Contract Balance Threshold Alert Tool

WHAT IT DOES

Contract Balance Threshold Alert Tool is a read-only security tool that monitors the native ETH balance of EVM smart contracts against user-configurable thresholds. It reads the contract's current balance via eth_getBalance, retrieves block number and chain ID metadata, and compares the balance against lower and upper thresholds. The tool provides a visual gauge display showing the current balance relative to thresholds, color-coded status indicators, detailed balance information, and an alert stub for threshold breaches. It helps developers and security teams monitor contract funding levels, detect unexpected balance changes, and proactively respond to underfunded or overfunded contract states.

HOW TO USE

Connect your EVM-compatible wallet via the BGWallet bridge and select the network where your contract is deployed. Enter the contract address, a lower threshold (minimum acceptable balance), and optionally an upper threshold (maximum acceptable balance). Click "Check Balance" to fetch the current balance and evaluate it against the configured thresholds. Results include the current balance in ETH, block number, chain ID, a visual gauge showing balance relative to thresholds, status indicator (Normal/Below/Above), detailed alert information if thresholds are breached, and an alert stub for notification integration. The tool provides a progress bar showing the balance's position within the threshold range. All analysis is read-only—no signatures or transactions are submitted.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 to fetch contract state via the provider. It retrieves the contract balance using provider.getBalance(address), which returns the native ETH balance in wei. The balance is converted to ETH by dividing by 1e18. The tool also fetches the current block number via provider.getBlockNumber() and chain ID via provider.getNetwork() for metadata context. The user-provided lower and upper thresholds are parsed as floating-point numbers in ETH. The tool compares the current balance against both thresholds: if the balance is below the lower threshold, it triggers a "below" alert; if the balance exceeds the upper threshold, it triggers an "above" alert. If both thresholds are provided and the balance is within the range, the status is "normal." The tool generates a visual progress bar showing the balance's position within the threshold range (percentage calculation: (balance - lower) / (upper - lower) * 100), with color-coding (red for near thresholds, teal for normal). The alert stub provides a placeholder for integration with external notification systems (email, Slack, Discord, etc.). The tool does not store any data—results are generated on-demand and displayed in the UI.

WHAT IT CANNOT SEE

This tool has fundamental limitations that users must understand. It cannot actually send alerts or notifications—the tool provides an alert stub but requires external infrastructure for actual notifications. It cannot monitor balances in real-time without continuous polling—the tool performs one-time balance checks and does not maintain a persistent connection. It cannot detect balance changes that occur between poll intervals—only the balance at the time of the check is reported. It cannot monitor token balances (ERC-20, ERC-721) beyond native ETH balance—the tool only checks native token balances. It cannot monitor multiple contracts simultaneously without separate checks—only one contract at a time. It cannot automatically trigger actions based on threshold breaches without manual integration. It cannot detect balance changes that are not reflected in the native balance. It cannot provide historical balance data or trends—only the current balance is checked. It cannot predict future balance changes. The tool's thresholds are static and require manual updates if monitoring requirements change.

PLEASE NOTE

This tool only supports EVM-compatible blockchains (Ethereum, Polygon, BSC, Avalanche C-Chain, Optimism, Arbitrum, and their testnets). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool is free, open-source, requires no API keys, and uses the wallet's native provider for all read operations. For production alerting, integrate the tool's output with external notification systems.