diff --git a/src/Kompas.Mcp.Core/Documents/DocumentService.cs b/src/Kompas.Mcp.Core/Documents/DocumentService.cs
index c3f1363..f409288 100644
--- a/src/Kompas.Mcp.Core/Documents/DocumentService.cs
+++ b/src/Kompas.Mcp.Core/Documents/DocumentService.cs
@@ -64,6 +64,26 @@ public sealed class DocumentService
         => _dispatcher.InvokeAsync(() => WithActive(d =>
             d.Close(save ? DocumentCloseOptions.kdSaveChanges : DocumentCloseOptions.kdDoNotSaveChanges)), ct);
 
+    /// <summary>
+    /// Закрыть ВСЕ открытые документы без сохранения; возвращает число закрытых. Применяется для
+    /// очистки между тестами, чтобы не накапливались вкладки-пустышки. Закрываем активный документ
+    /// в цикле (после закрытия активным становится следующий) с защитой от зацикливания: если очередной
+    /// документ закрыть не удалось, прекращаем, чтобы не крутить впустую на одном и том же.
+    /// </summary>
+    public Task<int> CloseAllAsync(CancellationToken ct = default)
+        => _dispatcher.InvokeAsync(() =>
+        {
+            int closed = 0;
+            for (int guard = 0; guard < 256; guard++)
+            {
+                var doc = _session.Application.ActiveDocument;
+                if (doc is null) break;
+                try { doc.Close(DocumentCloseOptions.kdDoNotSaveChanges); closed++; }
+                finally { ComHelper.Release(doc); }
+            }
+            return closed;
+        }, ct);
+
     private void WithActive(Action<IKompasDocument> action)
         => WithActive(d => { action(d); return true; });
 
diff --git a/tests/Kompas.Mcp.Tests/Integration/AssemblyTests.cs b/tests/Kompas.Mcp.Tests/Integration/AssemblyTests.cs
index 0c28a0b..945ce61 100644
--- a/tests/Kompas.Mcp.Tests/Integration/AssemblyTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/AssemblyTests.cs
@@ -8,14 +8,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: вставка компонента в сборку (API7 IParts7.AddFromFile + Placement).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class AssemblyTests
+public sealed class AssemblyTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly AssemblyService _assembly;
     private readonly QueryService _query;
 
-    public AssemblyTests(KompasFixture fx)
+    public AssemblyTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/ConnectionTests.cs b/tests/Kompas.Mcp.Tests/Integration/ConnectionTests.cs
index 2d0da18..99d91d0 100644
--- a/tests/Kompas.Mcp.Tests/Integration/ConnectionTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/ConnectionTests.cs
@@ -3,11 +3,11 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: подключение к КОМПАС. Требует установленный КОМПАС-3D.</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class ConnectionTests
+public sealed class ConnectionTests : IntegrationTestBase
 {
     private readonly KompasFixture _fx;
 
-    public ConnectionTests(KompasFixture fx) => _fx = fx;
+    public ConnectionTests(KompasFixture fx) : base(fx) => _fx = fx;
 
     [Fact]
     public void Connects_to_kompas()
diff --git a/tests/Kompas.Mcp.Tests/Integration/ConversionTests.cs b/tests/Kompas.Mcp.Tests/Integration/ConversionTests.cs
index e49ffb2..a7db39b 100644
--- a/tests/Kompas.Mcp.Tests/Integration/ConversionTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/ConversionTests.cs
@@ -8,14 +8,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: импорт/экспорт STEP и обход компонентов сборки.</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class ConversionTests
+public sealed class ConversionTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly ConversionService _conv;
     private readonly QueryService _query;
 
-    public ConversionTests(KompasFixture fx)
+    public ConversionTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/DocumentTests.cs b/tests/Kompas.Mcp.Tests/Integration/DocumentTests.cs
index dc803ab..0d0d688 100644
--- a/tests/Kompas.Mcp.Tests/Integration/DocumentTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/DocumentTests.cs
@@ -5,11 +5,11 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: жизненный цикл документов.</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class DocumentTests
+public sealed class DocumentTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
 
-    public DocumentTests(KompasFixture fx)
+    public DocumentTests(KompasFixture fx) : base(fx)
         => _docs = new DocumentService(fx.Session, fx.Dispatcher);
 
     [Fact]
diff --git a/tests/Kompas.Mcp.Tests/Integration/FaceEditTests.cs b/tests/Kompas.Mcp.Tests/Integration/FaceEditTests.cs
index 94cb163..87aa6b1 100644
--- a/tests/Kompas.Mcp.Tests/Integration/FaceEditTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/FaceEditTests.cs
@@ -8,14 +8,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: прямое редактирование — перемещение грани (FaceMover).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class FaceEditTests
+public sealed class FaceEditTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly FaceEditService _faceEdit;
     private readonly QueryService _query;
 
-    public FaceEditTests(KompasFixture fx)
+    public FaceEditTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/FeatureOpsTests.cs b/tests/Kompas.Mcp.Tests/Integration/FeatureOpsTests.cs
index 4d01397..805398f 100644
--- a/tests/Kompas.Mcp.Tests/Integration/FeatureOpsTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/FeatureOpsTests.cs
@@ -7,13 +7,13 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: формообразующие операции пакетов B и C (массивы, зеркало).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class FeatureOpsTests
+public sealed class FeatureOpsTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly QueryService _query;
 
-    public FeatureOpsTests(KompasFixture fx)
+    public FeatureOpsTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/HoleTests.cs b/tests/Kompas.Mcp.Tests/Integration/HoleTests.cs
index c2eac0c..3cedbff 100644
--- a/tests/Kompas.Mcp.Tests/Integration/HoleTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/HoleTests.cs
@@ -7,14 +7,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: операция «Отверстие» (API7 IHoles3D/IHole3D).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class HoleTests
+public sealed class HoleTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly HoleService _holes;
     private readonly QueryService _query;
 
-    public HoleTests(KompasFixture fx)
+    public HoleTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/InspectionTests.cs b/tests/Kompas.Mcp.Tests/Integration/InspectionTests.cs
index 3eaa16f..30eabcf 100644
--- a/tests/Kompas.Mcp.Tests/Integration/InspectionTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/InspectionTests.cs
@@ -7,13 +7,13 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: структурное «зрение» — дерево, топология, drill-down, измерения.</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class InspectionTests
+public sealed class InspectionTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly ModelInspectionService _inspect;
 
-    public InspectionTests(KompasFixture fx)
+    public InspectionTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/IntegrationTestBase.cs b/tests/Kompas.Mcp.Tests/Integration/IntegrationTestBase.cs
new file mode 100644
index 0000000..cc9e527
--- /dev/null
+++ b/tests/Kompas.Mcp.Tests/Integration/IntegrationTestBase.cs
@@ -0,0 +1,21 @@
+using Kompas.Mcp.Core.Documents;
+
+namespace Kompas.Mcp.Tests.Integration;
+
+/// <summary>
+/// Базовый класс интеграционных тестов: после КАЖДОГО теста закрывает все открытые документы
+/// КОМПАС без сохранения, чтобы не копились вкладки-пустышки (и чтобы упавший Assert не оставлял
+/// открытый документ). xUnit создаёт новый экземпляр тест-класса на каждый тест-метод, поэтому
+/// <see cref="DisposeAsync"/> вызывается per-test — это и есть точка очистки.
+/// </summary>
+public abstract class IntegrationTestBase : IAsyncLifetime
+{
+    private readonly DocumentService _cleanupDocs;
+
+    protected IntegrationTestBase(KompasFixture fx)
+        => _cleanupDocs = new DocumentService(fx.Session, fx.Dispatcher);
+
+    public Task InitializeAsync() => Task.CompletedTask;
+
+    public Task DisposeAsync() => _cleanupDocs.CloseAllAsync();
+}
diff --git a/tests/Kompas.Mcp.Tests/Integration/ModelingTests.cs b/tests/Kompas.Mcp.Tests/Integration/ModelingTests.cs
index 4f5d3b4..914ba0c 100644
--- a/tests/Kompas.Mcp.Tests/Integration/ModelingTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/ModelingTests.cs
@@ -8,14 +8,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: построение 3D (эскиз → выдавливание) и снимок.</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class ModelingTests
+public sealed class ModelingTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly SnapshotService _snap;
     private readonly QueryService _query;
 
-    public ModelingTests(KompasFixture fx)
+    public ModelingTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/QueryTests.cs b/tests/Kompas.Mcp.Tests/Integration/QueryTests.cs
index b390c1c..0ad095c 100644
--- a/tests/Kompas.Mcp.Tests/Integration/QueryTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/QueryTests.cs
@@ -7,13 +7,13 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: массово-центровочные характеристики (get_part_info).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class QueryTests
+public sealed class QueryTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly QueryService _query;
 
-    public QueryTests(KompasFixture fx)
+    public QueryTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/SketchPrimitivesTests.cs b/tests/Kompas.Mcp.Tests/Integration/SketchPrimitivesTests.cs
index e108e53..cb85ac0 100644
--- a/tests/Kompas.Mcp.Tests/Integration/SketchPrimitivesTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/SketchPrimitivesTests.cs
@@ -7,13 +7,13 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: новые примитивы эскиза (профиль → выдавливание → объём).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class SketchPrimitivesTests
+public sealed class SketchPrimitivesTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly QueryService _query;
 
-    public SketchPrimitivesTests(KompasFixture fx)
+    public SketchPrimitivesTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/SnapshotTests.cs b/tests/Kompas.Mcp.Tests/Integration/SnapshotTests.cs
index 1b8d00a..69d8b73 100644
--- a/tests/Kompas.Mcp.Tests/Integration/SnapshotTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/SnapshotTests.cs
@@ -6,12 +6,12 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: снимок модели в растр («зрение агента»).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class SnapshotTests
+public sealed class SnapshotTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly SnapshotService _snap;
 
-    public SnapshotTests(KompasFixture fx)
+    public SnapshotTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _snap = new SnapshotService(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/SolidEditTests.cs b/tests/Kompas.Mcp.Tests/Integration/SolidEditTests.cs
index a66e46f..4f0d374 100644
--- a/tests/Kompas.Mcp.Tests/Integration/SolidEditTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/SolidEditTests.cs
@@ -9,7 +9,7 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: рассечение тела, перемещение тела, объединение (cut→spread→union).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class SolidEditTests
+public sealed class SolidEditTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
@@ -18,7 +18,7 @@ public sealed class SolidEditTests
     private readonly QueryService _query;
     private readonly ValidationService _validation;
 
-    public SolidEditTests(KompasFixture fx)
+    public SolidEditTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/ValidationTests.cs b/tests/Kompas.Mcp.Tests/Integration/ValidationTests.cs
index 39cb0f0..c15f8b6 100644
--- a/tests/Kompas.Mcp.Tests/Integration/ValidationTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/ValidationTests.cs
@@ -7,13 +7,13 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: валидация построения (ошибки/перестроение операций).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class ValidationTests
+public sealed class ValidationTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly ValidationService _validation;
 
-    public ValidationTests(KompasFixture fx)
+    public ValidationTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);
diff --git a/tests/Kompas.Mcp.Tests/Integration/VariableTests.cs b/tests/Kompas.Mcp.Tests/Integration/VariableTests.cs
index 3e192dc..c13228a 100644
--- a/tests/Kompas.Mcp.Tests/Integration/VariableTests.cs
+++ b/tests/Kompas.Mcp.Tests/Integration/VariableTests.cs
@@ -7,14 +7,14 @@ namespace Kompas.Mcp.Tests.Integration;
 /// <summary>Интеграция: переменные модели (параметрика, API5 ksVariable).</summary>
 [Trait("Category", "Integration")]
 [Collection(KompasCollection.Name)]
-public sealed class VariableTests
+public sealed class VariableTests : IntegrationTestBase
 {
     private readonly DocumentService _docs;
     private readonly PartModeler _modeler;
     private readonly VariableService _vars;
     private readonly ModelInspectionService _inspect;
 
-    public VariableTests(KompasFixture fx)
+    public VariableTests(KompasFixture fx) : base(fx)
     {
         _docs = new DocumentService(fx.Session, fx.Dispatcher);
         _modeler = new PartModeler(fx.Session, fx.Dispatcher);