> For the complete documentation index, see [llms.txt](https://docs.iexexchanger.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.iexexchanger.com/get-started/exchanger-api/kak-ustroen-api/envelopes-and-headers.md).

# Формат запросов, ответов и headers

Большинство endpoints возвращает JSON в едином формате.

## Успешный ответ

```json
{
  "state": 0,
  "message": "OK",
  "result": {
    "id": 25
  },
  "meta": {
    "request_id": "req_01J...",
    "correlation_id": "cor_01J...",
    "timestamp": "2026-06-23T10:00:00+00:00"
  }
}
```

| Поле                  | Значение                              |
| --------------------- | ------------------------------------- |
| `state`               | `0` значит успех.                     |
| `message`             | Короткое сообщение.                   |
| `result`              | Основные данные ответа.               |
| `meta.request_id`     | ID запроса для обращения в поддержку. |
| `meta.correlation_id` | ID цепочки связанных запросов.        |

## Ответ с ошибкой

```json
{
  "state": 1,
  "message": "Validation failed",
  "result": null,
  "error": {
    "code": "validation_error",
    "details": {
      "amount": ["The amount field is required."]
    }
  },
  "meta": {
    "request_id": "req_01J...",
    "correlation_id": "cor_01J...",
    "timestamp": "2026-06-23T10:00:00+00:00"
  }
}
```

| Поле            | Значение                    |
| --------------- | --------------------------- |
| `state`         | `1` значит ошибка.          |
| `error.code`    | Машинный код ошибки.        |
| `error.details` | Детали, часто ошибки полей. |

## Headers для JSON-запроса

```http
Accept: application/json
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
```

`Content-Type` нужен для запросов с body: `POST`, `PUT`, `PATCH`.

## Headers для HMAC

```http
X-Api-Timestamp: 1782190000
X-Api-Nonce: req-20260623-001
X-Api-Signature: sha256=...
```

## Headers для защиты от дублей

```http
Idempotency-Key: create-order-user-42-001
```

## Полезные headers ответа

| Header                  | Что означает                                   |
| ----------------------- | ---------------------------------------------- |
| `X-Request-Id`          | ID запроса для обращения в поддержку.          |
| `X-Correlation-Id`      | ID цепочки запросов.                           |
| `X-RateLimit-Limit`     | Лимит запросов в текущем окне.                 |
| `X-RateLimit-Remaining` | Сколько осталось запросов.                     |
| `Retry-After`           | Сколько ждать после `429`.                     |
| `Idempotency-Replayed`  | Ответ взят из сохраненного idempotency-result. |

## Исключение: XML

`GET /public/rates.xml` возвращает XML, а не JSON envelope.


---

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