💰 MicroSave Student — CoinStash

VICSTA Hackathon – Grand Finale | VIT College, Kondhwa Campus | 5th – 6th March

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Team Details

Team Name: Shadow Ledgers
Members: 3
Domain: Fintech & Money Management

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The Problem

Students spend impulsively on small purchases — coffee, fast food, streaming — without realising how much those micro-transactions add up. Traditional savings tools require discipline and large deposits, creating a barrier for students with irregular incomes and no financial literacy.

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Our Solution

CoinStash is a fintech tool that automatically rounds up every digital transaction and invests the spare change into a low-risk, blockchain-secured educational fund.

Spend ₹47 on chai? We round it up to ₹50 and save ₹3 — silently, automatically, and with a multiplier if you spent on fast food.

Key Features

• Smart Round-Up Engine — category-based multipliers (Fast Food 2×, Entertainment 2×, Education 0.5×) applied automatically on every transaction
• Trust Score System — a 0–1000 decentralised credibility score based on savings frequency, volume, streaks, and lesson completion. Powers micro-loan and grant eligibility
• Blockchain Vault — funds locked in a Solidity smart contract (Hardhat/local testnet) with penalty-free withdrawal for verified educational expenses
• MicroLearn Streak System — financial literacy lessons unlocked by Trust Score milestones, each worth +20 points
• Live Dashboard — real-time savings tracker, transaction ledger, category breakdown, savings growth chart, and vault progress

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Tech Stack

Layer	Technology
Frontend	React, Tailwind CSS, Recharts
Backend	Node.js, Express.js
Blockchain	Solidity, Hardhat, Ethers.js
Database	PostgreSQL, Sequelize

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Project Structure

Hackarena/
├── frontend/          # React app — dashboard, login, register, simulate
│   └── src/
│       ├── components/   # Login.jsx, Register.jsx, all page components
│       └── services/     # api.js — all backend fetch calls
├── backend/           # Node/Express REST API
│   └── src/
│       ├── controllers/  # userController, transactionController
│       ├── models/       # User, Transaction (Sequelize + PostgreSQL)
│       ├── routes/       # userRoutes, transactionRoutes
│       └── services/     # RoundUpService, TrustScoreService, BlockchainService
└── smart-contracts/   # Solidity vault contract (Hardhat)
    └── contracts/        # EducationalVault.sol

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Getting Started

Prerequisites

• Node.js v18+
• PostgreSQL
• MetaMask (optional, for on-chain interaction)

1. Clone the repo

git clone https://github.com/your-username/microsave-student.git
cd microsave-student

2. Backend setup

cd backend
npm install

Create a .env file:

PORT=5000
DB_NAME=microsave
DB_USER=postgres
DB_PASSWORD=yourpassword
DB_HOST=localhost
DB_PORT=5432

Sync the database and start:

node src/config/syncDb.js
npm start

3. Smart contract (local testnet)

cd smart-contracts
npm install
npx hardhat node          # Terminal 1 — keep running
npx hardhat run scripts/deploy.js --network localhost

4. Frontend setup

cd frontend
npm install
npm start

App runs at http://localhost:3000

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Snippets from the site:

API Endpoints

Method	Endpoint	Description
POST	/api/users	Register new user
POST	/api/users/login	Login
GET	/api/users/:id	Get user profile
GET	/api/users/:id/trust-score	Get trust score + breakdown
POST	/api/transactions/simulate	Simulate a round-up transaction
GET	/api/transactions/:userId	Get all transactions for user
POST	/api/transactions/roundup/calculate	Preview round-up (no DB write)
GET	/api/transactions/roundup/multipliers	Get category multiplier config

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Attribution

Library / API	Purpose	License
React	Frontend UI framework	MIT
Tailwind CSS	Utility-first styling	MIT
Recharts	Chart components	MIT
Express	Backend web framework	MIT
Sequelize	PostgreSQL ORM	MIT
Hardhat	Ethereum development environment	MIT
Ethers.js	Blockchain interaction	MIT
dotenv	Environment variable management	BSD-2

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Team — Shadow Ledgers

-Prerna Bora (leader)
-Shruti Bhosale (member)
-Ananya Palnitkar (member)

Thank You!!