Learn Brownie - 10 Code Examples & CST Typing Practice Test

Brownie is an open-source Python-based framework for Ethereum smart contract development, testing, and deployment. It integrates with Ethereum networks and provides a full-featured environment for building decentralized applications (dApps).

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Brownie Minimal Smart Contract Deployment Brownie ERC20 Token Deployment Brownie Smart Contract Interaction Example Brownie Event Listening Example Brownie Funding Contract Example Brownie Multi-Account Transaction Example Brownie Upgradeable Contract Example Brownie Testing Smart Contracts Example Brownie Interaction with ERC721 NFT Brownie Gas Estimation Example

Learn BROWNIE with Real Code Examples

Updated Nov 24, 2025

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Code Sample Descriptions

Brownie Minimal Smart Contract Deployment

# contracts/Counter.sol
pragma solidity ^0.8.0;

contract Counter {
    uint256 public count = 0;
    function increment() public { count += 1; }
}

# deploy.py
from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    counter.increment({'from': acct})
    print('Counter value:', counter.count())

A minimal example showing how to deploy and interact with a simple Solidity smart contract using Brownie.

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Brownie ERC20 Token Deployment

# contracts/MyToken.sol
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/token/ERC20/ERC20.sol';

contract MyToken is ERC20 {
    constructor(uint256 initialSupply) ERC20('MyToken','MTK') {
        _mint(msg.sender, initialSupply);
    }
}

# deploy.py
from brownie import MyToken, accounts

def main():
    acct = accounts[0]
    token = MyToken.deploy(1000*10**18, {'from': acct})
    print('Token deployed at:', token.address)

Deploy a simple ERC20 token using Brownie.

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Brownie Smart Contract Interaction Example

from brownie import Contract, accounts

def main():
    acct = accounts[0]
    counter = Contract('0xYourDeployedAddress')
    counter.increment({'from': acct})
    print('Counter value:', counter.count())

Interact with an already deployed contract using Brownie.

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Brownie Event Listening Example

from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter[-1]  # Last deployed instance

    tx = counter.increment({'from': acct})
    for event in tx.events:
        print('Event emitted:', event)

Listen to events emitted by a smart contract using Brownie.

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Brownie Funding Contract Example

# contracts/FundMe.sol
pragma solidity ^0.8.0;

contract FundMe {
    uint256 public balance = 0;
    function fund() public payable { balance += msg.value; }
}

# deploy.py
from brownie import FundMe, accounts

def main():
    acct = accounts[0]
    fund_me = FundMe.deploy({'from': acct})
    fund_me.fund({'from': acct, 'value': 1000000000000000000})  # 1 ETH
    print('Contract balance:', fund_me.balance())

Deploy and fund a smart contract with Ether using Brownie.

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Brownie Multi-Account Transaction Example

from brownie import accounts

def main():
    sender = accounts[0]
    receiver = accounts[1]
    sender.transfer(receiver, '1 ether')
    print('Transferred 1 ETH from sender to receiver')

Send transactions between multiple accounts in Brownie.

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Brownie Upgradeable Contract Example

# contracts/LogicV1.sol
pragma solidity ^0.8.0;

contract LogicV1 {
    uint public x;
    function setX(uint _x) public { x = _x; }
}

# deploy.py
from brownie import LogicV1, accounts

def main():
    acct = accounts[0]
    logic = LogicV1.deploy({'from': acct})
    logic.setX(42, {'from': acct})
    print('Value set in proxy logic:', logic.x())

Deploy an upgradeable proxy contract using Brownie.

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Brownie Testing Smart Contracts Example

import pytest
from brownie import Counter, accounts

def test_increment():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    counter.increment({'from': acct})
    assert counter.count() == 1

Writing tests for a Solidity smart contract using Brownie.

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Brownie Interaction with ERC721 NFT

# contracts/MyNFT.sol
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/token/ERC721/ERC721.sol';

contract MyNFT is ERC721 {
    constructor() ERC721('MyNFT','MNFT') {}
    function mint(address to, uint256 tokenId) public { _mint(to, tokenId); }
}

# deploy.py
from brownie import MyNFT, accounts

def main():
    acct = accounts[0]
    nft = MyNFT.deploy({'from': acct})
    nft.mint(acct, 1, {'from': acct})
    print('Minted NFT ID 1 to account:', acct)

Deploy and interact with an ERC721 NFT smart contract using Brownie.

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Brownie Gas Estimation Example

from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    gas_estimate = counter.increment.estimate_gas({'from': acct})
    print('Estimated gas for increment():', gas_estimate)

Estimate gas usage for a smart contract function using Brownie.

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Frequently Asked Questions about Brownie

What is Brownie?

What are the primary use cases for Brownie?

Writing Ethereum smart contracts in Solidity. Testing contracts using Python-based frameworks. Deploying contracts to Ethereum testnets or mainnet. Automating interaction with deployed contracts. Integrating blockchain contracts with Python backend scripts

What are the strengths of Brownie?

Pythonic workflow makes blockchain development more accessible. Strong testing ecosystem with pytest. Easy deployment to multiple Ethereum networks. Good documentation and community support. Supports both local and remote Ethereum nodes

What are the limitations of Brownie?

Limited support for non-Ethereum blockchains. Primarily focused on Python developers. Requires familiarity with Solidity for contract writing. Complex DeFi protocols may require advanced configurations. Smaller ecosystem compared to JavaScript frameworks like Hardhat or Truffle

How can I practice Brownie typing speed?

CodeSpeedTest offers 10+ real Brownie code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.

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Code Sample Descriptions

Brownie Minimal Smart Contract Deployment

# contracts/Counter.sol
pragma solidity ^0.8.0;

contract Counter {
    uint256 public count = 0;
    function increment() public { count += 1; }
}

# deploy.py
from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    counter.increment({'from': acct})
    print('Counter value:', counter.count())

A minimal example showing how to deploy and interact with a simple Solidity smart contract using Brownie.

Let’s Try →

Brownie ERC20 Token Deployment

# contracts/MyToken.sol
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/token/ERC20/ERC20.sol';

contract MyToken is ERC20 {
    constructor(uint256 initialSupply) ERC20('MyToken','MTK') {
        _mint(msg.sender, initialSupply);
    }
}

# deploy.py
from brownie import MyToken, accounts

def main():
    acct = accounts[0]
    token = MyToken.deploy(1000*10**18, {'from': acct})
    print('Token deployed at:', token.address)

Deploy a simple ERC20 token using Brownie.

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Brownie Smart Contract Interaction Example

from brownie import Contract, accounts

def main():
    acct = accounts[0]
    counter = Contract('0xYourDeployedAddress')
    counter.increment({'from': acct})
    print('Counter value:', counter.count())

Interact with an already deployed contract using Brownie.

Let’s Try →

Brownie Event Listening Example

from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter[-1]  # Last deployed instance

    tx = counter.increment({'from': acct})
    for event in tx.events:
        print('Event emitted:', event)

Listen to events emitted by a smart contract using Brownie.

Let’s Try →

Brownie Funding Contract Example

# contracts/FundMe.sol
pragma solidity ^0.8.0;

contract FundMe {
    uint256 public balance = 0;
    function fund() public payable { balance += msg.value; }
}

# deploy.py
from brownie import FundMe, accounts

def main():
    acct = accounts[0]
    fund_me = FundMe.deploy({'from': acct})
    fund_me.fund({'from': acct, 'value': 1000000000000000000})  # 1 ETH
    print('Contract balance:', fund_me.balance())

Deploy and fund a smart contract with Ether using Brownie.

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Brownie Multi-Account Transaction Example

from brownie import accounts

def main():
    sender = accounts[0]
    receiver = accounts[1]
    sender.transfer(receiver, '1 ether')
    print('Transferred 1 ETH from sender to receiver')

Send transactions between multiple accounts in Brownie.

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Brownie Upgradeable Contract Example

# contracts/LogicV1.sol
pragma solidity ^0.8.0;

contract LogicV1 {
    uint public x;
    function setX(uint _x) public { x = _x; }
}

# deploy.py
from brownie import LogicV1, accounts

def main():
    acct = accounts[0]
    logic = LogicV1.deploy({'from': acct})
    logic.setX(42, {'from': acct})
    print('Value set in proxy logic:', logic.x())

Deploy an upgradeable proxy contract using Brownie.

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Brownie Testing Smart Contracts Example

import pytest
from brownie import Counter, accounts

def test_increment():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    counter.increment({'from': acct})
    assert counter.count() == 1

Writing tests for a Solidity smart contract using Brownie.

Let’s Try →

Brownie Interaction with ERC721 NFT

# contracts/MyNFT.sol
pragma solidity ^0.8.0;

import '@openzeppelin/contracts/token/ERC721/ERC721.sol';

contract MyNFT is ERC721 {
    constructor() ERC721('MyNFT','MNFT') {}
    function mint(address to, uint256 tokenId) public { _mint(to, tokenId); }
}

# deploy.py
from brownie import MyNFT, accounts

def main():
    acct = accounts[0]
    nft = MyNFT.deploy({'from': acct})
    nft.mint(acct, 1, {'from': acct})
    print('Minted NFT ID 1 to account:', acct)

Deploy and interact with an ERC721 NFT smart contract using Brownie.

Let’s Try →

Brownie Gas Estimation Example

from brownie import Counter, accounts

def main():
    acct = accounts[0]
    counter = Counter.deploy({'from': acct})
    gas_estimate = counter.increment.estimate_gas({'from': acct})
    print('Estimated gas for increment():', gas_estimate)

Estimate gas usage for a smart contract function using Brownie.

Let’s Try →

Frequently Asked Questions about Brownie

What is Brownie?

What are the primary use cases for Brownie?

What are the strengths of Brownie?

What are the limitations of Brownie?

How can I practice Brownie typing speed?

CodeSpeedTest offers 10+ real Brownie code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.