Forex API-Convert Real Time Value from xignite converts an amount from one currency to another using the real-time rate. If the real-time rate is not available for a currency pair (e.g. on a weekend), then the most recent available rate is used. Over 29,000 historical and real-time currency pairs are covered.
The API uptime is at least 99.9% and the data is updated in true real-time as new quotes are issued from market participants. Data is returned in XML, JSON, or CSV format.