env-look

Catch .env drift before it breaks a deploy.

env-look compares your .env against .env.example and tells you exactly what's out of sync — missing keys, stray keys nobody documented, empty values, and duplicate definitions. Zero dependencies, works in any Node project regardless of framework.

The problem

Someone adds a new required env var, forgets to update .env.example, and three days later a teammate's local setup — or worse, a CI pipeline — breaks with a cryptic error, five layers away from the actual missing variable. env-look catches this in one command, and can gate CI so it never reaches production.

Install

npm install -g env-look

Or run it without installing:

npx env-look check

Usage

Check for drift

env-look check

env-look checking .env against .env.example

✖ Missing (1) - in .env.example but not .env:
  - DB_PORT

⚠ Extra (1) - in .env but not .env.example:
  - EXTRA_LEGACY_VAR

⚠ Empty values (1):
  - API_KEY

Options:

Flag	Description	Default
--env <file>	path to the env file to check	.env
--example <file>	path to the example file	.env.example
--strict	exit with code 1 if any issue is found	off
--json	print a machine-readable report instead	off

Generate .env.example from an existing .env

env-look init

Keeps every key, comment, and blank line from your .env, strips every real value, so nothing secret ends up in the file you commit.

Options: --env <file>, --out <file>, --force (overwrite if the output already exists).

Using it in CI

# GitHub Actions example
- name: Check env vars are in sync
  run: npx env-look check --strict

This fails the build the moment .env.example and the actual required config drift apart, instead of failing later at deploy time with a much less obvious error.

What it checks

• Missing — keys documented in .env.example but absent from .env
• Extra — keys in .env that aren't documented in .env.example (often dead config nobody cleaned up)
• Empty — keys present but with no value set
• Duplicates — the same key defined more than once in .env (the last one silently wins, which is a common source of confusing bugs)

Why zero dependencies

A tool that reads your environment configuration is a reasonable thing to be careful about. env-look ships with no runtime dependencies at all — nothing to audit beyond this repo's own code.

Contributing

Issues and PRs welcome. Run the test suite with:

npm test

License

MIT