Custom event to make a Rest call with an Ordered List "[]"

There is a requirement of a Cloud Customer to make a REST Call using a Custom Event.

Jason Body is bit complex and has Array Elements on it.

Is there a way to fetch Array of Data to a REST Event without doing any Business Logic Changes? 

Only possible solution I can think of is to eliminate array elements and to send multiple messages against each Array Element, but the customer prefers to sent just one message with all elements.

Appreciate any advice or recommendations.