> ## Documentation Index
> Fetch the complete documentation index at: https://nayax-44d6e37b-docs-marshall-faq-redistribution.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Payment Flows

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:

## Single Session Flows

<CardGroup cols={3}>
  <Card icon="hand-pointer" title="Single Session with Pre-Selection" href="/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel">
    Separate product selection from payment authorization in a single transaction.
  </Card>

  <Card icon="shield-check" title="Single Session with Pre-Authorization" href="/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-auth">
    Approve payment before the customer selects a product to minimize risk.
  </Card>

  <Card icon="server" title="Single Session Pre-Authorization with External Settlement" href="/docs/integrate-pos-device/marshall/payment-flows/external-settlement-marshall">
    Let a third-party server trigger final settlement or cancellation.
  </Card>
</CardGroup>

## Multi-Vend Flows

<CardGroup cols={2}>
  <Card icon="cart-shopping" title="Multi-Vending with Pre-Selection" href="/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-vend-with-pre-sel">
    Dispense multiple selected products after the customer completes one payment.
  </Card>

  <Card icon="layer-group" title="Multi-Vending with Pre-Authorization" href="/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-vend-with-pre-auth">
    Let customers buy multiple products after a single upfront authorization.
  </Card>
</CardGroup>

## Multi-Session Flows

<CardGroup cols={2}>
  <Card icon="users" title="Multi-Session" href="/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session">
    Separate product selection from authorization and settlement across sessions.
  </Card>

  <Card icon="network-wired" title="Multi-Session Pre-Authorization with External Settlement" href="/docs/integrate-pos-device/marshall/payment-flows/multi-session-pre-authorization-with-external-settlement">
    Manage multiple parallel transactions with an external settlement server.
  </Card>
</CardGroup>

## Additional Flows & Features

<CardGroup cols={3}>
  <Card icon="puzzle-piece" title="Sub Flows & Features" href="/docs/integrate-pos-device/marshall/payment-flows/sub-flows-features">
    Start a transaction from product selection when full pre-selection isn't available.
  </Card>
</CardGroup>

## 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.

<Frame>
  <img src="https://mintcdn.com/nayax-44d6e37b-docs-marshall-faq-redistribution/Hbgg7w3lQTggebWl/images/docs/faq-marshall-flowconfigurations/image1.png?fit=max&auto=format&n=Hbgg7w3lQTggebWl&q=85&s=2851a802f22951d774a5ea72fa3cc906" alt="SDK log showing the authorization arriving before Begin Session for a prepaid card" width="995" height="687" data-path="images/docs/faq-marshall-flowconfigurations/image1.png" />
</Frame>

With every other card type, Begin Session comes first and the authorization follows.

<Frame>
  <img src="https://mintcdn.com/nayax-44d6e37b-docs-marshall-faq-redistribution/Hbgg7w3lQTggebWl/images/docs/faq-marshall-flowconfigurations/image2.png?fit=max&auto=format&n=Hbgg7w3lQTggebWl&q=85&s=82f182e85ab643a5f2f80cdf5f6800af" alt="SDK log showing Begin Session arriving before the authorization" width="994" height="689" data-path="images/docs/faq-marshall-flowconfigurations/image2.png" />
</Frame>

## Recommended Flows

If you are unsure which flow is ideal for your machine type, the following table shows the recommended flow and configuration.

| Machine Type          | Recommended Flow                                                                                                                                                                          | Recommended Configuration                                           |
| --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------- |
| Vending Machine       | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| Coin Exchanger        | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| Cotton Candy          | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle + Explicit Vend Success                                 |
| Photo Booth           | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| Coffee Machine        | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| Massage Chair         | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| Car Washing Machine   | [Single Session + Pre-Selection](/docs/integrate-pos-device/marshall/payment-flows/marshall-single-session-with-pre-sel)                                                                  | Always Idle                                                         |
| EV Charger 1          | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final                                                     |
| EV Charger 2          | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final + Mifare approved by VMC                            |
| EV Charger 3          | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final + Mifare approved by VMC + Info Session             |
| EV Charger 4          | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final + Mifare approved by VMC + Info Session + Always On |
| Smart Fridge          | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)+ [Sub flows / features](/docs/integrate-pos-device/marshall/payment-flows/sub-flows-features#/) | Price not final + Always On                                         |
| Power Bank            | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)+ [Sub flows / features](/docs/integrate-pos-device/marshall/payment-flows/sub-flows-features#/) | Price not final + Always On                                         |
| Locker                | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final                                                     |
| Racket Rental Machine | [Multi Session](/docs/integrate-pos-device/marshall/payment-flows/marshall-multi-session)                                                                                                 | Price not final + Always Idle                                       |

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