export declare const MAX_PROVIDER_KEYS = 10;
export declare const MULTI_KEY_ATTEMPTS = 2;
export declare const RATE_LIMIT_RETRY_WAIT_MS: readonly number[];
export declare function rateLimitRetryWaitMs(attempt: number, maxMs?: number): number;
export declare function providerRetryAfterMs(error: unknown): number | undefined;
export declare function rateLimitWaitMsFor(error: unknown, attempt: number, maxMs?: number): number;
export declare function buildKeyAttemptPlan(n: number, startIndex: number): number[];
export declare function attemptsPerKey(keyCount: number, singleKeyMaxAttempts: number): number;
export declare function isAuthKeyError(error: unknown): boolean;
export declare function isQuotaKeyError(error: unknown): boolean;
export declare function isImmediateKeySwitchError(error: unknown): boolean;
export declare function isKeyRotatableError(error: unknown, isRetriable: (e: unknown) => boolean): boolean;
export declare function isKeyCircleStopError(error: unknown): boolean;
export type ProviderKeyEventType = "using" | "retry" | "switch" | "endpoint" | "exhausted";
export interface ProviderKeyEvent {
    readonly type: ProviderKeyEventType;
    readonly provider: string;
    readonly maskedTail: string;
    readonly reason?: string | undefined;
    readonly waitMs?: number | undefined;
    readonly keyIndex?: number | undefined;
    readonly keyCount?: number | undefined;
}
export declare function formatKeyEventStatus(event: ProviderKeyEvent): string;
export declare function isProviderFailureStatus(text: string): boolean;