Skip to main content
POST
/
942aad90bb6a082676497030b81e40ba
eth_chainId
curl --request POST \
  --url https://nd-363-550-219.p2pify.com/942aad90bb6a082676497030b81e40ba \
  --header 'Content-Type: application/json' \
  --data '
{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": []
}
'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": "<string>"
}
Polygon zkEVM API method that returns the current chain ID. Chain ID is used to sign replay-protected transactions and verify whether a network is the desired one. It was introduced in EIP-155.
Get your own node endpoint todayStart for free and get your app to production levels immediately. No credit card required.You can sign up with your GitHub, X, Google, or Microsoft account.

​
Parameters

  • none

​
Response

  • quantity — EIP-155 Chain ID
Use the Chainstack EVM Knife to convert the Chain ID from Hexadecimal to Decimal.

​
eth_chainId code examples

const { Web3 } = require("web3");
const NODE_URL = "CHAINSTACK_NODE_URL";
const web3 = new Web3(NODE_URL);

async function getChainId() {
  const chain = await web3.eth.getChainId();
  console.log(chain);
}

getChainId();

​
Use case

One possible use case for the eth_chainId method is to determine which chain a user is connected to when using a DApp with the MetaMask browser extension. This can be useful to provide a customized user experience based on the specific chain that the user is interacting with.

Body

application/json
​
id
integer
default:1
​
jsonrpc
string
default:2.0
​
method
string
default:eth_chainId
​
params
array

Response

200 - application/json

The network Chain ID

​
jsonrpc
string
​
id
integer
​
result
string
Last modified on May 18, 2026