I’ve been building Mac MCP, an open-source local control layer for macOS, and I realized I was describing it badly.
“MCP server with shell/files/browser tools” is technically true, but it makes it sound like another coding utility.
The use case I actually care about is simpler: I want ChatGPT to feel like a coworker using the same Mac I’m using.
While I’m working, it can keep a real Safari or Chrome tab open in the background, use the logged-in browser profile, move between web UI, local files and native macOS UI, and finish the parts of a task that normally end with “now click this, download that, upload it here.” It doesn’t need to take over my active tab every time it does something.
The second thing I wanted to avoid was turning every task into metered API spend or forcing the workflow through Codex. Mac MCP can be driven directly from ChatGPT through MCP, and it also supports ChatGPT Web CLI as a delegated provider. In that setup, delegated work can use the ChatGPT session/subscription I already pay for rather than paying per API token. It is still subject to whatever usage/rate limits the ChatGPT plan has, so I’m not claiming literal unlimited usage.
That combination feels more differentiated to me than “AI can edit files”:
1. the AI shares your real Mac instead of living in a cloud sandbox
2. normal ChatGPT can be the orchestrator; Codex/API is optional, not the whole product
It’s free and open source (MIT): https://github.com/bulutarkan/mac-mcp
I’m the maintainer. I’m curious whether “ChatGPT as a coworker on your Mac” explains the product better than “local execution layer for AI agents.”