Keycloak 14 has support for FAPI 1 Advanced (Plain FAPI). OpenBanking Brasil has some additional requirements, which will be tracked in this JIRA.
Some requirements can be possibly addressed with the Keycloak extensions for the short term perspective. Some others will need changes in Keycloak for both the short term and long term perspectives.
For the long term perspective, it will be great to have nice support for all the required capabilities OOTB without need to do any hacks (EG. Avoid manually creating protocol mapper for "acr" claim, but rather have proper support for step-up authentication including proper flow for "acr").
FAPI-BR Example Configuration
Brazil DCR Example Configuration
Consent API (openapi docs)