ChronoBank ⏳💰

ChronoBank is a secure time-based banking web application built with Flask and PostgreSQL,
where time (in hours/seconds) functions as the currency instead of money.

Users can deposit, withdraw, invest, and borrow time — just like in traditional banking.
It features fraud detection, real-time transaction logging, and applies design patterns for scalable architecture.

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✨ Features

• Core Banking with Time as Currency

  • Deposit, withdraw, invest, and take loans in time units
  • Real-time transaction updates and bonuses (e.g., 36000 seconds bonus applied)

• Fraud Detection

  • /api/fraud-alerts endpoint monitors suspicious activities
  • Notifications and logging integrated into the transaction flow

• API-Driven Communication

  • Flask provides REST APIs for page-to-page communication
  • Routes like /accounts/create, /accounts/{id}/deposit, /notifications/count

• Security

  • Session-based authentication & access control
  • PostgreSQL-backed persistent storage
  • Transaction logs for auditing

🧩 Design Patterns Used

Creational

• Builder → Step-by-step construction of complex account objects
• Factory → Dynamic creation of account types (Savings, Investment, Loan)
• Singleton → Ensures only one database/session manager instance

Structural

• Facade → Unified interface for multi-step operations (e.g., loan processing)
• Decorator → Extend account functionality (fraud checks, bonus application)
• Adapter → Bridge between different services/APIs

Behavioral

• Command → Encapsulates operations (deposit, withdraw, transfer) as objects
• Observer → Notify fraud detection and notification services on transaction events
• Strategy → Flexible algorithms for interest calculation, fraud detection, loan repayment

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🛠️ Tech Stack

• Backend: Flask (Python)
• Database: PostgreSQL (SQLAlchemy ORM)
• Frontend: HTML, CSS, Jinja2 templates
• APIs: REST endpoints for accounts, transactions, notifications, fraud alerts

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🚀 Getting Started

Prerequisites

• Python 3.8+
• PostgreSQL (running locally or remote)

Installation

1. Clone repo

git clone https://github.com/harsh-parakh22/ChronoBank.git
cd ChronoBank

2. Set up virtual environment

• python3 -m venv venv
• source venv/bin/activate # Linux/Mac
• venv\Scripts\activate # Windows

3.Install dependencies

• pip install -r requirements.txt

4.Configure database Create a PostgreSQL database:

• CREATE DATABASE chronobank; Update DB URI in config.py or .env:
• DATABASE_URL=postgresql://username:password@localhost/chronobank

5.Initialize migrations

• flask db init
• flask db migrate
• flask db upgrade

6.Run the app

• python run.py

📡 Example Routes

• POST /accounts/create → create account
• POST /accounts//deposit → deposit time
• GET /accounts/ → view account info
• GET /notifications/count → get notification count
• GET /api/fraud-alerts/count → check fraud alerts

🏦 Core Banking Operations

• Deposit Time → Add hours to your account balance
• Withdraw Time → Deduct hours from balance
• Invest Time → Earn interest over time deposits
• Take Loan → Borrow time with repayment schedules
• Upgrade Account → Switch between account types (handled by Factory pattern)

🔐 Fraud Detection

• User performs a transaction
• Command pattern executes the operation
• Observer pattern notifies fraud detection & notification systems
• Decorator pattern applies fraud-check logic before committing
• Fraud alerts recorded via /api/fraud-alerts

🔐 Security

• Session-based authentication
• Transaction logging for all account activities
• Role-based access (regular user, admin)