diff --git a/api/application-service/application_service.yaml b/api/application-service/application_service.yaml
index 45a53946..c39ce198 100644
--- a/api/application-service/application_service.yaml
+++ b/api/application-service/application_service.yaml
@@ -31,6 +31,7 @@ paths:
       description: |-
         This API is called by the HS when the HS wants to push an event (or
         batch of events) to the AS.
+      operationId: sendTransaction
       parameters:
         - in: path
           name: txnId
@@ -100,6 +101,7 @@ paths:
         aliases inside the application service's ``aliases`` namespace. The
         homeserver will send this request when it receives a request to join a
         room alias within the application service's namespace.
+      operationId: queryRoomByAlias
       parameters:
         - in: path
           name: roomAlias
@@ -158,6 +160,7 @@ paths:
         inside the application service's ``users`` namespace. The homeserver will
         send this request when it receives an event for an unknown user ID in
         the application service's namespace.
+      operationId: queryUserById
       parameters:
         - in: path
           name: userId
diff --git a/api/client-server/account-data.yaml b/api/client-server/account-data.yaml
index d8e93ef4..76b2b156 100644
--- a/api/client-server/account-data.yaml
+++ b/api/client-server/account-data.yaml
@@ -34,6 +34,7 @@ paths:
         Set some account_data for the client. This config is only visible to the user
         that set the account_data. The config will be synced to clients in the
         top-level ``account_data``.
+      operationId: setAccountData
       security:
         - accessToken: []
       parameters:
@@ -75,6 +76,7 @@ paths:
         Set some account_data for the client on a given room. This config is only
         visible to the user that set the account_data. The config will be synced to
         clients in the per-room ``account_data``.
+      operationId: setAccountDataPerRoom
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/admin.yaml b/api/client-server/admin.yaml
index d5b964b3..2fdac82b 100644
--- a/api/client-server/admin.yaml
+++ b/api/client-server/admin.yaml
@@ -36,6 +36,7 @@ paths:
         This API may be restricted to only be called by the user being looked
         up, or by a server admin. Server-local administrator privileges are not
         specified in this document.
+      operationId: getWhoIs
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/administrative_contact.yaml b/api/client-server/administrative_contact.yaml
index e9b7caa4..e7381a55 100644
--- a/api/client-server/administrative_contact.yaml
+++ b/api/client-server/administrative_contact.yaml
@@ -39,6 +39,7 @@ paths:
 
         Identifiers in this list may be used by the homeserver as, for example,
         identifiers that it will accept to reset the user's account password.
+      operationId: getAccount3PIDs
       security:
         - accessToken: []
       responses:
@@ -74,6 +75,7 @@ paths:
     post:
       summary: Adds contact information to the user's account.
       description: Adds contact information to the user's account.
+      operationId: post3PIDs
       security:
         - accessToken: []
       parameters:
@@ -139,6 +141,7 @@ paths:
         validation tokens when adding an email address to an account. This API's
         parameters and response is identical to that of the HS API
         |/register/email/requestToken|_ endpoint.
+      operationId: requestTokenTo3PID
       responses:
         200:
           description: An email was sent to the given address
diff --git a/api/client-server/banning.yaml b/api/client-server/banning.yaml
index 517552a6..3877f0e9 100644
--- a/api/client-server/banning.yaml
+++ b/api/client-server/banning.yaml
@@ -36,6 +36,7 @@ paths:
         When a user is banned from a room, they may not join it or be invited to it until they are unbanned.
 
         The caller must have the required power level in order to perform this operation.
+      operationId: ban
       security:
         - accessToken: []
       parameters:
@@ -91,6 +92,7 @@ paths:
         and join if they would otherwise be allowed to join according to its join rules.
 
         The caller must have the required power level in order to perform this operation.
+      operationId: unban
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/cas_login_redirect.yaml b/api/client-server/cas_login_redirect.yaml
index 7a4cec5d..abe9069b 100644
--- a/api/client-server/cas_login_redirect.yaml
+++ b/api/client-server/cas_login_redirect.yaml
@@ -37,6 +37,7 @@ paths:
         ``redirectUrl=https://client.example.com/?q=p``, it might redirect to
         ``https://cas.example.com/?service=https%3A%2F%2Fserver.example.com%2F_matrix%2Fclient%2F%CLIENT_MAJOR_VERSION%%2Flogin%2Fcas%2Fticket%3FredirectUrl%3Dhttps%253A%252F%252Fclient.example.com%252F%253Fq%253Dp``.
 
+      operationId: redirectToCAS
       parameters:
         - in: query
           type: string
diff --git a/api/client-server/cas_login_ticket.yaml b/api/client-server/cas_login_ticket.yaml
index 02469489..a08565a0 100644
--- a/api/client-server/cas_login_ticket.yaml
+++ b/api/client-server/cas_login_ticket.yaml
@@ -39,6 +39,7 @@ paths:
 
         If validation is unsuccessful, the server should respond with a ``401
         Unauthorized`` error, the body of which will be displayed to the user.
+      operationId: loginByCASTicket
       parameters:
         - in: query
           type: string
diff --git a/api/client-server/content-repo.yaml b/api/client-server/content-repo.yaml
index e8f23c12..a17ba21d 100644
--- a/api/client-server/content-repo.yaml
+++ b/api/client-server/content-repo.yaml
@@ -32,6 +32,7 @@ paths:
   "/upload":
     post:
       summary: Upload some content to the content repository.
+      operationId: uploadContent
       produces: ["application/json"]
       security:
         - accessToken: []
@@ -77,6 +78,7 @@ paths:
   "/download/{serverName}/{mediaId}":
     get:
       summary: "Download content from the content repository."
+      operationId: getContent
       produces: ["*/*"]
       parameters:
         - in: path
@@ -114,6 +116,7 @@ paths:
   "/download/{serverName}/{mediaId}/{fileName}":
     get:
       summary: "Download content from the content repository as a given filename."
+      operationId: getContentOverrideName
       produces: ["*/*"]
       parameters:
         - in: path
@@ -158,6 +161,7 @@ paths:
   "/thumbnail/{serverName}/{mediaId}":
     get:
       summary: "Download a thumbnail of the content from the content repository."
+      operationId: getContentThumbnail
       produces: ["image/jpeg", "image/png"]
       parameters:
         - in: path
@@ -213,6 +217,7 @@ paths:
   "/preview_url":
     get:
       summary: "Get information about a URL for a client"
+      operationId: getUrlPreview
       produces: ["application/json"]
       security:
         - accessToken: []
diff --git a/api/client-server/create_room.yaml b/api/client-server/create_room.yaml
index 5c80716a..d1a0e97a 100644
--- a/api/client-server/create_room.yaml
+++ b/api/client-server/create_room.yaml
@@ -49,6 +49,7 @@ paths:
 
         4. Invite events implied by ``invite`` and ``invite_3pid``.
 
+      operationId: createRoom
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/device_management.yaml b/api/client-server/device_management.yaml
index 3ee9c746..2f7d322b 100644
--- a/api/client-server/device_management.yaml
+++ b/api/client-server/device_management.yaml
@@ -33,6 +33,7 @@ paths:
       summary: List registered devices for the current user
       description: |-
         Gets information about all devices for the current user.
+      operationId: getDevices
       security:
         - accessToken: []
       responses:
@@ -66,6 +67,7 @@ paths:
       summary: Get a single device
       description: |-
         Gets information on a single device, by device id.
+      operationId: getDevice
       security:
         - accessToken: []
       parameters:
@@ -97,6 +99,7 @@ paths:
       summary: Update a device
       description: |-
         Updates the metadata on the given device.
+      operationId: updateDevice
       security:
         - accessToken: []
       parameters:
@@ -137,6 +140,7 @@ paths:
         This API endpoint uses the `User-Interactive Authentication API`_.
 
         Deletes the given device, and invalidates any access token assoicated with it.
+      operationId: deleteDevice
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/directory.yaml b/api/client-server/directory.yaml
index bfa71a73..a50bab62 100644
--- a/api/client-server/directory.yaml
+++ b/api/client-server/directory.yaml
@@ -30,6 +30,7 @@ paths:
   "/room/{roomAlias}":
     put:
       summary: Create a new mapping from room alias to room ID.
+      operationId: setRoomAlias
       security:
         - accessToken: []
       parameters:
@@ -78,6 +79,7 @@ paths:
         domain part of the alias does not correspond to the server's own
         domain.
 
+      operationId: getRoomIdByAlias
       parameters:
         - in: path
           type: string
@@ -124,6 +126,7 @@ paths:
         Remove a mapping of room alias to room ID.
 
         Servers may choose to implement additional access control checks here, for instance that room aliases can only be deleted by their creator or a server administrator.
+      operationId: deleteRoomAlias
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/event_context.yaml b/api/client-server/event_context.yaml
index 14889819..91da3cf4 100644
--- a/api/client-server/event_context.yaml
+++ b/api/client-server/event_context.yaml
@@ -34,6 +34,7 @@ paths:
         This API returns a number of events that happened just before and
         after the specified event. This allows clients to get the context
         surrounding an event.
+      operationId: getEventContext
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/filter.yaml b/api/client-server/filter.yaml
index 68db7a94..b34da7b6 100644
--- a/api/client-server/filter.yaml
+++ b/api/client-server/filter.yaml
@@ -33,6 +33,7 @@ paths:
         Uploads a new filter definition to the homeserver.
         Returns a filter ID that may be used in future requests to
         restrict which events are returned to the client.
+      operationId: defineFilter
       security:
         - accessToken: []
       parameters:
@@ -96,6 +97,7 @@ paths:
   "/user/{userId}/filter/{filterId}":
     get:
       summary: Download a filter
+      operationId: getFilter
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/inviting.yaml b/api/client-server/inviting.yaml
index 942be63e..47f51bd4 100644
--- a/api/client-server/inviting.yaml
+++ b/api/client-server/inviting.yaml
@@ -51,6 +51,7 @@ paths:
         ``m.room.member`` event to the room.
 
         .. _third party invites section: `invite-by-third-party-id-endpoint`_
+      operationId: inviteUser
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/joining.yaml b/api/client-server/joining.yaml
index c2388c2f..da4e4337 100644
--- a/api/client-server/joining.yaml
+++ b/api/client-server/joining.yaml
@@ -44,6 +44,7 @@ paths:
         If a ``third_party_signed`` was supplied, the homeserver must verify
         that it matches a pending ``m.room.third_party_invite`` event in the
         room, and perform key validity checking if required by the event.
+      operationId: joinRoomById
       security:
         - accessToken: []
       parameters:
@@ -132,6 +133,7 @@ paths:
         If a ``third_party_signed`` was supplied, the homeserver must verify
         that it matches a pending ``m.room.third_party_invite`` event in the
         room, and perform key validity checking if required by the event.
+      operationId: joinRoom
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/keys.yaml b/api/client-server/keys.yaml
index e77d5325..096e63b3 100644
--- a/api/client-server/keys.yaml
+++ b/api/client-server/keys.yaml
@@ -32,6 +32,7 @@ paths:
       summary: Upload end-to-end encryption keys.
       description: |-
         Publishes end-to-end encryption keys for the device.
+      operationId: uploadKeys
       security:
         - accessToken: []
       parameters:
@@ -100,6 +101,7 @@ paths:
       summary: Download device identity keys.
       description: |-
         Returns the current devices and identity keys for the given users.
+      operationId: queryKeys
       security:
         - accessToken: []
       parameters:
@@ -208,6 +210,7 @@ paths:
       summary: Claim one-time encryption keys.
       description: |-
         Claims one-time keys for use in pre-key messages.
+      operationId: claimKeys
       security:
         - accessToken: []
       parameters:
@@ -293,6 +296,7 @@ paths:
           membership state ``join``); *and*
         * added new device identity keys or removed an existing device with
           identity keys, between ``from`` and ``to``.
+      operationId: getKeysChanges
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/kicking.yaml b/api/client-server/kicking.yaml
index fbc0db72..ef43c0ee 100644
--- a/api/client-server/kicking.yaml
+++ b/api/client-server/kicking.yaml
@@ -34,6 +34,7 @@ paths:
         Kick a user from the room.
 
         The caller must have the required power level in order to perform this operation.
+      operationId: kick
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/leaving.yaml b/api/client-server/leaving.yaml
index a70b8a80..36351fd4 100644
--- a/api/client-server/leaving.yaml
+++ b/api/client-server/leaving.yaml
@@ -42,6 +42,7 @@ paths:
 
         The user will still be allowed to retrieve history from the room which
         they were previously allowed to see.
+      operationId: leaveRoom
       security:
         - accessToken: []
       parameters:
@@ -79,6 +80,7 @@ paths:
 
         If the user is currently joined to the room, they will implicitly leave
         the room as part of this API call.
+      operationId: forgetRoom
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/list_joined_rooms.yaml b/api/client-server/list_joined_rooms.yaml
index a239871a..19ad8649 100644
--- a/api/client-server/list_joined_rooms.yaml
+++ b/api/client-server/list_joined_rooms.yaml
@@ -32,6 +32,7 @@ paths:
       summary: Lists the user's current rooms.
       description: |-
         This API returns a list of the user's current rooms.
+      operationId: getJoinedRooms
       security:
         - accessToken: []
       responses:
@@ -54,4 +55,4 @@ paths:
                 ]
               }
       tags:
-        - Room membership
\ No newline at end of file
+        - Room membership
diff --git a/api/client-server/list_public_rooms.yaml b/api/client-server/list_public_rooms.yaml
index 86e15095..6d25a1ac 100644
--- a/api/client-server/list_public_rooms.yaml
+++ b/api/client-server/list_public_rooms.yaml
@@ -33,6 +33,7 @@ paths:
 
         This API returns paginated responses. The rooms are ordered by the number
         of joined members, with the largest rooms first.
+      operationId: getPublicRooms
       parameters:
         - in: query
           name: limit
@@ -158,6 +159,7 @@ paths:
 
         This API returns paginated responses. The rooms are ordered by the number
         of joined members, with the largest rooms first.
+      operationId: queryPublicRooms
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/login.yaml b/api/client-server/login.yaml
index c6dc0848..ff3eb392 100644
--- a/api/client-server/login.yaml
+++ b/api/client-server/login.yaml
@@ -41,6 +41,7 @@ paths:
         supplied by the client or generated by the server. The server may
         invalidate any access token previously associated with that device. See
         `Relationship between access tokens and devices`_.
+      operationId: login
       parameters:
         - in: body
           name: body
diff --git a/api/client-server/logout.yaml b/api/client-server/logout.yaml
index eed4ee44..3a2f71e9 100644
--- a/api/client-server/logout.yaml
+++ b/api/client-server/logout.yaml
@@ -33,6 +33,7 @@ paths:
       description: |-
         Invalidates an existing access token, so that it can no longer be used for
         authorization.
+      operationId: logout
       security:
         - accessToken: []
       responses:
diff --git a/api/client-server/message_pagination.yaml b/api/client-server/message_pagination.yaml
index 734565ec..71406653 100644
--- a/api/client-server/message_pagination.yaml
+++ b/api/client-server/message_pagination.yaml
@@ -33,6 +33,7 @@ paths:
       description: |-
         This API returns a list of message and state events for a room. It uses
         pagination query parameters to paginate history in the room.
+      operationId: getRoomEvents
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/notifications.yaml b/api/client-server/notifications.yaml
index 3c92e310..e10e5bfd 100644
--- a/api/client-server/notifications.yaml
+++ b/api/client-server/notifications.yaml
@@ -34,6 +34,7 @@ paths:
       description: |-
         This API is used to paginate through the list of events that the
         user has been, or would have been notified about.
+      operationId: getNotifications
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/old_sync.yaml b/api/client-server/old_sync.yaml
index c4da0ea1..dd633069 100644
--- a/api/client-server/old_sync.yaml
+++ b/api/client-server/old_sync.yaml
@@ -38,6 +38,7 @@ paths:
         should instead call the |/sync|_ API with a ``since`` parameter. See
         the `migration guide
         <https://matrix.org/docs/guides/client-server-migrating-from-v1.html#deprecated-endpoints>`_.
+      operationId: getEvents
       security:
         - accessToken: []
       parameters:
@@ -114,6 +115,7 @@ paths:
         should instead call the |/sync|_ API with no ``since`` parameter. See
         the `migration guide
         <https://matrix.org/docs/guides/client-server-migrating-from-v1.html#deprecated-endpoints>`_.
+      operationId: initialSync
       security:
         - accessToken: []
       parameters:
@@ -406,6 +408,7 @@ paths:
 
         This endpoint was deprecated in r0 of this specification. Clients
         should instead call the |/rooms/{roomId}/context/{eventId}|_ API.
+      operationId: getOneEvent
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/peeking_events.yaml b/api/client-server/peeking_events.yaml
index 7c109ce7..2f66bae7 100644
--- a/api/client-server/peeking_events.yaml
+++ b/api/client-server/peeking_events.yaml
@@ -41,6 +41,7 @@ paths:
         Note that the normal ``/events`` endpoint has been deprecated. This
         API will also be deprecated at some point, but its replacement is not
         yet known.
+      operationId: peekEvents
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/presence.yaml b/api/client-server/presence.yaml
index f17f9c73..ba202c2d 100644
--- a/api/client-server/presence.yaml
+++ b/api/client-server/presence.yaml
@@ -35,6 +35,7 @@ paths:
         the activity time is updated to reflect that activity; the client does
         not need to specify the ``last_active_ago`` field. You cannot set the
         presence state of another user.
+      operationId: setPresence
       security:
         - accessToken: []
       parameters:
@@ -81,6 +82,7 @@ paths:
       summary: Get this user's presence state.
       description: |-
         Get the given user's presence state.
+      operationId: getPresence
       parameters:
         - in: path
           type: string
@@ -126,6 +128,7 @@ paths:
       summary: Add or remove users from this presence list.
       description: |-
         Adds or removes users from this presence list.
+      operationId: modifyPresenceList
       security:
         - accessToken: []
       parameters:
@@ -180,6 +183,7 @@ paths:
       summary: Get presence events for this presence list.
       description: |-
         Retrieve a list of presence events for every user on this list.
+      operationId: getPresenceForList
       parameters:
         - in: path
           type: string
diff --git a/api/client-server/profile.yaml b/api/client-server/profile.yaml
index 10e2a369..0cada0ca 100644
--- a/api/client-server/profile.yaml
+++ b/api/client-server/profile.yaml
@@ -33,6 +33,7 @@ paths:
       description: |-
         This API sets the given user's display name. You must have permission to
         set this user's display name, e.g. you need to have their ``access_token``.
+      operationId: setDisplayName
       security:
         - accessToken: []
       parameters:
@@ -75,6 +76,7 @@ paths:
         Get the user's display name. This API may be used to fetch the user's
         own displayname or to query the name of other users; either locally or
         on remote homeservers.
+      operationId: getDisplayName
       parameters:
         - in: path
           type: string
@@ -105,6 +107,7 @@ paths:
       description: |-
         This API sets the given user's avatar URL. You must have permission to
         set this user's avatar URL, e.g. you need to have their ``access_token``.
+      operationId: setAvatarUrl
       security:
         - accessToken: []
       parameters:
@@ -147,6 +150,7 @@ paths:
         Get the user's avatar URL. This API may be used to fetch the user's
         own avatar URL or to query the URL of other users; either locally or
         on remote homeservers.
+      operationId: getAvatarUrl
       parameters:
         - in: path
           type: string
@@ -179,6 +183,7 @@ paths:
         to fetch the user's own profile information or other users; either
         locally or on remote homeservers. This API may return keys which are not
         limited to ``displayname`` or ``avatar_url``.
+      operationId: getUserProfile
       parameters:
         - in: path
           type: string
diff --git a/api/client-server/pusher.yaml b/api/client-server/pusher.yaml
index 0183520f..9cf40a06 100644
--- a/api/client-server/pusher.yaml
+++ b/api/client-server/pusher.yaml
@@ -32,6 +32,7 @@ paths:
       summary: Gets the current pushers for the authenticated user
       description: |-
           Gets all currently active pushers for the authenticated user
+      operationId: getPushers
       security:
         - accessToken: []
       responses:
@@ -123,6 +124,7 @@ paths:
         This endpoint allows the creation, modification and deletion of `pushers`_
         for this user ID. The behaviour of this endpoint varies depending on the
         values in the JSON body.
+      operationId: postPusher
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/pushrules.yaml b/api/client-server/pushrules.yaml
index 2bc7e2a8..801349ef 100644
--- a/api/client-server/pushrules.yaml
+++ b/api/client-server/pushrules.yaml
@@ -35,6 +35,7 @@ paths:
         the rulesets by suffixing a ``scope`` to this path e.g.
         ``/pushrules/global/``. This will return a subset of this data under the
         specified key e.g. the ``global`` key.
+      operationId: getPushRules
       security:
         - accessToken: []
       responses:
@@ -247,6 +248,7 @@ paths:
       summary: Retrieve a push rule.
       description: |-
         Retrieve a single specified push rule.
+      operationId: getPushRule
       security:
         - accessToken: []
       parameters:
@@ -299,6 +301,7 @@ paths:
       summary: Delete a push rule.
       description: |-
         This endpoint removes the push rule defined in the path.
+      operationId: deletePushRule
       security:
         - accessToken: []
       parameters:
@@ -340,6 +343,7 @@ paths:
         This endpoint allows the creation, modification and deletion of pushers
         for this user ID. The behaviour of this endpoint varies depending on the
         values in the JSON body.
+      operationId: setPushRule
       security:
         - accessToken: []
       parameters:
@@ -446,6 +450,7 @@ paths:
       summary: "Get whether a push rule is enabled"
       description:
         This endpoint gets whether the specified push rule is enabled.
+      operationId: isPushRuleEnabled
       security:
         - accessToken: []
       parameters:
@@ -490,6 +495,7 @@ paths:
       summary: "Enable or disable a push rule."
       description: |-
         This endpoint allows clients to enable or disable the specified push rule.
+      operationId: setPushRuleEnabled
       security:
         - accessToken: []
       parameters:
@@ -545,6 +551,7 @@ paths:
       summary: "The actions for a push rule"
       description:
         This endpoint get the actions for the specified push rule.
+      operationId: getPushRuleActions
       security:
         - accessToken: []
       parameters:
@@ -592,6 +599,7 @@ paths:
       description: |-
         This endpoint allows clients to change the actions of a push rule.
         This can be used to change the actions of builtin rules.
+      operationId: setPushRuleActions
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/receipts.yaml b/api/client-server/receipts.yaml
index 8d2cc631..e46359a9 100644
--- a/api/client-server/receipts.yaml
+++ b/api/client-server/receipts.yaml
@@ -33,6 +33,7 @@ paths:
       description: |-
         This API updates the marker for the given receipt type to the event ID
         specified.
+      operationId: postReceipt
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/redaction.yaml b/api/client-server/redaction.yaml
index 029dd05c..752d841a 100644
--- a/api/client-server/redaction.yaml
+++ b/api/client-server/redaction.yaml
@@ -39,6 +39,7 @@ paths:
         Users may redact their own events, and any user with a power level
         greater than or equal to the `redact` power level of the room may
         redact events there.
+      operationId: redactEvent
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/registration.yaml b/api/client-server/registration.yaml
index a01d2559..280ec3e1 100644
--- a/api/client-server/registration.yaml
+++ b/api/client-server/registration.yaml
@@ -59,6 +59,7 @@ paths:
         supplied by the client or generated by the server. The server may
         invalidate any access token previously associated with that device. See
         `Relationship between access tokens and devices`_.
+      operationId: register
       parameters:
         - in: query
           name: kind
@@ -192,6 +193,7 @@ paths:
         this API takes JSON objects, though the Identity Server API takes
         ``x-www-form-urlencoded`` parameters. See the Identity Server API for
         further information.
+      operationId: requestTokenToRegister
       parameters:
         - in: body
           name: body
@@ -258,6 +260,7 @@ paths:
         valid access token is provided.
       security:
         - accessToken: []
+      operationId: changePassword
       parameters:
         - in: body
           name: body
@@ -309,6 +312,7 @@ paths:
         .. |/register/email/requestToken| replace:: ``/register/email/requestToken``
 
         .. _/register/email/requestToken: #post-matrix-client-%CLIENT_MAJOR_VERSION%-register-email-requesttoken
+      operationId: requestTokenToResetPassword
       responses:
         200:
           description: An email was sent to the given address
@@ -328,6 +332,7 @@ paths:
         valid access token is provided.
       security:
         - accessToken: []
+      operationId: deactivateAccount
       parameters:
         - in: body
           name: body
diff --git a/api/client-server/room_initial_sync.yaml b/api/client-server/room_initial_sync.yaml
index 64eca5c0..c27f0f24 100644
--- a/api/client-server/room_initial_sync.yaml
+++ b/api/client-server/room_initial_sync.yaml
@@ -24,6 +24,7 @@ paths:
         direct replacement; the relevant information is returned by the
         |/sync|_ API. See the `migration guide
         <https://matrix.org/docs/guides/client-server-migrating-from-v1.html#deprecated-endpoints>`_.
+      operationId: roomInitialSync
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/room_send.yaml b/api/client-server/room_send.yaml
index 5326ab59..0bb1bbcb 100644
--- a/api/client-server/room_send.yaml
+++ b/api/client-server/room_send.yaml
@@ -38,6 +38,7 @@ paths:
         The body of the request should be the content object of the event; the
         fields in this object will vary depending on the type of event. See
         `Room Events`_ for the m. event specification.
+      operationId: sendMessage
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/room_state.yaml b/api/client-server/room_state.yaml
index ae50eec3..042b5eed 100644
--- a/api/client-server/room_state.yaml
+++ b/api/client-server/room_state.yaml
@@ -42,6 +42,7 @@ paths:
         The body of the request should be the content object of the event; the
         fields in this object will vary depending on the type of event. See
         `Room Events`_ for the ``m.`` event specification.
+      operationId: setRoomStateWithKey
       security:
         - accessToken: []
       parameters:
@@ -104,6 +105,7 @@ paths:
         The body of the request should be the content object of the event; the
         fields in this object will vary depending on the type of event. See
         `Room Events`_ for the ``m.`` event specification.
+      operationId: setRoomState
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/rooms.yaml b/api/client-server/rooms.yaml
index 26308acc..176d9fc9 100644
--- a/api/client-server/rooms.yaml
+++ b/api/client-server/rooms.yaml
@@ -35,6 +35,7 @@ paths:
         joined to the room then the state is taken from the current
         state of the room. If the user has left the room then the state is
         taken from the state of the room when they left.
+      operationId: getRoomStateWithKey
       security:
         - accessToken: []
       parameters:
@@ -82,6 +83,7 @@ paths:
         taken from the state of the room when they left.
 
         This looks up the state event with the empty state key.
+      operationId: getRoomStateByType
       security:
         - accessToken: []
       parameters:
@@ -118,6 +120,7 @@ paths:
       summary: Get all state events in the current state of a room.
       description: |-
         Get the state events for the current state of a room.
+      operationId: getRoomState
       security:
         - accessToken: []
       parameters:
@@ -234,6 +237,7 @@ paths:
       summary: Get the m.room.member events for the room.
       description:
         Get the list of members for this room.
+      operationId: getMembersByRoom
       parameters:
         - in: path
           type: string
@@ -303,6 +307,7 @@ paths:
       description:
         This API returns a map of MXIDs to member info objects for members of the room. The current user must be in the room for it to work, unless it is an Application Service in which case any of the AS's users must be in the room.
         This API is primarily for Application Services and should be faster to respond than ``/members`` as it can be implemented more efficiently on the server.
+      operationId: getJoinedMembersByRoom
       parameters:
         - in: path
           type: string
diff --git a/api/client-server/search.yaml b/api/client-server/search.yaml
index 37e49490..946d1ba7 100644
--- a/api/client-server/search.yaml
+++ b/api/client-server/search.yaml
@@ -32,6 +32,7 @@ paths:
       summary: Perform a server-side search.
       description: |-
         Performs a full text search across different categories.
+      operationId: search
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/sync.yaml b/api/client-server/sync.yaml
index 2276317f..34659dd0 100644
--- a/api/client-server/sync.yaml
+++ b/api/client-server/sync.yaml
@@ -34,6 +34,7 @@ paths:
         Clients use this API when they first log in to get an initial snapshot
         of the state on the server, and then continue to call this API to get
         incremental deltas to the state, and to receive new messages.
+      operationId: sync
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/tags.yaml b/api/client-server/tags.yaml
index 686d52a5..9310b25f 100644
--- a/api/client-server/tags.yaml
+++ b/api/client-server/tags.yaml
@@ -32,6 +32,7 @@ paths:
       summary: List the tags for a room.
       description: |-
         List the tags set by a user on a room.
+      operationId: getRoomTags
       security:
         - accessToken: []
       parameters:
@@ -74,6 +75,7 @@ paths:
       summary: Add a tag to a room.
       description: |-
         Add a tag to the room.
+      operationId: setRoomTag
       security:
         - accessToken: []
       parameters:
@@ -123,6 +125,7 @@ paths:
       summary: Remove a tag from the room.
       description: |-
         Remove a tag from the room.
+      operationId: deleteRoomTag
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/third_party_membership.yaml b/api/client-server/third_party_membership.yaml
index 51b5c7d4..612b22d0 100644
--- a/api/client-server/third_party_membership.yaml
+++ b/api/client-server/third_party_membership.yaml
@@ -75,6 +75,7 @@ paths:
         append a ``m.room.third_party_invite`` event to the room.
 
         .. _joining rooms section: `invite-by-user-id-endpoint`_
+      operationId: inviteBy3PID
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/to_device.yaml b/api/client-server/to_device.yaml
index 6c1f1e57..739d9a4f 100644
--- a/api/client-server/to_device.yaml
+++ b/api/client-server/to_device.yaml
@@ -34,6 +34,7 @@ paths:
       description: |-
         This endpoint is used to send send-to-device events to a set of
         client devices.
+      operationId: sendToDevice
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/typing.yaml b/api/client-server/typing.yaml
index c4a8aea7..e2a8f9bd 100644
--- a/api/client-server/typing.yaml
+++ b/api/client-server/typing.yaml
@@ -35,6 +35,7 @@ paths:
         milliseconds where N is the value specified in the ``timeout`` key.
         Alternatively, if ``typing`` is ``false``, it tells the server that the
         user has stopped typing.
+      operationId: setTyping
       security:
         - accessToken: []
       parameters:
diff --git a/api/client-server/versions.yaml b/api/client-server/versions.yaml
index 189e9b75..d3aa0359 100644
--- a/api/client-server/versions.yaml
+++ b/api/client-server/versions.yaml
@@ -33,6 +33,7 @@ paths:
 
         Only the latest ``Z`` value will be reported for each supported ``X.Y`` value.
         i.e. if the server implements ``r0.0.0``, ``r0.0.1``, and ``r1.2.0``, it will report ``r0.0.1`` and ``r1.2.0``.
+      operationId: getVersions
       responses:
         200:
           description: The versions supported by the server.
diff --git a/api/client-server/voip.yaml b/api/client-server/voip.yaml
index f853c3a3..6d6136a5 100644
--- a/api/client-server/voip.yaml
+++ b/api/client-server/voip.yaml
@@ -33,6 +33,7 @@ paths:
       description: |-
         This API provides credentials for the client to use when initiating
         calls.
+      operationId: getTurnServer
       security:
         - accessToken: []
       responses:
diff --git a/api/client-server/whoami.yaml b/api/client-server/whoami.yaml
index 4d9d6ceb..e3262fe4 100644
--- a/api/client-server/whoami.yaml
+++ b/api/client-server/whoami.yaml
@@ -30,6 +30,7 @@ paths:
       summary: Gets information about the owner of an access token.
       description: |-
         Gets information about the owner of a given access token.
+      operationId: getTokenOwner
       security:
         - accessToken: []
       parameters: []
diff --git a/api/identity/lookup.yaml b/api/identity/lookup.yaml
index 7cd7fded..bfd2153e 100644
--- a/api/identity/lookup.yaml
+++ b/api/identity/lookup.yaml
@@ -29,6 +29,7 @@ paths:
     get:
       summary: Look up the Matrix user ID for a 3pid.
       description: Look up the Matrix user ID for a 3pid.
+      operationId: lookupUser
       parameters:
         - in: query
           type: string
@@ -89,6 +90,7 @@ paths:
     post:
       summary: Lookup Matrix user IDs for a list of 3pids.
       description: Lookup Matrix user IDs for a list of 3pids.
+      operationId: lookupUsers
       parameters:
         - in: body
           name: body
diff --git a/api/identity/pubkey.yaml b/api/identity/pubkey.yaml
index d78cd33f..00796975 100644
--- a/api/identity/pubkey.yaml
+++ b/api/identity/pubkey.yaml
@@ -28,6 +28,7 @@ paths:
       summary: Get a public key.
       description: |-
         Get the public key for the passed key ID.
+      operationId: getPubKey
       parameters:
         - in: path
           type: string
@@ -56,6 +57,7 @@ paths:
       summary: Check whether a long-term public key is valid.
       description: |-
         Check whether a long-term public key is valid.
+      operationId: isPubKeyValid
       parameters:
         - in: query
           type: string
@@ -83,6 +85,7 @@ paths:
       summary: Check whether a short-term public key is valid.
       description: |-
         Check whether a short-term public key is valid.
+      operationId: isEphemeralPubKeyValid
       parameters:
         - in: query
           type: string
diff --git a/api/push-gateway/push_notifier.yaml b/api/push-gateway/push_notifier.yaml
index 6e3720c3..9b6e78d3 100644
--- a/api/push-gateway/push_notifier.yaml
+++ b/api/push-gateway/push_notifier.yaml
@@ -46,7 +46,7 @@ paths:
         Notifications are sent to the URL configured when the pusher is
         created. This means that the HTTP path may be different depending on the
         push gateway.
-
+      operationId: notify
       parameters:
         - in: body
           name: notification
diff --git a/api/validator.js b/api/validator.js
index 0d76c09d..c20dd993 100644
--- a/api/validator.js
+++ b/api/validator.js
@@ -34,38 +34,53 @@ var errFn = function(err, api) {
     process.exit(1);
 };
 
-var isDir = fs.lstatSync(opts.schema).isDirectory()
+/**
+ * @brief Produce a handler for parser.validate().
+ * Recommended usage: `parser.validate(filename, makeHandler(filename));`
+ * or `parser.validate(schema, makeHandler());`.
+ * @param scope - usually a filename, this will be used to denote
+ *                an (in)valid schema in console output; "Schema" if undefined
+ * @returns {function} the handler that can be passed to parser.validate
+ */
+function makeHandler(scope) {
+    if (!scope)
+        scope = "Schema";
+    return function(err, api, metadata) {
+        if (err) {
+            console.error("%s is not valid.", scope || "Schema");
+            errFn(err, api, metadata); // Won't return
+        }
+
+        Object.keys(api.paths).forEach(function (endpoint) {
+            var operationsMap = api.paths[endpoint];
+            Object.keys(operationsMap).forEach(function (verb) {
+                if (!operationsMap[verb]["operationId"]) {
+                    console.error("%s is not valid", scope);
+                    errFn("operationId is missing in " + endpoint + ", verb " + verb, api);
+                }
+            })
+        });
+
+        console.log("%s is valid.", scope);
+    }
+}
+
+var isDir = fs.lstatSync(opts.schema).isDirectory();
 if (isDir) {
     console.log("Checking directory %s for .yaml files...", opts.schema);
     fs.readdir(opts.schema, function(err, files) {
         if (err) {
-            console.error(err);
-            process.exit(1);
+            errFn(err); // Won't return
         }
         files.forEach(function(f) {
             var suffix = ".yaml";
             if (f.indexOf(suffix, f.length - suffix.length) > 0) {
-                parser.validate(path.join(opts.schema, f), function(err, api, metadata) {
-                    if (!err) {
-                        console.log("%s is valid.", f);
-                    }
-                    else {
-                        console.error("%s is not valid.", f);
-                        errFn(err, api, metadata);
-                    }
-                });
-            } 
+                parser.validate(path.join(opts.schema, f), makeHandler(f));
+            }
         });
     });
 }
 else{
-    parser.validate(opts.schema, function(err, api) {
-        if (!err) {
-            console.log("%s is valid", opts.schema);
-        }
-        else {
-            errFn(err, api);
-        }
-    });
-};
+    parser.validate(opts.schema, makeHandler(opts.schema));
+}