The SaaS Entitlement Engine Builder

 Build a SaaS entitlement engine that converts subscription plans, feature limits, usage quotas, add-ons, trials, and organization policies into a centralized access-control system. Generate a plan editor, entitlement evaluation service, usage counters, upgrade and downgrade rules, grace periods, and audit logs. Handle edge cases such as expired trials, failed renewals, plan changes during active usage, and administrators with custom permissions. Include backend enforcement, test cases for every plan transition, and a clear separation between billing status and actual feature authorization.