What do you mean with API?
Quote from nasdaqmadness:
I have been using Bracket Trader with IB and this works really well. 1 click entry for multiple contracts. instantly transmits your stops and targets. Nice scale in or out feature, and best of all its free. I mostly scalp ES and YM so this type of set up is a must. FT (Futures Trader) is also great front end for IB. Happy Trading
Links below
www.futures-trader.net/
www.bracket-trader.com/