“I need access to the system to get access to all data.”
No.
What you need is an endpoint you can call whenever you want to get only the data you need.
Customers come to us with needs, in the middle there are always wants and stretching towards what they want (ask for the ocean and get the lake you need).
The goal is to separate what they want from what they need but also to give them what they haven’t asked for that they are going to need.
Needs aren’t less than the wants, they are what is required to deliver and make everyone happy.