eth_chainId

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();