diff --git a/lib/services/api_service.dart b/lib/services/api_service.dart
index 27dbde0..5b3a1ef 100644
--- a/lib/services/api_service.dart
+++ b/lib/services/api_service.dart
@@ -299,6 +299,169 @@ class BoxDeleteResult {
   BoxDeleteResult({required this.success, this.errorMessage});
 }
 
+// === 附件模块数据类 ===
+
+class AttachmentCategoryData {
+  final int id;
+  final String name;
+  final int sortOrder;
+
+  AttachmentCategoryData({
+    required this.id,
+    required this.name,
+    required this.sortOrder,
+  });
+
+  factory AttachmentCategoryData.fromJson(Map<String, dynamic> json) {
+    return AttachmentCategoryData(
+      id: json['id'] as int,
+      name: json['name'] as String,
+      sortOrder: json['sort_order'] as int,
+    );
+  }
+}
+
+class AttachmentCategoryResult {
+  final bool success;
+  final String? errorMessage;
+  final List<AttachmentCategoryData> categories;
+
+  AttachmentCategoryResult({
+    required this.success,
+    this.errorMessage,
+    this.categories = const [],
+  });
+}
+
+class AttachmentStatusItemData {
+  final int categoryId;
+  final String name;
+  final int expectedQty;
+  final int boxedQty;
+  final String? locationCode;
+  final bool complete;
+
+  AttachmentStatusItemData({
+    required this.categoryId,
+    required this.name,
+    required this.expectedQty,
+    required this.boxedQty,
+    this.locationCode,
+    required this.complete,
+  });
+
+  factory AttachmentStatusItemData.fromJson(Map<String, dynamic> json) {
+    return AttachmentStatusItemData(
+      categoryId: json['category_id'] as int,
+      name: json['name'] as String,
+      expectedQty: json['expected_qty'] as int,
+      boxedQty: json['boxed_qty'] as int,
+      locationCode: json['location_code']?.toString(),
+      complete: json['complete'] as bool,
+    );
+  }
+}
+
+class AttachmentStatusResult {
+  final bool success;
+  final String? errorMessage;
+  final String determination;
+  final bool allComplete;
+  final List<AttachmentStatusItemData> items;
+
+  AttachmentStatusResult({
+    required this.success,
+    this.errorMessage,
+    this.determination = 'undetermined',
+    this.allComplete = false,
+    this.items = const [],
+  });
+}
+
+class AttachmentConfigItemData {
+  final int categoryId;
+  final int expectedQty;
+
+  const AttachmentConfigItemData({
+    required this.categoryId,
+    required this.expectedQty,
+  });
+
+  Map<String, dynamic> toJson() => {
+    'category_id': categoryId,
+    'expected_qty': expectedQty,
+  };
+}
+
+class AttachmentConfigResult {
+  final bool success;
+  final String? errorMessage;
+  final String? errorCode;
+  final String determination;
+  final bool allComplete;
+  final List<AttachmentStatusItemData> items;
+
+  AttachmentConfigResult({
+    required this.success,
+    this.errorMessage,
+    this.errorCode,
+    this.determination = 'undetermined',
+    this.allComplete = false,
+    this.items = const [],
+  });
+}
+
+class AttachmentLocationResult {
+  final bool success;
+  final bool isDuplicate;
+  final bool isAlreadyOffShelf;
+  final String? errorMessage;
+  final String? locationCode;
+  final String? previousLocation;
+  final Map<String, dynamic>? conflictInfo;
+
+  AttachmentLocationResult({
+    required this.success,
+    this.isDuplicate = false,
+    this.isAlreadyOffShelf = false,
+    this.errorMessage,
+    this.locationCode,
+    this.previousLocation,
+    this.conflictInfo,
+  });
+}
+
+class AttachmentBoxResult {
+  final bool success;
+  final bool isDuplicate;
+  final String? errorMessage;
+  final int? boxItemId;
+  final String? paichanNo;
+  final int? boxNo;
+  final String? zongpaiNo;
+  final int? categoryId;
+  final int? quantity;
+
+  AttachmentBoxResult({
+    required this.success,
+    this.isDuplicate = false,
+    this.errorMessage,
+    this.boxItemId,
+    this.paichanNo,
+    this.boxNo,
+    this.zongpaiNo,
+    this.categoryId,
+    this.quantity,
+  });
+}
+
+class AttachmentBoxDeleteResult {
+  final bool success;
+  final String? errorMessage;
+
+  AttachmentBoxDeleteResult({required this.success, this.errorMessage});
+}
+
 class ApiService {
   final http.Client _client;
   final Duration timeout;
@@ -534,4 +697,341 @@ class ApiService {
       return false;
     }
   }
+
+  /// 查询附件类型列表 — GET /CargoTrace/attachment/categories
+  Future<AttachmentCategoryResult> fetchAttachmentCategories({
+    required String baseUrl,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/categories');
+    try {
+      final response = await _client
+          .get(uri, headers: {'Content-Type': 'application/json'})
+          .timeout(timeout);
+      if (response.statusCode == 200) {
+        final list = (jsonDecode(response.body) as List)
+            .map(
+              (e) => AttachmentCategoryData.fromJson(e as Map<String, dynamic>),
+            )
+            .toList();
+        return AttachmentCategoryResult(success: true, categories: list);
+      }
+      return AttachmentCategoryResult(
+        success: false,
+        errorMessage: '加载失败 (${response.statusCode})',
+      );
+    } catch (e) {
+      return AttachmentCategoryResult(
+        success: false,
+        errorMessage: '网络异常，请检查网络连接',
+      );
+    }
+  }
+
+  /// 查询附件状态 — GET /CargoTrace/attachment/status
+  Future<AttachmentStatusResult> fetchAttachmentStatus({
+    required String baseUrl,
+    required String zongpaiNo,
+  }) async {
+    final uri = Uri.parse(
+      '$baseUrl/CargoTrace/attachment/status',
+    ).replace(queryParameters: {'zongpai_no': zongpaiNo});
+    try {
+      final response = await _client
+          .get(uri, headers: {'Content-Type': 'application/json'})
+          .timeout(timeout);
+      if (response.statusCode == 200) {
+        final body = jsonDecode(response.body) as Map<String, dynamic>;
+        final items =
+            (body['items'] as List?)
+                ?.map(
+                  (e) => AttachmentStatusItemData.fromJson(
+                    e as Map<String, dynamic>,
+                  ),
+                )
+                .toList() ??
+            [];
+        return AttachmentStatusResult(
+          success: true,
+          determination: body['determination']?.toString() ?? 'undetermined',
+          allComplete: body['all_complete'] as bool? ?? false,
+          items: items,
+        );
+      }
+      return AttachmentStatusResult(
+        success: false,
+        errorMessage: '查询失败 (${response.statusCode})',
+      );
+    } catch (e) {
+      return AttachmentStatusResult(
+        success: false,
+        errorMessage: '网络异常，请检查网络连接',
+      );
+    }
+  }
+
+  /// 定稿附件清单 — PUT /CargoTrace/attachment/config
+  Future<AttachmentConfigResult> putAttachmentConfig({
+    required String baseUrl,
+    required String zongpaiNo,
+    required String determination,
+    required List<AttachmentConfigItemData> items,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/config');
+    try {
+      final response = await _client
+          .put(
+            uri,
+            headers: {'Content-Type': 'application/json'},
+            body: jsonEncode({
+              'zongpai_no': zongpaiNo,
+              'determination': determination,
+              'items': items.map((i) => i.toJson()).toList(),
+            }),
+          )
+          .timeout(timeout);
+      if (response.statusCode == 200) {
+        final body = jsonDecode(response.body) as Map<String, dynamic>;
+        final respItems =
+            (body['items'] as List?)
+                ?.map(
+                  (e) => AttachmentStatusItemData.fromJson(
+                    e as Map<String, dynamic>,
+                  ),
+                )
+                .toList() ??
+            [];
+        return AttachmentConfigResult(
+          success: true,
+          determination: body['determination']?.toString() ?? 'has',
+          allComplete: body['all_complete'] as bool? ?? false,
+          items: respItems,
+        );
+      }
+      final body = jsonDecode(response.body) as Map<String, dynamic>;
+      return AttachmentConfigResult(
+        success: false,
+        errorMessage: body['message']?.toString() ?? '配置失败',
+        errorCode: body['error_code']?.toString(),
+      );
+    } catch (e) {
+      return AttachmentConfigResult(
+        success: false,
+        errorMessage: '网络异常，请检查网络连接',
+      );
+    }
+  }
+
+  /// 附件上架 — POST /CargoTrace/attachment/location
+  Future<AttachmentLocationResult> registerAttachmentLocation({
+    required String baseUrl,
+    required String zongpaiNo,
+    required int categoryId,
+    required String locationCode,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/location');
+    try {
+      final response = await _client
+          .post(
+            uri,
+            headers: {'Content-Type': 'application/json'},
+            body: jsonEncode({
+              'zongpai_no': zongpaiNo,
+              'category_id': categoryId,
+              'location_code': locationCode,
+            }),
+          )
+          .timeout(timeout);
+      switch (response.statusCode) {
+        case 200:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentLocationResult(
+            success: true,
+            locationCode: body['location_code']?.toString(),
+            previousLocation: body['previous_location']?.toString(),
+          );
+        case 400:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentLocationResult(
+            success: false,
+            errorMessage: body['message']?.toString() ?? '请求参数错误',
+          );
+        case 409:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          final errorCode = body['error_code']?.toString();
+          if (errorCode == 'DUPLICATE_LOCATION') {
+            return AttachmentLocationResult(
+              success: false,
+              isDuplicate: true,
+              conflictInfo: body,
+            );
+          }
+          if (errorCode == 'ALREADY_OFF_SHELF') {
+            return AttachmentLocationResult(
+              success: false,
+              isAlreadyOffShelf: true,
+              errorMessage: body['message']?.toString(),
+              conflictInfo: body,
+            );
+          }
+          return AttachmentLocationResult(
+            success: false,
+            errorMessage: body['message']?.toString() ?? '提交失败',
+          );
+        default:
+          return AttachmentLocationResult(
+            success: false,
+            errorMessage: '提交失败 (${response.statusCode})',
+          );
+      }
+    } catch (e) {
+      return AttachmentLocationResult(
+        success: false,
+        errorMessage: '网络异常，请检查网络连接',
+      );
+    }
+  }
+
+  /// 附件装箱 — POST /CargoTrace/attachment/box
+  Future<AttachmentBoxResult> saveAttachmentBox({
+    required String baseUrl,
+    required String zongpaiNo,
+    required int categoryId,
+    required int boxNo,
+    required int quantity,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/box');
+    try {
+      final response = await _client
+          .post(
+            uri,
+            headers: {'Content-Type': 'application/json'},
+            body: jsonEncode({
+              'zongpai_no': zongpaiNo,
+              'category_id': categoryId,
+              'box_no': boxNo,
+              'quantity': quantity,
+            }),
+          )
+          .timeout(timeout);
+      switch (response.statusCode) {
+        case 200:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentBoxResult(
+            success: true,
+            boxItemId: body['box_item_id'] as int?,
+            paichanNo: body['paichan_no']?.toString(),
+            boxNo: body['box_no'] as int?,
+            zongpaiNo: body['zongpai_no']?.toString(),
+            categoryId: body['category_id'] as int?,
+            quantity: body['quantity'] as int?,
+          );
+        case 400:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentBoxResult(
+            success: false,
+            errorMessage: body['message']?.toString() ?? '请求参数错误',
+          );
+        case 404:
+          return AttachmentBoxResult(
+            success: false,
+            errorMessage: '未找到该总排号或附件类型',
+          );
+        case 409:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentBoxResult(
+            success: false,
+            isDuplicate: true,
+            errorMessage: body['message']?.toString(),
+            paichanNo: body['paichan_no']?.toString(),
+            boxNo: body['box_no'] as int?,
+          );
+        default:
+          return AttachmentBoxResult(
+            success: false,
+            errorMessage: '提交失败 (${response.statusCode})',
+          );
+      }
+    } catch (e) {
+      return AttachmentBoxResult(success: false, errorMessage: '网络异常，请检查网络连接');
+    }
+  }
+
+  /// 修改附件装箱明细 — PATCH /CargoTrace/attachment/box/{itemId}
+  Future<AttachmentBoxResult> updateAttachmentBox({
+    required String baseUrl,
+    required int boxItemId,
+    required int boxNo,
+    required int quantity,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/box/$boxItemId');
+    try {
+      final response = await _client
+          .patch(
+            uri,
+            headers: {'Content-Type': 'application/json'},
+            body: jsonEncode({'box_no': boxNo, 'quantity': quantity}),
+          )
+          .timeout(timeout);
+      switch (response.statusCode) {
+        case 200:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentBoxResult(
+            success: true,
+            boxItemId: body['box_item_id'] as int?,
+            paichanNo: body['paichan_no']?.toString(),
+            boxNo: body['box_no'] as int?,
+            zongpaiNo: body['zongpai_no']?.toString(),
+            categoryId: body['category_id'] as int?,
+            quantity: body['quantity'] as int?,
+          );
+        case 400:
+          final body = jsonDecode(response.body) as Map<String, dynamic>;
+          return AttachmentBoxResult(
+            success: false,
+            errorMessage: body['message']?.toString() ?? '请求参数错误',
+          );
+        case 404:
+          return AttachmentBoxResult(success: false, errorMessage: '指定装箱明细不存在');
+        default:
+          return AttachmentBoxResult(
+            success: false,
+            errorMessage: '修改失败 (${response.statusCode})',
+          );
+      }
+    } catch (e) {
+      return AttachmentBoxResult(success: false, errorMessage: '网络异常，请检查网络连接');
+    }
+  }
+
+  /// 删除附件装箱明细 — DELETE /CargoTrace/attachment/box/{itemId}
+  Future<AttachmentBoxDeleteResult> deleteAttachmentBox({
+    required String baseUrl,
+    required int boxItemId,
+  }) async {
+    final uri = Uri.parse('$baseUrl/CargoTrace/attachment/box/$boxItemId');
+    try {
+      final response = await _client
+          .delete(uri, headers: {'Content-Type': 'application/json'})
+          .timeout(timeout);
+      switch (response.statusCode) {
+        case 200:
+          return AttachmentBoxDeleteResult(success: true);
+        case 404:
+          return AttachmentBoxDeleteResult(
+            success: false,
+            errorMessage: '指定装箱明细不存在',
+          );
+        default:
+          return AttachmentBoxDeleteResult(
+            success: false,
+            errorMessage: '删除失败 (${response.statusCode})',
+          );
+      }
+    } catch (e) {
+      return AttachmentBoxDeleteResult(
+        success: false,
+        errorMessage: '网络异常，请检查网络连接',
+      );
+    }
+  }
 }
diff --git a/test/services/api_service_test.dart b/test/services/api_service_test.dart
index 854f3b6..9d5d4ca 100644
--- a/test/services/api_service_test.dart
+++ b/test/services/api_service_test.dart
@@ -372,6 +372,248 @@ void main() {
       expect(missing.errorMessage, '指定装箱明细不存在');
     });
   });
+
+  group('ApiService attachment APIs', () {
+    test('fetchAttachmentCategories parses list', () async {
+      final mockClient = _MockClient((request) async {
+        return http.Response(
+          jsonEncode([
+            {'id': 1, 'name': '检验证书', 'sort_order': 1},
+            {'id': 2, 'name': '增发', 'sort_order': 2},
+          ]),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.fetchAttachmentCategories(
+        baseUrl: 'http://localhost',
+      );
+      expect(result.success, isTrue);
+      expect(result.categories.length, 2);
+      expect(result.categories.first.name, '检验证书');
+    });
+
+    test('fetchAttachmentCategories handles network failure', () async {
+      final mockClient = _MockClient((request) async {
+        throw Exception('Connection refused');
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.fetchAttachmentCategories(
+        baseUrl: 'http://localhost',
+      );
+      expect(result.success, isFalse);
+      expect(result.errorMessage, '网络异常，请检查网络连接');
+    });
+
+    test('fetchAttachmentStatus parses undetermined zongpai', () async {
+      final mockClient = _MockClient((request) async {
+        return http.Response(
+          jsonEncode({
+            'zongpai_no': '26BW0011',
+            'determination': 'undetermined',
+            'all_complete': false,
+            'items': [],
+          }),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.fetchAttachmentStatus(
+        baseUrl: 'http://localhost',
+        zongpaiNo: '26BW0011',
+      );
+      expect(result.success, isTrue);
+      expect(result.determination, 'undetermined');
+      expect(result.items, isEmpty);
+    });
+
+    test('putAttachmentConfig sends full payload', () async {
+      late Map<String, dynamic> body;
+      final mockClient = _MockClient((request) async {
+        final req = request as http.Request;
+        body = jsonDecode(req.body) as Map<String, dynamic>;
+        return http.Response(
+          jsonEncode({
+            'zongpai_no': '26BW0011',
+            'determination': 'has',
+            'all_complete': false,
+            'items': [
+              {
+                'category_id': 1,
+                'name': '检验证书',
+                'expected_qty': 80,
+                'boxed_qty': 0,
+                'location_code': null,
+                'complete': false,
+              },
+            ],
+          }),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.putAttachmentConfig(
+        baseUrl: 'http://localhost',
+        zongpaiNo: '26BW0011',
+        determination: 'has',
+        items: [AttachmentConfigItemData(categoryId: 1, expectedQty: 80)],
+      );
+      expect(result.success, isTrue);
+      expect(result.items.single.complete, isFalse);
+      expect(body['items'], [
+        {'category_id': 1, 'expected_qty': 80},
+      ]);
+    });
+
+    test('registerAttachmentLocation returns 200 with data', () async {
+      final mockClient = _MockClient((request) async {
+        return http.Response(
+          jsonEncode({
+            'zongpai_no': '26BW0011',
+            'category_id': 1,
+            'location_code': 'A01-01-01',
+            'created_at': '2026-08-12T10:00:00',
+            'previous_location': null,
+          }),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.registerAttachmentLocation(
+        baseUrl: 'http://localhost',
+        zongpaiNo: '26BW0011',
+        categoryId: 1,
+        locationCode: 'A01-01-01',
+      );
+      expect(result.success, isTrue);
+      expect(result.locationCode, 'A01-01-01');
+    });
+
+    test('saveAttachmentBox sends request with category_id', () async {
+      late Map<String, dynamic> body;
+      final mockClient = _MockClient((request) async {
+        final req = request as http.Request;
+        body = jsonDecode(req.body) as Map<String, dynamic>;
+        return http.Response(
+          jsonEncode({
+            'box_item_id': 1,
+            'paichan_no': 'W00009',
+            'box_no': 10,
+            'zongpai_no': '26BW0011',
+            'category_id': 1,
+            'quantity': 30,
+            'created_at': '2026-08-12T10:00:00',
+          }),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.saveAttachmentBox(
+        baseUrl: 'http://localhost',
+        zongpaiNo: '26BW0011',
+        categoryId: 1,
+        boxNo: 10,
+        quantity: 30,
+      );
+      expect(result.success, isTrue);
+      expect(result.boxItemId, 1);
+      expect(body['category_id'], 1);
+    });
+
+    test('saveAttachmentBox returns duplicate on 409', () async {
+      final mockClient = _MockClient((request) async {
+        return http.Response(
+          jsonEncode({
+            'error_code': 'DUPLICATE_BOX_NO',
+            'message': '排产号 W00009 下箱号 10 已存在',
+            'paichan_no': 'W00009',
+            'box_no': 10,
+          }),
+          409,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.saveAttachmentBox(
+        baseUrl: 'http://localhost',
+        zongpaiNo: '26BW0011',
+        categoryId: 1,
+        boxNo: 10,
+        quantity: 30,
+      );
+      expect(result.success, isFalse);
+      expect(result.isDuplicate, isTrue);
+    });
+
+    test('updateAttachmentBox sends PATCH with box_no and quantity', () async {
+      late Map<String, dynamic> body;
+      final mockClient = _MockClient((request) async {
+        final req = request as http.Request;
+        body = jsonDecode(req.body) as Map<String, dynamic>;
+        return http.Response(
+          jsonEncode({
+            'box_item_id': 1,
+            'paichan_no': 'W00009',
+            'box_no': 11,
+            'zongpai_no': '26BW0011',
+            'category_id': 1,
+            'quantity': 20,
+            'updated_at': '2026-08-12T10:00:00',
+          }),
+          200,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final result = await svc.updateAttachmentBox(
+        baseUrl: 'http://localhost',
+        boxItemId: 1,
+        boxNo: 11,
+        quantity: 20,
+      );
+      expect(result.success, isTrue);
+      expect(body, {'box_no': 11, 'quantity': 20});
+    });
+
+    test('deleteAttachmentBox handles success and not found', () async {
+      var calls = 0;
+      final mockClient = _MockClient((request) async {
+        calls += 1;
+        if (calls == 1) {
+          return http.Response(
+            jsonEncode({'box_item_id': 1, 'deleted': true}),
+            200,
+            headers: {'content-type': 'application/json; charset=utf-8'},
+          );
+        }
+        return http.Response(
+          jsonEncode({
+            'error_code': 'BOX_ITEM_NOT_FOUND',
+            'message': '指定装箱明细不存在',
+          }),
+          404,
+          headers: {'content-type': 'application/json; charset=utf-8'},
+        );
+      });
+      final svc = ApiService(client: mockClient);
+      final ok = await svc.deleteAttachmentBox(
+        baseUrl: 'http://localhost',
+        boxItemId: 1,
+      );
+      final missing = await svc.deleteAttachmentBox(
+        baseUrl: 'http://localhost',
+        boxItemId: 999,
+      );
+      expect(ok.success, isTrue);
+      expect(missing.success, isFalse);
+      expect(missing.errorMessage, '指定装箱明细不存在');
+    });
+  });
 }
 
 class _MockClient extends http.BaseClient {