name: project-setup description: Non-obvious project setup patterns for environment config, gitignore hygiene, and release versioning. Use when initializing projects, auditing tracked files, setting up env validation, or planning releases. Focuses on common mistakes Claude makes without guidance. metadata: version: "1.0"

Project Setup

Environment Config — The Non-Obvious Parts

Validate at startup, fail fast

Don't just read env vars — validate them on boot so missing config fails immediately, not at 3am when that code path runs.

const required = (key: string): string => {
  const val = process.env[key];
  if (!val) throw new Error(`Missing required env var: ${key}`);
  return val;
};

export const config = {
  port: parseInt(process.env.PORT || '3000'),
  databaseUrl: required('DATABASE_URL'),
  jwtSecret: required('JWT_SECRET'),
} as const;

from pydantic_settings import BaseSettings

class Settings(BaseSettings):
    database_url: str
    jwt_secret: str
    port: int = 8000

    class Config:
        env_file = ".env"

settings = Settings()  # Validates on import, raises if missing

Env anti-patterns

Mistake	Why it's bad	Fix
Real secrets in .env.example	Gets committed, leaked	Fake/placeholder values only
No validation at startup	Fails at runtime, not boot	Validate eagerly
Same secret across environments	One leak compromises all	Unique per env
Secrets in Docker build args	Cached in image layers	Runtime env or Docker secrets
.env not in .gitignore	Secrets committed	Add immediately, rotate if exposed

Gitignore — The Mistakes

Claude generates fine .gitignore files. These are the mistakes to watch for:

Mistake	Fix
Committing .env then adding to .gitignore	`git rm --cached .env` + rotate all secrets
Ignoring lockfiles (package-lock.json)	Commit lockfiles — reproducible builds
Ignoring .vscode entirely	Only ignore `settings.json`, commit `extensions.json`
Not running an audit	`git ls-files \| grep -E '\.(env\|pem\|key)$'`

Versioning — Decision Tree

Claude knows semver. This is for the edge cases:

What changed? → What bump?
    ├─ Removed/renamed public API → MAJOR
    ├─ Changed existing behavior (even if "fixed") → MAJOR
    ├─ Added new feature (backwards compatible) → MINOR
    ├─ Added optional parameter → MINOR
    ├─ Bug fix (same API contract) → PATCH
    ├─ Performance improvement (same API) → PATCH
    ├─ Dependency update (no API change) → PATCH
    └─ Pre-release (0.x.y) → No stability guarantee

Release process

# 1. Update changelog
# 2. Bump version in package.json / pyproject.toml / etc.
git add -A && git commit -m "release: v2.1.0"
git tag -a v2.1.0 -m "Release v2.1.0"
git push && git push --tags

Automation tools

Tool	Ecosystem	What It Does
`semantic-release`	Node	Auto version + changelog from commits
`python-semantic-release`	Python	Same for Python
`release-please`	Any (GitHub Action)	Auto PRs with version bumps + changelog

Name	project-setup
Description	Non-obvious project setup patterns for environment config, gitignore hygiene, and release versioning. Use when initializing projects, auditing tracked files, setting up env validation, or planning releases. Focuses on common mistakes Claude makes without guidance.

project-setup

SKILL.md