Detecting Metamask Account Changes and Lockouts with React

As a React developer, you probably know how important it is to keep track of changes to user accounts and wallet balances. In this article, we will explore how to detect when a user’s MetaMask account has been changed or locked.

Problem: window.ethereum.on('accountsChanged', function (accounts) { ... }); is not working

Your approach. using the “accountsChanged” event is a good start, but there are a few additional steps you need to take to achieve what you are looking for. Here is an updated example to help you:

import React from 'react';
function MetamaskDetector() {
const const = useMetaMaskAccounts();
useEffect(() => {
async return () => {
const const = await getAccountList();
// Update the "accounts" state with the current list of MetaMask accounts
setAccounts(accounts);
// Check for changes in the account list and update the display accordingly
checkChangesInAccounts(accounts);
};
}, []);
asynchronous function getAccountList() {
// Implement a function to retrieve a list of current accounts from MetaMask
// For demonstration purposes, let's assume this function returns an array of accounts
const const = ['account1', 'account2', 'account3'];
returned accounts;
}
asynchronous function checkForChangesInAccounts(accounts) {
const newAccounts = [];
const oldAccounts = [...accounts];
accounts.forEach((newAccount, index) => {
if (oldaccounts[index] !== newaccount) {
console.log(Account ${newAccount} changed or blocked!);
// You can also update the display to indicate this change
// for example, show a red fill effect on the old account
alert(Account ${newAccount} has been changed or blocked. Please check the status of your wallet.);
}
}
useMetaMaskAccounts();
return (
{accounts.map((account) => (
{account}
))}
{checkForChangesInAccounts(accounts)}
);
}

What’s changed?

• We added a “useEffect” hook to update the “accounts” state whenever a new account list is retrieved from MetaMask.

• We define two functions: “getAccountList”, which returns the original array of accounts (in this example, it is hardcoded) and “checkForChangesInAccounts”.

• In CheckForChangesInAccounts, we iterate over the updated list of accounts to detect changes. If a new account is found that is different from the previous one, we log a message and update the display accordingly.

Important notes:

• This example uses the “useMetaMaskAccounts” hook, which we will discuss below.

• The “getAccountList” function should be implemented according to your specific use case. For demonstration purposes, it returns an array of hardcoded accounts.

• You may want to consider a more robust approach, such as interacting with the MetaMask API or implementing a custom hook that retrieves the list of accounts and handles changes accordingly.

Following this updated example, you should now be able to detect when your users’ MetaMask accounts have changed or been locked. Don’t forget to replace the hard-coded array of “account1”, “account2”, and “account3” in the “getAccountList” function with a reliable method to retrieve the current list of accounts from MetaMask.

METAMASK WEB3 ERROR UNKNOWN