Run Google Antigravity in a tab

Agents: antigravity · On: phone, desktop · beta

A tab can run Antigravity, Google's agent CLI (agy). Fezu starts agy once for each message, and its replies and tool calls show in the transcript like the other agents'.

Why you would use it

You have a personal Google account and want Antigravity's models from your phone. A personal account gets a free weekly quota. Google publishes no numbers for it, so the usage meters have no row for Antigravity.

How to use it

Install the CLI if the workstation does not have it. See install-an-agent. The install runs curl -fsSL https://antigravity.google/cli/install.sh | bash, which puts agy in ~/.local/bin.
Log in. Tap Log in on Antigravity's row in the cog's Agents card, or send /login in an Antigravity tab. The card shows 1. Open the link and approve. and the link.
- Open the link and sign in with your Google account. The page then shows a code.
- Copy the code. The card shows 2. Paste the code it shows. Paste it into the field (Paste the code from the page) and tap Submit. Enter submits too.
- The card shows Checking the code… until the login ends.
- agy waits 60 seconds for the code, so paste it within that time.
- If the card says Antigravity signs in only in a terminal here: run agy in a terminal on this computer and sign in with Google., run agy in a terminal on the workstation and sign in there. Shell mode is a terminal too.
- If Google refuses the code, the card shows agy's reason, such as Error: authentication failed: token exchange failed: …. Tap Log in again for a new link.
Pick Antigravity in the agent picker (#agentpick), then a model in the model menu (#modelpick).
Pick the level, Ask or Full. Full is the default. See Options and settings.

What you see

Text streams in as the reply is written.
Each tool call is a card: a command, a file read, an edit, a search or a fetch. The card's title is the tool's name and its first argument, such as run_command: ls.
An edit card has no diff, because agy sends none. The changed-files view still lists the file, since it compares the folder with git.
At Ask, edits in the folder and fezu commands run. Any other command ends the run there, because agy cannot stop to ask you. The command's card turns to an error, and a warn row reads Antigravity stopped at a command (RunCommand): at Ask it runs only fezu commands. Set the tab to Full and send again. The name is the one agy gives the refused action.
The status bar shows the context the last reply used.
A message you send during a turn waits for the turn to end, then runs as the next run.
Stop ends the run at once.
The conversation carries on after a Fezu restart. The next message continues the same conversation.
/compact and automatic compaction build the next message's context from the transcript, as Junie's one-shot runs do. See auto-compact.
If your login ends mid-run, the turn fails with Antigravity is not logged in. Log in from its row in Settings, Agents.
A run that ends without a result fails the turn with the last line agy wrote to stderr, or agy exited code=<code> signal=<signal> without a result.
A run that ends with a status other than SUCCESS fails the turn with the first line of agy's error, or Antigravity ended the turn: <status>.
If agy is not installed, the tab fails with Antigravity CLI (agy) is not installed.

Options and settings

Option	Default	What it changes
Level, `Ask` or `Full`	`Full`	`Ask` runs edits in the folder and `fezu` commands, and the first other command ends the turn; its menu note reads `edits and fezu commands run; any other command stops the turn`. `Full` asks nothing and runs the run with `--dangerously-skip-permissions`. There is no Auto and no Plan.
Model, `#modelpick`	`agy`'s own default, sent as no `--model`	The model the next run uses. On the workstation this page was checked on, `agy models` listed Gemini 3.8 Flash in High, Medium and Low, Claude Sonnet 4.6, Claude Opus 4.6 and GPT-OSS 120B.
Update every hour, `agentUpdate.antigravity`	off	Runs `agy update` once an hour when no Antigravity tab is working. See update-agents-automatically.

The effort is part of each model's name, so there is no effort dial. An effort change is refused with antigravity has no effort dial; pick a model with /model instead.

The model list stays until /refresh-models asks again. Logged out, the list is empty.

Limits and known gaps

The phone login was checked up to Google on a logged-out box: the link shows and the pasted code reaches Google. A sign-in that finishes was not tried from the phone.
The login needs a terminal for agy. Fezu gives it one with script (Debian, Ubuntu, macOS) or Python's pty module (Fedora). With neither, and on Windows, sign in from a terminal. The macOS path is not verified.
Not available on an Antigravity tab:
- Steering. A message sent mid-turn waits for the next run.
- Attachments. A message with one fails with Attachments are not available on Antigravity tabs.
- Plan. The Plan row is not offered, and setting Plan is refused with Plan is not available on Antigravity tabs.
- Side questions, fork, and /mcp.
- The resume list. Fezu lists and adopts no Antigravity conversations. The tab's own conversation comes back after a restart.
- Fusion. The model menu has no Fusion row.
- Approval cards. At Ask, a refused command ends the turn; nothing waits for you.
- A diff on an edit card.
Auto is not a level. Antigravity has no reviewer to decide a request.
Windows: the install runs irm https://antigravity.google/cli/install.ps1 | iex. Where that puts agy.exe is not verified. Fezu finds agy on Path.
Linux and macOS: Fezu uses ~/.local/bin/agy if it exists, else agy on PATH.