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/kws-projects/react-boilerplate/best-practicesgit clone --depth 1 https://github.com/kws-projects/react-boilerplateWhat 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 | $0.00734 | $0.00734 |
| Opus 5 | $0.00367 | $0.00367 |
| Sonnet 5 | $0.00147 | $0.00147 |
| Haiku 4.5 | $0.00073 | $0.00073 |
Grade A, and why
best-practices 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 2d ago.
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.
How it starts
The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Best Practices
Follow framework and language best practices. Write clean, readable, and maintainable code. Avoid hacky workarounds.
General
- Match the existing code style and project structure. Read neighbouring files before adding new ones.
- Prefer clarity over cleverness. Keep functions small and focused.
- Do not add
// @ts-ignore,any, or eslint-disable to silence problems without a justified reason. Fix the root cause. - No dead code, leftover debug logs, or commented-out blocks.
React / TypeScript
- Use strict, explicit types. Avoid
any; prefer precise types and generics. - Keep components pure; isolate side effects in
useEffect, providers, orlib/adapters. - Data fetching goes through React Query, not ad-hoc
useEffectfetches. - Access env only via
@/config/env; access external SDKs only via@/libadapters. Never import@sentry/reactor callwindow.gtagoutside ofsrc/lib/monitoring.tsandsrc/lib/analytics.tsrespectively. - Track analytics events via
analytics.track(...)oruseAnalytics(). Define new event shapes insrc/types/analytics.ts. - Capture errors via
monitoring.captureException(...)oruseMonitoring(). Add context withtags,extras, andbreadcrumbsfor debuggability. - All user-facing text uses i18n; support both LTR and RTL layouts (use logical
CSS properties / Tailwind
start/endutilities, not hardcoded left/right). - Use semantic color tokens (
bg-primary,text-destructive,bg-success, etc.) — never raw hex, rgb, or oklch values in component classNames. Add new colors viasrc/index.css(see thecolor-managementskill).
Responsive design
- Mobile-first: write the base/mobile layout first, then layer on
breakpoints (
sm:,md:,lg:,xl:). Avoidmax-*:overrides when a mobile-first approach works. - Use Tailwind breakpoints — do not write custom
@mediaqueries or inlinewindow.innerWidthchecks. The responsive system is built into every utility class (grid-cols-1 md:grid-cols-2 lg:grid-cols-3). - Content widths: constrain page content with
max-w-*+mx-auto+ horizontal padding (px-4). Avoid fixed-pixel widths. - Touch targets: interactive elements should be at least
h-9/44pxon mobile (shadcn defaults already satisfy this). - Text scaling: use Tailwind's responsive text utilities
(
text-base md:text-lg) rather than hardcoded font sizes. - Container queries: for component-level responsiveness (cards, widgets),
prefer
@container/@lg:over viewport breakpoints where appropriate. shadcn'sCardHeaderalready uses@container.
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.
- 2d ago First seen · 62 lines · 734 tokens per session scan A 882a2739524c
best-practices is a cursor rule published in the GitHub repository kws-projects/react-boilerplate (3 stars, last pushed 3mo ago), licensed MIT. It adds 734 tokens to every session, about $0.0037 per session on Opus 5. 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.
Other cursor rules, from other repositories
app_rules
This document outlines the essential rules and guidelines for developing with the MobileLauncher LT boilerplate. Follow these rules to maintain consistency, scalability, and code quality across the project.
app_feature_first_architecture
Feature-first architecture is a design pattern that organizes code by business features rather than technical layers. This approach promotes better maintainability, scalability, and team collaboration by keeping related functionality together and reducing coupling between different parts of the application.
server-actions
Guidelines for Server Actions — validation, error handling, and when to use Route Handlers instead.
best_practices
Advanced Best Practices covering Error Handling, Environment Variables, Performance, and Accessibility rules.
database-design
Database schema design patterns for Supabase with proper types and relationships.
hydration-safety
React hydration mismatch prevention.