Stop letting missing environment variables crash your production builds

We’ve all experienced it. You push a new feature to staging or production, the deployment finishes, and then... a sudden crash.

You open the logs only to find a familiar error: process.env.STRIPE_API_KEY is undefined or invalid port: "3000px".

Someone added a new third-party API key to the codebase, or defined a PORT as a word instead of a number in their local environment, but forgot to update the staging configurations.

To solve this problem once and for all, I built envguard: an offline-first linter and validator for environment variables, written in Go.

What is envguard?

Traditional dotenv validators only check if files exist, often causing config drifts. envguard is different: it statically scans your codebase files to find what environment variables your code is actually referencing, and validates them against your .env configuration file.

It warns you about:

• ❌ Missing variables: Your code uses them (e.g. process.env.DB_URL), but they are not defined in .env.


• ⚠️ Unused variables: They exist in .env, but your code doesn't actually use them.


• 🚫 Invalid formats: A database URL that isn't a valid URL, or a port that is not a number.

⚡ Zero-Install Quick Start

If you have Node.js installed, you can scan your project instantly without installing anything:

bash

# Set up a validation config (one-time setup)

npx envguard-bin init



# Audit your environment variables

npx envguard-bin audit

If you prefer to run it globally or use other languages:



# Go

go install github.com/Vamshavardhan50/envguard@latest



# Python

pip install envguard-bin



# NPM

npm install -g envguard-bin