Estimate Gas for Transaction

POST

https://sys-evm.nownodes.io/

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Simulates a transaction and returns an estimate of how much gas would be used.

Body

application/json

jsonrpcstringrequired

JSON-RPC protocol version

methodstringrequired

The method name

paramsArray<object | string>required

The transaction call object and an optional block tag.

Show child attributes

One of

fromstring

Address the transaction is sent from (optional)

tostringrequired

Destination address of the call

gasstring

Gas limit provided for execution (optional)

gasPricestring

Gas price in wei (optional)

valuestring

Amount of ETH to send, in hexadecimal wei (optional)

datastring

The compiled input data for the transaction (optional)

Optional block tag (e.g., "latest", "earliest", or a block number)

string

idintegerrequired

Request identifier

Response

200OK

Estimated gas amount

Estimate Gas for Transaction

curl -X POST 'https://sys-evm.nownodes.io/' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_estimateGas",
    "params": [
      {
        "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
        "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
        "gas": "0x76c0",
        "gasPrice": "0x9184e72a000",
        "value": "0x0",
        "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
      }
    ],
    "id": 1
  }'

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://sys-evm.nownodes.io/");
const result = await provider.send("eth_estimateGas", [
  {
    "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0x0",
    "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
  }
]);
console.log(result);

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

uri = URI('https://sys-evm.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
  "jsonrpc": "2.0",
  "method": "eth_estimateGas",
  "params": [
    {
      "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
      "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0x0",
      "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
    }
  ],
  "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://sys-evm.nownodes.io/"))
response = w3.provider.make_request("eth_estimateGas", [
  {
    "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0x0",
    "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
  }
])
print(response)

import { createPublicClient, http } from "viem";

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

const result = await client.request({
  method: "eth_estimateGas",
  params: [
  {
    "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0x0",
    "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
  }
],
});

console.log(result);

const endpoint = "https://sys-evm.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: "eth_estimateGas", params: [
  {
    "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
    "gas": "0x76c0",
    "gasPrice": "0x9184e72a000",
    "value": "0x0",
    "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
  }
], id: 1 });
console.log(result);

const response = await fetch('https://sys-evm.nownodes.io/', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "jsonrpc": "2.0",
      "method": "eth_estimateGas",
      "params": [
        {
          "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
          "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
          "gas": "0x76c0",
          "gasPrice": "0x9184e72a000",
          "value": "0x0",
          "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
        }
      ],
      "id": 1
    }),
});

const data = await response.json();

import requests

payload = {
  "jsonrpc": "2.0",
  "method": "eth_estimateGas",
  "params": [
    {
      "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
      "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0x0",
      "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
    }
  ],
  "id": 1
}

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

require 'net/http'
require 'json'

uri = URI('https://sys-evm.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "jsonrpc": "2.0",
    "method": "eth_estimateGas",
    "params": [
      {
        "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
        "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
        "gas": "0x76c0",
        "gasPrice": "0x9184e72a000",
        "value": "0x0",
        "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
      }
    ],
    "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": "eth_estimateGas",
  "params": [
    {
      "from": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
      "to": "0x6b175474e89094c44da98b954eedeac495271d0f",
      "gas": "0x76c0",
      "gasPrice": "0x9184e72a000",
      "value": "0x0",
      "data": "0x70a08231000000000000000000000000a0df350d2637096571f7a701cbc1c5fd"
    }
  ],
  "id": 1
}

200

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x5208"
}

Documentation

How to migrate to NOWNodes

Estimate Gas for Transaction

Authorizations

Body

Response