API (Application Programming Interface), is an interface which allow applications use other applications' functions. Simply, API allows you, using functions of Application X on your own Application Y.
API is used by software and application developers.
You can use BtcTurk | PRO API for monitoring prices, orderbook and trading. To create your API Key, navigate to Account > API Access page on BtcTurk | PRO website and press the CREATE API KEY button. If you would like you can limit permissions or restrict access to your API Key for one IP address. You can also turn off / on or delete your API key after you create it.
Please visit https://docs.btcturk.com/ for API documentation and code samples.
Support for API is being provided by BTCTrade development team. You can send your requests or ask questions using Issues section on BTCTrader's Github repo.