OpenAI Codex
OpenAI coding agent for the terminal, IDE, desktop and cloud
About OpenAI Codex
Codex is OpenAI's coding agent, and the thing to understand first is that it is four surfaces sharing one account rather than a single app. There is a command-line agent that runs locally, an extension for VS Code, Cursor and Windsurf, a macOS desktop app, and Codex Web, a cloud runner that picks up tasks without your machine being involved. You sign in once with ChatGPT and the same agent, the same configuration and the same task history follow you between them.
The commercial shape is worth stating plainly before anyone compares it to the open source agents. The CLI is Apache-2.0 and free to install with npm, Homebrew or a curl script, but installing it is not the same as using it: the agent runs on OpenAI models, reached either through a ChatGPT plan or an OpenAI API key. There is no free tier on the plan chooser. That makes Codex a single-vendor product wearing an open source binary, which is a different trade from a model-agnostic agent, and whether it is the right trade depends entirely on whether you were going to pay OpenAI anyway. What you get for the lock-in is the parts most open agents do not have: managed cloud environments, scheduled background runs and a code review pass, all maintained by the same team that trains the models.
Install the CLI with npm install -g @openai/codex, brew install --cask codex, or the install script, then run codex in a project directory and sign in with your ChatGPT account. Describe the task and the agent reads the codebase, plans, edits files, runs commands and checks the result. Built-in git worktrees let several agents work in parallel on the same repository without stepping on each other, so a refactor and a bug fix can run at the same time. Skills are instruction files you commit alongside the code that teach Codex your team conventions, and they apply automatically on every task rather than being pasted into a prompt each time. Schedules hand the agent recurring work such as issue triage, alert monitoring or CI failures, and the cloud runner executes those without your laptop open. Anything started in the terminal can be picked up in the IDE extension or the desktop app, because the session lives on the account rather than the machine.
- •Four Surfaces, One Account - Terminal CLI, IDE extension for VS Code, Cursor and Windsurf, a macOS desktop app, and Codex Web in the cloud, all sharing sessions and configuration
- •Parallel Agents on Worktrees - Built-in git worktree support and cloud environments so multiple agents work on the same repository concurrently
- •Skills - Committed instruction sets that teach the agent your team standards and workflows, applied consistently instead of re-prompted
- •Scheduled Background Work - Recurring runs for triage, monitoring and CI, executed in the cloud with no local machine required
- •Code Review - A dedicated review pass over pull requests rather than only generating code
- •Apache-2.0 CLI - The command-line client is open source and installable from npm, Homebrew, a curl script or GitHub Releases
Teams already paying for ChatGPT Plus, Pro or Business, where Codex is included in a subscription they hold anyway and adding it costs nothing extra. It suits people running several agents at once on a large repository, and teams who want an agent doing unattended overnight work such as triage and CI babysitting, which is the part hard to replicate with a purely local tool. It is a poor fit if you care about model choice: there is no way to point Codex at Claude, Gemini or a local model, so your agent and your model vendor are the same decision. It is also a poor fit for anyone wanting to try before paying, because the plan chooser has no free option. Developers who want the same loop without the lock-in should look at OpenCode or Cline instead.
Pricing
Priced in another currency
No free tier. Requires a ChatGPT plan (Plus, Pro or Business) or an OpenAI API key. Their plan chooser rendered in EUR from Europe on 2026-08-27: Plus 23 EUR/month, Pro from 85 EUR/month, Business 17 EUR/user/month for 2+ seats billed annually. USD figures were not confirmed, so price_from and price_to are left NULL. The Codex CLI itself is Apache-2.0 and free to install.
From the vendor pricing page, 2026-09-16
