How Do I Make AI Use My Computer Safely?
How Do I Make AI Use My Computer Safely?
The question everyone asks when they first see a desktop AI agent - "how do I make sure it does not delete my files or send emails I did not approve?" The answer is MCP servers combined with the macOS accessibility API.
MCP Servers as the Control Layer
Model Context Protocol servers act as a controlled interface between the AI and your system. Instead of giving an AI raw shell access, you expose specific capabilities through MCP tools. Each tool does one thing - click a button, read a window's contents, type text into a field.
The key insight is that the AI never has direct system access. Every action goes through an MCP server that you control. You decide which tools exist, what permissions they have, and what approval flows they require.
The macOS Accessibility API
Apple built the accessibility API so assistive technologies could interact with apps on behalf of users. It turns out this is exactly what desktop AI agents need - a structured way to read screen contents and perform actions without brittle screenshot parsing.
The accessibility API gives you the UI tree of every running app. Buttons, text fields, menus, labels - all as structured data. The agent knows what it is clicking because it can read the element's role and label, not just its pixel coordinates.
Safety Boundaries That Work
Three layers make this safe in practice. First, read-only tools that auto-approve - letting the agent see what is on screen costs nothing. Second, write actions that require confirmation - clicking buttons, typing text, sending messages. Third, blocked actions - no file deletion, no system preferences changes, no password manager access.
The MCP server enforces these boundaries. The AI model cannot bypass them because it only sees the tools you expose.
Getting Started
Enable accessibility permissions in System Settings for your agent app. Set up MCP tools with clear permission tiers. Start with read-only automation and expand as you build trust.
Fazm is an open source macOS AI agent. Open source on GitHub.