The Alpaca Data API is a new data product that provides real-time stock price data with up to 99.95% price accuracy, making it an essential tool for developers building algorithmic trading strategies or trading/investing applications. The API offers comprehensive coverage of the US stock market, true streaming market data via Websockets, and large historical data sets, allowing users to develop and test their strategies with confidence. With customizable bar data options, including intraday scalping algorithms and long-term asset allocation strategies, developers can build robust trading applications that provide high-quality display data to end-users. The API is completely free to use for all Alpaca users, regardless of account type or country of residence.