Antigravity in Adom Hydrogen

Google Antigravity is Google's agent-first coding tool. This wiki app puts it inside your Adom workspace, next to Claude Code, Codex and Kimi:

• The editor extension (Open VSX Google.google-antigravity) installed into Hydrogen's code-server, so the Antigravity side bar appears in your editor. Sign in with Google inside the panel.
• The agy command line installed into ~/.local/bin of your container by Google's own installer, so an Antigravity terminal tab works like the Claude and Codex TUIs.
• A dock dashboard that installs both, shows what is installed, opens the panel, and offers the starter phrases to say to your AI.

Everything lands in the container (the WSL2 Adom-Workspace on Windows, the Lima container on a Mac). Nothing is installed on Windows or macOS itself.

Use it

Click the Antigravity card on the Dock Bar (or add adom/antigravity through Dock settings). The dashboard's LED row says what is missing; the two Install buttons fix it. After the extension installs, reload the editor once.

From a terminal or an AI thread:

adom-antigravity status              # extension, cli, editor, runtime as JSON
adom-antigravity install-extension   # code-server --install-extension Google.google-antigravity
adom-antigravity install-cli         # curl -fsSL https://antigravity.google/cli/install.sh | bash
adom-antigravity open [--new]        # focus the Antigravity panel (or start a new conversation)
adom-antigravity serve --print-url   # the dashboard (what a dock click runs)

Where Antigravity shows up

The extension starts Antigravity's own web UI (a local "hub") inside the container and frames it in the editor's side bar. That frame needs the editor to hand out forwarded ports as http://<port>.localhost:<proxy port>/ (Hydrogen 1.0.224 and later do: Hydrogen's own reverse proxy serves that form with the app's paths untouched and a loopback Host upstream, because the hub's page uses absolute asset paths and refuses non-localhost hosts; nothing in code-server or the container image is patched). On an older Hydrogen or on Web Hydrogen, which path-proxy ports as /proxy/<port>/, the panel is blank; there the dashboard's Open Antigravity turns the dashboard tab into that UI instead. The CLI agy works in a terminal tab everywhere.

For Google: a <base href> on the hub page, or relative asset paths, would make the panel work behind any path proxy.

Sign-in

The extension signs in with Google inside its own panel. The CLI opens a browser on first run; inside a container it prints the sign-in link instead, open it on your desktop. For headless or scripted use, set GEMINI_API_KEY and "modelProvider": "gemini" in ~/.gemini/antigravity-cli/settings.json (CLI install and auth).

What the AI launch bar does with it

adom-vscode's AI launch bar (the icons in the editor's title bar) lists Antigravity as soon as the extension is installed: one click opens the panel, the TUI entry opens a terminal running agy.