Frankfurter is an open-source exchange rate API. To keep its dataset current, it fetches the reference exchange rates published by central banks and official institutions.

User-Agent

Mozilla/5.0 (compatible; Frankfurter; +https://frankfurter.dev/bot)

Schedule

Aligned to each source's publication window, usually once a day

Scope

Only the published exchange rate feed, API endpoint, or rate table

Operator

Line of Flight B.V., Amsterdam

What we fetch

Each adapter requests only the URL where an institution publishes its daily, weekly, or monthly exchange rates. We poll around the scheduled publication window and stop once the latest rates are in. We don't crawl unrelated pages or follow links across a site.

How to verify it's us

Anyone can copy a User-Agent string, so our requests also carry an RFC 9421 Ed25519 signature (Web Bot Auth) with Signature-Agent: "https://api.frankfurter.dev". You or your CDN can verify it against the public key directory at api.frankfurter.dev/.well-known/http-message-signatures-directory.

We also fetch from a fixed server IP address. Write to us if you need it for a firewall allowlist.

Contact

If your firewall or bot protection is turning our fetcher away and you'd like to let it through, or if you'd rather we stopped polling your server, write to [email protected].