Author: IBL News

Mikel Amigot, IBL News | New York

OpenAI launched a paid software engineering agent called Codex yesterday. The agent iteratively runs tests on its code until it achieves passing results.

Vibe coding tools have surged in popularity in recent months, and OpenAI is attempting to capture a share of that market segment. In early May, the maker of ChatGPT reportedly closed a deal to acquire Windsurf, the developer behind another popular AI coding platform, for $3 billion. The launch of Codex shows that OpenAI is also building its own AI coding tools.

Issued as a research preview, Codex can work on many tasks in parallel, write features, answer questions about the user’s codebase, fix bugs, and propose pull requests for review.

Each task runs on a sandboxed virtual computer in the cloud, preloaded with the repository.

According to OpenAI, it generates code that closely mirrors human style and PR preferences, adheres precisely to instructions, and can iteratively run tests until it receives a passing result.

Codex, accessible through the sidebar in ChatGPT, is powered by Codex-1, a version of OpenAI o3 AI reasoning model optimized for software engineering tasks.

OpenAI is also updating Codex CLI, the company’s recently launched open-source coding agent that runs in the user’s terminal, with a version of its o4-mini model that’s optimized for software engineering.

In OpenAI’s API, it costs $1.50 per 1M input tokens (750,000 words) and $6 per 1M output tokens.