Metamask: MetaMask – RPC Error: The requested account and/or method has not been authorized by the user

RPC Error: The requested account and/or method has not been authorized by the user

When implementing one-click login flows with MetaMask, it is crucial to ensure that users are properly authenticated before proceeding. Unfortunately, a common issue occurs when the user is prompted to authorize access to their Metamask wallet. This error message appears when the request fails due to the user’s lack of authorization.

RPC Error Information

Remote Procedure Call (RPC) errors occur when an application is unable to communicate with its underlying systems or services. In this case, it appears that MetaMask is unable to authenticate requests from your application due to insufficient permissions.

The Problem: Unauthorized Account and Method

When a user initiates the login flow for your application using MetaMask, you need to request access to their wallet and account information. However, if the user does not authorize these requests, your application will not be able to proceed.

To illustrate this issue, let’s revisit the example given in the tutorial on one-click login flows with MetaMask:

const metamask = window.ethereum;
if (!metamask && !metamask.isMetaMask) {
console.log('The user is not authenticated or has not authorized the application to access their wallet.');
} else if (metamask && metamask accounts.length === 0) {
console.log('No MetaMask accounts found. Connect your wallet and authorize the application.');
} else {
// Proceed with login
}

The solution: Check account and method authorization

To solve this issue, you need to check whether the required account and method have been authorized by the user. Here’s an updated example:

const metamask = window.ethereum;
if (!metamask && !metamask.isMetaMask) {
console.log('The user is not authenticated or has not authorized the application to access their wallet.');
} else if (metamask && metamask.accounts.length > 0) {
const accounts = metamask.accounts;
const method = window.web3.eth.createAccount;
for (const accounts account) {
try {
await method(account);
// Proceed with login
break;
} catch (error) {
console.log(Error accessing wallet: ${error});
}
}
} else if (!metamask && metamask.isMetaMask) {
const accounts = metamask.accounts;
for (const accounts account) {
try {
await method(account);
// Proceed with login
break;
} catch (error) {
console.log(Error accessing wallet: ${error});
}
}
} else if (metamask && metamask.accounts.length === 0) {
console.log('No MetaMask accounts found. Connect your wallet and authorize the application.');
}

Best practices

To avoid this issue in the future, consider implementing additional security measures:

• Always verify authorization before proceeding with user authentication.

• Use metamask accounts.length > 0 instead of directly accessing the accounts array to ensure that only authorized accounts are opened.

• Logs any errors that occur when accessing the wallet to help diagnose issues.

By following these guidelines, you can implement robust one-click login flows with MetaMask and minimize RPC errors.