Permit2 Signature Revoker

WHAT IT DOES

Permit2 Signature Revoker lets you view and revoke approvals made through the Uniswap Permit2 contract. Permit2 allows users to sign off-chain messages that grant token allowances without submitting an on-chain approve() transaction, saving gas and enabling better user experiences. However, these approvals remain active until they expire or are explicitly revoked. This tool reads your active Permit2 allowances—including the approved amount, expiration, and nonce—and lets you revoke them by setting the allowance to zero or by invalidating entire batches of nonces, effectively canceling all pending permit signatures for a given word position.

HOW TO USE

Connect your EVM wallet and select the network. Enter the Permit2 contract address (the tool pre-fills the standard Uniswap Permit2 address), the token address, and the spender address you want to inspect. Click "Scan Permit2 approvals" to fetch the current allowance details. The tool displays the approved amount, nonce, and expiration for that token-spender pair. You can revoke individual approvals by clicking "Revoke" next to the row, or use "Revoke selected" to clear all displayed approvals. The "Revoke all" button invalidates entire nonce words (0–9) to cancel all pending permits for the connected wallet.

TECHNICAL MECHANISM

The tool interacts directly with the Permit2 contract using its standard interface. It calls allowance(address owner, address token, address spender) to retrieve the current allowance details—amount, expiration, and nonce. It also reads the nonceBitmap for the connected wallet to identify used nonces across multiple word positions. Revocations are performed by calling approve(address token, address spender, uint160 amount, uint48 expiration) with amount=0, which sets the allowance to zero. For bulk invalidation, the tool calls invalidateNonces(uint256 wordPos, uint256 mask) with a full mask (2^256-1) to invalidate all nonces in the specified word, effectively canceling any pending permits that rely on those nonces. All transactions are submitted sequentially with progress feedback.

WHAT IT CANNOT SEE

This tool cannot revoke off-chain signed permit messages that have not yet been submitted to the chain—it can only invalidate nonces or set on-chain allowances to zero. It does not detect or revoke standard ERC-20 approvals made outside the Permit2 contract (e.g., regular approve() calls). It only works with Uniswap Permit2-compatible contracts and standard ERC-20 tokens; NFTs and non-standard token implementations are not supported. The tool also does not automatically detect all tokens or spenders—you must specify each pair manually.

PLEASE NOTE

Revoking a Permit2 approval by setting the amount to zero does not invalidate already-signed permits that were submitted before the revocation. Invalidation of nonces is the most comprehensive way to cancel pending permits. Always verify the on-chain state after revoking. This tool is for EVM chains only and does not support non-EVM networks.