Although the CorePro API is intended to be very simple to consume, having a pre-built SDK that handles all the details for you makes it just that much simpler.
See corepro-sdk-csharp on GitHub for source code.
Alternatively, install the CorePro.SDK NuGet package.
To install using Visual Studio, simply:
Manage NuGet Packages...
Onlineis selected in the upper left
See corepro-sdk-java on GitHub for source code.
See corepro-sdk-ruby on GitHub for source code.
Alternatively, install the corepro ruby gem.
See corepro-sdk-nodejs on GitHub for source code.
See corepro-sdk-python on GitHub.
See corepro-sdk-php on GitHub.