- 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))
