env-setup

Env Setup

Scan the codebase for environment variable usage, generate or update .env.example, validate .env completeness, and detect leaked secrets.

Anti-Hallucination Guidelines

Only report variables that are actually found in the code:

1. Grep before reporting: Never invent variable names; only list what grep actually returns
2. Read .env.example before writing: Preserve existing entries; only add/update what changed
3. No actual secrets: .env.example must only contain placeholder values (e.g., your_api_key_here)
4. Verify .gitignore: Actually read the file before claiming .env is ignored
5. Never echo a found secret value: when Phase 6 flags a leaked secret, report the variable name and file:line only. Never print, quote, or write the actual value into chat output, a report file, or anywhere else: the scan's job is to locate leaks, not to create a second one.

Workflow

Phase 1: Scan Codebase

Grep for environment variable usage matching the project's actual language/framework: see references/scan-patterns.md for the ready-to-run pattern per language (Node/TS, Python, Ruby, Rust, Java/Kotlin, Docker Compose, client-exposed prefixes). Only run the pattern(s) for stacks present in the repo.

Also scan:

• .env.example (existing entries to preserve)
• config/ directory for config files referencing env vars
• Framework config files (next.config.js, vite.config.ts, etc.)

Phase 2: Categorize Variables

Group discovered variables by prefix/service: see the service prefix table in references/scan-patterns.md for the standard groupings (Database, Cache, Auth, OAuth, Stripe, AWS, Email, App config, Client vars).

Classify each variable:

• Required vs Optional (required if no default/fallback in code)
• Secret vs Config (secret if it contains key/secret/password/token in name)
• Client-exposed (NEXT_PUBLIC_*, VITE_*: flag if contains secrets)

Phase 3: Compare with .env.example

Read existing .env.example (if it exists):

# Variables in code but NOT in .env.example (missing)
# Variables in .env.example but NOT in code (undocumented/stale)
# Variables in both (up to date)

Report:

• Missing vars (need to be added to .env.example)
• Stale vars (in .env.example but no longer used)
• Up-to-date vars

Phase 4: Generate / Update .env.example

For scan or sync operations:

Generate .env.example with:

• SCREAMING_SNAKE_CASE variable names
• Grouped by service (with section comments)
• Placeholder values for secrets, real defaults for config
• Type and description comments

# =============================================================================
# Database
# =============================================================================
DATABASE_URL=postgresql://user:password@localhost:5432/app_development
JWT_SECRET=your_jwt_secret_here  # openssl rand -hex 32

Full section-header style and rules (preserve existing entries, only add what's missing, never a real value), see references/env-example-template.md, load it when writing the actual file.

Phase 5: Validate .env (if validate subcommand or .env exists)

Read .env and check:

1. Missing required variables: Every variable in code without a default/fallback must be set
2. Empty values: VAR= with no value is suspicious for required vars
3. Stale variables: Present in .env but not found in codebase scan
4. .gitignore check: Verify .env (and .env.local) are in .gitignore

grep -E "^\.env" .gitignore 2>/dev/null

Warn clearly if .env is NOT in .gitignore.

Phase 6: Secret Detection (if --check-secrets)

Scan .env for high-entropy strings and known secret patterns:

# Check for common secret patterns
grep -iE "(password|secret|api_key|private_key|token|auth_key)\s*=\s*['\"]?[A-Za-z0-9+/_.=-]{16,}" .env 2>/dev/null

The character class includes _, -, . alongside base64's +/=: most real key formats (sk_live_..., xoxb-..., AKIA...) contain underscores or hyphens, and a base64-only class silently misses them.

Check git history for leaked secrets:

git log --all --full-history --diff-filter=A -p -- .env 2>/dev/null | grep -iE "(password|secret|key)\s*=" | head -20

Report each hit as a commit + file:line reference (e.g. git log output line, or .env:12), never paste the matched value itself into the report.

Flag client-exposed secrets:

• Check NEXT_PUBLIC_*, VITE_*, REACT_APP_* variables
• If any contain "secret", "key", "password", "token" in the name, warn loudly, by variable name only

Recommend pre-commit tools:

• detect-secrets (Python): pip install detect-secrets && detect-secrets scan > .secrets.baseline
• gitleaks: gitleaks detect --source=.

Argument Parsing

• scan (default): Scan codebase, generate/update .env.example
• validate: Validate .env against discovered variables
• sync: Sync .env.example to match current codebase (add missing, mark stale)
• --check-secrets: Enable secret detection in .env and git history

Important Notes

• Never include real secrets in .env.example: only placeholder values
• Never echo a found secret's value: report variable name + file:line only, whether the finding goes to chat or a report file
• Client-exposed vars (NEXT_PUBLIC_*, VITE_*) are bundled into the frontend: flag if their name suggests a secret
• .env must be gitignored: verify and warn if not
• Historical leaks matter: even if .env is gitignored now, it may have been committed in the past
• Stale variables in .env can be security risks: document and remove unused ones