Running Browser in Windows 11 from antigravity IDE does not load web pages

Google Antigravity
1

Since installing antigravity V2, I can’t get it to use the browser for tests. I’ve got a standard Windows 11 setup with no VPN. I’ve not found others with this problem but an hour with Gemini 3.1 Pro couldn’t resolve the problem.

On a clean, default installation of Antigravity:

  1. The User Request: You give the agent a standard instruction to view or interact with a webpage:

    “Open http://localhost:8080 in the browser”

  2. Antigravity’s Automatic Launch:

    • Antigravity automatically calls its internal browser_subagent tool.

    • The subagent automatically launches its managed browser (Chromium) in the background, enabling the remote debugging port.

  3. The Internal Connection Mismatch:

    • The Browser’s Listener: On Windows 11, the automatically launched browser binds its remote debugging interface to the IPv6 loopback ([::1]).

    • The Subagent’s Connector: The subagent’s internal connection client tries to connect to that debugging port using the IPv4 loopback (127.0.0.1).

  4. The Result: The connection immediately times out or gets refused because the browser is listening on IPv6 while the client is connecting on IPv4. The browser_subagent fails, and Antigravity reports a browser connection error.

I tried sticking a shim between antigravity and Chrome as a work around but that really didn’t work.

  1. You aren’t trapped in a container. The subagent is successfully reaching out to your native Windows host and triggering your local Chrome executable (as evidenced by the C:\Users\markb\ path).

  2. The IPv4/IPv6 mismatch is real. Look closely at the arguments the IDE is passing: --remote-debugging-port=9222. It is not passing --remote-debugging-address=127.0.0.1. Without that address flag, Windows Chrome defaults to the IPv6 loopback (::1), while the Antigravity agent is hardcoded to look for the IPv4 loopback (127.0.0.1).

Again, this is unique to V2. It used to work fine. I’m not a network guy and it seems neither me nor the Gemini models are creative enough to get a solution working. I could use some help.

P.S. Using Playwright works fine.

2

It is working now. Did someone fix it? some weird environment problems? Who knows, but I can drive the browser again.