PSD2
PSD2 is the European Union directive that opened bank payment accounts to licensed third parties, mandating that banks provide access to accounts (XS2A) for account-information and payment-initiation services under strong customer authentication. It is the legal foundation of open banking across the EU and, as retained law, the UK — implemented technically by the OBIE standard in the UK and the Berlin Group NextGenPSD2 framework across the continent.
Countries
Where this binds. Each links to the providers apis.io has catalogued there.
Industries
Each links to that industry as a scored cohort — so the question "how ready is this sector for the regime that governs it?" becomes one you can actually look at.
Implemented by these standards
A regulation is the law; a standard is the machine-readable contract that satisfies it. Almost every regime in this catalog restricts an interface rather than requiring one — where a standard exists, it is the part a provider can actually publish.