Set Up with OpenAI Codex

OpenAI Codex is OpenAI’s coding agent. It supports MCP servers through its configuration UI, letting Codex control ButterKit programmatically, enabling things like:

• Localize screenshots in one command. Add languages, translate every artboard and App Store metadata field, then export, all in seconds.
• Design and iterate from a prompt. Describe the layout you want, swap copy, adjust 3D devices, and preview renders without switching windows.
• Upload straight to App Store Connect. Push finished screenshots and metadata to your store listing as soon as they’re ready.
• Wire it into your build process. Pair Codex + Fastlane with ButterKit to capture new Simulator screenshots, design around them, translate, and publish in a single session.

2 minute video tutorial

Prerequisites

• ButterKit running with MCP enabled (Settings > MCP)
• OpenAI Codex installed

Configuration

Open the MCP config

In the Codex MCP configuration UI, add a new server with the following details:

Enter connection details

Field	Value
Name	butterkit
Transport	STDIO
Command to launch	/Applications/ButterKit.app/Contents/MacOS/butterkit-mcp
Arguments	(none, or --auto-launch to start ButterKit automatically)

See Auto-Launch for more on this option.

Verify the connection

Start a new Codex session. ButterKit’s 40 tools should be available. Confirm by asking Codex to list your open documents.

Start using it

Ask Codex to work with your ButterKit project. For example:

• “Show me all artboards in my ButterKit document”
• “Set the background to a blue gradient on the first artboard”
• “Export all artboards as @2x PNGs”

Tips

• Codex runs tasks in sandboxed environments, so make sure ButterKit is running on your machine before starting a session.
• For step-by-step recipes, see Workflows.