coding-guidelines

A set of coding rules for TypeScript and Next.js projects, covering strict typing, server components, error handling, performance, and accessibility.

In plain words
What is it for?
Use it when writing TypeScript types, configuring the compiler, building Next.js routes and components, handling errors, and checking web accessibility and performance.
Why use it?
It gives a team consistent engineering standards and reduces common problems such as unsafe types, unhandled failures, slow pages, and inaccessible interfaces.

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/smeubank/cursor-template/coding-guidelines
Clone the repo
git clone --depth 1 https://github.com/smeubank/cursor-template

Made for: Cursor.

Per session 2,893 This file is loaded in full into every session.
When invoked 2,893 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 $0.02893 $0.02893
Opus 5 $0.01447 $0.01447
Sonnet 5 $0.00579 $0.00579
Haiku 4.5 $0.00289 $0.00289

Measured yesterday against content hash a7b5f3789d03, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

coding-guidelines 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/coding-guidelines.mdc · 455 lines

How it starts

The opening of the file, as written. The whole thing — 455 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Coding Guidelines

🎯 Core Principles

  1. TypeScript First: All code must be TypeScript with strict type checking
  2. Server Components Default: Use Server Components unless interactivity is required
  3. Error Boundaries: Every route and major component must handle errors gracefully
  4. Performance: Optimize for Core Web Vitals and user experience
  5. Accessibility: Follow WCAG 2.1 AA standards

📝 TypeScript Standards

Type Definitions

// types/index.ts
export interface BusinessHour {
  id: number
  day_of_week: number
  open_time: string
  close_time: string
  is_open: boolean
  created_at: string
  updated_at: string
}

export interface BookingRequest {
  name: string
  email: string
  phone: string
  service: string
  preferred_date: string
  message?: string
}

export type BookingResponse = {
  id: number
  status: 'pending' | 'confirmed' | 'cancelled'
  created_at: string
} & BookingRequest

Strict Configuration

// tsconfig.json
{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "exactOptionalPropertyTypes": true
  }
}

🏗️ Next.js App Router Standards

File Organization

app/
├── (public)/           # Public routes group
│   ├── page.tsx        # Homepage
│   ├── about/
│   └── contact/
├── (admin)/            # Admin routes group
│   ├── dashboard/
│   └── settings/
├── api/                # API routes
├── globals.css         # Global styles
└── layout.tsx          # Root layout

Route Conventions

  • Server Components: Default for data fetching and static content
  • Client Components: Use 'use client' only when needed
  • Loading States: loading.tsx for each route segment
  • Error Boundaries: error.tsx for each route segment
  • Not Found: not-found.tsx for 404 handling

Metadata Standards

// app/page.tsx
import { Metadata } from 'next'

export const metadata: Metadata = {
  title: '[Your Project Name] - [Tagline]',
  description: '[Your project description and value proposition]',
  openGraph: {
    title: '[Your Project Name]',
    description: '[Brief project description]',
    type: 'website',
    locale: 'en_US',
  },
}

Read the full file on GitHub · 455 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 · 455 lines · 2,893 tokens per session scan A a7b5f3789d03

Subscribe to this mod's changes

coding-guidelines is a cursor rule published in the GitHub repository smeubank/cursor-template (6 stars, last pushed 1y ago), licensed MIT. It adds 2,893 tokens to every session, about $0.0145 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.