QuickBuild supports single sign-on via SAML2 protocol like below:
With this setup, QuickBuild works as SAML service provider, and you should at least configure it with SP private key, SP certificate and metadata from SAML identify provider.
Check here for an example setup.
SSO only takes effect when visit the web UI. User agent, RESTful API access and tray monitor have to authenticate to QuickBuild with normal user name and password.