[!CAUTION]
⚠️ Risk Warning — Read Before Use

This project turns a desktop client into a headless API via CDP injection. This violates Antigravity's Terms of Service and carries real risks:

• Account throttling — Rate limits, degraded responses, shadow-banning
• Account ban — Your Google account may be suspended, potentially affecting other Google services (GCP, Workspace, Gmail)
• Detection is trivial — CDP debugger attachment, Security.setIgnoreCertificateErrors, and non-human interaction patterns (zero typing delay, no cursor movement) are all easily detectable

Protect yourself:

1. 🚫 Never use your primary Google account — Register a throwaway account
2. 🐢 Add delays between requests — Mimic human typing speed, avoid high concurrency
3. 🧪 Personal research only — Do not use as a production API or multi-user backend
4. 💀 Expect breakage — This is a cat-and-mouse game; the channel can be killed at any time

Use at your own risk. The authors are not responsible for any account actions taken by Google/Antigravity.

😡 The Problem

"Opus 4.6 API costs hundreds per month"
"Gemini 3.1 Pro is free but has no convenient API"
"I want my agent to use multiple models without paying for each"

Antigravity Bridge wraps Antigravity — Google's AI desktop app — into a local REST API via Chrome DevTools Protocol (CDP). One endpoint for the models listed in Antigravity's UI.

🚀 Quick Start

1. Install & Start

# Install Antigravity from https://antigravity.google
# The scripts here target macOS (tested on Apple Silicon, per `language_server_macos_arm`)

git clone https://github.com/ythx-101/antigravity-bridge.git
cd antigravity-bridge
pip install -r requirements.txt   # equivalent: pip install websockets

Pick one of the two ways to start (don't run both — the port would already be in use):

# Option A: one script starts Antigravity (CDP on 9229) AND the bridge (log: /tmp/ag_bridge.log)
bash scripts/start_antigravity.sh

# Option B: manual
open -a Antigravity --args --remote-debugging-port=9229
python3 scripts/bridge.py

2. Use the API

# Chat with Opus
curl -X POST http://localhost:19999/chat \
  -H 'Content-Type: application/json' \
  -d '{"prompt":"Explain quantum computing","model":"Claude Opus 4.6 (Thinking)"}'

# Async mode (recommended for long tasks)
curl -X POST http://localhost:19999/async \
  -d '{"prompt":"Deep analysis...","timeout":600}'
# → {"status":"accepted","task_id":"abc123"}
curl http://localhost:19999/task/abc123

# New conversation (clear context)
curl -X POST http://localhost:19999/new

# Health check
curl http://localhost:19999/health

🤖 Available Models

📡 API Reference

📊 Architecture

Your Agent / Script
    │
    ├── curl http://localhost:19999/chat
    │
    └── bridge.py (:19999)
          │ WebSocket (CDP)
          ▼
        Antigravity (CDP :9229)
          │ Security.setIgnoreCertificateErrors ← v1.3.0 fix
          ▼
        language_server_macos_arm
          │ gRPC over TLS
          ▼
        googleapis.com (AI models)

🔧 How It Works

1. Antigravity is launched with --remote-debugging-port=9229 (start_antigravity.sh does this via open -a Antigravity --args ..., or run that command yourself)
2. bridge.py connects via CDP WebSocket to the Antigravity chat UI
3. Messages are injected into the Lexical editor via document.execCommand('insertText')
4. Responses are polled from the DOM until completion markers appear
5. SSL Fix: Antigravity's language_server uses a self-signed cert (CN=localhost). The bridge calls Security.setIgnoreCertificateErrors to allow the renderer's fetch() to communicate with it

⚠️ Known Issues & Solutions

"Messages send but no response" (most common)

Root cause: Electron's fetch() rejects the self-signed SSL cert used by language_server_macos_arm.

Fix (applied in v1.3.0): The bridge automatically calls Security.setIgnoreCertificateErrors({ignore: true}) before each chat.

"gRPC connection fails"

The language_server connects to daily-cloudcode-pa.googleapis.com via gRPC. If this endpoint is unreachable (e.g., blocked by firewall), models will show as placeholders and won't respond.

Fix: Ensure your network can reach googleapis.com.

Planning mode gets stuck

Some long prompts trigger Antigravity's "Planning" mode which can hang.

Fix: The bridge auto-switches to "Fast" mode. Keep prompts concise.

💻 CLI helper (ag)

scripts/ag_chat.sh prints a plain-text reply. Set it up as an alias:

alias ag="bash $(pwd)/scripts/ag_chat.sh"
ag "Your question" [model] [timeout]     # model defaults to opus, timeout to 180s

Model shorthands: opus, sonnet, gemini, gemini-low, flash, gpt (any other value is passed through as the full model name). It retries up to 3 times on high traffic.

To reach a bridge on another machine, set the full URL: AG_BRIDGE_HOST=http://<mac-ip>:19999 ag "hi".

🧑‍💻 IDE Agent mode (agy_invoke.sh)

bash scripts/agy_invoke.sh "Task description" [--model opus|gemini|sonnet|flash] triggers the Antigravity IDE agent over SSH + CDP. It needs SSH (Remote Login) access to the Mac, and Node.js with the ws package on the Mac. Configure with MAC_SSH_HOST, MAC_SSH_USER, MAC_SSH_PORT, AGY_NODE_PATH (env vars or ~/.remote-mac.conf); see the header of the script.

⚖️ When to use / When not to use

Use the bridge for personal experiments with a throwaway account. For anything else, use the official APIs.

❓ FAQ

Will my Google account get banned? / 会被封号吗？

There is a real risk — see the Risk Warning (CAUTION block) at the top of this README and Issue #1. Use a throwaway account, never your primary one, and add delays between requests.

Does it work on Windows / Linux? / 能在 Windows / Linux 上用吗？

The scripts target macOS only (open -a, osascript, language_server_macos_arm). Other platforms are untested.

Messages are sent but I never get a reply / 消息发出去但没有回复

See "Messages send but no response" under Known Issues (self-signed cert, fixed in v1.3.0) and make sure your network can reach googleapis.com.

Port 19999 is already in use / 端口 19999 被占用

start_antigravity.sh already starts a bridge in the background. Use Option A or Option B, not both.

Which models are available? / 有哪些模型可用？

Whatever Antigravity shows in its UI. The MODELS list in bridge.py is hard-coded and may be outdated; GET /models shows it.

Is it OpenAI API compatible? / 兼容 OpenAI API 吗？

No. It uses custom endpoints, see API Reference.

Can I call it from another machine? / 能从另一台机器调用吗？

Yes — the bridge listens on 0.0.0.0 (use AG_BRIDGE_HOST with ag). There is no authentication, so only do this on a trusted network.

Production or multi-user use? / 能用于生产或多用户吗？

No.

📁 Files

antigravity-bridge/
├── README.md
├── CHANGELOG.md
├── LICENSE
├── SKILL.md
├── llms.txt                  # Summary for LLMs
├── requirements.txt          # websockets>=10
├── tests/test_bridge.py      # Offline tests (no Antigravity needed)
└── scripts/
    ├── bridge.py             # REST API server
    ├── start_antigravity.sh  # Starts Antigravity with CDP and the bridge
    ├── ag_chat.sh            # `ag` CLI helper
    ├── agy_invoke.sh         # Trigger the IDE agent over SSH + CDP
    └── cdp_inject.js         # Node.js CDP injection script used by agy_invoke.sh

Run the tests: python3 -m unittest discover -s tests

📝 Requirements

• macOS with Antigravity installed
• Python 3.8+ with websockets package (requirements.txt)
• Network access to googleapis.com

License

MIT