Coding agent by OpenAI. Available with a ChatGPT subscription, including the $0 Free plan, and separately with an API key billed on token use; both routes are current. OpenAI's Codex pricing page lists Free ($0/month, "Explore Codex capabilities on quick coding tasks") and Go ($8/month, "Use Codex for lightweight coding tasks"), both with GPT-6 Luna at Standard speed in the desktop app, subject to rollout. Plus ($20/month) adds Codex on the web, in the CLI, in the IDE extension and on iOS, cloud code review and Slack integrations, and GPT-6.1 Sol and GPT-6 Luna. Pro plans are Pro 100 ($100/month), Pro 200 ($200/month), and Pro 500 ($500/month). Ultrafast mode is only on Pro 500. Pro plans have no five-hour limit. On 2026-10-29 OpenAI canceled the Pro 200 allowance reduction it had announced on September 29, 2026. Every Pro 200 subscription, new or existing, now has the same Work and Codex allowance at $200 a month. Pro 100 and Pro 500 now include twice their previous Work and Codex allowance. Plus usage is unchanged. ChatGPT Business has two seat types, both carrying Codex: Standard at $20/user/mo billed annually ($25 monthly) and Premium at $100/user/mo billed annually ($125 monthly), where Premium buys 5x more usage than Standard and removes the five-hour usage limit. The Codex pricing page we cite lists only the Standard seat — the Premium seat is published on OpenAI's business pricing page. Codex-only pay-as-you-go seats closed to new Business workspaces on 2026-06-24; existing seats continue. With an API key, Codex runs in the CLI, SDK or IDE extension at API prices, without the cloud features.
- Since 2026-10-28, ChatGPT Pro and Business subscriptions include monthly OpenAI API credits. These credits do not pay for Codex used with an API key. They do not raise ChatGPT or signed-in Codex usage limits. (From developers.openai.com/api/docs/guides/chatgpt-api-credits, read 2026-10-29.)
- On Free, Plus, and Pro, OpenAI may use your content to train its models. This includes Codex tasks. By default, OpenAI does not use inputs or outputs from ChatGPT Business, ChatGPT Enterprise, ChatGPT Edu, or the API to improve its models. (From help.openai.com/en/articles/5722486-how-your-data-is-used-to-improve-model-performance, read 2026-10-30.)
- To opt out, turn off Improve the model for everyone under Settings > Data controls in ChatGPT, or select Do not train on my content in the Privacy Portal. Either option applies to ChatGPT and Codex. Codex has a separate Include environments setting for training on full environments, which those settings do not change. (From help.openai.com/en/articles/5722486-how-your-data-is-used-to-improve-model-performance, read 2026-10-30.)
- OpenAI's Terms of Use for its services for individuals state you retain ownership rights in Input and own the Output. You may not use Output to develop models that compete with OpenAI. No restriction on commercial use is listed. (From openai.com/policies/terms-of-use, read 2026-10-30.)