ChatGPT Codex

ChatGPT Codex is an agentic coding assistant built by OpenAI and integrated directly into the ChatGPT app, available as a web experience, desktop app, IDE extension, and CLI. It is designed to handle real engineering work—from hard-to-find bugs and complex refactors to new feature development and automated pull request reviews—running tasks in parallel cloud environments that persist even when your laptop is closed.

What It Is

Codex is OpenAI's coding agent, positioned as a multi-surface tool that works wherever engineers work: inside ChatGPT on the web and desktop, in editors like VS Code, Cursor, and Windsurf via an IDE extension, and in the terminal via the open-source Codex CLI. The CLI is licensed under Apache 2.0 and available on GitHub. The broader Codex platform (cloud agent, web app, IDE extension) is a commercial product included in ChatGPT plans. OpenAI notes that Codex was renamed and moved into the ChatGPT app alongside ChatGPT Work.

How the Multi-Surface Architecture Works

Codex is designed around a single agent identity that spans multiple surfaces, all connected through a ChatGPT account:

• Codex in ChatGPT — the primary web and desktop interface for managing tasks, reviewing agent progress, and steering work across repositories
• Codex Cloud — reusable cloud environments per repo that keep tasks running after you close your laptop; accessible from any device
• Codex IDE Extension — integrates into VS Code, Cursor, and Windsurf for in-editor code review and task delegation
• Codex CLI — an open-source, locally-running coding agent installable via npm (npm install -g @openai/codex), Homebrew, or standalone installers for macOS, Linux, and Windows; written in Rust and currently at version 0.159.0

Multi-Agent Workflow and PR Review

The platform is built for parallel agent execution. Multiple agents can run simultaneously, using computer and browser tools to verify their own work against requirements. A dedicated code review capability automatically reviews pull requests, surfaces findings, and answers questions about changes. The Codex page quotes engineers from Ramp, Duolingo, Cisco Meraki, Harvey, and Sierra describing productivity improvements, though these are vendor-published testimonials.

Plugin and Tool Integration

Codex connects to external tools and services through ChatGPT's plugin system. Integrations shown on the product page include Supabase, Slack, Notion, Google Drive, and Google Calendar, allowing agents to pull context and take action across apps during engineering tasks.

Update: Codex CLI v0.159.0

The Codex CLI repository on GitHub (openai/codex) shows active development with 127,000+ stars and nearly 20,000 forks as of late 2026. The latest release is version 0.159.0 (published September 29, 2026), written in Rust. The repository was created in April 2025 and has seen continuous releases since. OpenAI has also signaled a product direction shift by moving the Codex brand into the ChatGPT app alongside ChatGPT Work, consolidating the agentic coding experience under the ChatGPT umbrella rather than as a standalone product.

Audience and Deployment Model

Codex targets professional software engineers and engineering teams. Individual developers can access it through ChatGPT Plus or Pro plans. Teams can use it through ChatGPT Business, which provides a shared workspace with admin controls. Enterprise deployments are available via sales contact. The open-source CLI can also be used independently with an API key, though sign-in via a ChatGPT account is the recommended path for plan-based access.