Environment Variables Skill

Conventions and security practices for managing environment variables in Next.js projects.

When to Use This Skill

• Setting up a new project's environment configuration
• Adding new environment variables
• Reviewing security of environment handling
• Creating .env.example templates
• Troubleshooting environment issues

Core Principles

1. Never commit secrets - .env* files with real values stay out of git
2. Document with examples - .env.example shows structure without values
3. Prefix client-safe vars - Only NEXT_PUBLIC_* reaches the browser
4. Validate at startup - Fail fast if required vars are missing
5. Use typed configuration - Type-safe access to environment