Expense Tracker Web App Using Blockchain

This repository contains a blockchain-based expense tracker web application. It leverages blockchain technology to log and manage expenses securely and transparently. The project uses Ethereum's blockchain network via Ganache, Metamask for wallet integration, and a Python Flask application for the user interface.

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Table of Contents

• Features
• Technologies Used
• Setup and Installation
• Application Workflow
• Smart Contract Details
• Screenshots

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Features

• User Authentication: Login system to access the application.
• Expense Logging: Add expenses with category, description, and amount.
• Blockchain Integration: Securely stores expense data on the blockchain.
• Expense Retrieval: View expenses logged on the blockchain.
• Account Management: Displays Ether balance and deducts total expenses.

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Technologies Used

Backend

• Python (Flask): For web application development.
• Web3.py: To interact with the Ethereum blockchain.
• Ganache: Local Ethereum blockchain for development.

Frontend

• HTML/CSS: For the web interface.
• Bootstrap: For responsive design.

Blockchain

• Solidity: Smart contract development.
• Remix IDE: To write and deploy smart contracts.
• Metamask: Ethereum wallet for transactions.

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Setup and Installation

Prerequisites

• Python 3.7 or above
• Ganache (Local Blockchain Network)
• Node.js (for Metamask integration)
• Metamask (Browser Wallet)

Steps

1. Clone the repository:

   git clone https://github.com/SirineMaaroufi/Expense-Tracker-Blockchain-WebApp.git
   cd expense-tracker

2. Install Python dependencies:

   pip install -r requirements.txt

3. Start Ganache and note the RPC server URL (e.g., http://127.0.0.1:7545).

4. Deploy the smart contract using Remix IDE:

   • Load the ExpenseTracker.sol file.
   • Deploy it to your Ganache network.
   • Copy the deployed contract address.

5. Update the contract details in app.py:

   • Replace contract_address with your deployed contract's address.
   • Replace ABI.json with your deployed contract's ABI.
   • Replace the private key with one from your Ganache accounts.

6. Start the Flask application:

   python app.py

7. Access the app in your browser at http://127.0.0.1:5000.

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Application Workflow

1. Login: Authenticate using a username and password.
2. Log Expense: Add an expense with category, description, and amount.
3. Blockchain Storage: Expense data is securely stored on the blockchain.
4. View Expenses: Retrieve and display logged expenses from the blockchain.
5. Manage Finances: View account balance and total expenses.

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Smart Contract Details

Contract: ExpenseTracker.sol

• logExpense: Logs an expense with category, description, and amount.
• getExpense: Retrieves a specific expense by index.
• getExpenseCount: Returns the total number of expenses logged.

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Screenshots

1. Login Page

2. Home Page

3. Logging Expense

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License

This project is licensed under the MIT License - see the LICENSE file for details.