Struct risc0_steel::Contract

pub struct Contract<E> { /* private fields */ }

Represents a contract that is initialized with a specific environment and contract address.

Note: This contract is not type-safe. Ensure that the deployed contract at the specified address matches the ABI used for making calls.

Usage

• Preflight calls on the Host: To prepare calls on the host environment and build the necessary proof, use Contract::preflight. The environment can be initialized using the EthEvmEnv::builder or EvmEnv::builder.
  • For calls with many storage accesses, consider using CallBuilder::call_with_prefetch to optimize preflight time by reducing the number of RPC calls.
• Calls in the Guest: To initialize the contract in the guest environment, use Contract::new. The environment should be constructed using EvmInput::into_env.

Examples

let contract_address = address!("dAC17F958D2ee523a2206206994597C13D831ec7");
sol! {
    interface IERC20 {
        function balanceOf(address account) external view returns (uint);
    }
}
let account = address!("F977814e90dA44bFA03b6295A0616a897441aceC");
let get_balance = IERC20::balanceOfCall { account };

// Host:
let url = "https://ethereum-rpc.publicnode.com".parse()?;
let mut env = EthEvmEnv::builder().rpc(url).build().await?;
let mut contract = Contract::preflight(contract_address, &mut env);
contract.call_builder(&get_balance).call().await?;

// For calls with many storage accesses, use call_with_prefetch to optimize:
// contract.call_builder(&get_balance).call_with_prefetch().await?;

let evm_input = env.into_input().await?;

// Guest:
let evm_env = evm_input.into_env();
let contract = Contract::new(contract_address, &evm_env);
contract.call_builder(&get_balance).call();

Implementations

impl<'a, D: Database, H, C> Contract<&'a mut EvmEnv<ProofDb<D>, H, HostCommit<C>>>

pub fn preflight( address: Address, env: &'a mut EvmEnv<ProofDb<D>, H, HostCommit<C>>, ) -> Self

Available on crate feature host only.

Constructor for preflighting calls to an Ethereum contract on the host.

Initializes the environment for calling functions on the Ethereum contract, fetching necessary data via the [Provider], and generating a storage proof for any accessed elements using EvmEnv::into_input.

pub fn call_builder<S: SolCall>( &mut self, call: &S, ) -> CallBuilder<S, &mut EvmEnv<ProofDb<D>, H, HostCommit<C>>>

Available on crate feature host only.

Initializes a call builder to execute a call on the contract.

impl<'a, H> Contract<&'a EvmEnv<StateDb, H, Commitment>>

pub fn new(address: Address, env: &'a EvmEnv<StateDb, H, Commitment>) -> Self

Constructor for executing calls to an Ethereum contract in the guest.

pub fn call_builder<S: SolCall>( &self, call: &S, ) -> CallBuilder<S, &EvmEnv<StateDb, H, Commitment>>

Initializes a call builder to execute a call on the contract.