Cua Local

Use ChatGPT with MCP to control your local Mac, similar to Computer Use.

cua-local is a small local bridge that lets ChatGPT, or another MCP-compatible AI client, observe and operate your own Mac in a controlled loop:

observe -> act -> observe

It can expose basic tools for reading app/screen state, moving the mouse, clicking, typing, scrolling, dragging, pressing keys, and opening URLs. Everything runs locally on macOS, while the AI assistant connects through MCP.

How it works

cua-local uses native macOS capabilities:

• AppleScript / Apple Events for app control
• System Events for keyboard input
• screencapture for screen observation
• Swift + CGEvent for mouse movement, clicks, scroll, and drag

In other words: it gives ChatGPT a local Computer Use-like control layer for your Mac through MCP. It is inspired by the Computer Use idea, but it is not an official Computer Use client and not a full desktop automation product.

Quick start

Requirements:

macOS
Node.js >= 20
Xcode Command Line Tools

Run:

npm run doctor
npm run check
npm run smoke
npm run demo

npm run doctor prints a ready-to-copy MCP config for the current checkout.

Does it require DevSpace?

No. cua-local itself is just a local MCP server and can run on its own.

DevSpace is only one possible bridge when you want to call this local MCP server from ChatGPT. If your AI client can launch local MCP servers directly, you do not need DevSpace. If the client runs in the cloud and cannot directly reach your Mac, you need some bridge such as DevSpace, a tunnel, or another remote MCP connection layer.

Typical setups:

Local MCP client -> cua-local -> your Mac
ChatGPT -> DevSpace/tunnel/bridge -> cua-local -> your Mac

MCP config

Use absolute paths on the target machine:

{
  "mcpServers": {
    "computer-use-local": {
      "command": "node",
      "args": ["/ABSOLUTE/PATH/TO/cua-local/cua-local.mjs"],
      "cwd": "/ABSOLUTE/PATH/TO/cua-local"
    }
  }
}

Scripts

npm run start      # start MCP server over stdio
npm run doctor     # check dependencies and macOS permissions
npm run check      # syntax-check project scripts
npm run smoke      # lightweight core validation
npm run demo       # safe observe -> move pointer -> observe sample

Tools

• list_apps
• get_app_state
• get_screen_state
• health_check
• open_url
• type_text
• press_key
• move_mouse
• click
• scroll
• drag
• set_value

Safety

This tool can operate the local computer. Only connect it to MCP hosts you trust.

click blocks common high-risk labels such as Buy, Purchase, Pay, Delete, Remove, Send, Submit, Publish, Share, Update, and Install unless confirm_risk_action=true is explicitly provided.

Do not expose this server to the public internet.

Local files not to commit

cua-local.mcp.json
.env
traces/
/tmp/cua-local-*
~/.cua-local/

Limitations

• Native app support is partial and app-specific.
• Chrome webpage DOM exposure is limited by macOS Accessibility.
• Multi-display screenshot stitching still needs hardening.
• Trace writing is opt-in via CUA_LOCAL_TRACE=1 or CUA_LOCAL_TRACE_DIR=....

License

MIT. See LICENSE.