In modern web applications, it is very common to have user authentication and authorization systems. These systems provide user-specific functionality and data, which requires that each user has a certain level of access and control over the resources they own. However, when these resources are accessed in a rapid and repetitive manner, it can lead to abuse or misuse of the system, which can lead to resource depletion, denial of service, and other security concerns. Therefore, implementing user base rate limiting is essential to protect your application and ensure its availability.

In this blog, we will discuss how to implement user base rate limiting using the express-rate-limit package in Node.js. express-rate-limit is a middleware that can be used to limit the number of requests a user can make to an API endpoint. By default, it allows only a limited number of requests per IP address per windowMs (by default, 1 request per windowMs) but we can also set up rate limiting based on other user identifiers such as user ID, email, or other custom properties.

Here are the steps we will follow:

Step 1: Install the express-rate-limit package

To get started, we first need to install the express-rate-limit package. You can install it using the following command in your terminal:

npm install express-rate-limit

Step 2: Define the rate limiting middleware function

The next step is to define the rate limiting middleware function that will be used to limit the number of requests a user can make. This function will use the express-rate-limit package to limit the requests based on a user identifier.

const rateLimit = require('express-rate-limit');

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // limit each IP/user to 100 requests per windowMs
  keyGenerator: function (req) {
    return req.user.id; // use user ID as the key
  },
  handler: function (req, res, next) {
    res.status(429).json({
      message: "Too many requests, please try again later.",
    });
  },
});

The above code defines a rate limiting middleware function that limits the number of requests per user ID to 100 requests per 15 minutes. If a user exceeds this limit, the middleware function returns a 429 status code with a JSON response containing a message indicating that the user has made too many requests.

Step 3: Add the rate limiting middleware to our Express app

The final step is to add the rate limiting middleware to our Express app. We can do this by calling the use() method of our Express app and passing in the limiter middleware function.

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

app.use(limiter); // add rate limiting middleware

// other middleware and routes

By adding the limiter middleware function to our Express app, we are limiting the number of requests that each user can make to our API endpoints. This helps to prevent abuse and misuse of the system and ensures that our resources remain available and accessible to all users.

In conclusion, implementing user base rate limiting using the express-rate-limit package in Node.js is a straightforward process. By following the steps outlined above, you can easily add rate limiting to your Express app and provide a more secure and reliable experience for your users.