envpatch

Never deploy with a broken .env again — validate, diff, and sync environment files in one command.

Demo

$ envpatch check

✗ Missing keys (2):
  - DATABASE_URL
  - REDIS_URL

⚠ Empty values (1):
  ~ APP_KEY

3 issues found

$ envpatch sync

Added 2 keys to .env:
  + DATABASE_URL=
  + REDIS_URL=

$ envpatch check

✓ .env is valid

Features

• Catch broken deploys early — spot missing keys before they cause production errors
• Visual diff — see exactly what's different between .env and .env.example at a glance
• One-command sync — copy missing keys from .env.example to .env automatically
• Safe by default — --dry-run previews all changes before writing anything
• Custom paths — works with any naming convention (--env, --example flags)
• Zero config — drop it into any project, no setup required

Getting Started

Prerequisites

• Node.js 18+

Install globally

npm install -g envpatch

Or run without installing

npx envpatch check

Usage

# Create .env from .env.example (replaces: cp .env.example .env)
envpatch init

# Create with a custom output name
envpatch init --out .env.staging

# Check for missing or empty keys
envpatch check

# Show a visual diff
envpatch diff

# Add missing keys from .env.example to .env
envpatch sync

# Preview sync without writing
envpatch sync --dry-run

# Use custom file paths
envpatch check --env .env.staging --example .env.example
envpatch diff  --env .env.staging --example .env.staging.example

In CI pipelines

# GitHub Actions — fail the build if .env is out of sync
- run: npx envpatch check

In package.json scripts

{
  "scripts": {
    "env:check": "envpatch check",
    "env:sync": "envpatch sync --dry-run",
    "predev": "envpatch check"
  }
}

Stack

| | | |---|---| | Language | TypeScript 5 | | Runtime | Node.js 18+ | | CLI framework | Commander | | Output | Chalk |

Contributing

Pull requests are welcome. For major changes, open an issue first to discuss what you'd like to change.

License

MIT

Support

If envpatch saves you from a broken deploy, consider sponsoring on GitHub.