OpenAI Launches Codex, an AI Coding Agent
OpenAI has unveiled Codex, its most advanced AI tool for software developers to date. The new coding agent is powered by codex-1, a specialized version of OpenAI’s o3 reasoning model, tuned for coding tasks. It can build features, fix bugs, and answer questions—all in a cloud-based sandbox.
Unlike earlier tools, Codex doesn’t just generate code. It runs tests on its work and improves results iteratively. Connected to GitHub, it can preload your repositories, making the tool deeply contextual and ready to help fast. In many cases, Codex will complete tasks in under 30 minutes.
A Developer’s Virtual Teammate
Codex handles multiple jobs at once. Whether you need to debug, scaffold new features, or write documentation, it’s designed to assist. OpenAI’s agents lead, Josh Tobin, says the goal is for Codex to operate like a “virtual teammate.” Some tasks that take engineers hours—or even days—can now be completed faster.
Also read: OpenAI Launches Codex CLI to Bring AI-Powered Coding to the Terminal
Users on ChatGPT Pro, Team, or Enterprise can access Codex starting today. The tool appears in the ChatGPT sidebar and includes new buttons to assign tasks or ask questions about your code. OpenAI says usage will be generous at first, with limits introduced later. Additional credits will be available for purchase.
Safety, Speed, and Real-World Limits
Codex doesn’t have access to the open internet or external APIs. This keeps it secure, reducing the risk of misuse. It also means Codex may have trouble with tasks that require online data. Still, OpenAI says safety work from its o3 model carries over, and that Codex will refuse to create harmful code.
At the same time, the Codex CLI terminal agent is getting an upgrade. The new default model, o4-mini, is now available via OpenAI’s API. Developers can expect faster performance and cleaner output.
OpenAI’s push into coding tools is clear. With the release of Codex, it joins a growing race to make AI a core part of software engineering. And it may just change how developers write code forever.
