Check transaction validity

POST

https://band.nownodes.io/

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Validate a transaction without adding it to the mempool. Returns transaction check results including gas usage and validation errors.

Body

application/json

jsonrpcstring2.0required

JSON-RPC version identifier

idinteger | stringrequired

Request identifier for matching responses

methodstringcheck_txrequired

The JSON-RPC method name for transaction validation

paramsobjectrequired

Show child attributes

txstringrequired

Hexadecimal encoded transaction data to validate

Response

200OK

Transaction validation result

Check transaction validity

curl -X POST 'https://band.nownodes.io/' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "check_tx",
    "params": {
      "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
    }
  }'

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://band.nownodes.io/");
const result = await provider.send("check_tx", {
  "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
});
console.log(result);

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

uri = URI('https://band.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
  "jsonrpc": "2.0",
  "method": "check_tx",
  "params": {
    "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
  },
  "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://band.nownodes.io/"))
response = w3.provider.make_request("check_tx", {
  "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
})
print(response)

import { createPublicClient, http } from "viem";

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

const result = await client.request({
  method: "check_tx",
  params: {
  "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
},
});

console.log(result);

const endpoint = "https://band.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: "check_tx", params: {
  "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
}, id: 1 });
console.log(result);

const response = await fetch('https://band.nownodes.io/', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "jsonrpc": "2.0",
      "id": 1,
      "method": "check_tx",
      "params": {
        "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
      }
    }),
});

const data = await response.json();

import requests

payload = {
  "jsonrpc": "2.0",
  "id": 1,
  "method": "check_tx",
  "params": {
    "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
  }
}

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

require 'net/http'
require 'json'

uri = URI('https://band.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "check_tx",
    "params": {
      "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
    }
  }'

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",
  "id": 1,
  "method": "check_tx",
  "params": {
    "tx": "1DA4FE365E3665BC74DEFA6918B9DBE5376CB95D2DB94AEA6D9675F72923B868"
  }
}

200

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "code": 2,
    "data": null,
    "log": "expected 2 wire type, got 4: tx parse error",
    "info": "",
    "gas_wanted": "0",
    "gas_used": "19809",
    "events": [],
    "codespace": "sdk",
    "sender": "",
    "priority": "0",
    "mempoolError": ""
  }
}

Documentation

How to migrate to NOWNodes

Check transaction validity

Authorizations

Body

Response