U.S. Treasury / Official Treasury exchange rates for foreign currencies

The Treasury Reporting Rates of Exchange: the official rate the US government uses to convert foreign currency amounts to USD, about 170 country-currency pairs, published quarterly (and amended when a rate moves 10% or more). exchange_rate is foreign currency units per 1 USD. Filter by country_currency_desc (Canada-Dollar, Euro Zone-Euro, Mexico-Peso, Japan-Yen) or country, e.g. country_currency_desc:in:(Canada-Dollar,Mexico-Peso). Answer: data (rows, all values as strings), meta (count, total-count, total-pages, labels, dataTypes) and links. An unknown field in filter or fields is a clean 400. Source: U.S. Department of the Treasury, Bureau of the Fiscal Service (fiscaldata.treasury.gov), free and without restriction. Free on looot: $0 per call.