OpenAI Codex
OpenAI's coding agent, available as a CLI, IDE extension, desktop app and cloud agent, included with ChatGPT plans or billed through the API.
- Free plan
- Agentic tool
- Vendor-sourced
- Verified 4 Nov 2026Sources are dated on this profile
- 5 sourcesLinked, typed and dated
- Vendor and official documentationHow this profile was compiled
- Not an endorsementStack18 has not tested this product
What is OpenAI Codex?
OpenAI Codex is OpenAI's software engineering agent. It runs in a terminal CLI, an IDE extension, a desktop app and a cloud environment, signs in with a ChatGPT account or an API key, and uses OpenAI's models.
- Best forChatGPT subscribers who write code
- PricingIncluded with ChatGPT: Go $8, Plus $20, Pro from $100 per month; Business and Enterprise by plan; API key billed per token. Free plan available.
- Main limitationSupports OpenAI's models rather than several vendors' models.
- AlternativesClaude Code, GitHub Copilot, Gemini CLI, Cursor · compare all
OpenAI Codex overview: who it is for and what it does.
OpenAI Codex lets developers delegate coding work to an agent from several places. OpenAI's quickstart describes an IDE extension, a CLI and a cloud agent, and a developer can delegate tasks to the cloud agent from the IDE extension. OpenAI's documentation also covers Codex cloud environments, code review, internet access controls, a TypeScript SDK and a GitHub Action.
There is no separate Codex subscription. OpenAI's pricing page presents Codex as included with ChatGPT plans: Free and Go for light use, Plus at $20 per month, Pro at higher usage tiers, and Business, Enterprise and Edu plans for organisations. Plus lists Codex on the web, in the CLI, in the IDE extension and on iOS, with cloud-based integrations such as code review and Slack. Developers can also use an API key, billed per token at API rates, for the CLI, SDK or IDE extension.
Third-party guides describe the Codex CLI as open source under the Apache-2.0 licence and written in Rust. OpenAI's pricing for Codex has changed during 2026, including a move toward token-based rates, so budgets should be checked against OpenAI's current pricing page.
Main problem it solves
Lets developers hand coding tasks to an OpenAI-powered agent locally or in the cloud, and review the results, without a separate subscription for people who already use ChatGPT.
Typical customer segment
Individuals through enterprises, through ChatGPT Free, Go, Plus, Pro, Business, Enterprise and Edu plans, or an API key.
Target users
- Developers who already pay for ChatGPT Plus or Pro
- Teams that want parallel cloud tasks and automated code review
- Organisations that need ChatGPT Business or Enterprise controls for coding agents
Primary use cases
- Terminal coding sessions with the Codex CLI
- Editing in VS Code or JetBrains through the Codex extension
- Delegating longer tasks to cloud environments
- Automated code review on GitHub
- Scripted workflows through the SDK and GitHub Action
What makes it distinct
- Included with ChatGPT plans, so there is no separate Codex subscription.
- One agent across CLI, IDE, desktop app, web and iOS.
- An SDK and GitHub Action for scripted and CI use.
OpenAI Codex features explained.
Where Codex runs
- Codex CLI
- A terminal agent that signs in with ChatGPT or an API key. Third-party guides describe it as open source (Apache-2.0).
- IDE extension
- Use Codex inside the editor; OpenAI's quickstart also shows delegating tasks to the cloud agent from the extension.
- Cloud agent and web
- Delegate tasks to Codex cloud environments, with documented environments and internet-access settings.
Automation and review
- Code review
- Automatic code review on GitHub is listed as a cloud-based integration on Plus and above.
- Slack integration
- Listed alongside code review as a cloud-based integration on Plus.
- SDK and GitHub Action
- A TypeScript library and a GitHub Action for scripted and CI use, per OpenAI's documentation.
Administration
- Enterprise and security admin guides
- OpenAI documents separate enterprise administration and security admin guides for Codex.
- Local and cloud controls
- OpenAI's help centre describes separate admin controls for local use (CLI, IDE, app) and for delegated cloud tasks.
- Compliance API logging
- OpenAI says Codex usage, including local clients and cloud-delegated usage, is available in the Compliance API.
OpenAI Codex pricing and plans.
Figures reported consistently by independent sources; vendor page not reviewed directly. Checked 4 Nov 2026 against OpenAI Developers · UI Bakery.
Pricing model
Included with ChatGPT plans, with usage limits that vary by plan. API-key use is billed per token at OpenAI API rates, and eligible users can buy credits after reaching limits.
Free plan
Yes
Free trial
Not documented Not confirmed in the sources reviewed.
OpenAI Codex plans and prices (USD)
Free
Free
n/a
Light exploration of Codex on quick coding tasks, per OpenAI's pricing page.
Go
$8 per month
Monthly
Described as for lightweight coding tasks.
Plus
$20 per month
Monthly
Codex on the web, in the CLI, in the IDE extension and on iOS, with cloud integrations such as code review and Slack.
Pro
$100 or $200 per month
Monthly
The $100 tier is described as 5x the Codex usage of Plus and the $200 tier as 20x, per a third-party summary of OpenAI's help pages.
Business, Enterprise and Edu
Custom or per seat
Per seat or contract
Organisation plans with administration controls; pricing was not reviewed in detail.
API key
Usage-based
Per token
For the CLI, SDK or IDE extension; no cloud-only features, and billed through the OpenAI Platform at API rates.
OpenAI changed how Codex usage is measured during 2026, including a move toward API token-based rates in April 2026, according to a third-party summary. Limits and promotions change often, so confirm current figures on OpenAI's Codex pricing page.
Prices change. Confirm current plans and terms on the vendor's site before you decide.
Visit official website (external) ↗See alternativesOpenAI Codex integrations, API and platforms.
Important integrations
- GitHub code review
- Slack
- VS Code and JetBrains IDE extensions
- TypeScript SDK and GitHub Action
- ChatGPT sign-in or OpenAI API key
Supported platforms
- CLI
- IDE extension
- Desktop app
- Web (ChatGPT)
- iOS
API
Codex can run with an OpenAI API key and has an SDK; API usage is billed at standard API rates.
Data import and export
Not reviewed for this profile.
Plans and surfaces are from OpenAI's pricing page and quickstart; the desktop app and JetBrains support come from a third-party summary.
How OpenAI Codex works as an AI product.
Attributes are listed only where documented. We do not infer autonomy levels, certifications or model capabilities.
Classification: Agentic tool. A human-directed tool that can plan, edit and run actions, with the user reviewing or approving changes. Developer: OpenAI.
| Attribute | Details |
|---|---|
| Supported models | OpenAI models. The pricing page lists GPT-5.5, GPT-5.4 and GPT-5.3-Codex on Plus at the time of review, and notes delayed model access on API-key use. [1] |
| Tools and integrations | GitHub code review, Slack, an IDE extension, a CLI, an SDK and a GitHub Action. [1] [2] |
| Ability to execute actions | OpenAI's quickstart describes Codex working in the IDE, in the CLI and as a cloud agent to which tasks can be delegated. [2] |
| Execution environment | Local use through the CLI, IDE extension and app, and delegated tasks in OpenAI cloud environments with internet-access settings. [1] [2] |
| Human-in-the-loop controls | Not documented in the sources reviewed. |
| Permissions and access | Not documented in the sources reviewed. |
| Memory and context | Not documented in the sources reviewed. |
| Deployment options | Sold through ChatGPT plans, or used with an API key billed through the OpenAI Platform. Organisation plans are Business, Enterprise and Edu. [1] |
| Data handling and privacy | Not documented in the sources reviewed. |
| Security and compliance | OpenAI says Codex usage across local clients and cloud-delegated tasks is available in the Compliance API, and describes separate admin controls for local use and cloud tasks. [3] |
| Pricing and usage limits | Usage depends on plan; Pro tiers are described as multiples of Plus usage. API-key use has no cloud-based features such as code review or Slack. [1] [4] |
| Languages and platforms | Not documented in the sources reviewed. |
| Limitations and known constraints | Uses OpenAI models only. Cloud-based features are tied to ChatGPT plans, and plan limits and rates have changed during 2026. [1] [4] |
Primary tasks
- Writing and editing code across files
- Running tasks in cloud environments
- Code review on GitHub
- Scripted and CI workflows
Best-fit workflows
- Developers who already use ChatGPT and want a coding agent in the same plan
- Teams that want a CLI, IDE extension and cloud tasks from one vendor
- Workflows that benefit from automated GitHub code review
OpenAI Codex pros and cons.
Strengths, limitations and best fit. Each point cites a source; editorial summaries are not customer reviews.
Strengths
- Included with ChatGPT plans, so existing subscribers do not pay for a separate product. [1]
- Runs in the CLI, IDE, web and iOS from one account. [1]
- Offers an API-key route billed per token for developers who prefer usage-based pricing. [1]
- Documents an SDK, GitHub Action and enterprise and security admin guides. [2]
Limitations
- Supports OpenAI's models rather than several vendors' models. [1]
- API-key use does not include cloud-based features such as GitHub code review and Slack. [1]
- Pricing and usage measurement changed during 2026, so published guides go stale quickly. [4]
- Human-approval and permission controls were not reviewed in the sources used here. [2]
Best for
- ChatGPT subscribers who write code
- Teams that want cloud task delegation and automated review
- Developers who want an open-source-style CLI with OpenAI models
May be less suited to
- Teams that need to choose between several model vendors
- Developers who need a documented self-hosted deployment
Top OpenAI Codex alternatives and competitors.
OpenAI Codex alternatives
Developers look for OpenAI Codex alternatives when they want another model vendor, an open-source tool, or a…
Explore →Related productClaude Code
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Explore →Related productGitHub Copilot
GitHub's AI coding assistant and agent: code completions, chat, a cloud agent, a CLI and code review, across…
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Google's open-source terminal agent for Gemini models, with a free tier for personal Google accounts and a…
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Explore →OpenAI Codex compared with similar AI coding agents.
Summaries come from each profile. This is a side-by-side aid, not a ranking.
| Product | Interface | Model choice | Free tier | Pricing model | Human oversight |
|---|---|---|---|---|---|
| OpenAI Codex | CLI, IDE extension, desktop app, web and iOS | OpenAI models | Yes (limited, via ChatGPT Free) | Included in ChatGPT plans, or API per token | Not documented in sources reviewed |
| Aider | Terminal (command line) | Almost any LLM, including local models | Yes (open source) | Free software; pay model usage | Git commits can be reviewed and undone (third-party) |
| Amp | CLI and editor extensions | Several frontier models | Yes (ad-supported daily grant) | Credits and subscriptions | Not documented in sources reviewed |
| Augment Code | VS Code, JetBrains, CLI and Slack | Frontier models; credit cost varies | No (trial reported) | Credit-based subscriptions | Not documented in sources reviewed |
| Bolt.new | Browser-based AI app builder | Not documented in sources reviewed | Yes (1M tokens a month) | Subscription with token allowances | Not documented in sources reviewed |
| Claude Code Compare | Terminal, VS Code, JetBrains, desktop app, web | Claude models (Anthropic) | Not documented in sources reviewed | Included in paid Claude plans, or usage-based API billing | Permissions, sandboxing and checkpoints documented |
OpenAI Codex vs competitors: head-to-head comparisons.
Claude Code vs OpenAI Codex
Claude Code and OpenAI Codex are agents from two model vendors that both work in the terminal. Claude Code…
Explore →ComparisonOpenAI Codex vs Ona
OpenAI Codex and Ona both run coding agents in the cloud, and OpenAI announced plans to acquire Ona in June…
Explore →OpenAI Codex discussions and buying questions.
No published discussions mention this product yet.
OpenAI Codex questions and answers
What is OpenAI Codex?
OpenAI Codex is OpenAI's coding agent. It works in a terminal CLI, an IDE extension, a desktop app and cloud environments, and uses OpenAI's models.
Is OpenAI Codex free?
OpenAI's pricing page lists Codex as included in ChatGPT Free and Go for lighter use, with Plus at $20 per month and higher tiers for heavier use. Free is scoped for exploration, so productive daily use usually needs a paid plan or an API key.
How much does Codex cost?
There is no separate Codex subscription. It is included with ChatGPT plans (Go $8, Plus $20, Pro from $100 per month per OpenAI's pricing and help pages), or billed per token through an API key.
Is the Codex CLI open source?
Third-party guides describe the Codex CLI as open source under the Apache-2.0 licence. Check OpenAI's repository for the current licence.
Is Codex an autonomous agent?
We classify it as an agentic tool. OpenAI documents delegating tasks to a cloud agent, but the sources reviewed here do not describe fully unsupervised operation, and developers review the results.
What is the difference between Codex CLI and Codex cloud?
The CLI and IDE extension run locally in your environment, while Codex cloud runs delegated tasks in OpenAI-hosted environments and enables cloud-based integrations such as code review.
How does OpenAI Codex compare with Claude Code?
Both are terminal-capable agents from model vendors. Codex uses OpenAI models and is bundled with ChatGPT plans, while Claude Code uses Anthropic's Claude models. See the Claude Code vs OpenAI Codex comparison.
What integrations does OpenAI Codex support?
Documented integrations and ecosystem items include GitHub code review, Slack, VS Code and JetBrains IDE extensions, TypeScript SDK and GitHub Action, ChatGPT sign-in or OpenAI API key. API details: Codex can run with an OpenAI API key and has an SDK; API usage is billed at standard API rates.
What are the limitations of OpenAI Codex?
Supports OpenAI's models rather than several vendors' models. API-key use does not include cloud-based features such as GitHub code review and Slack. Pricing and usage measurement changed during 2026, so published guides go stale quickly.
Which platforms does OpenAI Codex run on?
OpenAI Codex is documented as available on: CLI, IDE extension, Desktop app, Web (ChatGPT), iOS.
Is OpenAI Codex an AI agent or an AI assistant?
We classify OpenAI Codex as: Agentic tool. A human-directed tool that can plan, edit and run actions, with the user reviewing or approving changes. The classification is based on vendor documentation and is not an endorsement.
When was the OpenAI Codex profile last verified?
Sources for this profile were last reviewed on 4 Nov 2026. 5 sources are listed under Sources, and prices and plans can change, so confirm with the vendor.
What are the main alternatives to OpenAI Codex?
The main alternatives to OpenAI Codex covered on Stack18 are Claude Code, GitHub Copilot, Gemini CLI and Cursor. Claude Code may suit Terminal-first developers. GitHub Copilot may suit developers and teams standardised on GitHub. Gemini CLI may suit developers who want to start free in the terminal. See the OpenAI Codex alternatives guide for a side-by-side table.
Where this information comes from.
- Codex Pricing OpenAI Developers Official docs Accessed 4 Nov 2026
- Codex quickstart OpenAI Developers Official docs Accessed 4 Nov 2026
- Codex help article: admin controls and Compliance API OpenAI Help Center Official Accessed 4 Nov 2026
- OpenAI Codex Pricing 2026: Plans, Credits, Rate Card, and Usage Limits Explained UI Bakery Third-party Accessed 4 Nov 2026 Used for the Pro tier multiples and the April 2026 pricing change.
- Codex CLI, plainly A Guide to Cloud Third-party Accessed 4 Nov 2026 Used only for the CLI licence and implementation language.
Further official pages: Codex pricing (external) · Codex documentation (external)
Plans, surfaces and integrations were checked against OpenAI's Codex pricing page and quickstart. Pro tier multiples, the CLI licence and the 2026 pricing change come from third-party summaries. Agent behaviour was not tested.
Stack18 has not tested this product or received anything from the vendor for this profile. Editorial summaries of vendor information are not endorsements. Confirm details with the vendor before buying.
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