Function handleUpgradeRequest

src/server.ts:2844–2932

(
    req: http.IncomingMessage,
    socket: import("node:net").Socket,
    head: Buffer,
  )

  );

  async function handleUpgradeRequest(
    req: http.IncomingMessage,
    socket: import("node:net").Socket,
    head: Buffer,
  ): Promise<void> {
    const parsedUrl = new URL(req.url ?? "/", `http://${req.headers.host ?? "localhost"}`);
    let pathname = parsedUrl.pathname;

    // Dispatch to mounted services before any path rewrites
    if (mounts) {
      for (const { path: mountPath, handler } of mounts) {
        if (
          (pathname === mountPath || pathname.startsWith(mountPath + "/")) &&
          handler.handleUpgrade
        ) {
          const subPath = pathname.slice(mountPath.length) || "/";
          if (await handler.handleUpgrade(socket, head, subPath)) return;
        }
      }
    }

    // Normalize OpenAI-compatible paths (strip /openai/ prefix + rewrite arbitrary prefixes)
    // Skip Azure deployment paths — they have their own rewrite in the HTTP handler
    if (!pathname.match(AZURE_DEPLOYMENT_RE)) {
      pathname = normalizeCompatPath(pathname, logger);
    }

    if (
      pathname !== RESPONSES_PATH &&
      pathname !== REALTIME_PATH &&
      pathname !== GEMINI_LIVE_PATH
    ) {
      socket.write("HTTP/1.1 404 Not Found\r\n\r\n");
      socket.destroy();
      return;
    }

    // Push any buffered data back before upgrading
    if (head.length > 0) {
      socket.unshift(head);
    }

    let ws: WebSocketConnection;
    try {
      ws = upgradeToWebSocket(req, socket);
    } catch (err: unknown) {
      const msg = err instanceof Error ? err.message : "WebSocket upgrade failed";
      logger.error(`WebSocket upgrade error: ${msg}`);
      if (!socket.destroyed) socket.destroy();
      return;
    }

    activeConnections.add(ws);

    ws.on("error", (err: Error) => {
      logger.error(`WebSocket error: ${err.message}`);
      activeConnections.delete(ws);
    });