Synapse will now refuse to start up if open registration is enabled, in order to help mitigate
abuse across the federation. If you would like
to provide registration to anyone, consider adding [email](https://github.com/matrix-org/synapse/blob/8a519f8abc6de772167c2cca101d22ee2052fafc/docs/sample_config.yaml#L1285),
- Allow registering server administrators using the module API. Contributed by Famedly. ([\#12250](https://github.com/matrix-org/synapse/issues/12250))
- Fix a long-standing bug which caused the `/_matrix/federation/v1/state` and `/_matrix/federation/v1/state_ids` endpoints to return incorrect or invalid data when called for an event which we have stored as an "outlier". ([\#12087](https://github.com/matrix-org/synapse/issues/12087))
- Fix a long-standing bug where events from ignored users would still be considered for relations. ([\#12227](https://github.com/matrix-org/synapse/issues/12227), [\#12232](https://github.com/matrix-org/synapse/issues/12232), [\#12285](https://github.com/matrix-org/synapse/issues/12285))
- Fix a bug introduced in Synapse 1.53.0 where an unnecessary query could be performed when fetching bundled aggregations for threads. ([\#12228](https://github.com/matrix-org/synapse/issues/12228))
- Fix a bug introduced in Synapse 1.52.0 where admins could not deactivate and GDPR-erase a user if Synapse was configured with limits on avatars. ([\#12261](https://github.com/matrix-org/synapse/issues/12261))
- Correct Authentik OpenID typo, and add notes on troubleshooting. Contributed by @IronTooch. ([\#12275](https://github.com/matrix-org/synapse/issues/12275))
- Rename `shared_rooms` to `mutual_rooms` ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), as per proposal changes. ([\#12036](https://github.com/matrix-org/synapse/issues/12036))
- Remove check on `update_user_directory` for shared rooms handler ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), and update/expand documentation. ([\#12038](https://github.com/matrix-org/synapse/issues/12038))
- Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`. ([\#12083](https://github.com/matrix-org/synapse/issues/12083), [\#12304](https://github.com/matrix-org/synapse/issues/12304))
- Refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config flag `enable_registration_without_verification` is set to `true`. ([\#12091](https://github.com/matrix-org/synapse/issues/12091), [\#12322](https://github.com/matrix-org/synapse/issues/12322))
- Add missing type hints for storage. ([\#12248](https://github.com/matrix-org/synapse/issues/12248), [\#12255](https://github.com/matrix-org/synapse/issues/12255))
- Add type hints to tests files. ([\#12224](https://github.com/matrix-org/synapse/issues/12224), [\#12240](https://github.com/matrix-org/synapse/issues/12240), [\#12256](https://github.com/matrix-org/synapse/issues/12256))
- Use the `ignored_users` table in additional places instead of re-parsing the account data. ([\#12225](https://github.com/matrix-org/synapse/issues/12225))
- Refactor the relations endpoints to add a `RelationsHandler`. ([\#12237](https://github.com/matrix-org/synapse/issues/12237))
- Generate announcement links in the release script. ([\#12242](https://github.com/matrix-org/synapse/issues/12242))
- Improve error message when dependencies check finds a broken installation. ([\#12244](https://github.com/matrix-org/synapse/issues/12244))
- Compress metrics HTTP resource when enabled. Contributed by Nick @ Beeper. ([\#12258](https://github.com/matrix-org/synapse/issues/12258))
- Refuse to start if the PostgreSQL database has a non-`C` locale, unless the config flag `allow_unsafe_db_locale` is set to true. ([\#12262](https://github.com/matrix-org/synapse/issues/12262), [\#12288](https://github.com/matrix-org/synapse/issues/12288))
- Optionally include account validity expiration information to experimental [MSC3720](https://github.com/matrix-org/matrix-doc/pull/3720) account status responses. ([\#12266](https://github.com/matrix-org/synapse/issues/12266))
- Add a new cache `_get_membership_from_event_id` to speed up push rule calculations in large rooms. ([\#12272](https://github.com/matrix-org/synapse/issues/12272))
- Re-enable Complement concurrency in CI. ([\#12283](https://github.com/matrix-org/synapse/issues/12283))
- Remove unused test utilities. ([\#12291](https://github.com/matrix-org/synapse/issues/12291))
- Enhance logging for inbound federation events. ([\#12301](https://github.com/matrix-org/synapse/issues/12301))
- Fix compatibility with the recently-released Jinja 3.1. ([\#12313](https://github.com/matrix-org/synapse/issues/12313))
- Avoid trying to calculate the state at outlier events. ([\#12314](https://github.com/matrix-org/synapse/issues/12314))
This patch version reverts the earlier fixes from Synapse 1.55.1, which could cause problems in certain deployments, and instead adds a cap to the version of Jinja to be installed. Again, this is to fix an incompatibility with version 3.1.0 of the [Jinja](https://pypi.org/project/Jinja2/) library, and again, deployments of Synapse using the `matrixdotorg/synapse` Docker image or Debian packages from packages.matrix.org are not affected.
Internal Changes
----------------
- Pin Jinja to <3.1.0,asSynapsefailstostartwithJinja3.1.0.([\#12297](https://github.com/matrix-org/synapse/issues/12297))
This is a patch release that fixes an incompatibility with version 3.1.0 of the [Jinja](https://pypi.org/project/Jinja2/) library, released on March 24th, 2022. Deployments of Synapse using the `matrixdotorg/synapse` Docker image or Debian packages from packages.matrix.org are not affected.
- Remove uses of the long-deprecated `jinja2.Markup` which would prevent Synapse from starting with Jinja 3.1.0 or above installed. ([\#12289](https://github.com/matrix-org/synapse/issues/12289))
This release removes a workaround introduced in Synapse 1.50.0 for Mjolnir compatibility. **This breaks compatibility with Mjolnir 1.3.1 and earlier. ([\#11700](https://github.com/matrix-org/synapse/issues/11700))**; Mjolnir users should upgrade Mjolnir before upgrading Synapse to this version.
This release also moves the location of the `synctl` script; see the [upgrade notes](https://github.com/matrix-org/synapse/blob/develop/docs/upgrade.md#synctl-script-has-been-moved) for more details.
- Tweak copy for default Single Sign-On account details template to better adhere to mobile app store guidelines. ([\#12265](https://github.com/matrix-org/synapse/issues/12265), [\#12260](https://github.com/matrix-org/synapse/issues/12260))
- Improve performance of logging in for large accounts. ([\#12132](https://github.com/matrix-org/synapse/issues/12132))
- Add experimental env var `SYNAPSE_ASYNC_IO_REACTOR` that causes Synapse to use the asyncio reactor for Twisted. ([\#12135](https://github.com/matrix-org/synapse/issues/12135))
- Support the stable identifiers from [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440): threads. ([\#12151](https://github.com/matrix-org/synapse/issues/12151))
- Add a new Jinja2 template filter to extract the local part of an email address. ([\#12212](https://github.com/matrix-org/synapse/issues/12212))
Bugfixes
--------
- Use the proper serialization format for bundled thread aggregations. The bug has existed since Synapse v1.48.0. ([\#12090](https://github.com/matrix-org/synapse/issues/12090))
- Fix a long-standing bug when redacting events with relations. ([\#12113](https://github.com/matrix-org/synapse/issues/12113), [\#12121](https://github.com/matrix-org/synapse/issues/12121), [\#12130](https://github.com/matrix-org/synapse/issues/12130), [\#12189](https://github.com/matrix-org/synapse/issues/12189))
- Fix a bug introduced in Synapse 1.7.2 whereby background updates are never run with the default background batch size. ([\#12157](https://github.com/matrix-org/synapse/issues/12157))
- Fix a bug where non-standard information was returned from the `/hierarchy` API. Introduced in Synapse v1.41.0. ([\#12175](https://github.com/matrix-org/synapse/issues/12175))
- Fix a bug introduced in Synapse 1.54.0 that broke background updates on sqlite homeservers while search was disabled. ([\#12215](https://github.com/matrix-org/synapse/issues/12215))
- Fix a long-standing bug when a `filter` argument with `event_fields` which did not include the `unsigned` field could result in a 500 error on `/sync`. ([\#12234](https://github.com/matrix-org/synapse/issues/12234))
- Fix complexity checking config example in [Resource Constrained Devices](https://matrix-org.github.io/synapse/v1.54/other/running_synapse_on_single_board_computers.html) docs page. ([\#11998](https://github.com/matrix-org/synapse/issues/11998))
- Improve documentation for demo scripts. ([\#12143](https://github.com/matrix-org/synapse/issues/12143))
- Updates to the Room DAG concepts development document. ([\#12179](https://github.com/matrix-org/synapse/issues/12179))
- Document that the `typing`, `to_device`, `account_data`, `receipts`, and `presence` stream writer can only be used on a single worker. ([\#12196](https://github.com/matrix-org/synapse/issues/12196))
- Document that contributors can sign off privately by email. ([\#12204](https://github.com/matrix-org/synapse/issues/12204))
- **Remove workaround introduced in Synapse 1.50.0 for Mjolnir compatibility. Breaks compatibility with Mjolnir 1.3.1 and earlier. ([\#11700](https://github.com/matrix-org/synapse/issues/11700))**
- **`synctl` has been moved into into `synapse._scripts` and is exposed as an entry point; see [upgrade notes](https://github.com/matrix-org/synapse/blob/develop/docs/upgrade.md#synctl-script-has-been-moved). ([\#12140](https://github.com/matrix-org/synapse/issues/12140))
- Remove backwards compatibilty with pagination tokens from the `/relations` and `/aggregations` endpoints generated from Synapse <v1.52.0.([\#12138](https://github.com/matrix-org/synapse/issues/12138))
- The groups/communities feature in Synapse has been deprecated. ([\#12200](https://github.com/matrix-org/synapse/issues/12200))
Internal Changes
----------------
- Simplify the `ApplicationService` class' set of public methods related to interest checking. ([\#11915](https://github.com/matrix-org/synapse/issues/11915))
- Add config settings for background update parameters. ([\#11980](https://github.com/matrix-org/synapse/issues/11980))
- Correct type hints for txredis. ([\#12042](https://github.com/matrix-org/synapse/issues/12042))
- Limit the size of `aggregation_key` on annotations. ([\#12101](https://github.com/matrix-org/synapse/issues/12101))
- Add type hints to tests files. ([\#12108](https://github.com/matrix-org/synapse/issues/12108), [\#12146](https://github.com/matrix-org/synapse/issues/12146), [\#12207](https://github.com/matrix-org/synapse/issues/12207), [\#12208](https://github.com/matrix-org/synapse/issues/12208))
- Move scripts to Synapse package and expose as setuptools entry points. ([\#12118](https://github.com/matrix-org/synapse/issues/12118))
- Add support for cancellation to `ReadWriteLock`. ([\#12120](https://github.com/matrix-org/synapse/issues/12120))
- Fix data validation to compare to lists, not sequences. ([\#12128](https://github.com/matrix-org/synapse/issues/12128))
- Fix CI not attaching source distributions and wheels to the GitHub releases. ([\#12131](https://github.com/matrix-org/synapse/issues/12131))
- Remove unused mocks from `test_typing`. ([\#12136](https://github.com/matrix-org/synapse/issues/12136))
- Give `scripts-dev` scripts suffixes for neater CI config. ([\#12137](https://github.com/matrix-org/synapse/issues/12137))
- Move the snapcraft configuration file to `contrib`. ([\#12142](https://github.com/matrix-org/synapse/issues/12142))
- Enable [MSC3030](https://github.com/matrix-org/matrix-doc/pull/3030) Complement tests in CI. ([\#12144](https://github.com/matrix-org/synapse/issues/12144))
- Enable [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) Complement tests in CI. ([\#12145](https://github.com/matrix-org/synapse/issues/12145))
- Add test for `ObservableDeferred`'s cancellation behaviour. ([\#12149](https://github.com/matrix-org/synapse/issues/12149))
- Use `ParamSpec` in type hints for `synapse.logging.context`. ([\#12150](https://github.com/matrix-org/synapse/issues/12150))
- Prune unused jobs from `tox` config. ([\#12152](https://github.com/matrix-org/synapse/issues/12152))
- Move CI checks out of tox, to facilitate a move to using poetry. ([\#12153](https://github.com/matrix-org/synapse/issues/12153))
- Avoid generating state groups for local out-of-band leaves. ([\#12154](https://github.com/matrix-org/synapse/issues/12154))
- Avoid trying to calculate the state at outlier events. ([\#12155](https://github.com/matrix-org/synapse/issues/12155), [\#12173](https://github.com/matrix-org/synapse/issues/12173), [\#12202](https://github.com/matrix-org/synapse/issues/12202))
- Fix some type annotations. ([\#12156](https://github.com/matrix-org/synapse/issues/12156))
- Add type hints for `ObservableDeferred` attributes. ([\#12159](https://github.com/matrix-org/synapse/issues/12159))
- Use a prebuilt Action for the `tests-done` CI job. ([\#12161](https://github.com/matrix-org/synapse/issues/12161))
- Reduce number of DB queries made during processing of `/sync`. ([\#12163](https://github.com/matrix-org/synapse/issues/12163))
- Add `delay_cancellation` utility function, which behaves like `stop_cancellation` but waits until the original `Deferred` resolves before raising a `CancelledError`. ([\#12180](https://github.com/matrix-org/synapse/issues/12180))
- Retry HTTP replication failures, this should prevent 502's when restarting stateful workers (main, event persisters, stream writers). Contributed by Nick @ Beeper. ([\#12182](https://github.com/matrix-org/synapse/issues/12182))
- Add cancellation support to `@cached` and `@cachedList` decorators. ([\#12183](https://github.com/matrix-org/synapse/issues/12183))
- Fix a bug introduced in Synapse 1.54.0rc1 preventing the new module callbacks introduced in this release from being registered by modules. ([\#12141](https://github.com/matrix-org/synapse/issues/12141))
- Fix a bug introduced in Synapse 1.54.0rc1 where runtime dependency version checks would mistakenly check development dependencies if they were present and would not accept pre-release versions of dependencies. ([\#12129](https://github.com/matrix-org/synapse/issues/12129), [\#12177](https://github.com/matrix-org/synapse/issues/12177))
- Update release script to insert the previous version when writing "No significant changes" line in the changelog. ([\#12127](https://github.com/matrix-org/synapse/issues/12127))
- Relax the version guard for "packaging" added in [\#12088](https://github.com/matrix-org/synapse/issues/12088). ([\#12166](https://github.com/matrix-org/synapse/issues/12166))
- Add support for [MSC3202](https://github.com/matrix-org/matrix-doc/pull/3202): sending one-time key counts and fallback key usage states to Application Services. ([\#11617](https://github.com/matrix-org/synapse/issues/11617))
- Improve the generated URL previews for some web pages. Contributed by @AndrewRyanChama. ([\#11985](https://github.com/matrix-org/synapse/issues/11985))
- Track cache invalidations in Prometheus metrics, as already happens for cache eviction based on size or time. ([\#12000](https://github.com/matrix-org/synapse/issues/12000))
- Implement experimental support for [MSC3720](https://github.com/matrix-org/matrix-doc/pull/3720) (account status endpoints). ([\#12001](https://github.com/matrix-org/synapse/issues/12001), [\#12067](https://github.com/matrix-org/synapse/issues/12067))
- Enable modules to set a custom display name when registering a user. ([\#12009](https://github.com/matrix-org/synapse/issues/12009))
- Advertise Matrix 1.1 and 1.2 support on `/_matrix/client/versions`. ([\#12020](https://github.com/matrix-org/synapse/issues/12020), ([\#12022](https://github.com/matrix-org/synapse/issues/12022))
- Support only the stable identifier for [MSC3069](https://github.com/matrix-org/matrix-doc/pull/3069)'s `is_guest` on `/_matrix/client/v3/account/whoami`. ([\#12021](https://github.com/matrix-org/synapse/issues/12021))
- Use room version 9 as the default room version (per [MSC3589](https://github.com/matrix-org/matrix-doc/pull/3589)). ([\#12058](https://github.com/matrix-org/synapse/issues/12058))
- Add module callbacks to react to user deactivation status changes (i.e. deactivations and reactivations) and profile updates. ([\#12062](https://github.com/matrix-org/synapse/issues/12062))
- Fix a bug introduced in Synapse 1.48.0 where an edit of the latest event in a thread would not be properly applied to the thread summary. ([\#11992](https://github.com/matrix-org/synapse/issues/11992))
- Fix long-standing bug where the `get_rooms_for_user` cache was not correctly invalidated for remote users when the server left a room. ([\#11999](https://github.com/matrix-org/synapse/issues/11999))
- Fix a 500 error with Postgres when looking backwards with the [MSC3030](https://github.com/matrix-org/matrix-doc/pull/3030) `/timestamp_to_event?dir=b` endpoint. ([\#12024](https://github.com/matrix-org/synapse/issues/12024))
- Properly fix a long-standing bug where wrong data could be inserted into the `event_search` table when using SQLite. This could block running `synapse_port_db` with an `argument of type 'int' is not iterable` error. This bug was partially fixed by a change in Synapse 1.44.0. ([\#12037](https://github.com/matrix-org/synapse/issues/12037))
- Fix slow performance of `/logout` in some cases where refresh tokens are in use. The slowness existed since the initial implementation of refresh tokens in version 1.38.0. ([\#12056](https://github.com/matrix-org/synapse/issues/12056))
- Fix a long-standing bug where Synapse would make additional failing requests over federation for missing data. ([\#12077](https://github.com/matrix-org/synapse/issues/12077))
- Fix occasional `Unhandled error in Deferred` error message. ([\#12089](https://github.com/matrix-org/synapse/issues/12089))
- Fix a bug introduced in Synapse 1.51.0 where incoming federation transactions containing at least one EDU would be dropped if debug logging was enabled for `synapse.8631_debug`. ([\#12098](https://github.com/matrix-org/synapse/issues/12098))
- Fix a long-standing bug which could cause push notifications to malfunction if `use_frozen_dicts` was set in the configuration. ([\#12100](https://github.com/matrix-org/synapse/issues/12100))
- Fix an extremely rare, long-standing bug in `ReadWriteLock` that would cause an error when a newly unblocked writer completes instantly. ([\#12105](https://github.com/matrix-org/synapse/issues/12105))
- Make a `POST` to `/rooms/<room_id>/receipt/m.read/<event_id>` only trigger a push notification if the count of unread messages is different to the one in the last successfully sent push. This reduces server load and load on the receiving device. ([\#11835](https://github.com/matrix-org/synapse/issues/11835))
- The Docker image no longer automatically creates a temporary volume at `/data`. This is not expected to affect normal usage. ([\#11997](https://github.com/matrix-org/synapse/issues/11997))
- Use Python 3.9 in Docker images by default. ([\#12112](https://github.com/matrix-org/synapse/issues/12112))
Improved Documentation
----------------------
- Document support for the `to_device`, `account_data`, `receipts`, and `presence` stream writers for workers. ([\#11599](https://github.com/matrix-org/synapse/issues/11599))
- Explain the meaning of spam checker callbacks' return values. ([\#12003](https://github.com/matrix-org/synapse/issues/12003))
- Clarify information about external Identity Provider IDs. ([\#12004](https://github.com/matrix-org/synapse/issues/12004))
Deprecations and Removals
-------------------------
- Deprecate using `synctl` with the config option `synctl_cache_factor` and print a warning if a user still uses this option. ([\#11865](https://github.com/matrix-org/synapse/issues/11865))
- Remove support for the legacy structured logging configuration (please see the the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#legacy-structured-logging-configuration-removal) if you are using `structured: true` in the Synapse configuration). ([\#12008](https://github.com/matrix-org/synapse/issues/12008))
- Drop support for [MSC3283](https://github.com/matrix-org/matrix-doc/pull/3283) unstable flags now that the stable flags are supported. ([\#12018](https://github.com/matrix-org/synapse/issues/12018))
- Remove the unstable `/spaces` endpoint from [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#12073](https://github.com/matrix-org/synapse/issues/12073))
- Make the `get_room_version` method use `get_room_version_id` to benefit from caching. ([\#11808](https://github.com/matrix-org/synapse/issues/11808))
- Add missing type hints to storage classes. ([\#11984](https://github.com/matrix-org/synapse/issues/11984))
- Refactor the search code for improved readability. ([\#11991](https://github.com/matrix-org/synapse/issues/11991))
- Move common deduplication code down into `_auth_and_persist_outliers`. ([\#11994](https://github.com/matrix-org/synapse/issues/11994))
- Limit concurrent joins from applications services. ([\#11996](https://github.com/matrix-org/synapse/issues/11996))
- Preparation for faster-room-join work: when parsing the `send_join` response, get the `m.room.create` event from `state`, not `auth_chain`. ([\#12005](https://github.com/matrix-org/synapse/issues/12005), [\#12039](https://github.com/matrix-org/synapse/issues/12039))
- Preparation for faster-room-join work: persist information on which events and rooms have partial state to the database. ([\#12012](https://github.com/matrix-org/synapse/issues/12012))
- Preparation for faster-room-join work: Support for calling `/federation/v1/state` on a remote server. ([\#12013](https://github.com/matrix-org/synapse/issues/12013))
- Configure `tox` to use `venv` rather than `virtualenv`. ([\#12015](https://github.com/matrix-org/synapse/issues/12015))
- Fix bug in `StateFilter.return_expanded()` and add some tests. ([\#12016](https://github.com/matrix-org/synapse/issues/12016))
- Use Matrix v1.1 endpoints (`/_matrix/client/v3/auth/...`) in fallback auth HTML forms. ([\#12019](https://github.com/matrix-org/synapse/issues/12019))
- Update the `olddeps` CI job to use an old version of `markupsafe`. ([\#12025](https://github.com/matrix-org/synapse/issues/12025))
- Minor typing fixes. ([\#12034](https://github.com/matrix-org/synapse/issues/12034), [\#12069](https://github.com/matrix-org/synapse/issues/12069))
- After joining a room, create a dedicated logcontext to process the queued events. ([\#12041](https://github.com/matrix-org/synapse/issues/12041))
- Tidy up GitHub Actions config which builds distributions for PyPI. ([\#12051](https://github.com/matrix-org/synapse/issues/12051))
- Move configuration out of `setup.cfg`. ([\#12052](https://github.com/matrix-org/synapse/issues/12052), [\#12059](https://github.com/matrix-org/synapse/issues/12059))
- Fix error message when a worker process fails to talk to another worker process. ([\#12060](https://github.com/matrix-org/synapse/issues/12060))
- Fix using the `complement.sh` script without specifying a directory or a branch. Contributed by Nico on behalf of Famedly. ([\#12063](https://github.com/matrix-org/synapse/issues/12063))
- Add type hints to `tests/rest/client`. ([\#12066](https://github.com/matrix-org/synapse/issues/12066), [\#12072](https://github.com/matrix-org/synapse/issues/12072), [\#12084](https://github.com/matrix-org/synapse/issues/12084), [\#12094](https://github.com/matrix-org/synapse/issues/12094))
- Add some logging to `/sync` to try and track down #11916. ([\#12068](https://github.com/matrix-org/synapse/issues/12068))
- Inspect application dependencies using `importlib.metadata` or its backport. ([\#12088](https://github.com/matrix-org/synapse/issues/12088))
- Use `assertEqual` instead of the deprecated `assertEquals` in test code. ([\#12092](https://github.com/matrix-org/synapse/issues/12092))
- Move experimental support for [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440) to `/versions`. ([\#12099](https://github.com/matrix-org/synapse/issues/12099))
- Add experimental support for sending to-device messages to application services, as specified by [MSC2409](https://github.com/matrix-org/matrix-doc/pull/2409). ([\#11215](https://github.com/matrix-org/synapse/issues/11215), [\#11966](https://github.com/matrix-org/synapse/issues/11966))
- Experimental support for [MSC3666](https://github.com/matrix-org/matrix-doc/pull/3666): including bundled aggregations in server side search results. ([\#11837](https://github.com/matrix-org/synapse/issues/11837))
- Enable cache time-based expiry by default. The `expiry_time` config flag has been superseded by `expire_caches` and `cache_entry_ttl`. ([\#11849](https://github.com/matrix-org/synapse/issues/11849))
- Add a callback to allow modules to allow or forbid a 3PID (email address, phone number) from being associated to a local account. ([\#11854](https://github.com/matrix-org/synapse/issues/11854))
- Stabilize support and remove unstable endpoints for [MSC3231](https://github.com/matrix-org/matrix-doc/pull/3231). Clients must switch to the stable identifier and endpoint. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#stablisation-of-msc3231) for more information. ([\#11867](https://github.com/matrix-org/synapse/issues/11867))
- Allow modules to retrieve the current instance's server name and worker name. ([\#11868](https://github.com/matrix-org/synapse/issues/11868))
- Use a dedicated configurable rate limiter for 3PID invites. ([\#11892](https://github.com/matrix-org/synapse/issues/11892))
- Support the stable API endpoint for [MSC3283](https://github.com/matrix-org/matrix-doc/pull/3283): new settings in `/capabilities` endpoint. ([\#11933](https://github.com/matrix-org/synapse/issues/11933), [\#11989](https://github.com/matrix-org/synapse/issues/11989))
- Support the `dir` parameter on the `/relations` endpoint, per [MSC3715](https://github.com/matrix-org/matrix-doc/pull/3715). ([\#11941](https://github.com/matrix-org/synapse/issues/11941))
- Experimental implementation of [MSC3706](https://github.com/matrix-org/matrix-doc/pull/3706): extensions to `/send_join` to support reduced response size. ([\#11967](https://github.com/matrix-org/synapse/issues/11967))
Bugfixes
--------
- Fix [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) historical messages backfilling in random order on remote homeservers. ([\#11114](https://github.com/matrix-org/synapse/issues/11114))
- Fix a bug introduced in Synapse 1.51.0 where incoming federation transactions containing at least one EDU would be dropped if debug logging was enabled for `synapse.8631_debug`. ([\#11890](https://github.com/matrix-org/synapse/issues/11890))
- Fix a long-standing bug where some unknown endpoints would return HTML error pages instead of JSON `M_UNRECOGNIZED` errors. ([\#11930](https://github.com/matrix-org/synapse/issues/11930))
- Implement an allow list of content types for which we will attempt to preview a URL. This prevents Synapse from making useless longer-lived connections to streaming media servers. ([\#11936](https://github.com/matrix-org/synapse/issues/11936))
- Fix a long-standing bug where pagination tokens from `/sync` and `/messages` could not be provided to the `/relations` API. ([\#11952](https://github.com/matrix-org/synapse/issues/11952))
- Require that modules register their callbacks using keyword arguments. ([\#11975](https://github.com/matrix-org/synapse/issues/11975))
- Fix a long-standing bug where `M_WRONG_ROOM_KEYS_VERSION` errors would not include the specced `current_version` field. ([\#11988](https://github.com/matrix-org/synapse/issues/11988))
Improved Documentation
----------------------
- Fix typo in User Admin API: unpind -> unbind. ([\#11859](https://github.com/matrix-org/synapse/issues/11859))
- Document images returned by the User List Media Admin API can include those generated by URL previews. ([\#11862](https://github.com/matrix-org/synapse/issues/11862))
- Correct the structured logging configuration example. Contributed by Brad Jones. ([\#11946](https://github.com/matrix-org/synapse/issues/11946))
- Add information on the Synapse release cycle. ([\#11954](https://github.com/matrix-org/synapse/issues/11954))
- Fix broken link in the README to the admin API for password reset. ([\#11955](https://github.com/matrix-org/synapse/issues/11955))
Deprecations and Removals
-------------------------
- Drop support for `webclient` listeners and configuring `web_client_location` to a non-HTTP(S) URL. Deprecated configurations are a configuration error. ([\#11895](https://github.com/matrix-org/synapse/issues/11895))
- Remove deprecated `user_may_create_room_with_invites` spam checker callback. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html#removal-of-user_may_create_room_with_invites) for more information. ([\#11950](https://github.com/matrix-org/synapse/issues/11950))
- No longer build `.deb` packages for Ubuntu 21.04 Hirsute Hippo, which has now EOLed. ([\#11961](https://github.com/matrix-org/synapse/issues/11961))
- Enhance user registration test helpers to make them more useful for tests involving application services and devices. ([\#11615](https://github.com/matrix-org/synapse/issues/11615), [\#11616](https://github.com/matrix-org/synapse/issues/11616))
- Improve performance when fetching bundled aggregations for multiple events. ([\#11660](https://github.com/matrix-org/synapse/issues/11660), [\#11752](https://github.com/matrix-org/synapse/issues/11752))
- Fix type errors introduced by new annotations in the Prometheus Client library. ([\#11832](https://github.com/matrix-org/synapse/issues/11832))
- Add missing type hints to replication code. ([\#11856](https://github.com/matrix-org/synapse/issues/11856), [\#11938](https://github.com/matrix-org/synapse/issues/11938))
- Ensure that `opentracing` scopes are activated and closed at the right time. ([\#11869](https://github.com/matrix-org/synapse/issues/11869))
- Improve opentracing for incoming federation requests. ([\#11870](https://github.com/matrix-org/synapse/issues/11870))
- Improve internal docstrings in `synapse.util.caches`. ([\#11876](https://github.com/matrix-org/synapse/issues/11876))
- Do not needlessly clear the `get_users_in_room` and `get_users_in_room_with_profiles` caches when any room state changes. ([\#11878](https://github.com/matrix-org/synapse/issues/11878))
- Convert `ApplicationServiceTestCase` to use `simple_async_mock`. ([\#11880](https://github.com/matrix-org/synapse/issues/11880))
- Remove experimental changes to the default push rules which were introduced in Synapse 1.19.0 but never enabled. ([\#11884](https://github.com/matrix-org/synapse/issues/11884))
- Disable coverage calculation for olddeps build. ([\#11888](https://github.com/matrix-org/synapse/issues/11888))
- Preparation to support sending device list updates to application services. ([\#11905](https://github.com/matrix-org/synapse/issues/11905))
- Add a test that checks users receive their own device list updates down `/sync`. ([\#11909](https://github.com/matrix-org/synapse/issues/11909))
- Run Complement tests sequentially. ([\#11910](https://github.com/matrix-org/synapse/issues/11910))
- Various refactors to the application service notifier code. ([\#11911](https://github.com/matrix-org/synapse/issues/11911), [\#11912](https://github.com/matrix-org/synapse/issues/11912))
- Tests: replace mocked `Authenticator` with the real thing. ([\#11913](https://github.com/matrix-org/synapse/issues/11913))
- Various refactors to the typing notifications code. ([\#11914](https://github.com/matrix-org/synapse/issues/11914))
- Remove account data (including client config, push rules and ignored users) upon user deactivation. ([\#11621](https://github.com/matrix-org/synapse/issues/11621), [\#11788](https://github.com/matrix-org/synapse/issues/11788), [\#11789](https://github.com/matrix-org/synapse/issues/11789))
- Add an admin API to get a list of rooms that federate with a given remote homeserver. ([\#11658](https://github.com/matrix-org/synapse/issues/11658))
- Add a module callback to set username at registration. ([\#11790](https://github.com/matrix-org/synapse/issues/11790))
- Allow configuring a maximum file size as well as a list of allowed content types for avatars. ([\#11846](https://github.com/matrix-org/synapse/issues/11846))
Bugfixes
--------
- Include the bundled aggregations in the `/sync` response, per [MSC2675](https://github.com/matrix-org/matrix-doc/pull/2675). ([\#11612](https://github.com/matrix-org/synapse/issues/11612))
- Fix a long-standing bug when previewing Reddit URLs which do not contain an image. ([\#11767](https://github.com/matrix-org/synapse/issues/11767))
- Fix a long-standing bug that media streams could cause long-lived connections when generating URL previews. ([\#11784](https://github.com/matrix-org/synapse/issues/11784))
- Include a `prev_content` field in state events sent to Application Services. Contributed by @totallynotvaishnav. ([\#11798](https://github.com/matrix-org/synapse/issues/11798))
- Fix a bug introduced in Synapse 0.33.3 causing requests to sometimes log strings such as `HTTPStatus.OK` instead of integer status codes. ([\#11827](https://github.com/matrix-org/synapse/issues/11827))
Improved Documentation
----------------------
- Update pypi installation docs to indicate that we now support Python 3.10. ([\#11820](https://github.com/matrix-org/synapse/issues/11820))
- Add missing steps to the contribution submission process in the documentation. Contributed by @sequentialread. ([\#11821](https://github.com/matrix-org/synapse/issues/11821))
- Remove not needed old table of contents in documentation. ([\#11860](https://github.com/matrix-org/synapse/issues/11860))
- Consolidate the `access_token` information at the top of each relevant page in the Admin API documentation. ([\#11861](https://github.com/matrix-org/synapse/issues/11861))
Deprecations and Removals
-------------------------
- Drop support for Python 3.6, which is EOL. ([\#11683](https://github.com/matrix-org/synapse/issues/11683))
- Remove the `experimental_msc1849_support_enabled` flag as the features are now stable. ([\#11843](https://github.com/matrix-org/synapse/issues/11843))
Internal Changes
----------------
- Preparation for database schema simplifications: add `state_key` and `rejection_reason` columns to `events` table. ([\#11792](https://github.com/matrix-org/synapse/issues/11792))
- Add `FrozenEvent.get_state_key` and use it in a couple of places. ([\#11793](https://github.com/matrix-org/synapse/issues/11793))
- Preparation for database schema simplifications: stop reading from `event_reference_hashes`. ([\#11794](https://github.com/matrix-org/synapse/issues/11794))
- Drop unused table `public_room_list_stream`. ([\#11795](https://github.com/matrix-org/synapse/issues/11795))
- Preparation for reducing Postgres serialization errors: allow setting transaction isolation level. Contributed by Nick @ Beeper. ([\#11799](https://github.com/matrix-org/synapse/issues/11799), [\#11847](https://github.com/matrix-org/synapse/issues/11847))
- Docker: skip the initial amd64-only build and go straight to multiarch. ([\#11810](https://github.com/matrix-org/synapse/issues/11810))
- Run Complement on the Github Actions VM and not inside a Docker container. ([\#11811](https://github.com/matrix-org/synapse/issues/11811))
- Log module names at startup. ([\#11813](https://github.com/matrix-org/synapse/issues/11813))
- Improve type safety of bundled aggregations code. ([\#11815](https://github.com/matrix-org/synapse/issues/11815))
- Correct a type annotation in the event validation logic. ([\#11817](https://github.com/matrix-org/synapse/issues/11817), [\#11830](https://github.com/matrix-org/synapse/issues/11830))
- Minor updates and documentation for database schema delta files. ([\#11823](https://github.com/matrix-org/synapse/issues/11823))
- Workaround a type annotation problem in `prometheus_client` 0.13.0. ([\#11834](https://github.com/matrix-org/synapse/issues/11834))
- Minor performance improvement in room state lookup. ([\#11836](https://github.com/matrix-org/synapse/issues/11836))
- Fix some indentation inconsistencies in the sample config. ([\#11838](https://github.com/matrix-org/synapse/issues/11838))
- Add type hints to `tests/rest/admin`. ([\#11851](https://github.com/matrix-org/synapse/issues/11851))
Synapse 1.51.0 deprecates `webclient` listeners and non-HTTP(S) `web_client_location`s. Support for these will be removed in Synapse 1.53.0, at which point Synapse will not be capable of directly serving a web client for Matrix. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#upgrading-to-v1510).
- Fix a bug introduced in Synapse 1.40.0 that caused Synapse to fail to process incoming federation traffic after handling a large amount of events in a v1 room. ([\#11806](https://github.com/matrix-org/synapse/issues/11806))
- Fix a bug introduced in Synapse 1.40.0 that caused Synapse to fail to process incoming federation traffic after handling a large amount of events in a v1 room. ([\#11806](https://github.com/matrix-org/synapse/issues/11806))
- Add `track_puppeted_user_ips` config flag to record client IP addresses against puppeted users, and include the puppeted users in monthly active user counts. ([\#11561](https://github.com/matrix-org/synapse/issues/11561), [\#11749](https://github.com/matrix-org/synapse/issues/11749), [\#11757](https://github.com/matrix-org/synapse/issues/11757))
- Include whether the requesting user has participated in a thread when generating a summary for [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440). ([\#11577](https://github.com/matrix-org/synapse/issues/11577))
- Return an `M_FORBIDDEN` error code instead of `M_UNKNOWN` when a spam checker module prevents a user from creating a room. ([\#11672](https://github.com/matrix-org/synapse/issues/11672))
- Add a flag to the `synapse_review_recent_signups` script to ignore and filter appservice users. ([\#11675](https://github.com/matrix-org/synapse/issues/11675), [\#11770](https://github.com/matrix-org/synapse/issues/11770))
Bugfixes
--------
- Fix a long-standing issue which could cause Synapse to incorrectly accept data in the unsigned field of events
received over federation. ([\#11530](https://github.com/matrix-org/synapse/issues/11530))
- Fix a long-standing bug where Synapse wouldn't cache a response indicating that a remote user has no devices. ([\#11587](https://github.com/matrix-org/synapse/issues/11587))
- Fix an error that occurs whilst trying to get the federation status of a destination server that was working normally. This admin API was newly introduced in Synapse v1.49.0. ([\#11593](https://github.com/matrix-org/synapse/issues/11593))
- Fix bundled aggregations not being included in the `/sync` response, per [MSC2675](https://github.com/matrix-org/matrix-doc/pull/2675). ([\#11612](https://github.com/matrix-org/synapse/issues/11612), [\#11659](https://github.com/matrix-org/synapse/issues/11659), [\#11791](https://github.com/matrix-org/synapse/issues/11791))
- Fix the `/_matrix/client/v1/room/{roomId}/hierarchy` endpoint returning incorrect fields which have been present since Synapse 1.49.0. ([\#11667](https://github.com/matrix-org/synapse/issues/11667))
- Fix preview of some GIF URLs (like tenor.com). Contributed by Philippe Daouadi. ([\#11669](https://github.com/matrix-org/synapse/issues/11669))
- Fix a bug where only the first 50 rooms from a space were returned from the `/hierarchy` API. This has existed since the introduction of the API in Synapse v1.41.0. ([\#11695](https://github.com/matrix-org/synapse/issues/11695))
- Fix a bug introduced in Synapse v1.18.0 where password reset and address validation emails would not be sent if their subject was configured to use the 'app' template variable. Contributed by @br4nnigan. ([\#11710](https://github.com/matrix-org/synapse/issues/11710), [\#11745](https://github.com/matrix-org/synapse/issues/11745))
- Fix a long-standing bug where space hierarchy over federation would only work correctly some of the time. ([\#11775](https://github.com/matrix-org/synapse/issues/11775))
- Fix a bug introduced in Synapse v1.46.0 that prevented `on_logged_out` module callbacks from being correctly awaited by Synapse. ([\#11786](https://github.com/matrix-org/synapse/issues/11786))
- Warn against using a Let's Encrypt certificate for TLS/DTLS TURN server client connections, and suggest using ZeroSSL certificate instead. This works around client-side connectivity errors caused by WebRTC libraries that reject Let's Encrypt certificates. Contibuted by @AndrewFerr. ([\#11686](https://github.com/matrix-org/synapse/issues/11686))
- Document the new `SYNAPSE_TEST_PERSIST_SQLITE_DB` environment variable in the contributing guide. ([\#11715](https://github.com/matrix-org/synapse/issues/11715))
- Remove the `password_hash` field from the response dictionaries of the [Users Admin API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html). ([\#11576](https://github.com/matrix-org/synapse/issues/11576))
- **Deprecate support for `webclient` listeners and non-HTTP(S) `web_client_location` configuration. ([\#11774](https://github.com/matrix-org/synapse/issues/11774), [\#11783](https://github.com/matrix-org/synapse/issues/11783))**
- Run `pyupgrade --py37-plus --keep-percent-format` on Synapse. ([\#11685](https://github.com/matrix-org/synapse/issues/11685))
- Use buildkit's cache feature to speed up docker builds. ([\#11691](https://github.com/matrix-org/synapse/issues/11691))
- Use `auto_attribs` and native type hints for attrs classes. ([\#11692](https://github.com/matrix-org/synapse/issues/11692), [\#11768](https://github.com/matrix-org/synapse/issues/11768))
- Remove debug logging for #4422, which has been closed since Synapse 0.99. ([\#11693](https://github.com/matrix-org/synapse/issues/11693))
- Remove fallback code for Python 2. ([\#11699](https://github.com/matrix-org/synapse/issues/11699))
- Add a test for [an edge case](https://github.com/matrix-org/synapse/pull/11532#discussion_r769104461) in the `/sync` logic. ([\#11701](https://github.com/matrix-org/synapse/issues/11701))
- Minor efficiency improvements when inserting many values into the database. ([\#11742](https://github.com/matrix-org/synapse/issues/11742))
- Invite PR authors to give themselves credit in the changelog. ([\#11744](https://github.com/matrix-org/synapse/issues/11744))
- Add optional debugging to investigate [issue 8631](https://github.com/matrix-org/synapse/issues/8631). ([\#11760](https://github.com/matrix-org/synapse/issues/11760))
- Remove `log_function` utility function and its uses. ([\#11761](https://github.com/matrix-org/synapse/issues/11761))
- Add a unit test that checks both `client` and `webclient` resources will function when simultaneously enabled. ([\#11765](https://github.com/matrix-org/synapse/issues/11765))
- Allow overriding complement commit using `COMPLEMENT_REF`. ([\#11766](https://github.com/matrix-org/synapse/issues/11766))
- Add some comments and type annotations for `_update_outliers_txn`. ([\#11776](https://github.com/matrix-org/synapse/issues/11776))
This release fixes a bug in Synapse 1.50.0 that could prevent clients from being able to connect to Synapse if the `webclient` resource was enabled. Further details are available in [this issue](https://github.com/matrix-org/synapse/issues/11763).
- Fix a bug introduced in Synapse 1.50.0rc1 that could cause Matrix clients to be unable to connect to Synapse instances with the `webclient` resource enabled. ([\#11764](https://github.com/matrix-org/synapse/issues/11764))
- Fix a bug introduced in Synapse v1.0.0 whereby some device list updates would not be sent to remote homeservers if there were too many to send at once. ([\#11729](https://github.com/matrix-org/synapse/issues/11729))
- Fix a bug introduced in Synapse v1.50.0rc1 whereby outbound federation could fail because too many EDUs were produced for device updates. ([\#11730](https://github.com/matrix-org/synapse/issues/11730))
Improved Documentation
----------------------
- Document that now the minimum supported PostgreSQL version is 10. ([\#11725](https://github.com/matrix-org/synapse/issues/11725))
Internal Changes
----------------
- Fix a typechecker problem related to our (ab)use of `nacl.signing.SigningKey`s. ([\#11714](https://github.com/matrix-org/synapse/issues/11714))
- Allow guests to send state events per [MSC3419](https://github.com/matrix-org/matrix-doc/pull/3419). ([\#11378](https://github.com/matrix-org/synapse/issues/11378))
- Add experimental support for part of [MSC3202](https://github.com/matrix-org/matrix-doc/pull/3202): allowing application services to masquerade as specific devices. ([\#11538](https://github.com/matrix-org/synapse/issues/11538))
- Fix a long-standing bug where relations from other rooms could be included in the bundled aggregations of an event. ([\#11516](https://github.com/matrix-org/synapse/issues/11516))
- Fix a long-standing bug which could cause `AssertionError`s to be written to the log when Synapse was restarted after purging events from the database. ([\#11536](https://github.com/matrix-org/synapse/issues/11536), [\#11642](https://github.com/matrix-org/synapse/issues/11642))
- Fix a bug introduced in Synapse 1.17.0 where a pusher created for an email with capital letters would fail to be created. ([\#11547](https://github.com/matrix-org/synapse/issues/11547))
- Fix a long-standing bug where responses included bundled aggregations when they should not, per [MSC2675](https://github.com/matrix-org/matrix-doc/pull/2675). ([\#11592](https://github.com/matrix-org/synapse/issues/11592), [\#11623](https://github.com/matrix-org/synapse/issues/11623))
- Fix a long-standing bug that some unknown endpoints would return HTML error pages instead of JSON `M_UNRECOGNIZED` errors. ([\#11602](https://github.com/matrix-org/synapse/issues/11602))
- Fix a bug introduced in Synapse 1.19.3 which could sometimes cause `AssertionError`s when backfilling rooms over federation. ([\#11632](https://github.com/matrix-org/synapse/issues/11632))
Improved Documentation
----------------------
- Update Synapse install command for FreeBSD as the package is now prefixed with `py38`. Contributed by @itchychips. ([\#11267](https://github.com/matrix-org/synapse/issues/11267))
- Document the usage of refresh tokens. ([\#11427](https://github.com/matrix-org/synapse/issues/11427))
- Add details for how to configure a TURN server when behind a NAT. Contibuted by @AndrewFerr. ([\#11553](https://github.com/matrix-org/synapse/issues/11553))
- Add references for using Postgres to the Docker documentation. ([\#11640](https://github.com/matrix-org/synapse/issues/11640))
- Fix the documentation link in newly-generated configuration files. ([\#11678](https://github.com/matrix-org/synapse/issues/11678))
- Correct the documentation for `nginx` to use a case-sensitive url pattern. Fixes an error introduced in v1.21.0. ([\#11680](https://github.com/matrix-org/synapse/issues/11680))
- Clarify SSO mapping provider documentation by writing `def` or `async def` before the names of methods, as appropriate. ([\#11681](https://github.com/matrix-org/synapse/issues/11681))
Deprecations and Removals
-------------------------
- Replace `mock` package by its standard library version. ([\#11588](https://github.com/matrix-org/synapse/issues/11588))
- Allow specific, experimental events to be created without `prev_events`. Used by [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716). ([\#11243](https://github.com/matrix-org/synapse/issues/11243))
- A test helper (`wait_for_background_updates`) no longer depends on classes defining a `store` property. ([\#11331](https://github.com/matrix-org/synapse/issues/11331))
- Add type hints to `synapse.appservice`. ([\#11360](https://github.com/matrix-org/synapse/issues/11360))
- Add missing type hints to `synapse.config` module. ([\#11480](https://github.com/matrix-org/synapse/issues/11480))
- Add test to ensure we share the same `state_group` across the whole historical batch when using the [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint. ([\#11487](https://github.com/matrix-org/synapse/issues/11487))
- Refactor `tests.util.setup_test_homeserver` and `tests.server.setup_test_homeserver`. ([\#11503](https://github.com/matrix-org/synapse/issues/11503))
- Move `glob_to_regex` and `re_word_boundary` to `matrix-python-common`. ([\#11505](https://github.com/matrix-org/synapse/issues/11505), [\#11687](https://github.com/matrix-org/synapse/issues/11687))
- Minor efficiency improvements in event persistence. ([\#11560](https://github.com/matrix-org/synapse/issues/11560))
- Add some safety checks that storage functions are used correctly. ([\#11564](https://github.com/matrix-org/synapse/issues/11564), [\#11580](https://github.com/matrix-org/synapse/issues/11580))
- Make `get_device` return `None` if the device doesn't exist rather than raising an exception. ([\#11565](https://github.com/matrix-org/synapse/issues/11565))
- Split the HTML parsing code from the URL preview resource code. ([\#11566](https://github.com/matrix-org/synapse/issues/11566))
- Remove redundant `COALESCE()`s around `COUNT()`s in database queries. ([\#11570](https://github.com/matrix-org/synapse/issues/11570))
- Add missing type hints to `synapse.http`. ([\#11571](https://github.com/matrix-org/synapse/issues/11571))
- Add [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) and [MSC3030](https://github.com/matrix-org/matrix-doc/pull/3030) to `/versions` -> `unstable_features` to detect server support. ([\#11582](https://github.com/matrix-org/synapse/issues/11582))
- Add type hints to `synapse/tests/rest/admin`. ([\#11590](https://github.com/matrix-org/synapse/issues/11590))
- Drop end-of-life Python 3.6 and Postgres 9.6 from CI. ([\#11595](https://github.com/matrix-org/synapse/issues/11595))
- Update black version and run it on all the files. ([\#11596](https://github.com/matrix-org/synapse/issues/11596))
- Add opentracing type stubs and fix associated mypy errors. ([\#11603](https://github.com/matrix-org/synapse/issues/11603), [\#11622](https://github.com/matrix-org/synapse/issues/11622))
- Update the `/capabilities` response to include whether support for [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440) is available. ([\#11690](https://github.com/matrix-org/synapse/issues/11690))
- Work around Mjolnir compatibility issue by adding an import for `glob_to_regex` in `synapse.util`, where it moved from. ([\#11696](https://github.com/matrix-org/synapse/issues/11696))
This release fixes a regression introduced in Synapse 1.49.0 which could cause `/sync` requests to take significantly longer. This would particularly affect "initial" syncs for users participating in a large number of rooms, and in extreme cases, could make it impossible for such users to log in on a new client.
**Note:** in line with our [deprecation policy](https://matrix-org.github.io/synapse/latest/deprecation_policy.html) for platform dependencies, this will be the last release to support Python 3.6 and PostgreSQL 9.6, both of which have now reached upstream end-of-life. Synapse will require Python 3.7+ and PostgreSQL 10+.
- Add [MSC3030](https://github.com/matrix-org/matrix-doc/pull/3030) experimental client and federation API endpoints to get the closest event to a given timestamp. ([\#9445](https://github.com/matrix-org/synapse/issues/9445))
- Include bundled relation aggregations during a limited `/sync` request and `/relations` request, per [MSC2675](https://github.com/matrix-org/matrix-doc/pull/2675). ([\#11284](https://github.com/matrix-org/synapse/issues/11284), [\#11478](https://github.com/matrix-org/synapse/issues/11478))
- Add plugin support for controlling database background updates. ([\#11306](https://github.com/matrix-org/synapse/issues/11306), [\#11475](https://github.com/matrix-org/synapse/issues/11475), [\#11479](https://github.com/matrix-org/synapse/issues/11479))
- Support the stable API endpoints for [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946): the room `/hierarchy` endpoint. ([\#11329](https://github.com/matrix-org/synapse/issues/11329))
- Add admin API to get some information about federation status with remote servers. ([\#11407](https://github.com/matrix-org/synapse/issues/11407))
- Support expiry of refresh tokens and expiry of the overall session when refresh tokens are in use. ([\#11425](https://github.com/matrix-org/synapse/issues/11425))
- Stabilise support for [MSC2918](https://github.com/matrix-org/matrix-doc/blob/main/proposals/2918-refreshtokens.md#msc2918-refresh-tokens) refresh tokens as they have now been merged into the Matrix specification. ([\#11435](https://github.com/matrix-org/synapse/issues/11435), [\#11522](https://github.com/matrix-org/synapse/issues/11522))
- Update [MSC2918 refresh token](https://github.com/matrix-org/matrix-doc/blob/main/proposals/2918-refreshtokens.md#msc2918-refresh-tokens) support to confirm with the latest revision: accept the `refresh_tokens` parameter in the request body rather than in the URL parameters. ([\#11430](https://github.com/matrix-org/synapse/issues/11430))
- Support configuring the lifetime of non-refreshable access tokens separately to refreshable access tokens. ([\#11445](https://github.com/matrix-org/synapse/issues/11445))
- Expose `synapse_homeserver` and `synapse_worker` commands as entry points to run Synapse's main process and worker processes, respectively. Contributed by @Ma27. ([\#11449](https://github.com/matrix-org/synapse/issues/11449))
-`synctl stop` will now wait for Synapse to exit before returning. ([\#11459](https://github.com/matrix-org/synapse/issues/11459), [\#11490](https://github.com/matrix-org/synapse/issues/11490))
- Extend the "delete room" admin api to work correctly on rooms which have previously been partially deleted. ([\#11523](https://github.com/matrix-org/synapse/issues/11523))
- Add support for the `/_matrix/client/v3/login/sso/redirect/{idpId}` API from Matrix v1.1. This endpoint was overlooked when support for v3 endpoints was added in Synapse 1.48.0rc1. ([\#11451](https://github.com/matrix-org/synapse/issues/11451))
- Fix using [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) batch sending in combination with event persistence workers. Contributed by @tulir at Beeper. ([\#11220](https://github.com/matrix-org/synapse/issues/11220))
- Fix a long-standing bug where all requests that read events from the database could get stuck as a result of losing the database connection, properly this time. Also fix a race condition introduced in the previous insufficient fix in Synapse 1.47.0. ([\#11376](https://github.com/matrix-org/synapse/issues/11376))
- The `/send_join` response now includes the stable `event` field instead of the unstable field from [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083). ([\#11413](https://github.com/matrix-org/synapse/issues/11413))
- Fix a bug introduced in Synapse 1.47.0 where `send_join` could fail due to an outdated `ijson` version. ([\#11439](https://github.com/matrix-org/synapse/issues/11439), [\#11441](https://github.com/matrix-org/synapse/issues/11441), [\#11460](https://github.com/matrix-org/synapse/issues/11460))
- Fix a bug introduced in Synapse 1.36.0 which could cause problems fetching event-signing keys from trusted key servers. ([\#11440](https://github.com/matrix-org/synapse/issues/11440))
- Fix a bug introduced in Synapse 1.47.1 where the media repository would fail to work if the media store path contained any symbolic links. ([\#11446](https://github.com/matrix-org/synapse/issues/11446))
- Fix an `LruCache` corruption bug, introduced in Synapse 1.38.0, that would cause certain requests to fail until the next Synapse restart. ([\#11454](https://github.com/matrix-org/synapse/issues/11454))
- Fix a long-standing bug where invites from ignored users were included in incremental syncs. ([\#11511](https://github.com/matrix-org/synapse/issues/11511))
- Fix a regression in Synapse 1.48.0 where presence workers would not clear their presence updates over replication on shutdown. ([\#11518](https://github.com/matrix-org/synapse/issues/11518))
- Fix a regression in Synapse 1.48.0 where the module API's `looping_background_call` method would spam errors to the logs when given a non-async function. ([\#11524](https://github.com/matrix-org/synapse/issues/11524))
- Update the media repository documentation. ([\#11415](https://github.com/matrix-org/synapse/issues/11415))
- Update section about backward extremities in the room DAG concepts doc to correct the misconception about backward extremities indicating whether we have fetched an events' `prev_events`. ([\#11469](https://github.com/matrix-org/synapse/issues/11469))
Internal Changes
----------------
- Add `Final` annotation to string constants in `synapse.api.constants` so that they get typed as `Literal`s. ([\#11356](https://github.com/matrix-org/synapse/issues/11356))
- Add a check to ensure that users cannot start the Synapse master process when `worker_app` is set. ([\#11416](https://github.com/matrix-org/synapse/issues/11416))
- Add a note about postgres memory management and hugepages to postgres doc. ([\#11467](https://github.com/matrix-org/synapse/issues/11467))
- Add missing type hints to `synapse.federation`. ([\#11483](https://github.com/matrix-org/synapse/issues/11483))
- Add type annotations to `tests.storage.test_appservice`. ([\#11488](https://github.com/matrix-org/synapse/issues/11488), [\#11492](https://github.com/matrix-org/synapse/issues/11492))
- Convert status codes to `HTTPStatus` in `synapse.rest.admin`. ([\#11452](https://github.com/matrix-org/synapse/issues/11452), [\#11455](https://github.com/matrix-org/synapse/issues/11455))
- Extend the `scripts-dev/sign_json` script to support signing events. ([\#11486](https://github.com/matrix-org/synapse/issues/11486))
- Improve internal types in push code. ([\#11409](https://github.com/matrix-org/synapse/issues/11409))
- Improve type annotations in `synapse.module_api`. ([\#11029](https://github.com/matrix-org/synapse/issues/11029))
- Improve type hints for `LruCache`. ([\#11453](https://github.com/matrix-org/synapse/issues/11453))
- Refactor `backfilled` into specific behavior function arguments (`_persist_events_and_state_updates` and downstream calls). ([\#11417](https://github.com/matrix-org/synapse/issues/11417))
- Refactor `get_version_string` to fix-up types and duplicated code. ([\#11468](https://github.com/matrix-org/synapse/issues/11468))
- Refactor various parts of the `/sync` handler. ([\#11494](https://github.com/matrix-org/synapse/issues/11494), [\#11515](https://github.com/matrix-org/synapse/issues/11515))
- Remove unnecessary `json.dumps` from `tests.rest.admin`. ([\#11461](https://github.com/matrix-org/synapse/issues/11461))
- Save the OpenID Connect session ID on login. ([\#11482](https://github.com/matrix-org/synapse/issues/11482))
- Update and clean up recently ported documentation pages. ([\#11466](https://github.com/matrix-org/synapse/issues/11466))
- Experimental support for the thread relation defined in [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440). ([\#11161](https://github.com/matrix-org/synapse/issues/11161))
- Support filtering by relation senders & types per [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440). ([\#11236](https://github.com/matrix-org/synapse/issues/11236))
- Add support for the `/_matrix/client/v3` and `/_matrix/media/v3` APIs from Matrix v1.1. ([\#11318](https://github.com/matrix-org/synapse/issues/11318), [\#11371](https://github.com/matrix-org/synapse/issues/11371))
- Support the stable version of [MSC2778](https://github.com/matrix-org/matrix-doc/pull/2778): the `m.login.application_service` login type. Contributed by @tulir. ([\#11335](https://github.com/matrix-org/synapse/issues/11335))
- Add a new version of delete room admin API `DELETE /_synapse/admin/v2/rooms/<room_id>` to run it in the background. Contributed by @dklimpel. ([\#11223](https://github.com/matrix-org/synapse/issues/11223))
- Allow the admin [Delete Room API](https://matrix-org.github.io/synapse/latest/admin_api/rooms.html#delete-room-api) to block a room without the need to join it. ([\#11228](https://github.com/matrix-org/synapse/issues/11228))
- Add an admin API to un-shadow-ban a user. ([\#11347](https://github.com/matrix-org/synapse/issues/11347))
- Add an admin API to run background database schema updates. ([\#11352](https://github.com/matrix-org/synapse/issues/11352))
- Add an admin API for blocking a room. ([\#11324](https://github.com/matrix-org/synapse/issues/11324))
- Fix a long-standing bug wherein display names or avatar URLs containing null bytes cause an internal server error when stored in the DB. ([\#11230](https://github.com/matrix-org/synapse/issues/11230))
- Prevent [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) historical state events from being pushed to an application service via `/transactions`. ([\#11265](https://github.com/matrix-org/synapse/issues/11265))
- Fix a long-standing bug where uploading extremely thin images (e.g. 1000x1) would fail. Contributed by @Neeeflix. ([\#11288](https://github.com/matrix-org/synapse/issues/11288))
- Fix a bug, introduced in Synapse 1.46.0, which caused the `check_3pid_auth` and `on_logged_out` callbacks in legacy password authentication provider modules to not be registered. Modules using the generic module interface were not affected. ([\#11340](https://github.com/matrix-org/synapse/issues/11340))
- Fix a bug introduced in 1.41.0 where space hierarchy responses would be incorrectly reused if multiple users were to make the same request at the same time. ([\#11355](https://github.com/matrix-org/synapse/issues/11355))
- Fix a bug introduced in 1.45.0 where the `read_templates` method of the module API would error. ([\#11377](https://github.com/matrix-org/synapse/issues/11377))
- Fix an issue introduced in 1.47.0 which prevented servers re-joining rooms they had previously left, if their signing keys were replaced. ([\#11379](https://github.com/matrix-org/synapse/issues/11379))
- Fix a bug introduced in 1.13.0 where creating and publishing a room could cause errors if `room_list_publication_rules` is configured. ([\#11392](https://github.com/matrix-org/synapse/issues/11392))
- Improve performance of various background database updates. ([\#11421](https://github.com/matrix-org/synapse/issues/11421), [\#11422](https://github.com/matrix-org/synapse/issues/11422))
- Suggest users of the Debian packages add configuration to `/etc/matrix-synapse/conf.d/` to prevent, upon upgrade, being asked to choose between their configuration and the maintainer's. ([\#11281](https://github.com/matrix-org/synapse/issues/11281))
- Fix typos in the documentation for the `username_available` admin API. Contributed by Stanislav Motylkov. ([\#11286](https://github.com/matrix-org/synapse/issues/11286))
- Fix missing quotes for wildcard domains in `federation_certificate_verification_whitelist`. ([\#11381](https://github.com/matrix-org/synapse/issues/11381))
- Add type annotations to `synapse.metrics`. ([\#10847](https://github.com/matrix-org/synapse/issues/10847))
- Split out federated PDU retrieval function into a non-cached version. ([\#11242](https://github.com/matrix-org/synapse/issues/11242))
- Clean up code relating to to-device messages and sending ephemeral events to application services. ([\#11247](https://github.com/matrix-org/synapse/issues/11247))
- Fix a small typo in the error response when a relation type other than 'm.annotation' is passed to `GET /rooms/{room_id}/aggregations/{event_id}`. ([\#11278](https://github.com/matrix-org/synapse/issues/11278))
- Require all files in synapse/ and tests/ to pass mypy unless specifically excluded. ([\#11282](https://github.com/matrix-org/synapse/issues/11282), [\#11285](https://github.com/matrix-org/synapse/issues/11285), [\#11359](https://github.com/matrix-org/synapse/issues/11359))
- Add missing type hints to `synapse.app`. ([\#11287](https://github.com/matrix-org/synapse/issues/11287))
- Remove unused parameters on `FederationEventHandler._check_event_auth`. ([\#11292](https://github.com/matrix-org/synapse/issues/11292))
- Add type hints to `synapse._scripts`. ([\#11297](https://github.com/matrix-org/synapse/issues/11297))
- Fix an issue which prevented the `remove_deleted_devices_from_device_inbox` background database schema update from running when updating from a recent Synapse version. ([\#11303](https://github.com/matrix-org/synapse/issues/11303))
- Add type hints to storage classes. ([\#11307](https://github.com/matrix-org/synapse/issues/11307), [\#11310](https://github.com/matrix-org/synapse/issues/11310), [\#11311](https://github.com/matrix-org/synapse/issues/11311), [\#11312](https://github.com/matrix-org/synapse/issues/11312), [\#11313](https://github.com/matrix-org/synapse/issues/11313), [\#11314](https://github.com/matrix-org/synapse/issues/11314), [\#11316](https://github.com/matrix-org/synapse/issues/11316), [\#11322](https://github.com/matrix-org/synapse/issues/11322), [\#11332](https://github.com/matrix-org/synapse/issues/11332), [\#11339](https://github.com/matrix-org/synapse/issues/11339), [\#11342](https://github.com/matrix-org/synapse/issues/11342))
- Add type hints to `synapse.util`. ([\#11321](https://github.com/matrix-org/synapse/issues/11321), [\#11328](https://github.com/matrix-org/synapse/issues/11328))
- Improve type annotations in Synapse's test suite. ([\#11323](https://github.com/matrix-org/synapse/issues/11323), [\#11330](https://github.com/matrix-org/synapse/issues/11330))
- Test that room alias deletion works as intended. ([\#11327](https://github.com/matrix-org/synapse/issues/11327))
- Add type annotations for some methods and properties in the module API. ([\#11341](https://github.com/matrix-org/synapse/issues/11341))
- Fix running `scripts-dev/complement.sh`, which was broken in v1.47.0rc1. ([\#11368](https://github.com/matrix-org/synapse/issues/11368))
- Rename internal functions for token generation to better reflect what they do. ([\#11369](https://github.com/matrix-org/synapse/issues/11369), [\#11370](https://github.com/matrix-org/synapse/issues/11370))
- Keep fallback key marked as used if it's re-uploaded. ([\#11382](https://github.com/matrix-org/synapse/issues/11382))
- Use `auto_attribs` on the `attrs` class `RefreshTokenLookupResult`. ([\#11386](https://github.com/matrix-org/synapse/issues/11386))
- Rename unstable `access_token_lifetime` configuration option to `refreshable_access_token_lifetime` to make it clear it only concerns refreshable access tokens. ([\#11388](https://github.com/matrix-org/synapse/issues/11388))
- Do not run the broken MSC2716 tests when running `scripts-dev/complement.sh`. ([\#11389](https://github.com/matrix-org/synapse/issues/11389))
- Remove dead code from supporting ACME. ([\#11393](https://github.com/matrix-org/synapse/issues/11393))
- Refactor including the bundled relations when serializing an event. ([\#11408](https://github.com/matrix-org/synapse/issues/11408))
This release fixes a security issue in the media store, affecting all prior releases of Synapse. Server administrators are encouraged to update Synapse as soon as possible. We are not aware of these vulnerabilities being exploited in the wild.
Server administrators who are unable to update Synapse may use the workarounds described in the linked GitHub Security Advisory below.
Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory, potentially outside the media store directory.
The last two directories and file name of the path are chosen randomly by Synapse and cannot be controlled by an attacker, which limits the impact.
Homeservers with the media repository disabled are unaffected. Homeservers configured with a federation whitelist are also unaffected.
Fixed by [91f2bd090](https://github.com/matrix-org/synapse/commit/91f2bd090).
- Fix a bug introduced in 1.47.0rc1 which caused worker processes to not halt startup in the presence of outstanding database migrations. ([\#11346](https://github.com/matrix-org/synapse/issues/11346))
- Fix a bug introduced in 1.47.0rc1 which prevented the 'remove deleted devices from `device_inbox` column' background process from running when updating from a recent Synapse version. ([\#11303](https://github.com/matrix-org/synapse/issues/11303), [\#11353](https://github.com/matrix-org/synapse/issues/11353))
- The `user_may_create_room_with_invites` module callback is now deprecated. Please refer to the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#upgrading-to-v1470) for more information. ([\#11206](https://github.com/matrix-org/synapse/issues/11206))
- Remove deprecated admin API to delete rooms (`POST /_synapse/admin/v1/rooms/<room_id>/delete`). ([\#11213](https://github.com/matrix-org/synapse/issues/11213))
- Add an `on_new_event` third-party rules callback to allow Synapse modules to act after an event has been sent into a room. ([\#11126](https://github.com/matrix-org/synapse/issues/11126))
- Add a module API method to update a user's membership in a room. ([\#11147](https://github.com/matrix-org/synapse/issues/11147))
- Add metrics for thread pool usage. ([\#11178](https://github.com/matrix-org/synapse/issues/11178))
- Support the stable room type field for [MSC3288](https://github.com/matrix-org/matrix-doc/pull/3288). ([\#11187](https://github.com/matrix-org/synapse/issues/11187))
- Add a module API method to retrieve the current state of a room. ([\#11204](https://github.com/matrix-org/synapse/issues/11204))
- Calculate a default value for `public_baseurl` based on `server_name`. ([\#11210](https://github.com/matrix-org/synapse/issues/11210))
- Add support for serving `/.well-known/matrix/server` files, to redirect federation traffic to port 443. ([\#11211](https://github.com/matrix-org/synapse/issues/11211))
- Fix a long-standing bug which allowed hidden devices to receive to-device messages, resulting in unnecessary database bloat. ([\#10097](https://github.com/matrix-org/synapse/issues/10097))
- Fix a long-standing bug where messages in the `device_inbox` table for deleted devices would persist indefinitely. Contributed by @dklimpel and @JohannesKleine. ([\#10969](https://github.com/matrix-org/synapse/issues/10969), [\#11212](https://github.com/matrix-org/synapse/issues/11212))
- Do not accept events if a third-party rule `check_event_allowed` callback raises an exception. ([\#11033](https://github.com/matrix-org/synapse/issues/11033))
- Fix long-standing bug where verification requests could fail in certain cases if a federation whitelist was in place but did not include your own homeserver. ([\#11129](https://github.com/matrix-org/synapse/issues/11129))
- Allow an empty list of `state_events_at_start` to be sent when using the [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint and the author of the historical messages is already part of the current room state at the given `?prev_event_id`. ([\#11188](https://github.com/matrix-org/synapse/issues/11188))
- Fix a bug introduced in Synapse 1.45.0 which prevented the `synapse_review_recent_signups` script from running. Contributed by @samuel-p. ([\#11191](https://github.com/matrix-org/synapse/issues/11191))
- Delete `to_device` messages for hidden devices that will never be read, reducing database size. ([\#11199](https://github.com/matrix-org/synapse/issues/11199))
- Fix a long-standing bug wherein a missing `Content-Type` header when downloading remote media would cause Synapse to throw an error. ([\#11200](https://github.com/matrix-org/synapse/issues/11200))
- Fix a long-standing bug which could result in serialization errors and potentially duplicate transaction data when sending ephemeral events to application services. Contributed by @Fizzadar at Beeper. ([\#11207](https://github.com/matrix-org/synapse/issues/11207))
- Fix a bug introduced in Synapse 1.35.0 which made it impossible to join rooms that return a `send_join` response containing floats. ([\#11217](https://github.com/matrix-org/synapse/issues/11217))
- Fix long-standing bug where cross signing keys were not included in the response to `/r0/keys/query` the first time a remote user was queried. ([\#11234](https://github.com/matrix-org/synapse/issues/11234))
- Fix a long-standing bug where all requests that read events from the database could get stuck as a result of losing the database connection. ([\#11240](https://github.com/matrix-org/synapse/issues/11240))
- Fix a bug preventing Synapse from being rolled back to an earlier version when using workers. ([\#11255](https://github.com/matrix-org/synapse/issues/11255), [\#11276](https://github.com/matrix-org/synapse/issues/11276))
- Fix a bug introduced in Synapse 1.37.1 which caused a remote event being processed by a worker to not get processed on restart if the worker was killed. ([\#11262](https://github.com/matrix-org/synapse/issues/11262))
- Only allow old Element/Riot Android clients to send read receipts without a request body. All other clients must include a request body as required by the specification. Contributed by @rogersheu. ([\#11157](https://github.com/matrix-org/synapse/issues/11157))
- Avoid changing user ID when started as a non-root user, and no explicit `UID` is set. ([\#11209](https://github.com/matrix-org/synapse/issues/11209))
- Improve example HAProxy config in the docs to properly handle HTTP `Host` headers with port information. This is required for federation over port 443 to work correctly. ([\#11128](https://github.com/matrix-org/synapse/issues/11128))
- Add documentation for using Authentik as an OpenID Connect Identity Provider. Contributed by @samip5. ([\#11151](https://github.com/matrix-org/synapse/issues/11151))
- Clarify lack of support for Windows. ([\#11198](https://github.com/matrix-org/synapse/issues/11198))
- Improve code formatting and fix a few typos in docs. Contributed by @sumnerevans at Beeper. ([\#11221](https://github.com/matrix-org/synapse/issues/11221))
- Add documentation for using LemonLDAP as an OpenID Connect Identity Provider. Contributed by @l00ptr. ([\#11257](https://github.com/matrix-org/synapse/issues/11257))
Internal Changes
----------------
- Add type annotations for the `log_function` decorator. ([\#10943](https://github.com/matrix-org/synapse/issues/10943))
- Add type hints to `synapse.events`. ([\#11098](https://github.com/matrix-org/synapse/issues/11098))
- Remove and document unnecessary `RoomStreamToken` checks in application service ephemeral event code. ([\#11137](https://github.com/matrix-org/synapse/issues/11137))
- Add type hints so that `synapse.http` passes `mypy` checks. ([\#11164](https://github.com/matrix-org/synapse/issues/11164))
- Update scripts to pass Shellcheck lints. ([\#11166](https://github.com/matrix-org/synapse/issues/11166))
- Add knock information in admin export. Contributed by Rafael Gonçalves. ([\#11171](https://github.com/matrix-org/synapse/issues/11171))
- Add tests to check that `ClientIpStore.get_last_client_ip_by_device` and `get_user_ip_and_agents` combine database and in-memory data correctly. ([\#11179](https://github.com/matrix-org/synapse/issues/11179))
- Refactor `Filter` to check different fields depending on the data type. ([\#11194](https://github.com/matrix-org/synapse/issues/11194))
- Improve type hints for the relations datastore. ([\#11205](https://github.com/matrix-org/synapse/issues/11205))
- Replace outdated links in the pull request checklist with links to the rendered documentation. ([\#11225](https://github.com/matrix-org/synapse/issues/11225))
- Fix a bug in unit test `test_block_room_and_not_purge`. ([\#11226](https://github.com/matrix-org/synapse/issues/11226))
- Minor speed up to start up times and getting updates for groups by adding missing index to `local_group_updates.stream_id`. ([\#11231](https://github.com/matrix-org/synapse/issues/11231))
- Add `twine` and `towncrier` as dev dependencies, as they're used by the release script. ([\#11233](https://github.com/matrix-org/synapse/issues/11233))
- Allow `stream_writers.typing` config to be a list of one worker. ([\#11237](https://github.com/matrix-org/synapse/issues/11237))
- Remove debugging statement in tests. ([\#11239](https://github.com/matrix-org/synapse/issues/11239))
- Fix [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) historical messages backfilling in random order on remote homeservers. ([\#11244](https://github.com/matrix-org/synapse/issues/11244))
- Add an additional test for the `cachedList` method decorator. ([\#11246](https://github.com/matrix-org/synapse/issues/11246))
- Make minor correction to the type of `auth_checkers` callbacks. ([\#11253](https://github.com/matrix-org/synapse/issues/11253))
- Clean up trivial aspects of the Debian package build tooling. ([\#11269](https://github.com/matrix-org/synapse/issues/11269), [\#11273](https://github.com/matrix-org/synapse/issues/11273))
- Blacklist new SyTest that checks that key uploads are valid pending the validation being implemented in Synapse. ([\#11270](https://github.com/matrix-org/synapse/issues/11270))
The cause of the [performance regression affecting Synapse 1.44](https://github.com/matrix-org/synapse/issues/11049) has been identified and fixed. ([\#11177](https://github.com/matrix-org/synapse/issues/11177))
- Fix a bug introduced in v1.46.0rc1 where URL previews of some XML documents would fail. ([\#11196](https://github.com/matrix-org/synapse/issues/11196))
- Port the Password Auth Providers module interface to the new generic interface. ([\#10548](https://github.com/matrix-org/synapse/issues/10548), [\#11180](https://github.com/matrix-org/synapse/issues/11180))
- Experimental support for the thread relation defined in [MSC3440](https://github.com/matrix-org/matrix-doc/pull/3440). ([\#11088](https://github.com/matrix-org/synapse/issues/11088), [\#11181](https://github.com/matrix-org/synapse/issues/11181), [\#11192](https://github.com/matrix-org/synapse/issues/11192))
- Users admin API can now also modify user type in addition to allowing it to be set on user creation. ([\#11174](https://github.com/matrix-org/synapse/issues/11174))
Bugfixes
--------
- Newly-created public rooms are now only assigned an alias if the room's creation has not been blocked by permission settings. Contributed by @AndrewFerr. ([\#10930](https://github.com/matrix-org/synapse/issues/10930))
- Fix a long-standing bug which meant that events received over federation were sometimes incorrectly accepted into the room state. ([\#11001](https://github.com/matrix-org/synapse/issues/11001), [\#11009](https://github.com/matrix-org/synapse/issues/11009), [\#11012](https://github.com/matrix-org/synapse/issues/11012))
- Fix 500 error on `/messages` when the server accumulates more than 5 backwards extremities at a given depth for a room. ([\#11027](https://github.com/matrix-org/synapse/issues/11027))
- Fix a bug where setting a user's `external_id` via the admin API returns 500 and deletes user's existing external mappings if that external ID is already mapped. ([\#11051](https://github.com/matrix-org/synapse/issues/11051))
- Fix a long-standing bug where users excluded from the user directory were added into the directory if they belonged to a room which became public or private. ([\#11075](https://github.com/matrix-org/synapse/issues/11075))
- Fix a long-standing bug when attempting to preview URLs which are in the `windows-1252` character encoding. ([\#11077](https://github.com/matrix-org/synapse/issues/11077), [\#11089](https://github.com/matrix-org/synapse/issues/11089))
- Fix broken export-data admin command and add test script checking the command to CI. ([\#11078](https://github.com/matrix-org/synapse/issues/11078))
- Show an error when timestamp in seconds is provided to the `/purge_media_cache` Admin API. ([\#11101](https://github.com/matrix-org/synapse/issues/11101))
- Fix local users who left all their rooms being removed from the user directory, even if the `search_all_users` config option was enabled. ([\#11103](https://github.com/matrix-org/synapse/issues/11103))
- Fix a bug which caused the module API's `get_user_ip_and_agents` function to always fail on workers. `get_user_ip_and_agents` was introduced in 1.44.0 and did not function correctly on worker processes at the time. ([\#11112](https://github.com/matrix-org/synapse/issues/11112))
- Identity server connection is no longer ignoring `ip_range_whitelist`. ([\#11120](https://github.com/matrix-org/synapse/issues/11120))
- Fix a bug introduced in Synapse 1.45.0 breaking the configuration file parsing script. ([\#11145](https://github.com/matrix-org/synapse/issues/11145))
- Fix a performance regression introduced in 1.44.0 which could cause client requests to time out when making large numbers of outbound requests. ([\#11177](https://github.com/matrix-org/synapse/issues/11177), [\#11190](https://github.com/matrix-org/synapse/issues/11190))
- Resolve and share `state_groups` for all [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) historical events in batch. ([\#10975](https://github.com/matrix-org/synapse/issues/10975))
- Fix broken links relating to module API deprecation in the upgrade notes. ([\#11069](https://github.com/matrix-org/synapse/issues/11069))
- Add more information about what happens when a user is deactivated. ([\#11083](https://github.com/matrix-org/synapse/issues/11083))
- Clarify the the sample log config can be copied from the documentation without issue. ([\#11092](https://github.com/matrix-org/synapse/issues/11092))
- Update the admin API documentation with an updated list of the characters allowed in registration tokens. ([\#11093](https://github.com/matrix-org/synapse/issues/11093))
- Document Synapse's behaviour when dealing with multiple modules registering the same callbacks and/or handlers for the same HTTP endpoints. ([\#11096](https://github.com/matrix-org/synapse/issues/11096))
- Fix instances of `[example]{.title-ref}` in the upgrade documentation as a result of prior RST to Markdown conversion. ([\#11118](https://github.com/matrix-org/synapse/issues/11118))
- Document the version of Synapse each module callback was introduced in. ([\#11132](https://github.com/matrix-org/synapse/issues/11132))
- Document the version of Synapse that introduced each module API method. ([\#11183](https://github.com/matrix-org/synapse/issues/11183))
Internal Changes
----------------
- Fix spurious warnings about losing the logging context on the `ReplicationCommandHandler` when losing the replication connection. ([\#10984](https://github.com/matrix-org/synapse/issues/10984))
- Include rejected status when we log events. ([\#11008](https://github.com/matrix-org/synapse/issues/11008))
- Add some extra logging to the event persistence code. ([\#11014](https://github.com/matrix-org/synapse/issues/11014))
- Rearrange the internal workings of the incremental user directory updates. ([\#11035](https://github.com/matrix-org/synapse/issues/11035))
- Fix a long-standing bug where users excluded from the directory could still be added to the `users_who_share_private_rooms` table after a regular user joins a private room. ([\#11143](https://github.com/matrix-org/synapse/issues/11143))
- Add and improve type hints. ([\#10972](https://github.com/matrix-org/synapse/issues/10972), [\#11055](https://github.com/matrix-org/synapse/issues/11055), [\#11066](https://github.com/matrix-org/synapse/issues/11066), [\#11076](https://github.com/matrix-org/synapse/issues/11076), [\#11095](https://github.com/matrix-org/synapse/issues/11095), [\#11109](https://github.com/matrix-org/synapse/issues/11109), [\#11121](https://github.com/matrix-org/synapse/issues/11121), [\#11146](https://github.com/matrix-org/synapse/issues/11146))
- Mark the Synapse package as containing type annotations and fix export declarations so that Synapse pluggable modules may be type checked against Synapse. ([\#11054](https://github.com/matrix-org/synapse/issues/11054))
- Remove dead code from `MediaFilePaths`. ([\#11056](https://github.com/matrix-org/synapse/issues/11056))
- Be more lenient when parsing oEmbed response versions. ([\#11065](https://github.com/matrix-org/synapse/issues/11065))
- Create a separate module for the retention configuration. ([\#11070](https://github.com/matrix-org/synapse/issues/11070))
- Clean up some of the federation event authentication code for clarity. ([\#11115](https://github.com/matrix-org/synapse/issues/11115), [\#11116](https://github.com/matrix-org/synapse/issues/11116), [\#11122](https://github.com/matrix-org/synapse/issues/11122))
- Add docstrings and comments to the application service ephemeral event sending code. ([\#11138](https://github.com/matrix-org/synapse/issues/11138))
- Update the `sign_json` script to support inline configuration of the signing key. ([\#11139](https://github.com/matrix-org/synapse/issues/11139))
- Fix broken link in the docker image README. ([\#11144](https://github.com/matrix-org/synapse/issues/11144))
- Always dump logs from unit tests during CI runs. ([\#11068](https://github.com/matrix-org/synapse/issues/11068))
- Add tests for `MediaFilePaths` class. ([\#11057](https://github.com/matrix-org/synapse/issues/11057))
- Simplify the user admin API tests. ([\#11048](https://github.com/matrix-org/synapse/issues/11048))
- Add a test for the workaround introduced in [\#11042](https://github.com/matrix-org/synapse/pull/11042) concerning the behaviour of third-party rule modules and `SynapseError`s. ([\#11071](https://github.com/matrix-org/synapse/issues/11071))
- Revert change to counting of deactivated users towards the monthly active users limit, introduced in 1.45.0rc1. ([\#11127](https://github.com/matrix-org/synapse/issues/11127))
- A suspected [performance regression](https://github.com/matrix-org/synapse/issues/11049) which was first reported after the release of 1.44.0 remains unresolved.
We have not been able to identify a probable cause. Affected users report that setting up a federation sender worker appears to alleviate symptoms of the regression.
- Reword changelog to clarify concerns about a suspected performance regression in 1.44.0. ([\#11117](https://github.com/matrix-org/synapse/issues/11117))
This release candidate [fixes](https://github.com/matrix-org/synapse/issues/11053) a user directory [bug](https://github.com/matrix-org/synapse/issues/11025) present in 1.45.0rc1.
- A suspected [performance regression](https://github.com/matrix-org/synapse/issues/11049) which was first reported after the release of 1.44.0 remains unresolved.
We have not been able to identify a probable cause. Affected users report that setting up a federation sender worker appears to alleviate symptoms of the regression.
- Fix a long-standing bug when using multiple event persister workers where events were not correctly sent down `/sync` due to a race. ([\#11045](https://github.com/matrix-org/synapse/issues/11045))
- Fix a bug introduced in Synapse 1.45.0rc1 where the user directory would stop updating if it processed an event from a
user not in the `users` table. ([\#11053](https://github.com/matrix-org/synapse/issues/11053))
- Add an 'approximate difference' method to `StateFilter`. ([\#10825](https://github.com/matrix-org/synapse/issues/10825))
- Fix inconsistent behavior of `get_last_client_by_ip` when reporting data that has not been stored in the database yet. ([\#10970](https://github.com/matrix-org/synapse/issues/10970))
- Fix a bug introduced in Synapse 1.21.0 that causes opentracing and Prometheus metrics for replication requests to be measured incorrectly. ([\#10996](https://github.com/matrix-org/synapse/issues/10996))
- Ensure that cache config tests do not share state. ([\#11036](https://github.com/matrix-org/synapse/issues/11036))
**Note:** Media storage providers module that read from Synapse's configuration need changes as of this version, see the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#upgrading-to-v1450) for more information.
- We are aware of [a bug](https://github.com/matrix-org/synapse/issues/11025) with the user directory when using application services. A second release candidate is expected which will resolve this.
- Add [MSC3069](https://github.com/matrix-org/matrix-doc/pull/3069) support to `/account/whoami`. ([\#9655](https://github.com/matrix-org/synapse/issues/9655))
- Support autodiscovery of oEmbed previews. ([\#10822](https://github.com/matrix-org/synapse/issues/10822))
- Add a `user_may_send_3pid_invite` spam checker callback for modules to allow or deny 3PID invites. ([\#10894](https://github.com/matrix-org/synapse/issues/10894))
- Add a spam checker callback to allow or deny room joins. ([\#10910](https://github.com/matrix-org/synapse/issues/10910))
- Include an `update_synapse_database` script in the distribution. Contributed by @Fizzadar at Beeper. ([\#10954](https://github.com/matrix-org/synapse/issues/10954))
- Include exception information in JSON logging output. Contributed by @Fizzadar at Beeper. ([\#11028](https://github.com/matrix-org/synapse/issues/11028))
Bugfixes
--------
- Fix a minor bug in the response to `/_matrix/client/r0/voip/turnServer`. Contributed by @lukaslihotzki. ([\#10922](https://github.com/matrix-org/synapse/issues/10922))
- Fix a bug where empty `yyyy-mm-dd/` directories would be left behind in the media store's `url_cache_thumbnails/` directory. ([\#10924](https://github.com/matrix-org/synapse/issues/10924))
- Fix a bug introduced in Synapse v1.40.0 where the signature checks for room version 8 and 9 could be applied to earlier room versions in some situations. ([\#10927](https://github.com/matrix-org/synapse/issues/10927))
- Fix a long-standing bug wherein deactivated users still count towards the monthly active users limit. ([\#10947](https://github.com/matrix-org/synapse/issues/10947))
- Fix a long-standing bug which meant that events received over federation were sometimes incorrectly accepted into the room state. ([\#10956](https://github.com/matrix-org/synapse/issues/10956))
- Fix a long-standing bug where rebuilding the user directory wouldn't exclude support and deactivated users. ([\#10960](https://github.com/matrix-org/synapse/issues/10960))
- Fix [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint rejecting subsequent batches with unknown batch ID error in existing room versions from the room creator. ([\#10962](https://github.com/matrix-org/synapse/issues/10962))
- Fix a bug that could leak local users' per-room nicknames and avatars when the user directory is rebuilt. ([\#10981](https://github.com/matrix-org/synapse/issues/10981))
- Fix a long-standing bug where the remainder of a batch of user directory changes would be silently dropped if the server left a room early in the batch. ([\#10982](https://github.com/matrix-org/synapse/issues/10982))
- Correct a bugfix introduced in Synapse v1.44.0 that would catch the wrong error if a connection is lost before a response could be written to it. ([\#10995](https://github.com/matrix-org/synapse/issues/10995))
- Fix a long-standing bug where local users' per-room nicknames/avatars were visible to anyone who could see you in the user directory. ([\#11002](https://github.com/matrix-org/synapse/issues/11002))
- Fix a long-standing bug where a user's per-room nickname/avatar would overwrite their profile in the user directory when a room was made public. ([\#11003](https://github.com/matrix-org/synapse/issues/11003))
- Work around a regression, introduced in Synapse v1.39.0, that caused `SynapseError`s raised by the experimental third-party rules module callback `check_event_allowed` to be ignored. ([\#11042](https://github.com/matrix-org/synapse/issues/11042))
- Fix a bug in [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) insertion events in rooms that could cause cross-talk/conflicts between batches. ([\#10877](https://github.com/matrix-org/synapse/issues/10877))
- Change wording ("reference homeserver") in Synapse repository documentation. Contributed by @maxkratz. ([\#10971](https://github.com/matrix-org/synapse/issues/10971))
- Fix a dead URL in development documentation (SAML) and change wording from "Riot" to "Element". Contributed by @maxkratz. ([\#10973](https://github.com/matrix-org/synapse/issues/10973))
- Add additional content to the Welcome and Overview page of the documentation. ([\#10990](https://github.com/matrix-org/synapse/issues/10990))
- Update links to MSCs in documentation. Contributed by @dklimpel. ([\#10991](https://github.com/matrix-org/synapse/issues/10991))
Internal Changes
----------------
- Improve type hinting in `synapse.util`. ([\#10888](https://github.com/matrix-org/synapse/issues/10888))
- Add further type hints to `synapse.storage.util`. ([\#10892](https://github.com/matrix-org/synapse/issues/10892))
- Fix type hints to be compatible with an upcoming change to Twisted. ([\#10895](https://github.com/matrix-org/synapse/issues/10895))
- Update utility code to handle C implementations of frozendict. ([\#10902](https://github.com/matrix-org/synapse/issues/10902))
- Drop old functionality which maintained database compatibility with Synapse versions before v1.31. ([\#10903](https://github.com/matrix-org/synapse/issues/10903))
- Clean-up configuration helper classes for the `ServerConfig` class. ([\#10915](https://github.com/matrix-org/synapse/issues/10915))
- Use direct references to config flags. ([\#10916](https://github.com/matrix-org/synapse/issues/10916), [\#10959](https://github.com/matrix-org/synapse/issues/10959), [\#10985](https://github.com/matrix-org/synapse/issues/10985))
- Clean up some of the federation event authentication code for clarity. ([\#10926](https://github.com/matrix-org/synapse/issues/10926), [\#10940](https://github.com/matrix-org/synapse/issues/10940), [\#10986](https://github.com/matrix-org/synapse/issues/10986), [\#10987](https://github.com/matrix-org/synapse/issues/10987), [\#10988](https://github.com/matrix-org/synapse/issues/10988), [\#11010](https://github.com/matrix-org/synapse/issues/11010), [\#11011](https://github.com/matrix-org/synapse/issues/11011))
- Refactor various parts of the codebase to use `RoomVersion` objects instead of room version identifier strings. ([\#10934](https://github.com/matrix-org/synapse/issues/10934))
- Refactor user directory tests in preparation for upcoming changes. ([\#10935](https://github.com/matrix-org/synapse/issues/10935))
- Include the event id in the logcontext when handling PDUs received over federation. ([\#10936](https://github.com/matrix-org/synapse/issues/10936))
- Fix logged errors in unit tests. ([\#10939](https://github.com/matrix-org/synapse/issues/10939))
- Fix a broken test to ensure that consent configuration works during registration. ([\#10945](https://github.com/matrix-org/synapse/issues/10945))
- Add type hints to filtering classes. ([\#10958](https://github.com/matrix-org/synapse/issues/10958))
- Add type-hint to `HomeserverTestcase.setup_test_homeserver`. ([\#10961](https://github.com/matrix-org/synapse/issues/10961))
- Fix the test utility function `create_room_as` so that `is_public=True` will explicitly set the `visibility` parameter of room creation requests to `public`. Contributed by @AndrewFerr. ([\#10963](https://github.com/matrix-org/synapse/issues/10963))
- Make the release script more robust and transparent. ([\#10966](https://github.com/matrix-org/synapse/issues/10966))
- Refactor [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` mega function into smaller handler functions. ([\#10974](https://github.com/matrix-org/synapse/issues/10974))
- Log stack traces when a missing opentracing span is detected. ([\#10983](https://github.com/matrix-org/synapse/issues/10983))
- Update GHA config to run tests against Python 3.10 and PostgreSQL 14. ([\#10992](https://github.com/matrix-org/synapse/issues/10992))
- Fix a long-standing bug where `ReadWriteLock`s could drop logging contexts on exit. ([\#10993](https://github.com/matrix-org/synapse/issues/10993))
- Add a `CODEOWNERS` file to automatically request reviews from the `@matrix-org/synapse-core` team on new pull requests. ([\#10994](https://github.com/matrix-org/synapse/issues/10994))
- Add further type hints to `synapse.state`. ([\#11004](https://github.com/matrix-org/synapse/issues/11004))
- Remove the deprecated `BaseHandler` object. ([\#11005](https://github.com/matrix-org/synapse/issues/11005))
- Bump mypy version for CI to 0.910, and pull in new type stubs for dependencies. ([\#11006](https://github.com/matrix-org/synapse/issues/11006))
- Fix CI to run the unit tests without optional deps. ([\#11017](https://github.com/matrix-org/synapse/issues/11017))
- Ensure that cache config tests do not share state. ([\#11019](https://github.com/matrix-org/synapse/issues/11019))
- Add additional type hints to `synapse.server_notices`. ([\#11021](https://github.com/matrix-org/synapse/issues/11021))
- Add additional type hints for `synapse.push`. ([\#11023](https://github.com/matrix-org/synapse/issues/11023))
- When installing the optional developer dependencies, also include the dependencies needed for type-checking and unit testing. ([\#11034](https://github.com/matrix-org/synapse/issues/11034))
- Remove unnecessary list comprehension from `synapse_port_db` to satisfy code style requirements. ([\#11043](https://github.com/matrix-org/synapse/issues/11043))
- Fix a bug introduced in Synapse v1.40.0 where changing a user's display name or avatar in a restricted room would cause an authentication error. ([\#10933](https://github.com/matrix-org/synapse/issues/10933))
- Fix `/admin/whois/{user_id}` endpoint, which was broken in v1.44.0rc1. ([\#10968](https://github.com/matrix-org/synapse/issues/10968))
- Fix a bug introduced in v1.44.0rc1 which caused the experimental [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint to return a 500 error. ([\#10938](https://github.com/matrix-org/synapse/issues/10938))
- Fix a bug introduced in v1.44.0rc1 which prevented sending presence events to application services. ([\#10944](https://github.com/matrix-org/synapse/issues/10944))
Improved Documentation
----------------------
- Minor updates to the installation instructions. ([\#10919](https://github.com/matrix-org/synapse/issues/10919))
- Only allow the [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send?chunk_id=xxx` endpoint to connect to an already existing insertion event. ([\#10776](https://github.com/matrix-org/synapse/issues/10776))
- Improve oEmbed URL previews by processing the author name, photo, and video information. ([\#10814](https://github.com/matrix-org/synapse/issues/10814), [\#10819](https://github.com/matrix-org/synapse/issues/10819))
- Speed up responding with large JSON objects to requests. ([\#10868](https://github.com/matrix-org/synapse/issues/10868), [\#10905](https://github.com/matrix-org/synapse/issues/10905))
- Add a `user_may_create_room_with_invites` spam checker callback to allow modules to allow or deny a room creation request based on the invites and/or 3PID invites it includes. ([\#10898](https://github.com/matrix-org/synapse/issues/10898))
Bugfixes
--------
- Fix a long-standing bug that caused an `AssertionError` when purging history in certain rooms. Contributed by @Kokokokoka. ([\#10690](https://github.com/matrix-org/synapse/issues/10690))
- Fix a long-standing bug which caused deactivated users that were later reactivated to be missing from the user directory. ([\#10782](https://github.com/matrix-org/synapse/issues/10782))
- Fix a long-standing bug that caused unbanning a user by sending a membership event to fail. Contributed by @aaronraimist. ([\#10807](https://github.com/matrix-org/synapse/issues/10807))
- Fix a long-standing bug where logging contexts would go missing when federation requests time out. ([\#10810](https://github.com/matrix-org/synapse/issues/10810))
- Fix a long-standing bug causing an error in the deprecated `/initialSync` endpoint when using the undocumented `from` and `to` parameters. ([\#10827](https://github.com/matrix-org/synapse/issues/10827))
- Fix a bug causing the `remove_stale_pushers` background job to repeatedly fail and log errors. This bug affected Synapse servers that had been upgraded from version 1.28 or older and are using SQLite. ([\#10843](https://github.com/matrix-org/synapse/issues/10843))
- Fix a long-standing bug in Unicode support of the room search admin API breaking search for rooms with non-ASCII characters. ([\#10859](https://github.com/matrix-org/synapse/issues/10859))
- Fix a bug introduced in Synapse 1.37.0 which caused `knock` membership events which we sent to remote servers to be incorrectly stored in the local database. ([\#10873](https://github.com/matrix-org/synapse/issues/10873))
- Fix invalidating one-time key count cache after claiming keys. The bug was introduced in Synapse v1.41.0. Contributed by Tulir at Beeper. ([\#10875](https://github.com/matrix-org/synapse/issues/10875))
- Fix a long-standing bug causing application service users to be subject to MAU blocking if the MAU limit had been reached, even if configured not to be blocked. ([\#10881](https://github.com/matrix-org/synapse/issues/10881))
- Fix a long-standing bug which could cause events pulled over federation to be incorrectly rejected. ([\#10907](https://github.com/matrix-org/synapse/issues/10907))
- Fix a long-standing bug causing URL cache files to be stored in storage providers. Server admins may safely delete the `url_cache/` and `url_cache_thumbnails/` directories from any configured storage providers to reclaim space. ([\#10911](https://github.com/matrix-org/synapse/issues/10911))
- Fix a long-standing bug leading to race conditions when creating media store and config directories. ([\#10913](https://github.com/matrix-org/synapse/issues/10913))
- Fix some crashes in the Module API example code, by adding JSON encoding/decoding. ([\#10845](https://github.com/matrix-org/synapse/issues/10845))
- Add developer documentation about experimental configuration flags. ([\#10865](https://github.com/matrix-org/synapse/issues/10865))
- Properly remove deleted files from GitHub pages when generating the documentation. ([\#10869](https://github.com/matrix-org/synapse/issues/10869))
Internal Changes
----------------
- Fix GitHub Actions config so we can run sytest on synapse from parallel branches. ([\#10659](https://github.com/matrix-org/synapse/issues/10659))
- Split out [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) meta events to their own fields in the `/batch_send` response. ([\#10777](https://github.com/matrix-org/synapse/issues/10777))
- Add missing type hints to REST servlets. ([\#10785](https://github.com/matrix-org/synapse/issues/10785), [\#10817](https://github.com/matrix-org/synapse/issues/10817))
- Simplify the internal logic which maintains the user directory database tables. ([\#10796](https://github.com/matrix-org/synapse/issues/10796))
- Use direct references to config flags. ([\#10812](https://github.com/matrix-org/synapse/issues/10812), [\#10885](https://github.com/matrix-org/synapse/issues/10885), [\#10893](https://github.com/matrix-org/synapse/issues/10893), [\#10897](https://github.com/matrix-org/synapse/issues/10897))
- Specify the type of token in generic "Invalid token" error messages. ([\#10815](https://github.com/matrix-org/synapse/issues/10815))
- Make `StateFilter` frozen so it is hashable. ([\#10816](https://github.com/matrix-org/synapse/issues/10816))
- Fix a long-standing bug where an `m.room.message` event containing a null byte would cause an internal server error. ([\#10820](https://github.com/matrix-org/synapse/issues/10820))
- Add type hints to the state database. ([\#10823](https://github.com/matrix-org/synapse/issues/10823))
- Opt out of cache expiry for `get_users_who_share_room_with_user`, to hopefully improve `/sync` performance when you
- Add missing type hints to `synapse.handlers`. ([\#10831](https://github.com/matrix-org/synapse/issues/10831), [\#10856](https://github.com/matrix-org/synapse/issues/10856))
- Extend the Module API to let plug-ins check whether an ID is local and to access IP + User Agent data. ([\#10833](https://github.com/matrix-org/synapse/issues/10833))
- Factor out PNG image data to a constant to be used in several tests. ([\#10834](https://github.com/matrix-org/synapse/issues/10834))
- Add a test to ensure state events sent by modules get persisted correctly. ([\#10835](https://github.com/matrix-org/synapse/issues/10835))
- Rename [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) fields and event types from `chunk` to `batch` to match the `/batch_send` endpoint. ([\#10838](https://github.com/matrix-org/synapse/issues/10838))
- Rename [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` query parameter from `?prev_event` to more obvious usage with `?prev_event_id`. ([\#10839](https://github.com/matrix-org/synapse/issues/10839))
- Add type hints to `synapse.http.site`. ([\#10867](https://github.com/matrix-org/synapse/issues/10867))
- Include outlier status when we log V2 or V3 events. ([\#10879](https://github.com/matrix-org/synapse/issues/10879))
- Break down Grafana's cache expiry time series based on reason for eviction, c.f. [\#10829](https://github.com/matrix-org/synapse/issues/10829). ([\#10880](https://github.com/matrix-org/synapse/issues/10880))
- Clean up some of the federation event authentication code for clarity. ([\#10883](https://github.com/matrix-org/synapse/issues/10883), [\#10884](https://github.com/matrix-org/synapse/issues/10884), [\#10896](https://github.com/matrix-org/synapse/issues/10896), [\#10901](https://github.com/matrix-org/synapse/issues/10901))
- Allow the `.` and `~` characters when creating registration tokens as per the change to [MSC3231](https://github.com/matrix-org/matrix-doc/pull/3231). ([\#10887](https://github.com/matrix-org/synapse/issues/10887))
- Clean up some unnecessary parentheses in places around the codebase. ([\#10889](https://github.com/matrix-org/synapse/issues/10889))
- Improve type hinting in the user directory code. ([\#10891](https://github.com/matrix-org/synapse/issues/10891))
- Update development testing script `test_postgresql.sh` to use a supported Python version and make re-runs quicker. ([\#10906](https://github.com/matrix-org/synapse/issues/10906))
This release drops support for the deprecated, unstable API for [MSC2858 (Multiple SSO Identity Providers)](https://github.com/matrix-org/matrix-doc/blob/master/proposals/2858-Multiple-SSO-Identity-Providers.md#unstable-prefix), as well as the undocumented `experimental.msc2858_enabled` config option. Client authors should update their clients to use the stable API, available since Synapse 1.30.
The documentation has been updated with configuration for routing `/spaces`, `/hierarchy` and `/summary` to workers. See [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.43/docs/upgrade.md#upgrading-to-v1430) for more details.
- Added opentracing logging to help debug [\#9424](https://github.com/matrix-org/synapse/issues/9424). ([\#10828](https://github.com/matrix-org/synapse/issues/10828))
- Allow room creators to send historical events specified by [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) in existing room versions. ([\#10566](https://github.com/matrix-org/synapse/issues/10566))
- Add config option to use non-default manhole password and keys. ([\#10643](https://github.com/matrix-org/synapse/issues/10643))
- Skip final GC at shutdown to improve restart performance. ([\#10712](https://github.com/matrix-org/synapse/issues/10712))
- Allow configuration of the oEmbed URLs used for URL previews. ([\#10714](https://github.com/matrix-org/synapse/issues/10714), [\#10759](https://github.com/matrix-org/synapse/issues/10759))
- Prefer [room version 9](https://github.com/matrix-org/matrix-doc/pull/3375) for restricted rooms per the [room version capabilities](https://github.com/matrix-org/matrix-doc/pull/3244) API. ([\#10772](https://github.com/matrix-org/synapse/issues/10772))
Bugfixes
--------
- Fix a long-standing bug where room avatars were not included in email notifications. ([\#10658](https://github.com/matrix-org/synapse/issues/10658))
- Fix a bug where the ordering algorithm was skipping the `origin_server_ts` step in the spaces summary resulting in unstable room orderings. ([\#10730](https://github.com/matrix-org/synapse/issues/10730))
- Fix edge case when persisting events into a room where there are multiple events we previously hadn't calculated auth chains for (and hadn't marked as needing to be calculated). ([\#10743](https://github.com/matrix-org/synapse/issues/10743))
- Fix a bug which prevented calls to `/createRoom` that included the `room_alias_name` parameter from being handled by worker processes. ([\#10757](https://github.com/matrix-org/synapse/issues/10757))
- Fix a bug which prevented user registration via SSO to require consent tracking for SSO mapping providers that don't prompt for Matrix ID selection. Contributed by @AndrewFerr. ([\#10733](https://github.com/matrix-org/synapse/issues/10733))
- Only return the stripped state events for the `m.space.child` events in a room for the spaces summary from [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#10760](https://github.com/matrix-org/synapse/issues/10760))
- Properly handle room upgrades of spaces. ([\#10774](https://github.com/matrix-org/synapse/issues/10774))
- Fix a bug which generated invalid homeserver config when the `frontend_proxy` worker type was passed to the Synapse Worker-based Complement image. ([\#10783](https://github.com/matrix-org/synapse/issues/10783))
Improved Documentation
----------------------
- Minor fix to the `media_repository` developer documentation. Contributed by @cuttingedge1109. ([\#10556](https://github.com/matrix-org/synapse/issues/10556))
- Update the documentation to note that the `/spaces` and `/hierarchy` endpoints can be routed to workers. ([\#10648](https://github.com/matrix-org/synapse/issues/10648))
- Clarify admin API documentation on undoing room deletions. ([\#10735](https://github.com/matrix-org/synapse/issues/10735))
- Split up the modules documentation and add examples for module developers. ([\#10758](https://github.com/matrix-org/synapse/issues/10758))
- Fix a wording mistake in the sample configuration. Contributed by @bramvdnheuvel:nltrix.net. ([\#10804](https://github.com/matrix-org/synapse/issues/10804))
- Remove the [unstable MSC2858 API](https://github.com/matrix-org/matrix-doc/blob/master/proposals/2858-Multiple-SSO-Identity-Providers.md#unstable-prefix), including the undocumented `experimental.msc2858_enabled` config option. The unstable API has been deprecated since Synapse 1.35. Client authors should update their clients to use the stable API introduced in Synapse 1.30 if they have not already done so. ([\#10693](https://github.com/matrix-org/synapse/issues/10693))
- Add OpenTracing logging to help debug stuck messages (as described by issue [#9424](https://github.com/matrix-org/synapse/issues/9424)). ([\#10704](https://github.com/matrix-org/synapse/issues/10704))
- Add type annotations to the `synapse.util` package. ([\#10601](https://github.com/matrix-org/synapse/issues/10601))
- Ensure `rooms.creator` field is always populated for easy lookup in [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) usage later. ([\#10697](https://github.com/matrix-org/synapse/issues/10697))
- Add missing type hints to REST servlets. ([\#10707](https://github.com/matrix-org/synapse/issues/10707), [\#10728](https://github.com/matrix-org/synapse/issues/10728), [\#10736](https://github.com/matrix-org/synapse/issues/10736))
- Do not include rooms with unknown room versions in the spaces summary results. ([\#10727](https://github.com/matrix-org/synapse/issues/10727))
- Additional error checking for the `preset` field when creating a room. ([\#10738](https://github.com/matrix-org/synapse/issues/10738))
- Clean up some of the federation event authentication code for clarity. ([\#10744](https://github.com/matrix-org/synapse/issues/10744), [\#10745](https://github.com/matrix-org/synapse/issues/10745), [\#10746](https://github.com/matrix-org/synapse/issues/10746), [\#10771](https://github.com/matrix-org/synapse/issues/10771), [\#10773](https://github.com/matrix-org/synapse/issues/10773), [\#10781](https://github.com/matrix-org/synapse/issues/10781))
- Add an index to `presence_stream` to hopefully speed up startups a little. ([\#10748](https://github.com/matrix-org/synapse/issues/10748))
- Refactor event size checking code to simplify searching the codebase for the origins of certain error strings that are occasionally emitted. ([\#10750](https://github.com/matrix-org/synapse/issues/10750))
- Use `attrs` internally for the URL preview code & update documentation. ([\#10753](https://github.com/matrix-org/synapse/issues/10753))
- Minor speed ups when joining large rooms over federation. ([\#10754](https://github.com/matrix-org/synapse/issues/10754), [\#10755](https://github.com/matrix-org/synapse/issues/10755), [\#10756](https://github.com/matrix-org/synapse/issues/10756), [\#10780](https://github.com/matrix-org/synapse/issues/10780), [\#10784](https://github.com/matrix-org/synapse/issues/10784))
- Add a constant for `m.federate`. ([\#10775](https://github.com/matrix-org/synapse/issues/10775))
- Add a script to update the Debian changelog in a Docker container for systems that are not Debian-based. ([\#10778](https://github.com/matrix-org/synapse/issues/10778))
- Change the format of authenticated users in logs when a user is being puppeted by and admin user. ([\#10779](https://github.com/matrix-org/synapse/issues/10779))
- Ensure the Rust reporter passes type checking with jaeger-client 4.7's type annotations. ([\#10799](https://github.com/matrix-org/synapse/issues/10799))
This version of Synapse removes deprecated room-management admin APIs, removes out-of-date email pushers, and improves error handling for fallback templates for user-interactive authentication. For more information on these points, server administrators are encouraged to read [the upgrade notes](docs/upgrade.md#upgrading-to-v1420).
- Support room version 9 from [MSC3375](https://github.com/matrix-org/matrix-doc/pull/3375). ([\#10747](https://github.com/matrix-org/synapse/issues/10747))
Internal Changes
----------------
- Print a warning when using one of the deprecated `template_dir` settings. ([\#10768](https://github.com/matrix-org/synapse/issues/10768))
- Add support for [MSC3231](https://github.com/matrix-org/matrix-doc/pull/3231): Token authenticated registration. Users can be required to submit a token during registration to authenticate themselves. Contributed by Callum Brown. ([\#10142](https://github.com/matrix-org/synapse/issues/10142))
- Add support for [MSC3283](https://github.com/matrix-org/matrix-doc/pull/3283): Expose `enable_set_displayname` in capabilities. ([\#10452](https://github.com/matrix-org/synapse/issues/10452))
- Port the `PresenceRouter` module interface to the new generic interface. ([\#10524](https://github.com/matrix-org/synapse/issues/10524))
- Add pagination to the spaces summary based on updates to [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#10613](https://github.com/matrix-org/synapse/issues/10613), [\#10725](https://github.com/matrix-org/synapse/issues/10725))
Bugfixes
--------
- Validate new `m.room.power_levels` events. Contributed by @aaronraimist. ([\#10232](https://github.com/matrix-org/synapse/issues/10232))
- Display an error on User-Interactive Authentication fallback pages when authentication fails. Contributed by Callum Brown. ([\#10561](https://github.com/matrix-org/synapse/issues/10561))
- Remove pushers when deleting an e-mail address from an account. Pushers for old unlinked emails will also be deleted. ([\#10581](https://github.com/matrix-org/synapse/issues/10581), [\#10734](https://github.com/matrix-org/synapse/issues/10734))
- Reject Client-Server `/keys/query` requests which provide `device_ids` incorrectly. ([\#10593](https://github.com/matrix-org/synapse/issues/10593))
- Rooms with unsupported room versions are no longer returned via `/sync`. ([\#10644](https://github.com/matrix-org/synapse/issues/10644))
- Enforce the maximum length for per-room display names and avatar URLs. ([\#10654](https://github.com/matrix-org/synapse/issues/10654))
- Fix a bug which caused the `synapse_user_logins_total` Prometheus metric not to be correctly initialised on restart. ([\#10677](https://github.com/matrix-org/synapse/issues/10677))
- Fix long-standing issue which caused an error when a thumbnail is requested and there are multiple thumbnails with the same quality rating. ([\#10684](https://github.com/matrix-org/synapse/issues/10684))
- Fix a regression introduced in v1.41.0 which affected the performance of concurrent fetches of large sets of events, in extreme cases causing the process to hang. ([\#10703](https://github.com/matrix-org/synapse/issues/10703))
- Fix a regression introduced in Synapse 1.41 which broke email transmission on Systems using older versions of the Twisted library. ([\#10713](https://github.com/matrix-org/synapse/issues/10713))
- Add documentation on how to connect Django with Synapse using OpenID Connect and django-oauth-toolkit. Contributed by @HugoDelval. ([\#10192](https://github.com/matrix-org/synapse/issues/10192))
- Advertise https://matrix-org.github.io/synapse documentation in the `README` and `CONTRIBUTING` files. ([\#10595](https://github.com/matrix-org/synapse/issues/10595))
- Fix some of the titles not rendering in the OpenID Connect documentation. ([\#10639](https://github.com/matrix-org/synapse/issues/10639))
- Remove table of contents from the top of installation and contributing documentation pages. ([\#10711](https://github.com/matrix-org/synapse/issues/10711))
- Improve type hints for the proxy agent and SRV resolver modules. Contributed by @dklimpel. ([\#10608](https://github.com/matrix-org/synapse/issues/10608))
- Clean up some of the federation event authentication code for clarity. ([\#10614](https://github.com/matrix-org/synapse/issues/10614), [\#10615](https://github.com/matrix-org/synapse/issues/10615), [\#10624](https://github.com/matrix-org/synapse/issues/10624), [\#10640](https://github.com/matrix-org/synapse/issues/10640))
- Add a comment asking developers to leave a reason when bumping the database schema version. ([\#10621](https://github.com/matrix-org/synapse/issues/10621))
- Remove not needed database updates in modify user admin API. ([\#10627](https://github.com/matrix-org/synapse/issues/10627))
- Convert room member storage tuples to `attrs` classes. ([\#10629](https://github.com/matrix-org/synapse/issues/10629), [\#10642](https://github.com/matrix-org/synapse/issues/10642))
- Use auto-attribs for the attrs classes used in sync. ([\#10630](https://github.com/matrix-org/synapse/issues/10630))
- Make `backfill` and `get_missing_events` use the same codepath. ([\#10645](https://github.com/matrix-org/synapse/issues/10645))
- Improve the performance of the `/hierarchy` API (from [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946)) by caching responses received over federation. ([\#10647](https://github.com/matrix-org/synapse/issues/10647))
- Run a nightly CI build against Twisted trunk. ([\#10651](https://github.com/matrix-org/synapse/issues/10651), [\#10672](https://github.com/matrix-org/synapse/issues/10672))
- Do not print out stack traces for network errors when fetching data over federation. ([\#10662](https://github.com/matrix-org/synapse/issues/10662))
- Simplify tests for device admin rest API. ([\#10664](https://github.com/matrix-org/synapse/issues/10664))
- Add missing type hints to REST servlets. ([\#10665](https://github.com/matrix-org/synapse/issues/10665), [\#10666](https://github.com/matrix-org/synapse/issues/10666), [\#10674](https://github.com/matrix-org/synapse/issues/10674))
- Flatten the `tests.synapse.rests` package by moving the contents of `v1` and `v2_alpha` into the parent. ([\#10667](https://github.com/matrix-org/synapse/issues/10667))
- Update `complement.sh` to rebuild the base Docker image when run with workers. ([\#10686](https://github.com/matrix-org/synapse/issues/10686))
- Split the event-processing methods in `FederationHandler` into a separate `FederationEventHandler`. ([\#10692](https://github.com/matrix-org/synapse/issues/10692))
Due to the two security issues highlighted below, server administrators are encouraged to update Synapse. We are not aware of these vulnerabilities being exploited in the wild.
Security advisory
-----------------
The following issues are fixed in v1.41.1.
- **[GHSA-3x4c-pq33-4w3q](https://github.com/matrix-org/synapse/security/advisories/GHSA-3x4c-pq33-4w3q) / [CVE-2021-39164](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39164): Enumerating a private room's list of members and their display names.**
If an unauthorized user both knows the Room ID of a private room *and* that room's history visibility is set to `shared`, then they may be able to enumerate the room's members, including their display names.
The unauthorized user must be on the same homeserver as a user who is a member of the target room.
Fixed by [52c7a51cf](https://github.com/matrix-org/synapse/commit/52c7a51cf).
- **[GHSA-jj53-8fmw-f2w2](https://github.com/matrix-org/synapse/security/advisories/GHSA-jj53-8fmw-f2w2) / [CVE-2021-39163](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39163): Disclosing a private room's name, avatar, topic, and number of members.**
If an unauthorized user knows the Room ID of a private room, then its name, avatar, topic, and number of members may be disclosed through Group / Community features.
The unauthorized user must be on the same homeserver as a user who is a member of the target room, and their homeserver must allow non-administrators to create groups (`enable_group_creation` in the Synapse configuration; off by default).
Fixed by [cb35df940a](https://github.com/matrix-org/synapse/commit/cb35df940a), [\#10723](https://github.com/matrix-org/synapse/issues/10723).
Bugfixes
--------
- Fix a regression introduced in Synapse 1.41 which broke email transmission on systems using older versions of the Twisted library. ([\#10713](https://github.com/matrix-org/synapse/issues/10713))
This release adds support for Debian 12 (Bookworm), but **removes support for Ubuntu 20.10 (Groovy Gorilla)**, which reached End of Life last month.
Note that when using workers the `/_synapse/admin/v1/users/{userId}/media` must now be handled by media workers. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html) for more information.
- Enable room capabilities ([MSC3244](https://github.com/matrix-org/matrix-doc/pull/3244)) by default and set room version 8 as the preferred room version when creating restricted rooms. ([\#10571](https://github.com/matrix-org/synapse/issues/10571))
- Add `get_userinfo_by_id` method to ModuleApi. ([\#9581](https://github.com/matrix-org/synapse/issues/9581))
- Initial local support for [MSC3266](https://github.com/matrix-org/synapse/pull/10394), Room Summary over the unstable `/rooms/{roomIdOrAlias}/summary` API. ([\#10394](https://github.com/matrix-org/synapse/issues/10394))
- Experimental support for [MSC3288](https://github.com/matrix-org/matrix-doc/pull/3288), sending `room_type` to the identity server for 3pid invites over the `/store-invite` API. ([\#10435](https://github.com/matrix-org/synapse/issues/10435))
- Add support for sending federation requests through a proxy. Contributed by @Bubu and @dklimpel. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html) for more information. ([\#10596](https://github.com/matrix-org/synapse/issues/10596)). ([\#10475](https://github.com/matrix-org/synapse/issues/10475))
- Add support for "marker" events which makes historical events discoverable for servers that already have all of the scrollback history (part of [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)). ([\#10498](https://github.com/matrix-org/synapse/issues/10498))
- Add a configuration setting for the time a `/sync` response is cached for. ([\#10513](https://github.com/matrix-org/synapse/issues/10513))
- The default logging handler for new installations is now `PeriodicallyFlushingMemoryHandler`, a buffered logging handler which periodically flushes itself. ([\#10518](https://github.com/matrix-org/synapse/issues/10518))
- Add support for new redaction rules for historical events specified in [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716). ([\#10538](https://github.com/matrix-org/synapse/issues/10538))
- Add a setting to disable TLS when sending email. ([\#10546](https://github.com/matrix-org/synapse/issues/10546))
- Add pagination to the spaces summary based on updates to [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#10549](https://github.com/matrix-org/synapse/issues/10549), [\#10560](https://github.com/matrix-org/synapse/issues/10560), [\#10569](https://github.com/matrix-org/synapse/issues/10569), [\#10574](https://github.com/matrix-org/synapse/issues/10574), [\#10575](https://github.com/matrix-org/synapse/issues/10575), [\#10579](https://github.com/matrix-org/synapse/issues/10579), [\#10583](https://github.com/matrix-org/synapse/issues/10583))
- Admin API to delete several media for a specific user. Contributed by @dklimpel. ([\#10558](https://github.com/matrix-org/synapse/issues/10558), [\#10628](https://github.com/matrix-org/synapse/issues/10628))
- Add support for routing `/createRoom` to workers. ([\#10564](https://github.com/matrix-org/synapse/issues/10564))
- Update the Synapse Grafana dashboard. ([\#10570](https://github.com/matrix-org/synapse/issues/10570))
- Add an admin API (`GET /_synapse/admin/username_available`) to check if a username is available (regardless of registration settings). ([\#10578](https://github.com/matrix-org/synapse/issues/10578))
- Allow editing a user's `external_ids` via the "Edit User" admin API. Contributed by @dklimpel. ([\#10598](https://github.com/matrix-org/synapse/issues/10598))
- The Synapse manhole no longer needs coroutines to be wrapped in `defer.ensureDeferred`. ([\#10602](https://github.com/matrix-org/synapse/issues/10602))
- Add option to allow modules to run periodic tasks on all instances, rather than just the one configured to run background tasks. ([\#10638](https://github.com/matrix-org/synapse/issues/10638))
Bugfixes
--------
- Add some clarification to the sample config file. Contributed by @Kentokamoto. ([\#10129](https://github.com/matrix-org/synapse/issues/10129))
- Fix a long-standing bug where protocols which are not implemented by any appservices were incorrectly returned via `GET /_matrix/client/r0/thirdparty/protocols`. ([\#10532](https://github.com/matrix-org/synapse/issues/10532))
- Fix exceptions in logs when failing to get remote room list. ([\#10541](https://github.com/matrix-org/synapse/issues/10541))
- Fix longstanding bug which caused the user's presence "status message" to be reset when the user went offline. Contributed by @dklimpel. ([\#10550](https://github.com/matrix-org/synapse/issues/10550))
- Allow public rooms to be previewed in the spaces summary APIs from [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#10580](https://github.com/matrix-org/synapse/issues/10580))
- Fix a bug introduced in v1.37.1 where an error could occur in the asynchronous processing of PDUs when the queue was empty. ([\#10592](https://github.com/matrix-org/synapse/issues/10592))
- Fix errors on /sync when read receipt data is a string. Only affects homeservers with the experimental flag for [MSC2285](https://github.com/matrix-org/matrix-doc/pull/2285) enabled. Contributed by @SimonBrandner. ([\#10606](https://github.com/matrix-org/synapse/issues/10606))
- Additional validation for the spaces summary API to avoid errors like `ValueError: Stop argument for islice() must be None or an integer`. The missing validation has existed since v1.31.0. ([\#10611](https://github.com/matrix-org/synapse/issues/10611))
- Revert behaviour introduced in v1.38.0 that strips `org.matrix.msc2732.device_unused_fallback_key_types` from `/sync` when its value is empty. This field should instead always be present according to [MSC2732](https://github.com/matrix-org/matrix-doc/blob/master/proposals/2732-olm-fallback-keys.md). ([\#10623](https://github.com/matrix-org/synapse/issues/10623))
- Updated the reverse proxy documentation to highlight the homserver configuration that is needed to make Synapse aware that is is intentionally reverse proxied. ([\#10551](https://github.com/matrix-org/synapse/issues/10551))
- Update CONTRIBUTING.md to fix index links and the instructions for SyTest in docker. ([\#10599](https://github.com/matrix-org/synapse/issues/10599))
- No longer build `.deb` packages for Ubuntu 20.10 Groovy Gorilla, which has now EOLed. ([\#10588](https://github.com/matrix-org/synapse/issues/10588))
- The `template_dir` configuration settings in the `sso`, `account_validity` and `email` sections of the configuration file are now deprecated in favour of the global `templates.custom_template_directory` setting. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html) for more information. ([\#10596](https://github.com/matrix-org/synapse/issues/10596))
Internal Changes
----------------
- Improve event caching mechanism to avoid having multiple copies of an event in memory at a time. ([\#10119](https://github.com/matrix-org/synapse/issues/10119))
- Reduce errors in PostgreSQL logs due to concurrent serialization errors. ([\#10504](https://github.com/matrix-org/synapse/issues/10504))
- Include room ID in ignored EDU log messages. Contributed by @ilmari. ([\#10507](https://github.com/matrix-org/synapse/issues/10507))
- Add pagination to the spaces summary based on updates to [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946). ([\#10527](https://github.com/matrix-org/synapse/issues/10527), [\#10530](https://github.com/matrix-org/synapse/issues/10530))
- Fix CI to not break when run against branches rather than pull requests. ([\#10529](https://github.com/matrix-org/synapse/issues/10529))
- Mark all events stemming from the [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint as historical. ([\#10537](https://github.com/matrix-org/synapse/issues/10537))
- Clean up some of the federation event authentication code for clarity. ([\#10539](https://github.com/matrix-org/synapse/issues/10539), [\#10591](https://github.com/matrix-org/synapse/issues/10591))
- Convert `Transaction` and `Edu` objects to attrs. ([\#10542](https://github.com/matrix-org/synapse/issues/10542))
- Update `/batch_send` endpoint to only return `state_events` created by the `state_events_from_before` passed in. ([\#10552](https://github.com/matrix-org/synapse/issues/10552))
- Update contributing.md to warn against rebasing an open PR. ([\#10563](https://github.com/matrix-org/synapse/issues/10563))
- Remove the unused public rooms replication stream. ([\#10565](https://github.com/matrix-org/synapse/issues/10565))
- Clarify error message when failing to join a restricted room. ([\#10572](https://github.com/matrix-org/synapse/issues/10572))
- Remove references to BuildKite in favour of GitHub Actions. ([\#10573](https://github.com/matrix-org/synapse/issues/10573))
- Move `/batch_send` endpoint defined by [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) to the `/v2_alpha` directory. ([\#10576](https://github.com/matrix-org/synapse/issues/10576))
- Allow multiple custom directories in `read_templates`. ([\#10587](https://github.com/matrix-org/synapse/issues/10587))
- Re-organize the `synapse.federation.transport.server` module to create smaller files. ([\#10590](https://github.com/matrix-org/synapse/issues/10590))
- Flatten the `synapse.rest.client` package by moving the contents of `v1` and `v2_alpha` into the parent. ([\#10600](https://github.com/matrix-org/synapse/issues/10600))
- Build Debian packages for Debian 12 (Bookworm). ([\#10612](https://github.com/matrix-org/synapse/issues/10612))
- Fix up a couple of links to the database schema documentation. ([\#10620](https://github.com/matrix-org/synapse/issues/10620))
- Fix a broken link to the upgrade notes. ([\#10631](https://github.com/matrix-org/synapse/issues/10631))
- Support [MSC3289: room version 8](https://github.com/matrix-org/matrix-doc/pull/3289). ([\#10449](https://github.com/matrix-org/synapse/issues/10449))
Bugfixes
--------
- Mark the experimental room version from [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) as unstable. ([\#10449](https://github.com/matrix-org/synapse/issues/10449))
Improved Documentation
----------------------
- Fix broken links in `upgrade.md`. Contributed by @dklimpel. ([\#10543](https://github.com/matrix-org/synapse/issues/10543))
- Fix the `PeriodicallyFlushingMemoryHandler` inhibiting application shutdown because of its background thread. ([\#10517](https://github.com/matrix-org/synapse/issues/10517))
- Fix a bug introduced in Synapse v1.40.0rc1 that could cause Synapse to respond with an error when clients would update read receipts. ([\#10531](https://github.com/matrix-org/synapse/issues/10531))
- Add support for [MSC2033](https://github.com/matrix-org/matrix-doc/pull/2033): `device_id` on `/account/whoami`. ([\#9918](https://github.com/matrix-org/synapse/issues/9918))
- Update support for [MSC2716 - Incrementally importing history into existing rooms](https://github.com/matrix-org/matrix-doc/pull/2716). ([\#10245](https://github.com/matrix-org/synapse/issues/10245), [\#10432](https://github.com/matrix-org/synapse/issues/10432), [\#10463](https://github.com/matrix-org/synapse/issues/10463))
- Update support for [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083) to consider changes in the MSC around which servers can issue join events. ([\#10254](https://github.com/matrix-org/synapse/issues/10254), [\#10447](https://github.com/matrix-org/synapse/issues/10447), [\#10489](https://github.com/matrix-org/synapse/issues/10489))
- Initial support for [MSC3244](https://github.com/matrix-org/matrix-doc/pull/3244), Room version capabilities over the /capabilities API. ([\#10283](https://github.com/matrix-org/synapse/issues/10283))
- Add a buffered logging handler which periodically flushes itself. ([\#10407](https://github.com/matrix-org/synapse/issues/10407), [\#10515](https://github.com/matrix-org/synapse/issues/10515))
- Add support for https connections to a proxy server. Contributed by @Bubu and @dklimpel. ([\#10411](https://github.com/matrix-org/synapse/issues/10411))
- Support for [MSC2285 (hidden read receipts)](https://github.com/matrix-org/matrix-doc/pull/2285). Contributed by @SimonBrandner. ([\#10413](https://github.com/matrix-org/synapse/issues/10413))
- Email notifications now state whether an invitation is to a room or a space. ([\#10426](https://github.com/matrix-org/synapse/issues/10426))
- Allow setting transaction limit for database connections. ([\#10440](https://github.com/matrix-org/synapse/issues/10440), [\#10511](https://github.com/matrix-org/synapse/issues/10511))
- Improve character set detection in URL previews by supporting underscores (in addition to hyphens). Contributed by @srividyut. ([\#10410](https://github.com/matrix-org/synapse/issues/10410))
- Fix events being incorrectly rejected over federation if they reference auth events that the server needed to fetch. ([\#10439](https://github.com/matrix-org/synapse/issues/10439))
- Fix `synapse_federation_server_oldest_inbound_pdu_in_staging` Prometheus metric to not report a max age of 51 years when the queue is empty. ([\#10455](https://github.com/matrix-org/synapse/issues/10455))
- Fix a bug which caused an explicit assignment of power-level 0 to a user to be misinterpreted in rare circumstances. ([\#10499](https://github.com/matrix-org/synapse/issues/10499))
Improved Documentation
----------------------
- Fix hierarchy of providers on the OpenID page. ([\#10445](https://github.com/matrix-org/synapse/issues/10445))
- Consolidate development documentation to `docs/development/`. ([\#10453](https://github.com/matrix-org/synapse/issues/10453))
- Add some developer docs to explain room DAG concepts like `outliers`, `state_groups`, `depth`, etc. ([\#10464](https://github.com/matrix-org/synapse/issues/10464))
- Document how to use Complement while developing a new Synapse feature. ([\#10483](https://github.com/matrix-org/synapse/issues/10483))
- Add type hints to `synapse.federation.transport.client` module. ([\#10408](https://github.com/matrix-org/synapse/issues/10408))
- Remove shebang line from module files. ([\#10415](https://github.com/matrix-org/synapse/issues/10415))
- Drop backwards-compatibility code that was required to support Ubuntu Xenial. ([\#10429](https://github.com/matrix-org/synapse/issues/10429))
- Use a docker image cache for the prerequisites for the debian package build. ([\#10431](https://github.com/matrix-org/synapse/issues/10431))
- Improve servlet type hints. ([\#10437](https://github.com/matrix-org/synapse/issues/10437), [\#10438](https://github.com/matrix-org/synapse/issues/10438))
- Replace usage of `or_ignore` in `simple_insert` with `simple_upsert` usage, to stop spamming postgres logs with spurious ERROR messages. ([\#10442](https://github.com/matrix-org/synapse/issues/10442))
- Update the `tests-done` Github Actions status. ([\#10444](https://github.com/matrix-org/synapse/issues/10444), [\#10512](https://github.com/matrix-org/synapse/issues/10512))
- Update type annotations to work with forthcoming Twisted 21.7.0 release. ([\#10446](https://github.com/matrix-org/synapse/issues/10446), [\#10450](https://github.com/matrix-org/synapse/issues/10450))
- Cancel redundant GHA workflows when a new commit is pushed. ([\#10451](https://github.com/matrix-org/synapse/issues/10451))
- Mitigate media repo XSS attacks on IE11 via the non-standard X-Content-Security-Policy header. ([\#10468](https://github.com/matrix-org/synapse/issues/10468))
- Additional type hints in the state handler. ([\#10482](https://github.com/matrix-org/synapse/issues/10482))
- Update syntax used to run complement tests. ([\#10488](https://github.com/matrix-org/synapse/issues/10488))
- Fix up type annotations to work with Twisted 21.7. ([\#10490](https://github.com/matrix-org/synapse/issues/10490))
- Improve type annotations for `ObservableDeferred`. ([\#10491](https://github.com/matrix-org/synapse/issues/10491))
- Extend release script to also tag and create GitHub releases. ([\#10496](https://github.com/matrix-org/synapse/issues/10496))
- Fix a bug which caused production debian packages to be incorrectly marked as 'prerelease'. ([\#10500](https://github.com/matrix-org/synapse/issues/10500))
- Fix a bug introduced in Synapse 1.38 which caused an exception at startup when SAML authentication was enabled. ([\#10477](https://github.com/matrix-org/synapse/issues/10477))
- Fix a long-standing bug where Synapse would not inform clients that a device had exhausted its one-time-key pool, potentially causing problems decrypting events. ([\#10485](https://github.com/matrix-org/synapse/issues/10485))
- Fix an error which prevented the Github Actions workflow to build the docker images from running. ([\#10461](https://github.com/matrix-org/synapse/issues/10461))
- Fix release script to correctly version debian changelog when doing RCs. ([\#10465](https://github.com/matrix-org/synapse/issues/10465))
- Always include `device_one_time_keys_count` key in `/sync` response to work around a bug in Element Android that broke encryption for new devices. ([\#10457](https://github.com/matrix-org/synapse/issues/10457))
The Third-Party Event Rules module interface has been deprecated in favour of the generic module interface introduced in Synapse v1.37.0. Support for the old interface is planned to be removed in September 2021. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html#upgrading-to-v1390) for more information.
- The spaces summary API now returns any joinable rooms, not only rooms which are world-readable. ([\#10298](https://github.com/matrix-org/synapse/issues/10298), [\#10305](https://github.com/matrix-org/synapse/issues/10305))
- Add a new version of the R30 phone-home metric, which removes a false impression of retention given by the old R30 metric. ([\#10332](https://github.com/matrix-org/synapse/issues/10332), [\#10427](https://github.com/matrix-org/synapse/issues/10427))
- Allow providing credentials to `http_proxy`. ([\#10360](https://github.com/matrix-org/synapse/issues/10360))
- Add base starting insertion event when no chunk ID is specified in the historical batch send API. ([\#10250](https://github.com/matrix-org/synapse/issues/10250))
- Fix historical batch send endpoint (MSC2716) rejecting batches with messages from multiple senders. ([\#10276](https://github.com/matrix-org/synapse/issues/10276))
- Fix purging rooms that other homeservers are still sending events for. Contributed by @ilmari. ([\#10317](https://github.com/matrix-org/synapse/issues/10317))
- Fix errors during backfill caused by previously purged redaction events. Contributed by Andreas Rammhold (@andir). ([\#10343](https://github.com/matrix-org/synapse/issues/10343))
- Fix the user directory becoming broken (and noisy errors being logged) when knocking and room statistics are in use. ([\#10344](https://github.com/matrix-org/synapse/issues/10344))
- Fix newly added `synapse_federation_server_oldest_inbound_pdu_in_staging` prometheus metric to measure age rather than timestamp. ([\#10355](https://github.com/matrix-org/synapse/issues/10355))
- Fix PostgreSQL sometimes using table scans for queries against `state_groups_state` table, taking a long time and a large amount of IO. ([\#10359](https://github.com/matrix-org/synapse/issues/10359))
- Fix `make_room_admin` failing for users that have left a private room. ([\#10367](https://github.com/matrix-org/synapse/issues/10367))
- Fix a number of logged errors caused by remote servers being down. ([\#10400](https://github.com/matrix-org/synapse/issues/10400), [\#10414](https://github.com/matrix-org/synapse/issues/10414))
- Responses from `/make_{join,leave,knock}` no longer include signatures, which will turn out to be invalid after events are returned to `/send_{join,leave,knock}`. ([\#10404](https://github.com/matrix-org/synapse/issues/10404))
Improved Documentation
----------------------
- Updated installation dependencies for newer macOS versions and ARM Macs. Contributed by Luke Walsh. ([\#9971](https://github.com/matrix-org/synapse/issues/9971))
- Simplify structure of room admin API. ([\#10313](https://github.com/matrix-org/synapse/issues/10313))
- Refresh the logcontext dev documentation. ([\#10353](https://github.com/matrix-org/synapse/issues/10353)), ([\#10337](https://github.com/matrix-org/synapse/issues/10337))
- Add delegation example for caddy in the reverse proxy documentation. Contributed by @moritzdietz. ([\#10368](https://github.com/matrix-org/synapse/issues/10368))
- Fix and clarify some links in `docs` and `contrib`. ([\#10370](https://github.com/matrix-org/synapse/issues/10370)), ([\#10322](https://github.com/matrix-org/synapse/issues/10322)), ([\#10399](https://github.com/matrix-org/synapse/issues/10399))
- Remove functionality associated with the unused `room_stats_historical` and `user_stats_historical` tables. Contributed by @xmunoz. ([\#9721](https://github.com/matrix-org/synapse/issues/9721))
- The third-party event rules module interface is deprecated in favour of the generic module interface introduced in Synapse v1.37.0. See the [upgrade notes](https://matrix-org.github.io/synapse/latest/upgrade.html#upgrading-to-v1390) for more information. ([\#10386](https://github.com/matrix-org/synapse/issues/10386))
Internal Changes
----------------
- Convert `room_depth.min_depth` column to a `BIGINT`. ([\#10289](https://github.com/matrix-org/synapse/issues/10289))
- Add tests to characterise the current behaviour of R30 phone-home metrics. ([\#10315](https://github.com/matrix-org/synapse/issues/10315))
- Rebuild event context and auth when processing specific results from `ThirdPartyEventRules` modules. ([\#10316](https://github.com/matrix-org/synapse/issues/10316))
- Minor change to the code that populates `user_daily_visits`. ([\#10324](https://github.com/matrix-org/synapse/issues/10324))
- Re-enable Sytests that were disabled for the 1.37.1 release. ([\#10345](https://github.com/matrix-org/synapse/issues/10345), [\#10357](https://github.com/matrix-org/synapse/issues/10357))
- Run `pyupgrade` on the codebase. ([\#10347](https://github.com/matrix-org/synapse/issues/10347), [\#10348](https://github.com/matrix-org/synapse/issues/10348))
- Switch `application_services_txns.txn_id` database column to `BIGINT`. ([\#10349](https://github.com/matrix-org/synapse/issues/10349))
- Convert internal type variable syntax to reflect wider ecosystem use. ([\#10350](https://github.com/matrix-org/synapse/issues/10350), [\#10380](https://github.com/matrix-org/synapse/issues/10380), [\#10381](https://github.com/matrix-org/synapse/issues/10381), [\#10382](https://github.com/matrix-org/synapse/issues/10382), [\#10418](https://github.com/matrix-org/synapse/issues/10418))
- Make the Github Actions workflow configuration more efficient. ([\#10383](https://github.com/matrix-org/synapse/issues/10383))
- Add type hints to `get_{domain,localpart}_from_id`. ([\#10385](https://github.com/matrix-org/synapse/issues/10385))
- When building Debian packages for prerelease versions, set the Section accordingly. ([\#10391](https://github.com/matrix-org/synapse/issues/10391))
- Add type hints and comments to event auth code. ([\#10393](https://github.com/matrix-org/synapse/issues/10393))
- Stagger sending of presence update to remote servers, reducing CPU spikes caused by starting many connections to remote servers at once. ([\#10398](https://github.com/matrix-org/synapse/issues/10398))
This release includes a database schema update which could result in elevated disk usage. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#upgrading-to-v1380) for more information.
- Build the Debian packages in CI. ([\#10247](https://github.com/matrix-org/synapse/issues/10247), [\#10379](https://github.com/matrix-org/synapse/issues/10379))
- Fix bug where inbound federation in a room could be delayed due to not correctly dropping a lock. Introduced in v1.37.1. ([\#10336](https://github.com/matrix-org/synapse/issues/10336))
- Implement refresh tokens as specified by [MSC2918](https://github.com/matrix-org/matrix-doc/pull/2918). ([\#9450](https://github.com/matrix-org/synapse/issues/9450))
- Add support for evicting cache entries based on last access time. ([\#10205](https://github.com/matrix-org/synapse/issues/10205))
- Omit empty fields from the `/sync` response. Contributed by @deepbluev7. ([\#10214](https://github.com/matrix-org/synapse/issues/10214))
- Improve validation on federation `send_{join,leave,knock}` endpoints. ([\#10225](https://github.com/matrix-org/synapse/issues/10225), [\#10243](https://github.com/matrix-org/synapse/issues/10243))
- Add SSO `external_ids` to the Query User Account admin API. ([\#10261](https://github.com/matrix-org/synapse/issues/10261))
- Mark events received over federation which fail a spam check as "soft-failed". ([\#10263](https://github.com/matrix-org/synapse/issues/10263))
- Add metrics for new inbound federation staging area. ([\#10284](https://github.com/matrix-org/synapse/issues/10284))
- Add script to print information about recently registered users. ([\#10290](https://github.com/matrix-org/synapse/issues/10290))
Bugfixes
--------
- Fix a long-standing bug which meant that invite rejections and knocks were not sent out over federation in a timely manner. ([\#10223](https://github.com/matrix-org/synapse/issues/10223))
- Fix a bug introduced in v1.26.0 where only users who have set profile information could be deactivated with erasure enabled. ([\#10252](https://github.com/matrix-org/synapse/issues/10252))
- Fix a long-standing bug where Synapse would return errors after 2<sup>31</sup> events were handled by the server. ([\#10264](https://github.com/matrix-org/synapse/issues/10264), [\#10267](https://github.com/matrix-org/synapse/issues/10267), [\#10282](https://github.com/matrix-org/synapse/issues/10282), [\#10286](https://github.com/matrix-org/synapse/issues/10286), [\#10291](https://github.com/matrix-org/synapse/issues/10291), [\#10314](https://github.com/matrix-org/synapse/issues/10314), [\#10326](https://github.com/matrix-org/synapse/issues/10326))
- Fix the prometheus `synapse_federation_server_pdu_process_time` metric. Broke in v1.37.1. ([\#10279](https://github.com/matrix-org/synapse/issues/10279))
- Ensure that inbound events from federation that were being processed when Synapse was restarted get promptly processed on start up. ([\#10303](https://github.com/matrix-org/synapse/issues/10303))
Improved Documentation
----------------------
- Move the upgrade notes to [docs/upgrade.md](https://github.com/matrix-org/synapse/blob/develop/docs/upgrade.md) and convert them to markdown. ([\#10166](https://github.com/matrix-org/synapse/issues/10166))
- Choose Welcome & Overview as the default page for synapse documentation website. ([\#10242](https://github.com/matrix-org/synapse/issues/10242))
- Adjust the URL in the README.rst file to point to irc.libera.chat. ([\#10258](https://github.com/matrix-org/synapse/issues/10258))
- Fix homeserver config option name in presence router documentation. ([\#10288](https://github.com/matrix-org/synapse/issues/10288))
- Fix link pointing at the wrong section in the modules documentation page. ([\#10302](https://github.com/matrix-org/synapse/issues/10302))
- Drop `Origin` and `Accept` from the value of the `Access-Control-Allow-Headers` response header. ([\#10114](https://github.com/matrix-org/synapse/issues/10114))
- Add type hints to the federation servlets. ([\#10213](https://github.com/matrix-org/synapse/issues/10213))
- Improve the reliability of auto-joining remote rooms. ([\#10237](https://github.com/matrix-org/synapse/issues/10237))
- Update the release script to use the semver terminology and determine the release branch based on the next version. ([\#10239](https://github.com/matrix-org/synapse/issues/10239))
- Fix type hints for computing auth events. ([\#10253](https://github.com/matrix-org/synapse/issues/10253))
- Improve the performance of the spaces summary endpoint by only recursing into spaces (and not rooms in general). ([\#10256](https://github.com/matrix-org/synapse/issues/10256))
- Move event authentication methods from `Auth` to `EventAuthHandler`. ([\#10268](https://github.com/matrix-org/synapse/issues/10268))
This release resolves issues (such as [#9490](https://github.com/matrix-org/synapse/issues/9490)) where one busy room could cause head-of-line blocking, starving Synapse from processing events in other rooms, and causing all federated traffic to fall behind. Synapse 1.37.1 processes inbound federation traffic asynchronously, ensuring that one busy room won't impact others. Please upgrade to Synapse 1.37.1 as soon as possible, in order to increase resilience to other traffic spikes.
This release deprecates the current spam checker interface. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#deprecation-of-the-current-spam-checker-interface) for more information on how to update to the new generic module interface.
This release also removes support for fetching and renewing TLS certificates using the ACME v1 protocol, which has been fully decommissioned by Let's Encrypt on June 1st 2021. Admins previously using this feature should use a [reverse proxy](https://matrix-org.github.io/synapse/develop/reverse_proxy.html) to handle TLS termination, or use an external ACME client (such as [certbot](https://certbot.eff.org/)) to retrieve a certificate and key and provide them to Synapse using the `tls_certificate_path` and `tls_private_key_path` configuration settings.
- Implement "room knocking" as per [MSC2403](https://github.com/matrix-org/matrix-doc/pull/2403). Contributed by @Sorunome and anoa. ([\#6739](https://github.com/matrix-org/synapse/issues/6739), [\#9359](https://github.com/matrix-org/synapse/issues/9359), [\#10167](https://github.com/matrix-org/synapse/issues/10167), [\#10212](https://github.com/matrix-org/synapse/issues/10212), [\#10227](https://github.com/matrix-org/synapse/issues/10227))
- Add experimental support for backfilling history into rooms ([MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)). ([\#9247](https://github.com/matrix-org/synapse/issues/9247))
- Implement config option `sso.update_profile_information` to sync SSO users' profile information with the identity provider each time they login. Currently only displayname is supported. ([\#10108](https://github.com/matrix-org/synapse/issues/10108))
- Ensure that errors during startup are written to the logs and the console. ([\#10191](https://github.com/matrix-org/synapse/issues/10191))
Bugfixes
--------
- Fix a bug introduced in Synapse v1.25.0 that prevented the `ip_range_whitelist` configuration option from working for federation and identity servers. Contributed by @mikure. ([\#10115](https://github.com/matrix-org/synapse/issues/10115))
- Remove a broken import line in Synapse's `admin_cmd` worker. Broke in Synapse v1.33.0. ([\#10154](https://github.com/matrix-org/synapse/issues/10154))
- Fix a bug introduced in Synapse v1.21.0 which could cause `/sync` to return immediately with an empty response. ([\#10157](https://github.com/matrix-org/synapse/issues/10157), [\#10158](https://github.com/matrix-org/synapse/issues/10158))
- Fix a minor bug in the response to `/_matrix/client/r0/user/{user}/openid/request_token` causing `expires_in` to be a float instead of an integer. Contributed by @lukaslihotzki. ([\#10175](https://github.com/matrix-org/synapse/issues/10175))
- Always require users to re-authenticate for dangerous operations: deactivating an account, modifying an account password, and adding 3PIDs. ([\#10184](https://github.com/matrix-org/synapse/issues/10184))
- Fix a bug introduced in Synpase v1.7.2 where remote server count metrics collection would be incorrectly delayed on startup. Found by @heftig. ([\#10195](https://github.com/matrix-org/synapse/issues/10195))
- Fix a bug introduced in Synapse v1.35.1 where an `allow` key of a `m.room.join_rules` event could be applied for incorrect room versions and configurations. ([\#10208](https://github.com/matrix-org/synapse/issues/10208))
- Fix performance regression in responding to user key requests over federation. Introduced in Synapse v1.34.0rc1. ([\#10221](https://github.com/matrix-org/synapse/issues/10221))
- Add a new guide to decoding request logs. ([\#8436](https://github.com/matrix-org/synapse/issues/8436))
- Mention in the sample homeserver config that you may need to configure max upload size in your reverse proxy. Contributed by @aaronraimist. ([\#10122](https://github.com/matrix-org/synapse/issues/10122))
- Fix broken links in documentation. ([\#10180](https://github.com/matrix-org/synapse/issues/10180))
- Deploy a snapshot of the documentation website upon each new Synapse release. ([\#10198](https://github.com/matrix-org/synapse/issues/10198))
- The current spam checker interface is deprecated in favour of a new generic modules system. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#deprecation-of-the-current-spam-checker-interface) for more information on how to update to the new system. ([\#10062](https://github.com/matrix-org/synapse/issues/10062), [\#10210](https://github.com/matrix-org/synapse/issues/10210), [\#10238](https://github.com/matrix-org/synapse/issues/10238))
- Remove Synapse's support for automatically fetching and renewing certificates using the ACME v1 protocol. This protocol has been fully turned off by Let's Encrypt for existing installations on June 1st 2021. Admins previously using this feature should use a [reverse proxy](https://matrix-org.github.io/synapse/develop/reverse_proxy.html) to handle TLS termination, or use an external ACME client (such as [certbot](https://certbot.eff.org/)) to retrieve a certificate and key and provide them to Synapse using the `tls_certificate_path` and `tls_private_key_path` configuration settings. ([\#10194](https://github.com/matrix-org/synapse/issues/10194))
- Update the database schema versioning to support gradual migration away from legacy tables. ([\#9933](https://github.com/matrix-org/synapse/issues/9933))
- Add type hints to the federation servlets. ([\#10080](https://github.com/matrix-org/synapse/issues/10080))
- Improve OpenTracing for event persistence. ([\#10134](https://github.com/matrix-org/synapse/issues/10134), [\#10193](https://github.com/matrix-org/synapse/issues/10193))
- Document `SYNAPSE_TEST_LOG_LEVEL` to see the logger output when running tests. ([\#10148](https://github.com/matrix-org/synapse/issues/10148))
- Update the Complement build tags in GitHub Actions to test currently experimental features. ([\#10155](https://github.com/matrix-org/synapse/issues/10155))
- Add a `synapse_federation_soft_failed_events_total` metric to track how often events are soft failed. ([\#10156](https://github.com/matrix-org/synapse/issues/10156))
- Update [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083) support with modifications from the MSC. ([\#10189](https://github.com/matrix-org/synapse/issues/10189))
- Fix a bug which caused presence updates to stop working some time after a restart, when using a presence writer worker. Broke in v1.33.0. ([\#10149](https://github.com/matrix-org/synapse/issues/10149))
- Fix a bug when using federation sender worker where it would send out more presence updates than necessary, leading to high resource usage. Broke in v1.33.0. ([\#10163](https://github.com/matrix-org/synapse/issues/10163))
- Fix a bug where Synapse could send the same presence update to a remote twice. ([\#10165](https://github.com/matrix-org/synapse/issues/10165))
- Add new endpoint `/_matrix/client/r0/rooms/{roomId}/aliases` from Client-Server API r0.6.1 (previously [MSC2432](https://github.com/matrix-org/matrix-doc/pull/2432)). ([\#9224](https://github.com/matrix-org/synapse/issues/9224))
- Improve performance of incoming federation transactions in large rooms. ([\#9953](https://github.com/matrix-org/synapse/issues/9953), [\#9973](https://github.com/matrix-org/synapse/issues/9973))
- Rewrite logic around verifying JSON object and fetching server keys to be more performant and use less memory. ([\#10035](https://github.com/matrix-org/synapse/issues/10035))
- Add new admin APIs for unprotecting local media from quarantine. Contributed by @dklimpel. ([\#10040](https://github.com/matrix-org/synapse/issues/10040))
- Add new admin APIs to remove media by media ID from quarantine. Contributed by @dklimpel. ([\#10044](https://github.com/matrix-org/synapse/issues/10044))
- Make reason and score parameters optional for reporting content. Implements [MSC2414](https://github.com/matrix-org/matrix-doc/pull/2414). Contributed by Callum Brown. ([\#10077](https://github.com/matrix-org/synapse/issues/10077))
- Add support for routing more requests to workers. ([\#10084](https://github.com/matrix-org/synapse/issues/10084))
- Report OpenTracing spans for database activity. ([\#10113](https://github.com/matrix-org/synapse/issues/10113), [\#10136](https://github.com/matrix-org/synapse/issues/10136), [\#10141](https://github.com/matrix-org/synapse/issues/10141))
- Significantly reduce memory usage of joining large remote rooms. ([\#10117](https://github.com/matrix-org/synapse/issues/10117))
Bugfixes
--------
- Fixed a bug causing replication requests to fail when receiving a lot of events via federation. ([\#10082](https://github.com/matrix-org/synapse/issues/10082))
- Fix a bug in the `force_tracing_for_users` option introduced in Synapse v1.35 which meant that the OpenTracing spans produced were missing most tags. ([\#10092](https://github.com/matrix-org/synapse/issues/10092))
- Fixed a bug that could cause Synapse to stop notifying application services. Contributed by Willem Mulder. ([\#10107](https://github.com/matrix-org/synapse/issues/10107))
- Fix bug where the server would attempt to fetch the same history in the room from a remote server multiple times in parallel. ([\#10116](https://github.com/matrix-org/synapse/issues/10116))
- Fix a bug introduced in Synapse 1.33.0 which caused replication requests to fail when receiving a lot of very large events via federation. ([\#10118](https://github.com/matrix-org/synapse/issues/10118))
- Fix bug when using workers where pagination requests failed if a remote server returned zero events from `/backfill`. Introduced in 1.35.0. ([\#10133](https://github.com/matrix-org/synapse/issues/10133))
Improved Documentation
----------------------
- Clarify security note regarding hosting Synapse on the same domain as other web applications. ([\#9221](https://github.com/matrix-org/synapse/issues/9221))
- Update CAPTCHA documentation to mention turning off the verify origin feature. Contributed by @aaronraimist. ([\#10046](https://github.com/matrix-org/synapse/issues/10046))
- Tweak wording of database recommendation in `INSTALL.md`. Contributed by @aaronraimist. ([\#10057](https://github.com/matrix-org/synapse/issues/10057))
- Add initial infrastructure for rendering Synapse documentation with mdbook. ([\#10086](https://github.com/matrix-org/synapse/issues/10086))
- Convert the remaining Admin API documentation files to markdown. ([\#10089](https://github.com/matrix-org/synapse/issues/10089))
- Make a link in docs use HTTPS. Contributed by @RhnSharma. ([\#10130](https://github.com/matrix-org/synapse/issues/10130))
- Fix broken link in Docker docs. ([\#10132](https://github.com/matrix-org/synapse/issues/10132))
Deprecations and Removals
-------------------------
- Remove the experimental `spaces_enabled` flag. The spaces features are always available now. ([\#10063](https://github.com/matrix-org/synapse/issues/10063))
Internal Changes
----------------
- Tell CircleCI to build Docker images from `main` branch. ([\#9906](https://github.com/matrix-org/synapse/issues/9906))
- Simplify naming convention for release branches to only include the major and minor version numbers. ([\#10013](https://github.com/matrix-org/synapse/issues/10013))
- Add `parse_strings_from_args` for parsing an array from query parameters. ([\#10048](https://github.com/matrix-org/synapse/issues/10048), [\#10137](https://github.com/matrix-org/synapse/issues/10137))
- Remove some dead code regarding TLS certificate handling. ([\#10054](https://github.com/matrix-org/synapse/issues/10054))
- Fix a bug introduced in v1.35.0 where invite-only rooms would be shown to all users in a space, regardless of if the user had access to it. ([\#10109](https://github.com/matrix-org/synapse/issues/10109))
Note that [the tag](https://github.com/matrix-org/synapse/releases/tag/v1.35.0rc3) and [docker images](https://hub.docker.com/layers/matrixdotorg/synapse/v1.35.0rc3/images/sha256-34ccc87bd99a17e2cbc0902e678b5937d16bdc1991ead097eee6096481ecf2c4?context=explore) for `v1.35.0rc3` were incorrectly built. If you are experiencing issues with either, it is recommended to upgrade to the equivalent tag or docker image for the `v1.35.0` release.
- The core Synapse development team plan to drop support for the [unstable API of MSC2858](https://github.com/matrix-org/matrix-doc/blob/master/proposals/2858-Multiple-SSO-Identity-Providers.md#unstable-prefix), including the undocumented `experimental.msc2858_enabled` config option, in August 2021. Client authors should ensure that their clients are updated to use the stable API (which has been supported since Synapse 1.30) well before that time, to give their users time to upgrade. ([\#10101](https://github.com/matrix-org/synapse/issues/10101))
- Fixed a bug causing replication requests to fail when receiving a lot of events via federation. Introduced in v1.33.0. ([\#10082](https://github.com/matrix-org/synapse/issues/10082))
- Fix HTTP response size limit to allow joining very large rooms over federation. Introduced in v1.33.0. ([\#10093](https://github.com/matrix-org/synapse/issues/10093))
- Fix a bug introduced in v1.35.0rc1 when calling the spaces summary API via a GET request. ([\#10079](https://github.com/matrix-org/synapse/issues/10079))
- Add experimental support to allow a user who could join a restricted room to view it in the spaces summary. ([\#9922](https://github.com/matrix-org/synapse/issues/9922), [\#10007](https://github.com/matrix-org/synapse/issues/10007), [\#10038](https://github.com/matrix-org/synapse/issues/10038))
- Reduce memory usage when joining very large rooms over federation. ([\#9958](https://github.com/matrix-org/synapse/issues/9958))
- Add a configuration option which allows enabling opentracing by user id. ([\#9978](https://github.com/matrix-org/synapse/issues/9978))
- Enable experimental support for [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946) (spaces summary API) and [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083) (restricted join rules) by default. ([\#10011](https://github.com/matrix-org/synapse/issues/10011))
Bugfixes
--------
- Fix a bug introduced in v1.26.0 which meant that `synapse_port_db` would not correctly initialise some postgres sequences, requiring manual updates afterwards. ([\#9991](https://github.com/matrix-org/synapse/issues/9991))
- Fix `synctl`'s `--no-daemonize` parameter to work correctly with worker processes. ([\#9995](https://github.com/matrix-org/synapse/issues/9995))
- Fix a validation bug introduced in v1.34.0 in the ordering of spaces in the space summary API. ([\#10002](https://github.com/matrix-org/synapse/issues/10002))
- Fixed deletion of new presence stream states from database. ([\#10014](https://github.com/matrix-org/synapse/issues/10014), [\#10033](https://github.com/matrix-org/synapse/issues/10033))
- Fixed a bug with very high resolution image uploads throwing internal server errors. ([\#10029](https://github.com/matrix-org/synapse/issues/10029))
Updates to the Docker image
---------------------------
- Fix bug introduced in Synapse 1.33.0 which caused a `Permission denied: '/homeserver.log'` error when starting Synapse with the generated log configuration. Contributed by Sergio Miguéns Iglesias. ([\#10045](https://github.com/matrix-org/synapse/issues/10045))
Improved Documentation
----------------------
- Add hardened systemd files as proposed in [#9760](https://github.com/matrix-org/synapse/issues/9760) and added them to `contrib/`. Change the docs to reflect the presence of these files. ([\#9803](https://github.com/matrix-org/synapse/issues/9803))
- Clarify documentation around SSO mapping providers generating unique IDs and localparts. ([\#9980](https://github.com/matrix-org/synapse/issues/9980))
- Updates to the PostgreSQL documentation (`postgres.md`). ([\#9988](https://github.com/matrix-org/synapse/issues/9988), [\#9989](https://github.com/matrix-org/synapse/issues/9989))
- Fix broken link in user directory documentation. Contributed by @junquera. ([\#10016](https://github.com/matrix-org/synapse/issues/10016))
- Add missing room state entry to the table of contents of room admin API. ([\#10043](https://github.com/matrix-org/synapse/issues/10043))
Deprecations and Removals
-------------------------
- Removed support for the deprecated `tls_fingerprints` configuration setting. Contributed by Jerin J Titus. ([\#9280](https://github.com/matrix-org/synapse/issues/9280))
Internal Changes
----------------
- Allow sending full presence to users via workers other than the one that called `ModuleApi.send_local_online_presence_to`. ([\#9823](https://github.com/matrix-org/synapse/issues/9823))
- Update comments in the space summary handler. ([\#9974](https://github.com/matrix-org/synapse/issues/9974))
- Minor enhancements to the `@cachedList` descriptor. ([\#9975](https://github.com/matrix-org/synapse/issues/9975))
- Split multipart email sending into a dedicated handler. ([\#9977](https://github.com/matrix-org/synapse/issues/9977))
- Run `black` on files in the `scripts` directory. ([\#9981](https://github.com/matrix-org/synapse/issues/9981))
- Add missing type hints to `synapse.util` module. ([\#9982](https://github.com/matrix-org/synapse/issues/9982))
- Simplify a few helper functions. ([\#9984](https://github.com/matrix-org/synapse/issues/9984), [\#9985](https://github.com/matrix-org/synapse/issues/9985), [\#9986](https://github.com/matrix-org/synapse/issues/9986))
- Remove unnecessary property from SQLBaseStore. ([\#9987](https://github.com/matrix-org/synapse/issues/9987))
- Remove `keylen` param on `LruCache`. ([\#9993](https://github.com/matrix-org/synapse/issues/9993))
- Update the Grafana dashboard in `contrib/`. ([\#10001](https://github.com/matrix-org/synapse/issues/10001))
- Add a batching queue implementation. ([\#10017](https://github.com/matrix-org/synapse/issues/10017))
- Reduce memory usage when verifying signatures on large numbers of events at once. ([\#10018](https://github.com/matrix-org/synapse/issues/10018))
- Properly invalidate caches for destination retry timings every (instead of expiring entries every 5 minutes). ([\#10036](https://github.com/matrix-org/synapse/issues/10036))
- Fix running complement tests with Synapse workers. ([\#10039](https://github.com/matrix-org/synapse/issues/10039))
- Fix typo in `get_state_ids_for_event` docstring where the return type was incorrect. ([\#10050](https://github.com/matrix-org/synapse/issues/10050))
This release deprecates the `room_invite_state_types` configuration setting. See the [upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.34.0/UPGRADE.rst#upgrading-to-v1340) for instructions on updating your configuration file to use the new `room_prejoin_state` setting.
This release also deprecates the `POST /_synapse/admin/v1/rooms/<room_id>/delete` admin API route. Server administrators are encouraged to update their scripts to use the new `DELETE /_synapse/admin/v1/rooms/<room_id>` route instead.
- Add experimental option to track memory usage of the caches. ([\#9881](https://github.com/matrix-org/synapse/issues/9881))
- Add support for `DELETE /_synapse/admin/v1/rooms/<room_id>`. ([\#9889](https://github.com/matrix-org/synapse/issues/9889))
- Add limits to how often Synapse will GC, ensuring that large servers do not end up GC thrashing if `gc_thresholds` has not been correctly set. ([\#9902](https://github.com/matrix-org/synapse/issues/9902))
- Improve performance of sending events for worker-based deployments using Redis. ([\#9905](https://github.com/matrix-org/synapse/issues/9905), [\#9950](https://github.com/matrix-org/synapse/issues/9950), [\#9951](https://github.com/matrix-org/synapse/issues/9951))
- Improve performance after joining a large room when presence is enabled. ([\#9910](https://github.com/matrix-org/synapse/issues/9910), [\#9916](https://github.com/matrix-org/synapse/issues/9916))
- Support stable identifiers for [MSC1772](https://github.com/matrix-org/matrix-doc/pull/1772) Spaces. `m.space.child` events will now be taken into account when populating the experimental spaces summary response. Please see [the upgrade notes](https://github.com/matrix-org/synapse/blob/release-v1.34.0/UPGRADE.rst#upgrading-to-v1340) if you have customised `room_invite_state_types` in your configuration. ([\#9915](https://github.com/matrix-org/synapse/issues/9915), [\#9966](https://github.com/matrix-org/synapse/issues/9966))
- Improve performance of backfilling in large rooms. ([\#9935](https://github.com/matrix-org/synapse/issues/9935))
- Add a config option to allow you to prevent device display names from being shared over federation. Contributed by @aaronraimist. ([\#9945](https://github.com/matrix-org/synapse/issues/9945))
- Update support for [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946): Spaces Summary. ([\#9947](https://github.com/matrix-org/synapse/issues/9947), [\#9954](https://github.com/matrix-org/synapse/issues/9954))
Bugfixes
--------
- Fix a bug introduced in v1.32.0 where the associated connection was improperly logged for SQL logging statements. ([\#9895](https://github.com/matrix-org/synapse/issues/9895))
- Correct the type hint for the `user_may_create_room_alias` method of spam checkers. It is provided a `RoomAlias`, not a `str`. ([\#9896](https://github.com/matrix-org/synapse/issues/9896))
- Fix bug where user directory could get out of sync if room visibility and membership changed in quick succession. ([\#9910](https://github.com/matrix-org/synapse/issues/9910))
- Include the `origin_server_ts` property in the experimental [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946) support to allow clients to properly sort rooms. ([\#9928](https://github.com/matrix-org/synapse/issues/9928))
- Fix bugs introduced in v1.23.0 which made the PostgreSQL port script fail when run with a newly-created SQLite database. ([\#9930](https://github.com/matrix-org/synapse/issues/9930))
- Fix a bug introduced in Synapse 1.29.0 which caused `m.room_key_request` to-device messages sent from one user to another to be dropped. ([\#9961](https://github.com/matrix-org/synapse/issues/9961), [\#9965](https://github.com/matrix-org/synapse/issues/9965))
- Fix a bug introduced in v1.27.0 preventing users and appservices exempt from ratelimiting from creating rooms with many invitees. ([\#9968](https://github.com/matrix-org/synapse/issues/9968))
- Add `startup_delay` to docker healthcheck to reduce waiting time for coming online and update the documentation with extra options. Contributed by @Maquis196. ([\#9913](https://github.com/matrix-org/synapse/issues/9913))
Due to the security issue highlighted below, server administrators are encouraged to update Synapse. We are not aware of these vulnerabilities being exploited in the wild.
This release fixes a denial of service attack ([CVE-2021-29471](https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85)) against Synapse's push rules implementation. Server admins are encouraged to upgrade.
- Fix bug where `/sync` would break if using the latest version of `attrs` dependency, by pinning to a previous version. ([\#9937](https://github.com/matrix-org/synapse/issues/9937))
- Fix tight loop when handling presence replication when using workers. Introduced in v1.33.0rc1. ([\#9900](https://github.com/matrix-org/synapse/issues/9900))
- Update experimental support for [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083): restricting room access via group membership. ([\#9800](https://github.com/matrix-org/synapse/issues/9800), [\#9814](https://github.com/matrix-org/synapse/issues/9814))
- Add experimental support for handling presence on a worker. ([\#9819](https://github.com/matrix-org/synapse/issues/9819), [\#9820](https://github.com/matrix-org/synapse/issues/9820), [\#9828](https://github.com/matrix-org/synapse/issues/9828), [\#9850](https://github.com/matrix-org/synapse/issues/9850))
- Return a new template when an user attempts to renew their account multiple times with the same token, stating that their account is set to expire. This replaces the invalid token template that would previously be shown in this case. This change concerns the optional account validity feature. ([\#9832](https://github.com/matrix-org/synapse/issues/9832))
- Fixes the OIDC SSO flow when using a `public_baseurl` value including a non-root URL path. ([\#9726](https://github.com/matrix-org/synapse/issues/9726))
- Fix thumbnail generation for some sites with non-standard content types. Contributed by @rkfg. ([\#9788](https://github.com/matrix-org/synapse/issues/9788))
- Add some sanity checks to identity server passed to 3PID bind/unbind endpoints. ([\#9802](https://github.com/matrix-org/synapse/issues/9802))
- Limit the size of HTTP responses read over federation. ([\#9833](https://github.com/matrix-org/synapse/issues/9833))
- Fix a bug which could cause Synapse to get stuck in a loop of resyncing device lists. ([\#9867](https://github.com/matrix-org/synapse/issues/9867))
- Fix a long-standing bug where errors from federation did not propagate to the client. ([\#9868](https://github.com/matrix-org/synapse/issues/9868))
Improved Documentation
----------------------
- Add a note to the docker docs mentioning that we mirror upstream's supported Docker platforms. ([\#9801](https://github.com/matrix-org/synapse/issues/9801))
Internal Changes
----------------
- Add a dockerfile for running Synapse in worker-mode under Complement. ([\#9162](https://github.com/matrix-org/synapse/issues/9162))
- Apply `pyupgrade` across the codebase. ([\#9786](https://github.com/matrix-org/synapse/issues/9786))
- Move some replication processing out of `generic_worker`. ([\#9796](https://github.com/matrix-org/synapse/issues/9796))
- Replace `HomeServer.get_config()` with inline references. ([\#9815](https://github.com/matrix-org/synapse/issues/9815))
- Rename some handlers and config modules to not duplicate the top-level module. ([\#9816](https://github.com/matrix-org/synapse/issues/9816))
- Fix a long-standing bug which caused `max_upload_size` to not be correctly enforced. ([\#9817](https://github.com/matrix-org/synapse/issues/9817))
- Reduce CPU usage of the user directory by reusing existing calculated room membership. ([\#9821](https://github.com/matrix-org/synapse/issues/9821))
- Small speed up for joining large remote rooms. ([\#9825](https://github.com/matrix-org/synapse/issues/9825))
- Introduce flake8-bugbear to the test suite and fix some of its lint violations. ([\#9838](https://github.com/matrix-org/synapse/issues/9838))
- Only store the raw data in the in-memory caches, rather than objects that include references to e.g. the data stores. ([\#9845](https://github.com/matrix-org/synapse/issues/9845))
- Limit length of accepted email addresses. ([\#9855](https://github.com/matrix-org/synapse/issues/9855))
- Remove redundant `synapse.types.Collection` type definition. ([\#9856](https://github.com/matrix-org/synapse/issues/9856))
- Handle recently added rate limits correctly when using `--no-rate-limit` with the demo scripts. ([\#9858](https://github.com/matrix-org/synapse/issues/9858))
- Disable invite rate-limiting by default when running the unit tests. ([\#9871](https://github.com/matrix-org/synapse/issues/9871))
- Pass a reactor into `SynapseSite` to make testing easier. ([\#9874](https://github.com/matrix-org/synapse/issues/9874))
- Make `DomainSpecificString` an `attrs` class. ([\#9875](https://github.com/matrix-org/synapse/issues/9875))
- Add type hints to `synapse.api.auth` and `synapse.api.auth_blocking` modules. ([\#9876](https://github.com/matrix-org/synapse/issues/9876))
- Remove redundant `_PushHTTPChannel` test class. ([\#9878](https://github.com/matrix-org/synapse/issues/9878))
- Remove backwards-compatibility code for Python versions <3.6.([\#9879](https://github.com/matrix-org/synapse/issues/9879))
- Small performance improvement around handling new local presence updates. ([\#9887](https://github.com/matrix-org/synapse/issues/9887))
- Fix a regression in Synapse 1.32.0 and 1.32.1 which caused `LoggingContext` errors in plugins. ([\#9857](https://github.com/matrix-org/synapse/issues/9857))
- Fix a regression in Synapse 1.32.0 which caused Synapse to report large numbers of Prometheus time series, potentially overwhelming Prometheus instances. ([\#9854](https://github.com/matrix-org/synapse/issues/9854))
**Note:** This release requires Python 3.6+ and Postgres 9.6+ or SQLite 3.22+.
This release removes the deprecated `GET /_synapse/admin/v1/users/<user_id>` admin API. Please use the [v2 API](https://github.com/matrix-org/synapse/blob/develop/docs/admin_api/user_admin_api.rst#query-user-account) instead, which has improved capabilities.
This release requires Application Services to use type `m.login.application_service` when registering users via the `/_matrix/client/r0/register` endpoint to comply with the spec. Please ensure your Application Services are up to date.
- Add a Synapse module for routing presence updates between users. ([\#9491](https://github.com/matrix-org/synapse/issues/9491))
- Add an admin API to manage ratelimit for a specific user. ([\#9648](https://github.com/matrix-org/synapse/issues/9648))
- Include request information in structured logging output. ([\#9654](https://github.com/matrix-org/synapse/issues/9654))
- Add `order_by` to the admin API `GET /_synapse/admin/v2/users`. Contributed by @dklimpel. ([\#9691](https://github.com/matrix-org/synapse/issues/9691))
- Replace the `room_invite_state_types` configuration setting with `room_prejoin_state`. ([\#9700](https://github.com/matrix-org/synapse/issues/9700))
- Add experimental support for [MSC3083](https://github.com/matrix-org/matrix-doc/pull/3083): restricting room access via group membership. ([\#9717](https://github.com/matrix-org/synapse/issues/9717), [\#9735](https://github.com/matrix-org/synapse/issues/9735))
- Update experimental support for Spaces: include `m.room.create` in the room state sent with room-invites. ([\#9710](https://github.com/matrix-org/synapse/issues/9710))
- Synapse now requires Python 3.6 or later. It also requires Postgres 9.6 or later or SQLite 3.22 or later. ([\#9766](https://github.com/matrix-org/synapse/issues/9766))
Bugfixes
--------
- Prevent `synapse_forward_extremities` and `synapse_excess_extremity_events` Prometheus metrics from initially reporting zero-values after startup. ([\#8926](https://github.com/matrix-org/synapse/issues/8926))
- Fix recently added ratelimits to correctly honour the application service `rate_limited` flag. ([\#9711](https://github.com/matrix-org/synapse/issues/9711))
- Fix longstanding bug which caused `duplicate key value violates unique constraint "remote_media_cache_thumbnails_media_origin_media_id_thumbna_key"` errors. ([\#9725](https://github.com/matrix-org/synapse/issues/9725))
- Fix bug where sharded federation senders could get stuck repeatedly querying the DB in a loop, using lots of CPU. ([\#9770](https://github.com/matrix-org/synapse/issues/9770))
- Fix duplicate logging of exceptions thrown during federation transaction processing. ([\#9780](https://github.com/matrix-org/synapse/issues/9780))
Updates to the Docker image
---------------------------
- Move opencontainers labels to the final Docker image such that users can inspect them. ([\#9765](https://github.com/matrix-org/synapse/issues/9765))
Improved Documentation
----------------------
- Make the `allowed_local_3pids` regex example in the sample config stricter. ([\#9719](https://github.com/matrix-org/synapse/issues/9719))
Deprecations and Removals
-------------------------
- Remove old admin API `GET /_synapse/admin/v1/users/<user_id>`. ([\#9401](https://github.com/matrix-org/synapse/issues/9401))
- Make `/_matrix/client/r0/register` expect a type of `m.login.application_service` when an Application Service registers a user, to align with [the relevant spec](https://spec.matrix.org/unstable/application-service-api/#server-admin-style-permissions). ([\#9548](https://github.com/matrix-org/synapse/issues/9548))
- Replace deprecated `imp` module with successor `importlib`. Contributed by Cristina Muñoz. ([\#9718](https://github.com/matrix-org/synapse/issues/9718))
- Experiment with GitHub Actions for CI. ([\#9661](https://github.com/matrix-org/synapse/issues/9661))
- Introduce flake8-bugbear to the test suite and fix some of its lint violations. ([\#9682](https://github.com/matrix-org/synapse/issues/9682))
- Update `scripts-dev/complement.sh` to use a local checkout of Complement, allow running a subset of tests and have it use Synapse's Complement test blacklist. ([\#9685](https://github.com/matrix-org/synapse/issues/9685))
- Improve Jaeger tracing for `to_device` messages. ([\#9686](https://github.com/matrix-org/synapse/issues/9686))
- Add release helper script for automating part of the Synapse release process. ([\#9713](https://github.com/matrix-org/synapse/issues/9713))
- Add type hints to expiring cache. ([\#9730](https://github.com/matrix-org/synapse/issues/9730))
- Convert various testcases to `HomeserverTestCase`. ([\#9736](https://github.com/matrix-org/synapse/issues/9736))
- Start linting mypy with `no_implicit_optional`. ([\#9742](https://github.com/matrix-org/synapse/issues/9742))
- Add missing type hints to federation handler and server. ([\#9743](https://github.com/matrix-org/synapse/issues/9743))
- Check that a `ConfigError` is raised, rather than simply `Exception`, when appropriate in homeserver config file generation tests. ([\#9753](https://github.com/matrix-org/synapse/issues/9753))
- Fix incompatibility with `tox` 2.5. ([\#9769](https://github.com/matrix-org/synapse/issues/9769))
- Enable Complement tests for [MSC2946](https://github.com/matrix-org/matrix-doc/pull/2946): Spaces Summary API. ([\#9771](https://github.com/matrix-org/synapse/issues/9771))
- Use mock from the standard library instead of a separate package. ([\#9772](https://github.com/matrix-org/synapse/issues/9772))
- Update Black configuration to target Python 3.6. ([\#9781](https://github.com/matrix-org/synapse/issues/9781))
- Add option to skip unit tests when building Debian packages. ([\#9793](https://github.com/matrix-org/synapse/issues/9793))
**Note:** As announced in v1.25.0, and in line with the deprecation policy for platform dependencies, this is the last release to support Python 3.5 and PostgreSQL 9.5. Future versions of Synapse will require Python 3.6+ and PostgreSQL 9.6+, as per our [deprecation policy](docs/deprecation_policy.md).
- Add support to OpenID Connect login for requiring attributes on the `userinfo` response. Contributed by Hubbe King. ([\#9609](https://github.com/matrix-org/synapse/issues/9609))
- Add initial experimental support for a "space summary" API. ([\#9643](https://github.com/matrix-org/synapse/issues/9643), [\#9652](https://github.com/matrix-org/synapse/issues/9652), [\#9653](https://github.com/matrix-org/synapse/issues/9653))
- Add support for the busy presence state as described in [MSC3026](https://github.com/matrix-org/matrix-doc/pull/3026). ([\#9644](https://github.com/matrix-org/synapse/issues/9644))
- Add support for credentials for proxy authentication in the `HTTPS_PROXY` environment variable. ([\#9657](https://github.com/matrix-org/synapse/issues/9657))
Bugfixes
--------
- Fix a longstanding bug that could cause issues when editing a reply to a message. ([\#9585](https://github.com/matrix-org/synapse/issues/9585))
- Fix the `/capabilities` endpoint to return `m.change_password` as disabled if the local password database is not used for authentication. Contributed by @dklimpel. ([\#9588](https://github.com/matrix-org/synapse/issues/9588))
- Fix a bug where federation sending can stall due to `concurrent access` database exceptions when it falls behind. ([\#9639](https://github.com/matrix-org/synapse/issues/9639))
- Fix a bug introduced in Synapse 1.30.1 which meant the suggested `pip` incantation to install an updated `cryptography` was incorrect. ([\#9699](https://github.com/matrix-org/synapse/issues/9699))
Updates to the Docker image
---------------------------
- Speed up Docker builds and make it nicer to test against Complement while developing (install all dependencies before copying the project). ([\#9610](https://github.com/matrix-org/synapse/issues/9610))
- Include [opencontainers labels](https://github.com/opencontainers/image-spec/blob/master/annotations.md#pre-defined-annotation-keys) in the Docker image. ([\#9612](https://github.com/matrix-org/synapse/issues/9612))
Improved Documentation
----------------------
- Clarify that `register_new_matrix_user` is present also when installed via non-pip package. ([\#9074](https://github.com/matrix-org/synapse/issues/9074))
- Update source install documentation to mention platform prerequisites before the source install steps. ([\#9667](https://github.com/matrix-org/synapse/issues/9667))
- Improve worker documentation for fallback/web auth endpoints. ([\#9679](https://github.com/matrix-org/synapse/issues/9679))
- Update the sample configuration for OIDC authentication. ([\#9695](https://github.com/matrix-org/synapse/issues/9695))
Internal Changes
----------------
- Preparatory steps for removing redundant `outlier` data from `event_json.internal_metadata` column. ([\#9411](https://github.com/matrix-org/synapse/issues/9411))
- Add type hints to the caching module. ([\#9442](https://github.com/matrix-org/synapse/issues/9442))
- Introduce flake8-bugbear to the test suite and fix some of its lint violations. ([\#9499](https://github.com/matrix-org/synapse/issues/9499), [\#9659](https://github.com/matrix-org/synapse/issues/9659))
- Add additional type hints to the Homeserver object. ([\#9631](https://github.com/matrix-org/synapse/issues/9631), [\#9638](https://github.com/matrix-org/synapse/issues/9638), [\#9675](https://github.com/matrix-org/synapse/issues/9675), [\#9681](https://github.com/matrix-org/synapse/issues/9681))
- Only save remote cross-signing and device keys if they're different from the current ones. ([\#9634](https://github.com/matrix-org/synapse/issues/9634))
- Rename storage function to fix spelling and not conflict with another function's name. ([\#9637](https://github.com/matrix-org/synapse/issues/9637))
- Improve performance of federation catch up by sending the latest events in the room to the remote, rather than just the last event sent by the local server. ([\#9640](https://github.com/matrix-org/synapse/issues/9640), [\#9664](https://github.com/matrix-org/synapse/issues/9664))
- In the `federation_client` commandline client, stop automatically adding the URL prefix, so that servlets on other prefixes can be tested. ([\#9645](https://github.com/matrix-org/synapse/issues/9645))
- In the `federation_client` commandline client, handle inline `signing_key`s in `homeserver.yaml`. ([\#9647](https://github.com/matrix-org/synapse/issues/9647))
- Fixed some antipattern issues to improve code quality. ([\#9649](https://github.com/matrix-org/synapse/issues/9649))
- Add a storage method for pulling all current user presence state from the database. ([\#9650](https://github.com/matrix-org/synapse/issues/9650))
- Import `HomeServer` from the proper module. ([\#9665](https://github.com/matrix-org/synapse/issues/9665))
- Add type hints to third party event rules and visibility modules. ([\#9676](https://github.com/matrix-org/synapse/issues/9676))
- Bump mypy-zope to 0.2.13 to fix "Cannot determine consistent method resolution order (MRO)" errors when running mypy a second time. ([\#9678](https://github.com/matrix-org/synapse/issues/9678))
- Use interpreter from `$PATH` via `/usr/bin/env` instead of absolute paths in various scripts. ([\#9689](https://github.com/matrix-org/synapse/issues/9689))
- Make it possible to use `dmypy`. ([\#9692](https://github.com/matrix-org/synapse/issues/9692))
- Suppress "CryptographyDeprecationWarning: int_from_bytes is deprecated". ([\#9698](https://github.com/matrix-org/synapse/issues/9698))
- Use `dmypy run` in lint script for improved performance in type-checking while developing. ([\#9701](https://github.com/matrix-org/synapse/issues/9701))
- Fix undetected mypy error when using Python 3.6. ([\#9703](https://github.com/matrix-org/synapse/issues/9703))
- Fix type-checking CI on develop. ([\#9709](https://github.com/matrix-org/synapse/issues/9709))
- Ensure that the docker container has up to date versions of openssl. ([\#9697](https://github.com/matrix-org/synapse/issues/9697))
Internal Changes
----------------
- Enforce that `cryptography` dependency is up to date to ensure it has the most recent openssl patches. ([\#9697](https://github.com/matrix-org/synapse/issues/9697))
- Add prometheus metrics for number of users successfully registering and logging in. ([\#9510](https://github.com/matrix-org/synapse/issues/9510), [\#9511](https://github.com/matrix-org/synapse/issues/9511), [\#9573](https://github.com/matrix-org/synapse/issues/9573))
- Add `synapse_federation_last_sent_pdu_time` and `synapse_federation_last_received_pdu_time` prometheus metrics, which monitor federation delays by reporting the timestamps of messages sent and received to a set of remote servers. ([\#9540](https://github.com/matrix-org/synapse/issues/9540))
- Add support for generating JSON Web Tokens dynamically for use as OIDC client secrets. ([\#9549](https://github.com/matrix-org/synapse/issues/9549))
- Optimise handling of incomplete room history for incoming federation. ([\#9601](https://github.com/matrix-org/synapse/issues/9601))
- Finalise support for allowing clients to pick an SSO Identity Provider ([MSC2858](https://github.com/matrix-org/matrix-doc/pull/2858)). ([\#9617](https://github.com/matrix-org/synapse/issues/9617))
- Tell spam checker modules about the SSO IdP a user registered through if one was used. ([\#9626](https://github.com/matrix-org/synapse/issues/9626))
Bugfixes
--------
- Fix long-standing bug when generating thumbnails for some images with transparency: `TypeError: cannot unpack non-iterable int object`. ([\#9473](https://github.com/matrix-org/synapse/issues/9473))
- Purge chain cover indexes for events that were purged prior to Synapse v1.29.0. ([\#9542](https://github.com/matrix-org/synapse/issues/9542), [\#9583](https://github.com/matrix-org/synapse/issues/9583))
- Fix bug where federation requests were not correctly retried on 5xx responses. ([\#9567](https://github.com/matrix-org/synapse/issues/9567))
- Fix a bug introduced in Synapse 1.20 which caused incoming federation transactions to stack up, causing slow recovery from outages. ([\#9597](https://github.com/matrix-org/synapse/issues/9597))
- Fix a bug introduced in v1.28.0 where the OpenID Connect callback endpoint could error with a `MacaroonInitException`. ([\#9620](https://github.com/matrix-org/synapse/issues/9620))
- Fix Internal Server Error on `GET /_synapse/client/saml2/authn_response` request. ([\#9623](https://github.com/matrix-org/synapse/issues/9623))
- Add relayd entry to reverse proxy example configurations. ([\#9508](https://github.com/matrix-org/synapse/issues/9508))
- Improve the SAML2 upgrade notes for 1.27.0. ([\#9550](https://github.com/matrix-org/synapse/issues/9550))
- Link to the "List user's media" admin API from the media admin API docs. ([\#9571](https://github.com/matrix-org/synapse/issues/9571))
- Clarify the spam checker modules documentation example to mention that `parse_config` is a required method. ([\#9580](https://github.com/matrix-org/synapse/issues/9580))
- Clarify the sample configuration for `stats` settings. ([\#9604](https://github.com/matrix-org/synapse/issues/9604))
Deprecations and Removals
-------------------------
- The `synapse_federation_last_sent_pdu_age` and `synapse_federation_last_received_pdu_age` prometheus metrics have been removed. They are replaced by `synapse_federation_last_sent_pdu_time` and `synapse_federation_last_received_pdu_time`. ([\#9540](https://github.com/matrix-org/synapse/issues/9540))
- Registering an Application Service user without using the `m.login.application_service` login type will be unsupported in an upcoming Synapse release. ([\#9559](https://github.com/matrix-org/synapse/issues/9559))
Internal Changes
----------------
- Add tests to ResponseCache. ([\#9458](https://github.com/matrix-org/synapse/issues/9458))
- Add type hints to purge room and server notice admin API. ([\#9520](https://github.com/matrix-org/synapse/issues/9520))
- Add extra logging to ObservableDeferred when callbacks throw exceptions. ([\#9523](https://github.com/matrix-org/synapse/issues/9523))
- Fix incorrect type hints. ([\#9528](https://github.com/matrix-org/synapse/issues/9528), [\#9543](https://github.com/matrix-org/synapse/issues/9543), [\#9591](https://github.com/matrix-org/synapse/issues/9591), [\#9608](https://github.com/matrix-org/synapse/issues/9608), [\#9618](https://github.com/matrix-org/synapse/issues/9618))
- Add an additional test for purging a room. ([\#9541](https://github.com/matrix-org/synapse/issues/9541))
- Add a `.git-blame-ignore-revs` file with the hashes of auto-formatting. ([\#9560](https://github.com/matrix-org/synapse/issues/9560))
- Increase the threshold before which outbound federation to a server goes into "catch up" mode, which is expensive for the remote server to handle. ([\#9561](https://github.com/matrix-org/synapse/issues/9561))
- Fix spurious errors reported by the `config-lint.sh` script. ([\#9562](https://github.com/matrix-org/synapse/issues/9562))
- Fix type hints and tests for BlacklistingAgentWrapper and BlacklistingReactorWrapper. ([\#9563](https://github.com/matrix-org/synapse/issues/9563))
- Do not have mypy ignore type hints from unpaddedbase64. ([\#9568](https://github.com/matrix-org/synapse/issues/9568))
- Improve efficiency of calculating the auth chain in large rooms. ([\#9576](https://github.com/matrix-org/synapse/issues/9576))
- Convert `synapse.types.Requester` to an `attrs` class. ([\#9586](https://github.com/matrix-org/synapse/issues/9586))
- Add logging for redis connection setup. ([\#9590](https://github.com/matrix-org/synapse/issues/9590))
- Improve logging when processing incoming transactions. ([\#9596](https://github.com/matrix-org/synapse/issues/9596))
- Remove unused `stats.retention` setting, and emit a warning if stats are disabled. ([\#9604](https://github.com/matrix-org/synapse/issues/9604))
- Prevent attempting to bundle aggregations for state events in /context APIs. ([\#9619](https://github.com/matrix-org/synapse/issues/9619))
Note that synapse now expects an `X-Forwarded-Proto` header when used with a reverse proxy. Please see the [upgrade notes](docs/upgrade.md#upgrading-to-v1290) for more details on this change.
- Add rate limiters to cross-user key sharing requests. ([\#8957](https://github.com/matrix-org/synapse/issues/8957))
- Add `order_by` to the admin API `GET /_synapse/admin/v1/users/<user_id>/media`. Contributed by @dklimpel. ([\#8978](https://github.com/matrix-org/synapse/issues/8978))
- Add some configuration settings to make users' profile data more private. ([\#9203](https://github.com/matrix-org/synapse/issues/9203))
- The `no_proxy` and `NO_PROXY` environment variables are now respected in proxied HTTP clients with the lowercase form taking precedence if both are present. Additionally, the lowercase `https_proxy` environment variable is now respected in proxied HTTP clients on top of existing support for the uppercase `HTTPS_PROXY` form and takes precedence if both are present. Contributed by Timothy Leung. ([\#9372](https://github.com/matrix-org/synapse/issues/9372))
- Add a configuration option, `user_directory.prefer_local_users`, which when enabled will make it more likely for users on the same server as you to appear above other users. ([\#9383](https://github.com/matrix-org/synapse/issues/9383), [\#9385](https://github.com/matrix-org/synapse/issues/9385))
- Add support for regenerating thumbnails if they have been deleted but the original image is still stored. ([\#9438](https://github.com/matrix-org/synapse/issues/9438))
- Add support for `X-Forwarded-Proto` header when using a reverse proxy. ([\#9472](https://github.com/matrix-org/synapse/issues/9472), [\#9501](https://github.com/matrix-org/synapse/issues/9501), [\#9512](https://github.com/matrix-org/synapse/issues/9512), [\#9539](https://github.com/matrix-org/synapse/issues/9539))
Bugfixes
--------
- Fix a bug where users' pushers were not all deleted when they deactivated their account. ([\#9285](https://github.com/matrix-org/synapse/issues/9285), [\#9516](https://github.com/matrix-org/synapse/issues/9516))
- Fix a bug where a lot of unnecessary presence updates were sent when joining a room. ([\#9402](https://github.com/matrix-org/synapse/issues/9402))
- Fix a bug that caused multiple calls to the experimental `shared_rooms` endpoint to return stale results. ([\#9416](https://github.com/matrix-org/synapse/issues/9416))
- Fix a bug in single sign-on which could cause a "No session cookie found" error. ([\#9436](https://github.com/matrix-org/synapse/issues/9436))
- Fix bug introduced in v1.27.0 where allowing a user to choose their own username when logging in via single sign-on did not work unless an `idp_icon` was defined. ([\#9440](https://github.com/matrix-org/synapse/issues/9440))
- Fix a bug introduced in v1.26.0 where some sequences were not properly configured when running `synapse_port_db`. ([\#9449](https://github.com/matrix-org/synapse/issues/9449))
- Fix deleting pushers when using sharded pushers. ([\#9465](https://github.com/matrix-org/synapse/issues/9465), [\#9466](https://github.com/matrix-org/synapse/issues/9466), [\#9479](https://github.com/matrix-org/synapse/issues/9479), [\#9536](https://github.com/matrix-org/synapse/issues/9536))
- Fix missing startup checks for the consistency of certain PostgreSQL sequences. ([\#9470](https://github.com/matrix-org/synapse/issues/9470))
- Fix a long-standing bug where the media repository could leak file descriptors while previewing media. ([\#9497](https://github.com/matrix-org/synapse/issues/9497))
- Properly purge the event chain cover index when purging history. ([\#9498](https://github.com/matrix-org/synapse/issues/9498))
- Fix missing chain cover index due to a schema delta not being applied correctly. Only affected servers that ran development versions. ([\#9503](https://github.com/matrix-org/synapse/issues/9503))
- Fix a bug introduced in v1.25.0 where `/_synapse/admin/join/` would fail when given a room alias. ([\#9506](https://github.com/matrix-org/synapse/issues/9506))
- Prevent presence background jobs from running when presence is disabled. ([\#9530](https://github.com/matrix-org/synapse/issues/9530))
- Fix rare edge case that caused a background update to fail if the server had rejected an event that had duplicate auth events. ([\#9537](https://github.com/matrix-org/synapse/issues/9537))
Improved Documentation
----------------------
- Update the example systemd config to propagate reloads to individual units. ([\#9463](https://github.com/matrix-org/synapse/issues/9463))
Internal Changes
----------------
- Add documentation and type hints to `parse_duration`. ([\#9432](https://github.com/matrix-org/synapse/issues/9432))
- Remove vestiges of `uploads_path` configuration setting. ([\#9462](https://github.com/matrix-org/synapse/issues/9462))
- Add a comment about systemd-python. ([\#9464](https://github.com/matrix-org/synapse/issues/9464))
- Test that we require validated email for email pushers. ([\#9496](https://github.com/matrix-org/synapse/issues/9496))
- Allow python to generate bytecode for synapse. ([\#9502](https://github.com/matrix-org/synapse/issues/9502))
- Fix incorrect type hints. ([\#9515](https://github.com/matrix-org/synapse/issues/9515), [\#9518](https://github.com/matrix-org/synapse/issues/9518))
- Add type hints to device and event report admin API. ([\#9519](https://github.com/matrix-org/synapse/issues/9519))
- Add type hints to user admin API. ([\#9521](https://github.com/matrix-org/synapse/issues/9521))
- Bump the versions of mypy and mypy-zope used for static type checking. ([\#9529](https://github.com/matrix-org/synapse/issues/9529))
Note that this release drops support for ARMv7 in the official Docker images, due to repeated problems building for ARMv7 (and the associated maintenance burden this entails).
This release also fixes the documentation included in v1.27.0 around the callback URI for SAML2 identity providers. If your server is configured to use single sign-on via a SAML2 IdP, you may need to make configuration changes. Please review the [upgrade notes](docs/upgrade.md) for more details on these changes.
- New admin API to get the context of an event: `/_synapse/admin/rooms/{roomId}/context/{eventId}`. ([\#9150](https://github.com/matrix-org/synapse/issues/9150))
- Further improvements to the user experience of registration via single sign-on. ([\#9300](https://github.com/matrix-org/synapse/issues/9300), [\#9301](https://github.com/matrix-org/synapse/issues/9301))
- Add hook to spam checker modules that allow checking file uploads and remote downloads. ([\#9311](https://github.com/matrix-org/synapse/issues/9311))
- Add support for receiving OpenID Connect authentication responses via form `POST`s rather than `GET`s. ([\#9376](https://github.com/matrix-org/synapse/issues/9376))
- Fix long-standing bug where sending email notifications would fail for rooms that the server had since left. ([\#9257](https://github.com/matrix-org/synapse/issues/9257))
- Fix bug introduced in Synapse 1.27.0rc1 which meant the "session expired" error page during SSO registration was badly formatted. ([\#9296](https://github.com/matrix-org/synapse/issues/9296))
- Assert a maximum length for some parameters for spec compliance. ([\#9321](https://github.com/matrix-org/synapse/issues/9321), [\#9393](https://github.com/matrix-org/synapse/issues/9393))
- Fix additional errors when previewing URLs: "AttributeError 'NoneType' object has no attribute 'xpath'" and "ValueError: Unicode strings with encoding declaration are not supported. Please use bytes input or XML fragments without declaration.". ([\#9333](https://github.com/matrix-org/synapse/issues/9333))
- Fix a bug causing Synapse to impose the wrong type constraints on fields when processing responses from appservices to `/_matrix/app/v1/thirdparty/user/{protocol}`. ([\#9361](https://github.com/matrix-org/synapse/issues/9361))
- Fix bug where Synapse would occasionally stop reconnecting to Redis after the connection was lost. ([\#9391](https://github.com/matrix-org/synapse/issues/9391))
- Fix a long-standing bug when upgrading a room: "TypeError: '>' not supported between instances of 'NoneType' and 'int'". ([\#9395](https://github.com/matrix-org/synapse/issues/9395))
- Reduce the amount of memory used when generating the URL preview of a file that is larger than the `max_spider_size`. ([\#9421](https://github.com/matrix-org/synapse/issues/9421))
- Fix a long-standing bug in the deduplication of old presence, resulting in no deduplication. ([\#9425](https://github.com/matrix-org/synapse/issues/9425))
- The `ui_auth.session_timeout` config option can now be specified in terms of number of seconds/minutes/etc/. Contributed by Rishabh Arya. ([\#9426](https://github.com/matrix-org/synapse/issues/9426))
- Fix a bug introduced in v1.27.0: "TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType." related to the user directory. ([\#9428](https://github.com/matrix-org/synapse/issues/9428))
Updates to the Docker image
---------------------------
- Drop support for ARMv7 in Docker images. ([\#9433](https://github.com/matrix-org/synapse/issues/9433))
- Add note to `auto_join_rooms` config option explaining existing rooms must be publicly joinable. ([\#9291](https://github.com/matrix-org/synapse/issues/9291))
- Correct name of Synapse's service file in TURN howto. ([\#9308](https://github.com/matrix-org/synapse/issues/9308))
- Fix the braces in the `oidc_providers` section of the sample config. ([\#9317](https://github.com/matrix-org/synapse/issues/9317))
- Update installation instructions on Fedora. ([\#9322](https://github.com/matrix-org/synapse/issues/9322))
- Add HTTP/2 support to the nginx example configuration. Contributed by David Vo. ([\#9390](https://github.com/matrix-org/synapse/issues/9390))
- Update docs for using Gitea as OpenID provider. ([\#9404](https://github.com/matrix-org/synapse/issues/9404))
- Document that pusher instances are shardable. ([\#9407](https://github.com/matrix-org/synapse/issues/9407))
- Fix erroneous documentation from v1.27.0 about updating the SAML2 callback URL. ([\#9434](https://github.com/matrix-org/synapse/issues/9434))
Deprecations and Removals
-------------------------
- Deprecate old admin API `GET /_synapse/admin/v1/users/<user_id>`. ([\#9429](https://github.com/matrix-org/synapse/issues/9429))
Internal Changes
----------------
- Fix 'object name reserved for internal use' errors with recent versions of SQLite. ([\#9003](https://github.com/matrix-org/synapse/issues/9003))
- Add experimental support for running Synapse with PyPy. ([\#9123](https://github.com/matrix-org/synapse/issues/9123))
- Deny access to additional IP addresses by default. ([\#9240](https://github.com/matrix-org/synapse/issues/9240))
- Update the `Cursor` type hints to better match PEP 249. ([\#9299](https://github.com/matrix-org/synapse/issues/9299))
- Add debug logging for SRV lookups. Contributed by @Bubu. ([\#9305](https://github.com/matrix-org/synapse/issues/9305))
- Improve logging for OIDC login flow. ([\#9307](https://github.com/matrix-org/synapse/issues/9307))
- Share the code for handling required attributes between the CAS and SAML handlers. ([\#9326](https://github.com/matrix-org/synapse/issues/9326))
- Clean up the code to load the metadata for OpenID Connect identity providers. ([\#9362](https://github.com/matrix-org/synapse/issues/9362))
- Convert tests to use `HomeserverTestCase`. ([\#9377](https://github.com/matrix-org/synapse/issues/9377), [\#9396](https://github.com/matrix-org/synapse/issues/9396))
- Update the version of black used to 20.8b1. ([\#9381](https://github.com/matrix-org/synapse/issues/9381))
- Allow OIDC config to override discovered values. ([\#9384](https://github.com/matrix-org/synapse/issues/9384))
- Remove some dead code from the acceptance of room invites path. ([\#9394](https://github.com/matrix-org/synapse/issues/9394))
- Clean up an unused method in the presence handler code. ([\#9408](https://github.com/matrix-org/synapse/issues/9408))
Note that this release includes a change in Synapse to use Redis as a cache ─ as well as a pub/sub mechanism ─ if Redis support is enabled for workers. No action is needed by server administrators, and we do not expect resource usage of the Redis instance to change dramatically.
This release also changes the callback URI for OpenID Connect (OIDC) and SAML2 identity providers. If your server is configured to use single sign-on via an OIDC/OAuth2 or SAML2 IdP, you may need to make configuration changes. Please review the [upgrade notes](docs/upgrade.md) for more details on these changes.
This release also changes escaping of variables in the HTML templates for SSO or email notifications. If you have customised these templates, please review the [upgrade notes](docs/upgrade.md) for more details on these changes.
- Fix ratelimiting introduced in v1.27.0rc1 for invites to respect the `ratelimit` flag on application services. ([\#9302](https://github.com/matrix-org/synapse/issues/9302))
- Do not automatically calculate `public_baseurl` since it can be wrong in some situations. Reverts behaviour introduced in v1.26.0. ([\#9313](https://github.com/matrix-org/synapse/issues/9313))
- Add an admin API for getting and deleting forward extremities for a room. ([\#9062](https://github.com/matrix-org/synapse/issues/9062))
- Add an admin API for retrieving the current room state of a room. ([\#9168](https://github.com/matrix-org/synapse/issues/9168))
- Add experimental support for allowing clients to pick an SSO Identity Provider ([MSC2858](https://github.com/matrix-org/matrix-doc/pull/2858)). ([\#9183](https://github.com/matrix-org/synapse/issues/9183), [\#9242](https://github.com/matrix-org/synapse/issues/9242))
- Add an admin API endpoint for shadow-banning users. ([\#9209](https://github.com/matrix-org/synapse/issues/9209))
- Add ratelimits to the 3PID `/requestToken` APIs. ([\#9238](https://github.com/matrix-org/synapse/issues/9238))
- Add support to the OpenID Connect integration for adding the user's email address. ([\#9245](https://github.com/matrix-org/synapse/issues/9245))
- Add ratelimits to invites in rooms and to specific users. ([\#9258](https://github.com/matrix-org/synapse/issues/9258))
- Improve the user experience of setting up an account via single-sign on. ([\#9262](https://github.com/matrix-org/synapse/issues/9262), [\#9272](https://github.com/matrix-org/synapse/issues/9272), [\#9275](https://github.com/matrix-org/synapse/issues/9275), [\#9276](https://github.com/matrix-org/synapse/issues/9276), [\#9277](https://github.com/matrix-org/synapse/issues/9277), [\#9286](https://github.com/matrix-org/synapse/issues/9286), [\#9287](https://github.com/matrix-org/synapse/issues/9287))
- Add phone home stats for encrypted messages. ([\#9283](https://github.com/matrix-org/synapse/issues/9283))
- Update the redirect URI for OIDC authentication. ([\#9288](https://github.com/matrix-org/synapse/issues/9288))
Bugfixes
--------
- Fix spurious errors in logs when deleting a non-existant pusher. ([\#9121](https://github.com/matrix-org/synapse/issues/9121))
- Fix a long-standing bug where Synapse would return a 500 error when a thumbnail did not exist (and auto-generation of thumbnails was not enabled). ([\#9163](https://github.com/matrix-org/synapse/issues/9163))
- Fix a long-standing bug where an internal server error was raised when attempting to preview an HTML document in an unknown character encoding. ([\#9164](https://github.com/matrix-org/synapse/issues/9164))
- Fix a long-standing bug where invalid data could cause errors when calculating the presentable room name for push. ([\#9165](https://github.com/matrix-org/synapse/issues/9165))
- Fix bug where we sometimes didn't detect that Redis connections had died, causing workers to not see new data. ([\#9218](https://github.com/matrix-org/synapse/issues/9218))
- Fix a bug where `None` was passed to Synapse modules instead of an empty dictionary if an empty module `config` block was provided in the homeserver config. ([\#9229](https://github.com/matrix-org/synapse/issues/9229))
- Fix a bug in the `make_room_admin` admin API where it failed if the admin with the greatest power level was not in the room. Contributed by Pankaj Yadav. ([\#9235](https://github.com/matrix-org/synapse/issues/9235))
- Prevent password hashes from getting dropped if a client failed threepid validation during a User Interactive Auth stage. Removes a workaround for an ancient bug in Riot Web <v0.7.4.([\#9265](https://github.com/matrix-org/synapse/issues/9265))
- Fix single-sign-on when the endpoints are routed to synapse workers. ([\#9271](https://github.com/matrix-org/synapse/issues/9271))
Improved Documentation
----------------------
- Add docs for using Gitea as OpenID provider. ([\#9134](https://github.com/matrix-org/synapse/issues/9134))
- Add link to Matrix VoIP tester for turn-howto. ([\#9135](https://github.com/matrix-org/synapse/issues/9135))
- Add notes on integrating with Facebook for SSO login. ([\#9244](https://github.com/matrix-org/synapse/issues/9244))
Deprecations and Removals
-------------------------
- The `service_url` parameter in `cas_config` is deprecated in favor of `public_baseurl`. ([\#9199](https://github.com/matrix-org/synapse/issues/9199))
- Add new endpoint `/_synapse/client/saml2` for SAML2 authentication callbacks, and deprecate the old endpoint `/_matrix/saml2`. ([\#9289](https://github.com/matrix-org/synapse/issues/9289))
Internal Changes
----------------
- Add tests to `test_user.UsersListTestCase` for List Users Admin API. ([\#9045](https://github.com/matrix-org/synapse/issues/9045))
- Various improvements to the federation client. ([\#9129](https://github.com/matrix-org/synapse/issues/9129))
- Speed up chain cover calculation when persisting a batch of state events at once. ([\#9176](https://github.com/matrix-org/synapse/issues/9176))
- Add a `long_description_type` to the package metadata. ([\#9180](https://github.com/matrix-org/synapse/issues/9180))
- Speed up batch insertion when using PostgreSQL. ([\#9181](https://github.com/matrix-org/synapse/issues/9181), [\#9188](https://github.com/matrix-org/synapse/issues/9188))
- Emit an error at startup if different Identity Providers are configured with the same `idp_id`. ([\#9184](https://github.com/matrix-org/synapse/issues/9184))
- Improve performance of concurrent use of `StreamIDGenerators`. ([\#9190](https://github.com/matrix-org/synapse/issues/9190))
- Add some missing source directories to the automatic linting script. ([\#9191](https://github.com/matrix-org/synapse/issues/9191))
- Precompute joined hosts and store in Redis. ([\#9198](https://github.com/matrix-org/synapse/issues/9198), [\#9227](https://github.com/matrix-org/synapse/issues/9227))
- Fix the Python 3.5 old dependencies build. ([\#9217](https://github.com/matrix-org/synapse/issues/9217))
- Update `isort` to v5.7.0 to bypass a bug where it would disagree with `black` about formatting. ([\#9222](https://github.com/matrix-org/synapse/issues/9222))
- Add type hints to handlers code. ([\#9223](https://github.com/matrix-org/synapse/issues/9223), [\#9232](https://github.com/matrix-org/synapse/issues/9232))
- Fix Debian package building on Ubuntu 16.04 LTS (Xenial). ([\#9254](https://github.com/matrix-org/synapse/issues/9254))
- Minor performance improvement during TLS handshake. ([\#9255](https://github.com/matrix-org/synapse/issues/9255))
- Refactor the generation of summary text for email notifications. ([\#9260](https://github.com/matrix-org/synapse/issues/9260))
- Restore PyPy compatibility by not calling CPython-specific GC methods when under PyPy. ([\#9270](https://github.com/matrix-org/synapse/issues/9270))
- Fix receipts and account data not being sent down sync. Introduced in v1.26.0rc1. ([\#9193](https://github.com/matrix-org/synapse/issues/9193), [\#9195](https://github.com/matrix-org/synapse/issues/9195))
- Fix chain cover update to handle events with duplicate auth events. Introduced in v1.26.0rc1. ([\#9210](https://github.com/matrix-org/synapse/issues/9210))
Internal Changes
----------------
- Add an `oidc-` prefix to any `idp_id`s which are given in the `oidc_providers` configuration. ([\#9189](https://github.com/matrix-org/synapse/issues/9189))
- During user-interactive authentication via single-sign-on, give a better error if the user uses the wrong account on the SSO IdP. ([\#9091](https://github.com/matrix-org/synapse/issues/9091))
- Give the `public_baseurl` a default value, if it is not explicitly set in the configuration file. ([\#9159](https://github.com/matrix-org/synapse/issues/9159))
- Implement [MSC2176](https://github.com/matrix-org/matrix-doc/pull/2176) in an experimental room version. ([\#8984](https://github.com/matrix-org/synapse/issues/8984))
- Add an admin API for protecting local media from quarantine. ([\#9086](https://github.com/matrix-org/synapse/issues/9086))
- Remove a user's avatar URL and display name when deactivated with the Admin API. ([\#8932](https://github.com/matrix-org/synapse/issues/8932))
- Update `/_synapse/admin/v1/users/<user_id>/joined_rooms` to work for both local and remote users. ([\#8948](https://github.com/matrix-org/synapse/issues/8948))
- Add experimental support for handling to-device messages on worker processes. ([\#9042](https://github.com/matrix-org/synapse/issues/9042), [\#9043](https://github.com/matrix-org/synapse/issues/9043), [\#9044](https://github.com/matrix-org/synapse/issues/9044), [\#9130](https://github.com/matrix-org/synapse/issues/9130))
- Add experimental support for handling `/keys/claim` and `/room_keys` APIs on worker processes. ([\#9068](https://github.com/matrix-org/synapse/issues/9068))
- Add experimental support for handling `/devices` API on worker processes. ([\#9092](https://github.com/matrix-org/synapse/issues/9092))
- Add experimental support for moving off receipts and account data persistence off master. ([\#9104](https://github.com/matrix-org/synapse/issues/9104), [\#9166](https://github.com/matrix-org/synapse/issues/9166))
- Fix a long-standing issue where an internal server error would occur when requesting a profile over federation that did not include a display name / avatar URL. ([\#9023](https://github.com/matrix-org/synapse/issues/9023))
- Fix a minor bug which could cause confusing error messages from invalid configurations. ([\#9054](https://github.com/matrix-org/synapse/issues/9054))
- Fix incorrect exit code when there is an error at startup. ([\#9059](https://github.com/matrix-org/synapse/issues/9059))
- Fix `JSONDecodeError` spamming the logs when sending transactions to remote servers. ([\#9070](https://github.com/matrix-org/synapse/issues/9070))
- Fix "Failed to send request" errors when a client provides an invalid room alias. ([\#9071](https://github.com/matrix-org/synapse/issues/9071))
- Fix bugs in federation catchup logic that caused outbound federation to be delayed for large servers after start up. Introduced in v1.8.0 and v1.21.0. ([\#9114](https://github.com/matrix-org/synapse/issues/9114), [\#9116](https://github.com/matrix-org/synapse/issues/9116))
- Fix corruption of `pushers` data when a postgres bouncer is used. ([\#9117](https://github.com/matrix-org/synapse/issues/9117))
- Fix minor bugs in handling the `clientRedirectUrl` parameter for SSO login. ([\#9128](https://github.com/matrix-org/synapse/issues/9128))
- Fix "Unhandled error in Deferred: BodyExceededMaxSize" errors when .well-known files that are too large. ([\#9108](https://github.com/matrix-org/synapse/issues/9108))
- Fix "UnboundLocalError: local variable 'length' referenced before assignment" errors when the response body exceeds the expected size. This bug was introduced in v1.25.0. ([\#9145](https://github.com/matrix-org/synapse/issues/9145))
- Fix a long-standing bug "ValueError: invalid literal for int() with base 10" when `/publicRooms` is requested with an invalid `server` parameter. ([\#9161](https://github.com/matrix-org/synapse/issues/9161))
Improved Documentation
----------------------
- Add some extra docs for getting Synapse running on macOS. ([\#8997](https://github.com/matrix-org/synapse/issues/8997))
- Add missing `user_mapping_provider` configuration to the Keycloak OIDC example. Contributed by @chris-ruecker. ([\#9057](https://github.com/matrix-org/synapse/issues/9057))
- Quote `pip install` packages when extras are used to avoid shells interpreting bracket characters. ([\#9151](https://github.com/matrix-org/synapse/issues/9151))
Deprecations and Removals
-------------------------
- Remove broken and unmaintained `demo/webserver.py` script. ([\#9039](https://github.com/matrix-org/synapse/issues/9039))
Internal Changes
----------------
- Improve efficiency of large state resolutions. ([\#8868](https://github.com/matrix-org/synapse/issues/8868), [\#9029](https://github.com/matrix-org/synapse/issues/9029), [\#9115](https://github.com/matrix-org/synapse/issues/9115), [\#9118](https://github.com/matrix-org/synapse/issues/9118), [\#9124](https://github.com/matrix-org/synapse/issues/9124))
- Various clean-ups to the structured logging and logging context code. ([\#8939](https://github.com/matrix-org/synapse/issues/8939))
- Ensure rejected events get added to some metadata tables. ([\#9016](https://github.com/matrix-org/synapse/issues/9016))
- Ignore date-rotated homeserver logs saved to disk. ([\#9018](https://github.com/matrix-org/synapse/issues/9018))
- Add a `-noextras` factor to `tox.ini`, to support running the tests with no optional dependencies. ([\#9030](https://github.com/matrix-org/synapse/issues/9030))
- Fix running unit tests when optional dependencies are not installed. ([\#9031](https://github.com/matrix-org/synapse/issues/9031))
- Allow bumping schema version when using split out state database. ([\#9033](https://github.com/matrix-org/synapse/issues/9033))
- Configure the linters to run on a consistent set of files. ([\#9038](https://github.com/matrix-org/synapse/issues/9038))
- Various cleanups to device inbox store. ([\#9041](https://github.com/matrix-org/synapse/issues/9041))
- Drop unused database tables. ([\#9055](https://github.com/matrix-org/synapse/issues/9055))
- Add type hints to media repository. ([\#9093](https://github.com/matrix-org/synapse/issues/9093))
- Fix the wrong arguments being passed to `BlacklistingAgentWrapper` from `MatrixFederationAgent`. Contributed by Timothy Leung. ([\#9098](https://github.com/matrix-org/synapse/issues/9098))
- Reduce the scope of caught exceptions in `BlacklistingAgentWrapper`. ([\#9106](https://github.com/matrix-org/synapse/issues/9106))
- Replace the old `perspectives` option in the Synapse docker config file template with `trusted_key_servers`. ([\#9157](https://github.com/matrix-org/synapse/issues/9157))
With this release, the Synapse team is announcing a formal deprecation policy for our platform dependencies, like Python and PostgreSQL:
All future releases of Synapse will follow the upstream end-of-life schedules.
Which means:
* This is the last release which guarantees support for Python 3.5.
* We will end support for PostgreSQL 9.5 early next month.
* We will end support for Python 3.6 and PostgreSQL 9.6 near the end of the year.
Crucially, this means __we will not produce .deb packages for Debian 9 (Stretch) or Ubuntu 16.04 (Xenial)__ beyond the transition period described below.
The website https://endoflife.date/ has convenient summaries of the support schedules for projects like [Python](https://endoflife.date/python) and [PostgreSQL](https://endoflife.date/postgresql).
We will make a good faith attempt to avoid breaking compatibility in all releases through the end of March 2021. However, critical security vulnerabilities in dependencies or other unanticipated circumstances may arise which necessitate breaking compatibility earlier.
We intend to continue producing .deb packages for Debian 9 (Stretch) and Ubuntu 16.04 (Xenial) through the transition period.
- Fix HTTP proxy support when using a proxy that is on a blacklisted IP. Introduced in v1.25.0rc1. Contributed by @Bubu. ([\#9084](https://github.com/matrix-org/synapse/issues/9084))
- Add an admin API that lets server admins get power in rooms in which local users have power. ([\#8756](https://github.com/matrix-org/synapse/issues/8756))
- Add optional HTTP authentication to replication endpoints. ([\#8853](https://github.com/matrix-org/synapse/issues/8853))
- Improve the error messages printed as a result of configuration problems for extension modules. ([\#8874](https://github.com/matrix-org/synapse/issues/8874))
- Add `X-Robots-Tag` header to stop web crawlers from indexing media. Contributed by Aaron Raimist. ([\#8887](https://github.com/matrix-org/synapse/issues/8887))
- Spam-checkers may now define their methods as `async`. ([\#8890](https://github.com/matrix-org/synapse/issues/8890))
- Add support for allowing users to pick their own user ID during a single-sign-on login. ([\#8897](https://github.com/matrix-org/synapse/issues/8897), [\#8900](https://github.com/matrix-org/synapse/issues/8900), [\#8911](https://github.com/matrix-org/synapse/issues/8911), [\#8938](https://github.com/matrix-org/synapse/issues/8938), [\#8941](https://github.com/matrix-org/synapse/issues/8941), [\#8942](https://github.com/matrix-org/synapse/issues/8942), [\#8951](https://github.com/matrix-org/synapse/issues/8951))
- Add an `email.invite_client_location` configuration option to send a web client location to the invite endpoint on the identity server which allows customisation of the email template. ([\#8930](https://github.com/matrix-org/synapse/issues/8930))
- The search term in the list room and list user Admin APIs is now treated as case-insensitive. ([\#8931](https://github.com/matrix-org/synapse/issues/8931))
- Apply an IP range blacklist to push and key revocation requests. ([\#8821](https://github.com/matrix-org/synapse/issues/8821), [\#8870](https://github.com/matrix-org/synapse/issues/8870), [\#8954](https://github.com/matrix-org/synapse/issues/8954))
- Add an option to allow re-use of user-interactive authentication sessions for a period of time. ([\#8970](https://github.com/matrix-org/synapse/issues/8970))
- Allow running the redact endpoint on workers. ([\#8994](https://github.com/matrix-org/synapse/issues/8994))
Bugfixes
--------
- Fix bug where we might not correctly calculate the current state for rooms with multiple extremities. ([\#8827](https://github.com/matrix-org/synapse/issues/8827))
- Fix a long-standing bug in the register admin endpoint (`/_synapse/admin/v1/register`) when the `mac` field was not provided. The endpoint now properly returns a 400 error. Contributed by @edwargix. ([\#8837](https://github.com/matrix-org/synapse/issues/8837))
- Fix a long-standing bug on Synapse instances supporting Single-Sign-On, where users would be prompted to enter their password to confirm certain actions, even though they have not set a password. ([\#8858](https://github.com/matrix-org/synapse/issues/8858))
- Fix a longstanding bug where a 500 error would be returned if the `Content-Length` header was not provided to the upload media resource. ([\#8862](https://github.com/matrix-org/synapse/issues/8862))
- Add additional validation to pusher URLs to be compliant with the specification. ([\#8865](https://github.com/matrix-org/synapse/issues/8865))
- Fix the error code that is returned when a user tries to register on a homeserver on which new-user registration has been disabled. ([\#8867](https://github.com/matrix-org/synapse/issues/8867))
- Fix a bug where `PUT /_synapse/admin/v2/users/<user_id>` failed to create a new user when `avatar_url` is specified. Bug introduced in Synapse v1.9.0. ([\#8872](https://github.com/matrix-org/synapse/issues/8872))
- Fix a 500 error when attempting to preview an empty HTML file. ([\#8883](https://github.com/matrix-org/synapse/issues/8883))
- Fix occasional deadlock when handling SIGHUP. ([\#8918](https://github.com/matrix-org/synapse/issues/8918))
- Fix login API to not ratelimit application services that have ratelimiting disabled. ([\#8920](https://github.com/matrix-org/synapse/issues/8920))
- Fix bug where we ratelimited auto joining of rooms on registration (using `auto_join_rooms` config). ([\#8921](https://github.com/matrix-org/synapse/issues/8921))
- Fix a bug where deactivated users appeared in the user directory when their profile information was updated. ([\#8933](https://github.com/matrix-org/synapse/issues/8933), [\#8964](https://github.com/matrix-org/synapse/issues/8964))
- Fix bug introduced in Synapse v1.24.0 which would cause an exception on startup if both `enabled` and `localdb_enabled` were set to `False` in the `password_config` setting of the configuration file. ([\#8937](https://github.com/matrix-org/synapse/issues/8937))
- Fix a bug where 500 errors would be returned if the `m.room_history_visibility` event had invalid content. ([\#8945](https://github.com/matrix-org/synapse/issues/8945))
- Fix a bug causing common English words to not be considered for a user directory search. ([\#8959](https://github.com/matrix-org/synapse/issues/8959))
- Fix bug where application services couldn't register new ghost users if the server had reached its MAU limit. ([\#8962](https://github.com/matrix-org/synapse/issues/8962))
- Fix a long-standing bug where a `m.image` event without a `url` would cause errors on push. ([\#8965](https://github.com/matrix-org/synapse/issues/8965))
- Fix a small bug in v2 state resolution algorithm, which could also cause performance issues for rooms with large numbers of power levels. ([\#8971](https://github.com/matrix-org/synapse/issues/8971))
- Add validation to the `sendToDevice` API to raise a missing parameters error instead of a 500 error. ([\#8975](https://github.com/matrix-org/synapse/issues/8975))
- Fix the "Event persist rate" section of the included grafana dashboard by adding missing prometheus rules. ([\#8802](https://github.com/matrix-org/synapse/issues/8802))
- Combine related media admin API docs. ([\#8839](https://github.com/matrix-org/synapse/issues/8839))
- Fix an error in the documentation for the SAML username mapping provider. ([\#8873](https://github.com/matrix-org/synapse/issues/8873))
- Clarify comments around template directories in `sample_config.yaml`. ([\#8891](https://github.com/matrix-org/synapse/issues/8891))
- Move instructions for database setup, adjusted heading levels and improved syntax highlighting in [INSTALL.md](../INSTALL.md). Contributed by @fossterer. ([\#8987](https://github.com/matrix-org/synapse/issues/8987))
- Update the example value of `group_creation_prefix` in the sample configuration. ([\#8992](https://github.com/matrix-org/synapse/issues/8992))
- Link the Synapse developer room to the development section in the docs. ([\#9002](https://github.com/matrix-org/synapse/issues/9002))
Deprecations and Removals
-------------------------
- Deprecate Shutdown Room and Purge Room Admin APIs. ([\#8829](https://github.com/matrix-org/synapse/issues/8829))
Internal Changes
----------------
- Properly store the mapping of external ID to Matrix ID for CAS users. ([\#8856](https://github.com/matrix-org/synapse/issues/8856), [\#8958](https://github.com/matrix-org/synapse/issues/8958))
- Remove some unnecessary stubbing from unit tests. ([\#8861](https://github.com/matrix-org/synapse/issues/8861))
- Remove unused `FakeResponse` class from unit tests. ([\#8864](https://github.com/matrix-org/synapse/issues/8864))
- Pass `room_id` to `get_auth_chain_difference`. ([\#8879](https://github.com/matrix-org/synapse/issues/8879))
- Add type hints to push module. ([\#8880](https://github.com/matrix-org/synapse/issues/8880), [\#8882](https://github.com/matrix-org/synapse/issues/8882), [\#8901](https://github.com/matrix-org/synapse/issues/8901), [\#8940](https://github.com/matrix-org/synapse/issues/8940), [\#8943](https://github.com/matrix-org/synapse/issues/8943), [\#9020](https://github.com/matrix-org/synapse/issues/9020))
- Simplify logic for handling user-interactive-auth via single-sign-on servers. ([\#8881](https://github.com/matrix-org/synapse/issues/8881))
- Skip the SAML tests if the requirements (`pysaml2` and `xmlsec1`) aren't available. ([\#8905](https://github.com/matrix-org/synapse/issues/8905))
- Don't publish `latest` docker image until all archs are built. ([\#8909](https://github.com/matrix-org/synapse/issues/8909))
- Various clean-ups to the structured logging and logging context code. ([\#8916](https://github.com/matrix-org/synapse/issues/8916), [\#8935](https://github.com/matrix-org/synapse/issues/8935))
- Automatically drop stale forward-extremities under some specific conditions. ([\#8929](https://github.com/matrix-org/synapse/issues/8929))
- Refactor test utilities for injecting HTTP requests. ([\#8946](https://github.com/matrix-org/synapse/issues/8946))
- Add a maximum size of 50 kilobytes to .well-known lookups. ([\#8950](https://github.com/matrix-org/synapse/issues/8950))
- Fix bug in `generate_log_config` script which made it write empty files. ([\#8952](https://github.com/matrix-org/synapse/issues/8952))
- Clean up tox.ini file; disable coverage checking for non-test runs. ([\#8963](https://github.com/matrix-org/synapse/issues/8963))
- Add type hints to the admin and room list handlers. ([\#8973](https://github.com/matrix-org/synapse/issues/8973))
- Add type hints to the receipts and user directory handlers. ([\#8976](https://github.com/matrix-org/synapse/issues/8976))
- Drop the unused `local_invites` table. ([\#8979](https://github.com/matrix-org/synapse/issues/8979))
- Add type hints to the base storage code. ([\#8980](https://github.com/matrix-org/synapse/issues/8980))
- Support using PyJWT v2.0.0 in the test suite. ([\#8986](https://github.com/matrix-org/synapse/issues/8986))
- Fix `tests.federation.transport.RoomDirectoryFederationTests` and ensure it runs in CI. ([\#8998](https://github.com/matrix-org/synapse/issues/8998))
- Add type hints to the crypto module. ([\#8999](https://github.com/matrix-org/synapse/issues/8999))
* Administrators who have installed Synapse from distribution packages should
consult the information from their distributions.
Bugfixes
--------
- Fix a bug in some federation APIs which could lead to unexpected behaviour if different parameters were set in the URI and the request body. ([\#8776](https://github.com/matrix-org/synapse/issues/8776))
Internal Changes
----------------
- Add a maximum version for pysaml2 on Python 3.5. ([\#8898](https://github.com/matrix-org/synapse/issues/8898))
- Fix a regression in v1.24.0rc1 which failed to allow SAML mapping providers which were unable to redirect users to an additional page. ([\#8878](https://github.com/matrix-org/synapse/issues/8878))
- Add support for the `prometheus_client` newer than 0.9.0. Contributed by Jordan Bancino. ([\#8875](https://github.com/matrix-org/synapse/issues/8875))
- Add admin API for logging in as a user. ([\#8617](https://github.com/matrix-org/synapse/issues/8617))
- Allow specification of the SAML IdP if the metadata returns multiple IdPs. ([\#8630](https://github.com/matrix-org/synapse/issues/8630))
- Add support for re-trying generation of a localpart for OpenID Connect mapping providers. ([\#8801](https://github.com/matrix-org/synapse/issues/8801), [\#8855](https://github.com/matrix-org/synapse/issues/8855))
- Add a config option, `push.group_by_unread_count`, which controls whether unread message counts in push notifications are defined as "the number of rooms with unread messages" or "total unread messages". ([\#8820](https://github.com/matrix-org/synapse/issues/8820))
- Add `force_purge` option to delete-room admin api. ([\#8843](https://github.com/matrix-org/synapse/issues/8843))
Bugfixes
--------
- Fix a bug where appservices may be sent an excessive amount of read receipts and presence. Broke in v1.22.0. ([\#8744](https://github.com/matrix-org/synapse/issues/8744))
- Fix a bug in some federation APIs which could lead to unexpected behaviour if different parameters were set in the URI and the request body. ([\#8776](https://github.com/matrix-org/synapse/issues/8776))
- Fix a bug where synctl could spawn duplicate copies of a worker. Contributed by Waylon Cude. ([\#8798](https://github.com/matrix-org/synapse/issues/8798))
- Allow per-room profiles to be used for the server notice user. ([\#8799](https://github.com/matrix-org/synapse/issues/8799))
- Fix `register_new_matrix_user` failing with "Bad Request" when trailing slash is included in server URL. Contributed by @angdraug. ([\#8823](https://github.com/matrix-org/synapse/issues/8823))
- Fix a minor long-standing bug in login, where we would offer the `password` login type if a custom auth provider supported it, even if password login was disabled. ([\#8835](https://github.com/matrix-org/synapse/issues/8835))
- Fix a long-standing bug which caused Synapse to require unspecified parameters during user-interactive authentication. ([\#8848](https://github.com/matrix-org/synapse/issues/8848))
- Fix a bug introduced in v1.20.0 where the user-agent and IP address reported during user registration for CAS, OpenID Connect, and SAML were of the wrong form. ([\#8784](https://github.com/matrix-org/synapse/issues/8784))
- Remove extraneous comma from JSON example in User Admin API docs. ([\#8771](https://github.com/matrix-org/synapse/issues/8771))
- Update `turn-howto.md` with troubleshooting notes. ([\#8779](https://github.com/matrix-org/synapse/issues/8779))
- Fix the example on how to set the `Content-Type` header in nginx for the Client Well-Known URI. ([\#8793](https://github.com/matrix-org/synapse/issues/8793))
- Improve the documentation for the admin API to list all media in a room with respect to encrypted events. ([\#8795](https://github.com/matrix-org/synapse/issues/8795))
- Update the formatting of the `push` section of the homeserver config file to better align with the [code style guidelines](https://github.com/matrix-org/synapse/blob/develop/docs/code_style.md#configuration-file-format). ([\#8818](https://github.com/matrix-org/synapse/issues/8818))
- Improve documentation how to configure prometheus for workers. ([\#8822](https://github.com/matrix-org/synapse/issues/8822))
- Update example prometheus console. ([\#8824](https://github.com/matrix-org/synapse/issues/8824))
- Remove old `/_matrix/client/*/admin` endpoints which were deprecated since Synapse 1.20.0. ([\#8785](https://github.com/matrix-org/synapse/issues/8785))
- Disable pretty printing JSON responses for curl. Users who want pretty-printed output should use [jq](https://stedolan.github.io/jq/) in combination with curl. Contributed by @tulir. ([\#8833](https://github.com/matrix-org/synapse/issues/8833))
Internal Changes
----------------
- Simplify the way the `HomeServer` object caches its internal attributes. ([\#8565](https://github.com/matrix-org/synapse/issues/8565), [\#8851](https://github.com/matrix-org/synapse/issues/8851))
- Add an example and documentation for clock skew to the SAML2 sample configuration to allow for clock/time difference between the homserver and IdP. Contributed by @localguru. ([\#8731](https://github.com/matrix-org/synapse/issues/8731))
- Generalise `RoomMemberHandler._locally_reject_invite` to apply to more flows than just invite. ([\#8751](https://github.com/matrix-org/synapse/issues/8751))
- Generalise `RoomStore.maybe_store_room_on_invite` to handle other, non-invite membership events. ([\#8754](https://github.com/matrix-org/synapse/issues/8754))
- Refactor test utilities for injecting HTTP requests. ([\#8757](https://github.com/matrix-org/synapse/issues/8757), [\#8758](https://github.com/matrix-org/synapse/issues/8758), [\#8759](https://github.com/matrix-org/synapse/issues/8759), [\#8760](https://github.com/matrix-org/synapse/issues/8760), [\#8761](https://github.com/matrix-org/synapse/issues/8761), [\#8777](https://github.com/matrix-org/synapse/issues/8777))
- Consolidate logic between the OpenID Connect and SAML code. ([\#8765](https://github.com/matrix-org/synapse/issues/8765))
- Use `TYPE_CHECKING` instead of magic `MYPY` variable. ([\#8770](https://github.com/matrix-org/synapse/issues/8770))
- Add a commandline script to sign arbitrary json objects. ([\#8772](https://github.com/matrix-org/synapse/issues/8772))
- Minor log line improvements for the SSO mapping code used to generate Matrix IDs from SSO IDs. ([\#8773](https://github.com/matrix-org/synapse/issues/8773))
- Add additional error checking for OpenID Connect and SAML mapping providers. ([\#8774](https://github.com/matrix-org/synapse/issues/8774), [\#8800](https://github.com/matrix-org/synapse/issues/8800))
- Add type hints to HTTP abstractions. ([\#8806](https://github.com/matrix-org/synapse/issues/8806), [\#8812](https://github.com/matrix-org/synapse/issues/8812))
- Remove unnecessary function arguments and add typing to several membership replication classes. ([\#8809](https://github.com/matrix-org/synapse/issues/8809))
- Optimise the lookup for an invite from another homeserver when trying to reject it. ([\#8815](https://github.com/matrix-org/synapse/issues/8815))
- Add tests for `password_auth_provider`s. ([\#8819](https://github.com/matrix-org/synapse/issues/8819))
- Drop redundant database index on `event_json`. ([\#8845](https://github.com/matrix-org/synapse/issues/8845))
- Refactor `password_auth_provider` support code. ([\#8849](https://github.com/matrix-org/synapse/issues/8849))
- Add missing `ordering` to background database updates. ([\#8850](https://github.com/matrix-org/synapse/issues/8850))
- Allow for specifying a room version when creating a room in unit tests via `RestHelper.create_room_as`. ([\#8854](https://github.com/matrix-org/synapse/issues/8854))
**Note**: We are aware of a trivially exploitable denial of service vulnerability in versions of Synapse prior to 1.20.0. Complete details will be disclosed on Monday, November 23rd. If you have not upgraded recently, please do so.
- Fix a dependency versioning bug in the Dockerfile that prevented Synapse from starting. ([\#8767](https://github.com/matrix-org/synapse/issues/8767))
- Add an admin api to delete a single file or files that were not used for a defined time from server. Contributed by @dklimpel. ([\#8519](https://github.com/matrix-org/synapse/issues/8519))
- Split admin API for reported events (`GET /_synapse/admin/v1/event_reports`) into detail and list endpoints. This is a breaking change to #8217 which was introduced in Synapse v1.21.0. Those who already use this API should check their scripts. Contributed by @dklimpel. ([\#8539](https://github.com/matrix-org/synapse/issues/8539))
- Support generating structured logs via the standard logging configuration. ([\#8607](https://github.com/matrix-org/synapse/issues/8607), [\#8685](https://github.com/matrix-org/synapse/issues/8685))
- Add an admin API to allow server admins to list users' pushers. Contributed by @dklimpel. ([\#8610](https://github.com/matrix-org/synapse/issues/8610), [\#8689](https://github.com/matrix-org/synapse/issues/8689))
- Add an admin API `GET /_synapse/admin/v1/users/<user_id>/media` to get information about uploaded media. Contributed by @dklimpel. ([\#8647](https://github.com/matrix-org/synapse/issues/8647))
- Add an admin API for local user media statistics. Contributed by @dklimpel. ([\#8700](https://github.com/matrix-org/synapse/issues/8700))
- Add `displayname` to Shared-Secret Registration for admins. ([\#8722](https://github.com/matrix-org/synapse/issues/8722))
Bugfixes
--------
- Fix fetching of E2E cross signing keys over federation when only one of the master key and device signing key is cached already. ([\#8455](https://github.com/matrix-org/synapse/issues/8455))
- Fix a bug where Synapse would blindly forward bad responses from federation to clients when retrieving profile information. ([\#8580](https://github.com/matrix-org/synapse/issues/8580))
- Fix a bug where the account validity endpoint would silently fail if the user ID did not have an expiration time. It now returns a 400 error. ([\#8620](https://github.com/matrix-org/synapse/issues/8620))
- Fix email notifications for invites without local state. ([\#8627](https://github.com/matrix-org/synapse/issues/8627))
- Fix handling of invalid group IDs to return a 400 rather than log an exception and return a 500. ([\#8628](https://github.com/matrix-org/synapse/issues/8628))
- Fix handling of User-Agent headers that are invalid UTF-8, which caused user agents of users to not get correctly recorded. ([\#8632](https://github.com/matrix-org/synapse/issues/8632))
- Fix a bug in the `joined_rooms` admin API if the user has never joined any rooms. The bug was introduced, along with the API, in v1.21.0. ([\#8643](https://github.com/matrix-org/synapse/issues/8643))
- Fix exception during handling multiple concurrent requests for remote media when using multiple media repositories. ([\#8682](https://github.com/matrix-org/synapse/issues/8682))
- Fix bug that prevented Synapse from recovering after losing connection to the database. ([\#8726](https://github.com/matrix-org/synapse/issues/8726))
- Fix bug where the `/_synapse/admin/v1/send_server_notice` API could send notices to non-notice rooms. ([\#8728](https://github.com/matrix-org/synapse/issues/8728))
- Fix PostgreSQL port script fails when DB has no backfilled events. Broke in v1.21.0. ([\#8729](https://github.com/matrix-org/synapse/issues/8729))
- Fix PostgreSQL port script to correctly handle foreign key constraints. Broke in v1.21.0. ([\#8730](https://github.com/matrix-org/synapse/issues/8730))
- Fix PostgreSQL port script so that it can be run again after a failure. Broke in v1.21.0. ([\#8755](https://github.com/matrix-org/synapse/issues/8755))
- Instructions for Azure AD in the OpenID Connect documentation. Contributed by peterk. ([\#8582](https://github.com/matrix-org/synapse/issues/8582))
- Improve the sample configuration for single sign-on providers. ([\#8635](https://github.com/matrix-org/synapse/issues/8635))
- Fix the filepath of Dex's example config and the link to Dex's Getting Started guide in the OpenID Connect docs. ([\#8657](https://github.com/matrix-org/synapse/issues/8657))
- Note support for Python 3.9. ([\#8665](https://github.com/matrix-org/synapse/issues/8665))
- Minor updates to docs on running tests. ([\#8666](https://github.com/matrix-org/synapse/issues/8666))
- Notes on SSO logins and media_repository worker. ([\#8701](https://github.com/matrix-org/synapse/issues/8701))
- Document experimental support for running multiple event persisters. ([\#8706](https://github.com/matrix-org/synapse/issues/8706))
- Add information regarding the various sources of, and expected contributions to, Synapse's documentation to `CONTRIBUTING.md`. ([\#8714](https://github.com/matrix-org/synapse/issues/8714))
- Migrate documentation `docs/admin_api/event_reports` to markdown. ([\#8742](https://github.com/matrix-org/synapse/issues/8742))
- Add some helpful hints to the README for new Synapse developers. Contributed by @chagai95. ([\#8746](https://github.com/matrix-org/synapse/issues/8746))
Internal Changes
----------------
- Optimise `/createRoom` with multiple invited users. ([\#8559](https://github.com/matrix-org/synapse/issues/8559))
- Type hints for `RegistrationStore`. ([\#8615](https://github.com/matrix-org/synapse/issues/8615))
- Change schema to support access tokens belonging to one user but granting access to another. ([\#8616](https://github.com/matrix-org/synapse/issues/8616))
- Run `mypy` as part of the lint.sh script. ([\#8633](https://github.com/matrix-org/synapse/issues/8633))
- Correct Synapse's PyPI package name in the OpenID Connect installation instructions. ([\#8634](https://github.com/matrix-org/synapse/issues/8634))
- Catch exceptions during initialization of `password_providers`. Contributed by Nicolai Søborg. ([\#8636](https://github.com/matrix-org/synapse/issues/8636))
- Fix typos and spelling errors in the code. ([\#8639](https://github.com/matrix-org/synapse/issues/8639))
- Reduce number of OpenTracing spans started. ([\#8640](https://github.com/matrix-org/synapse/issues/8640), [\#8668](https://github.com/matrix-org/synapse/issues/8668), [\#8670](https://github.com/matrix-org/synapse/issues/8670))
- Add field `total` to device list in admin API. ([\#8644](https://github.com/matrix-org/synapse/issues/8644))
- Add more type hints to the application services code. ([\#8655](https://github.com/matrix-org/synapse/issues/8655), [\#8693](https://github.com/matrix-org/synapse/issues/8693))
- Tell Black to format code for Python 3.5. ([\#8664](https://github.com/matrix-org/synapse/issues/8664))
- Don't pull event from DB when handling replication traffic. ([\#8669](https://github.com/matrix-org/synapse/issues/8669))
- Abstract some invite-related code in preparation for landing knocking. ([\#8671](https://github.com/matrix-org/synapse/issues/8671), [\#8688](https://github.com/matrix-org/synapse/issues/8688))
- Clarify representation of events in logfiles. ([\#8679](https://github.com/matrix-org/synapse/issues/8679))
- Don't require `hiredis` package to be installed to run unit tests. ([\#8680](https://github.com/matrix-org/synapse/issues/8680))
- Fix typing info on cache call signature to accept `on_invalidate`. ([\#8684](https://github.com/matrix-org/synapse/issues/8684))
- Fail tests if they do not await coroutines. ([\#8690](https://github.com/matrix-org/synapse/issues/8690))
- Improve start time by adding an index to `e2e_cross_signing_keys.stream_id`. ([\#8694](https://github.com/matrix-org/synapse/issues/8694))
- Re-organize the structured logging code to separate the TCP transport handling from the JSON formatting. ([\#8697](https://github.com/matrix-org/synapse/issues/8697))
- Use Python 3.8 in Docker images by default. ([\#8698](https://github.com/matrix-org/synapse/issues/8698))
- Remove the "draft" status of the Room Details Admin API. ([\#8702](https://github.com/matrix-org/synapse/issues/8702))
- Improve the error returned when a non-string displayname or avatar_url is used when updating a user's profile. ([\#8705](https://github.com/matrix-org/synapse/issues/8705))
- Block attempts by clients to send server ACLs, or redactions of server ACLs, that would result in the local server being blocked from the room. ([\#8708](https://github.com/matrix-org/synapse/issues/8708))
- Add metrics the allow the local sysadmin to track 3PID `/requestToken` requests. ([\#8712](https://github.com/matrix-org/synapse/issues/8712))
- Consolidate duplicated lists of purged tables that are checked in tests. ([\#8713](https://github.com/matrix-org/synapse/issues/8713))
- Add some `mdui:UIInfo` element examples for `saml2_config` in the homeserver config. ([\#8718](https://github.com/matrix-org/synapse/issues/8718))
- Improve the error message returned when a remote server incorrectly sets the `Content-Type` header in response to a JSON request. ([\#8719](https://github.com/matrix-org/synapse/issues/8719))
- Speed up repeated state resolutions on the same room by caching event ID to auth event ID lookups. ([\#8752](https://github.com/matrix-org/synapse/issues/8752))
- Fix a bug where an appservice may not be forwarded events for a room it was recently invited to. Broke in v1.22.0. ([\#8676](https://github.com/matrix-org/synapse/issues/8676))
- Fix `Object of type frozendict is not JSON serializable` exceptions when using third-party event rules. Broke in v1.22.0. ([\#8678](https://github.com/matrix-org/synapse/issues/8678))
- Fix bugs where ephemeral events were not sent to appservices. Broke in v1.22.0rc1. ([\#8648](https://github.com/matrix-org/synapse/issues/8648), [\#8656](https://github.com/matrix-org/synapse/issues/8656))
- Fix `user_daily_visits` table to not have duplicate rows per user/device due to multiple user agents. Broke in v1.22.0rc1. ([\#8654](https://github.com/matrix-org/synapse/issues/8654))
- Add a configuration option for always using the "userinfo endpoint" for OpenID Connect. This fixes support for some identity providers, e.g. GitLab. Contributed by Benjamin Koch. ([\#7658](https://github.com/matrix-org/synapse/issues/7658))
- Add ability for `ThirdPartyEventRules` modules to query and manipulate whether a room is in the public rooms directory. ([\#8292](https://github.com/matrix-org/synapse/issues/8292), [\#8467](https://github.com/matrix-org/synapse/issues/8467))
- Add support for olm fallback keys ([MSC2732](https://github.com/matrix-org/matrix-doc/pull/2732)). ([\#8312](https://github.com/matrix-org/synapse/issues/8312), [\#8501](https://github.com/matrix-org/synapse/issues/8501))
- Add support for running background tasks in a separate worker process. ([\#8369](https://github.com/matrix-org/synapse/issues/8369), [\#8458](https://github.com/matrix-org/synapse/issues/8458), [\#8489](https://github.com/matrix-org/synapse/issues/8489), [\#8513](https://github.com/matrix-org/synapse/issues/8513), [\#8544](https://github.com/matrix-org/synapse/issues/8544), [\#8599](https://github.com/matrix-org/synapse/issues/8599))
- Add support for device dehydration ([MSC2697](https://github.com/matrix-org/matrix-doc/pull/2697)). ([\#8380](https://github.com/matrix-org/synapse/issues/8380))
- Add support for [MSC2409](https://github.com/matrix-org/matrix-doc/pull/2409), which allows sending typing, read receipts, and presence events to appservices. ([\#8437](https://github.com/matrix-org/synapse/issues/8437), [\#8590](https://github.com/matrix-org/synapse/issues/8590))
- Change default room version to "6", per [MSC2788](https://github.com/matrix-org/matrix-doc/pull/2788). ([\#8461](https://github.com/matrix-org/synapse/issues/8461))
- Add the ability to send non-membership events into a room via the `ModuleApi`. ([\#8479](https://github.com/matrix-org/synapse/issues/8479))
- Increase default upload size limit from 10M to 50M. Contributed by @Akkowicz. ([\#8502](https://github.com/matrix-org/synapse/issues/8502))
- Add support for modifying event content in `ThirdPartyRules` modules. ([\#8535](https://github.com/matrix-org/synapse/issues/8535), [\#8564](https://github.com/matrix-org/synapse/issues/8564))
- Fix a longstanding bug where invalid ignored users in account data could break clients. ([\#8454](https://github.com/matrix-org/synapse/issues/8454))
- Fix a bug where backfilling a room with an event that was missing the `redacts` field would break. ([\#8457](https://github.com/matrix-org/synapse/issues/8457))
- Don't attempt to respond to some requests if the client has already disconnected. ([\#8465](https://github.com/matrix-org/synapse/issues/8465))
- Fix message duplication if something goes wrong after persisting the event. ([\#8476](https://github.com/matrix-org/synapse/issues/8476))
- Fix incremental sync returning an incorrect `prev_batch` token in timeline section, which when used to paginate returned events that were included in the incremental sync. Broken since v0.16.0. ([\#8486](https://github.com/matrix-org/synapse/issues/8486))
- Expose the `uk.half-shot.msc2778.login.application_service` to clients from the login API. This feature was added in v1.21.0, but was not exposed as a potential login flow. ([\#8504](https://github.com/matrix-org/synapse/issues/8504))
- Fix error code for `/profile/{userId}/displayname` to be `M_BAD_JSON`. ([\#8517](https://github.com/matrix-org/synapse/issues/8517))
- Fix a bug introduced in v1.7.0 that could cause Synapse to insert values from non-state `m.room.retention` events into the `room_retention` database table. ([\#8527](https://github.com/matrix-org/synapse/issues/8527))
- Fix not sending events over federation when using sharded event writers. ([\#8536](https://github.com/matrix-org/synapse/issues/8536))
- Fix a long standing bug where email notifications for encrypted messages were blank. ([\#8545](https://github.com/matrix-org/synapse/issues/8545))
- Fix increase in the number of `There was no active span...` errors logged when using OpenTracing. ([\#8567](https://github.com/matrix-org/synapse/issues/8567))
- Fix a bug that prevented errors encountered during execution of the `synapse_port_db` from being correctly printed. ([\#8585](https://github.com/matrix-org/synapse/issues/8585))
- Fix appservice transactions to only include a maximum of 100 persistent and 100 ephemeral events. ([\#8606](https://github.com/matrix-org/synapse/issues/8606))
- Added multi-arch support (arm64,arm/v7) for the docker images. Contributed by @maquis196. ([\#7921](https://github.com/matrix-org/synapse/issues/7921))
- Add support for passing commandline args to the synapse process. Contributed by @samuel-p. ([\#8390](https://github.com/matrix-org/synapse/issues/8390))
Improved Documentation
----------------------
- Update the directions for using the manhole with coroutines. ([\#8462](https://github.com/matrix-org/synapse/issues/8462))
- Improve readme by adding new shield.io badges. ([\#8493](https://github.com/matrix-org/synapse/issues/8493))
- Added note about docker in manhole.md regarding which ip address to bind to. Contributed by @Maquis196. ([\#8526](https://github.com/matrix-org/synapse/issues/8526))
- Document the new behaviour of the `allowed_lifetime_min` and `allowed_lifetime_max` settings in the room retention configuration. ([\#8529](https://github.com/matrix-org/synapse/issues/8529))
Deprecations and Removals
-------------------------
- Drop unused `device_max_stream_id` table. ([\#8589](https://github.com/matrix-org/synapse/issues/8589))
Internal Changes
----------------
- Check for unreachable code with mypy. ([\#8432](https://github.com/matrix-org/synapse/issues/8432))
- Add unit test for event persister sharding. ([\#8433](https://github.com/matrix-org/synapse/issues/8433))
- Allow events to be sent to clients sooner when using sharded event persisters. ([\#8439](https://github.com/matrix-org/synapse/issues/8439), [\#8488](https://github.com/matrix-org/synapse/issues/8488), [\#8496](https://github.com/matrix-org/synapse/issues/8496), [\#8499](https://github.com/matrix-org/synapse/issues/8499))
- Configure `public_baseurl` when using demo scripts. ([\#8443](https://github.com/matrix-org/synapse/issues/8443))
- Add SQL logging on queries that happen during startup. ([\#8448](https://github.com/matrix-org/synapse/issues/8448))
- Speed up unit tests when using PostgreSQL. ([\#8450](https://github.com/matrix-org/synapse/issues/8450))
- Reduce inconsistencies between codepaths for membership and non-membership events. ([\#8463](https://github.com/matrix-org/synapse/issues/8463))
- Combine `SpamCheckerApi` with the more generic `ModuleApi`. ([\#8464](https://github.com/matrix-org/synapse/issues/8464))
- Additional testing for `ThirdPartyEventRules`. ([\#8468](https://github.com/matrix-org/synapse/issues/8468))
- Add `-d` option to `./scripts-dev/lint.sh` to lint files that have changed since the last git commit. ([\#8472](https://github.com/matrix-org/synapse/issues/8472))
- Unblacklist some sytests. ([\#8474](https://github.com/matrix-org/synapse/issues/8474))
- Include the log level in the phone home stats. ([\#8477](https://github.com/matrix-org/synapse/issues/8477))
- Remove outdated sphinx documentation, scripts and configuration. ([\#8480](https://github.com/matrix-org/synapse/issues/8480))
- Clarify error message when plugin config parsers raise an error. ([\#8492](https://github.com/matrix-org/synapse/issues/8492))
- Remove the deprecated `Handlers` object. ([\#8494](https://github.com/matrix-org/synapse/issues/8494))
- Fix a threadsafety bug in unit tests. ([\#8497](https://github.com/matrix-org/synapse/issues/8497))
- Add user agent to user_daily_visits table. ([\#8503](https://github.com/matrix-org/synapse/issues/8503))
- Add type hints to various parts of the code base. ([\#8407](https://github.com/matrix-org/synapse/issues/8407), [\#8505](https://github.com/matrix-org/synapse/issues/8505), [\#8507](https://github.com/matrix-org/synapse/issues/8507), [\#8547](https://github.com/matrix-org/synapse/issues/8547), [\#8562](https://github.com/matrix-org/synapse/issues/8562), [\#8609](https://github.com/matrix-org/synapse/issues/8609))
- Remove unused code from the test framework. ([\#8514](https://github.com/matrix-org/synapse/issues/8514))
- Apply some internal fixes to the `HomeServer` class to make its code more idiomatic and statically-verifiable. ([\#8515](https://github.com/matrix-org/synapse/issues/8515))
- Factor out common code between `RoomMemberHandler._locally_reject_invite` and `EventCreationHandler.create_event`. ([\#8537](https://github.com/matrix-org/synapse/issues/8537))
- Improve database performance by executing more queries without starting transactions. ([\#8542](https://github.com/matrix-org/synapse/issues/8542))
- Rename `Cache` to `DeferredCache`, to better reflect its purpose. ([\#8548](https://github.com/matrix-org/synapse/issues/8548))
- Move metric registration code down into `LruCache`. ([\#8561](https://github.com/matrix-org/synapse/issues/8561), [\#8591](https://github.com/matrix-org/synapse/issues/8591))
- Replace `DeferredCache` with the lighter-weight `LruCache` where possible. ([\#8563](https://github.com/matrix-org/synapse/issues/8563))
- Add virtualenv-generated folders to `.gitignore`. ([\#8566](https://github.com/matrix-org/synapse/issues/8566))
- Add `get_immediate` method to `DeferredCache`. ([\#8568](https://github.com/matrix-org/synapse/issues/8568))
- Fix mypy not properly checking across the codebase, additionally, fix a typing assertion error in `handlers/auth.py`. ([\#8569](https://github.com/matrix-org/synapse/issues/8569))
- Modify `DeferredCache.get()` to return `Deferred`s instead of `ObservableDeferred`s. ([\#8572](https://github.com/matrix-org/synapse/issues/8572))
- Adjust a protocol-type definition to fit `sqlite3` assertions. ([\#8577](https://github.com/matrix-org/synapse/issues/8577))
- Support macOS on the `synmark` benchmark runner. ([\#8578](https://github.com/matrix-org/synapse/issues/8578))
- Update `mypy` static type checker to 0.790. ([\#8583](https://github.com/matrix-org/synapse/issues/8583), [\#8600](https://github.com/matrix-org/synapse/issues/8600))
- Re-organize the structured logging code to separate the TCP transport handling from the JSON formatting. ([\#8587](https://github.com/matrix-org/synapse/issues/8587))
- Remove extraneous unittest logging decorators from unit tests. ([\#8592](https://github.com/matrix-org/synapse/issues/8592))
- Minor optimisations in caching code. ([\#8593](https://github.com/matrix-org/synapse/issues/8593), [\#8594](https://github.com/matrix-org/synapse/issues/8594))
Debian packages and Docker images have been rebuilt using the latest versions of dependency libraries, including authlib 0.15.1. Please see bugfixes below.
- An updated version of the authlib dependency is included in the Docker and Debian images to fix an issue using OpenID Connect. See [\#8534](https://github.com/matrix-org/synapse/issues/8534) for details.
- Fix duplication of events on high traffic servers, caused by PostgreSQL `could not serialize access due to concurrent update` errors. ([\#8456](https://github.com/matrix-org/synapse/issues/8456))
- Do not expose the experimental `uk.half-shot.msc2778.login.application_service` flow in the login API, which caused a compatibility problem with Element iOS. ([\#8440](https://github.com/matrix-org/synapse/issues/8440))
- Fix DB query on startup for negative streams which caused long start up times. Introduced in [\#8374](https://github.com/matrix-org/synapse/issues/8374). ([\#8447](https://github.com/matrix-org/synapse/issues/8447))
- Require the user to confirm that their password should be reset after clicking the email confirmation link. ([\#8004](https://github.com/matrix-org/synapse/issues/8004))
- Add an admin API `GET /_synapse/admin/v1/event_reports` to read entries of table `event_reports`. Contributed by @dklimpel. ([\#8217](https://github.com/matrix-org/synapse/issues/8217))
- Consolidate the SSO error template across all configuration. ([\#8248](https://github.com/matrix-org/synapse/issues/8248), [\#8405](https://github.com/matrix-org/synapse/issues/8405))
- Add a configuration option to specify a whitelist of domains that a user can be redirected to after validating their email or phone number. ([\#8275](https://github.com/matrix-org/synapse/issues/8275), [\#8417](https://github.com/matrix-org/synapse/issues/8417))
- Add experimental support for sharding event persister. ([\#8294](https://github.com/matrix-org/synapse/issues/8294), [\#8387](https://github.com/matrix-org/synapse/issues/8387), [\#8396](https://github.com/matrix-org/synapse/issues/8396), [\#8419](https://github.com/matrix-org/synapse/issues/8419))
- Add the room topic and avatar to the room details admin API. ([\#8305](https://github.com/matrix-org/synapse/issues/8305))
- Add an admin API for querying rooms where a user is a member. Contributed by @dklimpel. ([\#8306](https://github.com/matrix-org/synapse/issues/8306))
- Add `uk.half-shot.msc2778.login.application_service` login type to allow appservices to login. ([\#8320](https://github.com/matrix-org/synapse/issues/8320))
- Add a configuration option that allows existing users to log in with OpenID Connect. Contributed by @BBBSnowball and @OmmyZhang. ([\#8345](https://github.com/matrix-org/synapse/issues/8345))
- Add prometheus metrics for replication requests. ([\#8406](https://github.com/matrix-org/synapse/issues/8406))
- Support passing additional single sign-on parameters to the client. ([\#8413](https://github.com/matrix-org/synapse/issues/8413))
- Add experimental reporting of metrics on expensive rooms for state-resolution. ([\#8420](https://github.com/matrix-org/synapse/issues/8420))
- Add experimental prometheus metric to track numbers of "large" rooms for state resolutiom. ([\#8425](https://github.com/matrix-org/synapse/issues/8425))
- Add prometheus metrics to track federation delays. ([\#8430](https://github.com/matrix-org/synapse/issues/8430))
Bugfixes
--------
- Fix a bug in the media repository where remote thumbnails with the same size but different crop methods would overwrite each other. Contributed by @deepbluev7. ([\#7124](https://github.com/matrix-org/synapse/issues/7124))
- Fix inconsistent handling of non-existent push rules, and stop tracking the `enabled` state of removed push rules. ([\#7796](https://github.com/matrix-org/synapse/issues/7796))
- Fix a longstanding bug when storing a media file with an empty `upload_name`. ([\#7905](https://github.com/matrix-org/synapse/issues/7905))
- Fix messages not being sent over federation until an event is sent into the same room. ([\#8230](https://github.com/matrix-org/synapse/issues/8230), [\#8247](https://github.com/matrix-org/synapse/issues/8247), [\#8258](https://github.com/matrix-org/synapse/issues/8258), [\#8272](https://github.com/matrix-org/synapse/issues/8272), [\#8322](https://github.com/matrix-org/synapse/issues/8322))
- Fix a longstanding bug where files that could not be thumbnailed would result in an Internal Server Error. ([\#8236](https://github.com/matrix-org/synapse/issues/8236), [\#8435](https://github.com/matrix-org/synapse/issues/8435))
- Upgrade minimum version of `canonicaljson` to version 1.4.0, to fix an unicode encoding issue. ([\#8262](https://github.com/matrix-org/synapse/issues/8262))
- Fix stack overflow when stderr is redirected to the logging system, and the logging system encounters an error. ([\#8268](https://github.com/matrix-org/synapse/issues/8268))
- Fix a bug which cause the logging system to report errors, if `DEBUG` was enabled and no `context` filter was applied. ([\#8278](https://github.com/matrix-org/synapse/issues/8278))
- Fix edge case where push could get delayed for a user until a later event was pushed. ([\#8287](https://github.com/matrix-org/synapse/issues/8287))
- Fix fetching malformed events from remote servers. ([\#8324](https://github.com/matrix-org/synapse/issues/8324))
- Fix `UnboundLocalError` from occuring when appservices send a malformed register request. ([\#8329](https://github.com/matrix-org/synapse/issues/8329))
- Don't send push notifications to expired user accounts. ([\#8353](https://github.com/matrix-org/synapse/issues/8353))
- Fix a regression in v1.19.0 with reactivating users through the admin API. ([\#8362](https://github.com/matrix-org/synapse/issues/8362))
- Fix a bug where during device registration the length of the device name wasn't limited. ([\#8364](https://github.com/matrix-org/synapse/issues/8364))
- Include `guest_access` in the fields that are checked for null bytes when updating `room_stats_state`. Broke in v1.7.2. ([\#8373](https://github.com/matrix-org/synapse/issues/8373))
- Fix theoretical race condition where events are not sent down `/sync` if the synchrotron worker is restarted without restarting other workers. ([\#8374](https://github.com/matrix-org/synapse/issues/8374))
- Fix a bug which could cause errors in rooms with malformed membership events, on servers using sqlite. ([\#8385](https://github.com/matrix-org/synapse/issues/8385))
- Fix "Re-starting finished log context" warning when receiving an event we already had over federation. ([\#8398](https://github.com/matrix-org/synapse/issues/8398))
- Fix incorrect handling of timeouts on outgoing HTTP requests. ([\#8400](https://github.com/matrix-org/synapse/issues/8400))
- Fix a regression in v1.20.0 in the `synapse_port_db` script regarding the `ui_auth_sessions_ips` table. ([\#8410](https://github.com/matrix-org/synapse/issues/8410))
- Remove unnecessary 3PID registration check when resetting password via an email address. Bug introduced in v0.34.0rc2. ([\#8414](https://github.com/matrix-org/synapse/issues/8414))
Improved Documentation
----------------------
- Add `/_synapse/client` to the reverse proxy documentation. ([\#8227](https://github.com/matrix-org/synapse/issues/8227))
- Add note to the reverse proxy settings documentation about disabling Apache's mod_security2. Contributed by Julian Fietkau (@jfietkau). ([\#8375](https://github.com/matrix-org/synapse/issues/8375))
- Improve description of `server_name` config option in `homserver.yaml`. ([\#8415](https://github.com/matrix-org/synapse/issues/8415))
Deprecations and Removals
-------------------------
- Drop support for `prometheus_client` older than 0.4.0. ([\#8426](https://github.com/matrix-org/synapse/issues/8426))
Internal Changes
----------------
- Fix tests on distros which disable TLSv1.0. Contributed by @danc86. ([\#8208](https://github.com/matrix-org/synapse/issues/8208))
- Simplify the distributor code to avoid unnecessary work. ([\#8216](https://github.com/matrix-org/synapse/issues/8216))
- Remove the `populate_stats_process_rooms_2` background job and restore functionality to `populate_stats_process_rooms`. ([\#8243](https://github.com/matrix-org/synapse/issues/8243))
- Clean up type hints for `PaginationConfig`. ([\#8250](https://github.com/matrix-org/synapse/issues/8250), [\#8282](https://github.com/matrix-org/synapse/issues/8282))
- Track the latest event for every destination and room for catch-up after federation outage. ([\#8256](https://github.com/matrix-org/synapse/issues/8256))
- Fix non-user visible bug in implementation of `MultiWriterIdGenerator.get_current_token_for_writer`. ([\#8257](https://github.com/matrix-org/synapse/issues/8257))
- Switch to the JSON implementation from the standard library. ([\#8259](https://github.com/matrix-org/synapse/issues/8259))
- Add type hints to `synapse.util.async_helpers`. ([\#8260](https://github.com/matrix-org/synapse/issues/8260))
- Simplify tests that mock asynchronous functions. ([\#8261](https://github.com/matrix-org/synapse/issues/8261))
- Add type hints to `StreamToken` and `RoomStreamToken` classes. ([\#8279](https://github.com/matrix-org/synapse/issues/8279))
- Change `StreamToken.room_key` to be a `RoomStreamToken` instance. ([\#8281](https://github.com/matrix-org/synapse/issues/8281))
- Refactor notifier code to correctly use the max event stream position. ([\#8288](https://github.com/matrix-org/synapse/issues/8288))
- Use slotted classes where possible. ([\#8296](https://github.com/matrix-org/synapse/issues/8296))
- Support testing the local Synapse checkout against the [Complement homeserver test suite](https://github.com/matrix-org/complement/). ([\#8317](https://github.com/matrix-org/synapse/issues/8317))
- Update outdated usages of `metaclass` to python 3 syntax. ([\#8326](https://github.com/matrix-org/synapse/issues/8326))
- Move lint-related dependencies to package-extra field, update CONTRIBUTING.md to utilise this. ([\#8330](https://github.com/matrix-org/synapse/issues/8330), [\#8377](https://github.com/matrix-org/synapse/issues/8377))
- Use the `admin_patterns` helper in additional locations. ([\#8331](https://github.com/matrix-org/synapse/issues/8331))
- Fix test logging to allow braces in log output. ([\#8335](https://github.com/matrix-org/synapse/issues/8335))
- Remove `__future__` imports related to Python 2 compatibility. ([\#8337](https://github.com/matrix-org/synapse/issues/8337))
- Simplify `super()` calls to Python 3 syntax. ([\#8344](https://github.com/matrix-org/synapse/issues/8344))
- Fix bad merge from `release-v1.20.0` branch to `develop`. ([\#8354](https://github.com/matrix-org/synapse/issues/8354))
- Factor out a `_send_dummy_event_for_room` method. ([\#8370](https://github.com/matrix-org/synapse/issues/8370))
- Improve logging of state resolution. ([\#8371](https://github.com/matrix-org/synapse/issues/8371))
- Add type annotations to `SimpleHttpClient`. ([\#8372](https://github.com/matrix-org/synapse/issues/8372))
- Refactor ID generators to use `async with` syntax. ([\#8383](https://github.com/matrix-org/synapse/issues/8383))
- Create a mechanism for marking tests "logcontext clean". ([\#8399](https://github.com/matrix-org/synapse/issues/8399))
- A pair of tiny cleanups in the federation request code. ([\#8401](https://github.com/matrix-org/synapse/issues/8401))
- Add checks on startup that PostgreSQL sequences are consistent with their associated tables. ([\#8402](https://github.com/matrix-org/synapse/issues/8402))
- Do not include appservice users when calculating the total MAU for a server. ([\#8404](https://github.com/matrix-org/synapse/issues/8404))
- Typing fixes for `synapse.handlers.federation`. ([\#8422](https://github.com/matrix-org/synapse/issues/8422))
- Various refactors to simplify stream token handling. ([\#8423](https://github.com/matrix-org/synapse/issues/8423))
- Make stream token serializing/deserializing async. ([\#8427](https://github.com/matrix-org/synapse/issues/8427))
- Fix a bug introduced in v1.20.0 which caused variables to be incorrectly escaped in Jinja2 templates. ([\#8394](https://github.com/matrix-org/synapse/issues/8394))
- Fix a longstanding bug where back pagination over federation could get stuck if it failed to handle a received event. ([\#8349](https://github.com/matrix-org/synapse/issues/8349))
Internal Changes
----------------
- Blacklist [MSC2753](https://github.com/matrix-org/matrix-doc/pull/2753) SyTests until it is implemented. ([\#8285](https://github.com/matrix-org/synapse/issues/8285))
- Partially mitigate bug where newly joined servers couldn't get past events in a room when there is a malformed event. ([\#8350](https://github.com/matrix-org/synapse/issues/8350))
- Fix a bug introduced in v1.20.0rc1 where the wrong exception was raised when invalid JSON data is encountered. ([\#8291](https://github.com/matrix-org/synapse/issues/8291))
- Fix a bug introduced in v1.20.0rc1 causing some features related to notifications to misbehave following the implementation of unread counts. ([\#8280](https://github.com/matrix-org/synapse/issues/8280))
Some older clients used a [disallowed character](https://matrix.org/docs/spec/client_server/r0.6.1#post-matrix-client-r0-register-email-requesttoken) (`:`) in the `client_secret` parameter of various endpoints. The incorrect behaviour was allowed for backwards compatibility, but is now being removed from Synapse as most users have updated their client. Further context can be found at [\#6766](https://github.com/matrix-org/synapse/issues/6766).
Features
--------
- Add an endpoint to query your shared rooms with another user as an implementation of [MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666). ([\#7785](https://github.com/matrix-org/synapse/issues/7785))
- Iteratively encode JSON to avoid blocking the reactor. ([\#8013](https://github.com/matrix-org/synapse/issues/8013), [\#8116](https://github.com/matrix-org/synapse/issues/8116))
- Add support for shadow-banning users (ignoring any message send requests). ([\#8034](https://github.com/matrix-org/synapse/issues/8034), [\#8092](https://github.com/matrix-org/synapse/issues/8092), [\#8095](https://github.com/matrix-org/synapse/issues/8095), [\#8142](https://github.com/matrix-org/synapse/issues/8142), [\#8152](https://github.com/matrix-org/synapse/issues/8152), [\#8157](https://github.com/matrix-org/synapse/issues/8157), [\#8158](https://github.com/matrix-org/synapse/issues/8158), [\#8176](https://github.com/matrix-org/synapse/issues/8176))
- Use the default template file when its equivalent is not found in a custom template directory. ([\#8037](https://github.com/matrix-org/synapse/issues/8037), [\#8107](https://github.com/matrix-org/synapse/issues/8107), [\#8252](https://github.com/matrix-org/synapse/issues/8252))
- Add unread messages count to sync responses, as specified in [MSC2654](https://github.com/matrix-org/matrix-doc/pull/2654). ([\#8059](https://github.com/matrix-org/synapse/issues/8059), [\#8254](https://github.com/matrix-org/synapse/issues/8254), [\#8270](https://github.com/matrix-org/synapse/issues/8270), [\#8274](https://github.com/matrix-org/synapse/issues/8274))
- Optimise `/federation/v1/user/devices/` API by only returning devices with encryption keys. ([\#8198](https://github.com/matrix-org/synapse/issues/8198))
Bugfixes
--------
- Fix a memory leak by limiting the length of time that messages will be queued for a remote server that has been unreachable. ([\#7864](https://github.com/matrix-org/synapse/issues/7864))
- Synapse now correctly enforces the valid characters in the `client_secret` parameter used in various endpoints. ([\#8101](https://github.com/matrix-org/synapse/issues/8101))
- Fix a bug introduced in v1.7.2 impacting message retention policies that would allow federated homeservers to dictate a retention period that's lower than the configured minimum allowed duration in the configuration file. ([\#8104](https://github.com/matrix-org/synapse/issues/8104))
- Fix a long-standing bug where invalid JSON would be accepted by Synapse. ([\#8106](https://github.com/matrix-org/synapse/issues/8106))
- Fix a bug introduced in Synapse v1.12.0 which could cause `/sync` requests to fail with a 404 if you had a very old outstanding room invite. ([\#8110](https://github.com/matrix-org/synapse/issues/8110))
- Return a proper error code when the rooms of an invalid group are requested. ([\#8129](https://github.com/matrix-org/synapse/issues/8129))
- Fix a bug which could cause a leaked postgres connection if synapse was set to daemonize. ([\#8131](https://github.com/matrix-org/synapse/issues/8131))
- Clarify the error code if a user tries to register with a numeric ID. This bug was introduced in v1.15.0. ([\#8135](https://github.com/matrix-org/synapse/issues/8135))
- Fix a bug where appservices with ratelimiting disabled would still be ratelimited when joining rooms. This bug was introduced in v1.19.0. ([\#8139](https://github.com/matrix-org/synapse/issues/8139))
- Fix a longstanding bug where user directory updates could break when unexpected profile data was included in events. ([\#8223](https://github.com/matrix-org/synapse/issues/8223))
- Fix a longstanding bug where stats updates could break when unexpected profile data was included in events. ([\#8226](https://github.com/matrix-org/synapse/issues/8226))
- Fix slow start times for large servers by removing a table scan of the `users` table from startup code. ([\#8271](https://github.com/matrix-org/synapse/issues/8271))
Updates to the Docker image
---------------------------
- Fix builds of the Docker image on non-x86 platforms. ([\#8144](https://github.com/matrix-org/synapse/issues/8144))
- Added curl for healthcheck support and readme updates for the change. Contributed by @maquis196. ([\#8147](https://github.com/matrix-org/synapse/issues/8147))
Improved Documentation
----------------------
- Link to matrix-synapse-rest-password-provider in the password provider documentation. ([\#8111](https://github.com/matrix-org/synapse/issues/8111))
- Updated documentation to note that Synapse does not follow `HTTP 308` redirects due to an upstream library not supporting them. Contributed by Ryan Cole. ([\#8120](https://github.com/matrix-org/synapse/issues/8120))
- Explain better what GDPR-erased means when deactivating a user. ([\#8189](https://github.com/matrix-org/synapse/issues/8189))
Internal Changes
----------------
- Add filter `name` to the `/users` admin API, which filters by user ID or displayname. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#7377](https://github.com/matrix-org/synapse/issues/7377), [\#8163](https://github.com/matrix-org/synapse/issues/8163))
- Reduce run times of some unit tests by advancing the reactor a fewer number of times. ([\#7757](https://github.com/matrix-org/synapse/issues/7757))
- Don't fail `/submit_token` requests on incorrect session ID if `request_token_inhibit_3pid_errors` is turned on. ([\#7991](https://github.com/matrix-org/synapse/issues/7991))
- Convert various parts of the codebase to async/await. ([\#8071](https://github.com/matrix-org/synapse/issues/8071), [\#8072](https://github.com/matrix-org/synapse/issues/8072), [\#8074](https://github.com/matrix-org/synapse/issues/8074), [\#8075](https://github.com/matrix-org/synapse/issues/8075), [\#8076](https://github.com/matrix-org/synapse/issues/8076), [\#8087](https://github.com/matrix-org/synapse/issues/8087), [\#8100](https://github.com/matrix-org/synapse/issues/8100), [\#8119](https://github.com/matrix-org/synapse/issues/8119), [\#8121](https://github.com/matrix-org/synapse/issues/8121), [\#8133](https://github.com/matrix-org/synapse/issues/8133), [\#8156](https://github.com/matrix-org/synapse/issues/8156), [\#8162](https://github.com/matrix-org/synapse/issues/8162), [\#8166](https://github.com/matrix-org/synapse/issues/8166), [\#8168](https://github.com/matrix-org/synapse/issues/8168), [\#8173](https://github.com/matrix-org/synapse/issues/8173), [\#8191](https://github.com/matrix-org/synapse/issues/8191), [\#8192](https://github.com/matrix-org/synapse/issues/8192), [\#8193](https://github.com/matrix-org/synapse/issues/8193), [\#8194](https://github.com/matrix-org/synapse/issues/8194), [\#8195](https://github.com/matrix-org/synapse/issues/8195), [\#8197](https://github.com/matrix-org/synapse/issues/8197), [\#8199](https://github.com/matrix-org/synapse/issues/8199), [\#8200](https://github.com/matrix-org/synapse/issues/8200), [\#8201](https://github.com/matrix-org/synapse/issues/8201), [\#8202](https://github.com/matrix-org/synapse/issues/8202), [\#8207](https://github.com/matrix-org/synapse/issues/8207), [\#8213](https://github.com/matrix-org/synapse/issues/8213), [\#8214](https://github.com/matrix-org/synapse/issues/8214))
- Remove some unused database functions. ([\#8085](https://github.com/matrix-org/synapse/issues/8085))
- Add type hints to various parts of the codebase. ([\#8090](https://github.com/matrix-org/synapse/issues/8090), [\#8127](https://github.com/matrix-org/synapse/issues/8127), [\#8187](https://github.com/matrix-org/synapse/issues/8187), [\#8241](https://github.com/matrix-org/synapse/issues/8241), [\#8140](https://github.com/matrix-org/synapse/issues/8140), [\#8183](https://github.com/matrix-org/synapse/issues/8183), [\#8232](https://github.com/matrix-org/synapse/issues/8232), [\#8235](https://github.com/matrix-org/synapse/issues/8235), [\#8237](https://github.com/matrix-org/synapse/issues/8237), [\#8244](https://github.com/matrix-org/synapse/issues/8244))
- Return the previous stream token if a non-member event is a duplicate. ([\#8093](https://github.com/matrix-org/synapse/issues/8093), [\#8112](https://github.com/matrix-org/synapse/issues/8112))
- Separate `get_current_token` into two since there are two different use cases for it. ([\#8113](https://github.com/matrix-org/synapse/issues/8113))
- Reduce the amount of whitespace in JSON stored and sent in responses. ([\#8124](https://github.com/matrix-org/synapse/issues/8124))
- Update the test federation client to handle streaming responses. ([\#8130](https://github.com/matrix-org/synapse/issues/8130))
- Micro-optimisations to `get_auth_chain_ids`. ([\#8132](https://github.com/matrix-org/synapse/issues/8132))
- Refactor `StreamIdGenerator` and `MultiWriterIdGenerator` to have the same interface. ([\#8161](https://github.com/matrix-org/synapse/issues/8161))
- Add functions to `MultiWriterIdGen` used by events stream. ([\#8164](https://github.com/matrix-org/synapse/issues/8164), [\#8179](https://github.com/matrix-org/synapse/issues/8179))
- Fix tests that were broken due to the merge of 1.19.1. ([\#8167](https://github.com/matrix-org/synapse/issues/8167))
- Make `SlavedIdTracker.advance` have the same interface as `MultiWriterIDGenerator`. ([\#8171](https://github.com/matrix-org/synapse/issues/8171))
- Remove unused `is_guest` parameter from, and add safeguard to, `MessageHandler.get_room_data`. ([\#8174](https://github.com/matrix-org/synapse/issues/8174), [\#8181](https://github.com/matrix-org/synapse/issues/8181))
- Standardize the mypy configuration. ([\#8175](https://github.com/matrix-org/synapse/issues/8175))
- Refactor some of `LoginRestServlet`'s helper methods, and move them to `AuthHandler` for easier reuse. ([\#8182](https://github.com/matrix-org/synapse/issues/8182))
- Fix `wait_for_stream_position` to allow multiple waiters on same stream ID. ([\#8196](https://github.com/matrix-org/synapse/issues/8196))
- Make `MultiWriterIDGenerator` work for streams that use negative values. ([\#8203](https://github.com/matrix-org/synapse/issues/8203))
- Refactor queries for device keys and cross-signatures. ([\#8204](https://github.com/matrix-org/synapse/issues/8204), [\#8205](https://github.com/matrix-org/synapse/issues/8205), [\#8222](https://github.com/matrix-org/synapse/issues/8222), [\#8224](https://github.com/matrix-org/synapse/issues/8224), [\#8225](https://github.com/matrix-org/synapse/issues/8225), [\#8231](https://github.com/matrix-org/synapse/issues/8231), [\#8233](https://github.com/matrix-org/synapse/issues/8233), [\#8234](https://github.com/matrix-org/synapse/issues/8234))
- Fix type hints for functions decorated with `@cached`. ([\#8240](https://github.com/matrix-org/synapse/issues/8240))
- Remove obsolete `order` field from federation send queues. ([\#8245](https://github.com/matrix-org/synapse/issues/8245))
- Stop sub-classing from object. ([\#8249](https://github.com/matrix-org/synapse/issues/8249))
- Add more logging to debug slow startup. ([\#8264](https://github.com/matrix-org/synapse/issues/8264))
- Do not attempt to upgrade database schema on worker processes. ([\#8266](https://github.com/matrix-org/synapse/issues/8266), [\#8276](https://github.com/matrix-org/synapse/issues/8276))
- Fix a bug introduced in v1.19.0 where appservices with ratelimiting disabled would still be ratelimited when joining rooms. ([\#8139](https://github.com/matrix-org/synapse/issues/8139))
- Fix a bug introduced in v1.19.0 that would cause e.g. profile updates to fail due to incorrect application of rate limits on join requests. ([\#8153](https://github.com/matrix-org/synapse/issues/8153))
- Add option to allow server admins to join rooms which fail complexity checks. Contributed by @lugino-emeritus. ([\#7902](https://github.com/matrix-org/synapse/issues/7902))
- Add an option to purge room or not with delete room admin endpoint (`POST /_synapse/admin/v1/rooms/<room_id>/delete`). Contributed by @dklimpel. ([\#7964](https://github.com/matrix-org/synapse/issues/7964))
- Add rate limiting to users joining rooms. ([\#8008](https://github.com/matrix-org/synapse/issues/8008))
- Add a `/health` endpoint to every configured HTTP listener that can be used as a health check endpoint by load balancers. ([\#8048](https://github.com/matrix-org/synapse/issues/8048))
- Allow login to be blocked based on the values of SAML attributes. ([\#8052](https://github.com/matrix-org/synapse/issues/8052))
- Allow guest access to the `GET /_matrix/client/r0/rooms/{room_id}/members` endpoint, according to MSC2689. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#7314](https://github.com/matrix-org/synapse/issues/7314))
- Fix a bug introduced in Synapse v1.7.2 which caused inaccurate membership counts in the room directory. ([\#7977](https://github.com/matrix-org/synapse/issues/7977))
- Fix a long standing bug: 'Duplicate key value violates unique constraint "event_relations_id"' when message retention is configured. ([\#7978](https://github.com/matrix-org/synapse/issues/7978))
- Fix "no create event in auth events" when trying to reject invitation after inviter leaves. Bug introduced in Synapse v1.10.0. ([\#7980](https://github.com/matrix-org/synapse/issues/7980))
- Fix various comments and minor discrepencies in server notices code. ([\#7996](https://github.com/matrix-org/synapse/issues/7996))
- Fix a long standing bug where HTTP HEAD requests resulted in a 400 error. ([\#7999](https://github.com/matrix-org/synapse/issues/7999))
- Fix a long-standing bug which caused two copies of some log lines to be written when synctl was used along with a MemoryHandler logger. ([\#8011](https://github.com/matrix-org/synapse/issues/8011), [\#8012](https://github.com/matrix-org/synapse/issues/8012))
- We no longer publish Docker images with the `-py3` tag suffix, as [announced in the upgrade notes](https://github.com/matrix-org/synapse/blob/develop/docs/upgrade.md#upgrading-to-v1180). ([\#8056](https://github.com/matrix-org/synapse/issues/8056))
- Document how to set up a client .well-known file and fix several pieces of outdated documentation. ([\#7899](https://github.com/matrix-org/synapse/issues/7899))
- Fix typo in `docs/workers.md`. ([\#7992](https://github.com/matrix-org/synapse/issues/7992))
- Add documentation for how to undo a room shutdown. ([\#7998](https://github.com/matrix-org/synapse/issues/7998), [\#8010](https://github.com/matrix-org/synapse/issues/8010))
Internal Changes
----------------
- Reduce the amount of whitespace in JSON stored and sent in responses. Contributed by David Vo. ([\#7372](https://github.com/matrix-org/synapse/issues/7372))
- Switch to the JSON implementation from the standard library and bump the minimum version of the canonicaljson library to 1.2.0. ([\#7936](https://github.com/matrix-org/synapse/issues/7936), [\#7979](https://github.com/matrix-org/synapse/issues/7979))
- Convert various parts of the codebase to async/await. ([\#7947](https://github.com/matrix-org/synapse/issues/7947), [\#7948](https://github.com/matrix-org/synapse/issues/7948), [\#7949](https://github.com/matrix-org/synapse/issues/7949), [\#7951](https://github.com/matrix-org/synapse/issues/7951), [\#7963](https://github.com/matrix-org/synapse/issues/7963), [\#7973](https://github.com/matrix-org/synapse/issues/7973), [\#7975](https://github.com/matrix-org/synapse/issues/7975), [\#7976](https://github.com/matrix-org/synapse/issues/7976), [\#7981](https://github.com/matrix-org/synapse/issues/7981), [\#7987](https://github.com/matrix-org/synapse/issues/7987), [\#7989](https://github.com/matrix-org/synapse/issues/7989), [\#8003](https://github.com/matrix-org/synapse/issues/8003), [\#8014](https://github.com/matrix-org/synapse/issues/8014), [\#8016](https://github.com/matrix-org/synapse/issues/8016), [\#8027](https://github.com/matrix-org/synapse/issues/8027), [\#8031](https://github.com/matrix-org/synapse/issues/8031), [\#8032](https://github.com/matrix-org/synapse/issues/8032), [\#8035](https://github.com/matrix-org/synapse/issues/8035), [\#8042](https://github.com/matrix-org/synapse/issues/8042), [\#8044](https://github.com/matrix-org/synapse/issues/8044), [\#8045](https://github.com/matrix-org/synapse/issues/8045), [\#8061](https://github.com/matrix-org/synapse/issues/8061), [\#8062](https://github.com/matrix-org/synapse/issues/8062), [\#8063](https://github.com/matrix-org/synapse/issues/8063), [\#8066](https://github.com/matrix-org/synapse/issues/8066), [\#8069](https://github.com/matrix-org/synapse/issues/8069), [\#8070](https://github.com/matrix-org/synapse/issues/8070))
- Move some database-related log lines from the default logger to the database/transaction loggers. ([\#7952](https://github.com/matrix-org/synapse/issues/7952))
- Add a script to detect source code files using non-unix line terminators. ([\#7965](https://github.com/matrix-org/synapse/issues/7965), [\#7970](https://github.com/matrix-org/synapse/issues/7970))
- Log the SAML session ID during creation. ([\#7971](https://github.com/matrix-org/synapse/issues/7971))
- Implement new experimental push rules for some users. ([\#7997](https://github.com/matrix-org/synapse/issues/7997))
- Remove redundant and unreliable signature check for v1 Identity Service lookup responses. ([\#8001](https://github.com/matrix-org/synapse/issues/8001))
- Improve the performance of the register endpoint. ([\#8009](https://github.com/matrix-org/synapse/issues/8009))
- Reduce less useful output in the newsfragment CI step. Add a link to the changelog section of the contributing guide on error. ([\#8024](https://github.com/matrix-org/synapse/issues/8024))
- Rename storage layer objects to be more sensible. ([\#8033](https://github.com/matrix-org/synapse/issues/8033))
- Change the default log config to reduce disk I/O and storage for new servers. ([\#8040](https://github.com/matrix-org/synapse/issues/8040))
- Add a comment to `ServerContextFactory` about the use of `SSLv23_METHOD`. ([\#8043](https://github.com/matrix-org/synapse/issues/8043))
- Log `OPTIONS` requests at `DEBUG` rather than `INFO` level to reduce amount logged at `INFO`. ([\#8049](https://github.com/matrix-org/synapse/issues/8049))
- It is no longer necessary to explicitly define `filters` in the logging configuration. (Continuing to do so is redundant but harmless.) ([\#8051](https://github.com/matrix-org/synapse/issues/8051))
- Add and improve type hints. ([\#8058](https://github.com/matrix-org/synapse/issues/8058), [\#8064](https://github.com/matrix-org/synapse/issues/8064), [\#8060](https://github.com/matrix-org/synapse/issues/8060), [\#8067](https://github.com/matrix-org/synapse/issues/8067))
From 10th August 2020, we will no longer publish Docker images with the `-py3` tag suffix. The images tagged with the `-py3` suffix have been identical to the non-suffixed tags since release 0.99.0, and the suffix is obsolete.
On 10th August, we will remove the `latest-py3` tag. Existing per-release tags (such as `v1.18.0-py3`) will not be removed, but no new `-py3` tags will be added.
Scripts relying on the `-py3` suffix will need to be updated.
### TCP-based Replication
When setting up worker processes, we now recommend the use of a Redis server for replication. The old direct TCP connection method is deprecated and will be removed in a future release. See [docs/workers.md](https://github.com/matrix-org/synapse/blob/release-v1.18.0/docs/workers.md) for more details.
- Fix an `AssertionError` exception introduced in v1.18.0rc1. ([\#7876](https://github.com/matrix-org/synapse/issues/7876))
- Fix experimental support for moving typing off master when worker is restarted, which is broken in v1.18.0rc1. ([\#7967](https://github.com/matrix-org/synapse/issues/7967))
Internal Changes
----------------
- Further optimise queueing of inbound replication commands. ([\#7876](https://github.com/matrix-org/synapse/issues/7876))
- Include room states on invite events that are sent to application services. Contributed by @Sorunome. ([\#6455](https://github.com/matrix-org/synapse/issues/6455))
- Add experimental support for running multiple federation sender processes. ([\#7798](https://github.com/matrix-org/synapse/issues/7798))
- Add the option to validate the `iss` and `aud` claims for JWT logins. ([\#7827](https://github.com/matrix-org/synapse/issues/7827))
- Add support for handling registration requests across multiple client reader workers. ([\#7830](https://github.com/matrix-org/synapse/issues/7830))
- Add an admin API to list the users in a room. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#7842](https://github.com/matrix-org/synapse/issues/7842))
- Allow email subjects to be customised through Synapse's configuration. ([\#7846](https://github.com/matrix-org/synapse/issues/7846))
- Add the ability to re-activate an account from the admin API. ([\#7847](https://github.com/matrix-org/synapse/issues/7847), [\#7908](https://github.com/matrix-org/synapse/issues/7908))
- Add experimental support for running multiple pusher workers. ([\#7855](https://github.com/matrix-org/synapse/issues/7855))
- Add experimental support for moving typing off master. ([\#7869](https://github.com/matrix-org/synapse/issues/7869), [\#7959](https://github.com/matrix-org/synapse/issues/7959))
- Report CPU metrics to prometheus for time spent processing replication commands. ([\#7879](https://github.com/matrix-org/synapse/issues/7879))
- Support oEmbed for media previews. ([\#7920](https://github.com/matrix-org/synapse/issues/7920))
- Abort federation requests where the client disconnects before the ratelimiter expires. ([\#7930](https://github.com/matrix-org/synapse/issues/7930))
- Cache responses to `/_matrix/federation/v1/state_ids` to reduce duplicated work. ([\#7931](https://github.com/matrix-org/synapse/issues/7931))
Bugfixes
--------
- Fix detection of out of sync remote device lists when receiving events from remote users. ([\#7815](https://github.com/matrix-org/synapse/issues/7815))
- Fix bug where Synapse fails to process an incoming event over federation if the server is missing too much of the event's auth chain. ([\#7817](https://github.com/matrix-org/synapse/issues/7817))
- Fix a bug causing Synapse to misinterpret the value `off` for `encryption_enabled_by_default_for_room_type` in its configuration file(s) if that value isn't surrounded by quotes. This bug was introduced in v1.16.0. ([\#7822](https://github.com/matrix-org/synapse/issues/7822))
- Fix bug where we did not always pass in `app_name` or `server_name` to email templates, including e.g. for registration emails. ([\#7829](https://github.com/matrix-org/synapse/issues/7829))
- Errors which occur while using the non-standard JWT login now return the proper error: `403 Forbidden` with an error code of `M_FORBIDDEN`. ([\#7844](https://github.com/matrix-org/synapse/issues/7844))
- Fix "AttributeError: 'str' object has no attribute 'get'" error message when applying per-room message retention policies. The bug was introduced in Synapse 1.7.0. ([\#7850](https://github.com/matrix-org/synapse/issues/7850))
- Fix a bug introduced in Synapse 1.10.0 which could cause a "no create event in auth events" error during room creation. ([\#7854](https://github.com/matrix-org/synapse/issues/7854))
- Fix a bug which allowed empty rooms to be rejoined over federation. ([\#7859](https://github.com/matrix-org/synapse/issues/7859))
- Fix 'Unable to find a suitable guest user ID' error when using multiple client_reader workers. ([\#7866](https://github.com/matrix-org/synapse/issues/7866))
- Fix a long standing bug where the tracing of async functions with opentracing was broken. ([\#7872](https://github.com/matrix-org/synapse/issues/7872), [\#7961](https://github.com/matrix-org/synapse/issues/7961))
- Fix "TypeError in `synapse.notifier`" exceptions. ([\#7880](https://github.com/matrix-org/synapse/issues/7880))
- Fix deprecation warning due to invalid escape sequences. ([\#7895](https://github.com/matrix-org/synapse/issues/7895))
Updates to the Docker image
---------------------------
- Base docker image on Debian Buster rather than Alpine Linux. Contributed by @maquis196. ([\#7839](https://github.com/matrix-org/synapse/issues/7839))
Improved Documentation
----------------------
- Provide instructions on using `register_new_matrix_user` via docker. ([\#7885](https://github.com/matrix-org/synapse/issues/7885))
- Change the sample config postgres user section to use `synapse_user` instead of `synapse` to align with the documentation. ([\#7889](https://github.com/matrix-org/synapse/issues/7889))
- Reorder database paragraphs to promote postgres over sqlite. ([\#7933](https://github.com/matrix-org/synapse/issues/7933))
- Update the dates of ACME v1's end of life in [`ACME.md`](https://github.com/matrix-org/synapse/blob/master/docs/ACME.md). ([\#7934](https://github.com/matrix-org/synapse/issues/7934))
- Remove Ubuntu Eoan from the list of `.deb` packages that we build as it is now end-of-life. Contributed by @gary-kim. ([\#7888](https://github.com/matrix-org/synapse/issues/7888))
- Convert various parts of the codebase to async/await. ([\#7851](https://github.com/matrix-org/synapse/issues/7851), [\#7860](https://github.com/matrix-org/synapse/issues/7860), [\#7868](https://github.com/matrix-org/synapse/issues/7868), [\#7871](https://github.com/matrix-org/synapse/issues/7871), [\#7873](https://github.com/matrix-org/synapse/issues/7873), [\#7874](https://github.com/matrix-org/synapse/issues/7874), [\#7884](https://github.com/matrix-org/synapse/issues/7884), [\#7912](https://github.com/matrix-org/synapse/issues/7912), [\#7935](https://github.com/matrix-org/synapse/issues/7935), [\#7939](https://github.com/matrix-org/synapse/issues/7939), [\#7942](https://github.com/matrix-org/synapse/issues/7942), [\#7944](https://github.com/matrix-org/synapse/issues/7944))
and `get_previous_frame` from `synapse.logging.utils` module. ([\#7897](https://github.com/matrix-org/synapse/issues/7897))
- Lint the `contrib/` directory in CI and linting scripts, add `synctl` to the linting script for consistency with CI. ([\#7914](https://github.com/matrix-org/synapse/issues/7914))
- Use Element CSS and logo in notification emails when app name is Element. ([\#7919](https://github.com/matrix-org/synapse/issues/7919))
- Optimisation to /sync handling: skip serializing the response if the client has already disconnected. ([\#7927](https://github.com/matrix-org/synapse/issues/7927))
- When a client disconnects, don't log it as 'Error processing request'. ([\#7928](https://github.com/matrix-org/synapse/issues/7928))
- Add debugging to `/sync` response generation (disabled by default). ([\#7929](https://github.com/matrix-org/synapse/issues/7929))
- Update comments that refer to Deferreds for async functions. ([\#7945](https://github.com/matrix-org/synapse/issues/7945))
- Simplify error handling in federation handler. ([\#7950](https://github.com/matrix-org/synapse/issues/7950))
In some distributions of Synapse 1.16.0, we incorrectly included a database migration which added a new, unused table. This release removes the redundant table.
- Drop table `local_rejections_stream` which was incorrectly added in Synapse 1.16.0. ([\#7816](https://github.com/matrix-org/synapse/issues/7816), [b1beb3ff5](https://github.com/matrix-org/synapse/commit/b1beb3ff5))
- Fix inconsistent handling of upper and lower case in email addresses when used as identifiers for login, etc. Contributed by @dklimpel. ([\#7021](https://github.com/matrix-org/synapse/issues/7021))
- Fix "Tried to close a non-active scope!" error messages when opentracing is enabled. ([\#7732](https://github.com/matrix-org/synapse/issues/7732))
- Fix incorrect error message when database CTYPE was set incorrectly. ([\#7760](https://github.com/matrix-org/synapse/issues/7760))
- Fix to not ignore `set_tweak` actions in Push Rules that have no `value`, as permitted by the specification. ([\#7766](https://github.com/matrix-org/synapse/issues/7766))
- Fix synctl to handle empty config files correctly. Contributed by @kotovalexarian. ([\#7779](https://github.com/matrix-org/synapse/issues/7779))
- Fixes a long standing bug in worker mode where worker information was saved in the devices table instead of the original IP address and user agent. ([\#7797](https://github.com/matrix-org/synapse/issues/7797))
- Fix 'stuck invites' which happen when we are unable to reject a room invite received over federation. ([\#7804](https://github.com/matrix-org/synapse/issues/7804), [\#7809](https://github.com/matrix-org/synapse/issues/7809), [\#7810](https://github.com/matrix-org/synapse/issues/7810))
Updates to the Docker image
---------------------------
- Include libwebp in the Docker file to properly handle webp image uploads. ([\#7791](https://github.com/matrix-org/synapse/issues/7791))
Improved Documentation
----------------------
- Improve the documentation of the non-standard JSON web token login type. ([\#7776](https://github.com/matrix-org/synapse/issues/7776))
- Update doc links for caddy. Contributed by Nicolai Søborg. ([\#7789](https://github.com/matrix-org/synapse/issues/7789))
Internal Changes
----------------
- Refactor getting replication updates from database. ([\#7740](https://github.com/matrix-org/synapse/issues/7740))
- Send push notifications with a high or low priority depending upon whether they may generate user-observable effects. ([\#7765](https://github.com/matrix-org/synapse/issues/7765))
- Use symbolic names for replication stream names. ([\#7768](https://github.com/matrix-org/synapse/issues/7768))
- Add early returns to `_check_for_soft_fail`. ([\#7769](https://github.com/matrix-org/synapse/issues/7769))
- Fix up `synapse.handlers.federation` to pass mypy. ([\#7770](https://github.com/matrix-org/synapse/issues/7770))
- Convert the appserver handler to async/await. ([\#7775](https://github.com/matrix-org/synapse/issues/7775))
- Allow to use higher versions of prometheus_client <0.9.0whichareexpectedtointroducenobreakingchanges.ContributedbyOliverKurz.([\#7780](https://github.com/matrix-org/synapse/issues/7780))
- Update linting scripts and codebase to be compatible with `isort` v5. ([\#7786](https://github.com/matrix-org/synapse/issues/7786))
Please see [below](#synapse-1152-2020-07-02) for more details.
Improved Documentation
----------------------
- Update postgres image in example `docker-compose.yaml` to tag `12-alpine`. ([\#7696](https://github.com/matrix-org/synapse/issues/7696))
Internal Changes
----------------
- Add some metrics for inbound and outbound federation latencies: `synapse_federation_server_pdu_process_time` and `synapse_event_processing_lag_by_event`. ([\#7771](https://github.com/matrix-org/synapse/issues/7771))
- Add support for running multiple media repository workers. See [docs/workers.md](https://github.com/matrix-org/synapse/blob/release-v1.16.0/docs/workers.md) for instructions. ([\#7706](https://github.com/matrix-org/synapse/issues/7706))
- Media can now be marked as safe from quarantined. ([\#7718](https://github.com/matrix-org/synapse/issues/7718))
- Expand the configuration options for auto-join rooms. ([\#7763](https://github.com/matrix-org/synapse/issues/7763))
Bugfixes
--------
- Remove `user_id` from the response to `GET /_matrix/client/r0/presence/{userId}/status` to match the specification. ([\#7606](https://github.com/matrix-org/synapse/issues/7606))
- Accept the proper field (`phone`) for the `m.id.phone` identifier type. The legacy field of `number` is still accepted as a fallback. Bug introduced in v0.20.0. ([\#7687](https://github.com/matrix-org/synapse/issues/7687))
- Fix "Starting db txn 'get_completed_ui_auth_stages' from sentinel context" warning. The bug was introduced in 1.13.0. ([\#7688](https://github.com/matrix-org/synapse/issues/7688))
- Compare the URI and method during user interactive authentication (instead of the URI twice). Bug introduced in 1.13.0. ([\#7689](https://github.com/matrix-org/synapse/issues/7689))
- Fix a long standing bug where the response to the `GET room_keys/version` endpoint had the incorrect type for the `etag` field. ([\#7691](https://github.com/matrix-org/synapse/issues/7691))
- Fix logged error during device resync in opentracing. Broke in v1.14.0. ([\#7698](https://github.com/matrix-org/synapse/issues/7698))
- Do not break push rule evaluation when receiving an event with a non-string body. This is a long-standing bug. ([\#7701](https://github.com/matrix-org/synapse/issues/7701))
- Fixs a long standing bug which resulted in an exception: "TypeError: argument of type 'ObservableDeferred' is not iterable". ([\#7708](https://github.com/matrix-org/synapse/issues/7708))
- The `synapse_port_db` script no longer fails when the `ui_auth_sessions` table is non-empty. This bug has existed since v1.13.0. ([\#7711](https://github.com/matrix-org/synapse/issues/7711))
- Synapse will now fetch media from the proper specified URL (using the r0 prefix instead of the unspecified v1). ([\#7714](https://github.com/matrix-org/synapse/issues/7714))
- Fix the tables ignored by `synapse_port_db` to be in sync the current database schema. ([\#7717](https://github.com/matrix-org/synapse/issues/7717))
- Fix missing `Content-Length` on HTTP responses from the metrics handler. ([\#7730](https://github.com/matrix-org/synapse/issues/7730))
- Fix large state resolutions from stalling Synapse for seconds at a time. ([\#7735](https://github.com/matrix-org/synapse/issues/7735), [\#7746](https://github.com/matrix-org/synapse/issues/7746))
Improved Documentation
----------------------
- Spelling correction in sample_config.yaml. ([\#7652](https://github.com/matrix-org/synapse/issues/7652))
- Added instructions for how to use Keycloak via OpenID Connect to authenticate with Synapse. ([\#7659](https://github.com/matrix-org/synapse/issues/7659))
- Corrected misspelling of PostgreSQL. ([\#7724](https://github.com/matrix-org/synapse/issues/7724))
Deprecations and Removals
-------------------------
- Deprecate `m.login.jwt` login method in favour of `org.matrix.login.jwt`, as `m.login.jwt` is not part of the Matrix spec. ([\#7675](https://github.com/matrix-org/synapse/issues/7675))
Internal Changes
----------------
- Refactor getting replication updates from database. ([\#7636](https://github.com/matrix-org/synapse/issues/7636))
- Clean-up the login fallback code. ([\#7657](https://github.com/matrix-org/synapse/issues/7657))
- Convert the device message and pagination handlers to async/await. ([\#7678](https://github.com/matrix-org/synapse/issues/7678))
- Convert typing handler to async/await. ([\#7679](https://github.com/matrix-org/synapse/issues/7679))
- Require `parameterized` package version to be at least 0.7.0. ([\#7680](https://github.com/matrix-org/synapse/issues/7680))
- Refactor handling of `listeners` configuration settings. ([\#7681](https://github.com/matrix-org/synapse/issues/7681))
- Replace uses of `six.iterkeys`/`iteritems`/`itervalues` with `keys()`/`items()`/`values()`. ([\#7692](https://github.com/matrix-org/synapse/issues/7692))
- Add support for using `rust-python-jaeger-reporter` library to reduce jaeger tracing overhead. ([\#7697](https://github.com/matrix-org/synapse/issues/7697))
- Make Tox actions work on Debian 10. ([\#7703](https://github.com/matrix-org/synapse/issues/7703))
- Replace all remaining uses of `six` with native Python 3 equivalents. Contributed by @ilmari. ([\#7704](https://github.com/matrix-org/synapse/issues/7704))
- Fix broken link in sample config. ([\#7712](https://github.com/matrix-org/synapse/issues/7712))
- Speed up state res v2 across large state differences. ([\#7725](https://github.com/matrix-org/synapse/issues/7725))
- Convert directory handler to async/await. ([\#7727](https://github.com/matrix-org/synapse/issues/7727))
- Move `flake8` to the end of `scripts-dev/lint.sh` as it takes the longest and could cause the script to exit early. ([\#7738](https://github.com/matrix-org/synapse/issues/7738))
- Explain the "test" conditional requirement for dependencies is not all of the modules necessary to run the unit tests. ([\#7751](https://github.com/matrix-org/synapse/issues/7751))
- Add some metrics for inbound and outbound federation latencies: `synapse_federation_server_pdu_process_time` and `synapse_event_processing_lag_by_event`. ([\#7755](https://github.com/matrix-org/synapse/issues/7755))
- Fix a bug introduced in v1.15.0 that would crash Synapse on start when using certain password auth providers. ([\#7684](https://github.com/matrix-org/synapse/issues/7684))
- Fix a bug introduced in v1.15.0 which meant that some 3PID management endpoints were not accessible on the correct URL. ([\#7685](https://github.com/matrix-org/synapse/issues/7685))
- Advertise support for Client-Server API r0.6.0 and remove related unstable feature flags. ([\#6585](https://github.com/matrix-org/synapse/issues/6585))
- Add an option to disable autojoining rooms for guest accounts. ([\#6637](https://github.com/matrix-org/synapse/issues/6637))
- For SAML authentication, add the ability to pass email addresses to be added to new users' accounts via SAML attributes. Contributed by Christopher Cooper. ([\#7385](https://github.com/matrix-org/synapse/issues/7385))
- Add admin APIs to allow server admins to manage users' devices. Contributed by @dklimpel. ([\#7481](https://github.com/matrix-org/synapse/issues/7481))
- Add support for generating thumbnails for WebP images. Previously, users would see an empty box instead of preview image. Contributed by @WGH-. ([\#7586](https://github.com/matrix-org/synapse/issues/7586))
- Allow new users to be registered via the admin API even if the monthly active user limit has been reached. Contributed by @dklimpel. ([\#7263](https://github.com/matrix-org/synapse/issues/7263))
- Fix email notifications not being enabled for new users when created via the Admin API. ([\#7267](https://github.com/matrix-org/synapse/issues/7267))
- Fix str placeholders in an instance of `PrepareDatabaseException`. Introduced in Synapse v1.8.0. ([\#7575](https://github.com/matrix-org/synapse/issues/7575))
- Fix a bug in automatic user creation during first time login with `m.login.jwt`. Regression in v1.6.0. Contributed by @olof. ([\#7585](https://github.com/matrix-org/synapse/issues/7585))
- Fix a bug causing the cross-signing keys to be ignored when resyncing a device list. ([\#7594](https://github.com/matrix-org/synapse/issues/7594))
- Fix metrics failing when there is a large number of active background processes. ([\#7597](https://github.com/matrix-org/synapse/issues/7597))
- Fix bug where returning rooms for a group would fail if it included a room that the server was not in. ([\#7599](https://github.com/matrix-org/synapse/issues/7599))
- Fix duplicate key violation when persisting read markers. ([\#7607](https://github.com/matrix-org/synapse/issues/7607))
- Prevent an entire iteration of the device list resync loop from failing if one server responds with a malformed result. ([\#7609](https://github.com/matrix-org/synapse/issues/7609))
- Fix exceptions when fetching events from a remote host fails. ([\#7622](https://github.com/matrix-org/synapse/issues/7622))
- Make `synctl restart` start synapse if it wasn't running. ([\#7624](https://github.com/matrix-org/synapse/issues/7624))
- Pass device information through to the login endpoint when using the login fallback. ([\#7629](https://github.com/matrix-org/synapse/issues/7629))
- Advertise the `m.login.token` login flow when OpenID Connect is enabled. ([\#7631](https://github.com/matrix-org/synapse/issues/7631))
- Fix bug in account data replication stream. ([\#7656](https://github.com/matrix-org/synapse/issues/7656))
Improved Documentation
----------------------
- Update the OpenBSD installation instructions. ([\#7587](https://github.com/matrix-org/synapse/issues/7587))
- Advertise Python 3.8 support in `setup.py`. ([\#7602](https://github.com/matrix-org/synapse/issues/7602))
- Add a link to `#synapse:matrix.org` in the troubleshooting section of the README. ([\#7603](https://github.com/matrix-org/synapse/issues/7603))
- Clarifications to the admin api documentation. ([\#7647](https://github.com/matrix-org/synapse/issues/7647))
Internal Changes
----------------
- Convert the identity handler to async/await. ([\#7561](https://github.com/matrix-org/synapse/issues/7561))
- Improve query performance for fetching state from a PostgreSQL database. Contributed by @ilmari. ([\#7567](https://github.com/matrix-org/synapse/issues/7567))
- Speed up processing of federation stream RDATA rows. ([\#7584](https://github.com/matrix-org/synapse/issues/7584))
- Add comment to systemd example to show postgresql dependency. ([\#7591](https://github.com/matrix-org/synapse/issues/7591))
- Refactor `Ratelimiter` to limit the amount of expensive config value accesses. ([\#7595](https://github.com/matrix-org/synapse/issues/7595))
- Convert groups handlers to async/await. ([\#7600](https://github.com/matrix-org/synapse/issues/7600))
- Clean up exception handling in `SAML2ResponseResource`. ([\#7614](https://github.com/matrix-org/synapse/issues/7614))
- Check that all asynchronous tasks succeed and general cleanup of `MonthlyActiveUsersTestCase` and `TestMauLimit`. ([\#7619](https://github.com/matrix-org/synapse/issues/7619))
- Convert `get_user_id_by_threepid` to async/await. ([\#7620](https://github.com/matrix-org/synapse/issues/7620))
- Switch to upstream `dh-virtualenv` rather than our fork for Debian package builds. ([\#7621](https://github.com/matrix-org/synapse/issues/7621))
- Update CI scripts to check the number in the newsfile fragment. ([\#7623](https://github.com/matrix-org/synapse/issues/7623))
- Check if the localpart of a Matrix ID is reserved for guest users earlier in the registration flow, as well as when responding to requests to `/register/available`. ([\#7625](https://github.com/matrix-org/synapse/issues/7625))
- Minor cleanups to OpenID Connect integration. ([\#7628](https://github.com/matrix-org/synapse/issues/7628))
- Attempt to fix flaky test: `PhoneHomeStatsTestCase.test_performance_100`. ([\#7634](https://github.com/matrix-org/synapse/issues/7634))
- Fix typos of `m.olm.curve25519-aes-sha2` and `m.megolm.v1.aes-sha2` in comments, test files. ([\#7637](https://github.com/matrix-org/synapse/issues/7637))
- Convert user directory, state deltas, and stats handlers to async/await. ([\#7640](https://github.com/matrix-org/synapse/issues/7640))
- Remove some unused constants. ([\#7644](https://github.com/matrix-org/synapse/issues/7644))
- Fix type information on `assert_*_is_admin` methods. ([\#7645](https://github.com/matrix-org/synapse/issues/7645))
- Convert registration handler to async/await. ([\#7649](https://github.com/matrix-org/synapse/issues/7649))
- Fix cache config to not apply cache factor to event cache. Regression in v1.14.0rc1. ([\#7578](https://github.com/matrix-org/synapse/issues/7578))
- Fix bug where `ReplicationStreamer` was not always started when replication was enabled. Bug introduced in v1.14.0rc1. ([\#7579](https://github.com/matrix-org/synapse/issues/7579))
- Fix specifying individual cache factors for caches with special characters in their name. Regression in v1.14.0rc1. ([\#7580](https://github.com/matrix-org/synapse/issues/7580))
- Synapse's cache factor can now be configured in `homeserver.yaml` by the `caches.global_factor` setting. Additionally, `caches.per_cache_factors` controls the cache factors for individual caches. ([\#6391](https://github.com/matrix-org/synapse/issues/6391))
- Add OpenID Connect login/registration support. Contributed by Quentin Gliech, on behalf of [les Connecteurs](https://connecteu.rs). ([\#7256](https://github.com/matrix-org/synapse/issues/7256), [\#7457](https://github.com/matrix-org/synapse/issues/7457))
- Implement room version 6 per [MSC2240](https://github.com/matrix-org/matrix-doc/pull/2240). ([\#7506](https://github.com/matrix-org/synapse/issues/7506))
- Fix a bug where event updates might not be sent over replication to worker processes after the stream falls behind. ([\#7384](https://github.com/matrix-org/synapse/issues/7384))
- Allow expired user accounts to log out their device sessions. ([\#7443](https://github.com/matrix-org/synapse/issues/7443))
- Fix a bug that would cause Synapse not to resync out-of-sync device lists. ([\#7453](https://github.com/matrix-org/synapse/issues/7453))
- Prevent rooms with 0 members or with invalid version strings from breaking group queries. ([\#7465](https://github.com/matrix-org/synapse/issues/7465))
- Workaround for an upstream Twisted bug that caused Synapse to become unresponsive after startup. ([\#7473](https://github.com/matrix-org/synapse/issues/7473))
- Fix Redis reconnection logic that can result in missed updates over replication if master reconnects to Redis without restarting. ([\#7482](https://github.com/matrix-org/synapse/issues/7482))
- When sending `m.room.member` events, omit `displayname` and `avatar_url` if they aren't set instead of setting them to `null`. Contributed by Aaron Raimist. ([\#7497](https://github.com/matrix-org/synapse/issues/7497))
- Fix incorrect `method` label on `synapse_http_matrixfederationclient_{requests,responses}` prometheus metrics. ([\#7503](https://github.com/matrix-org/synapse/issues/7503))
- Ignore incoming presence events from other homeservers if presence is disabled locally. ([\#7508](https://github.com/matrix-org/synapse/issues/7508))
- Fix a long-standing bug that broke the update remote profile background process. ([\#7511](https://github.com/matrix-org/synapse/issues/7511))
- Hash passwords as early as possible during password reset. ([\#7538](https://github.com/matrix-org/synapse/issues/7538))
- Fix bug where a local user leaving a room could fail under rare circumstances. ([\#7548](https://github.com/matrix-org/synapse/issues/7548))
- Fix "Missing RelayState parameter" error when using user interactive authentication with SAML for some SAML providers. ([\#7552](https://github.com/matrix-org/synapse/issues/7552))
- Fix exception `'GenericWorkerReplicationHandler' object has no attribute 'send_federation_ack'`, introduced in v1.13.0. ([\#7564](https://github.com/matrix-org/synapse/issues/7564))
-`synctl` now warns if it was unable to stop Synapse and will not attempt to start Synapse if nothing was stopped. Contributed by Romain Bouyé. ([\#6598](https://github.com/matrix-org/synapse/issues/6598))
- Update docker runtime image to Alpine v3.11. Contributed by @Starbix. ([\#7398](https://github.com/matrix-org/synapse/issues/7398))
Improved Documentation
----------------------
- Update information about mapping providers for SAML and OpenID. ([\#7458](https://github.com/matrix-org/synapse/issues/7458))
- Add additional reverse proxy example for Caddy v2. Contributed by Jeff Peeler. ([\#7463](https://github.com/matrix-org/synapse/issues/7463))
- Fix copy-paste error in `ServerNoticesConfig` docstring. Contributed by @ptman. ([\#7477](https://github.com/matrix-org/synapse/issues/7477))
- Improve the formatting of `reverse_proxy.md`. ([\#7514](https://github.com/matrix-org/synapse/issues/7514))
- Change the systemd worker service to check that the worker config file exists instead of silently failing. Contributed by David Vo. ([\#7528](https://github.com/matrix-org/synapse/issues/7528))
- Minor clarifications to the TURN docs. ([\#7533](https://github.com/matrix-org/synapse/issues/7533))
Internal Changes
----------------
- Add typing annotations in `synapse.federation`. ([\#7382](https://github.com/matrix-org/synapse/issues/7382))
- Convert the room handler to async/await. ([\#7396](https://github.com/matrix-org/synapse/issues/7396))
- Improve performance of `get_e2e_cross_signing_key`. ([\#7428](https://github.com/matrix-org/synapse/issues/7428))
- Improve performance of `mark_as_sent_devices_by_remote`. ([\#7429](https://github.com/matrix-org/synapse/issues/7429), [\#7562](https://github.com/matrix-org/synapse/issues/7562))
- Add type hints to the SAML handler. ([\#7445](https://github.com/matrix-org/synapse/issues/7445))
- Remove storage method `get_hosts_in_room` that is no longer called anywhere. ([\#7448](https://github.com/matrix-org/synapse/issues/7448))
- Convert the federation handler to async/await. ([\#7459](https://github.com/matrix-org/synapse/issues/7459))
- Convert the search handler to async/await. ([\#7460](https://github.com/matrix-org/synapse/issues/7460))
- Add type hints to `synapse.event_auth`. ([\#7505](https://github.com/matrix-org/synapse/issues/7505))
- Convert the room member handler to async/await. ([\#7507](https://github.com/matrix-org/synapse/issues/7507))
- Add type hints to room member handler. ([\#7513](https://github.com/matrix-org/synapse/issues/7513))
- Fix typing annotations in `tests.replication`. ([\#7518](https://github.com/matrix-org/synapse/issues/7518))
- Remove some redundant Python 2 support code. ([\#7519](https://github.com/matrix-org/synapse/issues/7519))
- All endpoints now respond with a 200 OK for `OPTIONS` requests. ([\#7534](https://github.com/matrix-org/synapse/issues/7534), [\#7560](https://github.com/matrix-org/synapse/issues/7560))
- Synapse now exports [detailed allocator statistics](https://doc.pypy.org/en/latest/gc_info.html#gc-get-stats) and basic GC timings as Prometheus metrics (`pypy_gc_time_seconds_total` and `pypy_memory_bytes`) when run under PyPy. Contributed by Ivan Shapovalov. ([\#7536](https://github.com/matrix-org/synapse/issues/7536))
- Remove Ubuntu Cosmic and Disco from the list of distributions which we provide `.deb`s for, due to end-of-life. ([\#7539](https://github.com/matrix-org/synapse/issues/7539))
- Make worker processes return a stubbed-out response to `GET /presence` requests. ([\#7545](https://github.com/matrix-org/synapse/issues/7545))
- Optimise some references to `hs.config`. ([\#7546](https://github.com/matrix-org/synapse/issues/7546))
- On upgrade room only send canonical alias once. ([\#7547](https://github.com/matrix-org/synapse/issues/7547))
- Fix some indentation inconsistencies in the sample config. ([\#7550](https://github.com/matrix-org/synapse/issues/7550))
- Include `synapse.http.site` in type checking. ([\#7553](https://github.com/matrix-org/synapse/issues/7553))
- Fix some test code to not mangle stacktraces, to make it easier to debug errors. ([\#7554](https://github.com/matrix-org/synapse/issues/7554))
- Update the version of dh-virtualenv we use to build debs, and add focal to the list of target distributions. ([\#7526](https://github.com/matrix-org/synapse/issues/7526))
- Fix a long-standing bug which could cause messages not to be sent over federation, when state events with state keys matching user IDs (such as custom user statuses) were received. ([\#7376](https://github.com/matrix-org/synapse/issues/7376))
- Restore compatibility with non-compliant clients during the user interactive authentication process, fixing a problem introduced in v1.13.0rc1. ([\#7483](https://github.com/matrix-org/synapse/issues/7483))
- Extend the `web_client_location` option to accept an absolute URL to use as a redirect. Adds a warning when running the web client on the same hostname as homeserver. Contributed by Martin Milata. ([\#7006](https://github.com/matrix-org/synapse/issues/7006))
- Set `Referrer-Policy` header to `no-referrer` on media downloads. ([\#7009](https://github.com/matrix-org/synapse/issues/7009))
- Add support for running replication over Redis when using workers. ([\#7040](https://github.com/matrix-org/synapse/issues/7040), [\#7325](https://github.com/matrix-org/synapse/issues/7325), [\#7352](https://github.com/matrix-org/synapse/issues/7352), [\#7401](https://github.com/matrix-org/synapse/issues/7401), [\#7427](https://github.com/matrix-org/synapse/issues/7427), [\#7439](https://github.com/matrix-org/synapse/issues/7439), [\#7446](https://github.com/matrix-org/synapse/issues/7446), [\#7450](https://github.com/matrix-org/synapse/issues/7450), [\#7454](https://github.com/matrix-org/synapse/issues/7454))
- Admin API `POST /_synapse/admin/v1/join/<roomIdOrAlias>` to join users to a room like `auto_join_rooms` for creation of users. ([\#7051](https://github.com/matrix-org/synapse/issues/7051))
- Add options to prevent users from changing their profile or associated 3PIDs. ([\#7096](https://github.com/matrix-org/synapse/issues/7096))
- Support SSO in the user interactive authentication workflow. ([\#7102](https://github.com/matrix-org/synapse/issues/7102), [\#7186](https://github.com/matrix-org/synapse/issues/7186), [\#7279](https://github.com/matrix-org/synapse/issues/7279), [\#7343](https://github.com/matrix-org/synapse/issues/7343))
- Allow server admins to define and enforce a password policy ([MSC2000](https://github.com/matrix-org/matrix-doc/issues/2000)). ([\#7118](https://github.com/matrix-org/synapse/issues/7118))
- Improve the support for SSO authentication on the login fallback page. ([\#7152](https://github.com/matrix-org/synapse/issues/7152), [\#7235](https://github.com/matrix-org/synapse/issues/7235))
- Always whitelist the login fallback in the SSO configuration if `public_baseurl` is set. ([\#7153](https://github.com/matrix-org/synapse/issues/7153))
- Admin users are no longer required to be in a room to create an alias for it. ([\#7191](https://github.com/matrix-org/synapse/issues/7191))
- Require admin privileges to enable room encryption by default. This does not affect existing rooms. ([\#7230](https://github.com/matrix-org/synapse/issues/7230))
- Add a config option for specifying the value of the Accept-Language HTTP header when generating URL previews. ([\#7265](https://github.com/matrix-org/synapse/issues/7265))
- Allow `/requestToken` endpoints to hide the existence (or lack thereof) of 3PID associations on the homeserver. ([\#7315](https://github.com/matrix-org/synapse/issues/7315))
- Add a configuration setting to tweak the threshold for dummy events. ([\#7422](https://github.com/matrix-org/synapse/issues/7422))
Bugfixes
--------
- Don't attempt to use an invalid sqlite config if no database configuration is provided. Contributed by @nekatak. ([\#6573](https://github.com/matrix-org/synapse/issues/6573))
- Fix single-sign on with CAS systems: pass the same service URL when requesting the CAS ticket and when calling the `proxyValidate` URL. Contributed by @Naugrimm. ([\#6634](https://github.com/matrix-org/synapse/issues/6634))
- Fix missing field `default` when fetching user-defined push rules. ([\#6639](https://github.com/matrix-org/synapse/issues/6639))
- Improve error responses when accessing remote public room lists. ([\#6899](https://github.com/matrix-org/synapse/issues/6899), [\#7368](https://github.com/matrix-org/synapse/issues/7368))
- Transfer alias mappings on room upgrade. ([\#6946](https://github.com/matrix-org/synapse/issues/6946))
- Ensure that a user interactive authentication session is tied to a single request. ([\#7068](https://github.com/matrix-org/synapse/issues/7068), [\#7455](https://github.com/matrix-org/synapse/issues/7455))
- Fix a bug in the federation API which could cause occasional "Failed to get PDU" errors. ([\#7089](https://github.com/matrix-org/synapse/issues/7089))
- Return the proper error (`M_BAD_ALIAS`) when a non-existant canonical alias is provided. ([\#7109](https://github.com/matrix-org/synapse/issues/7109))
- Fix a bug which meant that groups updates were not correctly replicated between workers. ([\#7117](https://github.com/matrix-org/synapse/issues/7117))
- Fix starting workers when federation sending not split out. ([\#7133](https://github.com/matrix-org/synapse/issues/7133))
- Ensure `is_verified` is a boolean in responses to `GET /_matrix/client/r0/room_keys/keys`. Also warn the user if they forgot the `version` query param. ([\#7150](https://github.com/matrix-org/synapse/issues/7150))
- Fix error page being shown when a custom SAML handler attempted to redirect when processing an auth response. ([\#7151](https://github.com/matrix-org/synapse/issues/7151))
- Avoid importing `sqlite3` when using the postgres backend. Contributed by David Vo. ([\#7155](https://github.com/matrix-org/synapse/issues/7155))
- Fix excessive CPU usage by `prune_old_outbound_device_pokes` job. ([\#7159](https://github.com/matrix-org/synapse/issues/7159))
- Fix a bug which could cause outbound federation traffic to stop working if a client uploaded an incorrect e2e device signature. ([\#7177](https://github.com/matrix-org/synapse/issues/7177))
- Fix a bug which could cause incorrect 'cyclic dependency' error. ([\#7178](https://github.com/matrix-org/synapse/issues/7178))
- Fix a bug that could cause a user to be invited to a server notices (aka System Alerts) room without any notice being sent. ([\#7199](https://github.com/matrix-org/synapse/issues/7199))
- Fix some worker-mode replication handling not being correctly recorded in CPU usage stats. ([\#7203](https://github.com/matrix-org/synapse/issues/7203))
- Do not allow a deactivated user to login via SSO. ([\#7240](https://github.com/matrix-org/synapse/issues/7240), [\#7259](https://github.com/matrix-org/synapse/issues/7259))
- Fix room publish permissions not being checked on room creation. ([\#7260](https://github.com/matrix-org/synapse/issues/7260))
- Reject unknown session IDs during user interactive authentication instead of silently creating a new session. ([\#7268](https://github.com/matrix-org/synapse/issues/7268))
- Fix a SQL query introduced in Synapse 1.12.0 which could cause large amounts of logging to the postgres slow-query log. ([\#7274](https://github.com/matrix-org/synapse/issues/7274))
- Persist user interactive authentication sessions across workers and Synapse restarts. ([\#7302](https://github.com/matrix-org/synapse/issues/7302))
- Fixed backwards compatibility logic of the first value of `trusted_third_party_id_servers` being used for `account_threepid_delegates.email`, which occurs when the former, deprecated option is set and the latter is not. ([\#7316](https://github.com/matrix-org/synapse/issues/7316))
- Fix a bug where event updates might not be sent over replication to worker processes after the stream falls behind. ([\#7337](https://github.com/matrix-org/synapse/issues/7337), [\#7358](https://github.com/matrix-org/synapse/issues/7358))
- Fix bad error handling that would cause Synapse to crash if it's provided with a YAML configuration file that's either empty or doesn't parse into a key-value map. ([\#7341](https://github.com/matrix-org/synapse/issues/7341))
- Fix incorrect metrics reporting for `renew_attestations` background task. ([\#7344](https://github.com/matrix-org/synapse/issues/7344))
- Prevent non-federating rooms from appearing in responses to federated `POST /publicRoom` requests when a filter was included. ([\#7367](https://github.com/matrix-org/synapse/issues/7367))
- Fix a bug which would cause the room durectory to be incorrectly populated if Synapse was upgraded directly from v1.2.1 or earlier to v1.4.0 or later. Note that this fix does not apply retrospectively; see the [upgrade notes](docs/upgrade.md#upgrading-to-v1130) for more information. ([\#7387](https://github.com/matrix-org/synapse/issues/7387))
- Fix bug in `EventContext.deserialize`. ([\#7393](https://github.com/matrix-org/synapse/issues/7393))
Improved Documentation
----------------------
- Update Debian installation instructions to recommend installing the `virtualenv` package instead of `python3-virtualenv`. ([\#6892](https://github.com/matrix-org/synapse/issues/6892))
- Improve the documentation for database configuration. ([\#6988](https://github.com/matrix-org/synapse/issues/6988))
- Improve the documentation of application service configuration files. ([\#7091](https://github.com/matrix-org/synapse/issues/7091))
- Update pre-built package name for FreeBSD. ([\#7107](https://github.com/matrix-org/synapse/issues/7107))
- Update postgres docs with login troubleshooting information. ([\#7119](https://github.com/matrix-org/synapse/issues/7119))
- Clean up INSTALL.md a bit. ([\#7141](https://github.com/matrix-org/synapse/issues/7141))
- Add documentation for running a local CAS server for testing. ([\#7147](https://github.com/matrix-org/synapse/issues/7147))
- Improve README.md by being explicit about public IP recommendation for TURN relaying. ([\#7167](https://github.com/matrix-org/synapse/issues/7167))
- Fix a small typo in the `metrics_flags` config option. ([\#7171](https://github.com/matrix-org/synapse/issues/7171))
- Update the contributed documentation on managing synapse workers with systemd, and bring it into the core distribution. ([\#7234](https://github.com/matrix-org/synapse/issues/7234))
- Add documentation to the `password_providers` config option. Add known password provider implementations to docs. ([\#7238](https://github.com/matrix-org/synapse/issues/7238), [\#7248](https://github.com/matrix-org/synapse/issues/7248))
- Modify suggested nginx reverse proxy configuration to match Synapse's default file upload size. Contributed by @ProCycleDev. ([\#7251](https://github.com/matrix-org/synapse/issues/7251))
- Documentation of media_storage_providers options updated to avoid misunderstandings. Contributed by Tristan Lins. ([\#7272](https://github.com/matrix-org/synapse/issues/7272))
- Add documentation on monitoring workers with Prometheus. ([\#7357](https://github.com/matrix-org/synapse/issues/7357))
- Clarify endpoint usage in the users admin api documentation. ([\#7361](https://github.com/matrix-org/synapse/issues/7361))
Deprecations and Removals
-------------------------
- Remove nonfunctional `captcha_bypass_secret` option from `homeserver.yaml`. ([\#7137](https://github.com/matrix-org/synapse/issues/7137))
Internal Changes
----------------
- Add benchmarks for LruCache. ([\#6446](https://github.com/matrix-org/synapse/issues/6446))
- Return total number of users and profile attributes in admin users endpoint. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#6881](https://github.com/matrix-org/synapse/issues/6881))
- Change device list streams to have one row per ID. ([\#7010](https://github.com/matrix-org/synapse/issues/7010))
- Remove concept of a non-limited stream. ([\#7011](https://github.com/matrix-org/synapse/issues/7011))
- Move catchup of replication streams logic to worker. ([\#7024](https://github.com/matrix-org/synapse/issues/7024), [\#7195](https://github.com/matrix-org/synapse/issues/7195), [\#7226](https://github.com/matrix-org/synapse/issues/7226), [\#7239](https://github.com/matrix-org/synapse/issues/7239), [\#7286](https://github.com/matrix-org/synapse/issues/7286), [\#7290](https://github.com/matrix-org/synapse/issues/7290), [\#7318](https://github.com/matrix-org/synapse/issues/7318), [\#7326](https://github.com/matrix-org/synapse/issues/7326), [\#7378](https://github.com/matrix-org/synapse/issues/7378), [\#7421](https://github.com/matrix-org/synapse/issues/7421))
- Convert some of synapse.rest.media to async/await. ([\#7110](https://github.com/matrix-org/synapse/issues/7110), [\#7184](https://github.com/matrix-org/synapse/issues/7184), [\#7241](https://github.com/matrix-org/synapse/issues/7241))
- De-duplicate / remove unused REST code for login and auth. ([\#7115](https://github.com/matrix-org/synapse/issues/7115))
- Convert `*StreamRow` classes to inner classes. ([\#7116](https://github.com/matrix-org/synapse/issues/7116))
- Clean up some LoggingContext code. ([\#7120](https://github.com/matrix-org/synapse/issues/7120), [\#7181](https://github.com/matrix-org/synapse/issues/7181), [\#7183](https://github.com/matrix-org/synapse/issues/7183), [\#7408](https://github.com/matrix-org/synapse/issues/7408), [\#7426](https://github.com/matrix-org/synapse/issues/7426))
- Add explicit `instance_id` for USER_SYNC commands and remove implicit `conn_id` usage. ([\#7128](https://github.com/matrix-org/synapse/issues/7128))
- Refactored the CAS authentication logic to a separate class. ([\#7136](https://github.com/matrix-org/synapse/issues/7136))
- Run replication streamers on workers. ([\#7146](https://github.com/matrix-org/synapse/issues/7146))
- Add tests for outbound device pokes. ([\#7157](https://github.com/matrix-org/synapse/issues/7157))
- Fix device list update stream ids going backward. ([\#7158](https://github.com/matrix-org/synapse/issues/7158))
- Use `stream.current_token()` and remove `stream_positions()`. ([\#7172](https://github.com/matrix-org/synapse/issues/7172))
- Move client command handling out of TCP protocol. ([\#7185](https://github.com/matrix-org/synapse/issues/7185))
- Move server command handling out of TCP protocol. ([\#7187](https://github.com/matrix-org/synapse/issues/7187))
- Fix consistency of HTTP status codes reported in log lines. ([\#7188](https://github.com/matrix-org/synapse/issues/7188))
- Only run one background database update at a time. ([\#7190](https://github.com/matrix-org/synapse/issues/7190))
- Remove sent outbound device list pokes from the database. ([\#7192](https://github.com/matrix-org/synapse/issues/7192))
- Add a background database update job to clear out duplicate `device_lists_outbound_pokes`. ([\#7193](https://github.com/matrix-org/synapse/issues/7193))
- Remove some extraneous debugging log lines. ([\#7207](https://github.com/matrix-org/synapse/issues/7207))
- Add explicit Python build tooling as dependencies for the snapcraft build. ([\#7213](https://github.com/matrix-org/synapse/issues/7213))
- Add typing information to federation server code. ([\#7219](https://github.com/matrix-org/synapse/issues/7219))
- Extend room admin api (`GET /_synapse/admin/v1/rooms`) with additional attributes. ([\#7225](https://github.com/matrix-org/synapse/issues/7225))
- Unblacklist '/upgrade creates a new room' sytest for workers. ([\#7228](https://github.com/matrix-org/synapse/issues/7228))
- Remove redundant checks on `daemonize` from synctl. ([\#7233](https://github.com/matrix-org/synapse/issues/7233))
- Upgrade jQuery to v3.4.1 on fallback login/registration pages. ([\#7236](https://github.com/matrix-org/synapse/issues/7236))
- Change log line that told user to implement onLogin/onRegister fallback js functions to a warning, instead of an info, so it's more visible. ([\#7237](https://github.com/matrix-org/synapse/issues/7237))
- Correct the parameters of a test fixture. Contributed by Isaiah Singletary. ([\#7243](https://github.com/matrix-org/synapse/issues/7243))
- Convert auth handler to async/await. ([\#7261](https://github.com/matrix-org/synapse/issues/7261))
- Add some unit tests for replication. ([\#7278](https://github.com/matrix-org/synapse/issues/7278))
- Improve typing annotations in `synapse.replication.tcp.streams.Stream`. ([\#7291](https://github.com/matrix-org/synapse/issues/7291))
- Reduce log verbosity of url cache cleanup tasks. ([\#7295](https://github.com/matrix-org/synapse/issues/7295))
- Fix sample SAML Service Provider configuration. Contributed by @frcl. ([\#7300](https://github.com/matrix-org/synapse/issues/7300))
- Fix StreamChangeCache to work with multiple entities changing on the same stream id. ([\#7303](https://github.com/matrix-org/synapse/issues/7303))
- Fix an incorrect import in IdentityHandler. ([\#7319](https://github.com/matrix-org/synapse/issues/7319))
- Reduce logging verbosity for successful federation requests. ([\#7321](https://github.com/matrix-org/synapse/issues/7321))
- Convert some federation handler code to async/await. ([\#7338](https://github.com/matrix-org/synapse/issues/7338))
- Fix collation for postgres for unit tests. ([\#7359](https://github.com/matrix-org/synapse/issues/7359))
- Convert RegistrationWorkerStore.is_server_admin and dependent code to async/await. ([\#7363](https://github.com/matrix-org/synapse/issues/7363))
- Add an `instance_name` to `RDATA` and `POSITION` replication commands. ([\#7364](https://github.com/matrix-org/synapse/issues/7364))
- Thread through instance name to replication client. ([\#7369](https://github.com/matrix-org/synapse/issues/7369))
- Convert synapse.server_notices to async/await. ([\#7394](https://github.com/matrix-org/synapse/issues/7394))
- Convert synapse.notifier to async/await. ([\#7395](https://github.com/matrix-org/synapse/issues/7395))
- Fix issues with the Python package manifest. ([\#7404](https://github.com/matrix-org/synapse/issues/7404))
- Prevent methods in `synapse.handlers.auth` from polling the homeserver config every request. ([\#7420](https://github.com/matrix-org/synapse/issues/7420))
- Speed up fetching device lists changes when handling `/sync` requests. ([\#7423](https://github.com/matrix-org/synapse/issues/7423))
- Run group attestation renewal in series rather than parallel for performance. ([\#7442](https://github.com/matrix-org/synapse/issues/7442))
- Fix a bug that prevented cross-signing with users on worker-mode synapses. ([\#7255](https://github.com/matrix-org/synapse/issues/7255))
- Do not treat display names as globs in push rules. ([\#7271](https://github.com/matrix-org/synapse/issues/7271))
- Fix a bug with cross-signing devices belonging to remote users who did not share a room with any user on the local homeserver. ([\#7289](https://github.com/matrix-org/synapse/issues/7289))
- Fix starting workers when federation sending not split out. ([\#7133](https://github.com/matrix-org/synapse/issues/7133)). Introduced in v1.12.0.
- Avoid importing `sqlite3` when using the postgres backend. Contributed by David Vo. ([\#7155](https://github.com/matrix-org/synapse/issues/7155)). Introduced in v1.12.0rc1.
- Fix a bug which could cause outbound federation traffic to stop working if a client uploaded an incorrect e2e device signature. ([\#7177](https://github.com/matrix-org/synapse/issues/7177)). Introduced in v1.11.0.
- Publishing/removing a room from the room directory now requires the user to have a power level capable of modifying the canonical alias, instead of the room aliases. ([\#6965](https://github.com/matrix-org/synapse/issues/6965))
- Users with a power level sufficient to modify the canonical alias of a room can now delete room aliases. ([\#6986](https://github.com/matrix-org/synapse/issues/6986))
- Implement updated authorization rules and redaction rules for aliases events, from [MSC2261](https://github.com/matrix-org/matrix-doc/pull/2261) and [MSC2432](https://github.com/matrix-org/matrix-doc/pull/2432). ([\#7037](https://github.com/matrix-org/synapse/issues/7037))
- Stop sending m.room.aliases events during room creation and upgrade. ([\#6941](https://github.com/matrix-org/synapse/issues/6941))
- Synapse no longer uses room alias events to calculate room names for push notifications. ([\#6966](https://github.com/matrix-org/synapse/issues/6966))
- The room list endpoint no longer returns a list of aliases. ([\#6970](https://github.com/matrix-org/synapse/issues/6970))
- Remove special handling of aliases events from [MSC2260](https://github.com/matrix-org/matrix-doc/pull/2260) added in v1.10.0rc1. ([\#7034](https://github.com/matrix-org/synapse/issues/7034))
- Expose the `synctl`, `hash_password` and `generate_config` commands in the snapcraft package. Contributed by @devec0. ([\#6315](https://github.com/matrix-org/synapse/issues/6315))
- Check that server_name is correctly set before running database updates. ([\#6982](https://github.com/matrix-org/synapse/issues/6982))
- Break down monthly active users by `appservice_id` and emit via Prometheus. ([\#7030](https://github.com/matrix-org/synapse/issues/7030))
- Render a configurable and comprehensible error page if something goes wrong during the SAML2 authentication process. ([\#7058](https://github.com/matrix-org/synapse/issues/7058), [\#7067](https://github.com/matrix-org/synapse/issues/7067))
- Add an optional parameter to control whether other sessions are logged out when a user's password is modified. ([\#7085](https://github.com/matrix-org/synapse/issues/7085))
- Add prometheus metrics for the number of active pushers. ([\#7103](https://github.com/matrix-org/synapse/issues/7103), [\#7106](https://github.com/matrix-org/synapse/issues/7106))
- Improve performance when making HTTPS requests to sygnal, sydent, etc, by sharing the SSL context object between connections. ([\#7094](https://github.com/matrix-org/synapse/issues/7094))
Bugfixes
--------
- When a user's profile is updated via the admin API, also generate a displayname/avatar update for that user in each room. ([\#6572](https://github.com/matrix-org/synapse/issues/6572))
- Fix a couple of bugs in email configuration handling. ([\#6962](https://github.com/matrix-org/synapse/issues/6962))
- Fix an issue affecting worker-based deployments where replication would stop working, necessitating a full restart, after joining a large room. ([\#6967](https://github.com/matrix-org/synapse/issues/6967))
- Fix `duplicate key` error which was logged when rejoining a room over federation. ([\#6968](https://github.com/matrix-org/synapse/issues/6968))
- Prevent user from setting 'deactivated' to anything other than a bool on the v2 PUT /users Admin API. ([\#6990](https://github.com/matrix-org/synapse/issues/6990))
- Fix py35-old CI by using native tox package. ([\#7018](https://github.com/matrix-org/synapse/issues/7018))
- Fix a bug causing `org.matrix.dummy_event` to be included in responses from `/sync`. ([\#7035](https://github.com/matrix-org/synapse/issues/7035))
- Fix a bug that renders UTF-8 text files incorrectly when loaded from media. Contributed by @TheStranjer. ([\#7044](https://github.com/matrix-org/synapse/issues/7044))
- Fix a bug that would cause Synapse to respond with an error about event visibility if a client tried to request the state of a room at a given token. ([\#7066](https://github.com/matrix-org/synapse/issues/7066))
- Repair a data-corruption issue which was introduced in Synapse 1.10, and fixed in Synapse 1.11, and which could cause `/sync` to return with 404 errors about missing events and unknown rooms. ([\#7070](https://github.com/matrix-org/synapse/issues/7070))
- Fix a bug causing account validity renewal emails to be sent even if the feature is turned off in some cases. ([\#7074](https://github.com/matrix-org/synapse/issues/7074))
Improved Documentation
----------------------
- Updated CentOS8 install instructions. Contributed by Richard Kellner. ([\#6925](https://github.com/matrix-org/synapse/issues/6925))
- Fix `POSTGRES_INITDB_ARGS` in the `contrib/docker/docker-compose.yml` example docker-compose configuration. ([\#6984](https://github.com/matrix-org/synapse/issues/6984))
- Change date in [INSTALL.md](./INSTALL.md#tls-certificates) for last date of getting TLS certificates to November 2019. ([\#7015](https://github.com/matrix-org/synapse/issues/7015))
- Document that the fallback auth endpoints must be routed to the same worker node as the register endpoints. ([\#7048](https://github.com/matrix-org/synapse/issues/7048))
- Remove the unused query_auth federation endpoint per [MSC2451](https://github.com/matrix-org/matrix-doc/pull/2451). ([\#7026](https://github.com/matrix-org/synapse/issues/7026))
- Add type hints to `logging/context.py`. ([\#6309](https://github.com/matrix-org/synapse/issues/6309))
- Add some clarifications to `README.md` in the database schema directory. ([\#6615](https://github.com/matrix-org/synapse/issues/6615))
- Refactoring work in preparation for changing the event redaction algorithm. ([\#6874](https://github.com/matrix-org/synapse/issues/6874), [\#6875](https://github.com/matrix-org/synapse/issues/6875), [\#6983](https://github.com/matrix-org/synapse/issues/6983), [\#7003](https://github.com/matrix-org/synapse/issues/7003))
- Improve performance of v2 state resolution for large rooms. ([\#6952](https://github.com/matrix-org/synapse/issues/6952), [\#7095](https://github.com/matrix-org/synapse/issues/7095))
- Reduce time spent doing GC, by freezing objects on startup. ([\#6953](https://github.com/matrix-org/synapse/issues/6953))
- Minor perfermance fixes to `get_auth_chain_ids`. ([\#6954](https://github.com/matrix-org/synapse/issues/6954))
- Don't record remote cross-signing keys in the `devices` table. ([\#6956](https://github.com/matrix-org/synapse/issues/6956))
- Use flake8-comprehensions to enforce good hygiene of list/set/dict comprehensions. ([\#6957](https://github.com/matrix-org/synapse/issues/6957))
- Remove redundant `store_room` call from `FederationHandler._process_received_pdu`. ([\#6979](https://github.com/matrix-org/synapse/issues/6979))
- Update warning for incorrect database collation/ctype to include link to documentation. ([\#6985](https://github.com/matrix-org/synapse/issues/6985))
- Add some type annotations to the database storage classes. ([\#6987](https://github.com/matrix-org/synapse/issues/6987))
- Port `synapse.handlers.presence` to async/await. ([\#6991](https://github.com/matrix-org/synapse/issues/6991), [\#7019](https://github.com/matrix-org/synapse/issues/7019))
- Add some type annotations to the federation base & client classes. ([\#6995](https://github.com/matrix-org/synapse/issues/6995))
- Port `synapse.rest.keys` to async/await. ([\#7020](https://github.com/matrix-org/synapse/issues/7020))
- Add a type check to `is_verified` when processing room keys. ([\#7045](https://github.com/matrix-org/synapse/issues/7045))
- Add type annotations and comments to the auth handler. ([\#7063](https://github.com/matrix-org/synapse/issues/7063))
This release includes a security fix impacting installations using Single Sign-On (i.e. SAML2 or CAS) for authentication. Administrators of such installations are encouraged to upgrade as soon as possible.
The release also includes fixes for a couple of other bugs.
Bugfixes
--------
- Add a confirmation step to the SSO login flow before redirecting users to the redirect URL. ([b2bd54a2](https://github.com/matrix-org/synapse/commit/b2bd54a2e31d9a248f73fadb184ae9b4cbdb49f9), [65c73cdf](https://github.com/matrix-org/synapse/commit/65c73cdfec1876a9fec2fd2c3a74923cd146fe0b), [a0178df1](https://github.com/matrix-org/synapse/commit/a0178df10422a76fd403b82d2b2a4ed28a9a9d1e))
- Fixed set a user as an admin with the admin API `PUT /_synapse/admin/v2/users/<user_id>`. Contributed by @dklimpel. ([\#6910](https://github.com/matrix-org/synapse/issues/6910))
- Fix bug introduced in Synapse 1.11.0 which sometimes caused errors when joining rooms over federation, with `'coroutine' object has no attribute 'event_id'`. ([\#6996](https://github.com/matrix-org/synapse/issues/6996))
- Admin API to add or modify threepids of user accounts. ([\#6769](https://github.com/matrix-org/synapse/issues/6769))
- Limit the number of events that can be requested by the backfill federation API to 100. ([\#6864](https://github.com/matrix-org/synapse/issues/6864))
- Add ability to run some group APIs on workers. ([\#6866](https://github.com/matrix-org/synapse/issues/6866))
- Implement new `GET /_matrix/client/unstable/org.matrix.msc2432/rooms/{roomId}/aliases` endpoint as per [MSC2432](https://github.com/matrix-org/matrix-doc/pull/2432). ([\#6939](https://github.com/matrix-org/synapse/issues/6939), [\#6948](https://github.com/matrix-org/synapse/issues/6948), [\#6949](https://github.com/matrix-org/synapse/issues/6949))
- Fixed third party event rules function `on_create_room`'s return value being ignored. ([\#6781](https://github.com/matrix-org/synapse/issues/6781))
- Allow URL-encoded User IDs on `/_synapse/admin/v2/users/<user_id>[/admin]` endpoints. Thanks to @NHAS for reporting. ([\#6825](https://github.com/matrix-org/synapse/issues/6825))
- Fix Synapse refusing to start if `federation_certificate_verification_whitelist` option is blank. ([\#6849](https://github.com/matrix-org/synapse/issues/6849))
- Fix errors from logging in the purge jobs related to the message retention policies support. ([\#6945](https://github.com/matrix-org/synapse/issues/6945))
- Return a 404 instead of 200 for querying information of a non-existant user through the admin API. ([\#6901](https://github.com/matrix-org/synapse/issues/6901))
Updates to the Docker image
---------------------------
- The deprecated "generate-config-on-the-fly" mode is no longer supported. ([\#6918](https://github.com/matrix-org/synapse/issues/6918))
Improved Documentation
----------------------
- Add details of PR merge strategy to contributing docs. ([\#6846](https://github.com/matrix-org/synapse/issues/6846))
- Spell out that the last event sent to a room won't be deleted by a purge. ([\#6891](https://github.com/matrix-org/synapse/issues/6891))
- Update Synapse's documentation to warn about the deprecation of ACME v1. ([\#6905](https://github.com/matrix-org/synapse/issues/6905), [\#6907](https://github.com/matrix-org/synapse/issues/6907), [\#6909](https://github.com/matrix-org/synapse/issues/6909))
- Add documentation for the spam checker. ([\#6906](https://github.com/matrix-org/synapse/issues/6906))
- Fix worker docs to point `/publicised_groups` API correctly. ([\#6938](https://github.com/matrix-org/synapse/issues/6938))
- Clean up and update docs on setting up federation. ([\#6940](https://github.com/matrix-org/synapse/issues/6940))
- Add a warning about indentation to generated configuration files. ([\#6920](https://github.com/matrix-org/synapse/issues/6920))
- Databases created using the compose file in contrib/docker will now always have correct encoding and locale settings. Contributed by Fridtjof Mund. ([\#6921](https://github.com/matrix-org/synapse/issues/6921))
- Remove `m.lazy_load_members` from `unstable_features` since lazy loading is in the stable Client-Server API version r0.5.0. ([\#6877](https://github.com/matrix-org/synapse/issues/6877))
Internal Changes
----------------
- Add type hints to `SyncHandler`. ([\#6821](https://github.com/matrix-org/synapse/issues/6821))
- Refactoring work in preparation for changing the event redaction algorithm. ([\#6823](https://github.com/matrix-org/synapse/issues/6823), [\#6827](https://github.com/matrix-org/synapse/issues/6827), [\#6854](https://github.com/matrix-org/synapse/issues/6854), [\#6856](https://github.com/matrix-org/synapse/issues/6856), [\#6857](https://github.com/matrix-org/synapse/issues/6857), [\#6858](https://github.com/matrix-org/synapse/issues/6858))
- Fix stacktraces when using `ObservableDeferred` and async/await. ([\#6836](https://github.com/matrix-org/synapse/issues/6836))
- Port much of `synapse.handlers.federation` to async/await. ([\#6837](https://github.com/matrix-org/synapse/issues/6837), [\#6840](https://github.com/matrix-org/synapse/issues/6840))
- Populate `rooms.room_version` database column at startup, rather than in a background update. ([\#6847](https://github.com/matrix-org/synapse/issues/6847))
- Reduce amount we log at `INFO` level. ([\#6833](https://github.com/matrix-org/synapse/issues/6833), [\#6862](https://github.com/matrix-org/synapse/issues/6862))
- Fix a bug introduced in Synapse 1.10.0 which would cause room state to be cleared in the database if Synapse was upgraded direct from 1.2.1 or earlier to 1.10.0. ([\#6924](https://github.com/matrix-org/synapse/issues/6924))
**WARNING to client developers**: As of this release Synapse validates `client_secret` parameters in the Client-Server API as per the spec. See [\#6766](https://github.com/matrix-org/synapse/issues/6766) for details.
- Fix the filtering introduced in 1.10.0rc3 to also apply to the state blocks returned by `/sync`. ([\#6884](https://github.com/matrix-org/synapse/issues/6884))
- Filter out `m.room.aliases` from the CS API to mitigate abuse while a better solution is specced. ([\#6878](https://github.com/matrix-org/synapse/issues/6878))
- Fix continuous integration failures with old versions of `pip`, which were introduced by a release of the `zipp` library. ([\#6880](https://github.com/matrix-org/synapse/issues/6880))
- Fix an issue with cross-signing where device signatures were not sent to remote servers. ([\#6844](https://github.com/matrix-org/synapse/issues/6844))
- Add experimental support for updated authorization rules for aliases events, from [MSC2260](https://github.com/matrix-org/matrix-doc/pull/2260). ([\#6787](https://github.com/matrix-org/synapse/issues/6787), [\#6790](https://github.com/matrix-org/synapse/issues/6790), [\#6794](https://github.com/matrix-org/synapse/issues/6794))
- Warn if postgres database has a non-C locale, as that can cause issues when upgrading locales (e.g. due to upgrading OS). ([\#6734](https://github.com/matrix-org/synapse/issues/6734))
- Minor fixes to `PUT /_synapse/admin/v2/users` admin api. ([\#6761](https://github.com/matrix-org/synapse/issues/6761))
- Validate `client_secret` parameter using the regex provided by the Client-Server API, temporarily allowing `:` characters for older clients. The `:` character will be removed in a future release. ([\#6767](https://github.com/matrix-org/synapse/issues/6767))
- Fix persisting redaction events that have been redacted (or otherwise don't have a redacts key). ([\#6771](https://github.com/matrix-org/synapse/issues/6771))
- Fix bug where querying a remote user's device keys that weren't cached resulted in only returning a single device. ([\#6796](https://github.com/matrix-org/synapse/issues/6796))
- Fix race in federation sender worker that delayed sending of device updates. ([\#6799](https://github.com/matrix-org/synapse/issues/6799), [\#6800](https://github.com/matrix-org/synapse/issues/6800))
- Fix bug where Synapse didn't invalidate cache of remote users' devices when Synapse left a room. ([\#6801](https://github.com/matrix-org/synapse/issues/6801))
- Fix waking up other workers when remote server is detected to have come back online. ([\#6811](https://github.com/matrix-org/synapse/issues/6811))
Improved Documentation
----------------------
- Clarify documentation related to `user_dir` and `federation_reader` workers. ([\#6775](https://github.com/matrix-org/synapse/issues/6775))
Internal Changes
----------------
- Record room versions in the `rooms` table. ([\#6729](https://github.com/matrix-org/synapse/issues/6729), [\#6788](https://github.com/matrix-org/synapse/issues/6788), [\#6810](https://github.com/matrix-org/synapse/issues/6810))
- Propagate cache invalidates from workers to other workers. ([\#6748](https://github.com/matrix-org/synapse/issues/6748))
- Remove some unnecessary admin handler abstraction methods. ([\#6751](https://github.com/matrix-org/synapse/issues/6751))
- Add some debugging for media storage providers. ([\#6757](https://github.com/matrix-org/synapse/issues/6757))
- Detect unknown remote devices and mark cache as stale. ([\#6776](https://github.com/matrix-org/synapse/issues/6776), [\#6819](https://github.com/matrix-org/synapse/issues/6819))
- Attempt to resync remote users' devices when detected as stale. ([\#6786](https://github.com/matrix-org/synapse/issues/6786))
- Delete current state from the database when server leaves a room. ([\#6792](https://github.com/matrix-org/synapse/issues/6792))
- When a client asks for a remote user's device keys check if the local cache for that user has been marked as potentially stale. ([\#6797](https://github.com/matrix-org/synapse/issues/6797))
- Add background update to clean out left rooms from current state. ([\#6802](https://github.com/matrix-org/synapse/issues/6802), [\#6816](https://github.com/matrix-org/synapse/issues/6816))
- Refactoring work in preparation for changing the event redaction algorithm. ([\#6803](https://github.com/matrix-org/synapse/issues/6803), [\#6805](https://github.com/matrix-org/synapse/issues/6805), [\#6806](https://github.com/matrix-org/synapse/issues/6806), [\#6807](https://github.com/matrix-org/synapse/issues/6807), [\#6820](https://github.com/matrix-org/synapse/issues/6820))
- Fix bug where setting `mau_limit_reserved_threepids` config would cause Synapse to refuse to start. ([\#6793](https://github.com/matrix-org/synapse/issues/6793))
**WARNING**: As of this release, Synapse no longer supports versions of SQLite before 3.11, and will refuse to start when configured to use an older version. Administrators are recommended to migrate their database to Postgres (see instructions [here](docs/postgres.md)).
If your Synapse deployment uses workers, note that the reverse-proxy configurations for the `synapse.app.media_repository`, `synapse.app.federation_reader` and `synapse.app.event_creator` workers have changed, with the addition of a few paths (see the updated configurations [here](docs/workers.md#available-worker-applications)). Existing configurations will continue to work.
- Allow admin to create or modify a user. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#5742](https://github.com/matrix-org/synapse/issues/5742))
- Add new quarantine media admin APIs to quarantine by media ID or by user who uploaded the media. ([\#6681](https://github.com/matrix-org/synapse/issues/6681), [\#6756](https://github.com/matrix-org/synapse/issues/6756))
- Add `org.matrix.e2e_cross_signing` to `unstable_features` in `/versions` as per [MSC1756](https://github.com/matrix-org/matrix-doc/pull/1756). ([\#6712](https://github.com/matrix-org/synapse/issues/6712))
- Add a new admin API to list and filter rooms on the server. ([\#6720](https://github.com/matrix-org/synapse/issues/6720))
Bugfixes
--------
- Correctly proxy HTTP errors due to API calls to remote group servers. ([\#6654](https://github.com/matrix-org/synapse/issues/6654))
- Fix media repo admin APIs when using a media worker. ([\#6664](https://github.com/matrix-org/synapse/issues/6664))
- Fix "CRITICAL" errors being logged when a request is received for a uri containing non-ascii characters. ([\#6682](https://github.com/matrix-org/synapse/issues/6682))
- Fix a bug where we would assign a numeric user ID if somebody tried registering with an empty username. ([\#6690](https://github.com/matrix-org/synapse/issues/6690))
- Fix a bug causing Synapse to not always purge quiet rooms with a low `max_lifetime` in their message retention policies when running the automated purge jobs. ([\#6714](https://github.com/matrix-org/synapse/issues/6714))
- Fix the `synapse_port_db` not correctly running background updates. Thanks @tadzik for reporting. ([\#6718](https://github.com/matrix-org/synapse/issues/6718))
- Fix monthly active user limiting support for worker mode, fixes [#4639](https://github.com/matrix-org/synapse/issues/4639). ([\#6742](https://github.com/matrix-org/synapse/issues/6742))
- Fix bug when setting `account_validity` to an empty block in the config. Thanks to @Sorunome for reporting. ([\#6747](https://github.com/matrix-org/synapse/issues/6747))
- Fix `AttributeError: 'NoneType' object has no attribute 'get'` in `hash_password` when configuration has an empty `password_config`. Contributed by @ivilata. ([\#6753](https://github.com/matrix-org/synapse/issues/6753))
- Fix the `docker-compose.yaml` overriding the entire `/etc` folder of the container. Contributed by Fabian Meyer. ([\#6656](https://github.com/matrix-org/synapse/issues/6656))
- Fix a typo in the configuration example for purge jobs in the sample configuration file. ([\#6621](https://github.com/matrix-org/synapse/issues/6621))
- Add complete documentation of the message retention policies support. ([\#6624](https://github.com/matrix-org/synapse/issues/6624), [\#6665](https://github.com/matrix-org/synapse/issues/6665))
- Clarify the `account_validity` and `email` sections of the sample configuration. ([\#6685](https://github.com/matrix-org/synapse/issues/6685))
- Add more endpoints to the documentation for Synapse workers. ([\#6698](https://github.com/matrix-org/synapse/issues/6698))
Deprecations and Removals
-------------------------
- Synapse no longer supports versions of SQLite before 3.11, and will refuse to start when configured to use an older version. Administrators are recommended to migrate their database to Postgres (see instructions [here](docs/postgres.md)). ([\#6675](https://github.com/matrix-org/synapse/issues/6675))
Internal Changes
----------------
- Add `local_current_membership` table for tracking local user membership state in rooms. ([\#6655](https://github.com/matrix-org/synapse/issues/6655), [\#6728](https://github.com/matrix-org/synapse/issues/6728))
- Port `synapse.replication.tcp` to async/await. ([\#6666](https://github.com/matrix-org/synapse/issues/6666))
- Fixup `synapse.replication` to pass mypy checks. ([\#6667](https://github.com/matrix-org/synapse/issues/6667))
- Allow `additional_resources` to implement `IResource` directly. ([\#6686](https://github.com/matrix-org/synapse/issues/6686))
- Allow REST endpoint implementations to raise a `RedirectException`, which will redirect the user's browser to a given location. ([\#6687](https://github.com/matrix-org/synapse/issues/6687))
- Updates and extensions to the module API. ([\#6688](https://github.com/matrix-org/synapse/issues/6688))
- Updates to the SAML mapping provider API. ([\#6689](https://github.com/matrix-org/synapse/issues/6689), [\#6723](https://github.com/matrix-org/synapse/issues/6723))
- Don't block processing of incoming EDUs behind processing PDUs in the same transaction. ([\#6697](https://github.com/matrix-org/synapse/issues/6697))
- Remove duplicate check for the `session` query parameter on the `/auth/xxx/fallback/web` Client-Server endpoint. ([\#6702](https://github.com/matrix-org/synapse/issues/6702))
- Attempt to retry sending a transaction when we detect a remote server has come back online, rather than waiting for a transaction to be triggered by new data. ([\#6706](https://github.com/matrix-org/synapse/issues/6706))
- Add a `DeltaState` to track changes to be made to current state during event persistence. ([\#6716](https://github.com/matrix-org/synapse/issues/6716))
- Add more logging around message retention policies support. ([\#6717](https://github.com/matrix-org/synapse/issues/6717))
- When processing a SAML response, log the assertions for easier configuration. ([\#6724](https://github.com/matrix-org/synapse/issues/6724))
- Fixup `synapse.rest` to pass mypy. ([\#6732](https://github.com/matrix-org/synapse/issues/6732), [\#6764](https://github.com/matrix-org/synapse/issues/6764))
**WARNING**: As of this release Synapse will refuse to start if the `log_file` config option is specified. Support for the option was removed in v1.3.0.
- Add v2 APIs for the `send_join` and `send_leave` federation endpoints (as described in [MSC1802](https://github.com/matrix-org/matrix-doc/pull/1802)). ([\#6349](https://github.com/matrix-org/synapse/issues/6349))
- Add option `limit_profile_requests_to_users_who_share_rooms` to prevent requirement of a local user sharing a room with another user to query their profile information. ([\#6523](https://github.com/matrix-org/synapse/issues/6523))
- Add an `export_signing_key` script to extract the public part of signing keys when rotating them. ([\#6546](https://github.com/matrix-org/synapse/issues/6546))
- Prevent redacted events from being returned during message search. ([\#6377](https://github.com/matrix-org/synapse/issues/6377), [\#6522](https://github.com/matrix-org/synapse/issues/6522))
- Prevent error on trying to search a upgraded room when the server is not in the predecessor room. ([\#6385](https://github.com/matrix-org/synapse/issues/6385))
- Improve performance of looking up cross-signing keys. ([\#6486](https://github.com/matrix-org/synapse/issues/6486))
- Fix race which occasionally caused deleted devices to reappear. ([\#6514](https://github.com/matrix-org/synapse/issues/6514))
- Fix missing row in `device_max_stream_id` that could cause unable to decrypt errors after server restart. ([\#6555](https://github.com/matrix-org/synapse/issues/6555))
- Fix a bug which meant that we did not send systemd notifications on startup if acme was enabled. ([\#6571](https://github.com/matrix-org/synapse/issues/6571))
- Fix exception when fetching the `matrix.org:ed25519:auto` key. ([\#6625](https://github.com/matrix-org/synapse/issues/6625))
- Fix bug where a moderator upgraded a room and became an admin in the new room. ([\#6633](https://github.com/matrix-org/synapse/issues/6633))
- Fix exceptions in the synchrotron worker log when events are rejected. ([\#6645](https://github.com/matrix-org/synapse/issues/6645))
- Ensure that upgraded rooms are removed from the directory. ([\#6648](https://github.com/matrix-org/synapse/issues/6648))
- Fix a bug causing Synapse not to fetch missing events when it believes it has every event in the room. ([\#6652](https://github.com/matrix-org/synapse/issues/6652))
Improved Documentation
----------------------
- Document the Room Shutdown Admin API. ([\#6541](https://github.com/matrix-org/synapse/issues/6541))
- Reword sections of [docs/federate.md](docs/federate.md) that explained delegation at time of Synapse 1.0 transition. ([\#6601](https://github.com/matrix-org/synapse/issues/6601))
- Add *experimental* support for multiple physical databases and split out state storage to separate data store. ([\#6245](https://github.com/matrix-org/synapse/issues/6245), [\#6510](https://github.com/matrix-org/synapse/issues/6510), [\#6511](https://github.com/matrix-org/synapse/issues/6511), [\#6513](https://github.com/matrix-org/synapse/issues/6513), [\#6564](https://github.com/matrix-org/synapse/issues/6564), [\#6565](https://github.com/matrix-org/synapse/issues/6565))
- Port sections of code base to async/await. ([\#6496](https://github.com/matrix-org/synapse/issues/6496), [\#6504](https://github.com/matrix-org/synapse/issues/6504), [\#6505](https://github.com/matrix-org/synapse/issues/6505), [\#6517](https://github.com/matrix-org/synapse/issues/6517), [\#6559](https://github.com/matrix-org/synapse/issues/6559), [\#6647](https://github.com/matrix-org/synapse/issues/6647), [\#6653](https://github.com/matrix-org/synapse/issues/6653))
- Remove `SnapshotCache` in favour of `ResponseCache`. ([\#6506](https://github.com/matrix-org/synapse/issues/6506))
- Silence mypy errors for files outside those specified. ([\#6512](https://github.com/matrix-org/synapse/issues/6512))
- Clean up some logging when handling incoming events over federation. ([\#6515](https://github.com/matrix-org/synapse/issues/6515))
- Test more folders against mypy. ([\#6534](https://github.com/matrix-org/synapse/issues/6534))
- Update `mypy` to new version. ([\#6537](https://github.com/matrix-org/synapse/issues/6537))
- Adjust the sytest blacklist for worker mode. ([\#6538](https://github.com/matrix-org/synapse/issues/6538))
- Remove unused `get_pagination_rows` methods from `EventSource` classes. ([\#6557](https://github.com/matrix-org/synapse/issues/6557))
- Clean up logs from the push notifier at startup. ([\#6558](https://github.com/matrix-org/synapse/issues/6558))
- Improve diagnostics on database upgrade failure. ([\#6570](https://github.com/matrix-org/synapse/issues/6570))
- Reduce the reconnect time when worker replication fails, to make it easier to catch up. ([\#6617](https://github.com/matrix-org/synapse/issues/6617))
- Add a workaround for synapse raising exceptions when fetching the notary's own key from the notary. ([\#6620](https://github.com/matrix-org/synapse/issues/6620))
- Automate generation of the sample log config. ([\#6627](https://github.com/matrix-org/synapse/issues/6627))
- Simplify event creation code by removing redundant queries on the `event_reference_hashes` table. ([\#6629](https://github.com/matrix-org/synapse/issues/6629))
- Fix errors when `frozen_dicts` are enabled. ([\#6642](https://github.com/matrix-org/synapse/issues/6642))
This release fixes some regressions introduced in Synapse 1.7.0 and 1.7.1.
Bugfixes
--------
- Fix a regression introduced in Synapse 1.7.1 which caused errors when attempting to backfill rooms over federation. ([\#6576](https://github.com/matrix-org/synapse/issues/6576))
- Fix a bug introduced in Synapse 1.7.0 which caused an error on startup when upgrading from versions before 1.3.0. ([\#6578](https://github.com/matrix-org/synapse/issues/6578))
This release includes several security fixes as well as a fix to a bug exposed by the security fixes. Administrators are encouraged to upgrade as soon as possible.
- Fix a bug which could cause room events to be incorrectly authorized using events from a different room. ([\#6501](https://github.com/matrix-org/synapse/issues/6501), [\#6503](https://github.com/matrix-org/synapse/issues/6503), [\#6521](https://github.com/matrix-org/synapse/issues/6521), [\#6524](https://github.com/matrix-org/synapse/issues/6524), [\#6530](https://github.com/matrix-org/synapse/issues/6530), [\#6531](https://github.com/matrix-org/synapse/issues/6531))
- Fix a bug causing responses to the `/context` client endpoint to not use the pruned version of the event. ([\#6553](https://github.com/matrix-org/synapse/issues/6553))
- Fix a cause of state resets in room versions 2 onwards. ([\#6556](https://github.com/matrix-org/synapse/issues/6556), [\#6560](https://github.com/matrix-org/synapse/issues/6560))
Bugfixes
--------
- Fix a bug which could cause the federation server to incorrectly return errors when handling certain obscure event graphs. ([\#6526](https://github.com/matrix-org/synapse/issues/6526), [\#6527](https://github.com/matrix-org/synapse/issues/6527))
This release changes the default settings so that only local authenticated users can query the server's room directory. See the [upgrade notes](docs/upgrade.md#upgrading-to-v170) for details.
Administrators are reminded that SQLite should not be used for production instances. Instructions for migrating to Postgres are available [here](docs/postgres.md). A future release of synapse will, by default, disable federation for servers using SQLite.
- Fix incorrect error message for invalid requests when setting user's avatar URL. ([\#6497](https://github.com/matrix-org/synapse/issues/6497))
- Fix support for SQLite 3.7. ([\#6499](https://github.com/matrix-org/synapse/issues/6499))
- Fix regression where sending email push would not work when using a pusher worker. ([\#6507](https://github.com/matrix-org/synapse/issues/6507), [\#6509](https://github.com/matrix-org/synapse/issues/6509))
- Add etag and count fields to key backup endpoints to help clients guess if there are new keys. ([\#5858](https://github.com/matrix-org/synapse/issues/5858))
- Require User-Interactive Authentication for `/account/3pid/add`, meaning the user's password will be required to add a third-party ID to their account. ([\#6119](https://github.com/matrix-org/synapse/issues/6119))
- Implement the `/_matrix/federation/unstable/net.atleastfornow/state/<context>` API as drafted in MSC2314. ([\#6176](https://github.com/matrix-org/synapse/issues/6176))
- Add ephemeral messages support by partially implementing [MSC2228](https://github.com/matrix-org/matrix-doc/pull/2228). ([\#6409](https://github.com/matrix-org/synapse/issues/6409))
- Add support for [MSC 2367](https://github.com/matrix-org/matrix-doc/pull/2367), which allows specifying a reason on all membership events. ([\#6434](https://github.com/matrix-org/synapse/issues/6434))
- Transfer non-standard power levels on room upgrade. ([\#6237](https://github.com/matrix-org/synapse/issues/6237))
- Fix error from the Pillow library when uploading RGBA images. ([\#6241](https://github.com/matrix-org/synapse/issues/6241))
- Correctly apply the event filter to the `state`, `events_before` and `events_after` fields in the response to `/context` requests. ([\#6329](https://github.com/matrix-org/synapse/issues/6329))
- Fix caching devices for remote users when using workers, so that we don't attempt to refetch (and potentially fail) each time a user requests devices. ([\#6332](https://github.com/matrix-org/synapse/issues/6332))
- Prevent account data syncs getting lost across TCP replication. ([\#6333](https://github.com/matrix-org/synapse/issues/6333))
- Fix bug: TypeError in `register_user()` while using LDAP auth module. ([\#6406](https://github.com/matrix-org/synapse/issues/6406))
- Fix an intermittent exception when handling read-receipts. ([\#6408](https://github.com/matrix-org/synapse/issues/6408))
- Fix broken guest registration when there are existing blocks of numeric user IDs. ([\#6420](https://github.com/matrix-org/synapse/issues/6420))
- Fix startup error when http proxy is defined. ([\#6421](https://github.com/matrix-org/synapse/issues/6421))
- Fix error when using synapse_port_db on a vanilla synapse db. ([\#6449](https://github.com/matrix-org/synapse/issues/6449))
- Fix uploading multiple cross signing signatures for the same user. ([\#6451](https://github.com/matrix-org/synapse/issues/6451))
- Fix bug which lead to exceptions being thrown in a loop when a cross-signed device is deleted. ([\#6462](https://github.com/matrix-org/synapse/issues/6462))
- Fix `synapse_port_db` not exiting with a 0 code if something went wrong during the port process. ([\#6470](https://github.com/matrix-org/synapse/issues/6470))
- Improve sanity-checking when receiving events over federation. ([\#6472](https://github.com/matrix-org/synapse/issues/6472))
- Fix small performance regression for sending invites. ([\#6493](https://github.com/matrix-org/synapse/issues/6493))
- Back out cross-signing code added in Synapse 1.5.0, which caused a performance regression. ([\#6494](https://github.com/matrix-org/synapse/issues/6494))
Improved Documentation
----------------------
- Update documentation and variables in user contributed systemd reference file. ([\#6369](https://github.com/matrix-org/synapse/issues/6369), [\#6490](https://github.com/matrix-org/synapse/issues/6490))
- Fix link in the user directory documentation. ([\#6388](https://github.com/matrix-org/synapse/issues/6388))
- Add build instructions to the docker readme. ([\#6390](https://github.com/matrix-org/synapse/issues/6390))
- Switch Ubuntu package install recommendation to use python3 packages in INSTALL.md. ([\#6443](https://github.com/matrix-org/synapse/issues/6443))
- Write some docs for the quarantine_media api. ([\#6458](https://github.com/matrix-org/synapse/issues/6458))
- Convert CONTRIBUTING.rst to markdown (among other small fixes). ([\#6461](https://github.com/matrix-org/synapse/issues/6461))
- Remove fallback for federation with old servers which lack the /federation/v1/state_ids API. ([\#6488](https://github.com/matrix-org/synapse/issues/6488))
Internal Changes
----------------
- Add benchmarks for structured logging and improve output performance. ([\#6266](https://github.com/matrix-org/synapse/issues/6266))
- Improve the performance of outputting structured logging. ([\#6322](https://github.com/matrix-org/synapse/issues/6322))
- Refactor some code in the event authentication path for clarity. ([\#6343](https://github.com/matrix-org/synapse/issues/6343), [\#6468](https://github.com/matrix-org/synapse/issues/6468), [\#6480](https://github.com/matrix-org/synapse/issues/6480))
- Clean up some unnecessary quotation marks around the codebase. ([\#6362](https://github.com/matrix-org/synapse/issues/6362))
- Complain on startup instead of 500'ing during runtime when `public_baseurl` isn't set when necessary. ([\#6379](https://github.com/matrix-org/synapse/issues/6379))
- Add a test scenario to make sure room history purges don't break `/messages` in the future. ([\#6392](https://github.com/matrix-org/synapse/issues/6392))
- Clarifications for the email configuration settings. ([\#6423](https://github.com/matrix-org/synapse/issues/6423))
- Add more tests to the blacklist when running in worker mode. ([\#6429](https://github.com/matrix-org/synapse/issues/6429))
- Refactor data store layer to support multiple databases in the future. ([\#6454](https://github.com/matrix-org/synapse/issues/6454), [\#6464](https://github.com/matrix-org/synapse/issues/6464), [\#6469](https://github.com/matrix-org/synapse/issues/6469), [\#6487](https://github.com/matrix-org/synapse/issues/6487))
This release includes a security fix ([\#6426](https://github.com/matrix-org/synapse/issues/6426), below). Administrators are encouraged to upgrade as soon as possible.
Bugfixes
--------
- Clean up local threepids from user on account deactivation. ([\#6426](https://github.com/matrix-org/synapse/issues/6426))
- Fix startup error when http proxy is defined. ([\#6421](https://github.com/matrix-org/synapse/issues/6421))
- Fix a bug which could cause the background database update hander for event labels to get stuck in a loop raising exceptions. ([\#6407](https://github.com/matrix-org/synapse/issues/6407))
- Add federation support for cross-signing. ([\#5727](https://github.com/matrix-org/synapse/issues/5727))
- Increase default room version from 4 to 5, thereby enforcing server key validity period checks. ([\#6220](https://github.com/matrix-org/synapse/issues/6220))
- Add support for outbound http proxying via http_proxy/HTTPS_PROXY env vars. ([\#6238](https://github.com/matrix-org/synapse/issues/6238))
- Implement label-based filtering on `/sync` and `/messages` ([MSC2326](https://github.com/matrix-org/matrix-doc/pull/2326)). ([\#6301](https://github.com/matrix-org/synapse/issues/6301), [\#6310](https://github.com/matrix-org/synapse/issues/6310), [\#6340](https://github.com/matrix-org/synapse/issues/6340))
Bugfixes
--------
- Fix LruCache callback deduplication for Python 3.8. Contributed by @V02460. ([\#6213](https://github.com/matrix-org/synapse/issues/6213))
- Remove a room from a server's public rooms list on room upgrade. ([\#6232](https://github.com/matrix-org/synapse/issues/6232), [\#6235](https://github.com/matrix-org/synapse/issues/6235))
- Delete keys from key backup when deleting backup versions. ([\#6253](https://github.com/matrix-org/synapse/issues/6253))
- Make notification of cross-signing signatures work with workers. ([\#6254](https://github.com/matrix-org/synapse/issues/6254))
- Fix exception when remote servers attempt to join a room that they're not allowed to join. ([\#6278](https://github.com/matrix-org/synapse/issues/6278))
- Prevent errors from appearing on Synapse startup if `git` is not installed. ([\#6284](https://github.com/matrix-org/synapse/issues/6284))
- Appservice requests will no longer contain a double slash prefix when the appservice url provided ends in a slash. ([\#6306](https://github.com/matrix-org/synapse/issues/6306))
- Fix the `hidden` field in the `devices` table for SQLite versions prior to 3.23.0. ([\#6313](https://github.com/matrix-org/synapse/issues/6313))
- Fix bug which casued rejected events to be persisted with the wrong room state. ([\#6320](https://github.com/matrix-org/synapse/issues/6320))
- Fix bug where `rc_login` ratelimiting would prematurely kick in. ([\#6335](https://github.com/matrix-org/synapse/issues/6335))
- Prevent the server taking a long time to start up when guest registration is enabled. ([\#6338](https://github.com/matrix-org/synapse/issues/6338))
- Fix bug where upgrading a guest account to a full user would fail when account validity is enabled. ([\#6359](https://github.com/matrix-org/synapse/issues/6359))
- Fix `to_device` stream ID getting reset every time Synapse restarts, which had the potential to cause unable to decrypt errors. ([\#6363](https://github.com/matrix-org/synapse/issues/6363))
- Fix permission denied error when trying to generate a config file with the docker image. ([\#6389](https://github.com/matrix-org/synapse/issues/6389))
Improved Documentation
----------------------
- Contributor documentation now mentions script to run linters. ([\#6164](https://github.com/matrix-org/synapse/issues/6164))
- Modify CAPTCHA_SETUP.md to update the terms `private key` and `public key` to `secret key` and `site key` respectively. Contributed by Yash Jipkate. ([\#6257](https://github.com/matrix-org/synapse/issues/6257))
- Update `INSTALL.md` Email section to talk about `account_threepid_delegates`. ([\#6272](https://github.com/matrix-org/synapse/issues/6272))
- Fix a small typo in `account_threepid_delegates` configuration option. ([\#6273](https://github.com/matrix-org/synapse/issues/6273))
Internal Changes
----------------
- Add a CI job to test the `synapse_port_db` script. ([\#6140](https://github.com/matrix-org/synapse/issues/6140), [\#6276](https://github.com/matrix-org/synapse/issues/6276))
- Convert EventContext to an attrs. ([\#6218](https://github.com/matrix-org/synapse/issues/6218))
- Move `persist_events` out from main data store. ([\#6240](https://github.com/matrix-org/synapse/issues/6240), [\#6300](https://github.com/matrix-org/synapse/issues/6300))
- Reduce verbosity of user/room stats. ([\#6250](https://github.com/matrix-org/synapse/issues/6250))
- Reduce impact of debug logging. ([\#6251](https://github.com/matrix-org/synapse/issues/6251))
- Expose some homeserver functionality to spam checkers. ([\#6259](https://github.com/matrix-org/synapse/issues/6259))
- Change cache descriptors to always return deferreds. ([\#6263](https://github.com/matrix-org/synapse/issues/6263), [\#6291](https://github.com/matrix-org/synapse/issues/6291))
- Fix incorrect comment regarding the functionality of an `if` statement. ([\#6269](https://github.com/matrix-org/synapse/issues/6269))
- Update CI to run `isort` over the `scripts` and `scripts-dev` directories. ([\#6270](https://github.com/matrix-org/synapse/issues/6270))
- Replace every instance of `logger.warn` method with `logger.warning` as the former is deprecated. ([\#6271](https://github.com/matrix-org/synapse/issues/6271), [\#6314](https://github.com/matrix-org/synapse/issues/6314))
- Port replication http server endpoints to async/await. ([\#6274](https://github.com/matrix-org/synapse/issues/6274))
- Port room rest handlers to async/await. ([\#6275](https://github.com/matrix-org/synapse/issues/6275))
- Remove redundant CLI parameters on CI's `flake8` step. ([\#6277](https://github.com/matrix-org/synapse/issues/6277))
- Port `federation_server.py` to async/await. ([\#6279](https://github.com/matrix-org/synapse/issues/6279))
- Port receipt and read markers to async/wait. ([\#6280](https://github.com/matrix-org/synapse/issues/6280))
- Split out state storage into separate data store. ([\#6294](https://github.com/matrix-org/synapse/issues/6294), [\#6295](https://github.com/matrix-org/synapse/issues/6295))
- Refactor EventContext for clarity. ([\#6298](https://github.com/matrix-org/synapse/issues/6298))
- Update the version of black used to 19.10b0. ([\#6304](https://github.com/matrix-org/synapse/issues/6304))
- Add some documentation about worker replication. ([\#6305](https://github.com/matrix-org/synapse/issues/6305))
- Move admin endpoints into separate files. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#6308](https://github.com/matrix-org/synapse/issues/6308))
- Document the use of `lint.sh` for code style enforcement & extend it to run on specified paths only. ([\#6312](https://github.com/matrix-org/synapse/issues/6312))
- Add optional python dependencies and dependant binary libraries to snapcraft packaging. ([\#6317](https://github.com/matrix-org/synapse/issues/6317))
- Remove the dependency on psutil and replace functionality with the stdlib `resource` module. ([\#6318](https://github.com/matrix-org/synapse/issues/6318), [\#6336](https://github.com/matrix-org/synapse/issues/6336))
- Improve documentation for EventContext fields. ([\#6319](https://github.com/matrix-org/synapse/issues/6319))
- Add some checks that we aren't using state from rejected events. ([\#6330](https://github.com/matrix-org/synapse/issues/6330))
- Add continuous integration for python 3.8. ([\#6341](https://github.com/matrix-org/synapse/issues/6341))
- Correct spacing/case of various instances of the word "homeserver". ([\#6357](https://github.com/matrix-org/synapse/issues/6357))
- Temporarily blacklist the failing unit test PurgeRoomTestCase.test_purge_room. ([\#6361](https://github.com/matrix-org/synapse/issues/6361))
- Limit the length of data returned by url previews, to prevent DoS attacks. ([\#6331](https://github.com/matrix-org/synapse/issues/6331), [\#6334](https://github.com/matrix-org/synapse/issues/6334))
This release includes a security fix ([\#6262](https://github.com/matrix-org/synapse/issues/6262), below). Administrators are encouraged to upgrade as soon as possible.
Bugfixes
--------
- Fix bug where room directory search was case sensitive. ([\#6268](https://github.com/matrix-org/synapse/issues/6268))
- Update list of boolean columns in `synapse_port_db`. ([\#6247](https://github.com/matrix-org/synapse/issues/6247))
- Fix /keys/query API on workers. ([\#6256](https://github.com/matrix-org/synapse/issues/6256))
- Improve signature checking on some federation APIs. ([\#6262](https://github.com/matrix-org/synapse/issues/6262))
Internal Changes
----------------
- Move schema delta files to the correct data store. ([\#6248](https://github.com/matrix-org/synapse/issues/6248))
- Small performance improvement by removing repeated config lookups in room stats calculation. ([\#6255](https://github.com/matrix-org/synapse/issues/6255))
- Improve quality of thumbnails for 1-bit/8-bit color palette images. ([\#2142](https://github.com/matrix-org/synapse/issues/2142))
- Add ability to upload cross-signing signatures. ([\#5726](https://github.com/matrix-org/synapse/issues/5726))
- Allow uploading of cross-signing keys. ([\#5769](https://github.com/matrix-org/synapse/issues/5769))
- CAS login now provides a default display name for users if a `displayname_attribute` is set in the configuration file. ([\#6114](https://github.com/matrix-org/synapse/issues/6114))
- Reject all pending invites for a user during deactivation. ([\#6125](https://github.com/matrix-org/synapse/issues/6125))
- Add config option to suppress client side resource limit alerting. ([\#6173](https://github.com/matrix-org/synapse/issues/6173))
Bugfixes
--------
- Return an HTTP 404 instead of 400 when requesting a filter by ID that is unknown to the server. Thanks to @krombel for contributing this! ([\#2380](https://github.com/matrix-org/synapse/issues/2380))
- Fix a bug where users could be invited twice to the same group. ([\#3436](https://github.com/matrix-org/synapse/issues/3436))
- Fix `/createRoom` failing with badly-formatted MXIDs in the invitee list. Thanks to @wener291! ([\#4088](https://github.com/matrix-org/synapse/issues/4088))
- Make the `synapse_port_db` script create the right indexes on a new PostgreSQL database. ([\#6102](https://github.com/matrix-org/synapse/issues/6102), [\#6178](https://github.com/matrix-org/synapse/issues/6178), [\#6243](https://github.com/matrix-org/synapse/issues/6243))
- Fix bug when uploading a large file: Synapse responds with `M_UNKNOWN` while it should be `M_TOO_LARGE` according to spec. Contributed by Anshul Angaria. ([\#6109](https://github.com/matrix-org/synapse/issues/6109))
- Don't 500 when trying to exchange a revoked 3PID invite. ([\#6147](https://github.com/matrix-org/synapse/issues/6147))
- Fix transferring notifications and tags when joining an upgraded room that is new to your server. ([\#6155](https://github.com/matrix-org/synapse/issues/6155))
- Fix bug where guest account registration can wedge after restart. ([\#6161](https://github.com/matrix-org/synapse/issues/6161))
- Fix bug where we were updating censored events as bytes rather than text, occaisonally causing invalid JSON being inserted breaking APIs that attempted to fetch such events. ([\#6186](https://github.com/matrix-org/synapse/issues/6186))
- Fix occasional missed updates in the room and user directories. ([\#6187](https://github.com/matrix-org/synapse/issues/6187))
- Fix bug where presence would not get timed out correctly if a synchrotron worker is used and restarted. ([\#6212](https://github.com/matrix-org/synapse/issues/6212))
- synapse_port_db: Add 2 additional BOOLEAN_COLUMNS to be able to convert from database schema v56. ([\#6216](https://github.com/matrix-org/synapse/issues/6216))
- Fix a bug where the Synapse demo script blacklisted `::1` (ipv6 localhost) from receiving federation traffic. ([\#6229](https://github.com/matrix-org/synapse/issues/6229))
- Fix logging getting lost for the docker image. ([\#6197](https://github.com/matrix-org/synapse/issues/6197))
Internal Changes
----------------
- Update `user_filters` table to have a unique index, and non-null columns. Thanks to @pik for contributing this. ([\#1172](https://github.com/matrix-org/synapse/issues/1172), [\#6175](https://github.com/matrix-org/synapse/issues/6175), [\#6184](https://github.com/matrix-org/synapse/issues/6184))
- Move lookup-related functions from RoomMemberHandler to IdentityHandler. ([\#5978](https://github.com/matrix-org/synapse/issues/5978))
- Improve performance of the public room list directory. ([\#6019](https://github.com/matrix-org/synapse/issues/6019), [\#6152](https://github.com/matrix-org/synapse/issues/6152), [\#6153](https://github.com/matrix-org/synapse/issues/6153), [\#6154](https://github.com/matrix-org/synapse/issues/6154))
- Edit header dicts docstrings in `SimpleHttpClient` to note that `str` or `bytes` can be passed as header keys. ([\#6077](https://github.com/matrix-org/synapse/issues/6077))
- Use Postgres ANY for selecting many values. ([\#6156](https://github.com/matrix-org/synapse/issues/6156))
- Add more caching to `_get_joined_users_from_context` DB query. ([\#6159](https://github.com/matrix-org/synapse/issues/6159))
- Add some metrics on the federation sender. ([\#6160](https://github.com/matrix-org/synapse/issues/6160))
- Add some logging to the rooms stats updates, to try to track down a flaky test. ([\#6167](https://github.com/matrix-org/synapse/issues/6167))
- Remove unused `timeout` parameter from `_get_public_room_list`. ([\#6179](https://github.com/matrix-org/synapse/issues/6179))
- Reject (accidental) attempts to insert bytes into postgres tables. ([\#6186](https://github.com/matrix-org/synapse/issues/6186))
- Make `version` optional in body of `PUT /room_keys/version/{version}`, since it's redundant. ([\#6189](https://github.com/matrix-org/synapse/issues/6189))
- Make storage layer responsible for adding device names to key, rather than the handler. ([\#6193](https://github.com/matrix-org/synapse/issues/6193))
- Fix bug where redacted events were sometimes incorrectly censored in the database, breaking APIs that attempted to fetch such events. ([\#6185](https://github.com/matrix-org/synapse/issues/6185), [5b0e9948](https://github.com/matrix-org/synapse/commit/5b0e9948eaae801643e594b5abc8ee4b10bd194e))
- Fix bug in background update that adds last seen information to the `devices` table, and improve its performance on Postgres. ([\#6135](https://github.com/matrix-org/synapse/issues/6135))
- Fix bad performance of censoring redactions background task. ([\#6141](https://github.com/matrix-org/synapse/issues/6141))
- Fix fetching censored redactions from DB, which caused APIs like initial sync to fail if it tried to include the censored redaction. ([\#6145](https://github.com/matrix-org/synapse/issues/6145))
- Fix exceptions when storing large retry intervals for down remote servers. ([\#6146](https://github.com/matrix-org/synapse/issues/6146))
Internal Changes
----------------
- Fix up sample config entry for `redaction_retention_period` option. ([\#6117](https://github.com/matrix-org/synapse/issues/6117))
- Add the ability to send registration emails from the homeserver rather than delegating to an identity server. ([\#5835](https://github.com/matrix-org/synapse/issues/5835), [\#5940](https://github.com/matrix-org/synapse/issues/5940), [\#5993](https://github.com/matrix-org/synapse/issues/5993), [\#5994](https://github.com/matrix-org/synapse/issues/5994), [\#5868](https://github.com/matrix-org/synapse/issues/5868))
- Replace `trust_identity_server_for_password_resets` config option with `account_threepid_delegates`, and make the `id_server` parameteter optional on `*/requestToken` endpoints, as per [MSC2263](https://github.com/matrix-org/matrix-doc/pull/2263). ([\#5876](https://github.com/matrix-org/synapse/issues/5876), [\#5969](https://github.com/matrix-org/synapse/issues/5969), [\#6028](https://github.com/matrix-org/synapse/issues/6028))
- Switch to using the v2 Identity Service `/lookup` API where available, with fallback to v1. (Implements [MSC2134](https://github.com/matrix-org/matrix-doc/pull/2134) plus `id_access_token authentication` for v2 Identity Service APIs from [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140)). ([\#5897](https://github.com/matrix-org/synapse/issues/5897))
- Remove `bind_email` and `bind_msisdn` parameters from `/register` ala [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140). ([\#5964](https://github.com/matrix-org/synapse/issues/5964))
- Add `m.id_access_token` to `unstable_features` in `/versions` as per [MSC2264](https://github.com/matrix-org/matrix-doc/pull/2264). ([\#5974](https://github.com/matrix-org/synapse/issues/5974))
- Use the v2 Identity Service API for 3PID invites. ([\#5979](https://github.com/matrix-org/synapse/issues/5979))
- Add `POST /_matrix/client/unstable/account/3pid/unbind` endpoint from [MSC2140](https://github.com/matrix-org/matrix-doc/pull/2140) for unbinding a 3PID from an identity server without removing it from the homeserver user account. ([\#5980](https://github.com/matrix-org/synapse/issues/5980), [\#6062](https://github.com/matrix-org/synapse/issues/6062))
- Use `account_threepid_delegate.email` and `account_threepid_delegate.msisdn` for validating threepid sessions. ([\#6011](https://github.com/matrix-org/synapse/issues/6011))
- Allow homeserver to handle or delegate email validation when adding an email to a user's account. ([\#6042](https://github.com/matrix-org/synapse/issues/6042))
- Implement new Client Server API endpoints `/account/3pid/add` and `/account/3pid/bind` as per [MSC2290](https://github.com/matrix-org/matrix-doc/pull/2290). ([\#6043](https://github.com/matrix-org/synapse/issues/6043))
- Add an unstable feature flag for separate add/bind 3pid APIs. ([\#6044](https://github.com/matrix-org/synapse/issues/6044))
- Remove `bind` parameter from Client Server POST `/account` endpoint as per [MSC2290](https://github.com/matrix-org/matrix-doc/pull/2290/). ([\#6067](https://github.com/matrix-org/synapse/issues/6067))
- Add `POST /add_threepid/msisdn/submit_token` endpoint for proxying submitToken on an `account_threepid_handler`. ([\#6078](https://github.com/matrix-org/synapse/issues/6078))
- Add `submit_url` response parameter to `*/msisdn/requestToken` endpoints. ([\#6079](https://github.com/matrix-org/synapse/issues/6079))
- Add `m.require_identity_server` flag to /version's unstable_features. ([\#5972](https://github.com/matrix-org/synapse/issues/5972))
- Enhancements to OpenTracing support:
- Make OpenTracing work in worker mode. ([\#5771](https://github.com/matrix-org/synapse/issues/5771))
- Pass OpenTracing contexts between servers when transmitting EDUs. ([\#5852](https://github.com/matrix-org/synapse/issues/5852))
- OpenTracing for device list updates. ([\#5853](https://github.com/matrix-org/synapse/issues/5853))
- Add a tag recording a request's authenticated entity and corresponding servlet in OpenTracing. ([\#5856](https://github.com/matrix-org/synapse/issues/5856))
- Add minimum OpenTracing for client servlets. ([\#5983](https://github.com/matrix-org/synapse/issues/5983))
- Check at setup that OpenTracing is installed if it's enabled in the config. ([\#5985](https://github.com/matrix-org/synapse/issues/5985))
- Include missing OpenTracing contexts in outbout replication requests. ([\#5982](https://github.com/matrix-org/synapse/issues/5982))
- Fix sending of EDUs when OpenTracing is enabled with an empty whitelist. ([\#5984](https://github.com/matrix-org/synapse/issues/5984))
- Fix invalid references to None while OpenTracing if the log context slips. ([\#5988](https://github.com/matrix-org/synapse/issues/5988), [\#5991](https://github.com/matrix-org/synapse/issues/5991))
- OpenTracing for room and e2e keys. ([\#5855](https://github.com/matrix-org/synapse/issues/5855))
- Add OpenTracing span over HTTP push processing. ([\#6003](https://github.com/matrix-org/synapse/issues/6003))
- Add an admin API to purge old rooms from the database. ([\#5845](https://github.com/matrix-org/synapse/issues/5845))
- Retry well-known lookups if we have recently seen a valid well-known record for the server. ([\#5850](https://github.com/matrix-org/synapse/issues/5850))
- Add support for filtered room-directory search requests over federation ([MSC2197](https://github.com/matrix-org/matrix-doc/pull/2197), in order to allow upcoming room directory query performance improvements. ([\#5859](https://github.com/matrix-org/synapse/issues/5859))
- Correctly retry all hosts returned from SRV when we fail to connect. ([\#5864](https://github.com/matrix-org/synapse/issues/5864))
- Add admin API endpoint for setting whether or not a user is a server administrator. ([\#5878](https://github.com/matrix-org/synapse/issues/5878))
- Enable cleaning up extremities with dummy events by default to prevent undue build up of forward extremities. ([\#5884](https://github.com/matrix-org/synapse/issues/5884))
- Add config option to sign remote key query responses with a separate key. ([\#5895](https://github.com/matrix-org/synapse/issues/5895))
- Add support for config templating. ([\#5900](https://github.com/matrix-org/synapse/issues/5900))
- Users with the type of "support" or "bot" are no longer required to consent. ([\#5902](https://github.com/matrix-org/synapse/issues/5902))
- Let synctl accept a directory of config files. ([\#5904](https://github.com/matrix-org/synapse/issues/5904))
- Increase max display name size to 256. ([\#5906](https://github.com/matrix-org/synapse/issues/5906))
- Add admin API endpoint for getting whether or not a user is a server administrator. ([\#5914](https://github.com/matrix-org/synapse/issues/5914))
-`synapse_federation_known_servers`: represents the total number of servers your server knows about (i.e. is in rooms with), including itself. Enable by setting `metrics_flags.known_servers` to True in the configuration.([\#5981](https://github.com/matrix-org/synapse/issues/5981))
-`synapse_build_info`: exposes the Python version, OS version, and Synapse version of the running server. ([\#6005](https://github.com/matrix-org/synapse/issues/6005))
- Give appropriate exit codes when synctl fails. ([\#5992](https://github.com/matrix-org/synapse/issues/5992))
- Apply the federation blacklist to requests to identity servers. ([\#6000](https://github.com/matrix-org/synapse/issues/6000))
- Add `report_stats_endpoint` option to configure where stats are reported to, if enabled. Contributed by @Sorunome. ([\#6012](https://github.com/matrix-org/synapse/issues/6012))
- Add config option to increase ratelimits for room admins redacting messages. ([\#6015](https://github.com/matrix-org/synapse/issues/6015))
- Stop sending federation transactions to servers which have been down for a long time. ([\#6026](https://github.com/matrix-org/synapse/issues/6026))
- Make the process for mapping SAML2 users to matrix IDs more flexible. ([\#6037](https://github.com/matrix-org/synapse/issues/6037))
- Return a clearer error message when a timeout occurs when attempting to contact an identity server. ([\#6073](https://github.com/matrix-org/synapse/issues/6073))
- Return 403 on `/register/available` if registration has been disabled. ([\#6082](https://github.com/matrix-org/synapse/issues/6082))
- Explicitly log when a homeserver does not have the `trusted_key_servers` config field configured. ([\#6090](https://github.com/matrix-org/synapse/issues/6090))
- Add support for pruning old rows in `user_ips` table. ([\#6098](https://github.com/matrix-org/synapse/issues/6098))
Bugfixes
--------
- Don't create broken room when `power_level_content_override.users` does not contain `creator_id`. ([\#5633](https://github.com/matrix-org/synapse/issues/5633))
- Fix database index so that different backup versions can have the same sessions. ([\#5857](https://github.com/matrix-org/synapse/issues/5857))
- Fix Synapse looking for config options `password_reset_failure_template` and `password_reset_success_template`, when they are actually `password_reset_template_failure_html`, `password_reset_template_success_html`. ([\#5863](https://github.com/matrix-org/synapse/issues/5863))
- Fix stack overflow when recovering an appservice which had an outage. ([\#5885](https://github.com/matrix-org/synapse/issues/5885))
- Fix error message which referred to `public_base_url` instead of `public_baseurl`. Thanks to @aaronraimist for the fix! ([\#5909](https://github.com/matrix-org/synapse/issues/5909))
- Fix 404 for thumbnail download when `dynamic_thumbnails` is `false` and the thumbnail was dynamically generated. Fix reported by rkfg. ([\#5915](https://github.com/matrix-org/synapse/issues/5915))
- Fix a cache-invalidation bug for worker-based deployments. ([\#5920](https://github.com/matrix-org/synapse/issues/5920))
- Fix admin API for listing media in a room not being available with an external media repo. ([\#5966](https://github.com/matrix-org/synapse/issues/5966))
- Fix list media admin API always returning an error. ([\#5967](https://github.com/matrix-org/synapse/issues/5967))
- Fix room and user stats tracking. ([\#5971](https://github.com/matrix-org/synapse/issues/5971), [\#5998](https://github.com/matrix-org/synapse/issues/5998), [\#6029](https://github.com/matrix-org/synapse/issues/6029))
- Return a `M_MISSING_PARAM` if `sid` is not provided to `/account/3pid`. ([\#5995](https://github.com/matrix-org/synapse/issues/5995))
-`federation_certificate_verification_whitelist` now will not cause `TypeErrors` to be raised (a regression in 1.3). Additionally, it now supports internationalised domain names in their non-canonical representation. ([\#5996](https://github.com/matrix-org/synapse/issues/5996))
- Only count real users when checking for auto-creation of auto-join room. ([\#6004](https://github.com/matrix-org/synapse/issues/6004))
- Ensure support users can be registered even if MAU limit is reached. ([\#6020](https://github.com/matrix-org/synapse/issues/6020))
- Fix bug where login error was shown incorrectly on SSO fallback login. ([\#6024](https://github.com/matrix-org/synapse/issues/6024))
- Fix bug in calculating the federation retry backoff period. ([\#6025](https://github.com/matrix-org/synapse/issues/6025))
- Prevent exceptions being logged when extremity-cleanup events fail due to lack of user consent to the terms of service. ([\#6053](https://github.com/matrix-org/synapse/issues/6053))
- Remove POST method from password-reset `submit_token` endpoint until we implement `submit_url` functionality. ([\#6056](https://github.com/matrix-org/synapse/issues/6056))
- Fix logcontext spam on non-Linux platforms. ([\#6059](https://github.com/matrix-org/synapse/issues/6059))
- Ensure query parameters in email validation links are URL-encoded. ([\#6063](https://github.com/matrix-org/synapse/issues/6063))
- Fix a bug which caused SAML attribute maps to be overridden by defaults. ([\#6069](https://github.com/matrix-org/synapse/issues/6069))
- Fix the logged number of updated items for the `users_set_deactivated_flag` background update. ([\#6092](https://github.com/matrix-org/synapse/issues/6092))
- Add `sid` to `next_link` for email validation. ([\#6097](https://github.com/matrix-org/synapse/issues/6097))
- Threepid validity checks on msisdns should not be dependent on `threepid_behaviour_email`. ([\#6104](https://github.com/matrix-org/synapse/issues/6104))
- Ensure that servers which are not configured to support email address verification do not offer it in the registration flows. ([\#6107](https://github.com/matrix-org/synapse/issues/6107))
- Convert documentation to markdown (from rst) ([\#5849](https://github.com/matrix-org/synapse/issues/5849))
- Update `INSTALL.md` to say that Python 2 is no longer supported. ([\#5953](https://github.com/matrix-org/synapse/issues/5953))
- Add developer documentation for using SAML2. ([\#6032](https://github.com/matrix-org/synapse/issues/6032))
- Add some notes on rolling back to v1.3.1. ([\#6049](https://github.com/matrix-org/synapse/issues/6049))
- Update the upgrade notes. ([\#6050](https://github.com/matrix-org/synapse/issues/6050))
Deprecations and Removals
-------------------------
- Remove shared-secret registration from `/_matrix/client/r0/register` endpoint. Contributed by Awesome Technologies Innovationslabor GmbH. ([\#5877](https://github.com/matrix-org/synapse/issues/5877))
- Deprecate the `trusted_third_party_id_servers` option. ([\#5875](https://github.com/matrix-org/synapse/issues/5875))
Internal Changes
----------------
- Lay the groundwork for structured logging output. ([\#5680](https://github.com/matrix-org/synapse/issues/5680))
- Retry well-known lookup before the cache expires, giving a grace period where the remote well-known can be down but we still use the old result. ([\#5844](https://github.com/matrix-org/synapse/issues/5844))
- Remove log line for debugging issue #5407. ([\#5860](https://github.com/matrix-org/synapse/issues/5860))
- Refactor the Appservice scheduler code. ([\#5886](https://github.com/matrix-org/synapse/issues/5886))
- Compatibility with v2 Identity Service APIs other than /lookup. ([\#5892](https://github.com/matrix-org/synapse/issues/5892), [\#6013](https://github.com/matrix-org/synapse/issues/6013))
- Stop populating some unused tables. ([\#5893](https://github.com/matrix-org/synapse/issues/5893), [\#6047](https://github.com/matrix-org/synapse/issues/6047))
- Add missing index on `users_in_public_rooms` to improve the performance of directory queries. ([\#5894](https://github.com/matrix-org/synapse/issues/5894))
- Move Buildkite pipeline config to the pipelines repo. ([\#5943](https://github.com/matrix-org/synapse/issues/5943))
- Remove unnecessary return statements in the codebase which were the result of a regex run. ([\#5962](https://github.com/matrix-org/synapse/issues/5962))
- Remove left-over methods from v1 registration API. ([\#5963](https://github.com/matrix-org/synapse/issues/5963))
- Cleanup event auth type initialisation. ([\#5975](https://github.com/matrix-org/synapse/issues/5975))
- Clean up dependency checking at setup. ([\#5989](https://github.com/matrix-org/synapse/issues/5989))
- Update OpenTracing docs to use the unified `trace` method. ([\#5776](https://github.com/matrix-org/synapse/issues/5776))
- Small refactor of function arguments and docstrings in` RoomMemberHandler`. ([\#6009](https://github.com/matrix-org/synapse/issues/6009))
- Remove unused `origin` argument on `FederationHandler.add_display_name_to_third_party_invite`. ([\#6010](https://github.com/matrix-org/synapse/issues/6010))
- Add a `failure_ts` column to the `destinations` database table. ([\#6016](https://github.com/matrix-org/synapse/issues/6016), [\#6072](https://github.com/matrix-org/synapse/issues/6072))
- Clean up some code in the retry logic. ([\#6017](https://github.com/matrix-org/synapse/issues/6017))
- Fix the structured logging tests stomping on the global log configuration for subsequent tests. ([\#6023](https://github.com/matrix-org/synapse/issues/6023))
- Clean up the sample config for SAML authentication. ([\#6064](https://github.com/matrix-org/synapse/issues/6064))
- Change mailer logging to reflect Synapse doesn't just do chat notifications by email now. ([\#6075](https://github.com/matrix-org/synapse/issues/6075))
- Move last-seen info into devices table. ([\#6089](https://github.com/matrix-org/synapse/issues/6089))
- Remove unused parameter to `get_user_id_by_threepid`. ([\#6099](https://github.com/matrix-org/synapse/issues/6099))
- Refactor the user-interactive auth handling. ([\#6105](https://github.com/matrix-org/synapse/issues/6105))
- Refactor code for calculating registration flows. ([\#6106](https://github.com/matrix-org/synapse/issues/6106))
- Drop hard dependency on `sdnotify` python package. ([\#5871](https://github.com/matrix-org/synapse/issues/5871))
Bugfixes
--------
- Fix startup issue (hang on ACME provisioning) due to ordering of Twisted reactor startup. Thanks to @chrismoos for supplying the fix. ([\#5867](https://github.com/matrix-org/synapse/issues/5867))
- Use `M_USER_DEACTIVATED` instead of `M_UNKNOWN` for errcode when a deactivated user attempts to login. ([\#5686](https://github.com/matrix-org/synapse/issues/5686))
- Add sd_notify hooks to ease systemd integration and allows usage of Type=Notify. ([\#5732](https://github.com/matrix-org/synapse/issues/5732))
- Synapse will no longer serve any media repo admin endpoints when `enable_media_repo` is set to False in the configuration. If a media repo worker is used, the admin APIs relating to the media repo will be served from it instead. ([\#5754](https://github.com/matrix-org/synapse/issues/5754), [\#5848](https://github.com/matrix-org/synapse/issues/5848))
- Synapse can now be configured to not join remote rooms of a given "complexity" (currently, state events) over federation. This option can be used to prevent adverse performance on resource-constrained homeservers. ([\#5783](https://github.com/matrix-org/synapse/issues/5783))
- Allow defining HTML templates to serve the user on account renewal attempt when using the account validity feature. ([\#5807](https://github.com/matrix-org/synapse/issues/5807))
Bugfixes
--------
- Fix UISIs during homeserver outage. ([\#5693](https://github.com/matrix-org/synapse/issues/5693), [\#5789](https://github.com/matrix-org/synapse/issues/5789))
- Fix stack overflow in server key lookup code. ([\#5724](https://github.com/matrix-org/synapse/issues/5724))
- start.sh no longer uses deprecated cli option. ([\#5725](https://github.com/matrix-org/synapse/issues/5725))
- Log when we receive an event receipt from an unexpected origin. ([\#5743](https://github.com/matrix-org/synapse/issues/5743))
- Correctly handle redactions of redactions. ([\#5788](https://github.com/matrix-org/synapse/issues/5788))
- Return 404 instead of 403 when accessing /rooms/{roomId}/event/{eventId} for an event without the appropriate permissions. ([\#5798](https://github.com/matrix-org/synapse/issues/5798))
- Fix check that tombstone is a state event in push rules. ([\#5804](https://github.com/matrix-org/synapse/issues/5804))
- Fix error when trying to login as a deactivated user when using a worker to handle login. ([\#5806](https://github.com/matrix-org/synapse/issues/5806))
- Fix bug where user `/sync` stream could get wedged in rare circumstances. ([\#5825](https://github.com/matrix-org/synapse/issues/5825))
- The purge_remote_media.sh script was fixed. ([\#5839](https://github.com/matrix-org/synapse/issues/5839))
Deprecations and Removals
-------------------------
- Synapse now no longer accepts the `-v`/`--verbose`, `-f`/`--log-file`, or `--log-config` command line flags, and removes the deprecated `verbose` and `log_file` configuration file options. Users of these options should migrate their options into the dedicated log configuration. ([\#5678](https://github.com/matrix-org/synapse/issues/5678), [\#5729](https://github.com/matrix-org/synapse/issues/5729))
- Make Jaeger fully configurable. ([\#5694](https://github.com/matrix-org/synapse/issues/5694))
- Add precautionary measures to prevent future abuse of `window.opener` in default welcome page. ([\#5695](https://github.com/matrix-org/synapse/issues/5695))
- Reduce database IO usage by optimising queries for current membership. ([\#5706](https://github.com/matrix-org/synapse/issues/5706), [\#5738](https://github.com/matrix-org/synapse/issues/5738), [\#5746](https://github.com/matrix-org/synapse/issues/5746), [\#5752](https://github.com/matrix-org/synapse/issues/5752), [\#5770](https://github.com/matrix-org/synapse/issues/5770), [\#5774](https://github.com/matrix-org/synapse/issues/5774), [\#5792](https://github.com/matrix-org/synapse/issues/5792), [\#5793](https://github.com/matrix-org/synapse/issues/5793))
- Improve caching when fetching `get_filtered_current_state_ids`. ([\#5713](https://github.com/matrix-org/synapse/issues/5713))
- Don't accept opentracing data from clients. ([\#5715](https://github.com/matrix-org/synapse/issues/5715))
- Speed up PostgreSQL unit tests in CI. ([\#5717](https://github.com/matrix-org/synapse/issues/5717))
- Update the coding style document. ([\#5719](https://github.com/matrix-org/synapse/issues/5719))
- Improve database query performance when recording retry intervals for remote hosts. ([\#5720](https://github.com/matrix-org/synapse/issues/5720))
- Add a set of opentracing utils. ([\#5722](https://github.com/matrix-org/synapse/issues/5722))
- Cache result of get_version_string to reduce overhead of `/version` federation requests. ([\#5730](https://github.com/matrix-org/synapse/issues/5730))
- Return 'user_type' in admin API user endpoints results. ([\#5731](https://github.com/matrix-org/synapse/issues/5731))
- Don't package the sytest test blacklist file. ([\#5733](https://github.com/matrix-org/synapse/issues/5733))
- Replace uses of returnValue with plain return, as returnValue is not needed on Python 3. ([\#5736](https://github.com/matrix-org/synapse/issues/5736))
- Blacklist some flakey tests in worker mode. ([\#5740](https://github.com/matrix-org/synapse/issues/5740))
- Fix some error cases in the caching layer. ([\#5749](https://github.com/matrix-org/synapse/issues/5749))
- Add a prometheus metric for pending cache lookups. ([\#5750](https://github.com/matrix-org/synapse/issues/5750))
- Stop trying to fetch events with event_id=None. ([\#5753](https://github.com/matrix-org/synapse/issues/5753))
- Convert RedactionTestCase to modern test style. ([\#5768](https://github.com/matrix-org/synapse/issues/5768))
- Allow looping calls to be given arguments. ([\#5780](https://github.com/matrix-org/synapse/issues/5780))
- Set the logs emitted when checking typing and presence timeouts to DEBUG level, not INFO. ([\#5785](https://github.com/matrix-org/synapse/issues/5785))
- Remove DelayedCall debugging from the test suite, as it is no longer required in the vast majority of Synapse's tests. ([\#5787](https://github.com/matrix-org/synapse/issues/5787))
- Remove some spurious exceptions from the logs where we failed to talk to a remote server. ([\#5790](https://github.com/matrix-org/synapse/issues/5790))
- Improve performance when making `.well-known` requests by sharing the SSL options between requests. ([\#5794](https://github.com/matrix-org/synapse/issues/5794))
- Disable codecov GitHub comments on PRs. ([\#5796](https://github.com/matrix-org/synapse/issues/5796))
- Don't allow clients to send tombstone events that reference the room it's sent in. ([\#5801](https://github.com/matrix-org/synapse/issues/5801))
- Deny redactions of events sent in a different room. ([\#5802](https://github.com/matrix-org/synapse/issues/5802))
- Deny sending well known state types as non-state events. ([\#5805](https://github.com/matrix-org/synapse/issues/5805))
- Handle incorrectly encoded query params correctly by returning a 400. ([\#5808](https://github.com/matrix-org/synapse/issues/5808))
- Handle pusher being deleted during processing rather than logging an exception. ([\#5809](https://github.com/matrix-org/synapse/issues/5809))
- Return 502 not 500 when failing to reach any remote server. ([\#5810](https://github.com/matrix-org/synapse/issues/5810))
- Reduce global pauses in the events stream caused by expensive state resolution during persistence. ([\#5826](https://github.com/matrix-org/synapse/issues/5826))
- Add a lower bound to well-known lookup cache time to avoid repeated lookups. ([\#5836](https://github.com/matrix-org/synapse/issues/5836))
- Whitelist history visbility sytests in worker mode tests. ([\#5843](https://github.com/matrix-org/synapse/issues/5843))
- Prevent an attack where a federated server could send redactions for arbitrary events in v1 and v2 rooms. ([\#5767](https://github.com/matrix-org/synapse/issues/5767))
- Prevent a denial-of-service attack where cycles of redaction events would make Synapse spin infinitely. Thanks to `@lrizika:matrix.org` for identifying and responsibly disclosing this issue. ([0f2ecb961](https://github.com/matrix-org/synapse/commit/0f2ecb961))
- Prevent an attack where users could be joined or parted from public rooms without their consent. Thanks to @dylangerdaly for identifying and responsibly disclosing this issue. ([\#5744](https://github.com/matrix-org/synapse/issues/5744))
Additionally, the following fix was in Synapse **1.2.0**, but was not correctly
identified during the original release:
- It was possible for a room moderator to send a redaction for an `m.room.create` event, which would downgrade the room to version 1. Thanks to `/dev/ponies` for identifying and responsibly disclosing this issue! ([\#5701](https://github.com/matrix-org/synapse/issues/5701))
- Fix a regression introduced in v1.2.0rc1 which led to incorrect labels on some prometheus metrics. ([\#5734](https://github.com/matrix-org/synapse/issues/5734))
This update included a security fix which was initially incorrectly flagged as
a regular bug fix.
- It was possible for a room moderator to send a redaction for an `m.room.create` event, which would downgrade the room to version 1. Thanks to `/dev/ponies` for identifying and responsibly disclosing this issue! ([\#5701](https://github.com/matrix-org/synapse/issues/5701))
- Add support for opentracing. ([\#5544](https://github.com/matrix-org/synapse/issues/5544), [\#5712](https://github.com/matrix-org/synapse/issues/5712))
- Add ability to pull all locally stored events out of synapse that a particular user can see. ([\#5589](https://github.com/matrix-org/synapse/issues/5589))
- Add a basic admin command app to allow server operators to run Synapse admin commands separately from the main production instance. ([\#5597](https://github.com/matrix-org/synapse/issues/5597))
- Add `sender` and `origin_server_ts` fields to `m.replace`. ([\#5613](https://github.com/matrix-org/synapse/issues/5613))
- Add default push rule to ignore reactions. ([\#5623](https://github.com/matrix-org/synapse/issues/5623))
- Include the original event when asking for its relations. ([\#5626](https://github.com/matrix-org/synapse/issues/5626))
- Implement `session_lifetime` configuration option, after which access tokens will expire. ([\#5660](https://github.com/matrix-org/synapse/issues/5660))
- Return "This account has been deactivated" when a deactivated user tries to login. ([\#5674](https://github.com/matrix-org/synapse/issues/5674))
- Enable aggregations support by default ([\#5714](https://github.com/matrix-org/synapse/issues/5714))
Bugfixes
--------
- Fix 'utime went backwards' errors on daemonization. ([\#5609](https://github.com/matrix-org/synapse/issues/5609))
- Various minor fixes to the federation request rate limiter. ([\#5621](https://github.com/matrix-org/synapse/issues/5621))
- Forbid viewing relations on an event once it has been redacted. ([\#5629](https://github.com/matrix-org/synapse/issues/5629))
- Fix requests to the `/store_invite` endpoint of identity servers being sent in the wrong format. ([\#5638](https://github.com/matrix-org/synapse/issues/5638))
- Fix newly-registered users not being able to lookup their own profile without joining a room. ([\#5644](https://github.com/matrix-org/synapse/issues/5644))
- Fix bug in #5626 that prevented the original_event field from actually having the contents of the original event in a call to `/relations`. ([\#5654](https://github.com/matrix-org/synapse/issues/5654))
- Fix 3PID bind requests being sent to identity servers as `application/x-form-www-urlencoded` data, which is deprecated. ([\#5658](https://github.com/matrix-org/synapse/issues/5658))
- Fix some problems with authenticating redactions in recent room versions. ([\#5699](https://github.com/matrix-org/synapse/issues/5699), [\#5700](https://github.com/matrix-org/synapse/issues/5700), [\#5707](https://github.com/matrix-org/synapse/issues/5707))
Updates to the Docker image
---------------------------
- Base Docker image on a newer Alpine Linux version (3.8 -> 3.10). ([\#5619](https://github.com/matrix-org/synapse/issues/5619))
- Add missing space in default logging file format generated by the Docker image. ([\#5620](https://github.com/matrix-org/synapse/issues/5620))
Improved Documentation
----------------------
- Add information about nginx normalisation to reverse_proxy.rst. Contributed by @skalarproduktraum - thanks! ([\#5397](https://github.com/matrix-org/synapse/issues/5397))
- --no-pep517 should be --no-use-pep517 in the documentation to setup the development environment. ([\#5651](https://github.com/matrix-org/synapse/issues/5651))
- Improvements to Postgres setup instructions. Contributed by @Lrizika - thanks! ([\#5661](https://github.com/matrix-org/synapse/issues/5661))
- Minor tweaks to postgres documentation. ([\#5675](https://github.com/matrix-org/synapse/issues/5675))
Deprecations and Removals
-------------------------
- Remove support for the `invite_3pid_guest` configuration setting. ([\#5625](https://github.com/matrix-org/synapse/issues/5625))
Internal Changes
----------------
- Move logging code out of `synapse.util` and into `synapse.logging`. ([\#5606](https://github.com/matrix-org/synapse/issues/5606), [\#5617](https://github.com/matrix-org/synapse/issues/5617))
- Add a blacklist file to the repo to blacklist certain sytests from failing CI. ([\#5611](https://github.com/matrix-org/synapse/issues/5611))
- Make runtime errors surrounding password reset emails much clearer. ([\#5616](https://github.com/matrix-org/synapse/issues/5616))
- Remove dead code for persiting outgoing federation transactions. ([\#5622](https://github.com/matrix-org/synapse/issues/5622))
- Add `lint.sh` to the scripts-dev folder which will run all linting steps required by CI. ([\#5627](https://github.com/matrix-org/synapse/issues/5627))
- Move RegistrationHandler.get_or_create_user to test code. ([\#5628](https://github.com/matrix-org/synapse/issues/5628))
- Add some more common python virtual-environment paths to the black exclusion list. ([\#5630](https://github.com/matrix-org/synapse/issues/5630))
- Some counter metrics exposed over Prometheus have been renamed, with the old names preserved for backwards compatibility and deprecated. See `docs/metrics-howto.rst` for details. ([\#5636](https://github.com/matrix-org/synapse/issues/5636))
- Unblacklist some user_directory sytests. ([\#5637](https://github.com/matrix-org/synapse/issues/5637))
- Factor out some redundant code in the login implementation. ([\#5639](https://github.com/matrix-org/synapse/issues/5639))
- Update ModuleApi to avoid register(generate_token=True). ([\#5640](https://github.com/matrix-org/synapse/issues/5640))
- Remove access-token support from `RegistrationStore.register`, and rename it. ([\#5642](https://github.com/matrix-org/synapse/issues/5642))
- Improve logging for auto-join when a new user is created. ([\#5643](https://github.com/matrix-org/synapse/issues/5643))
- Remove unused and unnecessary check for FederationDeniedError in _exception_to_failure. ([\#5645](https://github.com/matrix-org/synapse/issues/5645))
- Fix a small typo in a code comment. ([\#5655](https://github.com/matrix-org/synapse/issues/5655))
- Clean up exception handling around client access tokens. ([\#5656](https://github.com/matrix-org/synapse/issues/5656))
- Add a mechanism for per-test homeserver configuration in the unit tests. ([\#5657](https://github.com/matrix-org/synapse/issues/5657))
This release also deprecates the use of environment variables to configure the
docker image. See the [docker README](https://github.com/matrix-org/synapse/blob/release-v1.1.0/docker/README.md#legacy-dynamic-configuration-file-support)
- Removed the `SYNAPSE_SMTP_*` docker container environment variables. Using these environment variables prevented the docker container from starting in Synapse v1.0, even though they didn't actually allow any functionality anyway. ([\#5596](https://github.com/matrix-org/synapse/issues/5596))
- Added possibilty to disable local password authentication. Contributed by Daniel Hoffend. ([\#5092](https://github.com/matrix-org/synapse/issues/5092))
- Add monthly active users to phonehome stats. ([\#5252](https://github.com/matrix-org/synapse/issues/5252))
- Allow expired user to trigger renewal email sending manually. ([\#5363](https://github.com/matrix-org/synapse/issues/5363))
- Statistics on forward extremities per room are now exposed via Prometheus. ([\#5384](https://github.com/matrix-org/synapse/issues/5384), [\#5458](https://github.com/matrix-org/synapse/issues/5458), [\#5461](https://github.com/matrix-org/synapse/issues/5461))
- Add --no-daemonize option to run synapse in the foreground, per issue #4130. Contributed by Soham Gumaste. ([\#5412](https://github.com/matrix-org/synapse/issues/5412), [\#5587](https://github.com/matrix-org/synapse/issues/5587))
- Fully support SAML2 authentication. Contributed by [Alexander Trost](https://github.com/galexrt) - thank you! ([\#5422](https://github.com/matrix-org/synapse/issues/5422))
- Allow server admins to define implementations of extra rules for allowing or denying incoming events. ([\#5440](https://github.com/matrix-org/synapse/issues/5440), [\#5474](https://github.com/matrix-org/synapse/issues/5474), [\#5477](https://github.com/matrix-org/synapse/issues/5477))
- Add support for handling pagination APIs on client reader worker. ([\#5505](https://github.com/matrix-org/synapse/issues/5505), [\#5513](https://github.com/matrix-org/synapse/issues/5513), [\#5531](https://github.com/matrix-org/synapse/issues/5531))
- Improve help and cmdline option names for --generate-config options. ([\#5512](https://github.com/matrix-org/synapse/issues/5512))
- Allow configuration of the path used for ACME account keys. ([\#5516](https://github.com/matrix-org/synapse/issues/5516), [\#5521](https://github.com/matrix-org/synapse/issues/5521), [\#5522](https://github.com/matrix-org/synapse/issues/5522))
- Add --data-dir and --open-private-ports options. ([\#5524](https://github.com/matrix-org/synapse/issues/5524))
- Split public rooms directory auth config in two settings, in order to manage client auth independently from the federation part of it. Obsoletes the "restrict_public_rooms_to_local_users" configuration setting. If "restrict_public_rooms_to_local_users" is set in the config, Synapse will act as if both new options are enabled, i.e. require authentication through the client API and deny federation requests. ([\#5534](https://github.com/matrix-org/synapse/issues/5534))
- The minimum TLS version used for outgoing federation requests can now be set with `federation_client_minimum_tls_version`. ([\#5550](https://github.com/matrix-org/synapse/issues/5550))
- Optimise devices changed query to not pull unnecessary rows from the database, reducing database load. ([\#5559](https://github.com/matrix-org/synapse/issues/5559))
- Add new metrics for number of forward extremities being persisted and number of state groups involved in resolution. ([\#5476](https://github.com/matrix-org/synapse/issues/5476))
Bugfixes
--------
- Fix bug processing incoming events over federation if call to `/get_missing_events` fails. ([\#5042](https://github.com/matrix-org/synapse/issues/5042))
- Fix a bug where running synapse_port_db would cause the account validity feature to fail because it didn't set the type of the email_sent column to boolean. ([\#5325](https://github.com/matrix-org/synapse/issues/5325))
- Warn about disabling email-based password resets when a reset occurs, and remove warning when someone attempts a phone-based reset. ([\#5387](https://github.com/matrix-org/synapse/issues/5387))
- Fix email notifications for unnamed rooms with multiple people. ([\#5388](https://github.com/matrix-org/synapse/issues/5388))
- Fix exceptions in federation reader worker caused by attempting to renew attestations, which should only happen on master worker. ([\#5389](https://github.com/matrix-org/synapse/issues/5389))
- Fix handling of failures fetching remote content to not log failures as exceptions. ([\#5390](https://github.com/matrix-org/synapse/issues/5390))
- Fix a bug where deactivated users could receive renewal emails if the account validity feature is on. ([\#5394](https://github.com/matrix-org/synapse/issues/5394))
- Fix missing invite state after exchanging 3PID invites over federaton. ([\#5464](https://github.com/matrix-org/synapse/issues/5464))
- Fix intermittent exceptions on Apple hardware. Also fix bug that caused database activity times to be under-reported in log lines. ([\#5498](https://github.com/matrix-org/synapse/issues/5498))
- Fix logging error when a tampered event is detected. ([\#5500](https://github.com/matrix-org/synapse/issues/5500))
- Fix bug where clients could tight loop calling `/sync` for a period. ([\#5507](https://github.com/matrix-org/synapse/issues/5507))
- Fix bug with `jinja2` preventing Synapse from starting. Users who had this problem should now simply need to run `pip install matrix-synapse`. ([\#5514](https://github.com/matrix-org/synapse/issues/5514))
- Fix a regression where homeservers on private IP addresses were incorrectly blacklisted. ([\#5523](https://github.com/matrix-org/synapse/issues/5523))
- Fixed m.login.jwt using unregistred user_id and added pyjwt>=1.6.4 as jwt conditional dependencies. Contributed by Pau Rodriguez-Estivill. ([\#5555](https://github.com/matrix-org/synapse/issues/5555), [\#5586](https://github.com/matrix-org/synapse/issues/5586))
- Fix a bug that would cause invited users to receive several emails for a single 3PID invite in case the inviter is rate limited. ([\#5576](https://github.com/matrix-org/synapse/issues/5576))
- Add ability to change Docker containers [timezone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) with the `TZ` variable. ([\#5383](https://github.com/matrix-org/synapse/issues/5383))
- Update docker image to use Python 3.7. ([\#5546](https://github.com/matrix-org/synapse/issues/5546))
- Deprecate the use of environment variables for configuration, and make the use of a static configuration the default. ([\#5561](https://github.com/matrix-org/synapse/issues/5561), [\#5562](https://github.com/matrix-org/synapse/issues/5562), [\#5566](https://github.com/matrix-org/synapse/issues/5566), [\#5567](https://github.com/matrix-org/synapse/issues/5567))
- Increase default log level for docker image to INFO. It can still be changed by editing the generated log.config file. ([\#5547](https://github.com/matrix-org/synapse/issues/5547))
- Send synapse logs to the docker logging system, by default. ([\#5565](https://github.com/matrix-org/synapse/issues/5565))
- Open the non-TLS port by default. ([\#5568](https://github.com/matrix-org/synapse/issues/5568))
- Fix failure to start under docker with SAML support enabled. ([\#5490](https://github.com/matrix-org/synapse/issues/5490))
- Use a sensible location for data files when generating a config file. ([\#5563](https://github.com/matrix-org/synapse/issues/5563))
- Python 2.7 is no longer a supported platform. Synapse now requires Python 3.5+ to run. ([\#5425](https://github.com/matrix-org/synapse/issues/5425))
- PostgreSQL 9.4 is no longer supported. Synapse requires Postgres 9.5+ or above for Postgres support. ([\#5448](https://github.com/matrix-org/synapse/issues/5448))
- Remove support for cpu_affinity setting. ([\#5525](https://github.com/matrix-org/synapse/issues/5525))
Improved Documentation
----------------------
- Improve README section on performance troubleshooting. ([\#4276](https://github.com/matrix-org/synapse/issues/4276))
- Add information about how to install and run `black` on the codebase to code_style.rst. ([\#5537](https://github.com/matrix-org/synapse/issues/5537))
- Improve install docs on choosing server_name. ([\#5558](https://github.com/matrix-org/synapse/issues/5558))
Internal Changes
----------------
- Add logging to 3pid invite signature verification. ([\#5015](https://github.com/matrix-org/synapse/issues/5015))
- Update example haproxy config to a more compatible setup. ([\#5313](https://github.com/matrix-org/synapse/issues/5313))
- Track deactivated accounts in the database. ([\#5378](https://github.com/matrix-org/synapse/issues/5378), [\#5465](https://github.com/matrix-org/synapse/issues/5465), [\#5493](https://github.com/matrix-org/synapse/issues/5493))
- Clean up code for sending federation EDUs. ([\#5381](https://github.com/matrix-org/synapse/issues/5381))
- Add a sponsor button to the repo. ([\#5382](https://github.com/matrix-org/synapse/issues/5382), [\#5386](https://github.com/matrix-org/synapse/issues/5386))
- Don't log non-200 responses from federation queries as exceptions. ([\#5383](https://github.com/matrix-org/synapse/issues/5383))
- Update Python syntax in contrib/ to Python 3. ([\#5446](https://github.com/matrix-org/synapse/issues/5446))
- Update federation_client dev script to support `.well-known` and work with python3. ([\#5447](https://github.com/matrix-org/synapse/issues/5447))
- SyTest has been moved to Buildkite. ([\#5459](https://github.com/matrix-org/synapse/issues/5459))
- Demo script now uses python3. ([\#5460](https://github.com/matrix-org/synapse/issues/5460))
- Synapse can now handle RestServlets that return coroutines. ([\#5475](https://github.com/matrix-org/synapse/issues/5475), [\#5585](https://github.com/matrix-org/synapse/issues/5585))
- The demo servers talk to each other again. ([\#5478](https://github.com/matrix-org/synapse/issues/5478))
- Add an EXPERIMENTAL config option to try and periodically clean up extremities by sending dummy events. ([\#5480](https://github.com/matrix-org/synapse/issues/5480))
- Synapse's codebase is now formatted by `black`. ([\#5482](https://github.com/matrix-org/synapse/issues/5482))
- Some cleanups and sanity-checking in the CPU and database metrics. ([\#5499](https://github.com/matrix-org/synapse/issues/5499))
- Fix "Unexpected entry in 'full_schemas'" log warning. ([\#5509](https://github.com/matrix-org/synapse/issues/5509))
- Improve logging when generating config files. ([\#5510](https://github.com/matrix-org/synapse/issues/5510))
- Refactor and clean up Config parser for maintainability. ([\#5511](https://github.com/matrix-org/synapse/issues/5511))
- Make the config clearer in that email.template_dir is relative to the Synapse's root directory, not the `synapse/` folder within it. ([\#5543](https://github.com/matrix-org/synapse/issues/5543))
- Update v1.0.0 release changelog to include more information about changes to password resets. ([\#5545](https://github.com/matrix-org/synapse/issues/5545))
- Remove non-functioning check_event_hash.py dev script. ([\#5548](https://github.com/matrix-org/synapse/issues/5548))
- Synapse will now only allow TLS v1.2 connections when serving federation, if it terminates TLS. As Synapse's allowed ciphers were only able to be used in TLSv1.2 before, this does not change behaviour. ([\#5550](https://github.com/matrix-org/synapse/issues/5550))
- Logging when running GC collection on generation 0 is now at the DEBUG level, not INFO. ([\#5557](https://github.com/matrix-org/synapse/issues/5557))
- Reduce the amount of stuff we send in the docker context. ([\#5564](https://github.com/matrix-org/synapse/issues/5564))
- Point the reverse links in the Purge History contrib scripts at the intended location. ([\#5570](https://github.com/matrix-org/synapse/issues/5570))
- Remove redundant warning about key server response validation. ([\#5392](https://github.com/matrix-org/synapse/issues/5392))
- Fix bug where old keys stored in the database with a null valid until timestamp caused all verification requests for that key to fail. ([\#5415](https://github.com/matrix-org/synapse/issues/5415))
- Fix excessive memory using with default `federation_verify_certificates: true` configuration. ([\#5417](https://github.com/matrix-org/synapse/issues/5417))
- Synapse now more efficiently collates room statistics. ([\#4338](https://github.com/matrix-org/synapse/issues/4338), [\#5260](https://github.com/matrix-org/synapse/issues/5260), [\#5324](https://github.com/matrix-org/synapse/issues/5324))
- Add experimental support for relations (aka reactions and edits). ([\#5220](https://github.com/matrix-org/synapse/issues/5220))
- Ability to configure default room version. ([\#5223](https://github.com/matrix-org/synapse/issues/5223), [\#5249](https://github.com/matrix-org/synapse/issues/5249))
- Allow configuring a range for the account validity startup job. ([\#5276](https://github.com/matrix-org/synapse/issues/5276))
- CAS login will now hit the r0 API, not the deprecated v1 one. ([\#5286](https://github.com/matrix-org/synapse/issues/5286))
- Validate federation server TLS certificates by default (implements [MSC1711](https://github.com/matrix-org/matrix-doc/blob/master/proposals/1711-x509-for-federation.md)). ([\#5359](https://github.com/matrix-org/synapse/issues/5359))
- Update /_matrix/client/versions to reference support for r0.5.0. ([\#5360](https://github.com/matrix-org/synapse/issues/5360))
- Add a script to generate new signing-key files. ([\#5361](https://github.com/matrix-org/synapse/issues/5361))
- Update upgrade and installation guides ahead of 1.0. ([\#5371](https://github.com/matrix-org/synapse/issues/5371))
- Replace the `perspectives` configuration section with `trusted_key_servers`, and make validating the signatures on responses optional (since TLS will do this job for us). ([\#5374](https://github.com/matrix-org/synapse/issues/5374))
- Add ability to perform password reset via email without trusting the identity server. **As a result of this PR, password resets will now be disabled on the default configuration.**
Password reset emails are now sent from the homeserver by default, instead of the identity server. To enable this functionality, ensure `email` and `public_baseurl` config options are filled out.
If you would like to re-enable password resets being sent from the identity server (warning: this is dangerous! See [#5345](https://github.com/matrix-org/synapse/pull/5345)), set `email.trust_identity_server_for_password_resets` to true. ([\#5377](https://github.com/matrix-org/synapse/issues/5377))
- Set default room version to v4. ([\#5379](https://github.com/matrix-org/synapse/issues/5379))
Bugfixes
--------
- Fixes client-server API not sending "m.heroes" to lazy-load /sync requests when a rooms name or its canonical alias are empty. Thanks to @dnaf for this work! ([\#5089](https://github.com/matrix-org/synapse/issues/5089))
- Prevent federation device list updates breaking when processing multiple updates at once. ([\#5156](https://github.com/matrix-org/synapse/issues/5156))
- Fix worker registration bug caused by ClientReaderSlavedStore being unable to see get_profileinfo. ([\#5200](https://github.com/matrix-org/synapse/issues/5200))
- Fix race when backfilling in rooms with worker mode. ([\#5221](https://github.com/matrix-org/synapse/issues/5221))
- Ensure that server_keys fetched via a notary server are correctly signed. ([\#5251](https://github.com/matrix-org/synapse/issues/5251))
- Show the correct error when logging out and access token is missing. ([\#5256](https://github.com/matrix-org/synapse/issues/5256))
- Fix error code when there is an invalid parameter on /_matrix/client/r0/publicRooms ([\#5257](https://github.com/matrix-org/synapse/issues/5257))
- Fix error when downloading thumbnail with missing width/height parameter. ([\#5258](https://github.com/matrix-org/synapse/issues/5258))
- Fix schema update for account validity. ([\#5268](https://github.com/matrix-org/synapse/issues/5268))
- Fix bug where we leaked extremities when we soft failed events, leading to performance degradation. ([\#5274](https://github.com/matrix-org/synapse/issues/5274), [\#5278](https://github.com/matrix-org/synapse/issues/5278), [\#5291](https://github.com/matrix-org/synapse/issues/5291))
- Fix dropped logcontexts during high outbound traffic. ([\#5277](https://github.com/matrix-org/synapse/issues/5277))
- Fix a bug where it is not possible to get events in the federation format with the request `GET /_matrix/client/r0/rooms/{roomId}/messages`. ([\#5293](https://github.com/matrix-org/synapse/issues/5293))
- Fix performance problems with the rooms stats background update. ([\#5294](https://github.com/matrix-org/synapse/issues/5294))
- Fix noisy 'no key for server' logs. ([\#5300](https://github.com/matrix-org/synapse/issues/5300))
- Fix bug where a notary server would sometimes forget old keys. ([\#5307](https://github.com/matrix-org/synapse/issues/5307))
- Prevent users from setting huge displaynames and avatar URLs. ([\#5309](https://github.com/matrix-org/synapse/issues/5309))
- Fix handling of failures when processing incoming events where calling `/event_auth` on remote server fails. ([\#5317](https://github.com/matrix-org/synapse/issues/5317))
- Ensure that we have an up-to-date copy of the signing key when validating incoming federation requests. ([\#5321](https://github.com/matrix-org/synapse/issues/5321))
- Fix various problems which made the signing-key notary server time out for some requests. ([\#5333](https://github.com/matrix-org/synapse/issues/5333))
- Fix bug which would make certain operations (such as room joins) block for 20 minutes while attemoting to fetch verification keys. ([\#5334](https://github.com/matrix-org/synapse/issues/5334))
- Fix a bug where we could rapidly mark a server as unreachable even though it was only down for a few minutes. ([\#5335](https://github.com/matrix-org/synapse/issues/5335), [\#5340](https://github.com/matrix-org/synapse/issues/5340))
- Fix a bug where account validity renewal emails could only be sent when email notifs were enabled. ([\#5341](https://github.com/matrix-org/synapse/issues/5341))
- Fix failure when fetching batches of events during backfill, etc. ([\#5342](https://github.com/matrix-org/synapse/issues/5342))
- Add a new room version where the timestamps on events are checked against the validity periods on signing keys. ([\#5348](https://github.com/matrix-org/synapse/issues/5348), [\#5354](https://github.com/matrix-org/synapse/issues/5354))
- Fix room stats and presence background updates to correctly handle missing events. ([\#5352](https://github.com/matrix-org/synapse/issues/5352))
- Include left members in room summaries' heroes. ([\#5355](https://github.com/matrix-org/synapse/issues/5355))
- Fix missing logcontext warnings on shutdown. ([\#5369](https://github.com/matrix-org/synapse/issues/5369))
Improved Documentation
----------------------
- Fix docs on resetting the user directory. ([\#5282](https://github.com/matrix-org/synapse/issues/5282))
- Fix notes about ACME in the MSC1711 faq. ([\#5357](https://github.com/matrix-org/synapse/issues/5357))
Internal Changes
----------------
- Synapse will now serve the experimental "room complexity" API endpoint. ([\#5216](https://github.com/matrix-org/synapse/issues/5216))
- The base classes for the v1 and v2_alpha REST APIs have been unified. ([\#5226](https://github.com/matrix-org/synapse/issues/5226), [\#5328](https://github.com/matrix-org/synapse/issues/5328))
- Simplifications and comments in do_auth. ([\#5227](https://github.com/matrix-org/synapse/issues/5227))
- Remove urllib3 pin as requests 2.22.0 has been released supporting urllib3 1.25.2. ([\#5230](https://github.com/matrix-org/synapse/issues/5230))
- Preparatory work for key-validity features. ([\#5232](https://github.com/matrix-org/synapse/issues/5232), [\#5234](https://github.com/matrix-org/synapse/issues/5234), [\#5235](https://github.com/matrix-org/synapse/issues/5235), [\#5236](https://github.com/matrix-org/synapse/issues/5236), [\#5237](https://github.com/matrix-org/synapse/issues/5237), [\#5244](https://github.com/matrix-org/synapse/issues/5244), [\#5250](https://github.com/matrix-org/synapse/issues/5250), [\#5296](https://github.com/matrix-org/synapse/issues/5296), [\#5299](https://github.com/matrix-org/synapse/issues/5299), [\#5343](https://github.com/matrix-org/synapse/issues/5343), [\#5347](https://github.com/matrix-org/synapse/issues/5347), [\#5356](https://github.com/matrix-org/synapse/issues/5356))
- Specify the type of reCAPTCHA key to use. ([\#5283](https://github.com/matrix-org/synapse/issues/5283))
- Improve sample config for monthly active user blocking. ([\#5284](https://github.com/matrix-org/synapse/issues/5284))
- Remove spurious debug from MatrixFederationHttpClient.get_json. ([\#5287](https://github.com/matrix-org/synapse/issues/5287))
- Improve logging for logcontext leaks. ([\#5288](https://github.com/matrix-org/synapse/issues/5288))
- Clarify that the admin change password API logs the user out. ([\#5303](https://github.com/matrix-org/synapse/issues/5303))
- New installs will now use the v54 full schema, rather than the full schema v14 and applying incremental updates to v54. ([\#5320](https://github.com/matrix-org/synapse/issues/5320))
- Improve docstrings on MatrixFederationClient. ([\#5332](https://github.com/matrix-org/synapse/issues/5332))
- Clean up FederationClient.get_events for clarity. ([\#5344](https://github.com/matrix-org/synapse/issues/5344))
- Various improvements to debug logging. ([\#5353](https://github.com/matrix-org/synapse/issues/5353))
- Don't run CI build checks until sample config check has passed. ([\#5370](https://github.com/matrix-org/synapse/issues/5370))
- Automatically retry buildkite builds (max twice) when an agent is lost. ([\#5380](https://github.com/matrix-org/synapse/issues/5380))
