API stands for Application Programming Interface. It defines the rules by which one system can communicate with another — what requests it accepts, what data format to use, and what it returns in response.
APIs are how agents interact with the outside world: reading from a CRM, writing to an ERP, checking a database, triggering a downstream process. An agent without API access is limited to what it knows from its training data. API access is what allows agents to take action in real systems.
