Google Antigravity Setup

Omnodex supports tracing Google Antigravity sessions via hooks and MCP proxy interception. All Antigravity surfaces share a single agent harness, so hooks registered once apply to the CLI, Desktop App, and IDE extensions.

How the Integration Works

Antigravity supports project-level hooks in `.agents/hooks.json`. Omnodex registers hooks for three events:

• PreToolUse - captures every tool invocation with parameters
• PostToolUse - captures tool completion, duration, and errors
• Stop - captures session end

For MCP tool calls, Omnodex also provides an MCP proxy that sits between Antigravity and your upstream MCP servers, giving full visibility into MCP traffic.

Hooks fire synchronously but are designed to be fast (under 50ms typical). They observe only and never block tool execution.

Installation

CLI (agy)

1. Install hooks into your project:

   Run this once per project you want to trace, from the project root:

   npx omnodex install antigravity

   This creates an `.agents/hooks.json` file that routes Antigravity events through Omnodex.

2. Verify the configuration:

   npx omnodex status

3. (Optional) Add MCP proxy for MCP tool visibility:

   To also trace MCP tool calls, install the MCP proxy plugin and configure it:

   # Install the plugin (unzip first - agy expects a directory)
   mkdir -p /tmp/omnodex-antigravity
   unzip -o omnodex-antigravity.plugin -d /tmp/omnodex-antigravity
   agy plugin install /tmp/omnodex-antigravity
   
   # Configure the MCP proxy with absolute paths
   npx omnodex install antigravity --mcp

   Verify inside an agy session:

   /mcp

   `omnodex` should appear in the MCP server list.

4. Run Antigravity normally. Traced events appear in the Omnodex dashboard alongside events from other platforms.

Desktop App

The Desktop App shares the same agent harness as the CLI. Hooks registered in `.agents/hooks.json` apply automatically.

1. Install hooks into your project:

   macOS / Linux

   npx omnodex install antigravity /path/to/your/project

   Windows (PowerShell)

   Run from PowerShell (not WSL) so the hook commands use Windows-native paths:

   node path\to\omnodex\packages\cli\dist\index.js install antigravity "C:\path\to\your\project"

2. Verify:

   npx omnodex status /path/to/your/project

3. (Optional) Configure the MCP proxy:

   Add the Omnodex MCP proxy to your project’s `.agents/mcp_config.json`. The proxy sits between Antigravity and your upstream MCP servers.

4. Open the project in Antigravity Desktop. Events flow to the same Omnodex event log as CLI sessions.

Windows: Install from the correct shell

On Windows, the Desktop App runs as a native Windows process and executes hooks via `cmd.exe`. Hooks installed from WSL contain Linux paths that the Desktop App cannot execute. Always install hooks from PowerShell when targeting the Desktop App.

Hooks installed from WSL work correctly with `agy` running inside WSL.

IDE Extensions

Antigravity IDE extensions (VS Code, JetBrains) use the same shared agent harness. Hooks installed in `.agents/hooks.json` apply automatically when you open the project in your IDE.

No additional setup is needed beyond the CLI or Desktop installation above.

What Gets Traced

Event Type	Source	Description
`tool.invoked`	Hooks	A tool was called (name, parameters)
`tool.completed`	Hooks	A tool finished (duration, status, errors)
`session.ended`	Hooks	The execution loop terminated
MCP tool calls	MCP Proxy	Full request/response for proxied MCP tools

Note

Antigravity does not have a `SessionStart` hook event. The session is auto-created when the first tool call arrives. This is handled transparently by the Omnodex projector.

Viewing Results

# Open the live dashboard
npx omnodex dashboard

# Or run detection on collected events
npx omnodex detect

Antigravity events are tagged with `interceptor: “antigravity-hook”` and appear with an orange badge in the dashboard. Hook events and MCP proxy events from the same project appear together.

Troubleshooting

Hooks not firing:

• Verify `.agents/hooks.json` exists in the project with an `“omnodex”` key
• On Windows Desktop: ensure hooks were installed from PowerShell, not WSL
• Check that Node.js is accessible at the path embedded in the hook command

Plugin MCP server not appearing:

• Verify the plugin was installed from an unzipped directory, not the `.plugin` zip directly
• Run `agy plugin list` to confirm `omnodex-antigravity` is installed
• Check `/mcp` inside an agy session

Events not appearing in dashboard:

• Ensure the dashboard roots include the `OMNODEX_HOME` where events are being written
• Run `npx omnodex replay` to rebuild the read model

Next Steps

• Running Detection - Risk detection works the same across all interceptors
• Using the Dashboard - Navigate the real-time dashboard
• Events and Traces - Understand the event model