import type http from 'node:http';
export declare class EnvProxyRouter<TProxyAgent> {
    private readonly scheme;
    private readonly defaultPort;
    private readonly createProxyAgent;
    private readonly proxyCache;
    private cacheLimitWarned;
    constructor(scheme: 'http' | 'https', defaultPort: number, createProxyAgent: (proxyUrl: string) => TProxyAgent);
    resolve(options: http.RequestOptions): TProxyAgent | undefined;
    private cacheAgent;
    private resolvePort;
}