How to Effectively Listen to Transfers Events of ETH (Native Token)

Discover how to monitor and log `ETH transfers` using ethers.js and Infura in an efficient way. Learn more about extracting internal transactions and events! --- This video is based on the question https://stackoverflow.com/q/74561210/ asked by the user 'ldls' ( https://stackoverflow.com/u/5450352/ ) and on the answer https://stackoverflow.com/a/74561416/ provided by the user 'Petr Hejda' ( https://stackoverflow.com/u/1693192/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to listen to Transfers events/logs of ETH (native token) Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Understanding ETH Transfers Events When it comes to blockchain technology, particularly on the Ethereum network, developers often focus on tracking transactions. For ERC-20 tokens like USDT, listening for transfer events is relatively straightforward since these tokens emit specific event logs. However, the approach to tracking transfers of the native token, ETH, is not as direct. The Challenge If you've been using ethers.js and Infura to handle ERC-20 transfer events, you might have noticed that the native ETH transfers don't emit event logs. This can be a bit confusing, especially when you want comprehensive tracking of all transactions on the network. Why Don't ETH Transfers Emit Events? In Ethereum, native token transfers typically don't emit event logs unless they are part of an EVM message call or internal transaction. Here's a simple breakdown: Event Logging: Standard ERC-20 token transfers emit logs as a part of their implementation. For example, a standard ERC-20 token contract may have an event like this: [[See Video to Reveal this Text or Code Snippet]] For ETH Transfers: The transfer of ETH requires a specific implementation in the smart contract if you want to log events. Here’s a basic example: [[See Video to Reveal this Text or Code Snippet]] In the above contract, only transfers made via the transferETH function will log the event Transferred. Therefore, without explicit tracking in the contract, ETH transfers will not be logged. How to Track ETH Transfers Option 1: Use an Aggregated Database To get native ETH transfers of an address, you can rely on an existing data source. Several platforms aggregate blockchain data, making it easy to track a variety of transactions without building everything from scratch. Option 2: Build Your Own Tracking System If you prefer a more hands-on approach, you can create your own mechanism to track ETH transfers. Here's how you could do it: Loop through All Transaction Receipts: You will need to gather the transaction receipts from blocks. This means fetching all transactions in the specified blocks. Internal Transactions: Remember, internal transactions will not be available in the transaction receipts. You will need to reconstruct them. You can do this using the debug_traceTransaction method from Geth or other Ethereum clients. Here’s a simple workflow: Fetch all blocks using the block explorer API. Retrieve each block's transaction hashes. For each transaction hash, use debug_traceTransaction to access internal transaction details. Set Up a Monitoring Mechanism: Use event listeners in your JavaScript code with ethers.js, similar to this example for ERC-20 tokens. However, since ETH transfers don’t emit logs, you’ll rely heavily on the monitoring of the transaction receipts. Example Code If you're using ethers.js to listen for ERC-20 token transfers, your code might look like this: [[See Video to Reveal this Text or Code Snippet]] Conclusion Listening to transfers of native ETH can be tricky due to the lack of event logs in standard transfers. By either relying on existing aggregated databases or by creating your own logging mechanism, you can effectively monitor ETH transactions. Whether you choose a simpler or a more comprehensive approach, understanding how the Ethereum network handles such transactions will allow you to create more powerful blockchain applications. By being mindful of these intricacies, you can ensure that you capture all relevant transaction data in your development projects.