worldline

Documentation

WPI version 2.0

Revision #7

Table of contents

  1. Overview

  2. Interface Structure

  3. Payment Solution Implementation

  4. Data Dictionary

Overview

The Worldline Payment Interface (WPI) is an Android intent-based interface that enables easy and fast integration with payment apps. It is designed to allow additional business applications to execute payments on any Worldline offered SmartPOS device. A SmartPOS device is a payment device that runs Android.

All Worldline Payment Solutions support WPI, which means that business applications that use this interface can run everywhere without any change of code. This makes it easy for developers to build payment apps that are compatible with a wide range of payment devices and payment protocols.

The WPI interface is built on top of the Android Intent mechanism, which allows different parts of an app to communicate with each other in a structured way. By using intents to trigger payment-related actions, the WPI interface simplifies the payment integration process and makes it easier for developers to build business applications on top of Payment Solutions.

What's new

  • Interface structure extension

    • Gather information from Payment Solution

    • Session support

      • WPI_ERR_COND_SESSION_ID_ALREADY_IN_USE

      • Print Receipt Session ID

      • Last Transaction Requests uses Session ID

    • WPI_VERSION changed from Integer to String

    • Clarified the use of messenger service for background actions

  • Management functional extensions:

    • Payment Parameterization

    • Acquirer Parameterization

    • Print Receipt

    • Abort Ongoing Payment

  • Financial extensions

    • Request fields added

      • productRecords

      • receiptFormat

      • recognitionTimeout

      • recognitionOptions

      • receiptTarget

    • Response fields added

      • dccUsed

      • softwareVersion

      • terminalIdentifier

      • supportedLanguages

      • cardholderDefaultLanguage

      • merchantLanguage

      • countryCode

      • defaultCurrency

      • supportedCurrencies

      • shopInfo

      • acquirerProtocol

      • supportedTicketFormats

      • paymentInformation

      • paymentSolutionSupportedServiceTypes

      • entryMode

      • isoTrack1

      • isoTrack2

      • isoTrack3

      • token

      • pan

      • mediaType

      • mediaUniqueIdentifier

      • waitForNextAction

      • nextActionWaitTime

      • tipAmount

Revision History

  • Revision#7

    • 3. Payment Solution Implementation

      • Clarification added for QR Code printed on the receipt

    • 4.1.2.5 Receipt

      • JSON format example updated

  • Revision#6

    • Reservation / Reservation Adjustment / Purchase Reservation

      • Chapters renamed to "Pre-authorization, "Update Pre-authorization" and "Payment Completion" respectively

      • Clarification on paymentSolutionReference usage provided

    • Payment Instrumentation Recognition

      • isoTrack1 and isoTrack2 data types changed to String in Response

Interface Structure

The WPI provides a set of intents that developers can use to build apps that work with the interface. The following table lists each intent, along with its purpose:

Type

Category

Intent

Purpose

Financial

Display Action

com.worldline.payment.action.PROCESS_TRANSACTION

Process a financial transaction

Management

Display Action

com.worldline.payment.action.PROCESS_MANAGEMENT

Trigger payment solution managed actions

Information

Background Action

com.worldline.payment.action.PROCESS_INFORMATION

Background management of payment solution specific information

We have two type of categories for the Interface:

  • Display Actions : These actions start the payment solution that are processing financial transactions or require user interaction.

  • Background Actions : These actions perform background processing that doesn't require user interaction.

    • Messenger service is used

    • The Message.what attribute of the Messenger Service should be set to the code 895349 for any WPI message.

    • The Message.obj should be  a bundle formatted just like the WPI Extras.

    • Those extras are being transported through a different mean but the same structure and rules applies

Extras

An extra in Android intents is a way to pass additional data or parameters to another component in order to provide more context or information for the requested action. In WPI we have extras for request and response. The request extras needs to be provided by the Business Application that is using the interface and the response extra is provided by the Payment Solution.

Request

Extra

Description

Type

Condition

WPI_SERVICE_TYPE

Specify the subtype of action to be executed.

String

Mandatory

WPI_REQUEST

The request contains JSON structured data mandatory for given service type, in some specific cases this field is not given or empty.

String

Mandatory for Financial

Optional for Management

WPI_VERSION

Used WPI version.

String

Mandatory

WPI_SESSION_ID

Used as an identifier of a WPI exchange (a request/response) between a client application and a payment application. Is used to recover the status of the exchange in case of an unexpected failure. Is provided by the client and is part of the response.

The session id :

  • must be unique

  • must be part of the response

  • must not be reused for subsequent requests (except for the last transaction request as it is used to do the recovery)

Any business application should store the WPI_SESSION_ID before sending the intent. Due to this the business application can do a recovery with the last transaction function to check the outcome of the previous transaction in case that the business application has crashed.

String

Mandatory

Response

Extra

Description

Type

Condition

WPI_SERVICE_TYPE

Specify the subtype of action that was executed.

String

Mandatory

WPI_RESPONSE

The response contains JSON structured data processed for the requested service type.

String

Mandatory

WPI_VERSION

Used WPI version.

String

Mandatory

WPI_SESSION_ID

Identifier of a WPI exchange provided by the client.

String

Mandatory

Service Types

Each intent has several service types that specify the request.

FINANCIAL

Service type

Purpose

WPI_SVC_PAYMENT

Used to perform a simple sale transaction also known as purchase.

WPI_SVC_CANCEL_PAYMENT

Used to reverse a previous transaction.

WPI_SVC_REFUND

Used to refund a previous transaction.

WPI_SVC_PRE_AUTHORIZATION

Used to perform a reservation.

WPI_SVC_CANCEL_PRE_AUTHORIZATION

Used to cancel a previous reservation.

WPI_SVC_UPDATE_PRE_AUTHORIZATION

Used to increment a previous reservation.

WPI_SVC_CANCEL_UPDATE_PRE_AUTHORIZATION

Used to cancel the previous incrementation of a reservation.

WPI_SVC_PAYMENT_COMPLETION

Used to purchase a reservation / incremented reservation.

WPI_SVC_CANCEL_PAYMENT_COMPLETION

Used to cancel the purchased reservation.

WPI_SVC_DEFERRED_PAYMENT_AUTHORIZATION

Used to execute a deferred payment authorization (energy solution use-case).

WPI_SVC_DEFERRED_PAYMENT_COMPLETION

Used to execute a deferred payment completion of a previous authorization(energy solution use-case).

WPI_SVC_PAYMENT_INSTRUMENT_RECOGNITION

Used to do a payment card of non payment card recognition request without performing a real transaction (token).

WPI_SVC_FOLLOW_ON_CREDIT

Used to do a referenced based credit transaction based on a previous transaction.

MANAGEMENT

Service type

Purpose

WPI_SVC_PAYMENT_MENU

Used to open the payment solution menu.

WPI_SVC_DAY_END

Used to upload the transactions (online and offline) to perform the final settlement.

WPI_SVC_PAYMENT_PARAMETERIZATION

Used to fetch the latest payment solution configuration from the payment solution related configuration system.

WPI_SVC_ACQUIRER_PARAMETERIZATION

Used to fetch the latest acquirer parameters from the acquirer.

WPI_SVC_PRINT_RECEIPT

Used for receipt printing.

WPI_SVC_ABORT

Used to abort an ongoing transaction.

INFORMATION

Service type

Purpose

WPI_SVC_LAST_TRANSACTION

Used to return the last transaction result.

WPI_SVC_PAYMENT_INFORMATION

Used to retrieve the payment solution information especially which service types are supported.

Payment Solution Implementation

  • Mandatory Attributes and Result Structure

    • The technical design is based on defining only the mandatory attributes in the request needed to meet every requested business use case aiming to be payment protocol agnostic.

    • The payment solution shall support every combination of attributes defined in the request.

    • The result structure contains every possible attribute to be returned to meet every use case.

  • Payment Solution Reference

    • The payment solution reference must be designed in a unique way so that all follow on transactions can be handled with this. For example if you do a reservation, it needs to contain all payment-specific fields to do all follow-on transactions like cancel reservation, purchase reservation, and so on. WPI supports the so-called reference, for more details check Data Dictionary 4.1.1 Request Data, this field is also known as a merchant reference and used for reconciliation.

    • The payment solution will print the paymentSolutionReference on the receipt as QR Code:

      • compliant with ISO/IEC 18004:2015 (or higher) standard.

      • highest (H) error correction level must be ensured.

      • QR Code version should be selected according to the length of data that given Payment Solution will return.

      • QR Code content should be limited to paymentSolutionReference value with no additional data (i.e. raw data).

    • The payment solution reference shall be as short as possible and easy to type manually within another Android application.

  • Remark and Error Handling

    • The payment solution shall provide a remark that is understandable by a third-party integrator and only in case of an error condition not equal to WPI_ERR_COND_NONE.

    • The payment solution shall send back the errorCondition WPI_ERR_COND_BUSY in case of a transaction currently in progress.

  • Payment Instrumentation Recognition Request

    • In case of a Payment Instrumentation Recognition Request, the terminal shall:

      • perform the card withdrawal in case of no amount & currency is present.

      • not wait for another action in case of no amount & currency is present.

      • return a token for the card PAN or the NFC UID (in case of NFC non-payment related cards) that was read. The token should be a hash which is generated by the Payment Solution and can be reproduced at least on the same device.

  • Other Requirements

    • The payment solution must store the SESSION_ID for the last transaction as well as the last transaction object of each business application. Due to this, a recovery procedure can be implemented with the last transaction request.

    • The payment solution should support several WPI major versions.

    • Password-protected transaction types such as refund, credit, and follow-on credit must be password protected. In case of a standalone configuration of the payment solution, password entry and validation must be done by the payment solution.

    • The payment solution shall always take care off the receipt handling - depending on the TMS configuration. Business applications can override (deactivate) the default behavior by setting the receiptDelegation to false.

Versioning

The WPI uses versioning with the format Y.X (e.g., 1.0, 2.1) to track and manage different releases of our software. Additionally, each revision within a minor version is assigned a unique number, such as "3.2 Revision #9."

  • Y (Major Version): Signifies a significant milestone with potential breaking changes. A payment solution for version 1.1 must remain compatible with the version 1.0.

  • X (Minor Version): Represents a release with new features or improvements that are backward compatible within the same major version. However, a version 2.2 request cannot be used with version 1.1.

  • Revision Number: Each revision is assigned a unique number, indicating the specific iteration of a minor version (e.g., "3.2 Revision #9"). Revisions mainly include small fixes, updates, and improvements. They address minor bugs or add slight enhancements/clarifications.

Data Dictionary

Data

All the data here below are the possible fields including the description and type for all services. As this is just a dictionary, the detailed responses per service check are listed in subsequent chapters.

Request Data

All data has to be provided as JSON and needs to be provided as WPI_REQUEST extra.

Field name

Description

Type

currency

Currency of the amount. Alpha code value defined in ISO 4217 (e.g. EUR ).

String

requestedAmount

Total payment amount as minor unit. The fractional digits are evaluated based in the currency. For example, 11.91€ must be sent as 1191 and the currency as EUR.

Integer

paymentSolutionReference

A previous transaction reference used for subsequent transactions like a Reversal. This value is defined by the payment application and contains all necessary data to perform subsequent transactions. This value can differ based on the payment application and can only be used on the same device.

String

reference

Reference to be send to the payment solution for reconciliation.

String

productRecords

Product catalogue for energy solution based use-cases. This records needs the format that the issuer can understand. Most often used for petrol use-cases.

Array ( Product Record Item )

receiptFormat

To override the default receipt format.

Array ( Receipt Format ).

receiptDelegation

This flag is used to deactivate the payment solution receipt handling. Per default the payment solution will take care about the receipt delivery as configured by the corresponding TMS. To deactivate the payment solution specific receipt handling false has to be set.

Default: true

Boolean

recognitionTimeout

Defines the timeout before an error will be returned in milliseconds.

Integer

recognitionOptions

Card recognition options.

Array ( Recognition Option )

receiptTarget

Defines the receipt which shall be printed.

String ( Receipt Target )

Product Record Item

Product Records are items that will be exchanged between the integrator and the issuer. Those two parties also needs to agree on the content. The Payment Solution is just the sending the information. Example: Item ID = 55 means Carwash program "full". Each record has the following fields.

Field name

Description

Type

itemId

Identifier of the item that was aligned with the issuer

Integer

label

Label of the item

String

unitAmount

Unit price as minor unit

Integer

quantity

Number of units

Integer

totalAmount

Total amount as minor unit

Integer

currency

Currency of the amount. Alpha code value defined in ISO 4217 (e.g. EUR)

String

Receipt Format

The receipt format defines how to retrieve the receipt. Default is formatted. If an empty array is sent no receipt will be returned. The following values are possible.

Value (String)

Purpose

FORMATTED

Return the receipt in a payment response as String (default).

JSON

Return the receipt in a payment response as JSON.

Recognition Option

Value (String)

Purpose

WPI_RECOGNITION_OPTION_RETURN_CUSTOMER_TOKEN

Used to create a token for the card that was read.

WPI_RECOGNITION_OPTION_RETURN_MIFARE_DETAILS

Used to recognize a non payment card, like MIFARE. The UID and card type will be evaluated.

Receipt Target

Value (String)

Purpose

CARDHOLDER

Used to print the cardholder receipt.

MERCHANT

Used to print the merchant receipt.

BOTH

Used to print the merchant and cardholder receipt one after the other.

Response Data

All data has to be provided as JSON and will be provided as WPI_RESPONSE extra.

Field name

Description

Type

result

Result of the transaction (success or failure).

String (pre-defined Result )

errorCondition

Specific error reason (see table below).

String (pre-defined Error Condition )

actionCode

Specific action to be performed by the business application.

String (pre-defined  Action Code )

remark

Terminal / transaction specific message for detailed error descriptions. Text provided by the acquirer and forwarded by the payment application. Content can therefore vary between acquirer and will most likely be provided in the merchant language.

String

timestamp

Date and time of the transaction, indicated by the payment application towards the acquirer.

Format according to ISO 8601 (extended format) =>  yyyy-mm-hhThh:mm:ss±hh:mm

String

currency

Currency code of the transaction. Alpha code value defined in ISO 4217 e.g.  EUR

String

authorizedAmount

Amount of the transaction, including TIP. The fraction is taken from the currency code. Example:

currency = EUR

authorizedAmount= 3190

=> 31,90 €

Integer

brandName

Brand name of used payment card, like MasterCard, VISA, AMEX and so on.

String

customerLanguage

Language used on all screens towards the cardholder and when formatting the receipt. Language code will be returned for english > en

Format according to ISO 630-1 (alpha-2 code)

String

applicationIdentifier

Payment card application identifier dependent on the used card e.g. for MasterCard A00000041010

String

applicationLabel

Payment card application label, depending on the used card e.g. MasterCard DEBIT

String

receipt

Contains the requested receipts. Depending on the format for more details check the receipt chapter.

Object ( Receipt )

paymentSolutionReference

Transaction specific and unique identification. This value is defined by the payment application and contains all necessary data to perform subsequent transactions. This value can differ based on the payment application and can only be used on the same device.

String

dccUsed

Whether DCC was used or not for the transaction. This field is present as soon as DCC is activated for this payment solution.

Boolean

tipAmount

The tip amount that was entered by the cardholder during the transaction with the payment solution. This field is present as soon as TIP is activated for this payment solution.

Integer

reference

Reference to be send to the payment app for reconciliation. The reference will be the same value as in the request.

String

softwareVersion

Payment Solution software version

String

terminalIdentifier

The terminal identifier configured for the payment solution

String

supportedLanguages

List of language that are supported

Format according to ISO 630-1 (alpha-2 code)

Array

cardholderDefaultLanguage

The configured cardholder default language

Format according to ISO 630-1 (alpha-2 code)

String

merchantLanguage

The configured merchant default language

Format according to ISO 630-1 (alpha-2 code)

String

countryCode

The country code of the terminal ISO 3166-1 (alpha-2 code)

String

defaultCurrency

The default currency that is configured for the payment solution.

Alpha code value defined in ISO 4217 e.g.  EUR

String

supportedCurrencies

All currencies that are supported by the payment solution.

Alpha code value defined in ISO 4217 e.g.  EUR

Array

shopInfo

The shop information of the terminal. Usually these are the first three lines of each receipt.

Object ( ShopInfo )

acquirerProtocol

The used acquirer protocol by the payment solution, usually this is the official acronym like CTAP.

String (pre-defined  Acquirer Protocol )

supportedTicketFormats

The supported ticket formats by the payment solution.

String (pre-defined  Receipt Format )

supportsReceiptDelegation

Whether the payment application supports receipt delegation or not. Receipt delegation is when any business application asked the payment solution to handle the receipt. Any payment solution can handle the receipt if a printer or a digital solution is available. If both are not available and the payment solution cannot handle the receipt false is returned. 

Boolean

paymentInformation

Detailed payment solution information per brand & acquirer.

Array ( Payment Information )

paymentSolutionSupportedServiceTypes

The service types supported by the payment solution are independent of the card brand. Each payment solution can support multiple service types, but often not every service type is supported by every card brand.

Array (  Financial Service Types  &   Management Service Types )

entryMode

The technology that was used to read the card.

String (pre-defined Supported Technologies )

isoTrack1

ISO track 1 data 

String

isoTrack2

ISO track 2 data (due to PCI regulatory payment card PAN data are always masked)

String

isoTrack3

ISO track 3 data

String

token

The token of the card PAN / UID (in case of NFC non payment related card) that was read. The token should be an unique value, generated by the payment solution and can be reproduced on the same device. This token is used to identify the customer.

String

pan

PAN of the card (due to PCI regulatory payment card PAN data are always masked).

String

mediaType

Media type of NFC non payment card. e.g. MIFARE Ultralight.

String

mediaUniqueIdentifier

UID of NFC based non payment card.

String

waitForNextAction

Whether the payment solution keeps the card in read mode for a subsequent transaction or not.

Boolean

nextActionWaitTime

The time how long the card is kept in read mode, in milliseconds.

Integer

ShopInfo

Field name

Description

Type

name

Name of the shop.

String

address

Address of the shop usually street and number.

String

zipCode

ZIP code of the shop.

String

city

City of the shop.

String

country

Country of the ship.

String

logo

Content provider URI of the logo to be used.

String

RESULT

Result

Description

WPI_RESULT_SUCCESS

In case of successful transaction.

WPI_RESULT_FAILURE

In case of failed transaction.

ERROR CONDITIONS

Error condition

Description

WPI_ERR_COND_NONE

Will always be present if no error occurred.

WPI_ERR_COND_SERVICE_NOT_SUPPORTED

The requested service type is not supported by the Payment Application/Service.

WPI_ERR_COND_ABORTED

The initiator of the request has sent an abort request, which was accepted and processed.

WPI_ERR_COND_BUSY

The Payment Application/Service is busy. Try later.

WPI_ERR_COND_CARD_READ_ERR

The payment application was not able to read the card. Either due to inconsistent data or wrong card handling.

WPI_ERR_COND_USER_CANCEL

The user has aborted the transaction.

WPI_ERR_COND_USER_TIMEOUT

A timeout occurred while waiting for user interaction.

WPI_ERR_COND_HOST_REFUSAL

The Acquirer/Issuer refused the transaction.

WPI_ERR_COND_NETWORK_ISSUE

Network issue occurred (host not reachable, network down, … )

WPI_ERR_COND_TRANSACTION_TIMEOUT

Timeout occurred during transaction (other than with user interaction ).

WPI_ERR_COND_ENCRYPTION_ISSUE

Encryption issue (PAN, PIN …) caused the transaction to be aborted.

WPI_ERR_COND_INVALID_KEY

The secure component of the terminal is missing a key it needs to perform the transaction.

WPI_ERR_COND_INVALID_TRANSACTION_REQ

Invalid transaction request received. One of the fields in the transaction request object was invalid.

WPI_ERR_COND_INTERNAL

Internal error within payment service.

WPI_ERR_COND_INVALID_AMOUNT

Entered invalid amount

WPI_ERR_COND_INVALID_CURRENCY

Transaction started with invalid currency. The currency is a global attribute of the underlying payment service.

WPI_ERR_COND_APP_NOT_SUPPORTED

None of the applications on the EMV NFC/IC chip card are accepted or the ISO/PAN on the magnetic stripe track didn’t result in a brand being accepted.

WPI_ERR_COND_MISSING_MANDATORY_PARAMETER

A mandatory parameter is missing in the request.

WPI_ERR_COND_GENERIC

A generic error that is not specified in detail

WPI_ERR_COND_NOT_INITIALIZED

The payment solution is not configured and cannot process the request.

WPI_ERR_COND_WPI_VERSION_NOT_SUPPORTED

The request contains a WPI version which is 

WPI_ERR_COND_SESSION_ID_ALREADY_IN_USE

In case of the SESSION ID was already used and the payment solution would not be able to identify the last transaction for recovery then this error code is returned.

WPI_ERR_COND_INVALID_PASSWORD

For password protected transactions, this error code is returned if the password entered in the payment solution, by the merchant, is incorrect.

WPI_ERR_COND_RECEIPT_DELEGATION_NOT_SUPPORTED

If a transaction was started with receipt delegation and receipt delegation is not supported this error code is returned.

ACTION CODES

Action codes

Description

WPI_ACTION_CODE_NONE

No additional action to be performed.

WPI_ACTION_CODE_ASK_LEGAL_IDENTIFICATION

Ask the cardholder for a legal identification and write the identification data down on the receipt.

WPI_ACTION_CODE_ASK_SIGNATURE

Ask the cardholder to sign the merchant receipt to complete the authorization.

RECEIPTS

Field name

Description

Type

formatted

Merchant and cardholder receipt are contained in this field. Both receipts are available as text preformatted. The receipt wide is defined by the payment application (often 32 characters) and depends on the printer capabilities or configuration.

JSON object (check example below).

json

Merchant and cardholder receipt are contained in this field. Both receipts are represented in a JSON format. This is used to create a own format.

An own format should be compliant with the local, payment solution and EMV specification!

JSON object (check example below).

The receipt language is the same as it is for the payment app. As it is written in the JSON specification ( https://www.ietf.org/rfc/rfc4627.txt ) every control character has to be escaped like shown below but on the same line.

FORMATTED format:

formatted: {
    "merchant":"    This is to confirm your transaction\\n
        registered at:\\n
        ----------------------------------------\\n
                 SPS-Softpos Pilot 02\\n
                  Grzybowska 4/246\\n
                   00-131 Warszawa\\n
        ----------------------------------------\\n
        15.02.2023 22:36\\n
        0,03 PLN\\n
        Visa **** **** **** 7984\\n
                Transaction details: \\n
        Status:                       AUTHORIZED\\n
        Authorization code:           (0) 741451\\n
        ARQC:                   61BC5EDC34F63979\\n
        AID:                      A0000000031010\\n
        Contactless\\n
        Type:                               Sale\\n
        POS ID:                         APP00002\\n
        MID:                           103810047\\n
        VISA CARD",
    "client":"    This is to confirm your transaction\\n
        registered at:\\n
        ----------------------------------------\\n
                 SPS-Softpos Pilot 02\\n
                  Grzybowska 4/246\\n
                   00-131 Warszawa\\n
        ----------------------------------------\\n
        15.02.2023 22:36\\n
        0,03 PLN\\n
        Visa **** **** **** 7984\\n
                Transaction details: \\n
        Status:                       AUTHORIZED\\n
        Authorization code:           (0) 741451\\n
        ARQC:                   61BC5EDC34F63979\\n
        AID:                      A0000000031010\\n
        Contactless\\n
        Type:                               Sale\\n
        POS ID:                         APP00002\\n
        MID:                           103810047\\n
        VISA CARD"
    }
}

JSON Format:

"json":{
    "receiptTargets":{
        "merchant":{
            "description": "List of field names of the receipt to be included for the merchant receipt"
            "type":"array",
            "items":{
                "type":"string"
            }
        },
        "client":{
            "description": "List of field names of the receipt to be included for the client receipt"
            "type":"array",
            "items":{
                "type":"string"
            }
        }
    },
    "duplicate":{
        "type":"boolean"
    },
    "shopInfo":{
        "name":{
            "type":"string"
        },
        "address":{
            "type":"string"
        },
        "zipCode":{
            "type":"string"
        },
        "city":{
            "type":"string"
        },
        "country":{
            "type":"string"
        },
        "logo":{
            "type":"string" // Content provider uri to the logo file
        }
    },
    "terminalIdentifier":{
        "type":"string"
    },
    "period":{
        "type":"string"
    },
    "transactionIdentifier":{
        "type":"string"
    },
    "currency":{
        "type":"string"
    },
    "amount":{
        "type":"integer"
    },
    "cashbackAmount":{
        "type":"integer"
    }
    "tipAmount":{
        "type":"integer"
    },
    "token":{
        "type":"string"
    },
    "par":{
        "type":"string"
    },
    "brandName":{
        "type":"string"
    },
    "applicationIdentifier":{
        "type":"string"
    },
    "issuerName":{
        "type":"string"
    },
    "pan":{
        "type":"string"
    },
    "maskedPan":{
        "type":"string"
    },
    "cardSequence":{
        "type":"string"
    },
    "cardExpiration":{
        "type":"string"
    },
    "serviceName":{
        "type":"string"
    },
    "timestamp":{
        "type":"string"
    },
    "authorizationCode":{
        "type":"string"
    },
    "reference":{
        "type":"string"
    },
    "acquirerIdentifier":{
        "type":"string"
    },
    "entryMode":{
        "type":"string"
    },
    "cardDataInput":{
        "type":"string"
    },
    "cardholderVerificationMethod":{
        "type":"string"
    },
  "legalIdentificationRequired":{
        "type":"boolean"
    },
    "cardBalance":{
        "old":{
            "type":"string"
        },
        "new":{
            "type":"string"
        },
        "cardholderText":{
            "type":"string"
        }
    },
    "paymentSolutionReference":{
        "type":"string"
    },
    "productRecords":{
        "type":"array",
        "items":{
            "itemId":{
                "type":"integer"
            },
            "label":{
                "type":"string"
            },
            "unitAmount":{
                "type":"integer"
            },
            "quantity":{
                "type":"integer"
            },
            "totalAmount":{
                "type":"integer"
            },
            "currency":{
                "type":"string"
            }
        }
    },
    "operatorIdentifier":{
        "type":"string"
    },
    "cardholderReceiptText":{
        "type":"string"
    },
    "acquirerReceiptText":{
        "type":"string"
    },
    "footerLines":{
        "type":"array",
        "items":{
            "line":{
                "type":"string"
            }
        }
    },
    "additionalData":{
        "type":"array",
        "items":{
            "key":{
                "type":"string"
            },
            "value":{
                "type":"dynamic"
            }
        }
    }
}


PAYMENT INFORMATION ITEM

Field name

Description

Type

acquirerIdentifier

The acquirer identifier for the given brand.

String

merchantIdentifier

Merchant identifier that is used by the acquirer.

String

acquirerTerminalIdentifier

Terminal identifier that is used by the acquirer to identify the terminal.

String

brandIdentifer

Brand specific identifier, also known as AID. This is scheme specific e.g. A0000000041010 is Mastercard.

String

brandName

The brand name like Mastercard

String

supportedServiceTypes

Supported service types for the brand

Array ( Financial Service Types )

cancellableServiceTypes

Service types that can be reversed

Array ( Financial Service Types )

numberOfCancellableTransactions

Number of last (successful) transactions that can be reversed.

Integer

supportedTechnologies

Supported technologies for card reading

Array ( Supported Technologies )

supportsDCC

Whether Dynamic Currency Conversion (DCC) is supported or not

Boolean


SUPPORTED TECHNOLOGIES

Entry mode

Description

WPI_ENTRY_MODE_MAGSTRIPE

Magnetic stripe support

WPI_ENTRY_MODE_CHIP

EMV chip (ICC) support

WPI_ENTRY_MODE_NFC

EMV NFC chip support

WPI_ENTRY_MODE_NFC_MIFARE

NFC MIFARE support

WPI_ENTRY_MODE_QR_CODE

Alternative payment method support, via QR Code

SUPPORTED TICKET FORMAT

The supported ticket formats are defined in  Receipt Format

ACQUIRER PROTOCOL

Acquirer protocol

ep2

CTAP

CB2A

NEXO

ZVT

Financial

Each financial transaction has a minimum set of fields that needs to be there per service type. In the subsequent chapters this is described in detail.

The response contains the following fields:

Response :

Field name

Type

Condition

result

String

Mandatory

errorCondition

String

Mandatory

remark

String

Conditional

- only for not successful transactions

actionCode

String

Conditional

- only for not successful transactions

timestamp

String (ISO 8601)

Conditional

- only for successful transactions

currency

String

Conditional

- only for successful transactions

authorizedAmount

Integer

Conditional

- only for successful transactions

customerLanguage

String

Conditional

- only for successful transactions in which a payment card was used

(e.g. on reference based transactions the card is not inserted and therefore we cannot get these data)

brandName

String

Conditional

- only for successful transactions in which a payment card was used

(e.g. on reference based transactions the card is not inserted and therefore we cannot get these data)

applicationIdentifier

String

Conditional

- only for successful transactions in which a payment card was used

(e.g. on reference based transactions the card is not inserted and therefore we cannot get these data)

applicationLabel

String

Conditional

- only for successful transactions in which a payment card was used

(e.g. on reference based transactions the card is not inserted and therefore we cannot get these data)

receipt

Object ( Receipt )

Conditional

- always present for successful transactions

- optional for failed transactions

paymentSolutionReference

String

Conditional

- always present for successful transactions

- optional for failed transactions

productRecords

Array

Conditional

- in case of the product records are present in the request

Payment

Service Type : WPI_SVC_PAYMENT

Request :

Field name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

reference

String

Optional

productRecords

Array

Optional

- usually used for energy solutions (e.g. petrol retail).

Cancellation

The cancellation is also known as reversal. The cancellation can be executed for several service types, the cancellation service type depends on the initial service type and needs to be set and used correctly by the business application.

Service Type : WPI_SVC_CANCEL_PAYMENT, WPI_SVC_CANCEL_PRE_AUTHORIZATION, WPI_SVC_CANCEL_UPDATE_PRE_AUTHORIZATION, WPI_SVC_CANCEL_PAYMENT_COMPLETION

Request :

Field name

Type

Condition

paymentSolutionReference

String

Mandatory

Refund

Service Type : WPI_SVC_REFUND

Request :

Field name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

reference

String

Optional

Pre-authorization

Service Type : WPI_SVC_PRE_AUTHORIZATION

Request :

Field name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

reference

String

Optional

Update Pre-authorization

This service is used to increase the pre-authorization amount, which involves specifying the requested amount for the increment. The reference of pre-authorization is provided through the paymentSolutionReference , which will be use to make the update pre-authorization. The requestedAmount is just the amount that shall be incremented, not the total one

Service Type : WPI_SVC_UPDATE_PRE_AUTHORIZATION

Request :

Field name

Type

Confition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

paymentSolutionReference

String

Mandatory

reference

String

Optional

Payment Completion

To complete a previous pre-authorization the paymentSolutionReference has to be used. The final amount should be equal to or less than the total pre-authorization amount (this includes all previous Update pre-authorization calls). If you use a higher amount for the completion, the transaction may not be successful because the higher amount was not reserved - we do not recommend to use higher amounts.

Service Type : WPI_SVC_PAYMENT_COMPLETION

Request :

Field name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

paymentSolutionReference

String

Mandatory

reference

String

Optional

Deferred Payment

Deferred payment for petrol transaction processing refers to a payment arrangement where the actual payment for fuel is delayed or postponed until a later time. The transaction is split into two parts: authorization and completion.

  1. Authorization: The first part of the deferred payment process is authorization. When a customer swipes their payment card or provides their payment details at the petrol station, the system checks if the card is valid and has sufficient funds or credit available. This initial authorization ensures that the customer's payment method is valid and can cover the cost of the fuel. However, the actual payment is not processed at this stage.

  2. Completion: The second part of the deferred payment process is completion. After the authorization is successful, the petrol station temporarily reserves the funds or credit limit on the customer's card to cover the estimated cost of the fuel. This reserved amount is typically a pre-authorization hold or pending transaction. The petrol station then dispenses the fuel to the customer.

Later, the petrol station completes the transaction by submitting the final payment request to the customer's bank or credit card company. At this stage, the reserved funds are transferred from the customer's account to the petrol station's account, completing the payment process. The exact timing for completing the authorization may vary depending on the specific payment system and agreements between the petrol station and the customer's financial institution.

The delay between the “Authorization Exchange” and the “Completion Exchange” can be quite long (e.g., in case of tank filling). Therefore, to increase the availability of the terminals using the “Deferred Payment” service, the “Multi-Session” concept is usually configured for performing “Parallel Transactions”. The authorization exchange provides the terminal with an authorized amount as upper limit, and the completion exchange notifies the acquirer of the final amount as actually applicable. The “Deferred Payment” is indifferently meant for attended or unattended terminals. 

PSD2 imposes the amount to be present in the request.

AUTHORIZATION

Service Type : WPI_SVC_DEFERRED_PAYMENT_AUTHORIZATION

Request :

Field Name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

reference

String

Optional

Service Type : WPI_SVC_DEFERRED_PAYMENT_COMPLETION

Request :

Field Name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

paymentSolutionReference

String

Mandatory

reference

String

Optional

productRecords

Array

Optional

Payment Instrumentation Recognition

The intention is to avoid double tap under the condition the payment instrument is a contactless entry mode. The payment solution needs information about the transaction service type, requested amount, currency and reference that should be used for the subsequent transaction. There are two possibilities to do a payment instrumentation recognition token retrieval only and card recognition with further payment processing afterwards. The response differs from the standard response as described below. 

Service Type : WPI_SVC_PAYMENT_INSTRUMENT_RECOGNITION

Request :

Field Name

Type

Condition

currency

String

Optional
- in case of transaction processing should happen afterwards

requestedAmount

Integer

Optional
- in case of transaction processing should happen afterwards

serviceType

String

Optional
- in case of transaction processing should happen afterwards

recognitionTimeout

Integer

Mandatory

recognitionOptions

Array

Mandatory

Response :

Field Name

Type

Condition

result

String

Mandatory

errorCondition

String

Mandatory

entryMode

String

Conditional
- (Mandatory) in case of WPI_RESULT_SUCCESS 

customerLanguage

String

Conditional
- (Mandatory) in case of WPI_RESULT_SUCCESS 

isoTrack1

String

Conditional
- in case of magnetic stripe card 

isoTrack2

String

Conditional
- in case of magnetic stripe card 

isoTrack3

String

Conditional
- in case of magnetic stripe card 

token

String

Conditional
- (Mandatory) in case of payment card processing

pan

String

Conditional
- (Mandatory) in case of payment card processing

mediaType

String

Conditional
- (Mandatory) in case of non payment card processing

mediaUniqueIdentifier

String

Conditional
- (Mandatory) in case of non payment card processing

waitForNextAction

Boolean

Conditional
- (Mandatory) in case of success

nextActionWaitTime

Integer

Conditional
- (Mandatory) in case of success

Follow on Credit

Follow on Credit is a card not present transaction which is used to perform the credit transaction with the card data of a previous transaction. The reference of the card is given by the paymentSolutionReference of the previous transaction.

Service Type : WPI_SVC_FOLLOW_ON_CREDIT

Request :

Field Name

Type

Condition

currency

String

Mandatory

requestedAmount

Integer

Mandatory

reference

String

Optional

paymentSolutionReference

String

Mandatory

Management

Management actions has an empty request JSON content, except for services that contain a receipt, like Day-End and the parameterizations. The receipt format can be set in the request with the receiptFormat field (defined in Receipt Format ). If a receipt format is also defined for a management services that does not have a receipt the receiptFormat will be ignored by the payment solution.

The response for every management action contains the following fields

Response :

Field Name

Type

Condition

result

String

Mandatory

errorCondition

String

Mandatory

receipt

Object ( Receipt )

Conditional
- only for Management services that contains a receipt

Payment Menu

This is used to open the payment solution menu to trigger payment solution specific actions.

Service Type : WPI_SVC_PAYMENT_MENU

Day-End

The day-end is used to upload the offline transactions to the host and sends back a receipt with the transaction summary per brand with no of transactions as well as the full amount since the last day-end.

Service Type : WPI_SVC_DAY_END

Payment Parameterization

The payment configuration is used to synchronize the payment solution specific parameters with the corresponding management system.

Service Type : WPI_SVC_PAYMENT_PARAMETERIZATION

Acquirer Parameterization

The Acquirer parameterization is used to synchronize with the acquirer system corresponding to the payment solution. This includes brands, limits and any other parameter that is mandatory to process a financial transaction. Multi-Acquirer solutions will do the parameterization synchronization for all acquirers.

Service Type : WPI_SVC_ACQUIRER_PARAMETERIZATION

Print Receipt

This function is intended to provide a compliant receipt by the payment solution. A receipt can be provided in case of

  • A previous transaction was done and due to this the payment solution has a last transaction with a corresponding session ID for this business application

  • The SESSION_ID of the print receipt request in the Android Extras has to be the previous request SESSION_ID and not a new one

  • The payment solution supports receipt delivery, for example printing or digital receipt based delivery

  • Referenced request (by SESSION_ID) has a receipt available

The Android Extras in the response are close to a standard transaction response except for the conditional presence of WPI_RESPONSE. An initial check on this extra property provides information about the existence of the session. If not available the session ID is not existing.

Be aware any payment solution will just store the last SESSION_ID and response per application (package name). This implies that no other WPI requests shall be done before printing the receipt.

Hint: The receipt cannot be provided under the following circumstances:

Circumstance

Description

ErrorCondition

Paper empty

Receipt cannot be printed as the paper is empty

WPI_ERR_COND_GENERIC

Printer defect

Printer cannot be used to reprint the receipt as it is defect

WPI_ERR_COND_GENERIC

Receipt delivery not available

Neither a printer nor a digital receipt is available, mainly happens in unattended environments. The service type support for print receipt can be checked with the  Payment Solution Information

WPI_ERR_COND_SERVICE_NOT_SUPPORTED

Receipt not available

Not every WPI request has receipt´s or a receipt of the requested receiptTarget . For example a configuration receipt cannot be printed with the receiptTarget CARDHOLDER as this is a merchant receipt.

WPI_ERR_COND_GENERIC

Service Type : WPI_SVC_PRINT_RECEIPT

Request :

Field Name

Type

Condition

receiptTarget

String (pre-defined )

Mandatory

Response

Field Name

Type

Condition

result

String (pre-defined )

Mandatory

errorCondition

String (pre-defined )

Mandatory

remark

String

Conditional
- In case of an errorCondition not equal to NONE 

Abort Ongoing Payment

Abort the current ongoing financial transaction. If the transaction was successfully aborted or there was no running transaction WPI_RESULT_SUCCESS will be returned in all other cases WPI_RESULT_FAILURE.

Service Type : WPI_SVC_ABORT

Information

Retrieval of Payment Solution specific information that does not require user interaction. There request does not contain any parameter. The response is specific per service type.

Last Transaction

In case of the last transaction response is not known any more it can be requested by this service. It will return the last financial transaction response independent of the result, failed or success. This is a recovery feature as the payment solution will remember the last SESSION_ID as well as corresponding transaction response. The Android Extras are close to a standard transaction response except for the conditional presence of WPI_SERVICE_TYPE & WPI_RESPONSE . An initial check on one of these extra properties can provide information about the existence of the session.

Be aware any payment solution will just store the last response. That implies that no other WPI request shall be done before the recovery. 

Service Type : WPI_SVC_LAST_TRANSACTION

Request :

Extra

Description

Type

Condition

WPI_SERVICE_TYPE

Specify the subtype of action to be executed 

String

Mandatory

WPI_VERSION

Used WPI version

String

Mandatory

WPI_SESSION_ID

The session id of the requested session NOT a new session id

String

Mandatory

Response :

Extra

Description

Type

Condition

WPI_SERVICE_TYPE

This will be the service type of the recovered transaction not "WPI_SVC_LAST_TRANSACTION"

String

Session id known by the payment solution and transaction was executed (failure or success)

WPI_RESPONSE

The Financial Payment Response object of the corresponding SESSION_ID

String 

Session id known by the payment solution and transaction was executed (failure or success)

WPI_VERSION

Used WPI version

String

Mandatory

WPI_SESSION_ID

Identifier of a WPI exchange

String

Mandatory

Payment Solution Information 

The payment should provide all the required information, in case of a lack or issue of configuration / initialization the response should provide the WPI_ERR_COND_NOT_INITIALIZED as an errorCondition.

Service Type : WPI_SVC_PAYMENT_INFORMATION

Response :

Field Name

Type

Condition

result

String

Mandatory

errorCondition

String

Mandatory

softwareVersion

String

Conditional
- In case of WPI_RESULT_SUCCESS  

terminalIdentifier

String

Conditional
- In case of WPI_RESULT_SUCCESS

terminalModel

String

Conditional
- In case of WPI_RESULT_SUCCESS

macAddress

String

Conditional
- In case of WPI_RESULT_SUCCESS

supportedLanguages

Array

Conditional
- In case of WPI_RESULT_SUCCESS

cardholderDefaultLanguage

String

Conditional
- In case of WPI_RESULT_SUCCESS

merchantLanguage

String

Conditional
- In case of WPI_RESULT_SUCCESS

countryCode

String

Conditional
- In case of WPI_RESULT_SUCCESS

defaultCurrency

String

Conditional
- In case of WPI_RESULT_SUCCESS

supportedCurrencies

Array

Conditional
- In case of WPI_RESULT_SUCCESS

shopInfo

Object ( ShopInfo )

Conditional
- In case of WPI_RESULT_SUCCESS

acquirerProtocol

String

Conditional
- In case of WPI_RESULT_SUCCESS

supportedTicketFormats

Array

Conditional
- In case of WPI_RESULT_SUCCESS

supportReceiptDelegation

Boolean

Conditional
- In case of WPI_RESULT_SUCCESS

paymentInformation

Array

Conditional
- In case of WPI_RESULT_SUCCESS

paymentSolutionSupportedServiceTypes

Array

Conditional
- In case of WPI_RESULT_SUCCESS