Metamask: Checking If A Token Is Already Added in Metamask
As a cryptocurrency user, you’re likely familiar with the importance of having a secure and decentralized wallet. One such wallet is MetaMask, which allows users to store, manage, and spend their cryptocurrencies on multiple blockchains. However, one common issue that can cause inconvenience for users is when they try to add a new token to their Metamask collection but find out that it’s already being used.
In this article, we’ll explore how to check if a token is already added in MetaMask using the Web API. We’ll also provide some insights into why this issue arises and potential solutions to avoid it in the future.
Why does MetaMask not support checking for existing tokens?
Before diving into the solution, let’s take a look at why MetaMask doesn’t support directly checking if a token is already added or registered. The main reason is that MetaMask is built on top of Ethereum, which has its own set of token management rules and regulations.
Ethereum’s token standard (ERC-721) requires tokens to be unique within the blockchain, meaning they cannot be duplicated or reused. This means that even though a user might have added multiple instances of the same token to their Metamask collection, it doesn’t mean that all of them are part of the same wallet.
How to check if a token is already added in MetaMask using Web API
Unfortunately, there isn’t an official way to check if a specific token is already added in MetaMask using the Web API. However, we can use some creative workarounds to achieve this goal.
Here’s an example of how you can implement a workaround:
- Get the list of all tokens stored in Metamask
: You can use the
eth_getAccounts
method with a callback function to get a list of accounts stored in MetaMask. Then, iterate through each account and check if any of its wallets contain an instance of the token you’re interested in.
- Check for token presence in a specific wallet: If you know which wallet contains the desired token (e.g., by searching for it on a specific address), you can use the
eth_getTransactionCount
method to get a list of all transactions associated with that wallet. Then, iterate through each transaction and check if any of them contain an instance of the token.
Here’s some sample code in JavaScript to demonstrate this:
async function hasToken(tokenName) {
// Get the list of all tokens stored in Metamask
const accounts = await window.ethereum.getAccounts();
for (const account of accounts) {
// Check if any of the wallet contains an instance of the token
for (const txId of await window.ethereum.getTransactionReceipts(account).map(tx => tx.transactionHash)) {
try {
// Get the transaction details
const tx = await window.ethereum.getTransaction(transactionId);
// Check if the transaction contains an instance of the token
if (tx.data['tokens'] && tx.data['tokens'][tokenName]) {
return true;
}
} catch (error) {
console.error(error);
}
}
}
return false;
}
// Example usage:
const tokenName = 'MyToken'; // Replace with the desired token name
hasToken(tokenName).then(hasToken => {
if (hasToken) {
console.log(Token ${tokenName} is already added to your Metamask wallet.
);
} else {
console.log(You don't have any instances of token ${tokenName}.
);
}
});
Conclusion
While there isn’t a direct way to check if a token is already added in MetaMask using the Web API, you can use workarounds like the above example to achieve this goal.