fix(realtime): release the websocket when the initial session config fails

src/agents/realtime/openai_realtime.py

@@ -588,7 +588,14 @@ async def connect(self, options: RealtimeModelConfig) -> None:
             transport_config=self._transport_config,
         )
         self._websocket_task = asyncio.create_task(self._listen_for_messages())
-        await self._update_session_config(model_settings)
+        try:
+            await self._update_session_config(model_settings)
+        except BaseException:
+            # The websocket and its listener task are owned by this method, so release them
+            # when the initial session config fails. Otherwise the connection stays open and
+            # the model can never be reconnected because of the asserts above.
+            await self.close()
+            raise
 
     async def _create_websocket_connection(
         self,

tests/realtime/test_openai_realtime.py

@@ -10,7 +10,7 @@
 import websockets
 from pydantic import TypeAdapter
 
-from agents import Agent, function_tool
+from agents import Agent, WebSearchTool, function_tool
 from agents.exceptions import UserError
 from agents.handoffs import handoff
 from agents.realtime.model import RealtimeModelConfig
@@ -338,6 +338,30 @@ async def test_connect_websocket_failure_propagates(self, model):
         assert model._websocket is None
         assert model._websocket_task is None
 
+    @pytest.mark.asyncio
+    async def test_connect_session_config_failure_releases_websocket(self, model, mock_websocket):
+        """A failure while sending the initial session config must not leak the connection."""
+        config: RealtimeModelConfig = {
+            "api_key": "test-key",
+            # A hosted tool is rejected by `_tools_to_session_tools`, which runs only after the
+            # websocket is open and the listener task has started.
+            "initial_model_settings": {"tools": [WebSearchTool()]},
+        }
+
+        async def async_websocket(*args, **kwargs):
+            return mock_websocket
+
+        with patch("websockets.connect", side_effect=async_websocket):
+            with pytest.raises(UserError, match="Must be a function tool"):
+                await model.connect(config)
+
+        # The websocket and its listener task are owned by connect(), so a failure after they
+        # were acquired must release them. Otherwise the socket stays open and the model is
+        # permanently unusable because connect() asserts `_websocket is None`.
+        assert model._websocket is None
+        assert model._websocket_task is None
+        mock_websocket.close.assert_awaited()
+
     @pytest.mark.asyncio
     async def test_connect_with_empty_transport_config(self, mock_websocket):
         """Test that empty transport configuration works without error."""