Introduction
App-to-app payment integration with the POS+ application using the PlusPay A2A packages.
PlusPay A2A (app-to-app) lets your application start payments, cancellations, end-of-day and parameter operations on the POS+ application that runs on the same Android device, query the state of transactions and orders, and receive a strongly-typed result back.
Your app never talks to the card reader or the banking network directly. It hands a request to POS+, POS+ performs the payment on its certified payment stack, and returns the outcome to your app.
How it works
┌─────────────┐ 1. request (Intent) ┌─────────────┐
│ │ ───────────────────────▶ │ │
│ Your App │ │ POS+ │
│ │ ◀─────────────────────── │ │
└─────────────┘ 2. result (broadcast) └─────────────┘- Your app builds a typed request and calls a method on the A2A client.
- The client launches POS+ through an Android Intent.
- POS+ runs the transaction (card, cash, wallet, EFT-POS, …).
- POS+ returns the result; the client parses it into a typed response object, or throws a typed error.
Because the integration is Intent + broadcast based, it is Android only. There is no iOS support.
Which package do I use?
There are three packages that expose the same capabilities. Pick the one that matches your app's technology:
pluspay_a2a (Flutter)
A Flutter plugin. Use it from Dart/Flutter apps. Strongly-typed Freezed request/response models.
pluspay_a2a_native (Android)
A native Android library (.aar). Use it from Kotlin or Java apps. Offers
both callback and Kotlin coroutine APIs.
pluspay_a2a_react_native (React Native)
A React Native module. Use it from JavaScript/TypeScript apps. Android only.
Throughout this documentation every code sample is shown for Flutter, Kotlin, Java and React Native in a tabbed block, so the same flow is described once for all of them.
Supported operations
| Operation | Method | Result |
|---|---|---|
| Start a payment | startPayment | PPStartPaymentResponseModel |
| Cancel a payment | cancelPayment | PPStartPaymentResponseModel |
| Start an EFT-POS payment | startEftPayment | PPStartPaymentResponseModel |
| Cancel an EFT-POS payment | cancelEftPayment | PPStartPaymentResponseModel |
| Pay an existing order | startOrderPayment | PPOrderPaymentResponseModel |
| Multi-payment / order | startMultiPayment | PPMultiPaymentResponseModel |
| Create an order without payment ¹ | createOrder | PPOrderCreateResponseModel |
| End-of-day (settlement) | triggerEod | PPEodResponseModel |
| Parameter update | triggerParameters | PPParametersResponseModel |
| Available payment methods ¹ | getAvailablePaymentMethods | PPAvailablePaymentMethodsResponseModel |
| Query a transaction ¹ | getTransactionResult | PPStartPaymentResponseModel |
| Query an order ¹ | getOrderResult | PPOrderPaymentResponseModel |
| Technical cancel ¹ | technicalCancel | PPTechnicalCancelResponseModel |
¹ Flutter and React Native only. The native Android package does not support these operations yet. The last three need Flutter 0.8.0 / React Native 0.4.0.
Authentication
A2A runs entirely on-device: your app and POS+ exchange data through Android intents, so there is no API key or token to configure. POS+ authenticates the cardholder and settles the transaction with the bank.
Next steps
Installation
Add the package to your Flutter, Android or React Native project.
Initialization
Create and manage the A2A client lifecycle.
Payments
Start, cancel, EFT and order payments.
Status queries & recovery
Find out what happened to a transaction and reverse it if needed.
Reference
Enums and response model fields.