API (Application Programming Interface) trading allows traders to connect their strategies or software directly to a broker’s system, enabling automated execution of trades without manual intervention. This technology is foundational for algorithmic trading. In this module, you’ll understand what APIs are, how they work in trading, and how to get started with APIs provided by brokers like Zerodha, Angel One, or Upstox. You’ll learn how to generate API keys, authenticate sessions, and place orders using POST or GET requests through Python. Key concepts like REST APIs, endpoints, rate limits, webhooks, and JSON payloads are explained in simple terms. A typical use case involves using an API to fetch live market data, apply your trading logic, and execute buy/sell orders instantly. With API trading, you can also build dashboards, set alerts, and automate your entire portfolio. However, one must follow compliance and exchange regulations, as unapproved usage can lead to penalties. Security, error handling, and continuous monitoring are also essential to prevent wrong trades. Overall, API trading empowers you to turn your trading ideas into fully automated systems, provided you have the right technical and risk-management setup.