W3HC Hardhat Template

A comprehensive development environment for Ethereum-compatible networks using Hardhat.

Features

• Typescript
• Ethers v6
• OpenZeppelin Contracts v5.1.0
• Hardhat Verify plugin
• Hardhat Deploy plugin

Supported Networks

Network	Chain ID	Documentation
Optimism Mainnet	10	Documentation
Sepolia Testnet	11155111	Documentation
OP Sepolia Testnet	11155420	Documentation
Base Sepolia Testnet	84532	Documentation

Contract Verification

Network	Explorer URL	API URL	API Key Variable
Sepolia	https://sepolia.etherscan.io	https://api-sepolia.etherscan.io/api	ETHERSCAN_API_KEY
Optimism	https://optimistic.etherscan.io	https://api-optimistic.etherscan.io/api	OP_ETHERSCAN_API_KEY
OP Sepolia	https://sepolia-optimism.etherscan.io	https://api-sepolia-optimistic.etherscan.io/api	OP_ETHERSCAN_API_KEY
Base Sepolia	https://sepolia.basescan.org	https://api-sepolia.basescan.org/api	BASE_ETHERSCAN_API_KEY

Contract Verification

Network	Explorer URL	API URL	API Key Variable
Sepolia	https://sepolia.etherscan.io	https://api-sepolia.etherscan.io/api	ETHERSCAN_API_KEY
Optimism	https://optimistic.etherscan.io	https://api-optimistic.etherscan.io/api	OP_ETHERSCAN_API_KEY
Base	https://basescan.org	https://api.basescan.org/api	BASE_ETHERSCAN_API_KEY
OP Sepolia	https://sepolia-optimism.etherscan.io	https://api-sepolia-optimistic.etherscan.io/api	OP_ETHERSCAN_API_KEY
Base Sepolia	https://sepolia.basescan.org	https://api-sepolia.basescan.org/api	BASE_ETHERSCAN_API_KEY

Manual Contract Verification

When deploying, you may see this error:

ContractStatusPollingResponseNotOkError: The Etherscan API responded with a failure status.
Reason: Fail - Unable to verify. Unable to locate ContractCode at <address>

This is normal - it means the contract needs time to be indexed. Wait 1-2 minutes, then run:

npx hardhat verify --network <NETWORK_NAME> <CONTRACT_ADDRESS> "10000000000000000000000"

Where:

• <NETWORK_NAME>: optimism, base, op-sepolia, or base-sepolia
• <CONTRACT_ADDRESS>: The address where your contract was deployed

Note: The constructor argument represents the initial supply in wei (e.g., "10000000000000000000000" for 10,000 tokens with 18 decimals)

If the verification fails with "Unable to locate ContractCode", wait a few minutes for the contract to be indexed by the block explorer and try again.

Alternative Manual Verification via Block Explorers:

• Optimism: https://optimistic.etherscan.io/verifyContract
• Base: https://basescan.org/verifyContract
• OP Sepolia: https://sepolia-optimism.etherscan.io/verifyContract
• Base Sepolia: https://sepolia.basescan.org/verifyContract

When verifying through block explorers:

1. Choose "Solidity (Single file)"
2. Fill in:
   • Contract Address
   • Compiler: v0.8.20
   • License: GPL-3.0
   • Optimization: Yes (200 runs)
   • Contract code from Basic.sol
   • Constructor Arguments: 10000000000000000000000

Installation

1. Install dependencies:

pnpm install

2. Configure environment:

cp .env.template .env

3. Update .env with your configuration:

# Required Configuration
OPTIMISM_MAINNET_RPC_ENDPOINT_URL="your_optimism_rpc_url"
OPTIMISM_MAINNET_PRIVATE_KEY="your_private_key"
OP_ETHERSCAN_API_KEY="your_api_key"

# Additional networks...

Usage

Testing

Execute the test suite:

pnpm test

Deployment

Deploy to supported networks:

pnpm deploy:<network>

Supported values for <network>: sepolia, optimism, op-sepolia, base-sepolia

Network Operations

Check wallet balance:

pnpm bal <network>

Mint tokens:

pnpm mint:<network> <amount>

Transfer tokens:

pnpm send:<network> <amount>

Core Dependencies

• Node v20.9.0
• PNPM v9.10.0
• Hardhat v2.22.16
• OpenZeppelin Contracts v5.1.0
• Ethers v6.13.4

Support

Feel free to reach out to Julien: Farcaster, Element, Status, Telegram, Twitter, Discord, or LinkedIn.