Approval Risk Capper

WHAT IT DOES

Approval Risk Capper helps you limit the maximum amount a spender can access by capping allowances to a percentage of your current token balance. Instead of granting unlimited approvals or manually calculating a safe amount, you define a risk threshold—for example, 10%—and the tool sets the allowance to exactly that percentage of your balance. If your balance increases, the cap stays fixed at the old amount; if it decreases, you can re-apply the cap to stay within your risk tolerance. This reduces the damage a compromised spender could cause while still allowing your dApps to function.

HOW TO USE

Connect your EVM wallet and select the network. Enter the token contract address and the spender address you want to cap. Set your desired risk cap percentage (1–100%). Click "Check current" to see your balance, current allowance, and the calculated cap amount. The tool will show whether your allowance exceeds the cap. If it does, click "Apply cap" to submit an approve() transaction that sets the allowance to the capped amount. If the allowance is already below the cap, no change is made. The status area shows a visual risk meter and transaction history.

TECHNICAL MECHANISM

The tool reads your token balance and current allowance directly from the chain using balanceOf() and allowance(). It calculates the capped amount as (balance × capPercent) / 100, using integer arithmetic to avoid rounding issues. If the current allowance exceeds the capped amount, it calls approve(spender, cappedAmount) through your wallet. The tool uses receipt.effectiveGasPrice for accurate gas reporting (post‑EIP‑1559) and displays the result in a clear status panel. The cap is enforced at the moment of the transaction—it does not automatically adjust if your balance changes later, which is stated honestly as a limit.

WHAT IT CANNOT SEE

This tool cannot enforce caps dynamically if your balance changes after the approval is set—the cap is a one‑time snapshot. It does not detect or modify approvals set through proxy contracts, delegate‑call patterns, or non‑standard token implementations. It only works with standard ERC‑20 tokens that implement approve() and allowance(). The tool does not scan across multiple tokens or spenders at once; you must check each pair individually. It also cannot prevent a spender from using the allowance before you apply the cap.

PLEASE NOTE

The cap is based on your balance at the time of the transaction. If your balance later increases, the approval amount does not automatically increase—your risk remains capped at the old amount. If your balance decreases, you may want to re‑apply the cap to lower the approval further. Always verify the new allowance on‑chain after applying the cap. This tool is for EVM chains only and does not support non‑EVM networks.