NestJS Authentication in 5 Minutes 🔐

Authentication in NestJS sounds complicated at first…

But the actual flow is surprisingly simple 👇

User Login

↓

Verify Credentials

↓

Generate JWT Token

↓

Protected Routes

↓

Validate Token

1️⃣ Install required packages

npm install @nestjs/jwt @nestjs/passport passport passport-jwt bcrypt

npm install -D @types/passport-jwt

2️⃣ Generate auth files

nest g module auth

nest g service auth

nest g controller auth

3️⃣ Configure JWT (auth.module.ts)

@Module({

  imports: [

    JwtModule.register({

      secret: "super-secret-key",

      signOptions: {

        expiresIn: "1d",

      },

    }),

  ],

})

export class AuthModule {}

4️⃣ Create login function (auth.service.ts)

@Injectable()

export class AuthService {

  constructor(

    private jwtService: JwtService,

  ) {}



  async login(user: any) {

    const payload = {

      id: user.id,

      email: user.email,

    };



    return {

      access_token:

        this.jwtService.sign(payload),

    };

  }

}

5️⃣ Protect routes with JWT

@UseGuards(AuthGuard("jwt"))

@get("profile")

getProfile(@Request() req) {

return req.user;

}

Authentication = Login → Token → Verify → Access 🔥

⚠️ Bonus tip: Never store passwords directly. Use:

bcrypt.hash()

bcrypt.compare()

What confused you most when learning authentication? 👇