The Bank of England and Bank for International Settlements have developed application programming interface (API) prototypes for a retail central bank digital currency (CBDC) ecosystem. 

Project Rosalind was led by the UK arm of the BIS Innovation Hub. Participants and advisers included the Bank of Canada, the Central Bank of Hungary, Visa, Mastercard and Amazon. 

APIs offer a set of “standardised functionalities” to allow different systems to interoperate, the Project Rosalind report says