Broadcast a raw transaction using the request body.

POST

https://arb-blockbook.nownodes.io/api/v2/sendtx

Authorizations

ApiKeyAuthApiKeyAuth

api-key string

NOWNodes API key passed in the api-key header.

Modified between 0.5.0 and 0.6.0: POST body size limited to 8 MiB; alternative broadcast provider support server-side; per-client rate limiting. Documented as it exists in 0.6.0.

Broadcasts hex-encoded raw transaction data from the request body. The trailing slash is mandatory in the Blockbook handler. POST bodies are limited to 8 MiB.

Load estimate: High; validates and forwards to the backend, with cost growing with transaction size and backend mempool policy checks.

Body

text/plain

string

Response

200OK

HTTP 200 Arbitrum Blockbook response for sendTransactionByPost.

400Bad Request

Domain or validation error. JSON body {"error": "..."}.

401Unauthorized

Unauthorized: missing or invalid api-key header. The NOWNodes gateway returns the plain-text body "Unknown API_key".

405Method Not Allowed

Method Not Allowed: gateway-level response for unknown routes.

500Internal Server Error

Internal Server Error. JSON body {"error":"Internal server error"}.

Broadcast a raw transaction using the request body.

curl -X POST 'https://arb-blockbook.nownodes.io/api/v2/sendtx/' \
  -H 'Content-Type: text/plain' \
  -d '"02000000000101662a..."'

const response = await fetch('https://arb-blockbook.nownodes.io/api/v2/sendtx/', {
  method: 'POST',
  headers: {
    'Content-Type': 'text/plain',
  },
  body: JSON.stringify("02000000000101662a..."),
});

const data = await response.json();

require 'net/http'
require 'json'

uri = URI('https://arb-blockbook.nownodes.io/api/v2/sendtx/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'text/plain'
request.body = '"02000000000101662a..."'

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

import requests

payload = "02000000000101662a..."

response = requests.post('https://arb-blockbook.nownodes.io/api/v2/sendtx/', json=payload)
data = response.json()

const response = await fetch('https://arb-blockbook.nownodes.io/api/v2/sendtx/', {
  method: 'POST',
  headers: {
    'Content-Type': 'text/plain',
  },
  body: JSON.stringify("02000000000101662a..."),
});

const data = await response.json();

const endpoint = "https://arb-blockbook.nownodes.io/api/v2/sendtx/";
const apiKey = "YOUR_API_KEY";

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

  return response.json();
}

const result = await nownodesRequest("02000000000101662a...");
console.log(result);

const response = await fetch('https://arb-blockbook.nownodes.io/api/v2/sendtx/', {
  method: 'POST',
  headers: {
    'Content-Type': 'text/plain',
  },
  body: JSON.stringify("02000000000101662a..."),
});

const data = await response.json();

import requests

payload = "02000000000101662a..."

response = requests.post('https://arb-blockbook.nownodes.io/api/v2/sendtx/', json=payload)
data = response.json()

require 'net/http'
require 'json'

uri = URI('https://arb-blockbook.nownodes.io/api/v2/sendtx/')
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'text/plain'
request.body = '"02000000000101662a..."'

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

Request Body

02000000000101662a...

{
  "result": "7c3be24063f268aaa1ed81b64776798f56088757641a34fb156c4f51ed2e9d25"
}

{
  "error": "Invalid transaction hex"
}

{
  "error": "Invalid transaction hex"
}

Unknown API_key

Method Not Allowed

{
  "error": "Internal server error"
}