The described technology provides a capability for web applications from different domains to interact within one application environment. For example, an enterprise web application executing on a client terminal is provided the capability to monitor a second web application from a third party vendor even when the second web application is independently executing within an iframe or the like within the enterprise web applications container or context. In some example embodiments, the communication is enabled by a composite cookie or key that incorporates portions of an enterprise web application cookie or key and also portions of a vendor web application cookie or key.