> ## Documentation Index > Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # ResponsesRequestServiceTier The service tier to use for processing this request. `fast` is accepted as an alias for `priority`. ## Example Usage ```python theme={null} from openrouter.components import ResponsesRequestServiceTier # Open enum: unrecognized values are captured as UnrecognizedStr value: ResponsesRequestServiceTier = "auto" ``` ## Values This is an open enum. Unrecognized values will not fail type checks. * `"auto"` * `"default"` * `"fast"` * `"flex"` * `"priority"` * `"scale"`