How Rules Work

Understanding how project rules influence AI behavior

What Are Rules

Rules provide system-level instructions for AI Agents. They package prompts, scripts, and other content together, making it easy to manage and share workflows within teams.

Cursor supports four types of rules:

This article focuses on the working principles of project rules.

How Rules Work

When rules are applied, their content is added to the beginning of the model’s context. This provides consistent guidance for AI when generating code, understanding edits, or assisting with workflows.

Rule Application Flow

Project Rules Deep Dive

Project rules are located in the .cursor/rules directory, version controlled, and scoped to your codebase.

Why Choose Project Rules

Using project rules allows you to:

• ✅ Crystallize domain knowledge - Solidify expertise related to your codebase
• ✅ Automate workflows - Standardize project-specific templates and processes
• ✅ Unify technical decisions - Ensure consistency in style and architecture
• ✅ Team collaboration - Share via Git, onboard new members quickly

Rule Folder Structure

Each rule folder can contain:

• .cursor
  • rules
    • my-rule
      • RULE.md
      • scripts
      • template.ts

• RULE.md — Main rule file with frontmatter metadata and instructions
• Scripts and prompts — Other files referenced by the rule (optional)

Rule File Structure

Each rule corresponds to a folder containing a RULE.md file with frontmatter metadata and body content.

---
description: "This rule provides standards for frontend components"
globs: ["src/components/**"]
alwaysApply: false
---
 
- Define all components using TypeScript
- Components must use PascalCase naming
- Exported functions must specify return types
 
@component-template.tsx

Frontmatter Field Descriptions

Rule Application Methods

You can control how rules are applied via the type dropdown menu:

Practical Examples

Global Rules (Always Active)

---
alwaysApply: true
---
 
# Global Project Rules
 
## Tech Stack
- React 18 with TypeScript
- Vite as build tool
- TanStack Router for routing
 
## Directory Structure
- `src/pages/` - Page components
- `src/components/` - Reusable components
- `src/clients/` - API clients

File-Matched Rules (Active for Specific Files)

---
description: "API client development standards"
globs: ["src/clients/**"]
alwaysApply: false
---
 
# API Rules
 
- Use axios for HTTP requests
- All API functions must have error handling
- Use SWR for data fetching in components

Manually Triggered Rules

---
description: "Template for creating new feature modules"
alwaysApply: false
---
 
# Feature Template
 
Use this structure when creating a new feature...

Use @feature-template in chat to trigger this rule.

Creating Rules

There are two ways to create rules:

1. Using Command - Run the New Cursor Rule command
2. Using Settings - Create in Cursor Settings > Rules, Commands

This creates a new rule folder in .cursor/rules. You can view all rules and their status in settings.

Rule File Format Specification

A RULE.md file is a Markdown file with frontmatter metadata and body content.

---
description: "This rule provides standards for frontend components and API validation"
globs: ["src/components/**", "src/clients/**"]
alwaysApply: false
---
 
# Component and API Standards
 
## Components
- Use functional components with hooks
- Props interface must be exported
 
## API Validation
- Validate all API responses with zod schemas

Next Steps

Now that you understand how rules work, learn how to write high-quality rules.

If your project needs to manage extensive domain knowledge, explore Managing Memory with Rules.