Overpayment Refund Batch Sender (Ethereum L1)

WHAT IT DOES

Overpayment Refund Batch Sender (Ethereum L1) is a specialised blockchain audit tool that enables project teams and finance managers to prepare and verify batch overpayment refund distributions on Ethereum mainnet. It reads on-chain refund contract balances, checks token balances for multiple recipient wallets simultaneously, fetches token decimals to ensure accurate formatting, and retrieves current gas price estimates for cost planning. The tool also queries overpayment refund contract records, including program name and total refunded amounts, providing a consolidated view of the proposed refund plan alongside actual on-chain holdings. All data is presented in a clean table with per-address breakdowns, making it easy to spot discrepancies between intended refund amounts and on-chain balances. The interface is designed for rapid auditing of large recipient lists without requiring any on-chain transactions.

HOW TO USE

Connect your wallet to Ethereum mainnet using the built-in wallet bridge. Enter the overpayment refund contract address, optionally specify a token contract address (leave blank for native ETH), and a list of recipient addresses with their refund amounts (format: address,amount — one per line). Click the scan button — the tool will read the refund contract balance, query each recipient address for its current token balance, and calculate the total allocation against the contract balance. A progress bar shows real-time status, and results appear in a sortable table with refund amounts and current balance columns. You can then use this data to prepare your overpayment refund distribution transaction with confidence. All operations are read-only and do not modify any state.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 to interact with the blockchain via the injected wallet provider. It performs batched eth_call requests with controlled concurrency (4 simultaneous queries) to avoid rate limits while maintaining responsiveness. For the refund contract address, it queries the total balance using the provider's getBalance method or the ERC-20 balanceOf method, and also attempts to read contract state including programName and totalRefunded via standard overpayment refund contract interfaces. For each recipient, it fetches the current balance to show the pre-refund state. The tool parses refund amounts, converts them using the correct decimals, and sums them to compare against the contract balance. Gas price is fetched using ethers' getFeeData(), which returns the current network fee estimate. All queries use the view/pure function pattern, meaning they consume no gas and execute instantly.

WHAT IT CANNOT SEE

This tool cannot verify overpayment refund eligibility. It does not confirm whether recipients are entitled to refunds based on payment or overpayment records. It cannot validate refund entitlement amounts — these must be provided by the finance team based on their own records. The tool has no access to off-chain payment data, overpayment records, or private decision-making records. It cannot determine whether the refund plan is compliant with financial policies or has received proper authorisation. It only reads what is publicly available on the blockchain through the contract interfaces you specify.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible chains, specifically Ethereum mainnet. It does not support non-EVM networks or L2 chains. The refund contract address you provide should implement standard overpayment refund distribution interfaces. Always verify the recipient list and refund amounts before relying on the scan output. The tool is read-only and does not execute transfers or modifications. Always double-check that you are connected to Ethereum mainnet before scanning.