Various exemplary embodiments relate to a method and related network node including one or more of the following: receiving a Diameter message at the DRA from an origin device, wherein the Diameter message includes an attribute-value pair (AVP) having a first value represented according to a first data type; establishing a context object in response to receiving the Diameter message; establishing, within the context object, a custom attribute object that corresponds to the AVP and provides access to at least a portion of the first value represented according to a second data type, wherein the second data type is different from the first data type; evaluating a rule that includes a context object reference, wherein the evaluation includes accessing the custom attribute object based on the context object reference; and transmitting a message based on the evaluation of the rule.