fix: clear balance stream cache in deleteDatabase() and reset()

fix: use deterministic transaction ID for send/mint metadata

lib/providers/wallet_provider.dart

@@ -68,6 +68,10 @@ class WalletProvider extends ChangeNotifier {
   /// Caché de MintInfo por URL (nombre, logo, contactos, etc.)
   final Map<String, MintInfo> _mintInfoCache = {};
 
+  /// Caché del balance stream para evitar recrear StreamSink en cada build().
+  Stream<BigInt>? _cachedBalanceStream;
+  String? _cachedBalanceKey;
+
   /// Mint activo actualmente
   String? _activeMintUrl;
 
@@ -602,8 +606,21 @@ class WalletProvider extends ChangeNotifier {
   // ============================================================
 
   /// Stream de balance del wallet activo (reactivo).
+  /// Cacheado para que StreamBuilder reciba el mismo objeto entre rebuilds
+  /// y no mate el StreamSink de Rust.
   Stream<BigInt>? streamBalance() {
-    return activeWallet?.streamBalance();
+    final wallet = activeWallet;
+    if (wallet == null) {
+      _cachedBalanceStream = null;
+      _cachedBalanceKey = null;
+      return null;
+    }
+    final key = '$_activeMintUrl:$_activeUnit';
+    if (_cachedBalanceKey != key) {
+      _cachedBalanceStream = wallet.streamBalance().asBroadcastStream();
+      _cachedBalanceKey = key;
+    }
+    return _cachedBalanceStream;
   }
 
   /// Obtiene el balance del wallet activo.
@@ -979,45 +996,33 @@ class WalletProvider extends ChangeNotifier {
   Future<String> confirmSend(PreparedSend prepared, String? memo) async {
     final wallet = await getActiveWallet();
 
-    final token = await wallet.send(
+    final result = await wallet.send(
       send: prepared,
       memo: memo,
       includeMemo: memo != null && memo.isNotEmpty,
     );
 
-    // Guardar token en storage local para mostrar en detalles del historial.
-    // Usamos hash del token como key temporal; después buscaremos la transacción.
-    await _saveTokenForRecentTransaction(token.encoded);
-
-    notifyListeners();
-    return token.encoded;
-  }
-
-  /// Guarda el token para la transacción más reciente de tipo send.
-  Future<void> _saveTokenForRecentTransaction(String tokenEncoded) async {
-    try {
-      // Obtener transacciones outgoing más recientes
-      final wallet = await getActiveWallet();
-      final txs = await wallet.listTransactions(
-        direction: TransactionDirection.outgoing,
-      );
-
-      if (txs.isNotEmpty) {
-        // La más reciente debería ser la que acabamos de crear
-        final recentTx = txs.first;
-
+    // Save token metadata using the deterministic transaction ID returned by CDK
+    // (SHA-256 of sorted proof Y values — no racy listTransactions needed)
+    // Best-effort: don't fail the send if metadata persistence fails
+    final txId = result.transactionId;
+    if (txId != null && txId.isNotEmpty) {
+      try {
         await _txMetaStorage.save(
-          recentTx.id,
+          txId,
           TransactionMeta(
             type: TransactionType.cashu,
-            token: tokenEncoded,
+            token: result.token.encoded,
           ),
         );
-        debugPrint('Token guardado para tx ${recentTx.id}');
+        debugPrint('Token guardado para tx $txId');
+      } catch (e) {
+        debugPrint('Error guardando send metadata: $e');
       }
-    } catch (e) {
-      debugPrint('Error guardando token metadata: $e');
     }
+
+    notifyListeners();
+    return result.token.encoded;
   }
 
   /// Cancela un envío preparado (libera proofs reservados).
@@ -1129,12 +1134,14 @@ class WalletProvider extends ChangeNotifier {
       _activeMintController!.close();
     }
 
-    // StreamController que la UI puede escuchar y cancelar libremente
-    final controller = StreamController<MintQuote>();
+    // StreamController que la UI puede escuchar y cancelar libremente.
+    // sync: true para no perder eventos rápidos (paid → issued en µs).
+    final controller = StreamController<MintQuote>(sync: true);
     _activeMintController = controller;
 
-    // Cancelar suscripción anterior si existe (await evita race de callbacks)
-    await _activeMintSubscription?.cancel();
+    // Cancelar suscripción anterior sin await: el task de Rust (polling + WS)
+    // puede tardar en cerrar y bloquearía la creación de una nueva factura.
+    _activeMintSubscription?.cancel();
     _activeMintSubscription = null;
 
     // Suscribirse al stream del CDK desde el provider (persiste sin UI)
@@ -1142,7 +1149,7 @@ class WalletProvider extends ChangeNotifier {
       amount: amount,
       description: description,
     ).listen(
-      (quote) {
+      (quote) async {
         // Guardar invoice temprano en SharedPreferences
         if (quote.state == MintQuoteState.unpaid) {
           invoiceBolt11 = quote.request;
@@ -1151,8 +1158,10 @@ class WalletProvider extends ChangeNotifier {
 
         // Cuando se completa, guardar metadata, confetti, limpiar pending
         if (quote.state == MintQuoteState.issued && invoiceBolt11 != null) {
-          _saveMintMetadata(wallet, invoiceBolt11!);
-          _removePendingMintInvoice(quote.id);
+          final saved = await _saveMintMetadata(wallet, invoiceBolt11!, quote.transactionId);
+          // Only remove pending invoice if metadata was saved;
+          // otherwise _matchPendingMintInvoices can recover it on next startup
+          if (saved) _removePendingMintInvoice(quote.id);
         }
 
         // Reenviar a la UI (si sigue escuchando)
@@ -1386,28 +1395,30 @@ class WalletProvider extends ChangeNotifier {
   }
 
   /// Guarda metadata para una transacción de mint (Lightning deposit).
-  Future<void> _saveMintMetadata(Wallet wallet, String invoice) async {
+  /// Returns true if metadata was actually saved.
+  Future<bool> _saveMintMetadata(Wallet wallet, String invoice, String? transactionId) async {
     try {
-      final txs = await wallet.listTransactions(
-        direction: TransactionDirection.incoming,
-      );
-
-      if (txs.isNotEmpty) {
-        final recentTx = txs.first;
-
+      if (transactionId != null && transactionId.isNotEmpty) {
         await _txMetaStorage.save(
-          recentTx.id,
+          transactionId,
           TransactionMeta(
             type: TransactionType.lightning,
             invoice: invoice,
           ),
         );
-        debugPrint('Mint metadata guardada para tx ${recentTx.id}');
+        debugPrint('Mint metadata guardada para tx $transactionId');
         confettiController.fire();
         notifyListeners();
+        return true;
+      } else {
+        debugPrint('Mint metadata: no transaction ID available');
+        confettiController.fire();
+        notifyListeners();
+        return false;
       }
     } catch (e) {
       debugPrint('Error guardando mint metadata: $e');
+      return false;
     }
   }
 
@@ -1735,7 +1746,7 @@ class WalletProvider extends ChangeNotifier {
               // Enviar todo el balance
               final prepared =
                   await tempWallet.prepareSend(amount: tempBalance);
-              final token = await tempWallet.send(
+              final result = await tempWallet.send(
                 send: prepared,
                 memo: 'Recuperación El Caju',
                 includeMemo: true,
@@ -1743,7 +1754,7 @@ class WalletProvider extends ChangeNotifier {
 
               // Reclamar en nuestro wallet
               final ourWallet = await getWallet(mintUrl, unit);
-              final received = await ourWallet.receive(token: token);
+              final received = await ourWallet.receive(token: result.token);
               totalRecovered += received;
             }
           } catch (e) {
@@ -1782,6 +1793,8 @@ class WalletProvider extends ChangeNotifier {
       _activeUnit = 'sat';
       _mnemonic = null;
       _db = null;
+      _cachedBalanceStream = null;
+      _cachedBalanceKey = null;
 
       // Limpiar metadata de transacciones
       await _txMetaStorage.clear();
@@ -1810,6 +1823,8 @@ class WalletProvider extends ChangeNotifier {
     _activeUnit = 'sat';
     _mnemonic = null;
     _db = null;
+    _cachedBalanceStream = null;
+    _cachedBalanceKey = null;
     notifyListeners();
   }
 
@@ -1985,6 +2000,8 @@ class WalletProvider extends ChangeNotifier {
     if (_activeMintController != null && !_activeMintController!.isClosed) {
       _activeMintController!.close();
     }
+    _cachedBalanceStream = null;
+    _cachedBalanceKey = null;
     confettiController.dispose();
     super.dispose();
   }

lib/screens/12_request/request_screen.dart

@@ -11,7 +11,8 @@ import 'package:elcaju/l10n/app_localizations.dart';
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
 import '../../core/utils/formatters.dart';
-import '../../core/utils/bip321_builder.dart';
+// TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+// import '../../core/utils/bip321_builder.dart';
 import '../../core/services/nfc_service.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
@@ -45,7 +46,9 @@ class _RequestScreenState extends State<RequestScreen> {
   // Payment data
   String? _creqB;
   String? _bolt11;
-  QrMode _activeMode = QrMode.cashu;
+  // TODO: re-enable QrMode.cashu / universal once CDK fixes NIP-17 sender pubkey bug
+  // See: https://github.com/cashubtc/cdk/issues/1807
+  // QrMode _activeMode = QrMode.lightning;
   bool _paymentHandled = false;
 
   // Listeners
@@ -72,10 +75,11 @@ class _RequestScreenState extends State<RequestScreen> {
   @override
   void dispose() {
     _descriptionController.dispose();
+    // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+    // No-op while Nostr is disabled (_nostrSubscription is always null, _creqB is always null)
     _nostrSubscription?.cancel();
     _mintSubscription?.cancel();
     if (_nfcEmulating) NfcService.stopEmulating();
-    // Clear persisted request if user abandoned without receiving payment
     if (!_paymentHandled && _creqB != null) {
       _walletProvider.removePendingNostrRequest();
     }
@@ -349,42 +353,37 @@ class _RequestScreenState extends State<RequestScreen> {
                           version: QrVersions.auto,
                           size: 260,
                           backgroundColor: Colors.white,
-                          errorCorrectionLevel: _activeMode == QrMode.universal
-                              ? QrErrorCorrectLevel.M
-                              : QrErrorCorrectLevel.H,
+                          // TODO: use QrErrorCorrectLevel.M for universal mode once CDK fixes NIP-17 (cashubtc/cdk#1807)
+                          errorCorrectionLevel: QrErrorCorrectLevel.H,
                         ),
-                        if (_activeMode == QrMode.cashu)
-                          Container(
-                            width: 48,
-                            height: 48,
-                            decoration: BoxDecoration(
-                              color: Colors.white,
-                              borderRadius: BorderRadius.circular(10),
-                              border: Border.all(color: Colors.white, width: 4),
-                            ),
-                            child: ClipRRect(
-                              borderRadius: BorderRadius.circular(6),
-                              child: Image.asset(
-                                'assets/img/cashu.png',
-                                fit: BoxFit.contain,
-                              ),
-                            ),
+                        // TODO: re-enable Cashu logo overlay once CDK fixes NIP-17 (cashubtc/cdk#1807)
+                        // if (_activeMode == QrMode.cashu)
+                        //   Container(
+                        //     width: 48, height: 48,
+                        //     decoration: BoxDecoration(
+                        //       color: Colors.white,
+                        //       borderRadius: BorderRadius.circular(10),
+                        //       border: Border.all(color: Colors.white, width: 4),
+                        //     ),
+                        //     child: ClipRRect(
+                        //       borderRadius: BorderRadius.circular(6),
+                        //       child: Image.asset('assets/img/cashu.png', fit: BoxFit.contain),
+                        //     ),
+                        //   ),
+                        Container(
+                          width: 48,
+                          height: 48,
+                          decoration: BoxDecoration(
+                            color: AppColors.bitcoinOrange,
+                            borderRadius: BorderRadius.circular(10),
+                            border: Border.all(color: Colors.white, width: 4),
                           ),
-                        if (_activeMode == QrMode.lightning)
-                          Container(
-                            width: 48,
-                            height: 48,
-                            decoration: BoxDecoration(
-                              color: AppColors.bitcoinOrange,
-                              borderRadius: BorderRadius.circular(10),
-                              border: Border.all(color: Colors.white, width: 4),
-                            ),
-                            child: const Icon(
-                              LucideIcons.zap,
-                              color: Colors.white,
-                              size: 28,
-                            ),
+                          child: const Icon(
+                            LucideIcons.zap,
+                            color: Colors.white,
+                            size: 28,
                           ),
+                        ),
                       ],
                     ),
                   ),
@@ -437,73 +436,66 @@ class _RequestScreenState extends State<RequestScreen> {
   }
 
   Widget _buildModeToggle() {
-    return Container(
-      padding: const EdgeInsets.all(4),
-      decoration: BoxDecoration(
-        color: Colors.white.withValues(alpha: 0.1),
-        borderRadius: BorderRadius.circular(12),
-      ),
-      child: Row(
-        children: [
-          _buildToggleButton(
-            label: L10n.of(context)!.universal,
-            mode: QrMode.universal,
-            enabled: _bolt11 != null,
-          ),
-          _buildToggleButton(
-            label: 'Cashu',
-            mode: QrMode.cashu,
-            enabled: true,
-          ),
-          _buildToggleButton(
-            label: 'Lightning',
-            mode: QrMode.lightning,
-            enabled: _bolt11 != null,
-          ),
-        ],
-      ),
+    // TODO: re-enable Universal/Cashu tabs once CDK fixes NIP-17 (cashubtc/cdk#1807)
+    // Hidden while only Lightning is available (single button toggle is a no-op)
+    return const SizedBox.shrink(
+      // child: Container(
+      //   padding: const EdgeInsets.all(4),
+      //   decoration: BoxDecoration(
+      //     color: Colors.white.withValues(alpha: 0.1),
+      //     borderRadius: BorderRadius.circular(12),
+      //   ),
+      //   child: Row(
+      //     children: [
+      //       _buildToggleButton(label: L10n.of(context)!.universal, mode: QrMode.universal, enabled: _bolt11 != null),
+      //       _buildToggleButton(label: 'Cashu', mode: QrMode.cashu, enabled: true),
+      //       _buildToggleButton(label: 'Lightning', mode: QrMode.lightning, enabled: _bolt11 != null),
+      //     ],
+      //   ),
+      // ),
     );
   }
 
-  Widget _buildToggleButton({
-    required String label,
-    required QrMode mode,
-    required bool enabled,
-  }) {
-    final isActive = _activeMode == mode;
-    return Expanded(
-      child: GestureDetector(
-        onTap: enabled
-            ? () {
-                setState(() => _activeMode = mode);
-                _updateNfcPayload();
-              }
-            : null,
-        child: Container(
-          padding: const EdgeInsets.symmetric(vertical: 10),
-          decoration: BoxDecoration(
-            gradient: isActive
-                ? const LinearGradient(colors: AppColors.buttonGradient)
-                : null,
-            borderRadius: BorderRadius.circular(10),
-          ),
-          child: Center(
-            child: Text(
-              label,
-              style: TextStyle(
-                fontFamily: 'Inter',
-                fontSize: 13,
-                fontWeight: isActive ? FontWeight.w600 : FontWeight.w400,
-                color: enabled
-                    ? (isActive ? Colors.white : AppColors.textSecondary)
-                    : Colors.white.withValues(alpha: 0.3),
-              ),
-            ),
-          ),
-        ),
-      ),
-    );
-  }
+  // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+  // Widget _buildToggleButton({
+  //   required String label,
+  //   required QrMode mode,
+  //   required bool enabled,
+  // }) {
+  //   final isActive = _activeMode == mode;
+  //   return Expanded(
+  //     child: GestureDetector(
+  //       onTap: enabled
+  //           ? () {
+  //               setState(() => _activeMode = mode);
+  //               _updateNfcPayload();
+  //             }
+  //           : null,
+  //       child: Container(
+  //         padding: const EdgeInsets.symmetric(vertical: 10),
+  //         decoration: BoxDecoration(
+  //           gradient: isActive
+  //               ? const LinearGradient(colors: AppColors.buttonGradient)
+  //               : null,
+  //           borderRadius: BorderRadius.circular(10),
+  //         ),
+  //         child: Center(
+  //           child: Text(
+  //             label,
+  //             style: TextStyle(
+  //               fontFamily: 'Inter',
+  //               fontSize: 13,
+  //               fontWeight: isActive ? FontWeight.w600 : FontWeight.w400,
+  //               color: enabled
+  //                   ? (isActive ? Colors.white : AppColors.textSecondary)
+  //                   : Colors.white.withValues(alpha: 0.3),
+  //             ),
+  //           ),
+  //         ),
+  //       ),
+  //     ),
+  //   );
+  // }
 
   Widget _buildActionButtons() {
     return Row(
@@ -712,11 +704,12 @@ class _RequestScreenState extends State<RequestScreen> {
 
   // ─── Logic ───
 
-  static const List<String> _defaultNostrRelays = [
-    'wss://relay.damus.io',
-    'wss://relay.primal.net',
-    'wss://nos.lol',
-  ];
+  // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+  // static const List<String> _defaultNostrRelays = [
+  //   'wss://relay.damus.io',
+  //   'wss://relay.primal.net',
+  //   'wss://nos.lol',
+  // ];
 
   Future<void> _generateRequest() async {
     final walletProvider = context.read<WalletProvider>();
@@ -734,7 +727,9 @@ class _RequestScreenState extends State<RequestScreen> {
     _paymentHandled = false;
     _creqB = null;
     _bolt11 = null;
-    _activeMode = QrMode.cashu;
+    // TODO: re-enable Cashu/Nostr payment request once CDK fixes NIP-17 sender pubkey bug
+    // See: https://github.com/cashubtc/cdk/issues/1807
+    // _activeMode = QrMode.lightning;
 
     setState(() => _status = RequestStatus.generating);
 
@@ -751,35 +746,39 @@ class _RequestScreenState extends State<RequestScreen> {
           ? _descriptionController.text
           : null;
 
-      // 1. Create payment request (creqB + Nostr keys)
-      final request = await wallet.createPaymentRequest(
-        params: CreateRequestParams(
-          amount: _amount,
-          unit: _activeUnit,
-          description: description,
-          nostrRelays: _defaultNostrRelays,
-        ),
+      // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+      // // 1. Create payment request (creqB + Nostr keys)
+      // final request = await wallet.createPaymentRequest(
+      //   params: CreateRequestParams(
+      //     amount: _amount,
+      //     unit: _activeUnit,
+      //     description: description,
+      //     nostrRelays: _defaultNostrRelays,
+      //   ),
+      // );
+      //
+      // _creqB = request.creqB;
+      //
+      // // Persist handle for recovery if app is killed
+      // await walletProvider.savePendingNostrRequest(
+      //   request.listenerHandle.toPersisted(),
+      // );
+      //
+      // // 2. Start Nostr listener
+      // _nostrSubscription = wallet
+      //     .waitForNostrPayment(handle: request.listenerHandle)
+      //     .listen(_onNostrEvent);
+
+      // Lightning invoice generation via wallet provider
+      // (walletProvider.mintTokens handles pending invoice persistence and metadata)
+      final mintStream = await walletProvider.mintTokens(
+        _amount,
+        description,
       );
-
-      _creqB = request.creqB;
-
-      // Persist handle for recovery if app is killed
-      await walletProvider.savePendingNostrRequest(
-        request.listenerHandle.toPersisted(),
-      );
-
-      // 2. Start Nostr listener
-      _nostrSubscription = wallet
-          .waitForNostrPayment(handle: request.listenerHandle)
-          .listen(_onNostrEvent);
-
-      // 3. Start Lightning invoice generation directly via CDK
-      _mintSubscription = wallet
-          .mint(amount: _amount, description: description)
-          .listen(_onMintEvent);
-
-      setState(() => _status = RequestStatus.waiting);
+      if (!mounted) return;
+      _mintSubscription = mintStream.listen(_onMintEvent);
     } catch (e) {
+      if (!mounted) return;
       setState(() {
         _status = RequestStatus.error;
         _errorMessage = e.toString();
@@ -787,14 +786,15 @@ class _RequestScreenState extends State<RequestScreen> {
     }
   }
 
-  void _onNostrEvent(NostrPaymentEvent event) {
-    if (!mounted || _paymentHandled) return;
-    if (event.state == NostrPaymentState.received) {
-      _paymentHandled = true;
-      _mintSubscription?.cancel();
-      _onPaymentSuccess(event.amount ?? _amount);
-    }
-  }
+  // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+  // void _onNostrEvent(NostrPaymentEvent event) {
+  //   if (!mounted || _paymentHandled) return;
+  //   if (event.state == NostrPaymentState.received) {
+  //     _paymentHandled = true;
+  //     _mintSubscription?.cancel();
+  //     _onPaymentSuccess(event.amount ?? _amount);
+  //   }
+  // }
 
   void _onMintEvent(MintQuote quote) {
     if (!mounted) return;
@@ -803,7 +803,9 @@ class _RequestScreenState extends State<RequestScreen> {
         if (_bolt11 == null) {
           setState(() {
             _bolt11 = quote.request;
-            _activeMode = QrMode.universal;
+            // TODO: switch to QrMode.universal once CDK fixes NIP-17 (cashubtc/cdk#1807)
+            // _activeMode = QrMode.lightning;
+            _status = RequestStatus.waiting;
           });
           _updateNfcPayload();
         }
@@ -816,7 +818,17 @@ class _RequestScreenState extends State<RequestScreen> {
         }
         break;
       case MintQuoteState.error:
-        // Lightning failed, but Nostr listener continues
+        // No Nostr fallback while CDK NIP-17 bug is open (cashubtc/cdk#1807)
+        if (!_paymentHandled) {
+          if (_nfcEmulating) {
+            NfcService.stopEmulating();
+            _nfcEmulating = false;
+          }
+          setState(() {
+            _status = RequestStatus.error;
+            _errorMessage = quote.error ?? L10n.of(context)!.unknownError;
+          });
+        }
         break;
       default:
         break;
@@ -831,20 +843,22 @@ class _RequestScreenState extends State<RequestScreen> {
     });
     final walletProvider = context.read<WalletProvider>();
     walletProvider.confettiController.fire();
-    await walletProvider.removePendingNostrRequest();
+    // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+    // Only remove pending Nostr request if this screen created one.
+    // Disabled while Nostr payment requests are disabled to avoid
+    // deleting a recovery record from a previous session.
+    // await walletProvider.removePendingNostrRequest();
   }
 
   // ─── QR Content ───
 
   String _getActiveQrContent() {
-    switch (_activeMode) {
-      case QrMode.universal:
-        return buildUnifiedUri(creqB: _creqB!, bolt11: _bolt11);
-      case QrMode.cashu:
-        return _creqB!.toUpperCase();
-      case QrMode.lightning:
-        return _bolt11?.toUpperCase() ?? '';
-    }
+    // TODO: re-enable once CDK fixes NIP-17 (cashubtc/cdk#1807)
+    // case QrMode.universal:
+    //   return buildUnifiedUri(creqB: _creqB!, bolt11: _bolt11);
+    // case QrMode.cashu:
+    //   return _creqB!.toUpperCase();
+    return _bolt11?.toUpperCase() ?? '';
   }
 
   // ─── Actions ───

lib/src/rust/api/wallet.dart

@@ -109,7 +109,7 @@ abstract class Wallet implements RustOpaqueInterface {
 
   Future<void> restore();
 
-  Future<Token> send({
+  Future<SendResult> send({
     required PreparedSend send,
     String? memo,
     bool? includeMemo,
@@ -182,6 +182,9 @@ class MintQuote {
   final Token? token;
   final String? error;
 
+  /// Deterministic transaction ID (set when state == Issued)
+  final String? transactionId;
+
   const MintQuote({
     required this.id,
     required this.request,
@@ -190,6 +193,7 @@ class MintQuote {
     required this.state,
     this.token,
     this.error,
+    this.transactionId,
   });
 
   @override
@@ -200,7 +204,8 @@ class MintQuote {
       expiry.hashCode ^
       state.hashCode ^
       token.hashCode ^
-      error.hashCode;
+      error.hashCode ^
+      transactionId.hashCode;
 
   @override
   bool operator ==(Object other) =>
@@ -213,7 +218,8 @@ class MintQuote {
           expiry == other.expiry &&
           state == other.state &&
           token == other.token &&
-          error == other.error;
+          error == other.error &&
+          transactionId == other.transactionId;
 }
 
 enum MintQuoteState { unpaid, paid, issued, error }
@@ -260,6 +266,29 @@ class SendOptions {
           includeFee == other.includeFee;
 }
 
+/// Result of a confirmed send, carrying both the ecash token and the
+/// deterministic transaction ID so Dart can save metadata without a racy
+/// listTransactions lookup.
+class SendResult {
+  final Token token;
+
+  /// Deterministic transaction ID (None if computation failed)
+  final String? transactionId;
+
+  const SendResult({required this.token, this.transactionId});
+
+  @override
+  int get hashCode => token.hashCode ^ transactionId.hashCode;
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is SendResult &&
+          runtimeType == other.runtimeType &&
+          token == other.token &&
+          transactionId == other.transactionId;
+}
+
 class Transaction {
   final String id;
   final String mintUrl;

lib/src/rust/frb_generated.dart

@@ -280,7 +280,7 @@ abstract class RustLibApi extends BaseApi {
 
   Future<void> crateApiWalletWalletRestore({required Wallet that});
 
-  Future<Token> crateApiWalletWalletSend({
+  Future<SendResult> crateApiWalletWalletSend({
     required Wallet that,
     required PreparedSend send,
     String? memo,
@@ -2005,7 +2005,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
       const TaskConstMeta(debugName: "Wallet_restore", argNames: ["that"]);
 
   @override
-  Future<Token> crateApiWalletWalletSend({
+  Future<SendResult> crateApiWalletWalletSend({
     required Wallet that,
     required PreparedSend send,
     String? memo,
@@ -2033,7 +2033,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
           );
         },
         codec: SseCodec(
-          decodeSuccessData: sse_decode_token,
+          decodeSuccessData: sse_decode_send_result,
           decodeErrorData: sse_decode_error,
         ),
         constMeta: kCrateApiWalletWalletSendConstMeta,
@@ -3044,8 +3044,8 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
   MintQuote dco_decode_mint_quote(dynamic raw) {
     // Codec=Dco (DartCObject based), see doc to use other codecs
     final arr = raw as List<dynamic>;
-    if (arr.length != 7)
-      throw Exception('unexpected arr length: expect 7 but see ${arr.length}');
+    if (arr.length != 8)
+      throw Exception('unexpected arr length: expect 8 but see ${arr.length}');
     return MintQuote(
       id: dco_decode_String(arr[0]),
       request: dco_decode_String(arr[1]),
@@ -3054,6 +3054,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
       state: dco_decode_mint_quote_state(arr[4]),
       token: dco_decode_opt_box_autoadd_token(arr[5]),
       error: dco_decode_opt_String(arr[6]),
+      transactionId: dco_decode_opt_String(arr[7]),
     );
   }
 
@@ -3289,6 +3290,18 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     );
   }
 
+  @protected
+  SendResult dco_decode_send_result(dynamic raw) {
+    // Codec=Dco (DartCObject based), see doc to use other codecs
+    final arr = raw as List<dynamic>;
+    if (arr.length != 2)
+      throw Exception('unexpected arr length: expect 2 but see ${arr.length}');
+    return SendResult(
+      token: dco_decode_token(arr[0]),
+      transactionId: dco_decode_opt_String(arr[1]),
+    );
+  }
+
   @protected
   SupportedSettings dco_decode_supported_settings(dynamic raw) {
     // Codec=Dco (DartCObject based), see doc to use other codecs
@@ -4056,6 +4069,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     var var_state = sse_decode_mint_quote_state(deserializer);
     var var_token = sse_decode_opt_box_autoadd_token(deserializer);
     var var_error = sse_decode_opt_String(deserializer);
+    var var_transactionId = sse_decode_opt_String(deserializer);
     return MintQuote(
       id: var_id,
       request: var_request,
@@ -4064,6 +4078,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
       state: var_state,
       token: var_token,
       error: var_error,
+      transactionId: var_transactionId,
     );
   }
 
@@ -4379,6 +4394,14 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     return SendOptions(pubkey: var_pubkey, includeFee: var_includeFee);
   }
 
+  @protected
+  SendResult sse_decode_send_result(SseDeserializer deserializer) {
+    // Codec=Sse (Serialization based), see doc to use other codecs
+    var var_token = sse_decode_token(deserializer);
+    var var_transactionId = sse_decode_opt_String(deserializer);
+    return SendResult(token: var_token, transactionId: var_transactionId);
+  }
+
   @protected
   SupportedSettings sse_decode_supported_settings(
     SseDeserializer deserializer,
@@ -5177,6 +5200,7 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     sse_encode_mint_quote_state(self.state, serializer);
     sse_encode_opt_box_autoadd_token(self.token, serializer);
     sse_encode_opt_String(self.error, serializer);
+    sse_encode_opt_String(self.transactionId, serializer);
   }
 
   @protected
@@ -5465,6 +5489,13 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
     sse_encode_opt_box_autoadd_bool(self.includeFee, serializer);
   }
 
+  @protected
+  void sse_encode_send_result(SendResult self, SseSerializer serializer) {
+    // Codec=Sse (Serialization based), see doc to use other codecs
+    sse_encode_token(self.token, serializer);
+    sse_encode_opt_String(self.transactionId, serializer);
+  }
+
   @protected
   void sse_encode_supported_settings(
     SupportedSettings self,
@@ -5881,7 +5912,7 @@ class WalletImpl extends RustOpaque implements Wallet {
   Future<void> restore() =>
       RustLib.instance.api.crateApiWalletWalletRestore(that: this);
 
-  Future<Token> send({
+  Future<SendResult> send({
     required PreparedSend send,
     String? memo,
     bool? includeMemo,

lib/src/rust/frb_generated.io.dart

@@ -378,6 +378,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   SendOptions dco_decode_send_options(dynamic raw);
 
+  @protected
+  SendResult dco_decode_send_result(dynamic raw);
+
   @protected
   SupportedSettings dco_decode_supported_settings(dynamic raw);
 
@@ -781,6 +784,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   SendOptions sse_decode_send_options(SseDeserializer deserializer);
 
+  @protected
+  SendResult sse_decode_send_result(SseDeserializer deserializer);
+
   @protected
   SupportedSettings sse_decode_supported_settings(SseDeserializer deserializer);
 
@@ -1273,6 +1279,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   void sse_encode_send_options(SendOptions self, SseSerializer serializer);
 
+  @protected
+  void sse_encode_send_result(SendResult self, SseSerializer serializer);
+
   @protected
   void sse_encode_supported_settings(
     SupportedSettings self,

lib/src/rust/frb_generated.web.dart

@@ -380,6 +380,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   SendOptions dco_decode_send_options(dynamic raw);
 
+  @protected
+  SendResult dco_decode_send_result(dynamic raw);
+
   @protected
   SupportedSettings dco_decode_supported_settings(dynamic raw);
 
@@ -783,6 +786,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   SendOptions sse_decode_send_options(SseDeserializer deserializer);
 
+  @protected
+  SendResult sse_decode_send_result(SseDeserializer deserializer);
+
   @protected
   SupportedSettings sse_decode_supported_settings(SseDeserializer deserializer);
 
@@ -1275,6 +1281,9 @@ abstract class RustLibApiImplPlatform extends BaseApiImpl<RustLibWire> {
   @protected
   void sse_encode_send_options(SendOptions self, SseSerializer serializer);
 
+  @protected
+  void sse_encode_send_result(SendResult self, SseSerializer serializer);
+
   @protected
   void sse_encode_supported_settings(
     SupportedSettings self,

rust/src/api/payment_request.rs

@@ -461,18 +461,17 @@ async fn wait_for_nostr_payment_inner(
         .await
         .map_err(|_| Error::Network("Relay connection timed out".to_string()))?;
 
+    // Create the broadcast receiver BEFORE subscribing so we capture historical
+    // events the relay sends back in response to our subscription filter.
+    // (broadcast::Receiver only sees messages sent after its creation)
+    let mut notifications = client.notifications();
+
     // Subscribe to NIP-17 gift-wrap events (kind 1059) addressed to our ephemeral pubkey
     let filter = Filter::new().pubkey(pubkey).kind(Kind::GiftWrap);
     client
         .subscribe(filter, None)
         .await
         .map_err(|e| Error::Cdk(format!("Subscription failed: {e}")))?;
-
-    // Listen for notifications with periodic cancellation check.
-    // Every 1s we check if the Dart stream is still alive by attempting
-    // a sink.add(). If it fails, the Dart side disposed the stream and
-    // we disconnect cleanly. Short interval minimizes "Fail to post" spam.
-    let mut notifications = client.notifications();
     loop {
         match tokio::time::timeout(Duration::from_secs(1), notifications.recv()).await {
             Ok(Ok(notification)) => {

rust/src/api/wallet.rs

@@ -12,19 +12,21 @@ use cdk::{
     wallet::{
         MeltQuote as CdkMeltQuote, MintQuote as CdkMintQuote, PreparedSend as CdkPreparedSend,
         ReceiveOptions as CdkReceiveOptions, SendMemo, SendOptions as CdkSendOptions,
-        Wallet as CdkWallet,
+        Wallet as CdkWallet, WalletSubscription,
     },
 };
 use cdk_common::{
     util::unix_time,
     wallet::{
         Transaction as CdkTransaction, TransactionDirection as CdkTransactionDirection,
+        TransactionId,
     },
+    NotificationPayload,
 };
 use cdk_sqlite::WalletSqliteDatabase;
 use flutter_rust_bridge::frb;
 use log::info;
-use tokio::{sync::broadcast, time::sleep};
+use tokio::sync::broadcast;
 use uuid::Uuid;
 
 use crate::frb_generated::StreamSink;
@@ -131,12 +133,12 @@ impl Wallet {
         send: PreparedSend,
         memo: Option<String>,
         include_memo: Option<bool>,
-    ) -> Result<Token, Error> {
+    ) -> Result<SendResult, Error> {
         let send_memo = memo.map(|m| SendMemo {
             memo: m,
             include_memo: include_memo.unwrap_or_default(),
         });
-        let token = self
+        let cdk_token = self
             .inner
             .confirm_send(
                 send.operation_id,
@@ -148,10 +150,35 @@ impl Wallet {
                 send.cdk_send_fee,
                 send_memo,
             )
-            .await?
-            .to_string();
+            .await?;
+
+        // Compute the deterministic transaction ID from the token's proofs
+        // (SHA-256 of sorted Y values — same as CDK uses internally)
+        // Best-effort: send is already committed, don't fail on ID computation
+        let tx_id = match self.inner.get_mint_keysets().await {
+            Ok(keysets) => match cdk_token.proofs(&keysets) {
+                Ok(proofs) => TransactionId::try_from(proofs)
+                    .map(|id| id.to_string())
+                    .map_err(|e| info!("Failed to compute tx ID from proofs: {e}"))
+                    .ok(),
+                Err(e) => {
+                    info!("Failed to extract proofs from token: {e}");
+                    None
+                }
+            },
+            Err(e) => {
+                info!("Failed to fetch keysets for tx ID: {e}");
+                None
+            }
+        };
+
+        let token_str = cdk_token.to_string();
         self.update_balance_streams().await;
-        Ok(Token::from_str(&token)?)
+
+        Ok(SendResult {
+            token: Token::from_str(&token_str)?,
+            transaction_id: tx_id,
+        })
     }
 
     pub async fn cancel_send(&self, send: PreparedSend) -> Result<(), Error> {
@@ -184,50 +211,38 @@ impl Wallet {
             return Ok(());
         }
 
+        // Subscribe to quote state changes via WebSocket (NUT-17) with HTTP polling fallback
+        let mut subscription = self
+            .inner
+            .subscribe(WalletSubscription::Bolt11MintQuoteState(vec![quote.id.clone()]))
+            .await
+            .map_err(|e| Error::Cdk(e.to_string()))?;
+
         let _self = self.clone();
         flutter_rust_bridge::spawn(async move {
-            loop {
-                sleep(Duration::from_secs(3)).await;
+            // Timeout: time until quote expires + 30s buffer, or 1 hour if no expiry
+            let remaining = quote.expiry.saturating_sub(unix_time());
+            let timeout_dur = if quote.expiry == 0 {
+                Duration::from_secs(3600)
+            } else {
+                Duration::from_secs(remaining + 30)
+            };
 
-                // Check if the Dart stream is still alive before polling
-                if sink
-                    .add(MintQuote {
-                        id: quote.id.clone(),
-                        request: quote.request.clone(),
-                        amount: quote.amount.map(|a| a.into()),
-                        expiry: Some(quote.expiry),
-                        state: MintQuoteState::Unpaid,
-                        token: None,
-                        error: None,
-                    })
-                    .is_err()
-                {
-                    info!("Mint polling stopped: Dart stream closed for {}", quote.id);
-                    break;
-                }
+            // Clone for the timeout error path (originals are moved into the async block)
+            let expired_id = quote.id.clone();
+            let expired_request = quote.request.clone();
+            let expired_amount = quote.amount;
+            let expired_expiry = quote.expiry;
 
-                info!("Checking mint quote state for {}", quote.id);
-                match _self.inner.check_mint_quote_status(&quote.id).await {
-                    Ok(state_res) => match state_res.state {
-                        CdkMintQuoteState::Unpaid => {
-                            if state_res.expiry < unix_time() {
-                                let _ = sink.add(MintQuote {
-                                    id: quote.id,
-                                    request: quote.request,
-                                    amount: quote.amount.map(|a| a.into()),
-                                    expiry: Some(state_res.expiry),
-                                    state: MintQuoteState::Error,
-                                    token: None,
-                                    error: Some("Quote expired".to_string()),
-                                });
-                                break;
-                            }
-                            continue;
-                        }
-                        CdkMintQuoteState::Issued => {
-                            break;
-                        }
-                        CdkMintQuoteState::Paid => {
+            let result = tokio::time::timeout(timeout_dur, async {
+                while let Some(event) = subscription.recv().await {
+                    match event.into_inner() {
+                        NotificationPayload::MintQuoteBolt11Response(info)
+                            if info.state == CdkMintQuoteState::Paid =>
+                        {
+                            info!("Mint quote {} paid via subscription", quote.id);
+
+                            // Notify Dart: payment detected
                             let _ = sink.add(MintQuote {
                                 id: quote.id.clone(),
                                 request: quote.request.clone(),
@@ -236,13 +251,26 @@ impl Wallet {
                                 state: CdkMintQuoteState::Paid.into(),
                                 token: None,
                                 error: None,
+                                transaction_id: None,
                             });
+
+                            // Mint the ecash tokens
                             match _self
                                 .inner
                                 .mint(&quote.id, SplitTarget::None, None)
                                 .await
                             {
                                 Ok(mint_proofs) => {
+                                    let tx_id = match TransactionId::try_from(
+                                        mint_proofs.clone(),
+                                    ) {
+                                        Ok(id) => Some(id.to_string()),
+                                        Err(e) => {
+                                            info!("Failed to compute mint tx ID: {e}");
+                                            None
+                                        }
+                                    };
+
                                     let mint_amount =
                                         mint_proofs.total_amount().unwrap_or_default();
                                     let _ = sink.add(MintQuote {
@@ -259,9 +287,9 @@ impl Wallet {
                                         ))
                                         .ok(),
                                         error: None,
+                                        transaction_id: tx_id,
                                     });
                                     _self.update_balance_streams().await;
-                                    break;
                                 }
                                 Err(e) => {
                                     let _ = sink.add(MintQuote {
@@ -272,25 +300,48 @@ impl Wallet {
                                         state: MintQuoteState::Error,
                                         token: None,
                                         error: Some(e.to_string()),
+                                        transaction_id: None,
                                     });
-                                    break;
                                 }
                             }
+                            return;
                         }
-                    },
-                    Err(e) => {
-                        let _ = sink.add(MintQuote {
-                            id: quote.id,
-                            request: quote.request,
-                            amount: quote.amount.map(|a| a.into()),
-                            expiry: Some(quote.expiry),
-                            state: MintQuoteState::Error,
-                            token: None,
-                            error: Some(e.to_string()),
-                        });
-                        break;
+                        NotificationPayload::MintQuoteBolt11Response(info)
+                            if info.state == CdkMintQuoteState::Issued =>
+                        {
+                            // Already issued (recovered from previous session) — notify Dart
+                            // so it can clean up pending metadata and show success UI
+                            let _ = sink.add(MintQuote {
+                                id: quote.id.clone(),
+                                request: quote.request.clone(),
+                                amount: quote.amount.map(|a| a.into()),
+                                expiry: Some(quote.expiry),
+                                state: CdkMintQuoteState::Issued.into(),
+                                token: None,
+                                error: None,
+                                transaction_id: None,
+                            });
+                            _self.update_balance_streams().await;
+                            return;
+                        }
+                        _ => continue,
                     }
                 }
+            })
+            .await;
+
+            if result.is_err() {
+                // Timeout: quote expired
+                let _ = sink.add(MintQuote {
+                    id: expired_id,
+                    request: expired_request,
+                    amount: expired_amount.map(|a| a.into()),
+                    expiry: Some(expired_expiry),
+                    state: MintQuoteState::Error,
+                    token: None,
+                    error: Some("Quote expired".to_string()),
+                    transaction_id: None,
+                });
             }
         });
         Ok(())
@@ -460,6 +511,15 @@ impl Wallet {
 // Types
 // ========================================================================
 
+/// Result of a confirmed send, carrying both the ecash token and the
+/// deterministic transaction ID so Dart can save metadata without a racy
+/// listTransactions lookup.
+pub struct SendResult {
+    pub token: Token,
+    /// Deterministic transaction ID (None if computation failed)
+    pub transaction_id: Option<String>,
+}
+
 pub struct MintQuote {
     pub id: String,
     pub request: String,
@@ -468,6 +528,8 @@ pub struct MintQuote {
     pub state: MintQuoteState,
     pub token: Option<Token>,
     pub error: Option<String>,
+    /// Deterministic transaction ID (set when proofs are available, typically on Issued)
+    pub transaction_id: Option<String>,
 }
 
 impl From<CdkMintQuote> for MintQuote {
@@ -480,6 +542,7 @@ impl From<CdkMintQuote> for MintQuote {
             state: quote.state.into(),
             token: None,
             error: None,
+            transaction_id: None,
         }
     }
 }

rust/src/frb_generated.rs

@@ -3597,6 +3597,7 @@ impl SseDecode for crate::api::wallet::MintQuote {
         let mut var_state = <crate::api::wallet::MintQuoteState>::sse_decode(deserializer);
         let mut var_token = <Option<crate::api::token::Token>>::sse_decode(deserializer);
         let mut var_error = <Option<String>>::sse_decode(deserializer);
+        let mut var_transactionId = <Option<String>>::sse_decode(deserializer);
         return crate::api::wallet::MintQuote {
             id: var_id,
             request: var_request,
@@ -3605,6 +3606,7 @@ impl SseDecode for crate::api::wallet::MintQuote {
             state: var_state,
             token: var_token,
             error: var_error,
+            transaction_id: var_transactionId,
         };
     }
 }
@@ -3948,6 +3950,18 @@ impl SseDecode for crate::api::wallet::SendOptions {
     }
 }
 
+impl SseDecode for crate::api::wallet::SendResult {
+    // Codec=Sse (Serialization based), see doc to use other codecs
+    fn sse_decode(deserializer: &mut flutter_rust_bridge::for_generated::SseDeserializer) -> Self {
+        let mut var_token = <crate::api::token::Token>::sse_decode(deserializer);
+        let mut var_transactionId = <Option<String>>::sse_decode(deserializer);
+        return crate::api::wallet::SendResult {
+            token: var_token,
+            transaction_id: var_transactionId,
+        };
+    }
+}
+
 impl SseDecode for crate::api::mint_info::SupportedSettings {
     // Codec=Sse (Serialization based), see doc to use other codecs
     fn sse_decode(deserializer: &mut flutter_rust_bridge::for_generated::SseDeserializer) -> Self {
@@ -4526,6 +4540,7 @@ impl flutter_rust_bridge::IntoDart for crate::api::wallet::MintQuote {
             self.state.into_into_dart().into_dart(),
             self.token.into_into_dart().into_dart(),
             self.error.into_into_dart().into_dart(),
+            self.transaction_id.into_into_dart().into_dart(),
         ]
         .into_dart()
     }
@@ -4790,6 +4805,27 @@ impl flutter_rust_bridge::IntoIntoDart<crate::api::wallet::SendOptions>
     }
 }
 // Codec=Dco (DartCObject based), see doc to use other codecs
+impl flutter_rust_bridge::IntoDart for crate::api::wallet::SendResult {
+    fn into_dart(self) -> flutter_rust_bridge::for_generated::DartAbi {
+        [
+            self.token.into_into_dart().into_dart(),
+            self.transaction_id.into_into_dart().into_dart(),
+        ]
+        .into_dart()
+    }
+}
+impl flutter_rust_bridge::for_generated::IntoDartExceptPrimitive
+    for crate::api::wallet::SendResult
+{
+}
+impl flutter_rust_bridge::IntoIntoDart<crate::api::wallet::SendResult>
+    for crate::api::wallet::SendResult
+{
+    fn into_into_dart(self) -> crate::api::wallet::SendResult {
+        self
+    }
+}
+// Codec=Dco (DartCObject based), see doc to use other codecs
 impl flutter_rust_bridge::IntoDart for crate::api::mint_info::SupportedSettings {
     fn into_dart(self) -> flutter_rust_bridge::for_generated::DartAbi {
         [self.supported.into_into_dart().into_dart()].into_dart()
@@ -5300,6 +5336,7 @@ impl SseEncode for crate::api::wallet::MintQuote {
         <crate::api::wallet::MintQuoteState>::sse_encode(self.state, serializer);
         <Option<crate::api::token::Token>>::sse_encode(self.token, serializer);
         <Option<String>>::sse_encode(self.error, serializer);
+        <Option<String>>::sse_encode(self.transaction_id, serializer);
     }
 }
 
@@ -5568,6 +5605,14 @@ impl SseEncode for crate::api::wallet::SendOptions {
     }
 }
 
+impl SseEncode for crate::api::wallet::SendResult {
+    // Codec=Sse (Serialization based), see doc to use other codecs
+    fn sse_encode(self, serializer: &mut flutter_rust_bridge::for_generated::SseSerializer) {
+        <crate::api::token::Token>::sse_encode(self.token, serializer);
+        <Option<String>>::sse_encode(self.transaction_id, serializer);
+    }
+}
+
 impl SseEncode for crate::api::mint_info::SupportedSettings {
     // Codec=Sse (Serialization based), see doc to use other codecs
     fn sse_encode(self, serializer: &mut flutter_rust_bridge::for_generated::SseSerializer) {