> ## 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.

# ChatRequestServiceTier

The service tier to use for processing this request. `fast` is accepted as an alias for `priority`.

## Example Usage

```typescript theme={null}
import { ChatRequestServiceTier } from "@openrouter/sdk/models";

let value: ChatRequestServiceTier = "auto";

// Open enum: unrecognized values are captured as Unrecognized<string>
```

## Values

```typescript theme={null}
"auto" | "default" | "fast" | "flex" | "priority" | "scale" | Unrecognized<string>
```