RPC client for canisters on the Internet Computer to access Ethereum networks, powered by the Internet Computer's threshold ECDSA signature and outbound http call features.
- Perform RPC calls to Ethereum networks within canisters
- Sign messages with IC's threshold ECDSA
- Send transactions to Ethereum networks within canisters
- Query/call Ethereum contracts within canisters
Add the following to your Cargo.toml:
[dependencies]
ic-web3 = { git = "https://github.com/rocklabs-io/ic-web3" }
Note: you should have dfx 0.11.2 or above.
Please refer to example for the complete example.
use candid::candid_method;
use ic_cdk_macros::{self, update};
use std::str::FromStr;
use ic_web3::transports::ICHttp;
use ic_web3::Web3;
use ic_web3::ic::{get_eth_addr, KeyInfo};
use ic_web3::{
contract::{Contract, Options},
ethabi::ethereum_types::{U64, U256},
types::{Address, TransactionParameters, BlockId, BlockNumber, Block},
};
const URL: &str = "<GOERLI-RPC-URL>";
const CHAIN_ID: u64 = 5;
const KEY_NAME: &str = "dfx_test_key";
const TOKEN_ABI: &[u8] = include_bytes!("../src/contract/res/token.json");
type Result<T, E> = std::result::Result<T, E>;
#[update(name = "get_eth_gas_price")]
#[candid_method(update, rename = "get_eth_gas_price")]
async fn get_eth_gas_price() -> Result<String, String> {
let w3 = match ICHttp::new(URL, None) {
Ok(v) => { Web3::new(v) },
Err(e) => { return Err(e.to_string()) },
};
let gas_price = w3.eth().gas_price().await.map_err(|e| format!("get gas price failed: {}", e))?;
ic_cdk::println!("gas price: {}", gas_price);
Ok(format!("{}", gas_price))
}
// get canister's ethereum address
#[update(name = "get_canister_addr")]
#[candid_method(update, rename = "get_canister_addr")]
async fn get_canister_addr() -> Result<String, String> {
match get_eth_addr(None, None, KEY_NAME.to_string()).await {
Ok(addr) => { Ok(hex::encode(addr)) },
Err(e) => { Err(e) },
}
}
// send tx to eth
#[update(name = "send_eth")]
#[candid_method(update, rename = "send_eth")]
async fn send_eth(to: String, value: u64) -> Result<String, String> {
// ecdsa key info
let derivation_path = vec![ic_cdk::id().as_slice().to_vec()];
let key_info = KeyInfo{ derivation_path: derivation_path, key_name: KEY_NAME.to_string() };
// get canister eth address
let from_addr = get_eth_addr(None, None, KEY_NAME.to_string())
.await
.map_err(|e| format!("get canister eth addr failed: {}", e))?;
// get canister the address tx count
let w3 = match ICHttp::new(URL, None) {
Ok(v) => { Web3::new(v) },
Err(e) => { return Err(e.to_string()) },
};
let tx_count = w3.eth()
.transaction_count(from_addr, None)
.await
.map_err(|e| format!("get tx count error: {}", e))?;
ic_cdk::println!("canister eth address {} tx count: {}", hex::encode(from_addr), tx_count);
// construct a transaction
let to = Address::from_str(&to).unwrap();
let tx = TransactionParameters {
to: Some(to),
nonce: Some(tx_count), // remember to fetch nonce first
value: U256::from(value),
gas_price: Some(U256::exp10(10)), // 10 gwei
gas: U256::from(21000),
..Default::default()
};
// sign the transaction and get serialized transaction + signature
let signed_tx = w3.accounts()
.sign_transaction(tx, key_info, CHAIN_ID)
.await
.map_err(|e| format!("sign tx error: {}", e))?;
match w3.eth().send_raw_transaction(signed_tx.raw_transaction).await {
Ok(txhash) => {
ic_cdk::println!("txhash: {}", hex::encode(txhash.0));
Ok(format!("{}", hex::encode(txhash.0)))
},
Err(e) => { Err(e.to_string()) },
}
}Start a local replica:
dfx start --background --clean --enable-canister-http
Deploy the example canister:
dfx deploy
This repo is modified from the rust-web3 project.