-export-user-data). ([\#14969](https://github.com/matrix-org/synapse/issues/14969))
- Implement [MSC3873](https://github.com/matrix-org/matrix-spec-proposals/pull/3873) to disambiguate push rule keys with dots in them. ([\#15004](https://github.com/matrix-org/synapse/issues/15004))
- Allow Synapse to use a specific Redis [logical database](https://redis.io/commands/select/) in worker-mode deployments. ([\#15034](https://github.com/matrix-org/synapse/issues/15034))
- Tag opentracing spans for federation requests with the name of the worker serving the request. ([\#15042](https://github.com/matrix-org/synapse/issues/15042))
- Remove spurious `dont_notify` action from the defaults for the `.m.rule.reaction` pushrule. ([\#15073](https://github.com/matrix-org/synapse/issues/15073))
- Update the error code returned when user sends a duplicate annotation. ([\#15075](https://github.com/matrix-org/synapse/issues/15075))
Bugfixes
--------
- Prevent clients from reporting nonexistent events. ([\#13779](https://github.com/matrix-org/synapse/issues/13779))
- Return spec-compliant JSON errors when unknown endpoints are requested. ([\#14605](https://github.com/matrix-org/synapse/issues/14605))
- Fix a long-standing bug where the room aliases returned could be corrupted. ([\#15038](https://github.com/matrix-org/synapse/issues/15038))
- Fix a bug introduced in Synapse 1.76.0 where partially-joined rooms could not be deleted using the [purge room API](https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#delete-room-api). ([\#15068](https://github.com/matrix-org/synapse/issues/15068))
- Fix a long-standing bug where federated joins would fail if the first server in the list of servers to try is not in the room. ([\#15074](https://github.com/matrix-org/synapse/issues/15074))
- Fix a bug introduced in Synapse v1.74.0 where searching with colons when using ICU for search term tokenisation would fail with an error. ([\#15079](https://github.com/matrix-org/synapse/issues/15079))
- Reduce the likelihood of a rare race condition where rejoining a restricted room over federation would fail. ([\#15080](https://github.com/matrix-org/synapse/issues/15080))
- Fix a bug introduced in Synapse 1.76 where workers would fail to start if the `health` listener was configured. ([\#15096](https://github.com/matrix-org/synapse/issues/15096))
- Fix a bug introduced in Synapse 1.75 where the [portdb script](https://matrix-org.github.io/synapse/release-v1.78/postgres.html#porting-from-sqlite) would fail to run after a room had been faster-joined. ([\#15108](https://github.com/matrix-org/synapse/issues/15108))
- Document how to start Synapse with Poetry. Contributed by @thezaidbintariq. ([\#14892](https://github.com/matrix-org/synapse/issues/14892), [\#15022](https://github.com/matrix-org/synapse/issues/15022))
- Update delegation documentation to clarify that SRV DNS delegation does not eliminate all needs to serve files from .well-known locations. Contributed by @williamkray. ([\#14959](https://github.com/matrix-org/synapse/issues/14959))
- Fix a mistake in registration_shared_secret_path docs. ([\#15078](https://github.com/matrix-org/synapse/issues/15078))
- Refer to a more recent blog post on the [Database Maintenance Tools](https://matrix-org.github.io/synapse/latest/usage/administration/database_maintenance_tools.html) page. Contributed by @jahway603. ([\#15083](https://github.com/matrix-org/synapse/issues/15083))
Internal Changes
----------------
- Re-type hint some collections as read-only. ([\#13755](https://github.com/matrix-org/synapse/issues/13755))
- Faster joins: don't stall when another user joins during a partial-state room resync. ([\#14606](https://github.com/matrix-org/synapse/issues/14606))
- Add a class `UnpersistedEventContext` to allow for the batching up of storing state groups. ([\#14675](https://github.com/matrix-org/synapse/issues/14675))
- Add a check to ensure that locked dependencies have source distributions available. ([\#14742](https://github.com/matrix-org/synapse/issues/14742))
- Tweak comment on `_is_local_room_accessible` as part of room visibility in `/hierarchy` to clarify the condition for a room being visible. ([\#14834](https://github.com/matrix-org/synapse/issues/14834))
- Prevent `WARNING: there is already a transaction in progress` lines appearing in PostgreSQL's logs on some occasions. ([\#14840](https://github.com/matrix-org/synapse/issues/14840))
- Use `StrCollection` to avoid potential bugs with `Collection[str]`. ([\#14929](https://github.com/matrix-org/synapse/issues/14929))
- Improve performance of `/sync` in a few situations. ([\#14973](https://github.com/matrix-org/synapse/issues/14973))
- Limit concurrent event creation for a room to avoid state resolution when sending bursts of events to a local room. ([\#14977](https://github.com/matrix-org/synapse/issues/14977))
- Skip calculating unread push actions in /sync when enable_push is false. ([\#14980](https://github.com/matrix-org/synapse/issues/14980))
- Add a schema dump symlinks inside `contrib`, to make it easier for IDEs to interrogate Synapse's database schema. ([\#14982](https://github.com/matrix-org/synapse/issues/14982))
- Update [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952) support based on changes to the MSC. ([\#15037](https://github.com/matrix-org/synapse/issues/15037))
- Avoid mutating a cached value in `get_user_devices_from_cache`. ([\#15040](https://github.com/matrix-org/synapse/issues/15040))
- Fix a rare exception in logs on start up. ([\#15041](https://github.com/matrix-org/synapse/issues/15041))
- Update pyo3-log to v0.8.1. ([\#15043](https://github.com/matrix-org/synapse/issues/15043))
- Avoid mutating cached values in `_generate_sync_entry_for_account_data`. ([\#15047](https://github.com/matrix-org/synapse/issues/15047))
- Refactor arguments of `try_unbind_threepid` and `_try_unbind_threepid_with_id_server` to not use dictionaries. ([\#15053](https://github.com/matrix-org/synapse/issues/15053))
- Merge debug logging from the hotfixes branch. ([\#15054](https://github.com/matrix-org/synapse/issues/15054))
- Faster joins: omit device list updates originating from partial state rooms in /sync responses without lazy loading of members enabled. ([\#15069](https://github.com/matrix-org/synapse/issues/15069))
- Upper-bound frozendict dependency. This works around us being unable to test installing our wheels against Python 3.11 in CI. ([\#15114](https://github.com/matrix-org/synapse/issues/15114))
- Tweak logging for when a worker waits for its view of a replication stream to catch up. ([\#15120](https://github.com/matrix-org/synapse/issues/15120))
- Bump bleach from 5.0.1 to 6.0.0. ([\#15059](https://github.com/matrix-org/synapse/issues/15059))
- Bump cryptography from 38.0.4 to 39.0.1. ([\#15020](https://github.com/matrix-org/synapse/issues/15020))
- Bump ruff version from 0.0.230 to 0.0.237. ([\#15033](https://github.com/matrix-org/synapse/issues/15033))
- Bump dtolnay/rust-toolchain from 9cd00a88a73addc8617065438eff914dd08d0955 to 25dc93b901a87e864900a8aec6c12e9aa794c0c3. ([\#15060](https://github.com/matrix-org/synapse/issues/15060))
- Bump systemd-python from 234 to 235. ([\#15061](https://github.com/matrix-org/synapse/issues/15061))
- Bump serde_json from 1.0.92 to 1.0.93. ([\#15062](https://github.com/matrix-org/synapse/issues/15062))
- Bump types-requests from 2.28.11.8 to 2.28.11.12. ([\#15063](https://github.com/matrix-org/synapse/issues/15063))
- Bump types-pillow from 9.4.0.5 to 9.4.0.10. ([\#15064](https://github.com/matrix-org/synapse/issues/15064))
- Bump sentry-sdk from 1.13.0 to 1.15.0. ([\#15065](https://github.com/matrix-org/synapse/issues/15065))
- Bump types-jsonschema from 4.17.0.3 to 4.17.0.5. ([\#15099](https://github.com/matrix-org/synapse/issues/15099))
- Bump types-bleach from 5.0.3.1 to 6.0.0.0. ([\#15100](https://github.com/matrix-org/synapse/issues/15100))
- Bump dtolnay/rust-toolchain from 25dc93b901a87e864900a8aec6c12e9aa794c0c3 to e12eda571dc9a5ee5d58eecf4738ec291c66f295. ([\#15101](https://github.com/matrix-org/synapse/issues/15101))
- Bump dawidd6/action-download-artifact from 2.24.3 to 2.25.0. ([\#15102](https://github.com/matrix-org/synapse/issues/15102))
- Bump types-pillow from 9.4.0.10 to 9.4.0.13. ([\#15104](https://github.com/matrix-org/synapse/issues/15104))
- Bump types-setuptools from 67.1.0.0 to 67.3.0.1. ([\#15105](https://github.com/matrix-org/synapse/issues/15105))
- Fix bug where retried replication requests would return a failure. Introduced in v1.76.0. ([\#15024](https://github.com/matrix-org/synapse/issues/15024))
Internal Changes
----------------
- Prepare for future database schema changes. ([\#15036](https://github.com/matrix-org/synapse/issues/15036))
- Experimental support to suppress notifications from message edits ([MSC3958](https://github.com/matrix-org/matrix-spec-proposals/pull/3958)). ([\#14960](https://github.com/matrix-org/synapse/issues/14960), [\#15016](https://github.com/matrix-org/synapse/issues/15016))
- Add profile information, devices and connections to the command line [user data export tool](https://matrix-org.github.io/synapse/v1.77/usage/administration/admin_faq.html#how-can-i-export-user-data). ([\#14894](https://github.com/matrix-org/synapse/issues/14894))
- Fix a bug introduced in Synapse 1.53.0 where `next_batch` tokens from `/sync` could not be used with the `/relations` endpoint. ([\#14866](https://github.com/matrix-org/synapse/issues/14866))
- Fix a bug introduced in Synapse 1.35.0 where the module API's `send_local_online_presence_to` would fail to send presence updates over federation. ([\#14880](https://github.com/matrix-org/synapse/issues/14880))
- Fix a bug introduced in Synapse 1.70.0 where the background updates to add non-thread unique indexes on receipts could fail when upgrading from 1.67.0 or earlier. ([\#14915](https://github.com/matrix-org/synapse/issues/14915))
- Fix a regression introduced in Synapse 1.69.0 which can result in database corruption when database migrations are interrupted on sqlite. ([\#14926](https://github.com/matrix-org/synapse/issues/14926))
- Fix a bug introduced in Synapse 1.68.0 where we were unable to service remote joins in rooms with `@room` notification levels set to `null` in their (malformed) power levels. ([\#14942](https://github.com/matrix-org/synapse/issues/14942))
- Fix a bug introduced in Synapse 1.64.0 where boolean power levels were erroneously permitted in [v10 rooms](https://spec.matrix.org/v1.5/rooms/v10/). ([\#14944](https://github.com/matrix-org/synapse/issues/14944))
- Fix a long-standing bug where sending messages on servers with presence enabled would spam "Re-starting finished log context" log lines. ([\#14947](https://github.com/matrix-org/synapse/issues/14947))
- Fix a bug introduced in Synapse 1.68.0 where logging from the Rust module was not properly logged. ([\#14976](https://github.com/matrix-org/synapse/issues/14976))
- Fix various long-standing bugs in Synapse's config, event and request handling where booleans were unintentionally accepted where an integer was expected. ([\#14945](https://github.com/matrix-org/synapse/issues/14945))
- Improve performance of `/sync` in a few situations. ([\#14908](https://github.com/matrix-org/synapse/issues/14908), [\#14970](https://github.com/matrix-org/synapse/issues/14970))
- Document how to handle Dependabot pull requests. ([\#14916](https://github.com/matrix-org/synapse/issues/14916))
- Fix typo in release script. ([\#14920](https://github.com/matrix-org/synapse/issues/14920))
- Update build system requirements to allow building with poetry-core 1.5.0. ([\#14949](https://github.com/matrix-org/synapse/issues/14949), [\#15019](https://github.com/matrix-org/synapse/issues/15019))
- Add an [lnav](https://lnav.org) config file for Synapse logs to `/contrib/lnav`. ([\#14953](https://github.com/matrix-org/synapse/issues/14953))
- Faster joins: Refactor internal handling of servers in room to never store an empty list. ([\#14954](https://github.com/matrix-org/synapse/issues/14954))
- Faster joins: tag `v2/send_join/` requests to indicate if they served a partial join response. ([\#14950](https://github.com/matrix-org/synapse/issues/14950))
- Allow running `cargo` without the `extension-module` option. ([\#14965](https://github.com/matrix-org/synapse/issues/14965))
- Preparatory work for adding a denormalised event stream ordering column in the future. Contributed by Nick @ Beeper (@fizzadar). ([\#14979](https://github.com/matrix-org/synapse/issues/14979), [9cd7610](https://github.com/matrix-org/synapse/commit/9cd7610f86ab5051c9365dd38d1eec405a5f8ca6), [f10caa7](https://github.com/matrix-org/synapse/commit/f10caa73eee0caa91cf373966104d1ededae2aee); see [\#15014](https://github.com/matrix-org/synapse/issues/15014))
- Bump dtolnay/rust-toolchain from e645b0cf01249a964ec099494d38d2da0f0b349f to 9cd00a88a73addc8617065438eff914dd08d0955. ([\#14968](https://github.com/matrix-org/synapse/issues/14968))
- Bump docker/build-push-action from 3 to 4. ([\#14952](https://github.com/matrix-org/synapse/issues/14952))
The 1.76 release is the first to enable faster joins ([MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706) and [MSC3902](https://github.com/matrix-org/matrix-spec-proposals/pull/3902)) by default. Admins can opt-out: see [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/docs/upgrade.md#faster-joins-are-enabled-by-default) for more details.
The upgrade from 1.75 to 1.76 changes the account data replication streams in a backwards-incompatible manner. Server operators running a multi-worker deployment should consult [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/docs/upgrade.md#changes-to-the-account-data-replication-streams).
Those who are `poetry install`ing from source using our lockfile should ensure their poetry version is 1.3.2 or higher; [see upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.76/docs/upgrade.md#minimum-version-of-poetry-is-now-132).
The faster joins project sees the most benefit when joining a room with a large number of members (joined or historical). We expect it to be particularly useful for joining large public rooms like the [Matrix HQ](https://matrix.to/#/#matrix:matrix.org) or [Synapse Admins](https://matrix.to/#/#synapse:matrix.org) rooms.
- Faster joins: Fix a bug introduced in Synapse 1.69 where device list EDUs could fail to be handled after a restart when a faster join sync is in progress. ([\#14914](https://github.com/matrix-org/synapse/issues/14914))
Internal Changes
----------------
- Faster joins: Improve performance of looking up partial-state status of rooms. ([\#14917](https://github.com/matrix-org/synapse/issues/14917))
- Update the default room version to [v10](https://spec.matrix.org/v1.5/rooms/v10/) ([MSC 3904](https://github.com/matrix-org/matrix-spec-proposals/pull/3904)). Contributed by @FSG-Cat. ([\#14111](https://github.com/matrix-org/synapse/issues/14111))
- Add a `set_displayname()` method to the module API for setting a user's display name. ([\#14629](https://github.com/matrix-org/synapse/issues/14629))
- Implement support for [MSC3890](https://github.com/matrix-org/matrix-spec-proposals/pull/3890): Remotely silence local notifications. ([\#14775](https://github.com/matrix-org/synapse/issues/14775))
- Implement experimental support for [MSC3930](https://github.com/matrix-org/matrix-spec-proposals/pull/3930): Push rules for ([MSC3381](https://github.com/matrix-org/matrix-spec-proposals/pull/3381)) Polls. ([\#14787](https://github.com/matrix-org/synapse/issues/14787))
- Per [MSC3925](https://github.com/matrix-org/matrix-spec-proposals/pull/3925), bundle the whole of the replacement with any edited events, and optionally inhibit server-side replacement. ([\#14811](https://github.com/matrix-org/synapse/issues/14811))
- Faster joins: always serve a partial join response to servers that request it with the stable query param. ([\#14839](https://github.com/matrix-org/synapse/issues/14839))
- Faster joins: allow non-lazy-loading ("eager") syncs to complete after a partial join by omitting partial state rooms until they become fully stated. ([\#14870](https://github.com/matrix-org/synapse/issues/14870))
- Faster joins: request partial joins by default. Admins can opt-out of this for the time being---see the upgrade notes. ([\#14905](https://github.com/matrix-org/synapse/issues/14905))
Bugfixes
--------
- Add index to improve performance of the `/timestamp_to_event` endpoint used for jumping to a specific date in the timeline of a room. ([\#14799](https://github.com/matrix-org/synapse/issues/14799))
- Fix a long-standing bug where Synapse would exhaust the stack when processing many federation requests where the remote homeserver has disconencted early. ([\#14812](https://github.com/matrix-org/synapse/issues/14812), [\#14842](https://github.com/matrix-org/synapse/issues/14842))
- Fix rare races when using workers. ([\#14820](https://github.com/matrix-org/synapse/issues/14820))
- Fix a bug introduced in Synapse 1.64.0 when using room version 10 with frozen events enabled. ([\#14864](https://github.com/matrix-org/synapse/issues/14864))
- Fix a long-standing bug where the `populate_room_stats` background job could fail on broken rooms. ([\#14873](https://github.com/matrix-org/synapse/issues/14873))
- Faster joins: Fix a bug in worker deployments where the room stats and user directory would not get updated when finishing a fast join until another event is sent or received. ([\#14874](https://github.com/matrix-org/synapse/issues/14874))
- Faster joins: Fix incompatibility with joins into restricted rooms where no local users have the ability to invite. ([\#14882](https://github.com/matrix-org/synapse/issues/14882))
- Fix a regression introduced in Synapse 1.69.0 which can result in database corruption when database migrations are interrupted on sqlite. ([\#14910](https://github.com/matrix-org/synapse/issues/14910))
Updates to the Docker image
---------------------------
- Bump default Python version in the Dockerfile from 3.9 to 3.11. ([\#14875](https://github.com/matrix-org/synapse/issues/14875))
Improved Documentation
----------------------
- Include `x_forwarded` entry in the HTTP listener example configs and remove the remaining `worker_main_http_uri` entries. ([\#14667](https://github.com/matrix-org/synapse/issues/14667))
- Remove duplicate commands from the Code Style documentation page; point to the Contributing Guide instead. ([\#14773](https://github.com/matrix-org/synapse/issues/14773))
- Add missing documentation for `tag` to `listeners` section. ([\#14803](https://github.com/matrix-org/synapse/issues/14803))
- Updated documentation in configuration manual for `user_directory.search_all_users`. ([\#14818](https://github.com/matrix-org/synapse/issues/14818))
- Add `worker_manhole` to configuration manual. ([\#14824](https://github.com/matrix-org/synapse/issues/14824))
- Fix the example config missing the `id` field in [application service documentation](https://matrix-org.github.io/synapse/latest/application_services.html). ([\#14845](https://github.com/matrix-org/synapse/issues/14845))
- Minor corrections to the logging configuration documentation. ([\#14868](https://github.com/matrix-org/synapse/issues/14868))
- Document the export user data command. Contributed by @thezaidbintariq. ([\#14883](https://github.com/matrix-org/synapse/issues/14883))
Deprecations and Removals
-------------------------
- Poetry 1.3.2 or higher is now required when `poetry install`ing from source. ([\#14860](https://github.com/matrix-org/synapse/issues/14860))
Internal Changes
----------------
- Faster remote room joins (worker mode): do not populate external hosts-in-room cache when sending events as this requires blocking for full state. ([\#14749](https://github.com/matrix-org/synapse/issues/14749))
- Enable Complement tests for Faster Remote Room Joins against worker-mode Synapse. ([\#14752](https://github.com/matrix-org/synapse/issues/14752))
- Add some clarifying comments and refactor a portion of the `Keyring` class for readability. ([\#14804](https://github.com/matrix-org/synapse/issues/14804))
- Add local poetry config files (`poetry.toml`) to `.gitignore`. ([\#14807](https://github.com/matrix-org/synapse/issues/14807))
- Add missing type hints. ([\#14816](https://github.com/matrix-org/synapse/issues/14816), [\#14885](https://github.com/matrix-org/synapse/issues/14885), [\#14889](https://github.com/matrix-org/synapse/issues/14889))
- Re-enable some linting that was disabled when we switched to ruff. ([\#14821](https://github.com/matrix-org/synapse/issues/14821))
- Add `cargo fmt` and `cargo clippy` to the lint script. ([\#14822](https://github.com/matrix-org/synapse/issues/14822))
- Drop unused table `presence`. ([\#14825](https://github.com/matrix-org/synapse/issues/14825))
- Merge the two account data and the two device list replication streams. ([\#14826](https://github.com/matrix-org/synapse/issues/14826), [\#14833](https://github.com/matrix-org/synapse/issues/14833))
- Faster joins: use stable identifiers from [MSC3706](https://github.com/matrix-org/matrix-spec-proposals/pull/3706). ([\#14832](https://github.com/matrix-org/synapse/issues/14832), [\#14841](https://github.com/matrix-org/synapse/issues/14841))
- Add a parameter to control whether the federation client performs a partial state join. ([\#14843](https://github.com/matrix-org/synapse/issues/14843))
- Add check to avoid starting duplicate partial state syncs. ([\#14844](https://github.com/matrix-org/synapse/issues/14844))
- Add an early return when handling no-op presence updates. ([\#14855](https://github.com/matrix-org/synapse/issues/14855))
- Fix `wait_for_stream_position` to correctly wait for the right instance to advance its token. ([\#14856](https://github.com/matrix-org/synapse/issues/14856), [\#14872](https://github.com/matrix-org/synapse/issues/14872))
- Fix a bug introduced in Synapse 1.75.0rc1 where device lists could be miscalculated with some sync filters. ([\#14810](https://github.com/matrix-org/synapse/issues/14810))
- Fix race where calling `/members` or `/state` with an `at` parameter could fail for newly created rooms, when using multiple workers. ([\#14817](https://github.com/matrix-org/synapse/issues/14817))
- Add a `cached` function to `synapse.module_api` that returns a decorator to cache return values of functions. ([\#14663](https://github.com/matrix-org/synapse/issues/14663))
- Add experimental support for [MSC3391](https://github.com/matrix-org/matrix-spec-proposals/pull/3391) (removing account data). ([\#14714](https://github.com/matrix-org/synapse/issues/14714))
- Support [RFC7636](https://datatracker.ietf.org/doc/html/rfc7636) Proof Key for Code Exchange for OAuth single sign-on. ([\#14750](https://github.com/matrix-org/synapse/issues/14750))
- Support non-OpenID compliant userinfo claims for subject and picture. ([\#14753](https://github.com/matrix-org/synapse/issues/14753))
- Improve performance of `/sync` when filtering all rooms, message types, or senders. ([\#14786](https://github.com/matrix-org/synapse/issues/14786))
- Fix the *MAU Limits* section of the Grafana dashboard relying on a specific `job` name for the workers of a Synapse deployment. ([\#14644](https://github.com/matrix-org/synapse/issues/14644))
- Fix a bug introduced in Synapse 1.70.0 which could cause spurious `UNIQUE constraint failed` errors in the `rotate_notifs` background job. ([\#14669](https://github.com/matrix-org/synapse/issues/14669))
- Ensure stream IDs are always updated after caches get invalidated with workers. Contributed by Nick @ Beeper (@fizzadar). ([\#14723](https://github.com/matrix-org/synapse/issues/14723))
- Remove the unspecced `device` field from `/pushrules` responses. ([\#14727](https://github.com/matrix-org/synapse/issues/14727))
- Fix a bug introduced in Synapse 1.73.0 where the `picture_claim` configured under `oidc_providers` was unused (the default value of `"picture"` was used instead). ([\#14751](https://github.com/matrix-org/synapse/issues/14751))
- Declare support for Python 3.11. ([\#14673](https://github.com/matrix-org/synapse/issues/14673))
- Fix `target_memory_usage` being used in the description for the actual `cache_autotune` sub-option `target_cache_memory_usage`. ([\#14674](https://github.com/matrix-org/synapse/issues/14674))
- Move `email` to Server section in config file documentation. ([\#14730](https://github.com/matrix-org/synapse/issues/14730))
- Fix broken links in the Synapse documentation. ([\#14744](https://github.com/matrix-org/synapse/issues/14744))
- Add missing worker settings to shared configuration documentation. ([\#14748](https://github.com/matrix-org/synapse/issues/14748))
- Document using Twitter as a OAuth 2.0 authentication provider. ([\#14778](https://github.com/matrix-org/synapse/issues/14778))
- Fix Synapse 1.74 upgrade notes to correctly explain how to install pyICU when installing Synapse from PyPI. ([\#14797](https://github.com/matrix-org/synapse/issues/14797))
- Update link to towncrier in contribution guide. ([\#14801](https://github.com/matrix-org/synapse/issues/14801))
- Faster remote room joins: stream the un-partial-stating of events over replication. ([\#14545](https://github.com/matrix-org/synapse/issues/14545), [\#14546](https://github.com/matrix-org/synapse/issues/14546))
- Use [ruff](https://github.com/charliermarsh/ruff/) instead of flake8. ([\#14633](https://github.com/matrix-org/synapse/issues/14633), [\#14741](https://github.com/matrix-org/synapse/issues/14741))
- Change `handle_new_client_event` signature so that a 429 does not reach clients on `PartialStateConflictError`, and internally retry when needed instead. ([\#14665](https://github.com/matrix-org/synapse/issues/14665))
- Remove dependency on jQuery on reCAPTCHA page. ([\#14672](https://github.com/matrix-org/synapse/issues/14672))
- Faster joins: make `compute_state_after_events` consistent with other state-fetching functions that take a `StateFilter`. ([\#14676](https://github.com/matrix-org/synapse/issues/14676))
- Add missing type hints. ([\#14680](https://github.com/matrix-org/synapse/issues/14680), [\#14681](https://github.com/matrix-org/synapse/issues/14681), [\#14687](https://github.com/matrix-org/synapse/issues/14687))
- Improve type annotations for the helper methods on a `CachedFunction`. ([\#14685](https://github.com/matrix-org/synapse/issues/14685))
- Check that the SQLite database file exists before porting to PostgreSQL. ([\#14692](https://github.com/matrix-org/synapse/issues/14692))
- Add `.direnv/` directory to .gitignore to prevent local state generated by the [direnv](https://direnv.net/) development tool from being committed. ([\#14707](https://github.com/matrix-org/synapse/issues/14707))
- Batch up replication requests to request the resyncing of remote users's devices. ([\#14716](https://github.com/matrix-org/synapse/issues/14716))
- If debug logging is enabled, log the `msgid`s of any to-device messages that are returned over `/sync`. ([\#14724](https://github.com/matrix-org/synapse/issues/14724))
- Change GHA CI job to follow best practices. ([\#14772](https://github.com/matrix-org/synapse/issues/14772))
- Switch to our fork of `dh-virtualenv` to work around an upstream Python 3.11 incompatibility. ([\#14774](https://github.com/matrix-org/synapse/issues/14774))
- Skip testing built wheels for PyPy 3.7 on Linux x86_64 as we lack new required dependencies in the build environment. ([\#14802](https://github.com/matrix-org/synapse/issues/14802))
