Sell fail in BSC chain

[rakibmia7254]

i tried to sell tokens in bsc chain but its just failed
https://bscscan.com/tx/0xd485d57204d9d2a869598be225cedbebb92a2cab1cb27dfffb485eb01d9fcfbd

encoded_input = (
    self.codec
    .encode
    .chain()
    .permit2_permit(permit_data, signable_message)
    .v2_swap_exact_in(FunctionRecipient.SENDER, self.amount_out, self.min_amount_in, self.path, payer_is_sender=False)
    .build(self.codec.get_default_deadline())
)

trx_params = {
    "from": self.account.address,
    "to": self.router,
    "gas": 200000,
    "maxPriorityFeePerGas": self.w3.eth.max_priority_fee,
    "maxFeePerGas":  50 * 10**9,
    "type": '0x2',
    "chainId": self.chain_id,
    "value": 0,
    "nonce": self.w3.eth.get_transaction_count(self.account.address)+1,
    "data": encoded_input,
}
raw_transaction = self.w3.eth.account.sign_transaction(trx_params, self.account.key).rawTransaction
trx_hash = self.w3.eth.send_raw_transaction(raw_transaction)
# wait for the transaction to be mined
self.w3.eth.wait_for_transaction_receipt(trx_hash)
return trx_hash.hex()

[Elnaril]

Hi @rakibmia7254 !

There is at least one error in how you build the encoded_input: you should have payer_is_sender=True i/o payer_is_sender=False. Indeed, in your case, the router does not have the tokens to sell yet when you call v2_swap_exact_in().
You can check this integration test: it's a similar case but for v3.

Also, just in case:

1. Have you approved the permit2 contract with the contract of the token you intend to sell?
2. Are you sure of your nonce? Usually it's just get_transaction_count(), not get_transaction_count() + 1

[rakibmia7254]

sure about nonce and the token i am trying to sell just bought from there, actually i am trying this on pancakeswap

    def Approve(self):
        permit2_allowance = 2**256 - 1  # max
        contract_function = self.w3.eth.contract(address=self.token_address, abi=self.erc20abi).functions.approve(
                self.permit2_address,
                permit2_allowance
        )
        trx_params = contract_function.build_transaction(
                {
                    "from": self.account.address,
                    "gas": 200000,
                    "maxPriorityFeePerGas": self.w3.eth.max_priority_fee,
                    "maxFeePerGas": 10 * 10**9,
                    "type": '0x2',
                    "chainId": self.chain_id,
                    "value": 0,
                    "nonce": self.w3.eth.get_transaction_count(self.account.address),
                }
            )
        raw_transaction = self.w3.eth.account.sign_transaction(trx_params, self.account.key).rawTransaction
        trx_hash = self.w3.eth.send_raw_transaction(raw_transaction)
        # wait for the transaction to be mined
        self.w3.eth.wait_for_transaction_receipt(trx_hash)

        # check allowance
        p2_amount, p2_expiration, p2_nonce = self.codec.fetch_permit2_allowance(
                self.account.address,
                self.token_address,
                self.router,
                permit2=self.permit2_address
        )

        # permit_data and signable_message
        allowance_amount = 2**160 - 1  # max/infinite
        permit_data, signable_message = self.codec.create_permit2_signable_message(
                self.token_address,
                allowance_amount,
                self.codec.get_default_expiration(),  # 30 days
                p2_nonce,
                self.router,
                self.codec.get_default_deadline(),  # 180 seconds
                self.chain_id,
                verifying_contract=self.permit2_address
            )
        
        signed_message = self.account.sign_message(signable_message)
        
        return permit_data, signed_message
    


    def execute(self):
        if not self.CheckAllowance():
            permit_data, signed_message = self.Approve()
        
            encoded_input = (
                self.codec
                .encode
                .chain()
                .permit2_permit(permit_data, signed_message)
                .v3_swap_exact_in(FunctionRecipient.SENDER, self.amount_out, self.min_amount_in, self.path, payer_is_sender=False)
                .build(self.codec.get_default_deadline())
            )
        
        else:
            encoded_input = (
                self.codec
                .encode
                .chain()
                .v3_swap_exact_in(FunctionRecipient.SENDER, self.amount_out, self.min_amount_in, self.path, payer_is_sender=False)
                .build(self.codec.get_default_deadline())
            )
        
        trx_params = {
            "from": self.account.address,
            "to": self.router,
            "gas": 200000,
            "maxPriorityFeePerGas": self.w3.eth.max_priority_fee,
            "maxFeePerGas":  10 * 10**9,
            "type": '0x2',
            "chainId": self.chain_id,
            "value": 0,
            "nonce": self.w3.eth.get_transaction_count(self.account.address)+1,
            "data": encoded_input,
        }
        raw_transaction = self.w3.eth.account.sign_transaction(trx_params, self.account.key).rawTransaction
        trx_hash = self.w3.eth.send_raw_transaction(raw_transaction)
        # wait for the transaction to be mined
        self.w3.eth.wait_for_transaction_receipt(trx_hash)
        return trx_hash.hex()

is there any problem in my code?

[Elnaril]

Well, apart from the nonce that I'm still not sure how it could work (but it's unlikely the reason of this failure), I don't see anything else obvious ...
I would suggest to split the transaction in 2, so you can figure out if it comes from the permit2 or the swap itself.

On a side note, with the latest lib version (v1.2), you can build directly the full transaction, not just the input data. See doc here

Also, have you tried to sell a standard/well known token like WBNB ?

[Elnaril]

Moving to discussions as "issues" are for issues in the library itself (or new features). Will move it back if it turns out it's actually one.