Decoding MetaMask Errors: A Guide for dApp Developers
MetaMask is a powerful tool that allows users to access decentralized applications (dApps) and interact with the blockchain. However, like any complex technology, it’s not immune to errors. As a dApp developer, understanding these errors is crucial to providing a seamless user experience.
Common MetaMask Errors and Solutions
4001: User Cancelled Request
This error occurs when a user cancels a request, such as a transaction or contract interaction. The error JSON response will look like this:
json
{
"code": 4001,
"message": "User cancelled request"
}
4100: Unauthorized Account
This error happens when a dApp tries to access an unauthorized account. To fix this, use the eth_requestAccounts method to request account permission from MetaMask.
javascript
ethereum.request({
method: 'eth_requestAccounts',
});
4200: Unsupported Method
This error is returned when a dApp tries to use an unsupported method. Check the official MetaMask documentation for supported methods.
4900: Disconnected Chain
This error occurs when a user’s wallet is disconnected from the chain. Use the ethereum.isConnected() method to check the connection status.
javascript
if (!ethereum.isConnected()) {
console.log('Wallet is disconnected');
}
4901: Incorrect Chain
This error happens when a user is on the wrong chain for a transaction. Use the chainChanged event to detect chain changes and update your app accordingly.
javascript
ethereum.on('chainChanged', (chainId) => {
console.log(`Chain changed to ${chainId}`);
});
32700: Invalid Request Object
This error occurs when a dApp sends an incomplete or invalid request object. Make sure to include all required fields in your requests.
32600: Invalid Request Structure
This error happens when a request has an invalid structure or properties. Double-check your request format and fields.
32601: Method Not Found
This error is returned when a dApp tries to use a non-existent method. Check the official MetaMask documentation for available methods.
32602: Invalid Arguments
This error occurs when a dApp passes invalid arguments to a method. Make sure to use the correct argument types and formats.
32603: Internal Error
This error is a catch-all for internal MetaMask errors. Try updating MetaMask to the latest version or checking the official documentation for solutions.
32000: Contract Address Mismatch
This error happens when a contract address used in production is different from the one deployed on the testnet. Update your contract addresses to match the current chain.
32001: Resource Not Found
This error occurs when a requested resource, such as a block number, does not exist. Make sure to use valid resource identifiers.
32002: Resource Unavailable
This error happens when a requested resource is temporarily unavailable. Try again later or implement a retry mechanism.
32003: Transaction Rejected
This error occurs when a transaction is rejected due to insufficient funds, incorrect sender address, or other issues. Double-check your transaction parameters and try again.
32004: Method Not Supported
This error is returned when a dApp tries to use an unsupported method. Check the official MetaMask documentation for available methods.
32005: Rate Limit Exceeded
This error occurs when a dApp exceeds the rate limit for requests. Implement a rate limiting mechanism or increase the rate limit.
By understanding these common MetaMask errors, dApp developers can provide a better user experience and improve the overall quality of their applications.