ZeroGravity

OpenAI-compatible proxy that intercepts and relays requests to Google's Antigravity language server, impersonating the real Electron webview.

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graph LR
    Client["Client"] -->|"OpenAI / Gemini API"| Proxy["Proxy :8741"]
    Proxy -->|"gRPC (dummy prompt)"| LS["Standalone LS"]
    LS -->|"HTTPS :443"| MITM["MITM :8742"]
    MITM -->|"Modified request<br/>(real prompt + tools)"| Google["Google API"]
    Google -->|"SSE response"| MITM
    MITM -->|"Usage, errors,<br/>function calls"| Proxy
    LS -.->|"iptables redirect<br/>(UID-scoped)"| MITM

    style Proxy fill:#4a4a4a,color:#e0e0e0,stroke:#888
    style MITM fill:#3a3a3a,color:#e0e0e0,stroke:#888
    style LS fill:#505050,color:#e0e0e0,stroke:#888
    style Google fill:#444,color:#e0e0e0,stroke:#888

Models

Name	Label	Notes
opus-4.6	Claude Opus 4.6 (Thinking)	Default model
opus-4.5	Claude Opus 4.5 (Thinking)	—
gemini-3-pro-high	Gemini 3 Pro (High)	—
gemini-3-pro	Gemini 3 Pro (Low)	—
gemini-3-flash	Gemini 3 Flash	Recommended for dev

Quick Start

# Headless mode (no running Antigravity app needed)
RUST_LOG=info ./target/release/zerogravity --headless

# Or use the daemon manager
zg start

Setup

Linux

# Prerequisites: Rust toolchain, iptables
./scripts/setup-linux.sh

Creates a zerogravity-ls system user for UID-scoped iptables isolation, installs a systemd user service, and builds the release binary.

# Start the service
systemctl --user enable --now zerogravity

# Or use the daemon manager
zg start

macOS

# Prerequisites: Rust toolchain
./scripts/setup-macos.sh

Installs a launchd plist for automatic startup. No UID isolation — runs in headless/HTTPS_PROXY mode only.

# Start the service
launchctl load ~/Library/LaunchAgents/com.zerogravity.proxy.plist

# Or use the daemon manager
zg start

Windows

# Prerequisites: Rust toolchain
# Run as Administrator
powershell -ExecutionPolicy Bypass -File scripts\setup-windows.ps1

Creates config directories, builds the release binary, and installs a scheduled task for automatic startup at logon.

# Start now
schtasks /run /tn "ZeroGravity Proxy"

# Or manually
.\target\release\zerogravity.exe

Endpoints

Method	Path	Description
POST	/v1/responses	Responses API (sync + streaming)
POST	/v1/chat/completions	Chat Completions API (OpenAI compat)
POST	/v1beta/models/{model}:{action}	Official Gemini v1beta routes
GET/POST	/v1/search	Web Search via Google grounding ⚠️ WIP
GET	/v1/models	List available models
GET	/v1/sessions	List active sessions
DELETE	/v1/sessions/{id}	Delete a session
POST	/v1/token	Set OAuth token at runtime
GET	/v1/usage	MITM-intercepted token usage
GET	/v1/quota	LS quota and rate limits
GET	/health	Health check

Authentication

The proxy needs an OAuth token:

1. Env var: ZEROGRAVITY_TOKEN=ya29.xxx
2. Token file: ~/.config/zerogravity-token
3. Runtime: curl -X POST http://localhost:8741/v1/token -d '{"token":"ya29.xxx"}'

zg Commands

Command	Description
zg start	Start the proxy daemon
zg stop	Stop the proxy daemon
zg restart	Rebuild + restart
zg rebuild	Build release binary only
zg status	Service status + quota + usage
zg logs [N]	Tail last N lines + follow
zg test [msg]	Quick test request
zg health	Health check

Documentation

Doc	Contents
architecture.md	System overview, module map, request lifecycle (mermaid)
mitm.md	MITM proxy internals, event flow, request modification
traces.md	Per-call debug trace system
extension-server-analysis.md	Extension server protocol reverse engineering
ls-binary-analysis.md	LS binary reverse engineering — model catalog, gRPC services, protos

License

Private. Do not distribute.