Function defaultMakeSocksAgent

packages/agent-core/src/utils/proxy.ts:219–253

({ proxy, noProxy })

  new EnvHttpProxyAgent({ httpProxy, httpsProxy, noProxy });

const defaultMakeSocksAgent: ProxyAgentFactories['makeSocksAgent'] = ({ proxy, noProxy }) => {
  // undici has no SOCKS support, so we drive a custom connector: tunnel the
  // destination through the SOCKS proxy with the `socks` client, then hand the
  // established socket back to undici's connector — which performs the TLS
  // upgrade for https targets (reusing undici's ALPN/servername handling).
  const directConnect = buildConnector({});
  const bypass = makeNoProxyMatcher(noProxy);
  const connect: typeof directConnect = (options, callback) => {
    if (bypass(options.hostname, options.port)) {
      directConnect(options, callback);
      return;
    }
    void (async () => {
      try {
        const isTls = options.protocol === 'https:';
        const port = Number(options.port) || (isTls ? 443 : 80);
        const { socket } = await SocksClient.createConnection({
          proxy: { host: proxy.host, port: proxy.port, type: proxy.type, userId: proxy.userId, password: proxy.password },
          command: 'connect',
          destination: { host: options.hostname, port },
        });
        if (isTls) {
          // Upgrade the SOCKS socket to TLS via undici's own connector.
          directConnect({ ...options, httpSocket: socket } as Parameters<typeof directConnect>[0], callback);
        } else {
          socket.setNoDelay(true);
          callback(null, socket);
        }
      } catch (error) {
        callback(error instanceof Error ? error : new Error(String(error)), null);
      }
    })();
  };
  return new Agent({ connect });
};

/**
 * Build an undici dispatcher that routes outbound `fetch` through the