OpenAI Codex: coding help included with ChatGPT plans
Codex is OpenAI’s coding tool for writing, changing and reviewing software. It works across an app, the terminal and editor integrations, with access tied to your account or API use.
Limited access included with ChatGPT Free
How I use OpenAI Codex
I use Codex to build and update websites, investigate faults and check changes. Sideperk is one of the projects I work on with it.
What makes it different?
It connects coding work to OpenAI’s own models and account plans, with interfaces for desktop, terminal and editor use.
Competitors
- ZCode: A desktop coding environment with connected providers
- OpenCode: An open-source coding agent with provider choice
Product source checked 2026-09-08.
Who it is for
AI coding and development.
Who can claim it?
Use is subject to the provider’s supported platforms, account requirements and current terms.
Limitations of the free tier
Usage is limited by the account plan and the work requested. API-key usage is billed separately from a ChatGPT subscription.
Billing and renewal
Free access has a limited allowance. Paid ChatGPT plans and API billing have their own terms.
- Tax basis
- Not applicable to the free software or plan
- Card required
- Provider’s signup terms
- Expiry
- No fixed offer end date established.
- Public research date
- 8 Sept 2026
- Source checked
- 8 Sept 2026
Further official evidence
More about OpenAI Codex and its offers