fix(duplex): a control timeout maps to server_error, not invalid_request_error

tests/engine/duplex/test_duplex_events.py

@@ -153,6 +153,8 @@ def test_error_event_maps_codes_to_openai_error_types_and_echoes_client_event_id
     assert REALTIME_ERROR_TYPES_BY_CODE["resource_exhausted"] == "rate_limit_error"
     assert REALTIME_ERROR_TYPES_BY_CODE["internal_error"] == "server_error"
     assert REALTIME_ERROR_TYPES_BY_CODE["bad_event"] == "invalid_request_error"
+    # A control timeout is the server failing to answer, not a bad request.
+    assert REALTIME_ERROR_TYPES_BY_CODE["timeout"] == "server_error"
 
     error = ErrorEvent(
         code="resource_exhausted",
@@ -177,6 +179,15 @@ def test_error_event_maps_codes_to_openai_error_types_and_echoes_client_event_id
     assert wire["error"] == error.error
     # The server event id and the echoed client event id are distinct.
     assert wire["event_id"] != "evt_client"
+
+    # The bucket must survive the envelope serialization, not only the lookup:
+    # a control timeout is the server failing to answer, not a bad request.
+    timeout_wire = ErrorEvent(code="timeout", message="handshake timed out").to_realtime()
+    assert timeout_wire["error"]["type"] == "server_error"
+    assert timeout_wire["error"]["code"] == "timeout"
+    # ``config_timeout`` is the caller's own budget and stays a client error.
+    assert REALTIME_ERROR_TYPES_BY_CODE["config_timeout"] == "invalid_request_error"
+
     assert ErrorEvent(code="never-seen-code").error_type == "invalid_request_error"
 
 

vllm_omni/protocol/duplex/errors.py

@@ -77,6 +77,12 @@
     "tool_result_retirement_failed": "server_error",
     "server_vad_unavailable": "server_error",
     "semantic_vad_unavailable": "server_error",
+    # A bare ``timeout`` is the engine failing to answer a control RPC, not the
+    # caller sending a malformed request: ``duplex_omni_engine.py`` raises
+    # ``DuplexSessionError(code="timeout")`` when the open (or an in-session
+    # RPC) runs out of budget. ``config_timeout`` above is the caller's own
+    # config budget and stays a client error.
+    "timeout": "server_error",
 }