Google Antigravity Setup

Omnodex traces Google Antigravity in the Desktop App, the agy CLI, and the standalone Antigravity IDE.

What gets installed

There are two independent parts. You can use either one, and the full setup uses both.

Part	What it does	How you install it
Hooks	Record session start and end, and every tool call the agent makes	omnodex install antigravity in each project
Omnodex MCP server	Routes the MCP servers you choose through the Omnodex proxy, records each call at the MCP protocol layer, and adds the omnodex_status, omnodex_connect, and omnodex_connection_status tools	An omnodex entry in Antigravity’s mcp_config.json

Only MCP servers listed in the Omnodex proxy configuration are recorded by the MCP server. Servers you leave in Antigravity’s own mcp_config.json keep working, but Omnodex sees their calls only through hooks.

Choose where Antigravity runs

The Antigravity surfaces read their MCP configuration from different files. A project’s .agents/ folder is shared by all of them.

File	Desktop App and IDE	agy CLI
MCP servers, all projects	~/.gemini/config/mcp_config.json	~/.gemini/antigravity-cli/mcp_config.json
MCP servers, one project	<project>/.agents/mcp_config.json	<project>/.agents/mcp_config.json
Hooks, one project	<project>/.agents/hooks.json	<project>/.agents/hooks.json
Hooks, all projects	~/.gemini/config/hooks.json	~/.gemini/config/hooks.json

On macOS and Linux every surface shares one home directory, so one setup covers all of them.

On Windows, the Desktop App is a native Windows program and uses C:\Users\<you>\.gemini\ and C:\Users\<you>\.omnodex\. The agy CLI inside WSL is a separate host with its own /home/<you>/.gemini/ and /home/<you>/.omnodex/. Set up each host you use, with that host’s path style, and never put C:\... paths in WSL configuration or /mnt/c/... paths in Windows configuration. Windows and WSL covers running both.

Before you start

On the host where Antigravity runs:

1. Install Omnodex from source, including the omnodex-config.json step for hooks.
2. Find the absolute path of Node.js. The Desktop App may not see the same PATH as your terminal, so the MCP server entry below uses an absolute path.

Windows (PowerShell)

where.exe node
where.exe npx

macOS / Linux / WSL

which node
which npx

3. Note the full path of the Omnodex proxy in your build: <repo>/packages/mcp-proxy/dist/bin/omnodex-mcp-proxy.js.

Register the Omnodex MCP server

The steps below use the Desktop App’s global file, ~/.gemini/config/mcp_config.json. For the agy CLI, make the same change in ~/.gemini/antigravity-cli/mcp_config.json. To limit Omnodex to one project, use <project>/.agents/mcp_config.json instead.

1. Create the proxy configuration.

   The proxy starts the MCP servers you want Omnodex to see and forwards every call to them. Create omnodex-proxy.json in your Omnodex home:

   Windows

   C:\Users\<you>\.omnodex\omnodex-proxy.json:

   {
     "version": 1,
     "redact_parameters": false,
     "upstream_servers": [
       {
         "name": "filesystem",
         "transport": "stdio",
         "command": "C:\\Program Files\\nodejs\\npx.cmd",
         "args": ["-y", "@modelcontextprotocol/server-filesystem", "C:\\Users\\<you>\\Documents\\project"]
       }
     ]
   }

   Use the npx.cmd path that where.exe npx printed. Backslashes are doubled in JSON.

   macOS / Linux / WSL

   ~/.omnodex/omnodex-proxy.json:

   {
     "version": 1,
     "redact_parameters": false,
     "upstream_servers": [
       {
         "name": "filesystem",
         "transport": "stdio",
         "command": "/usr/local/bin/npx",
         "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/<you>/project"]
       }
     ]
   }

   Use the npx path that which npx printed.

   The filesystem server is a good first upstream because its calls are easy to recognize. Replace it with the MCP servers you want Omnodex to see. Only stdio upstreams are supported. Put secrets in environment variables and reference them as ${VAR} in an upstream’s env, never as literal values. See Configuration.

   Check that the proxy starts before you point Antigravity at it. It waits for input; press Ctrl+C to stop it:

   node /path/to/omnodex/packages/mcp-proxy/dist/bin/omnodex-mcp-proxy.js --config ~/.omnodex/omnodex-proxy.json

2. Look at your current mcp_config.json.

   If the file does not exist yet, create it with an empty { "mcpServers": {} }. If you already use MCP servers in Antigravity, it looks something like this, with one entry per server under mcpServers:

   {
     "mcpServers": {
       "issue-tracker": {
         "serverUrl": "https://mcp.example.com/mcp"
       },
       "github": {
         "command": "npx",
         "args": ["-y", "@modelcontextprotocol/server-github"],
         "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "..." }
       }
     }
   }

   Remote servers use serverUrl. Local servers use command and args.

3. Add omnodex next to the existing entries.

   Add an omnodex key inside mcpServers. Keep every other entry as it is.

   Windows

   C:\Users\<you>\.gemini\config\mcp_config.json:

   {
     "mcpServers": {
       "issue-tracker": {
         "serverUrl": "https://mcp.example.com/mcp"
       },
       "github": {
         "command": "npx",
         "args": ["-y", "@modelcontextprotocol/server-github"],
         "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "..." }
       },
       "omnodex": {
         "command": "C:\\Program Files\\nodejs\\node.exe",
         "args": [
           "C:\\path\\to\\omnodex\\packages\\mcp-proxy\\dist\\bin\\omnodex-mcp-proxy.js",
           "--config",
           "C:\\Users\\<you>\\.omnodex\\omnodex-proxy.json"
         ]
       }
     }
   }

   macOS / Linux / WSL

   ~/.gemini/config/mcp_config.json (or ~/.gemini/antigravity-cli/mcp_config.json for agy):

   {
     "mcpServers": {
       "issue-tracker": {
         "serverUrl": "https://mcp.example.com/mcp"
       },
       "github": {
         "command": "npx",
         "args": ["-y", "@modelcontextprotocol/server-github"],
         "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "..." }
       },
       "omnodex": {
         "command": "/usr/local/bin/node",
         "args": [
           "/Users/<you>/src/omnodex/packages/mcp-proxy/dist/bin/omnodex-mcp-proxy.js",
           "--config",
           "/Users/<you>/.omnodex/omnodex-proxy.json"
         ]
       }
     }
   }

   JSON does not expand ~, so write the full home path.

   Field	Value
   command	The absolute Node.js path from Before you start
   args[0]	The absolute path to omnodex-mcp-proxy.js in your build
   args[1], args[2]	--config and the absolute path to your omnodex-proxy.json

   Always pass --config. Antigravity does not set OMNODEX_HOME when it starts the server.

   To have Omnodex record one of the servers you already had, such as github above, move it: add it to upstream_servers in omnodex-proxy.json (with "transport": "stdio" and absolute paths), then delete its entry from mcp_config.json. If a server is in both files, the agent gets two copies of its tools, and only the copy named github__<tool> is recorded by the proxy.

4. (Windows Desktop App) Create the tool cache folder.

   The Desktop App caches each MCP server’s tool list under ~/.gemini/antigravity/mcp/<server>/. If that folder is missing, the tools can stay disabled in settings:

   New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.gemini\antigravity\mcp\omnodex"

5. Restart Antigravity and approve the server.

   Fully quit and reopen the Desktop App, or start a new agy session. Antigravity asks you to approve a new MCP server the first time it connects.

6. Verify.

   • Desktop App: open Settings > MCP Servers, confirm omnodex is connected, and enable its tools.
   • agy: enter /mcp and confirm omnodex is listed without errors.

   Ask the agent to call omnodex_status. It returns the proxy version and your upstream servers. Then ask it to use a routed tool. Routed tools appear as <server>__<tool>, for example filesystem__list_allowed_directories.

Alternative: omnodex install antigravity --mcp

omnodex install antigravity --mcp writes the omnodex entry to <project>/.agents/mcp_config.json for you, merging with any servers already there. The entry it writes runs the launcher from the Omnodex Antigravity plugin, so it has two extra requirements:

• The plugin must be unpacked first, in ~/.gemini/config/plugins/omnodex-antigravity/ (Desktop App) or installed with agy plugin install <unzipped folder> (CLI). The command stops with a warning if it cannot find the plugin.
• omnodex-proxy.json must include proxy_bin, the absolute path to omnodex-mcp-proxy.js, so the launcher can find your build.

If you do not need the plugin for anything else, the manual entry above has fewer moving parts.

Install the hooks

1. Install into the project.

   From the project directory, in the shell of the host where Antigravity runs:

   macOS / Linux / WSL

   omnodex install antigravity

   Windows (PowerShell)

   Run from PowerShell, not WSL, so the hook commands use Windows paths:

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

   This writes an omnodex entry to <project>/.agents/hooks.json for five events:

   • PreInvocation and PostInvocation: session start and end
   • PreToolUse and PostToolUse: every tool call, with timing and status
   • Stop: the agent loop ending

   The hooks observe only. They never block a tool call.

   When it finishes, the command offers to connect this host to the hosted dashboard. Press Ctrl+C to skip; the hooks are already installed.

2. Verify.

   omnodex status

   Then start a session in the project and have the agent run a command. A session file for it appears under event-log/sessions/ in your Omnodex home.

Windows: one project, one host

The hook commands in .agents/hooks.json contain the paths of the host that installed them. Hooks installed from WSL cannot run in the Windows Desktop App, and hooks installed from PowerShell cannot run in agy inside WSL. To use both on one project, reinstall from the host you are about to use, or keep a separate copy of the project for each.

Antigravity IDE

The IDE reads the same .agents/hooks.json, so no extra setup is needed. If hooks do not fire in the IDE, confirm the same project works in the CLI or Desktop App first.

Trust and approval

Hooks in .agents/hooks.json and ~/.gemini/config/hooks.json load automatically. There is no separate approval step.

Antigravity asks you to approve each MCP server on its first connection and remembers the answer.

The CLI’s --sandbox flag changes which tools the agent can use. It does not affect hooks.

What gets traced

Activity	Recorded by	Notes
Session start and end	Hooks	session.started and session.ended
Built-in tool calls (shell, file reads and edits)	Hooks	tool.invoked and tool.completed with timing and status
MCP tool calls routed through Omnodex	Omnodex MCP server and hooks	The proxy records parameters (unless redacted), timing, status, and response size
MCP servers left in mcp_config.json	Hooks only	The proxy does not see them

Hooks and the MCP server record different layers, so a routed call can appear once from each. Use redact_parameters in omnodex-proxy.json to keep parameter values out of the proxy’s records.

Connect to the hosted dashboard

On each host, run:

omnodex connect

This starts a device code flow: the CLI shows a short code and a URL. Open the URL, sign in or create an account, and enter the code. The API token and sync passphrase are stored in stream-config.json in that host’s Omnodex home.

If you already have an API token from the dashboard:

omnodex connect --token omx_your_token_here

With the Omnodex MCP server connected, you can also ask the agent to call omnodex_connect, which runs the same flow without the CLI.

If a stream is disconnected or revoked in the dashboard, run omnodex connect again. Your earlier history stays under the original stream.

View results

omnodex dashboard

Antigravity events carry interceptor: "antigravity-hook" (hooks) or interceptor: "mcp-proxy" (MCP server), so you can tell the sources apart.

Troubleshooting

omnodex is missing or shows an error in MCP settings or /mcp:

• Run the command and args from the entry yourself, in the host’s shell. The proxy should start and wait for input. If it exits, fix omnodex-proxy.json: the proxy starts even when an upstream is down, but a config file it cannot parse is still an error.
• Check that the JSON is valid and that omnodex sits inside mcpServers, next to your other servers, not beside mcpServers.
• Check that every path is absolute, uses the host’s path style, and uses doubled backslashes on Windows.
• Confirm you edited the file for the surface you are using: ~/.gemini/config/ for the Desktop App, ~/.gemini/antigravity-cli/ for agy.
• Fully restart Antigravity after changing MCP servers.

omnodex connects but its tools are greyed out (Windows Desktop App): create the tool cache folder from step 4 and restart.

Hooks not firing:

• Run omnodex status in the project and confirm .agents/hooks.json has an omnodex entry.
• On Windows, confirm the hooks were installed from the same host (PowerShell or WSL) that runs Antigravity.
• Check launcher.log in your Omnodex home. Could not locate antigravity hook shim means omnodex-config.json is missing or has the wrong antigravity path.

Events not appearing in the dashboard:

• On Windows with both hosts in use, events are split between C:\Users\<you>\.omnodex and /home/<you>/.omnodex. See Windows and WSL to view both.
• Run omnodex replay to rebuild the read model.

Next steps

• MCP Proxy for Any Client - How the proxy works with other clients
• Running Detection - Risk detection works the same across all interceptors
• Events and Traces - The event model