App: add Use Option as Meta for the integrated terminal on macOS

What variant of Codex are you using?

App (ChatGPT desktop / Codex desktop) on macOS

What feature would you like to see?

Please add a setting so the integrated terminal can treat the Option key as Meta, like Terminal.app’s Use Option as Meta key and iTerm2 / Ghostty / VS Code (terminal.integrated.macOptionIsMeta).

Use case. On macOS, Option is the usual Meta stand-in for readline / Emacs / zsh / fish bindings:

• Option+F / Option+B — forward / backward word
• Option+Backspace / Option+D — kill previous / next word
• Option+. — insert last argument

Those chords are muscle memory in every other terminal I use. In Codex’s integrated terminal they currently type macOS Option characters (ƒ, ∫, …) instead of sending Meta / ESC sequences to the PTY.

Current behavior. The app’s terminal settings only cover:

• default terminal location (bottom / right)
• integrated terminal shell

Settings > Keyboard Shortcuts remaps app commands, not PTY input. There is no Option-as-Meta toggle in the UI or in ~/.codex/config.toml.

The integrated terminal is xterm.js. xterm already has macOptionIsMeta (default false). The app constructs the terminal with font / cursor / theme options and does not pass macOptionIsMeta, so Option stays a third-level shift.

Suggested behavior.

1. Add a macOS-only setting, e.g. Use Option as Meta key, under General / terminal settings.
2. Persist it (same store as defaultTerminalLocation is fine).
3. When creating or updating the xterm instance, set macOptionIsMeta from that setting and apply it to already-open tabs.
4. Document the tradeoff: enabling it disables Option-based special-character input (ø, é, …) in that terminal, same as Terminal.app.

Default can stay off for existing users. A left/right Option split (iTerm-style) would be nice later, but a single toggle is enough.

Additional information

• App: ChatGPT / Codex desktop 26.810.52044 (com.openai.codex)
• OS: macOS 26.5.2 (25F84), Apple Silicon
• Related CLI issues (host terminal, not the app’s xterm): #3298, #4341, #9161
• Related app terminal customization: #25281

The desktop app source is not in this repo, and contributing.md says external PRs are not accepted, so this is a feature request rather than a patch.

The issue identifies the integrated terminal's xterm.js instance and the terminal settings store as the relevant entry points, but states that the desktop app source is not in this repository. First read docs/contributing.md and verify whether the desktop source is available elsewhere. Done means a persisted macOS-only toggle updates existing and newly opened terminals and documents the loss of Option-based special-character input.