core

A set of architecture and code-quality rules for building React interfaces with Vite, shadcn/ui, and TypeScript. It defines how to organize files, components, shared logic, and imports.

In plain words
What is it for?
Use it when creating or reviewing React pages, components, hooks, API services, forms, and shared TypeScript code in a Vite project.
Why use it?
It helps keep a growing frontend easier to understand and maintain by preventing oversized components, repeated code, and inconsistent file organization.

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/chihebnabil/lovable-boilerplate/core
Clone the repo
git clone --depth 1 https://github.com/chihebnabil/lovable-boilerplate

Made for: Cursor.

Per session 633 This file is loaded in full into every session.
When invoked 633 The same file — it is already loaded in full.
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 $0.00633 $0.00633
Opus 5 $0.00316 $0.00316
Sonnet 5 $0.00127 $0.00127
Haiku 4.5 $0.00063 $0.00063

Measured 2d ago against content hash 4e30c647c70a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

core 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.

.cursor/rules/core.mdc · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

React + Vite + shadcn/ui Template - Core Rules

CRITICAL ARCHITECTURE RULES

Component Size & Organization

  • NEVER create components over 300 lines
  • ALWAYS break down complex components into smaller, focused pieces (20-100 lines)
  • EXTRACT reusable logic to custom hooks, not copy-paste
  • USE composition patterns - build complex UI from smaller components

File Structure Requirements

src/
├── components/
│   ├── ui/              # shadcn/ui components (READ-ONLY)
│   ├── common/          # Reusable components
│   ├── forms/           # Form components
│   └── features/        # Feature-specific components
├── hooks/               # Custom React hooks
├── lib/
│   ├── utils.ts         # Utilities (includes cn function)
│   ├── types.ts         # Shared TypeScript types
│   ├── constants.ts     # App constants
│   └── validations/     # Zod schemas
├── pages/               # Route components (composition only)
├── services/            # API calls
└── context/             # React context providers

Import Organization

// 1. React imports
import React, { useState, useEffect } from 'react'

// 2. Third-party libraries
import { useQuery } from '@tanstack/react-query'
import { zodResolver } from '@hookform/resolvers/zod'

// 3. UI components
import { Button } from '@/components/ui/button'
import { Card } from '@/components/ui/card'

// 4. Local components
import { UserCard } from '@/components/common/UserCard'

// 5. Hooks and utilities
import { useDisclosure } from '@/hooks/useDisclosure'
import { cn } from '@/lib/utils'

// 6. Types and constants
import type { User } from '@/lib/types'
import { API_ENDPOINTS } from '@/lib/constants'

Essential Commands

npm run dev          # Start development server (port 8080)
npm run build        # Production build  
npm run lint         # Run ESLint - MUST pass before shipping

Quality Gates

  • BEFORE SHIPPING: Run npm run lint and fix all issues
  • ACCESSIBILITY: Maintain WCAG 2.1 AA contrast (4.5:1 minimum)
  • NO CONSOLE ERRORS: Zero warnings in browser console
  • RESPONSIVE: Test on mobile and desktop
  • DESIGN QUALITY: Industry-appropriate visual identity with purposeful color psychology
  • CUSTOM DESIGN: Interfaces should feel premium and custom-crafted, not template-like

Read the full file on GitHub · 75 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. 2d ago First seen · 75 lines · 633 tokens per session scan A 4e30c647c70a

Subscribe to this mod's changes

core is a cursor rule published in the GitHub repository chihebnabil/lovable-boilerplate (65 stars, last pushed 1mo ago), licensed MIT. It adds 633 tokens to every session, about $0.0032 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 2026-08-30.