v1.2.9 – Processing Fees Bug Fixes

By: Ben Blodgett, CTO on March 17, 2017

Today we shipped major improvements to how processing fees are handled through the API. If you’ve been using the Hopsie API since the start you know how much time has been spent on processing fees. This is an integral part of online payments, and even more important for donation processing as many donors will include processing fees as part of their donation. It’s important that our platform is flexible for different processing fees across credit card providers and payment gateways.

We shipped a bug fix that was related to 1 cent variance that was being seen on certain transactions due to a rounding bug. We can finally say that we are 100% confident that all transaction fees are being calculated and reported accurately now.

The next step was to make processing fees dynamic based on the credit card that was used and the payment gateway that was set up for the user. This is important because some payment gateways charge more for American Express cards and in general we wanted to be fully extensible for the use of any payment gateway and any card type. Now all fees are calculated dynamically depending on the payment gateway and card type combination.


  • Reworked fee calculations to fix 1 cent rounding issue
  • Added support for 3.5% amex fees and discounted npo plans
  • Added gateway fees to JSON repsonse
  • Moved fee determination from donation processing code to database