Codex runs in a few places depending on how you use it: in the Codex app on macOS and Windows, in the Codex CLI as a local cross-platform agent, and in cloud workflows like GitHub Copilot or managed enterprise platforms. The simplest answer is that it can run locally or in the cloud , depending on the product setup.

Where it runs

  • Desktop app: OpenAI’s Codex app is available on macOS and Windows.
  • Local CLI: Codex CLI is described as a cross-platform local software agent.
  • GitHub workflows: Codex can run inside GitHub.com, GitHub Mobile, and VS Code for Copilot users.
  • Enterprise platforms: Some companies route Codex through managed infrastructure like Amazon Bedrock or unified agent control planes.

Practical takeaway

If you mean “where does the code actually execute?”, the answer is usually in a sandboxed environment managed by the platform , not directly on your laptop alone. For local CLI use, part of the workflow happens on your machine; for cloud and enterprise setups, the execution happens remotely in managed infrastructure.

Quick scoop

So, in plain English: Codex can run locally, in a desktop app, or in the cloud , and the exact place depends on which Codex product or integration you’re using.