NetCore8583 is a library that helps parse/read and generate ISO 8583 messages. It does not handle sending or reading them over a network connection, but it does parse the data you have read and can generate the data you need to write over a network connection.
The Best Bank Portugal Connect is a open source C# library that helps to connect to the Best Bank's Open Banking PSD2 API, a bank based in Portugal. Features:
-Authorization flow (OAuth 2)
-Make payments via portuguese standarts.