react-patterns

A set of review rules for React, a JavaScript library for building user interfaces. It checks component and hook usage, including hooks such as useEffect and useState.

In plain words
What is it for?
It is for checking hook dependencies, related state variables, memoization, functional components, and TypeScript prop types.
Why use it?
It helps spot common React mistakes and patterns that can make code harder to maintain or less efficient.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/abderrahimghazali/cursor-rules/react-patterns
Clone the repo
git clone --depth 1 https://github.com/abderrahimghazali/cursor-rules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 245 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00245
Opus 5 $0.00000 $0.00122
Sonnet 5 $0.00000 $0.00049
Haiku 4.5 $0.00000 $0.00024

Measured yesterday against content hash 7a12b31e5b4a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react-patterns 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.

.cursor/rules/react-patterns.mdc · 40 lines

What it actually says

React Patterns and Best Practices

Ensures React components follow recommended patterns and hook usage.

actions:

  • type: enforce conditions:

    • pattern: "useEffect\([^,]+\)" message: "Specify dependencies array in useEffect"

    • pattern: "useState\([^)]*\).useState\([^)]\)" message: "Consider combining related state variables"

    • pattern: "React\.memo\(.*\)" message: "Ensure React.memo is used appropriately for performance"

  • type: suggest message: | React Best Practices:

    • Use functional components with hooks
    • Implement proper memoization
    • Follow the Rules of Hooks
    • Use TypeScript for prop types
    • Consider custom hooks for reusable logic

metadata: priority: high version: 1.0

Changes

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.

  1. yesterday First seen · 40 lines · 245 tokens per session scan A 7a12b31e5b4a

Subscribe to this mod's changes

react-patterns is a cursor rule published in the GitHub repository abderrahimghazali/cursor-rules (2 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 245 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.