ARTICLE AD BOX
I’m integrating NearPay SDK into a Flutter application to process NFC payments on an iMin POS device and print receipts using an iMin printer.
Environment
Flutter: 3.35.5
Android: minSdkVersion 26
NearPay SDK: latest version
Environment: Sandbox
Device: iMin POS (e.g. S1)
What works
NearPay SDK initializes successfully
NFC permissions are granted
The device and terminal are powered on
Problem
When attempting to connect to the terminal, the operation fails with the following error: user not found This happens even though the SDK initialization completes without any issues.
import 'package:donations/core/nearpay/terminal_config.dart';
import 'package:flutter/material.dart';
import 'package:flutter_terminal_sdk/flutter_terminal_sdk.dart';
import 'package:flutter_terminal_sdk/models/card_reader_callbacks.dart';
import 'package:flutter_terminal_sdk/models/data/ui_dock_position.dart';
import 'package:flutter_terminal_sdk/models/nearpay_user_response.dart';
import 'package:flutter_terminal_sdk/models/purchase_callbacks.dart';
import 'package:flutter_terminal_sdk/models/terminal_response.dart';
import 'package:uuid/uuid.dart';
final FlutterTerminalSdk _terminalSdk = FlutterTerminalSdk();
Future<void> initialize() async {
// initializing the terminalSDK may throw an exception, so wrap it in a try-catch block
try {
await \_terminalSdk.initialize( environment: Environment.sandbox, // Choose sandbox, production, internal googleCloudProjectNumber: 162056333315, // Add your google cloud project number huaweiSafetyDetectApiKey: "3lA5jiaqe14enqRRgsVPj0O5FRmEL4LUjsoDlqqXwNs7Jy7eO0pUFvAGhy4w", // Add your huawei safety detect api key uiDockPosition: UiDockPosition.BOTTOM_CENTER, // Optional: set the location of the Tap to Pay modal country: Country.sa, // Choose country: sa, tr, usa );} catch (e) {
print("Error initializing TerminalSDK: $e");}
}
Future<void> sendOtp(String mobile) async {
try {
await \_terminalSdk.sendMobileOtp(mobile); print("✅ OTP sent to $mobile");} catch (e) {
print("❌ Error sending OTP: $e");}
}
Future<TerminalModel?> connectToTerminal() async {
try {
print("🔄 جاري الاتصال بالـ Terminal (TID: ${TerminalConfig.tid})..."); // await initialize(); final result = await \_terminalSdk.connectTerminal( tid: TerminalConfig.tid, userUUID: TerminalConfig.userUUID, terminalUUID: TerminalConfig.terminalUUID, ); print(result); return result;} catch (e) {
print("❌ خطأ أثناء الاتصال: $e"); print(e.toString()); if (e.toString().contains("timeout")) { print("⏰ الجهاز غير متصل بالشبكة أو بعيد"); } else if (e.toString().contains("invalid")) { print("🔑 تأكدي من TID أو UUID"); } return null;}
}
Future<bool> transaction1(BuildContext context, String amount) async {
//await initialize();
final mobile = "+966509738300";
if (TerminalConfig.userUUID.isEmpty) {
await sendOtp(mobile); final code = await promptForOtp(context); if (code == null || code.isEmpty) { print("❌ User cancelled OTP entry"); return false; } final verified = await verifyOtp(mobile, code); if (!verified) { print("❌ OTP verification failed, aborting transaction"); return false; }} // خد userUUID
final connectedTerminal = await connectToTerminal();
if (connectedTerminal == null) {
print("فشل الاتصال بالترمينال، لا يمكن إتمام العملية"); return false;}
print(connectedTerminal?.tid ?? "");
double? amountDouble = double.tryParse(amount.replaceAll(',', ''));
try {
final intentUUID = const Uuid().v4(); final customerReferenceNumber = "01142674856"; await connectedTerminal?.purchase( intentUUID: intentUUID, amount: amountDouble?.toInt() ?? 0, callbacks: PurchaseCallbacks( cardReaderCallbacks: CardReaderCallbacks( onCardReadSuccess: () { print("success"); }, onReaderDismissed: () { print("Reader dismissed by user"); }, ), ), );print("connectedTerminal.terminalUUID:${connectedTerminal?.terminalUUID}"); print("connectedTerminal.name:${connectedTerminal?.name}");
print("connectedTerminal.tid:${connectedTerminal?.tid}");
return true;} catch (e) {
print(e.toString()); return false;}
}
Future<String?> promptForOtp(BuildContext context) async {
String otp = '';
return showDialog<String>(
context: context, barrierDismissible: false, builder: (context) =\> AlertDialog( title: Text('Enter OTP'), content: TextField( keyboardType: TextInputType.number, onChanged: (value) =\> otp = value, decoration: InputDecoration(hintText: "OTP code"), ), actions: \[ TextButton( onPressed: () =\> Navigator.of(context).pop(otp), child: Text('Submit'), ), \], ),);
}
Future<bool> verifyOtp(String mobile, String code) async {
try {
final user = await \_terminalSdk.verifyMobileOtp( mobileNumber: mobile, code: code, ); TerminalConfig.userUUID = user.userUUID ?? ""; print("✅ OTP verified, userUUID: ${TerminalConfig.userUUID}"); return TerminalConfig.userUUID.isNotEmpty;} catch (e) {
print("❌ Error verifying OTP: $e"); return false;}
}
I use transaction1 function
Question
Does the user not found error indicate that the terminal is not linked to the same merchant/user account as the API credentials, even though SDK initialization succeeds?
If so, what is the correct way to validate or fix the terminal–merchant configuration for sandbox testing?
