Capital One is the only one (I think) in the US with an open API platform on the programmable web.
Credit Card API “The Credit Offers API provides developers with tools to offer Capital One credit products (credit cards, in particular) to their customers. Currently, the API contains a single resource and endpoint that lists the credit cards that are tailored for a specific customer. This API is currently in beta.”
ING seems to be flirting with the idea but really keeping it internally (so more like a private blockchain).
"ING is building a new wave of dashboard products for business intelligence that are all API-enabled, but these are being prototyped and developed for in-house teams and in an alpha release by their innovation lab. "