# API Specification Common Rules

### Protocol Rules 

The following specifies the rules for calling the API when accessing ReelPay

| Rule                       | Description                                                      |
| -------------------------- | ---------------------------------------------------------------- |
| Transfer Mode              | Use HTTPS for secure transactions.                               |
| Submit Mode                | POST, depends on the API.                                        |
| Data Format (content-type) | Data submitted and response are both in application/json format. |
| Char Encoding              | Use UTF-8 character encoding.                                    |
| Signature Algorithm        | Hmac-SHA-256                                                     |

### Request **Header**

| Name         | Type   | Description      |
| ------------ | ------ | ---------------- |
| X-Sign       | string | Signature        |
| X-Timestamp  | int    | Timestamp（sec）   |
| X-Appid      | string | Merchant APPID   |
| content-type | string | application/json |

[View error code](https://docs.reelpay.com/error-code)