OpenAI recently launched Codex, and now the company has updated the model with smarter agentic coding and deeper integrations. Designed for real-world software engineering, GPT-5-Codex isn’t just faster, it’s more capable of handling long, complex projects while catching critical bugs before they ship. Here are the five key updates that you should know about if you are a developer using Codex.
1. GPT-5-Codex
The new model is trained specifically on complex engineering tasks like building full projects, debugging, adding features and tests, and large-scale refactoring. It is now capable enough to dynamically adjust how long it “thinks” based on task complexity. Besides, it is snappier for small fixes, and is now able to work independently for 7+ hours on big refactors or feature builds.
2. Sharper Code Reviews
The GPT-5 Codex is not your regular AI model that writes code. It can now review the code that matches the intent of a pull request to actual changes, reasons across your entire codebase, and run tests to validate behavior. In tests with open-source commits, its comments were less likely to be incorrect or unimportant, helping teams focus on real issues. Plus, you can also summon it in GitHub with “@codex review” or ask for targeted checks like security vulnerabilities.
3. Unified Codex Experience
Two weeks ago, OpenAI unified Codex into a single product experience connected to your ChatGPT account. That means you can move between your IDE, terminal, the web, GitHub, or even the ChatGPT iOS app without losing context. Now the GPT-5-Codex is the default model for cloud tasks and reviews, but you can also opt in locally via the Codex CLI or IDE extension.
4. Revamped Codex CLI and IDE Extension
The Codex CLI has been rebuilt with agentic coding workflows and a cleaner terminal UI. You can now attach screenshots, wireframes, or diagrams to provide context, and Codex tracks its progress with to-do lists. Apart from that, approval modes are simplified to three levels for better control, and extended sessions are easier to manage thanks to conversation compaction.
Furthermore, the IDE extension brings Codex directly into VS Code, Cursor, and forks, allowing you to preview local changes, edit code faster, and shift work between the cloud and your local setup without losing continuity.
5. Faster and Smarter Cloud Performance
According to the company, they have improved Codex’s cloud infrastructure with 90% faster task completion times thanks to container caching. It is said to automatically set up environments by scanning for common scripts, install dependencies at runtime, and even spin up a browser to inspect its own work. It now allows you to share frontend design specs or UI bugs as images, and Codex will iterate visually and attach screenshots of its progress to tasks or PRs.
That’s all about Codex for now. All these updates make one thing clear: the AI model is now sharper, faster, and more reliable. It is now capable of catching bugs and managing the entire project single-handedly. However, how successful the updates turn out to be in the real world is something only time will tell. But so far, on paper, the update looks promising.
