I want to understand how technologies for connecting to liquidity providers work, what models exist (A-book, B-book, hybrid) and how they af

My task is not just to choose an LP, but to integrate it correctly from the technical side. I have heard about A-book (STP) models, where orders are sent directly to the provider, and B-book, where they remain within the platform. There are also hybrid models, where some orders are hedged and some are serviced internally. But I do not fully understand how these models are implemented technically, what protocols are used to connect (FIX API, WebSocket, REST API), and how all this affects the end user. I am also concerned about transparency: how to track transaction execution to be sure of the honesty of the LP? Tell me, which model is better to choose for a young but ambitious crypto exchange?