Accessing OpenAI Codex depends on which version you want to use and your subscription level with OpenAI. The current cloud-based Codex agent is available through ChatGPT to Plus, Pro, Enterprise, and Team subscribers. If you have a ChatGPT Plus subscription (the $20/month plan), you can access Codex directly through the ChatGPT interface. As of June 2025, Codex became available to Plus users after initially being limited to higher-tier plans. To use it, you simply navigate to the Codex section in the ChatGPT sidebar and can assign new coding tasks by typing a prompt and clicking “Code” or ask questions about your codebase by clicking “Ask.”
For developers who prefer working in the terminal, OpenAI also offers Codex CLI, which is a lightweight coding agent that runs locally on your computer. This version is open source and available on GitHub. You can install it globally using npm with the command npm install -g @openai/codex or through Homebrew with brew install codex. Alternatively, you can download the appropriate binary for your platform from the latest GitHub release. To use the CLI version, you’ll need to set your OpenAI API key as an environment variable, and it requires either macOS, Linux, or Windows with WSL2.
The access model for Codex includes generous usage limits during the initial preview period, with OpenAI providing essentially unmetered access for the first few weeks to allow users to explore its capabilities. After this trial period, usage will be subject to rate limits based on your subscription tier, though the exact limits haven’t been fully detailed yet. Enterprise customers can also access Codex through Microsoft’s Azure OpenAI Service. It’s worth noting that the original Codex API from 2021 was deprecated in March 2023, so the current access methods represent the new generation of Codex capabilities rather than the legacy API.