1. About WeChat Pay(via PPRO)

1.1 General information about WeChat Pay

Info

Typ

WeChat is a free, cross-platform and instant messaging application developed by Tencent. It was first released in January 2011 and was one of the largest standalone messaging apps by monthly active users. As of May 2016, WeChat has over a billion created accounts, 700 million active users; with more than 70 million outside of China (as of December 2015). In 2016, WeChat reached 864 million active users.

Payments by Wallet

WeChat Pay is a payment solution completely integrated inside the social and messaging application WeChat. WeChat payment functionality appears in the “Wallet” section of the application.

WeChat supports Payment and Money Transfer

Users can perform a variety of transactions using WeChat Pay, including and not limited to:

• Transferring money to friends (especially as “red envelopes” shared during Chinese festivals)
• Performing transactions on e-commerce websites
• Topping up their mobile

1.2 Process flow chart

2 1cs Online Payment System-interface

2.1 Definitions

Data formats:

Format	Description
a	alphabetical
as	alphabetical with special characters
n	numeric
an	alphanumeric
ans	alphanumeric with special characters
ns	numeric with special characters
bool	boolean expression (true or false)
3	fixed length with 3 digits/characters
..3	variable length with maximum 3 digits/characters
enum	enumeration of allowed values
dttm	ISODateTime (YYYY-MM-DDThh:mm:ss)

Abbreviations:

Abbreviation	Description	Comment
CND	condition
M	mandatory	If a parameter is mandatory, then it must be present
O	optional	If a parameter is optional, then it can be present, but it is not required
C	conditional	If a parameter is conditional, then there is a conditional rule which specifies whether it is mandatory or optional

Notice: Please note that the names of parameters can be returned in upper or lower case.

2.2 Payment with Blik via 1cs OPS form interface

To make a payment with WeChat Pay, please use the following URL:

https://www.computop-paygate.com/wechat.aspx

Notice: For security reasons, the 1cs Online Payment System rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

Key	Format	CND	Description
MerchantID	ans..30	M	MerchantID, assigned by First Cash Solution. Additionally this parameter has to be passed in plain language too.
TransID	ans..64	M	TransactionID provided by you which should be unique for each payment
RefNr	ans..40	O	Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Amount	n..10	M	Amount in the smallest currency unit (e.g. EUR Cent). Please contact the 1cs Support, if you want to capture amounts <100 (smallest currency unit).
Currency	a3	M	Currency, three digits DIN / ISO 4217, e.g. EUR, USD, GBP. Only PLN and EUR is permissible. Please find an overview here: Currency table
MAC	an64	M	Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here: HMAC Authentication (Request) HMAC Authentication (Notify)
OrderDesc	ans..768	M	Description of goods and prices. Intended purpose on the statement of account.
URLSuccess	ans..256	M	Complete URL which calls up 1cs Online Payment System if payment has been successful. The URL may be called up only via port 443. This URL may not contain parameters: In order to exchange values between 1cs Online Payment Systemand shop, please use the parameter UserData. Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS. However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
URLFailure	ans..256	M	Complete URL which calls up 1cs Online Payment System if payment has been unsuccessful. The URL may not be called up only via port 443. In order to exchange values between 1cs OPS and shop, please use the parameter User Data. Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS. However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
Response	a7	O	Status response sent by 1cs OPS to URLSuccess and URLFailure, should be encrypted. For this purpose, transmit Response=encrypt parameter.
URLNotify	ans..256	M	Complete URL which 1cs OPS calls up in order to notify the shop about the payment result. The URL may be called up only via port 443. It may not contain parameters: Use the UserData parameter instead. Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS. However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
UserData	ans..1024	O	If specified at request, 1cs OPS forwards the parameter with the payment result to the shop.
ReqId	ans..32	O	To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, 1cs Online Payment System will not carry out the payment or new action, but will just return the status of the original transaction or action. Please note that the 1cs OPS must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on 1cs OPS does not take effect. Submissions with identical ReqID for an open status will be processed regularly. Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the 1cs OPS.
SellingPoint	ans..50	O	Selling point
Service	ans..50	O	products or service sold
Channel	ans..64	O	Configuration channel of the PPRO contract (account and ContractID are stored in the system). If it exists, it may overwrite channels stored in the system.
Language	a2	O	2-letter language code (e.g. de) that should be preferred when presenting payment pages to the consumer
AccOwner	ans3..50	M	Name of account holder
AddrCountryCode	a2	M	Country code for the account holder’s invoicing address, 2 characters according to ISO 3166. Only PL allowed, defined within the code.
Plain	ans..50	O	A single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID.  “Plain”-parameter is part of encrypted “Data” in 1cs OPS and therefore protected against manipulation.
Custom	ans..1024	O	“Custom”-parameter is added to the request data before encryption and is part of encrypted “Data” in 1cs OPS request. By this they are protected against manipulation by a consumer.  The Custom-value is added to the 1cs OPS response in plain text and the “|” is replaced by a “&”. By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose.  Please find a samples here: Custom

The following table gives the result parameters which 1cs Online Payment System transmits to URLSuccess or URLFailure and URLNotify. If you have specified the Response=encrypt parameter, the following parameters are sent Blowfish encrypted to your system:

 pls. be prepared to receive additional parameters at any time and do not check the order of parameters

 the key (e.g. MerchantId, RefNr) should not be checked case-sentive

Parameter	Format	CND	Description
mid	ans..30	M	MerchantID, assigned by the First Cash Solution
PayID	an32	M	ID assigned by 1cs OPS for the payment, e.g. for referencing in batch files as well as for capture or credit request.
XID	an32	M	ID for all single transactions (authorisation, capture, credit note) for one payment assigned by the 1cs OPS
TransID	ans..64	M	TransactionID provided by you which should be unique for each payment
refnr	ans..40	O	Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Status	a…50	M	OK or AUTHORIZE_REQUEST (URLSuccess) as well as FAILED (URLFailure)
Description	ans..1024	M	Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!
Code	n8	M	Error code according to 1cs OPS Response Codes (Error codes)
MAC	an64	M	Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here: HMAC Authentication (Request) HMAC Authentication (Notify)
UserData	ans..1024	O	If specified at request, 1cs OPS forwards the parameter with the payment result to the shop.
PaymentPurpose	ans..26	O	Purpose of payment
PaymentGuarantee	a..12	O	Value+ Description: NONE – no payment guarantee VALIDATED – customer account valid, but no payment guarantee FULL – payment guarantee Notice: This parameter is only returned if the Status=OK.
ErrorText	ans..128	C	Detailed PPRO error message. Notice: Is returned only if Status=FAILED. Use is possible only in agreement with the First Cash Solution
TransactionID	an..20	O	Unique transaction number with PPRO
Plain	ans..50	O	A single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID.  “Plain”-parameter is part of encrypted “Data” in the 1cs OPS and therefore protected against manipulation.
Custom	ans..1024	O	“Custom”-parameter is added to the request data before encryption and is part of encrypted “Data” in 1cs OPS request. By this they are protected against manipulation by a consumer.  The Custom-value is added to 1cs OPS response in plain text and the “|” is replaced by a “&”. By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose.  Please find a samples here: Custom

2.3 Credit with reference

Credits (refunds) are possible via a Server-to-Server connection. For a Credit with reference to a capture the amount of the Credit is limited to the amount of the previous capture. To carry out a credit with a reference transaction, please use the following URL:

https://www.computop-paygate.com/credit.aspx

Notice: For security reasons, 1cs OPS rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

Parameter	Format	CND	Description
MerchantID	ans..30	M	MerchantID, assigned by the First Cash Solution. Additionally this parameter has to be passed in plain language too.
PayID	an32	M	ID assigned by 1cs OPS for the payment to be credited
TransID	ans..64	M	TransactionID provided by you which should be unique for each payment
refnr	ans..40	O	Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Amount	n..10	M	Amount in the smallest currency unit (e.g. EUR Cent). Please contact the First Cash Solution, if you want to capture amounts <100 (smallest currency unit).
Currency	a3	M	Currency, three digits DIN / ISO 4217, e.g. EUR, USD, GBP. Please find an overview here: Currency table
MAC	an64	M	Hash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here: HMAC Authentication (Request) HMAC Authentication (Notify)
ReqId	ans..32	O	To avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, 1cs Online Payment System will not carry out the payment or new action, but will just return the status of the original transaction or action. Please note that the 1cs OPS must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on 1cs OPS does not take effect. Submissions with identical ReqID for an open status will be processed regularly. Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the 1cs OPS.

The following table describes the result parameters with which the 1cs OPS responds to your system

 pls. be prepared to receive additional parameters at any time and do not check the order of parameters

 the key (e.g. MerchantId, RefNr) should not be checked case-sentive

Parameter	Format	CND	Description
mid	ans..30	M	MerchantID, assigned by the First Cash Solution
PayID	an32	M	ID assigned by 1cs OPS for the payment, e.g. for referencing in batch files as well as for capture or credit request.
XID	an32	M	ID for all single transactions (authorisation, capture, credit note) for one payment assigned by the 1cs OPS
TransID	ans..64	M	TransactionID provided by you which should be unique for each payment
Status	a…50	M	OK or /URLSuccess) or FAILED (URLFailure)
Description	ans..1024	M	Further details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!
Code	n8	M	Error code according to 1cs OPS Response Codes (Error codes)
refnr	ans..40	O	Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
ErrorText	ans..128	C	Detailed PPRO error message. Notice: Is returned only if Status=FAILED. Use is possible only in agreement with the First Cash Solution