fix(realtime): disable SSL for ws:// WebSocket connections (#19345)

When using http:// api_base (converted to ws://), the websockets library
throws "ssl argument is incompatible with a ws:// URI". Only pass SSL
context for secure wss:// connections.

Co-authored-by: Krish Dholakia <krrishdholakia@gmail.com>

litellm/llms/openai/realtime/handler.py

@@ -56,7 +56,9 @@ class OpenAIRealtime(OpenAIChatCompletion):
         url = self._construct_url(api_base, query_params)
 
         try:
-            ssl_context = get_shared_realtime_ssl_context()
+            # Only use SSL context for secure websocket connections (wss://)
+            # websockets library doesn't accept ssl argument for ws:// URIs
+            ssl_context = None if url.startswith("ws://") else get_shared_realtime_ssl_context()
             # Log a masked request preview consistent with other endpoints.
             logging_obj.pre_call(
                 input=None,

tests/test_litellm/llms/openai/realtime/test_openai_realtime_handler.py

@@ -265,3 +265,61 @@ async def test_async_realtime_uses_max_size_parameter():
 
         mock_realtime_streaming.assert_called_once()
         mock_streaming_instance.bidirectional_forward.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_async_realtime_ws_url_has_no_ssl():
+    """
+    Test that when using http:// api_base (converted to ws://), the ssl argument
+    is set to None. The websockets library doesn't accept ssl argument for ws:// URIs.
+
+    This verifies the fix for: https://github.com/BerriAI/litellm/issues/19222
+    """
+    from litellm.llms.openai.realtime.handler import OpenAIRealtime
+    from litellm.types.realtime import RealtimeQueryParams
+
+    handler = OpenAIRealtime()
+    api_base = "http://localhost:8113"  # Non-SSL local server
+    api_key = "test-key"
+    model = "test-model"
+    query_params: RealtimeQueryParams = {"model": model}
+
+    dummy_websocket = AsyncMock()
+    dummy_logging_obj = MagicMock()
+    mock_backend_ws = AsyncMock()
+
+    class DummyAsyncContextManager:
+        def __init__(self, value):
+            self.value = value
+        async def __aenter__(self):
+            return self.value
+        async def __aexit__(self, exc_type, exc, tb):
+            return None
+
+    with patch("websockets.connect", return_value=DummyAsyncContextManager(mock_backend_ws)) as mock_ws_connect, \
+         patch("litellm.llms.openai.realtime.handler.RealTimeStreaming") as mock_realtime_streaming:
+
+        mock_streaming_instance = MagicMock()
+        mock_realtime_streaming.return_value = mock_streaming_instance
+        mock_streaming_instance.bidirectional_forward = AsyncMock()
+
+        await handler.async_realtime(
+            model=model,
+            websocket=dummy_websocket,
+            logging_obj=dummy_logging_obj,
+            api_base=api_base,
+            api_key=api_key,
+            query_params=query_params,
+        )
+
+        # Verify websockets.connect was called
+        mock_ws_connect.assert_called_once()
+        called_url = mock_ws_connect.call_args[0][0]
+        called_kwargs = mock_ws_connect.call_args[1]
+
+        # Verify URL was converted from http:// to ws://
+        assert called_url.startswith("ws://localhost:8113/v1/realtime?")
+        assert f"model={model}" in called_url
+
+        # Verify ssl is None for ws:// URLs (the fix for issue #19222)
+        assert called_kwargs["ssl"] is None