universal_permit2_abstract.py

#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# UNISWAP UNIVERSAL ROUTER V3 SWAP WITH OFFCHAIN PERMIT SIGNATURE - ABSTRACT VERSION (USING ETH SIGN TYPED DATA)
#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# A more general write up of python's signed typed data by Marc Garreau can be found here: 
# - https://snakecharmers.ethereum.org/typed-data-message-signing/

from web3 import Web3; w3 = Web3(Web3.HTTPProvider('https://polygon-rpc.com')) # example uses polygon
from os import getenv
from dotenv import load_dotenv
load_dotenv()
eoa = w3.eth.account.from_key(getenv('TKEY'))                                # replace with your own set up

#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# --- CONSTANTS AND CONFIGS --- - 
#---------------------------------------------------------------------------------------------------------------------------------------------------------#
PERMIT_ADDRESS  = '0x000000000022D473030F116dDEE9F6B43aC78BA3'
USDC_ADDRESS    = '0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359'
WETH_ADDRESS    = '0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619'
ROUTER_ADDRESS  = '0xec7BE89e9d109e7e3Fec59c222CF297125FEFda2'               # always double check the addresses 

ROUTER_ABI = '''
[{"inputs":[{"components":[{"internalType":"address","name":"permit2","type":"address"},{"internalType":"address","name":"weth9","type":"address"},{"internalType":"address","name":"seaportV1_5","type":"address"},{"internalType":"address","name":"seaportV1_4","type":"address"},{"internalType":"address","name":"openseaConduit","type":"address"},{"internalType":"address","name":"nftxZap","type":"address"},{"internalType":"address","name":"x2y2","type":"address"},{"internalType":"address","name":"foundation","type":"address"},{"internalType":"address","name":"sudoswap","type":"address"},{"internalType":"address","name":"elementMarket","type":"address"},{"internalType":"address","name":"nft20Zap","type":"address"},{"internalType":"address","name":"cryptopunks","type":"address"},{"internalType":"address","name":"looksRareV2","type":"address"},{"internalType":"address","name":"routerRewardsDistributor","type":"address"},{"internalType":"address","name":"looksRareRewardsDistributor","type":"address"},{"internalType":"address","name":"looksRareToken","type":"address"},{"internalType":"address","name":"v2Factory","type":"address"},{"internalType":"address","name":"v3Factory","type":"address"},{"internalType":"bytes32","name":"pairInitCodeHash","type":"bytes32"},{"internalType":"bytes32","name":"poolInitCodeHash","type":"bytes32"}],"internalType":"struct RouterParameters","name":"params","type":"tuple"}],"stateMutability":"nonpayable","type":"constructor"},{"inputs":[],"name":"BalanceTooLow","type":"error"},{"inputs":[],"name":"BuyPunkFailed","type":"error"},{"inputs":[],"name":"ContractLocked","type":"error"},{"inputs":[],"name":"ETHNotAccepted","type":"error"},{"inputs":[{"internalType":"uint256","name":"commandIndex","type":"uint256"},{"internalType":"bytes","name":"message","type":"bytes"}],"name":"ExecutionFailed","type":"error"},{"inputs":[],"name":"FromAddressIsNotOwner","type":"error"},{"inputs":[],"name":"InsufficientETH","type":"error"},{"inputs":[],"name":"InsufficientToken","type":"error"},{"inputs":[],"name":"InvalidBips","type":"error"},{"inputs":[{"internalType":"uint256","name":"commandType","type":"uint256"}],"name":"InvalidCommandType","type":"error"},{"inputs":[],"name":"InvalidOwnerERC1155","type":"error"},{"inputs":[],"name":"InvalidOwnerERC721","type":"error"},{"inputs":[],"name":"InvalidPath","type":"error"},{"inputs":[],"name":"InvalidReserves","type":"error"},{"inputs":[],"name":"InvalidSpender","type":"error"},{"inputs":[],"name":"LengthMismatch","type":"error"},{"inputs":[],"name":"SliceOutOfBounds","type":"error"},{"inputs":[],"name":"TransactionDeadlinePassed","type":"error"},{"inputs":[],"name":"UnableToClaim","type":"error"},{"inputs":[],"name":"UnsafeCast","type":"error"},{"inputs":[],"name":"V2InvalidPath","type":"error"},{"inputs":[],"name":"V2TooLittleReceived","type":"error"},{"inputs":[],"name":"V2TooMuchRequested","type":"error"},{"inputs":[],"name":"V3InvalidAmountOut","type":"error"},{"inputs":[],"name":"V3InvalidCaller","type":"error"},{"inputs":[],"name":"V3InvalidSwap","type":"error"},{"inputs":[],"name":"V3TooLittleReceived","type":"error"},{"inputs":[],"name":"V3TooMuchRequested","type":"error"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"RewardsSent","type":"event"},{"inputs":[{"internalType":"bytes","name":"looksRareClaim","type":"bytes"}],"name":"collectRewards","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes","name":"commands","type":"bytes"},{"internalType":"bytes[]","name":"inputs","type":"bytes[]"}],"name":"execute","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"bytes","name":"commands","type":"bytes"},{"internalType":"bytes[]","name":"inputs","type":"bytes[]"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"name":"execute","outputs":[],"stateMutability":"payable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"uint256[]","name":"","type":"uint256[]"},{"internalType":"uint256[]","name":"","type":"uint256[]"},{"internalType":"bytes","name":"","type":"bytes"}],"name":"onERC1155BatchReceived","outputs":[{"internalType":"bytes4","name":"","type":"bytes4"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"bytes","name":"","type":"bytes"}],"name":"onERC1155Received","outputs":[{"internalType":"bytes4","name":"","type":"bytes4"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"uint256","name":"","type":"uint256"},{"internalType":"bytes","name":"","type":"bytes"}],"name":"onERC721Received","outputs":[{"internalType":"bytes4","name":"","type":"bytes4"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"bytes4","name":"interfaceId","type":"bytes4"}],"name":"supportsInterface","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"pure","type":"function"},{"inputs":[{"internalType":"int256","name":"amount0Delta","type":"int256"},{"internalType":"int256","name":"amount1Delta","type":"int256"},{"internalType":"bytes","name":"data","type":"bytes"}],"name":"uniswapV3SwapCallback","outputs":[],"stateMutability":"nonpayable","type":"function"},{"stateMutability":"payable","type":"receive"}]
'''
PERMIT_ABI = '''
[{"inputs":[{"internalType":"uint256","name":"deadline","type":"uint256"}],"name":"AllowanceExpired","type":"error"},{"inputs":[],"name":"ExcessiveInvalidation","type":"error"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"InsufficientAllowance","type":"error"},{"inputs":[{"internalType":"uint256","name":"maxAmount","type":"uint256"}],"name":"InvalidAmount","type":"error"},{"inputs":[],"name":"InvalidContractSignature","type":"error"},{"inputs":[],"name":"InvalidNonce","type":"error"},{"inputs":[],"name":"InvalidSignature","type":"error"},{"inputs":[],"name":"InvalidSignatureLength","type":"error"},{"inputs":[],"name":"InvalidSigner","type":"error"},{"inputs":[],"name":"LengthMismatch","type":"error"},{"inputs":[{"internalType":"uint256","name":"signatureDeadline","type":"uint256"}],"name":"SignatureExpired","type":"error"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"token","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint160","name":"amount","type":"uint160"},{"indexed":false,"internalType":"uint48","name":"expiration","type":"uint48"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":false,"internalType":"address","name":"token","type":"address"},{"indexed":false,"internalType":"address","name":"spender","type":"address"}],"name":"Lockdown","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"token","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint48","name":"newNonce","type":"uint48"},{"indexed":false,"internalType":"uint48","name":"oldNonce","type":"uint48"}],"name":"NonceInvalidation","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"token","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint160","name":"amount","type":"uint160"},{"indexed":false,"internalType":"uint48","name":"expiration","type":"uint48"},{"indexed":false,"internalType":"uint48","name":"nonce","type":"uint48"}],"name":"Permit","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":false,"internalType":"uint256","name":"word","type":"uint256"},{"indexed":false,"internalType":"uint256","name":"mask","type":"uint256"}],"name":"UnorderedNonceInvalidation","type":"event"},{"inputs":[],"name":"DOMAIN_SEPARATOR","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"uint48","name":"expiration","type":"uint48"},{"internalType":"uint48","name":"nonce","type":"uint48"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"uint48","name":"expiration","type":"uint48"}],"name":"approve","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"token","type":"address"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint48","name":"newNonce","type":"uint48"}],"name":"invalidateNonces","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"wordPos","type":"uint256"},{"internalType":"uint256","name":"mask","type":"uint256"}],"name":"invalidateUnorderedNonces","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"internalType":"struct IAllowanceTransfer.TokenSpenderPair[]","name":"approvals","type":"tuple[]"}],"name":"lockdown","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"uint256","name":"","type":"uint256"}],"name":"nonceBitmap","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"uint48","name":"expiration","type":"uint48"},{"internalType":"uint48","name":"nonce","type":"uint48"}],"internalType":"struct IAllowanceTransfer.PermitDetails[]","name":"details","type":"tuple[]"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"sigDeadline","type":"uint256"}],"internalType":"struct IAllowanceTransfer.PermitBatch","name":"permitBatch","type":"tuple"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"uint48","name":"expiration","type":"uint48"},{"internalType":"uint48","name":"nonce","type":"uint48"}],"internalType":"struct IAllowanceTransfer.PermitDetails","name":"details","type":"tuple"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"sigDeadline","type":"uint256"}],"internalType":"struct IAllowanceTransfer.PermitSingle","name":"permitSingle","type":"tuple"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"internalType":"struct ISignatureTransfer.TokenPermissions","name":"permitted","type":"tuple"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct ISignatureTransfer.PermitTransferFrom","name":"permit","type":"tuple"},{"components":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"requestedAmount","type":"uint256"}],"internalType":"struct ISignatureTransfer.SignatureTransferDetails","name":"transferDetails","type":"tuple"},{"internalType":"address","name":"owner","type":"address"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permitTransferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"internalType":"struct ISignatureTransfer.TokenPermissions[]","name":"permitted","type":"tuple[]"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct ISignatureTransfer.PermitBatchTransferFrom","name":"permit","type":"tuple"},{"components":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"requestedAmount","type":"uint256"}],"internalType":"struct ISignatureTransfer.SignatureTransferDetails[]","name":"transferDetails","type":"tuple[]"},{"internalType":"address","name":"owner","type":"address"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permitTransferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"internalType":"struct ISignatureTransfer.TokenPermissions","name":"permitted","type":"tuple"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct ISignatureTransfer.PermitTransferFrom","name":"permit","type":"tuple"},{"components":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"requestedAmount","type":"uint256"}],"internalType":"struct ISignatureTransfer.SignatureTransferDetails","name":"transferDetails","type":"tuple"},{"internalType":"address","name":"owner","type":"address"},{"internalType":"bytes32","name":"witness","type":"bytes32"},{"internalType":"string","name":"witnessTypeString","type":"string"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permitWitnessTransferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"components":[{"internalType":"address","name":"token","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"internalType":"struct ISignatureTransfer.TokenPermissions[]","name":"permitted","type":"tuple[]"},{"internalType":"uint256","name":"nonce","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"}],"internalType":"struct ISignatureTransfer.PermitBatchTransferFrom","name":"permit","type":"tuple"},{"components":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"requestedAmount","type":"uint256"}],"internalType":"struct ISignatureTransfer.SignatureTransferDetails[]","name":"transferDetails","type":"tuple[]"},{"internalType":"address","name":"owner","type":"address"},{"internalType":"bytes32","name":"witness","type":"bytes32"},{"internalType":"string","name":"witnessTypeString","type":"string"},{"internalType":"bytes","name":"signature","type":"bytes"}],"name":"permitWitnessTransferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"components":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"address","name":"token","type":"address"}],"internalType":"struct IAllowanceTransfer.AllowanceTransferDetails[]","name":"transferDetails","type":"tuple[]"}],"name":"transferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint160","name":"amount","type":"uint160"},{"internalType":"address","name":"token","type":"address"}],"name":"transferFrom","outputs":[],"stateMutability":"nonpayable","type":"function"}]
'''
ERC20_ABI  = '''
[{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"src","type":"address"},{"indexed":true,"internalType":"address","name":"guy","type":"address"},{"indexed":false,"internalType":"uint256","name":"wad","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"dst","type":"address"},{"indexed":false,"internalType":"uint256","name":"wad","type":"uint256"}],"name":"Deposit","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"src","type":"address"},{"indexed":true,"internalType":"address","name":"dst","type":"address"},{"indexed":false,"internalType":"uint256","name":"wad","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"src","type":"address"},{"indexed":false,"internalType":"uint256","name":"wad","type":"uint256"}],"name":"Withdrawal","type":"event"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"constant":true,"inputs":[{"internalType":"address","name":"","type":"address"},{"internalType":"address","name":"","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"guy","type":"address"},{"internalType":"uint256","name":"wad","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"deposit","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"dst","type":"address"},{"internalType":"uint256","name":"wad","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"src","type":"address"},{"internalType":"address","name":"dst","type":"address"},{"internalType":"uint256","name":"wad","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"uint256","name":"wad","type":"uint256"}],"name":"withdraw","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"}]
'''

router    = w3.eth.contract(address=ROUTER_ADDRESS, abi=ROUTER_ABI)
permit    = w3.eth.contract(address=PERMIT_ADDRESS, abi=PERMIT_ABI)
token_in  = w3.eth.contract(address=USDC_ADDRESS,  abi=ERC20_ABI )
token_out = w3.eth.contract(address=WETH_ADDRESS,  abi=ERC20_ABI )

#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# --- EXAMPLE ---
#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# In this scenario we want to swap on Uniswap Universal Router and we want to 
# send our permit with the swap as opposed to approving the router in a prior
# transaction. Note we still have to approve the permit contract in its own tx 
# as we aren't using a custom contract and all calls will be from an EOA.

# We will swap from a single usdc and only permit the router to spend up to that amount
swap_amount      = 1 * 10 ** 6

# Will use a deadline far in the future
expiration       = 2 * 10 ** 10

# We can get a nonce by calling the permit contract and passing owner, token, spender
nonce            = permit.functions.allowance(eoa.address, token_in.address, router.address).call()[2]


DOMAIN_DATA = {
  'name'              : 'Permit2',
  'chainId'           : w3.eth.chain_id,
  'verifyingContract' : permit.address
}

PERMIT2_PERMIT_TYPE = {
 'PermitDetails' : [
    { 'name' : 'token',       'type': 'address'       },
    { 'name' : 'amount',      'type': 'uint160'       },
    { 'name' : 'expiration',  'type': 'uint48'        },
    { 'name' : 'nonce',       'type': 'uint48'        },
  ],

  'PermitSingle' : [
    { 'name' : 'details',     'type': 'PermitDetails' },
    { 'name' : 'spender',     'type': 'address'       },
    { 'name' : 'sigDeadline', 'type': 'uint256'       },
  ],
}

details = {
  'token'       : token_in.address, 
  'amount'      : swap_amount, 
  'expiration'  : expiration, 
  'nonce'       : nonce
}

message = {
  'details'     : details,
  'spender'     : router.address,
  'sigDeadline' : expiration
}

signed_hash = w3.eth.account.sign_typed_data(eoa.key, DOMAIN_DATA, PERMIT2_PERMIT_TYPE, message)

#---------------------------------------------------------------------------------------------------------------------------------------------------------#
# --- MAIN --- 
#---------------------------------------------------------------------------------------------------------------------------------------------------------#
from eth_abi import encode
from eth_abi.packed import encode_packed
def main():

  # Will skip details on command byte mechanics as a more in depth step through can be found in the dedicated 
  # universal_router.md in the uni_router folder. 
  # To summarise we will pass the permit, then use it to transfer the tokens and swap.
  PERMIT2_PERMIT        = '0a'
  V3_SWAP_EXACT_IN      = '00'
  commands              = '0x' + PERMIT2_PERMIT + V3_SWAP_EXACT_IN 

  permit2_permit        = encode(
    [ '(address,uint160,uint48,uint48)','address','uint256', 'bytes'],
    [ (token_in.address, swap_amount, expiration, nonce), router.address, expiration, signed_hash.signature ]
  )

  to          = eoa.address
  slippage    = 0     # use something close to desired amount
  fee         = 500   # effects the pool that address that will be calculated, check this for your case.
  path        = encode_packed(['address','uint24','address'], [token_in.address, fee, token_out.address])

  from_eoa    = True
  v3_calldata = encode(['address', 'uint256', 'uint256', 'bytes', 'bool'], [to, swap_amount, slippage, path, from_eoa])

  execute     = router.functions.execute(commands, [ permit2_permit, v3_calldata ], expiration)
  
  # --

  # can max this to only ever do it once for all protocols that support the contract on that chain
  approval    = token_in.functions.approve(permit.address, swap_amount) 

  # --

  tx = { 
         'from' : eoa.address, 'value'       : 0,                    'chainId'             : w3.eth.chain_id, 
         'gas'  : 250000,      'maxFeePerGas': w3.eth.gas_price * 2, 'maxPriorityFeePerGas': w3.eth.max_priority_fee*2, 
         'nonce': w3.eth.get_transaction_count(eoa.address)
 
       }

  # We can't do this approval in the same transaction when from EOA.
  approve     = approval.build_transaction(tx)
  print ('[-] Approving permit... ')
  tx_hash     = send_tx(sign_tx(approve, eoa.key))
  receipt     = w3.eth.wait_for_transaction_receipt(tx_hash)
  print (f'[+] Approved PERMIT2 at TOKEN contract: {tx_hash}\n[>] {receipt}')

  tx.update({'nonce': w3.eth.get_transaction_count(eoa.address)})

  # Now we can swap using the permit.
  swap        = execute.build_transaction(tx)
  print(swap)
  print('[-] Simulating swap...')
  w3.eth.call(swap)
  print('[-] Attempting swap...')
  tx_hash     = send_tx(sign_tx(swap, eoa.key))
  receipt     = w3.eth.wait_for_transaction_receipt(tx_hash)
  print (f'[>] Hash of swap: {tx_hash}\n[>] {receipt}')
  
# --- END MAIN ---

def sign_tx(tx, key):
  return w3.eth.account.sign_transaction(tx, private_key=key)

def send_tx(signed_tx):
  return w3.eth.send_raw_transaction(signed_tx.raw_transaction)
if __name__ == '__main__': 
  main()

#---------------------------------------------------------------------------------------------------------------------------------------------------------#