*How SAML works * SAML (Security Assertion Markup Language) is an XML-based protocol for Single Sign-On. The core idea: instead of every app managing its own login, one trusted system (the IdP) handles authentication and vouches for you to other apps (SPs) via a signed XML token. There are two flows — SP-initiated (most common — user hits the app first) and IdP-initiated (user starts from an IdP p