V2_SWAP_EXACT_OUT

[p-and14]

I am trying to exchange WETH for DOGE.
But I get an error: web3.exceptions.ContractCustomError: 0xd81b2f2e0000000000000000000000000000000000000000000000000000000000000000
What could be the reason?

token_address = web3.to_checksum_address("0x1121acc14c63f3c872bfca497d10926a6098aac5")
gas_price = await web3_async.eth.gas_price
latest_block = await web3_async.eth.get_block("latest")
amount_out = 500000000000000000000 # 500 DOGE
amount_in_max = 4745760000000000 # 0,00474576 ETH
path = [WETH_ADDRESS, token_address]
gas_price_increase_value += 2000000000

encoded_input = (
  RouterCodec().encode.chain()
  .v2_swap_exact_out(FunctionRecipient.SENDER, amount_out, amount_in_max, path, payer_is_sender=True)
  .build(latest_block["timestamp"] + 25)
)

tx = {
  "from": MY_WALLET.address,
  "to": uniswap_ur.ur_address,
  "gas": gas,
  "maxFeePerGas": int(gas_price * 1.2) + gas_price_increase_value,
  "maxPriorityFeePerGas": gas_price_increase_value,
  "type": '0x2',
  "chainId": 1,
  "value": 0,
  "nonce": await web3_async.eth.get_transaction_count(MY_WALLET.address),
  "data": encoded_input,
}

gas = await web3_async.eth.estimate_gas(tx)

[Elnaril]

Hi @p-and14 !

With the latest SDK version (v2.0.0) you can decode some possible ContractCustomError:

codec.decode.contract_error("0xd81b2f2e0000000000000000000000000000000000000000000000000000000000000000")

The result for this particular error is:

('AllowanceExpired(uint256)', {'deadline': 0})

=> Are you sure you have permit2'ed the Universal Router and approved the permit2 contract for WETH ?

[p-and14]

Hi @p-and14 !

With the latest SDK version (v2.0.0) you can decode some possible ContractCustomError:

codec.decode.contract_error("0xd81b2f2e0000000000000000000000000000000000000000000000000000000000000000")

The result for this particular error is:

('AllowanceExpired(uint256)', {'deadline': 0})

=> Are you sure you have permit2'ed the Universal Router and approved the permit2 contract for WETH ?

Thanks, didn't know about that feature! Didn't update decoder to the latest version.
I didn't use permit2, I realized the mistake.
If I add wrap_eth, what quantity do I need to specify?
.wrap_eth(FunctionRecipient.ROUTER, amount_in_max)

In this situation, I get an error:
('InsufficientETH()', {})
There is enough ETH on the balance sheet

[Elnaril]

You would need to set the tx value field to amount_in_max as well, and add a call to .sweep() before.build((), to get back the remaining ETH.

[p-and14]

It worked, thanks!