Multi-chain deployment in Blockchain / Solidity - Mini Project: Build & Apply

Multi-chain Deployment

📖 Scenario: You are a blockchain developer who wants to deploy the same smart contract on multiple blockchain networks. Each network has its own unique chain ID and RPC URL. You want to automate the deployment process to save time and avoid errors.

🎯 Goal: Build a script that deploys a simple smart contract to multiple blockchain networks by iterating over a configuration dictionary containing network details.

📋 What You'll Learn

Create a dictionary called networks with chain IDs as keys and RPC URLs as values

Create a variable called contract_code containing the smart contract source code as a string

Write a loop that iterates over networks.items() with variables chain_id and rpc_url

Inside the loop, print a deployment message showing the chain_id and rpc_url

💡 Why This Matters

🌍 Real World

Deploying the same smart contract to multiple blockchains is common when building cross-chain decentralized applications.

💼 Career

Blockchain developers often automate multi-chain deployments to save time and reduce mistakes in production environments.

1

Create the networks dictionary

Create a dictionary called networks with these exact entries: 1: 'https://mainnet.infura.io/v3/your-api-key', 137: 'https://polygon-rpc.com', 56: 'https://bsc-dataseed.binance.org/'

Blockchain / Solidity

# Create the networks dictionary with chain IDs and RPC URLs
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with chain IDs as keys and RPC URLs as values.

2

Add the contract code variable

Create a variable called contract_code and assign it the string value 'contract SimpleStorage { uint storedData; function set(uint x) public { storedData = x; } function get() public view returns (uint) { return storedData; } }'

Blockchain / Solidity

networks = {
    1: 'https://mainnet.infura.io/v3/your-api-key',
    137: 'https://polygon-rpc.com',
    56: 'https://bsc-dataseed.binance.org/'
}
# Create the contract_code variable with the smart contract source code string
# Your code here

Need a hint?

Use a string variable to hold the smart contract source code exactly as given.

3

Write the deployment loop

Write a for loop using for chain_id, rpc_url in networks.items() to iterate over the networks dictionary

Blockchain / Solidity

networks = {
    1: 'https://mainnet.infura.io/v3/your-api-key',
    137: 'https://polygon-rpc.com',
    56: 'https://bsc-dataseed.binance.org/'
}

contract_code = 'contract SimpleStorage { uint storedData; function set(uint x) public { storedData = x; } function get() public view returns (uint) { return storedData; } }'

# Write a for loop to iterate over networks.items() with chain_id and rpc_url
# Your code here

Need a hint?

Use for chain_id, rpc_url in networks.items(): to loop through the dictionary.

4

Print deployment messages

Inside the for loop, write a print statement that outputs exactly: Deploying contract to chain ID {chain_id} using RPC URL {rpc_url} using an f-string

Blockchain / Solidity

networks = {
    1: 'https://mainnet.infura.io/v3/your-api-key',
    137: 'https://polygon-rpc.com',
    56: 'https://bsc-dataseed.binance.org/'
}

contract_code = 'contract SimpleStorage { uint storedData; function set(uint x) public { storedData = x; } function get() public view returns (uint) { return storedData; } }'

for chain_id, rpc_url in networks.items():
    # Print deployment message using f-string
    # Your code here

Need a hint?

Use print(f"Deploying contract to chain ID {chain_id} using RPC URL {rpc_url}") inside the loop.