Foreign exchange rate API: official ECB reference rate for any fiat currency pair (USD/EUR, GBP/JPY — ~30 major ISO 4217

Foreign exchange rate API: official ECB reference rate for any fiat currency pair (USD/EUR, GBP/JPY — ~30 major ISO 4217 currencies) via the open-source Frankfurter API. Published once per business day around 16:00 CET — a daily reference rate for settlement and normalization, not a live trading feed. Use for currency conversion, pricing normalization, and financial reporting by agents. Cached up to 1 hour.