env-file-generator

name	env-file-generator
description	Scan codebase for environment variable references and generate a complete .env.example file with safe placeholders. Use when the user asks to create or update .env.example or audit env var usage.

Skill: Env File Generator

Scan source code for process.env.* references and produce a comprehensive .env.example with documentation and safe placeholder values.

Trigger

When the user asks to create .env.example, audit environment variables, or ensure all required env vars are documented.

Prerequisites

• Access to project source code
• Knowledge of which env vars are required vs optional

Steps

Step 1: Scan for Environment Variable References

• Search for process.env. patterns across source files
• Search for os.environ / os.getenv (Python projects)
• Search for System.getenv (Java projects)
• Check existing config loader files for env var mappings
• Check Docker/compose files for environment: and ${VAR} references
• Check CI/CD config for required secrets

Step 2: Catalog Variables

For each variable found:

• Name (e.g., DB_PASSWORD)
• Where it's used (file and line)
• Whether it has a default value in code
• Whether it's required (no default, throws if missing)
• Data type (string, number, boolean, URL)
• Category (database, auth, cloud, feature flags, etc.)

Step 3: Classify Sensitivity

Level	Examples	Placeholder Format
Secret	DB_PASSWORD, JWT_SECRET, API_KEY	your-secret-here
Infrastructure	DB_HOST, REDIS_URL, S3_BUCKET	localhost / descriptive example
Config	PORT, LOG_LEVEL, NODE_ENV	Actual default value
Feature	ENABLE_FEATURE_X, MAX_RETRIES	true / false / number

Step 4: Generate .env.example

# ============================================
# {{CONFIG.project.name}} Environment Variables
# ============================================
# Copy this file to .env and fill in the values
# NEVER commit .env to version control
# ============================================

# ---------------------
# Application
# ---------------------
NODE_ENV=development
PORT=3000
LOG_LEVEL=info

# ---------------------
# Database
# ---------------------
DB_HOST=localhost
DB_PORT=5432
DB_NAME={{CONFIG.project.name}}
DB_USERNAME=your-db-username
DB_PASSWORD=your-db-password

# ---------------------
# Authentication
# ---------------------
JWT_SECRET=your-jwt-secret-min-32-chars
JWT_EXPIRY=15m

# ---------------------
# Cloud / AWS
# ---------------------
AWS_REGION=us-east-1
AWS_ACCESS_KEY_ID=your-access-key
AWS_SECRET_ACCESS_KEY=your-secret-key

# ---------------------
# External Services
# ---------------------
# REDIS_URL=redis://localhost:6379
# SMTP_HOST=smtp.example.com

Step 5: Cross-Reference

• Compare with existing .env.example (if any) to find new/removed vars
• Check .gitignore includes .env (add if missing)
• Verify config validation code matches the env var list
• Flag any env vars in code that are NOT in .env.example

Step 6: Generate Validation Code (Optional)

const required = ['DB_PASSWORD', 'JWT_SECRET'] as const;
for (const key of required) {
  if (!process.env[key]) {
    throw new Error(`Missing required environment variable: ${key}`);
  }
}

Step 7: Output

• Present .env.example content
• List any discrepancies (vars in code but not in example, or vice versa)
• Note which vars are required at startup

Rules

• NEVER put real secret values in .env.example
• ALWAYS use safe placeholder values (your-xxx-here, localhost, defaults)
• ALWAYS include comments explaining each section
• ALWAYS verify .env is in .gitignore
• Group variables by category with section headers
• Mark optional variables with comments (prefix with #)
• Include type hints in comments where ambiguous

Completion

Complete .env.example with all environment variables, grouped by category, with safe placeholders and documentation.

If a Step Fails

• Too many vars (>50): Group by service/module, add a table of contents comment
• Dynamic env var names: Flag for manual review (e.g., process.env[varName])
• Can't determine required vs optional: Default to required, flag for user review
• Existing .env.example out of date: Show diff of changes (added/removed vars)