diff --git a/tests/test_gui_integration.py b/tests/test_gui_integration.py
new file mode 100644
index 0000000..8b03a36
--- /dev/null
+++ b/tests/test_gui_integration.py
@@ -0,0 +1,131 @@
+"""
+Tests for GUI integration with core modules.
+Verifies MainWindow properly integrates with ProjectManager, LogWatcher, etc.
+"""
+
+import pytest
+import sys
+from pathlib import Path
+from unittest.mock import Mock, MagicMock, patch
+
+# Add project to path
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+
+class TestProjectDataCompatibility:
+    """Test that GUI uses correct ProjectData attributes."""
+    
+    def test_project_data_has_required_fields(self):
+        """Verify ProjectData has fields used by GUI."""
+        from core.project_manager import ProjectData
+        
+        project = ProjectData(
+            id=1,
+            name="Test Project",
+            type="hunt",
+            status="active"
+        )
+        
+        # Fields used by GUI
+        assert hasattr(project, 'id')
+        assert hasattr(project, 'name')
+        assert hasattr(project, 'type')
+        assert hasattr(project, 'status')
+        
+        # Fields NOT in ProjectData (GUI was incorrectly using these)
+        assert not hasattr(project, 'session_count')
+        assert not hasattr(project, 'description')
+    
+    def test_project_manager_methods_exist(self):
+        """Verify ProjectManager has methods called by GUI."""
+        from core.project_manager import ProjectManager
+        
+        pm = ProjectManager()
+        
+        # Methods GUI uses
+        assert hasattr(pm, 'list_projects')
+        assert hasattr(pm, 'load_project')
+        assert hasattr(pm, 'create_project')
+        assert hasattr(pm, 'start_session')
+        assert hasattr(pm, 'end_session')
+        assert hasattr(pm, 'record_loot')
+        
+        # Methods GUI should NOT call (old placeholder names)
+        assert not hasattr(pm, 'get_all_projects')
+        assert not hasattr(pm, 'get_project')
+
+
+class TestLogWatcherCompatibility:
+    """Test LogWatcher integration."""
+    
+    def test_log_watcher_has_subscribe(self):
+        """Verify LogWatcher has subscribe method."""
+        from core.log_watcher import LogWatcher
+        
+        # Can't instantiate without file, but can check class
+        assert hasattr(LogWatcher, 'subscribe')
+        assert hasattr(LogWatcher, 'start')
+        assert hasattr(LogWatcher, 'stop')
+
+
+class TestMainWindowIntegration:
+    """Test MainWindow integration with core modules."""
+    
+    @pytest.fixture
+    def mock_qapp(self):
+        """Create mock QApplication."""
+        with patch('PyQt6.QtWidgets.QApplication') as mock_app:
+            mock_instance = Mock()
+            mock_app.instance.return_value = mock_instance
+            yield mock_instance
+    
+    def test_main_window_imports(self, mock_qapp):
+        """Test MainWindow can import without errors."""
+        with patch('ui.main_window.DatabaseManager') as mock_db, \
+             patch('ui.main_window.ProjectManager') as mock_pm, \
+             patch('ui.main_window.HUDOverlay'), \
+             patch('ui.main_window.QMainWindow'):
+            
+            mock_db_instance = Mock()
+            mock_db_instance.initialize.return_value = True
+            mock_db.return_value = mock_db_instance
+            
+            mock_pm_instance = Mock()
+            mock_pm_instance.list_projects.return_value = []
+            mock_pm.return_value = mock_pm_instance
+            
+            from ui.main_window import MainWindow
+            # Should not raise ImportError or AttributeError
+
+
+class TestProjectManagerMethodSignatures:
+    """Test ProjectManager method signatures match GUI expectations."""
+    
+    def test_create_project_signature(self):
+        """Test create_project accepts correct arguments."""
+        from core.project_manager import ProjectManager
+        import inspect
+        
+        sig = inspect.signature(ProjectManager.create_project)
+        params = list(sig.parameters.keys())
+        
+        # Should have: self, name, project_type, description=""
+        assert 'name' in params
+        assert 'project_type' in params
+        assert 'description' in params
+    
+    def test_list_projects_signature(self):
+        """Test list_projects has correct signature."""
+        from core.project_manager import ProjectManager
+        import inspect
+        
+        sig = inspect.signature(ProjectManager.list_projects)
+        params = list(sig.parameters.keys())
+        
+        # Should have optional filters
+        assert 'project_type' in params
+        assert 'status' in params
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])
\ No newline at end of file
diff --git a/tests/test_gui_simple.py b/tests/test_gui_simple.py
new file mode 100644
index 0000000..3f41720
--- /dev/null
+++ b/tests/test_gui_simple.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""
+Simple test runner for GUI integration - no pytest required.
+Run: python tests/test_gui_simple.py
+"""
+
+import sys
+from pathlib import Path
+
+# Add project to path
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+def test_project_data_fields():
+    """Test ProjectData has fields GUI uses."""
+    from core.project_manager import ProjectData
+    
+    project = ProjectData(
+        id=1,
+        name="Test Project",
+        type="hunt",
+        status="active"
+    )
+    
+    # Required fields
+    assert hasattr(project, 'id'), "Missing: id"
+    assert hasattr(project, 'name'), "Missing: name"
+    assert hasattr(project, 'type'), "Missing: type"
+    assert hasattr(project, 'status'), "Missing: status"
+    
+    # These fields caused AttributeErrors
+    assert not hasattr(project, 'session_count'), "Unexpected: session_count"
+    assert not hasattr(project, 'description'), "Unexpected: description"
+    
+    print("✅ ProjectData fields correct")
+    return True
+
+def test_project_manager_methods():
+    """Test ProjectManager has methods GUI calls."""
+    from core.project_manager import ProjectManager
+    
+    pm = ProjectManager()
+    
+    # Required methods
+    assert hasattr(pm, 'list_projects'), "Missing: list_projects"
+    assert hasattr(pm, 'load_project'), "Missing: load_project"
+    assert hasattr(pm, 'create_project'), "Missing: create_project"
+    assert hasattr(pm, 'start_session'), "Missing: start_session"
+    assert hasattr(pm, 'end_session'), "Missing: end_session"
+    assert hasattr(pm, 'record_loot'), "Missing: record_loot"
+    
+    # These were wrong method names
+    assert not hasattr(pm, 'get_all_projects'), "Should not have: get_all_projects"
+    assert not hasattr(pm, 'get_project'), "Should not have: get_project"
+    
+    print("✅ ProjectManager methods correct")
+    return True
+
+def test_create_project_signature():
+    """Test create_project has correct signature."""
+    from core.project_manager import ProjectManager
+    import inspect
+    
+    sig = inspect.signature(ProjectManager.create_project)
+    params = list(sig.parameters.keys())
+    
+    # Correct signature: create_project(name, project_type, metadata=None)
+    assert 'name' in params, "Missing: name"
+    assert 'project_type' in params, "Missing: project_type"
+    assert 'metadata' in params, "Missing: metadata"
+    
+    print("✅ create_project signature correct")
+    return True
+
+def test_list_projects_signature():
+    """Test list_projects returns list."""
+    from core.project_manager import ProjectManager
+    
+    pm = ProjectManager()
+    projects = pm.list_projects()
+    
+    assert isinstance(projects, list), "list_projects should return list"
+    
+    print(f"✅ list_projects works (found {len(projects)} projects)")
+    return True
+
+def test_log_watcher_methods():
+    """Test LogWatcher has required methods."""
+    from core.log_watcher import LogWatcher
+    
+    assert hasattr(LogWatcher, 'subscribe'), "Missing: subscribe"
+    assert hasattr(LogWatcher, 'start'), "Missing: start"
+    assert hasattr(LogWatcher, 'stop'), "Missing: stop"
+    
+    print("✅ LogWatcher methods correct")
+    return True
+
+def run_all_tests():
+    """Run all tests."""
+    print("="*60)
+    print("GUI INTEGRATION TESTS")
+    print("="*60)
+    print()
+    
+    tests = [
+        test_project_data_fields,
+        test_project_manager_methods,
+        test_create_project_signature,
+        test_list_projects_signature,
+        test_log_watcher_methods,
+    ]
+    
+    passed = 0
+    failed = 0
+    
+    for test in tests:
+        try:
+            if test():
+                passed += 1
+        except Exception as e:
+            print(f"❌ {test.__name__} FAILED: {e}")
+            failed += 1
+    
+    print()
+    print("="*60)
+    print(f"RESULTS: {passed} passed, {failed} failed")
+    print("="*60)
+    
+    return failed == 0
+
+if __name__ == "__main__":
+    success = run_all_tests()
+    sys.exit(0 if success else 1)
\ No newline at end of file
diff --git a/ui/main_window.py b/ui/main_window.py
index 95f0b1d..d107609 100644
--- a/ui/main_window.py
+++ b/ui/main_window.py
@@ -797,7 +797,8 @@ class MainWindow(QMainWindow):
         dialog = NewProjectDialog(self)
         if dialog.exec() == QDialog.DialogCode.Accepted:
             name, description = dialog.get_project_data()
-            project = self.project_manager.create_project(name, 'hunt', description)
+            metadata = {"description": description} if description else None
+            project = self.project_manager.create_project(name, 'hunt', metadata)
             self.refresh_project_list()
             self.log_info("ProjectManager", f"Created project: {project.name}")
             self.status_bar.showMessage(f"Project '{name}' created", 3000)