Overview

Give every model that handles money a consistent interface, without adding another pair of amount and currency columns to its table. Midas stores values in a shared, polymorphic Coin ledger:

class Product < ApplicationRecord
  include WhittakerTech::Midas::Bankable
  has_coin :price
end

Use the same approach for prices, fees, balances, or several independent values on one record. Midas handles currency-aware amounts and conversion, so money behavior can stay consistent as your application grows.

From monetary values to auditable flows

For everyday model attributes, Coin and Bankable are the core. When billing or payments also need a clear, auditable explanation of how balances changed, Midas adds a double-entry Ledger with balanced, immutable postings. The Ledger complements the simpler value model; it does not replace it. See the documentation for the API and implementation details.

Key features

Polymorphic Coin ledger

One Coin model stores every monetary value, for any model.

Multi-currency support

Built on the money gem, with conversion between currencies.

Declarative DSL

has_coin and has_coins attach money to a model in one line.

Zero schema duplication

No more price_cents and currency columns repeated across tables.

Headless currency input

A Stimulus-powered input field that leaves the markup to you.

Tested and documented

90%+ test coverage, full API documentation and an architecture overview.

Additive double-entry ledger

Record balanced, immutable postings when a monetary workflow needs an auditable trail.

Installation

Gemfile

gem "whittaker_tech-midas"

Install

bundle install

Install Midas and run the migrations

bin/rails generate whittaker_tech:midas:install
bin/rails db:migrate

Next steps

Read the full documentation for configuration, usage and API guides.

View documentation

Common use cases

Product catalogs and configurable pricing

Multi-currency applications

Invoices, billing, fees and payments

Models with multiple independent monetary values