Optional instructionsBackend instructions, separate from the voice persona.
Optional maxMaximum tokens per backend response; the service requires at least 16.
Optional modelDefaults to gpt-5.6-luna.
Optional parallelAllow the backend to request multiple tools in one response.
Optional reasoningReasoning effort for the backend model.
Optional serviceProcessing tier for backend responses.
Optional textText format and verbosity for backend responses.
Optional toolRestrict backend tool selection. Null restores automatic selection.
Settings for the backend Responses model. Unset fields use the service defaults.