Codex

Codex is OpenAI's open-source terminal AI coding assistant. It understands code, edits files, and runs commands in your local project directory, helping developers move from requirements to a verifiable implementation. This is the Codex CLI command-line tool.

Main features

• Reads the codebase, explains implementation and project structure, and helps locate issues.
• Modifies code, fixes errors, and adds features and tests based on natural-language requirements.
• Runs development commands such as builds and tests, and continues working on tasks based on the results.
• Assists with code review, checks changes, and finds potential issues.
• Connects to external tools through MCP and reuses workflows through Skills; specific features depend on the installed version.
• Controls file, command, and network access through sandbox and approval settings.

Who it's for Suitable for developers and maintainers who are accustomed to the terminal, as well as those who need to complete development and troubleshooting tasks in an existing codebase. Before use, you should understand the purpose of the project and commands, and review the generated code.

Installation and usage You can install this Cask through Homebrew. After installation, enter your project directory in the terminal and run codex. macOS provides official binaries for Apple Silicon and Intel; the current store download size corresponds to the Apple Silicon installer and does not represent the installed footprint.

Account and costs You can sign in with an eligible ChatGPT account, or configure an OpenAI API Key. Available features, usage, and costs depend on your account plan or API billing rules; please refer to OpenAI's official documentation. The program operates on code on your local machine, and model services usually require a network connection.

Open-source license The project is open source under the Apache-2.0 license. Official documentation: https://developers.openai.com/codex/cli Source code and release history: https://github.com/openai/codex