diff --git a/tests/unit/app/endpoints/test_query.py b/tests/unit/app/endpoints/test_query.py
index db9698e7..fcb53faf 100644
--- a/tests/unit/app/endpoints/test_query.py
+++ b/tests/unit/app/endpoints/test_query.py
@@ -94,6 +94,20 @@ def test_select_model_id_invalid_model(mocker):
     )
 
 
+def test_no_available_models(mocker):
+    """Test the select_model_id function with an invalid model."""
+    mock_client = mocker.Mock()
+    # empty list of models
+    mock_client.models.list.return_value = []
+
+    query_request = QueryRequest(query="What is OpenStack?", model=None, provider=None)
+
+    with pytest.raises(Exception) as exc_info:
+        select_model_id(mock_client, query_request)
+
+    assert "No LLM model found in available models" in str(exc_info.value)
+
+
 def test_validate_attachments_metadata():
     """Test the validate_attachments_metadata function."""
     attachments = [
@@ -151,7 +165,7 @@ def test_validate_attachments_metadata_invalid_content_type():
     )
 
 
-def test_retrieve_response(mocker):
+def test_retrieve_response_no_available_shields(mocker):
     """Test the retrieve_response function."""
     mock_agent = mocker.Mock()
     mock_agent.create_turn.return_value.output_message.content = "LLM answer"
@@ -172,3 +186,147 @@ def test_retrieve_response(mocker):
         documents=[],
         stream=False,
     )
+
+
+def test_retrieve_response_one_available_shield(mocker):
+    """Test the retrieve_response function."""
+
+    class MockShield:
+        def __init__(self, identifier):
+            self.identifier = identifier
+
+        def identifier(self):
+            return self.identifier
+
+    mock_agent = mocker.Mock()
+    mock_agent.create_turn.return_value.output_message.content = "LLM answer"
+    mock_client = mocker.Mock()
+    mock_client.shields.list.return_value = [MockShield("shield1")]
+
+    mocker.patch("app.endpoints.query.Agent", return_value=mock_agent)
+
+    query_request = QueryRequest(query="What is OpenStack?")
+    model_id = "fake_model_id"
+
+    response = retrieve_response(mock_client, model_id, query_request)
+
+    assert response == "LLM answer"
+    mock_agent.create_turn.assert_called_once_with(
+        messages=[UserMessage(content="What is OpenStack?", role="user", context=None)],
+        session_id=mocker.ANY,
+        documents=[],
+        stream=False,
+    )
+
+
+def test_retrieve_response_two_available_shields(mocker):
+    """Test the retrieve_response function."""
+
+    class MockShield:
+        def __init__(self, identifier):
+            self.identifier = identifier
+
+        def identifier(self):
+            return self.identifier
+
+    mock_agent = mocker.Mock()
+    mock_agent.create_turn.return_value.output_message.content = "LLM answer"
+    mock_client = mocker.Mock()
+    mock_client.shields.list.return_value = [
+        MockShield("shield1"),
+        MockShield("shield2"),
+    ]
+
+    mocker.patch("app.endpoints.query.Agent", return_value=mock_agent)
+
+    query_request = QueryRequest(query="What is OpenStack?")
+    model_id = "fake_model_id"
+
+    response = retrieve_response(mock_client, model_id, query_request)
+
+    assert response == "LLM answer"
+    mock_agent.create_turn.assert_called_once_with(
+        messages=[UserMessage(content="What is OpenStack?", role="user", context=None)],
+        session_id=mocker.ANY,
+        documents=[],
+        stream=False,
+    )
+
+
+def test_retrieve_response_with_one_attachment(mocker):
+    """Test the retrieve_response function."""
+    mock_agent = mocker.Mock()
+    mock_agent.create_turn.return_value.output_message.content = "LLM answer"
+    mock_client = mocker.Mock()
+    mock_client.shields.list.return_value = []
+
+    attachments = [
+        Attachment(
+            attachment_type="log",
+            content_type="text/plain",
+            content="this is attachment",
+        ),
+    ]
+    mocker.patch("app.endpoints.query.Agent", return_value=mock_agent)
+
+    query_request = QueryRequest(query="What is OpenStack?", attachments=attachments)
+    model_id = "fake_model_id"
+
+    response = retrieve_response(mock_client, model_id, query_request)
+
+    assert response == "LLM answer"
+    mock_agent.create_turn.assert_called_once_with(
+        messages=[UserMessage(content="What is OpenStack?", role="user", context=None)],
+        session_id=mocker.ANY,
+        stream=False,
+        documents=[
+            {
+                "content": "this is attachment",
+                "mime_type": "text/plain",
+            },
+        ],
+    )
+
+
+def test_retrieve_response_with_two_attachments(mocker):
+    """Test the retrieve_response function."""
+    mock_agent = mocker.Mock()
+    mock_agent.create_turn.return_value.output_message.content = "LLM answer"
+    mock_client = mocker.Mock()
+    mock_client.shields.list.return_value = []
+
+    attachments = [
+        Attachment(
+            attachment_type="log",
+            content_type="text/plain",
+            content="this is attachment",
+        ),
+        Attachment(
+            attachment_type="configuration",
+            content_type="application/yaml",
+            content="kind: Pod\n metadata:\n name:    private-reg",
+        ),
+    ]
+    mocker.patch("app.endpoints.query.Agent", return_value=mock_agent)
+
+    query_request = QueryRequest(query="What is OpenStack?", attachments=attachments)
+    model_id = "fake_model_id"
+
+    response = retrieve_response(mock_client, model_id, query_request)
+
+    assert response == "LLM answer"
+    mock_agent.create_turn.assert_called_once_with(
+        messages=[UserMessage(content="What is OpenStack?", role="user", context=None)],
+        session_id=mocker.ANY,
+        stream=False,
+        documents=[
+            {
+                "content": "this is attachment",
+                "mime_type": "text/plain",
+            },
+            {
+                "content": "kind: Pod\n" " metadata:\n" " name:    private-reg",
+                "mime_type": "application/yaml",
+            },
+        ],
+    )