Frankfurter

About Frankfurter

Frankfurter is a free exchange rates and currency data API tracking daily rates from 84 central banks, covering 201 currencies back to 1948. The public API is hosted at api.frankfurter.dev and requires no API key; the project is open source and can also be self-hosted via Docker for full control, including production API key configuration through its deploy guide.

The API provides endpoints for latest, historical, and time-series exchange rates, with support for changing the base currency, filtering target currencies, grouping time series by week or month, and scoping results to specific data providers. Responses are available as JSON, CSV, or NDJSON (for streaming large time series), and provider attribution can be included to show which sources contributed to a blended rate. There is no dedicated conversion endpoint; conversion is done by fetching a rate and calculating the result in application code.

The service is suited for developers building applications that need currency conversion or exchange-rate data, including AI agents (via an llms.txt file and an MCP server). There are no monthly or daily call quotas, though requests are rate-limited to prevent abuse; integrations are documented for Excel, Google Sheets, JavaScript, pandas, and Python. The v1 API remains supported alongside the newer v2 API.

Key features

• Daily exchange rates from 84 central banks covering 201 currencies back to 1948
• No API key required for the public API
• Historical rates and time series queries with date ranges and grouping by week or month
• CSV and NDJSON output formats for large or streaming responses
• Provider filtering and attribution to see which sources contributed to each rate
• Open source with self-hosting support via Docker

Frequently asked questions