import type { CompletionRequest, ReasoningEffort, ReasoningPreference } from "../types.js";
export declare const EFFORT_LADDER: readonly ReasoningEffort[];
export declare function fallbackEffortsFor(requested: ReasoningEffort): ReasoningEffort[];
export declare function effortCandidates(thinking: ReasoningPreference | undefined): ReasoningEffort[];
export declare function isEffortRejectedError(error: unknown): boolean;
export declare function withEffortFallback<T>(request: CompletionRequest, attempt: (thinking: CompletionRequest["thinking"]) => Promise<T>, onExhausted: () => never): Promise<T>;