curl -X POST https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions \
  -H "Authorization: Bearer $PAYVEN_TOKEN" \
  -H "Idempotency-Key: order-1001" \
  -d '{ ...payload... }'

const res = await fetch(
  "https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions",
  {
    method: "POST",
    headers: {
      Authorization: `Bearer ${accessToken}`,
      "Idempotency-Key": "order-1001",
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ /* payload */ }),
  },
);
const data = await res.json();

import httpx
res = httpx.post(
    "https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions",
    headers={
        "Authorization": f"Bearer {access_token}",
        "Idempotency-Key": "order-1001",
    },
    json={ ... },
)
data = res.json()

var req = new HttpRequestMessage(HttpMethod.Post, "https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions");
req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
req.Headers.Add("Idempotency-Key", "order-1001");
// Content = JsonContent.Create(payload);
var resp = await http.SendAsync(req);

req, _ := http.NewRequest("POST", "https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions", nil)
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("Idempotency-Key", "order-1001")
// req.Body = bytes.NewReader(payloadJSON)
resp, _ := http.DefaultClient.Do(req)

$ch = curl_init("https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions");
curl_setopt_array($ch, [
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer $accessToken",
    "Idempotency-Key: order-1001",
  ],
  CURLOPT_POSTFIELDS => json_encode(\$payload),
]);
$data = json_decode(curl_exec($ch), true);

HttpResponse<String> response = Unirest.post("https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"amount\": 15000,\n  \"currency\": \"TRY\",\n  \"merchant_name\": \"Acme Online\",\n  \"allowed_installments\": [\n    123\n  ],\n  \"description\": \"Sipariş ödemesi\",\n  \"external_id\": \"ORDER-1001\",\n  \"basket_id\": \"BASKET-2026-001\",\n  \"customer_email\": \"musteri@example.com\",\n  \"customer_phone\": \"<string>\",\n  \"metadata\": {},\n  \"allow_pre_auth\": true,\n  \"is_test_session\": true,\n  \"success_url\": \"<string>\",\n  \"cancel_url\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://vpos-sandbox.payven.com.tr/api/v1/checkout/sessions")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"amount\": 15000,\n  \"currency\": \"TRY\",\n  \"merchant_name\": \"Acme Online\",\n  \"allowed_installments\": [\n    123\n  ],\n  \"description\": \"Sipariş ödemesi\",\n  \"external_id\": \"ORDER-1001\",\n  \"basket_id\": \"BASKET-2026-001\",\n  \"customer_email\": \"musteri@example.com\",\n  \"customer_phone\": \"<string>\",\n  \"metadata\": {},\n  \"allow_pre_auth\": true,\n  \"is_test_session\": true,\n  \"success_url\": \"<string>\",\n  \"cancel_url\": \"<string>\"\n}"

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

{
  "session_id": "<string>",
  "checkout_url": "<string>",
  "expires_at": "2023-11-07T05:31:56Z"
}

{
  "type": "https://docs.payven.com.tr/errors/bad_request",
  "title": "Geçersiz istek",
  "status": 400,
  "code": "bad_request",
  "detail": "amount.amount alanı zorunlu.",
  "correlation_id": "9f1c8e76-2a3b-4f12-9c8d-12cb24a8a8a8"
}

{
  "type": "https://docs.payven.com.tr/errors/invalid_token",
  "title": "Geçersiz token",
  "status": 401,
  "code": "invalid_token",
  "detail": "Access token geçersiz veya süresi dolmuş — refresh edin."
}

{
  "type": "https://docs.payven.com.tr/errors/forbidden",
  "title": "Yetki yok",
  "status": 403,
  "code": "forbidden",
  "detail": "Bu rol bu kaynağı göremez."
}

{
  "type": "https://docs.payven.com.tr/errors/idempotency_key_in_use",
  "title": "Idempotency-Key çakışması",
  "status": 409,
  "code": "idempotency_key_in_use",
  "detail": "Bu Idempotency-Key daha önce farklı bir istek gövdesi ile kullanıldı."
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>"
}

{
  "type": "https://docs.payven.com.tr/errors/rate_limit_exceeded",
  "title": "İstek limiti aşıldı",
  "status": 429,
  "code": "rate_limit_exceeded"
}

{
  "type": "https://docs.payven.com.tr/errors/internal_server_error",
  "title": "Sunucu hatası",
  "status": 500,
  "code": "internal_server_error"
}

{
  "type": "https://docs.payven.com.tr/errors/connector_unavailable",
  "title": "Konnektör erişilemez",
  "status": 503,
  "code": "connector_unavailable"
}