The finance industry mainly uses OFX as the standard for online access to statements/transaction downloads (as does quicken, QuickBooks and gnucash...etc). Some banks do not support it and others go through aggregators to provide access.

You are doing people a huge disservice by identifying the companies you listed as "the finance industry". They are scraping data (in most cases against TOS) and exposing it as a paid API service.

It's a terrible state of affairs that easy access to ownership of this critical data is so hard to come by and has essentially forced people to give up their most valuable credentials to in a lot of cases unknown or untrustworthy parties.

At least mint has partnered with some banks that actually provide supported APIs for transaction data (Chase), but that is so far from the norm right now it makes me queasy.