Ever approved tokens on various Dapps and you now worry that those Dapps and the smart contracts might sneakily take away your funds because they have access to your wallet address and some funds? You are not alone, hacks and scams occur a lot in the world of cryptocurrencies. One small mistake and your funds could be gone.
As people get opportunity to manage their own funds with DeFi and blockchain, it also comes with a great responsibility of protecting the fund. I wrote a detailed article earlier on how people lose funds and what are some common sense things that they could do save their funds. If you would like to learn more on how funds are lost and what you could do to minimize, read that article.
In this article I will show you, how you can revoke access to certain smart contracts.
Many of the blockchain explorers are copies of EtherScan implementation, that’s why many explorers looks so similar, which is good thing because you have similar experience across different explorers and changes are some of the urls are going to be similar as well.
Many blockchain explorers provide URLs where you can go and check the prior token approvals. The URLs and even the functionalities look similar on each of these explorers. Below are just for a few major blockchains and their token approval checker links. You can always google to find the token approval checkers for other blockchains.
- BSCScan Token Approval Checker
- Etherscan Token Approval Checker
- Cronoscan Token Approval Checker
- PolygonScan Token Approval Checker
So how does it work?
Let’s say you would want to see what all token approvals you have provided on your wallet address on a particular blockchain, click on the link above for that particular blockchain. I am going to use BSCScan Token Approval Checker as an example.
Here is how the screen looks like.
On that screen you can search by a wallet address and hit the search icon. In order to view the token approvals, you don’t need to connect your wallet. You could even check other people’s token approvals. I just took a random address and see what approvals this particular address had.
As you can see above, the wallet had 7 token approvals. Four contracts were accessing LIQ token (unlimited amount of LIQ), one contract had access to unlimited MLP token and there were two other contracts one of which had access to unlimited Cake-LP token and another contract had access to 8.6788 Cake-LP token.
This probably needed to provide access to various tokens in order to interact with it. But if you see anything in the list that either you don’t recognize or want the access removed, then you can do it via the same screen.
Although reading the token approvals is public process, and anyone can view anyone’s approvals as long as they have wallet address, approval removal can only be done by a signed in wallet.
How do I sign in to remove the access?
On the screen above, just below the search filed, there is an option to “Connect to Web3”, this allows you to connect your wallet. These screenshots are from my desktop, you might have a slightly different experience when you use a dapp browser.
Then select the wallets you want to connect to, although you can select multiple wallets, it has to be the wallet you want to make changes.
Once connected, you will have the revoke buttons enabled. You can then click the the revoke button, pay some gas fee by confirming the transactions. Make sure the transaction was successful
You’ve now successfully revoked the access to a token that you provided to a particular smart contract !
Thank you for reading this article and potentially protecting your fund !