Payments Library for CodeIgniter

I started a github project a few months ago when I needed an API integration with PayPal payments. The original idea was that one should be able to use one interface to process transactions through multiple payment systems.

I've been looking into the payments ecosystem and trying to figure out what would make really good library code for a payments interface.

2 things I ran across were Chargify and Spreedly. They let you use their API to accept payments and process through payment gateways all over the world - the mantra being you build the app, we'll handle the billing.

Are there any other similar sites / services that I should integrate with as well that you know of? If you are a PHP framework user, do you have anything to add about what YOU need or want to see in a payments library? Any potential "gotchas" or "hey, think about this" you can add?

开发者_如何学JAVAI appreciate it!

Very helpful - libraries that come really close to what I was looking for:

Active Merchant for Ruby on Rails

Payment Process 2 for PHP