A computer server includes processor and memory hardware. The processor hardware executes instructions including parsing a hypertext transfer protocol (HTTP) request from a first user agent to identify a first data object matching a set of characteristics and generating a new data element based on the HTTP request. The instructions include, in response to the first data object being present: extracting a first set of serialized data elements and serializing them with the new data element to generate a second data object. The instructions include, in response to the first data object being absent and a user associated with the first user agent being identifiable: determining a second set of serialized data elements based on an identity of the user, and serializing them with the new data element to generate the second data object. The instructions include transmitting an HTTP response including the second data object.