explaingit

openai/codex

🔥 Hot★ 83,547RustAudience · developerComplexity · 2/5ActiveLicenseSetup · moderate

TLDR

A terminal-based AI coding assistant from OpenAI that runs locally on your computer, letting you ask questions about code and get help without leaving the command line.

Mindmap

mindmap
  root((Codex CLI))
    What it does
      Terminal assistant
      Code questions
      Local execution
    How to use
      ChatGPT account
      API key auth
      npm or Homebrew
    Integrations
      VS Code
      Cursor IDE
      Windsurf
    Tech stack
      Rust
      OpenAI API
      npm packages
    Use cases
      Code review
      Debugging help
      Project modification

Things people build with this

USE CASE 1

Ask an AI assistant about your code directly in the terminal while working on a project.

USE CASE 2

Get help debugging or understanding code without switching to a browser or IDE plugin.

USE CASE 3

Have the agent suggest changes or take actions on files in your local directory.

Tech stack

RustOpenAI APInpmHomebrew

Getting it running

Difficulty · moderate Time to first run · 30min

Requires OpenAI API key and either Rust compilation or Homebrew/npm installation.

Use freely for any purpose, including commercial use, as long as you include the original copyright and license notice.

In plain English

Codex CLI is a coding agent from OpenAI that runs locally on your computer, in the terminal. The idea is to give you an assistant you can talk to about your code right where you already work, at the command line, instead of having to switch to a browser or a separate app. Once installed, you simply run the command codex and start interacting. The repository describes Codex as lightweight, and it ties into OpenAI's broader Codex ecosystem. There are companion ways to use it: integrations for code editors such as VS Code, Cursor, and Windsurf if you want the assistant inside your IDE; a desktop app experience launched with codex app; and a cloud-based version called Codex Web available on chatgpt.com/codex. To use it, you sign in with your ChatGPT account so Codex runs as part of your existing Plus, Pro, Business, Edu, or Enterprise plan. Alternatively you can authenticate with an API key, which requires extra setup. Installation is done globally through npm or through Homebrew on macOS as a cask, and prebuilt binaries are also published on the GitHub Releases page for macOS (Apple Silicon and x86_64) and Linux (x86_64 and arm64). Someone would actually use Codex CLI when they want an AI coding helper available next to their existing workflow without leaving the terminal, for example while writing or modifying a project, asking questions about code, or having the agent take actions on the local machine. The project is written in Rust and the repository is licensed under Apache-2.0.

Copy-paste prompts

Prompt 1
How do I install Codex CLI and authenticate it with my ChatGPT account?
Prompt 2
Show me how to use Codex CLI to ask questions about a specific file in my project.
Prompt 3
What are the differences between using Codex CLI, the VS Code extension, and Codex Web?
Prompt 4
How do I set up Codex CLI with an API key instead of my ChatGPT account?
Open on GitHub → Explain another repo

Generated 2026-05-18 · Model: sonnet-4-6 · Verify against the repo before relying on details.