How to Write Scoped Cursor Rules for Next.js App Router Projects

A tutorial published on DEV Community outlines how to create three focused Cursor rules for Next.js App Router projects instead of relying on a single catch-all instruction file. The rules target distinct concerns: app and component conventions, server-side mutations and data access, and security boundaries covering authentication, authorization, and secret handling. Each rule uses glob patterns to activate only in relevant file paths, keeping guidance contextual and reducing noise during development. The security rule is intentionally broader since authorization or secret-handling mistakes can surface across routes, libraries, and components alike. The approach prioritizes placing the right reminder next to the code where an error would be most costly, rather than making an AI agent fully autonomous.