For the API side, we use 3scale. It’s an API management platform that also manages billing. We have 3scale integrated with Authorize.Net to manage credit card processing. 3scale calculates invoices on a monthly basis, then sends that data to Authorize.Net, where the credit card transactions take place.
Co-founder - FullContact
1%Stacklist Startups Are Using 3scale
Visit the website: http://www.3scale.net/