diff --git a/api/tests/unit_tests/controllers/console/datasets/test_datasets.py b/api/tests/unit_tests/controllers/console/datasets/test_datasets.py
index e5e4f907947..1952e8f94e5 100644
--- a/api/tests/unit_tests/controllers/console/datasets/test_datasets.py
+++ b/api/tests/unit_tests/controllers/console/datasets/test_datasets.py
@@ -9,6 +9,7 @@ import services
 from controllers.console import console_ns
 from controllers.console.app.error import ProviderNotInitializeError
 from controllers.console.datasets.datasets import (
+    ConsoleDatasetListQuery,
     DatasetApi,
     DatasetApiBaseUrlApi,
     DatasetApiDeleteApi,
@@ -164,6 +165,11 @@ class TestDatasetList:
         assert get_datasets_mock.call_args.kwargs["tag_names"] == ["Finance", "Support"]
         assert status == 200
 
+    def test_query_model_trims_empty_tag_names(self):
+        query = ConsoleDatasetListQuery.model_validate({"tag_names": ["", " Finance ", "Support", "   "]})
+
+        assert query.tag_names == ["Finance", "Support"]
+
     def test_embedding_available_false(self, app: Flask):
         api = DatasetListApi()
         method = unwrap(api.get)
diff --git a/api/tests/unit_tests/services/test_dataset_service_dataset.py b/api/tests/unit_tests/services/test_dataset_service_dataset.py
index 3d08b6fd096..2d70b4152c9 100644
--- a/api/tests/unit_tests/services/test_dataset_service_dataset.py
+++ b/api/tests/unit_tests/services/test_dataset_service_dataset.py
@@ -15,6 +15,7 @@ from .dataset_service_test_helpers import (
     ProviderTokenNotInitError,
     RagPipelineDatasetCreateEntity,
     SimpleNamespace,
+    TenantAccountRole,
     _make_knowledge_configuration,
     _make_retrieval_model,
     _make_session_context,
@@ -24,6 +25,60 @@ from .dataset_service_test_helpers import (
 )
 
 
+class TestDatasetServiceList:
+    """Unit tests for dataset list filtering."""
+
+    def test_get_datasets_filters_by_tag_names(self):
+        dataset = DatasetServiceUnitDataFactory.create_dataset_mock(dataset_id="dataset-1")
+        user = SimpleNamespace(id="user-1", current_role=TenantAccountRole.OWNER)
+
+        with (
+            patch("services.dataset_service.db") as mock_db,
+            patch(
+                "services.dataset_service.TagService.get_target_ids_by_tag_names",
+                return_value=["dataset-1"],
+            ) as tag_mock,
+        ):
+            mock_db.session.scalars.return_value.all.return_value = []
+            mock_db.paginate.return_value = SimpleNamespace(items=[dataset], total=1)
+
+            datasets, total = DatasetService.get_datasets(
+                page=1,
+                per_page=20,
+                tenant_id="tenant-1",
+                user=user,
+                include_all=True,
+                tag_names=["Finance", "Support"],
+            )
+
+        assert datasets == [dataset]
+        assert total == 1
+        tag_mock.assert_called_once_with("knowledge", "tenant-1", ["Finance", "Support"])
+        mock_db.paginate.assert_called_once()
+
+    def test_get_datasets_returns_empty_when_tag_names_match_no_targets(self):
+        user = SimpleNamespace(id="user-1", current_role=TenantAccountRole.OWNER)
+
+        with (
+            patch("services.dataset_service.db") as mock_db,
+            patch("services.dataset_service.TagService.get_target_ids_by_tag_names", return_value=[]),
+        ):
+            mock_db.session.scalars.return_value.all.return_value = []
+
+            datasets, total = DatasetService.get_datasets(
+                page=1,
+                per_page=20,
+                tenant_id="tenant-1",
+                user=user,
+                include_all=True,
+                tag_names=["Unknown"],
+            )
+
+        assert datasets == []
+        assert total == 0
+        mock_db.paginate.assert_not_called()
+
+
 class TestDatasetServiceValidation:
     """Unit tests for DatasetService validation helpers."""
 
diff --git a/web/features/tag-management/__tests__/tag-selector.spec.tsx b/web/features/tag-management/__tests__/tag-selector.spec.tsx
index f33470825bc..ec360172c3c 100644
--- a/web/features/tag-management/__tests__/tag-selector.spec.tsx
+++ b/web/features/tag-management/__tests__/tag-selector.spec.tsx
@@ -128,6 +128,20 @@ describe('TagSelector', () => {
     expect(screen.getByRole('option', { name: /Backend/i })).toBeInTheDocument()
   })
 
+  it('reports active state when the popup opens and closes', async () => {
+    const user = userEvent.setup()
+    const onActiveChange = vi.fn()
+    render(<TagSelector {...defaultProps} onActiveChange={onActiveChange} />)
+
+    const trigger = screen.getByRole('combobox', { name: /Frontend/i })
+    await user.click(trigger)
+    await screen.findByRole('combobox', { name: i18n.selectorPlaceholder })
+    await user.click(trigger)
+
+    expect(onActiveChange).toHaveBeenNthCalledWith(1, true)
+    expect(onActiveChange).toHaveBeenNthCalledWith(2, false)
+  })
+
   it('applies added tags only when the popup closes', async () => {
     const user = userEvent.setup()
     render(<TagSelector {...defaultProps} />)
diff --git a/web/service/knowledge/use-dataset.spec.tsx b/web/service/knowledge/use-dataset.spec.tsx
new file mode 100644
index 00000000000..76f431b87fa
--- /dev/null
+++ b/web/service/knowledge/use-dataset.spec.tsx
@@ -0,0 +1,69 @@
+import type { ReactNode } from 'react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { renderHook, waitFor } from '@testing-library/react'
+import { get } from '../base'
+import { useDatasetList, useInfiniteDatasets } from './use-dataset'
+
+vi.mock('../base', () => ({
+  get: vi.fn(),
+  post: vi.fn(),
+}))
+
+const createWrapper = () => {
+  const queryClient = new QueryClient({
+    defaultOptions: {
+      queries: { retry: false },
+    },
+  })
+
+  return ({ children }: { children: ReactNode }) => (
+    <QueryClientProvider client={queryClient}>
+      {children}
+    </QueryClientProvider>
+  )
+}
+
+const datasetListResponse = {
+  data: [],
+  has_more: false,
+  limit: 20,
+  page: 1,
+  total: 0,
+}
+
+describe('dataset list hooks', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.mocked(get).mockResolvedValue(datasetListResponse)
+  })
+
+  it('serializes dataset list filters with tag names', async () => {
+    renderHook(
+      () => useDatasetList({
+        initialPage: 1,
+        limit: 20,
+        tag_names: ['Finance', 'Support'],
+      }),
+      { wrapper: createWrapper() },
+    )
+
+    await waitFor(() => {
+      expect(get).toHaveBeenCalledWith('/datasets?tag_names=Finance&tag_names=Support&limit=20&page=1')
+    })
+  })
+
+  it('normalizes infinite dataset list filters with tag names', async () => {
+    renderHook(
+      () => useInfiniteDatasets({
+        page: 2,
+        limit: 10,
+        tag_names: ['Finance'],
+      }),
+      { wrapper: createWrapper() },
+    )
+
+    await waitFor(() => {
+      expect(get).toHaveBeenCalledWith('/datasets?page=2&limit=10&tag_names=Finance')
+    })
+  })
+})