pi-antigravity

A Pi Coding Agent provider for Google Antigravity / Cloud Code Assist models. It adds provider antigravity, Google OAuth login, native streaming, model routing, and quota diagnostics—without invoking an external Antigravity CLI.

Unofficial integration. This project is not affiliated with or endorsed by Google. Use it only with an account and services you are authorized to access, and review its source before granting OAuth permissions.

Requirements

• Pi Coding Agent and Pi AI version 0.80.0 or later
• A Google account that can use the relevant Cloud Code Assist / Antigravity services
• A browser on the same machine as Pi for the OAuth sign-in flow

Install

Install from npm:

pi install npm:pi-antigravity

Or install the latest repository version:

pi install git:github.com/Rahularya01/pi-antigravity

Restart Pi (or run /reload) after installation. To update the npm package later, use pi update npm:pi-antigravity.

Quick start

1. Start Pi and run /login antigravity.

2. Complete Google sign-in in your browser.

3. Select a model, for example:

   /model antigravity/gemini-3.5-flash
   

4. Start working. Use /antigravity.doctor if a request fails.

Authentication and credential safety

The provider uses OAuth 2.0 Authorization Code flow with PKCE.

1. /login antigravity opens Google sign-in and starts a temporary callback listener at http://localhost:51121/oauth-callback.
2. After approval, Pi exchanges the callback code for tokens and stores the provider credentials in Pi's auth store (normally ~/.pi/agent/auth.json).
3. Pi refreshes access tokens when needed.

The callback listener binds only to a loopback host. The auth file contains sensitive access and refresh tokens: do not commit it, paste it into issues, or share its contents.

The login requests these Google OAuth scopes:

• cloud-platform
• userinfo.email and userinfo.profile
• cclog
• experimentsandconfigs

Review these permissions before approving access. Re-run /login antigravity to replace expired or revoked credentials.

Commands

Command	Description
/login antigravity	Sign in to Google and configure the provider.
/model antigravity/<model-id>	Choose a registered Antigravity model.
/antigravity.usage	Show the server-reported shared quota groups and reset times.
/antigravity.models	List available runtime models, remaining shared-pool quota, and capabilities.
/antigravity.models all	Include tab/chat models normally hidden from the model list.
/antigravity.doctor	Show sanitized provider diagnostics, including the endpoint, status, and resolved runtime model.

Model availability, entitlement, quota groups, and resets are returned by the service and can differ by account. The quota percentage shown for a model can represent a shared pool, not a private per-model allowance.

Models and routing

The static model IDs registered by this extension match the Antigravity CLI catalog (agy models). Use /antigravity.models to see live availability and quota for your account.

agy models currently lists eight display entries (Flash Low/Medium/High, Pro Low/High, Claude Sonnet/Opus Thinking, GPT-OSS Medium). Pi collapses those into five public model IDs and maps Low/Medium/High through thinking effort.

Why Claude and GPT-OSS appear

Antigravity / Cloud Code Assist exposes a multi-provider catalog. Depending on your account, its Google-authenticated API can advertise Google Gemini models alongside Claude models served through Anthropic Vertex and GPT-OSS served through OpenAI Vertex. This extension intentionally exposes those advertised Claude and GPT-OSS models through the single antigravity provider; they are not separate Pi providers and do not use a separate Anthropic or OpenAI login.

The backend's display labels do not always match its runtime IDs. For example, gemini-3.5-flash-extra-low, gemini-3.5-flash-low, and gemini-3-flash-agent can be displayed as Gemini 3.5 Flash Low, Medium, and High. The routing below uses the runtime IDs returned by the service.

Public model ID	Input	Thinking	Request routing
gemini-3.5-flash	Text, image	Yes	Off/minimal → gemini-3.5-flash-extra-low; low/medium → gemini-3.5-flash-low; high/xhigh → gemini-3-flash-agent
gemini-3.1-pro	Text, image	Yes	Off/minimal/low/medium → gemini-3.1-pro-low; high/xhigh → gemini-pro-agent
claude-sonnet-4-6	Text, image	Yes	claude-sonnet-4-6 for every effort level
claude-opus-4-6	Text, image	Yes	claude-opus-4-6-thinking
gpt-oss-120b	Text	Yes	gpt-oss-120b-medium

To limit which models Pi cycles through, enable specific entries in ~/.pi/agent/settings.json:

{
  "models": {
    "antigravity/gemini-3.5-flash": { "enabled": true },
    "antigravity/gemini-3.1-pro": { "enabled": true },
    "antigravity/claude-sonnet-4-6": { "enabled": true }
  }
}

Configuration

All primary environment variables start with ANTIGRAVITY_. The legacy NOAGY_ prefix is also accepted for compatibility.

Variable	Purpose
ANTIGRAVITY_BASE_URL	Override the API base URL. It must be HTTPS, contain no URL credentials, and target an allowed Google APIs host.
ANTIGRAVITY_PROJECT_ID	Use a specific Cloud Code Assist project ID instead of discovery or the stable account fallback.
ANTIGRAVITY_CALLBACK_HOST	Bind OAuth callback to 127.0.0.1, ::1, or localhost only. Defaults to 127.0.0.1.
ANTIGRAVITY_USER_AGENT	Override the request user-agent.
ANTIGRAVITY_RUNTIME_MODEL	Pin requests to a runtime model ID, bypassing normal static routing.
ANTIGRAVITY_CLIENT_ID	Use a custom Google OAuth client ID.
ANTIGRAVITY_CLIENT_SECRET	Use a custom Google OAuth client secret. Keep it out of source control and shell history.

By default, the provider tries https://cloudcode-pa.googleapis.com and then its Google sandbox fallback if necessary. Prefer the built-in OAuth client unless you have a reason to use your own credentials.

Troubleshooting

• No credentials / 401 / 403: Run /login antigravity again, then check /antigravity.doctor.
• OAuth callback will not start: Ensure port 51121 is free and ANTIGRAVITY_CALLBACK_HOST is a permitted loopback address.
• Model is unavailable: Run /antigravity.models; availability is account- and service-dependent.
• Claude/GPT tool-call schema error: Upgrade to the latest package release. The provider adapts Pi's JSON Schema tool definitions for the Cloud Code Assist custom-tool bridge.
• Quota or rate limit: Run /antigravity.usage. A 429 response usually indicates quota or rate limiting; changing models may still draw from the same shared pool.
• Need a safe diagnostic: /antigravity.doctor redacts recognized secrets from its error output. Still review output before sharing it publicly.

Development

npm install
npm run check

The package declares its Pi extension in package.json under pi.extensions. See the Pi package documentation for package installation, manifest, and gallery conventions.

License

MIT