diff --git a/litellm/llms/gemini/realtime/transformation.py b/litellm/llms/gemini/realtime/transformation.py
index 93cdd7c75df..1ae0706920e 100644
--- a/litellm/llms/gemini/realtime/transformation.py
+++ b/litellm/llms/gemini/realtime/transformation.py
@@ -235,6 +235,10 @@ class GeminiRealtimeConfig(BaseRealtimeConfig):
             client_session_configuration_request = self.map_openai_params(
                 optional_params={}, non_default_params=json_message["session"]
             )
+            generation_config = client_session_configuration_request.setdefault(
+                "generationConfig", {}
+            )
+            generation_config.setdefault("responseModalities", ["AUDIO"])
             client_session_configuration_request["model"] = f"models/{model}"
             gemini_setup_msg = json.dumps({"setup": client_session_configuration_request})
             verbose_logger.debug(
@@ -682,13 +686,18 @@ class GeminiRealtimeConfig(BaseRealtimeConfig):
         verbose_logger.debug(
             f"Gemini Realtime: Transforming {len(function_calls)} tool call(s) to OpenAI format"
         )
+        has_multiple_calls = len(function_calls) > 1
         
         return [
             {
                 "type": "response.function_call_arguments.done",
                 "event_id": f"event_{uuid.uuid4()}",
                 "response_id": resolved_response_id,
-                "item_id": resolved_output_item_id,
+                "item_id": (
+                    f"{resolved_output_item_id}_tool_{idx}"
+                    if has_multiple_calls
+                    else resolved_output_item_id
+                ),
                 "output_index": idx,
                 "call_id": fc.get("id", ""),
                 "name": fc.get("name", ""),
diff --git a/tests/test_litellm/llms/gemini/realtime/test_gemini_realtime_transformation.py b/tests/test_litellm/llms/gemini/realtime/test_gemini_realtime_transformation.py
index b42f428dd3a..8c2aebe3fb0 100644
--- a/tests/test_litellm/llms/gemini/realtime/test_gemini_realtime_transformation.py
+++ b/tests/test_litellm/llms/gemini/realtime/test_gemini_realtime_transformation.py
@@ -372,6 +372,26 @@ def test_gemini_realtime_session_update_with_tools():
     assert "parameters" in function_decl
 
 
+def test_gemini_session_update_defaults_to_audio_modality():
+    config = GeminiRealtimeConfig()
+
+    session_update = {
+        "type": "session.update",
+        "session": {
+            "instructions": "You are a helpful assistant.",
+            # No modalities on purpose
+        },
+    }
+
+    messages = config.transform_realtime_request(
+        json.dumps(session_update), "gemini-2.5-flash", session_configuration_request=None
+    )
+
+    assert len(messages) == 1
+    setup_payload = json.loads(messages[0])["setup"]
+    assert setup_payload["generationConfig"]["responseModalities"] == ["AUDIO"]
+
+
 def test_gemini_requires_session_configuration_feature_flag(monkeypatch):
     config = GeminiRealtimeConfig()
 
@@ -472,3 +492,53 @@ def test_return_new_content_delta_events_without_session_config_does_not_error()
 
     assert len(events) >= 1
     assert events[0]["type"] == "response.created"
+
+
+def test_gemini_realtime_multi_tool_calls_have_unique_item_ids():
+    config = GeminiRealtimeConfig()
+    logging_obj = MagicMock()
+    logging_obj.litellm_trace_id = "test-trace-123"
+
+    gemini_tool_call = {
+        "toolCall": {
+            "functionCalls": [
+                {
+                    "id": "call_1",
+                    "name": "get_weather",
+                    "args": {"location": "SF"},
+                },
+                {
+                    "id": "call_2",
+                    "name": "get_weather",
+                    "args": {"location": "NYC"},
+                },
+            ]
+        }
+    }
+
+    result = config.transform_realtime_response(
+        json.dumps(gemini_tool_call),
+        "gemini-2.5-flash",
+        logging_obj,
+        realtime_response_transform_input={
+            "session_configuration_request": None,
+            "current_output_item_id": "item_123",
+            "current_response_id": "resp_123",
+            "current_conversation_id": None,
+            "current_delta_chunks": [],
+            "current_item_chunks": [],
+            "current_delta_type": None,
+        },
+    )
+
+    responses = [
+        ev
+        for ev in result["response"]
+        if ev.get("type") == "response.function_call_arguments.done"
+    ]
+    assert len(responses) == 2
+    assert responses[0]["response_id"] == "resp_123"
+    assert responses[1]["response_id"] == "resp_123"
+    assert responses[0]["item_id"] != responses[1]["item_id"]
+    assert responses[0]["output_index"] == 0
+    assert responses[1]["output_index"] == 1