Hello, FcgidAccessChecker restricts response to 200, 401, 403 only. With a SSO system, Access Checker should be able to reply with a 302 code to give SSO url. I'm developer of https://lemonldap-ng.org a full SSO system. Until now, we use a PerlAccessHandler to do this. We would like to replace our Perl Handler by an external FastCGI server (to build a sort of SSOaaS, see https://lemonldap-ng.org/documentation/2.0/ssoaas). But for now, we can't do it with Apache since FcgidAccessChecker does not permits 302 redirection, neither add headers to authorized queries. Contact me if this is not clear (I'm not English native ;-)) Best regards, Xavier