ChatGPT Codex

ChatGPT Codex is OpenAI's coding agent, now integrated directly into the ChatGPT app alongside a CLI and IDE extension. It is designed to handle real engineering work end to end—from routine pull requests to complex refactors, migrations, and feature builds—powered by OpenAI's frontier coding models. The Codex CLI is open source under the Apache 2.0 license, while the cloud-based Codex Web experience lives inside ChatGPT.

What It Is

Codex is a multi-surface coding agent that operates across three environments: Codex in ChatGPT (the cloud-based web app), the Codex IDE extension (for VS Code, Cursor, Windsurf, and similar editors), and the Codex CLI (a locally-running terminal agent). All three surfaces connect through a single ChatGPT account. The cloud agent uses built-in worktrees and cloud environments to run agents in parallel across projects, while the CLI runs locally on macOS, Linux, and Windows.

How the Agent Works

Codex is built around multi-agent workflows. Key capabilities include:

• Parallel execution: Multiple agents work simultaneously across repositories using built-in worktrees and cloud environments.
• Skills: Teams can teach Codex their standards, workflows, and conventions so it applies them consistently across tasks with less supervision.
• Scheduled background work: Codex can be set to handle routine but important tasks like issue triage, alert monitoring, and CI/CD work autonomously.
• Code review: Codex performs high-signal PR reviews, catching bugs and quality issues before they ship.
• End-to-end task completion: Builds features, handles complex refactors, generates tests, and completes migrations.

Surfaces and Deployment

Codex is available in three distinct deployment modes:

• Codex in ChatGPT: The cloud-based command center, accessible via chatgpt.com/codex. Currently in waitlist access for the app experience.
• Codex IDE Extension: Installable directly in VS Code, Cursor, Windsurf, and other compatible editors via developers.openai.com/codex/ide.
• Codex CLI: An open-source, locally-running agent installable via npm (npm install -g @openai/codex), Homebrew, or a shell script. The CLI is written in Rust and licensed under Apache 2.0, with nearly 97,000 GitHub stars as of mid-2026.

Update: Codex Moves into ChatGPT

OpenAI renamed and moved Codex into the ChatGPT app, consolidating it alongside ChatGPT Work. The current landing page at chatgpt.com/codex positions Codex as a first-class feature within ChatGPT plans rather than a standalone product. The CLI repository (github.com/openai/codex) reached version 0.144.1 as of July 2026, with active development continuing on the main branch. The project was created in April 2025 and has accumulated over 14,000 forks.

Who It's For

Codex targets software engineering teams that want to accelerate development velocity. The product page attributes quotes from engineers at companies including Wonderful, Harvey, Sierra, Ramp, Cisco Meraki, and Duolingo, describing use cases like cutting early iteration time, handling cross-team refactors, and improving PR review quality. The Business plan is positioned for teams using Codex across multiple repositories with admin controls.