Cryptsy is an online crypto-currency trading service that allows users to trade Bitcoins for a variety of alternative currencies and fiat currencies. The Cryptsy API has both public and authenticated methods. The public methods do not require an API key and allow users to query for general market data and general orderbook data. Authenticated methods permit users to query for advanced information such as market data, user transactions, market trades, market orders, user trades and user orders, as well as the creation and execution of trades. The service sues REST calls, returns JSON, and uses both SSL and an API key for authentication.