diff --git a/changelogs/application_service/newsfragments/1744.clarification b/changelogs/application_service/newsfragments/1744.clarification
new file mode 100644
index 00000000..908c48ab
--- /dev/null
+++ b/changelogs/application_service/newsfragments/1744.clarification
@@ -0,0 +1 @@
+Clarify that the `/login` and `/register` endpoints should fail when using the `m.login.application_service` login type without a valid `as_token`.
diff --git a/changelogs/client_server/newsfragments/1735.feature b/changelogs/client_server/newsfragments/1735.feature
new file mode 100644
index 00000000..1d764142
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1735.feature
@@ -0,0 +1 @@
+Add support for multi-stream VoIP, as per [MSC3077](https://github.com/matrix-org/matrix-spec-proposals/pull/3077).
\ No newline at end of file
diff --git a/changelogs/client_server/newsfragments/1748.clarification b/changelogs/client_server/newsfragments/1748.clarification
new file mode 100644
index 00000000..3ccb2333
--- /dev/null
+++ b/changelogs/client_server/newsfragments/1748.clarification
@@ -0,0 +1 @@
+Fix various typos throughout the specification.
diff --git a/changelogs/internal/newsfragments/1718.clarification b/changelogs/internal/newsfragments/1718.clarification
new file mode 100644
index 00000000..5b89875a
--- /dev/null
+++ b/changelogs/internal/newsfragments/1718.clarification
@@ -0,0 +1 @@
+Add some clarifications around implementation requirements for MSCs
diff --git a/changelogs/internal/newsfragments/1745.clarification b/changelogs/internal/newsfragments/1745.clarification
new file mode 100644
index 00000000..acd85892
--- /dev/null
+++ b/changelogs/internal/newsfragments/1745.clarification
@@ -0,0 +1 @@
+Factor out all the common parameters of the various `/relations` apis.
diff --git a/changelogs/internal/newsfragments/1751.clarification b/changelogs/internal/newsfragments/1751.clarification
new file mode 100644
index 00000000..50c50693
--- /dev/null
+++ b/changelogs/internal/newsfragments/1751.clarification
@@ -0,0 +1 @@
+Add support for `$ref` URIs containing fragments in OpenAPI definitions and JSON schemas.
diff --git a/content/application-service-api.md b/content/application-service-api.md
index f3db06cf..a7526e64 100644
--- a/content/application-service-api.md
+++ b/content/application-service-api.md
@@ -436,6 +436,12 @@ an application service-defined namespace will receive the same
 `M_EXCLUSIVE` error code, but only if the application service has
 defined the namespace as `exclusive`.
 
+If `/register` or `/login` is called with the `m.login.application_service`
+login type, but without a valid `as_token`, the endpoints will return an error
+with the `M_MISSING_TOKEN` or `M_UNKNOWN_TOKEN` error code and 401 as the HTTP
+status code. This is the same behavior as invalid auth in the client-server API
+(see [Using access tokens](/client-server-api/#using-access-tokens)).
+
 #### Pinging
 
 {{% added-in v="1.7" %}}
diff --git a/content/client-server-api/modules/sso_login.md b/content/client-server-api/modules/sso_login.md
index 95a3e23a..1a46c84d 100644
--- a/content/client-server-api/modules/sso_login.md
+++ b/content/client-server-api/modules/sso_login.md
@@ -10,7 +10,7 @@ This module allows a Matrix homeserver to delegate user authentication
 to an external authentication server supporting one of these protocols.
 In this process, there are three systems involved:
 
--   A Matrix client, using the APIs defined this specification, which
+-   A Matrix client, using the APIs defined in this specification, which
     is seeking to authenticate a user to a Matrix homeserver.
 -   A Matrix homeserver, implementing the APIs defined in this
     specification, but which is delegating user authentication to the
diff --git a/content/client-server-api/modules/voip_events.md b/content/client-server-api/modules/voip_events.md
index 102e3dcd..4df0ba13 100644
--- a/content/client-server-api/modules/voip_events.md
+++ b/content/client-server-api/modules/voip_events.md
@@ -171,18 +171,31 @@ In response to an incoming invite, a client may do one of several things:
 
 ##### Streams
 
-Clients are expected to send one stream with one track of kind `audio` (creating a
-voice call). They can optionally send a second track in the same stream of kind
-`video` (creating a video call).
+Clients may send more than one stream in a VoIP call. The streams should be
+differentiated by including metadata in the [`m.call.invite`](/client-server-api/#mcallinvite),
+[`m.call.answer`](/client-server-api/#mcallanswer) and [`m.call.negotiate`](/client-server-api/#mcallnegotiate)
+events, using the `sdp_stream_metadata` property.
 
-Clients implementing this specification use the first stream and will ignore
-any streamless tracks. Note that in the JavaScript WebRTC API, this means
-`addTrack()` must be passed two parameters: a track and a stream, not just a
-track, and in a video call the stream must be the same for both audio and video
-track.
+`sdp_stream_metadata` maps from the `id` of a stream in the session description, 
+to metadata about that stream. Currently only one property is defined for the
+metadata. This is `purpose`, which should be a string indicating the purpose of
+the stream. The following `purpose`s are defined:
 
-A client may send other streams and tracks but the behaviour of the other party
-with respect to presenting such streams and tracks is undefined.
+*  `m.usermedia` - stream that contains the webcam and/or microphone tracks
+*  `m.screenshare` - stream with the screen-sharing tracks
+
+If `sdp_stream_metadata` is present and an incoming stream is not listed in it,
+the stream should be ignored. If a stream has a `purpose` of an unknown type, it
+should also be ignored.
+
+For backwards compatibility, if `sdp_stream_metadata` is not present in the
+initial [`m.call.invite`](/client-server-api/#mcallinvite) or [`m.call.answer`](/client-server-api/#mcallanswer)
+event sent by the other party, the client should assume that this property is
+not supported by the other party. It means that multiple streams cannot be
+differentiated: the client should only use the first incoming stream and
+shouldn't send more than one stream.
+
+Clients implementing this specification should ignore any streamless tracks.
 
 ##### Invitees
 The `invitee` field should be added whenever the call is intended for one
diff --git a/content/proposals.md b/content/proposals.md
index dac520c9..b58a98be 100644
--- a/content/proposals.md
+++ b/content/proposals.md
@@ -380,9 +380,18 @@ As part of the proposal process the Spec Core Team will require evidence
 of the MSC working in order for it to move into FCP. This can usually be
 a branch/pull request to whichever implementation of choice that proves
 the MSC works in practice, though in some cases the MSC itself will be
-small enough to be considered proven. Where it's unclear if an MSC will
-require an implementation proof, ask in
-[\#matrix-spec:matrix.org](https://matrix.to/#/#matrix-spec:matrix.org).
+small enough to be considered proven. Implementations do not need to be
+merged or released, but must be of sufficient quality to show that the
+MSC works. Where it's unclear if an MSC will require an implementation
+proof, ask in [\#matrix-spec:matrix.org](https://matrix.to/#/#matrix-spec:matrix.org).
+Proposals may require both server-side and client-side implementations.
+
+Proposals that have not yet been implemented will have the
+`needs-implementation` label. After an implementation has been made, add a
+comment in the GitHub issue indicating so. After an implementation has been
+made, we will check it to verify that it implements the MSC. Proposals that
+have implementations that have not yet been checked will have the
+`implementation-needs-checking` label.
 
 ### Early release of an MSC/idea
 
diff --git a/data/api/client-server/relations.yaml b/data/api/client-server/relations.yaml
index 255a8061..c43ea2f3 100644
--- a/data/api/client-server/relations.yaml
+++ b/data/api/client-server/relations.yaml
@@ -33,89 +33,13 @@ paths:
       security:
         - accessToken: []
       parameters:
-        - in: path
-          name: roomId
-          description: The ID of the room containing the parent event.
-          required: true
-          example: "!636q39766251:matrix.org"
-          schema:
-            type: string
-        - in: path
-          name: eventId
-          description: The ID of the parent event whose child events are to be returned.
-          required: true
-          example: $asfDuShaf7Gafaw
-          schema:
-            type: string
-        - in: query
-          name: from
-          description: |-
-            The pagination token to start returning results from. If not supplied, results
-            start at the most recent topological event known to the server.
-
-            Can be a `next_batch` or `prev_batch` token from a previous call, or a returned
-            `start` token from [`/messages`](/client-server-api/#get_matrixclientv3roomsroomidmessages),
-            or a `next_batch` token from [`/sync`](/client-server-api/#get_matrixclientv3sync).
-          required: false
-          example: page2_token
-          schema:
-            type: string
-        - in: query
-          name: to
-          description: |-
-            The pagination token to stop returning results at. If not supplied, results
-            continue up to `limit` or until there are no more events.
-
-            Like `from`, this can be a previous token from a prior call to this endpoint
-            or from `/messages` or `/sync`.
-          required: false
-          example: page3_token
-          schema:
-            type: string
-        - in: query
-          name: limit
-          description: |-
-            The maximum number of results to return in a single `chunk`. The server can
-            and should apply a maximum value to this parameter to avoid large responses.
-
-            Similarly, the server should apply a default value when not supplied.
-          required: false
-          example: 20
-          schema:
-            type: integer
-        - in: query
-          name: dir
-          x-addedInMatrixVersion: "1.4"
-          description: |-
-            Optional (default `b`) direction to return events from. If this is set to `f`, events
-            will be returned in chronological order starting at `from`. If it
-            is set to `b`, events will be returned in *reverse* chronological
-            order, again starting at `from`.
-          schema:
-            type: string
-            enum:
-              - b
-              - f
-        - in: query
-          name: recurse
-          x-addedInMatrixVersion: "1.10"
-          required: false
-          description: |-
-            Whether to additionally include events which only relate indirectly to the
-            given event, ie. events related to the root events via one or more direct relationships.
-
-            If set to `false`, only events which have direct a relation with the given
-            event will be included.
-
-            If set to `true`, all events which relate to the given event, or relate to
-            events that relate to the given event, will be included.
-
-            It is recommended that at least 3 levels of relationships are traversed.
-            Implementations may perform more but should be careful to not infinitely recurse.
-
-            The default value is `false`.
-          schema:
-            type: boolean
+        - $ref: '#/components/parameters/roomId'
+        - $ref: '#/components/parameters/eventId'
+        - $ref: '#/components/parameters/from'
+        - $ref: '#/components/parameters/to'
+        - $ref: '#/components/parameters/limit'
+        - $ref: '#/components/parameters/dir'
+        - $ref: '#/components/parameters/recurse'
       responses:
         # note: this endpoint deliberately does not support rate limiting, therefore a
         # 429 error response is not included.
@@ -127,66 +51,24 @@ paths:
           content:
             application/json:
               schema:
-                type: object
-                properties:
-                  chunk:
-                    title: ChildEventsChunk
-                    type: array
-                    description: The child events of the requested event, ordered topologically
-                      most-recent first.
-                    items:
-                      allOf:
-                        - $ref: definitions/client_event.yaml
-                  next_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means there are no more results to fetch and the client should stop paginating.
-                  prev_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means this is the start of the result set, i.e. this is the first batch/page.
-                  recursion_depth:
-                    type: integer
-                    description: |-
-                      If the `recurse` parameter was supplied by the client, this response field is
-                      mandatory and gives the actual depth to which the server recursed. The the client
-                      did not specify the `recurse` parameter, this field must be absent.
-                required:
-                  - chunk
+                allOf:
+                  - $ref: '#/components/schemas/response'
+                  - type: object
+                    properties:
+                      chunk:
+                        title: ChildEventsChunk
+                        type: array
+                        description: The child events of the requested event, ordered topologically
+                          most-recent first.
+                        items:
+                          $ref: definitions/client_event.yaml
+                    required:
+                      - chunk
               examples:
                 response:
-                  value: {
-                    "chunk": [
-                      {
-                        "room_id": "!636q39766251:matrix.org",
-                        "$ref": "../../event-schemas/examples/m.room.message$m.text.yaml",
-                        "content": {
-                          "m.relates_to": {
-                            "rel_type": "org.example.my_relation",
-                            "event_id": "$asfDuShaf7Gafaw"
-                          }
-                        }
-                      }
-                    ],
-                    "next_batch": "page2_token",
-                    "prev_batch": "page1_token"
-                  }
+                  $ref: '#/components/examples/response'
         "404":
-          description: |-
-            The parent event was not found or the user does not have permission to read
-            this event (it might be contained in history that is not accessible to the user).
-          content:
-            application/json:
-              schema:
-                $ref: definitions/errors/error.yaml
-              examples:
-                response:
-                  value: {
-                    "errcode": "M_NOT_FOUND",
-                    "error": "Event not found."
-                  }
+          $ref: '#/components/responses/404'
       tags:
         - Event relationships
   # The same as above, with added `/{relType}`
@@ -208,97 +90,14 @@ paths:
       security:
         - accessToken: []
       parameters:
-        - in: path
-          name: roomId
-          description: The ID of the room containing the parent event.
-          required: true
-          example: "!636q39766251:matrix.org"
-          schema:
-            type: string
-        - in: path
-          name: eventId
-          description: The ID of the parent event whose child events are to be returned.
-          required: true
-          example: $asfDuShaf7Gafaw
-          schema:
-            type: string
-        - in: path
-          name: relType
-          description: The [relationship type](/client-server-api/#relationship-types) to
-            search for.
-          required: true
-          example: org.example.my_relation
-          schema:
-            type: string
-        - in: query
-          name: from
-          description: |-
-            The pagination token to start returning results from. If not supplied, results
-            start at the most recent topological event known to the server.
-
-            Can be a `next_batch` or `prev_batch` token from a previous call, or a returned
-            `start` token from [`/messages`](/client-server-api/#get_matrixclientv3roomsroomidmessages),
-            or a `next_batch` token from [`/sync`](/client-server-api/#get_matrixclientv3sync).
-          required: false
-          example: page2_token
-          schema:
-            type: string
-        - in: query
-          name: to
-          description: |-
-            The pagination token to stop returning results at. If not supplied, results
-            continue up to `limit` or until there are no more events.
-
-            Like `from`, this can be a previous token from a prior call to this endpoint
-            or from `/messages` or `/sync`.
-          required: false
-          example: page3_token
-          schema:
-            type: string
-        - in: query
-          name: limit
-          description: |-
-            The maximum number of results to return in a single `chunk`. The server can
-            and should apply a maximum value to this parameter to avoid large responses.
-
-            Similarly, the server should apply a default value when not supplied.
-          required: false
-          example: 20
-          schema:
-            type: integer
-        - in: query
-          name: dir
-          x-addedInMatrixVersion: "1.4"
-          description: |-
-            Optional (default `b`) direction to return events from. If this is set to `f`, events
-            will be returned in chronological order starting at `from`. If it
-            is set to `b`, events will be returned in *reverse* chronological
-            order, again starting at `from`.
-          schema:
-            type: string
-            enum:
-              - b
-              - f
-        - in: query
-          name: recurse
-          x-addedInMatrixVersion: "1.10"
-          required: false
-          description: |-
-            Whether to additionally include events which only relate indirectly to the
-            given event, ie. events related to the root events via one or more direct relationships.
-
-            If set to `false`, only events which have direct a relation with the given
-            event will be included.
-
-            If set to `true`, all events which relate to the given event, or relate to
-            events that relate to the given event, will be included.
-
-            It is recommended that at least 3 levels of relationships are traversed.
-            Implementations may perform more but should be careful to not infinitely recurse.
-
-            The default value is `false`.
-          schema:
-            type: boolean
+        - $ref: '#/components/parameters/roomId'
+        - $ref: '#/components/parameters/eventId'
+        - $ref: '#/components/parameters/relType'
+        - $ref: '#/components/parameters/from'
+        - $ref: '#/components/parameters/to'
+        - $ref: '#/components/parameters/limit'
+        - $ref: '#/components/parameters/dir'
+        - $ref: '#/components/parameters/recurse'
       responses:
         # note: this endpoint deliberately does not support rate limiting, therefore a
         # 429 error response is not included.
@@ -310,68 +109,26 @@ paths:
           content:
             application/json:
               schema:
-                type: object
-                properties:
-                  chunk:
-                    title: ChildEventsChunk
-                    type: array
-                    description: |-
-                      The child events of the requested event, ordered topologically
-                      most-recent first. The events returned will match the `relType`
-                      supplied in the URL.
-                    items:
-                      allOf:
-                        - $ref: definitions/client_event.yaml
-                  next_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means there are no more results to fetch and the client should stop paginating.
-                  prev_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means this is the start of the result set, i.e. this is the first batch/page.
-                  recursion_depth:
-                    type: integer
-                    description: |-
-                      If the `recurse` parameter was supplied by the client, this response field is
-                      mandatory and gives the actual depth to which the server recursed. The the client
-                      did not specify the `recurse` parameter, this field must be absent.
-                required:
-                  - chunk
+                allOf:
+                  - $ref: '#/components/schemas/response'
+                  - type: object
+                    properties:
+                      chunk:
+                        title: ChildEventsChunk
+                        type: array
+                        description: |-
+                          The child events of the requested event, ordered topologically
+                          most-recent first. The events returned will match the `relType`
+                          supplied in the URL.
+                        items:
+                          $ref: definitions/client_event.yaml
+                    required:
+                      - chunk
               examples:
                 response:
-                  value: {
-                    "chunk": [
-                      {
-                        "room_id": "!636q39766251:matrix.org",
-                        "$ref": "../../event-schemas/examples/m.room.message$m.text.yaml",
-                        "content": {
-                          "m.relates_to": {
-                            "rel_type": "org.example.my_relation",
-                            "event_id": "$asfDuShaf7Gafaw"
-                          }
-                        }
-                      }
-                    ],
-                    "next_batch": "page2_token",
-                    "prev_batch": "page1_token"
-                  }
+                  $ref: '#/components/examples/response'
         "404":
-          description: |-
-            The parent event was not found or the user does not have permission to read
-            this event (it might be contained in history that is not accessible to the user).
-          content:
-            application/json:
-              schema:
-                $ref: definitions/errors/error.yaml
-              examples:
-                response:
-                  value: {
-                    "errcode": "M_NOT_FOUND",
-                    "error": "Event not found."
-                  }
+          $ref: '#/components/responses/404'
       tags:
         - Event relationships
   # The same as above, with added `/{eventType}`
@@ -394,28 +151,9 @@ paths:
       security:
         - accessToken: []
       parameters:
-        - in: path
-          name: roomId
-          description: The ID of the room containing the parent event.
-          required: true
-          example: "!636q39766251:matrix.org"
-          schema:
-            type: string
-        - in: path
-          name: eventId
-          description: The ID of the parent event whose child events are to be returned.
-          required: true
-          example: $asfDuShaf7Gafaw
-          schema:
-            type: string
-        - in: path
-          name: relType
-          description: The [relationship type](/client-server-api/#relationship-types) to
-            search for.
-          required: true
-          example: org.example.my_relation
-          schema:
-            type: string
+        - $ref: '#/components/parameters/roomId'
+        - $ref: '#/components/parameters/eventId'
+        - $ref: '#/components/parameters/relType'
         - in: path
           name: eventType
           description: |-
@@ -427,75 +165,11 @@ paths:
           example: m.room.message
           schema:
             type: string
-        - in: query
-          name: from
-          description: |-
-            The pagination token to start returning results from. If not supplied, results
-            start at the most recent topological event known to the server.
-
-            Can be a `next_batch` or `prev_batch` token from a previous call, or a returned
-            `start` token from [`/messages`](/client-server-api/#get_matrixclientv3roomsroomidmessages),
-            or a `next_batch` token from [`/sync`](/client-server-api/#get_matrixclientv3sync).
-          required: false
-          example: page2_token
-          schema:
-            type: string
-        - in: query
-          name: to
-          description: |-
-            The pagination token to stop returning results at. If not supplied, results
-            continue up to `limit` or until there are no more events.
-
-            Like `from`, this can be a previous token from a prior call to this endpoint
-            or from `/messages` or `/sync`.
-          required: false
-          example: page3_token
-          schema:
-            type: string
-        - in: query
-          name: limit
-          description: |-
-            The maximum number of results to return in a single `chunk`. The server can
-            and should apply a maximum value to this parameter to avoid large responses.
-
-            Similarly, the server should apply a default value when not supplied.
-          required: false
-          example: 20
-          schema:
-            type: integer
-        - in: query
-          name: dir
-          x-addedInMatrixVersion: "1.4"
-          description: |-
-            Optional (default `b`) direction to return events from. If this is set to `f`, events
-            will be returned in chronological order starting at `from`. If it
-            is set to `b`, events will be returned in *reverse* chronological
-            order, again starting at `from`.
-          schema:
-            type: string
-            enum:
-              - b
-              - f
-        - in: query
-          name: recurse
-          x-addedInMatrixVersion: "1.10"
-          required: false
-          description: |-
-            Whether to additionally include events which only relate indirectly to the
-            given event, ie. events related to the root events via one or more direct relationships.
-
-            If set to `false`, only events which have direct a relation with the given
-            event will be included.
-
-            If set to `true`, all events which relate to the given event, or relate to
-            events that relate to the given event, will be included.
-
-            It is recommended that at least 3 levels of relationships are traversed.
-            Implementations may perform more but should be careful to not infinitely recurse.
-
-            The default value is `false`.
-          schema:
-            type: boolean
+        - $ref: '#/components/parameters/from'
+        - $ref: '#/components/parameters/to'
+        - $ref: '#/components/parameters/limit'
+        - $ref: '#/components/parameters/dir'
+        - $ref: '#/components/parameters/recurse'
       responses:
         # note: this endpoint deliberately does not support rate limiting, therefore a
         # 429 error response is not included.
@@ -507,68 +181,26 @@ paths:
           content:
             application/json:
               schema:
-                type: object
-                properties:
-                  chunk:
-                    title: ChildEventsChunk
-                    type: array
-                    description: |-
-                      The child events of the requested event, ordered topologically most-recent
-                      first. The events returned will match the `relType` and `eventType` supplied
-                      in the URL.
-                    items:
-                      allOf:
-                        - $ref: definitions/client_event.yaml
-                  next_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means there are no more results to fetch and the client should stop paginating.
-                  prev_batch:
-                    type: string
-                    description: |-
-                      An opaque string representing a pagination token. The absence of this token
-                      means this is the start of the result set, i.e. this is the first batch/page.
-                  recursion_depth:
-                    type: integer
-                    description: |-
-                      If the `recurse` parameter was supplied by the client, this response field is
-                      mandatory and gives the actual depth to which the server recursed. The the client
-                      did not specify the `recurse` parameter, this field must be absent.
-                required:
-                  - chunk
+                allOf:
+                  - $ref: '#/components/schemas/response'
+                  - type: object
+                    properties:
+                      chunk:
+                        title: ChildEventsChunk
+                        type: array
+                        description: |-
+                          The child events of the requested event, ordered topologically most-recent
+                          first. The events returned will match the `relType` and `eventType` supplied
+                          in the URL.
+                        items:
+                          $ref: definitions/client_event.yaml
+                    required:
+                      - chunk
               examples:
                 response:
-                  value: {
-                    "chunk": [
-                      {
-                        "room_id": "!636q39766251:matrix.org",
-                        "$ref": "../../event-schemas/examples/m.room.message$m.text.yaml",
-                        "content": {
-                          "m.relates_to": {
-                            "rel_type": "org.example.my_relation",
-                            "event_id": "$asfDuShaf7Gafaw"
-                          }
-                        }
-                      }
-                    ],
-                    "next_batch": "page2_token",
-                    "prev_batch": "page1_token"
-                  }
+                  $ref: '#/components/examples/response'
         "404":
-          description: |-
-            The parent event was not found or the user does not have permission to read
-            this event (it might be contained in history that is not accessible to the user).
-          content:
-            application/json:
-              schema:
-                $ref: definitions/errors/error.yaml
-              examples:
-                response:
-                  value: {
-                    "errcode": "M_NOT_FOUND",
-                    "error": "Event not found."
-                  }
+          $ref: '#/components/responses/404'
       tags:
         - Event relationships
 servers:
@@ -586,3 +218,156 @@ servers:
 components:
   securitySchemes:
     $ref: definitions/security.yaml
+  parameters:
+    roomId:
+      in: path
+      name: roomId
+      description: The ID of the room containing the parent event.
+      required: true
+      example: "!636q39766251:matrix.org"
+      schema:
+        type: string
+    eventId:
+      in: path
+      name: eventId
+      description: The ID of the parent event whose child events are to be returned.
+      required: true
+      example: $asfDuShaf7Gafaw
+      schema:
+        type: string
+    from:
+      in: query
+      name: from
+      description: |-
+        The pagination token to start returning results from. If not supplied, results
+        start at the most recent topological event known to the server.
+
+        Can be a `next_batch` or `prev_batch` token from a previous call, or a returned
+        `start` token from [`/messages`](/client-server-api/#get_matrixclientv3roomsroomidmessages),
+        or a `next_batch` token from [`/sync`](/client-server-api/#get_matrixclientv3sync).
+      required: false
+      example: page2_token
+      schema:
+        type: string
+    to:
+      in: query
+      name: to
+      description: |-
+        The pagination token to stop returning results at. If not supplied, results
+        continue up to `limit` or until there are no more events.
+
+        Like `from`, this can be a previous token from a prior call to this endpoint
+        or from `/messages` or `/sync`.
+      required: false
+      example: page3_token
+      schema:
+        type: string
+    limit:
+      in: query
+      name: limit
+      description: |-
+        The maximum number of results to return in a single `chunk`. The server can
+        and should apply a maximum value to this parameter to avoid large responses.
+
+        Similarly, the server should apply a default value when not supplied.
+      required: false
+      example: 20
+      schema:
+        type: integer
+    dir:
+      in: query
+      name: dir
+      x-addedInMatrixVersion: "1.4"
+      description: |-
+        Optional (default `b`) direction to return events from. If this is set to `f`, events
+        will be returned in chronological order starting at `from`. If it
+        is set to `b`, events will be returned in *reverse* chronological
+        order, again starting at `from`.
+      schema:
+        type: string
+        enum:
+          - b
+          - f
+    relType:
+      in: path
+      name: relType
+      description: The [relationship type](/client-server-api/#relationship-types) to
+        search for.
+      required: true
+      example: org.example.my_relation
+      schema:
+        type: string
+    recurse:
+      in: query
+      name: recurse
+      x-addedInMatrixVersion: "1.10"
+      required: false
+      description: |-
+        Whether to additionally include events which only relate indirectly to the
+        given event, ie. events related to the root events via one or more direct relationships.
+
+        If set to `false`, only events which have direct a relation with the given
+        event will be included.
+
+        If set to `true`, all events which relate to the given event, or relate to
+        events that relate to the given event, will be included.
+
+        It is recommended that at least 3 levels of relationships are traversed.
+        Implementations may perform more but should be careful to not infinitely recurse.
+
+        The default value is `false`.
+      schema:
+        type: boolean
+  schemas:
+    response:
+      type: object
+      properties:
+        next_batch:
+          type: string
+          description: |-
+            An opaque string representing a pagination token. The absence of this token
+            means there are no more results to fetch and the client should stop paginating.
+        prev_batch:
+          type: string
+          description: |-
+            An opaque string representing a pagination token. The absence of this token
+            means this is the start of the result set, i.e. this is the first batch/page.
+        recursion_depth:
+          type: integer
+          description: |-
+            If the `recurse` parameter was supplied by the client, this response field is
+            mandatory and gives the actual depth to which the server recursed. The the client
+            did not specify the `recurse` parameter, this field must be absent.
+  responses:
+    "404":
+      description: |-
+        The parent event was not found or the user does not have permission to read
+        this event (it might be contained in history that is not accessible to the user).
+      content:
+        application/json:
+          schema:
+            $ref: definitions/errors/error.yaml
+          examples:
+            response:
+              value: {
+                "errcode": "M_NOT_FOUND",
+                "error": "Event not found."
+              }
+  examples:
+    response:
+      value: {
+        "chunk": [
+          {
+            "room_id": "!636q39766251:matrix.org",
+            "$ref": "../../event-schemas/examples/m.room.message$m.text.yaml",
+            "content": {
+              "m.relates_to": {
+                "rel_type": "org.example.my_relation",
+                "event_id": "$asfDuShaf7Gafaw"
+              }
+            }
+          }
+        ],
+        "next_batch": "page2_token",
+        "prev_batch": "page1_token"
+      }
diff --git a/data/event-schemas/examples/m.call.answer.yaml b/data/event-schemas/examples/m.call.answer.yaml
index 78b48878..8a627360 100644
--- a/data/event-schemas/examples/m.call.answer.yaml
+++ b/data/event-schemas/examples/m.call.answer.yaml
@@ -8,6 +8,14 @@
     "answer": {
       "type" : "answer",
       "sdp" : "v=0\r\no=- 6584580628695956864 2 IN IP4 127.0.0.1[...]"
+    },
+    "sdp_stream_metadata": {
+        "271828182845": {
+            "purpose": "m.screenshare"
+        },
+        "314159265358": {
+            "purpose": "m.usermedia"
+        }
     }
   }
 }
diff --git a/data/event-schemas/examples/m.call.invite.yaml b/data/event-schemas/examples/m.call.invite.yaml
index 45600001..9547854b 100644
--- a/data/event-schemas/examples/m.call.invite.yaml
+++ b/data/event-schemas/examples/m.call.invite.yaml
@@ -9,6 +9,14 @@
     "offer": {
       "type" : "offer",
       "sdp" : "v=0\r\no=- 6584580628695956864 2 IN IP4 127.0.0.1[...]"
+    },
+    "sdp_stream_metadata": {
+        "271828182845": {
+            "purpose": "m.screenshare"
+        },
+        "314159265358": {
+            "purpose": "m.usermedia"
+        }
     }
   }
 }
diff --git a/data/event-schemas/examples/m.call.negotiate.yaml b/data/event-schemas/examples/m.call.negotiate.yaml
index fabb6add..aaf9daf2 100644
--- a/data/event-schemas/examples/m.call.negotiate.yaml
+++ b/data/event-schemas/examples/m.call.negotiate.yaml
@@ -9,6 +9,14 @@
     "description": {
       "type" : "offer",
       "sdp" : "v=0\r\no=- 6584580628695956864 2 IN IP4 127.0.0.1[...]"
+    },
+    "sdp_stream_metadata": {
+        "271828182845": {
+            "purpose": "m.screenshare"
+        },
+        "314159265358": {
+            "purpose": "m.usermedia"
+        }
     }
   }
 }
diff --git a/data/event-schemas/schema/components/sdp_stream_metadata.yaml b/data/event-schemas/schema/components/sdp_stream_metadata.yaml
new file mode 100644
index 00000000..f16b4cbd
--- /dev/null
+++ b/data/event-schemas/schema/components/sdp_stream_metadata.yaml
@@ -0,0 +1,27 @@
+type: object
+x-addedInMatrixVersion: "1.10"
+description: |-
+  Metadata describing the [streams](/client-server-api/#streams) that will be
+  sent.
+  
+  This is a map of stream ID to metadata about the stream.
+additionalProperties:
+  type: object
+  title: StreamMetadata
+  description: Metadata describing a stream.
+  properties:
+    purpose:
+      type: string
+      enum:
+        - m.usermedia
+        - m.screenshare
+      description: |-
+        The purpose of the stream.
+
+        The possible values are:
+
+        * `m.usermedia`: Stream that contains the webcam and/or microphone
+          tracks.
+        * `m.screenshare`: Stream with the screen-sharing tracks.
+  required:
+    - purpose
diff --git a/data/event-schemas/schema/m.call.answer.yaml b/data/event-schemas/schema/m.call.answer.yaml
index 163690be..15e07202 100644
--- a/data/event-schemas/schema/m.call.answer.yaml
+++ b/data/event-schemas/schema/m.call.answer.yaml
@@ -27,6 +27,9 @@
                         }
                     },
                     "required": ["type", "sdp"]
+                },
+                "sdp_stream_metadata": {
+                    "$ref": "components/sdp_stream_metadata.yaml"
                 }
             },
             "required": ["answer"]
diff --git a/data/event-schemas/schema/m.call.invite.yaml b/data/event-schemas/schema/m.call.invite.yaml
index 72020b26..c688d7b3 100644
--- a/data/event-schemas/schema/m.call.invite.yaml
+++ b/data/event-schemas/schema/m.call.invite.yaml
@@ -35,7 +35,10 @@
                 "invitee": {
                     "type": "string",
                     "description": "The ID of the user being called. If omitted, any user in the room can answer.",
-                    "x-addedInMatrixVersion": "1.7",
+                    "x-addedInMatrixVersion": "1.7"
+                },
+                "sdp_stream_metadata": {
+                    "$ref": "components/sdp_stream_metadata.yaml"
                 }
             },
             "required": ["offer", "lifetime"]
diff --git a/data/event-schemas/schema/m.call.negotiate.yaml b/data/event-schemas/schema/m.call.negotiate.yaml
index b2b47c1d..e1a14f6f 100644
--- a/data/event-schemas/schema/m.call.negotiate.yaml
+++ b/data/event-schemas/schema/m.call.negotiate.yaml
@@ -63,6 +63,8 @@ properties:
         type: integer
         description: The time in milliseconds that the negotiation is valid for.
           Once the negotiation age exceeds this value, clients should discard it.
+      sdp_stream_metadata:
+        $ref: components/sdp_stream_metadata.yaml
     required:
     - description
     - lifetime
diff --git a/layouts/partials/events/example.html b/layouts/partials/events/example.html
index 181de88f..90752fbd 100644
--- a/layouts/partials/events/example.html
+++ b/layouts/partials/events/example.html
@@ -1,13 +1,18 @@
 {{/*
 
-  Renders an event example.  Resolves `$ref`s, serializes as JSON, and ensures
+  Renders an event example. Resolves `$ref`s, serializes as JSON, and ensures
   that it can be included in HTML.
 
-  This partial is called with the example event object as its context.
+  Parameters:
+
+    * `schema`: the schema of the example
+    * `name`: the name of the example
 
 */}}
 
-{{ $example_content := partial "json-schema/resolve-refs" (dict "schema" . "path" "event-schemas/examples") }}
+{{ $path := delimit (slice "event-schemas/examples" .name) "/" }}
+
+{{ $example_content := partial "json-schema/resolve-refs" (dict "schema" .schema "path" $path) }}
 {{ $example_json := jsonify (dict "indent" "  ") $example_content }}
 {{ $example_json = replace $example_json "\\u003c" "<" }}
 {{ $example_json = replace $example_json "\\u003e" ">" | safeHTML }}
diff --git a/layouts/partials/events/render-event.html b/layouts/partials/events/render-event.html
index 70752721..71ba60bd 100644
--- a/layouts/partials/events/render-event.html
+++ b/layouts/partials/events/render-event.html
@@ -77,7 +77,7 @@
     */}}
     {{ if $desired_example_name }}
         {{ if eq $example_name $desired_example_name }}
-            {{ partial "events/example" $example }}
+            {{ partial "events/example" (dict "schema" $example "name" $example_name) }}
         {{ end }}
     {{/*
       If `$desired_example_name` is not given, we will include any
@@ -86,7 +86,7 @@
       the event name includes a "$".
     */}}
     {{ else if eq $event_name $example_name }}
-        {{ partial "events/example" $example }}
+        {{ partial "events/example" (dict "schema" $example "name" $example_name) }}
     {{/*
       If `$desired_example_name` is not given, we will include any
       examples whose first part (before "$") matches the event name
@@ -96,7 +96,7 @@
         {{ $pieces := split $example_name "$" }}
         {{ $example_base_name := index $pieces 0 }}
         {{ if eq $event_name $example_base_name }}
-             {{ partial "events/example" $example }}
+             {{ partial "events/example" (dict "schema" $example "name" $example_name) }}
         {{ end }}
     {{ end }}
 {{ end }}
diff --git a/layouts/partials/json-schema/resolve-refs.html b/layouts/partials/json-schema/resolve-refs.html
index 1d99201d..9a36e413 100644
--- a/layouts/partials/json-schema/resolve-refs.html
+++ b/layouts/partials/json-schema/resolve-refs.html
@@ -1,7 +1,10 @@
 {{/*
 
   Resolves the `$ref` JSON schema keyword, by recursively replacing
-  it with the object it points to.
+  it with the object it points to, given:
+
+  * `schema`: the schema where the references should be resolved
+  * `path`: the path of the file containing the schema
 
   This template uses [`Scratch`](https://gohugo.io/functions/scratch/)
   rather than a normal `dict` because with `dict` you can't replace key values:
@@ -20,8 +23,12 @@
     {{ $scratch.Set "result_map" dict }}
 
     {{ $ref_value := index $schema "$ref"}}
-    {{ if $ref_value}}
-        {{ $full_path := path.Join $path $ref_value }}
+    {{ if $ref_value }}
+        {{ $uri := urls.Parse $path }}
+        {{ $ref_uri := urls.Parse $ref_value }}
+        {{ $full_uri := $uri.ResolveReference $ref_uri }}
+
+        {{ $full_path := strings.TrimPrefix "/" $full_uri.Path }}
         {{/*
           Apparently Hugo doesn't give us a nice way to split the extension off a filename.
         */}}
@@ -30,11 +37,18 @@
 
         {{ $ref := index site.Data $pieces }}
 
+        {{/* If there is a fragment, follow the JSON Pointer */}}
+        {{ if $full_uri.Fragment }}
+            {{ $fragment := strings.TrimPrefix "/" $full_uri.Fragment }}
+            {{ $pieces := split $fragment "/" }}
+            {{ $ref = index $ref $pieces }}
+        {{ end }}
+
         {{ $new_path := (path.Split $full_path).Dir}}
         {{ $result_map := partial "json-schema/resolve-refs" (dict "schema" $ref "path" $new_path)}}
         {{ if $result_map}}
             {{ $scratch.Set "result_map" $result_map }}
-        {{end }}
+        {{ end }}
     {{ end }}
 
 
diff --git a/layouts/partials/openapi/render-parameters.html b/layouts/partials/openapi/render-parameters.html
index 925b0197..ecabfc05 100644
--- a/layouts/partials/openapi/render-parameters.html
+++ b/layouts/partials/openapi/render-parameters.html
@@ -5,6 +5,7 @@
   * `parameters`: OpenAPI data specifying the parameters
   * `type`: the type of parameters to render: "header, ""path", "query"
   * `caption`: caption to use for the table
+  * `path`: the path where this definition was found, to enable us to resolve "$ref"
 
   This template renders a single table containing parameters of the given type.
 
@@ -13,7 +14,9 @@
 {{ $parameters := .parameters }}
 {{ $type := .type }}
 {{ $caption := .caption }}
+{{ $path := .path }}
 
+{{ $parameters = partial "json-schema/resolve-refs" (dict "schema" $parameters "path" $path) }}
 {{ $parameters_of_type := where $parameters "in" $type }}
 
 {{ with $parameters_of_type }}
@@ -32,5 +35,4 @@
 
     {{/* and render the parameters */}}
     {{ partial "openapi/render-object-table" (dict "title" $caption "properties" $param_dict) }}
-
 {{ end }}
diff --git a/layouts/partials/openapi/render-request.html b/layouts/partials/openapi/render-request.html
index 3d4b0381..5ef55c64 100644
--- a/layouts/partials/openapi/render-request.html
+++ b/layouts/partials/openapi/render-request.html
@@ -26,9 +26,9 @@
     {{ if $parameters }}
 <h3>Request parameters</h3>
 
-        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "header" "caption" "header parameters") }}
-        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "path" "caption" "path parameters") }}
-        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "query" "caption" "query parameters") }}
+        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "header" "caption" "header parameters" "path" .path) }}
+        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "path" "caption" "path parameters" "path" .path) }}
+        {{ partial "openapi/render-parameters" (dict "parameters" $parameters "type" "query" "caption" "query parameters" "path" .path) }}
 
     {{ end }}
 
diff --git a/layouts/partials/openapi/render-responses.html b/layouts/partials/openapi/render-responses.html
index 99662ad0..82c2f954 100644
--- a/layouts/partials/openapi/render-responses.html
+++ b/layouts/partials/openapi/render-responses.html
@@ -26,6 +26,8 @@
   <th class="col-status-description">Description</th>
  </thead>
 
+{{ $responses = partial "json-schema/resolve-refs" (dict "schema" $responses "path" $path) }}
+
 {{ range $code, $response := $responses }}
 
  <tr>
@@ -49,8 +51,7 @@
                 Display the JSON schemas
             */}}
 
-            {{ $schema := partial "json-schema/resolve-refs" (dict "schema" $json_body.schema "path" $path) }}
-            {{ $schema := partial "json-schema/resolve-allof" $schema }}
+            {{ $schema := partial "json-schema/resolve-allof" $json_body.schema }}
 
             {{/*
             All this is to work out how to express the content of the response
diff --git a/layouts/shortcodes/definition.html b/layouts/shortcodes/definition.html
index 0699ff7b..23461878 100644
--- a/layouts/shortcodes/definition.html
+++ b/layouts/shortcodes/definition.html
@@ -22,10 +22,6 @@
   {{ errorf "site data %s not found" $path }}
 {{ end }}
 
-{{/* The base path, which we use to resolve $ref, omits the last component */}}
-{{ $pieces = first (sub (len $pieces) 1) $pieces}}
-{{ $path = delimit $pieces "/" }}
-
 {{/* Resolve $ref and allOf */}}
 {{ $definition = partial "json-schema/resolve-refs" (dict "schema" $definition "path" $path) }}
 {{ $definition = partial "json-schema/resolve-allof" $definition }}
diff --git a/layouts/shortcodes/event.html b/layouts/shortcodes/event.html
index a9838542..c671318a 100644
--- a/layouts/shortcodes/event.html
+++ b/layouts/shortcodes/event.html
@@ -25,7 +25,7 @@
 */}}
 
 {{ $event_data := index .Site.Data "event-schemas" "schema" .Params.event }}
-{{ $path := "event-schemas/schema" }}
+{{ $path := delimit (slice "event-schemas/schema" .Params.event) "/" }}
 
 {{ $event_data = partial "json-schema/resolve-refs" (dict "schema" $event_data "path" $path) }}
 {{ $event_data := partial "json-schema/resolve-allof" $event_data }}
diff --git a/layouts/shortcodes/http-api.html b/layouts/shortcodes/http-api.html
index a3b706db..43d08b9e 100644
--- a/layouts/shortcodes/http-api.html
+++ b/layouts/shortcodes/http-api.html
@@ -21,6 +21,6 @@
 
 {{ $api_data := index .Site.Data.api .Params.spec .Params.api }}
 {{ $base_url := (index $api_data.servers 0).variables.basePath.default }}
-{{ $path := delimit (slice "api" $spec) "/" }}
+{{ $path := delimit (slice "api" $spec $api) "/" }}
 
 {{ partial "openapi/render-api" (dict "api_data" $api_data "base_url" $base_url "path" $path) }}
diff --git a/layouts/shortcodes/msgtypes.html b/layouts/shortcodes/msgtypes.html
index ba731111..1ab28aae 100644
--- a/layouts/shortcodes/msgtypes.html
+++ b/layouts/shortcodes/msgtypes.html
@@ -6,7 +6,6 @@
 
 */}}
 
-{{ $path := "event-schemas/schema" }}
 {{ $compact := false }}
 
 {{/*
@@ -40,6 +39,7 @@
 {{ range $msgtypes }}
 
     {{ $event_data := index $site_data "event-schemas" "schema" . }}
+    {{ $path := delimit (slice "event-schemas/schema" .) "/" }}
     {{ $event_data = partial "json-schema/resolve-refs" (dict "schema" $event_data "path" $path) }}
     {{ $event_data := partial "json-schema/resolve-allof" $event_data }}
 
diff --git a/scripts/check-event-schema-examples.py b/scripts/check-event-schema-examples.py
index b258ca2e..9058ff4e 100755
--- a/scripts/check-event-schema-examples.py
+++ b/scripts/check-event-schema-examples.py
@@ -18,6 +18,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import helpers
 import sys
 import json
 import os
@@ -48,51 +49,16 @@ except ImportError as e:
     raise
 
 
-def load_file(path):
-    print("Loading reference: %s" % path)
-    if not path.startswith("file://"):
-        raise Exception("Bad ref: %s" % (path,))
-    path = path[len("file://"):]
-    with open(path, "r") as f:
-        if path.endswith(".json"):
-            return json.load(f)
-        else:
-            # We have to assume it's YAML because some of the YAML examples
-            # do not have file extensions.
-            return yaml.safe_load(f)
-
-
-def resolve_references(path, schema):
-    if isinstance(schema, dict):
-        # do $ref first
-        if '$ref' in schema:
-            value = schema['$ref']
-            path = os.path.abspath(os.path.join(os.path.dirname(path), value))
-            ref = load_file("file://" + path)
-            result = resolve_references(path, ref)
-            del schema['$ref']
-        else:
-            result = {}
-
-        for key, value in schema.items():
-            result[key] = resolve_references(path, value)
-        return result
-    elif isinstance(schema, list):
-        return [resolve_references(path, value) for value in schema]
-    else:
-        return schema
-
-
 def check_example_file(examplepath, schemapath):
     with open(examplepath) as f:
-        example = resolve_references(examplepath, json.load(f))
+        example = helpers.resolve_references(examplepath, json.load(f))
 
     with open(schemapath) as f:
         schema = yaml.safe_load(f)
 
     fileurl = "file://" + os.path.abspath(schemapath)
     schema["id"] = fileurl
-    resolver = jsonschema.RefResolver(fileurl, schema, handlers={"file": load_file})
+    resolver = jsonschema.RefResolver(fileurl, schema, handlers={"file": helpers.load_file_from_uri})
 
     print ("Checking schema for: %r %r" % (examplepath, schemapath))
     try:
diff --git a/scripts/check-json-schemas.py b/scripts/check-json-schemas.py
index 3901300f..06b24106 100755
--- a/scripts/check-json-schemas.py
+++ b/scripts/check-json-schemas.py
@@ -18,6 +18,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import helpers
 import sys
 import json
 import os
@@ -67,23 +68,11 @@ class SchemaDirReport:
     def add(self, other_report):
         self.files += other_report.files
         self.errors += other_report.errors
-
-def load_file(path):
-    if not path.startswith("file://"):
-        raise Exception(f"Bad ref: {path}")
-    path = path[len("file://"):]
-    with open(path, "r") as f:
-        if path.endswith(".json"):
-            return json.load(f)
-        else:
-            # We have to assume it's YAML because some of the YAML examples
-            # do not have file extensions.
-            return yaml.safe_load(f)
         
 def check_example(path, schema, example):
     # URI with scheme is necessary to make RefResolver work.
     fileurl = "file://" + os.path.abspath(path)
-    resolver = jsonschema.RefResolver(fileurl, schema, handlers={"file": load_file})
+    resolver = jsonschema.RefResolver(fileurl, schema, handlers={"file": helpers.load_file_from_uri})
     validator = jsonschema.Draft202012Validator(schema, resolver)
 
     validator.validate(example)
diff --git a/scripts/check-openapi-sources.py b/scripts/check-openapi-sources.py
index 467e8091..7f28d860 100755
--- a/scripts/check-openapi-sources.py
+++ b/scripts/check-openapi-sources.py
@@ -19,6 +19,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import helpers
 import sys
 import json
 import os
@@ -49,9 +50,7 @@ except ImportError as e:
 
 
 def check_schema(filepath, example, schema):
-    example = resolve_references(filepath, example)
-    schema = resolve_references(filepath, schema)
-    resolver = jsonschema.RefResolver(filepath, schema, handlers={"file": load_file})
+    resolver = jsonschema.RefResolver(filepath, schema, handlers={"file": helpers.load_file_from_uri})
     validator = jsonschema.Draft202012Validator(schema, resolver)
     validator.validate(example)
 
@@ -120,6 +119,8 @@ def check_openapi_file(filepath):
     with open(filepath) as f:
         openapi = yaml.safe_load(f)
 
+    openapi = helpers.resolve_references(filepath, openapi)
+
     openapi_version = openapi.get('openapi')
     if not openapi_version:
         # This is not an OpenAPI file, skip.
@@ -149,64 +150,6 @@ def check_openapi_file(filepath):
                     check_response(filepath, request, code, json_response)
 
 
-def resolve_references(path, schema):
-    """Recurse through a given schema until we find a $ref key. Upon doing so,
-    check that the referenced file exists, then load it up and check all of the
-    references in that file. Continue on until we've hit all dead ends.
-
-    $ref values are deleted from schemas as they are validated, to prevent
-    duplicate work.
-    """
-    if isinstance(schema, dict):
-        # do $ref first
-        if '$ref' in schema:
-            # Pull the referenced filepath from the schema
-            referenced_file = schema['$ref']
-
-            # Referenced filepaths are relative, so take the current path's
-            # directory and append the relative, referenced path to it.
-            inner_path = os.path.join(os.path.dirname(path), referenced_file)
-
-            # Then convert the path (which may contiain '../') into a
-            # normalised, absolute path
-            inner_path = os.path.abspath(inner_path)
-
-            # Load the referenced file
-            ref = load_file("file://" + inner_path)
-
-            # Check that the references in *this* file are valid
-            result = resolve_references(inner_path, ref)
-
-            # They were valid, and so were the sub-references. Delete
-            # the reference here to ensure we don't pass over it again
-            # when checking other files
-            del schema['$ref']
-        else:
-            result = {}
-
-        for key, value in schema.items():
-            result[key] = resolve_references(path, value)
-        return result
-    elif isinstance(schema, list):
-        return [resolve_references(path, value) for value in schema]
-    else:
-        return schema
-
-
-def load_file(path):
-    print("Loading reference: %s" % path)
-    if not path.startswith("file://"):
-        raise Exception("Bad ref: %s" % (path,))
-    path = path[len("file://"):]
-    with open(path, "r") as f:
-        if path.endswith(".json"):
-            return json.load(f)
-        else:
-            # We have to assume it's YAML because some of the YAML examples
-            # do not have file extensions.
-            return yaml.safe_load(f)
-
-
 if __name__ == '__main__':
     # Get the directory that this script is residing in
     script_directory = os.path.dirname(os.path.realpath(__file__))
diff --git a/scripts/dump-openapi.py b/scripts/dump-openapi.py
index 1cc2279c..490ac9bf 100755
--- a/scripts/dump-openapi.py
+++ b/scripts/dump-openapi.py
@@ -20,6 +20,7 @@
 
 import argparse
 import errno
+import helpers
 import json
 import logging
 import os.path
@@ -31,34 +32,6 @@ import yaml
 scripts_dir = os.path.dirname(os.path.abspath(__file__))
 api_dir = os.path.join(os.path.dirname(scripts_dir), "data", "api")
 
-def resolve_references(path, schema):
-    if isinstance(schema, dict):
-        # do $ref first
-        if '$ref' in schema:
-            value = schema['$ref']
-            previous_path = path
-            path = os.path.join(os.path.dirname(path), value)
-            try:
-                with open(path, encoding="utf-8") as f:
-                    ref = yaml.safe_load(f)
-                result = resolve_references(path, ref)
-                del schema['$ref']
-                path = previous_path
-            except FileNotFoundError:
-                print("Resolving {}".format(schema))
-                print("File not found: {}".format(path))
-                result = {}
-        else:
-            result = {}
-
-        for key, value in schema.items():
-            result[key] = resolve_references(path, value)
-        return result
-    elif isinstance(schema, list):
-        return [resolve_references(path, value) for value in schema]
-    else:
-        return schema
-
 def prefix_absolute_path_references(text, base_url):
     """Adds base_url to absolute-path references.
 
@@ -176,7 +149,7 @@ for filename in os.listdir(selected_api_dir):
     print("Reading OpenAPI: %s" % filepath)
     with open(filepath, "r") as f:
         api = yaml.safe_load(f.read())
-        api = resolve_references(filepath, api)
+        api = helpers.resolve_references(filepath, api)
 
         basePath = api['servers'][0]['variables']['basePath']['default']
         for path, methods in api["paths"].items():
diff --git a/scripts/helpers.py b/scripts/helpers.py
new file mode 100755
index 00000000..c35e8e2a
--- /dev/null
+++ b/scripts/helpers.py
@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+
+# Helpers to resolve $ref recursively in OpenAPI and JSON schemas.
+
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json
+import os
+import os.path
+import urllib.parse
+import yaml
+
+def resolve_references(path, schema):
+    """Recurse through a given schema until we find a $ref key. Upon doing so,
+    check that the referenced file exists, then load it up and check all of the
+    references in that file. Continue on until we've hit all dead ends.
+
+    $ref values are deleted from schemas as they are validated, to prevent
+    duplicate work.
+    """
+    if isinstance(schema, dict):
+        # do $ref first
+        if '$ref' in schema:
+            # Pull the referenced URI from the schema
+            ref_uri = schema['$ref']
+
+            # Join the referenced URI with the URI of the file, to resolve
+            # relative URIs
+            full_ref_uri = urllib.parse.urljoin("file://" + path, ref_uri)
+
+            # Separate the fragment.
+            (full_ref_uri, fragment) = urllib.parse.urldefrag(full_ref_uri)
+
+            # Load the referenced file
+            ref = load_file_from_uri(full_ref_uri)
+
+            if fragment:
+                # The fragment should be a JSON Pointer
+                keys = fragment.strip('/').split('/')
+                for key in keys:
+                    ref = ref[key]
+
+            # Check that the references in *this* file are valid
+            result = resolve_references(urllib.parse.urlsplit(full_ref_uri).path, ref)
+
+            # They were valid, and so were the sub-references. Delete
+            # the reference here to ensure we don't pass over it again
+            # when checking other files
+            del schema['$ref']
+        else:
+            result = {}
+
+        for key, value in schema.items():
+            result[key] = resolve_references(path, value)
+        return result
+    elif isinstance(schema, list):
+        return [resolve_references(path, value) for value in schema]
+    else:
+        return schema
+
+
+def load_file_from_uri(path):
+    """Load a JSON or YAML file from a file:// URI.
+    """
+    print("Loading reference: %s" % path)
+    if not path.startswith("file://"):
+        raise Exception("Bad ref: %s" % (path,))
+    path = path[len("file://"):]
+    with open(path, "r") as f:
+        if path.endswith(".json"):
+            return json.load(f)
+        else:
+            # We have to assume it's YAML because some of the YAML examples
+            # do not have file extensions.
+            return yaml.safe_load(f)
\ No newline at end of file