# APIs and SDKs

> This section introduces the APIs ande SDKs that are used in Cashier Payment.

This section introduces the APIs and SDKs that are provided in Alipay+ Cashier Payment.

## APIs

The following table lists the APIs in terms of category, endpoint, and calling direction. You can click the interface name to see the detailed specification of each API.

| **I****nterface name** | **Endpoint** | **Direction** |
| --- | --- | --- |
| [userInitiatedPay](../api_mpp/pay_private_order_code) | /aps/api/v1/payments/userInitiatedPay | MPP->Alipay+ |
| (Optional) [inquiryCodeRules](../api_mpp/inquiry_code_rules) | /aps/api/v1/payments/inquiryCodeRules | MPP->Alipay+ |
| [notifyPayment](../api_mpp/notify_payment) | /aps/api/v1/payments/notifyPayment | MPP->Alipay+ |
| [inquiryPayment](../api_mpp/inquiry_payment) | N/A | Alipay+->MPP |
| [cancelPayment](../api_mpp/cancel_payment) | N/A | Alipay+->MPP |
| [refund](../api_mpp/refund) | N/A | Alipay+->MPP |

## SDK

The following tables list the interfaces that are provided by the Alipay+ server SDK. You can click the interface name to see the detailed specification of each interface.

| **Interface name** | **Description** | **Direction** |
| --- | --- | --- |
| [ailpayconnect.code.CodeIdentificationService.init](../sdk_mpp/init) | Used to initialize the Alipay+ server SDK. | MPP server -> Alipay+ server SDK |
| [ailpayconnect.code.CodeIdentificationService.identifyCode](../sdk_mpp/identify_code) | Used to identify whether the code can be processed by Alipay+. | MPP server -> Alipay+ server SDK |

> **Note**: Only if the user scans the order code for payment, you need to integrate the Alipay+ server SDK.