iso4217

A tiny Ruby library that provides ISO 4217 currency codes and related information. It ships a JSON dataset and a simple API for listing currency codes or iterating over full currency records.

Add to your Gemfile and bundle:

gem "iso4217-rb"

Or install directly:

gem install iso4217-rb

Requires Ruby 3.0 or newer.

require "iso4217"

# Get the list of all ISO 4217 alpha codes (e.g., ["EUR", "USD", ...])
codes = ISO4217.codes

# Iterate over full currency records
ISO4217.currencies.each do |c|
  puts [c.country_name, c.currency_name, c.currency_code].join(" – ")
end

• ISO4217.codes → Array<String>

  • Returns all ISO 4217 currency codes.

• ISO4217.currencies → Array<ISO4217::Currency>

  • Returns structured currency entries. Each entry is an immutable Data object with the following fields:
    • country_name
    • currency_name (String)
    • currency_code (String)
    • currency_number (Integer) — numeric code as a string
    • minor_unit (Integer) — number of minor units (e.g., 2 for cents)
    • is_fund (true | false) — whether the entry represents a fund

The library exposes ISO4217::VERSION, which reflects the publication date of the underlying dataset in YYYY-MM-DD format.

The dataset is stored at config/currency_iso.json within the project and is loaded at runtime by the library.

A rake task is provided for updating the dataset, which should be run periodically

rake