cursorrules is a special file located in the root directory of your project that allows customization of AI assistant rules in Cursor. By defining specific rules in this file, you can provide AI with context on project background, coding standards, preferred libraries, file structures, and performance guidelines, ensuring that the AI-generated code and suggestions better meet your team's needs.

In simple terms, .cursorrules is the "communication bridge" between you and the AI. With it, you don’t have to manually adjust the AI's behavior every time; the AI will consistently provide suggestions within the scope of your project requirements.

How to Create an Optimal .cursorrules for Your Project? To fully leverage the .cursorrules file, you need to clearly convey the key aspects of your project to the AI. Here are some best practices for creating an effective .cursorrules file:

1. Provide Project Background Why is it important? AI does not know the background of your project, and background information helps the AI understand the project context to generate more relevant code.

Example:

Project Background

This is a multilingual blog web application based on Next.js, written using the Next.js framework. Explanation: At the beginning of the .cursorrules file, you can provide a brief project background introduction. Descriptions such as “This is a blog web application based on Next.js” enable the AI to choose appropriate syntax styles, file types, and methods when generating code.

2. Define Coding Standards Why is it important? Ensure that AI-generated code adheres to the team's coding conventions, avoiding inconsistent coding styles.

Example:

Coding Standards

• Use functional components and Hooks; avoid class components
• Prefer const for variable declarations over let
• Use camelCase for variable and function names; use PascalCase for component names Explanation: This snippet tells the AI that the team prefers functional components over class components. The AI will also prioritize using const for declaring variables and adhere to camelCase naming conventions for functions and variables, while component names follow PascalCase.

3. Specify Preferred Libraries and Frameworks Why is it important? If the AI doesn’t know your preferred libraries, it might generate inappropriate third-party dependencies.

Example:

Preferred Libraries

• Use Next.js for routing
• Use next-intl for internationalization
• Use Tailwind for CSS-in-JS styling Explanation: This indicates to the AI to prioritize Next.js for routing instead of other libraries (such as React Router). For styling, the AI will default to Tailwind rather than CSS modules or other CSS solutions.

4. Provide File Structure Information Why is it important? A clear file structure helps the AI generate more accurate file paths and import paths, reducing path errors.

Example:

File Structure

• components: Reusable UI components
• app/[locale]: Next.js pages supporting multiple languages
• data/blog: Multilingual blog files
• app/api: API service functions Explanation: Informing the AI about the directory structure helps it auto-generate import paths accurately. For instance, when you request the AI to create a new component, it will place it in the src/components directory rather than mistakenly placing it in src/pages.

5. Set Performance Optimization Guidelines Why is it important? If you don’t instruct the AI to focus on performance, it might generate code that does not adhere to performance best practices.

Example:

Performance Optimization Guidelines

• Use React.memo for pure functional components
• Implement lazy loading for routing components
• Optimize useEffect dependencies to prevent unnecessary re-renders Explanation: These rules help the AI generate more efficient code. For example, when the AI generates useEffect hooks, it will ensure the dependency array is complete to prevent unnecessary re-renders.

6. Set Testing Requirements Why is it important? If you have specific testing requirements, the AI can help you automatically generate test cases that comply with these standards.

Example:

Testing Requirements

• Use Jest and React Testing Library for unit tests
• Test coverage should be at least 80%
• Use snapshot testing for UI components Explanation: These rules tell the AI to use Jest and React Testing Library when generating test files and to automatically create snapshot tests to capture UI changes.

7. Write Documentation Standards Why is it important? Standardized documentation aids team collaboration and ensures AI-generated code includes annotations and explanations.

Example:

Documentation Standards

• Use JSDoc format for annotating functions and components
• Components must include PropTypes validation
• Each major directory must include a README.md file
• Provide README.md files in both English and Chinese Explanation: Using JSDoc rules ensures that AI-generated functions and components include annotations with function definitions, parameters descriptions, and return types.

8. Set Error Handling Preferences Why is it important? AI might not automatically consider error handling logic.

Example:

Error Handling

• Use try/catch blocks for handling async operations
• Implement a global error boundary component Explanation: These rules tell the AI to automatically use try/catch blocks within async functions and to possibly implement a global “error boundary” component within the project to catch runtime errors.

How to Use .cursorrules in Your Project? Create the File: Create the .cursorrules file in the root directory of your project. Define Rules: Define rules for project background, coding standards, and file structure as suggested above. Restart Cursor: Restart the AI assistant in Cursor to load the new .cursorrules file. Adjust in Real-time: Update the .cursorrules file timely as your project requirements change. How to Utilize “AI Rules” for Global Control? Apart from the project's .cursorrules file, you can also set global AI rules in Cursor’s “Settings > General > AI Rules.” These rules will automatically apply to every project, eliminating the need to manually create a .cursorrules file for each project.

Conclusion: Your Cursor Has Never Been So Smart By creating a .cursorrules file in your project, you can provide clear instructions to the AI, ensuring AI-generated code aligns with your project needs.

With these tips, you can not only accelerate development but also maintain a high standard of code quality.

We hope this guide helps you fully leverage the potential of Cursor and .cursorrules!