In a move to further integrate AI into software development, OpenAI has unveiled Codex CLI — a lightweight coding agent designed to run directly in the terminal.
Announced alongside the company’s newest models, o3 and o4-mini, Codex CLI connects OpenAI’s AI models with local development environments. The tool can write and modify code, execute tasks such as moving files, and interact with command-line interfaces.
OpenAI sees Codex CLI as a step toward its broader vision of “agentic coding.” CFO Sarah Friar recently introduced the idea of the “agentic software engineer” — a future where AI tools could take an app idea and autonomously develop and test it. Codex CLI doesn’t quite reach that level yet, but it lays the groundwork.
The tool is open source and designed for transparency and simplicity.
“Codex CLI is a lightweight, open-source coding agent that runs locally in your terminal,” an OpenAI spokesperson said. “The goal is to provide a minimal, transparent interface to connect models with code and computing tasks.”
OpenAI’s blog explains that users can combine screenshots or rough sketches with local code to take advantage of the models’ multimodal reasoning — all from the command line.
To encourage adoption, OpenAI is launching a $1 million grant program for developers. Selected projects will receive $25,000 in API credits to integrate and experiment with Codex CLI.
While powerful, AI coding tools come with inherent risks. Studies have shown that these tools can overlook or even introduce security vulnerabilities. Developers should exercise caution, especially when working with sensitive files or systems.
