curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/message \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "message": "I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.",
  "metadata": "OPTIONAL_METADATA",
  "note": "OPTIONAL_NOTE"
}
'

import requests

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

payload = {
    "message": "I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.",
    "metadata": "OPTIONAL_METADATA",
    "note": "OPTIONAL_NOTE"
}
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({
    message: 'I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.',
    metadata: 'OPTIONAL_METADATA',
    note: 'OPTIONAL_NOTE'
  })
};

fetch('https://api.blockradar.co/v1/wallets/{id}/addresses/{addressId}/signing/message', 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/message",
  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([
    'message' => 'I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.',
    'metadata' => 'OPTIONAL_METADATA',
    'note' => 'OPTIONAL_NOTE'
  ]),
  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/message"

	payload := strings.NewReader("{\n  \"message\": \"I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.\",\n  \"metadata\": \"OPTIONAL_METADATA\",\n  \"note\": \"OPTIONAL_NOTE\"\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/message")
  .header("x-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"message\": \"I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.\",\n  \"metadata\": \"OPTIONAL_METADATA\",\n  \"note\": \"OPTIONAL_NOTE\"\n}")
  .asString();

require 'uri'
require 'net/http'

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

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  \"message\": \"I am verifying ownership of the wallet address 0x... as customer cust_123. This message was signed on 2026-03-03 to confirm my control over this wallet.\",\n  \"metadata\": \"OPTIONAL_METADATA\",\n  \"note\": \"OPTIONAL_NOTE\"\n}"

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