How to Install OpenAI Codex CLI on Windows 11 (Step-by-Step)
Struggling to keep up with complex coding tasks? OpenAI's Codex CLI transforms your Windows terminal into an AI-powered coding assistant that can edit files, search the web, and even generate images - all from your command line. This guide shows you exactly how to install and configure this powerful tool in minutes.
What is OpenAI Codex CLI?
Most developers waste hours on repetitive coding tasks, debugging, and searching for solutions online. OpenAI Codex CLI changes this by bringing powerful AI assistance directly to your terminal. Unlike standard code completion tools, Codex CLI acts as an autonomous coding partner that understands your entire project context.
Developed by OpenAI, this lightweight but powerful tool leverages GPT-5 technology to help with everything from simple code edits to building complete applications. It can read your local files, modify source code securely, execute commands, and even search the web when needed - all while maintaining awareness of your specific project requirements.
Key differentiator: While similar to Anthropic's Claude Code, Codex CLI uniquely supports image generation and processing - allowing you to attach screenshots that the AI can analyze alongside your code.
Prerequisites for Installation
Before installing Codex CLI, ensure your Windows 11 system meets these requirements:
- Windows PowerShell 7+ (run
Get-Host | Select-Object Versionto check) - Administrator access for initial installation (though Codex can run without admin privileges)
- ChatGPT Plus subscription or higher (required for authentication)
- Stable internet connection during installation and use
At the 2:15 mark in the video tutorial, you'll see how to verify your PowerShell version. If you need to upgrade, Microsoft provides simple installation packages on their website.
Step-by-Step Installation Guide
Follow these steps carefully to install Codex CLI on your Windows 11 machine:
Step 1: Open PowerShell as Administrator
Right-click the Windows Start menu and select "Windows Terminal (Admin)" or "PowerShell (Admin)". This ensures you have the necessary permissions for installation.
Step 2: Run the Installation Command
Copy and paste the following command into your PowerShell window:
iwr -useb https://developers.openai.com/codexcli/install.ps1 | iex This command downloads and executes the official OpenAI installation script. As shown at 3:42 in the video, the installer will automatically detect your system architecture (x64 or ARM) and download the appropriate version.
Step 3: Wait for Installation to Complete
The installation process typically takes 2-5 minutes depending on your internet speed. You'll see progress indicators in your terminal. Don't interrupt this process.
Pro Tip: If the installation seems stuck (common on slower connections), wait at least 10 minutes before troubleshooting. The video shows this happening around the 4:30 mark, where the installation appears frozen but is actually downloading in the background.
Authentication and Setup
After successful installation, you'll need to authenticate with your OpenAI account:
Step 1: Launch Codex CLI
Type codex in your terminal and press Enter. This launches the Codex interface.
Step 2: Sign In with ChatGPT
Select the option to "Sign in with ChatGPT" when prompted. This will open your default browser to complete OAuth authentication.
Step 3: Grant Permissions
Follow the browser prompts to log in to your ChatGPT account (Plus subscription required) and grant Codex CLI the necessary permissions.
At 6:15 in the video, you can see the authentication flow where the terminal provides a verification code that must be entered in the browser. This links your local Codex installation to your OpenAI account.
Important: Codex CLI requires an active ChatGPT Plus ($20/month) or higher subscription. The free tier of ChatGPT doesn't provide access to Codex capabilities.
Sandbox Configuration
Codex CLI runs in a sandboxed environment for security. During first launch, you'll need to configure these settings:
Step 1: Choose Sandbox Type
You'll be presented with three options:
- Admin Sandbox (most secure but requires admin privileges)
- Non-Admin Sandbox (works without admin rights but with reduced security)
- No Sandbox (not recommended due to security risks)
Step 2: Set Directory Trust Levels
Codex will ask if you trust the current working directory. Trusting a directory allows:
- Project-specific configuration hooks
- Local exit policies to load
- Reduced warnings for common operations
Around 7:50 in the video, you can see the sandbox configuration process where the presenter chooses a non-admin sandbox for demonstration purposes. In production environments, always use the admin sandbox when possible.
Key Features and Capabilities
Once installed and configured, Codex CLI offers these powerful features:
1. Intelligent Code Editing
Codex can analyze and modify files in your working directory while maintaining context of your entire project structure.
2. Integrated Web Search
When stuck, Codex can search the web for solutions and incorporate relevant findings directly into your workflow.
3. Image Processing
Unique among coding AIs, Codex can analyze screenshots attached to your prompts and generate or edit images directly in the CLI.
4. Model Context Protocols
Connect to remote servers to synchronize data environments across different tools and team members.
Game-Changer: At 5:20 in the video, the presenter highlights how Codex's image generation capability sets it apart from competitors like Anthropic's Claude Code, which lacks visual processing features.
Watch the Full Tutorial
For a complete walkthrough of the installation process with troubleshooting tips, watch the full video tutorial below. Pay special attention to the 4:30 mark where we demonstrate how to handle slow download speeds during installation.
Key Takeaways
OpenAI Codex CLI brings powerful AI assistance directly to your Windows terminal, transforming how you write and manage code. With capabilities ranging from intelligent code completion to web search and even image generation, it's more than just another coding tool - it's a complete AI development environment in your command line.
In summary: Install with one PowerShell command, authenticate with your ChatGPT Plus account, configure appropriate sandbox settings, and unlock a new level of coding productivity with AI assistance that understands your entire project context.
Frequently Asked Questions
Common questions about this topic
OpenAI Codex CLI is a terminal-based AI coding assistant that can edit files, search the web, execute commands, and generate code using GPT-5 technology. Unlike standard auto-complete tools, it operates as an autonomous local collaborator that understands your entire project context.
Key capabilities include reading and modifying source code, built-in web search for problem solving, session resuming, and model context protocols for synchronizing data environments across tools.
- Acts as an AI pair programmer in your terminal
- Understands your project's full context
- Can generate complete applications from scratch
Yes, you need at least a ChatGPT Plus subscription ($20/month) to use Codex CLI with full functionality. The free tier of ChatGPT doesn't provide access to Codex capabilities. Enterprise and business plans also work.
During setup, Codex CLI will prompt you to authenticate using your ChatGPT account credentials. Without an active paid subscription, you'll be unable to proceed past the initial setup screen.
- Minimum requirement: ChatGPT Plus ($20/month)
- Enterprise plans provide additional features
- Free accounts cannot access Codex functionality
Codex CLI requires Windows 10 or 11 with PowerShell 7+ and at least 4GB RAM. The installation process automatically detects your system architecture (x64 or ARM) and downloads the appropriate version.
For optimal performance, we recommend systems with 8GB+ RAM and SSD storage. The tool works on both physical machines and virtual environments, though some sandbox features may be limited in VMs.
- Windows 10/11 (64-bit)
- PowerShell 7 or newer
- 4GB RAM minimum (8GB recommended)
Yes, Codex CLI can read and modify files in your working directory. However, it runs in a sandboxed environment by default to prevent unintended modifications. You can configure file access permissions during setup.
The tool will always warn you before making changes to files, and you can set up approval modes that require manual confirmation for certain types of operations. These guardrails help prevent accidental data loss.
- Reads files in current working directory
- Sandbox prevents unauthorized access
- Approval modes add extra protection
While both use AI for coding assistance, Codex CLI operates directly in your terminal with broader capabilities including file editing, web search, and image generation. Copilot focuses on code completion within IDEs. Codex CLI also offers more control over model behavior and reasoning.
Codex CLI functions more like an autonomous coding partner that can work across your entire project, while Copilot serves primarily as an intelligent autocomplete tool within specific files in your editor.
- Terminal-based vs. IDE-integrated
- Broader capabilities beyond code completion
- More control over model behavior
No, Codex CLI requires an active internet connection as it relies on OpenAI's cloud models. However, some basic functionality like file editing can work with cached model responses during temporary connectivity issues.
For offline work, you'd need to use traditional development tools. Codex CLI is designed as a cloud-connected AI assistant that leverages OpenAI's latest models, which require server access to function.
- Internet required for core functionality
- Limited cached operations possible
- Not designed as an offline tool
Codex CLI includes sandboxing, approval modes for dangerous commands, and configurable guardrails. It warns about prompt injection risks and lets you set trust levels for directories. For maximum security, run it with administrator sandboxing when possible.
The tool also implements model context protocols that help prevent unauthorized data exfiltration and includes built-in monitoring for suspicious command patterns that might indicate prompt injection attempts.
- Sandboxed execution environment
- Approval modes for risky operations
- Configurable trust levels
GrowwStacks helps businesses implement AI automation solutions like Codex CLI into their development workflows. We can configure custom sandbox environments, integrate Codex with your existing tools, and train your team on advanced usage.
Our free 30-minute consultation identifies the best AI coding solutions for your specific needs. We'll help you determine if Codex CLI is right for your team and show you how to maximize its potential in your development process.
- Custom sandbox configurations
- Team training and onboarding
- Integration with existing tools
Ready to Supercharge Your Development Workflow with AI?
Every hour spent on manual coding tasks is an hour not spent on innovation. Let GrowwStacks help you implement Codex CLI and other AI development tools to accelerate your productivity.