OpenAI's cloud-based autonomous coding agent (launched May 2025) integrated into ChatGPT. Runs parallel tasks in isolated cloud sandboxes with access to GitHub repos — reads code, executes tests, opens PRs, and fixes bugs with minimal supervision. Powered by the o3 model and available to Pro/Plus/Team subscribers.
OpenAI Codex can deterministically code-gen a CLI from a specification.
Reality check: Codex might not be worth it for multimodal tasks, where other tools may perform better.