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The Nayax Marshall SDK offers a diverse range of payment flows, each designed to meet specific operational needs and dictate precisely how your system handles vending sessions, payment authorizations, and transaction processing. The following pages provide a more detailed description of each one:

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Single Session Flows

Single Session with Pre-Selection

Separate product selection from payment authorization in a single transaction.

Single Session with Pre-Authorization

Approve payment before the customer selects a product to minimize risk.

Single Session Pre-Authorization with External Settlement

Let a third-party server trigger final settlement or cancellation.

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Multi-Vend Flows

Multi-Vending with Pre-Selection

Dispense multiple selected products after the customer completes one payment.

Multi-Vending with Pre-Authorization

Let customers buy multiple products after a single upfront authorization.

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Multi-Session Flows

Multi-Session

Separate product selection from authorization and settlement across sessions.

Multi-Session Pre-Authorization with External Settlement

Manage multiple parallel transactions with an external settlement server.

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Additional Flows & Features

Sub Flows & Features

Start a transaction from product selection when full pre-selection isn’t available.

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Session Start Order With Prepaid Cards

The order of Begin Session and the authorization depends on the card type, which matters when you are matching what you see in the SDK log against the flow diagrams. With prepaid cards, the authorization comes first and Begin Session follows.
SDK log showing the authorization arriving before Begin Session for a prepaid card
With every other card type, Begin Session comes first and the authorization follows.
SDK log showing Begin Session arriving before the authorization
If you are unsure which flow is ideal for your machine type, the following table shows the recommended flow and configuration.