Interacting with an external contract from truffle shell

Emmett · May 9, 2021, 5:09pm

I have connected to ropsten from truffle (truffle console --network ropsten) and I am tryign to interact with the test version of the USDC on ropsten which is at the address 0x07865c6e87b9f70255377e024ace6630c1eaa37f and has the following abi (far below):

Can someone show me how I can interact with this in the truffle shell and perhaps how to call symbol() for instance?

I’ve been trying var contract = new Contract(<abi>, <address>); but I don’t see the symbol function. It looks like theres some sort of proxy contract stuff going on ?

[{“constant”:false,“inputs”:[{“name”:“newImplementation”,“type”:“address”}],“name”:“upgradeTo”,“outputs”:[],“payable”:false,“stateMutability”:“nonpayable”,“type”:“function”},{“constant”:false,“inputs”:[{“name”:“newImplementation”,“type”:“address”},{“name”:“data”,“type”:“bytes”}],“name”:“upgradeToAndCall”,“outputs”:[],“payable”:true,“stateMutability”:“payable”,“type”:“function”},{“constant”:true,“inputs”:[],“name”:“implementation”,“outputs”:[{“name”:"",“type”:“address”}],“payable”:false,“stateMutability”:“view”,“type”:“function”},{“constant”:false,“inputs”:[{“name”:“newAdmin”,“type”:“address”}],“name”:“changeAdmin”,“outputs”:[],“payable”:false,“stateMutability”:“nonpayable”,“type”:“function”},{“constant”:true,“inputs”:[],“name”:“admin”,“outputs”:[{“name”:"",“type”:“address”}],“payable”:false,“stateMutability”:“view”,“type”:“function”},{“inputs”:[{“name”:"_implementation",“type”:“address”}],“payable”:false,“stateMutability”:“nonpayable”,“type”:“constructor”},{“payable”:true,“stateMutability”:“payable”,“type”:“fallback”},{“anonymous”:false,“inputs”:[{“indexed”:false,“name”:“previousAdmin”,“type”:“address”},{“indexed”:false,“name”:“newAdmin”,“type”:“address”}],“name”:“AdminChanged”,“type”:“event”},{“anonymous”:false,“inputs”:[{“indexed”:false,“name”:“implementation”,“type”:“address”}],“name”:“Upgraded”,“type”:“event”}]

dan-i · May 10, 2021, 7:43am

Hi @Emmett

You can indeed create an instance of the USDC contract by using web3.
The Contract constructor asks for the contract ABI and address:

new Contract(<abi>, <address>);

Regarding the symbol:

What’s the visibility of that function?
Does it show in your ABI (it does not seem from your post above)?

Cheers,
Dani

Emmett · May 10, 2021, 7:34pm

so the contract can be seen here: https://ropsten.etherscan.io/address/0x07865c6e87b9f70255377e024ace6630c1eaa37f#code

its supposed to be a version of the USDC erc20 token on ropsten… but its some sort of a ‘proxy’. If you however then click on the ‘read as proxy’ button you can then see the regular erc20 functions like symbol(), totalSupply etc. : https://ropsten.etherscan.io/address/0x07865c6e87b9f70255377e024ace6630c1eaa37f#readProxyContract

still

dan-i · May 11, 2021, 10:30am

Hi @Emmett

I tried and works fine.
You have to use the proxy contract address and the ABI of the implementation.
You can run this code (add your infura api)

const Web3 = require('web3');
const web3 = new Web3("https://ropsten.infura.io/v3/**your api key**");
const abi = [{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"authorizer","type":"address"},{"indexed":true,"internalType":"bytes32","name":"nonce","type":"bytes32"}],"name":"AuthorizationCanceled","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"authorizer","type":"address"},{"indexed":true,"internalType":"bytes32","name":"nonce","type":"bytes32"}],"name":"AuthorizationUsed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_account","type":"address"}],"name":"Blacklisted","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"newBlacklister","type":"address"}],"name":"BlacklisterChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"burner","type":"address"},{"indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Burn","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"newMasterMinter","type":"address"}],"name":"MasterMinterChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"minter","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"amount","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"minter","type":"address"},{"indexed":false,"internalType":"uint256","name":"minterAllowedAmount","type":"uint256"}],"name":"MinterConfigured","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"oldMinter","type":"address"}],"name":"MinterRemoved","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":false,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[],"name":"Pause","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"newAddress","type":"address"}],"name":"PauserChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"newRescuer","type":"address"}],"name":"RescuerChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"_account","type":"address"}],"name":"UnBlacklisted","type":"event"},{"anonymous":false,"inputs":[],"name":"Unpause","type":"event"},{"inputs":[],"name":"CANCEL_AUTHORIZATION_TYPEHASH","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"DOMAIN_SEPARATOR","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"PERMIT_TYPEHASH","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"RECEIVE_WITH_AUTHORIZATION_TYPEHASH","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"TRANSFER_WITH_AUTHORIZATION_TYPEHASH","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"authorizer","type":"address"},{"internalType":"bytes32","name":"nonce","type":"bytes32"}],"name":"authorizationState","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"blacklist","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"blacklister","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_amount","type":"uint256"}],"name":"burn","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"authorizer","type":"address"},{"internalType":"bytes32","name":"nonce","type":"bytes32"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"cancelAuthorization","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"minter","type":"address"},{"internalType":"uint256","name":"minterAllowedAmount","type":"uint256"}],"name":"configureMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"currency","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"decrement","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"increment","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"string","name":"tokenName","type":"string"},{"internalType":"string","name":"tokenSymbol","type":"string"},{"internalType":"string","name":"tokenCurrency","type":"string"},{"internalType":"uint8","name":"tokenDecimals","type":"uint8"},{"internalType":"address","name":"newMasterMinter","type":"address"},{"internalType":"address","name":"newPauser","type":"address"},{"internalType":"address","name":"newBlacklister","type":"address"},{"internalType":"address","name":"newOwner","type":"address"}],"name":"initialize","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"string","name":"newName","type":"string"}],"name":"initializeV2","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"lostAndFound","type":"address"}],"name":"initializeV2_1","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"isBlacklisted","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"isMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"masterMinter","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_amount","type":"uint256"}],"name":"mint","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"minter","type":"address"}],"name":"minterAllowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"}],"name":"nonces","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"pause","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"paused","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"pauser","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"deadline","type":"uint256"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"validAfter","type":"uint256"},{"internalType":"uint256","name":"validBefore","type":"uint256"},{"internalType":"bytes32","name":"nonce","type":"bytes32"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"receiveWithAuthorization","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"minter","type":"address"}],"name":"removeMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"contract IERC20","name":"tokenContract","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"rescueERC20","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"rescuer","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"from","type":"address"},{"internalType":"address","name":"to","type":"address"},{"internalType":"uint256","name":"value","type":"uint256"},{"internalType":"uint256","name":"validAfter","type":"uint256"},{"internalType":"uint256","name":"validBefore","type":"uint256"},{"internalType":"bytes32","name":"nonce","type":"bytes32"},{"internalType":"uint8","name":"v","type":"uint8"},{"internalType":"bytes32","name":"r","type":"bytes32"},{"internalType":"bytes32","name":"s","type":"bytes32"}],"name":"transferWithAuthorization","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"unBlacklist","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"unpause","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newBlacklister","type":"address"}],"name":"updateBlacklister","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newMasterMinter","type":"address"}],"name":"updateMasterMinter","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newPauser","type":"address"}],"name":"updatePauser","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"newRescuer","type":"address"}],"name":"updateRescuer","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"version","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"}]

async function getSymbol() {
  const instance = new web3.eth.Contract(abi, "0x07865c6E87B9F70255377e024ace6630C1Eaa37F");
  console.log(await instance.methods.symbol().call());
}

getSymbol()

Emmett · May 11, 2021, 1:52pm

ah, brilliant…

having a rough time getting to grips with the evm