curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "transaction": "{\"to\":\"0x000000000000000000000000000000000000dEaD\",\"value\":\"0x5af3107a4000\",\"nonce\":4,\"chainId\":11155111,\"gasLimit\":\"0x5208\",\"maxFeePerGas\":\"0x59682f00\",\"maxPriorityFeePerGas\":\"0x3b9aca00\",\"type\":2}",
  "reference": "eth-child-transfer-001",
  "metadata": {
    "source": "custom"
  }
}
'

import requests

url = "https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction"

payload = {
    "transaction": "{\"to\":\"0x000000000000000000000000000000000000dEaD\",\"value\":\"0x5af3107a4000\",\"nonce\":4,\"chainId\":11155111,\"gasLimit\":\"0x5208\",\"maxFeePerGas\":\"0x59682f00\",\"maxPriorityFeePerGas\":\"0x3b9aca00\",\"type\":2}",
    "reference": "eth-child-transfer-001",
    "metadata": { "source": "custom" }
}
headers = {
    "x-api-key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    transaction: '{"to":"0x000000000000000000000000000000000000dEaD","value":"0x5af3107a4000","nonce":4,"chainId":11155111,"gasLimit":"0x5208","maxFeePerGas":"0x59682f00","maxPriorityFeePerGas":"0x3b9aca00","type":2}',
    reference: 'eth-child-transfer-001',
    metadata: {source: 'custom'}
  })
};

fetch('https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'transaction' => '{"to":"0x000000000000000000000000000000000000dEaD","value":"0x5af3107a4000","nonce":4,"chainId":11155111,"gasLimit":"0x5208","maxFeePerGas":"0x59682f00","maxPriorityFeePerGas":"0x3b9aca00","type":2}',
    'reference' => 'eth-child-transfer-001',
    'metadata' => [
        'source' => 'custom'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "x-api-key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction"

	payload := strings.NewReader("{\n  \"transaction\": \"{\\\"to\\\":\\\"0x000000000000000000000000000000000000dEaD\\\",\\\"value\\\":\\\"0x5af3107a4000\\\",\\\"nonce\\\":4,\\\"chainId\\\":11155111,\\\"gasLimit\\\":\\\"0x5208\\\",\\\"maxFeePerGas\\\":\\\"0x59682f00\\\",\\\"maxPriorityFeePerGas\\\":\\\"0x3b9aca00\\\",\\\"type\\\":2}\",\n  \"reference\": \"eth-child-transfer-001\",\n  \"metadata\": {\n    \"source\": \"custom\"\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("x-api-key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction")
  .header("x-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"transaction\": \"{\\\"to\\\":\\\"0x000000000000000000000000000000000000dEaD\\\",\\\"value\\\":\\\"0x5af3107a4000\\\",\\\"nonce\\\":4,\\\"chainId\\\":11155111,\\\"gasLimit\\\":\\\"0x5208\\\",\\\"maxFeePerGas\\\":\\\"0x59682f00\\\",\\\"maxPriorityFeePerGas\\\":\\\"0x3b9aca00\\\",\\\"type\\\":2}\",\n  \"reference\": \"eth-child-transfer-001\",\n  \"metadata\": {\n    \"source\": \"custom\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/transaction")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"transaction\": \"{\\\"to\\\":\\\"0x000000000000000000000000000000000000dEaD\\\",\\\"value\\\":\\\"0x5af3107a4000\\\",\\\"nonce\\\":4,\\\"chainId\\\":11155111,\\\"gasLimit\\\":\\\"0x5208\\\",\\\"maxFeePerGas\\\":\\\"0x59682f00\\\",\\\"maxPriorityFeePerGas\\\":\\\"0x3b9aca00\\\",\\\"type\\\":2}\",\n  \"reference\": \"eth-child-transfer-001\",\n  \"metadata\": {\n    \"source\": \"custom\"\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "statusCode": 200,
  "message": "Transaction signed successfully",
  "data": {
    "id": "02f404a5-d13e-4bcf-8ad5-c5f51c04fa49",
    "reference": "eth-child-transfer-001",
    "senderAddress": "0x82888b11790ddC1946e1AA650E0127b2E9023233",
    "recipientAddress": "0x82888b11790ddC1946e1AA650E0127b2E9023233",
    "hash": "0xac4c73ca084608ac6b981e54db948dc80c15b4ea3ffd0c9f5781f3af7ad6fe51",
    "confirmed": true,
    "status": "SUCCESS",
    "type": "SIGNED",
    "createdChannel": "api",
    "reason": "Transaction signed",
    "network": "testnet",
    "chainId": 11155111,
    "metadata": null,
    "signedTransaction": "0x02f87383aa36a763843b9aca008459682f0082520894000000000000000000000000000000000000dead865af3107a400080c080a0b760...",
    "amount": null,
    "amountUSD": "0.00",
    "fee": null,
    "feeUSD": null,
    "currency": "USD",
    "createdAt": "2026-03-19T13:34:24.937Z",
    "updatedAt": "2026-03-19T13:34:24.937Z",
    "wallet": {
      "id": "3f9aca5c-38ee-4e1d-ab67-c084a2e37bb2",
      "name": "Ethereum Wallet",
      "address": "0xC887a3Cb8E7AbA4A77D7275AD4B242f71cbd5446",
      "isActive": true,
      "status": "ACTIVE",
      "network": "testnet"
    },
    "asset": null,
    "blockchain": {
      "id": "85ffc132-3972-4c9e-99a5-5cf0ccb688bf",
      "name": "ethereum",
      "symbol": "eth",
      "slug": "ethereum",
      "isEvmCompatible": true,
      "tokenStandard": "ERC20"
    },
    "beneficiary": null
  }
}

{
  "statusCode": 400,
  "message": "Invalid transaction format: expected a JSON string"
}