[Openid-specs-fapi] Practical FAPI/PISP Information

[Anders Rundgren]

Hi List,

I'm currently exploring Open Banking APIs for payments.
I have a hard time finding public  information regarding how to deal with OAuth tokens:
https://standards.openbanking.org.uk/customer-experience-guidelines/pis-core-journeys/single-domestic-payments-supplementary-information/latest/
http://w3c.github.io/payment-method-credit-transfer/#payer-initiated-through-payee

Is there any mailing list dealing with such issues?

This is my current (probably very n00b) problem/question:
In order to perform any operation you must have a valid OAuth token, right?
If the payer has no relation with the PISP, a new OAuth token must be created for each payment, right?
Doesn't that lead to building an ever increasing heap of OAuth tokens in the ASPSP unless it caches the combination User + PISP?

Does somebody out there have a complete flow chart for a Merchant/PISP/PSU/ASPSP payment?

thanx
Anders