What is Codex by OpenAI?

Codex by OpenAI is a desktop application for macOS (and now Windows) that serves as a command center for AI-powered software development. It enables developers to manage multiple AI coding agents simultaneously, run tasks in parallel, and collaborate with agents over long-running, complex projects. The app redefines how software gets built—from pairing with a single agent on targeted edits to supervising coordinated teams of agents across the full lifecycle of designing, building, shipping, and maintaining software.

Who it's for

• Professional developers who need to delegate complex, multi-step coding tasks and supervise multiple agents working in parallel without losing context.
• Engineering teams that want to coordinate agents across shared repositories, using built-in worktree support to avoid conflicts while exploring different code paths.
• Hobbyists and learners who want to build software beyond simple code generation—using skills to create games, automate workflows, or tackle projects that span days or weeks.

Key features

Work with multiple agents in parallel

The Codex app provides a focused space for multi-tasking with agents. Agents run in separate threads organized by projects, so you can seamlessly switch between tasks without losing context. You can review changes in the thread, comment on the diff, and even open it in your editor to make manual adjustments. Built-in support for worktrees means multiple agents can work on the same repo without conflicts—each agent operates on an isolated copy of your code.

Go beyond code generation with skills

Codex evolves from an agent that writes code into one that uses code to get work done on your computer. With skills, you can extend Codex to tasks like gathering and synthesizing information, problem-solving, and writing. Skills bundle instructions, resources, and scripts so Codex can reliably connect to tools, run workflows, and complete tasks according to your team’s preferences. The app includes a dedicated interface to create and manage these skills.

Seamless session continuity

The app picks up your session history and configuration from the Codex CLI and IDE extension, so you can immediately start using it with your existing projects. This continuity means you can move between the app, terminal, and editor without losing progress or context.

What stands out

"The core challenge has shifted from what agents can do to how people can direct, supervise, and collaborate with them at scale."

This insight captures the essence of Codex. While other tools focus on what a single agent can accomplish, Codex addresses the real bottleneck: managing multiple agents working in parallel on long-running tasks. The app is purpose-built for this new way of working, where developers act as supervisors of coordinated agent teams rather than just pair programmers with a single AI.

Worth checking out if…

You're a developer or team lead who wants to move beyond single-agent coding assistants and orchestrate multiple AI agents across the full software lifecycle—from design through deployment and maintenance. If you've ever wished you could delegate a complex, multi-hour task to an agent while you focus on something else, or run several experiments in parallel without git conflicts, Codex is built for exactly that workflow. It's also worth exploring if you want to extend AI beyond code generation into broader automation tasks using skills.