In the mediation pattern of EAI, there's a central component that is responsible for the propagation of the events. For example, in the broker-based middleware model, whenever one of the applications generates an event, the event is handled by the middleware broker, which is then responsible for the propagation of the event to the other applications that are interested in that event.

In this type of integration pattern, usually the applications directly interact with each other, facilitated by the middleware broker who relays the events that happen, and after which the event handlers for the other application are responsible.

Another integration approach that usually implements the mediation pattern is the message bus approach, where the message bus acts as a mediator between the different applications delivering messages to each other to facilitate the communication between them.