OpenAI Codex
Verdict
Evidence: Editorial assessmentOpenAI Codex is OpenAI's coding agent. Its open-source CLI runs in the terminal and signs in with a ChatGPT Plus, Pro, Business, Edu or Enterprise account, so many developers already have access. We could not confirm current ChatGPT prices or the cloud agent's limits on OpenAI's site, so check those before you rely on it for a team.
Quick facts
| OpenAI Codex | |
|---|---|
| Maker | OpenAI |
| Category | AI Coding Assistants |
| Pricing model | Paid only |
| Status | Active |
| Official site | github.com |
| Data last checked | 5 October 2026 |
Key facts and sources
| Claim | Detail | Evidence | Source |
|---|---|---|---|
| What it is, licence and access | OpenAI describes Codex CLI as a lightweight coding agent that runs in your terminal. Apache License 2.0. Sign in with ChatGPT to use it as part of a Plus, Pro, Business, Edu or Enterprise plan, or use an API key. | Verified | openai/codex on GitHub, 5 October 2026 |
| Agent product releases | Reported: ChatGPT Work (27 August 2026), Codex with GPT-6 Astra (3 September) and an Agents API public beta (17 September). | Reported | ThursdAI release log, September 2026, 5 October 2026 |
| Release dates | GPT-6 Astra reported released 3 September 2026; GPT-6 Sol and Luna reported released 24 September 2026. A separate GPT-5.6 family with similar names shipped in July 2026. | Reported | ThursdAI release log, September 2026, 5 October 2026 |
Pricing
No prices are shown because we have not confirmed them on OpenAI Codex's own pricing page. Go to OpenAI Codex
Who should use it
- Developers who already pay for ChatGPT
- Terminal-based coding agent work with an open-source client
Who should skip it
- You need confirmed, published usage limits before buying (we could not verify them)
- You want an IDE-first experience with autocomplete
Limitations and risks
- ChatGPT plan prices are not shown here: openai.com could not be reached for verification on 5 October 2026.
- Reported September 2026 changes (GPT-6 Astra in Codex, Agents API beta) are not yet confirmed on OpenAI's site.
How it compares: OpenAI Codex alternatives
Claude Code
Anthropic's agentic coding tool that works in the terminal, in IDEs and on GitHub, editing files, running commands and handling git workflows.
Cursor
An AI code editor built on VS Code, with in-editor chat, multi-file agent edits and background agents.
GitHub Copilot
GitHub's AI coding assistant for code completion, chat, code review and agent tasks in major editors and on GitHub.
Gemini CLI
Google's open-source AI agent that brings Gemini models into the terminal for coding, file and shell tasks.
Shipable AI
Listed as a tool that automates parts of building and shipping code.
Rating
Not yet rated. We show a rating only when at least four of six criteria have documented evidence. How we rate AI tools
Common questions
Which ChatGPT plans include Codex?
OpenAI's Codex repository says you can sign in with ChatGPT to use Codex as part of a Plus, Pro, Business, Edu or Enterprise plan. You can also authenticate with an API key, which bills usage separately.
Is Codex CLI open source?
Yes. The Codex CLI is published on GitHub under the Apache 2.0 licence. The models it calls are not open source and are billed through ChatGPT or the API.
Sources
- openai/codex on GitHub · checked 5 October 2026
- ThursdAI release log, September 2026 · checked 5 October 2026