package

github.com/crystal-money/fx-calculator

master / published Jun 18, 2026 / repository

⚖️ Simple command line tool for currency rate conversion

FX-Calculator CI Releases License

Simple command line tool for calculating foreign exchange rates.

Installation

git clone https://github.com/crystal-money/fx-calculator.git
cd fx-calculator

shards install
shards build --release

Usage

[!NOTE] Available rate providers can be found at https://github.com/crystal-money/money/tree/master/src/money/currency/rate_provider.

Get a currency exchange rate between EUR and USD, using the FloatRates provider.

./bin/fx-calculator -p FloatRates 'EUR to USD'

Convert 200 USD to PLN (by providing the currency inline), using the FloatRates provider.

./bin/fx-calculator -p FloatRates '$200 in PLN'
./bin/fx-calculator -p FloatRates '$200 to PLN'

Convert 200 USD and 430 EUR to PLN (by setting the default currency), using the FloatRates provider.

./bin/fx-calculator -p FloatRates -C PLN '$200' '430 EUR'

You can use a configuration file (-c /path/to/config.yml) instead of providing options through the command line:

currency: EUR

exchange:
  rate_store:
    name: File
    options:
      path: ~/.cache/fx-calculator/currency-rates.json
      ttl: 15 minutes

  rate_provider:
    name: Compound
    options:
      providers:
        - name: FloatRates
        - name: UniRateAPI
          options:
            api_key: your-api-key

To see all available options run ./bin/fx-calculator --help.

Contributing

  1. Fork it (https://github.com/crystal-money/fx-calculator/fork)
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Contributors

API