This document summarizes PayPal's history and capabilities for providing payment APIs at scale. It outlines PayPal's origins in 1998 facilitating online payments through various services. It describes PayPal's many API and integration options for developers. The document notes that PayPal processes over $5 billion in total payment volume per second and handles over 7.5 million payments daily at global scale across many markets and currencies. Lastly, it provides some tips for API design emphasizing easy integration, consistency, and open standards.