OpenAI Codex

OpenAI Codex is OpenAI's coding agent for building and shipping software. It runs in the ChatGPT desktop app for macOS and Windows, in the Codex CLI, in an IDE extension for VS Code and compatible editors such as Cursor and Windsurf, on the web as Codex cloud, and on iOS, and Xcode and JetBrains IDEs provide their own Codex integrations. Codex writes features, fixes bugs, refactors code, runs tests and opens pull requests for review, working locally or in cloud environments. The Codex CLI is open source under the Apache-2.0 license on GitHub, where it has 126k stars, and OpenAI's Codex page quotes engineers from Ramp, Duolingo, Harvey AI, Sierra and Cisco Meraki. Codex can run several tasks in parallel in separate worktrees, delegate work to subagents and custom agents, and use Skills, plugins, connectors and MCP servers. Scheduled tasks let it run work on a schedule or from supported app events, and Sites, in public beta on eligible plans, publishes hosted web projects. Code review runs on GitHub pull requests and GitLab merge requests when users tag @codex or turn on automatic reviews, and a GitHub Action, the Codex SDK and codex exec support scripted and CI workflows. Codex cloud integrates with Slack and Linear, and local Codex surfaces can be configured to use OpenAI models through Amazon Bedrock. Codex connects to external MCP servers to use their tools. OpenAI removed the standalone codex mcp-server command and codex-mcp-server binary on September 5, 2026, after deprecating them on August 24, 2026, so Codex no longer runs as an MCP server for other assistants. Codex is included in ChatGPT plans and priced in USD on OpenAI's Codex pricing page. Free includes Codex for quick coding tasks, and Go at $8/month covers lightweight coding tasks, both with GPT-6 Luna in the desktop app subject to rollout. Plus at $20/month adds Codex on the web, in the CLI, in the IDE extension and on iOS, cloud integrations such as automatic code review and Slack, GPT-6 Sol and GPT-6 Luna, and extra usage through ChatGPT credits. Pro starts at $100/month for 5x or 20x the Codex usage of Plus. Business costs $20 per user per month billed annually or $25 billed monthly, for two or more users, and adds SAML SSO, MFA and no training on business data by default. Enterprise and Edu are sold through sales and add SCIM, EKM, role-based access control, audit logs through the Compliance API, and data retention and residency controls. Codex can also run with an API key at API pricing, without the cloud features. Usage limits are shared with ChatGPT Work and vary with the model, the size of the task and the context. Codex is best for developers and teams already on ChatGPT plans who want one coding agent across the terminal, the IDE, the desktop app and the cloud, tied into GitHub or GitLab review. Developers who want an agent built on Anthropic's Claude models should consider Claude Code, and developers who want the agent inside an AI-first code editor should consider Cursor. The Codex documentation covers GitHub and GitLab and does not mention Bitbucket. OpenAI lists SOC 2 Type 2 and ISO 27001 among the security certifications for its business plans. Business and Enterprise data is not used for training by default, while Free, Go, Plus and Pro follow ChatGPT's consumer setting, where content can be used to train OpenAI's models unless the user opts out. Current state Q3 2026: On September 22, 2026 OpenAI began rolling out GPT-6 Sol and GPT-6 Luna to Codex and ChatGPT Work at lower token prices than their GPT-5.6 predecessors. GPT-5.5 retires from ChatGPT, ChatGPT Work and Codex on all plans on October 14, 2026, and the OpenAI API is not affected. The Codex MCP server was removed on September 5, 2026.