Antigravity CLI Integration

cc-antigravity-plugin

A plugin for Claude Code and Codex that integrates the Antigravity CLI (AGY) as an agentic coding assistant — creates, edits, searches files, and executes commands autonomously over your codebase.

📖 Documentation in other languages:

• Português (Brazilian Portuguese)

Fork: This plugin is a fork of gemini-cli-plugin, originally created by thepushkarp for process automation with Gemini CLI.

Overview

AGY is Google's long-context CLI terminal (2M token window). This plugin bridges AGY to Claude Code and Codex via a shared Node.js bridge, exposing AGY as a tool_use endpoint that Claude can invoke.

When to use instead of native Claude Code:

• Multi-file refactorings needing broad repository context
• Code generation spanning multiple project layers
• Architecture analysis and change impact with complete context
• Tasks benefiting from Gemini Pro deep-reasoning models
• Multiple independent deliverables that can run in parallel via native Gemini subagents (--parallel)

Claude invoking agy directly vs via plugin

Claude can call agy directly via Bash (agy --print "task" --dangerously-skip-permissions --add-dir .) without any intermediary. However, the plugin delivers capabilities that raw agy cannot:

Capability	agy direct	Via plugin (bridge)
Headless model selection	No — lacks --model flag	Yes, via settings.json patch
Guaranteed coding-agent behavior	No — AGY tends to respond in text	Yes — <constraints> block instructs use of write_to_file, grep_search, etc.
Structured quota/auth signals	No — free-form text, no exit codes	Exit codes 10/11 + JSON-line parseable
Automatic file ingestion	Manual	--dirs, --files with binary detection and truncation
Parallelism via Gemini subagents	Manual	--parallel + --subagent-model
Fallback for 28k char limit (Windows)	Silent breakage	Auto-drop of inline files
Auditable logging	No	JSONL in %LOCALAPPDATA%\agy\cc-plugin-logs\
Process overhead	None	Node.js + ConPTY + version check
Visibility of AGY actions	Full — direct output	Black box — Claude doesn't validate before exec
Quota dependency	Claude only	Claude + AGY/Gemini

Summary: for automated workflows, skills, and coding tasks where consistent agentic behavior is required, the bridge is the right choice. For simple ad-hoc invocations, raw agy suffices.

Prerequisites

• Node.js 18+
• Antigravity CLI installed and authenticated

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

# Windows PowerShell
irm https://antigravity.google/cli/install.ps1 | iex

After installing, run agy once to log in and verify it works:

agy --print "what is 2+2"

The SessionStart hook automatically checks if AGY is installed and accessible on each Claude Code session start.

Installation

Claude Code (recommended)

Via CLI (terminal):

# Add the GitHub repository as a marketplace source
claude plugin marketplace add AllanHarlen/cc-antigravity-plugin

# Install the plugin
claude plugin install cc-antigravity-plugin@AllanHarlen/cc-antigravity-plugin

Via slash command (inside Claude Code):

/plugin marketplace add AllanHarlen/cc-antigravity-plugin
/plugin install cc-antigravity-plugin@AllanHarlen/cc-antigravity-plugin

To test a local copy of the repository:

cc --plugin-dir /path/to/cc-antigravity-plugin

Codex

git clone https://github.com/AllanHarlen/cc-antigravity-plugin.git \
  ~/.agents/skills/cc-antigravity-plugin

Restart Codex after cloning.

Usage

Correct Entry Point

For any coding request (creating, editing, deleting, moving, or formatting files), always use the direct command/skill path:

/cc-antigravity-plugin:antigravity --parallel --add-dir ./frontend "implement the requested components"

Do not use antigravity-agent for coding. That agent is read-only and exists only for analysis, planning, audits, and refactor-impact work.

If you specifically want the coding run tracked by the harness as a subagent, use the antigravity-coder agent instead of the read-only one. It is the sanctioned subagent path for implementation: it has no Write/Edit and no broad Bash — its only file-acting tool is the bridge, so AGY/Gemini performs the file generation and it does not spend Claude tokens writing file contents. The plain command/skill path remains the simplest option when you do not need a separate subagent layer.