OpenAI Codex

OpenAI Codex is a coding agent from OpenAI. It reads a code repository, edits files, runs commands and tests, and reviews changes. It runs on your computer in the Codex CLI, in an IDE extension (VS Code, Cursor, Windsurf; Xcode and JetBrains IDEs have their own integrations) and in the ChatGPT desktop app. It also runs in the cloud (Codex Cloud), where each task has its own workspace and can open a pull request.

Codex is included in ChatGPT plans (US prices): Free ($0) and Go ($8/month) with limited access, Plus ($20/month), Pro ($100, $200 or $500/month) and Business ($20 per user/month billed annually, or $25 billed monthly). Enterprise and Edu are priced by sales. It can also run with an OpenAI API key at API prices, without the cloud features.

The Codex CLI is open source under the Apache-2.0 licence and runs on macOS, Linux and Windows. OpenAI launched Codex in April 2025.

Made for

Software developers and engineering teams, from people on a personal ChatGPT plan to businesses and enterprises. OpenAI also shows designers, product managers and data scientists using it.

Use cases

• Fix bugs and refactor code in a local repository
• Review pull requests and uncommitted changes
• Run long coding tasks in the cloud
• Run several agents on different tasks in parallel
• Automate coding steps in scripts and CI with codex exec
• Connect external tools through MCP servers

An alternative to

• Claude Code

  Included in every ChatGPT plan, even Free and Go ($8 a month); Claude Code needs the $20 Pro plan or higher.

• Cursor

  Works in your terminal, your IDE, the ChatGPT desktop app and the cloud, inside a ChatGPT plan you may already have.

• GitHub Copilot

  The Codex CLI is open source under Apache 2.0, and cloud tasks each get their own workspace and can open a pull request.

Alternatives to OpenAI Codex 6

AI Agents

Claude Code

AI coding agent from Anthropic for the terminal, IDE, desktop and web

PaidWebMacWindowsLinuxAPI / CLI

Uses Anthropic's Claude models, and also runs through Amazon Bedrock, Google Cloud and Microsoft Foundry.

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Developer Tools

Cursor

AI code editor and coding agent for desktop, terminal, web and iPhone

FreemiumWebiOSMacWindowsLinuxAPI / CLI

Models from OpenAI, Anthropic, Google and others in one editor.

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AI Agents

Gemini CLI

Google's open-source AI agent that runs Gemini models in your terminal

Open sourceMacWindowsLinuxAPI / CLI

Uses Google's Gemini models with Google Search built in, through Gemini Code Assist or Vertex AI.

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Developer Tools

GitHub Copilot

AI coding assistant and agents in the editor, terminal, desktop app and GitHub

FreemiumWebiOSAndroidMacWindowsLinuxAPI / CLI

Built into github.com: assign an issue to the Copilot cloud agent and it opens a pull request.

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AI Agents

Grok Build

Open-source coding agent for the terminal, made by SpaceXSI

Open sourceMacWindowsLinuxAPI / CLI

Uses xAI's Grok models and shares one weekly usage pool with Cursor in the X Subscription.

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AI Agents

Hermes Agent

Open-source, self-hosted AI agent with memory that lasts between sessions

Open sourceAndroidMacWindowsLinuxAPI / CLI

Runs in a terminal, a desktop app or chat apps; the agent is free and the Nous Portal plan is optional.

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