OpenAI's Codex wants to become your AI coworker

OpenAI's Codex, a cloud-based agent, aims to become your AI coworker by handling entire development workflows, marking the first major shift from AI assistance to AI delegation in software engineering. The `codex-1` model powers this agent, operating as a full development agent that handles tasks such as debugging multi-file issues, writing comprehensive tests, and implementing features across complex codebases. Unlike earlier models, Codex is trained using reinforcement learning on actual coding tasks, achieving 75% accuracy on OpenAI's internal software engineering benchmarks and strong performance on SWE-Bench Verified. The system runs in isolated cloud containers with no internet access, reads AGENTS.md files for project-aware intelligence, and executes end-to-end workflows that include implementing features, running test suites, fixing errors, and committing changes. This represents a fundamental change in how AI assists knowledge work, shifting from making humans faster at manual tasks to taking over entire workflows while keeping humans in control of decisions and review.