Overview

Google Antigravity is a coding agent that The Test Cabinet drives non-interactively like the other harnesses. It authenticates only through a Google account, so it has no API-key mode and runs under subscription authentication alone — it is unavailable until you sign in with its agy CLI, and runnable once you have. See the project’s own site at antigravity.google and the Authentication page for how to sign in.

Subscription only

The antigravity adapter declares no API-key environment variable (api_key_env: None); it is authenticated by the Google-account OAuth token the agy CLI writes, copied into the run container. Until that token exists the harness reports itself unavailable with a hint to sign in. It also accepts no model ID — Antigravity drives a Google-account session rather than a chosen model — and reports no token usage in its non-interactive mode.

Model IDs

Antigravity accepts no model ID for a run. It drives a Google-account session rather than a chosen model, so there is no model ID to supply and none is passed through to the CLI.

Invocation

The CLI binary is agy, which the manifest installs into the run container at run time with:

curl -fsSL https://antigravity.google/cli/install.sh | bash

A single prompt is driven to completion with the non-interactive session flags:

agy --print --dangerously-skip-permissions <prompt>

--print requests non-interactive output and --dangerously-skip-permissions suppresses the interactive approval prompts. No model flag is passed, because no model ID is accepted. The harness authenticates from the Google-account OAuth token copied into the container (see Authentication); with no token present, the run reports the harness unavailable and fails before a session is spent.

See the Authentication page for signing in, the Events and Metrics pages for how Antigravity output is normalized, and Harnesses for the harness layer overall.