Credibles - Living Resume Project

A blockchain-based skill tracking system where users mint soul-bound NFTs (SkillPets) that evolve as they complete courses and earn attestations. Skills are tracked across four categories: Development, DeFi, Governance, and Social.

📋 Table of Contents

• Project Overview
• Architecture
• Prerequisites
• Quick Start
• Project Structure
• Current Deployment
• Development Workflow
• Key Features
• Environment Setup
• Common Tasks
• Troubleshooting

🎯 Project Overview

Credibles is a gamified learning platform that:

• Allows users to mint one soul-bound NFT per wallet (SkillPet)
• Tracks XP across 4 skill categories: Development, DeFi, Governance, Social
• Evolves NFTs from "Egg" → "Baby Dragon" → "Young Dragon" → "Dragon" based on total XP
• Supports daily tasks/quizzes that award XP directly to skill categories
• Integrates with EAS (Ethereum Attestation Service) for course completion attestations
• Features a modern Next.js frontend with light/dark mode support

🏗️ Architecture

WorkProof/
├── blockchain/          # Smart contracts (Hardhat)
│   ├── contracts/      # Solidity contracts
│   ├── scripts/        # Deployment & utility scripts
│   └── test/           # Contract tests
└── Credibles/          # Next.js frontend
    ├── app/            # Next.js app directory
    └── public/         # Static assets

Smart Contracts

1. Credibles.sol - Main NFT contract

   • ERC721 soul-bound tokens (non-transferable)
   • Tracks XP per skill category
   • Public minting (one per wallet)
   • Direct XP addition for daily tasks

2. AttestationResolver.sol - EAS integration

   • Resolves attestations to add XP to NFTs
   • Schema: (uint256 studentId, string category, uint256 xpValue)

Frontend

• Next.js 15 with App Router
• OnchainKit for wallet integration
• wagmi + viem for blockchain interactions
• TypeScript throughout

✅ Prerequisites

Before you begin, ensure you have:

• Node.js 22.10.0 or later (LTS recommended)

  node --version  # Should be v22.x.x or higher

• npm or yarn package manager
• A Base Sepolia wallet with testnet ETH
• Git for version control

Optional but Recommended

• nvm (Node Version Manager) for managing Node versions
• Hardhat account with private key for deployments
• BaseScan API key for contract verification

🚀 Quick Start

1. Clone and Install Dependencies

# Clone the repository
git clone <repository-url>
cd WorkProof

# Install blockchain dependencies
cd blockchain
npm install

# Install frontend dependencies
cd ../Credibles
npm install

2. Set Up Environment Variables

Blockchain (.env in blockchain/)

Create blockchain/.env:

PRIVATE_KEY=your_private_key_without_0x_prefix
RPC_URL=https://sepolia.base.org
BASESCAN_API_KEY=your_basescan_api_key_optional

Frontend (.env.local in Credibles/)

The frontend environment is automatically updated after deployment. If missing, create Credibles/.env.local:

NEXT_PUBLIC_CREDIBLES_CONTRACT_ADDRESS=0x725b47c5fcd4f9dc0d2819ba2682b957499adfa8
NEXT_PUBLIC_ATTESTATION_RESOLVER_ADDRESS=0x307502170787e06efa90fd751c4c625ab5932956
NEXT_PUBLIC_SCHEMA_UID=0x33b404644850244e8b14591c6e561039dfafbf5028fb14daa714361dcb0f9104

3. Run the Frontend

cd Credibles
npm run dev

Open http://localhost:3000 in your browser.

📁 Project Structure

WorkProof/
├── blockchain/
│   ├── contracts/
│   │   ├── Credibles.sol              # Main NFT contract
│   │   ├── AttestationResolver.sol    # EAS resolver
│   │   ├── IEAS.sol                   # EAS interface
│   │   └── ISchemaRegistry.sol        # Schema registry interface
│   ├── scripts/
│   │   ├── deploy.ts                  # Deploy contracts
│   │   ├── update-frontend-env.ts    # Update frontend env vars
│   │   ├── test-backend.ts           # Test contract connections
│   │   ├── list-deployments.ts       # List deployment history
│   │   └── mint.ts                   # Mint NFT (legacy, use frontend now)
│   ├── test/                         # Contract tests
│   ├── deployments.json              # Deployment history
│   └── hardhat.config.ts             # Hardhat configuration
│
└── Credibles/
    ├── app/
    │   ├── page.tsx                  # Main page component
    │   ├── layout.tsx                # Root layout
    │   ├── rootProvider.tsx           # Wallet provider setup
    │   ├── page.module.css           # Page styles
    │   ├── globals.css                # Global styles
    │   ├── api/
    │   │   └── headhunter/
    │   │       └── route.ts           # Headhunter API endpoint
    │   └── types/
    │       └── contracts.ts          # TypeScript contract types
    └── public/                       # Static assets

🌐 Current Deployment

Network: Base Sepolia Testnet

Latest Contracts (Deployed: Dec 4, 2025):

Contract	Address	Explorer
Credibles	0x725b47c5fcd4f9dc0d2819ba2682b957499adfa8	BaseScan
AttestationResolver	0x307502170787e06efa90fd751c4c625ab5932956	BaseScan
Schema UID	0x33b404644850244e8b14591c6e561039dfafbf5028fb14daa714361dcb0f9104	-

Contract Owner: 0x41b1e204e9c15fF5894bd47C6Dc3a7Fa98C775C7

🔄 Development Workflow

Making Contract Changes

1. Edit contracts in blockchain/contracts/
2. Compile contracts:

   cd blockchain
   npx hardhat compile

3. Test your changes:

   npx hardhat test

4. Deploy to Base Sepolia:

   npx hardhat run scripts/deploy.ts

5. Update frontend environment:

   npx hardhat run scripts/update-frontend-env.ts

6. Restart frontend dev server

Making Frontend Changes

1. Edit files in Credibles/app/
2. Hot reload - changes appear automatically in dev mode
3. Build for production:

   cd Credibles
   npm run build

✨ Key Features

1. Public NFT Minting

• Anyone can mint one NFT per wallet
• Auto-assigned token IDs
• Soul-bound (non-transferable)

2. Skill Tree System

• 4 Categories: Development, DeFi, Governance, Social
• XP Tracking: Each category tracks XP independently
• Level System: 1 level per 100 XP
• Evolution Stages:
  • Egg (0 XP)
  • Baby Dragon (100+ XP)
  • Young Dragon (300+ XP)
  • Dragon (600+ XP)

3. Daily Tasks

• Quiz questions per skill category
• 3 attempts per question
• 10 XP awarded for correct answers
• Direct on-chain XP addition

4. EAS Attestation Integration

• Course completion attestations
• Automatic XP addition via AttestationResolver
• GraphQL query for user attestations

5. Modern UI

• Light/dark mode support
• Responsive design
• Real-time XP updates
• Transaction status tracking

🔧 Environment Setup

Required Environment Variables

Blockchain (blockchain/.env)

PRIVATE_KEY=your_private_key_without_0x
RPC_URL=https://sepolia.base.org  # Optional, has default
BASESCAN_API_KEY=your_key  # Optional, for verification

Frontend (Credibles/.env.local)

NEXT_PUBLIC_CREDIBLES_CONTRACT_ADDRESS=0x...
NEXT_PUBLIC_ATTESTATION_RESOLVER_ADDRESS=0x...
NEXT_PUBLIC_SCHEMA_UID=0x...

Getting Testnet ETH

1. Go to Base Sepolia Faucet
2. Connect your wallet
3. Request testnet ETH

📝 Common Tasks

View Deployment History

cd blockchain
npm run deployments
# or
npx hardhat run scripts/list-deployments.ts

Test Backend Connection

cd blockchain
npm run test-backend

Deploy Contracts

cd blockchain
npm run deploy
# Automatically updates frontend env after deployment

Verify Contracts

cd blockchain
npm run verify

Mint an NFT (via Frontend)

1. Connect wallet on frontend
2. Click "Mint Your SkillPet NFT"
3. Approve transaction in wallet

Complete Daily Task

1. Navigate to Skill Tree section
2. Click "Complete Daily Task" on any skill card
3. Answer quiz question (3 attempts)
4. Earn 10 XP on correct answer

Create EAS Attestation

1. Go to Base Sepolia EAS Explorer
2. Connect wallet
3. Create attestation with:
   • Schema: 0x33b404644850244e8b14591c6e561039dfafbf5028fb14daa714361dcb0f9104
   • Recipient: Your wallet address
   • Data: Encode (uint256 studentId, string category, uint256 xpValue)
     • Example: Token ID 1, category "dev", XP 50

🐛 Troubleshooting

"Contract address not configured"

Solution:

cd blockchain
npm run update-frontend
# Then restart frontend dev server

"You already have an NFT"

This is expected - each wallet can only mint one NFT. The contract enforces this.

"NaN" values showing for XP

Fixed in latest deployment! If you still see this:

1. Ensure you're using the latest contract address
2. Check that characterStats is being read correctly
3. Verify your token ID exists

Node.js version error

Error: You are using Node.js 20.x.x which is not supported

Solution:

# Using nvm
nvm use 22
# or install Node 22+

Compilation errors

Solution:

cd blockchain
rm -rf cache artifacts
npx hardhat clean
npx hardhat compile

Frontend not connecting to wallet

1. Ensure you're on Base Sepolia network
2. Check wallet extension is installed
3. Try refreshing the page
4. Check browser console for errors

Transaction fails

1. Check you have enough Base Sepolia ETH
2. Verify network is Base Sepolia (not mainnet)
3. Check contract address is correct
4. Review transaction on BaseScan

📚 Useful Commands

Blockchain

cd blockchain

# Compile contracts
npx hardhat compile

# Run tests
npm test

# Deploy contracts
npm run deploy

# List deployments
npm run deployments

# Test backend
npm run test-backend

# Update frontend env
npm run update-frontend

# Verify contracts
npm run verify

Frontend

cd Credibles

# Start dev server
npm run dev

# Build for production
npm run build

# Start production server
npm start

# Lint code
npm run lint

🔗 Useful Links

• Base Sepolia Explorer: https://sepolia.basescan.org/
• EAS Explorer: https://base-sepolia.easscan.org/
• Base Sepolia Faucet: https://www.coinbase.com/faucets/base-ethereum-goerli-faucet
• OnchainKit Docs: https://docs.base.org/onchainkit
• Hardhat Docs: https://hardhat.org/docs

📖 Additional Documentation

• INTEGRATION_GUIDE.md - Integration checklist and testing guide
• blockchain/README.md - Hardhat project documentation
• Credibles/README.md - Next.js project documentation

🤝 Contributing

1. Create a feature branch
2. Make your changes
3. Test thoroughly (contracts + frontend)
4. Submit a pull request

📄 License

[Add your license here]

👥 Team

1. Reece Bailey (@reecebaileyy)
2. Niha (@nihaparkashuni-del)
3. Christian Huerta

For questions or issues, contact the team or open an issue in the repository.

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Last Updated: December 4, 2025
Contract Version: v2 (Public Minting + Daily Tasks)