PayPal API Confusion - Which one to use for ExpressCheckout

Question

I'm looking at the various integrations PayPal offer and as I just want to offer PayPal as a payment options, I'm going with Express Checkout. That being said, there are numerous ways this can be integrated it seems:

1. Name Value Pairs
2. Classic API (SDKs)
3. Restful API.

The issue I have is that the .NET SDK is part of the classic API set which is apparently being deprecated (source: https://github.com/paypal/merchant-sdk-dotnet). The RESTful API doesn't mention anything about ExpressCheckout so I am assuming NVP is the way to go.

Can someone clarify the best route to go down as I'd rather not have to rewrite it if things are being deprecated.

For info: I'm using ASP.NET MVC with C#.

Answer 1

First off, there are only two APIs:

1. Classic API
   • Request and response payloads are formatted as NVP and SOAP.
   • Official PayPal SDK support for Express Checkout available with the PayPal Merchant SDK for .NET (GitHub | NuGet)
2. REST API
   • Request and response payloads are formatted as JSON
   • Official PayPal SDK support available with the PayPal .NET SDK (GitHub | NuGet)

The PayPal Name-Value Pair API (NVP API) enables you to leverage the functionality of the PayPal API by simply sending an HTTP request to PayPal and specifying request parameters using name-value pairs. The NVP API is a lightweight alternative to the PayPal SOAP API and provides access to the same set of functionality as the SOAP API.

A few points to consider with respect to Classic API vs. REST API:

• Classic API is not going to be deprecated any time soon. You can use Classic API.
• Moreover REST API does not support many variables/parameters that work in Classic API.
• REST API can be used for both credit card and PayPal payments (express checkout architecture).

Since you are using .NET SDK, you can continue using it as it uses Classic API+NVP.