# lineofflight/frankfurter

💱 Currency data API

Repository: https://github.com/lineofflight/frankfurter
Canonical: https://ross.abutalabs.com/products/frankfurter
Homepage: https://frankfurter.dev
Language: Ruby
License: MIT
License Family: permissive
Topics: ruby, money, currency, api, currency-api, currency-converter, currency-exchange, currency-exchange-rates, forex
Last push: 2026-08-21T11:57:29+00:00

## Health v2 (maintenance only)
Score: 96/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 98, release rhythm 90, longevity 100
- inputs: {"age_days": 3100, "days_push": 12, "days_rel": 69, "gap_med": 2, "n_releases_24m": 12}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1804, forks 176 (observed 2026-08-28T04:05:38.279210+00:00)

## What it is
Frankfurter is an open-source currency data API that tracks daily exchange rates from 84 central banks covering 201 currencies back to 1948. It is available as a free public API at api.frankfurter.dev and can be self-hosted via Docker with optional API keys for additional central bank data providers.

## Use cases
- get latest exchange rates for currencies
- convert currency amounts in an app
- fetch historical exchange rates for a specific date
- download time series of exchange rates over a period
- pull exchange rates into Excel or Google Sheets
- self-host a currency rates API
- look up exchange rates from an AI assistant via MCP

## When to choose
- you need free, no-API-key access to daily exchange rates
- you need historical rates going back decades
- you want to self-host a currency API for full control
- you need rates from many central banks beyond the ECB

## When to avoid
- you need real-time intraday or tick-level forex quotes
- you need guaranteed SLAs of a commercial rates provider
- you need cryptocurrency exchange rates

## Facets
- artifact type: service
- maturity: active
- function: http-server, api-framework, search-engine
- domain: fintech, apis, self-hosted, developer-tools
- platform: self-hosted, ruby
- tags: currency-api, exchange-rates, forex, rest-api, mcp, central-bank-data, docker, web-server

## Member repositories
- lineofflight/frankfurter (main) score 96

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:38.279210+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:21:49.230846+00:00, confidence not recorded.
  - readme: https://github.com/lineofflight/frankfurter (fetched 2026-08-28T04:05:38.279210+00:00, sha 375c3963a178)
  - homepage: https://frankfurter.dev (fetched 2026-08-29T11:00:41.162818+00:00, sha f877e8a956e6)
  - site_page: https://frankfurter.dev/integrations (fetched 2026-08-29T11:00:41.172038+00:00, sha e2d6c85cbd01)
  - site_page: https://frankfurter.dev/v1 (fetched 2026-08-29T11:00:41.173806+00:00, sha b26e712df058)
- Data as of 2026-08-30T08:39:29.467469+00:00.