What is Codex CLI?
Codex CLI is a powerful, open-source command-line tool developed by OpenAI that brings the capabilities of advanced AI models directly into your terminal. It acts as an AI pair-programmer, capable of understanding the context of your local codebase to help you build features, fix bugs, and understand complex code. Because it runs locally, your code remains on your machine, ensuring privacy and security.
Key Features
- Full Codebase Context: Codex CLI can read and understand your entire project, allowing it to provide relevant and context-aware assistance.
- Code Modification and Generation: It can modify existing code, create new files, and implement new features based on natural language prompts.
- Terminal Command Execution: The tool can run terminal commands, such as installing dependencies, starting servers, or executing test suites.
- Interactive Sessions: You can start an interactive session and have a conversation with the AI, refining your requests and iterating on solutions.
- Multimodal Inputs: Codex CLI can work with multimodal inputs like screenshots and diagrams to better understand your requests.
Use Cases
- Rapid Prototyping: Quickly scaffold new applications or features by describing them in plain English.
- Bug Squashing: Describe a bug and let the AI analyze the code, suggest a fix, and even write the patch for you.
- Learning a New Codebase: Get up to speed on an unfamiliar project by asking the AI to explain different parts of the code.
- Automating Repetitive Tasks: Use it to write scripts, generate boilerplate code, or automate other development chores.
Getting Started
To get started with Codex CLI, you need to have Node.js (v22 or newer) installed.
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Install the package globally via npm:
npm install -g @openai/codex -
Navigate to your project’s root directory and start the tool:
cd /path/to/your/project codex -
Authenticate: The first time you run it, you will be prompted to sign in with your OpenAI account.
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Start Coding: You can now make requests in plain English. For example:
> Implement a new API endpoint at /users that returns a list of users.
Pricing
While the Codex CLI tool itself is open-source under the Apache-2.0 license, using it requires an active subscription to a relevant OpenAI plan, such as ChatGPT Plus, Pro, Business, or Enterprise. This makes the effective pricing model a subscription-based one.