End-to-end Web3 system with real-time on-chain analytics.

Full-stack Web3 dApp with an ERC-20 crowdsale, optional ERC-721 NFT receipts, and a real-time analytics pipeline powered by The Graph.

Includes a full analytics layer powered by The Graph for transforming raw blockchain events into structured, queryable data.

Demonstrates end-to-end blockchain system design: smart contracts → frontend → indexed on-chain data → queryable insights.

Built as part of the Dapp University Blockchain Developer Mentorship (Capstone Project).

• ERC-20 crowdsale with optional ERC-721 receipt NFTs
• Fully deployed on Sepolia testnet
• Real-time indexing using The Graph (subgraph + GraphQL)
• React + Tailwind frontend with wallet interaction
• End-to-end system: contract → events → indexing → UI

This project focuses on system design and data flow, not just contract deployment.

Raw blockchain logs are difficult to work with in real applications.

This project demonstrates how to transform on-chain events into structured, queryable data for real-world use cases:

• Real-time analytics
• Wallet behavior tracking
• Dashboard-ready insights
• Queryable Web3 data via GraphQL

Pipeline:
Smart Contract → Events → Subgraph → GraphQL → Analytics

• Smart contracts (ERC-20 token, crowdsale, ERC-721 receipt NFT)
• Deployment + testing (Hardhat + Foundry)
• Frontend (React + Tailwind, wallet integration)
• Subgraph (The Graph indexing + GraphQL queries)
• Full pipeline: contract events → indexed data → frontend display

✅ Live dApp (Sepolia):
https://cryptomachinegene.github.io/proofmint-project/

📦 Source Code Repo:
https://github.com/CryptoMachineGene/proofmint-project

🎥 Demo Walkthrough (YouTube):
https://www.youtube.com/watch?v=CatHeV8tclI

Proofmint is an ERC-20 crowdsale with ERC-721 NFT contribution receipts, built and tested with Hardhat + Foundry.

Network: Sepolia (Chain ID: 11155111)

• Crowdsale: 0xEcB940c13A1EF6D411f2D7E15345591eb9fce1d7

• Token (ERC-20): 0x9712820E18e5f2B8cBe3da25f31b8f2F8c8576bF

• ProofNFT (ERC-721, optional): 0xd3982fF82F27c790176138BC7115C6e32AFb0ED3

• Latest example tx: 0x09097d8066…

• Screenshots gallery: assets/SCREENSHOTS.md

• Tx Log: deployments/txlog.json

Live dApp: https://cryptomachinegene.github.io/proofmint-project/

Flow: connect → buy → verify on Etherscan → owner withdraw. (UI is intentionally minimal — focus is on smart contract architecture, testing, and deployment.)

Analytics flow: contract events → subgraph indexing → GraphQL queries → structured insights.

Includes subgraph-powered GraphQL queries for indexed analytics.

1. Open the dApp (read-only state shows via FALLBACK_RPC).
2. Connect wallet → allow/switch to Sepolia if prompted.
3. Buy 0.01 ETH → pending → confirmed → open Etherscan.
4. (Owner) Withdraw → state reflects updated balances.
5. Disconnect + hard refresh → read-only state persists.

Backend (Hardhat + Foundry)

• ERC-20 Token
• Crowdsale contract
• Optional ProofNFT (receipt NFT)

Frontend (React + Vite + Tailwind)

• Wallet connect (MetaMask/Brave)
• Live crowdsale stats
• Buy with ETH (auto-detects payable path)
• Owner withdraw

This project includes a full indexing and analytics pipeline using The Graph.

• Subgraph location: proofmint-subgraph/
• Indexes on-chain events from the Proofmint contracts
• Transforms raw blockchain logs into structured, queryable data

• Purchase events (crowdsale participation)
• Token distribution data
• NFT receipt minting
• Wallet-level activity

Captured from a live subgraph deployed on Sepolia, showing indexed on-chain data exposed via GraphQL queries.

• Prereqs: Node 18+
• Env: copy proofmint-frontend/.env.local.example → .env.local and set VITE_FALLBACK_RPC. (optional)

cd proofmint
npm install
npx hardhat compile
npx hardhat test
forge test -vv

npx hardhat run scripts/deploy/03_deploy_crowdsale.ts --network sepolia

cd proofmint-frontend
npm install
npm run dev
npm run build && npm run preview

VITE_CHAIN_ID=11155111
VITE_CHAIN_ID_HEX=0xaa36a7
VITE_FALLBACK_RPC=<YOUR_PUBLIC_SEPOLIA_RPC_URL>

VITE_CROWDSALE_ADDRESS=0xEcB940c13A1EF6D411f2D7E15345591eb9fce1d7
VITE_TOKEN_ADDRESS=0x9712820E18e5f2B8cBe3da25f31b8f2F8c8576bF
VITE_NFT_ADDRESS=0xd3982fF82F27c790176138BC7115C6e32AFb0ED3

White screen but Vite is running → Ensure index.html has <div id="root"></div> and src/main.tsx uses createRoot(...).

“Missing VITE_*” → Add keys to .env.local and restart npm run dev.

Auto-reconnect on refresh → remove localhost:5173 from wallet Connected sites, or use a Private window for the “disconnected + read-only” state.

Withdraw fails → only the owner can call withdraw() (enforced by the contract).

• proofmint/ — Hardhat + Foundry smart contracts and deployment scripts
• proofmint-frontend/ — React + Tailwind front-end
• proofmint-subgraph/ — Subgraph indexing + GraphQL analytics layer
• assets/SCREENSHOTS.md — full demo gallery
• deployments/sepolia.json — addresses & metadata
• deployments/txlog.json — recent tx log

MIT

Last updated: February 3, 2026 · Chain: Sepolia (11155111)