"Undefined" when trying to use web3Provider.network

Question

I want to get network chainId from web3Provider. This is my code.

const isBrowser = typeof window !== "undefined";
const web3provider = isBrowser ? new ethers.providers.Web3Provider(window.ethereum) : null;

const currentChainId = web3provider.network.chainId;

But I get this error. Cannot read properties of undefined (reading 'chainId')

Please tell me how can I access network attribute in web3provider. (Documentation says it's not safe way to access web3provider._network)

Answer 1

Try to await the network with getNetwork() (docs here), and then access the id with network.chainId (docs here).

Here is some example code:

const isBrowser = typeof window !== "undefined";
const web3provider = isBrowser ? new ethers.providers.Web3Provider(window.ethereum) : null;

// await network and return chainId
async function getCurrentChainId() {
  if (!web3provider) return null;
  const network = await web3provider.getNetwork();
  return network.chainId;
}

// await async function
const currentChainId = await getCurrentChainId();

// log the chainId
console.log(currentChainId);