OpenZeppelin Contracts for Cairo

A library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup.

Usage

⚠️ WARNING! ⚠️

This is repo contains highly experimental code. Expect rapid iteration. Use at your own risk.

First time?

Before installing Cairo on your machine, you need to install gmp:

sudo apt install -y libgmp3-dev # linux
brew install gmp # mac

If you have any troubles installing gmp on your Apple M1 computer, here’s a list of potential solutions.

Set up the project

Create a directory for your project, then cd into it and create a Python virtual environment.

mkdir my-project
cd my-project
python3 -m venv env
source env/bin/activate

Install the Nile development environment and then run init to kickstart a new project. Nile will create the project directory structure and install the Cairo language, a local network, and a testing framework.

pip install cairo-nile
nile init

Install the library

pip install openzeppelin-cairo-contracts

Use a basic preset

Presets are ready-to-use contracts that you can deploy right away. They also serve as examples of how to use library modules. Read more about presets.

# contracts/MyToken.cairo

%lang starknet

from openzeppelin.token.erc20.ERC20 import constructor

Compile and deploy it right away:

nile compile

nile deploy MyToken <name> <symbol> <decimals> <initial_supply> <recipient> --alias my_token

Note that <initial_supply> is expected to be two integers i.e. 1 0. See Uint256 for more information.

Write a custom contract using library modules

Read more about libraries.

%lang starknet

from starkware.cairo.common.cairo_builtins import HashBuiltin
from starkware.cairo.common.uint256 import Uint256
from openzeppelin.security.pausable import Pausable_when_not_paused
from openzeppelin.token.erc20.library import (
    ERC20_name,
    ERC20_symbol,
    ERC20_totalSupply,
    ERC20_decimals,
    ERC20_balanceOf,
    ERC20_allowance,

    ERC20_initializer,
    ERC20_approve,
    ERC20_increaseAllowance,
    ERC20_decreaseAllowance,
    ERC20_transfer,
    ERC20_transferFrom,
    ERC20_mint
)

(...)

@external
func transfer{
        syscall_ptr : felt*,
        pedersen_ptr : HashBuiltin*,
        range_check_ptr
    }(recipient: felt, amount: Uint256) -> (success: felt):
    Pausable_when_not_paused()
    ERC20_transfer(recipient, amount)
    return (TRUE)
end

Learn

Contract documentation

• Account
• ERC20
• ERC721
• Contract extensibility pattern
• Proxies and upgrades
• Utilities

Cairo

• StarkNet official documentation
• Cairo language documentation
• Perama's Cairo by example
• Cairo 101 workshops

Nile

• Getting started with StarkNet using Nile
• How to manage smart contract deployments with Nile

Development

Set up the project

Clone the repository

git clone [email protected]:OpenZeppelin/cairo-contracts.git

cd into it and create a Python virtual environment:

cd cairo-contracts
python3 -m venv env
source env/bin/activate

Install Nile:

pip install cairo-nile
nile install

Compile the contracts

nile compile --directory src

🤖 Compiling all Cairo contracts in the openzeppelin directory
🔨 Compiling openzeppelin/introspection/ERC165.cairo
🔨 Compiling openzeppelin/introspection/IERC165.cairo
🔨 Compiling openzeppelin/token/erc721/ERC721_Mintable_Burnable.cairo
🔨 Compiling openzeppelin/token/erc721/ERC721_Mintable_Pausable.cairo
🔨 Compiling openzeppelin/token/erc721/library.cairo
🔨 Compiling openzeppelin/token/erc721/interfaces/IERC721_Metadata.cairo
🔨 Compiling openzeppelin/token/erc721/interfaces/IERC721.cairo
🔨 Compiling openzeppelin/token/erc721/interfaces/IERC721_Receiver.cairo
🔨 Compiling openzeppelin/token/erc721/utils/ERC721_Holder.cairo
🔨 Compiling openzeppelin/token/erc20/ERC20_Mintable.cairo
🔨 Compiling openzeppelin/token/erc20/ERC20.cairo
🔨 Compiling openzeppelin/token/erc20/library.cairo
🔨 Compiling openzeppelin/token/erc20/ERC20_Pausable.cairo
🔨 Compiling openzeppelin/token/erc20/interfaces/IERC20.cairo
🔨 Compiling openzeppelin/token/erc721_enumerable/ERC721_Enumerable_Mintable_Burnable.cairo
🔨 Compiling openzeppelin/token/erc721_enumerable/library.cairo
🔨 Compiling openzeppelin/token/erc721_enumerable/interfaces/IERC721_Enumerable.cairo
🔨 Compiling openzeppelin/security/pausable.cairo
🔨 Compiling openzeppelin/security/safemath.cairo
🔨 Compiling openzeppelin/security/initializable.cairo
🔨 Compiling openzeppelin/access/ownable.cairo
🔨 Compiling openzeppelin/account/IAccount.cairo
🔨 Compiling openzeppelin/account/Account.cairo
🔨 Compiling openzeppelin/account/AddressRegistry.cairo
🔨 Compiling openzeppelin/utils/constants.cairo
✅ Done

Run tests

Run tests using tox, tox automatically creates an isolated testing environment:

tox

====================== test session starts ======================
platform linux -- Python 3.7.2, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: /home/readme/cairo-contracts
plugins: asyncio-0.16.0, web3-5.24.0, typeguard-2.13.0
collected 19 items                                                                                               

tests/test_Account.py ....                                 [ 21%]
tests/test_AddressRegistry.py ..                           [ 31%]
tests/test_ERC20.py ..........                             [ 84%]
tests/test_Initializable.py .                              [ 89%]
tests/test_Ownable.py ..                                   [100%]

Security

This project is still in a very early and experimental phase. It has never been audited nor thoroughly reviewed for security vulnerabilities. Do not use in production.

Please report any security issues you find to [email protected].

Contribute

OpenZeppelin Contracts for Cairo exists thanks to its contributors. There are many ways you can participate and help build high quality software. Check out the contribution guide!

License

OpenZeppelin Contracts for Cairo is released under the MIT License.