Any OOTB way we can see what is the request json being sent to pega from external system?
Check In Service Package rule Invocation history for the Request Json.
If its a service then you can turn on invocation history in the service package and check the json being received. If its a connector where you’re expecting a response for a request, then you’ll able to trace and get the response message json.
Yes, you can check the incoming request JSON using Pega’s built-in tools. When an external system sends data to Pega through a REST service, the request details are stored in clipboard pages like pyRequestData or pyInboundRequest. You can also use Tracer by enabling “Service Invocations” and “Clipboard” options to see the data during runtime. Another way is to turn on DEBUG logging for the class com.pega.pegarules.integration.engine.internal.services.RESTServiceHandler which helps capture full request details in the logs. You can then check the PegaRULES log file to view the request. These methods do not need any custom code and help you view the request easily