I have been relying on Frankfurter for several years now to enable multi-currency ecommerce in my web apps. It's close enough to the perfect microservice—reusable, reliable, and very easy to set up if you prefer to deploy privately.
Use our server or self-host. We do not require API keys or otherwise limit access.
Query current and historical rates in any base currency. Download time series data.
Thousands of developers and companies use Frankfurter (formerly known as Fixer) since 2013.