Perplexity Backend

This repository contains the backend API for the Perplexity project.

The backend implementation is located in the backend/ folder and includes:

• User registration with email verification
• Authentication using JWT
• User profile and list endpoints
• Email delivery through Gmail OAuth2
• MongoDB data persistence with Mongoose

Repository Structure

• backend/src/app.js - Express application setup and middleware
• backend/src/routes/ - Route definitions for auth, users, chats, and messages
• backend/src/controllers/ - Request handlers and business logic
• backend/src/models/ - Mongoose schemas and data models
• backend/src/services/ - Email sending and other shared services
• backend/.gitignore - Ignores local .env and other sensitive files
• backend/README.md - Backend-specific documentation and examples

Setup

1. Install dependencies:

cd backend
npm install

2. Create a local .env file in backend/ with the required variables:

MONGO_URI=mongodb://127.0.0.1:27017/perplexitydb
PORT=4000
JWT_SECRET=change_this_secret_in_prod
GOOGLE_CLIENT_ID=<your-client-id>
GOOGLE_CLIENT_SECRET=<your-client-secret>
GOOGLE_REFRESH_TOKEN=<your-refresh-token>
GOOGLE_USER=you@example.com

3. Start the backend server:

npm start

Important: Do not commit .env to git. The backend/.gitignore file already excludes it.

API Overview

Common API endpoints include:

• POST /api/auth/register - Create a new user and send a verification email
• POST /api/auth/login - Authenticate a user and return a JWT
• POST /api/auth/resend-verification - Resend email verification link
• GET /api/users - List users (authenticated access)
• GET /api/users/:id - Fetch a specific user by ID

Example registration request:

curl -X POST http://localhost:4000/api/auth/register \
  -H "Content-Type: application/json" \
  -d '{"username":"alice","email":"alice@example.com","password":"password123"}'

Security Notes

• The project uses JWT_SECRET to sign authentication tokens.
• Gmail OAuth credentials in backend/.env must remain secret.
• If secrets are exposed, rotate or revoke them immediately in Google Cloud.

CI Pipeline

A GitHub Actions CI workflow is defined in .github/workflows/ci-cd.yml.

This workflow:

• Installs backend dependencies
• Starts a MongoDB service
• Runs backend tests if a test script exists

More Information

For complete backend documentation, troubleshooting tips, and more examples, see backend/README.md.