feat(receive): auto-detect token unit from V3/V4 tokens

feat: add multi-unit currency support (sat, usd, eur)

lib/core/utils/formatters.dart

@@ -0,0 +1,123 @@
+import 'package:intl/intl.dart';
+
+/// Utilidades para formatear montos y unidades en El Caju.
+///
+/// USD y EUR usan centavos (multiplicador 100).
+/// SAT y otras unidades usan valores enteros.
+
+class UnitFormatter {
+  /// Multiplicador para convertir a unidad base.
+  /// USD/EUR almacenan centavos, display en unidades.
+  static int getMultiplier(String unit) {
+    switch (unit.toLowerCase()) {
+      case 'usd':
+      case 'eur':
+        return 100; // centavos
+      default:
+        return 1;
+    }
+  }
+
+  /// Formatea un balance para display.
+  /// Ejemplo: 1000 sat → "1,000", 500 usd → "5.00"
+  static String formatBalance(BigInt amount, String unit) {
+    final multiplier = getMultiplier(unit);
+
+    if (multiplier == 100) {
+      // USD/EUR: mostrar con 2 decimales
+      final value = amount.toDouble() / 100;
+      return value.toStringAsFixed(2);
+    } else {
+      // SAT y otros: entero con separador de miles
+      return NumberFormat('#,###').format(amount.toInt());
+    }
+  }
+
+  /// Formatea un balance con su unidad.
+  /// Ejemplo: 1000 sat → "1,000 BTC", 500 usd → "5.00 USD"
+  static String formatBalanceWithUnit(BigInt amount, String unit) {
+    final formatted = formatBalance(amount, unit);
+    final label = getUnitLabel(unit);
+    return '$formatted $label';
+  }
+
+  /// Obtiene la etiqueta de display para una unidad.
+  /// sat → BTC, usd → USD, eur → EUR, msat → MSAT
+  static String getUnitLabel(String unit) {
+    switch (unit.toLowerCase()) {
+      case 'sat':
+        return 'BTC';
+      case 'usd':
+        return 'USD';
+      case 'eur':
+        return 'EUR';
+      case 'msat':
+        return 'MSAT';
+      default:
+        return unit.toUpperCase();
+    }
+  }
+
+  /// Convierte input del usuario a BigInt para la unidad.
+  /// Ejemplo: "5.00" USD → BigInt(500)
+  static BigInt parseUserInput(String input, String unit) {
+    final multiplier = getMultiplier(unit);
+
+    // Limpiar input
+    final cleaned = input.replaceAll(',', '').replaceAll(' ', '');
+
+    if (multiplier == 100) {
+      // USD/EUR: parsear como decimal
+      final value = double.tryParse(cleaned) ?? 0.0;
+      return BigInt.from((value * 100).round());
+    } else {
+      // SAT: parsear como entero
+      return BigInt.from(int.tryParse(cleaned) ?? 0);
+    }
+  }
+
+  /// Obtiene el nombre del host de un mint URL.
+  /// Ejemplo: 'https://mint.cubabitcoin.org' → 'cubabitcoin.org'
+  static String getMintDisplayName(String mintUrl) {
+    try {
+      final uri = Uri.parse(mintUrl);
+      var host = uri.host;
+
+      // Limpiar prefijos comunes
+      host = host.replaceFirst('mint.', '');
+      host = host.replaceFirst('www.', '');
+
+      return host;
+    } catch (e) {
+      return mintUrl;
+    }
+  }
+
+  /// Formatea una fecha relativa.
+  /// Ejemplo: hace 5 min, hace 2 h, ayer, 15 ene
+  static String formatRelativeDate(DateTime date) {
+    final now = DateTime.now();
+    final difference = now.difference(date);
+
+    if (difference.inSeconds < 60) {
+      return 'Ahora';
+    } else if (difference.inMinutes < 60) {
+      return 'Hace ${difference.inMinutes} min';
+    } else if (difference.inHours < 24) {
+      return 'Hace ${difference.inHours} h';
+    } else if (difference.inDays == 1) {
+      return 'Ayer';
+    } else if (difference.inDays < 7) {
+      return 'Hace ${difference.inDays} días';
+    } else {
+      return DateFormat('d MMM').format(date);
+    }
+  }
+
+  /// Convierte timestamp BigInt (unix seconds) a DateTime.
+  static DateTime timestampToDateTime(BigInt timestamp) {
+    return DateTime.fromMillisecondsSinceEpoch(
+      timestamp.toInt() * 1000,
+    );
+  }
+}

lib/providers/settings_provider.dart

@@ -16,6 +16,8 @@ class SettingsProvider extends ChangeNotifier {
   static const _defaultMintKey = 'default_mint';
   static const _localeKey = 'locale';
   static const _pinEnabledKey = 'pin_enabled';
+  static const _activeUnitKey = 'active_unit';
+  static const _activeMintUrlKey = 'active_mint_url';
 
   // Estado interno
   bool _isInitialized = false;
@@ -24,6 +26,8 @@ class SettingsProvider extends ChangeNotifier {
   String? _pin;
   String _locale = 'es';
   String _defaultMint = 'https://mint.cubabitcoin.org';
+  String _activeUnit = 'sat';
+  String? _activeMintUrl;
 
   // Getters
   bool get isInitialized => _isInitialized;
@@ -32,6 +36,8 @@ class SettingsProvider extends ChangeNotifier {
   bool get hasPin => _pin != null && _pin!.isNotEmpty;
   String get locale => _locale;
   String get defaultMint => _defaultMint;
+  String get activeUnit => _activeUnit;
+  String? get activeMintUrl => _activeMintUrl;
 
   // ============================================================
   // INICIALIZACION
@@ -49,6 +55,8 @@ class SettingsProvider extends ChangeNotifier {
     _locale = _prefs?.getString(_localeKey) ?? 'es';
     _defaultMint = _prefs?.getString(_defaultMintKey) ?? 'https://mint.cubabitcoin.org';
     _pinEnabled = _prefs?.getBool(_pinEnabledKey) ?? false;
+    _activeUnit = _prefs?.getString(_activeUnitKey) ?? 'sat';
+    _activeMintUrl = _prefs?.getString(_activeMintUrlKey);
 
     // Cargar PIN si existe
     if (_pinEnabled) {
@@ -142,6 +150,28 @@ class SettingsProvider extends ChangeNotifier {
     notifyListeners();
   }
 
+  // ============================================================
+  // UNIDAD Y MINT ACTIVO
+  // ============================================================
+
+  /// Guarda la unidad activa (sat, usd, eur, etc.).
+  Future<void> setActiveUnit(String unit) async {
+    await _prefs?.setString(_activeUnitKey, unit);
+    _activeUnit = unit;
+    notifyListeners();
+  }
+
+  /// Guarda el mint activo.
+  Future<void> setActiveMintUrl(String? mintUrl) async {
+    if (mintUrl != null) {
+      await _prefs?.setString(_activeMintUrlKey, mintUrl);
+    } else {
+      await _prefs?.remove(_activeMintUrlKey);
+    }
+    _activeMintUrl = mintUrl;
+    notifyListeners();
+  }
+
   // ============================================================
   // BORRAR WALLET
   // ============================================================
@@ -156,12 +186,16 @@ class SettingsProvider extends ChangeNotifier {
     // Resetear preferencias
     await _prefs?.setBool(_hasWalletKey, false);
     await _prefs?.setBool(_pinEnabledKey, false);
+    await _prefs?.remove(_activeUnitKey);
+    await _prefs?.remove(_activeMintUrlKey);
     // Mantener locale y defaultMint (preferencias de app, no de wallet)
 
     // Resetear estado
     _hasWallet = false;
     _pinEnabled = false;
     _pin = null;
+    _activeUnit = 'sat';
+    _activeMintUrl = null;
 
     notifyListeners();
   }
@@ -180,6 +214,8 @@ class SettingsProvider extends ChangeNotifier {
     _pin = null;
     _locale = 'es';
     _defaultMint = 'https://mint.cubabitcoin.org';
+    _activeUnit = 'sat';
+    _activeMintUrl = null;
 
     notifyListeners();
   }

lib/screens/1_splash/splash_screen.dart

@@ -1,3 +1,4 @@
+import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
@@ -65,6 +66,12 @@ class _SplashScreenState extends State<SplashScreen>
 
           if (!mounted) return;
 
+          // Restaurar mint y unidad activa desde settings
+          await _restoreActiveState(settingsProvider, walletProvider);
+
+          // Verificar proofs en background (no bloquea navegación)
+          unawaited(_checkPendingTransactions(walletProvider));
+
           // Ir al Home
           _navigateTo(const HomeScreen());
         } else {
@@ -91,6 +98,41 @@ class _SplashScreenState extends State<SplashScreen>
     }
   }
 
+  /// Restaura el mint y unidad activa desde SettingsProvider.
+  Future<void> _restoreActiveState(
+    SettingsProvider settings,
+    WalletProvider wallet,
+  ) async {
+    try {
+      // Restaurar mint activo si está guardado
+      final savedMintUrl = settings.activeMintUrl;
+      if (savedMintUrl != null && wallet.mintUrls.contains(savedMintUrl)) {
+        await wallet.setActiveMint(savedMintUrl);
+      }
+
+      // Restaurar unidad activa si está guardada y es soportada
+      final savedUnit = settings.activeUnit;
+      if (wallet.activeUnits.contains(savedUnit)) {
+        await wallet.setActiveUnit(savedUnit);
+      }
+    } catch (e) {
+      debugPrint('Error restaurando estado activo: $e');
+      // No bloquear si falla, usar defaults
+    }
+  }
+
+  /// Verifica proofs pendientes en background.
+  /// Se ejecuta sin bloquear la navegación.
+  Future<void> _checkPendingTransactions(WalletProvider wallet) async {
+    try {
+      await wallet.checkPendingTransactions();
+      debugPrint('Verificación de proofs completada');
+    } catch (e) {
+      debugPrint('Error verificando proofs: $e');
+      // Silencioso - no mostrar error al usuario
+    }
+  }
+
   void _navigateTo(Widget screen) {
     Navigator.pushReplacement(
       context,

lib/screens/3_home/home_screen.dart

@@ -4,10 +4,12 @@ import 'package:lucide_icons/lucide_icons.dart';
 import 'package:cdk_flutter/cdk_flutter.dart' hide WalletProvider;
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/effects/cashu_confetti.dart';
 import '../../providers/wallet_provider.dart';
+import '../../providers/settings_provider.dart';
 import '../4_receive/receive_screen.dart';
 import '../5_send/send_screen.dart';
 import '../6_mint/mint_screen.dart';
@@ -131,6 +133,9 @@ class _HomeScreenState extends State<HomeScreen> {
 
   Widget _buildBalanceSection() {
     final walletProvider = context.watch<WalletProvider>();
+    final settingsProvider = context.read<SettingsProvider>();
+    final activeUnit = walletProvider.activeUnit;
+    final unitLabel = UnitFormatter.getUnitLabel(activeUnit);
 
     return Padding(
       padding: const EdgeInsets.symmetric(
@@ -160,15 +165,15 @@ class _HomeScreenState extends State<HomeScreen> {
           ),
           const SizedBox(height: 8),
 
-          // Balance reactivo con StreamBuilder
+          // Balance reactivo del mint activo
           StreamBuilder<BigInt>(
-            stream: walletProvider.streamTotalBalance(),
+            stream: walletProvider.streamBalance(),
             builder: (context, snapshot) {
               final balance = snapshot.data ?? BigInt.zero;
-              final balanceInt = balance.toInt();
+              final formattedBalance = UnitFormatter.formatBalance(balance, activeUnit);
 
               return Text(
-                _isBalanceVisible ? _formatBalance(balanceInt) : '••••••',
+                _isBalanceVisible ? formattedBalance : '••••••',
                 style: const TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 48,
@@ -180,20 +185,42 @@ class _HomeScreenState extends State<HomeScreen> {
           ),
           const SizedBox(height: 4),
 
-          // Unidad (siempre sats por ahora)
-          Container(
-            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
-            decoration: BoxDecoration(
-              color: AppColors.primaryAction.withValues(alpha: 0.15),
-              borderRadius: BorderRadius.circular(12),
-            ),
-            child: const Text(
-              'sats',
-              style: TextStyle(
-                fontFamily: 'Inter',
-                fontSize: 18,
-                fontWeight: FontWeight.w600,
-                color: AppColors.primaryAction,
+          // Unidad - tap para ciclar
+          GestureDetector(
+            onTap: () async {
+              // Ciclar unidad
+              await walletProvider.cycleUnit();
+              // Guardar en settings
+              await settingsProvider.setActiveUnit(walletProvider.activeUnit);
+            },
+            child: Container(
+              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
+              decoration: BoxDecoration(
+                color: AppColors.primaryAction.withValues(alpha: 0.15),
+                borderRadius: BorderRadius.circular(12),
+              ),
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Text(
+                    unitLabel,
+                    style: const TextStyle(
+                      fontFamily: 'Inter',
+                      fontSize: 18,
+                      fontWeight: FontWeight.w600,
+                      color: AppColors.primaryAction,
+                    ),
+                  ),
+                  // Mostrar indicador si hay más de una unidad
+                  if (walletProvider.activeUnits.length > 1) ...[
+                    const SizedBox(width: 4),
+                    Icon(
+                      LucideIcons.refreshCw,
+                      color: AppColors.primaryAction.withValues(alpha: 0.7),
+                      size: 14,
+                    ),
+                  ],
+                ],
               ),
             ),
           ),
@@ -206,16 +233,10 @@ class _HomeScreenState extends State<HomeScreen> {
     final walletProvider = context.watch<WalletProvider>();
     final activeMintUrl = walletProvider.activeMintUrl;
 
-    // Extraer solo el host del URL para mostrar
-    String displayMint = 'Sin mint';
-    if (activeMintUrl != null) {
-      try {
-        final uri = Uri.parse(activeMintUrl);
-        displayMint = uri.host;
-      } catch (_) {
-        displayMint = activeMintUrl;
-      }
-    }
+    // Extraer nombre del mint para mostrar
+    final displayMint = activeMintUrl != null
+        ? UnitFormatter.getMintDisplayName(activeMintUrl)
+        : 'Sin mint';
 
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: AppDimensions.paddingSmall),
@@ -406,17 +427,6 @@ class _HomeScreenState extends State<HomeScreen> {
       builder: (context) => const _HistoryModal(),
     );
   }
-
-  String _formatBalance(int amount) {
-    if (amount >= 1000) {
-      final formatted = amount.toString().replaceAllMapped(
-        RegExp(r'(\d{1,3})(?=(\d{3})+(?!\d))'),
-        (Match m) => '${m[1]},',
-      );
-      return formatted;
-    }
-    return amount.toString();
-  }
 }
 
 /// Botón de acción para el home

lib/screens/4_receive/receive_screen.dart

@@ -4,6 +4,7 @@ import 'package:provider/provider.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/common/primary_button.dart';
@@ -26,7 +27,8 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
   bool _isValidToken = false;
   bool _isProcessing = false;
   bool _showSuccess = false;
-  int _receivedAmount = 0;
+  BigInt _receivedAmount = BigInt.zero;
+  String? _receivedUnit; // Se asigna al reclamar desde walletProvider.activeUnit
   TokenInfo? _tokenInfo;
   String? _errorMessage;
 
@@ -132,14 +134,19 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
         const SizedBox(height: AppDimensions.paddingLarge),
 
         // Monto recibido
-        Text(
-          '+$_receivedAmount sats',
-          style: const TextStyle(
-            fontFamily: 'Inter',
-            fontSize: 36,
-            fontWeight: FontWeight.bold,
-            color: Colors.white,
-          ),
+        Builder(
+          builder: (context) {
+            final unit = _receivedUnit ?? context.read<WalletProvider>().activeUnit;
+            return Text(
+              '+${UnitFormatter.formatBalance(_receivedAmount, unit)} ${UnitFormatter.getUnitLabel(unit)}',
+              style: const TextStyle(
+                fontFamily: 'Inter',
+                fontSize: 36,
+                fontWeight: FontWeight.bold,
+                color: Colors.white,
+              ),
+            );
+          },
         ),
         const SizedBox(height: AppDimensions.paddingSmall),
 
@@ -229,14 +236,12 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
   }
 
   Widget _buildTokenPreview() {
-    final amount = _tokenInfo!.amount.toInt();
-
-    // Extraer solo el host del mint URL
-    String mintDisplay = _tokenInfo!.mintUrl;
-    try {
-      final uri = Uri.parse(_tokenInfo!.mintUrl);
-      mintDisplay = uri.host;
-    } catch (_) {}
+    final walletProvider = context.read<WalletProvider>();
+    final amount = _tokenInfo!.amount;
+    // Usar unidad detectada del token, o fallback a unidad activa
+    final tokenUnit = _tokenInfo!.unit ?? walletProvider.activeUnit;
+    final mintDisplay = UnitFormatter.getMintDisplayName(_tokenInfo!.mintUrl);
+    final unitDetected = _tokenInfo!.unit != null;
 
     return GlassCard(
       padding: const EdgeInsets.all(AppDimensions.paddingMedium),
@@ -271,7 +276,7 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
           ),
           const SizedBox(height: AppDimensions.paddingMedium),
 
-          // Monto
+          // Monto con unidad detectada
           Row(
             mainAxisAlignment: MainAxisAlignment.spaceBetween,
             children: [
@@ -283,14 +288,27 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
                   color: AppColors.textSecondary.withValues(alpha: 0.7),
                 ),
               ),
-              Text(
-                '$amount sats',
-                style: const TextStyle(
-                  fontFamily: 'Inter',
-                  fontSize: 18,
-                  fontWeight: FontWeight.bold,
-                  color: Colors.white,
-                ),
+              Row(
+                children: [
+                  Text(
+                    '${UnitFormatter.formatBalance(amount, tokenUnit)} ${UnitFormatter.getUnitLabel(tokenUnit)}',
+                    style: const TextStyle(
+                      fontFamily: 'Inter',
+                      fontSize: 18,
+                      fontWeight: FontWeight.bold,
+                      color: Colors.white,
+                    ),
+                  ),
+                  // Indicador si la unidad fue detectada automáticamente
+                  if (!unitDetected) ...[
+                    const SizedBox(width: 4),
+                    Icon(
+                      LucideIcons.helpCircle,
+                      color: AppColors.textSecondary.withValues(alpha: 0.5),
+                      size: 14,
+                    ),
+                  ],
+                ],
               ),
             ],
           ),
@@ -410,14 +428,18 @@ class _ReceiveScreenState extends State<ReceiveScreen> {
     try {
       final walletProvider = context.read<WalletProvider>();
 
-      // Reclamar token real
+      // Guardar unidad detectada del token ANTES de reclamar
+      final detectedUnit = _tokenInfo?.unit ?? walletProvider.activeUnit;
+
+      // Reclamar token (usa unidad detectada internamente)
       final amountReceived = await walletProvider.receiveToken(
         _tokenController.text.trim(),
       );
 
       if (mounted) {
         setState(() {
-          _receivedAmount = amountReceived.toInt();
+          _receivedAmount = amountReceived;
+          _receivedUnit = detectedUnit; // Usar unidad del token
           _showSuccess = true;
           _isProcessing = false;
         });

lib/screens/5_send/send_screen.dart

@@ -3,6 +3,7 @@ import 'package:provider/provider.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/common/primary_button.dart';
@@ -21,24 +22,24 @@ class _SendScreenState extends State<SendScreen> {
   final TextEditingController _amountController = TextEditingController();
   final TextEditingController _memoController = TextEditingController();
 
-  final String _unit = 'sats';
-
   bool _isProcessing = false;
   String? _errorMessage;
-  int _availableBalance = 0;
+  BigInt _availableBalance = BigInt.zero;
+  late String _activeUnit;
 
   @override
   void initState() {
     super.initState();
+    _activeUnit = context.read<WalletProvider>().activeUnit;
     _loadBalance();
   }
 
   Future<void> _loadBalance() async {
     final walletProvider = context.read<WalletProvider>();
-    final balance = await walletProvider.getTotalBalance();
+    final balance = await walletProvider.getBalance();
     if (mounted) {
       setState(() {
-        _availableBalance = balance.toInt();
+        _availableBalance = balance;
       });
     }
   }
@@ -50,8 +51,13 @@ class _SendScreenState extends State<SendScreen> {
     super.dispose();
   }
 
-  int get _amount => int.tryParse(_amountController.text) ?? 0;
-  bool get _isValidAmount => _amount > 0 && _amount <= _availableBalance;
+  /// Obtiene la etiqueta de la unidad para display
+  String get _unitLabel => UnitFormatter.getUnitLabel(_activeUnit);
+
+  /// Parsea el input del usuario a BigInt según la unidad
+  BigInt get _amount => UnitFormatter.parseUserInput(_amountController.text, _activeUnit);
+
+  bool get _isValidAmount => _amount > BigInt.zero && _amount <= _availableBalance;
 
   @override
   Widget build(BuildContext context) {
@@ -154,7 +160,7 @@ class _SendScreenState extends State<SendScreen> {
                 ),
               ),
               Text(
-                _unit,
+                _unitLabel,
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 18,
@@ -185,7 +191,7 @@ class _SendScreenState extends State<SendScreen> {
               child: Row(
                 children: [
                   Text(
-                    '$_availableBalance $_unit',
+                    '${UnitFormatter.formatBalance(_availableBalance, _activeUnit)} $_unitLabel',
                     style: TextStyle(
                       fontFamily: 'Inter',
                       fontSize: 14,
@@ -300,7 +306,8 @@ class _SendScreenState extends State<SendScreen> {
   }
 
   void _setMaxAmount() {
-    _amountController.text = _availableBalance.toString();
+    // Formatear el balance para el input (sin separadores de miles)
+    _amountController.text = UnitFormatter.formatBalance(_availableBalance, _activeUnit).replaceAll(',', '');
     setState(() {
       _errorMessage = null;
     });
@@ -312,7 +319,7 @@ class _SendScreenState extends State<SendScreen> {
       backgroundColor: Colors.transparent,
       builder: (context) => _ConfirmationModal(
         amount: _amount,
-        unit: _unit,
+        unit: _activeUnit,
         memo: _memoController.text.isNotEmpty ? _memoController.text : null,
         onConfirm: () {
           Navigator.pop(context);
@@ -334,10 +341,8 @@ class _SendScreenState extends State<SendScreen> {
 
       // Crear token real con cdk-flutter
       final memo = _memoController.text.isNotEmpty ? _memoController.text : null;
-      final token = await walletProvider.sendTokens(
-        BigInt.from(_amount),
-        memo,
-      );
+      final amount = _amount;
+      final token = await walletProvider.sendTokens(amount, memo);
 
       if (mounted) {
         Navigator.pushReplacement(
@@ -345,8 +350,8 @@ class _SendScreenState extends State<SendScreen> {
           MaterialPageRoute(
             builder: (context) => ShareTokenScreen(
               token: token,
-              amount: _amount,
-              unit: _unit,
+              amount: amount,
+              unit: _activeUnit,
               memo: memo,
             ),
           ),
@@ -373,7 +378,7 @@ class _SendScreenState extends State<SendScreen> {
 
 /// Modal de confirmacion
 class _ConfirmationModal extends StatelessWidget {
-  final int amount;
+  final BigInt amount;
   final String unit;
   final String? memo;
   final VoidCallback onConfirm;
@@ -443,7 +448,7 @@ class _ConfirmationModal extends StatelessWidget {
 
           // Monto
           Text(
-            '$amount $unit',
+            '${UnitFormatter.formatBalance(amount, unit)} ${UnitFormatter.getUnitLabel(unit)}',
             style: const TextStyle(
               fontFamily: 'Inter',
               fontSize: 32,

lib/screens/5_send/share_token_screen.dart

@@ -4,8 +4,10 @@ import 'package:flutter/services.dart';
 import 'package:qr_flutter/qr_flutter.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import 'package:share_plus/share_plus.dart';
+import 'package:cdk_flutter/cdk_flutter.dart' as cdk;
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/common/primary_button.dart';
@@ -13,7 +15,7 @@ import '../../widgets/common/primary_button.dart';
 /// Pantalla para compartir el token Cashu generado
 class ShareTokenScreen extends StatefulWidget {
   final String token;
-  final int amount;
+  final BigInt amount;
   final String unit;
   final String? memo;
 
@@ -30,61 +32,74 @@ class ShareTokenScreen extends StatefulWidget {
 }
 
 class _ShareTokenScreenState extends State<ShareTokenScreen> {
-  late PageController _pageController;
-  late List<String> _qrParts;
-  int _currentPage = 0;
-  Timer? _timer;
+  List<String> _urFragments = [];
+  int _currentFragment = 0;
+  Timer? _animationTimer;
+
+  // Configuración de velocidad (como cashu.me)
+  static const int _intervalFast = 100;    // ms
+  static const int _intervalMedium = 200;  // ms
+  static const int _intervalSlow = 400;    // ms
+  int _currentInterval = _intervalMedium;
+  String _speedLabel = 'M';
 
   @override
   void initState() {
     super.initState();
-    _pageController = PageController();
-    _qrParts = _encodeTokenToQR();
-    _startQRAnimation();
+    _encodeTokenToUR();
   }
 
   @override
   void dispose() {
-    _timer?.cancel();
-    _pageController.dispose();
+    _animationTimer?.cancel();
     super.dispose();
   }
 
-  List<String> _encodeTokenToQR() {
-    // TODO: Implementar con cdk-flutter cuando esté disponible
-    // final qrParts = encodeQrToken(token: widget.token);
+  void _encodeTokenToUR() {
+    // Parsear el token string a objeto Token de cdk-flutter
+    final token = cdk.Token.parse(encoded: widget.token);
 
-    // Por ahora, simulamos fragmentos UR para el token
-    if (widget.token.length <= 200) {
-      return [widget.token];
-    }
+    // Codificar a fragmentos UR usando cdk-flutter
+    // maxFragmentLength por defecto es 150 bytes
+    _urFragments = cdk.encodeQrToken(token: token);
 
-    // Simular fragmentación para tokens largos
-    final parts = <String>[];
-    const chunkSize = 200;
-    for (int i = 0; i < widget.token.length; i += chunkSize) {
-      final end = (i + chunkSize < widget.token.length)
-          ? i + chunkSize
-          : widget.token.length;
-      parts.add(widget.token.substring(i, end));
+    // Si hay múltiples fragmentos, iniciar animación
+    if (_urFragments.length > 1) {
+      _startAnimation();
     }
-    return parts;
   }
 
-  void _startQRAnimation() {
-    // Solo animar si hay múltiples fragmentos
-    if (_qrParts.length <= 1) return;
+  void _startAnimation() {
+    _animationTimer?.cancel();
+    _animationTimer = Timer.periodic(
+      Duration(milliseconds: _currentInterval),
+      (timer) {
+        if (mounted) {
+          setState(() {
+            _currentFragment = (_currentFragment + 1) % _urFragments.length;
+          });
+        }
+      },
+    );
+  }
 
-    _timer = Timer.periodic(const Duration(seconds: 2), (timer) {
-      if (mounted) {
-        final nextPage = (_currentPage + 1) % _qrParts.length;
-        _pageController.animateToPage(
-          nextPage,
-          duration: const Duration(milliseconds: 300),
-          curve: Curves.easeInOut,
-        );
+  void _cycleSpeed() {
+    setState(() {
+      if (_currentInterval == _intervalMedium) {
+        _currentInterval = _intervalSlow;
+        _speedLabel = 'S';
+      } else if (_currentInterval == _intervalSlow) {
+        _currentInterval = _intervalFast;
+        _speedLabel = 'F';
+      } else {
+        _currentInterval = _intervalMedium;
+        _speedLabel = 'M';
       }
     });
+    // Reiniciar timer con nueva velocidad
+    if (_urFragments.length > 1) {
+      _startAnimation();
+    }
   }
 
   @override
@@ -133,11 +148,6 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
                 // Token truncado
                 _buildTokenTextDisplay(),
 
-                const SizedBox(height: AppDimensions.paddingSmall),
-
-                // Indicador de página (si hay múltiples fragmentos)
-                if (_qrParts.length > 1) _buildPageIndicator(),
-
                 const SizedBox(height: AppDimensions.paddingMedium),
 
                 // Botones copiar y compartir
@@ -176,10 +186,13 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
   }
 
   Widget _buildAmountDisplay() {
+    final formattedAmount = UnitFormatter.formatBalance(widget.amount, widget.unit);
+    final unitLabel = UnitFormatter.getUnitLabel(widget.unit);
+
     return Column(
       children: [
         Text(
-          '${widget.amount} ${widget.unit}',
+          '$formattedAmount $unitLabel',
           style: const TextStyle(
             fontFamily: 'Inter',
             fontSize: 36,
@@ -204,58 +217,111 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
   }
 
   Widget _buildQRDisplay() {
+    if (_urFragments.isEmpty) {
+      return const SizedBox(
+        width: 220,
+        height: 220,
+        child: Center(child: CircularProgressIndicator()),
+      );
+    }
+
     final size = 220.0;
-    return Container(
-      width: size,
-      height: size,
-      decoration: BoxDecoration(
-        color: Colors.white,
-        borderRadius: BorderRadius.circular(20),
-        boxShadow: [
-          BoxShadow(
-            color: Colors.black.withValues(alpha: 0.2),
-            blurRadius: 20,
-            offset: const Offset(0, 8),
+    final isAnimated = _urFragments.length > 1;
+
+    return Column(
+      children: [
+        // QR Container
+        Container(
+          width: size,
+          height: size,
+          decoration: BoxDecoration(
+            color: Colors.white,
+            borderRadius: BorderRadius.circular(20),
+            boxShadow: [
+              BoxShadow(
+                color: Colors.black.withValues(alpha: 0.2),
+                blurRadius: 20,
+                offset: const Offset(0, 8),
+              ),
+            ],
           ),
-        ],
-      ),
-      child: ClipRRect(
-        borderRadius: BorderRadius.circular(20),
-        child: _qrParts.length > 1
-            ? PageView.builder(
-                controller: _pageController,
-                onPageChanged: (index) {
-                  setState(() {
-                    _currentPage = index;
-                  });
-                },
-                itemCount: _qrParts.length,
-                itemBuilder: (context, index) {
-                  return Center(
-                    child: Padding(
-                      padding: const EdgeInsets.all(20),
-                      child: QrImageView(
-                        data: _qrParts[index],
-                        version: QrVersions.auto,
-                        size: size - 40,
-                        backgroundColor: Colors.white,
-                        errorCorrectionLevel: QrErrorCorrectLevel.M,
-                      ),
-                    ),
-                  );
-                },
-              )
-            : Padding(
-                padding: const EdgeInsets.all(20),
-                child: QrImageView(
-                  data: _qrParts[0],
-                  version: QrVersions.auto,
-                  size: size - 40,
-                  backgroundColor: Colors.white,
-                  errorCorrectionLevel: QrErrorCorrectLevel.M,
+          child: ClipRRect(
+            borderRadius: BorderRadius.circular(20),
+            child: Padding(
+              padding: const EdgeInsets.all(16),
+              child: QrImageView(
+                data: _urFragments[_currentFragment],
+                version: QrVersions.auto,
+                size: size - 32,
+                backgroundColor: Colors.white,
+                errorCorrectionLevel: QrErrorCorrectLevel.L,
+              ),
+            ),
+          ),
+        ),
+
+        // Controles de animación (solo si hay múltiples fragmentos)
+        if (isAnimated) ...[
+          const SizedBox(height: 12),
+          Row(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              // Indicador de fragmento actual
+              Container(
+                padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                decoration: BoxDecoration(
+                  color: Colors.white.withValues(alpha: 0.1),
+                  borderRadius: BorderRadius.circular(20),
+                ),
+                child: Text(
+                  '${_currentFragment + 1} / ${_urFragments.length}',
+                  style: const TextStyle(
+                    fontFamily: 'Inter',
+                    fontSize: 14,
+                    fontWeight: FontWeight.w600,
+                    color: Colors.white,
+                  ),
                 ),
               ),
-      ),
+              const SizedBox(width: 12),
+              // Botón de velocidad
+              GestureDetector(
+                onTap: _cycleSpeed,
+                child: Container(
+                  padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                  decoration: BoxDecoration(
+                    color: AppColors.primaryAction.withValues(alpha: 0.2),
+                    borderRadius: BorderRadius.circular(20),
+                    border: Border.all(
+                      color: AppColors.primaryAction.withValues(alpha: 0.5),
+                    ),
+                  ),
+                  child: Row(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Icon(
+                        LucideIcons.gauge,
+                        color: AppColors.primaryAction,
+                        size: 16,
+                      ),
+                      const SizedBox(width: 6),
+                      Text(
+                        _speedLabel,
+                        style: TextStyle(
+                          fontFamily: 'Inter',
+                          fontSize: 14,
+                          fontWeight: FontWeight.w600,
+                          color: AppColors.primaryAction,
+                        ),
+                      ),
+                    ],
+                  ),
+                ),
+              ),
+            ],
+          ),
+        ],
+      ],
     );
   }
 
@@ -264,6 +330,8 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
         ? '${widget.token.substring(0, 25)}...${widget.token.substring(widget.token.length - 20)}'
         : widget.token;
 
+    final isAnimated = _urFragments.length > 1;
+
     return GlassCard(
       padding: const EdgeInsets.all(AppDimensions.paddingSmall),
       child: Column(
@@ -274,7 +342,9 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
               Icon(LucideIcons.bean, color: AppColors.primaryAction, size: 16),
               const SizedBox(width: 6),
               Text(
-                'Token Cashu (${_qrParts.length} ${_qrParts.length == 1 ? "parte" : "partes"})',
+                isAnimated
+                    ? 'Token Cashu (QR animado - ${_urFragments.length} fragmentos UR)'
+                    : 'Token Cashu',
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 12,
@@ -298,27 +368,6 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
     );
   }
 
-  Widget _buildPageIndicator() {
-    return Row(
-      mainAxisAlignment: MainAxisAlignment.center,
-      children: List.generate(
-        _qrParts.length,
-        (index) => AnimatedContainer(
-          duration: const Duration(milliseconds: 300),
-          margin: const EdgeInsets.symmetric(horizontal: 4),
-          width: index == _currentPage ? 24 : 8,
-          height: 8,
-          decoration: BoxDecoration(
-            color: index == _currentPage
-                ? AppColors.primaryAction
-                : AppColors.textSecondary.withValues(alpha: 0.3),
-            borderRadius: BorderRadius.circular(4),
-          ),
-        ),
-      ),
-    );
-  }
-
   Widget _buildActionButtons(BuildContext context) {
     return Row(
       children: [
@@ -438,10 +487,13 @@ class _ShareTokenScreenState extends State<ShareTokenScreen> {
         ? '\n"${widget.memo}"'
         : '';
 
+    final formattedAmount = UnitFormatter.formatBalance(widget.amount, widget.unit);
+    final unitLabel = UnitFormatter.getUnitLabel(widget.unit);
+
     await SharePlus.instance.share(
       ShareParams(
-        text: '${widget.amount} ${widget.unit}$memo\n\n${widget.token}',
-        subject: 'Token Cashu - ${widget.amount} ${widget.unit}',
+        text: '$formattedAmount $unitLabel$memo\n\n${widget.token}',
+        subject: 'Token Cashu - $formattedAmount $unitLabel',
       ),
     );
   }

lib/screens/6_mint/invoice_screen.dart

@@ -7,6 +7,7 @@ import 'package:lucide_icons/lucide_icons.dart';
 import 'package:cdk_flutter/cdk_flutter.dart' hide WalletProvider;
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/effects/cashu_confetti.dart';
@@ -17,7 +18,7 @@ enum MintStatus { loading, unpaid, paid, issued, error }
 
 /// Pantalla para mostrar el invoice generado y esperar el pago
 class InvoiceScreen extends StatefulWidget {
-  final int amount;
+  final BigInt amount;
   final String unit;
   final String? description;
 
@@ -57,7 +58,7 @@ class _InvoiceScreenState extends State<InvoiceScreen> {
 
     try {
       final mintStream = walletProvider.mintTokens(
-        BigInt.from(widget.amount),
+        widget.amount,
         widget.description,
       );
 
@@ -116,7 +117,7 @@ class _InvoiceScreenState extends State<InvoiceScreen> {
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
             content: Text(
-              '+${widget.amount} ${widget.unit} depositados',
+              '+${UnitFormatter.formatBalance(widget.amount, widget.unit)} ${UnitFormatter.getUnitLabel(widget.unit)} depositados',
             ),
             backgroundColor: AppColors.success,
             duration: const Duration(seconds: 3),
@@ -320,10 +321,13 @@ class _InvoiceScreenState extends State<InvoiceScreen> {
   }
 
   Widget _buildHeader() {
+    final formattedAmount = UnitFormatter.formatBalance(widget.amount, widget.unit);
+    final unitLabel = UnitFormatter.getUnitLabel(widget.unit);
+
     return Column(
       children: [
         Text(
-          'Depositar ${widget.amount} ${widget.unit}',
+          'Depositar $formattedAmount $unitLabel',
           style: const TextStyle(
             fontFamily: 'Inter',
             fontSize: 24,

lib/screens/6_mint/mint_screen.dart

@@ -3,6 +3,7 @@ import 'package:provider/provider.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/common/primary_button.dart';
@@ -21,11 +22,17 @@ class _MintScreenState extends State<MintScreen> {
   final TextEditingController _amountController = TextEditingController();
   final TextEditingController _descriptionController = TextEditingController();
 
-  final String _unit = 'sats';
+  late String _activeUnit;
 
   bool _isProcessing = false;
   String? _errorMessage;
 
+  @override
+  void initState() {
+    super.initState();
+    _activeUnit = context.read<WalletProvider>().activeUnit;
+  }
+
   @override
   void dispose() {
     _amountController.dispose();
@@ -33,8 +40,13 @@ class _MintScreenState extends State<MintScreen> {
     super.dispose();
   }
 
-  int get _amount => int.tryParse(_amountController.text) ?? 0;
-  bool get _isValidAmount => _amount > 0;
+  /// Obtiene la etiqueta de la unidad para display
+  String get _unitLabel => UnitFormatter.getUnitLabel(_activeUnit);
+
+  /// Parsea el input del usuario a BigInt según la unidad
+  BigInt get _amount => UnitFormatter.parseUserInput(_amountController.text, _activeUnit);
+
+  bool get _isValidAmount => _amount > BigInt.zero;
 
   @override
   Widget build(BuildContext context) {
@@ -137,7 +149,7 @@ class _MintScreenState extends State<MintScreen> {
                 ),
               ),
               Text(
-                _unit,
+                _unitLabel,
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 18,
@@ -242,7 +254,7 @@ class _MintScreenState extends State<MintScreen> {
       backgroundColor: Colors.transparent,
       builder: (context) => _ConfirmationModal(
         amount: _amount,
-        unit: _unit,
+        unit: _activeUnit,
         description: _descriptionController.text.isNotEmpty
             ? _descriptionController.text
             : null,
@@ -262,7 +274,7 @@ class _MintScreenState extends State<MintScreen> {
       MaterialPageRoute(
         builder: (context) => InvoiceScreen(
           amount: _amount,
-          unit: _unit,
+          unit: _activeUnit,
           description: _descriptionController.text.isNotEmpty
               ? _descriptionController.text
               : null,
@@ -274,7 +286,7 @@ class _MintScreenState extends State<MintScreen> {
 
 /// Modal de confirmación
 class _ConfirmationModal extends StatelessWidget {
-  final int amount;
+  final BigInt amount;
   final String unit;
   final String? description;
   final VoidCallback onConfirm;
@@ -344,7 +356,7 @@ class _ConfirmationModal extends StatelessWidget {
 
           // Monto
           Text(
-            '$amount $unit',
+            '${UnitFormatter.formatBalance(amount, unit)} ${UnitFormatter.getUnitLabel(unit)}',
             style: const TextStyle(
               fontFamily: 'Inter',
               fontSize: 32,

lib/screens/7_melt/melt_screen.dart

@@ -5,6 +5,7 @@ import 'package:lucide_icons/lucide_icons.dart';
 import 'package:cdk_flutter/cdk_flutter.dart' hide WalletProvider;
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
 import '../../widgets/common/primary_button.dart';
@@ -21,30 +22,34 @@ class MeltScreen extends StatefulWidget {
 class _MeltScreenState extends State<MeltScreen> {
   final TextEditingController _invoiceController = TextEditingController();
 
-  final String _unit = 'sats';
+  late String _activeUnit;
 
   bool _isValidInvoice = false;
   bool _isLoadingQuote = false;
   bool _isProcessing = false;
   MeltQuote? _quote;
-  int _invoiceAmount = 0;
-  int _feeReserve = 0;
-  int _total = 0;
-  int _availableBalance = 0;
+  BigInt _invoiceAmount = BigInt.zero;
+  BigInt _feeReserve = BigInt.zero;
+  BigInt _total = BigInt.zero;
+  BigInt _availableBalance = BigInt.zero;
   String? _errorMessage;
 
   @override
   void initState() {
     super.initState();
+    _activeUnit = context.read<WalletProvider>().activeUnit;
     _loadBalance();
   }
 
+  /// Obtiene la etiqueta de la unidad para display
+  String get _unitLabel => UnitFormatter.getUnitLabel(_activeUnit);
+
   Future<void> _loadBalance() async {
     final walletProvider = context.read<WalletProvider>();
-    final balance = await walletProvider.getTotalBalance();
+    final balance = await walletProvider.getBalance();
     if (mounted) {
       setState(() {
-        _availableBalance = balance.toInt();
+        _availableBalance = balance;
       });
     }
   }
@@ -274,7 +279,7 @@ class _MeltScreenState extends State<MeltScreen> {
                 ),
               ),
               Text(
-                '$_invoiceAmount $_unit',
+                '${UnitFormatter.formatBalance(_invoiceAmount, _activeUnit)} $_unitLabel',
                 style: const TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 18,
@@ -299,7 +304,7 @@ class _MeltScreenState extends State<MeltScreen> {
                 ),
               ),
               Text(
-                '~$_feeReserve $_unit',
+                '~${UnitFormatter.formatBalance(_feeReserve, _activeUnit)} $_unitLabel',
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 14,
@@ -328,7 +333,7 @@ class _MeltScreenState extends State<MeltScreen> {
                 ),
               ),
               Text(
-                '$_total $_unit',
+                '${UnitFormatter.formatBalance(_total, _activeUnit)} $_unitLabel',
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 20,
@@ -400,7 +405,7 @@ class _MeltScreenState extends State<MeltScreen> {
           ),
         ),
         Text(
-          '$_availableBalance $_unit',
+          '${UnitFormatter.formatBalance(_availableBalance, _activeUnit)} $_unitLabel',
           style: const TextStyle(
             fontFamily: 'Inter',
             fontSize: 14,
@@ -440,9 +445,9 @@ class _MeltScreenState extends State<MeltScreen> {
       _isValidInvoice = false;
 
       if (value.isEmpty) {
-        _invoiceAmount = 0;
-        _feeReserve = 0;
-        _total = 0;
+        _invoiceAmount = BigInt.zero;
+        _feeReserve = BigInt.zero;
+        _total = BigInt.zero;
         return;
       }
     });
@@ -475,8 +480,8 @@ class _MeltScreenState extends State<MeltScreen> {
       if (mounted) {
         setState(() {
           _quote = quote;
-          _invoiceAmount = quote.amount.toInt();
-          _feeReserve = quote.feeReserve.toInt();
+          _invoiceAmount = quote.amount;
+          _feeReserve = quote.feeReserve;
           _total = _invoiceAmount + _feeReserve;
           _isValidInvoice = true;
           _isLoadingQuote = false;
@@ -507,7 +512,7 @@ class _MeltScreenState extends State<MeltScreen> {
         amount: _invoiceAmount,
         fee: _feeReserve,
         total: _total,
-        unit: _unit,
+        unit: _activeUnit,
         onConfirm: () {
           Navigator.pop(context);
           _payInvoice();
@@ -535,7 +540,7 @@ class _MeltScreenState extends State<MeltScreen> {
         // Mostrar éxito y volver
         ScaffoldMessenger.of(context).showSnackBar(
           SnackBar(
-            content: Text('-${totalPaid.toInt()} $_unit enviados'),
+            content: Text('-${UnitFormatter.formatBalance(totalPaid, _activeUnit)} $_unitLabel enviados'),
             backgroundColor: AppColors.success,
             duration: const Duration(seconds: 3),
           ),
@@ -567,9 +572,9 @@ class _MeltScreenState extends State<MeltScreen> {
 
 /// Modal de confirmación
 class _ConfirmationModal extends StatelessWidget {
-  final int amount;
-  final int fee;
-  final int total;
+  final BigInt amount;
+  final BigInt fee;
+  final BigInt total;
   final String unit;
   final VoidCallback onConfirm;
   final VoidCallback onCancel;
@@ -639,7 +644,7 @@ class _ConfirmationModal extends StatelessWidget {
 
           // Detalles
           Text(
-            '$amount $unit',
+            '${UnitFormatter.formatBalance(amount, unit)} ${UnitFormatter.getUnitLabel(unit)}',
             style: const TextStyle(
               fontFamily: 'Inter',
               fontSize: 28,
@@ -648,7 +653,7 @@ class _ConfirmationModal extends StatelessWidget {
             ),
           ),
           Text(
-            '+ ~$fee $unit fee',
+            '+ ~${UnitFormatter.formatBalance(fee, unit)} ${UnitFormatter.getUnitLabel(unit)} fee',
             style: TextStyle(
               fontFamily: 'Inter',
               fontSize: 14,
@@ -657,7 +662,7 @@ class _ConfirmationModal extends StatelessWidget {
           ),
           const SizedBox(height: AppDimensions.paddingSmall),
           Text(
-            'Total: $total $unit',
+            'Total: ${UnitFormatter.formatBalance(total, unit)} ${UnitFormatter.getUnitLabel(unit)}',
             style: const TextStyle(
               fontFamily: 'Inter',
               fontSize: 16,

lib/screens/8_settings/mints_screen.dart

@@ -1,9 +1,9 @@
 import 'package:flutter/material.dart';
 import 'package:lucide_icons/lucide_icons.dart';
 import 'package:provider/provider.dart';
-import 'package:cdk_flutter/cdk_flutter.dart' hide WalletProvider;
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../providers/wallet_provider.dart';
 import '../../widgets/common/gradient_background.dart';
 import '../../widgets/common/glass_card.dart';
@@ -42,51 +42,38 @@ class _MintsScreenState extends State<MintsScreen> {
         body: SafeArea(
           child: Consumer<WalletProvider>(
             builder: (context, walletProvider, child) {
-              return FutureBuilder<List<Mint>>(
-                future: walletProvider.listMints(),
-                builder: (context, snapshot) {
-                  if (snapshot.connectionState == ConnectionState.waiting && !snapshot.hasData) {
-                    return const Center(
-                      child: CircularProgressIndicator(
-                        color: AppColors.primaryAction,
-                      ),
-                    );
-                  }
+              final mintUrls = walletProvider.mintUrls;
 
-                  final mints = snapshot.data ?? [];
-
-                  return Padding(
-                    padding: const EdgeInsets.all(AppDimensions.paddingMedium),
-                    child: Column(
-                      crossAxisAlignment: CrossAxisAlignment.stretch,
-                      children: [
-                        // Lista de mints
-                        Expanded(
-                          child: mints.isEmpty
-                              ? _buildEmptyState()
-                              : ListView.builder(
-                                  itemCount: mints.length,
-                                  itemBuilder: (context, index) {
-                                    final mint = mints[index];
-                                    return Padding(
-                                      padding: const EdgeInsets.only(
-                                        bottom: AppDimensions.paddingMedium,
-                                      ),
-                                      child: _buildMintCard(
-                                        mint,
-                                        walletProvider,
-                                      ),
-                                    );
-                                  },
-                                ),
-                        ),
-
-                        // Botón agregar mint
-                        _buildAddMintButton(walletProvider),
-                      ],
+              return Padding(
+                padding: const EdgeInsets.all(AppDimensions.paddingMedium),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.stretch,
+                  children: [
+                    // Lista de mints
+                    Expanded(
+                      child: mintUrls.isEmpty
+                          ? _buildEmptyState()
+                          : ListView.builder(
+                              itemCount: mintUrls.length,
+                              itemBuilder: (context, index) {
+                                final mintUrl = mintUrls[index];
+                                return Padding(
+                                  padding: const EdgeInsets.only(
+                                    bottom: AppDimensions.paddingMedium,
+                                  ),
+                                  child: _buildMintCard(
+                                    mintUrl,
+                                    walletProvider,
+                                  ),
+                                );
+                              },
+                            ),
                     ),
-                  );
-                },
+
+                    // Botón agregar mint
+                    _buildAddMintButton(walletProvider),
+                  ],
+                ),
               );
             },
           ),
@@ -129,20 +116,21 @@ class _MintsScreenState extends State<MintsScreen> {
     );
   }
 
-  Widget _buildMintCard(Mint mint, WalletProvider walletProvider) {
-    final isActive = walletProvider.activeMintUrl == mint.url;
+  Widget _buildMintCard(String mintUrl, WalletProvider walletProvider) {
+    final isActive = walletProvider.activeMintUrl == mintUrl;
+    final units = walletProvider.getUnitsForMint(mintUrl);
 
-    return FutureBuilder<BigInt>(
-      future: walletProvider.getBalanceForMint(mint.url),
+    return FutureBuilder<Map<String, BigInt>>(
+      future: walletProvider.getBalancesForMint(mintUrl),
       builder: (context, balanceSnapshot) {
-        final balance = balanceSnapshot.data ?? BigInt.zero;
+        final balances = balanceSnapshot.data ?? {};
 
         return GlassCard(
           padding: const EdgeInsets.all(AppDimensions.paddingMedium),
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: [
-              // Header: URL + estado
+              // Header: URL + estado + refresh
               Row(
                 children: [
                   // Icono estado conexión (verde si es el activo)
@@ -156,10 +144,10 @@ class _MintsScreenState extends State<MintsScreen> {
                   ),
                   const SizedBox(width: 8),
 
-                  // URL del mint (solo el host)
+                  // URL del mint (display name)
                   Expanded(
                     child: Text(
-                      _extractHost(mint.url),
+                      UnitFormatter.getMintDisplayName(mintUrl),
                       style: const TextStyle(
                         fontFamily: 'Inter',
                         fontSize: 16,
@@ -170,6 +158,21 @@ class _MintsScreenState extends State<MintsScreen> {
                     ),
                   ),
 
+                  // Botón refresh
+                  GestureDetector(
+                    onTap: () => _refreshMint(mintUrl, walletProvider),
+                    child: Padding(
+                      padding: const EdgeInsets.all(4),
+                      child: Icon(
+                        LucideIcons.refreshCw,
+                        color: AppColors.textSecondary,
+                        size: 18,
+                      ),
+                    ),
+                  ),
+
+                  const SizedBox(width: 8),
+
                   // Badge activo
                   if (isActive)
                     Container(
@@ -198,7 +201,7 @@ class _MintsScreenState extends State<MintsScreen> {
 
               // URL completa (más pequeña)
               Text(
-                mint.url,
+                mintUrl,
                 style: TextStyle(
                   fontFamily: 'Inter',
                   fontSize: 12,
@@ -209,19 +212,19 @@ class _MintsScreenState extends State<MintsScreen> {
 
               const SizedBox(height: AppDimensions.paddingSmall),
 
-              // Balance
-              Row(
-                children: [
-                  Text(
-                    'Balance:',
-                    style: TextStyle(
-                      fontFamily: 'Inter',
-                      fontSize: 14,
-                      color: AppColors.textSecondary.withValues(alpha: 0.7),
+              // Balances por unidad
+              if (balanceSnapshot.connectionState == ConnectionState.waiting)
+                Row(
+                  children: [
+                    Text(
+                      'Balance:',
+                      style: TextStyle(
+                        fontFamily: 'Inter',
+                        fontSize: 14,
+                        color: AppColors.textSecondary.withValues(alpha: 0.7),
+                      ),
                     ),
-                  ),
-                  const SizedBox(width: 8),
-                  if (balanceSnapshot.connectionState == ConnectionState.waiting)
+                    const SizedBox(width: 8),
                     SizedBox(
                       width: 14,
                       height: 14,
@@ -229,19 +232,11 @@ class _MintsScreenState extends State<MintsScreen> {
                         strokeWidth: 2,
                         color: AppColors.textSecondary,
                       ),
-                    )
-                  else
-                    Text(
-                      '${_formatBalance(balance)} sats',
-                      style: const TextStyle(
-                        fontFamily: 'Inter',
-                        fontSize: 16,
-                        fontWeight: FontWeight.bold,
-                        color: Colors.white,
-                      ),
                     ),
-                ],
-              ),
+                  ],
+                )
+              else
+                _buildBalancesList(units, balances),
 
               const SizedBox(height: AppDimensions.paddingMedium),
 
@@ -252,7 +247,7 @@ class _MintsScreenState extends State<MintsScreen> {
                   if (!isActive)
                     Expanded(
                       child: GestureDetector(
-                        onTap: () => _setActiveMint(mint.url, walletProvider),
+                        onTap: () => _setActiveMint(mintUrl, walletProvider),
                         child: Container(
                           padding: const EdgeInsets.symmetric(vertical: 10),
                           decoration: BoxDecoration(
@@ -288,7 +283,7 @@ class _MintsScreenState extends State<MintsScreen> {
                   // Eliminar
                   Expanded(
                     child: GestureDetector(
-                      onTap: () => _showDeleteDialog(mint, balance, walletProvider),
+                      onTap: () => _showDeleteDialog(mintUrl, balances, walletProvider),
                       child: Container(
                         padding: const EdgeInsets.symmetric(vertical: 10),
                         decoration: BoxDecoration(
@@ -327,6 +322,87 @@ class _MintsScreenState extends State<MintsScreen> {
     );
   }
 
+  /// Construye la lista de balances por unidad.
+  Widget _buildBalancesList(List<String> units, Map<String, BigInt> balances) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        Text(
+          'Balances:',
+          style: TextStyle(
+            fontFamily: 'Inter',
+            fontSize: 14,
+            color: AppColors.textSecondary.withValues(alpha: 0.7),
+          ),
+        ),
+        const SizedBox(height: 4),
+        ...units.map((unit) {
+          final balance = balances[unit] ?? BigInt.zero;
+          final formattedBalance = UnitFormatter.formatBalance(balance, unit);
+          final unitLabel = UnitFormatter.getUnitLabel(unit);
+
+          return Padding(
+            padding: const EdgeInsets.only(left: 8, top: 2),
+            child: Row(
+              children: [
+                Container(
+                  width: 6,
+                  height: 6,
+                  decoration: BoxDecoration(
+                    color: balance > BigInt.zero
+                        ? AppColors.success
+                        : AppColors.textSecondary.withValues(alpha: 0.3),
+                    shape: BoxShape.circle,
+                  ),
+                ),
+                const SizedBox(width: 8),
+                Text(
+                  '$formattedBalance $unitLabel',
+                  style: TextStyle(
+                    fontFamily: 'Inter',
+                    fontSize: 14,
+                    fontWeight: balance > BigInt.zero ? FontWeight.w600 : FontWeight.normal,
+                    color: balance > BigInt.zero
+                        ? Colors.white
+                        : AppColors.textSecondary.withValues(alpha: 0.7),
+                  ),
+                ),
+              ],
+            ),
+          );
+        }),
+      ],
+    );
+  }
+
+  /// Refresca la información del mint (detecta nuevas unidades).
+  Future<void> _refreshMint(String mintUrl, WalletProvider walletProvider) async {
+    try {
+      final units = await walletProvider.refreshMint(mintUrl);
+
+      if (mounted) {
+        setState(() {}); // Rebuild para actualizar UI
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Unidades detectadas: ${units.join(", ")}'),
+            backgroundColor: AppColors.success,
+            duration: const Duration(seconds: 2),
+          ),
+        );
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Error: $e'),
+            backgroundColor: AppColors.error,
+            duration: const Duration(seconds: 3),
+          ),
+        );
+      }
+    }
+  }
+
   Widget _buildAddMintButton(WalletProvider walletProvider) {
     return PrimaryButton(
       text: 'Agregar mint',
@@ -335,23 +411,6 @@ class _MintsScreenState extends State<MintsScreen> {
     );
   }
 
-  String _extractHost(String url) {
-    try {
-      final uri = Uri.parse(url);
-      return uri.host;
-    } catch (e) {
-      return url;
-    }
-  }
-
-  String _formatBalance(BigInt balance) {
-    final value = balance.toInt();
-    if (value >= 1000) {
-      return '${(value / 1000).toStringAsFixed(value % 1000 == 0 ? 0 : 1)}k';
-    }
-    return value.toString();
-  }
-
   Future<void> _setActiveMint(String mintUrl, WalletProvider walletProvider) async {
     try {
       await walletProvider.setActiveMint(mintUrl);
@@ -379,19 +438,26 @@ class _MintsScreenState extends State<MintsScreen> {
     }
   }
 
-  void _showDeleteDialog(Mint mint, BigInt balance, WalletProvider walletProvider) {
-    final hasBalance = balance > BigInt.zero;
+  void _showDeleteDialog(String mintUrl, Map<String, BigInt> balances, WalletProvider walletProvider) {
+    // Verificar si hay balance en alguna unidad
+    final hasBalance = balances.values.any((b) => b > BigInt.zero);
+
+    // Calcular balance total para mostrar (simplificado)
+    final balanceStrings = balances.entries
+        .where((e) => e.value > BigInt.zero)
+        .map((e) => '${UnitFormatter.formatBalance(e.value, e.key)} ${UnitFormatter.getUnitLabel(e.key)}')
+        .toList();
 
     showModalBottomSheet(
       context: context,
       backgroundColor: Colors.transparent,
       builder: (context) => _DeleteMintModal(
-        mintUrl: mint.url,
+        mintUrl: mintUrl,
         hasBalance: hasBalance,
-        balance: balance.toInt(),
+        balanceDescription: balanceStrings.isEmpty ? '' : balanceStrings.join(', '),
         onConfirm: () async {
           Navigator.pop(context);
-          await _deleteMint(mint.url, walletProvider);
+          await _deleteMint(mintUrl, walletProvider);
         },
         onCancel: () => Navigator.pop(context),
       ),
@@ -443,14 +509,14 @@ class _MintsScreenState extends State<MintsScreen> {
 class _DeleteMintModal extends StatelessWidget {
   final String mintUrl;
   final bool hasBalance;
-  final int balance;
+  final String balanceDescription;
   final VoidCallback onConfirm;
   final VoidCallback onCancel;
 
   const _DeleteMintModal({
     required this.mintUrl,
     required this.hasBalance,
-    required this.balance,
+    required this.balanceDescription,
     required this.onConfirm,
     required this.onCancel,
   });
@@ -547,7 +613,7 @@ class _DeleteMintModal extends StatelessWidget {
                 Expanded(
                   child: Text(
                     hasBalance
-                        ? 'Este mint tiene $balance sats. Puedes recuperarlos después agregando el mint de nuevo.'
+                        ? 'Este mint tiene $balanceDescription. Puedes recuperarlos después agregando el mint de nuevo.'
                         : 'Perderás acceso a este mint',
                     style: TextStyle(
                       fontFamily: 'Inter',

lib/screens/8_settings/settings_screen.dart

@@ -4,6 +4,7 @@ import 'package:provider/provider.dart';
 import 'package:url_launcher/url_launcher.dart';
 import '../../core/constants/colors.dart';
 import '../../core/constants/dimensions.dart';
+import '../../core/utils/formatters.dart';
 import '../../providers/settings_provider.dart';
 import '../../providers/wallet_provider.dart';
 import '../../widgets/common/gradient_background.dart';
@@ -1227,10 +1228,9 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
 
   Future<void> _loadMints() async {
     final walletProvider = context.read<WalletProvider>();
-    final mints = await walletProvider.listMints();
     if (mounted) {
       setState(() {
-        _availableMints = mints.map((m) => m.url).toList();
+        _availableMints = walletProvider.mintUrls;
         _isLoadingMints = false;
         if (_availableMints.isNotEmpty) {
           _selectedMintUrl = _availableMints.first;
@@ -1749,27 +1749,46 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
       if (_useCurrentMnemonic) {
         // Usar mnemonic actual
         if (_scanAllMints) {
-          // Escanear todos los mints
+          // Escanear todos los mints (retorna Map<String, Map<String, BigInt>>)
           final results = await walletProvider.restoreAllMints();
 
           BigInt totalRecovered = BigInt.zero;
           int mintsScanned = 0;
           int mintsWithError = 0;
+          final recoveredDetails = <String>[];
 
-          for (final entry in results.entries) {
-            if (entry.value >= BigInt.zero) {
-              totalRecovered += entry.value;
-              mintsScanned++;
-            } else {
+          for (final mintEntry in results.entries) {
+            final mintUrl = mintEntry.key;
+            final unitBalances = mintEntry.value;
+            bool hasError = false;
+            BigInt mintTotal = BigInt.zero;
+
+            for (final unitEntry in unitBalances.entries) {
+              final unit = unitEntry.key;
+              final balance = unitEntry.value;
+              if (balance < BigInt.zero) {
+                hasError = true;
+              } else if (balance > BigInt.zero) {
+                mintTotal += balance;
+                final formatted = UnitFormatter.formatBalance(balance, unit);
+                final label = UnitFormatter.getUnitLabel(unit);
+                recoveredDetails.add('$formatted $label');
+              }
+            }
+
+            if (hasError) {
               mintsWithError++;
+            } else {
+              mintsScanned++;
+              totalRecovered += mintTotal;
             }
           }
 
           if (!mounted) return;
           setState(() {
             _isSuccess = true;
-            if (totalRecovered > BigInt.zero) {
-              _result = '¡Recuperados ${totalRecovered.toInt()} sats de $mintsScanned mint(s)!';
+            if (recoveredDetails.isNotEmpty) {
+              _result = '¡Recuperados ${recoveredDetails.join(", ")} de $mintsScanned mint(s)!';
             } else {
               _result = 'Escaneo completado. No se encontraron tokens nuevos.';
             }
@@ -1778,7 +1797,7 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
             }
           });
         } else {
-          // Escanear mint específico
+          // Escanear mint específico (retorna Map<String, BigInt>)
           if (_selectedMintUrl == null) {
             if (!mounted) return;
             setState(() {
@@ -1788,14 +1807,25 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
             return;
           }
 
-          final recovered = await walletProvider.restoreFromMint(_selectedMintUrl!);
-          final mintHost = Uri.parse(_selectedMintUrl!).host;
+          final unitBalances = await walletProvider.restoreFromMint(_selectedMintUrl!);
+          final mintHost = UnitFormatter.getMintDisplayName(_selectedMintUrl!);
+
+          final recoveredDetails = <String>[];
+          for (final entry in unitBalances.entries) {
+            final unit = entry.key;
+            final balance = entry.value;
+            if (balance > BigInt.zero) {
+              final formatted = UnitFormatter.formatBalance(balance, unit);
+              final label = UnitFormatter.getUnitLabel(unit);
+              recoveredDetails.add('$formatted $label');
+            }
+          }
 
           if (!mounted) return;
           setState(() {
             _isSuccess = true;
-            if (recovered > BigInt.zero) {
-              _result = '¡Recuperados ${recovered.toInt()} sats de $mintHost!';
+            if (recoveredDetails.isNotEmpty) {
+              _result = '¡Recuperados ${recoveredDetails.join(", ")} de $mintHost!';
             } else {
               _result = 'No se encontraron tokens en $mintHost.';
             }
@@ -1816,8 +1846,7 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
         }
 
         // Obtener lista de mints actuales para escanear
-        final mints = await walletProvider.listMints();
-        final mintUrls = mints.map((m) => m.url).toList();
+        final mintUrls = walletProvider.mintUrls;
 
         if (mintUrls.isEmpty) {
           if (!mounted) return;
@@ -1837,7 +1866,11 @@ class _RecoverTokensModalState extends State<_RecoverTokensModal> {
         setState(() {
           _isSuccess = true;
           if (recovered > BigInt.zero) {
-            _result = '¡Recuperados y transferidos ${recovered.toInt()} sats a tu wallet!';
+            // Usamos la unidad activa como aproximación para el formato
+            final activeUnit = walletProvider.activeUnit;
+            final formatted = UnitFormatter.formatBalance(recovered, activeUnit);
+            final label = UnitFormatter.getUnitLabel(activeUnit);
+            _result = '¡Recuperados y transferidos $formatted $label a tu wallet!';
           } else {
             _result = 'No se encontraron tokens asociados a ese mnemonic.';
           }

pubspec.lock

@@ -33,6 +33,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.0"
+  cbor:
+    dependency: "direct main"
+    description:
+      name: cbor
+      sha256: e60380c7329da6b415841be93884b8d4380cbd86cd4cecb2067baa221b8d88b5
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.5"
   cdk_flutter:
     dependency: "direct main"
     description:
@@ -66,6 +74,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.19.0"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      sha256: b30acd5944035672bc15c6b7a8b47d773e41e2f17de064350988c5d02adb1c68
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.2"
   cross_file:
     dependency: transitive
     description:
@@ -222,8 +238,16 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "6.3.0"
-  http:
+  hex:
     dependency: transitive
+    description:
+      name: hex
+      sha256: "4e7cd54e4b59ba026432a6be2dd9d96e4c5205725194997193bf871703b82c4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.2.0"
+  http:
+    dependency: "direct main"
     description:
       name: http
       sha256: "87721a4a50b19c7f1d49001e51409bddc46303966ce89a65af4f4e6004896412"
@@ -238,6 +262,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.1.2"
+  ieee754:
+    dependency: transitive
+    description:
+      name: ieee754
+      sha256: "7d87451c164a56c156180d34a4e93779372edd191d2c219206100b976203128c"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.3"
   intl:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -41,6 +41,12 @@ dependencies:
   # URL Launcher
   url_launcher: ^6.2.0
 
+  # HTTP client for mint API calls
+  http: ^1.2.0
+
+  # CBOR decoder for V4 tokens
+  cbor: ^6.3.0
+
 dev_dependencies:
   flutter_test:
     sdk: flutter