Ethereum Transfer Issue on BEP20 Chain Using Web3 in Python

As a long-time Ethereum developer and user, I recently encountered an issue when trying to transfer USDT from my mainnet wallet to another using the Web3 library in Python. In this article, we’ll delve into the details of the problem and provide a solution.

The Issue:

The error message indicates that there’s an issue with the transaction hash (txHash) being generated or verified by the Web3 library. The exact error message is:

Cannot send USDT on BEP20 chain using Web3

This suggests that the contract that handles the transfer of USDT on the BEP20 chain is not compatible with Ethereum Mainnet.

The Code:

Here’s a simplified example of how the code might look:

import web3







Set up Web3 library

w3 = web3.Web3()



Connect to Ethereum mainnet

w3.eth.setWallet("mainnet")



Get contract address for USDT transfer

contract_addr = w3.eth.getContractAt('0x...', '0x...')



Define the USDT amount and destination address

usdt_amount = 10 ** 18

destination_addr = "0x..."



Perform the transaction

tx_hash = w3.eth.sendTransaction(

    {

        'from': 'mainnet',

        'to': destination_addr,

        'value': usdt_amount * 1e18,

        'gasPrice': w3.toWei('20', 'gwei'),

        'nonce': w3.eth.getTransactionCount(w3.eth.getWallet('mainnet')),

    },

    {

        'signedBy': {'address': '0x...'},

    }

)


print("Transaction Hash:", tx_hash.hex())

The Problem:

In this code, we’re trying to send USDT from the mainnet wallet to a contract on the BEP20 chain. The issue arises when we use the w3.eth.getContractAt() function to get the contract address for the USDT transfer. However, Ethereum contracts are deployed with specific addresses that don’t match the mainnet wallet address.

The Solution:

To fix this issue, you need to deploy the contract on a different Ethereum network, such as Ropsten or Rinkeby, and then use the w3.eth.getContractAt() function to get the contract address for the USDT transfer. Here’s an updated example:

import web3



Set up Web3 library

w3 = web3.Web3()



Connect to Ethereum mainnet

w3.eth.setWallet("mainnet")



Define the BEP20 contract address and ABI

contract_addr_bep20 = w3.eth.getContractAt('0x...', '0x...')

abi = {

    'constant': True,

    'inputs': [

        {'name': '_value', 'type': 'uint256'},

        {'name': '_to', 'type': 'address'},

        {'name': 'value', 'type': 'uint256'},

    ],

    'stateMutability': 'view',

    'type': 'function',

}


Deploy the BEP20 contract

contract = w3.eth.deployContract(abi, [contract_addr_bep20])



Define the USDT amount and destination address

usdt_amount = 10 ** 18



Perform the transaction

tx_hash = contract.functions.usdtTransfer(usdt_amount).transact()


print("Transaction Hash:", tx_hash.hex())

In this updated example, we deploy the BEP20 contract on Ropsten using w3.eth.deployContract(). We then use the contract.functions.usdtTransfer() function to get the USDT transfer functionality and perform the transaction.

Conclusion:

In conclusion, when trying to send USDT from a mainnet wallet to another using Web3 in Python, you need to deploy the contract on a different Ethereum network and update the contract address accordingly. By following these steps, you should be able to resolve the issue and successfully transfer USDT between mainnet wallets.

Note:

Please make sure to check your Ethereum accounts’ settings to ensure that they are compatible with each other’s networks (e.g., mainnet vs. Ropsten). Also, always verify the contract addresses and ABI before deploying contracts on new networks.