setup-stylus-contracts

# Stylus Setup ## Rust & Cargo Stylus Setup Install the Rust toolchain and WASM target: ```bash curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh rustup target add wasm32-unknown-unknown ``` Install the Cargo Stylus CLI: ```bash cargo install --force cargo-stylus ``` Create a new Stylus project: ```bash cargo stylus new my_project ``` > A Rust nightly toolchain is required. The project should include a `rust-toolchain.toml` specifying the nightly channel, `rust-src` component, and `wasm32-unknown-unknown` target. Check the [rust-contracts-stylus repo](https://github.com/OpenZeppelin/rust-contracts-stylus) for the current recommended nightly date. ## Adding OpenZeppelin Dependencies Look up the current version from [crates.io/crates/openzeppelin-stylus](https://crates.io/crates/openzeppelin-stylus) before adding. Add to `Cargo.toml`: ```toml [dependencies] openzeppelin-stylus = "=<VERSION>" ``` Enable the `export-abi` feature flag for ABI generation: ```toml [features] export-abi = ["openzeppelin-stylus/export-abi"] ``` The crate must be compiled as both a library and a cdylib: ```toml [lib] crate-type = ["lib", "cdylib"] ``` ## Import Conventions Imports use `openzeppelin_stylus` (underscores) as the crate root: ```rust use openzeppelin_stylus::token::erc20::{Erc20, IErc20}; use openzeppelin_stylus::access::ownable::{Ownable, IOwnable}; use openzeppelin_stylus::utils::pausable::{Pausable, IPausable}; use openzeppelin_stylus::utils::introspection::erc165::IErc165; ``` Contracts use `#[storage]` and `#[entrypoint]` on the main struct, embedding OpenZeppelin components as fields: ```rust #[entrypoint] #[storage] struct MyToken { erc20: Erc20, ownable: Ownable, } ``` Public methods are exposed with `#[public]` and `#[implements(...)]`. The canonical pattern uses an empty impl block for dispatch registration, plus separate trait impl blocks: ```rust #[public] #[implements(IErc20<Error = erc20::Error>, IOwnable<Error = ownable::Error>)] impl MyToken {} #[public] impl IErc20 for MyToken { type Error = erc20::Error; // delegate to self.erc20 ... } ``` Top-level modules: `access`, `finance`, `proxy`, `token`, `utils`. ## Build & Deploy Basics Validate the contract compiles to valid Stylus WASM: ```bash cargo stylus check ``` Export the Solidity ABI: ```bash cargo stylus export-abi ``` Deploy to an Arbitrum Stylus endpoint: ```bash cargo stylus deploy --endpoint="<RPC_URL>" --private-key-path="<KEY_FILE>" ```