www.rtfxd.com is $1 a month.
www.oanda.com fx api is $400 a month or free with a demo account.
https://www.elitetrader.com/et/threads/real-time-fx-api-1.356040/
Start with an IB friends and family account. You can trade 15 accounts without spending $100,000 in legal fees to start a hedge fund.
Then sack the lowest account balance when you want to bring in a bigger account.