Merge f42ce28bfe into 7bc016bda6

* Part 1: Invites

* Part 2: Knocks

* Use correct schema and examples; Remind readers often about formats

* changelogs

* Add schema warning

* Name the objects

* Move changed-in and expand upon it

* Rename the example

* address review feedback

changelogs/client_server/newsfragments/2071.feature

@@ -1 +1 @@
-Update user profile endpoints to handle custom fields, and add a new `m.profile_fields` capability,as per [MSC4133](https://github.com/matrix-org/matrix-spec-proposals/pull/4133).
+Update user profile endpoints to handle custom fields, and add a new `m.profile_fields` capability, as per [MSC4133](https://github.com/matrix-org/matrix-spec-proposals/pull/4133).

changelogs/client_server/newsfragments/2188.clarification

@@ -0,0 +1 @@
+Clarify terminology for keys in cross-signing module.

changelogs/client_server/newsfragments/2204.clarification

@@ -0,0 +1 @@
+Clarify wording around the `world_readable` history visibility setting. Contributed by @HarHarLinks.

changelogs/client_server/newsfragments/2206.feature

@@ -0,0 +1 @@
+Add a profile field for a user's time zone, per [MSC4175](https://github.com/matrix-org/matrix-spec-proposals/pull/4175).

changelogs/client_server/newsfragments/2207.feature

@@ -0,0 +1 @@
+Invites and knocks are now expected to contain the `m.room.create` event in their stripped state entries, as per [MSC4311](https://github.com/matrix-org/matrix-spec-proposals/pull/4311).

changelogs/internal/newsfragments/2205.clarification

@@ -0,0 +1 @@
+Fix a grammatical typo on the Matrix Spec Process documentation page.

changelogs/server_server/newsfragments/2207.feature

@@ -0,0 +1 @@
+`invite_room_state` and `knock_room_state` now have additional requirements and validation depending on the room version, as per [MSC4311](https://github.com/matrix-org/matrix-spec-proposals/pull/4311).

content/client-server-api/_index.md

@@ -2818,6 +2818,14 @@ should be represented as stripped state events when possible:
 * [`m.room.canonical_alias`](#mroomcanonical_alias)
 * [`m.room.encryption`](#mroomencryption)
 
+{{% changed-in v="1.16" %}} The `m.room.create` event is now **required** in
+the following places:
+* [`invite_state`](#get_matrixclientv3sync_response-200_invited-room) and
+  [`knock_state`](#get_matrixclientv3sync_response-200_knocked-room) on
+  [`/sync`](#get_matrixclientv3sync) responses.
+* On [`m.room.member`](#mroommember) events, the `invite_room_state`
+  and `knock_room_state` under `unsigned` on the event.
+
 {{% boxes/note %}}
 Clients should inspect the list of stripped state events and not assume any
 particular event is present. The server might include events not described
@@ -2848,6 +2856,12 @@ events are not signed and could theoretically be modified, or outdated due to
 updates not being sent.
 {{% /boxes/warning %}}
 
+{{% boxes/warning %}}
+{{% added-in v="1.16" %}} Servers cannot pass through what they receive over
+federation to clients as stripped state. Servers are expected to prune the events
+into the stripped state schema below before passing the details onto clients.
+{{% /boxes/warning %}}
+
 {{% event-fields event_type="stripped_state" %}}
 
 ### Size limits

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

@@ -93,7 +93,7 @@ Example:
 ```
 
 `ed25519` and `curve25519` keys are used for [device keys](#device-keys).
-Additionally, `ed25519` keys are used for [cross-signing keys](#cross-signing).
+Additionally, `ed25519` keys are keys used for [cross-signing](#cross-signing).
 
 `signed_curve25519` keys are used for [one-time and fallback keys](#one-time-and-fallback-keys).
 
@@ -675,7 +675,7 @@ The process between Alice and Bob verifying each other would be:
 15. Assuming they match, Alice and Bob's devices each calculate Message
     Authentication Codes (MACs) for:
     * Each of the keys that they wish the other user to verify (usually their
-      device ed25519 key and their master cross-signing key).
+      device ed25519 key and their master key, see below).
     * The complete list of key IDs that they wish the other user to verify.
 
     The MAC calculation is defined [below](#mac-calculation).
@@ -931,16 +931,16 @@ and can be translated online:
 Rather than requiring Alice to verify each of Bob's devices with each of
 her own devices and vice versa, the cross-signing feature allows users
 to sign their device keys such that Alice and Bob only need to verify
-once. With cross-signing, each user has a set of cross-signing keys that
+once. With cross-signing, each user has a set of ed25519 key pairs that
 are used to sign their own device keys and other users' keys, and can be
 used to trust device keys that were not verified directly.
 
-Each user has three ed25519 key pairs for cross-signing:
+Each user has three ed25519 key pairs used for cross-signing:
 
--   a master key (MSK) that serves as the user's identity in
-    cross-signing and signs their other cross-signing keys;
+-   a master key (MK) that serves as the user's identity in
+    cross-signing and signs their user-signing and self-signing keys;
 -   a user-signing key (USK) -- only visible to the user that it belongs
-    to --that signs other users' master keys; and
+    to -- that signs other users' master keys; and
 -   a self-signing key (SSK) that signs the user's own device keys.
 
 The master key may also be used to sign other items such as the backup
@@ -950,13 +950,15 @@ previously verified Bob's device and Bob's device has signed his master
 key, then Alice's device can trust Bob's master key, and she can sign it
 with her user-signing key.
 
-Users upload their cross-signing keys to the server using [POST
+Users upload the public part of their master, user-signing and self-signing
+key to the server using [POST
 /\_matrix/client/v3/keys/device\_signing/upload](/client-server-api/#post_matrixclientv3keysdevice_signingupload). When Alice uploads
-new cross-signing keys, her user ID will appear in the `changed`
+new keys, her user ID will appear in the `changed`
 property of the `device_lists` field of the `/sync` of response of all
 users who share an encrypted room with her. When Bob sees Alice's user
 ID in his `/sync`, he will call [POST /\_matrix/client/v3/keys/query](/client-server-api/#post_matrixclientv3keysquery)
-to retrieve Alice's device and cross-signing keys.
+to retrieve Alice's device keys, as well as their master, user-signing and
+self-signing key.
 
 If Alice has a device and wishes to send an encrypted message to Bob,
 she can trust Bob's device if:
@@ -971,13 +973,13 @@ The following diagram illustrates how keys are signed:
 
 ```
     +------------------+                ..................   +----------------+
-    | +--------------+ |   ..................            :   | +------------+ |
-    | |              v v   v            :   :            v   v v            | |
-    | |           +-----------+         :   :         +-----------+         | |
-    | |           | Alice MSK |         :   :         |  Bob MSK  |         | |
-    | |           +-----------+         :   :         +-----------+         | |
-    | |             |       :           :   :           :       |           | |
-    | |          +--+       :...        :   :        ...:       +--+        | |
+    | +--------------+ |  ...................            :   | +------------+ |
+    | |              v v  v             :   :            v   v v            | |
+    | |           +----------+          :   :         +----------+          | |
+    | |           | Alice MK |          :   :         |  Bob MK  |          | |
+    | |           +----------+          :   :         +----------+          | |
+    | |             |      :            :   :           :      |            | |
+    | |          +--+      :....        :   :        ...:      +---+        | |
     | |          v             v        :   :        v             v        | |
     | |    +-----------+ .............  :   :  ............. +-----------+  | |
     | |    | Alice SSK | : Alice USK :  :   :  :  Bob USK  : |  Bob SSK  |  | |
@@ -1004,11 +1006,11 @@ signatures that she cannot see:
     +------------------+                +----------------+   +----------------+
     | +--------------+ |                |                |   | +------------+ |
     | |              v v                |                v   v v            | |
-    | |           +-----------+         |             +-----------+         | |
-    | |           | Alice MSK |         |             |  Bob MSK  |         | |
-    | |           +-----------+         |             +-----------+         | |
-    | |             |       |           |                       |           | |
-    | |          +--+       +--+        |                       +--+        | |
+    | |           +----------+          |             +----------+          | |
+    | |           | Alice MK |          |             |  Bob MK  |          | |
+    | |           +----------+          |             +----------+          | |
+    | |             |      |            |                      |            | |
+    | |          +--+      +---+        |                      +---+        | |
     | |          v             v        |                          v        | |
     | |    +-----------+ +-----------+  |                    +-----------+  | |
     | |    | Alice SSK | | Alice USK |  |                    |  Bob SSK  |  | |
@@ -1024,16 +1026,16 @@ signatures that she cannot see:
 ```
 
 [Verification methods](#device-verification) can be used to verify a
-user's master key by using the master public key, encoded using unpadded
+user's master key by treating the master public key, encoded using unpadded
 base64, as the device ID, and treating it as a normal device. For
 example, if Alice and Bob verify each other using SAS, Alice's
 `m.key.verification.mac` message to Bob may include
 `"ed25519:alices+master+public+key": "alices+master+public+key"` in the
 `mac` property. Servers therefore must ensure that device IDs will not
-collide with cross-signing public keys.
+collide with public keys used for cross-signing.
 
-The cross-signing private keys can be stored on the server or shared with other
-devices using the [Secrets](#secrets) module.  When doing so, the master,
+Using the [Secrets](#secrets) module the private keys used for cross-signing can
+be stored on the server or shared with other devices.  When doing so, the master,
 user-signing, and self-signing keys are identified using the names
 `m.cross_signing.master`, `m.cross_signing.user_signing`, and
 `m.cross_signing.self_signing`, respectively, and the keys are base64-encoded
@@ -1052,14 +1054,14 @@ If a user's client sees that any other user has changed their master
 key, that client must notify the user about the change before allowing
 communication between the users to continue.
 
-Since device key IDs (`ed25519:DEVICE_ID`) and cross-signing key IDs
-(`ed25519:PUBLIC_KEY`) occupy the same namespace, clients must ensure that they
-use the correct keys when verifying.
+Since device key IDs (`ed25519:DEVICE_ID`) as well as master, user-signing and
+self-signing key IDs (`ed25519:PUBLIC_KEY`) occupy the same namespace, clients
+must ensure that they use the correct keys when verifying.
 
-While servers MUST not allow devices to have the same IDs as cross-signing
-keys, a malicious server could construct such a situation, so clients must not
-rely on the server being well-behaved and should take the following precautions
-against this.
+While servers MUST not allow devices to have the same IDs as keys used for
+cross-signing, a malicious server could construct such a situation, so clients
+must not rely on the server being well-behaved and should take the following
+precautions against this:
 
 1. Clients MUST refer to keys by their public keys during the verification
    process, rather than only by the key ID.
@@ -1067,7 +1069,8 @@ against this.
    verification process, and ensure that they do not change in the course of
    verification.
 3. Clients SHOULD also display a warning and MUST refuse to verify a user when
-   they detect that the user has a device with the same ID as a cross-signing key.
+   they detect that the user has a device with the same ID as a key used for
+   cross-signing.
 
 A user's user-signing and self-signing keys are intended to be easily
 replaceable if they are compromised by re-issuing a new key signed by
@@ -1104,7 +1107,7 @@ user-signing keys.
 
 Verifying by QR codes provides a quick way to verify when one of the parties
 has a device capable of scanning a QR code. The QR code encodes both parties'
-master signing keys as well as a random shared secret that is used to allow
+master keys as well as a random shared secret that is used to allow
 bi-directional verification from a single scan.
 
 To advertise the ability to show a QR code, clients use the names
@@ -1202,15 +1205,14 @@ The binary segment MUST be of the following form:
     bytes of the ID as a UTF-8 string
   - the ID encoded as a UTF-8 string
 - the first key, as 32 bytes.  The key to use depends on the mode field:
-  - if `0x00` or `0x01`, then the current user's own master cross-signing public key
+  - if `0x00` or `0x01`, then the current user's own master public key
   - if `0x02`, then the current device's Ed25519 signing key
 - the second key, as 32 bytes.  The key to use depends on the mode field:
   - if `0x00`, then what the device thinks the other user's master
-    cross-signing public key is
+    public key is
   - if `0x01`, then what the device thinks the other device's Ed25519 signing
     public key is
-  - if `0x02`, then what the device thinks the user's master cross-signing public
-    key is
+  - if `0x02`, then what the device thinks the user's master public key is
 - a random shared secret, as a sequence of bytes.  It is suggested to use a secret
   that is about 8 bytes long.  Note: as we do not share the length of the
   secret, and it is not a fixed size, clients will just use the remainder of
@@ -1221,14 +1223,14 @@ For example, if Alice displays a QR code encoding the following binary data:
 ```
       "MATRIX"    |ver|mode| len   | event ID
  4D 41 54 52 49 58  02  00   00 2D   21 41 42 43 44 ...
-| user's cross-signing key    | other user's cross-signing key | shared secret
-  00 01 02 03 04 05 06 07 ...   10 11 12 13 14 15 16 17 ...      20 21 22 23 24 25 26 27
+| the first key               | the second key              | shared secret
+  00 01 02 03 04 05 06 07 ...   10 11 12 13 14 15 16 17 ...   20 21 22 23 24 25 26 27
 ```
 
-this indicates that Alice is verifying another user (say Bob), in response to
-the request from event "$ABCD...", her cross-signing key is
+Mode `0x00` indicates that Alice is verifying another user (say Bob), in
+response to the request from event "$ABCD...", her master key is
 `0001020304050607...` (which is "AAECAwQFBg..." in base64), she thinks that
-Bob's cross-signing key is `1011121314151617...` (which is "EBESExQVFh..." in
+Bob's master key is `1011121314151617...` (which is "EBESExQVFh..." in
 base64), and the shared secret is `2021222324252627` (which is "ICEiIyQlJic" in
 base64).
 
@@ -1300,8 +1302,8 @@ one of its variants.
 Clients must only store keys in backups after they have ensured that the
 `auth_data` is trusted. This can be done either by:
 
-- checking that it is signed by the user's [master cross-signing
-  key](#cross-signing) or by a verified device belonging to the same user, or
+- checking that it is signed by the user's [master key](#cross-signing)
+  or by a verified device belonging to the same user, or
 - deriving the public key from a private key that it obtained from a trusted
   source. Trusted sources for the private key include the user entering the
   key, retrieving the key stored in [secret storage](#secret-storage), or
@@ -1786,13 +1788,14 @@ a way to identify the server's support for fallback keys.
 
 | Parameter  | Type      | Description                                                                                                                                                      |
 |------------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| changed    | [string]  | List of users who have updated their device identity or cross-signing keys, or who now share an encrypted room with the client since the previous sync response. |
+| changed    | [string]  | List of users who have updated their device identity or their master, self-signing or user-signing keys, or who now share an encrypted room with the client since the previous sync response. |
 | left       | [string]  | List of users with whom we do not share any encrypted rooms anymore since the previous sync response.                                                            |
 
 {{% boxes/note %}}
 For optimal performance, Alice should be added to `changed` in Bob's
-sync only when she updates her devices or cross-signing keys, or when
-Alice and Bob now share a room but didn't share any room previously.
+sync only when she updates her devices or master, self-signing or
+user-signing keys, or when Alice and Bob now share a room but didn't
+share any room previously.
 However, for the sake of simpler logic, a server may add Alice to
 `changed` when Alice and Bob share a new room, even if they previously
 already shared a room.

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

@@ -16,8 +16,8 @@ The four options for the `m.room.history_visibility` event are:
 
 -   `world_readable` - All events while this is the
     `m.room.history_visibility` value may be shared by any participating
-    homeserver with anyone, regardless of whether they have ever joined
-    the room.
+    homeserver with any authenticated user, regardless of whether they have
+    ever joined the room. This includes [guest users](#guest-access).
 -   `shared` - Previous events are always accessible to newly joined
     members. All events in the room are accessible, even those sent when
     the member was not a part of the room.
@@ -44,7 +44,7 @@ setting at that time was more restrictive.
 #### Client behaviour
 
 Clients may want to display a notice that events may be read by
-non-joined people if the history visibility is set to `world_readable`.
+non-joined users if the history visibility is set to `world_readable`.
 
 #### Server behaviour
 

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

@@ -6,7 +6,7 @@ It is sometimes desirable to offer a preview of a room, where a user can
 This can be particularly effective when combined with [Guest Access](#guest-access).
 
 Previews are implemented via the `world_readable` [Room History
-Visibility](#room-history-visibility). setting, along with a special version of the [GET
+Visibility](#room-history-visibility) setting, along with a special version of the [GET
 /events](#get_matrixclientv3events) endpoint.
 
 #### Client behaviour

content/proposals.md

@@ -555,7 +555,7 @@ resolve to the desired MSC, whether it started as an issue or a PR.
 Other metadata:
 
 -   The MSC number is taken from the GitHub Pull Request ID. This is
-    carried for the lifetime of the proposal. These IDs do not necessary
+    carried for the lifetime of the proposal. These IDs do not necessarily
     represent a chronological order.
 -   The GitHub PR title will act as the MSC's title.
 -   Please link to the spec PR (if any) by adding a "PRs: \#1234" line

content/server-server-api.md

@@ -945,6 +945,18 @@ Note that invites are used to indicate that knocks were accepted. As such,
 receiving servers should be prepared to manually link up a previous knock
 to an invite if the invite event does not directly reference the knock.
 
+{{% boxes/note %}}
+{{% added-in v="1.16" %}} `invite_room_state` MUST now have its entries formatted
+according to the room's version (see [room version specification](/rooms)). However,
+servers SHOULD consider their local ecosystems before returning the described
+`400 M_MISSING_PARAM` error code. While migrating, servers SHOULD warn about
+invites which fail the validation rather than error in room versions 1 through 11.
+All invites to other room versions which fail validation SHOULD result in an error.
+
+The specification suggests that servers finish their migration no later than
+January 2026, though servers may extend this as required to support their users.
+{{% /boxes/note %}}
+
 {{% http-api spec="server-server" api="invites-v1" %}}
 
 {{% http-api spec="server-server" api="invites-v2" %}}

data/api/client-server/cross_signing.yaml

@@ -21,16 +21,16 @@ paths:
       x-addedInMatrixVersion: "1.1"
       x-changedInMatrixVersion:
         "1.11": UIA is not always required for this endpoint.
-      summary: Upload cross-signing keys.
+      summary: Upload keys used for cross-signing.
       description: |-
-        Publishes cross-signing keys for the user.
+        Publishes keys used for cross-signing for the user.
 
         This API endpoint uses the [User-Interactive Authentication API](/client-server-api/#user-interactive-authentication-api).
 
         User-Interactive Authentication MUST be performed, except in these cases:
-        - there is no existing cross-signing master key uploaded to the homeserver, OR
-        - there is an existing cross-signing master key and it exactly matches the
-          cross-signing master key provided in the request body. If there are any additional
+        - there is no existing master key uploaded to the homeserver, OR
+        - there is an existing master key and it exactly matches the
+          master key provided in the request body. If there are any additional
           keys provided in the request (self-signing key, user-signing key) they MUST also
           match the existing keys stored on the server. In other words, the request contains
           no new keys.

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

@@ -13,7 +13,7 @@
 # limitations under the License.
 type: object
 title: CrossSigningKey
-description: Cross signing key
+description: Key used for cross signing
 properties:
   user_id:
     type: string

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

@@ -43,7 +43,7 @@ properties:
     example: "All things general"
   world_readable:
     type: boolean
-    description: Whether the room may be viewed by guest users without joining.
+    description: Whether the room may be viewed by users without joining.
     example: false
   guest_can_join:
     type: boolean

data/api/client-server/keys.yaml

@@ -219,7 +219,7 @@ paths:
                     x-addedInMatrixVersion: "1.1"
                     type: object
                     description: |-
-                      Information on the master cross-signing keys of the queried users.
+                      Information on the master keys of the queried users.
                       A map from user ID, to master key information.  For each key, the
                       information returned will be the same as uploaded via
                       `/keys/device_signing/upload`, along with the signatures

data/api/client-server/profile.yaml

@@ -19,7 +19,7 @@ paths:
   "/profile/{userId}/{keyName}":
     put:
       x-changedInMatrixVersion:
-        "1.16": This endpoint now accepts a variable `keyName` parameter. Previously only `displayname` and `avatar_url` were accepted.
+        "1.16": This endpoint now accepts a variable `keyName` parameter and `m.tz` was added as a defined key. Previously only `displayname` and `avatar_url` were accepted.
       summary: Set a profile field for a user.
       description: |-
         Set or update a profile field for a user. Must be authenticated with an
@@ -44,13 +44,13 @@ paths:
         - in: path
           name: keyName
           description: The name of the profile field to set. This MUST be either
-            `avatar_url`, `displayname`, or a custom field following the
+            `avatar_url`, `displayname`, `m.tz`, or a custom field following the
             [Common Namespaced Identifier Grammar](/appendices/#common-namespaced-identifier-grammar).
           required: true
           example: "displayname"
           schema:
             type: string
-            pattern: '^(avatar_url|displayname|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
+            pattern: '^(avatar_url|displayname|m\.tz|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
       requestBody:
         description: A JSON object containing the property whose name matches
           the `keyName` specified in the URL. See `additionalProperties` for
@@ -69,6 +69,10 @@ paths:
                 
                 For `displayname`, the value MUST be a string.
                 
+                For `m.tz`, the value MUST be a valid identifier from the  [IANA Time Zone Database](https://www.iana.org/time-zones).
+                Servers MAY choose to validate the value. Clients MUST expect unknown or invalid
+                values.
+
                 For custom keys, any JSON type is allowed. Servers MAY not validate
                 these values, but clients SHOULD follow the format defined for that key.
               additionalProperties: true
@@ -137,7 +141,7 @@ paths:
         - User data
     get:
       x-changedInMatrixVersion:
-        "1.16": This endpoint now accepts a variable `keyName` parameter. Previously only `displayname` and `avatar_url` were accepted.
+        "1.16": This endpoint now accepts a variable `keyName` parameter and `m.tz` was added as a defined key. Previously only `displayname` and `avatar_url` were accepted.
       summary: Get a profile field for a user.
       description: Get the value of a profile field for a user.
       operationId: getProfileField
@@ -156,7 +160,7 @@ paths:
           example: "displayname"
           schema:
             type: string
-            pattern: '^(avatar_url|displayname|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
+            pattern: '^(avatar_url|displayname|m\.tz|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
       responses:
         "200":
           description: The profile field value was retrieved.
@@ -214,7 +218,7 @@ paths:
           example: "displayname"
           schema:
             type: string
-            pattern: '^(avatar_url|displayname|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
+            pattern: '^(avatar_url|displayname|m\.tz|[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)+)$'
       responses:
         "200":
           description: The profile field was deleted or it doesn't exist.
@@ -293,6 +297,10 @@ paths:
                     type: string
                     description: The user's display name if they have set one, otherwise not
                       present.
+                  m.tz:
+                    x-addedInMatrixVersion: "1.16"
+                    type: string
+                    description: The user's time zone.
                 additionalProperties:
                   x-addedInMatrixVersion: "1.16"
                   description: Additional profile fields.
@@ -302,6 +310,7 @@ paths:
                     {
                       "avatar_url": "mxc://matrix.org/SDGdghriugerRg",
                       "displayname": "Alice Margatroid",
+                      "m.tz": "Europe/London",
                       "m.example_field": "custom_value",
                     }
         "403":

data/api/server-server/definitions/event-schemas/m.signing_key_update.yaml

@@ -17,7 +17,7 @@ type: object
 title: m.signing_key_update
 description: |-
   An EDU that lets servers push details to each other when one of their users
-  updates their cross-signing keys.
+  updates their keys used for cross-signing.
 allOf:
   - $ref: ../edu.yaml
   - type: object
@@ -34,7 +34,7 @@ allOf:
         properties:
           user_id:
             type: string
-            description: The user ID whose cross-signing keys have changed.
+            description: The user ID whose keys have changed.
             example: "@alice:example.com"
           master_key:
             allOf:

data/api/server-server/examples/invite_or_knock_state.json

@@ -0,0 +1,9 @@
+[
+  {"$ref": "./minimal_pdu.json"},
+  {
+    "type": "m.room.create",
+    "content": {
+      "see_room_version_spec": "The event format changes depending on the room version."
+    }
+  }
+]

data/api/server-server/invites-v1.yaml

@@ -71,13 +71,32 @@ paths:
                       properties:
                         invite_room_state:
                           type: array
+                          x-changedInMatrixVersion:
+                            "1.16": |
+                              `m.room.create` and format requirements were added.
                           description: |-
-                            An optional list of [stripped state events](/client-server-api/#stripped-state)
-                            to help the receiver of the invite identify the room.
+                            A list of state events to help the receiver of the invite identify the room.
+                            Translated as [stripped state events](/client-server-api/#stripped-state)
+                            over the Client-Server API.
+
+                            MUST contain the `m.room.create` event for the room. All events listed
+                            MUST additionally be formatted according to the room version specification.
+
+                            Servers might need to apply validation to the `invite_room_state` depending
+                            on room version. See the `400 M_MISSING_PARAM` error definition for more
+                            information.
+
+                            Note that events have a different format depending on the room
+                            version - check the [room version specification](/rooms) for
+                            precise event formats.
                           items:
-                            $ref: ../../event-schemas/schema/core-event-schema/stripped_state.yaml
-                          example:
-                            $ref: ../../event-schemas/examples/invite_room_state.json
+                            type: object
+                            title: PDU
+                            properties: {}
+                            description: |-
+                              Note that events have a different format depending on the room
+                              version - check the [room version specification](/rooms) for
+                              precise event formats.
               type: object
         required: true
       responses:
@@ -118,24 +137,7 @@ paths:
                         "origin_server_ts": 1549041175876,
                         "sender": "@someone:example.org",
                         "unsigned": {
-                          "invite_room_state": [
-                            {
-                              "type": "m.room.name",
-                              "sender": "@bob:example.org",
-                              "state_key": "",
-                              "content": {
-                                "name": "Example Room"
-                              }
-                            },
-                            {
-                              "type": "m.room.join_rules",
-                              "sender": "@bob:example.org",
-                              "state_key": "",
-                              "content": {
-                                "join_rule": "invite"
-                              }
-                            }
-                          ]
+                          "invite_room_state": {"$ref": "./examples/invite_or_knock_state.json"}
                         },
                         "content": {
                           "membership": "invite"
@@ -168,6 +170,35 @@ paths:
                     "errcode": "M_FORBIDDEN",
                     "error": "User cannot invite the target user."
                   }
+        "400":
+          description: |-
+            The `M_MISSING_PARAM` error code is used to indicate one or more of
+            the following:
+
+            * The `m.room.create` event is missing from `invite_room_state`.
+            * One or more entries in `invite_room_state` are not formatted according
+              to the room's version.
+            * One or more events fails a [signature check](/server-server-api/#validating-hashes-and-signatures-on-received-events).
+            * One or more events does not reside in the same room as the invite.
+              Note: Some room versions may require calculating the room ID for an
+              event rather than relying on the presence of `room_id`.
+
+            Servers MAY apply the validation above to room versions 1 through 11,
+            and SHOULD apply the validation above to all other room versions.
+
+            If `M_MISSING_PARAM` is returned and the request is associated with a
+            Client-Server API request, the Client-Server API request SHOULD fail
+            with a 5xx error rather than being passed through.
+          content:
+            application/json:
+              schema:
+                $ref: ../client-server/definitions/errors/error.yaml
+              examples:
+                response:
+                  value: {
+                    "errcode": "M_MISSING_PARAM",
+                    "error": "Create event not among invite state entries."
+                  }
 servers:
   - url: "{protocol}://{hostname}{basePath}"
     variables:

data/api/server-server/invites-v2.yaml

@@ -72,13 +72,32 @@ paths:
                   $ref: definitions/invite_event.yaml
                 invite_room_state:
                   type: array
+                  x-changedInMatrixVersion:
+                    "1.16": |
+                      `m.room.create` and format requirements were added.
                   description: |-
-                    An optional list of [stripped state events](/client-server-api/#stripped-state)
-                    to help the receiver of the invite identify the room.
+                    A list of state events to help the receiver of the invite identify the room.
+                    Translated as [stripped state events](/client-server-api/#stripped-state)
+                    over the Client-Server API.
+
+                    MUST contain the `m.room.create` event for the room. All events listed
+                    MUST additionally be formatted according to the room version specification.
+
+                    Servers might need to apply validation to the `invite_room_state` depending
+                    on room version. See the `400 M_MISSING_PARAM` error definition for more
+                    information.
+
+                    Note that events have a different format depending on the room
+                    version - check the [room version specification](/rooms) for
+                    precise event formats.
                   items:
-                    $ref: ../../event-schemas/schema/core-event-schema/stripped_state.yaml
-                  example:
-                    $ref: ../../event-schemas/examples/invite_room_state.json
+                    type: object
+                    title: PDU
+                    properties: {}
+                    description: |-
+                      Note that events have a different format depending on the room
+                      version - check the [room version specification](/rooms) for
+                      precise event formats.
               required:
                 - room_version
                 - event
@@ -111,24 +130,7 @@ paths:
                       "origin_server_ts": 1549041175876,
                       "sender": "@someone:example.org",
                       "unsigned": {
-                        "invite_room_state": [
-                          {
-                            "type": "m.room.name",
-                            "sender": "@bob:example.org",
-                            "state_key": "",
-                            "content": {
-                              "name": "Example Room"
-                            }
-                          },
-                          {
-                            "type": "m.room.join_rules",
-                            "sender": "@bob:example.org",
-                            "state_key": "",
-                            "content": {
-                              "join_rule": "invite"
-                            }
-                          }
-                        ]
+                        "invite_room_state": {"$ref": "./examples/invite_or_knock_state.json"}
                       },
                       "content": {
                         "membership": "invite"
@@ -151,6 +153,24 @@ paths:
 
             The error should be passed through to clients so that they
             may give better feedback to users.
+
+            The `M_MISSING_PARAM` error code is used to indicate one or more of
+            the following:
+
+            * The `m.room.create` event is missing from `invite_room_state`.
+            * One or more entries in `invite_room_state` are not formatted according
+              to the room's version.
+            * One or more events fails a [signature check](/server-server-api/#validating-hashes-and-signatures-on-received-events).
+            * One or more events does not reside in the same room as the invite.
+              Note: Some room versions may require calculating the room ID for an
+              event rather than relying on the presence of `room_id`.
+
+            Servers MAY apply the validation above to room versions 1 through 11,
+            and SHOULD apply the validation above to all other room versions.
+
+            If `M_MISSING_PARAM` is returned and the request is associated with a
+            Client-Server API request, the Client-Server API request SHOULD fail
+            with a 5xx error rather than being passed through.
           content:
             application/json:
               schema:

data/api/server-server/knocks.yaml

@@ -293,19 +293,41 @@ paths:
                   knock_room_state:
                     type: array
                     items:
-                      $ref: ../../event-schemas/schema/core-event-schema/stripped_state.yaml
+                      type: object
+                      title: PDU
+                      properties: {}
+                      description: |-
+                        Note that events have a different format depending on the room
+                        version - check the [room version specification](/rooms) for
+                        precise event formats.
+                    x-changedInMatrixVersion:
+                      "1.16": |
+                        `m.room.create` and format requirements were added.
                     description: |-
-                      A list of [stripped state events](/client-server-api/#stripped-state)
-                      to help the initiator of the knock identify the room.
+                      A list of state events to help the initiator of the knock identify
+                      the room. Translated as [stripped state events](/client-server-api/#stripped-state)
+                      over the Client-Server API.
+
+                      MUST contain the `m.room.create` event for the room. All events
+                      listed MUST additionally be formatted according to the room
+                      version specification.
+
+                      Entries which are [improperly signed](/server-server-api/#validating-hashes-and-signatures-on-received-events)
+                      or formatted SHOULD be removed by the server prior to supplying
+                      them over the Client-Server API.
+
+                      Note that events have a different format depending on the room
+                      version - check the [room version specification](/rooms) for
+                      precise event formats.
                     example:
-                      $ref: ../../event-schemas/examples/knock_room_state.json
+                      "$ref": "./examples/invite_or_knock_state.json"
                 required:
                   - knock_room_state
               examples:
                 response:
                   value: {
                     "knock_room_state": {
-                      "$ref": "../../event-schemas/examples/knock_room_state.json"
+                      "$ref": "./examples/invite_or_knock_state.json"
                     }
                   }
         "403":

data/api/server-server/user_devices.yaml

@@ -79,7 +79,7 @@ paths:
                         - keys
                   master_key:
                     type: object
-                    description: The user\'s master cross-signing key.
+                    description: The user\'s master key.
                     allOf:
                       - $ref: ../client-server/definitions/cross_signing_key.yaml
                       - example:

data/api/server-server/user_keys.yaml

@@ -194,7 +194,7 @@ paths:
                     x-addedInMatrixVersion: "1.1"
                     type: object
                     description: |-
-                      Information on the master cross-signing keys of the queried users.
+                      Information on the master keys of the queried users.
                       A map from user ID, to master key information.  For each key, the
                       information returned will be the same as uploaded via
                       `/keys/device_signing/upload`, along with the signatures

data/event-schemas/schema/m.room.member.yaml

@@ -137,6 +137,9 @@ properties:
       - type: object
         properties:
           invite_room_state:
+            x-changedInMatrixVersion:
+              "1.16": |
+                `m.room.create` was made a required event type for stripped state.
             description: |-
               A subset of the state of the room at the time of the invite, if `membership` is `invite`.
               Note that this state is informational, and SHOULD NOT be trusted; once the client has
@@ -145,16 +148,21 @@ properties:
               they SHOULD behave properly (with possibly a degraded but not a broken experience) in
               the absence of any particular events here. If they are set on the room, at least the
               state for `m.room.avatar`, `m.room.canonical_alias`, `m.room.join_rules`, and `m.room.name`
-              SHOULD be included.
+              SHOULD be included. The `m.room.create` event MUST be included, though MAY be missing if
+              the server hasn't updated to support the Matrix 1.16 specification.
             items:
               $ref: "core-event-schema/stripped_state.yaml"
             type: array
           knock_room_state:
+            x-changedInMatrixVersion:
+              "1.16": |
+                `m.room.create` was made a required event type for stripped state.
             description: |-
               A subset of the state of the room at the time of the knock, if `membership` is `knock`.
               This has the same restrictions as `invite_room_state`. If they are set on the room, at least
               the state for `m.room.avatar`, `m.room.canonical_alias`, `m.room.join_rules`, `m.room.name`,
-              and `m.room.encryption` SHOULD be included.
+              and `m.room.encryption` SHOULD be included. The `m.room.create` event MUST be included,
+              though MAY be missing if the server hasn't updated to support the Matrix 1.16 specification.
             items:
               $ref: "core-event-schema/stripped_state.yaml"
             type: array