Codex Computer Use Tutorial: Let AI Automatically Control Your Computer to Complete Tasks

The Era of AI Commanding AI Has Arrived

OpenAI's Codex recently received a major upgrade — the addition of Computer Use functionality. This means Codex is no longer confined to code editors; it can now control your computer just like a human: moving the mouse, clicking buttons, opening applications, typing text, and even commanding other AI tools to collaboratively complete tasks.

The possibilities are enormous: you can have Codex open coding tools like Cursor, automatically create projects, write code, debug and run programs — all while you simply issue a command, go grab a coffee, and come back to find your project ready.

Why Computer Use Is a Critical Upgrade

After Anthropic released Claude Opus 4 and its Computer Use capability, the industry widely expected OpenAI to respond with GPT-6 or a more powerful vision model. However, OpenAI chose a more pragmatic path — giving Codex the ability to control computers as well.

Technical Background: How Computer Use Works

Computer Use is essentially a vision-based GUI automation technology. The AI captures screen images, uses vision models to identify interface elements (buttons, text fields, icons, etc.), and then simulates mouse clicks and keyboard inputs through system-level APIs. Unlike traditional RPA (Robotic Process Automation), Computer Use doesn't rely on fixed coordinates or scripts — instead, it "understands" the interface like a human before making decisions, giving it stronger generalization capabilities that can adapt to interface changes and previously unseen applications.

The logic behind this strategy is clear: code generation alone is no longer enough — AI needs end-to-end task execution capabilities. Computer Use evolves AI from "giving you answers" to "doing things for you" — a qualitative leap from tool to agent.

Concept Explained: The Essential Difference Between AI Agents and Tools

The core difference between an AI Agent and traditional AI tools lies in autonomy and goal-orientation. Tool-based AI passively responds to single instructions, while Agents possess planning, memory, tool invocation, and self-correction capabilities, able to decompose complex goals into multi-step action sequences and execute them continuously. Computer Use is precisely the critical infrastructure for Agent capabilities — it breaks AI free from the boundaries of pure text interaction, giving it the "hands and feet" to interact with real computing environments, truly enabling AI to "get things done" in the real world.

Industry Context: Anthropic's First-Mover Advantage

Anthropic first released Claude's Computer Use feature in October 2024, making it the industry's first publicly available large model computer control capability for developers. At the time, the feature was still in beta with notable limitations in recognition accuracy and operational stability, but its strategic significance lay in defining a new AI capability paradigm — letting large language models directly control graphical interfaces. OpenAI subsequently bringing Computer Use to Codex signals that this capability is moving from experimental feature to mainstream product deployment, and the competition between these two top AI companies has extended from model capabilities to the dimension of "what AI can actually do."

With Computer Use capabilities, Codex's boundaries are dramatically expanded:

• Cross-application collaboration: Switching between different software and transferring data
• AI commanding AI: Having Codex invoke Cursor, Claude, and other AI tools
• Full-process automation: From creating folders to writing code to running tests, all in one seamless flow

Three Steps to Enable Codex Computer Use

Step 1: Update Codex to the Latest Version

Make sure your Codex client has been updated to the latest version that supports Computer Use. If it hasn't auto-updated, you can manually check for updates.

Step 2: Install the Computer Use Component

1. Open Codex and click the Settings button
2. Find and click the "Computer Use" option in the left navigation bar
3. Click the "Install" button and wait for the installation to complete

Step 3: Launch and Complete Authorization

1. Start a new conversation
2. On the conversation page, type @ and select Computer Use
3. Enter your task instruction
4. The first execution requires authorization — it's recommended to check "Always Allow" to avoid repeated confirmations

Computer Use requires two system permissions to function properly:

• Accessibility permission: For simulating mouse and keyboard operations
• Screen capture permission: For "seeing" screen content and making decisions

Deep Dive on Permissions: What Accessibility Permission Means

The Accessibility permission on macOS and Windows was originally designed for users with disabilities, allowing third-party applications to read and control UI elements of other applications. Programs granted this permission can enumerate all interactive controls on screen and simulate arbitrary input events — an extremely high privilege level. This is why the system displays prominent warning prompts during authorization — if this permission is obtained by malicious software, it could lead to account theft, data leaks, and other serious consequences. Users should verify the source is trustworthy when granting authorization, regularly review the authorized application list in system "Privacy & Security" settings, and promptly revoke authorization for applications no longer in use.

Follow the system prompts to complete two authorizations and the configuration is done. After authorization is complete, Codex will automatically restart, and you can start executing tasks.

Practical Demos: From Playing Music to Auto-Building Websites

Demo 1: Having AI Open a Music App and Play a Song

The first test task is very simple: "Open the music app for me, play a song — you pick which one."

After authorization is complete, you can clearly see Codex operating autonomously on screen — an independent mouse cursor appears (distinct from the user's own mouse), automatically opening the music application, browsing the song list, and ultimately selecting a song to start playing.

The entire process is smooth and natural, with the AI's operational logic nearly identical to a human's.

Demo 2: Commanding Cursor to Automatically Create a Complete Project

The second task is significantly more complex, with the following instruction:

"Please open Cursor, create a folder on my desktop (you decide the folder name), use this folder as the project storage directory, and command Cursor to build an AI news information HTML page for me."

The brilliance of this task lies in: Codex needs to control another AI tool (Cursor) to complete the coding work. This is truly "AI commanding AI."

Architecture Explained: Multi-Agent Collaboration Systems

The scenario of Codex controlling Cursor is essentially an implementation of a Multi-Agent system. In this architecture, Codex serves as the Orchestrator responsible for task planning and instruction distribution, while Cursor serves as the Executor focused on code generation. This division of labor draws from the microservices philosophy in software engineering, letting each AI focus on its area of expertise and accomplish complex tasks through collaboration that a single AI would struggle to handle alone. Multi-Agent collaboration is currently one of the most active research directions in AI engineering, with OpenAI, Google, and Anthropic all continuously investing in this area. The core challenge lies in ensuring communication reliability between Agents and consistency of task execution.

Codex's execution steps were roughly as follows:

1. Create a new folder on the desktop
2. Open the Cursor editor
3. Set the new folder as the project directory
4. Write prompts in Cursor, commanding Cursor to generate HTML page code
5. Save and complete the project

Notably, the prompts Codex wrote for Cursor were quite high-quality, demonstrating AI's ability to decompose and re-express task requirements after understanding them. The final AI news information HTML page produced satisfying results.

Privacy and Security: Risks You Must Understand Before Using

Before enjoying the convenience that Computer Use brings, there's an important security issue that deserves serious attention:

Computer Use requires full screen access permission, meaning the AI can "see" everything on your screen, including:

• Web pages open in your browser (which may contain logged-in accounts)
• Files and documents on your desktop
• Conversation content in chat applications
• Any other visible private information

Recommended protective measures:

1. Close applications and web pages containing sensitive information before using Computer Use
2. Avoid running unattended for extended periods on computers with important private data
3. Consider using a separate user account or virtual machine to isolate the runtime environment
4. Regularly check authorization status and promptly disable related permissions when not in use

Security Extension: The New Threat of Prompt Injection Attacks

When AI gains screen reading and operation capabilities, a security threat called "Prompt Injection" becomes particularly noteworthy. Attackers may embed hidden instructions in web pages, documents, or images (such as white text or transparent layers), and when the AI "sees" these elements, it could potentially be manipulated into executing unintended actions. This represents an emerging attack vector that users should remain aware of as Computer Use technology matures.