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2026 Comprehensive Guide: Codex Download & Installation (Including Packages & Step-by-Step Instructions)

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2026 Comprehensive Guide: Codex Download & Installation (Including Packages & Step-by-Step Instructions)

A detailed guide covering Codex's capabilities, Windows download options, installation methods (desktop, VSCode plugin, CLI), login steps using API Key...

Codex AI Programming OpenAI Windows Installation VSCode Plugin CLI Tool API Key Login

Codex, developed by OpenAI, is an advanced AI programming agent that stands out in the AI coding tool ecosystem. Beyond generating code snippets, it actively participates in end-to-end project development—handling complex tasks like analyzing project contexts, modifying multi-file codebases, refactoring code, fixing bugs, running tests, and optimizing based on results. This allows developers to assign entire projects directly to Codex without breaking tasks into steps, significantly boosting programming efficiency.

Download Options for Windows

The latest Windows version of Codex (v26.623.19656.0) offers multiple installation packages to suit different needs:

  • Codex Installer.exe: Official installation via Microsoft Store.
  • OpenAI.Codex_26.623.19656.0_amd64.Msix: Extracted from Microsoft Store for AMD64 architecture.
  • OpenAI.Codex_26.623.19656.0_arm64.Msix: Extracted package for ARM64 architecture.

Installation Methods

Desktop App Installation (AMD64 Example)
For users facing Microsoft Store access issues, the Msix package is a viable alternative:

  1. Double-click the downloaded OpenAI.Codex_26.623.19656.0_amd64.Msix file to start installation.
  2. Click "Install" (note: default installation is on the system drive; refer to FAQs for location changes).
  3. Wait for the progress bar to reach 100%.
  4. Upon completion, the Codex window will launch automatically.

VSCode Plugin Installation
Integrate Codex into Visual Studio Code with these steps:

  1. Open VSCode and click the Extensions icon on the left sidebar.
  2. Search for "Codex" and select the official OpenAI version.
  3. Click "Install" and wait for completion.
  4. Access Codex via the OpenAI icon in the top-right corner or the "Chat" section.

CLI Installation
Install Codex CLI using one of the following commands:

  • PowerShell: powershell -ExecutionPolicy ByPass -c "irm https://chatgpt.com/codex/install.ps1 | iex"
  • npm: npm install -g @openai/codex
  • Homebrew: brew install --cask codex

Login Guide Using API Key

For users without an OpenAI subscription or facing phone verification issues, API Key login is a reliable option:

  1. Log in to OpenAI's auth page (https://auth.openai.com/log-in).
  2. Navigate to "API Keys" and click "Create new secret key."
  3. Name the key and click "Create secret key."
  4. Copy the key (save it securely as it won't be visible again) and click "Done."
  5. Open Codex desktop app, select "Sign in another way," paste the API Key, and click "Continue."

Common FAQs

1. How to Check System Architecture?
Press Win + R, type "cmd," and run echo %PROCESSOR_ARCHITECTURE%—the result will show "AMD64" or "ARM64."

2. Change Installation Location?
Before installation: Go to Windows Settings → System → Storage → Change where new content is saved. After installation: Use Windows' "Uninstall or change a program" to move Codex to another drive.

3. Domestic Model Integration?
OpenAI does not support domestic models like DeepSeek, but third-party tools (e.g., CC Switch, Codex++) offer this functionality.

4. Login Without Phone Number?
Use API Key login instead of OpenAI account credentials.

Sources

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