AI
Codex
OpenAI’s coding agent, the counterpart to Claude Code. It reads a codebase, makes changes across files, and runs commands from the terminal, an editor, or the cloud.
Codex is OpenAI’sThe AI company behind ChatGPT, the GPT models, and Codex. Its models also power much of Microsoft Copilot. coding agent. Like Claude CodeAnthropic's agentic coding tool. Runs in your terminal, reads files, writes code, and executes commands directly in your development environment., it doesn’t just suggest code: it reads a whole codebase, makes coordinated changes across many files, runs the tests, and works through the errors until the change works. It can be used from the terminal, inside a code editor, or in the cloud, where it can be handed a task to finish on its own.
The name has a history. OpenAI first used “Codex” in 2021 for a model trained on code, which powered the original GitHub Copilot. The current Codex is a different product, an agent built on OpenAI’s latest models.
For most teams, Codex and Claude Code are close substitutes, and the better choice usually depends on which AI platform the organization already uses.