OIDC supports Initiating Login from a Third Party: https://openid.net/specs/openid-connect-core-1_0.html#ThirdPartyInitiatedLogin https://openid.net/specs/openi

OIDC supports Initiating Login from a Third Party: https://openid.net/specs/openid-connect-core-1_0.html#ThirdPartyInitiatedLogin https://openid.net/specs/openid-connect-core-1_0.html#ThirdP... Unlike SAML's "take this assertion" IdP-initiated flow, OIDC went for a "start an authentication with this IdP, for this user, and send them back here". Much, much safer.