Smart Contracts

The Web3 variant includes sample smart contracts demonstrating an ERC20 token factory pattern. These serve as a starting point for your own contract development and show how QuickDapp integrates with on-chain contracts end-to-end.

Overview

The sample contracts use OpenZeppelin contracts and Foundry tooling. The factory deploys new ERC20 tokens with custom names, symbols, and initial supplies.

Both contracts live in sample-contracts/src/ERC20Factory.sol:

ERC20Factory - Deploys new ERC20 tokens and tracks them
SimpleERC20 - Basic ERC20 with mint/burn capabilities and custom transfer events

Directory Structure

sample-contracts/
├── src/
│   └── ERC20Factory.sol      # Factory and token contracts
├── devnet.ts                 # Local Hardhat blockchain
├── deploy.ts                 # Foundry deployment script
├── foundry.toml              # Foundry configuration
└── hardhat.config.cjs        # Hardhat node configuration

Local Development

Start the local blockchain and deploy contracts in separate terminals:

# Terminal 1: Start local blockchain
cd sample-contracts
bun devnet.ts

# Terminal 2: Deploy contracts
cd sample-contracts
bun deploy.ts

The deployment script uses Foundry's forge create to deploy ERC20Factory, then automatically updates .env.local with the deployed contract address.

Factory Interface

The factory tracks deployed tokens and emits events for indexing:

contract ERC20Factory {
    event ERC20NewToken(
        address indexed token,
        string name,
        string symbol,
        address indexed creator,
        uint256 initialSupply
    );

    function erc20DeployToken(
        ERC20TokenConfig memory config,
        uint256 initialBalance
    ) external returns (address);

    function getNumErc20s() external view returns (uint256);
    function getErc20Address(uint256 index) external view returns (address);
    function getAllErc20Addresses() external view returns (address[] memory);
}

Token configuration uses a struct:

struct ERC20TokenConfig {
    string name;
    string symbol;
    uint8 decimals;
}

Testnet Deployment

Deploy to Sepolia or other testnets by configuring environment variables:

# In your .env.local
WEB3_SUPPORTED_CHAINS=sepolia
WEB3_SEPOLIA_RPC=https://sepolia.infura.io/v3/YOUR_KEY
WEB3_SERVER_WALLET_PRIVATE_KEY=0x...

# Deploy
cd sample-contracts
bun deploy.ts

The script reads from the first chain in WEB3_SUPPORTED_CHAINS and uses the corresponding RPC endpoint.

Testing

Run Foundry tests for contract verification:

cd sample-contracts
forge test           # Run all tests
forge test -vvv      # Verbose output
forge test --gas-report

Frontend Integration

After deployment, the contract address is available via clientConfig.WEB3_FACTORY_CONTRACT_ADDRESS. ABIs are generated from Foundry build artifacts to src/shared/abi/generated.ts when you run bun run gen.

Use Wagmi hooks on the client for contract interactions. The ERC20NewToken and TokenTransferred events are tracked by the chain monitoring worker for real-time notifications.

Customization

To add your own contracts:

Add Solidity files to sample-contracts/src/
Run forge build to compile
Update deploy.ts to deploy your contracts
Run bun run gen to regenerate ABI types