env-shield

A robust, type-safe environment variable parser and validator for Node.js, Bun, and Frontend projects.

Ensure your application never starts with missing or malformed configuration.

Installation

npm install env-shield

Usage

Define your schema, and env-shield will automatically validate and infer TypeScript types!

import { parseEnv } from 'env-shield';

// By default it reads from process.env if available
const config = parseEnv({
  PORT: { type: 'number', default: 3000 },
  DATABASE_URL: { type: 'url' },
  NODE_ENV: { type: 'string', choices: ['development', 'production', 'test'], default: 'development' },
  ENABLE_FEATURE_X: { type: 'boolean', required: false }
});

// `config` is fully typed!
// config.PORT is `number`
// config.DATABASE_URL is `string`

If validation fails, it throws an EnvValidationError detailing exactly which variables are missing or incorrectly formatted, preventing cryptic runtime errors later in your application lifecycle.