Cross-Origin Requests with the CORS NPM Package

Cross-Origin Resource Sharing (CORS) is a security measure browser use to control requests between different web origins. When your web page wants to fetch data from a different domain, CORS ensures it’s done securely.

CORS Headers:

• Access-Control-Allow-Origin: Specifies which origins can access the resource.
• Access-Control-Allow-Methods: Defines which HTTP methods are allowed for accessing the resource.
• Access-Control-Allow-Headers: Lists allowed HTTP headers during the actual request.
• Access-Control-Allow-Credentials: Indicates whether credentials (like cookies) can be included in the request.

Using the CORS NPM Package:

Install CORS:

npm install cors

Implement in Express:

const express = require('express');
const cors = require('cors');

const app = express();

// Enable CORS for all routes
app.use(cors());

// Your routes and application logic go here

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
 console.log(`Server is running on port ${PORT}`);
});

The cors NPM package simplifies CORS implementation in Express, ensuring secure communication between your web app and different origins.