Uniswap v3: exactInputSingle token to ETH is wrapped

Question

I've made a python web3 script that swaps ETH to Token using exactInputSingle function on Uniswap v3 Abritrum chain.

Transactions are successful and the script is working, but the problem is, when I reverse the swap (selling tokens to get ETH), I receive wETH instead of ETH. On Uniswap v2, this can be easily be solved by using swapExactTokensForETH, but Uniswap v3 is different.

Here's a sample portion of the txn in my code:

    # Txn Params
    fee = 3000
    min_out = 0
    deadline = int(time()) + 900
    txn_params = (token_address, weth_address, fee, wallet_address, deadline, amount_to_sell, min_out, 0)

    uniswapv3_txn = router.functions.exactInputSingle(txn_params).buildTransaction(
        {
            'from': wallet_address,
            'gas': int(gas_limit),
            'maxFeePerGas': web3.toWei(data_gas_max_fee, 'gwei'),
            'maxPriorityFeePerGas': web3.toWei(gas_max_priority, 'gwei'),
            'nonce': web3.eth.get_transaction_count(wallet_address),
        })

        signed_txn = web3.eth.account.sign_transaction(uniswapv3_txn, private_key=private_key)
        tx_token = web3.eth.send_raw_transaction(signed_txn.rawTransaction)
        receipt = web3.eth.wait_for_transaction_receipt(tx_token, timeout=900)

How would I be able to receive ETH instead of wETH?

Answer 1

In this context I do not see similar function in UniswapV3 like you have in uniswapV2. But you can create a simple withdraw from weth contract after you have received WETH back.

You have to approve maximum weth to WETH contract and send transaction to withdraw(wethAmount).

1. wethContractAddress.approve(wethContractAddress, wethAmount)
2. wethContractAddress.withdraw(amountWeth)