Claude Codex AI Projects

Claude Codex AI Projects describes a way of working where two AI systems, Claude and Codex, cooperate on the same project instead of competing. Codex is OpenAI's agentic AI platform (software that plans and executes tasks), and Claude Code is Anthropic's comparable tool. The idea behind combining them is simple: AI systems do a poor job of grading their own work. Ask Codex how good Codex's work was, and it will say it was great; ask Claude the same about Claude, and it will say it did awesome. Bringing in an outside system to review the first one fixes that. One demonstrated skill has Claude generate a plan, then hands it to Codex, which reports what is right, what is wrong, and what to change. That skill walks through a four-phase process, starting with reconnaissance (searching the web to learn what the project should do).

Why does this matter for AI development? First, honesty about quality: Codex can agree or disagree with Claude's plan, and the disagreement itself is useful signal. Second, division of labor: Claude can focus on the core application and front-end experience, where it excels, while Codex handles market intelligence and research. Third, portability: because you are building a foundation rather than locking into one vendor, you can switch tools when something new appears. Codex also works through plugins and lets you ask what to work on next, and it pulls your data toward the AI rather than the reverse, which helps it stay focused.

To use Claude and Codex together on a project, start by giving every coding agent (an AI that writes code) an easy way to read your project. In your project, you likely have a Claude.md file, which is project memory. Codex reads a similar file called agents.md. Create an agents.md file that uses your Claude.md as inspiration, then ask Codex to create a dot Codex config, move your skills into a dot agents folder, and move your agents into a dot Codex folder. Tell it to research both the Codex and Claude Code documentation so everything important converts over.

Once set up, the two tools can coordinate on the same project. Claude Code can build one part, then directly ask Codex for a second opinion. Codex reviews the actual work and sends feedback back, and Claude immediately acts on it. One example is a skill that grades the work of the first system: when Claude creates something or generates a plan, this skill brings in Codex, and Codex says what is right, what is wrong, and what to change. A four-phase process covers this, starting with reconnaissance, where it searches the web to figure out what to do.

You can also have two agents independently work on your project, both looking at your linear board and picking the next task. That way you don't need to get Codex up to date with what Claude Code is doing.

A practical habit when building with AI coding tools is to use two systems together instead of trusting one. The core problem is that AI systems do a poor job grading their own work (judging their own output). Ask Codex how good Codex's work was and it says great; ask Claude the same and it agrees. The fix is bringing in an outside AI system to review the first one. One skill (a reusable capability you install) runs a four-phase process: reconnaissance, where it searches the web and asks you questions, then Claude and Codex go back and forth adversarially for multiple rounds, then one system builds it.

Choosing which to lead matters. Claude Code tends to excel at front-end design (the look and feel of an app), so let it own the interface. Codex is built around work trees from the ground up, letting every thread run without bumping into your main version. Speed favors Claude: one dashboard build finished in under two minutes versus nearly eight for Codex. A common workflow hands a stuck problem from Claude to Codex without starting a new project, keeping both side by side.

Avoid drift (slowly wandering off task) by building out all your tasks upfront so each system knows what comes next. Because skills transfer between tools, what you build isn't locked to one vendor.