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

RPC Error: User has not authorized the requested account and/or method

When implementing one-click login flows with MetaMask, it is very important to ensure that your user is properly authenticated before proceeding. Unfortunately, a common issue occurs when a user is asked to authorize access to their Metamask wallet. This error message is displayed when the request fails due to a lack of user authorization.

Understanding RPC Errors

RPC (Remote Procedure Call) 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 your application’s requests due to insufficient permissions.

Issue: Unauthorized Account and Method

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

To illustrate this issue, let’s look at the example given in the tutorial One-Click Login Flows with MetaMask:

const metamask = window.ethereum;
if (!metamask && !metamask.isMetaMask) {
console.log('User is not authenticated or does not have authorization for the application to access their wallet.');
} else if (metamask && metamask accounts.length === 0) {
console.log('MetaMask account not found. Please link your wallet and authorize the application.');
} else {
// Continue logging in
}

Solution: Checking Account and Method Authorization

To resolve this issue, you need to check if the user has authorized the requested account and method. Here is an updated example:

const metamask = window.ethereum;
if (!metamask && !metamask.isMetaMask) {
console.log('User is not authenticated or does not have authorization for 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 account of accounts) {
try {
await method (account);
// Continue logging in
break;
} catch (error) {
console.log(Error using wallet: ${error});
}
}
} else if (!metamask && metamask.isMetaMask) {
const accounts = metamask.accounts;
for (const account of accounts) {
try {
await method (account);
// Continue logging in
break;
} catch (error) {
console.log(Error while accessing wallet: ${error});
}
}
} else if (metamask && metamask.accounts.length === 0) {
console.log('MetaMask account not found. Please link your wallet and authorize the application.');
}

Best practices

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

• Always check authorization before proceeding with user authentication.

• Use the parameter “metamask accounts.length > 0” instead of directly using the accounts table to ensure that only authorized accounts are used.

• Log any errors that occur during wallet access so that you can diagnose issues.

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