/**
 * Factory functions for KeyPersistence.
 *
 * Provides convenient ways to create KeyPersistence instances
 * with auto-detection of storage backend.
 *
 * @module @frontmcp/utils/key-persistence
 */
import type { StorageAdapter } from '../../storage/types';
import { KeyPersistence } from './key-persistence';
import type { CreateKeyPersistenceOptions } from './types';
/**
 * Create a KeyPersistence instance with auto-detected storage.
 *
 * In Node.js: Uses filesystem storage at `.frontmcp/keys/` by default
 * In browser: Uses IndexedDB (persistent) with localStorage fallback
 * Fallback: Memory storage (keys lost on restart)
 *
 * @param options - Configuration options
 * @returns KeyPersistence instance (storage already connected)
 *
 * @example
 * ```typescript
 * // Auto-detect storage
 * const keys = await createKeyPersistence();
 *
 * // Force memory storage
 * const memKeys = await createKeyPersistence({ type: 'memory' });
 *
 * // Force IndexedDB (browser)
 * const idbKeys = await createKeyPersistence({ type: 'indexeddb' });
 *
 * // Force localStorage (browser)
 * const lsKeys = await createKeyPersistence({ type: 'localstorage' });
 *
 * // Custom directory for filesystem
 * const fsKeys = await createKeyPersistence({
 *   type: 'filesystem',
 *   baseDir: '.my-app/keys',
 * });
 * ```
 */
export declare function createKeyPersistence(options?: CreateKeyPersistenceOptions): Promise<KeyPersistence>;
/**
 * Create a KeyPersistence instance with an explicit storage adapter.
 *
 * Use this when you want to provide your own storage backend
 * (e.g., Redis, custom adapter).
 *
 * Note: The storage adapter must already be connected.
 *
 * @param storage - Connected storage adapter
 * @param options - Additional options
 * @returns KeyPersistence instance
 *
 * @example
 * ```typescript
 * import { createStorage } from '@frontmcp/utils';
 *
 * // Use Redis for distributed key storage
 * const redis = await createStorage({ type: 'redis' });
 * const keys = createKeyPersistenceWithStorage(redis);
 * ```
 */
export declare function createKeyPersistenceWithStorage(storage: StorageAdapter, options?: Pick<CreateKeyPersistenceOptions, 'throwOnInvalid' | 'enableCache'>): KeyPersistence;