/**
 * Vendor response cache — a small file-based TTL cache shared by vendor
 * clients so repeated lookups (e.g. category snapshots) avoid re-hitting
 * rate-limited public APIs.
 *
 * @module
 */
export interface CacheReadResult<T> {
    value: T;
    storedAt: number;
}
export interface VendorCache {
    get<T>(key: string): Promise<CacheReadResult<T> | null>;
    set<T>(key: string, value: T, ttlSeconds: number): Promise<void>;
}
/** Build a stable cache key from an ordered list of key parts. */
export declare function cacheKey(parts: Array<string | number | Record<string, unknown>>): string;
/** A cache that never stores or returns anything. Safe default for callers that opt out. */
export declare function createNoopVendorCache(): VendorCache;
/** A file-based TTL cache rooted at `${cacheDir}/vendors`. Failures are swallowed — caching is best-effort. */
export declare function createFileVendorCache(cacheDir: string): VendorCache;