The new authentication server (MAS) is at https://github.com/element-hq/matrix-authentication-service https://github.com/element-hq/matrix-authentication-servic

The new authentication server (MAS) is at https://github.com/element-hq/matrix-authentication-service https://github.com/element-hq/matrix-authentication-service (AGPLv3) and entirely self-hostable - e.g. https://github.com/element-hq/ess-helm https://github.com/element-hq/ess-helm for the brand new official helm charts from Element, or https://github.com/element-hq/element-docker-demo https://github.com/element-hq/element-docker-demo for a very quick and dirty docker-compose setup i threw together. MAS provides backwards compatibility for the old Matrix auth APIs for existing Matrix clients, so they do not need to be modified to keep working. However, to get the most out of all the new auth features (2FA, MFA, QR login etc. etc.) then clients will need to be upgraded to speak OIDC natively. Element X for instance is already OIDC-native. https://areweoidcyet.com https://areweoidcyet.com has more details.