Please check [the relevant section in the upgrade notes](https://github.com/element-hq/synapse/blob/develop/docs/upgrade.md#upgrading-to-v11360) as this release contains changes to MAS support, metrics labels and the module API which may require your attention when upgrading. - Add configurable rate limiting for the creation of rooms. ([\#18514](https://github.com/element-hq/synapse/issues/18514)) - Add support for [MSC4293](https://github.com/matrix-org/matrix-spec-proposals/pull/4293) - Redact on Kick/Ban. ([\#18540](https://github.com/element-hq/synapse/issues/18540)) - When admins enable themselves to see soft-failed events, they will also see if the cause is due to the policy server flagging them as spam via `unsigned`. ([\#18585](https://github.com/element-hq/synapse/issues/18585)) - Add ability to configure forward/outbound proxy via homeserver config instead of environment variables. See `http_proxy`, `https_proxy`, `no_proxy_hosts`. ([\#18686](https://github.com/element-hq/synapse/issues/18686)) - Advertise experimental support for [MSC4306](https://github.com/matrix-org/matrix-spec-proposals/pull/4306) (Thread Subscriptions) through `/_matrix/clients/versions` if enabled. ([\#18722](https://github.com/element-hq/synapse/issues/18722)) - Stabilise support for delegating authentication to [Matrix Authentication Service](https://github.com/element-hq/matrix-authentication-service/). ([\#18759](https://github.com/element-hq/synapse/issues/18759)) - Implement the push rules for experimental [MSC4306: Thread Subscriptions](https://github.com/matrix-org/matrix-doc/issues/4306). ([\#18762](https://github.com/element-hq/synapse/issues/18762)) - Allow return code 403 (allowed by C2S Spec since v1.2) when fetching profiles via federation. ([\#18696](https://github.com/element-hq/synapse/issues/18696)) - Register the MSC4306 (Thread Subscriptions) endpoints in the CS API when the experimental feature is enabled. ([\#18726](https://github.com/element-hq/synapse/issues/18726)) - Fix a long-standing bug where suspended users could not have server notices sent to them (a 403 was returned to the admin). ([\#18750](https://github.com/element-hq/synapse/issues/18750)) - Fix an issue that could cause logcontexts to be lost on rate-limited requests. Found by @realtyem. ([\#18763](https://github.com/element-hq/synapse/issues/18763)) - Fix invalidation of storage cache that was broken in 1.135.0. ([\#18786](https://github.com/element-hq/synapse/issues/18786)) - Minor improvements to README. ([\#18700](https://github.com/element-hq/synapse/issues/18700)) - Document that there can be multiple workers handling the `receipts` stream. ([\#18760](https://github.com/element-hq/synapse/issues/18760)) - Improve worker documentation for some device paths. ([\#18761](https://github.com/element-hq/synapse/issues/18761)) - Deprecate `run_as_background_process` exported as part of the module API interface in favor of `ModuleApi.run_as_background_process`. See [the relevant section in the upgrade notes](https://github.com/element-hq/synapse/blob/develop/docs/upgrade.md#upgrading-to-v11360) for more information. ([\#18737](https://github.com/element-hq/synapse/issues/18737)) - Add debug logging for HMAC digest verification failures when using the admin API to register users. ([\#18474](https://github.com/element-hq/synapse/issues/18474)) - Speed up upgrading a room with large numbers of banned users. ([\#18574](https://github.com/element-hq/synapse/issues/18574)) - Fix config documentation generation script on Windows by enforcing UTF-8. ([\#18580](https://github.com/element-hq/synapse/issues/18580)) - Refactor cache, background process, `Counter`, `LaterGauge`, `GaugeBucketCollector`, `Histogram`, and `Gauge` metrics to be homeserver-scoped. ([\#18656](https://github.com/element-hq/synapse/issues/18656), [\#18714](https://github.com/element-hq/synapse/issues/18714), [\#18715](https://github.com/element-hq/synapse/issues/18715), [\#18724](https://github.com/element-hq/synapse/issues/18724), [\#18753](https://github.com/element-hq/synapse/issues/18753), [\#18725](https://github.com/element-hq/synapse/issues/18725), [\#18670](https://github.com/element-hq/synapse/issues/18670), [\#18748](https://github.com/element-hq/synapse/issues/18748), [\#18751](https://github.com/element-hq/synapse/issues/18751)) - Reduce database usage in Sliding Sync by not querying for background update completion after the update is known to be complete. ([\#18718](https://github.com/element-hq/synapse/issues/18718)) - Improve order of validation and ratelimiting in room creation. ([\#18723](https://github.com/element-hq/synapse/issues/18723)) - Bump minimum version bound on Twisted to 21.2.0. ([\#18727](https://github.com/element-hq/synapse/issues/18727), [\#18729](https://github.com/element-hq/synapse/issues/18729)) - Use `twisted.internet.testing` module in tests instead of deprecated `twisted.test.proto_helpers`. ([\#18728](https://github.com/element-hq/synapse/issues/18728)) - Remove obsolete `/send_event` replication endpoint. ([\#18730](https://github.com/element-hq/synapse/issues/18730)) - Update metrics linting to be able to handle custom metrics. ([\#18733](https://github.com/element-hq/synapse/issues/18733)) - Work around `twisted.protocols.amp.TooLong` error by reducing logging in some tests. ([\#18736](https://github.com/element-hq/synapse/issues/18736)) - Prevent "Move labelled issues to correct projects" GitHub Actions workflow from failing when an issue is already on the project board. ([\#18755](https://github.com/element-hq/synapse/issues/18755)) - Bump minimum supported Rust version (MSRV) to 1.82.0. Missed in [#18553](https://github.com/element-hq/synapse/pull/18553) (released in Synapse 1.134.0). ([\#18757](https://github.com/element-hq/synapse/issues/18757)) - Make `Clock.sleep(...)` return a coroutine, so that mypy can catch places where we don't await on it. ([\#18772](https://github.com/element-hq/synapse/issues/18772)) - Update implementation of [MSC4306: Thread Subscriptions](https://github.com/matrix-org/matrix-doc/issues/4306) to include automatic subscription conflict prevention as introduced in later drafts. ([\#18756](https://github.com/element-hq/synapse/issues/18756)) * Bump gitpython from 3.1.44 to 3.1.45. ([\#18743](https://github.com/element-hq/synapse/issues/18743)) * Bump mypy-zope from 1.0.12 to 1.0.13. ([\#18744](https://github.com/element-hq/synapse/issues/18744)) * Bump phonenumbers from 9.0.9 to 9.0.10. ([\#18741](https://github.com/element-hq/synapse/issues/18741)) * Bump ruff from 0.12.4 to 0.12.5. ([\#18742](https://github.com/element-hq/synapse/issues/18742)) * Bump sentry-sdk from 2.32.0 to 2.33.2. ([\#18745](https://github.com/element-hq/synapse/issues/18745)) * Bump tokio from 1.46.1 to 1.47.0. ([\#18740](https://github.com/element-hq/synapse/issues/18740)) * Bump types-jsonschema from 4.24.0.20250708 to 4.25.0.20250720. ([\#18703](https://github.com/element-hq/synapse/issues/18703)) * Bump types-psycopg2 from 2.9.21.20250516 to 2.9.21.20250718. ([\#18706](https://github.com/element-hq/synapse/issues/18706))