Rate limiting with express-rate-limit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of rate limiting in an Express app?

Rate limiting helps protect your app by limiting how many requests a user can make in a set time. It stops overload and abuse, like too many requests from one user.

beginner

How do you add express-rate-limit middleware to an Express app?

You first install express-rate-limit, then import it. Create a limiter with options like max requests and window time. Use app.use() to apply it to routes.

beginner

What does the 'windowMs' option control in express-rate-limit?

It sets the time window in milliseconds for counting requests. For example, 60000 means requests are counted per minute.

beginner

What happens when a user exceeds the max number of requests in express-rate-limit?

The user gets a 429 status code (Too Many Requests) and a message telling them to slow down.

intermediate

How can you customize the message sent when rate limit is exceeded?

You can use the 'handler' option in express-rate-limit to define a custom function that sends your own message or response.

What package do you use to add rate limiting in an Express app?

A express-rate-limit

B express-session

C cors

D body-parser

express-rate-limit is the package designed to limit repeated requests to Express routes.

Which option sets the max number of requests allowed in express-rate-limit?

A windowMs

B max

C delayMs

D handler

'max' defines the maximum number of requests allowed during the time window.

What HTTP status code does express-rate-limit send when limit is exceeded?

A 403 Forbidden

B 401 Unauthorized

C 429 Too Many Requests

D 500 Internal Server Error

429 status code means the user sent too many requests in a given time.

How do you apply rate limiting to all routes in an Express app?

A Use app.use() with the limiter middleware

B Add limiter inside each route handler

C Set limiter in package.json

D Use a global variable

app.use(limiter) applies the rate limiter middleware to all routes.

Which option lets you customize the response when rate limit is hit?

A skip

B windowMs

C max

D handler

'handler' is a function you provide to send a custom response when the limit is exceeded.

Explain how to set up express-rate-limit in a new Express app to limit requests to 100 per 15 minutes.

Think about the steps from installing to applying middleware.

Describe what happens when a user sends too many requests and how express-rate-limit handles it.

Focus on the user experience and server response.