Role-Based Access Control (RBAC) in Next.js

As soon as you have an admin area or paid tiers, you need to control who can do what. Role-based access control (RBAC) is the standard, and it's straightforward in Next.js if you enforce it in the right places.

Model roles simply

Start with a `role` enum on your user model — often just USER and ADMIN. You can grow into more granular permissions later, but most products run happily on a small set of roles plus a few feature flags.

Enforce on the server, always

The golden rule: the UI can hide things, but security happens on the server. Check the user's role inside every protected server action and route handler. A hidden button is a convenience, not a defense — an attacker can call the action directly.

Layered checks

• Middleware: block unauthenticated users from whole route groups early.
• Layout: read the session and role to render (or redirect away from) the admin shell.
• Action: re-check the role before performing any mutation.
• Data layer: scope queries to the current user so nobody reads another tenant's data.

An env allowlist for super admins

A handy pattern: treat a list of admin emails from an environment variable as always-admin, in addition to the DB role. This gives you a reliable way in even if a role gets misconfigured, without hardcoding credentials.

KitCraft's SaaS templates implement this layered RBAC — middleware, role-gated layouts, guarded actions, and an env allowlist — so your admin area is secure by construction.