OpenAI unveils GPT-5 Codex for advanced developer workflows

OpenAI has introduced GPT-5 Codex, a specialized version of its GPT-5 model optimized for coding agent processes. The new model is intended to help engineers think freely, collaborate on little tasks, and work independently on complex assignments.

The model was trained on real-world software engineering tasks such as project start-up, restructuring huge codebases, documentation improvement, troubleshooting, and thorough code review.

A crucial innovation is its capacity to dynamically assign “thinking time” according to the complexity of work, delivering quick responses for simple requests and devoting more reasoning and iteration to harder jobs.
Internal tests revealed the model could work autonomously for more than seven continuous hours, during which it refined solutions and addressed test failures.

With more reliability, the model also showed enhanced capabilities in code reviews by assessing a pull request’s intent, outlining dependencies, and flagging required issues.

OpenAI recommends using GPT-5 Codex within its specialized environments to maximize functionality. The platform introduces new features and upgrades for the command-line interface (CLI), integrated development environment (IDE), and cloud integration.

Users can now attach screenshots and diagrams to preserve context during discussions, enhancing clarity and collaboration. There’s also a built-in to-do list that aids in task management, making it easier to track progress.

Furthermore, the integration with external tools has been enhanced, enabling more seamless connections to web search and other platforms. The terminal user interface has also undergone enhancements, featuring improved formatting for diffs and tool outputs.

Additionally, access modes have been simplified into read-only, auto, and full, providing developers with granular control over the agent’s autonomy.

A new IDE extension integrates directly with environments like VS Code, allowing for context-aware interactions. The system can see open files and current selections to generate faster, more precise results.

Codex Cloud integration has been enhanced to significantly reduce task start times. The system can now automatically detect setup scripts, configure dependencies, execute installation commands, and generate screenshots of web UI progress to attach to tasks or pull requests.

Safety is a top priority for OpenAI. GPT-5 Codex operates in a sandbox environment with no network access, requiring explicit permission for risky commands. Developers can customize security policies, including network limits and approvals. Each task includes logs and citations for human validation.

GPT-5 Codex is available through various ChatGPT subscription tiers (Plus, Pro, EDU, Business, and Enterprise) with usage limits based on the selected plan. It can also be accessed via the Responses API at the same cost as standard GPT-5. For developers, it serves as a context-aware collaborator, enhancing workflows and early bug detection.