I received an email from IB saying there will be change in API: "Due to an external SEC rule update (RIN 3235-AN23), we are required to enforce a change in the round lot sizes of US stock that will ...

TWS API (Trader Workstation API): The legacy, powerhouse API. It's extremely powerful, fast, and feature-rich, but it's also more complex and requires you to run the TWS desktop software or the IB ...