SaaStart is a B2B SaaS starter kit built with Next.js and Auth0 that provides multi-tenancy organization management, user authentication/authorization, self-service SSO configuration (OIDC and SAML), security policy management (including MFA), user profile and security settings, and SCIM provisioning capabilities. The application follows a modern Next.js App Router architecture with server and client components, uses Auth0 for identity management, and implements role-based access control with admin/member roles. Key features include organization creation and switching, user invitation workflows, domain verification for SSO, and comprehensive dashboard for managing organization settings, members, and connections.