OpenAI Codex ChatGPT

OpenAI Codex is a cloud-based software engineering agent designed to handle multiple coding tasks in parallel, accessible via ChatGPT Pro, Team, and Enterprise

Codex operates in isolated cloud sandboxes, where it can read, edit, and test code, with each task tracked and verifiable through logs and test outputs

Users interact with Codex through the ChatGPT sidebar, assigning tasks by prompt and selecting “Code,” with real-time progress tracking

Codex can write features, fix bugs, refactor, write tests, scaffold new features, draft documentation, and submit pull requests

The agent uses AGENTS.md files and project documentation to better understand project structure, commands, and best practices

Codex-1, an optimized version of OpenAI o3, powers Codex, trained on real-world coding tasks for human-like code and PR style

Codex CLI is a lightweight, open-source terminal agent using a scaled-down codex-1 (o4-mini) for fast code editing and Q&A

Security is prioritized: Codex runs in isolated containers, blocks internet access during execution, and only uses code from GitHub and user dependencies

Pricing for developers is $1.50 per 1M input tokens and $6 per 1M output tokens, with prompt caching discounts; initial access is free for some users

Future plans include more interactive workflows, mid-task coaching, deeper tool integrations, and asynchronous agent collaboration