How get network ID with ethers.js?

Question

Using web3js it is possible get network ID using the following method:

// Contract ABI Load
const ABISimpleStorage = require("./build/contracts/SimpleStorage.json");

// Besu Connection Web3 Load
let web3 = new Web3(
  new Web3.providers.WebsocketProvider("ws://127.0.0.1:8546")
);
    const netID = await web3.eth.net.getId();

How we could do same thing in ethers.js?

const ABISimpleStorage = require("./build/contracts/SimpleStorage.json");
let provider = new ethers.providers.JsonRpcProvider();

let contract = new ethers.Contract(
  ABISimpleStorage.networks["2020"].address,
  ABISimpleStorage.abi,
  provider
);

Thanks

Answer 1

This worked for me:

const { chainId } = await provider.getNetwork()
console.log(chainId) // 42

Answer 2

I was searching this today.

Try provider.getNetwork().chainId.

getNetwork().name gives human readable name like 'homestead'

Answer 3

Use the provider.getNetwork() function. It will return a Network type and in it contain the chainId. You can see in the doc here: https://docs.ethers.io/ethers.js/html/api-providers.html#id2

UPDATE: as it turn out i was wrong the chainID and networkID are the same most of the time, not all of the time and there aren’t any api in etherjs so you need to use json-rpc instead. To do that you use this: https://docs.ethers.io/v5/api/providers/jsonrpc-provider/#JsonRpcProvider-send. Where the method is “net_version” and the params is an empty array. It will return like this: https://eth.wiki/json-rpc/API#net_version.

Answer 4

This is a solution for ^6.3.0 version of ethers.js:

let userProvider = new ethers.BrowserProvider(provider);
let objectNetwork = await userProvider.getNetwork();
// returns a bigint
let chainId = parseInt(objectNetwork.chainId.toString());