/**
 * Retry policy — configurable exponential backoff with jitter.
 * Covers: 5xx server errors, network timeouts, ECONNREFUSED, ECONNRESET.
 * NOT retried: 4xx client errors (except 429 — handled separately), redirects.
 */
export interface RetryPolicyOpts {
    maxRetries?: number;
    baseDelayMs?: number;
    maxDelayMs?: number;
    jitterMs?: number;
    retryOn?: number[];
}
export interface RetryResult<T> {
    value: T;
    attempts: number;
    totalDelayMs: number;
}
export declare function withRetry<T>(fn: (attempt: number) => Promise<T>, opts?: RetryPolicyOpts): Promise<RetryResult<T>>;
/** Wraps fetch() with retry policy */
export declare function fetchWithRetry(url: string, init?: RequestInit, retryOpts?: RetryPolicyOpts): Promise<Response>;