- 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))
- Make historical events discoverable from backfill for servers without any scrollback history (part of MSC2716). ([\#10245](https://github.com/matrix-org/synapse/issues/10245))
- Make historical events discoverable from backfill for servers without any scrollback history (part of [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)). ([\#10245](https://github.com/matrix-org/synapse/issues/10245))
- 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, Room version capabilities over the /capabilities API. ([\#10283](https://github.com/matrix-org/synapse/issues/10283))
- 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))
- Add `creation_ts` to list users admin API. ([\#10448](https://github.com/matrix-org/synapse/issues/10448))
- Add `creation_ts` to "list users" admin API. ([\#10448](https://github.com/matrix-org/synapse/issues/10448))
Bugfixes
--------
- 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 with floating outlier state being rejected over federation. ([\#10439](https://github.com/matrix-org/synapse/issues/10439))
- 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))
...
...
@@ -37,12 +37,12 @@ Improved Documentation
Internal Changes
----------------
- Prune inbound federation inbound queues for a room if they get too large. ([\#10390](https://github.com/matrix-org/synapse/issues/10390))
- Prune inbound federation queues for a room if they get too large. ([\#10390](https://github.com/matrix-org/synapse/issues/10390))
- 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))
- Connect historical chunks together with chunk events instead of a content field (MSC2716). ([\#10432](https://github.com/matrix-org/synapse/issues/10432))
- Connect historical chunks together with chunk events instead of a content field ([MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)). ([\#10432](https://github.com/matrix-org/synapse/issues/10432))
- 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))
