OpenAI Codex
OpenAI's cloud-based coding agent that reads, edits, and runs code. Delegates tasks to cloud VMs, creates PRs, and automates code review — powered by GPT-5.5.
OpenAI Codex is OpenAI's coding agent that can read, edit, and run code. It helps you build faster, fix bugs, and understand unfamiliar code. With Codex cloud, tasks run in the background on cloud VMs, including in parallel, with automatic PR creation and code review.
Key Features
- Cloud execution: Tasks run on isolated cloud VMs, keeping your local environment clean
- Parallel tasks: Run multiple coding tasks simultaneously
- GitHub integration: Tag
@codexon issues and PRs to trigger tasks directly - Automatic code review: AI-powered review on every diff
- Multi-model support: GPT-5.5, GPT-5.4, GPT-5.4 mini, GPT-5.3-Codex-Spark
- IDE extension: Kick off cloud tasks from VS Code and monitor progress
- Slack integration: Trigger and receive updates via Slack
Pricing
Included in ChatGPT plans:
| Plan | Local Messages/5h | Cloud Tasks/5h | Code Reviews/5h | |------|-------------------|----------------|-----------------| | Free | Limited | — | — | | Plus | 15-80 (GPT-5.5) | — | — | | Pro 5x | 5x Plus | 5x Plus | 5x Plus | | Pro 20x | 20x Plus | 20x Plus | 20x Plus | | Business | Pay-as-you-go | Pay-as-you-go | Pay-as-you-go |
API key usage available at standard API rates for additional local tasks.
How It Works
- Connect GitHub: Link your repositories
- Write a prompt: Describe the task or reference an issue
- Codex plans: Reviews your codebase and generates a plan
- Cloud execution: Runs on a cloud VM with full shell access
- PR created: Reviews diff, creates pull request