About Fixer.io currency exchange rates
A lightweight FX-rate API with history back to 1999.
Fixer.io is a foreign-exchange rates API run by APILayer, the Vienna-based data-API provider. The service publishes rates for roughly 170 currencies, sourced from financial data providers and central banks (the European Central Bank is named on the product page). Latest, historical, time-series, fluctuation and convert endpoints all return the same JSON shape, with EUR as the default base on the free tier and arbitrary base currencies on paid plans. Historical rates reach back to January 1999, which covers the full euro era.
The reason to land Fixer.io in a warehouse is that an FX rate is only useful when it is joined to a line of business. A latest-rate call from your billing app gets you a number for that one charge, but the same rate also drives the export invoice booked an hour later, the supplier payout that leaves tomorrow, and the management report that consolidates the month next week. Pulled into one place and stored per day and per currency pair, Fixer rates become the single reference your e-commerce platform, your ERP, your payment processor and your boekhouding all read from, instead of each system holding its own slightly different number.