curl --request POST \
  --url https://api.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/transaction \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-Wallet-Auth: <x-wallet-auth>' \
  --data '
{
  "transaction": "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA="
}
'

import requests

url = "https://api.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/transaction"

payload = { "transaction": "AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA=" }
headers = {
    "X-Wallet-Auth": "<x-wallet-auth>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'X-Wallet-Auth': '<x-wallet-auth>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    transaction: 'AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA='
  })
};

fetch('https://api.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/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.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/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' => 'AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA='
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json",
    "X-Wallet-Auth: <x-wallet-auth>"
  ],
]);

$response = curl_exec($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.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/transaction"

	payload := strings.NewReader("{\n  \"transaction\": \"AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA=\"\n}")

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

	req.Header.Add("X-Wallet-Auth", "<x-wallet-auth>")
	req.Header.Add("Authorization", "Bearer <token>")
	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.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/transaction")
  .header("X-Wallet-Auth", "<x-wallet-auth>")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"transaction\": \"AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA=\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.cdp.coinbase.com/platform/v2/solana/accounts/{address}/sign/transaction")

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

request = Net::HTTP::Post.new(url)
request["X-Wallet-Auth"] = '<x-wallet-auth>'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"transaction\": \"AQABAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA=\"\n}"

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

{
  "signedTransaction": "AQACAdSOvpk0UJXs/rQRXYKSI9hcR0bkGp24qGv6t0/M1XjcQpHf6AHwLcPjEtKQI7p/U0Zo98lnJ5/PZMfVq/0BAgIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAQABAQECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8CBgMBAQAAAAIBAwQAAAAABgIAAAAAAAYDBQEBAAAGBAgAAAAABgUAAAAA6AMAAAAAAAAGBgUBAQEBBgcEAQAAAAYICgMBAQIDBgkCBgAAAAYKAwABAQEGCwMGAQEBBgwDAAABAQAAAAA="
}

{
  "errorType": "malformed_transaction",
  "errorMessage": "Malformed unsigned transaction."
}

{
  "errorType": "unauthorized",
  "errorMessage": "Wallet authentication error."
}

{
  "errorType": "payment_method_required",
  "errorMessage": "A valid payment method is required to complete this operation. Please add a payment method to your account at https://portal.cdp.coinbase.com."
}

{
  "errorType": "forbidden",
  "errorMessage": "Unable to sign transaction for this address."
}

{
  "errorType": "not_found",
  "errorMessage": "Solana account with the given address not found."
}

{
  "errorType": "already_exists",
  "errorMessage": "Another request with the same idempotency key is currently processing."
}

{
  "errorType": "idempotency_error",
  "errorMessage": "Idempotency key '8e03978e-40d5-43e8-bc93-6894a57f9324' was already used with a different request payload. Please try again with a new idempotency key."
}

{
  "errorType": "internal_server_error",
  "errorMessage": "An internal server error occurred. Please try again later."
}

{
  "errorType": "bad_gateway",
  "errorMessage": "Bad gateway. Please try again later."
}

{
  "errorType": "service_unavailable",
  "errorMessage": "Service unavailable. Please try again later."
}