export type RetryReason = "rate-limit" | "timeout" | "network" | "provider" | "validation" | "authentication" | "unsafe-endpoint" | "aborted" | "unknown";
export interface RetryPolicy {
    maxAttempts: number;
    baseDelayMs?: number;
    maxDelayMs?: number;
    jitter?: number;
    sleep?: (delayMs: number, signal: AbortSignal) => Promise<void>;
    random?: () => number;
    onRetry?: (attempt: RetryAttempt) => void;
}
export interface RetryAttempt {
    attempt: number;
    delayMs: number;
    reason?: RetryReason;
    error?: string;
}
export declare class RetryError extends Error {
    readonly retryAfterMs?: number | undefined;
    readonly status?: number | undefined;
    constructor(message: string, retryAfterMs?: number | undefined, status?: number | undefined);
}
export declare function classifyRetryReason(error: unknown): RetryReason;
export declare function isRetryable(reason: RetryReason): boolean;
export declare function retry<T>(operation: (attempt: number) => Promise<T>, policy: RetryPolicy, signal: AbortSignal): Promise<{
    value: T;
    attempts: RetryAttempt[];
}>;
export declare function withFallback<T>(models: string[], operation: (model: string) => Promise<T>, signal: AbortSignal): Promise<{
    value: T;
    model: string;
    attempts: string[];
}>;
export declare class CircuitBreaker {
    private readonly threshold;
    private readonly cooldownMs;
    private readonly now;
    private failures;
    private openedAt;
    constructor(threshold?: number, cooldownMs?: number, now?: () => number);
    get state(): "closed" | "open" | "half-open";
    canRequest(): boolean;
    recordSuccess(): void;
    recordFailure(): void;
}