The Authentication SPI is being refactored in 3.0. Like what happened
in Keycloak 2.x and the User Storage SPI, the Authentication SPI will be
refactored and improved through various 3.x releases. We'll clean up
areas, rewrite certain areas, and get the SPI ready so that it can be
stable and supportable for the foreseeable future. We are also doing
this work so that we can support things like step-up authentication and
FIDO etc. although the latter is for much later down the road.
The first area that will be tackled will be the Form SPI.
Regards,
Bill