agy-subagent-mcp

Run Google Antigravity (Gemini) as an autonomous subagent inside Claude Code.

agy-subagent-mcp is a Model Context Protocol (MCP) server that exposes Google Antigravity (agy CLI) as callable tools for Claude Code. Claude can delegate tasks—such as codebase exploration, architecture analysis, second opinions, and multi-file code generation—to Gemini without needing external API keys or cloud credentials.

Why Use This?

• Zero API Keys Required: Leverages your existing local agy authentication.

• Access to Gemini Models: Use Gemini 3.8 Flash, Gemini 3.1 Pro, and other models alongside Claude.

• Safety First:

  • agy_research runs sandboxed (read-only against real files; edits redirected to scratch).

  • agy_generate is opt-in (AGY_ALLOW_WRITES=1) to prevent unsupervised file modifications.

• Standard MCP Protocol: Compatible with Claude Code, Claude Desktop, and any other MCP-compliant client.

Related MCP server: mcp-gemini-assistant

Tools Exposed

Prerequisites

1. Antigravity CLI (agy):

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

   Verify with:

   agy --version

2. Python 3.10+ (tested on macOS / Linux).

Installation & Setup

1. Clone the Repository

git clone https://github.com/naren-m/agy-subagent-mcp.git ~/Projects/agy-subagent-mcp
cd ~/Projects/agy-subagent-mcp

2. Create Virtual Environment & Install Dependencies

python3 -m venv .venv
./.venv/bin/pip install -r requirements.txt

3. Register with Claude Code

Add the server to your user-wide Claude Code configuration:

claude mcp add --scope user agy-subagent -- \
  /Users/$USER/Projects/agy-subagent-mcp/.venv/bin/python3 \
  /Users/$USER/Projects/agy-subagent-mcp/server.py

Verify that the server is connected:

claude mcp list

Configuration

You can configure options via environment variables using claude mcp set-env:

# Change default model
claude mcp set-env agy-subagent AGY_MODEL=gemini-3.1-pro-high

# Increase timeout (seconds)
claude mcp set-env agy-subagent AGY_TIMEOUT=600

# Enable unsupervised code generation (agy_generate)
claude mcp set-env agy-subagent AGY_ALLOW_WRITES=1

Available Environment Variables

Example Usage in Claude Code

Once registered, you can prompt Claude naturally:

"Use agy_research to analyze how authentication and sessions are handled in this repository."

"Ask agy_ask to compare CRDTs and Operational Transformation for collaborative text editing."

"Use agy_generate to implement unit tests for the parser module." (requires AGY_ALLOW_WRITES=1)

License

MIT © Naren Mudivarthy