https://oa.dnc.global/id_token_hint-Silent-Re-authentication-of-subject-with-ID-Token.html Authenticating subject with ID Token is an option of OpenID Connect Authorization code flow. To fulfill the OpenID Connect certification, it is necessary to complete the test "OP-Req-id_token_hint". The Brent Shaffer's oauth2-server-php library does'nt process id_token_hint. OAuthSD will take care of it. The use case consist to call Authorize using prompt=none and passing ID Token in id_token_hint parameter. The specification states : id_token_hint OPTIONAL. ID Token previously (…) en SPIP - www.spip.net https://oa.dnc.global/local/cache-vignettes/L93xH94/arton143-ddb95.png?1794160535 https://oa.dnc.global/id_token_hint-Silent-Re-authentication-of-subject-with-ID-Token.html 94 93