Custom ADR outside from LoRaServer



I would like to start to implement my own ADR Algorithm (using metrics that are not provided to LoRaServer).
Any idea about a start point ?
As a first thing, I will have to disable LoRa Server ADR : how to proceed ?
Then I have to find gRPC modules that I can use to use my own ADR : is there documentation on ADR architecture some where ?