The TWS API is an interface to TWS or IB Gateway which offers functions such as order management, market data access and retrieval of account information. It requires that users first log into either the TWS or IB Gateway, both standalone desktop applications. The TWS API has an order rate limitation of 50 orders per second.
FIX/CTCI connectivity can be configured to connect either with IB Gateway or directly to IB. Unlike the TWS API, FIX/CTCI is only for order placement and can not be used to receive market data. In addition, there are monthly minimum commissions associated with the FIX/CTCI.
More information on FIX CTCI's Enhanced Network Connections required minimums can be found on our website.