NestJS NestJS Authentication & Security

Question 1

Which NestJS package integrates Passport.js strategies for authentication?

Accepted Answer

@nestjs/passport

Answer

@nestjs/jwt

Answer

@nestjs/security

Answer

@nestjs/auth

Question 2

What does `AuthGuard('jwt')` do in NestJS?

Accepted Answer

Validates the JWT token from the request and populates req.user

Answer

Generates a JWT token for the current user

Answer

Refreshes an expired JWT automatically

Answer

Signs outgoing responses with a JWT signature

Question 3

Which decorator applies a guard to an entire controller in NestJS?

Accepted Answer

@UseGuards() on the controller class

Answer

@ApplyGuard() on the controller class

Answer

@Guard() on each method

Answer

@Protect() on the module

Question 4

How do you make a single route publicly accessible when JWT auth is applied globally in NestJS?

Accepted Answer

Use a custom @Public() decorator combined with a reflector check in the guard

Answer

Set `optional: true` in AuthGuard options

Answer

Add the route to the `exclude` array in app.module

Answer

Use @SkipAuth() built-in decorator

Question 5

What is the purpose of the `validate()` method in a Passport strategy class?

Accepted Answer

It receives the decoded token payload and returns the user object to attach to the request

Answer

It validates the shape of the request body

Answer

It validates environment variables on startup

Answer

It runs input sanitization on query parameters

Question 6

Which NestJS package provides JWT signing and verification utilities?

Accepted Answer

@nestjs/jwt

Answer

@nestjs/security

Answer

@nestjs/crypto

Answer

@nestjs/passport