In today’s fragmented blockchain landscape, deploying smart contracts on multiple networks has become essential for maximizing reach, enhancing redundancy, and leveraging the unique advantages of each chain. This comprehensive guide will walk you through the process of deploying your smart contracts across various blockchain networks including Ethereum, Binance Smart Chain, Polygon, and more.
Deploying smart contracts across multiple blockchain networks offers several significant advantages that can enhance your project’s reach and resilience:
Before we begin deploying smart contracts on multiple blockchain networks, make sure you have the following tools and knowledge:
You’ll need Node.js (v14+), npm or yarn, and a code editor like VSCode with Solidity extensions.
Install Hardhat or Truffle to simplify the smart contract development and deployment process.
MetaMask or similar wallet with accounts configured for each target blockchain network.
Knowledge Requirements: This tutorial assumes you have basic familiarity with smart contract development, Solidity programming, and have previously deployed at least one contract to a single network.
The first step in deploying smart contracts on multiple blockchain networks is configuring your development environment to support each target chain.
Let’s start by creating a new project and initializing it with Hardhat:
mkdir multi-chain-deploy
cd multi-chain-deploy
npm init -y
npm install –save-dev hardhat
npx hardhat
When prompted by Hardhat, select “Create a JavaScript project” to set up a standard project structure.
Next, install the necessary dependencies for multi-chain deployment:
npm install –save-dev @nomiclabs/hardhat-ethers ethers @nomiclabs/hardhat-waffle ethereum-waffle chai dotenv @openzeppelin/contracts
Create a .env
file in your project root to store private keys and API endpoints securely:
PRIVATE_KEY=your_wallet_private_key
ETHEREUM_RPC_URL=https://mainnet.infura.io/v3/your_infura_key
BSC_RPC_URL=https://bsc-dataseed.binance.org/
POLYGON_RPC_URL=https://polygon-rpc.com
AVALANCHE_RPC_URL=https://api.avax.network/ext/bc/C/rpc
Security Warning: Never commit your .env file to version control. Always add it to .gitignore to protect your private keys and API endpoints.
Now, let’s update the Hardhat configuration file to support deployment to multiple blockchain networks.
Update your hardhat.config.js
file with the following configuration:
require(‘@nomiclabs/hardhat-waffle’);
require(‘@nomiclabs/hardhat-ethers’);
require(‘dotenv’).config();
module.exports = {
solidity: “0.8.17”,
networks: {
hardhat: {},
ethereum: {
url: process.env.ETHEREUM_RPC_URL,
accounts: [process.env.PRIVATE_KEY],
chainId: 1
},
bsc: {
url: process.env.BSC_RPC_URL,
accounts: [process.env.PRIVATE_KEY],
chainId: 56
},
polygon: {
url: process.env.POLYGON_RPC_URL,
accounts: [process.env.PRIVATE_KEY],
chainId: 137
},
avalanche: {
url: process.env.AVALANCHE_RPC_URL,
accounts: [process.env.PRIVATE_KEY],
chainId: 43114
}
}
};
For testing purposes, it’s recommended to use testnets instead of mainnets. Simply replace the RPC URLs and chain IDs with testnet values.
When deploying smart contracts on multiple blockchain networks, it’s important to ensure your contract is compatible with all target chains.
Create a file named MultiChainToken.sol
in the contracts
folder with the following content:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import “@openzeppelin/contracts/token/ERC20/ERC20.sol”;
import “@openzeppelin/contracts/access/Ownable.sol”;
contract MultiChainToken is ERC20, Ownable {
string private _networkName;
constructor(string memory name, string memory symbol, string memory networkName) ERC20(name, symbol) {
_networkName = networkName;
_mint(msg.sender, 1000000 * 10 ** decimals());
}
function getNetworkInfo() public view returns (string memory) {
return _networkName;
}
function mint(address to, uint256 amount) public onlyOwner {
_mint(to, amount);
}
}
This simple ERC20 token contract includes a network identifier to help track which network each deployment is on.
Now, let’s create deployment scripts that can adapt to different networks. We’ll use Hardhat’s deployment system to handle this efficiently.
Create a file named deploy.js
in the scripts
folder:
const hre = require(“hardhat”);
async function main() {
// Get network name for the contract
let networkName;
const { name } = hre.network;
switch(name) {
case ‘ethereum’:
networkName = ‘Ethereum Mainnet’;
break;
case ‘bsc’:
networkName = ‘Binance Smart Chain’;
break;
case ‘polygon’:
networkName = ‘Polygon Network’;
break;
case ‘avalanche’:
networkName = ‘Avalanche C-Chain’;
break;
default:
networkName = ‘Local Network’;
}
console.log(`Deploying to ${networkName}…`);
// Deploy the contract
const MultiChainToken = await hre.ethers.getContractFactory(“MultiChainToken”);
const token = await MultiChainToken.deploy(“Multi Chain Token”, “MCT”, networkName);
await token.deployed();
console.log(`MultiChainToken deployed to: ${token.address} on ${networkName}`);
console.log(`Verify with: npx hardhat verify –network ${name} ${token.address} “Multi Chain Token” “MCT” “${networkName}”`);
}
main()
.then(() => process.exit(0))
.catch((error) => {
console.error(error);
process.exit(1);
});
For convenience, let’s create a script to deploy to all networks sequentially. Create deploy-all.js
in the scripts
folder:
const { execSync } = require(‘child_process’);
const networks = [‘ethereum’, ‘bsc’, ‘polygon’, ‘avalanche’];
async function main() {
console.log(‘Starting multi-chain deployment…’);
for (const network of networks) {
try {
console.log(`\nDeploying to ${network}…`);
execSync(`npx hardhat run scripts/deploy.js –network ${network}`, { stdio: ‘inherit’ });
} catch (error) {
console.error(`Error deploying to ${network}:`, error.message);
}
}
console.log(‘\nMulti-chain deployment completed!’);
}
main()
.then(() => process.exit(0))
.catch((error) => {
console.error(error);
process.exit(1);
});
Now that we have our environment configured and scripts ready, let’s deploy our smart contract to multiple networks.
First, compile your smart contract:
npx hardhat compile
To deploy to a specific network, run:
npx hardhat run scripts/deploy.js –network ethereum
npx hardhat run scripts/deploy.js –network bsc
npx hardhat run scripts/deploy.js –network polygon
npx hardhat run scripts/deploy.js –network avalanche
To deploy to all configured networks at once:
node scripts/deploy-all.js
Tip: For production deployments, it’s often better to deploy to each network individually and verify the deployment before proceeding to the next network.
Different networks may require different gas settings. You can modify your deployment script to handle these differences:
// Inside your deploy.js
let overrides = {};
if (name === ‘ethereum’) {
overrides = {
gasPrice: ethers.utils.parseUnits(’50’, ‘gwei’)
};
} else if (name === ‘bsc’) {
overrides = {
gasPrice: ethers.utils.parseUnits(‘5’, ‘gwei’)
};
}
const token = await MultiChainToken.deploy(
“Multi Chain Token”,
“MCT”,
networkName,
overrides
);
After deploying your smart contracts on multiple blockchain networks, it’s important to verify them on each network’s block explorer.
First, install the Hardhat Etherscan plugin:
npm install –save-dev @nomiclabs/hardhat-etherscan
Update your hardhat.config.js
to include API keys for each block explorer:
require(‘@nomiclabs/hardhat-etherscan’);
// Add to your module.exports
etherscan: {
apiKey: {
mainnet: process.env.ETHERSCAN_API_KEY,
bsc: process.env.BSCSCAN_API_KEY,
polygon: process.env.POLYGONSCAN_API_KEY,
avalanche: process.env.SNOWTRACE_API_KEY
}
}
To verify your contract on each network:
npx hardhat verify –network ethereum DEPLOYED_CONTRACT_ADDRESS “Multi Chain Token” “MCT” “Ethereum Mainnet”
npx hardhat verify –network bsc DEPLOYED_CONTRACT_ADDRESS “Multi Chain Token” “MCT” “Binance Smart Chain”
npx hardhat verify –network polygon DEPLOYED_CONTRACT_ADDRESS “Multi Chain Token” “MCT” “Polygon Network”
npx hardhat verify –network avalanche DEPLOYED_CONTRACT_ADDRESS “Multi Chain Token” “MCT” “Avalanche C-Chain”
Each blockchain network has its own characteristics that affect smart contract deployment and operation. Here’s a comparison of the major networks:
Network | Avg. Gas Cost | Tx Speed | Security Model | EVM Compatible | Language Support |
Ethereum | High ($5-50) | Slow (5-15 min) | Proof of Stake | Yes | Solidity, Vyper |
Binance Smart Chain | Low ($0.10-0.30) | Fast (5-15 sec) | Proof of Staked Authority | Yes | Solidity, Vyper |
Polygon | Very Low ($0.01-0.05) | Fast (2-5 sec) | Proof of Stake | Yes | Solidity, Vyper |
Avalanche | Low ($0.10-0.50) | Very Fast (1-2 sec) | Proof of Stake | Yes | Solidity, Vyper |
Solana | Very Low ($0.00025) | Very Fast (400ms) | Proof of History + Stake | No | Rust, C, C++ |
Deploying smart contracts across multiple blockchain networks comes with several challenges. Here are the most common issues and their solutions:
Smart contracts deployed on different networks can’t directly interact with each other. This creates challenges for applications that need cross-chain functionality.
Testing smart contracts on multiple networks can be time-consuming and complex.
Maintaining contracts across multiple networks adds complexity, especially when upgrades are needed.
Follow these best practices to ensure successful deployment and management of smart contracts across multiple blockchain networks:
Pro Tip: Create a deployment checklist specific to each network to ensure you don’t miss any network-specific configurations or verifications.
Deploying smart contracts on multiple blockchain networks offers significant advantages in terms of user reach, redundancy, and leveraging the unique strengths of each chain. As the blockchain ecosystem continues to evolve, multi-chain strategies will become increasingly important for developers and projects.
The future of multi-chain deployment is likely to include:
By mastering multi-chain deployment now, you’re positioning yourself at the forefront of blockchain development, ready to leverage the full potential of the decentralized ecosystem.
Start by experimenting with the code examples in this tutorial on testnets. Share your experiences and results with the community to help advance multi-chain development practices.