Overview

When developing a Node.js application locally, you often need to:

Stop any previously running Node.js processes.
Set environment variables (such as passwords or secrets).
Start the application with the new configuration.

This guide explains each step.

Step 1: Stop All Running Node.js Processes

Get-Process node -ErrorAction SilentlyContinue | Stop-Process -Force

What this command does

Part	Description
`Get-Process node`	Finds all running Node.js processes.
`-ErrorAction SilentlyContinue`	Prevents PowerShell from showing an error if no Node.js process is running.
`Stop-Process -Force`	Immediately terminates all matching Node.js processes.

Why use it?

Sometimes an old Node.js process is still running in the background and holding a port (for example, port 3000 or 8080). Stopping it ensures you start with a clean environment.

Step 2: Set Environment Variables

$env:ADMIN_PASSWORD = "dev-password"
$env:SESSION_SECRET = "dev-secret"

What are Environment Variables?

Environment variables are values provided to your application outside of your source code.

Instead of writing secrets directly into your code:

❌ Bad

const password = "dev-password";

Use environment variables:

✅ Good

const password = process.env.ADMIN_PASSWORD;

This keeps sensitive information separate from your application code.

Understanding Each Variable

ADMIN_PASSWORD

$env:ADMIN_PASSWORD = "dev-password"

Your application can read this value as:

process.env.ADMIN_PASSWORD

Example usage:

if (inputPassword === process.env.ADMIN_PASSWORD) {
    console.log("Access granted");
}

SESSION_SECRET

$env:SESSION_SECRET = "dev-secret"

This secret is commonly used for:

Signing cookies
Signing JWT tokens
Encrypting sessions
Verifying authentication data

Example:

const secret = process.env.SESSION_SECRET;

Step 3: Verify the Variables (Optional)

You can check that the variables were set correctly.

echo $env:ADMIN_PASSWORD

Output

dev-password

Likewise,

echo $env:SESSION_SECRET

Output

dev-secret

Step 4: Start Your Application

After setting the variables, run your application in the same PowerShell window.

Example:

npm run dev

node app.js

Your application will now have access to both environment variables.

Important Note

Environment variables created like this are temporary.

They exist only for the current PowerShell session.

If you:

Close PowerShell
Open a new terminal
Restart your computer

you must set them again.

Complete Workflow

# Stop any running Node.js process
Get-Process node -ErrorAction SilentlyContinue | Stop-Process -Force

# Set development environment variables
$env:ADMIN_PASSWORD = "dev-password"
$env:SESSION_SECRET = "dev-secret"

# Start the application
npm run dev

Best Practices

✅ Store secrets in environment variables instead of hardcoding them.

✅ Use different values for development, testing, and production.

✅ Never commit real passwords or secrets to Git.

✅ Consider using a .env file with a library such as dotenv for local development.

Example .env file:

ADMIN_PASSWORD=dev-password
SESSION_SECRET=dev-secret

Summary

In this tutorial, you learned how to:

Stop existing Node.js processes.
Create temporary environment variables in PowerShell.
Access those variables from a Node.js application.
Start the application with the new configuration.
Follow basic security best practices for managing secrets during development.