OpenAI Codex: Codex CLI Coding Agent in 2025

Introduction

OpenAI Codex: Codex CLI Coding Agent in 2025 | Imagine typing “make a website” in your computer’s terminal, and an AI instantly creates a sleek webpage for you. That’s the power of OpenAI Codex, a name that’s been buzzing in tech since 2021. Back then, Codex was an AI that turned words into code, powering tools like GitHub Copilot. Fast forward to April 16, 2025, and OpenAI launched Codex CLI, a new open-source tool that lets you code, fix bugs, and even build apps right from your terminal. Whether you’re a beginner or a pro, Codex CLI makes coding feel like chatting with a smart friend.

Introduction
What Is OpenAI Codex?
My Experience with Codex CLI
Key Features of Codex CLI
Who Can Use It?
How to Set Up Codex CLI
Pro Tips for Using Codex CLI
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Conclusion
FAQs

What Is OpenAI Codex?

OpenAI Codex has two chapters:

Codex (2021): This was an AI model that turned plain English into code, like writing “//make a game” and getting a JavaScript game. It powered GitHub Copilot, helping coders in apps like Visual Studio Code. Trained on 159GB of Python code from GitHub, it worked in 12+ languages but was shut down in March 2023, per Wikipedia.
Codex CLI (2025): A new open-source tool, not related to the old model, launched April 16, 2025. It’s a terminal-based AI coding agent using OpenAI’s o4-mini model. You can tell it to write code, fix bugs, or explain projects, and it runs everything locally, per TechCrunch. It’s like having an AI coder in your terminal

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My Experience with Codex CLI

As a tech geek who loves gadgets like Sony WH-1000XM6 Best Noise-Canceling Headphones 2025, I was pumped to try Codex CLI. I opened my Mac’s terminal, typed “codex create a portfolio website,” and watched it build an HTML file with CSS in seconds. The terminal showed a preview, and I could approve or tweak it. It felt like magic, like using No More Language Barriers: AI Translation Earbuds. The only hiccup? I forgot to set my API key at first, but the error message guided me. This tool is a game-changer for quick projects!

Key Features of Codex CLI

Codex CLI, launched in 2025, shines with these features, per OpenAI:

Multimodal Inputs

Type text, paste screenshots, or sketch diagrams, and Codex CLI turns them into code. For example, upload a webpage sketch, and it builds HTML, per TechCrunch.

Approval Modes

Choose how much control you want:

Suggest: Codex suggests edits; you approve each one.
Auto Edit: It edits files but asks before running code.
Full Auto: It writes and runs code in a sandbox, perfect for big tasks, per The Indian Express.

Sandboxed Execution

Code runs in a secure, network-disabled sandbox to keep your system safe, per GitHub.

Open-Source

Anyone can view or improve the code on GitHub, making it free and flexible, per X post.

Compare Codex CLI to other AI coding tools:

Feature	Codex CLI (2025)	GitHub Copilot (2021)	Claude Code (Anthropic)
Runs in Terminal	Yes	No (IDE-based)	Yes
Open-Source	Yes	No	No
Multimodal Inputs	Yes (text, images)	No (text only)	Yes (limited)
Approval Modes	Suggest, Auto Edit, Full Auto	Manual edits	Suggest only
Sandboxing	Yes (network-disabled)	No	Yes (partial)

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Who Can Use It?

Codex CLI is for anyone with a computer and an OpenAI API key, per DataCamp:

System Requirements: macOS or Linux (Windows needs WSL2), Node.js 22+, Git 2.23+, 4GB RAM (8GB recommended).
API Key: Get one from OpenAI Platform.
Skill Level: Beginners can use Suggest mode; pros can go Full Auto.

OpenAI offers $1M in API grants for open-source projects using Codex CLI, per GitHub. Curious about AI APIs? See OpenAI API Verified ID 2025.

How to Set Up Codex CLI

Here’s how to start, per DataCamp:

Install Node.js: Download Node.js 22+ from nodejs.org.
Install Codex CLI: Open your terminal and run npm install -g @openai/codex.
Set API Key: Type export OPENAI_API_KEY=”<your_key>” (get your key from OpenAI).
Test It: In a project folder, type codex “explain this repo” to see it analyze your code.

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Pro Tips for Using Codex CLI

Maximize Codex CLI with these tricks:

Use Suggest Mode: Start with codex –suggest to learn how it works, per GitHub.
Add Screenshots: Paste a UI sketch to build interfaces, per TechCrunch.
Stay in Git: Run Codex in a Git repo to track changes, per DataCamp.
Check Sandbox: Ensure sandbox permissions for Full Auto, per The Indian Express.
Explore Forks: Try community forks like Open Codex for Gemini support, per X post.

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Conclusion

OpenAI Codex has evolved from a 2021 code-generating AI to the powerful Codex CLI in 2025, making coding as easy as chatting in your terminal. Whether you’re building websites, fixing bugs, or exploring repos, this open-source tool saves time and boosts creativity. With multimodal inputs and secure sandboxing, it’s perfect for beginners and pros. Try Codex CLI, Share them on X with #OpenAICodex! For more cool tech, keep exploring usashorts.com.