import type { UsagePayload } from './types';
/** Coerce an unknown to a finite, non-negative number, else 0. */
export declare function nonNeg(v: unknown): number;
/** Clamp a raw percent to 0..100 with one decimal place. */
export declare function clampPct(raw: number): number;
export declare abstract class ProviderUsage {
    abstract readonly family: string;
    abstract readonly defaultContextLimit: number;
    /** Build a usage snapshot from a provider-native payload, or null if empty. */
    abstract extract(raw: unknown, model?: string | null): UsagePayload | null;
    protected pack(input: number, output: number, context: number, limit: number): UsagePayload | null;
}