MODULE 3

Project Setup

3.1: The First 10 Minutes

Before writing a single line of application code, set up your project structure, guardrails, and documentation. This takes 10 minutes and prevents hours of disorganization later.

Create project structure

Create the key directories: docs/, scripts/, tests/. Never let files pile up at the project root.

Write your planning docs

Create docs/brainlift.md, docs/prd.md, and docs/gameplan.md from Module 2.

Set up .cursorrules

This file tells AI your coding standards, conventions, and guardrails. It's read automatically by Cursor.

Create a comprehensive .gitignore

Block secrets, build artifacts, IDE files, and OS files from day one. Never commit a .env file.

3.2: User Rules (.cursorrules)

Your .cursorrules file gives AI a "senior developer" identity. It enforces your coding standards on every interaction.

Here's a production-ready example:

# SECURITY
- Never trust user input -- validate and sanitize everything
- Never commit secrets or API keys
- Use parameterized queries (no SQL injection)
- Fail securely -- default to deny

# CODE QUALITY
- Single responsibility principle -- each function does ONE thing
- Write tests alongside code
- Build/compile before committing
- Minimize external dependencies

# ORGANIZATION
- Put docs in docs/, scripts in scripts/, tests in tests/
- Never create files at project root unless necessary
- Simple commit messages, no emojis

# PAID SERVICES
- SHOW THE MATH -- calculate and comment max monthly cost
- LIMIT EVERYTHING -- no operation without explicit maximum
- PREVENT LOOPS -- code must not trigger itself without guards

Without rules, AI makes common mistakes: adds unnecessary dependencies, creates god-functions, puts files everywhere, ignores security. Rules prevent this from the start.

3.3: File Organization

AI loves dumping files at the project root. Fight this explicitly:

project/
  docs/            # planning docs, brainlift, PRD
  src/             # application source code
    components/    # UI components
    services/      # business logic
    utils/         # shared utilities
  scripts/         # build scripts, migrations, one-off tools
  tests/           # test files
  .cursorrules     # AI guardrails
  .gitignore       # comprehensive from day one
  README.md        # project overview

When prompting AI, always specify exact paths:

Create the UserService in src/services/UserService.ts.
Follow the pattern from src/services/AuthService.ts.

Never say "create a user service" without specifying where it goes.

3.4: The .gitignore

Start with a comprehensive .gitignore from day one. Here's a baseline:

# Dependencies
node_modules/

# Build artifacts
.next/
out/
dist/
build/

# Environment & secrets
.env
.env.local
.env*.local

# IDE
.idea/
.vscode/
*.swp
*.swo

# OS
.DS_Store
Thumbs.db

# Logs
*.log
npm-debug.log*

# TypeScript
*.tsbuildinfo
next-env.d.ts

# Deployment
.vercel
.netlify

Before every commit, run git diff --staged and scan for API keys, tokens, passwords, or .env values. One leaked key can cost you thousands.

3.5: Git Workflow Basics

Set up clean git habits from the start:

Branch per feature: git checkout -b feature/user-auth
Build before commit: npm run build && npm run test
Short commit messages: "add user auth with JWT" not "Added authentication with JSON Web Tokens using the NextAuth.js library with credential provider"
Never push secrets: check git diff --staged every time

2. Planning Before You Build 4. The Build Process