viem example for mantle

index.js

const mantleTestnet = {
  id: 5001,
  name: "Mantle Testnet",
  network: "Mantle Testnet",
  nativeCurrency: {
    decimals: 18,
    name: "Mantle",
    symbol: "MNT",
  },
  rpcUrls: {
    public: { http: ["https://rpc.testnet.mantle.xyz"] },
    default: { http: ["https://rpc.testnet.mantle.xyz"] },
  },
  blockExplorers: {
    default: {
      name: "Mantle Explorer",
      url: "https://explorer.testnet.mantle.xyz/",
    },
  },
  contracts: {
    multicall3: {
      address: "0xca11bde05977b3631167028862be2a173976ca11",
      blockCreated: 56133,
    },
  },
};

import { createPublicClient, http, getContract } from "viem";

const client = createPublicClient({
  chain: mantleTestnet,
  transport: http(),
});

const abi = [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"}],"name":"approve","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"tokenOwner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"acceptOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"drip","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"spender","type":"address"},{"name":"tokens","type":"uint256"},{"name":"data","type":"bytes"}],"name":"approveAndCall","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"newOwner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"tokenAddress","type":"address"},{"name":"tokens","type":"uint256"}],"name":"transferAnyERC20Token","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"tokenOwner","type":"address"},{"name":"spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_from","type":"address"},{"indexed":true,"name":"_to","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"tokenOwner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"tokens","type":"uint256"}],"name":"Approval","type":"event"}];

const main = async () => {
  const contract = getContract({
    address: "0xa35d7f5dd89a336A427Ebb63C428C3068b6c3105",
    abi: abi,
    publicClient: client,
  });

  const totalSupply = await contract.read.totalSupply()
  console.log('total supply', totalSupply)

  const unwatch = contract.watchEvent.Transfer({}, {
    onLogs: (x) => {
      console.log(x);
    },
  });

  setTimeout(() => {
    console.log('unwatching transfer events')
    unwatch()
  }, 1000)
};
main();

For reference, you can achieve the same result using Web3.js v4. Below is a code sample showcasing:

• Initialize a Web3 instance with the Mantle mainnet provider.
• Fetch chain data, including the current chain ID (which returns 5000) and block number.
• Interact with a deployed USDC contract on the Mantle mainnet (reusing the ABI from the viem example above) by calling its methods to get the contract name and total supply.
• Subscribe to Transfer events emitted by the contract, starting from the latest block.
• Log each Transfer event when it occurs.
• Unsubscribe from events after 5 seconds and close the WebSocket connection to cleanly exit.

import { Web3 } from "web3";
import abi from "./abi.js";

// WebSocket provider is required for contract subscriptions
const web3 = new Web3("wss://mantle-rpc.publicnode.com");

// Alternatively, use an HTTP provider if you don't need subscriptions
// const web3 = new Web3("https://mantle-rpc.publicnode.com");

const main = async () => {
  // Fetch some chain data
  const chainId = await web3.eth.getChainId();
  console.log("Connected to chain with ID:", chainId.toString());

  const blockNumber = await web3.eth.getBlockNumber();
  console.log("Current block number:", blockNumber.toString());

  // Interact with a deployed contract (USDC on Mantle mainnet in this case)
  const contract = new web3.eth.Contract(
    abi,
    "0x09Bc4E0D864854c6aFB6eB9A9cdF58aC190D0dF9"
  );

  const name = await contract.methods.name().call();
  console.log("Contract name:", name);

  const totalSupply = await contract.methods.totalSupply().call();
  console.log("Total supply:", totalSupply);

  // Subscribe to Transfer events from the contract, starting from the latest block
  const subscription = contract.events.Transfer({
    fromBlock: blockNumber,
  });
  console.log("Subscribed to Transfer events from contract");

  subscription.on("data", (event) => {
    console.log("Transfer event:", event);
  });

  setTimeout(async () => {
    console.log("Unsubscribing from Transfer events...");
    await subscription.unsubscribe();

    // Close the WebSocket connection to gracefully end the program
    web3.currentProvider.disconnect();
    console.log("WebSocket connection closed.");
  }, 5 * 1000); // Unsubscribe after 5 seconds
};

main();