Merge e92c5ca539 into 966109da49

Signed-off-by: Johanna Stuber <johannas@element.io>

changelogs/appendices/newsfragments/2368.clarification

@@ -1 +0,0 @@
-Update the canonical JSON grammar with case sensitive strings and ABNF builtins to be easier to understand.

changelogs/appendices/newsfragments/2369.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/appendices/newsfragments/2395.clarification

@@ -1 +0,0 @@
-Clarify matrix.to RFC 3986 percent encoding requirements. Contributed by @HarHarLinks.

changelogs/appendices/newsfragments/2396.clarification

@@ -0,0 +1 @@
+Clarify that clients must avoid producing ambiguous matrix.to URIs. Contributed by @HarHarLinks.

changelogs/appendices/newsfragments/2398.clarification

@@ -1 +0,0 @@
-Add specification of URL-safe unpadded Base64.

changelogs/application_service/newsfragments/2351.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/client_server/newsfragments/2344.clarification

@@ -1 +0,0 @@
-Clarify SAS commitment calculation for `m.key.verification.accept` messages.

changelogs/client_server/newsfragments/2345.feature

@@ -1 +0,0 @@
-Specify `unsigned.replaces_state` in client-formatted events. Contributed by @nexy7574.

changelogs/client_server/newsfragments/2347.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2348.clarification

@@ -1 +0,0 @@
-Restore alphabetical order of common error codes.

changelogs/client_server/newsfragments/2349.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2351.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/client_server/newsfragments/2352.clarification

@@ -1 +0,0 @@
-Clarify how to find `via` parameter when following room upgrades.

changelogs/client_server/newsfragments/2354.feature

@@ -1 +0,0 @@
-Specify `m.key_backup` account data, as per [MSC4287](https://github.com/matrix-org/matrix-spec-proposals/pull/4287).

changelogs/client_server/newsfragments/2358.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2359.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2367.new

@@ -1 +0,0 @@
-Add `GET /_matrix/client/v1/mutual_rooms`, as per [MSC2666](https://github.com/matrix-org/matrix-spec-proposals/pull/2666).

changelogs/client_server/newsfragments/2370.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2371.clarification

@@ -1 +0,0 @@
-Clarify that room messages can be encrypted.

changelogs/client_server/newsfragments/2372.clarification

@@ -1 +0,0 @@
-Clarify how to paginate messages using the pagination tokens returned by `GET /rooms/{roomId}/context/{eventId}`.

changelogs/client_server/newsfragments/2374.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2375.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2376.clarification

@@ -1 +0,0 @@
-Clarify formats of string types.

changelogs/client_server/newsfragments/2377.clarification

@@ -1 +0,0 @@
-Clarify allowed characters in `mxc://` URIs.

changelogs/client_server/newsfragments/2379.clarification

@@ -1 +0,0 @@
-Add link to RFC 9700 OAuth 2.0 Best Current Practices.

changelogs/client_server/newsfragments/2381.clarification

@@ -1 +0,0 @@
-Add links from the Client-Server spec to the Olm message definitions.

changelogs/client_server/newsfragments/2382.clarification

@@ -1 +0,0 @@
-Disambiguate placeholder descriptions in OlmPayload example.

changelogs/client_server/newsfragments/2383.clarification

@@ -1 +0,0 @@
-Replace "Olm message" with "event encrypted using Olm" where not referring to the Olm message format.

changelogs/client_server/newsfragments/2386.clarification

@@ -1 +0,0 @@
-Removed unused components in OpenAPI definitions.

changelogs/client_server/newsfragments/2389.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/client_server/newsfragments/2392.feature

@@ -1 +0,0 @@
-The room directory now returns rooms in a server-defined order rather than largest first, as per [MSC4423](https://github.com/matrix-org/matrix-spec-proposals/pull/4423).

changelogs/client_server/newsfragments/2397.feature

@@ -1 +0,0 @@
-Add support for image packs (`m.room.image_pack` and `m.image_pack.rooms`), allowing custom emoticons and stickers to be organised into packs and shared between users, as per [MSC2545](https://github.com/matrix-org/matrix-spec-proposals/pull/2545).

changelogs/client_server/newsfragments/2398.clarification

@@ -1 +0,0 @@
-Clarify definitions of `EncryptedFile` structure.

changelogs/client_server/newsfragments/2399.feature

@@ -1 +0,0 @@
-Specify encrypted history sharing, as per [MSC4268](https://github.com/matrix-org/matrix-spec-proposals/pull/4268).

changelogs/client_server/newsfragments/2403.feature

@@ -1 +0,0 @@
-Specify `unsigned.replaces_state` in client-formatted events. Contributed by @nexy7574.

changelogs/client_server/newsfragments/2404.breaking

@@ -0,0 +1 @@
+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).

changelogs/client_server/newsfragments/2412.clarification

@@ -0,0 +1 @@
+Use the User ID type in OlmPayload and DeviceKeys.

changelogs/client_server/newsfragments/2417.clarification

@@ -0,0 +1 @@
+Wording improvements and spelling fixes. Contributed by @HarHarLinks.

changelogs/client_server/newsfragments/2418.clarification

@@ -0,0 +1 @@
+Rename OlmPayload to OlmPlaintext to avoid confusion with Olm message Payload Bytes.

changelogs/identity_service/newsfragments/2401.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/internal/newsfragments/2331.feature

@@ -1 +0,0 @@
-Add page search widget.

changelogs/internal/newsfragments/2343.clarification

@@ -1 +0,0 @@
-Update and fix GitHub Actions.

changelogs/internal/newsfragments/2346.clarification

@@ -1 +0,0 @@
-Upgrade Docsy theme to v0.14.3.

changelogs/internal/newsfragments/2364.clarification

@@ -1 +0,0 @@
-Configure a new changelog section for the Olm & Megolm specs.

changelogs/internal/newsfragments/2366.clarification

@@ -1,2 +0,0 @@
-Clarify use of UK vs US English in documentation style doc.
-

changelogs/internal/newsfragments/2369.clarification

@@ -1 +0,0 @@
-Update and fix GitHub Actions.

changelogs/internal/newsfragments/2373.clarification

@@ -1 +0,0 @@
-Ignore typos in copyright statements.

changelogs/internal/newsfragments/2400.clarification

@@ -1 +0,0 @@
-Update CODEOWNERS file.

changelogs/internal/newsfragments/2402.clarification

@@ -1 +0,0 @@
-Minor fixes to `check-newsfragments` CI script.

changelogs/olm_megolm/newsfragments/2361.clarification

@@ -1 +0,0 @@
-Update links to Olm in the Megolm section to point to the Matrix spec.

changelogs/olm_megolm/newsfragments/2369.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/olm_megolm/newsfragments/2387.clarification

@@ -1 +0,0 @@
-Update link from whispersystems.org to signal.org in the olm documentation.

changelogs/room_versions/newsfragments/2351.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/room_versions/newsfragments/2401.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/server_server/newsfragments/2326.clarification

@@ -1 +0,0 @@
-Clarify the behaviour and response format of `GET /_matrix/federation/v1/query/profile`.

changelogs/server_server/newsfragments/2334.clarification

@@ -1 +0,0 @@
-Clarify that server ACLs are case-insensitive, as per [MSC4436](https://github.com/matrix-org/matrix-spec-proposals/pull/4436).

changelogs/server_server/newsfragments/2341.clarification

@@ -1 +0,0 @@
-Clarify how multiple signatures should be handled during signature verification. Contributed by @nexy7574.

changelogs/server_server/newsfragments/2351.clarification

@@ -1 +0,0 @@
-Fix various typos throughout the specification.

changelogs/server_server/newsfragments/2385.clarification

@@ -1 +0,0 @@
-Clarify that policy servers might share a name with event origins, and that servers should avoid overwriting/discarding signatures for the event origin when getting a policy server signature.

changelogs/server_server/newsfragments/2392.feature

@@ -1 +0,0 @@
-The room directory now returns rooms in a server-defined order rather than largest first, as per [MSC4423](https://github.com/matrix-org/matrix-spec-proposals/pull/4423).

config/_default/hugo.toml

@@ -77,7 +77,7 @@ current_version_url = "https://spec.matrix.org/latest"
 # The following is used when status = "stable", and is displayed in various UI elements on a released version
 # of the spec.
 # major = "1"
-#minor = "18"
+# minor = "19"
 
 [[params.versions]]
 # We must include this parameter to enable docsy's version picker in the navbar. The picker

content/appendices.md

@@ -887,20 +887,22 @@ https://matrix.to/#/<identifier>/<extra parameter>?<additional arguments>
 
 The identifier may be a room ID, room alias, or user ID. The
 extra parameter is only used in the case of permalinks where an event ID
-is referenced. The matrix.to URI, when referenced, must always start
+is referenced. The matrix.to URI, when referenced, MUST always start
 with `https://matrix.to/#/` followed by the identifier.
 
 The `<additional arguments>` and the preceding question mark are
-optional and only apply in certain circumstances, documented below.
+OPTIONAL and only apply in certain circumstances, documented below.
 
-Clients should not rely on matrix.to URIs falling back to a web server
+Clients SHOULD NOT rely on matrix.to URIs falling back to a web server
-if accessed and instead should perform some sort of action within the
+if accessed and instead SHOULD perform some sort of action within the
 client. For example, if the user were to click on a matrix.to URI for a
-room alias, the client may open a view for the user to participate in
+room alias, the client MAY open a view for the user to participate in
 the room.
 
 The components of the matrix.to URI (`<identifier>` and
 `<extra parameter>`) MUST be percent-encoded as per RFC 3986.
+Failure to do so will result in downstream software misinterpreting
+the links as invalid/not turning them into clickable links in UI.
 
 Examples of matrix.to URIs are:
 

content/changelog/v1.19.md

@@ -0,0 +1,118 @@
+---
+title: v1.19 Changelog
+linkTitle: v1.19
+type: docs
+layout: changelog
+outputs:
+  - html
+  - checklist
+date: 2026-07-08
+---
+
+## Client-Server API
+
+**New Endpoints**
+
+- Add `GET /_matrix/client/v1/mutual_rooms`, as per [MSC2666](https://github.com/matrix-org/matrix-spec-proposals/pull/2666). ([#2367](https://github.com/matrix-org/matrix-spec/issues/2367))
+
+**Backwards Compatible Changes**
+
+- Specify `unsigned.replaces_state` in client-formatted events. Contributed by @nexy7574. ([#2345](https://github.com/matrix-org/matrix-spec/issues/2345), [#2403](https://github.com/matrix-org/matrix-spec/issues/2403))
+- Specify `m.key_backup` account data, as per [MSC4287](https://github.com/matrix-org/matrix-spec-proposals/pull/4287). ([#2354](https://github.com/matrix-org/matrix-spec/issues/2354))
+- The room directory now returns rooms in a server-defined order rather than largest first, as per [MSC4423](https://github.com/matrix-org/matrix-spec-proposals/pull/4423). ([#2392](https://github.com/matrix-org/matrix-spec/issues/2392))
+- Add support for image packs (`m.room.image_pack` and `m.image_pack.rooms`), allowing custom emoticons and stickers to be organised into packs and shared between users, as per [MSC2545](https://github.com/matrix-org/matrix-spec-proposals/pull/2545). ([#2397](https://github.com/matrix-org/matrix-spec/issues/2397))
+- Specify encrypted history sharing, as per [MSC4268](https://github.com/matrix-org/matrix-spec-proposals/pull/4268). ([#2399](https://github.com/matrix-org/matrix-spec/issues/2399))
+
+**Spec Clarifications**
+
+- Clarify SAS commitment calculation for `m.key.verification.accept` messages. ([#2344](https://github.com/matrix-org/matrix-spec/issues/2344))
+- Clarify formats of string types. ([#2347](https://github.com/matrix-org/matrix-spec/issues/2347), [#2349](https://github.com/matrix-org/matrix-spec/issues/2349), [#2358](https://github.com/matrix-org/matrix-spec/issues/2358), [#2359](https://github.com/matrix-org/matrix-spec/issues/2359), [#2370](https://github.com/matrix-org/matrix-spec/issues/2370), [#2374](https://github.com/matrix-org/matrix-spec/issues/2374), [#2375](https://github.com/matrix-org/matrix-spec/issues/2375), [#2376](https://github.com/matrix-org/matrix-spec/issues/2376))
+- Restore alphabetical order of common error codes. ([#2348](https://github.com/matrix-org/matrix-spec/issues/2348))
+- Fix various typos throughout the specification. ([#2351](https://github.com/matrix-org/matrix-spec/issues/2351), [#2389](https://github.com/matrix-org/matrix-spec/issues/2389))
+- Clarify how to find `via` parameter when following room upgrades. ([#2352](https://github.com/matrix-org/matrix-spec/issues/2352))
+- Clarify that room messages can be encrypted. ([#2371](https://github.com/matrix-org/matrix-spec/issues/2371))
+- Clarify how to paginate messages using the pagination tokens returned by `GET /rooms/{roomId}/context/{eventId}`. ([#2372](https://github.com/matrix-org/matrix-spec/issues/2372))
+- Clarify allowed characters in `mxc://` URIs. ([#2377](https://github.com/matrix-org/matrix-spec/issues/2377))
+- Add link to RFC 9700 OAuth 2.0 Best Current Practices. ([#2379](https://github.com/matrix-org/matrix-spec/issues/2379))
+- Add links from the Client-Server spec to the Olm message definitions. ([#2381](https://github.com/matrix-org/matrix-spec/issues/2381))
+- Disambiguate placeholder descriptions in OlmPayload example. ([#2382](https://github.com/matrix-org/matrix-spec/issues/2382))
+- Replace "Olm message" with "event encrypted using Olm" where not referring to the Olm message format. ([#2383](https://github.com/matrix-org/matrix-spec/issues/2383))
+- Removed unused components in OpenAPI definitions. ([#2386](https://github.com/matrix-org/matrix-spec/issues/2386))
+- Clarify definitions of `EncryptedFile` structure. ([#2398](https://github.com/matrix-org/matrix-spec/issues/2398))
+
+
+## Server-Server API
+
+**Backwards Compatible Changes**
+
+- The room directory now returns rooms in a server-defined order rather than largest first, as per [MSC4423](https://github.com/matrix-org/matrix-spec-proposals/pull/4423). ([#2392](https://github.com/matrix-org/matrix-spec/issues/2392))
+
+**Spec Clarifications**
+
+- Clarify the behaviour and response format of `GET /_matrix/federation/v1/query/profile`. ([#2326](https://github.com/matrix-org/matrix-spec/issues/2326))
+- Clarify that server ACLs are case-insensitive, as per [MSC4436](https://github.com/matrix-org/matrix-spec-proposals/pull/4436). ([#2334](https://github.com/matrix-org/matrix-spec/issues/2334))
+- Clarify how multiple signatures should be handled during signature verification. Contributed by @nexy7574. ([#2341](https://github.com/matrix-org/matrix-spec/issues/2341))
+- Fix various typos throughout the specification. ([#2351](https://github.com/matrix-org/matrix-spec/issues/2351))
+- Clarify that policy servers might share a name with event origins, and that servers should avoid overwriting/discarding signatures for the event origin when getting a policy server signature. ([#2385](https://github.com/matrix-org/matrix-spec/issues/2385))
+
+
+## Application Service API
+
+**Spec Clarifications**
+
+- Fix various typos throughout the specification. ([#2351](https://github.com/matrix-org/matrix-spec/issues/2351))
+
+
+## Identity Service API
+
+**Spec Clarifications**
+
+- Fix various typos throughout the specification. ([#2401](https://github.com/matrix-org/matrix-spec/issues/2401))
+
+
+## Push Gateway API
+
+No significant changes.
+
+
+## Room Versions
+
+**Spec Clarifications**
+
+- Fix various typos throughout the specification. ([#2351](https://github.com/matrix-org/matrix-spec/issues/2351), [#2401](https://github.com/matrix-org/matrix-spec/issues/2401))
+
+
+## Olm & Megolm
+
+**Spec Clarifications**
+
+- Update links to Olm in the Megolm section to point to the Matrix spec. ([#2361](https://github.com/matrix-org/matrix-spec/issues/2361))
+- Fix various typos throughout the specification. ([#2369](https://github.com/matrix-org/matrix-spec/issues/2369))
+- Update link from whispersystems.org to signal.org in the olm documentation. ([#2387](https://github.com/matrix-org/matrix-spec/issues/2387))
+
+
+## Appendices
+
+**Spec Clarifications**
+
+- Update the canonical JSON grammar with case sensitive strings and ABNF builtins to be easier to understand. ([#2368](https://github.com/matrix-org/matrix-spec/issues/2368))
+- Fix various typos throughout the specification. ([#2369](https://github.com/matrix-org/matrix-spec/issues/2369))
+- Clarify matrix.to RFC 3986 percent encoding requirements. Contributed by @HarHarLinks. ([#2395](https://github.com/matrix-org/matrix-spec/issues/2395))
+- Add specification of URL-safe unpadded Base64. ([#2398](https://github.com/matrix-org/matrix-spec/issues/2398))
+
+
+## Internal Changes/Tooling
+
+**Backwards Compatible Changes**
+
+- Add page search widget. ([#2331](https://github.com/matrix-org/matrix-spec/issues/2331))
+
+**Spec Clarifications**
+
+- Update and fix GitHub Actions. ([#2343](https://github.com/matrix-org/matrix-spec/issues/2343), [#2369](https://github.com/matrix-org/matrix-spec/issues/2369))
+- Upgrade Docsy theme to v0.14.3. ([#2346](https://github.com/matrix-org/matrix-spec/issues/2346))
+- Configure a new changelog section for the Olm & Megolm specs. ([#2364](https://github.com/matrix-org/matrix-spec/issues/2364))
+- Clarify use of UK vs US English in documentation style doc. ([#2366](https://github.com/matrix-org/matrix-spec/issues/2366))
+- Ignore typos in copyright statements. ([#2373](https://github.com/matrix-org/matrix-spec/issues/2373))
+- Update CODEOWNERS file. ([#2400](https://github.com/matrix-org/matrix-spec/issues/2400))
+- Minor fixes to `check-newsfragments` CI script. ([#2402](https://github.com/matrix-org/matrix-spec/issues/2402))

content/client-server-api/_index.md

@@ -429,6 +429,7 @@ Instead, they can be reached via HTTPS on the [server name](/appendices/#server-
 
 Servers hosting the `.well-known` JSON file SHOULD offer CORS headers,
 as per the [CORS](#web-browser-clients) section in this specification.
+{{% added-in v="1.20" %}} Servers SHOULD also ensure that each 30x redirect, if any, offers such CORS headers.
 {{% /boxes/note %}}
 
 The flow for auto-discovery is as follows:
@@ -437,6 +438,7 @@ The flow for auto-discovery is as follows:
     Matrix ID at the first colon.
 2.  Extract the hostname from the server name as described by the [grammar](/appendices/#server-name).
 3.  Make a GET request to `https://hostname/.well-known/matrix/client`.
+    {{% added-in v="1.20" %}} 30x redirects SHOULD be followed, however redirection loops should be avoided.
     1.  If the returned status code is 404, then `IGNORE`.
     2.  If the returned status code is not 200, or the response body is
         empty, then `FAIL_PROMPT`.
@@ -3654,7 +3656,7 @@ The actual aggregation format depends on the `rel_type`.
 
 When an event is served to the client through the APIs listed below, a
 `m.relations` property is included under `unsigned` if the event has child
-events which can be aggregated and point at it. The `m.relations` property is
+events which can be aggregated. The `m.relations` property is
 an object keyed by `rel_type` and value being the type-specific aggregated
 format for that `rel_type`. This `m.relations` property is known as a "bundled
 aggregation".

content/client-server-api/modules/end_to_end_encryption.md

@@ -1762,12 +1762,9 @@ Messages with type 1 can only be decrypted with an existing session. If
 there is no matching session, the client must treat this as an invalid
 message.
 
-The plaintext payload is of the form:
+The plaintext corresponding to the "Cipher-Text" in an an [Olm message](/olm-megolm/olm/#normal-messages) is of the form:
 
-{{% definition path="api/client-server/definitions/olm_payload" %}}
+{{% definition path="api/client-server/definitions/olm_plaintext" %}}
-
-The type and content of the plaintext message event are given in the
-payload.
 
 If a client has multiple sessions established with another device, it
 should use the session from which it last received and successfully

content/client-server-api/modules/threading.md

@@ -191,7 +191,7 @@ Note that, as in the example above, child events of the `latest_event` should
 themselves be aggregated and included under `m.relations` for that event. The
 server should be careful to avoid loops, though loops are not currently
 possible due to `m.thread` not being permitted to target an event with an
-`m.relates_to` property.
+`m.relates_to` property with a `rel_type`.
 
 `count` is simply the number of events using `m.thread` as a `rel_type` pointing to the target event.
 It does not include events sent by [ignored users](#ignoring-users).

data/api/client-server/definitions/device_keys.yaml

@@ -20,6 +20,8 @@ properties:
     description: |-
       The ID of the user the device belongs to. Must match the user ID used
       when logging in.
+    format: mx-user-id
+    pattern: "^@"
     example: "@alice:example.com"
   device_id:
     type: string

data/api/client-server/definitions/olm_plaintext.yaml

@@ -14,9 +14,9 @@
 
 
 type: object
-title: OlmPayload
+title: OlmPlaintext
 description: |-
-  The plaintext payload of an event encrypted using Olm.
+  The plaintext of an event encrypted using Olm.
 properties:
   type:
     type: string
@@ -27,9 +27,13 @@ properties:
   sender:
     type: string
     description: The user ID of the event sender.
+    format: mx-user-id
+    pattern: "^@"
   recipient:
     type: string
     description: The user ID of the intended event recipient.
+    format: mx-user-id
+    pattern: "^@"
   recipient_keys:
     description: The recipient's signing keys of the encrypted event.
     $ref: "#/components/schemas/SigningKeys"

data/api/client-server/wellknown.yaml

@@ -1,4 +1,5 @@
 # Copyright 2018 New Vector Ltd
+# Copyright 2026 Hagen Echzell
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -20,7 +21,11 @@ paths:
     get:
       summary: Gets Matrix server discovery information about the domain.
       description: |-
-        Gets discovery information about the domain. The file may include
+        Gets discovery information about the domain.
+        {{% added-in v="1.20" %}} Clients SHOULD follow 30x redirects, carefully
+        avoiding redirect loops, and use normal X.509 certificate validation.
+        
+        The file may include
         additional keys, which MUST follow the Java package naming convention,
         e.g. `com.example.myapp.property`. This ensures property names are
         suitably namespaced for each application and reduces the risk of

data/event-schemas/schema/m.room_key_bundle.yaml

@@ -13,7 +13,7 @@ description: |-
   [Olm](/client-server-api/#molmv1curve25519-aes-sha2).
 
   The `sender_device_keys` property in the [Olm
-  plaintext](/client-server-api/#definition-olmpayload) MUST be
+  plaintext](/client-server-api/#definition-olmplaintext) MUST be
   populated. Recipients SHOULD ignore `m.room_key_bundle` messages which omit
   them.
 properties: