simulate

POST

https://xrp.nownodes.io/

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Simulates a transaction without actually submitting it to the network. This method allows you to test transaction outcomes, check for errors, and see the exact ledger changes that would occur if the transaction were executed. The simulation runs against the current working ledger state.

Body

application/json

JSON-RPC request payload.

methodstringsimulaterequired

JSON-RPC method name. Must be "simulate" for transaction simulation.

paramsArray<object>required

Array containing transaction simulation parameters. Must contain exactly one object.

Show child attributes

tx_jsonobjectrequired

Transaction object to simulate. Contains all transaction fields except signatures.

Show child attributes

TransactionTypestringPaymentTrustSetOfferCreateOfferCancelPaymentChannelCreatePaymentChannelClaimPaymentChannelFundCheckCreateCheckCashCheckCancelEscrowCreateEscrowFinishEscrowCancelAccountSetSetRegularKeySignerListSetTicketCreateDepositPreauthrequired

Type of transaction to execute. For payment simulation, must be "Payment".

Accountstringrequired

XRP Ledger address of the transaction sender (source account). Must be a valid XRP address starting with 'r'.

Destinationstringrequired

XRP Ledger address of the transaction recipient. Must be a valid XRP address starting with 'r'.

Amountobjectrequired

Amount of issued currency (IOU) to send. Required for non-XRP payments.

Show child attributes

currencystringrequired

Three-letter ISO 4217 currency code or 160-bit hex string for custom currencies. For USD, use "USD".

valuestringrequired

Amount of currency to send as a decimal string. Can include decimal point.

issuerstringrequired

XRP Ledger address of the currency issuer. Must be a valid XRP address.

Feestring

Transaction fee in drops. Automatically calculated if omitted. For simulation, can be omitted or estimated.

Sequenceinteger>= 1

Transaction sequence number. Must be one greater than the sender's current sequence number. If omitted, uses next available sequence.

LastLedgerSequenceinteger>= 1

Highest ledger index in which the transaction can be validated. Provides transaction expiration. Recommended for reliable simulation.

Flagsinteger

Bitwise flags for transaction options. 2147483648 (0x80000000) indicates fully canonical signature.

SigningPubKeystring

Public key used to verify the transaction signature. Can be empty string for simulation.

TxnSignaturestring

Transaction signature. Can be empty string for simulation.

Response

200OK

HTTP 200 response for simulate. The body contains either a successful result or a method-level JSON-RPC error.

400Bad Request

Bad Request. The request body is malformed or contains invalid JSON-RPC parameters.

401Unauthorized

Unauthorized: API key is present but rejected by the NOWNodes gateway.

405Method Not Allowed

Method Not Allowed. Returned by the NOWNodes gateway for malformed or unsupported gateway-level requests.

422Unprocessable Entity

Missing API key. The NOWNodes gateway returns plain text for this error.

500Internal Server Error

Internal Server Error. The gateway or node failed while processing the request.

simulate

curl -X POST 'https://xrp.nownodes.io/' \
  -H 'Content-Type: application/json' \
  -d '{
    "method": "simulate",
    "params": [
      {
        "tx_json": {
          "TransactionType": "Payment",
          "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
          "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
          "Amount": {
            "currency": "USD",
            "value": "1",
            "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
          }
        }
      }
    ]
  }'

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://xrp.nownodes.io/");
const result = await provider.send("simulate", [
  {
    "tx_json": {
      "TransactionType": "Payment",
      "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
      "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
      "Amount": {
        "currency": "USD",
        "value": "1",
        "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
      }
    }
  }
]);
console.log(result);

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

uri = URI('https://xrp.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
  "jsonrpc": "2.0",
  "method": "simulate",
  "params": [
    {
      "tx_json": {
        "TransactionType": "Payment",
        "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
        "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
        "Amount": {
          "currency": "USD",
          "value": "1",
          "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
        }
      }
    }
  ],
  "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://xrp.nownodes.io/"))
response = w3.provider.make_request("simulate", [
  {
    "tx_json": {
      "TransactionType": "Payment",
      "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
      "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
      "Amount": {
        "currency": "USD",
        "value": "1",
        "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
      }
    }
  }
])
print(response)

import { createPublicClient, http } from "viem";

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

const result = await client.request({
  method: "simulate",
  params: [
  {
    "tx_json": {
      "TransactionType": "Payment",
      "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
      "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
      "Amount": {
        "currency": "USD",
        "value": "1",
        "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
      }
    }
  }
],
});

console.log(result);

const endpoint = "https://xrp.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: "simulate", params: [
  {
    "tx_json": {
      "TransactionType": "Payment",
      "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
      "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
      "Amount": {
        "currency": "USD",
        "value": "1",
        "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
      }
    }
  }
], id: 1 });
console.log(result);

const response = await fetch('https://xrp.nownodes.io/', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "method": "simulate",
      "params": [
        {
          "tx_json": {
            "TransactionType": "Payment",
            "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
            "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
            "Amount": {
              "currency": "USD",
              "value": "1",
              "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
            }
          }
        }
      ]
    }),
});

const data = await response.json();

import requests

payload = {
  "method": "simulate",
  "params": [
    {
      "tx_json": {
        "TransactionType": "Payment",
        "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
        "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
        "Amount": {
          "currency": "USD",
          "value": "1",
          "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
        }
      }
    }
  ]
}

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

require 'net/http'
require 'json'

uri = URI('https://xrp.nownodes.io/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "method": "simulate",
    "params": [
      {
        "tx_json": {
          "TransactionType": "Payment",
          "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
          "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
          "Amount": {
            "currency": "USD",
            "value": "1",
            "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
          }
        }
      }
    ]
  }'

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

Request Body

{
  "method": "simulate",
  "params": [
    {
      "tx_json": {
        "TransactionType": "Payment",
        "Account": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn",
        "Destination": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
        "Amount": {
          "currency": "USD",
          "value": "1",
          "issuer": "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
        }
      }
    }
  ]
}

{
  "result": {
    "ledger_index": 105281656,
    "status": "success",
    "validated": true
  }
}

{
  "result": {
    "error": "invalidParams",
    "error_code": 31,
    "error_message": "Invalid parameters.",
    "request": {
      "method": "simulate",
      "params": [
        {}
      ]
    },
    "status": "error"
  }
}

{
  "code": 400,
  "message": "Bad Request"
}

Unknown API_key

Method Not Allowed

Missing API_key

{
  "code": 500,
  "message": "Internal Server Error"
}

Documentation

How to migrate to NOWNodes

simulate

Authorizations

Body

Response