Are there any APIs that I can use to access my own credit info programmatically?

Emphasis on **my** info, obviously.

I’m a programmer, and I want to write a personal finance manager for myself. Of course a major part of that is being able to aggregate credit card transactions, balances, etc.

Are any of the APIs that all the existing programs use available for individual use?

Something like an endpoint that takes a POST request with auth credentials, or credentials in the body maybe?