* Deprecate groups APIs. Groups are no longer supported, only Synapse has support. They are being replaced by Spaces which build off of Rooms and are far more flexible. ([\#1792](https://github.com/matrix-org/matrix-js-sdk/pull/1792)).
* Add method for including extra fields when uploading to a tree space ([\#1850](https://github.com/matrix-org/matrix-js-sdk/pull/1850)).
* Fix broken voice calls, no ringing and broken call notifications ([\#1858](https://github.com/matrix-org/matrix-js-sdk/pull/1858)). Fixes vector-im/element-web#18578 vector-im/element-web#18538 and vector-im/element-web#18578. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Revert "Fix glare related regressions" ([\#1857](https://github.com/matrix-org/matrix-js-sdk/pull/1857)).
* Fix glare related regressions ([\#1851](https://github.com/matrix-org/matrix-js-sdk/pull/1851)). Fixes vector-im/element-web#18538 and vector-im/element-web#18538. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix temporary call messages being handled without call  ([\#1834](https://github.com/matrix-org/matrix-js-sdk/pull/1834)). Contributed by [Palid](https://github.com/Palid).
* Fix conditional on returning file tree spaces ([\#1841](https://github.com/matrix-org/matrix-js-sdk/pull/1841)).

* Fix a security issue with message key sharing. See https://matrix.org/blog/2021/09/13/vulnerability-disclosure-key-sharing
for details.

* [Release] Exclude opt-in Element performance metrics from encryption ([\#1901](https://github.com/matrix-org/matrix-js-sdk/pull/1901)).
* Give `MatrixCall` the capability to emit `LengthChanged` events ([\#1873](https://github.com/matrix-org/matrix-js-sdk/pull/1873)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Improve browser example ([\#1875](https://github.com/matrix-org/matrix-js-sdk/pull/1875)). Contributed by [psrpinto](https://github.com/psrpinto).
* Give `CallFeed` the capability to emit on volume changes ([\#1865](https://github.com/matrix-org/matrix-js-sdk/pull/1865)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix verification request cancellation ([\#1871](https://github.com/matrix-org/matrix-js-sdk/pull/1871)).

* Give `MatrixCall` the capability to emit `LengthChanged` events ([\#1873](https://github.com/matrix-org/matrix-js-sdk/pull/1873)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Improve browser example ([\#1875](https://github.com/matrix-org/matrix-js-sdk/pull/1875)). Contributed by [psrpinto](https://github.com/psrpinto).
* Give `CallFeed` the capability to emit on volume changes ([\#1865](https://github.com/matrix-org/matrix-js-sdk/pull/1865)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix verification request cancellation ([\#1871](https://github.com/matrix-org/matrix-js-sdk/pull/1871)).

* Add `getHistoryVisibility()` and `getGuestAccess()` ([\#1940](https://github.com/matrix-org/matrix-js-sdk/pull/1940)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `getBuffer()` to `QRCodeData` ([\#1927](https://github.com/matrix-org/matrix-js-sdk/pull/1927)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Added `createDataChannel()` and `CallEvent.DataChannel` to `MatrixCall` for creating and listening for WebRTC datachannels. ([\#1929](https://github.com/matrix-org/matrix-js-sdk/pull/1929)). Contributed by [robertlong](https://github.com/robertlong).
* Add file locking to MSC3089 branches ([\#1909](https://github.com/matrix-org/matrix-js-sdk/pull/1909)).
* Add `hasBeenCancelled` to `VerificationBase` ([\#1915](https://github.com/matrix-org/matrix-js-sdk/pull/1915)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `ISasEvent` ([\#1908](https://github.com/matrix-org/matrix-js-sdk/pull/1908)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Count notifications in encrypted rooms client-side ([\#1872](https://github.com/matrix-org/matrix-js-sdk/pull/1872)). Fixes vector-im/element-web#15393 and vector-im/element-web#15393. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Exclude opt-in Element performance metrics from encryption ([\#1897](https://github.com/matrix-org/matrix-js-sdk/pull/1897)).
* Fix race on automatic backup restore ([\#1936](https://github.com/matrix-org/matrix-js-sdk/pull/1936)). Fixes vector-im/element-web#17781 and vector-im/element-web#17781.

* Add `getHistoryVisibility()` and `getGuestAccess()` ([\#1940](https://github.com/matrix-org/matrix-js-sdk/pull/1940)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `getBuffer()` to `QRCodeData` ([\#1927](https://github.com/matrix-org/matrix-js-sdk/pull/1927)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Added `createDataChannel()` and `CallEvent.DataChannel` to `MatrixCall` for creating and listening for WebRTC datachannels. ([\#1929](https://github.com/matrix-org/matrix-js-sdk/pull/1929)). Contributed by [robertlong](https://github.com/robertlong).
* Add file locking to MSC3089 branches ([\#1909](https://github.com/matrix-org/matrix-js-sdk/pull/1909)).
* Add `hasBeenCancelled` to `VerificationBase` ([\#1915](https://github.com/matrix-org/matrix-js-sdk/pull/1915)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `ISasEvent` ([\#1908](https://github.com/matrix-org/matrix-js-sdk/pull/1908)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Count notifications in encrypted rooms client-side ([\#1872](https://github.com/matrix-org/matrix-js-sdk/pull/1872)). Fixes vector-im/element-web#15393 and vector-im/element-web#15393. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Exclude opt-in Element performance metrics from encryption ([\#1897](https://github.com/matrix-org/matrix-js-sdk/pull/1897)).
* Fix race on automatic backup restore ([\#1936](https://github.com/matrix-org/matrix-js-sdk/pull/1936)). Fixes vector-im/element-web#17781 and vector-im/element-web#17781.

* Support for call upgrades. `setLocalVideoMuted()` and `setMicrophoneMuted()` are now `async` and return the new mute state ([\#1827](https://github.com/matrix-org/matrix-js-sdk/pull/1827)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Implement file versioning for tree spaces ([\#1952](https://github.com/matrix-org/matrix-js-sdk/pull/1952)).
* Allow answering calls without audio/video ([\#1950](https://github.com/matrix-org/matrix-js-sdk/pull/1950)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `bound` to `IThreepid` ([\#1941](https://github.com/matrix-org/matrix-js-sdk/pull/1941)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `trusted_locally` to `TrustInfo` ([\#1942](https://github.com/matrix-org/matrix-js-sdk/pull/1942)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix incorrect return value type in getJoinedRooms() ([\#1959](https://github.com/matrix-org/matrix-js-sdk/pull/1959)). Contributed by [psrpinto](https://github.com/psrpinto).
* Make sure to set `callLengthInterval` only once ([\#1958](https://github.com/matrix-org/matrix-js-sdk/pull/1958)). Fixes vector-im/element-web#19221 and vector-im/element-web#19221. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix event partitioning from non threading ready clients ([\#1948](https://github.com/matrix-org/matrix-js-sdk/pull/1948)).
* Ensure unencrypted fields get exposed by getEffectiveEvent() ([\#1938](https://github.com/matrix-org/matrix-js-sdk/pull/1938)). Fixes vector-im/element-web#19062 and vector-im/element-web#19062.

* Support for call upgrades. `setLocalVideoMuted()` and `setMicrophoneMuted()` are now `async` and return the new mute state ([\#1827](https://github.com/matrix-org/matrix-js-sdk/pull/1827)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Implement file versioning for tree spaces ([\#1952](https://github.com/matrix-org/matrix-js-sdk/pull/1952)).
* Allow answering calls without audio/video ([\#1950](https://github.com/matrix-org/matrix-js-sdk/pull/1950)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `bound` to `IThreepid` ([\#1941](https://github.com/matrix-org/matrix-js-sdk/pull/1941)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `trusted_locally` to `TrustInfo` ([\#1942](https://github.com/matrix-org/matrix-js-sdk/pull/1942)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix incorrect return value type in getJoinedRooms() ([\#1959](https://github.com/matrix-org/matrix-js-sdk/pull/1959)). Contributed by [psrpinto](https://github.com/psrpinto).
* Make sure to set `callLengthInterval` only once ([\#1958](https://github.com/matrix-org/matrix-js-sdk/pull/1958)). Fixes vector-im/element-web#19221 and vector-im/element-web#19221. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix event partitioning from non threading ready clients ([\#1948](https://github.com/matrix-org/matrix-js-sdk/pull/1948)).
* Ensure unencrypted fields get exposed by getEffectiveEvent() ([\#1938](https://github.com/matrix-org/matrix-js-sdk/pull/1938)). Fixes vector-im/element-web#19062 and vector-im/element-web#19062.

* Support for call upgrades. `setLocalVideoMuted()` and `setMicrophoneMuted()` are now `async` and return the new mute state ([\#1827](https://github.com/matrix-org/matrix-js-sdk/pull/1827)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Implement file versioning for tree spaces ([\#1952](https://github.com/matrix-org/matrix-js-sdk/pull/1952)).
* Allow answering calls without audio/video ([\#1950](https://github.com/matrix-org/matrix-js-sdk/pull/1950)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `bound` to `IThreepid` ([\#1941](https://github.com/matrix-org/matrix-js-sdk/pull/1941)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Add `trusted_locally` to `TrustInfo` ([\#1942](https://github.com/matrix-org/matrix-js-sdk/pull/1942)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix incorrect return value type in getJoinedRooms() ([\#1959](https://github.com/matrix-org/matrix-js-sdk/pull/1959)). Contributed by [psrpinto](https://github.com/psrpinto).
* Make sure to set `callLengthInterval` only once ([\#1958](https://github.com/matrix-org/matrix-js-sdk/pull/1958)). Fixes vector-im/element-web#19221 and vector-im/element-web#19221. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Fix event partitioning from non threading ready clients ([\#1948](https://github.com/matrix-org/matrix-js-sdk/pull/1948)).
* Ensure unencrypted fields get exposed by getEffectiveEvent() ([\#1938](https://github.com/matrix-org/matrix-js-sdk/pull/1938)). Fixes vector-im/element-web#19062 and vector-im/element-web#19062.

* Use `ICallFeedOpts` in the `CallFeed` constructor. To construct a new `CallFeed` object you have to pass `ICallFeedOpts` e.g. `const callFeed = new CallFeed({client ([\#1964](https://github.com/matrix-org/matrix-js-sdk/pull/1964)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Make threads use 'm.thread' relation ([\#1980](https://github.com/matrix-org/matrix-js-sdk/pull/1980)).
* Try to answer a call without video if we can't access the camera  ([\#1972](https://github.com/matrix-org/matrix-js-sdk/pull/1972)). Fixes vector-im/element-web#17975 and vector-im/element-web#17975. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Make `opts` in `importRoomKeys()` optional ([\#1974](https://github.com/matrix-org/matrix-js-sdk/pull/1974)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Enable TypeScript declaration maps ([\#1966](https://github.com/matrix-org/matrix-js-sdk/pull/1966)). Contributed by [Alexendoo](https://github.com/Alexendoo).
* Fix `requestVerificationDM` with chronological `pendingEventOrdering` ([\#1943](https://github.com/matrix-org/matrix-js-sdk/pull/1943)). Contributed by [freaktechnik](https://github.com/freaktechnik).

* Use `ICallFeedOpts` in the `CallFeed` constructor. To construct a new `CallFeed` object you have to pass `ICallFeedOpts` e.g. `const callFeed = new CallFeed({client ([\#1964](https://github.com/matrix-org/matrix-js-sdk/pull/1964)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Make threads use 'm.thread' relation ([\#1980](https://github.com/matrix-org/matrix-js-sdk/pull/1980)).
* Try to answer a call without video if we can't access the camera  ([\#1972](https://github.com/matrix-org/matrix-js-sdk/pull/1972)). Fixes vector-im/element-web#17975 and vector-im/element-web#17975. Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Make `opts` in `importRoomKeys()` optional ([\#1974](https://github.com/matrix-org/matrix-js-sdk/pull/1974)). Contributed by [SimonBrandner](https://github.com/SimonBrandner).
* Enable TypeScript declaration maps ([\#1966](https://github.com/matrix-org/matrix-js-sdk/pull/1966)). Contributed by [Alexendoo](https://github.com/Alexendoo).
* Fix `requestVerificationDM` with chronological `pendingEventOrdering` ([\#1943](https://github.com/matrix-org/matrix-js-sdk/pull/1943)). Contributed by [freaktechnik](https://github.com/freaktechnik).

* Mark old verification methods as deprecated ([\#1994](https://github.com/matrix-org/matrix-js-sdk/pull/1994)).
* Try to set a sender on search result events if possible ([\#2004](https://github.com/matrix-org/matrix-js-sdk/pull/2004)).
* Port some changes from group calls branch to develop ([\#2001](https://github.com/matrix-org/matrix-js-sdk/pull/2001)). Contributed by @SimonBrandner.
* Fetch room membership from server rather than relying on stored data ([\#1998](https://github.com/matrix-org/matrix-js-sdk/pull/1998)).
* Add method to fetch the MSC3266 Room Summary of a Room ([\#1988](https://github.com/matrix-org/matrix-js-sdk/pull/1988)).
* Don't show `Unable to access microphone` when cancelling screensharing dialog ([\#2005](https://github.com/matrix-org/matrix-js-sdk/pull/2005)). Fixes vector-im/element-web#19533 and vector-im/element-web#19533. Contributed by @SimonBrandner.
* Strip direction override characters from display names ([\#1992](https://github.com/matrix-org/matrix-js-sdk/pull/1992)). Fixes vector-im/element-web#1712 and vector-im/element-web#1712.

* Mark old verification methods as deprecated ([\#1994](https://github.com/matrix-org/matrix-js-sdk/pull/1994)).
* Try to set a sender on search result events if possible ([\#2004](https://github.com/matrix-org/matrix-js-sdk/pull/2004)).
* Port some changes from group calls branch to develop ([\#2001](https://github.com/matrix-org/matrix-js-sdk/pull/2001)). Contributed by @SimonBrandner.
* Fetch room membership from server rather than relying on stored data ([\#1998](https://github.com/matrix-org/matrix-js-sdk/pull/1998)).
* Add method to fetch the MSC3266 Room Summary of a Room ([\#1988](https://github.com/matrix-org/matrix-js-sdk/pull/1988)).
* Don't show `Unable to access microphone` when cancelling screensharing dialog ([\#2005](https://github.com/matrix-org/matrix-js-sdk/pull/2005)). Fixes vector-im/element-web#19533 and vector-im/element-web#19533. Contributed by @SimonBrandner.
* Strip direction override characters from display names ([\#1992](https://github.com/matrix-org/matrix-js-sdk/pull/1992)). Fixes vector-im/element-web#1712 and vector-im/element-web#1712.

* Fix edit history being broken after editing an unencrypted event with an encrypted event ([\#2013](https://github.com/matrix-org/matrix-js-sdk/pull/2013)). Fixes vector-im/element-web#19651 and vector-im/element-web#19651. Contributed by @aaronraimist.
* Make events pagination responses parse threads ([\#2011](https://github.com/matrix-org/matrix-js-sdk/pull/2011)). Fixes vector-im/element-web#19587 and vector-im/element-web#19587.

* Fix edit history being broken after editing an unencrypted event with an encrypted event ([\#2013](https://github.com/matrix-org/matrix-js-sdk/pull/2013)). Fixes vector-im/element-web#19651 and vector-im/element-web#19651. Contributed by @aaronraimist.
* Make events pagination responses parse threads ([\#2011](https://github.com/matrix-org/matrix-js-sdk/pull/2011)). Fixes vector-im/element-web#19587 and vector-im/element-web#19587.

* Remove support for `ArrayBuffer` in unstable MSC3089 `createFile()` and `createNewVersion()` and instead use same content types as handled by `MatrixClient.uploadContent()`. This enables support for Node.js. ([\#2014](https://github.com/matrix-org/matrix-js-sdk/pull/2014)).
* Support for password-based backup on Node.js ([\#2021](https://github.com/matrix-org/matrix-js-sdk/pull/2021)).
* Add optional force parameter when ensuring Olm sessions ([\#2027](https://github.com/matrix-org/matrix-js-sdk/pull/2027)).
* Fix call upgrades ([\#2024](https://github.com/matrix-org/matrix-js-sdk/pull/2024)). Contributed by @SimonBrandner.

* Remove support for `ArrayBuffer` in unstable MSC3089 `createFile()` and `createNewVersion()` and instead use same content types as handled by `MatrixClient.uploadContent()`. This enables support for Node.js. ([\#2014](https://github.com/matrix-org/matrix-js-sdk/pull/2014)).
* Support for password-based backup on Node.js ([\#2021](https://github.com/matrix-org/matrix-js-sdk/pull/2021)).
* Add optional force parameter when ensuring Olm sessions ([\#2027](https://github.com/matrix-org/matrix-js-sdk/pull/2027)).
* Fix call upgrades ([\#2024](https://github.com/matrix-org/matrix-js-sdk/pull/2024)). Contributed by @SimonBrandner.

* Security release with updated version of Olm to fix https://matrix.org/blog/2021/12/03/pre-disclosure-upcoming-security-release-of-libolm-and-matrix-js-sdk

* Improve fallback key behaviour ([\#2037](https://github.com/matrix-org/matrix-js-sdk/pull/2037)).
* Add new room event filter fields ([\#2051](https://github.com/matrix-org/matrix-js-sdk/pull/2051)).
* Add method to fetch /account/whoami ([\#2046](https://github.com/matrix-org/matrix-js-sdk/pull/2046)).
* Filter out falsey opts in /relations API hits ([\#2059](https://github.com/matrix-org/matrix-js-sdk/pull/2059)). Fixes vector-im/element-web#20137.
* Fix paginateEventTimeline resolve to boolean ([\#2054](https://github.com/matrix-org/matrix-js-sdk/pull/2054)).
* Fix incorrect MSC3089 typings and add null checks ([\#2049](https://github.com/matrix-org/matrix-js-sdk/pull/2049)).