How do I get data regarding the type of token moved as a result of a smart contract's internal execution?

Question

I want to "join" transactions with the execution information (typically referred to as internal transactions).

Example scenario:

Someone sells Alice a token, tokenA, via a regular Ethereum transaction, for some Ethereum amount.

Alice interacts with a smart contract, which transfers ownership of tokenA to some other party for some value of Ethereum in return.

I need to find:

• the transaction where tokenA was initially sent to Alice
• information regarding how much Ethereum tokenA was exchanged for
• how to match these transactions together

How do I go about getting this information? I have tried looking at third party Ethereum APIs, such as Etherscan and Alchemy, but their APIs don't return the necessary "execution" information. The Etherscan API only returns how much Ethereum was internally moved as a result of an smart contract execution (although the website itself does show this information).

Thank you

Answer 1

I would try by listening to the token event

• Transfer(address from, address to, uint256 value)

You can also get all the past transfer event logs which i found from here

• get Transfer events from 0x0 address for ERC20 token

Maybe creating a nodejs script with etherjs to get past events and future events of transfer which in my opinion solves the issue you are having.

hope this was helpful cuz imposter syndrome :')