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POST
eth_chainId
curl --request POST \
  --url https://tempo-moderato.core.chainstack.com/a25a421add2280d53fdbc23417055501/ \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": [],
  "id": 1
}
'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": "<string>"
}
Tempo API method that returns the chain ID of the current network. The Tempo Moderato testnet chain ID is 42431 (0xa5bf in hexadecimal).
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​
Parameters

  • none

​
Response

  • result — the chain ID encoded as hexadecimal (0xa5bf for Tempo Moderato testnet, which is 42431 in 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 chainId = await web3.eth.getChainId();
  console.log(`Chain ID: ${chainId}`);
}

getChainId()

Body

application/json
​
jsonrpc
string
default:2.0
​
method
string
default:eth_chainId
​
params
any[]
​
id
integer
default:1

Response

200 - application/json

The chain ID

​
jsonrpc
string
​
id
integer
​
result
string

The chain ID encoded as hexadecimal (0xa5bd for Tempo testnet)

Last modified on January 23, 2026