Payyr - USDC Automated Payroll System on Arc Network

A modern, multi-tenant automated payroll system built on Arc Network, enabling seamless USDC payments to employees with a beautiful fintech-style interface. Self-service employer registration allows unlimited companies to share the same smart contracts.

🌟 Features

• Multi-Tenant Architecture: Unlimited companies share the same smart contracts with isolated operations
• Self-Service Registration: Any wallet can register as an employer - no admin needed
• Modern UI: Clean, fintech-inspired interface built with Next.js 14 and TailwindCSS
• Employee Management: Add, edit, and manage employee profiles with wallet addresses
• Automated Payroll: Schedule and execute automated USDC payments
• Dashboard Analytics: Real-time overview of payroll metrics and balances
• Smart Contracts: Solidity contracts built with Foundry for secure payments
• Arc Network Integration: Leveraging Arc Network for fast, low-cost transactions
• Role-Based Access Control: HR_ROLE for employers, ADMIN_ROLE for platform owner

🔄 How It Works

For Employers (Self-Service Flow)

1. Connect Wallet
   → Your wallet address is your identity

2. Register as Employer
   → Click "Register as Employer" button
   → Calls registerAsEmployer() contract function
   → Automatically granted HR_ROLE
   → Cost: ~$0.08 in gas

3. Add Your Employees
   → Go to Employees page
   → Click "Add Employee"
   → Enter: Name, Wallet Address, Salary, Role
   → Employee linked to your employer address
   → Only YOU can manage your employees
   → Cost: ~$0.19 per employee

4. Deposit USDC for Payroll
   → Go to Payroll page
   → Approve USDC spending (one-time)
   → Deposit desired amount
   → Funds tracked in your employer balance
   → Cost: ~$0.17 (approve + deposit)

5. Execute Payroll
   → Click "Pay All Employees"
   → Contract pays only YOUR employees
   → Deducts from your employer balance
   → Instant USDC transfers to employee wallets
   → Cost: ~$0.24 per employee

Multi-Tenant Isolation

All employers share the same contracts but operate independently:

// Each employer has their own balance
employerBalances[companyA] = 10_000 USDC
employerBalances[companyB] = 5_000 USDC

// Each employer manages only their employees
getEmployerEmployees(companyA) → [emp1, emp2, emp3]
getEmployerEmployees(companyB) → [emp4, emp5]

// Payroll is isolated
companyA.executePayroll() → pays emp1, emp2, emp3
companyB.executePayroll() → pays emp4, emp5

🏗️ Architecture

Smart Contracts

EmployeeRegistry (0x20B3dB45a351E92673112064A3F01951115eD6B7)

• Manages employee records
• Links employees to employers
• Handles employer registration
• Tracks employer-employee relationships

PayrollManager (0x1739715A3452BF1e336305cf8f9542d177cEa03A)

• Manages USDC deposits
• Executes payroll per employer
• Tracks employer balances
• Handles payroll history

Frontend Application

frontend/
├── app/
│   ├── dashboard/    # Platform overview & statistics
│   ├── employees/    # Employee management with employer registration
│   ├── payroll/      # USDC deposits & payroll execution
│   └── settings/    # User preferences
├── components/
│   ├── ui/          # shadcn/ui components
│   └── providers/  # Wallet & context providers
└── lib/
    └── abi/         # Smart contract ABIs

💰 Gas Costs

Deployment (Platform Owner - One-Time)

Contract	Est. Gas	Cost (USDC)
EmployeeRegistry	~1.5M	$2.40
PayrollManager	~2.6M	$4.16
Total Deployment	~4.1M	$6.56

User Operations

Operation	Est. Gas	Cost (USDC)
Register as Employer	50,000	$0.08
Add Employee	120,000	$0.19
Update Employee	90,000	$0.14
Deactivate Employee	80,000	$0.13
Approve USDC (once)	40,000	$0.06
Deposit Payroll	70,000	$0.11
Execute Payroll (per employee)	150,000	$0.24

Assumptions: 160 gwei gas price, $0.0016 per gas unit on Arc Network

Cost Example: Company with 5 Employees

• Register as employer: $0.08
• Add 5 employees: $0.95
• Approve USDC (one-time): $0.06
• Deposit $10,000: $0.11
• Execute payroll (5 employees): $1.20
• Total: $2.40 per payroll run

🚀 Getting Started

Prerequisites

• Node.js 18+ installed
• Foundry installed (for smart contract development)
• Wallet with Arc Network USDC

Backend (Smart Contracts)

cd Backend
forge install
forge build
forge test

# Deploy to Arc Network
forge script script/DeployDirect.s.sol --rpc-url $RPC_URL --broadcast

Frontend (Web Application)

cd frontend
npm install
npm run dev

Open http://localhost:3000 to view the application.

Quick Start for New Users

1. Connect your wallet - Click the connect button in the top right
2. Register as employer - Go to Employees page and click "Register as Employer"
3. Add your team - Add employees with their wallet addresses and salaries
4. Fund your payroll - Go to Payroll page and deposit USDC
5. Pay your team - Click "Pay All Employees" to execute payroll

🛠️ Tech Stack

Frontend

• Next.js 14 - React framework with app router
• TypeScript - Type-safe development
• TailwindCSS - Utility-first styling
• shadcn/ui - Modern component library
• Privy - Embedded wallet authentication
• Wagmi - React hooks for Ethereum
• Lucide React - Beautiful icons

Backend

• Foundry - Smart contract development framework
• Solidity - Smart contract programming language
• OpenZeppelin - Security libraries (AccessControl, ReentrancyGuard, Pausable)
• Arc Network - Layer 2 blockchain for fast, cheap transactions

📊 Pages & Features

Dashboard

• Platform-wide statistics
• Recent payroll runs
• Total contract balance (admin view)

Employees

• Employer Registration - Self-service onboarding
• Employee List - View your team members
• Add Employee - Add new team members
• Edit Employee - Update employee details
• Activate/Deactivate - Manage employee status

Payroll

• Deposit USDC - Fund your payroll account
• View Balance - Check your available funds
• Execute Payroll - Pay all active employees
• Payroll History - View past runs

Settings

• Company information
• Payment preferences
• Wallet management

🔐 Security Features

• Wallet-based authentication - Secure login via Privy
• Role-based access control - Employers only manage their employees
• Isolated employer balances - Funds separated per employer
• ReentrancyGuard - Prevent reentrancy attacks
• Pausable - Emergency pause functionality
• Audit-ready code - Clean, well-documented contracts

🎯 Why This Is Great for Arc Rewards

1. Multi-Tenant Design - Scalable to unlimited companies
2. Self-Service - No manual onboarding required
3. Gas Efficient - Shared contracts = lower costs for users
4. Real Utility - Actual payroll management use case
5. Production Ready - Complete frontend + backend
6. Low Barrier - $0.08 to become an employer

📄 License

This project is open source and available under the MIT License.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📞 Support

For support and questions, please open an issue in this repository.