Question

How do you manage API rate limiting on a Node.js backend with Redis?

I want to control how often users can make API requests to my Node.js backend to avoid overload or abuse. I’ve heard Redis is good for this, but I’m not sure how to set it up. How can I use Redis to track and limit the number of requests a user can make within a certain time frame?

Answer 1

Firstly we will install express , redis  , rete-limiter flexible 

npm install express redis rate-limiter flexible

then
we import necessary modules
const express = require('express');
const Redis = require('redis');
const { RateLimiterRedis } = require('rate-limiter-flexible');

in next line create a default Express application

const app = express();

Create a Redis client

```jsx
const redisClient = Redis.createClient({
host: 'localhost',
port: 6379,    
});
```

Then :- rate limiter initialize

```jsx
const rateLimiter = new RateLimiterRedis({
storeClient: redisClient,
keyPrefix: 'rateLimiter',
points: 5,   duration: 1, });
```

points: 5 === number of points which we want to allow

duration: 1 === time for window in sec

```jsx
// Middleware to handle rate limiting
const rateLimitMiddleware = (req, res, next) => {
// Get the user's IP address
const userIp = req.ip;
```

```jsx
// Consume a point
rateLimiter
.consume(userIp)
.then(() => {
next(); // Allowed to proceed
})
.catch(() => {
res.status(429).send('Too many requests, please try again later.');
    });
};
```

```jsx
to apply  use this command
app.use(rateLimitMiddleware);
```

```jsx
then add a sample route
app.get('/', (req, res) => {
res.send('Welcome to the API!');
});
```

```jsx
and in last Start the server
app.listen(3000, () => {
console.log('Server running on [http://localhost:3000](http://localhost:3000/)');
});
```

We can test the rate limiting by sending requests using tools like Postman or URL.

I am using Postman for this

1. Open Postman
2. Set Up the Request
3. Send Multiple Requests
4. Check Rate Limiting Behavior
5. Add Request to Collection:
6. Run and Observe the result

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