Js snippet to auto-add IOTA Smart Contracts Evm to Metamask

isc-evm-metamask.js

// This is an example to auto detect if the current chain is ISC EVM Testnet and if not, switch to it.
// If chain doesn't exist on Metamask yet, this script will also add it.
// A metamask pop-up will appear and you can approve after verifying the details.

// This config can be set for any EVM compatible chain as such.

const chainName = 'ISC Testnet'
const chainId = 1074 // ISC EVM
const rpcUrl = 'https://evm.wasp.sc.iota.org'
const blockExplorerUrl = 'https://explorer.wasp.sc.iota.org'
const currency = 'EIOTA'
const decimal = 18


async function networkSync() {
    if (window.ethereum) {
        console.log("Metamask detected...");
        // Check if current chain is the required chain
        if (window.ethereum.networkVersion !== chainId) {
            let hexParsedChainId = parseChainId(chainId);
            try {
                await window.ethereum.request({
                    method: 'wallet_switchEthereumChain',
                    params: [
                        {
                            chainId: hexParsedChainId
                        }
                    ]
                });
            } catch (err) {
                // console.log('err:', err);
                // This error code indicates that the chain has not been added to MetaMask
                if (err.code === 4902) {
                    // Add chain to Metamask
                    await window.ethereum.request({
                        method: 'wallet_addEthereumChain',
                        params: [
                            {
                                chainName: chainName,
                                chainId: hexParsedChainId,
                                nativeCurrency: {
                                    name: currency,
                                    decimals: decimal,
                                    symbol: currency
                                },
                                rpcUrls: [rpcUrl],
                                blockExplorerUrls: [blockExplorerUrl]
                            }
                        ]
                    });
                }
            }
        }
    } else {
        console.log("Metamask extensions not detected!");
    }
}

function parseChainId(chainId) {
    let hexChainId = ethers.utils.hexlify(chainId);
    // Trim any leading 0s
    return '0x' + hexChainId.split('0x')[1].replace(/^0+/, '');
}

networkSync(); // Call it on button click or on page load.