How to determine whether an address is a contract address

[linxianxi]

How to determine whether an address is a contract address

[novaknole]

Super simple..

try {
    const code = await provider.getCode(address);
    if (code !== '0x') return true;
  } catch (error) {}
// if it comes here, then it's not a contract.

[linxianxi]

thanks.

[ricmoo]

I agree with this answer in general and for most pragmatic purposes, but it is possible to deploy a contract with no bytecode, which would mean there could exist a contract with bytecode of 0x, but still have storage set and no method of signing messages or additional transactions as it has no private keys.

There are incredibly few cases where that distinction should matter.

[crazyrabbitLTC]

@ricmoo Thats fascinating. What would be the purpose of this example? Would you have constructor that simply sets storage and never deploys a contract? And then we could access this storage via smart contract using assembly?

[pironmind]

// @note ethers v6 hardhat env func.
async function isContract(value: any): Promise<boolean> {
    const result = await hre.ethers.provider.getCode(value)
    if (result === "0x") {
        return false;
    }
    return true;
}