Recurly is a full suite recurring payment service that lets you easily create subscription plans, billing cycles, handle customers, revenue etc.
But .Net as a platform, and C# as a language is not very well supported by Recurly. They don’t event provide a client library for creating those signatures.
I needed a client library and wrote this simple class that I’ve now uploaded to Nu Get. The package is called RecurlyJS, and the source code is on GitHub.