pi-agy

NOTE: THIS WAS VIBE CODED BY AADISH V (mail@aadishv.dev) USING CLAUDE OPUS 4.5 AS A FUN TEST OF CLAUDE CODE.

Antigravity OAuth + CLIProxyAPI integration for Pi coding agent.

What is Antigravity?

Antigravity provides access to various AI models (Claude, Gemini) through Google's cloudcode-pa.googleapis.com API using your Google account subscription. It uses Google OAuth for authentication.

Architecture

Since Antigravity uses a custom Gemini-like API format (not OpenAI or Anthropic format), we need CLIProxyAPI to translate between Anthropic API (which Pi speaks) and Antigravity's format.

┌─────────┐     ┌─────────────────┐     ┌─────────────────────┐
│   Pi    │────▶│   CLIProxyAPI   │────▶│  cloudcode-pa.      │
│  Agent  │◀────│ (localhost:8317)│◀────│  googleapis.com     │
└─────────┘     └─────────────────┘     └─────────────────────┘
     │                    │
     │ Anthropic API      │ Custom Gemini-like format
     │                    │ + Google OAuth token
     ▼                    ▼
~/.pi/agent/         ~/.pi-agy/
models.json          credentials.json

Installation

cd pi-agy
bun install

Usage

1. Login with Google OAuth

bun run dev login

This opens your browser to authenticate with Google. The OAuth credentials used are from Antigravity (Google OAuth client ID 1071006060591-...).

2. Quick Start - Run Pi with proxy

bun run dev run

This automatically starts the proxy in the background and launches Pi. When you exit Pi, the proxy stops automatically.

OR manually:

2a. Start the proxy

bun run dev proxy start

This downloads CLIProxyAPI (if needed) and starts it on port 8317. Keep this running in a terminal.

2b. Configure Pi (first time only)

bun run dev config

This adds Antigravity models to Pi's ~/.pi/agent/models.json.

2c. Use Pi

Start Pi and select an Antigravity model (e.g., gemini-claude-opus-4-5-thinking).

Commands

Command	Description
pi-agy login	Authenticate with Google OAuth
pi-agy logout	Clear stored credentials
pi-agy status	Show auth, proxy, and config status
pi-agy refresh	Manually refresh access token
pi-agy config	Add Antigravity models to Pi
pi-agy remove	Remove Antigravity from Pi config
pi-agy run	Start proxy in background and run Pi together
pi-agy proxy start	Start CLIProxyAPI server
pi-agy proxy stop	Stop CLIProxyAPI server
pi-agy proxy install	Download CLIProxyAPI binary
pi-agy help	Show help message

Available Models

• gemini-claude-opus-4-5-thinking - Claude Opus 4.5 with extended thinking
• gemini-claude-sonnet-4-5-thinking - Claude Sonnet 4.5 with extended thinking
• gemini-claude-sonnet-4-5 - Claude Sonnet 4.5
• gemini-3-pro-preview - Gemini 3 Pro

How it works

1. OAuth Login - Uses Google OAuth with Antigravity's client ID to get access tokens
2. Project Discovery - Calls loadCodeAssist API to get your GCP project ID
3. CLIProxyAPI - Runs as local proxy to translate Anthropic API → Antigravity format
4. Pi Configuration - Updates models.json to point Pi at the local proxy

Files

• ~/.pi-agy/credentials.json - OAuth tokens from Google
• ~/.pi-agy/proxy/ - CLIProxyAPI binary and config
• ~/.pi/agent/models.json - Pi's model configuration

Credits

OAuth flow and CLIProxyAPI integration based on:

• CLIProxyAPI - The translation proxy
• CCS - Claude Code Switch (inspiration for this project)