Codex App Setup

How to use Roblox MCP with OpenAI Codex App (macOS).

Released February 2, 2026 — A native macOS app supporting multi-agent workflows

Prerequisites

• Codex App installed (macOS)
• Roblox Studio plugin installation complete

Registering the MCP Server

Automatic Sync with Codex CLI Settings

If you have already configured MCP in Codex CLI, you can use it in the app without any additional setup.

CLI session history and settings are automatically synced to the app.

Setting Up for the First Time

Add via Settings → MCP Servers inside the app:

Server name: weppy-roblox-mcp
Command: npx -y @weppy/roblox-mcp

Connection Test

1. Launch Roblox Studio → Plugins tab → WEPPY → Connect
2. Start a new conversation in Codex App and test:

   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