Quote from: MacInTheNet on January 18, 2024, 09:48:44 PM

Hi, no expert here.

Please help me understand something if you can.

I've been starting to use ledger swap feature, Uniswap with ledger and so on.

I've understood I have to allow two things to happen.

Token approval first and then the swap.

I've spent a lot of money in fees because something wasn't working very fast and well so I did the same thing more than once but that's OK, my fault.

I hope you understood your fault. Make use of Etherscan explorer (https://etherscan.io/) to know about your transactions. If fee is too low, send 0 ETH transaction to yourself with high gas fee, it'll cancel old transaction and allow you to make new transaction with high fee. Repeatedly making more transactions for same purpose will just cause you to lose your money.

Quote

What I want to understand is:

Let's suppose I want to swap 500 usdc for eth.

Let's suppose I have just that amount of usdc in my wallet.

If I authorize the maximum amount and then I swap, does it end there?

I mean: if the next day I send other usdc to my address, is there the risk those usdc are spent without my will?

Is it recommended to revoke something after the swap if the token approval has no limit?

I hope I explained myself Cheesy

Thanks in advance

When you approve on uniswap, uniswap contract gets permission to spend your token, if you approve 500 USDC you won't have to approve again on uniswap (or when using other dapps using Uniswap contract) for future transactions involving less than or equal to 500 usdc, so you save gas fees for future approvals transactions, this being a pro of it.

While con being if Uniswap contract gets compromised, then hacker would be able to drain your USDC amounted <=500 without your consent. This con applies to malicious contracts to begin with or compromised legit contracts.

You can use revoke cash to remove approvals: https://revoke.cash/