Codex

Overview

Category: AI coding agent

OpenAI coding agent inside ChatGPT for reading, editing, explaining, and generating code.

Best for

Developers who want agentic help with coding tasks, bug fixes, refactors, and repository workflows.

Use cases

• Generate implementation plans
• Fix bugs from error logs
• Review or refactor code

Common example

Ask Codex to inspect a failing test, identify the likely source, and propose a code patch.

Pricing and free plan

Pricing model: Included or metered through eligible ChatGPT plans and workspace usage; additional usage may be credit- or API-billed. Check OpenAI Codex pricing for current limits.

Free plan / trial assessment: Access depends on ChatGPT plan and regional/product availability; usage is meaningfully limited by quotas or credits.

Limitations

Still needs developer review, tests, and security checks; long-running agent tasks can consume usage quickly.

ChatGPT / Claude comparison

Similar capability, but more specialized workflow — more integrated for coding tasks than general ChatGPT chat.

Alternatives

Claude Code, GitHub Copilot, Cursor, Devin