# Matrix Specification v1.18 Changelog

|   |   | 
|---|---|
| Git commit | https://github.com/matrix-org/matrix-spec/tree/v1.18 |
| Release date | March 25, 2026 |

## Client-Server API

**New Endpoints**

- [ ] Add `GET /_matrix/client/v1/admin/suspend/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323). ([#2278](https://github.com/matrix-org/matrix-spec/issues/2278))
- [ ] Add `PUT /_matrix/client/v1/admin/suspend/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323). ([#2278](https://github.com/matrix-org/matrix-spec/issues/2278))
- [ ] Add `GET /_matrix/client/v1/admin/lock/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323). ([#2278](https://github.com/matrix-org/matrix-spec/issues/2278))
- [ ] Add `PUT /_matrix/client/v1/admin/lock/{userId}`, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323). ([#2278](https://github.com/matrix-org/matrix-spec/issues/2278))

**Removed Endpoints**

- [ ] The `score` request parameter on `/_matrix/client/v3/rooms/{roomId}/report/{eventId}` was removed as per [MSC4277](https://github.com/matrix-org/matrix-spec-proposals/pull/4277). ([#2311](https://github.com/matrix-org/matrix-spec/issues/2311))

**Backwards Compatible Changes**

- [ ] Add the account management capabilities for the OAuth 2.0 authentication API, as per [MSC4191](https://github.com/matrix-org/matrix-spec-proposals/pull/4191). ([#2270](https://github.com/matrix-org/matrix-spec/issues/2270))
- [ ] Add OAuth 2.0 aware clients, as per [MSC3824](https://github.com/matrix-org/matrix-spec-proposals/pull/3824). ([#2272](https://github.com/matrix-org/matrix-spec/issues/2272))
- [ ] Add administrator endpoints to lock and suspend server-local users and add the `m.account_management` capability, as per [MSC4323](https://github.com/matrix-org/matrix-spec-proposals/pull/4323). ([#2278](https://github.com/matrix-org/matrix-spec/issues/2278))
- [ ] Add `m.recent_emoji` account data event to track recently used emoji as per [MSC4356](https://github.com/matrix-org/matrix-spec-proposals/pull/4356). ([#2291](https://github.com/matrix-org/matrix-spec/issues/2291))
- [ ] Add `m.forget_forced_upon_leave` capability for servers to transparently auto-forget rooms that the user leaves as per [MSC4267](https://github.com/matrix-org/matrix-spec-proposals/pull/4267). ([#2292](https://github.com/matrix-org/matrix-spec/issues/2292))
- [ ] Add support for `m.room.redaction` events at the `PUT /rooms/{roomId}/send/{eventType}/{txnId}` endpoint, as per [MSC4169](https://github.com/matrix-org/matrix-spec-proposals/pull/4169). ([#2298](https://github.com/matrix-org/matrix-spec/issues/2298))
- [ ] Clients supporting the `ol` HTML element must also support the `start` attribute, as per [MSC4313](https://github.com/matrix-org/matrix-spec-proposals/pull/4313). ([#2299](https://github.com/matrix-org/matrix-spec/issues/2299))
- [ ] Add recommendation about excluding non-cross-signed devices from encrypted conversations, as per [MSC4153](https://github.com/matrix-org/matrix-spec-proposals/pull/4153). ([#2301](https://github.com/matrix-org/matrix-spec/issues/2301))
- [ ] Add invite blocking, as per [MSC4380](https://github.com/matrix-org/matrix-spec-proposals/pull/4380). ([#2305](https://github.com/matrix-org/matrix-spec/issues/2305))
- [ ] `/_matrix/client/v3/rooms/{roomId}/report` and `/_matrix/client/v3/rooms/{roomId}/report/{eventId}` may respond with HTTP 200 regardless of the reported subject's existence or add a random delay when generating responses as per [MSC4277](https://github.com/matrix-org/matrix-spec-proposals/pull/4277). ([#2311](https://github.com/matrix-org/matrix-spec/issues/2311))
- [ ] Add `M_USER_LIMIT_EXCEEDED` common error code, as per [MSC4335](https://github.com/matrix-org/matrix-spec-proposals/pull/4335). ([#2315](https://github.com/matrix-org/matrix-spec/issues/2315))
- [ ] Add the OAuth 2.0 Device Authorization Grant (RFC 8628) as a supported grant type, as per [MSC4341](https://github.com/matrix-org/matrix-spec-proposals/pull/4341). ([#2320](https://github.com/matrix-org/matrix-spec/issues/2320))
- [ ] Add the `is_animated` flag to the `info` object of the `m.image` msgtype and the `m.sticker` event, as per [MSC4230](https://github.com/matrix-org/matrix-spec-proposals/pull/4230). ([#2328](https://github.com/matrix-org/matrix-spec/issues/2328), [#2338](https://github.com/matrix-org/matrix-spec/issues/2338))
- [ ] Add a "Policy Servers" module, as per [MSC4284](https://github.com/matrix-org/matrix-spec-proposals/pull/4284). ([#2332](https://github.com/matrix-org/matrix-spec/issues/2332))

**Spec Clarifications**

- [ ] The optional `submit_url` response parameter of the `/requestToken` endpoints uses the same request and response parameters and error codes as the Identity Service API's `POST /_matrix/identity/v2/validate/email/submitToken`, as per [MSC4183](https://github.com/matrix-org/matrix-spec-proposals/pull/4183). ([#2277](https://github.com/matrix-org/matrix-spec/issues/2277))
- [ ] Update non-historic mentions of matrix-doc repo to matrix-spec/-proposals. Contributed by @HarHarLinks. ([#2280](https://github.com/matrix-org/matrix-spec/issues/2280))
- [ ] Remove unintended TeX formatting. Contributed by @HarHarLinks. ([#2283](https://github.com/matrix-org/matrix-spec/issues/2283))
- [ ] Clarify the requiredness of `event_id` in `predecessor`. ([#2304](https://github.com/matrix-org/matrix-spec/issues/2304))
- [ ] Clarify terminology for keys in cross-signing module. ([#2306](https://github.com/matrix-org/matrix-spec/issues/2306))
- [ ] Add 404 responses to the OpenAPI of `GET /login` and `GET /auth_metadata` endpoints. The responses were already defined in text but not written in OpenAPI. ([#2316](https://github.com/matrix-org/matrix-spec/issues/2316))
- [ ] Fix various typos throughout the specification. Contributed by @HarHarLinks. ([#2318](https://github.com/matrix-org/matrix-spec/issues/2318))
- [ ] Clarified attachment encryption to require secure generation of keys and hash verification. ([#2324](https://github.com/matrix-org/matrix-spec/issues/2324))
- [ ] Order the common and other error codes alphabetically and remove duplicate `M_THREEPID_IN_USE` definition. ([#2336](https://github.com/matrix-org/matrix-spec/issues/2336))
- [ ] Fix various typos throughout the specification. ([#2337](https://github.com/matrix-org/matrix-spec/issues/2337))


## Server-Server API

**Removed Endpoints**

- [ ] Remove `/v1/send_join` and `/v1/send_leave`, as per [MSC4376](https://github.com/matrix-org/matrix-spec-proposals/pull/4376). ([#2319](https://github.com/matrix-org/matrix-spec/issues/2319))

**Backwards Compatible Changes**

- [ ] Add a concept of "Policy Servers", as per [MSC4284](https://github.com/matrix-org/matrix-spec-proposals/pull/4284). ([#2332](https://github.com/matrix-org/matrix-spec/issues/2332))

**Spec Clarifications**

- [ ] Clarify what the `minimum_valid_until_ts` field means when it is set in key queries. ([#2191](https://github.com/matrix-org/matrix-spec/issues/2191))
- [ ] Specify validation for PDUs passed to and returned from federation membership endpoints. ([#2284](https://github.com/matrix-org/matrix-spec/issues/2284))
- [ ] Specify that callers of `/_matrix/federation/v1/openid/userinfo` must validate the returned user ID. ([#2288](https://github.com/matrix-org/matrix-spec/issues/2288))
- [ ] Change `m.signing_update` typo to `m.signing_key_update`. Contributed by @velikopter ([#2300](https://github.com/matrix-org/matrix-spec/issues/2300))
- [ ] Add link to JSON signing algorithm in server-server auth section for clarity. Contributed by @thetayloredman. ([#2329](https://github.com/matrix-org/matrix-spec/issues/2329))
- [ ] Fix various typos throughout the specification. ([#2338](https://github.com/matrix-org/matrix-spec/issues/2338))


## Application Service API

**Spec Clarifications**

- [ ] Fix various typos throughout the specification. ([#2330](https://github.com/matrix-org/matrix-spec/issues/2330))


## Identity Service API

**Spec Clarifications**

- [ ] Clarify the error codes that can be returned with a 400 HTTP status code by the `POST /_matrix/identity/v2/validate/email/submitToken` and `POST /_matrix/identity/v2/validate/msisdn/submitToken` endpoints, introducing the `M_TOKEN_INCORRECT` error code, as per [MSC4183](https://github.com/matrix-org/matrix-spec-proposals/pull/4183). ([#2277](https://github.com/matrix-org/matrix-spec/issues/2277))
- [ ] Order the standard error codes alphabetically. ([#2336](https://github.com/matrix-org/matrix-spec/issues/2336))


## Push Gateway API

No significant changes.


## Room Versions

**Spec Clarifications**

- [ ] Clarify meaning of floating-point powerlevels. ([#2297](https://github.com/matrix-org/matrix-spec/issues/2297))
- [ ] Remove the post-1.16 release note for room version 12. ([#2303](https://github.com/matrix-org/matrix-spec/issues/2303))


## Appendices

**Spec Clarifications**

- [ ] Add identifier pronunciation guidelines. Contributed by @HarHarLinks. ([#2307](https://github.com/matrix-org/matrix-spec/issues/2307))


## Internal Changes/Tooling

**Backwards Compatible Changes**

- [ ] Include the spec release version in the filenames in the tarballs generated by CI. ([#2276](https://github.com/matrix-org/matrix-spec/issues/2276))

**Spec Clarifications**

- [ ] Clarify vendor prefixing requirements. ([#2222](https://github.com/matrix-org/matrix-spec/issues/2222))
- [ ] Auto-create draft releases when building release tags. ([#2275](https://github.com/matrix-org/matrix-spec/issues/2275))
- [ ] Replace the Twitter link in the footer with our BlueSky and Mastodon socials. ([#2282](https://github.com/matrix-org/matrix-spec/issues/2282))
- [ ] Upgrade to docsy v0.13.0. ([#2287](https://github.com/matrix-org/matrix-spec/issues/2287))
- [ ] Updates to the release documentation. ([#2289](https://github.com/matrix-org/matrix-spec/issues/2289))
- [ ] Remove unused leftover CSS files. ([#2290](https://github.com/matrix-org/matrix-spec/issues/2290))
- [ ] Update the footer social links to match matrix.org. Contributed by @HarHarLinks. ([#2317](https://github.com/matrix-org/matrix-spec/issues/2317))
- [ ] Fix various typos throughout the specification. Contributed by @HarHarLinks. ([#2318](https://github.com/matrix-org/matrix-spec/issues/2318))
- [ ] Render error code sections as definition lists to improve readability. ([#2323](https://github.com/matrix-org/matrix-spec/issues/2323))