Currency Index API
Live currency-index maths that FX desks run to turn a set of exchange rates into a single index value, computed on demand from the rates you pass in — no key, no cache, nothing stored. The dxy endpoint computes the US Dollar Index (USDX) from its six component rates using the official ICE weights and formula — feed in EUR/USD, USD/JPY, GBP/USD, USD/CAD, USD/SEK and USD/CHF and get the index value the way the exchanges calculate it. The index endpoint builds an arbitrary weighted index from your own components: geometric (the standard for currency indices) or arithmetic, with a scaling constant and negative weights for inversely-quoted pairs. The basket endpoint computes a trade-weighted index normalised to 100, showing how a currency has moved against a basket from a set of reference rates — above 100 means it strengthened. This is an index-construction engine, distinct from published effective-exchange-rate feeds and strength meters: you supply the rates and weights and it returns the index, deterministically. Works for any custom basket. Computed locally, so it is instant and private. Ideal for FX dashboards, custom dollar/euro indices, back-tests and macro tools. Live, nothing stored. 3 compute endpoints. For published effective-exchange-rate data use a central-bank or BIS API.
api.oanor.com/currencyindex-api