/**
 * Retry utility for transient network failures in the Trulioo Web SDK.
 *
 * ## Policy
 * - Up to `maxRetries` attempts (default 3 → 4 total).
 * - Exponential backoff: 500ms, 1000ms, 2000ms.
 * - Respects `Retry-After` header (integer seconds, capped at 30s).
 *
 * ## Retryable conditions
 * - Network errors: TypeError from fetch (connection refused, DNS failure, offline).
 * - HTTP status: 408, 429, 500, 502, 503, 504.
 *
 * ## Non-retryable
 * - Client errors (4xx except 408, 429).
 * - AbortError (intentional cancellation).
 * - Non-network errors.
 *
 * @internal
 */
declare const DEFAULT_MAX_RETRIES = 3;
declare const INITIAL_DELAY_MS = 500;
declare const MAX_RETRY_AFTER_MS = 30000;
declare const DEFAULT_REQUEST_TIMEOUT_MS = 30000;
/**
 * Wraps a fetch call with retry logic for transient failures.
 *
 * @param fetchFn - The fetch function to use (allows injection for testing).
 * @param input - The URL or Request to fetch.
 * @param init - Optional RequestInit (merged with timeout AbortController).
 * @param options - Retry and timeout options.
 * @returns The successful Response.
 * @throws TruliooTransportError with appropriate code when all retries are exhausted.
 */
export declare function fetchWithRetry(fetchFn: typeof globalThis.fetch, input: RequestInfo | URL, init?: RequestInit, options?: {
    maxRetries?: number;
    timeoutMs?: number;
}): Promise<Response>;
export { DEFAULT_MAX_RETRIES, INITIAL_DELAY_MS, MAX_RETRY_AFTER_MS, DEFAULT_REQUEST_TIMEOUT_MS };