chainHead_v1_call

POST

https://tao.nownodes.io/

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Calls a runtime method against the state at a specific block identified by two hex hashes.

Body

application/json

jsonrpcstringrequired

JSON-RPC protocol version. Must be "2.0".

methodstringchainHead_v1_callrequired

The RPC method to invoke.

paramsArray<string>required

Array containing four positional parameters: - first hex string (e.g., block hash) - second hex string (e.g., a sub-identifier) - method name (e.g., "Core_version") - hex-encoded call data (often "0x" for simple calls)

idintegerrequired

Request identifier.

Response

200OK

Successful response with the result of the runtime call.

chainHead_v1_call

curl -X POST 'https://tao.nownodes.io/' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "chainHead_v1_call",
    "params": [
      "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
      "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
      "Core_version",
      "0x"
    ],
    "id": 1
  }'

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://tao.nownodes.io/");
const result = await provider.send("chainHead_v1_call", [
  "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
  "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
  "Core_version",
  "0x"
]);
console.log(result);

require 'eth'
require 'json'
require 'net/http'

uri = URI('https://tao.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
  "jsonrpc": "2.0",
  "method": "chainHead_v1_call",
  "params": [
    "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
    "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
    "Core_version",
    "0x"
  ],
  "id": 1
}'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
  http.request(request)
end

puts JSON.parse(response.body)

from web3 import Web3

w3 = Web3(Web3.HTTPProvider("https://tao.nownodes.io/"))
response = w3.provider.make_request("chainHead_v1_call", [
  "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
  "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
  "Core_version",
  "0x"
])
print(response)

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://tao.nownodes.io/"),
});

const result = await client.request({
  method: "chainHead_v1_call",
  params: [
  "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
  "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
  "Core_version",
  "0x"
],
});

console.log(result);

const endpoint = "https://tao.nownodes.io/";
const apiKey = "YOUR_API_KEY";

async function nownodesRequest(payload) {
  const response = await fetch(endpoint, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "api-key": apiKey,
    },
    body: JSON.stringify(payload),
  });

  return response.json();
}

const result = await nownodesRequest({ jsonrpc: "2.0", method: "chainHead_v1_call", params: [
  "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
  "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
  "Core_version",
  "0x"
], id: 1 });
console.log(result);

const response = await fetch('https://tao.nownodes.io/', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "jsonrpc": "2.0",
      "method": "chainHead_v1_call",
      "params": [
        "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
        "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
        "Core_version",
        "0x"
      ],
      "id": 1
    }),
});

const data = await response.json();

import requests

payload = {
  "jsonrpc": "2.0",
  "method": "chainHead_v1_call",
  "params": [
    "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
    "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
    "Core_version",
    "0x"
  ],
  "id": 1
}

response = requests.post('https://tao.nownodes.io/', json=payload)
data = response.json()

require 'net/http'
require 'json'

uri = URI('https://tao.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "jsonrpc": "2.0",
    "method": "chainHead_v1_call",
    "params": [
      "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
      "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
      "Core_version",
      "0x"
    ],
    "id": 1
  }'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(request) }
data = JSON.parse(response.body)

Request Body

{
  "jsonrpc": "2.0",
  "method": "chainHead_v1_call",
  "params": [
    "0xe31b64304856f688094f3b095ebc920af0fcdc2078222729231201e389384bff",
    "0xdb348f3b095ebc920af0fcdc2078222729231201e389384be709bf950b330102",
    "Core_version",
    "0x"
  ],
  "id": 1
}

200

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "result": "limitReached"
  }
}

Documentation

How to migrate to NOWNodes

chainHead_v1_call

Authorizations

Body

Response