# Designing Secure Spring Boot APIs with JWT and RBAC

Security in a Spring Boot backend is more than adding JWT validation. A secure API needs a clear model for identity, roles, token lifecycle, validation, error handling, and audit events.

## Core Principles

- Authentication proves who the caller is.
- Authorization decides what the caller can do.
- Validation protects the service boundary.
- Audit logs preserve accountability for sensitive actions.
- Error responses should be useful without leaking secrets.

## JWT and RBAC Flow

In a typical JWT-backed system, login returns an access token and often a refresh token. The access token identifies the user and carries enough claims to resolve security context. Role checks should be enforced server-side through Spring Security and service-level guards.

For a SaaS platform like CloudCampus, role checks are not enough. A School Admin and a Teacher may both be authenticated, but their school context and allowed workflows are different. That means authorization must combine role, tenant, school, and domain-specific ownership rules.

## API Design Notes

- Keep request DTOs separate from persistence entities.
- Validate required fields at the controller boundary.
- Use centralized exception handling for consistent API responses.
- Avoid raw stack traces or internal implementation details in responses.
- Record audit events for login, invitation, role changes, tenant onboarding, and other sensitive flows.

## Next Improvements

- Add tests for unauthorized role access.
- Add tests for tenant and school boundary enforcement.
- Add rate limiting for login and password reset flows.
- Add security headers at hosting or reverse proxy level.