eth_chainId

Network: Optimism Sepolia · Testnet · Chain ID 11155420 (0xaa37dc)

Counts as 1 request. See Request Counting.

Returns the chain ID used for signing replay-protected transactions (EIP-155).

Parameters

None.

Returns

QUANTITY — The current chain ID.

Request


{
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": [],
  "id": 1
}

Response


{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0xaa37dc"
}

0xaa37dc = 11155420 (Optimism Sepolia)

Code Examples


curl -X POST https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}'


const response = await fetch("https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": [],
  "id": 1
}),
});
const data = await response.json();
console.log(data.result);


import requests

response = requests.post(
    "https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public",
    json={
  "jsonrpc": "2.0",
  "method": "eth_chainId",
  "params": [],
  "id": 1
}
)
print(response.json()["result"])


package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
)

func main() {
	payload := []byte(`{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}`)
	resp, err := http.Post(
		"https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public",
		"application/json",
		bytes.NewBuffer(payload),
	)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)
	var result map[string]interface{}
	json.Unmarshal(body, &result)
	fmt.Println(result["result"])
}


import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public"),
});

const result = await client.request({
  method: "eth_chainId",
  params: [],
});
console.log(result);


cast rpc --rpc-url https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public eth_chainId


const { ethers } = require("hardhat");

async function main() {
  const provider = new ethers.JsonRpcProvider("https://optimism-sepolia-rpc.blockreq.com/v1/rpc/public");
  const result = await provider.send("eth_chainId", []);
  console.log(result);
}

main();