Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/mitas/cursor-rules/reactgit clone --depth 1 https://github.com/mitas/cursor-rulesWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00454 | $0.00454 |
| Opus 5 | $0.00227 | $0.00227 |
| Sonnet 5 | $0.00091 | $0.00091 |
| Haiku 4.5 | $0.00045 | $0.00045 |
Grade A, and why
react scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
88% identical to react — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.
description: React best practices and patterns for modern web applications globs: /.tsx, **/.jsx, components//*
React Best Practices
Component Structure
- Use functional components over class components
- Keep components small and focused
- Extract reusable logic into custom hooks
- Use composition over inheritance
- Implement proper prop types with TypeScript
- Split large components into smaller, focused ones
Hooks
- Follow the Rules of Hooks
- Use custom hooks for reusable logic
- Keep hooks focused and simple
- Use appropriate dependency arrays in useEffect
- Implement cleanup in useEffect when needed
- Avoid nested hooks
State Management
- Use useState for local component state
- Implement useReducer for complex state logic
- Use Context API for shared state
- Keep state as close to where it's used as possible
- Avoid prop drilling through proper state management
- Use state management libraries only when necessary
Performance
- Implement proper memoization (useMemo, useCallback)
- Use React.memo for expensive components
- Avoid unnecessary re-renders
- Implement proper lazy loading
- Use proper key props in lists
- Profile and optimize render performance
Forms
- Use controlled components for form inputs
- Implement proper form validation
- Handle form submission states properly
- Show appropriate loading and error states
- Use form libraries for complex forms
- Implement proper accessibility for forms
Error Handling
- Implement Error Boundaries
- Handle async errors properly
- Show user-friendly error messages
- Implement proper fallback UI
- Log errors appropriately
- Handle edge cases gracefully
Testing
- Write unit tests for components
- Implement integration tests for complex flows
- Use React Testing Library
- Test user interactions
- Test error scenarios
- Implement proper mock data
Accessibility
- Use semantic HTML elements
- Implement proper ARIA attributes
- Ensure keyboard navigation
- Test with screen readers
- Handle focus management
- Provide proper alt text for images
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 78 lines · 454 tokens per session scan A 5b799b05bcf2
react is a cursor rule published in the GitHub repository mitas/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It adds 454 tokens to every session, about $0.0023 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to react, differing in 8 lines, and is treated as a copy.
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typescript
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coolify-ai-docs
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python_lib
Tips and guidelines specific to the development of the Streamlit Python library, not applicable to scripts and e2e tests.
specs
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