Fidel API | 9,705 followers on LinkedIn. Fidel API is a global financial infrastructure platform that enables developers to build programmable experiences at the moment a transaction occurs on any payment card. Its tools are transforming how merchants and users interact by powering real-time, event-driven engagements, best-in-class loyalty and rewards programs. Fidel API is trusted by start-ups through global enterprises including Google, British Airways, TopCashback, Perkbox, Royal Bank of Canada, and Blackhawk Networks, and is supported by the world’s largest card networks, including Visa, Mastercard and American Express.