1. Protocol Rules

Transmission Method: Use HTTP transmission (HTTPS recommended for production environments)

Submission Method: Use POST/GET submission

Content Type: application/x-www-form-urlencoded

Character Encoding: UTF-8

Signature Algorithm: MD5

1.1 Parameter Specifications

Transaction Amount: Unit is cents, parameter value cannot contain decimals.

1.2 Security Specifications

Signature Algorithm

General steps for signature generation are as follows

Step 1: Set all sent or received data as set M, sort the non-empty parameter values in set M by parameter name in ascending ASCII order (dictionary order), and concatenate them into stringA using URL key-value pair format (i.e., key1=value1&key2=value2…).

Pay special attention to the following important rules:

◆ Sort parameter names by ascending ASCII code (dictionary order);

◆ If the parameter value is empty, it does not participate in the signature;

◆ Parameter names are case-sensitive;

◆ When verifying the signature of the call return or payment center active notification, the transmitted sign parameter does not participate in the signature, and the generated signature is compared with this sign value for verification.

◆ The payment center interface may add fields, and signature verification must support added extension fields

Step 2: Append the key to the end of stringA[i.e., StringA + "&key=" + private key] to obtain the stringSignTemp string, perform MD5 operation on stringSignTemp, and convert all characters in the obtained string to uppercase to obtain the sign value signValue.

For example, the request payment system parameters are as follows (the following is just an example, in real signature, all fields except sign participate in signing):

    Map signMap = new HashMap<>();
    signMap.put("userId", "test01");
    signMap.put("type", "wechat");
    signMap.put("money", Double.valueOf(2));
    signMap.put("remark", "");
    signMap.put("outTradeNo", "P12312321123");

Value to be signed: money=2.0&outTradeNo=P12312321123&type=wechat&userId=test01&key=EWEFD123RGSRETYDFNGFGFGSHDFGH

Signature result: 5E0AA05DD4BB4FE5AB65608123EBA591

Final request payment system parameters: money=2.0&outTradeNo=P12312321123&type=wechat&userId=test01&sign=5E0AA05DD4BB4FE5AB65608123EBA591

> After logging into the merchant system, merchants can view or modify the private key through the security center.

2. Unified Order Placement

> Interface Description

Business can initiate payment orders for any third-party payment channels through the unified order placement interface. The business system does not need to worry about how to call third-party payments. The unified order placement interface will select the corresponding payment product based on the payment channel ID selected by the business system, initiate the order request, and then respond to the business system with the parameters required for the payment request.

> Interface Link

URL Address: {payUrl}/pay/create_order

> Request Parameters

> Response Result

The following fields are returned when retCode=0

> Response Data Example

URL method response data:

json
{
"payJumpUrl": "http://170.33.8.116:8182/payurl?mchOrderId=Pnull202011171714049724732&amount=686.00",
"payMethod": "formJump",
"payUrl": "<script>window.location.href = http://170.33.8.116:8182/payurl?mchOrderId=Pnull202011171714049724732&amount=686.00</script>",
"retCode": "0",
"sign": "3251661E4B84AAB6BAA1A6A025F40036"
}


APP payment response data:

{
    "payMethod": "alipayApp",
    "payParams": {
        "appStr": "trade_no=2020111704200341411064884895&biz_sub_type=peerpay_trade&presessionid=&app=tb&channel=&type2=gulupay&bizcontext={\"biz_type\":\"share_pp_pay\",\"type\":\"qogirpay\"}"
    },
    "retCode": "0",
    "sign": "6734227C78A110D7F9BF94BB9A217D3E"
}

3. Query Payment Order

> Interface Description

The business system obtains the latest payment order status through the query payment order interface and further processes the business logic based on the status result.

> Interface Link

URL Address: {payUrl}/pay/query_order

> Request Parameters

> Response Result

The following fields are returned when retCode=0

4. Payment Result Notification

> Interface Description

When the order payment is successful, the payment center will initiate a callback to the merchant's notifyUrl address to notify the order status.

> Interface Link

This link is set by the notifyUrl parameter submitted through the unified order placement interface. If the link cannot be accessed, the business system will not be able to receive notifications from the payment center.

> Notification Parameters

> Notification Example

POST: https://baidu.com/notifyUrl?income=10000000&payOrderId=P01202506170702572280020&amount=10000000&mchId=20000000&productId=8033&mchOrderNo=R571455762354668632&paySuccTime=1750143794000&sign=1EF29AF878ED5C163AFB0372773A00C7&channelOrderNo=&backType=2&reqTime=20250617070314¶m1=¶m2=&appId=7ca36fb15e8943b79d098ce8a36aec0a&status=2

> Return Result

After the business system processes, it synchronously returns to the payment center. Returning the string "success" indicates success. Returning non-success indicates processing failure, and the payment center will notify the business system again. (Notification frequency is 60/120/180/240/300, unit: seconds)

Note: The returned string must be lowercase and cannot have spaces before or after.

5. Payment Products

6. Error Codes