
Hourly exchange rates for 160+ currencies in JSON, XML or CSV with free plan 2,500 requests/month.
Rate-API is a free Currency Exchange API that requires apiKey authentication, is served over HTTPS and supports CORS, so it can be called from the browser.
Rate-API reference: endpoints, parameters and code examples for the latest and historical exchange rates on 160+ currencies. Free tier, JSON/XML/CSV.
Details from rate-api.com.

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Iran free-market USD, EUR, CNY, gold and coin rates in toman, live and daily archive since 2010
The Rate-API is provided by Rate-API (rate-api.com). Rate-API reference: endpoints, parameters and code examples for the latest and historical exchange rates on 160+ currencies. Free tier, JSON/XML/CSV.
Yes. The Rate-API is listed in the Currency Exchange category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Rate-API uses apiKey authentication, so you need to register for credentials before making requests.
Yes. The Rate-API supports CORS, so front-end JavaScript can call it directly.
Yes. The Rate-API is served over HTTPS, so it's safe to use in production.