Handling the MetaMask Popup Triggers: A Guide to Identifying Transaction Types

As a developer building applications that interact with decentralized finance (DeFi) protocols, you’re likely no stranger to the concept of MetaMask, the popular Ethereum browser extension that allows users to securely manage their digital wallets. However, when interacting with DeFi services such as lending platforms or stablecoin exchanges, you may encounter popup windows triggered by your MetaMask extension. In this article, we’ll delve into how to handle these popup triggers and identify the type of transaction being attempted.

Understanding Transaction Types

Before diving into the solution, it’s essential to understand the different types of transactions that can trigger MetaMask popups:

• Transfer: A transfer is a basic transaction where you’re moving assets from one wallet to another.

• Approval: An approval involves sending a message to a contract or a smart contract on the Ethereum blockchain, requesting permission for an action (e.g., transferring funds).

• Call: A call is a transaction that invokes a function on the Ethereum blockchain, which can be used to perform various actions such as logging transactions, updating balance information, or triggering other contracts.

• Send

  

  : A send is similar to a transfer, but it’s an outgoing transaction where assets are being sent from one wallet to another.

Action MetaMask Popup Triggers

When your MetaMask extension triggers a popup window, you’ll need to identify the type of transaction being attempted to prevent any potential security vulnerabilities or data breaches. Here are some steps you can take to handle these popup triggers:

• Check Transaction Details: Before triggering an action, inspect the transaction details provided by MetaMask. This will help you determine what kind of transaction is being attempted.

• Use contractAddress Field: The contractAddress field in the transaction payload contains information about the contract or smart contract that’s being invoked. If it matches a known contract address, you can proceed with your action.

• Check txHash Field: The txHash field also provides valuable information about the transaction, including its hash and timestamp. You can use this to verify whether the transaction is a valid attempt or not.

• Use a Transaction Checker: Consider implementing a transaction checker using libraries like Web3.js or Ethers.js. These libraries provide pre-built functions to check for certain transaction types (e.g., transfer, approval, call) and alert you when they’re detected.

Sample Code

To demonstrate the concept of handling MetaMask popup triggers, let’s use some example code in JavaScript:

const Web3 = require('web3');

const web3 = new Web3(new Window.EthernetProvider('


async function handlePopup ( transaction ) { ;

  const contractAddress = transaction.contractAddress;

  if (contractAddress &&(transaction.type === 'Transfer' || transaction.type === 'Approval')) {

    console.log(Transaction is ${transaction.type} for address ${contractAddress});

  } else if ( transaction . type === 'Call ' ) {

    console.log(Transaction is a call for contract ${contractAddress});

  } else {

    console.error('Unknown transaction type');

  } }

} }


const myContract = new web3.eth.Contract('0x...YOUR_CONTRACT_ADDRESS...', 'YOUR_CONTRACT_NAME');


// Simulate popup trigger

const transaction = {

  from: '0x...MY Accounts',

  to: '0x...OTHER accounts',

  contractAddress: '0x...CONTRACT ADDRESS',

  type: 'Transfer',

};


handlePopup ( transaction ) ;

In this example, we’re creating a contract instance and simulating a popup trigger for a transfer transaction.