Computer Use

Some tasks need eyes. An agent that just built a Mac app cannot verify it from a terminal; it needs to look at the window and click things.

Computer Use gives a session screenshots of the host’s screen and the ability to click, type and scroll on it — through a signed helper called the Offsite Agent Bridge.

Available on macOS hosts only.

Off by default, twice

This is the widest access Offsite can hand an agent, so it is gated twice:

1. The feature is off until you enable it, which requires granting macOS Screen Recording and Accessibility to the Agent Bridge.
2. Every session starts locked by default, even with the feature enabled. You unlock one specific session when you want it to have the screen. The host setting New sessions start unlocked changes that default; it applies to the next session you start.

The card’s pill switches a session at once and shows its live state — you can always see which sessions can touch your screen.

Two independent gates: enabling the feature on a host, and unlocking a single session.

The two macOS grants

Grant	Why
Screen Recording	to take screenshots
Accessibility	to move the pointer, click and type

macOS attributes both to Offsite Agent Bridge, the signed helper that holds them, so the dialog names something you can recognise and check.

Offsite asks for these while you are setting computer use up, not in the middle of a session, so the prompt never arrives on a screen nobody is watching.

Automation prompts

The first time an agent scripts a specific application, macOS asks once per target app: “Offsite Agent Bridge wants to control …”. The grant covers that app and nothing else.

Revoking

System Settings › Privacy & Security › Screen Recording / Accessibility, and remove the Agent Bridge. Nothing else in Offsite depends on those grants.

Details

• The Bridge is a separately signed helper with its own identity; the host pins that identity and refuses to talk to a binary whose signature changed unexpectedly.
• Communication is token-authenticated over a local channel; the token lives in ~/.offsite/agent-bridge/.
• The tool surface is the standard computer-use set plus a zoom tool — screenshot, click, type, key, scroll, drag, cursor position and friends.
• Computer use runs on macOS hosts, through the signed Agent Bridge.
• Capture needs a screen the Mac is actually driving: a display attached, or the built-in one open.
• The lock is per session: if a call reports that computer use is locked, unlock that session from its card.