Ethereum Token Balances Retriever

This is a Node.js script that uses the ethers.js library and the ethereum-block-by-date library to interact with the Ethereum blockchain. It retrieves token balances for a list of Ethereum addresses for a list of specified tokens and writes these balances to a CSV file. The balances are retrieved at a specific block, which is determined by a given date and time. This script is particularly useful for anyone needing to track balances for multiple addresses and tokens on the Ethereum blockchain at a certain point in time.

Prerequisites

Before running this script, ensure that you have Node.js installed in your environment. You will also need the following Node.js packages:

• ethers: Ethereum blockchain interaction
• ethereum-block-by-date: Fetch Ethereum block by date
• dotenv: Environment variable handler
• csv-parser: CSV parsing
• fs: File system interaction
• progress: Progress bar creation

Install these packages using npm:

npm install ethers dotenv csv-parser fs progress ethereum-block-by-date

You will also need an Alchemy API key, which is used to interact with the Ethereum blockchain. Sign up for an account on Alchemy's website to get your key.

Configuration

This script requires a config.json file in the root directory that should contain contract addresses for the tokens you're interested in. Here is an example format:

{
  "tokens": {
    "USDT": "0xdAC17F958D2ee523a2206206994597C13D831ec7",
    "USDC": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
    ...
  }
}

Additionally, the script uses a .env file to load the Alchemy API key. The .env file should look like this:

ALCHEMY_API_KEY=your_alchemy_api_key_here

Input

The input for this script is a CSV file named addresses.csv located in a data directory. Each line in the file should be a valid Ethereum address.

Example:

address
0xBc5809a7D398512b8bE44C439e05C5B3259aeC8B
...

Output

This script writes the output to a CSV file named ETH_Mainnet_Balances.csv in the data directory. The file contains balances for all the tokens and addresses specified.

Example:

address,USDT,USDC,ETH,...
0xBc5809a7D398512b8bE44C439e05C5B3259aeC8B,100,200,0.01,...
...

Running the Script

To run the script, use the following command:

node your_script_name.js

Replace your_script_name.js with the filename of this script.

Errors

If any errors occur while running the script, they will be printed to the console and the script will exit with a status code of 1.

Ethereum Block Retriever by Date Function

The getBlockNumber function in this script returns the Ethereum block number for a specific date and time. In this case, it's hardcoded to return the block number for '2022-12-31T16:59:59Z' (representing the cutoff on 31 December at midnight in the time zone UTC+7), but you can modify this date and time to suit your needs.

This function can also be run as a standalone function. To do so, uncomment the main function at the end of the script.

Future Improvements

This script can be improved by allowing users to specify the date and time for the block number retrieval, either through command line arguments or an additional configuration file, and could be extended to support different blockchains, additional tokens, or more input/output options.