Is there an ActiveMerchant for Sinatra?

Question

What payment gateway library works with Sinatra if you're looking to add ecommerce functionality to your app?

Answer 1

ActiveMerchant works excellently as a stand-alone library, as well as a Rails plugin.

It was developed to for (sic) usage in Ruby on Rails web applications and integrates seamlessly as a plugin but it also works excellently as a stand alone library.

gem install activemerchant