Codex: OpenAI's AI Agent That Acts Like a Real Engineer

Codex is an AI coding agent from OpenAI that can understand entire codebases, plan changes, execute them, run tests, and fix issues. Unlike traditional AI assistants that generate isolated snippets, Codex works like a team member, making multi-file changes and producing pull-request-ready code. This marks a shift from AI assistants to AI engineers, automating complex development workflows.