import { Agent as HttpAgent } from 'node:http';
/** Chooses the proxy the way gaxios does, then tunnels through it from a shared keep-alive agent. */
export declare function googleRequestAgent(url: URL): HttpAgent | undefined;
/**
 * Transport options for google-auth-library clients.
 *
 * gaxios builds its proxy agent without keep-alive, so behind a proxy every
 * request opens a new CONNECT tunnel and TLS session. Any agent passed to gaxios
 * replaces its proxy handling, so googleRequestAgent chooses the proxy using
 * gaxios's environment variable precedence. For HTTPS proxy endpoints or Node
 * versions without proxyEnv, HttpsProxyAgent provides a keep-alive tunnel.
 */
export declare function googleTransporterOptions(): {
    agent: (url: URL) => HttpAgent;
};
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