import type { RetryConfig } from '../types.ts';
import type { FetchPlugin } from '../engine/types.ts';
/**
 * Merges a per-call retry override over a base retry config, the same way
 * for every caller — the retry plugin's execute hook and the executor's
 * response metadata both resolve through this so the reported `res.config.retry`
 * can never drift from the config the request actually ran with.
 *
 * Per-call retry wins in both directions: it can remove retries from a
 * retrying engine and re-enable them on a `retry: false` engine. `false`/
 * `true` per-call values are expected already normalized upstream to
 * `{ maxAttempts: 0 }` / `{}` (executor.makeRequestOptions).
 *
 * @param baseConfig - The engine/plugin's current base retry config
 * @param perCallRetry - The current request's normalized per-call retry override, if any
 */
export declare function resolveRetryConfig(baseConfig: RetryConfig | false | undefined, perCallRetry: RetryConfig | undefined): Required<RetryConfig>;
/**
 * Factory function that creates a retry plugin for FetchEngine.
 *
 * The plugin installs an `execute` (pipe) hook at priority `-20` that
 * wraps the core request function in a retry loop with exponential backoff.
 *
 * @param defaultConfig - Default retry configuration for the engine
 * @returns FetchPlugin that can be installed via `engine.use()` or `plugins` config
 *
 * @example
 *     const api = new FetchEngine({
 *         baseUrl: 'https://api.example.com',
 *         plugins: [
 *             retryPlugin({ maxAttempts: 3, baseDelay: 1000 })
 *         ]
 *     });
 */
export declare function retryPlugin<H = unknown, P = unknown, S = unknown>(defaultConfig?: RetryConfig | false): FetchPlugin<H, P, S>;