If you have been active in DeFi for any length of time, your wallet has almost certainly accumulated a collection of token approvals that you no longer need, never intended to grant, or have entirely forgotten about. Each of these approvals represents a potential attack vector. In March 2026, with PeckShield reporting approximately $52 million in crypto exploits during the month alone, the urgency of understanding and managing your token approvals has never been greater. This advanced walkthrough teaches you how to systematically audit, map, and revoke every approval connected to your wallets.
The Objective
The goal is straightforward but the execution requires precision: achieve a state where your wallets have zero unnecessary token approvals, every remaining approval is intentional and well-understood, and you have a repeatable process for maintaining this state going forward. This is not a one-time exercise. DeFi participation inherently creates new approvals, and the audit process should become a regular part of your operational security routine.
The scope of this audit covers ERC-20 token approvals, ERC-721 and ERC-1155 NFT approvals, and permit-type approvals that some protocols use. Each category has distinct security implications and requires specific revocation techniques.
Prerequisites
Before beginning the audit process, ensure you have the following in place:
A Secure Environment: Perform this audit on a trusted device using a clean browser session. Clear your browser cache and cookies before starting. Consider using a dedicated browser profile for crypto operations. Never perform wallet security audits on public Wi-Fi networks or shared devices.
Wallet Access: You need access to every wallet you use for DeFi interactions. This includes hardware wallets connected through interfaces like MetaMask or Rabby, as well as any software wallets you use. Make sure your hardware wallet firmware is up to date before beginning.
Blockchain Explorer Access: Bookmark Etherscan, Arbiscan, Basescan, and any other block explorers for the networks you use regularly. You will need to verify contract addresses and review transaction details during the audit.
Approval Mapping Tools: Several tools are available for visualizing your approvals. Revoke.cash provides a comprehensive interface for viewing and revoking approvals across multiple networks. Unrekt.net offers similar functionality with additional contract verification features. Rabby wallet’s built-in approval scanner provides real-time visibility during the audit process.
Step-by-Step Walkthrough
Phase 1: Complete Inventory: Begin by creating a comprehensive list of every wallet address you have used for DeFi interactions over the past two years. Check your transaction history on each major network to identify any wallets you may have forgotten. Include hardware wallet derived addresses, imported wallets, and any wallets connected to centralized bridges or cross-chain protocols.
Phase 2: Approval Mapping: For each wallet, use Revoke.cash to generate a complete list of all active token approvals. Record the following information for each approval: the token contract address, the spender contract address, the approved amount (which may be the maximum uint256 value), the date the approval was granted, and the network on which it exists.
Pay special attention to approvals with unlimited spending limits. These appear as very large numbers, typically 115792089237316195423570985008687907853269984665640564039457584007913129639935. This represents the maximum uint256 value and grants the spender unlimited access to transfer the approved token from your wallet at any time.
Phase 3: Spender Classification: For each unique spender address identified in Phase 2, classify the contract into one of the following categories: known DeFi protocols you actively use (safe to keep), known DeFi protocols you no longer use (revoke), unknown or unverified contracts (revoke immediately), contracts on networks you no longer use (revoke), and contracts associated with protocols that have been compromised or are suspected of malicious behavior (revoke immediately and monitor for unauthorized transfers).
Verify each contract address against the protocol’s official documentation and social media channels. Scammers frequently create counterfeit contracts with similar names to legitimate protocols. Cross-reference with the protocol’s verified contract list on their official website.
Phase 4: Systematic Revocation: Begin revoking approvals in order of risk priority. Start with unlimited approvals to unknown or unverified contracts. Next, revoke all approvals on networks you no longer use. Then revoke approvals to protocols you no longer actively use. Finally, reduce remaining approvals for active protocols to the minimum required amount rather than unlimited access.
When revoking, use the tool’s interface to confirm each revocation transaction. For hardware wallet users, verify the transaction details on your device screen before signing. Each revocation requires a gas fee, so plan your revocation sessions to batch related operations when possible.
Phase 5: NFT Approval Audit: Repeat the process specifically for NFT-related approvals. These include marketplace approvals (OpenSea, Blur, and others), collection-level approvals that grant a contract access to all NFTs in a specific collection, and individual token approvals. NFT approvals are particularly dangerous because a single compromised approval can result in the loss of valuable assets with no possibility of recovery.
Phase 6: Permit and Signature Audit: Some protocols use permit-based approvals, where you sign an off-chain message that grants token spending permission without an on-chain transaction. These approvals do not appear in traditional approval scanners. Review your recent wallet signatures for any permit-type authorizations. Tools like Revoke.cash’s signature section can help identify these hidden approvals.
Troubleshooting
Failed Revocation Transactions: If a revocation transaction fails, the contract may have special restrictions. Try revoking directly through Etherscan’s Write Contract interface by calling the approve function with the spender address and zero as the amount. Ensure you have sufficient gas for the transaction.
Unknown Spender Contracts: If you cannot identify a spender contract, do not interact with it directly. Revoke the approval from the token side by setting the allowance to zero. If the contract appears suspicious, consider moving your assets to a fresh wallet address.
Cross-Chain Approvals: Approvals exist independently on each network. Revoking an approval on Ethereum does not affect approvals on Arbitrum, Base, or any other network. You must audit and revoke on each network separately.
Gas Cost Management: Revoking many approvals on Ethereum mainnet can be expensive. Consider performing bulk revocations during periods of low network activity when gas prices are lower. On Layer 2 networks, gas costs are minimal, so revoke freely.
Mastering the Skill
Once you have completed your initial audit, establish a maintenance routine to prevent approval creep from reaccumulating:
Post-Transaction Approval Check: After every DeFi interaction, note the approval you just granted. If it was a one-time operation, revoke the approval immediately after the transaction completes.
Weekly Approval Scans: Run a quick approval scan on your active wallets at the end of each week. This takes only a few minutes and catches any approvals you may have forgotten to clean up.
Monthly Full Audit: Conduct a comprehensive audit of all wallets, including those you use less frequently. This ensures that no dormant approvals create unexpected vulnerabilities.
Use Approval-Aware Wallets: Consider switching to wallets like Rabby that provide detailed approval information before you sign transactions. These wallets can warn you about risky approvals before you grant them, preventing problems rather than just detecting them after the fact.
The March 2026 security landscape, with its $52 million in reported losses, demonstrates that the cost of neglected approvals can be severe. Systematic approval management is one of the most impactful security practices available to DeFi users, and the tools to do it effectively are free and accessible. There is no excuse for skipping this step.
Disclaimer: This article is for informational purposes only and does not constitute financial or investment advice. Always conduct your own research before making any investment decisions.
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