Metamask: What is metamask waiting for when a transaction is pending?

Understanding Metamask Pending Transactions

As a developer building custom remote procedure call (RPC) endpoints for decentralized applications (dApps), you’re probably familiar with the concept of pending transactions on your blockchain. One frequently asked question when you encounter a pending transaction is: What’s taking up space while my application is waiting for confirmation?

In this article, we’ll explore how Metamask works and provide insight into its pending transactions.

What is Metamask?

Metamask is a popular browser extension that allows users to interact with their Ethereum wallet and access various dApps. It acts as an intermediary between the user’s local blockchain storage and the external applications they want to use.

Pending Transaction Regarding RPC

When you make a transaction using your custom RPC endpoint, Metamask creates a “pending” transaction in its database. This is standard practice, as some dApps need to wait a certain amount of time (e.g. 1 hour) before updating the interface with transaction information.

Why is metamask waiting?

In your case, when you call “sendRawTransaction” and receive an unconfirmed transaction RPC, it is likely due to:

• Internal processing: Metamask needs to perform internal validation, verification, or other tasks before allowing the transaction.

• External API requests: Depending on how your custom endpoint communicates with the dApp, you may need to send an external request (e.g. a POST request) to retrieve additional information about the unconfirmed transaction.

What does this mean for my application?

When an unconfirmed transaction is waiting for confirmation in Metamask, your application should continue to wait patiently. However, there is a slight difference:

• Your app will not be blocked: Unlike some other wallets that can delay or freeze transactions, you will not have the problem of your app being blocked.

• Transaction processing may take longer: Since Metamask internally processes the pending transaction, your application may take a little longer to receive a confirmation (e.g. 10-20 minutes).

Best Practices

To ensure smooth interaction between your custom RPC endpoint and metamask:

• Implement a timeout mechanism: Set a reasonable timeout value for a pending transaction to be able to determine when the pending transaction has been resolved.

• Use asynchronous communication: When sending an external request (e.g. to retrieve additional information), use asynchronous programming techniques to reduce application blocking.

• Update your RPC endpoint: Regularly update your custom RPC endpoint to ensure it remains compatible with the latest version of Metamask.

By understanding Metamask pending transactions and implementing best practices, you can create a more efficient and simpler experience for your dApp users.