Do you want to swap 10 DAI for ETH? Sure thing, we'll just need your approval to spend a BAJILLION DOLLARS!

Do you ever feel uneasy about the different dapps that you gave approval to spend ERC20 tokens from your account? revoke.cash allows you to inspect all the contracts you've approved to spend money on your behalf, and revoke their access for the ones you no longer need. If you don't want to completely revoke access, it's also possible to update the amount they are allowed to spend instead.

This repository also includes a list of spender addresses`, which is a mapping of smart contract addresses to the corresponding application. This allows revoke.cash to display application names like Aave or Compound instead of their smart contract addresses. This list can be used by any other application. The name mapping for an address can be accessed through this URL:

• https://raw.githubusercontent.com/RevokeCash/revoke.cash/master/data/spenders/{chainId}/{address}.json

Revoke.cash supports many different chains using different methods, including direct RPC calls, Etherscan and CovalentHQ.

If you want to learn more about (unlimited) token approvals, I wrote an article on my blog: Unlimited ERC20 allowances considered harmful.

Running locally

git clone git@github.com:rkalis/revoke.cash.git
cd revoke.cash
yarn
yarn dev

Environment variables

An .example.env file is provided that needs to be copied into a .env file and filled out.

Some of these variables are integral to the functioning of Revoke.cash:

• NEXT_PUBLIC_INFURA_API_KEY is used for reading data from Ethereum + Testnets.
• NEXT_PUBLIC_ALCHEMY_API_KEY is used for reading data from Polygon, Optimism and Arbitrum + Testnets
  • Alchemy is also used for ENS and UNS name resolutions - if omitted those resolutions will not work.
• COVALENT_API_KEY and COVALENT_IS_PREMIUM is used for certain chains such as Evmos and Harmony.
• ETHERSCAN_API_KEYS and ETHERSCAN_RATE_LIMITS are used for many of the other chains such as BNB Chain or Avalanche.
• NEXT_PUBLIC_NODE_URLS is used to override any RPC URLs on the frontend - e.g. if you want to use Alchemy instead of Infura.
• NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID is used for WalletConnect - if omitted, WalletConnect will not work.

If you omit any of these variables, Revoke.cash will not work for the chains you omitted.

Then there are a few less essential variables:

• IRON_SESSION_PASSWORD is used for encrypting session cookies and can be filled with any random 32-character string - if omitted many chains will not work.
• NEXT_PUBLIC_AMPLITUDE_API_KEY is used for Analytics - if omitted, no Analytics are collected.
• UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN are used for queueing third-party API calls - these are only necessary when hosting in a serverless environment such as Vercel.
• NEXT_PUBLIC_HARPIE_API_KEY is used to call Harpie's API for getting contract address labels - if omitted it only uses public label data sources.
• NODE_URLS is currently unused, but can be used for certain networks in the future.
• LOCALAZY_API_KEY is used for generating "Help Us Translate This Page" links - if omitted, those links will not work.

Credits

Website created by Rosco Kalis after discussing the idea with Paul Berg at Devcon 5 in Osaka. Uses ethers.js and wagmi for all Ethereum-related operations and Etherscan, CovalentHQ, Infura & Alchemy for extended multichain support. Built with Next.js, Tailwind and TypeScript. Uses Upstash for queueing.