Yeah, sorry, I didn't phrase that well at all. What I understand you to be saying is the NinjaTrader supports automated futures trading, just not through TD Ameritrade. Thanks very much for the clarification.
Not exactly accurate, let me further clarify. NinjaTrader supports automated trading for futures, stocks and forex at all brokerages that we support NinjaTrader supports TDA for stocks only NinjaTrader supports Interactive Brokers and NinjaTrader Brokerage for futures trading
The TT platform from Trading Technologies is browser based and may be used on a Mac and iOS. No bootcamp required. We also a support automated trading and algo creation with ADL (Algo Design Lab). https://www.tradingtechnologies.com/solutions/algo-trading/ https://www.tradingtechnologies.com/platforms/apis/ https://www.tradingtechnologies.com/try-tt/
If you are not looking to run bootcamp on your mac, just use a VPS provider who supports access to multiple platforms to try out, for automated trading. Mind you, you will need to purchase your own datafeed but in your case i can recommend Ninjatrader as you can register for a free Futures Demo account and sim trade and backtest your strategy until you are ready to purchase the full licence.