Interactive Brokers offers the ability to trade, monitor and manage your IB account using a single RESTful API. A brokerage session is necessary to access order information, place orders, or receive market data, and involves a distinct set of backend processes from other functionalities such as looking up historical account information. See this tutorial to get started https://www.tradersinsight.news/ibkr-quant-news/tutorial-web-api-connect-to-brokerage-session/