NestJS Twilio OTP/2FA Guide: Secure SMS Auth with Node.js

This guide provides a step-by-step walkthrough for implementing robust SMS-based Two-Factor Authentication (2FA) and phone number verification using One-Time Passwords (OTP) in a NestJS application. We'll leverage Twilio for SMS delivery and Prisma for database interactions with a PostgreSQL database.

Last Updated: October 26, 2023

Project Overview and Goals

We will build a secure NestJS backend application featuring:

User Sign-up: Basic user registration with email, phone number, and password.
User Login: Standard email/password authentication returning a JSON Web Token (JWT).
Phone Number Verification: Users must verify their phone number via an SMS OTP before enabling 2FA.
2FA Enable/Disable: Secure endpoints for users to opt-in or opt-out of 2FA, potentially requiring OTP confirmation for disabling.
2FA-Protected Login: If 2FA is enabled, users must provide a valid SMS OTP after successful password verification to receive their JWT.

Problem Solved: This implementation adds a critical layer of security beyond simple passwords, mitigating risks associated with compromised credentials by requiring access to the user's registered phone.

Technologies Used:

NestJS: A progressive Node.js framework for building efficient, reliable, and scalable server-side applications. Chosen for its modular architecture, built-in features (like pipes, guards, modules), and TypeScript support.
Node.js: The JavaScript runtime environment.
TypeScript: Superset of JavaScript adding static types, improving code quality and maintainability.
Twilio: A cloud communications platform used here to send SMS OTPs. Chosen for its reliable API and developer-friendly tools.
PostgreSQL: A powerful, open-source object-relational database system. Chosen for its reliability and robustness.
Prisma: A modern database toolkit for Node.js and TypeScript, simplifying database access with type safety. Chosen for its excellent developer experience and migration management.
JWT (JSON Web Tokens): Used for stateless session management after successful authentication.
bcrypt: Library for securely hashing passwords.
Joi: Library for data validation.

System Architecture:

The system involves the following components interacting:

Client (Browser/App): Interacts with the NestJS API.
NestJS API: Handles incoming requests, business logic, validation, authentication, and coordinates with other services (Prisma, Twilio). Contains Controllers, Services, Guards, and Pipes.
Prisma ORM: Manages database connections, queries, and migrations based on the defined schema. Acts as the data access layer.
Postgres Database: Stores user data, OTPs, and application state.
Twilio API: An external service used by the NestJS API to send SMS messages containing OTP codes and potentially receive delivery status updates.

Prerequisites:

Node.js (LTS version recommended, e.g., v18 or v20) and npm/yarn installed.
PostgreSQL server installed and running.
A Twilio account with credentials (Account SID, Auth Token, Twilio Phone Number).
Basic understanding of TypeScript, Node.js, REST APIs, and relational databases.
A code editor (like VS Code).
A tool for testing APIs (like Postman or curl).

Final Outcome: A functional NestJS API with secure user authentication, phone verification, and optional SMS-based 2FA.

1. Setting up the Project

Let's scaffold our NestJS project and configure the basic utilities.

1.1 Install NestJS CLI: If you haven't already, install the NestJS CLI globally.

bash

npm install -g @nestjs/cli

1.2 Create New Project: Generate a new NestJS project. Replace nestjs-twilio-2fa with your desired project name.

bash

nest new nestjs-twilio-2fa
cd nestjs-twilio-2fa

This creates a standard NestJS project structure.

1.3 Initial Cleanup (Optional): The default project includes sample controller and service files. Let's remove them for a clean start.

Delete src/app.controller.ts, src/app.service.ts, and src/app.controller.spec.ts.
Open src/app.module.ts and remove AppController from the controllers array and AppService from the providers array.

src/app.module.ts (after cleanup):

typescript

import { Module } from '@nestjs/common';

@Module({
  imports: [],
  controllers: [], // Remove AppController
  providers: [],   // Remove AppService
})
export class AppModule {}

1.4 Set Global API Prefix: It's good practice to prefix your API routes (e.g., /api/v1).

Edit src/main.ts:

typescript

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  // Set global prefix
  app.setGlobalPrefix('api/v1');

  await app.listen(process.env.PORT || 3000); // Use environment variable for port
  console.log(`Application is running on: ${await app.getUrl()}`);
}
bootstrap();

1.5 Configure Logging Middleware: NestJS has built-in logging, but a custom middleware provides more request context.

Create src/common/middleware/logger.middleware.ts:

typescript

import { Injectable, NestMiddleware, Logger } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';

@Injectable()
export class LoggerMiddleware implements NestMiddleware {
  private logger = new Logger('HTTP'); // Context for logger

  use(request: Request, response: Response, next: NextFunction): void {
    const { ip, method, originalUrl } = request;
    const userAgent = request.get('user-agent') || '';

    response.on('finish', () =&gt; {
      const { statusCode } = response;
      const contentLength = response.get('content-length');

      this.logger.log(
        `${method} ${originalUrl} ${statusCode} ${contentLength || 0} - ${userAgent} ${ip}`,
      );
    });

    next();
  }
}

typescript

import { Module, NestModule, MiddlewareConsumer } from '@nestjs/common';
import { LoggerMiddleware } from './common/middleware/logger.middleware'; // Adjust path if needed

@Module({
  imports: [],
  controllers: [],
  providers: [],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(LoggerMiddleware).forRoutes('*'); // Apply to all routes
  }
}

1.6 Custom Exception Filter: Handle errors gracefully and provide consistent error responses.

Create the custom filter (src/common/filters/custom-exception.filter.ts):

typescript

import {
  ExceptionFilter,
  Catch,
  ArgumentsHost,
  HttpException,
  HttpStatus,
  Logger,
} from '@nestjs/common';
import { Request, Response } from 'express';

@Catch() // Catch all types of exceptions
export class CustomExceptionFilter implements ExceptionFilter {
  private readonly logger = new Logger(CustomExceptionFilter.name); // Instantiate logger

  catch(exception: unknown, host: ArgumentsHost) { // Catch 'unknown' for broader compatibility
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response&gt;();
    const request = ctx.getRequest<Request&gt;();

    let status: number;
    let message: string;
    let errorName: string;
    let stack: string | undefined;

    if (exception instanceof HttpException) {
      status = exception.getStatus();
      const errorResponse = exception.getResponse();
      message = typeof errorResponse === 'string'
          ? errorResponse
          : (errorResponse as any)?.message || exception.message;
      errorName = exception.constructor.name;
      // Optionally log stack for specific HTTP errors if needed
      // stack = exception.stack;
    } else if (exception instanceof Error) {
      // Handle generic errors
      status = (exception as any)?.statusCode || HttpStatus.INTERNAL_SERVER_ERROR;
      message = exception.message || 'Internal server error';
      errorName = exception.name || 'InternalServerError';
      stack = exception.stack; // Capture stack for generic errors
    } else {
        // Handle non-Error exceptions
        status = HttpStatus.INTERNAL_SERVER_ERROR;
        message = 'An unexpected error occurred';
        errorName = 'UnknownError';
        // Try to stringify the exception for logging
        try {
            stack = JSON.stringify(exception);
        } catch {
            stack = 'Could not stringify the unknown exception.';
        }
    }

     // Log the error
     this.logger.error(
        `HTTP Status: ${status} Error: ${errorName} Message: ${message} Path: ${request.url}`,
        stack, // Log stack trace, especially for non-HttpExceptions
        CustomExceptionFilter.name, // Context for the logger
      );

    response.status(status).json({
      statusCode: status,
      timestamp: new Date().toISOString(),
      path: request.url,
      error: errorName,
      message: message,
    });
  }
}

typescript

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { CustomExceptionFilter } from './common/filters/custom-exception.filter'; // Adjust path

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.setGlobalPrefix('api/v1');
  app.useGlobalFilters(new CustomExceptionFilter()); // Register filter

  await app.listen(process.env.PORT || 3000);
  console.log(`Application is running on: ${await app.getUrl()}`);
}
bootstrap();

Why these choices?

Global Prefix: Standardizes API access.
Logger Middleware: Provides essential request visibility for debugging and monitoring.
Custom Exception Filter: Ensures consistent, informative error responses for clients and detailed server-side logging, crucial for production environments. Catches both NestJS HttpExceptions and standard JavaScript Errors.

2. Database Setup with Prisma

We'll set up PostgreSQL and use Prisma to interact with it.

2.1 Set up PostgreSQL Database: Using psql or a GUI tool, create your database.

sql

-- Connect using psql (replace 'postgres' with your superuser if different)
-- psql -U postgres

CREATE DATABASE nest_twilio_2fa_dev; -- Or your preferred name

2.2 Install Prisma: Install the Prisma CLI as a development dependency and the Prisma Client.

bash

npm install -D prisma
npm install @prisma/client

2.3 Initialize Prisma: This command creates a prisma directory with a schema.prisma file and a .env file at the project root.

bash

npx prisma init --datasource-provider postgresql

2.4 Configure Database Connection: Prisma automatically creates a .env file (or adds to an existing one). Update the DATABASE_URL with your PostgreSQL connection string.

.env:

bash

# Environment variables declared in this file are automatically made available to Prisma.
# See the documentation for more detail: https://pris.ly/d/prisma-schema#accessing-environment-variables-from-the-schema

# Prisma supports the native connection string format for PostgreSQL, MySQL, SQLite, SQL Server, MongoDB and CockroachDB.
# See the documentation for all the connection string options: https://pris.ly/d/connection-strings

# Syntax: DATABASE_URL=""protocol://USER:PASSWORD@HOST:PORT/DATABASE?schema=SCHEMA""
# Ensure special characters in the password or other parts are URL-encoded if needed.
DATABASE_URL=""postgresql://YOUR_DB_USER:YOUR_DB_PASSWORD@YOUR_DB_HOST:YOUR_DB_PORT/YOUR_DB_NAME?schema=public""

# Example:
# DATABASE_URL=""postgresql://postgres:mysecretpassword@localhost:5432/nest_twilio_2fa_dev?schema=public""

Replace placeholders (YOUR_DB_USER, YOUR_DB_PASSWORD, etc.) with your actual database credentials.
Ensure schema=public is present if you're using the default schema.
The entire connection string value should be enclosed in double quotes ("").

2.5 Define Data Models: Open prisma/schema.prisma and define the User and Otp models.

prisma/schema.prisma:

sql

// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

generator client {
  provider = ""prisma-client-js""
}

datasource db {
  provider = ""postgresql""
  url      = env(""DATABASE_URL"")
}

model User {
  id        String   @id @default(uuid())
  email     String   @unique
  phone     String   @unique // Ensure phone numbers are unique
  password  String   // Hashed password
  firstName String
  lastName  String
  twoFA     Boolean  @default(false) // 2FA status
  isPhoneVerified Boolean @default(false) // Phone verification status

  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  otps Otp[] // Relation to Otp model
}

model Otp {
  id        String   @id @default(uuid())
  code      String   // The OTP code itself
  userId    String   // Foreign key to User
  useCase   UseCase  // Purpose of the OTP
  expiresAt DateTime // Expiry timestamp

  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  owner User @relation(fields: [userId], references: [id], onDelete: Cascade) // Relation field

  @@index([userId, useCase]) // Index for faster lookups
}

// Enum for different OTP use cases
enum UseCase {
  PHONE_VERIFICATION // For verifying phone number initially
  TWO_FACTOR_AUTH    // For logging in when 2FA is enabled
  DISABLE_TWO_FACTOR // Optional: For confirming disabling 2FA
}

Explanation:

User: Stores user details, including flags for twoFA and isPhoneVerified.
Otp: Stores OTP codes, linked to a user (userId), with a specific useCase and an expiresAt timestamp.
UseCase Enum: Defines the distinct purposes for which an OTP can be generated, improving clarity and logic.
onDelete: Cascade: If a User is deleted, their associated OTPs are also deleted.
@@index: Improves query performance when finding OTPs for a specific user and use case.

2.6 Run Database Migration: Apply the schema changes to your database. Prisma generates SQL migration files and runs them.

bash

npx prisma migrate dev --name init_user_otp_schema

This command will:

Create a prisma/migrations folder.
Generate a SQL migration file based on your schema changes.
Apply the migration to your database, creating the User and Otp tables.
Generate/update the Prisma Client (@prisma/client) based on your schema.

Important: Whenever you change prisma/schema.prisma, run npx prisma migrate dev --name <descriptive_migration_name> to update your database and npx prisma generate to update the Prisma Client typings.

2.7 Create Prisma Service: Encapsulate Prisma Client logic within a dedicated NestJS service for better organization and testability.

Generate the module and service:

bash

nest generate module prisma
nest generate service prisma --no-spec # No spec file needed for this simple service

Implement the service (src/prisma/prisma.service.ts):

typescript

import { Injectable, OnModuleInit, INestApplication } from '@nestjs/common';
import { PrismaClient } from '@prisma/client';

@Injectable()
export class PrismaService extends PrismaClient implements OnModuleInit {
  async onModuleInit() {
    // Connect to the database when the module is initialized
    await this.$connect();
  }

  async enableShutdownHooks(app: INestApplication) {
    // Ensure Prisma disconnects gracefully on application shutdown
    // Listen for the 'beforeExit' event emitted by Prisma Client
    process.on('beforeExit', async () =&gt; {
      console.log('Closing NestJS application and disconnecting Prisma Client...');
      await app.close(); // This should trigger Prisma's own shutdown logic
      console.log('Prisma Client disconnected.');
    });
  }
}

Configure the module (src/prisma/prisma.module.ts):

typescript

import { Module, Global } from '@nestjs/common'; // Make it Global
import { PrismaService } from './prisma.service';

@Global() // Make PrismaService available globally without importing PrismaModule everywhere
@Module({
  providers: [PrismaService],
  exports: [PrismaService], // Export the service
})
export class PrismaModule {}

Import PrismaModule into the root AppModule (src/app.module.ts):

typescript

import { Module, NestModule, MiddlewareConsumer } from '@nestjs/common';
import { LoggerMiddleware } from './common/middleware/logger.middleware';
import { PrismaModule } from './prisma/prisma.module'; // Import PrismaModule

@Module({
  imports: [PrismaModule], // Add PrismaModule here
  controllers: [],
  providers: [],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(LoggerMiddleware).forRoutes('*');
  }
}

Enable shutdown hooks in src/main.ts:

typescript

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { CustomExceptionFilter } from './common/filters/custom-exception.filter';
import { PrismaService } from './prisma/prisma.service'; // Import PrismaService

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.setGlobalPrefix('api/v1');
  app.useGlobalFilters(new CustomExceptionFilter());

  // Get PrismaService instance and enable shutdown hooks
  const prismaService = app.get(PrismaService);
  await prismaService.enableShutdownHooks(app); // Call the hook setup

  await app.listen(process.env.PORT || 3000);
  console.log(`Application is running on: ${await app.getUrl()}`);
}
bootstrap();

Why these choices?

Prisma: Provides type safety, auto-completion, and simplifies database interactions and migrations significantly compared to writing raw SQL or using less integrated ORMs.
Prisma Service: Decouples database logic from business logic, adhering to SOLID principles.
Global Module: Makes the PrismaService easily injectable across the application.
Shutdown Hooks: Ensures the database connection is closed properly when the application stops.
UUIDs: Using UUIDs for primary keys is generally better for distributed systems and avoids exposing sequential information compared to auto-increment integers.

Create the endpoints and logic for user registration.

3.1 Install Dependencies:

bash

npm install joi bcrypt class-validator class-transformer
npm install -D @types/bcrypt @types/joi

joi: For request validation schemas used with our custom pipe.
bcrypt: For hashing passwords securely.
class-validator, class-transformer: Standard NestJS validation libraries. While this guide uses a Joi pipe for validation consistency, these are often used for DTO validation.

3.2 Create Account Module, Controller, Service:

bash

nest generate module account
nest generate controller account --no-spec
nest generate service account --no-spec

3.3 Create Validation Pipe: We need a pipe to validate incoming request bodies using Joi schemas.

Create src/common/pipes/joi-validation.pipe.ts:

typescript

import {
  PipeTransform,
  Injectable,
  ArgumentMetadata,
  BadRequestException,
} from '@nestjs/common';
import { ObjectSchema } from 'joi';

@Injectable()
export class JoiValidationPipe implements PipeTransform {
  constructor(private schema: ObjectSchema) {}

  transform(value: any, metadata: ArgumentMetadata) {
    // We only validate the body of the request
    if (metadata.type !== 'body' || !value) { // Also check if value exists
      return value;
    }

    const { error, value: validatedValue } = this.schema.validate(value, {
      abortEarly: false, // Return all validation errors
      allowUnknown: false, // Disallow properties not defined in the schema
      stripUnknown: true, // Remove unknown properties instead of throwing error
    });

    if (error) {
      // Format error messages for better readability
      const errorMessages = error.details.map((d) =&gt; d.message.replace(/"/g, "'")).join('; '); // Use single quotes and semicolon separator
      throw new BadRequestException(`Validation failed: ${errorMessages}`);
    }
    return validatedValue; // Return validated (and potentially stripped) value
  }
}

3.4 Create Sign-up DTO and Schema:

Define the expected request body structure.

Create src/account/dto/create-user.dto.ts:

typescript

// Although we use Joi pipe, DTO helps with type inference in service/controller
export class CreateUserDto {
  email: string;
  phone: string; // Consider validation for phone format if needed
  password: string;
  firstName: string;
  lastName: string;
}

Create the Joi validation schema src/account/validation/signup.schema.ts:

typescript

import * as Joi from 'joi';

// Basic password complexity: at least 8 chars, 1 letter, 1 number
const passwordRegex = /^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{8,}$/;
// Basic phone number regex (allows +, digits, spaces, hyphens - adjust as needed)
// Consider E.164 format for stricter validation: /^\+[1-9]\d{1,14}$/
const phoneRegex = /^[+\d\s-]+$/;


export const signupSchema = Joi.object({
  email: Joi.string().email().required().messages({
    'string.email': 'Email must be a valid email address',
    'any.required': 'Email is required',
  }),
  phone: Joi.string().pattern(phoneRegex).required().messages({
    'string.pattern.base': 'Phone number format is invalid',
    'any.required': 'Phone number is required',
  }),
  password: Joi.string().pattern(passwordRegex).required().messages({
    'string.pattern.base': 'Password must be at least 8 characters long and include at least one letter and one number',
    'any.required': 'Password is required',
  }),
  firstName: Joi.string().trim().min(1).required().messages({
    'string.empty': 'First name cannot be empty',
    'any.required': 'First name is required',
  }),
  lastName: Joi.string().trim().min(1).required().messages({
    'string.empty': 'Last name cannot be empty',
    'any.required': 'Last name is required',
  }),
});

3.5 Create Password Hashing Utility:

Create src/common/utils/password.util.ts:

typescript

import * as bcrypt from 'bcrypt';

const SALT_ROUNDS = 10; // Recommended salt rounds

export const hashPassword = async (password: string): Promise<string&gt; =&gt; {
  return bcrypt.hash(password, SALT_ROUNDS);
};

export const verifyPassword = async (
  password: string,
  hash: string,
): Promise<boolean&gt; =&gt; {
  return bcrypt.compare(password, hash);
};

3.6 Implement Sign-up Service Logic:

Inject PrismaService and implement the sign-up logic.

Edit src/account/account.service.ts:

typescript

import { Injectable, ConflictException, InternalServerErrorException, Logger } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service'; // Adjust path if needed
import { CreateUserDto } from './dto/create-user.dto';
import { hashPassword } from '../common/utils/password.util'; // Adjust path if needed
import { User } from '@prisma/client';
import { Prisma } from '@prisma/client'; // Import Prisma namespace for error handling

@Injectable()
export class AccountService {
  private readonly logger = new Logger(AccountService.name);

  constructor(private prisma: PrismaService) {}

  async signUp(createUserDto: CreateUserDto): Promise<Omit<User_ 'password'>&gt; {
    const { email, phone, password, firstName, lastName } = createUserDto;

    // 1. Check if user with email or phone already exists
    const existingUser = await this.prisma.user.findFirst({
      where: { OR: [{ email }, { phone }] },
      select: { email: true, phone: true } // Select only needed fields
    });

    if (existingUser) {
      if (existingUser.email === email) {
        this.logger.warn(`Signup attempt failed: Email ${email} already exists.`);
        throw new ConflictException('User with this email already exists');
      }
      if (existingUser.phone === phone) {
         this.logger.warn(`Signup attempt failed: Phone ${phone} already exists.`);
        throw new ConflictException('User with this phone number already exists');
      }
    }

    // 2. Hash the password
    const hashedPassword = await hashPassword(password);

    // 3. Create the user
    try {
      const user = await this.prisma.user.create({
        data: {
          email,
          phone,
          password: hashedPassword,
          firstName,
          lastName,
          // Defaults (isPhoneVerified, twoFA) are set in schema
        },
      });
      this.logger.log(`User created successfully: ${user.id} / ${user.email}`);

      // 4. Omit password from the returned user object
      const { password: _, ...result } = user;
      return result;

    } catch (error) {
        // Catch potential unique constraint violations (race condition safeguard)
        if (error instanceof Prisma.PrismaClientKnownRequestError && error.code === 'P2002') {
            const target = (error.meta as any)?.target;
            this.logger.warn(`Signup failed due to unique constraint violation on: ${target}`);
            if (target && target.includes('email')) {
                throw new ConflictException('User with this email already exists.');
            } else if (target && target.includes('phone')) {
                throw new ConflictException('User with this phone number already exists.');
            } else {
                throw new ConflictException('A user with these details already exists.');
            }
        }
        // Log and re-throw other errors
        this.logger.error(`Error during user signup: ${error.message}`, error.stack);
        throw new InternalServerErrorException('Could not create user account.');
    }
  }

  // ... other account service methods will go here
}

3.7 Implement Sign-up Controller Endpoint:

Define the route handler in the controller.

Edit src/account/account.controller.ts:

typescript

import { Controller, Post, Body, UsePipes, HttpStatus, HttpCode } from '@nestjs/common';
import { AccountService } from './account.service';
import { CreateUserDto } from './dto/create-user.dto';
import { signupSchema } from './validation/signup.schema'; // Adjust path
import { JoiValidationPipe } from '../common/pipes/joi-validation.pipe'; // Adjust path
import { User } from '@prisma/client';
// Optional: Import Swagger decorators if using Swagger
// import { ApiTags, ApiOperation, ApiResponse, ApiBody } from '@nestjs/swagger';

// @ApiTags('Account') // Example Swagger tag
@Controller('account') // Route prefix: /api/v1/account
export class AccountController {
  constructor(private readonly accountService: AccountService) {}

  @Post('signup') // POST /api/v1/account/signup
  // @ApiOperation({ summary: 'Register a new user account' }) // Example Swagger operation
  // @ApiBody({ type: CreateUserDto }) // Example Swagger body definition
  // @ApiResponse({ status: HttpStatus.CREATED, description: 'User created successfully.', type: CreateUserDto }) // Example Swagger response
  // @ApiResponse({ status: HttpStatus.BAD_REQUEST, description: 'Validation failed.' })
  // @ApiResponse({ status: HttpStatus.CONFLICT, description: 'Email or phone number already exists.' })
  @UsePipes(new JoiValidationPipe(signupSchema)) // Apply Joi validation
  @HttpCode(HttpStatus.CREATED) // Set default success status to 201
  async create(
    @Body() createUserDto: CreateUserDto,
  ): Promise<Omit<User_ 'password'>&gt; {
    return this.accountService.signUp(createUserDto);
  }

  // ... other account controller methods
}

Make sure the AccountService and AccountController are correctly listed in src/account/account.module.ts.

src/account/account.module.ts:

typescript

import { Module } from '@nestjs/common';
import { AccountService } from './account.service';
import { AccountController } from './account.controller';
// PrismaModule is global, no need to import here

@Module({
  controllers: [AccountController],
  providers: [AccountService],
  exports: [AccountService] // Export if needed by other modules like AuthModule
})
export class AccountModule {}

Import AccountModule into the root AppModule (src/app.module.ts):

typescript

import { Module, NestModule, MiddlewareConsumer } from '@nestjs/common';
import { LoggerMiddleware } from './common/middleware/logger.middleware';
import { PrismaModule } from './prisma/prisma.module';
import { AccountModule } from './account/account.module'; // Import AccountModule

@Module({
  imports: [
      PrismaModule,
      AccountModule // Add AccountModule here
    ],
  controllers: [],
  providers: [],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(LoggerMiddleware).forRoutes('*');
  }
}

Why these choices?

Joi Pipe: Provides robust, schema-based validation at the entry point of the controller.
DTO: Enforces type safety within TypeScript code.
bcrypt: Industry standard for password hashing.
Conflict Check: Prevents duplicate user registrations based on unique fields. Includes robust Prisma error handling.
Password Omission: Never return the hashed password to the client.

Set up the initial login mechanism using email and password, returning a JWT if credentials are valid but before handling the 2FA OTP step.

4.1 Install JWT Dependency:

bash

npm install @nestjs/jwt dotenv
# dotenv is likely already installed by NestJS CLI, ensure it is.

4.2 Configure JWT Module:

Define a JWT secret in your .env file. Use a strong, randomly generated secret in production.

.env:

bash

DATABASE_URL=""postgresql://postgres:mysecretpassword@localhost:5432/nest_twilio_2fa_dev?schema=public""

# Generate a strong secret (e.g., using openssl rand -hex 32)
JWT_SECRET=""your-very-strong-and-secret-jwt-key-CHANGE-ME""
JWT_EXPIRATION_TIME=""2h"" # Example: Token valid for 2 hours

Create a configuration file for easy access to constants (src/common/config/config.ts):

typescript

import * as dotenv from 'dotenv';
dotenv.config(); // Load .env file variables

export const config = {
  jwt: {
    secret: process.env.JWT_SECRET,
    expiresIn: process.env.JWT_EXPIRATION_TIME || '1h', // Default expiration
  },
  // Add other configs like Twilio later
};

// Validate essential config on startup
if (!config.jwt.secret || config.jwt.secret.length &lt; 10) { // Basic check for presence and minimum length
    console.error(""FATAL ERROR: JWT_SECRET environment variable is missing or too short."");
    process.exit(1); // Exit if critical config is missing
}

Frequently Asked Questions

This guide details setting up 2FA using NestJS, Twilio, Prisma, and PostgreSQL. It covers user sign-up, login, phone verification, and 2FA-protected login. Key technologies include JWT for session management, bcrypt for password hashing, and Joi for validation.

NestJS is the core backend framework, providing structure, features, and TypeScript support for building the API. It's chosen for its modularity and efficiency in handling requests and coordinating with services like Twilio and Prisma.

Twilio is a reliable cloud communication platform. It's used to send OTPs via SMS for phone verification and two-factor authentication, adding an extra security layer to user logins.

Logging middleware is crucial for debugging and monitoring, providing context for each request. It's recommended to set this up early in the project for visibility into HTTP requests and responses, helping track issues in development and production.

Create a custom exception filter that implements NestJS's `ExceptionFilter` interface. This allows you to catch and handle errors gracefully, providing consistent JSON error responses to clients, and logging errors with stack traces on the server-side, which is important for debugging and maintenance.

Install the Prisma CLI globally using `npm install -D prisma` and the client library with `npm install @prisma/client`. Initialize Prisma with `npx prisma init --datasource-provider postgresql`. This sets up the necessary files for defining your data models.

Prisma is a modern database toolkit that simplifies database access with type safety and migrations in Node.js and TypeScript. It's used as the Object-Relational Mapper (ORM) to interact with the PostgreSQL database, managing connections and queries.

Generate a module and service using the NestJS CLI: `nest generate module prisma` and `nest generate service prisma`. In the service, extend the `PrismaClient` and implement `onModuleInit` to establish a database connection when the module initializes.

Creating a Prisma service follows SOLID principles and improves code organization and testability. It centralizes database logic, making it easier to manage database interactions within your NestJS application.

The project uses PostgreSQL, chosen for its reliability and robustness. The Prisma schema defines User and OTP models, which are migrated to the database.

Joi is a data validation library. You create a schema and use it with a custom pipe in your NestJS controller. This validates incoming requests, ensuring they adhere to the schema, and provides specific error messages for improved DX.

Hashing protects sensitive data even if the database is compromised. This guide uses bcrypt with a recommended salt round of 10. Never store passwords in plain text.

Generate an account module, controller, and service. Implement the signup logic in the service and define the POST route handler in the controller. Use a validation pipe (e.g., Joi) for data integrity.

Before creating a new user, query the database to check if a user with the given email or phone number already exists. If a duplicate is found, throw a `ConflictException` to inform the client.

JWT (JSON Web Token) is used for stateless session management. After successful password verification, the server generates and returns a JWT, which the client uses for subsequent authenticated requests.

Project Overview and Goals

1. Setting up the Project

2. Database Setup with Prisma

Frequently Asked Questions

How to set up two-factor authentication with NestJS?

What is NestJS used for in this project?

Why use Twilio for SMS authentication?

When should I implement logging middleware in NestJS?

How to handle errors in NestJS with a custom exception filter?

How to install Prisma for database interactions?

What is Prisma used for in the NestJS project?

How to create a Prisma service in NestJS?

Why is a Prisma service recommended?

What database is used and why?

What is Joi and how to use it for validation?

Why hash passwords and how is it done?

How to create a user signup endpoint in NestJS?

How to prevent duplicate users during signup?

What is JWT used for in user login?

Project Overview and Goals

1. Setting up the Project

2. Database Setup with Prisma

3. Implementing User Sign-up

4. Implementing User Login (Password Phase)

Frequently Asked Questions

How to set up two-factor authentication with NestJS?

What is NestJS used for in this project?

Why use Twilio for SMS authentication?

When should I implement logging middleware in NestJS?

How to handle errors in NestJS with a custom exception filter?

How to install Prisma for database interactions?

What is Prisma used for in the NestJS project?

How to create a Prisma service in NestJS?

Why is a Prisma service recommended?

What database is used and why?

What is Joi and how to use it for validation?

Why hash passwords and how is it done?

How to create a user signup endpoint in NestJS?

How to prevent duplicate users during signup?

What is JWT used for in user login?