Antigravity

Antigravity (the agy binary) is Google’s harness, built on Gemini. It is fast and cheap, and good for well-scoped edits and quick fixes.

Vendor docs: antigravity-cli.

Connections

Connection	Supported
Subscription	Google account, personal use. Antigravity signs in from its own screen: sign in there, then quit it with ctrl+c to come back to Gluon.
API key	Gemini API, with a condition below
Amazon Bedrock	No
OpenRouter	No: Antigravity speaks only Gemini’s own API, and OpenRouter has no endpoint for it.

Caution

Antigravity uses GEMINI_API_KEY only when its own settings say modelProvider: gemini. Gluon never edits another tool’s settings. It tells you what to set, and you set it in Antigravity’s settings.json.

How Gluon launches it

Gluon starts agy in its own pseudo-terminal. The model and effort go in one option, because Antigravity’s model ids carry the effort. The spec goes in a prompt option written with =, so a spec that starts with a dash stays a value.

Antigravity reads AGENTS.md and GEMINI.md itself. Gluon tells it to read CLAUDE.md when your repository has one.

Modes

Antigravity has no read-only mode, only plan mode and accept-edits. So:

• explore starts it in its plan mode, and the row says explore (plan mode).
• plan starts it in its plan mode.

See Modes.

Sessions, cost and context

• Resume. It cannot be resumed: it has no hooks, and its --continue would take the newest session in the directory. A saved Antigravity session is offered to start again from its spec.
• Cost. — always. Antigravity reports no cost, and the token totals in its status line are the conversation’s size, not what requests billed. A per-request source is not available yet.
• Context. Shown only when you turn on cost.antigravity_statusline in the config. Gluon then sets one key, statusLine, in Antigravity’s own settings file. It touches nothing else, never writes through a symlink or over a status line of your own, and gluon uninstall removes only that key. It does not work on Windows, where context shows —.

See Cost and context.

Next steps

• Connections: why Antigravity needs its own setting for a key.
• Cost and context: what Antigravity shows and why.
• Grok Build: the next agent.