I have noticed that some applications provide functionality allowing the user to pull down transaction records (usually for credit cards) from an online banking system. Usually specific banks are supported.
What is the general method to achieve this (i.e., using an API, or something else)? I have seen a web app that supports the bank that I want to pull down transaction records from (ANZ), so I know it's achievable - but have not been able to find any references to any kind of online banking API.
I intend to implement a solution in Ruby on Rails, but I imagine the underlying method would hold regardless of the language used.