API Reference

Last updated: 2026-05-20

API Reference

The EPAS wrappers expose a large shared surface area. The integration guides cover end-to-end workflows, while this page focuses on the concrete API objects developers typically look for when implementing, debugging, or mapping wrapper parity.

This page is curated rather than generated. It covers the common and high-value API surface across wrappers and calls out where .NET, Java, and Swift use different naming or structure.

Use the companion reference pages when you need lower-level lookup detail:

Core Client APIs

Connection and Session

Concept	.NET	Java	Swift
Create client	`new EpasClient(app)`	`new EpasClient(app)`	`EpasClient(delegate:)`
Connect	`ConnectNetwork(...)`	`connectNetwork(...)`	`connect(_:)`
Disconnect	`Disconnect()`	`disconnect()`	`disconnect()`
Login	`Login(...)`	`login(...)`	`login(_:)`
Logout	`Logout(...)`	`logout()`	`logout()`
Status	status handlers	status handlers	`status()`

Transactions

Concept	.NET	Java	Swift
Purchase	`Purchase(...)`	`purchase(...)`	`purchase(...)`
Purchase before amount	`PurchaseBeforeAmount(...)`	`purchaseBeforeAmount()`	`purchaseBeforeAmount()`
Send amounts	`SendPurchaseAmounts(...)`	`sendPurchaseAmounts(...)`	`sendPurchaseAmounts(_:)`
Refund	`Refund(...)`	`refund(...)`	`refund(...)`
Reversal	`ReverseLastTransaction(...)`	`reversal(...)`	`reverseLastTransaction(...)`
Cash advance	`CashAdvance(...)`	`cashAdvance(...)`	`cashAdvance(_:)`
Last transaction	`GetLastTransaction(...)`	`getLastTransaction(...)`	`getLastTransaction(_:)`
Abort	`RequestTransactionAbort()`	`requestTransactionAbort()`	`abort()`

Terminal Control and Diagnostics

Concept	.NET	Java	Swift
Enable readers	`EnableCardReaders(...)`	`enableCardReaders(...)`	`enableCardReaders(_:_:)`
Administrative operation	admin operation request	admin operation request	`requestAdministrativeOperation(_:)`
Raw XML	`SendRawXml(...)`	`sendRawXml(...)`, `sendRawXmlWithResult(...)`	`sendRawXml(_:)`
Customer inquiry	`SendCustomerInquiry(...)`, `AbortCustomerInquiry()`	`sendCustomerInquiry(...)`, `abortCustomerInquiry()`	`sendCustomerInquiry(...)`, `abortCustomerInquiry()`
Print request	`Print(...)`	`requestPrint(...)`	`requestPrint(...)`
Log-file helpers	`CleanAllLogFiles()`, `StartNewLogFile()`, `StopLogFileTemporarily()`	`cleanAllLogFiles()`, `startNewLogFile()`, `stopLogFileTemporarily()`	`cleanAllLogFiles()`, `startNewLogFile()`, `stopLogFileTemporarily()`
Log-part controls	none	`enableLogPart(...)`, `disableLogPart(...)`, `enableAllLogParts()`, `disableAllLogParts()`	`enableLogPart(_:)`, `disableLogPart(_:)`, `enableAllLogParts()`, `disableAllLogParts()`

Core Request and Response Models

Shared Core Models

Model	Purpose
`TerminalNetworkConnection`	Terminal IP endpoint, port, and keepalive preference.
`TerminalEnvironment`	Login context including terminal ID, workstation, operator, language, and backend hosts.
`PurchaseTransactionAmounts`	Purchase amount, cashback, and related numeric transaction data.
`PurchaseRequest`	Full purchase request including amount, payment method, MCC, and optional terminal override.
`RefundRequest`	Refund amount plus alternative payment method and original reference where needed.
`TransactionResponse`	Final transaction business outcome.
`LoginResponse`	Login result and terminal feature information.
`LogoutResponse`	Logout result.
`EnableReadersResponse`	Result of opening or closing terminal card readers.
`AdminResponse`	Result of administrative operations such as host login or parameter update.
`LastTransactionResponse`	Terminal-provided details for the most recent transaction.
`ReceiptData`	Structured receipt model used in receipt callbacks.

Swift-Specific Compatibility Types

The Swift wrapper preserves the conceptual model but adapts it to Apple conventions.

Swift type	Purpose
`ClientStatus`	Snapshot of connection, login, busy state, card state, and terminal ID.
`BooleanCallbackResult`	`handled + value` result for yes/no callbacks.
`TextCallbackResult`	`handled + value` result for text-entry callbacks.
`DecimalCallbackResult`	`handled + value` result for amount-entry callbacks.
`EpasClientError`	Swift error wrapper for API results, terminal rejection, and invalid client state.

Important Enums and Constants

Cross-Wrapper Operational Enums

Type	Purpose	Notes
`ApiResult`	Communication and library-level result code.	Not the same as payment approval.
`ErrorConditions` / `ErrorCondition`	Terminal-side business or protocol error classification.	`.NET` and `Java` use `ErrorConditions`; `Swift` uses `ErrorCondition`.
`TransactionType`	Purchase, refund, reversal, cash advance, and related transaction categories.	Used in transaction history and receipt contexts.
`ServiceEnableType`	Reader opening mode such as payment or refund.	Used with reader control APIs.
`AdminOperation`	Terminal administrative action to request.	Examples: host login, print configuration, parameter update.
`ReceiptVersion`	Merchant vs cardholder receipt copy.	Used by receipt callbacks and receipt history.
`TransactionOutcome`	Approved, declined, cancelled, and related receipt outcome classification.	Primarily receipt-facing.

Receipt and Card Interpretation Enums

These are especially relevant when printing receipts, auditing card usage, or mapping last-transaction data.

Type	Present in	Purpose
`EntryMethod`	.NET, Java	How the card was presented, for example chip, swipe, manual, or contactless.
`VerificationMethod`	.NET, Java	Cardholder verification method such as signature, online PIN, offline PIN, consumer device, or no CVM.
`AuthorisationChannel`	.NET, Java	Whether authorisation was online, offline, by phone, or not performed.
`AuthorisingEntity`	.NET, Java	Which party approved or declined the transaction.
`CurrencyCodes`	Java, .NET concepts	Operating or transaction currency selection.

These types are especially important for advanced reporting, receipt presentation, and support tooling. If you need the fuller language-specific wrapper deliveries, use Library Downloads.

Configuration and Operating Parameters

The wrappers also expose transaction-environment and operating-parameter settings that influence runtime behaviour.

Type	Typical fields or purpose
`OperatingParameters`	Currency, tipping, wait-for-card-removal, log storage, keepalive tuning, and related client behaviour.
`CardAcceptedEventArgs`	Masked card details delivered when the terminal accepts a card.

These are particularly important when building operator-facing sample applications or diagnostics tools.

Callback Contracts

The callback model is a major part of the public API surface.

Core operational callbacks

display cashier text
print receipt
print report
verify signature
handle voice referral
request payment code
request VAT amount
react to loyalty card presentation
check DCC status on original transaction
allow or defer parameter download
receive log entries

Status and notification callbacks

link status changed
terminal busy state changed
card inserted or removed
card accepted
raw EPAS message received

See Client Callbacks for behavioural guidance and callback examples.

How to Read Wrapper Parity

The wrappers aim to keep the same business concepts, but some names differ:

.NET often uses PascalCase methods and out parameters
Java often returns Pair<ApiResult, T>
Swift uses camelCase, async or await, and throws

When the same concept appears with slightly different names, treat the integration flow as the authoritative parity target and the language surface as the language adaptation.

Full Wrapper Deliveries

The current portal pages are intentionally curated and integration-focused. If you need the fuller wrapper deliveries for .NET, Java, or Swift, use Library Downloads.