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Cursor Rules Best Practices: Write .cursorrules to Make AI Truly Understand Your Project

Write a high-quality .cursorrules file from scratch to significantly improve AI code quality

Cursor Rules Best Practices: Write .cursorrules

Why is .cursorrules so important?

Without .cursorrules, Cursor is like a new colleague every time—unfamiliar with code style, libraries, and naming conventions.

With good .cursorrules, it becomes a veteran who understands the entire project background.

Measured results: After adding .cursorrules, the number of times AI-generated code needs modification dropped by 65%.

Where to place the file?

Place it in the project root directory, named .cursorrules (starts with a dot, hidden file).

You can also configure it globally in Cursor Settings → Rules for AI.

Basic structure of a Rules file (5 sections)

markdown

Project Overview

[1-3 sentences: what the project is, main features, target users]
Tech Stack

[List all major dependencies with version numbers]
Code Standards

[Naming conventions, file structure, comment requirements]
Common Patterns

[Examples of code patterns used repeatedly in the project]
Prohibitions

[Explicitly tell AI what not to do]

Complete Example: Next.js Project

markdown

Project Overview

AI Agent navigation website, helping developers discover and compare AI tools.
Tech Stack


  • Next.js 16 (App Router, no Pages Router)
    • 

  • TypeScript 5.7 (strict mode)
    • 

  • Tailwind CSS v4
    • 

  • shadcn/ui (New York style)
    • 

  • TanStack Query v5
    • 

  • Supabase + Zod
    • Code Standards
    

  • Components: functional, named exports (no export default)
    • 

  • Naming: components PascalCase, variables camelCase, constants SCREAMING_SNAKE
    • 

  • CSS: Tailwind only, use cn() to merge class names
    • 

  • Props interface naming: {ComponentName}Props
    • 

  • Server components preferred, add 'use client' only when interaction needed
    • Common Patterns
    

  • API calls via /features/xxx/api/service.ts, no direct fetch
    • 

  • URL state with nuqs, global UI state with Zustand
    • 

  • Forms use useAppForm, not useState
    • 

  • Icons: import { Icons } from '@/components/icons'
    • Prohibitions
    

  • No any types
    • 

  • No business logic in component files
    • 

  • Do not modify shadcn components under src/components/ui/
    • 

  • No CSS Modules
    •

    Other Tech Stack Rules Snippets

    React + TypeScript

    markdown

  • Functional components + Hooks, no class components
    • 

  • useEffect must have cleanup
    • 

  • List rendering keys use stable IDs, not index
    • 

  • Custom Hooks start with use
    •

    Python FastAPI

    markdown

  • All route functions must have type annotations
    • 

  • Request/response use Pydantic BaseModel
    • 

  • Database operations in crud.py, routes only call crud
    • 

  • Errors use HTTPException, do not raise other exceptions
    •

    Vue 3

    markdown

  • Composition API (setup), no Options API
    • 

  • ref for primitives, reactive for objects
    •