diff --git a/api/client-server/room_initial_sync.yaml b/api/client-server/room_initial_sync.yaml
new file mode 100644
index 00000000..f7a7e114
--- /dev/null
+++ b/api/client-server/room_initial_sync.yaml
@@ -0,0 +1,228 @@
+swagger: '2.0'
+info:
+  title: "Matrix Client-Server Rooms API"
+  version: "1.0.0"
+host: localhost:8008
+schemes:
+  - https
+  - http
+basePath: /_matrix/client/%CLIENT_MAJOR_VERSION%
+consumes:
+  - application/json
+produces:
+  - application/json
+securityDefinitions:
+  $ref: definitions/security.yaml
+paths:
+  "/rooms/{roomId}/initialSync":
+    get:
+      summary: Snapshot the current state of a room and its most recent messages.
+      description: |-
+        Get a copy of the current state and the most recent messages in a room.
+      security:
+        - accessToken: []
+      parameters:
+        - in: path
+          type: string
+          name: roomId
+          description: The room to get the data.
+          required: true
+          x-example: "!636q39766251:example.com"
+      responses:
+        200:
+          description: The current state of the room
+          examples:
+            application/json: |-
+              {
+                "membership": "join",
+                "messages": {
+                  "chunk": [
+                    {
+                      "age": 343513403,
+                      "content": {
+                        "body": "foo",
+                        "msgtype": "m.text"
+                      },
+                      "event_id": "$14328044851tzTJS:example.com",
+                      "origin_server_ts": 1432804485886,
+                      "room_id": "!636q39766251:example.com",
+                      "type": "m.room.message",
+                      "sender": "@alice:example.com"
+                    },
+                    {
+                      "age": 343511809,
+                      "content": {
+                        "body": "bar",
+                        "msgtype": "m.text"
+                      },
+                      "event_id": "$14328044872spjFg:example.com",
+                      "origin_server_ts": 1432804487480,
+                      "room_id": "!636q39766251:example.com",
+                      "type": "m.room.message",
+                      "sender": "@bob:example.com"
+                    }
+                  ],
+                  "end": "s3456_9_0",
+                  "start": "t44-3453_9_0"
+                },
+                "room_id": "!636q39766251:example.com",
+                "state": [
+                  {
+                    "age": 7148266897,
+                    "content": {
+                      "join_rule": "public"
+                    },
+                    "event_id": "$14259997323TLwtb:example.com",
+                    "origin_server_ts": 1425999732392,
+                    "room_id": "!636q39766251:example.com",
+                    "state_key": "",
+                    "type": "m.room.join_rules",
+                    "sender": "@alice:example.com"
+                  },
+                  {
+                    "age": 6547561012,
+                    "content": {
+                      "avatar_url": "mxc://example.com/fzysBrHpPEeTGANCVLXWXNMI#auto",
+                      "membership": "join"
+                    },
+                    "event_id": "$1426600438280zExKY:example.com",
+                    "membership": "join",
+                    "origin_server_ts": 1426600438277,
+                    "room_id": "!636q39766251:example.com",
+                    "state_key": "@alice:example.com",
+                    "type": "m.room.member",
+                    "sender": "@alice:example.com"
+                  },
+                  {
+                    "age": 7148267200,
+                    "content": {
+                        "creator": "@alice:example.com"
+                    },
+                    "event_id": "$14259997320KhbwJ:example.com",
+                    "origin_server_ts": 1425999732089,
+                    "room_id": "!636q39766251:example.com",
+                    "state_key": "",
+                    "type": "m.room.create",
+                    "sender": "@alice:example.com"
+                  },
+                  {
+                    "age": 1622568720,
+                    "content": {
+                        "avatar_url": "mxc://example.com/GCmhgzMPRjqgpODLsNQzVuHZ#auto",
+                        "displayname": "Bob",
+                        "membership": "join"
+                    },
+                    "event_id": "$1431525430134MxlLX:example.com",
+                    "origin_server_ts": 1431525430569,
+                    "replaces_state": "$142652023736BSXcM:example.com",
+                    "room_id": "!636q39766251:example.com",
+                    "state_key": "@bob:example.com",
+                    "type": "m.room.member",
+                    "sender": "@bob:example.com"
+                  },
+                  {
+                    "age": 7148267004,
+                    "content": {
+                      "ban": 50,
+                      "events": {
+                        "m.room.name": 100,
+                        "m.room.power_levels": 100
+                      },
+                      "events_default": 0,
+                      "kick": 50,
+                      "redact": 50,
+                      "state_default": 50,
+                      "users": {
+                        "@alice:example.com": 100
+                      },
+                      "users_default": 0
+                    },
+                    "event_id": "$14259997322mqfaq:example.com",
+                    "origin_server_ts": 1425999732285,
+                    "room_id": "!636q39766251:example.com",
+                    "state_key": "",
+                    "type": "m.room.power_levels",
+                    "sender": "@alice:example.com"
+                  }
+                ],
+                "visibility": "private",
+                "account_data": [{
+                    "type": "m.tag",
+                    "content": {"tags": {"work": {"order": "1"}}}
+                }]
+              }
+          schema:
+            title: RoomInfo
+            type: object
+            properties:
+              room_id:
+                type: string
+                description: "The ID of this room."
+              membership:
+                type: string
+                description: "The user's membership state in this room."
+                enum: ["invite", "join", "leave", "ban"]
+              messages:
+                type: object
+                title: PaginationChunk
+                description: "The pagination chunk for this room."
+                properties:
+                  start:
+                    type: string
+                    description: |-
+                      A token which correlates to the first value in ``chunk``.
+                      Used for pagination.
+                  end:
+                    type: string
+                    description: |-
+                      A token which correlates to the last value in ``chunk``.
+                      Used for pagination.
+                  chunk:
+                    type: array
+                    description: |-
+                      If the user is a member of the room this will be a
+                      list of the most recent messages for this room. If
+                      the user has left the room this will be the
+                      messages that preceeded them leaving. This array
+                      will consist of at most ``limit`` elements.
+                    items:
+                      type: object
+                      title: RoomEvent
+                      allOf:
+                        - "$ref": "definitions/event-schemas/schema/core-event-schema/room_event.yaml"
+                required: ["start", "end", "chunk"]
+              state:
+                type: array
+                description: |-
+                  If the user is a member of the room this will be the
+                  current state of the room as a list of events. If the
+                  user has left the room this will be the state of the
+                  room when they left it.
+                items:
+                  title: StateEvent
+                  type: object
+                  allOf:
+                    - "$ref": "definitions/event-schemas/schema/core-event-schema/state_event.yaml"
+              visibility:
+                type: string
+                enum: ["private", "public"]
+                description: |-
+                  Whether this room is visible to the ``/publicRooms`` API
+                  or not."
+              account_data:
+                type: array
+                description: |-
+                  The private data that this user has attached to this room.
+                items:
+                  title: Event
+                  type: object
+                  allOf:
+                    - "$ref": "definitions/event-schemas/schema/core-event-schema/event.yaml"
+            required: ["room_id"]
+        403:
+          description: >
+            You aren't a member of the room and weren't previously a
+            member of the room.
+      tags:
+        - Room participation
+      deprecated: true
diff --git a/api/client-server/rooms.yaml b/api/client-server/rooms.yaml
index 0d3689ac..5cbd144f 100644
--- a/api/client-server/rooms.yaml
+++ b/api/client-server/rooms.yaml
@@ -230,218 +230,6 @@ paths:
             member of the room.
       tags:
         - Room participation
-  "/rooms/{roomId}/initialSync":
-    get:
-      summary: Snapshot the current state of a room and its most recent messages.
-      description: |-
-        Get a copy of the current state and the most recent messages in a room.
-      security:
-        - accessToken: []
-      parameters:
-        - in: path
-          type: string
-          name: roomId
-          description: The room to get the data.
-          required: true
-          x-example: "!636q39766251:example.com"
-      responses:
-        200:
-          description: The current state of the room
-          examples:
-            application/json: |-
-              {
-                "membership": "join",
-                "messages": {
-                  "chunk": [
-                    {
-                      "age": 343513403,
-                      "content": {
-                        "body": "foo",
-                        "msgtype": "m.text"
-                      },
-                      "event_id": "$14328044851tzTJS:example.com",
-                      "origin_server_ts": 1432804485886,
-                      "room_id": "!636q39766251:example.com",
-                      "type": "m.room.message",
-                      "sender": "@alice:example.com"
-                    },
-                    {
-                      "age": 343511809,
-                      "content": {
-                        "body": "bar",
-                        "msgtype": "m.text"
-                      },
-                      "event_id": "$14328044872spjFg:example.com",
-                      "origin_server_ts": 1432804487480,
-                      "room_id": "!636q39766251:example.com",
-                      "type": "m.room.message",
-                      "sender": "@bob:example.com"
-                    }
-                  ],
-                  "end": "s3456_9_0",
-                  "start": "t44-3453_9_0"
-                },
-                "room_id": "!636q39766251:example.com",
-                "state": [
-                  {
-                    "age": 7148266897,
-                    "content": {
-                      "join_rule": "public"
-                    },
-                    "event_id": "$14259997323TLwtb:example.com",
-                    "origin_server_ts": 1425999732392,
-                    "room_id": "!636q39766251:example.com",
-                    "state_key": "",
-                    "type": "m.room.join_rules",
-                    "sender": "@alice:example.com"
-                  },
-                  {
-                    "age": 6547561012,
-                    "content": {
-                      "avatar_url": "mxc://example.com/fzysBrHpPEeTGANCVLXWXNMI#auto",
-                      "membership": "join"
-                    },
-                    "event_id": "$1426600438280zExKY:example.com",
-                    "membership": "join",
-                    "origin_server_ts": 1426600438277,
-                    "room_id": "!636q39766251:example.com",
-                    "state_key": "@alice:example.com",
-                    "type": "m.room.member",
-                    "sender": "@alice:example.com"
-                  },
-                  {
-                    "age": 7148267200,
-                    "content": {
-                        "creator": "@alice:example.com"
-                    },
-                    "event_id": "$14259997320KhbwJ:example.com",
-                    "origin_server_ts": 1425999732089,
-                    "room_id": "!636q39766251:example.com",
-                    "state_key": "",
-                    "type": "m.room.create",
-                    "sender": "@alice:example.com"
-                  },
-                  {
-                    "age": 1622568720,
-                    "content": {
-                        "avatar_url": "mxc://example.com/GCmhgzMPRjqgpODLsNQzVuHZ#auto",
-                        "displayname": "Bob",
-                        "membership": "join"
-                    },
-                    "event_id": "$1431525430134MxlLX:example.com",
-                    "origin_server_ts": 1431525430569,
-                    "replaces_state": "$142652023736BSXcM:example.com",
-                    "room_id": "!636q39766251:example.com",
-                    "state_key": "@bob:example.com",
-                    "type": "m.room.member",
-                    "sender": "@bob:example.com"
-                  },
-                  {
-                    "age": 7148267004,
-                    "content": {
-                      "ban": 50,
-                      "events": {
-                        "m.room.name": 100,
-                        "m.room.power_levels": 100
-                      },
-                      "events_default": 0,
-                      "kick": 50,
-                      "redact": 50,
-                      "state_default": 50,
-                      "users": {
-                        "@alice:example.com": 100
-                      },
-                      "users_default": 0
-                    },
-                    "event_id": "$14259997322mqfaq:example.com",
-                    "origin_server_ts": 1425999732285,
-                    "room_id": "!636q39766251:example.com",
-                    "state_key": "",
-                    "type": "m.room.power_levels",
-                    "sender": "@alice:example.com"
-                  }
-                ],
-                "visibility": "private",
-                "account_data": [{
-                    "type": "m.tag",
-                    "content": {"tags": {"work": {"order": "1"}}}
-                }]
-              }
-          schema:
-            title: RoomInfo
-            type: object
-            properties:
-              room_id:
-                type: string
-                description: "The ID of this room."
-              membership:
-                type: string
-                description: "The user's membership state in this room."
-                enum: ["invite", "join", "leave", "ban"]
-              messages:
-                type: object
-                title: PaginationChunk
-                description: "The pagination chunk for this room."
-                properties:
-                  start:
-                    type: string
-                    description: |-
-                      A token which correlates to the first value in ``chunk``.
-                      Used for pagination.
-                  end:
-                    type: string
-                    description: |-
-                      A token which correlates to the last value in ``chunk``.
-                      Used for pagination.
-                  chunk:
-                    type: array
-                    description: |-
-                      If the user is a member of the room this will be a
-                      list of the most recent messages for this room. If
-                      the user has left the room this will be the
-                      messages that preceeded them leaving. This array
-                      will consist of at most ``limit`` elements.
-                    items:
-                      type: object
-                      title: RoomEvent
-                      allOf:
-                        - "$ref": "definitions/event-schemas/schema/core-event-schema/room_event.yaml"
-                required: ["start", "end", "chunk"]
-              state:
-                type: array
-                description: |-
-                  If the user is a member of the room this will be the
-                  current state of the room as a list of events. If the
-                  user has left the room this will be the state of the
-                  room when they left it.
-                items:
-                  title: StateEvent
-                  type: object
-                  allOf:
-                    - "$ref": "definitions/event-schemas/schema/core-event-schema/state_event.yaml"
-              visibility:
-                type: string
-                enum: ["private", "public"]
-                description: |-
-                  Whether this room is visible to the ``/publicRooms`` API
-                  or not."
-              account_data:
-                type: array
-                description: |-
-                  The private data that this user has attached to this room.
-                items:
-                  title: Event
-                  type: object
-                  allOf:
-                    - "$ref": "definitions/event-schemas/schema/core-event-schema/event.yaml"
-            required: ["room_id"]
-        403:
-          description: >
-            You aren't a member of the room and weren't previously a
-            member of the room.
-      tags:
-        - Room participation
-      deprecated: true
   "/rooms/{roomId}/members":
     get:
       summary: Get the m.room.member events for the room.
diff --git a/specification/client_server_api.rst b/specification/client_server_api.rst
index 0ad9c284..5d26ca62 100644
--- a/specification/client_server_api.rst
+++ b/specification/client_server_api.rst
@@ -839,9 +839,10 @@ There are several APIs provided to ``GET`` events for a room:
 
 {{rooms_cs_http_api}}
 
-
 {{message_pagination_cs_http_api}}
 
+{{room_initial_sync_cs_http_api}}
+
 
 Sending events to a room
 ~~~~~~~~~~~~~~~~~~~~~~~~