How to use Roblox MCP with Google Antigravity.

Antigravity is Google’s agent-based development platform where AI agents autonomously perform complex tasks spanning code editing, the terminal, and the browser.

Prerequisites

Antigravity installed (see the official docs for supported OS and requirements)
Node.js (v18.0.0 or higher, with npx available)
Roblox Studio plugin installation complete

Registering the MCP Server

In Antigravity, MCP servers are managed from the Agent pane.

Manual Registration via Raw Config (Recommended)

In the Agent pane, click ⋯ → MCP Servers → Manage MCP Servers → View raw config

Opening the MCP Servers menu

Add/merge the following into the displayed JSON config:

{
  "mcpServers": {
    "weppy-roblox-mcp": {
      "command": "npx",
      "args": ["-y", "@weppy/roblox-mcp"]
    }
  }
}

Editing raw config

Save and Refresh (or restart/reload as indicated by the UI)

The actual path and filename of the config file may vary by OS and Antigravity version — always modify the location shown in View raw config.

Optional: Adjust Port/Log via Environment Variables

Keeping the default (HTTP 127.0.0.1:3002) is recommended. If needed, you can set environment variables like this:

{
  "mcpServers": {
    "weppy-roblox-mcp": {
      "command": "npx",
      "args": ["-y", "@weppy/roblox-mcp"],
      "env": {
        "HTTP_HOST": "127.0.0.1",
        "HTTP_PORT": "3002",
        "LOG_LEVEL": "INFO"
      }
    }
  }
}

Connection Test

Launch Roblox Studio → Plugins tab → WEPPY → Connect

Enter the following in Antigravity:

Tell me what is currently selected in Roblox Studio

Troubleshooting

Server Won’t Start

Run the MCP server directly to see the error:

npx -y @weppy/roblox-mcp

Connection Fails

Confirm the Roblox Studio plugin shows Connected status
Check that port 3002 is not blocked by a firewall
Check server status via ⋯ → MCP Servers in the Agent pane
(Advanced) If you changed HTTP_PORT, make sure the Roblox Studio plugin and bridge settings also use the same port.

Antigravity Setup