How to extract incoming data from a http rest request in a service in Moqui?

I want to extract json data from incoming request in a Moqui Service

I have created a service in Moqui which processes incoming data, the problem is data comes as a direct json insted of being nested into one parent object. Ex

{"key": "value","key2": "value","key3": "value"}

If it was something like this -

{"parent":{"key": "value","key2": "value","key3": "value"}}

I could define one service parameter called parent and use it to get the data

I have tried creating mutiple serivce input parameters to get that data in my service but the incoming request can have numerous keys, I don't want to define so many input parameters in my service. Does anyone know a way to extract the whole request body as it is ?