antigravity

Google's current terminal agent, agy. Its default sign-in is a browser flow, so Jetty runs it in Gemini-API-key mode instead: the sandbox gets a settings file with modelProvider: gemini and the collection's GEMINI_API_KEY. Print mode, permissions auto-approved, a 120-minute print timeout in place of the CLI's five-minute default.

Providers	`google`
Model ids	agy's own catalog, not Gemini API ids: `gemini-3.7-flash`, `gemini-3.1-pro`, each with an effort tier. A tiered slug (`gemini-3.7-flash-medium`) carries the tier itself. Default `gemini-3.7-flash`. `gemini-2.5-pro` is rejected.
MCP	Yes, through `~/.gemini/config/mcp_config.json`; bearer tokens from `mcp_auth_tokens` are honoured.
Usage	Yes, including thinking tokens.
agent_env	`ANTIGRAVITY_EFFORT` (`low` / `medium` / `high`, default `high`; `none` omits the flag). `ANTIGRAVITY_PRINT_TIMEOUT` (a duration like `90m`, default `120m`).

The tier rules are agy's: a bare slug needs an effort, a tiered slug must not be combined with one, and gemini-3.1-pro only has low and high. Jetty normalises either form, so write whichever reads better and use ANTIGRAVITY_EFFORT to change the tier per run. high is the default because it is the one tier every catalog model accepts.

agent: antigravity
model: gemini-3.7-flash
model_provider: google
snapshot: prism-playwright

Cheaper tier for a routine run, no file change:

{ "init_params": { "agent_env": { "ANTIGRAVITY_EFFORT": "medium" } } }

Back: Runtime Configuration — the full comparison table, frontmatter defaults, and per-run overrides.