AG (Antigravity) Local Bridge

Exposes your running Antigravity instance as a local OpenAI-compatible API on localhost:11435.

Use your Antigravity subscription with any tool that speaks OpenAI — opencode, aider, continue.dev, or plain curl.

How it Works

Your tool → HTTP :11435 → VS Code extension → Antigravity sidecar (ConnectRPC) → Cloud AI

The extension runs inside Antigravity's VS Code process, discovers the sidecar via process inspection, intercepts CSRF tokens from Antigravity's own traffic, and proxies your requests through the same authenticated channel Antigravity uses internally.

Available Models

Model ID	Description
`antigravity-claude-sonnet-4-6`	Claude Sonnet 4.6 with Thinking (default)
`antigravity-claude-opus-4-6-thinking`	Claude Opus 4.6 with Thinking
`antigravity-gemini-3-flash`	Gemini 3 Flash
`antigravity-gemini-3.1-pro-high`	Gemini 3.1 Pro — High thinking
`antigravity-gemini-3.1-pro-low`	Gemini 3.1 Pro — Low thinking
`antigravity-gpt-oss-120b`	GPT-OSS 120B Medium

Installation

Locate your Antigravity extensions directory:
- Windows: %USERPROFILE%\.antigravity\extensions\
- macOS: ~/.antigravity/extensions/
- Linux: ~/.antigravity/extensions/

Copy this project into a folder there:

# Example (Windows)
git clone https://github.com/marcodiniz/ag-local-bridge "%USERPROFILE%\.antigravity\extensions\ag-local-bridge-1.0.0-universal"

Reload Antigravity (Ctrl+Shift+P → Developer: Reload Window)
Look for "AG Local Bridge" in the Output panel — you should see:
```
✅ Server running on http://localhost:11435
```

Usage

With opencode

Add to ~/.config/opencode/opencode.json:

{
  "provider": {
    "ag-local-bridge": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "AG Local Bridge",
      "options": {
        "baseURL": "http://localhost:11435/v1",
        "apiKey": "local"
      },
      "models": {
        "antigravity-claude-sonnet-4-6": {
          "name": "Claude Sonnet 4.6 (Antigravity)",
          "limit": { "context": 200000, "output": 64000 }
        },
        "antigravity-gemini-3.1-pro-high": {
          "name": "Gemini 3.1 Pro High (Antigravity)",
          "limit": { "context": 1048576, "output": 65535 }
        },
        "antigravity-gemini-3-flash": {
          "name": "Gemini 3 Flash (Antigravity)",
          "limit": { "context": 1048576, "output": 65536 }
        }
      }
    }
  }
}

Then select ag-bridge/antigravity-claude-sonnet-4-6 as your model.

With curl

# List models
curl http://localhost:11435/v1/models

# Chat completion
curl http://localhost:11435/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "antigravity-claude-sonnet-4-6",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": false
  }'

# Streaming
curl http://localhost:11435/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "antigravity-gemini-3.1-pro-high",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'

With any OpenAI-compatible client

Base URL: http://localhost:11435/v1
API Key:  anything (not validated)

API Endpoints

Method	Path	Description
`GET`	`/v1/models`	List available models
`POST`	`/v1/chat/completions`	Chat completion (streaming & non-streaming)
`GET`	`/v1/debug`	Debug info (sidecar ports, CSRF, captures)

Architecture

The extension uses a 2-tier fallback strategy:

Tier 1 — Sidecar ConnectRPC (preferred): Discovers the Antigravity sidecar process, connects via HTTP/2 with CSRF authentication, and uses the Cascade API (StartCascade → SendUserCascadeMessage → poll GetCascadeTrajectory). Conversations are multiplexed and the active workspace is auto-detected.
Tier 2 — Command Dispatch: Last resort — fires the message through antigravity.executeCascadeAction.

Commands

Command	Description
`AG Local Bridge: Start Server`	Start the HTTP server
`AG Local Bridge: Stop Server`	Stop the HTTP server
`AG Local Bridge: Show Status`	Display connection status
`AG Local Bridge: Probe Sidecar`	Test sidecar connectivity
`AG Local Bridge: List Available LM Models`	List configured models and sidecar status
`AG Local Bridge: List Available Chat Commands (Debug)`	List chat commands available for debugging

Configuration

Setting	Default	Description
`agLocalBridge.port`	`11435`	HTTP server port
`agLocalBridge.logRequests`	`false`	Log request/response details

Requirements

Antigravity installed and running
Active Antigravity subscription (Free/Pro/Teams/Enterprise)

License

MIT

AG Local Bridge

MarcoDiniz