Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.
Teller API - A single API to connect your app with any bank's account
TrueLayer - Simple Bank APIs to access real-time financial data
Mercury API - API for your business bank account
Nordigen - Free open banking API
ACH payments with Stripe - Accept bank payments with a few lines of code.