Top 20 NuGet checkout Packages

.NET SDK library for Klarna Services
Please Use: https://www.nuget.org/packages/Coinbase/ The Coinbase.Mvc DLL has been deprecated.
Yandex Checkout .NET Client
.NET SDK for Checkout RESTful APIs
For merchants who have built their app on Xamarin platform - Paytm provides a NuGet package for you to conveniently integrate All-in-One SDK.
Client for Svea Ekonomi checkout solution. Simplifies REST calls with securitytokens to simple class function calls.
Klarna Checkout
SDK for Klarna Checkout v3 and Order Management v1 APIs
A .NET implementation for the Coinbase API for online payments. The Coinbase API is a way to seamlessly pay for goods or services online utilizing Coinbase and Bitcoins for low-cost payment processing.
A .NET implementation of the Coinbase Commerce API for cryptocurrency payments. Coinbase Commerce is the easiest and safest way for a business to start accepting digital currency payments. Works with Bitcoin (BTC), Ethereum (ETH), Litecoin (LTC), and Bitcoin Cash (BCH)!
API wrapper for the Checkout.com Payment Gateway Docs: https://docs.checkout.com/docs/api-quickstart GitHub: https://github.com/checkout/checkout-net-library
Com.MasterCard.Masterpass.Merchant SDK. Masterpass Merchant Checkout Service SDK supports standard, connected and express checkouts.
Com.MasterCard.Merchant.Checkout SDK.
A .NET implementation for the Dwolla Checkout (off-site gateway) API for online payments. The Off-Site Gateway API is a way to seamlessly pay for goods or services online utilizing Dwolla's low-cost payment processing platform.
C#/.Net Standard 2.0 SDK for Svea WebPay REST API
Simple Paddle Checkout SDK for Windows
MPOSAir inter-service communication tools
Simple Paddle Checkout SDK for Windows
Google Checkout .NET Client Wrapper
Stripe Checkout (stripe-checkout) binding library for Bridge.NET projects.