env-guard-ts 🛡️

Ultra-fast, zero-dependency, type-safe environment variable validator for Node.js & TypeScript.
Parse, validate, cast, and secure process.env at startup with zero overhead.

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Features

• ⚡ Zero External Dependencies: Minimal footprint, instant startup.
• 🎯 Strict Type Inference: Inferred TypeScript types matching your schema.
• 🔄 Smart Casting: Auto-casts numbers, booleans (true/1), URLs, ports (1-65535), choices, and JSON.
• 🛠️ Defaults & Optionals: Fluent .default(val) and .optional() chainable helpers.
• 🚨 Clear Diagnostic Errors: Combines multiple environment failures into a single clean summary.

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Installation

npm install env-guard-ts
# or
pnpm add env-guard-ts

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Quick Start

import { validateEnv, str, num, bool, port, url, choice } from 'env-guard-ts';

export const env = validateEnv({
  NODE_ENV: choice(['development', 'production', 'test'] as const).default('development'),
  PORT: port().default(3000),
  ENABLE_METRICS: bool().default(false),
  DATABASE_URL: url(),
  API_SECRET: str(),
  MAX_CLIENTS: num().optional(),
});

// `env` is 100% strongly typed!
console.log(`Server starting on port ${env.PORT} in ${env.NODE_ENV} mode.`);

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Available Validators

Validator	Target Type	Description
str()	string	Validates non-empty string
num()	number	Parses numeric string to JS number
bool()	boolean	Parses "true"/"false"/"1"/"0"
port()	number	Validates integer port range (1-65535)
url()	string	Validates URL format via new URL()
choice(['a', 'b'])	'a' | 'b'	Enforces literal enum value set
json<T>()	T	Parses stringified JSON payload

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Contributing

Pull requests and bug reports are welcome! Please see CONTRIBUTING.md.

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License

MIT © Swaraj Jakanoor