There is a working API for event monitoring with filters, so the operator types for the where clause and the EventFilterResult should be available by default.
@@ -136,6 +136,7 @@ QueryDataSet
ParsingResult
ContentFilterElementResult
ContentFilterResult
+EventFilterResult
QueryFirstResponse
QueryNextRequest
QueryNextResponse
@@ -173,6 +174,9 @@ DeadbandType
DataChangeFilter
EventFilter
FilterOperand
+ElementOperand
+LiteralOperand
+AttributeOperand
SimpleAttributeOperand
EventNotificationList
EventFieldList