import { JsonRpcProvider } from 'ethers';
export declare const providerCache: Map<string, JsonRpcProvider>;
export declare const PROVIDER_CACHE_TTL = 60000;
export declare const providerCacheTimestamps: Map<string, number>;
/**
 * 获取缓存的 Provider 实例
 * - 根据 rpcUrl + chainId 作为缓存 key
 * - 60秒后自动失效，避免长连接问题
 */
export declare function getCachedProvider(rpcUrl: string, chainId: number, chainName: string): JsonRpcProvider;