I have a contract that tries to execute a swap which of course fails if the wanted pair doesn't exist. I though about writing a function that first checks if the swap is possible and only then executes it.

Is this a way to possibly save gas on failed attempts?

1 Answer 1


You can use Uniswap factory's getPair to check if the pair exists.

You will have to measure whether it is more gas efficient than a failed swap transaction.

Alternatively, if you're creating some kind of a bot, you can save all the pairs beforehand and then grab the pair from the list.

(You can even listen to events/mempool to make sure you are up to date).

Be careful of swapping tokens you know nothing about; some of them mighe be honeypots that won't allow you to sell them.

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