Monitoring Ethereum Contracts for specific function calls - missing methods in ABI

Question

I created a script to accept a contract address and watch that contract for specific "events." In this case, I want to check each time the Loot for Snail function is invoked on the EvoSnails NFT contract.

As you can see in the transactions, the method has been called quite a few times and it shows on the contract tx list. However, when I try to run my script to check for this event, the event does not exist in the contract.

A snippet of my code, which checks the Contract ABI for it's events and functions is here:

async function getContractABI(contractAddress) {
    let opts = {
        url: `http://api.etherscan.io/api?module=contract&action=getabi&address=${contractAddress}&apikey=${etherscanApiKey}`,
        responseType: 'json'
    }

    try {
        let response = await got(opts);
        const contractABI = JSON.parse(response.body.result);

        return contractABI;
    }

    catch (e) {
        console.log(e);
    }
}

const getContractEvents = async (contractAddress) => {
    let contractABI = await getContractABI(contractAddress);
    
    let contractEvents = contractABI.map(i => {
// i.type would be event but it doesn't appear for event or 'function'
        if (i.type === 'event'){
            return i.name;
        }
    })
    var results = contractEvents.reduce((results, item) => {
        if (typeof item === 'string') results.push(item) // modify is a fictitious function that would apply some change to the items in the array
        return results;
    }, [])

    return results;
}

getContractEvents("0x8a6e948a30ee8cb1391712710c1c59be553ab008");

As you can see, Loot for Snail is not here. How would I be able to monitor for this specific function when it is called?

Answer 1

The contract deployed at 0x8a6e948a30ee8cb1391712710c1c59be553ab008 is the OpenZeppelin TransparentUpgradeableProxy proxy (the original implementation of your NFT contract is here: 0x9539EAC4e19d0627815b166330b83f9c931A9e88

It means that you should listen to transaction to/from the proxy (0x8a6e) using the abi from the original contract (0x9539).

Check the Openzepellin post for additional details : https://blog.openzeppelin.com/the-transparent-proxy-pattern/