Systems and methods are disclosed for brokering data exchanges between on-board and off-board systems of a vehicle. One method comprises receiving, at a data broker engine, one or more data requests from an origination system, wherein each of the one or more data requests specifies at least one or more of a request type and a target system. Then the data broker engine determines whether the request type is a one-time transmission, a periodic transmission, an event-triggered transmission, or a change-triggered transmission. Following the determination, the data broker engine retrieves data from the target system based on the determined request type and transmits the data to the origination system.