feat(protocol/http, mcpserver, download): add checksum verification, MCP speed tool, pause webhook, and CLI flags (#1542)

ui/flutter/lib/api/model/options.dart

@@ -17,6 +17,21 @@ class Options {
   Map<String, dynamic> toJson() => _$OptionsToJson(this);
 }
 
+@JsonSerializable()
+class ChecksumOption {
+  String algorithm;
+  String expected;
+
+  ChecksumOption({
+    this.algorithm = '',
+    this.expected = '',
+  });
+
+  factory ChecksumOption.fromJson(Map<String, dynamic> json) => _$ChecksumOptionFromJson(json);
+
+  Map<String, dynamic> toJson() => _$ChecksumOptionToJson(this);
+}
+
 @JsonSerializable()
 class OptsExtraHttp {
   int connections;
@@ -25,6 +40,7 @@ class OptsExtraHttp {
   bool? autoExtract;
   String archivePassword;
   bool deleteAfterExtract;
+  ChecksumOption? checksum;
 
   OptsExtraHttp({
     this.connections = 0,
@@ -33,6 +49,7 @@ class OptsExtraHttp {
     this.autoExtract,
     this.archivePassword = '',
     this.deleteAfterExtract = false,
+    this.checksum,
   });
 
   factory OptsExtraHttp.fromJson(Map<String, dynamic> json) => _$OptsExtraHttpFromJson(json);

ui/flutter/lib/api/model/options.g.dart

@@ -22,6 +22,16 @@ Map<String, dynamic> _$OptionsToJson(Options instance) => <String, dynamic>{
   'extra': ?instance.extra,
 };
 
+ChecksumOption _$ChecksumOptionFromJson(Map<String, dynamic> json) => ChecksumOption(
+  algorithm: json['algorithm'] as String? ?? '',
+  expected: json['expected'] as String? ?? '',
+);
+
+Map<String, dynamic> _$ChecksumOptionToJson(ChecksumOption instance) => <String, dynamic>{
+  'algorithm': instance.algorithm,
+  'expected': instance.expected,
+};
+
 OptsExtraHttp _$OptsExtraHttpFromJson(Map<String, dynamic> json) => OptsExtraHttp(
   connections: (json['connections'] as num?)?.toInt() ?? 0,
   autoTorrent: json['autoTorrent'] as bool?,
@@ -29,6 +39,9 @@ OptsExtraHttp _$OptsExtraHttpFromJson(Map<String, dynamic> json) => OptsExtraHtt
   autoExtract: json['autoExtract'] as bool?,
   archivePassword: json['archivePassword'] as String? ?? '',
   deleteAfterExtract: json['deleteAfterExtract'] as bool? ?? false,
+  checksum: json['checksum'] == null
+      ? null
+      : ChecksumOption.fromJson(json['checksum'] as Map<String, dynamic>),
 );
 
 Map<String, dynamic> _$OptsExtraHttpToJson(OptsExtraHttp instance) => <String, dynamic>{
@@ -38,4 +51,5 @@ Map<String, dynamic> _$OptsExtraHttpToJson(OptsExtraHttp instance) => <String, d
   'autoExtract': ?instance.autoExtract,
   'archivePassword': instance.archivePassword,
   'deleteAfterExtract': instance.deleteAfterExtract,
+  'checksum': ?instance.checksum?.toJson(),
 };

ui/flutter/lib/features/tasks/presentation/pages/create_task_window_page.dart

@@ -66,6 +66,7 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
   final _httpHeadersController = AppHttpHeadersController(defaultNames: const ['User-Agent', 'Cookie', 'Referer']);
   final _trackersController = TextEditingController();
   final _archivePasswordController = TextEditingController();
+  final _checksumHashController = TextEditingController();
   final _formScrollController = ScrollController();
 
   String _httpMethod = 'GET';
@@ -74,6 +75,7 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
   Map<String, String>? _initialLabels;
   RequestProxyMode _proxyMode = RequestProxyMode.follow;
   String _proxyScheme = 'http';
+  String _checksumAlgorithm = 'md5';
   bool _skipVerifyCert = false;
   bool? _autoTorrent;
   bool? _deleteTorrentAfterDownload;
@@ -134,6 +136,7 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
     _httpHeadersController.dispose();
     _trackersController.dispose();
     _archivePasswordController.dispose();
+    _checksumHashController.dispose();
     _formScrollController.dispose();
     super.dispose();
   }
@@ -184,6 +187,10 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
       if (!_programmaticUrlChange && _fileDataUri.isNotEmpty) {
         _fileDataUri = '';
       }
+      if (_inputUrls().length > 1) {
+        _checksumHashController.clear();
+        _checksumAlgorithm = 'md5';
+      }
     }
     _recognizeMagnetUri(urlText.trim());
   }
@@ -193,6 +200,8 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
     final req = task.req;
     final opts = task.opts;
     setState(() {
+      _checksumAlgorithm = 'md5';
+      _checksumHashController.clear();
       if (req?.url.isNotEmpty == true) {
         _fileDataUri = '';
         _renameController.clear();
@@ -243,6 +252,12 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
           _autoExtract = extra.autoExtract;
           _archivePasswordController.text = extra.archivePassword;
           _deleteAfterExtract = extra.deleteAfterExtract;
+          if (extra.checksum != null) {
+            if (extra.checksum!.algorithm.isNotEmpty) {
+              _checksumAlgorithm = extra.checksum!.algorithm;
+            }
+            _checksumHashController.text = extra.checksum!.expected;
+          }
         }
       }
     });
@@ -668,6 +683,34 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
                                   ),
                                 ),
                               ],
+                              if (_inputUrls().length <= 1) ...[
+                                const SizedBox(height: 14),
+                                AppFormPair(
+                                  direction: stacked ? Axis.vertical : Axis.horizontal,
+                                  firstLabel: context.l10n.checksumAlgorithm,
+                                  secondLabel: context.l10n.checksumHash,
+                                  firstFlex: 382,
+                                  secondFlex: 618,
+                                  first: AppChoiceSegmentedControl<String>(
+                                    key: const ValueKey('create-task-checksum-algorithm'),
+                                    showIcons: false,
+                                    value: _checksumAlgorithm,
+                                    buttonKeyPrefix: 'create-task-checksum-algorithm',
+                                    alignment: WrapAlignment.start,
+                                    options: const [
+                                      AppChoiceOption(value: 'md5', label: 'MD5', icon: Icons.tag),
+                                      AppChoiceOption(value: 'sha1', label: 'SHA-1', icon: Icons.tag),
+                                      AppChoiceOption(value: 'sha256', label: 'SHA-256', icon: Icons.tag),
+                                    ],
+                                    onChanged: (value) => setState(() => _checksumAlgorithm = value),
+                                  ),
+                                  second: _WindowTextField(
+                                    key: const ValueKey('create-task-checksum-expected'),
+                                    controller: _checksumHashController,
+                                    hintText: context.l10n.checksumExpectedHint,
+                                  ),
+                                ),
+                              ],
                             ] else ...[
                               AppFormRow(
                                 direction: stacked ? Axis.vertical : Axis.horizontal,
@@ -950,6 +993,25 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
   }
 
   bool _validateAdvancedOptions() {
+    if (_protocolTab == 0 && _inputUrls().length <= 1) {
+      final checksumExpected = _checksumHashController.text.trim();
+      if (checksumExpected.isNotEmpty) {
+        final expectedLen = switch (_checksumAlgorithm.toLowerCase()) {
+          'md5' => 32,
+          'sha1' || 'sha-1' => 40,
+          'sha256' || 'sha-256' => 64,
+          _ => 0,
+        };
+        if (expectedLen > 0 && checksumExpected.length != expectedLen) {
+          _showToast(context.l10n.checksumInvalidLength(_checksumAlgorithm.toUpperCase(), expectedLen.toString()));
+          return false;
+        }
+        if (!RegExp(r'^[0-9a-fA-F]+$').hasMatch(checksumExpected)) {
+          _showToast(context.l10n.checksumInvalidHex);
+          return false;
+        }
+      }
+    }
     if (_proxyMode != RequestProxyMode.custom) {
       return true;
     }
@@ -1022,8 +1084,15 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
     return text.length == 40 && RegExp(r'^[0-9a-fA-F]+$').hasMatch(text);
   }
 
-  api_options.Options _buildOptions({String? name, List<int> selectFiles = const []}) {
+  api_options.Options _buildOptions({String? name, List<int> selectFiles = const [], bool omitChecksum = false}) {
     final connections = int.tryParse(_connectionsController.text.trim()) ?? 0;
+    final checksumExpected = _checksumHashController.text.trim();
+    final checksum = (!omitChecksum && _inputUrls().length <= 1 && checksumExpected.isNotEmpty)
+        ? api_options.ChecksumOption(
+            algorithm: _checksumAlgorithm,
+            expected: checksumExpected,
+          )
+        : null;
     return api_options.Options(
       name: name ?? _renameController.text.trim(),
       path: _directoryController.text.trim(),
@@ -1036,6 +1105,7 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
         autoExtract: _autoExtract,
         archivePassword: _archivePasswordController.text,
         deleteAfterExtract: _deleteAfterExtract,
+        checksum: checksum,
       ).toJson(),
     );
   }
@@ -1050,13 +1120,14 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
   Future<void> _submitResolved(Request request, ResolveResult result, List<int> selectedIndexes) async {
     final selected = (selectedIndexes.isEmpty ? result.res.files.asMap().keys.toList() : selectedIndexes.toList())
       ..sort();
+    final isMultiFile = selected.length > 1;
     if (result.id.isNotEmpty) {
       await ref
           .read(gopeedServiceProvider)
           .createTask(
             CreateTask(
               rid: result.id,
-              opts: _buildOptions(selectFiles: selected),
+              opts: _buildOptions(selectFiles: selected, omitChecksum: isMultiFile),
             ),
           );
       return;
@@ -1070,11 +1141,11 @@ class _CreateTaskWindowPageState extends ConsumerState<CreateTaskWindowPage> {
           opts: api_options.Options(
             name: file.name,
             path: path.join(_directoryController.text.trim(), result.res.name, file.path),
-            extra: _buildOptions().extra,
+            extra: _buildOptions(omitChecksum: isMultiFile).extra,
           ),
         );
       }).toList();
-      await ref.read(gopeedServiceProvider).createTaskBatch(CreateTaskBatch(reqs: reqs, opts: _buildOptions()));
+      await ref.read(gopeedServiceProvider).createTaskBatch(CreateTaskBatch(reqs: reqs, opts: _buildOptions(omitChecksum: isMultiFile)));
       return;
     }
 

ui/flutter/lib/l10n/app_ar.arb

@@ -164,6 +164,11 @@
   "autoExtract": "فك الضغط تلقائياً",
   "archivePassword": "كلمة مرور الملف المضغوط",
   "archivePasswordHint": "اتركه فارغاً إذا لم يكن محمياً بكلمة مرور",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "حذف الملف المضغوط بعد فك الضغط",
   "extracting": "جاري فك الضغط",
   "extractDone": "تم فك الضغط بنجاح",

ui/flutter/lib/l10n/app_az.arb

@@ -171,6 +171,11 @@
   "autoExtract": "Arxivləri Avtomatik Çıxar",
   "archivePassword": "Arxiv Parolu",
   "archivePasswordHint": "Parolla qorunmayıbsa boş buraxın",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Çıxarıldıqdan sonra arxivi sil",
   "extracting": "Çıxarılır",
   "extractDone": "Çıxarma tamamlandı",

ui/flutter/lib/l10n/app_ca.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Extreu els comprimits automàticament",
   "archivePassword": "Contrasenya del comprimit",
   "archivePasswordHint": "Deixeu-lo en blanc si no està protegit amb contrasenya",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Suprimeix el comprimit després de l'extracció",
   "extracting": "S'està extraient",
   "extractDone": "Extracció completada",

ui/flutter/lib/l10n/app_de.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Archive automatisch entpacken",
   "archivePassword": "Archiv-Passwort",
   "archivePasswordHint": "Leer lassen, wenn nicht passwortgeschützt",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Archiv nach Entpacken löschen",
   "extracting": "Wird entpackt",
   "extractDone": "Entpacken abgeschlossen",

ui/flutter/lib/l10n/app_en.arb

@@ -178,6 +178,11 @@
   "autoExtract": "Extract Archives Automatically",
   "archivePassword": "Archive Password",
   "archivePasswordHint": "Leave empty if not password protected",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Delete Archives After Extraction",
   "extracting": "Extracting",
   "extractDone": "Extraction completed",

ui/flutter/lib/l10n/app_es.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Extraer archivos automáticamente",
   "archivePassword": "Contraseña del archivo",
   "archivePasswordHint": "Dejar vacío si no tiene contraseña",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Eliminar archivo después de extraer",
   "extracting": "Extrayendo",
   "extractDone": "Extracción completada",

ui/flutter/lib/l10n/app_fa.arb

@@ -164,6 +164,11 @@
   "autoExtract": "استخراج خودکار بایگانی‌ها",
   "archivePassword": "رمز عبور بایگانی",
   "archivePasswordHint": "اگر رمز ندارد خالی بگذارید",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "حذف آرشیو پس از استخراج",
   "extracting": "در حال استخراج",
   "extractDone": "استخراج کامل شد",

ui/flutter/lib/l10n/app_fr.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Extraire automatiquement les archives",
   "archivePassword": "Mot de passe de l'archive",
   "archivePasswordHint": "Laisser vide si non protégé par mot de passe",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Supprimer l'archive après extraction",
   "extracting": "Extraction en cours",
   "extractDone": "Extraction terminée",

ui/flutter/lib/l10n/app_hu.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Archívumok automatikus kicsomagolása",
   "archivePassword": "Archívum jelszó",
   "archivePasswordHint": "Hagyja üresen, ha nincs jelszóval védve",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Archívum törlése kicsomagolás után",
   "extracting": "Kicsomagolás",
   "extractDone": "Kicsomagolás befejezve",

ui/flutter/lib/l10n/app_id.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Ekstrak Arsip Otomatis",
   "archivePassword": "Kata Sandi Arsip",
   "archivePasswordHint": "Kosongkan jika tidak dilindungi kata sandi",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Hapus arsip setelah ekstraksi",
   "extracting": "Mengekstrak",
   "extractDone": "Ekstraksi selesai",

ui/flutter/lib/l10n/app_it.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Estrai automaticamente gli archivi",
   "archivePassword": "Password archivio",
   "archivePasswordHint": "Lasciare vuoto se non protetto da password",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Elimina l'archivio dopo l'estrazione",
   "extracting": "Estrazione in corso",
   "extractDone": "Estrazione completata",

ui/flutter/lib/l10n/app_ja.arb

@@ -164,6 +164,11 @@
   "autoExtract": "アーカイブを自動展開",
   "archivePassword": "アーカイブパスワード",
   "archivePasswordHint": "パスワードなしの場合は空のままにしてください",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "展開後にアーカイブを削除",
   "extracting": "展開中",
   "extractDone": "展開完了",

ui/flutter/lib/l10n/app_ko.arb

@@ -164,6 +164,11 @@
   "autoExtract": "압축 파일 자동 압축 해제",
   "archivePassword": "압축 파일 비밀번호",
   "archivePasswordHint": "비밀번호가 없으면 비워 두세요",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "압축 해제 후 압축 파일 삭제",
   "extracting": "압축 해제 중",
   "extractDone": "압축 해제 완료",

ui/flutter/lib/l10n/app_pl.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Automatycznie wyodrębnij archiwa",
   "archivePassword": "Hasło archiwum",
   "archivePasswordHint": "Pozostaw puste, jeśli nie ma hasła",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Usuń archiwum po rozpakowaniu",
   "extracting": "Rozpakowywanie",
   "extractDone": "Rozpakowywanie zakończone",

ui/flutter/lib/l10n/app_pt.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Extrair arquivos automaticamente",
   "archivePassword": "Senha do arquivo",
   "archivePasswordHint": "Deixar vazio se não estiver protegido por senha",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Excluir arquivo após extração",
   "extracting": "Extraindo",
   "extractDone": "Extração concluída",

ui/flutter/lib/l10n/app_ru.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Автоматически распаковать архивы",
   "archivePassword": "Пароль архива",
   "archivePasswordHint": "Оставить пустым, если архив не защищён паролем",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Удалить архив после распаковки",
   "extracting": "Распаковка",
   "extractDone": "Распаковка завершена",

ui/flutter/lib/l10n/app_sk.arb

@@ -178,6 +178,11 @@
   "autoExtract": "Automaticky rozbaliť archívy",
   "archivePassword": "Heslo archívu",
   "archivePasswordHint": "Nechajte prázdne, ak nie je chránený heslom",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Po rozbalení odstrániť archívy",
   "extracting": "Rozbaľovanie",
   "extractDone": "Rozbalenie dokončené",

ui/flutter/lib/l10n/app_ta.arb

@@ -164,6 +164,11 @@
   "autoExtract": "காப்பகங்களை தானாக பிரித்தெடு",
   "archivePassword": "காப்பக கடவுச்சொல்",
   "archivePasswordHint": "கடவுச்சொல் இல்லையென்றால் காலியாக விடவும்",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "பிரித்தெடுத்த பிறகு காப்பகத்தை நீக்கு",
   "extracting": "பிரித்தெடுக்கிறது",
   "extractDone": "பிரித்தெடுத்தல் முடிந்தது",

ui/flutter/lib/l10n/app_tr.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Arşivleri Otomatik Çıkar",
   "archivePassword": "Arşiv Şifresi",
   "archivePasswordHint": "Şifre korumalı değilse boş bırakın",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Çıkardıktan sonra arşivi sil",
   "extracting": "Çıkarılıyor",
   "extractDone": "Çıkarma tamamlandı",

ui/flutter/lib/l10n/app_uk.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Автоматично розпаковувати архіви",
   "archivePassword": "Пароль архіву",
   "archivePasswordHint": "Залишити порожнім, якщо архів не захищений паролем",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Видалити архів після розпакування",
   "extracting": "Розпакування",
   "extractDone": "Розпакування завершено",

ui/flutter/lib/l10n/app_vi.arb

@@ -164,6 +164,11 @@
   "autoExtract": "Tự động giải nén tập tin nén",
   "archivePassword": "Mật khẩu tập tin nén",
   "archivePasswordHint": "Để trống nếu không có mật khẩu",
+  "checksumAlgorithm": "Checksum Algorithm",
+  "checksumHash": "Checksum Hash",
+  "checksumExpectedHint": "Expected hash (optional)",
+  "checksumInvalidLength": "Invalid checksum hash length for {algorithm}: expected {length} characters",
+  "checksumInvalidHex": "Invalid checksum hash: expected hexadecimal characters (0-9, a-f)",
   "deleteAfterExtract": "Xóa tập tin nén sau khi giải nén",
   "extracting": "Đang giải nén",
   "extractDone": "Giải nén hoàn tất",

ui/flutter/lib/l10n/app_zh.arb

@@ -164,6 +164,11 @@
   "autoExtract": "自动解压压缩包",
   "archivePassword": "压缩包密码",
   "archivePasswordHint": "如无密码请留空",
+  "checksumAlgorithm": "校验和算法",
+  "checksumHash": "校验和",
+  "checksumExpectedHint": "预期哈希值（可选）",
+  "checksumInvalidLength": "{algorithm} 校验和哈希长度无效：应为 {length} 个字符",
+  "checksumInvalidHex": "校验和哈希无效：应为十六进制字符（0-9，a-f）",
   "deleteAfterExtract": "解压后删除压缩包",
   "extracting": "正在解压",
   "extractDone": "解压完成",

ui/flutter/lib/l10n/app_zh_TW.arb

@@ -164,6 +164,11 @@
   "autoExtract": "自動解壓縮壓縮包",
   "archivePassword": "壓縮包密碼",
   "archivePasswordHint": "如無密碼請留空",
+  "checksumAlgorithm": "校驗和演算法",
+  "checksumHash": "校驗和",
+  "checksumExpectedHint": "預期雜湊值（可選）",
+  "checksumInvalidLength": "{algorithm} 校驗和雜湊長度無效：應為 {length} 個字元",
+  "checksumInvalidHex": "校驗和雜湊無效：應為十六進位字元（0-9，a-f）",
   "deleteAfterExtract": "解壓後刪除壓縮檔",
   "extracting": "正在解壓",
   "extractDone": "解壓完成",

ui/flutter/test/features/tasks/presentation/create_task_window_page_test.dart

@@ -26,6 +26,7 @@ import 'package:gopeed/shared/theme/app_design_tokens.dart';
 import 'package:gopeed/shared/theme/app_theme.dart';
 import 'package:gopeed/shared/widgets/app_loading_button.dart';
 import 'package:gopeed/shared/widgets/app_tooltip.dart';
+import 'package:gopeed/l10n/app_localizations.dart';
 import 'package:shadcn_flutter/shadcn_flutter.dart' as shad;
 
 void main() {
@@ -611,6 +612,355 @@ void main() {
     expect(find.byKey(const ValueKey('create-history-clear')), findsOneWidget);
     expect(find.byKey(const ValueKey('create-history-close')), findsOneWidget);
   });
+
+  testWidgets('checksum state is reset for each incoming task and not inherited (T1)', (tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    try {
+      tester.view.physicalSize = const Size(700, 900);
+      tester.view.devicePixelRatio = 1;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+
+      CreateTask? submitted;
+      final registry = CapabilityRegistry(createAppCapabilityCodecs())
+        ..bind(GopeedMethods.getConfig, (_) => DownloaderConfig(downloadDir: '/downloads'))
+        ..bind(GopeedMethods.createTask, (task) {
+          submitted = task;
+          return 'task-id';
+        })
+        ..bind(StorageMethods.saveCreateHistory, (_) => const RpcUnit());
+
+      final container = ProviderContainer(
+        overrides: [appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry)))],
+      );
+      addTearDown(container.dispose);
+
+      final pending = container.read(pendingCreateTaskProvider.notifier);
+      // Task A: with checksum
+      pending.set(
+        CreateTask(
+          req: Request(url: 'https://example.com/taskA.zip'),
+          opts: Options(
+            extra: OptsExtraHttp(
+              checksum: ChecksumOption(
+                algorithm: 'sha256',
+                expected: 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855',
+              ),
+            ).toJson(),
+          ),
+        ),
+      );
+
+      final router = GoRouter(
+        initialLocation: '/create',
+        routes: [
+          GoRoute(path: '/', builder: (_, _) => const SizedBox()),
+          GoRoute(path: '/create', builder: (_, _) => const CreateTaskWindowPage()),
+        ],
+      );
+      addTearDown(router.dispose);
+
+      await tester.pumpWidget(
+        UncontrolledProviderScope(
+          container: container,
+          child: shad.ShadcnApp.router(
+            theme: AppTheme.light(),
+            materialTheme: AppTheme.materialLight(),
+            routerConfig: router,
+            builder: (_, child) => AppComponentThemes(child: child!),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // Expand advanced
+      await tester.tap(find.text('Advanced'));
+      await tester.pumpAndSettle();
+      expect(_fieldText(tester, 'create-task-checksum-expected'), 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855');
+
+      // Task B form 1: null opts
+      pending.set(CreateTask(req: Request(url: 'https://example.com/taskB1.zip')));
+      router.go('/create');
+      await tester.pumpAndSettle();
+      expect(_fieldText(tester, 'create-task-checksum-expected'), '');
+
+      // Task B form 2: empty Options
+      pending.set(CreateTask(req: Request(url: 'https://example.com/taskB2.zip'), opts: Options()));
+      router.go('/create');
+      await tester.pumpAndSettle();
+      expect(_fieldText(tester, 'create-task-checksum-expected'), '');
+
+      // Task B form 3: HTTP extra with no checksum
+      pending.set(
+        CreateTask(
+          req: Request(url: 'https://example.com/taskB3.zip'),
+          opts: Options(extra: OptsExtraHttp(connections: 8).toJson()),
+        ),
+      );
+      router.go('/create');
+      await tester.pumpAndSettle();
+      expect(_fieldText(tester, 'create-task-checksum-expected'), '');
+
+      // Submit task B3 and ensure no checksum is sent
+      await tester.tap(find.byKey(const ValueKey('create-task-direct-download-toggle')));
+      await tester.tap(find.text('Confirm'));
+      await tester.pumpAndSettle();
+
+      expect(submitted?.opts?.extra, isNotNull);
+      final extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(submitted!.opts!.extra! as Map));
+      expect(extra.checksum, isNull);
+    } finally {
+      debugDefaultTargetPlatformOverride = null;
+    }
+  });
+
+  testWidgets('checksum input validation blocks submission on invalid input (T3-UI)', (tester) async {
+    tester.view.physicalSize = const Size(1024, 1200);
+    tester.view.devicePixelRatio = 1;
+    addTearDown(tester.view.resetPhysicalSize);
+    addTearDown(tester.view.resetDevicePixelRatio);
+
+    CreateTask? submitted;
+    final config = DownloaderConfig(downloadDir: '/downloads')..extra.defaultDirectDownload = true;
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getConfig, (_) => config)
+      ..bind(GopeedMethods.createTask, (task) {
+        submitted = task;
+        return 'task-id';
+      })
+      ..bind(StorageMethods.saveCreateHistory, (_) => const RpcUnit());
+
+    final container = ProviderContainer(
+      overrides: [appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry)))],
+    );
+    addTearDown(container.dispose);
+
+    final pending = container.read(pendingCreateTaskProvider.notifier);
+    pending.set(CreateTask(req: Request(url: 'https://example.com/file.zip')));
+
+    final router = GoRouter(
+      initialLocation: '/create',
+      routes: [
+        GoRoute(path: '/', builder: (_, _) => const SizedBox()),
+        GoRoute(path: '/create', builder: (_, _) => const CreateTaskWindowPage()),
+      ],
+    );
+    addTearDown(router.dispose);
+
+    await tester.pumpWidget(
+      UncontrolledProviderScope(
+        container: container,
+        child: shad.ShadcnApp.router(
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          theme: AppTheme.light(),
+          materialTheme: AppTheme.materialLight(),
+          routerConfig: router,
+          builder: (_, child) => AppComponentThemes(child: child!),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    // Expand advanced options
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+
+    // Test 1: "abc" for SHA-256
+    await tester.tap(find.text('SHA-256'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'abc');
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNull);
+
+    // Test 2: 64 x "g" (non-hex) for SHA-256
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'g' * 64);
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNull);
+
+    // Test 3: 63 x "a" (invalid length) for SHA-256
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'a' * 63);
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNull);
+
+    // Test 4: 65 x "a" (invalid length) for SHA-256
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'a' * 65);
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNull);
+
+    // Test 5: MD5 with sha256-length hash
+    await tester.tap(find.text('MD5'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'a' * 64);
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNull);
+
+    // Test 6: Valid MD5 in UPPER case
+    submitted = null;
+    await tester.tap(find.text('MD5'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), '0123456789ABCDEF0123456789ABCDEF');
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNotNull);
+    var extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(submitted!.opts!.extra! as Map));
+    expect(extra.checksum?.algorithm, 'md5');
+    expect(extra.checksum?.expected, '0123456789ABCDEF0123456789ABCDEF');
+
+    // Test 7: Valid SHA-1 in lower case
+    submitted = null;
+    pending.set(CreateTask(req: Request(url: 'https://example.com/file2.zip')));
+    router.go('/create');
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('SHA-1'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'da39a3ee5e6b4b0d3255bfef95601890afd80709');
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNotNull);
+    extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(submitted!.opts!.extra! as Map));
+    expect(extra.checksum?.algorithm, 'sha1');
+    expect(extra.checksum?.expected, 'da39a3ee5e6b4b0d3255bfef95601890afd80709');
+
+    // Test 8: Valid SHA-256 in lower case
+    submitted = null;
+    pending.set(CreateTask(req: Request(url: 'https://example.com/file3.zip')));
+    router.go('/create');
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('SHA-256'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855');
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNotNull);
+    extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(submitted!.opts!.extra! as Map));
+    expect(extra.checksum?.algorithm, 'sha256');
+    expect(extra.checksum?.expected, 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855');
+
+    // Test 9: Omitted checksum (empty hash)
+    submitted = null;
+    pending.set(CreateTask(req: Request(url: 'https://example.com/file4.zip')));
+    router.go('/create');
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+    await tester.enterText(find.byKey(const ValueKey('create-task-checksum-expected')), '   ');
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+    expect(submitted, isNotNull);
+    extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(submitted!.opts!.extra! as Map));
+    expect(extra.checksum, isNull);
+  });
+
+  testWidgets('multi-URL and multi-file batch creation omits checksum (T4)', (tester) async {
+    tester.view.physicalSize = const Size(1024, 1200);
+    tester.view.devicePixelRatio = 1;
+    addTearDown(tester.view.resetPhysicalSize);
+    addTearDown(tester.view.resetDevicePixelRatio);
+
+    final createdTasks = <CreateTask>[];
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getConfig, (_) => DownloaderConfig(downloadDir: '/downloads'))
+      ..bind(GopeedMethods.createTask, (task) {
+        createdTasks.add(task);
+        return 'task-id';
+      })
+      ..bind(StorageMethods.saveCreateHistory, (_) => const RpcUnit());
+
+    final container = ProviderContainer(
+      overrides: [appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry)))],
+    );
+    addTearDown(container.dispose);
+
+    final router = GoRouter(
+      initialLocation: '/create',
+      routes: [
+        GoRoute(path: '/', builder: (_, _) => const SizedBox()),
+        GoRoute(path: '/create', builder: (_, _) => const CreateTaskWindowPage()),
+      ],
+    );
+    addTearDown(router.dispose);
+
+    await tester.pumpWidget(
+      UncontrolledProviderScope(
+        container: container,
+        child: shad.ShadcnApp.router(
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          theme: AppTheme.light(),
+          materialTheme: AppTheme.materialLight(),
+          routerConfig: router,
+          builder: (_, child) => AppComponentThemes(child: child!),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    // Enter 2 URLs
+    await tester.enterText(
+      find.byKey(const ValueKey('create-task-url-input')),
+      'https://example.com/file1.zip\nhttps://example.com/file2.zip',
+    );
+    await tester.pumpAndSettle();
+
+    // Advanced options should hide the checksum field
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+    expect(find.byKey(const ValueKey('create-task-checksum-expected')), findsNothing);
+
+    // Confirm creation
+    await tester.tap(find.text('Confirm'));
+    await tester.pumpAndSettle();
+
+    expect(createdTasks.length, 2);
+    for (final t in createdTasks) {
+      final extra = OptsExtraHttp.fromJson(Map<String, dynamic>.from(t.opts!.extra! as Map));
+      expect(extra.checksum, isNull);
+    }
+  });
+
+  testWidgets('checksum UI uses localized labels (T5)', (tester) async {
+    tester.view.physicalSize = const Size(700, 1200);
+    tester.view.devicePixelRatio = 1;
+    addTearDown(tester.view.resetPhysicalSize);
+    addTearDown(tester.view.resetDevicePixelRatio);
+
+    final registry = CapabilityRegistry(createAppCapabilityCodecs())
+      ..bind(GopeedMethods.getConfig, (_) => DownloaderConfig(downloadDir: '/downloads'));
+
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [appCapabilitiesProvider.overrideWithValue(AppCapabilities(LocalCapabilityInvoker(registry)))],
+        child: shad.ShadcnApp(
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          theme: AppTheme.light(),
+          materialTheme: AppTheme.materialLight(),
+          home: AppComponentThemes(
+            child: CreateTaskWindowPage(
+              initialTask: CreateTask(req: Request(url: 'https://example.com/file.zip')),
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.text('Advanced'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Checksum Algorithm'), findsOneWidget);
+    expect(find.text('Checksum Hash'), findsOneWidget);
+  });
 }
 
 String _fieldText(WidgetTester tester, String key) {