How AI Agents Can Mark Up Your Screen—and What It Enables

A small Mac tool lets an AI agent point to a screen location without clicking, typing, or capturing the screen.

Tech & Online SafetyOctober 11, 20263 min readHow Sureno writes this

The short version

AI agents can mark a screen by displaying an arrow and sign in a transparent window above other windows; the featured tool is for macOS. ¹
The overlay is designed to let clicks pass through to the app underneath, keep keyboard focus there, and remove itself. ¹
Bigarrow points only: it does not click, type, or take screenshots. ¹
This can help an agent direct a person to a step that needs their attention, but it does not complete that step for them. ¹

How can an AI agent draw on your screen?

A computer agent can use a small utility to place a visual marker over the apps already open on a computer. In this case, the marker is an arrow and a sign in a transparent window. It appears above other windows and is intended to point out a location, such as a button the user needs to find. ¹

The project described here, big-arrow-on-the-screen, is a macOS command-line tool and also offers a skill for Claude Code and Codex. A command-line tool is software controlled by text commands rather than a regular window of buttons and menus. The project says it is available under the MIT license, which permits reuse under that license's terms. ¹

What can the screen arrow help with?

An agent may reach a point where a person needs to make a choice or take an action. Instead of only telling the user where to look in a terminal or message, the agent can point to the relevant spot on the screen. That may make a handoff easier to follow, or help someone learn where a control is. ¹

The project presents this as a way for an agent to guide a person, not as a way to automate the person's choice. The arrow can draw attention to a target, but the user still decides what to do. ¹

Does the arrow click or control your computer?

No. The project says the tool only points: it does not click, type, or capture the screen. It also says clicks pass through the overlay to the application below, keyboard focus remains with that application, and the arrow removes itself. ¹

Those limits matter. A visual marker is different from a tool that acts on a user's behalf or reads screen contents. The description does not establish that all AI agents or screen overlays behave this way, so these claims apply to this particular project. ¹

What does it need, and what does it run on?

The project describes bigarrow as one Swift binary for macOS, with no background service, menu-bar icon, account, or telemetry. It says drawing does not require macOS permission. It also says the overlay can appear across displays and Spaces, the separate work areas on a Mac. ¹

These are statements about the tool as described by its project page, not an independent security audit. The supplied information does not give test results across different Mac models or operating-system versions, and it does not establish that the tool is available for Windows or Linux. ¹

What should users keep in mind?

A pointer can show where to look, but it cannot tell a user whether a requested action is safe or appropriate. Before acting, the person still needs to understand what the app is asking and what the action will do. This is especially important when the agent is asking them to approve a change or proceed with an operation.

More broadly, generating instructions or code does not remove the need for human review. A report on a study of engineering work describes human code review as a constraint on the efficiency gains from AI coding tools. That finding concerns software development, not this screen-marking utility, but it is a reminder that assistance and verification are separate tasks. ²

What we don't know yet

The available source does not provide independent testing or a security review of bigarrow.
The source does not establish compatibility with every macOS version, display setup, or application.
It is not clear how often AI agents will use screen pointers or how much they improve users' ability to complete tasks.

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Questions people ask

Can an AI agent put an arrow on my Mac screen?

A macOS tool called bigarrow is designed to let agents display an arrow and sign above other windows. The project offers it as a command-line tool and provides a skill for Claude Code and Codex. ¹

Can bigarrow click a button for me?

No. Its project description says it only points and does not click or type. It is meant to direct the person, who can then decide whether to act. ¹

Does the overlay block clicks or take a screenshot?

The project says clicks pass through to the app underneath and keyboard focus stays there. It also says the tool does not capture the screen. ¹

Does bigarrow need a Mac permission or account?

The project says drawing needs no macOS permission and that the tool does not require an account. It also describes the software as having no telemetry, but those are claims from the project page rather than an independent audit. ¹

Can I use this screen-arrow tool on Windows?

The supplied project description identifies bigarrow as a macOS command-line tool. It does not say that a Windows version is available, so the sources do not confirm support for Windows. ¹

Sources

GitHub - franzenzenhofer/big-arrow-on-the-screen: Let your AI agents paint big arrows, boxes and text on your Mac screen. One CLI, click-through, gone by… — GitHub
AI coding agents generate more code, but not more software — Ars Technica, 2026-10-09

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