# Matrix Specification Changes since last release


## Client-Server API

**Breaking Changes**

- [ ] Clients are now supposed to follow 30x redirects from `/.well-known/matrix/client` as per [MSC4402](https://github.com/matrix-org/matrix-spec-proposals/pull/4402). ([#2404](https://github.com/matrix-org/matrix-spec/issues/2404))

**Spec Clarifications**

- [ ] Add further normative language in mutual rooms server behaviour. ([#2407](https://github.com/matrix-org/matrix-spec/issues/2407))
- [ ] Use the User ID type in OlmPayload and DeviceKeys. ([#2412](https://github.com/matrix-org/matrix-spec/issues/2412))
- [ ] Improve the format description of `m.room.encrypted` (Olm/Megolm) events. ([#2413](https://github.com/matrix-org/matrix-spec/issues/2413))
- [ ] Wording improvements and spelling fixes. Contributed by @HarHarLinks. ([#2417](https://github.com/matrix-org/matrix-spec/issues/2417))
- [ ] Rename OlmPayload to OlmPlaintext to avoid confusion with Olm message Payload Bytes. ([#2418](https://github.com/matrix-org/matrix-spec/issues/2418))
- [ ] Use MXC URI type for all user `avatar_url` fields. Contributed by @networkException. ([#2422](https://github.com/matrix-org/matrix-spec/issues/2422))


## Server-Server API

No significant changes.


## Application Service API

No significant changes.


## Identity Service API

No significant changes.


## Push Gateway API

No significant changes.


## Room Versions

No significant changes.


## Olm & Megolm

**Spec Clarifications**

- [ ] Fix typesetting of some symbols in the Olm/Megolm spec. ([#2421](https://github.com/matrix-org/matrix-spec/issues/2421))


## Appendices

**Spec Clarifications**

- [ ] Clarify that clients must avoid producing ambiguous matrix.to URIs. Contributed by @HarHarLinks. ([#2396](https://github.com/matrix-org/matrix-spec/issues/2396))


## Internal Changes/Tooling

No significant changes.