const ethers = require('ethers');
You can connect to Lisk by instantiating a new ethers.js JsonRpcProvider object with a RPC URL of the Lisk network:
const ethers = require('ethers');
const url = 'https://rpc.sepolia-api.lisk.com';
const provider = new ethers.providers.JsonRpcProvider(url);
const ethers = require('ethers');
const url = 'https://rpc.sepolia-api.lisk.com';
const provider = new ethers.JsonRpcProvider(url);
A Provider (in ethers.js) is a class which provides an abstraction for a connection to the Ethereum Network. It provides read-only access to the Blockchain and its status.
Once you have created a provider, you can use it to read data from the Lisk network.
For example, you can use the getBlockNumber method to get the latest block:
async function getLatestBlock() {
const latestBlock = await provider.getBlockNumber();
console.log(latestBlock);
}
In order to write data to the Lisk network, you need to create a Signer.
A Signer is a class which (usually) in some way directly or indirectly has access to a private key, which can sign messages and transactions to authorize the network to charge your account ether to perform operations.
You can create a Signer by instantiating a new ethers.js Wallet object, providing it with a private key and Provider.
const privateKey = 'PRIVATE_KEY';
const signer = new ethers.Wallet(privateKey, provider);
const privateKey = 'PRIVATE_KEY';
const signer = new ethers.Wallet(privateKey, provider);
// Send 1 ether to an ens name.
const tx = signer.sendTransaction({
to: "lisk.eth",
value: ethers.utils.parseEther("1.0")
});
PRIVATE_KEY is the private key of the wallet to use when creating the signer.
You can use ethers.js to interact with a smart contract on Lisk by instantiating a Contract object using the ABI and address of a deployed contract:
The ABI of a contract can be found on the respective contract page in BlockScout.
For example, you can find the ABI for the Hello contract here. Just scroll down to Contract ABI.
const abi = [
… // ABI of deployed contract
];
const contractAddress = "CONTRACT_ADDRESS"
// read only
const contract = new ethers.Contract(contractAddress, abi, provider);
For write-only contracts, provide a Signer object instead of a Provider object:
// write only
const contract = new ethers.Contract(contractAddress, abi, signer);
CONTRACT_ADDRESS is the address of the deployed contract.
A Contract (in ethers.js) is an abstraction which represents a connection to a specific contract on the Lisk Network, so that applications can use it like a normal JavaScript object.
For reading and writing to contracts, provide a Signer object instead of a Provider object:
// read & write
const contract = new ethers.Contract(contractAddress, abi, signer);
Once you have created a Contract object, you can use it to call desired methods on the smart contract:
async function setValue(value) {
const tx = await contract.set(value);
console.log(tx.hash);
}
async function getValue() {
const value = await contract.get();
console.log(value.toString());
}