Simulate transaction

POST

https://stacks.nownodes.io/v3/transactions/simulate

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Simulates a single fully signed Stacks transaction on top of a chain tip without committing any state changes.

By default, the transaction is simulated on top of the canonical chain tip. A specific chain tip can be selected using the tip query parameter.

The response includes the transaction execution result, generated events, execution cost, execution limit, and information about post-condition or VM errors.

The supplied transaction must be fully signed and valid.

Body

application/json

Fully signed SIP-005 encoded Stacks transaction represented as a hexadecimal string.

transaction_hexstringrequired

SIP-005 encoded transaction in hexadecimal format.

Parameters

tipstringquery

The chain tip on top of which the transaction should be simulated. If omitted, the canonical chain tip is used.

Response

200OK

Result of the simulated transaction

400Bad Request

Invalid request, invalid transaction, or a chain tip that cannot be used for transaction simulation.

401Unauthorized

Unauthorized.

404Not Found

Chain tip not found.

500Internal Server Error

Internal server error.

Simulate transaction

curl -X POST 'https://stacks.nownodes.io/v3/transactions/simulate' \
  -H 'Content-Type: application/json' \
  -d '{
    "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
  }'

const response = await fetch('https://stacks.nownodes.io/v3/transactions/simulate', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
    }),
});

const data = await response.json();

require 'net/http'
require 'json'

uri = URI('https://stacks.nownodes.io/v3/transactions/simulate')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
  }'

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

import requests

payload = {
  "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
}

response = requests.post('https://stacks.nownodes.io/v3/transactions/simulate', json=payload)
data = response.json()

const response = await fetch('https://stacks.nownodes.io/v3/transactions/simulate', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
    }),
});

const data = await response.json();

const endpoint = "https://stacks.nownodes.io/v3/transactions/simulate";
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({
    "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
  });
console.log(result);

const response = await fetch('https://stacks.nownodes.io/v3/transactions/simulate', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
      "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
    }),
});

const data = await response.json();

import requests

payload = {
  "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
}

response = requests.post('https://stacks.nownodes.io/v3/transactions/simulate', json=payload)
data = response.json()

require 'net/http'
require 'json'

uri = URI('https://stacks.nownodes.io/v3/transactions/simulate')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request.body = '{
    "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
  }'

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

Request Body

{
  "transaction_hex": "00000000010400f2bba6df751755ab9ac1df8b387d981cfe265cdf000000000020499f00000000000000b400018588430962cdc46929f7474d9bb1ba00cc61874fd8a2a1a60273bf3c4519de852632e0dbc5931509af496229124de6e45db31071b58a3726cfbf7b57850fd8b7030200000000000516fbd9a1702f4ecc44fc01f1894c72fcbb23a53ce8000000000000000100000000000000000000000000000000000000000000000000000000000000000000"
}

200

{
  "txid": "7b8f96e51642c17a7a72abfd05d9676a9e3563dabfbc58e03f8fcd9c04d652b1",
  "tip_block_id": "7b1e28707ab10c8bc3db1175ac14bfe9c135a9dd60ca1aba16a67194859c629e",
  "consensus_hash": "f4c00cf43d237042a08c226164f10595ec10cc48",
  "block_height": 8931185,
  "result_hex": "0x0703",
  "stx_burned": 0,
  "execution_cost": {
    "read_count": 1,
    "read_length": 1,
    "runtime": 1,
    "write_count": 0,
    "write_length": 0
  },
  "execution_limit": {
    "read_count": 15000,
    "read_length": 100000000,
    "runtime": 5000000000,
    "write_count": 15000,
    "write_length": 15000000
  },
  "events": [],
  "post_condition_aborted": false,
  "vm_error": null
}

Documentation

How to migrate to NOWNodes

Simulate transaction

Authorizations

Body

Parameters

Response