QFC Smart Contracts

A comprehensive library of smart contract examples and templates for the QFC blockchain.

Overview

This repository provides production-ready smart contract templates covering:

• Tokens - ERC-20, ERC-721, ERC-1155 implementations
• Staking - Staking pools with time-weighted rewards
• Governance - DAO governance with OpenZeppelin Governor
• DeFi - AMM swap and yield vault contracts
• Utilities - Multicall, CREATE2 factory, and more

Installation

npm install

Quick Start

Compile Contracts

npm run compile

Run Tests

npm test

Deploy to Local Network

npx hardhat node
npm run deploy

Deploy to Testnet

# Copy and configure environment
cp .env.example .env
# Edit .env with your private key

npm run deploy:testnet

Contracts

Tokens

QFCToken (ERC-20)

Full-featured ERC-20 token with:

• Minting with cap limit
• Burning
• Permit (gasless approvals)
• Batch transfers
• Owner-controlled minting

import "./tokens/QFCToken.sol";

QFCToken token = new QFCToken(
    "My Token",
    "MTK",
    1000000 ether,  // cap
    100000 ether    // initial supply
);

QFCNFT (ERC-721)

NFT collection with:

• Enumerable extension
• URI storage
• Mint price mechanism
• Owner-controlled minting
• Max supply limit

import "./tokens/QFCNFT.sol";

QFCNFT nft = new QFCNFT(
    "My NFT",
    "MNFT",
    "https://api.example.com/metadata/",
    10000,          // max supply
    0.1 ether       // mint price
);

QFCMultiToken (ERC-1155)

Multi-token with:

• Supply tracking per token ID
• Batch minting
• URI management
• Owner controls

Staking

StakingPool

Time-weighted staking rewards with:

• Configurable reward rate
• Lock period enforcement
• Emergency withdrawal
• Reward updates per block

import "./staking/StakingPool.sol";

StakingPool pool = new StakingPool(
    stakingTokenAddress,
    rewardTokenAddress,
    rewardPerSecond,
    lockPeriod
);

RewardDistributor

Merkle-tree based reward distribution:

• Epoch-based claims
• Merkle proof verification
• Multiple distribution rounds

Governance

QFCGovernor

OpenZeppelin Governor implementation:

• Token-based voting
• Timelock execution
• Configurable voting parameters
• Proposal lifecycle management

Treasury

DAO treasury management:

• Role-based access control
• ETH and token withdrawals
• Spending limits
• Proposer/executor roles

DeFi

SimpleSwap

Constant product AMM (x * y = k):

• Add/remove liquidity
• Swap token0 for token1 and vice versa
• 0.3% swap fee
• Price oracles

import "./defi/SimpleSwap.sol";

SimpleSwap swap = new SimpleSwap(token0Address, token1Address);

// Add liquidity
swap.addLiquidity(amount0, amount1);

// Swap
swap.swap0For1(amountIn, minAmountOut);

Vault

ERC4626-like yield vault:

• Deposit/withdraw underlying tokens
• Share-based accounting
• Management fee
• Harvest mechanism

Utilities

Multicall

Batch multiple contract calls:

• Aggregate calls in single transaction
• Optional failure tolerance
• Gas efficient

Create2Factory

Deterministic contract deployment:

• Predictable addresses
• Salt-based deployment
• Compute address before deployment

Project Structure

qfc-contracts/
├── contracts/
│   ├── tokens/
│   │   ├── QFCToken.sol      # ERC-20 token
│   │   ├── QFCNFT.sol        # ERC-721 NFT
│   │   └── QFCMultiToken.sol # ERC-1155 multi-token
│   ├── staking/
│   │   ├── StakingPool.sol       # Staking with rewards
│   │   └── RewardDistributor.sol # Merkle distribution
│   ├── governance/
│   │   ├── QFCGovernor.sol   # DAO governance
│   │   └── Treasury.sol      # DAO treasury
│   ├── defi/
│   │   ├── SimpleSwap.sol    # AMM DEX
│   │   └── Vault.sol         # Yield vault
│   └── utils/
│       ├── Multicall.sol     # Batch calls
│       └── Create2Factory.sol # Deterministic deploy
├── scripts/
│   ├── deploy.ts             # Token deployment
│   ├── deploy-staking.ts     # Staking deployment
│   └── deploy-defi.ts        # DeFi deployment
├── test/
│   ├── QFCToken.test.ts      # Token tests
│   └── SimpleSwap.test.ts    # Swap tests
├── hardhat.config.ts
└── package.json

Networks

Network	Chain ID	RPC URL
Localhost	31337	http://127.0.0.1:8545
QFC Testnet	9000	https://rpc.testnet.qfc.network
QFC Mainnet	9001	https://rpc.qfc.network

Scripts

# Compile contracts
npm run compile

# Run tests
npm test

# Run tests with coverage
npm run coverage

# Deploy to local network
npm run deploy

# Deploy to testnet
npm run deploy:testnet

# Deploy staking contracts
npm run deploy:staking

# Deploy DeFi contracts
npm run deploy:defi

# Verify contract on explorer
npx hardhat verify --network testnet <contract-address> <constructor-args>

Security Considerations

These contracts are provided as examples and templates. Before using in production:

1. Audit - Get professional security audits
2. Test - Write comprehensive tests for your use case
3. Review - Carefully review all parameters and configurations
4. Timelock - Use timelocks for privileged operations
5. Access Control - Properly configure admin roles

Dependencies

• OpenZeppelin Contracts - Security-audited implementations
• Hardhat - Development environment
• ethers.js - Ethereum library

License

MIT License - see LICENSE for details.