Antigravity

Antigravity plugin for Claude Code

Use Antigravity (agy) from inside Claude Code for code reviews or to delegate tasks.

This plugin is for Claude Code users who want an easy way to use Google's Antigravity models from the workflow they already have. This is the 2.0 rebrand of gemini-plugin-cc — the deprecated Gemini CLI backend was replaced with Antigravity's agy.

What You Get

• /antigravity:review for a normal read-only Antigravity review
• /antigravity:adversarial-review for a steerable challenge review
• /antigravity:rescue, /antigravity:status, /antigravity:result, and /antigravity:cancel to delegate work and manage background jobs

Requirements

• Antigravity with a signed-in Google account.
  • The agy CLI ships with Antigravity. Usage counts against your Antigravity limits.
• Node.js 18.18 or later
• git (reviews run inside disposable git worktrees)

Install

Add the marketplace in Claude Code:

/plugin marketplace add btli/antigravity-plugin-cc

Install the plugin:

/plugin install antigravity

Reload plugins:

/reload-plugins

Then run:

/antigravity:setup

/antigravity:setup will tell you whether agy is ready.

If agy is missing, install Antigravity — it bundles the CLI.

If agy is installed but not signed in yet, run it interactively once and complete the Google sign-in:

agy

After install, you should see:

• the slash commands listed below
• the antigravity:antigravity-rescue subagent in /agents

One simple first run is:

/antigravity:review --background
/antigravity:status
/antigravity:result

Usage

/antigravity:review

Runs a normal Antigravity review on your current work. It gives you a thorough code review covering bugs, security issues, performance problems, and maintainability concerns.

[!NOTE] Code review especially for multi-file changes might take a while. It's generally recommended to run it in the background.

Use it when you want:

• a review of your current uncommitted changes
• a review of your branch compared to a base branch like main

Use --base <ref> for branch review. It also supports --wait and --background. It is not steerable and does not take custom focus text. Use /antigravity:adversarial-review when you want to challenge a specific decision or risk area.

Examples:

/antigravity:review
/antigravity:review --base main
/antigravity:review --background

This command is read-only and will not perform any changes. When run in the background you can use /antigravity:status to check on the progress and /antigravity:cancel to cancel the ongoing task.

/antigravity:adversarial-review

Runs a steerable review that questions the chosen implementation and design.

It can be used to pressure-test assumptions, tradeoffs, failure modes, and whether a different approach would have been safer or simpler.

It uses the same review target selection as /antigravity:review, including --base <ref> for branch review. It also supports --wait and --background. Unlike /antigravity:review, it can take extra focus text after the flags.

Use it when you want:

• a review before shipping that challenges the direction, not just the code details
• review focused on design choices, tradeoffs, hidden assumptions, and alternative approaches
• pressure-testing around specific risk areas like auth, data loss, rollback, race conditions, or reliability

Examples:

/antigravity:adversarial-review
/antigravity:adversarial-review --base main challenge whether this was the right caching and retry design
/antigravity:adversarial-review --background look for race conditions and question the chosen approach

This command is read-only. It does not fix code.

/antigravity:rescue

Hands a task to Antigravity through the antigravity:antigravity-rescue subagent.

Use it when you want Antigravity to:

• investigate a bug
• try a fix
• continue a previous Antigravity task
• take a faster or cheaper pass with a smaller model

[!NOTE] Depending on the task and the model you choose these tasks might take a long time and it's generally recommended to force the task to be in the background or move the agent to the background.

It supports --background, --wait, --resume, and --fresh. If you omit --resume and --fresh, the plugin can offer to continue the latest rescue thread for this repo.

Examples:

/antigravity:rescue investigate why the tests started failing
/antigravity:rescue fix the failing test with the smallest safe patch
/antigravity:rescue --resume apply the top fix from the last run
/antigravity:rescue --model pro investigate the flaky integration test
/antigravity:rescue --model flash fix the issue quickly
/antigravity:rescue --background investigate the regression

You can also just ask for a task to be delegated to Antigravity:

Ask Antigravity to redesign the database connection to be more resilient.

Notes:

• if you do not pass --model, the plugin defaults to Gemini 3.1 Pro (High).
• if you say flash, the plugin maps that to Gemini 3.5 Flash (High)
• if you say pro, the plugin maps that to Gemini 3.1 Pro (High)
• if you say sonnet, the plugin maps that to Claude Sonnet 4.6 (Thinking)
• if you say opus, the plugin maps that to Claude Opus 4.6 (Thinking)
• follow-up rescue requests can continue the latest Antigravity task in the repo

/antigravity:status

Shows running and recent Antigravity jobs for the current repository.

Examples:

/antigravity:status
/antigravity:status task-abc123

Use it to:

• check progress on background work
• see the latest completed job
• confirm whether a task is still running

/antigravity:result

Shows the final stored Antigravity output for a finished job. When available, it also includes the agy conversation ID so you can reopen that run directly in Antigravity with agy --conversation <conversation-id>.

Examples:

/antigravity:result
/antigravity:result task-abc123

/antigravity:cancel

Gracefully cancels an active background Antigravity job. The plugin sends a cancel signal to the running job, waits for the worker to persist any partial output, and then confirms cancellation. If the worker does not exit cleanly within 3 seconds, it is force-terminated.

Examples:

/antigravity:cancel
/antigravity:cancel task-abc123

/antigravity:setup

Checks whether Antigravity is installed and authenticated.

You can also use /antigravity:setup to manage the optional review gate.

Enabling review gate

/antigravity:setup --enable-review-gate
/antigravity:setup --disable-review-gate

When the review gate is enabled, the plugin uses a Stop hook to run a targeted Antigravity review based on Claude's response. If that review finds issues, the stop is blocked so Claude can address them first.

[!WARNING] The review gate can create a long-running Claude/Antigravity loop and may drain usage limits quickly. Only enable it when you plan to actively monitor the session.

Models

The default model is Gemini 3.1 Pro (High). Pass --model <alias> to any review or rescue command:

Alias	Model
pro / pro-high (default)	Gemini 3.1 Pro (High)
pro-low	Gemini 3.1 Pro (Low)
flash / flash-high	Gemini 3.5 Flash (High)
flash-medium	Gemini 3.5 Flash (Medium)
flash-low	Gemini 3.5 Flash (Low)
sonnet	Claude Sonnet 4.6 (Thinking)
opus	Claude Opus 4.6 (Thinking)
gpt-oss	GPT-OSS 120B (Medium)

Unknown values are passed to agy verbatim (for custom models defined in your agy settings). If agy does not recognize the model it would silently fall back to Flash Medium — the plugin detects this and fails the run instead.

Typical Flows

Review Before Shipping

/antigravity:review

Hand A Problem To Antigravity

/antigravity:rescue investigate why the build is failing in CI

Start Something Long-Running

/antigravity:adversarial-review --background
/antigravity:rescue --background investigate the flaky test

Then check in with:

/antigravity:status
/antigravity:result

Architecture

This plugin mirrors the design of OpenAI's codex-plugin-cc, adapted for Google's Antigravity ecosystem.

	Codex plugin	Antigravity plugin
CLI	@openai/codex	agy (ships with Antigravity)
Protocol	JSON-RPC via Codex app server	agy --print subprocess, prompt via stdin
Session model	Managed by app server broker	Conversation IDs parsed from agy's per-job glog
Cancellation	JSON-RPC cancel to app server	SIGTERM to worker → SIGTERM to agy child
Auth	ChatGPT account or OpenAI API key	Google account via ~/.gemini
Model aliases	spark → gpt-5.3-codex-spark	flash → Gemini 3.5 Flash (High), pro → Gemini 3.1 Pro (High)

Both plugins share the same user-facing command surface (review, adversarial-review, rescue, status, result, cancel, setup) and the same background job system with foreground/background execution, conversation resume, and a stop-hook review gate.

How it works

The plugin spawns agy --print as a child process with the prompt written to stdin. Each task gets its own agy invocation with:

• Watchdog timeouts — agy's --print-timeout is the primary bound; a Node watchdog at timeout+30s catches hung processes.
• Graceful cancellation — background workers install a SIGTERM handler that forwards the signal to the active agy child. The cancel command sends SIGTERM to the worker first, waits up to 3 seconds for clean shutdown, and falls back to process tree termination.
• Partial output preservation — if a task fails (timeout, rate limit, crash), any output accumulated before the failure is returned instead of being discarded.
• Review worktree isolation — reviews run inside a disposable detached git worktree that mirrors the working state. agy has no read-only mode and auto-approves file writes in print mode; the worktree ensures stray writes never touch your real working tree.
• Conversation resume — conversation IDs are parsed from agy's per-job glog and stored in job state so you can resume with --resume-last or directly with agy --conversation <id>.

Antigravity Integration

The Antigravity plugin wraps the agy CLI that ships with Antigravity. It uses the global agy binary installed in your environment.

Moving The Work Over To Antigravity

Delegated tasks and any stop gate run can also be directly resumed inside Antigravity by running agy --conversation <conversation-id> with the specific conversation ID you received from running /antigravity:result or /antigravity:status.

This way you can review the Antigravity work or continue the work there.

Migrating from the Gemini plugin

Every /gemini:* command has a 1:1 /antigravity:* replacement (/gemini:review → /antigravity:review, etc.). Old Gemini job state is not migrated; finish or discard in-flight Gemini jobs before switching. Session resume now uses agy conversations: agy --conversation <conversation-id> replaces gemini --resume <session-id>.

Known limitations

• Read-only tasks rely on prompt guidance plus post-run git status drift detection (with a prominent warning); only reviews get hard worktree isolation.
• Review worktrees do not initialize git submodules; submodule content is absent from the worktree (the embedded diff still covers it).
• No streaming progress: /antigravity:status shows the job log, not token-level streaming.
• agy must be signed in via one interactive run before background jobs work.

FAQ

Do I need a separate account for this plugin?

If you are already signed into Antigravity on this machine, that account should work immediately here too. This plugin uses your local agy authentication stored in ~/.gemini.

If you only use Claude Code today and have not used Antigravity yet, you will need to sign in by running agy interactively once and completing Google sign-in. Run /antigravity:setup to check whether agy is ready.

Does the plugin use a separate runtime?

No. This plugin spawns your local agy CLI as a subprocess using print mode (--print). There is no separate broker or app server — the plugin writes the prompt to agy's stdin and reads the result from stdout.

That means:

• it uses the same agy install you would use directly
• it uses the same local authentication state
• it uses the same repository checkout and machine-local environment
• conversations created by the plugin can be resumed directly with agy --conversation <id>

License

Apache-2.0