Active Merchant is a simple payment abstraction library used in and sponsored by Shopify. It is written by Tobias Luetke, Cody Fauser, and contributors. The aim of the project is to feel natural to Ruby users and to abstract as many parts as possible away from the user to offer a consistent interface across all supported gateways.
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Active Merchant

This library is supposed to aid in creating e-commerce software in Ruby. In the future we want to support all “good” payment gateways.

This library is the foundation of commerce for

Please visit the ActiveMerchant homepage for more resources, tutorials and other information about this project.

Supported Direct Payment Gateways

The ActiveMerchant Wiki contains a table of features supported by each gateway.

Supported Offsite Payment Gateways


Currently this library is available with git from:



From Git

You can check out the latest source from git:

> git pull git://

As a Rails plugin

ActiveMerchant includes an init.rb file. This means that Rails will automatically load ActiveMerchant on startup. Run the following command from the root directory of your Rails project to install ActiveMerchant as a Rails plugin:

> ./script/plugin install git://

From Ruby Gems

Installation from RubyGems

> gem install activemerchant

Sample Usage

require 'rubygems'
require 'active_merchant'

# Use the TrustCommerce test servers
ActiveMerchant::Billing::Base.mode = :test

# ActiveMerchant accepts all amounts as Integer values in cents
# $10.00
amount = 1000

# The card verification value is also known as CVV2, CVC2, or CID 
credit_card =
                :first_name         => 'Bob',
                :last_name          => 'Bobsen',
                :number             => '4242424242424242',
                :month              => '8',
                :year               => '2012',
                :verification_value => '123'

# Validating the card automatically detects the card type
if credit_card.valid?

  # Create a gateway object for the TrustCommerce service
  gateway =
              :login => 'TestMerchant',
              :password => 'password'

  # Authorize for the amount
  response = gateway.purchase(amount, credit_card)

  if response.success?
    puts "Successfully charged $#{sprintf("%.2f", amount / 100)} to the credit card #{credit_card.display_number}"
    raise StandardError, response.message 


Please see the ActiveMerchant Guide to Contributing for information on adding a new gateway to ActiveMerchant.