Decent Revoker

Take back control—track and revoke unwanted token approvals with ease and security.

Comment

Inspiration

We’ve all heard the horror stories—people losing funds because they unknowingly left token approvals open. With so many DeFi platforms and dApps, it’s easy to forget which contracts have permission to spend your tokens. We wanted to build something that gives users full control over their approvals, making Web3 safer and more transparent.

What it does

Decent Revoker lets users see all the dApps and smart contracts they’ve approved to spend their tokens and revoke those permissions in a single click. It’s like a “reset” button for token approvals—so you stay in control of your assets.

How we built it

We used Next.js, TypeScript, Tailwind CSS, and ShadCN UI for the frontend, with RainbowKit and Wagmi for wallet connections. On the blockchain side, we used Ethers.js to fetch approval data directly from the Ethereum network, scanning past transactions to find which contracts have spending permissions. Everything is built for speed, security, and ease of use.

Challenges we ran into

  • Fetching all approvals dynamically: There’s no straightforward way to get a list of contracts a user has approved, so we had to scan blockchain logs and filter out invalid approvals.
  • Handling different ERC-20 implementations: Some tokens behave differently, so we had to account for edge cases where allowance methods didn’t return expected values.
  • Gas fees & user experience: Revoking approvals costs gas, so we optimized the process to make it clear, efficient, and user-friendly.

Accomplishments that we're proud of

Built a fully functional approval revoker that works across any ERC-20 token. Designed a clean, intuitive UI that makes Web3 security more accessible. Learned a lot about EVM logs, smart contract interactions, and optimizing blockchain queries.

What we learned

  • Blockchain data isn’t always easy to access—you have to get creative when querying the blockchain efficiently.
  • Security is everything—many people don’t realize they still have open approvals until it’s too late.
  • User experience matters—people won’t revoke approvals if the process is complicated, so simplicity is key.

What's next for Decent Revoker

We want to expand beyond ERC-20 tokens and support NFT approvals (ERC-721, ERC-1155). We’re also exploring multi-chain support, so users can revoke approvals across Ethereum, BSC, Polygon, and more. Long-term, we see Decent Revoker becoming a Web3 security hub where users can monitor and manage all their wallet permissions in one place.

Built With

Share this project:

Updates