Unofficial community guide for OpenAI Codex. Not affiliated with OpenAI. All trademarks belong to their owners.
People search for open ai codex with a space, but the product is written OpenAI Codex: a coding agent from OpenAI that runs inside ChatGPT, as a desktop app, and in the cloud, with a separate developer docs site for people who want to build on it. This guide collects what OpenAI's own Codex pages and its June 2026 knowledge-work report say about the product, so you can tell the ChatGPT route apart from the developer route and find the pricing and enterprise pages without guessing URLs.
Need a finished website or mobile app rather than an agent that works inside your repo? Try Begin.sh - turn a prompt or a URL into a downloadable static site or Expo app. You describe it, download the zip, and host it wherever you like; no hosting, backend or auth to set up.
OpenAI's Codex page introduces it as the same coding agent, now in ChatGPT, and positions it as built to drive real engineering work, from routine pull requests upward. The page lists Heidi, NVIDIA, Cisco and Shopify among the teams using it. Codex has its own section on chatgpt.com with an overview, a pricing page, an enterprise page, a link to developer docs at developers.openai.com and an events calendar, and the log-in button on that page sends you to the cloud version of Codex.
The product has grown past coding. On June 2, 2026 OpenAI published a report, The Next Era of Knowledge Work, stating that Codex has more than 5 million weekly active users, up more than 6x since the desktop app launched in February. Developers remain the largest group, but knowledge workers are about 20 percent of users and are growing more than three times as fast. They mostly use Codex to create reports, spreadsheets, presentations and contracts, and increasingly for research, data analysis, workflow automation and building lightweight tools that used to need an engineer. The report also notes that users increasingly run multiple Codex tasks in parallel.
There are two doors, and they lead to different things.
- The ChatGPT route. Go to the Codex overview on chatgpt.com and log in with a ChatGPT account. Codex is offered as part of ChatGPT, and the ChatGPT plan tiers listed on the site are Free, Go, Plus, Pro, Business and Enterprise. Which tiers include Codex, and with what limits, is on the Codex pricing page.
- The developer route. The Codex developer docs cover using Codex as a developer. If you want to build on OpenAI's models yourself rather than use the Codex agent, platform.openai.com/codex asks you to sign up or log in to the OpenAI API Platform (email, Google, Apple, Microsoft or phone) and then points to the developer docs, the API reference, starter apps and the Cookbook.
- Larger teams. The Codex enterprise page and contact sales cover organization-wide rollout.
The pages this guide is grounded on do not print the prices, so check the Codex pricing page for current rates and the general ChatGPT pricing page for what each plan tier includes.
- Decide which Codex you mean. Codex inside ChatGPT, the desktop app (launched February 2026) and the cloud version are the agent product; the API Platform is for building your own tools on OpenAI models. Signing up on the platform does not by itself give you the agent.
- Parallel tasks are a first-class workflow. The knowledge-work report highlights people running several Codex tasks at once to investigate data, draft material and automate workflows in the same sitting. Plan tasks so they do not need to share state.
- It is not only for engineers. Reports, spreadsheets, presentations and contracts are the top non-coding outputs in OpenAI's data, and research and data analysis are the fastest-growing tasks, so a marketing or finance team can pilot it without a repo.
- Enterprise has its own page. If you need central administration, start from the enterprise page rather than a personal ChatGPT plan.
- Events exist. OpenAI's academy lists upcoming Codex events, useful if you prefer a walkthrough to reading docs.
- Watch the news tag. OpenAI groups Codex announcements under a Codex tag on its news pages, which is the quickest way to see what changed.
| Codex in ChatGPT | OpenAI API Platform | Begin.sh | |
|---|---|---|---|
| What it is | a coding agent that works on engineering and knowledge-work tasks | sign-up to build with the OpenAI API using docs, API reference, starter apps and cookbooks | a generator that turns a prompt or a URL into a static site or an Expo app |
| How you get in | log in with a ChatGPT account | sign up with email, Google, Apple, Microsoft or phone | describe the site and download the zip |
| Output | changes to your code and work products such as reports and spreadsheets | whatever you build on the API | a downloadable static site or Expo app |
| Hosting, backend, auth | not the point; it works in your environment | you build and run them | none included by design |
| Pricing | see the Codex pricing page | see the API Platform | see the site |
Is it Open AI Codex or OpenAI Codex? The vendor writes OpenAI Codex. The two-word spelling is just how people search for it.
Is Codex only for developers? No. As of OpenAI's June 2026 report, developers are still the largest group but knowledge workers are about 20 percent of users and growing faster, using it for reports, spreadsheets, presentations, contracts, research and data analysis.
Where is the desktop app? OpenAI's report says the desktop app launched in February 2026; the download page is where ChatGPT apps are distributed. Check the Codex overview for the current install path.
Do I need an API key? Not for Codex in ChatGPT; you log in with a ChatGPT account. The API Platform sign-up is for building your own applications on OpenAI models.
How much does it cost? The grounding pages do not list prices. Use the Codex pricing page; plan names on the site are Free, Go, Plus, Pro, Business and Enterprise.
Codex is at its best when there is a codebase, an environment and a review process for it to work inside, and when the task is ongoing engineering or knowledge work. If what you actually need is a one-off deliverable, a landing page, a documentation site, a portfolio or an Expo app prototype, and you do not want to set up a repo, an environment and an agent workflow to get it, Try Begin.sh - turn a prompt or a URL into a downloadable static site or Expo app. You get a zip of files you own and can host anywhere; there is no hosting, backend or auth bundled, so there is nothing to keep running afterwards.
Last reviewed: 2026-09-22