safe-env-check

A small utility that validates required environment variables before your Node.js app starts.

Why use safe-env-check

Configuration mistakes are a common source of startup failures. safe-env-check helps you fail fast by validating required environment variables at startup.

• Stops startup when required variables are missing
• Prints a clear missing-variable list
• Exits with status code 1 for CI and deployment safety
• Works in JavaScript and TypeScript projects

Installation

npm install safe-env-check

Usage

TypeScript

import { checkEnv } from "safe-env-check";

checkEnv(["DATABASE_URL", "JWT_SECRET", "PORT"]);

console.log("App starting...");

JavaScript (ESM)

import { checkEnv } from "safe-env-check";

checkEnv(["DATABASE_URL", "JWT_SECRET", "PORT"]);

console.log("App starting...");

With dotenv

import "dotenv/config";
import { checkEnv } from "safe-env-check";

checkEnv(["DATABASE_URL", "API_KEY"]);

console.log("Server ready");

Example failure output

Missing environment variables:
   - DATABASE_URL
   - JWT_SECRET

API

checkEnv(requiredVars)

Validates required variables from process.env.

• Parameter: requiredVars (string[]) - list of required variable names
• Throws: Error if requiredVars is not an array
• Success: logs validation success
• Failure: logs missing variables and exits the process with code 1

Notes

• A variable is treated as missing when its value is falsy.
• Empty strings are treated as missing.

License

MIT