OpenAI Codex
OpenAI Codex by OpenAI: what it does, how it works, pricing and adoption — sourced and dated.
Coding agents Closed product ≈62.0K GitHub stars (2026-10)
Codex is OpenAI's coding agent system, relaunched in 2025 across four surfaces: an open-source Rust CLI (about 62,000 GitHub stars), an IDE extension, cloud tasks inside ChatGPT, and an SDK. You assign it tickets and tasks; it edits code, runs tests in a sandbox and returns diffs for review. Usage is metered through your ChatGPT plan.
How it works
Delegate whole tasks and review the result: cloud tasks run in isolated sandboxes in parallel, while the CLI and IDE extension work locally under your choice of approval mode (suggest, auto-edit, full-auto). Codex also reviews pull requests on GitHub when connected.
The facts
| Maker | OpenAI |
| Type | Agent product |
| Category | Coding agents |
| Status | Active |
| Launched | 2025 |
| License | Apache-2.0 (CLI) |
| Models | Runs on OpenAI's frontier models only (the GPT-5.6/GPT-6 generations in Codex-tuned variants). |
| GitHub stars | 62,000 (snapshot 2026-10) |
| Website | https://openai.com |
Pricing
Included with ChatGPT plans rather than sold separately: Free (limited, desktop app), Go $8/month, Plus $20/month, Pro $100/$200/$500 per month, Business $20/user/month billed annually; usage beyond plan limits via purchased credits. API-key use of the CLI/SDK/IDE extension is billed at API token rates and excludes cloud features such as GitHub code review.
Pricing model: Bundled subscription / API usage · Source: published tiers · checked Oct 14, 2026
Choosing the model underneath? See best AI for coding and the League standings.
Also in Coding agents
- Devin — Cognition
- Claude Code — Anthropic
- Cursor — Anysphere
- GitHub Copilot — GitHub (Microsoft)
Sources
- AICoolies — Codex vs GitHub Copilot (verified Oct 14, 2026)
- ScriptByAI — AI coding plan comparison 2026
- MorphLLM — OpenAI Codex vs GitHub Copilot (2026)
Profile verified Oct 14, 2026. Spotted an error? Every figure above links to its source.