Codex

What is Codex?

Codex is OpenAI's coding agent, available as a CLI, IDE extension, and cloud-based task runner. Rather than just autocompleting lines, it takes a task description, plans the steps, edits multiple files, runs tests, and reports back — closer to delegating work than writing alongside it.

Key features

• Task-based workflow: describe the goal, Codex plans and executes it
• Runs in a sandboxed environment with its own terminal access
• Can work on multiple tasks in parallel in the cloud
• Integrates with GitHub to open pull requests automatically
• CLI and IDE extension for local, interactive use
• Configurable permissions for how much it can do unsupervised

How to get started

1. Install the Codex CLI, or enable it inside ChatGPT or your IDE
2. Point it at a repository and describe the task in plain language
3. Review the plan Codex proposes before it starts making changes
4. Let it run in a sandbox, then review the diff or the opened pull request
5. Approve, request changes, or hand off the next task

Codex pricing

OpenAI Codex has no separate price. You reach it through a ChatGPT plan or the API.

Usage limits scale with your ChatGPT plan.

Our take: If you already pay for ChatGPT, Codex comes with it, so start there before adding API spend.

Prices change often. Check the official site above for current rates before you commit.

Use cases

• Delegating well-scoped bug fixes and small features
• Running multiple coding tasks in parallel in the background
• Generating pull requests directly from a task description
• Automated test writing and running
• Handling repetitive maintenance tasks across a codebase

Codex vs. alternatives

FAQ

Is Codex free to use?

Codex's plans: Included with ChatGPT Plus/Pro/Team, usage-based via API. Pricing and free-tier limits change over time, so check the official site above for the latest details.

What is Codex used for?

OpenAI's agentic coding tool that plans and executes tasks end to end.

Who is Codex best for?

Codex is a good fit for delegating well-scoped bug fixes and small features, or running multiple coding tasks in parallel in the background.

What are the alternatives to Codex?

Commonly compared alternatives include Cursor, GitHub Copilot, and Lovable, see the comparison above for how they differ.

How much does Codex cost?

There's no standalone Codex fee. It's bundled into ChatGPT Plus (about $20 a month) and Pro (about $200 a month), or you can run it per token on the OpenAI API.