Disaster Insurance — Parametric Insurance dApp

System flow (screenshots)

The screenshots below are in order of use: from opening the app through connecting the wallet, entering details, confirming the transaction, and seeing the result. Recruiters can follow the full flow without running the app.

Step	Description	Screenshot
1	App loads / landing
2	Connect wallet prompt
3	Wallet connected / form
4	Enter risk score & premium
5	Buy insurance action
6	MetaMask confirmation
7	Transaction submitted
8	Transaction confirmed
9	Success / policy feedback
10	Final state / overview

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A blockchain-based parametric disaster insurance application. Users purchase policies by paying a premium and providing a risk score; an admin can trigger payouts (5× premium) for valid policies within the policy window.

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Project Overview

This repository contains a full-stack dApp for parametric disaster insurance:

• Smart contract — On-chain policy creation and payout logic (Solidity).
• Blockchain tooling — Hardhat for local development, testing, and deployment.
• Frontend — React (Vite) app for wallet connection and policy purchase.
• Backend — Placeholder for a future risk-score API.

The system is intended for development and demonstration on a local Hardhat network. No real funds are used.

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Problem Statement

Traditional disaster insurance often involves slow, opaque claims and centralized underwriting. This project explores a parametric model:

• Parametric — Payout conditions are predefined (e.g. admin-attested qualifying event).
• On-chain — Policies and payouts are recorded on a blockchain for transparency and auditability.
• Transparent rules — Minimum risk score, policy duration (30 days), and payout multiplier (5×) are enforced in the contract.

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Features

• Purchase insurance — Connect MetaMask, enter risk score (60–100) and premium (ETH), and buy a policy in one transaction.
• On-chain policies — Each policy is stored on the contract with a unique ID, premium, risk score, and expiry.
• Admin payouts — Designated admin can trigger one payout per policy (5× premium) before the 30-day window expires.
• Service-layer frontend — Clear separation between UI, risk logic, and contract interaction; ready for a future risk-score API.
• Test suite — Hardhat tests for deployment, purchase, payout, admin, and view functions.

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Architecture

• contracts/ — Solidity source (DisasterInsurance.sol).
• blockchain/ — Hardhat config, deploy/utility scripts, and tests (contracts compiled from ../contracts).
• frontend/ — React app and services (wallet, risk, insurance); reads contract address and ABI from config.
• backend/ — Future API for risk score calculation.
• docs/ — Architecture, deployment, smart contract design, and walkthrough.

High-level flow: User → Frontend (MetaMask) → Local chain → Contract. Admin actions (payouts) are performed via scripts or a future admin UI.

See docs/architecture.md and docs/system-design.md for details.

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Tech Stack

Layer	Technology
Smart contract	Solidity ^0.8.24
Blockchain	Hardhat (local node, compile, test)
Frontend	React, Vite, ethers.js v5
Wallet	MetaMask (or compatible)
Backend	Planned (e.g. Node/Express)

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Smart Contract Design

• Constants: Policy duration 30 days, payout 5× premium, minimum risk score 60 (max 100).
• Roles: Single admin (deployer by default); only admin can call triggerPayout and changeAdmin.
• State: Policies stored by ID; each policy has policyholder, premium, purchase time, risk score, and payoutClaimed flag.
• Events: PolicyPurchased, PayoutTriggered.

See docs/smart-contract-design.md for full design and security notes.

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Setup Instructions

Prerequisites

• Node.js v16+
• npm
• MetaMask (for the frontend)

Install and compile

# From project root
cd blockchain && npm install --legacy-peer-deps
cd ../frontend && npm install
cd ..
npm run compile

Run local node and deploy

1. Terminal 1 — start node:
   npm run node
   Leave it running.

2. Terminal 2 — deploy:
   npm run deploy
   Copy the printed contract address.

3. Configure frontend:
   Open frontend/src/config/contract.js and set CONTRACT_ADDRESS to the address from step 2.

4. Optional — fund MetaMask:
   Set RECIPIENT to your MetaMask address and run npm run fund (with the node running).

5. Start frontend:
   cd frontend && npm run dev
   Open http://localhost:5173 and add the Hardhat Local network in MetaMask (RPC http://127.0.0.1:8545, Chain ID 31337).

Detailed steps and troubleshooting: docs/RUN_PROJECT.md and docs/deployment-guide.md.

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Demo Instructions

1. Follow the setup above (node running, contract deployed, frontend configured and running).
2. In the app: click Connect MetaMask, then enter Risk Score (e.g. 75) and Premium (ETH) (e.g. 0.1).
3. Click Buy Insurance and confirm the transaction in MetaMask.
4. To trigger a payout as admin: update CONTRACT_ADDRESS and POLICY_ID in blockchain/scripts/triggerPayout.js, then run:

   cd blockchain && npx hardhat run scripts/triggerPayout.js --network localhost

   See docs/ADMIN_PAYOUT_GUIDE.md for full admin flow.

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Documentation

Document	Description
docs/architecture.md	High-level architecture and components
docs/system-design.md	Problem, goals, and subsystems
docs/deployment-guide.md	Build, run, and deploy steps
docs/smart-contract-design.md	Contract design and security
docs/frontend-backend-flow.md	Frontend–backend and future API
docs/walkthrough.md	Step-by-step flow and design decisions
docs/RUN_PROJECT.md	How to run the project
docs/ADMIN_PAYOUT_GUIDE.md	Admin payout and verification

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License

ISC

Disaster-Insurance-Smart-Contract-System-Solidity-Hardhat-React-

A blockchain-based insurance platform that calculates policy eligibility using location-based natural calamity risk scores. Developed Solidity smart contracts with Hardhat and Ethers.js, integrated MetaMask for transactions, and implemented premium-based payouts with an admin settlement process.

2a80615409b98c02fd541a3dc0ed018995c7c2de