# Blockchain-Based-Voting-System

Block Vote — Decentralized Voting System

A secure, transparent voting web application that integrates a React frontend, Node/Express backend, and Ethereum smart contracts. This README explains how to set up, run, test, and deploy the project.

Repository links

Root package: package.json (see scripts such as scripts.start, scripts.dev, scripts.install-all)
Server entrypoint: server/index.js
Server helpers / docs: server/ganache-setup.md
Smart contract config: contracts/truffle-config.js
Deployment guide: DEPLOYMENT_GUIDE.md
Compiled contract artifact: server/VotingSystem.json
Client app: client (React app)

Contents

Overview
Prerequisites
Setup (install & env)
Local development (server + client)
Smart contracts (Ganache, Truffle, deployment)
MetaMask configuration
Building & Production
Deployment options & links
Troubleshooting

Overview

Frontend: React + Chakra UI (client)
Backend: Node.js + Express + SQLite (or production PostgreSQL) (server/index.js)
Smart contracts: Truffle-based contracts in contracts
Authentication: JWT, bcrypt
OTP email verification via Gmail (nodemailer)

Prerequisites

Node.js v14+ (recommend v16 or v18)
npm (or yarn)
Truffle (for contract deployment): npm install -g truffle
Ganache CLI or Ganache GUI (for local blockchain): see server/ganache-setup.md
MetaMask browser extension

Quick setup (local)

Clone the repo and open it: git clone cd block-vote
Install dependencies
- Install root dependencies and client/server: npm run install-all
- Or manually: npm install cd client && npm install cd ../server && npm install
Environment variables
- Create a .env in server/ (see below). Example: PORT=5000 NODE_ENV=development EMAIL_USER=your-gmail@gmail.com EMAIL_PASS=your-app-specific-password JWT_SECRET=your-secret-key-min-32-chars ETHEREUM_NODE_URL=http://127.0.0.1:7545 CONTRACT_ADDRESS=<deployed_contract_address> ADMIN_ETHEREUM_ADDRESS=<ganache_admin_address> CHAIN_ID=1337
- Frontend environment (for local dev you can use client/.env): REACT_APP_API_URL=http://localhost:5000 REACT_APP_NETWORK_ID=1337 REACT_APP_NETWORK_NAME=Local Ganache REACT_APP_RPC_URL=http://127.0.0.1:7545
Files referenced in this repo:
- server main: server/index.js
- contract config: contracts/truffle-config.js
- ganache guide: server/ganache-setup.md
- full deployment instructions: DEPLOYMENT_GUIDE.md

Local development (run app)

Start Ganache (see below) or ensure ETHEREUM_NODE_URL points to your node.
Start both server and client concurrently (recommended): npm run dev
- This runs the server (nodemon) and client (React dev server). See scripts.dev.
Alternatively run individually:

start server

cd server npm start

in another terminal start client

cd client npm start
Open browser:
- Frontend: http://localhost:3000
- API: http://localhost:5000 (default; matches PORT in .env)

Smart contracts (Ganache & Truffle)

Quick Ganache setup:
- CLI: ganache-cli -p 7545 -i 1337 --accounts 10 --defaultBalanceEther 100
- Or use Ganache GUI and set RPC server to http://127.0.0.1:7545, Network ID 1337.
- See full instructions and verification commands in server/ganache-setup.md.
Deploy contracts locally: cd contracts truffle migrate --reset --network development
- The Truffle network config lives in contracts/truffle-config.js.
- After deployment, copy the deployed contract address into server/.env as CONTRACT_ADDRESS. Also update ADMIN_ETHEREUM_ADDRESS.
Artifacts:
- Compiled contract JSON for server usage: server/VotingSystem.json

MetaMask setup

Install MetaMask browser extension.
Create or import an account.
Add a custom RPC network for Ganache:
- RPC URL: http://127.0.0.1:7545
- Chain ID: 1337
- Network name: Ganache Local
Import an account private key from Ganache (the private key printed by Ganache) into MetaMask for testing.
Ensure the wallet address matches ADMIN_ETHEREUM_ADDRESS in server/.env where needed.

Building for production

Build frontend: cd client npm run build
- The built files will be in client/build/.
Serve static frontend from server:
- The repo's DEPLOYMENT_GUIDE.md includes an example to update server/index.js to serve client/build when NODE_ENV === 'production'.
Run server (production): NODE_ENV=production PORT=8080 node server/index.js
- Or use process managers (pm2) or containerize (see below).

Deployment options

Short list (full steps in DEPLOYMENT_GUIDE.md):
- Frontend: Vercel or Netlify (deploy client/)
- Backend: Railway, Render, or Heroku (set root to server/ for Railway)
- All-in-one: Railway using a monorepo Dockerfile (see DEPLOYMENT_GUIDE.md)
- Database: SQLite is included. For production use PostgreSQL — the guide gives sample server/config/database.js adjustment.

Sample .env (server/.env.production) PORT=8080 NODE_ENV=production DATABASE_URL=postgres://username:password@host:5432/database EMAIL_USER=your-gmail@gmail.com EMAIL_PASS=your-app-specific-password JWT_SECRET=your-super-secret-jwt-key-min-32-chars CORS_ORIGIN=https://your-frontend-url.vercel.app

Useful scripts (from package.json)

npm start — run server (node server/index.js)
npm run client — start frontend dev server
npm run server — start backend with nodemon
npm run dev — run client & server concurrently
npm run install-all — install root, client, and server deps
npm run build — builds frontend: cd client && npm run build

Troubleshooting & tips

CORS errors: confirm CORS_ORIGIN in server env.
DB connection: ensure DATABASE_URL is valid for PostgreSQL; SQLite file included for local testing.
MetaMask network mismatch: set chain id / RPC as in Ganache or testnet RPC.
Email (OTP) not sending: verify Gmail app password and EMAIL_USER/EMAIL_PASS.
Contract issues: re-run truffle migrate --reset and update contract address in server/.env.