# Integration Paradigms

## Semi-Integrated <a href="#semi-integrated" id="semi-integrated"></a>

The payment device contains a complete payment application which interfaces to an external ECR/POS system, and handles all host interactions. The Payment SDK is embedded in the ECR/POS system.

{% @plantuml/diagram content="    @startuml

```
actor "Cashier"

component "BYOD\n" as byod <<device>> {
  rectangle "POS"
  rectangle "PSDK" as PSDK <<highlight>> {
    rectangle "Payment App\nProtocol Adapter" as ProtocolAdapter <<highlight>>
  }
  POS <<-d->> PSDK
  POS <<-l->> Cashier
}

component "POI\n" as POI <<device>> {
  rectangle "Payment App" as PaymentApp <<highlight>>
  ProtocolAdapter <<-r->> PaymentApp
}

actor "Customer"
PaymentApp <<-r->> Customer

cloud "Payment Host" as Host
PaymentApp <<-d->> Host

@enduml" %}
```

## Semi-Integrated <a href="#slim-integrated" id="slim-integrated"></a>

{% @plantuml/diagram content="    @startuml

```
actor "Cashier"

component "BYOD\n" as byod <<device>> {
  rectangle "POS"
  rectangle "PSDK" as PSDK <<highlight>> {
    rectangle "Payment App\nProtocol Adapter" as ProtocolAdapter <<highlight>>
  }
  POS <<-d->> PSDK
  POS <<-l->> Cashier
}

component "POI\n" as POI <<device>> {
  rectangle "Payment App" as PaymentApp <<highlight>>
  ProtocolAdapter <<-r->> PaymentApp
}

actor "Customer"
PaymentApp <<-r->> Customer

cloud "Payment Host" as Host
PaymentApp <<-d->> Host

@enduml" %}
```

## Slim-Integrated <a href="#slim-integrated" id="slim-integrated"></a>

In the slim-integrated model, supported only by the Android terminal, the payment application no longer communicates directly with the host, but rather sends a transaction event for host authorization/finalization to the POS application, which manages the host interactions.

{% @plantuml/diagram content="        @startuml
scale 300 width
scale 300 height

```
    component "Retailer ECR System\n" as ECR <<device>> #Ivory {
      rectangle "POS" #LightYellow {
        rectangle "Cross-Platform PSDK" #LightSkyBlue {
          rectangle "Payment Adapter" as PA
        }
      }
    }

    cloud "Payment Host" as HOST #ivory
    PA <<-d->> HOST

    component "Engage Payment Device\n" as Engage <<device>> 

    Engage -[hidden]> ECR
    hide Engage

    component "Android Payment Device\n" as Android <<device>> #Ivory {
      rectangle "POS Application" as POSAPP {
        rectangle "PSDK" as PSDKAND #LightSkyBlue
      }
      rectangle "Android Payment\nApplication" as AndroidAPP
      rectangle "Card Reader\nService" as CRS
      rectangle "Headless SDI" as HeadlessSDI #LightSalmon
      POSAPP <<-d->> AndroidAPP
      AndroidAPP <<-d->> CRS
      CRS <<-d->> HeadlessSDI 
      PA <<-r->> AndroidAPP
    }
   
    @enduml" %}
```

## Fully-integrated Android Design

{% @plantuml/diagram content="    @startuml

```
actor "Cashier"

component "BYOD\n" as byod <<device>> {
  rectangle "POS"
  rectangle "PSDK" as PSDK <<highlight>> {
    rectangle "Payment App\nProtocol Adapter" as ProtocolAdapter <<highlight>>
    rectangle "Host Module Adapter" as HostAdapter <<highlight>>
    ProtocolAdapter -[hidden]- HostAdapter
  }
  POS <<-d->> PSDK
  POS <<-l->> Cashier
}

component "POI\n" as POI <<device>> {
  rectangle "Payment App" as PaymentApp <<highlight>>
  rectangle "Host Module Proxy" as HostModule <<highlight>>
  PaymentApp <<-d->> HostModule
  ProtocolAdapter <<-r->> PaymentApp
  HostAdapter <<-r->> HostModule
}

actor "Customer"
PaymentApp <<-r->> Customer

cloud "Payment Host" as Host
POS <<-r->> Host

@enduml" %}
```

## Fully-integrated Engage Design

{% @plantuml/diagram content="    @startuml

```
actor "Cashier"

component "BYOD\n" as byod <<device>> {
  rectangle "POS"
  rectangle "PSDK" as PSDK <<highlight>> {
    rectangle "SDI\nProtocol Adapter" as ProtocolAdapter <<highlight>>
  }
  POS <<-d->> PSDK
  POS <<-l->> Cashier
}

component "POI\n" as POI <<device>> {
  rectangle "SDI Server" as PaymentApp <<highlight>>
  ProtocolAdapter <<-r->> PaymentApp
}

actor "Customer"
PaymentApp <<-r->> Customer

cloud "Payment Host" as Host
POS <<-r->> Host


@enduml" %}
```


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