Managing a unique DMZ

My team and I have encountered a unique issue when trying to find a solution for managing a unique DMZ -
We have a L7 gateway between us and the DMZ, that only supports http/ws
It also only accepts json/xml payloads (when coming into our network)

We’ve looked at receptors (doesn’t work for us from what we’ve seen)

We’ve also looked at ansible-pull that doesn’t use json/xml payloads even when cloning with https

Our leading idea is to implement our own “ansible-pull” mechanism that works with jsons

How would you guys tackle that?