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The Asymmetric Trust Problem - When Your AI Agent Has More Access Than You Intended

Fazm Team··3 min read
trustpermissionsaccessibility-apisecurityai-agent

Permission Granted Does Not Equal Permission Intended

When you enable accessibility permissions for an AI agent on macOS, you are granting access to an API designed for screen readers. Screen readers need to see everything - every button label, every text field value, every menu item, every piece of content on screen. That is the whole point.

The problem is that "everything" really means everything. Your password manager showing a credential in a text field. Your banking app displaying account balances. Your email client with the full body of every message. The accessibility API exposes all of it as structured, machine-readable data.

The Trust Asymmetry

When a user grants accessibility permissions, their mental model is usually "this app can control my mouse and keyboard." The reality is much broader. The app can read every piece of text displayed anywhere on the system, understand the structure of every application's UI, and interact with elements the user may not even be aware of.

This is asymmetric trust - the permission you think you granted is a small subset of what you actually granted. The constraints on what the agent does with this access are behavioral, not technical. The system prompt might say "only interact with Finder." But technically, the agent can read your email at the same time.

Why This Is Hard to Fix

You cannot easily scope accessibility permissions to specific apps. macOS grants it system-wide or not at all. This was fine when the only consumers were assistive technologies operated by humans who could see what the screen reader was accessing. It is less fine when the consumer is an autonomous agent making decisions about what to read and interact with.

What You Can Do

  • Minimize what is on screen during agent sessions. Close sensitive apps you are not actively using.
  • Use dedicated user accounts for agent workflows that do not need access to your full environment.
  • Audit agent logs to see what the agent actually read, not just what it acted on.
  • Prefer agents that log their accessibility tree reads so you can verify they are not reading unrelated apps.

The honest answer is that this is an unsolved problem. The accessibility API was not designed for this use case, and the permission model has not caught up.

Fazm is an open source macOS AI agent. Open source on GitHub.

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