Codex desktop app: OpenAI's app on Mac, Windows and Linux, and Codex CLI in tabs with its cost

There is a Codex desktop app: OpenAI folded it into the ChatGPT desktop app. Install ChatGPT for macOS or Windows, or the Linux preview, sign in, and choose Codex. OpenAI's app is a window for one agent, free with a plan. Caprock, a free desktop app, is the record across agents — Codex and Claude Code sessions whether or not it started them, limits across subscriptions, what each pull request cost — with Codex CLI in its tabs.

Where the Codex app went

developers.openai.com/codex/app now redirects to OpenAI's page for the ChatGPT desktop app. Its quickstart says it plainly: install ChatGPT, sign in, then "Choose ChatGPT or Codex". The Linux packages still download from a path named codex-app-prod. If you search for the Codex app, this is it.

Install the Codex desktop app

Open the app, sign in with your ChatGPT account, then open a folder or start a project and pick Codex.

What the Codex app does

From OpenAI's docs, read 20 October 2026:

• Worktrees. Pick Worktree under the composer and Codex works on a Git worktree of the branch you choose, so several chats in one repository do not collide. Handoff moves a chat and its code between the worktree and your own checkout.
• A terminal per chat, scoped to its project or worktree (Ctrl+`); the agent can read what it prints.
• On Windows, it runs in PowerShell with OpenAI's Windows sandbox, or inside WSL2.
• From the phone. The ChatGPT app for iOS or Android starts, steers and approves Codex work on a connected Mac or Windows PC, paired with a QR code. More in Codex remote control.

Plans and limits

OpenAI's pricing lists Codex in the desktop app on the Free and Go plans (GPT-6 Luna, "subject to rollout"); Plus, at $20 a month, adds Codex on the web, in the CLI, in the IDE extension and on iOS. Local messages and cloud chats share your plan's allowance, estimated per five-hour period for Plus (Pro plans currently have no five-hour limit), and "weekly limits may also apply". OpenAI's place to see where you stand is the usage dashboard, or /status inside a CLI session. The details, plan by plan: Codex pricing and usage.

What the Codex app does not cover

• One agent. It runs Codex. Claude Code, OpenCode or Gemini CLI need their own windows.
• Linux is a preview, and some features are not there yet: OpenAI names Computer Use as macOS and Windows only.
• A phone reaches a Mac or a Windows PC, signed in to the same ChatGPT account; OpenAI's mobile page names no Linux host.

Codex CLI in tabs: Caprock

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Caprock is a free, open-source desktop app for macOS, Windows and Linux that records every agent on the machine and runs the agents' own terminal programs. With Codex CLI installed, New agent offers Codex next to Claude Code, OpenCode, Gemini CLI, Grok Build and Hermes Agent:

• A terminal tab per session, in the project you pick; ⌘E opens a shell beside it, up to four panes a tab. Closing a tab ends an idle session, its conversation saved, and asks about one still working.
• A chat view of the same session: your prompts, what Codex wrote, each command on one line.
• Project instructions — a system prompt per project. What you write for a project reaches every Codex session Caprock starts there as Codex's developer instructions (-c developer_instructions=…), beside the repository's AGENTS.md. Since 0.82.0.
• What it costs. Codex reports tokens, not money; Caprock prices each turn from its table of OpenAI list prices and adds Codex to the same per-project table as Claude Code. A modelled figure, not a bill.
• Plan limits. Codex's 5-hour and weekly windows, as Codex last wrote them into a session transcript, on the Cost screen and in the menu bar. Some ChatGPT plans have no 5-hour window, and then none is shown.

It also reads the sessions you run in OpenAI's own app. The app writes the same transcripts as the CLI, under ~/.codex/sessions/, and names itself in each one. On my machine, 112 of the 195 Codex transcripts on disk on 7 October 2026 say they came from Codex Desktop; Caprock counts their cost with the rest, except the Claude Code sessions the app imported, which it already has from Claude Code. codex resume --all lists the app's threads in the terminal too: resuming Codex sessions.

What Caprock does not do for Codex

• It does not run OpenAI's app. It starts the codex CLI you installed, on your own sign-in.
• Permission prompts are answered in the terminal. Approve and Deny buttons on desktop notifications (macOS and Linux) and Telegram alerts are for Claude Code sessions only.
• Some costs are an upper bound. About half of Codex's token reports give a total without splitting cached input out; Caprock prices that total as fresh input.

Which to use

• The ChatGPT desktop app — you use Codex alone and want OpenAI's own window, its worktree Handoff and its phone link.
• Codex CLI in your terminal — you script it with codex exec, or you live in tmux.
• Caprock — you run Codex and Claude Code side by side and want one record of their limits and what each session and pull request cost. Install it, or see how it compares with other agent apps.