Eunoia Backend Server

Node.js/Express REST API for authentication, secure journaling, mood analytics, and chat session storage using MongoDB with field-level encryption.

Tech Stack

• Node.js + Express
• MongoDB (Mongoose)
• JWT for auth, bcrypt for hashing
• AES-256-GCM for sensitive field encryption

Features

• Auth: register, login, refresh tokens
• Journals: create/read/update/delete (encrypted content)
• Analytics: streaks, weekly mood trends, positivity score, pie chart data
• Chat: session creation, history persistence

Quick Start

1. Prerequisites: Node 18+, MongoDB
2. Install dependencies:

   npm install

3. Create .env (see below) and run in dev:

   npm run dev

Environment Variables (.env)

• MONGODB_URI=mongodb+srv://...
• JWT_SECRET=your_jwt_secret
• ENCRYPTION_KEY=32-byte-hex-or-base64
• PORT=3000
• CORS_ORIGIN=https://your-frontend

// Email configuration

• EMAIL_HOST=smtp.example.com
• EMAIL_PORT=587
• EMAIL_USER=your_smtp_username
• EMAIL_PASSWORD=your_smtp_password
• EMAIL_SECURE=false
• EMAIL_FROM="Eunoia no-reply@your-domain"

// bcrypt configuration

• BCRYPT_SALT_ROUNDS=10

API Overview

• Auth: POST /auth/register, POST /auth/login, POST /auth/refresh
• Journals: GET/POST /journals, GET/PUT/DELETE /journals/:id
• Analytics: GET /analytics/weekly, GET /analytics/streaks, GET /analytics/pie
• Chat: POST /chat/sessions, GET /chat/sessions/:id

Scripts

• npm run dev – start with nodemon
• npm start – start production server

Security Notes

• Sensitive fields encrypted at rest using AES-256-GCM
• JWT-based auth on protected routes

Deployment

• Works on Railway/Vercel/Render. Ensure environment variables are set and IP allowlist on MongoDB is configured.