Firebase Rules Aren’t Enough: Decoupling Authorization for Scalable, Fine-Grained Access Control

Firebase's built-in security rules are effective for basic access control in app development, but they become insufficient as applications grow and require more complex, fine-grained authorization. This inadequacy is due to Firebase's tight coupling of access control logic with its infrastructure, making it difficult to scale or adapt the authorization model as user roles and data interactions become more sophisticated. Fine-grained authorization, which incorporates role-based (RBAC), attribute-based (ABAC), and relationship-based (ReBAC) access control, is proposed as a solution to decouple permissions from Firebase's infrastructure. This approach allows developers to externalize authorization logic, making it possible to model user permissions based on application-specific business logic and dynamic conditions. Permit.io is highlighted as a tool to help implement this externalized authorization by centralizing permission management, enhancing policy definition, and enabling real-time enforcement of access control, thereby allowing Firebase to act as an enforcement point rather than the sole decision-maker for permissions.