# 4. Purchase interface

## 

| Interface Name | Test URL                               | Production URL                     |
| -------------- | -------------------------------------- | ---------------------------------- |
| Purchase       | <https://mchapi.allpayx.com/testjspay> | <https://mchapi.allpayx.com/jspay> |

Merchant could use purchase interface to initiate a transaction, send transaction information to payment channels through AllPay gateway. 



| Parameter     | Type         | Required | Description                                                  |
| ------------- | ------------ | -------- | ------------------------------------------------------------ |
| version       | String(12)   | M        | "VER000000002"                                               |
| charSet       | String(6)    | M        | “UTF-8”                                                      |
| transType     | String(4)    | M        | “PURC”                                                       |
| orderNum      | String(60)   | M        | Order number: it is defined by the merchant itself, and the order number must not be repeated for the same merchant number |
| orderAmount   | String(12)   | M        | Order amount: if 100 yuan, it will be 100 or 100.00          |
| orderCurrency | String(3)    | M        | Currency of the order: ISO standard, such as RMB filling in "CNY", us dollar filling in "USD" |
| frontURL      | String(400)  | M        | When the payment is complete, jump to the address            |
| backURL       | String(400)  | M        | Payment results are asynchronously notified to this address                                    |
| merReserve    | String(1024) | M        | Merchant reserved content, can pass any content, such as purchase information, account number, etc., but do not pass special symbols, such as commas.   |
| merID         | String(15)   | M        | Merchant ID, assigned by AllPay                              |
| acqID         | String(11)   | M        | "99020344"                                                   |
| paymentSchema | String(10)   | M        | UnionPay:"UP",Wechat:"WX,Alipay:"APMP"                       |
| goodsInfo     | String(60)   | M        | Goods Information                                            |
| transTime     | String(14)   | M        | Transaction time, format :" yyymmddhhmmss"                   |
| signType      | String(3)    | M        | MD5                                                          |
| signature     | String(32)   | M        | MD5 signature                                                |