Nuxt.js, a Vue-based framework, provides a robust platform for building applications with features like server-side rendering and API integrations, but it lacks built-in access control, necessitating custom solutions for managing user permissions. As Nuxt applications grow, implementing multi-tenant Role-Based Access Control (RBAC) becomes crucial, especially for apps serving multiple organizations or regions. This guide explores implementing multi-tenant RBAC in a Nuxt.js application using Permit.io, an authorization-as-a-service platform that eases role management and permission enforcement. The tutorial demonstrates building a food delivery system where users are scoped to cities, acting as tenants, with roles such as customer, vendor, rider, and admin, each having specific permissions within their city. The process involves modeling multitenancy, setting up RBAC policies, connecting frontend components to server-side authorization, synchronizing users and roles, and protecting both frontend and backend routes. The example showcases the integration of Permit.io into the Nuxt project, using tools like Pinia for state management, Tailwind CSS for styling, and PrimeVue for UI components, highlighting the importance of multitenancy in ensuring data isolation and secure access control.