react

A set of rules for writing React user interfaces, including how components receive data, how effects are handled, and how Tailwind CSS v4 styles are written.

In plain words
What is it for?
Use it when building or changing React components with TypeScript, a shared UI library, CSS variables, responsive layouts, or Tailwind v4.
Why use it?
It keeps React code consistent and avoids common problems such as unclear component inputs or incorrectly managed effects.

Cursor rule for Codex

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/udecode/plate-template/react
Clone the repo
git clone --depth 1 https://github.com/udecode/plate-template

Made for: Codex.

Per session 25 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 8,580 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00025 $0.08580
Opus 5 $0.00013 $0.04290
Sonnet 5 $0.00005 $0.01716
Haiku 4.5 $0.00003 $0.00858

Measured yesterday against content hash a63e70815a32, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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.

Origin

This is a copy

100% identical to react — 0 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.

.agents/rules/react.mdc · 1,206 lines

How it starts

The opening of the file, as written. The whole thing — 1,206 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Requirements

  • Always use destructured props in function parameters
  • Define TypeScript types inline with the destructured props
  • Avoid creating separate interfaces for component props
  • Avoid non-destructured props that require additional destructuring inside the component
  • Use available UI components from the component library
  • Use CSS variables from globals.css for consistent theming
  • Use Tailwind v4 syntax (see Tailwind v4 Syntax)
  • DO NOT add icon margin in Button, DropdownMenuItem: use gap-2 instead
  • Use useEffectEvent to extract non-reactive logic from Effects (see Separating Events from Effects)
  • NEVER suppress the dependency linter with eslint-disable - use useEffectEvent instead
  • Use custom breakpoint syntax for responsive design (see App-Specific Rules)

Tailwind v4 Syntax

  • Inline opacity: Use / for opacity (bg-black/50 text-white/80)
    • v3: bg-black bg-opacity-50 text-white text-opacity-80
    • Removed: bg-opacity-*, text-opacity-*, border-opacity-*
  • Renamed utilities: shadow-smshadow-xs, rounded-smrounded-xs, blur-smblur-xs
  • CSS variables: Use parentheses bg-(--brand-color) instead of brackets bg-[--brand-color]
  • Important modifier: Exclamation mark at the end (size-5!) instead of beginning (!size-5)
  • Descendant selectors: Use **: for all descendants (replaces [&_*]:) and *: for direct children (replaces [&>*]:)
    • All descendants: **:px-4 instead of [&_*]:px-4
    • Direct children: *:px-4 instead of [&>*]:px-4
    • Element filtering: *:[a]:underline instead of [&>a]:underline, **:[a]:underline instead of [&_a]:underline
    • Data attributes: *:data-[slot=field-label]:flex-auto instead of *:[[data-slot=field-label]]:flex-auto. Keep [[data-...]] if there are other selectors.
    • Context-aware (in-): in-data-[slot=tooltip-content]:text-background instead of [[data-slot=tooltip-content]_&]:text-background
  • Composable variants: Chain variants together (group-has-data-selected:opacity-100, data-highlighted:ring-2)
  • Canonical classes: Always prefer built-in utilities over arbitrary values (e.g., w-full instead of w-[100%], translate-x-full instead of translate-x-[100%])
  • Default changes: Border color now currentColor (was gray-200), ring width now 1px (was 3px)

Read the full file on GitHub · 1,206 lines

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 · 1,206 lines · 25 tokens per session scan A a63e70815a32

Subscribe to this mod's changes

react is a cursor rule published in the GitHub repository udecode/plate-template (59 stars, last pushed 1mo ago), licensed MIT. It adds 25 tokens to every session and 8,580 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to react, differing in 0 lines, and is treated as a copy.

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