codex - 💡(How to fix) Fix Codex Desktop Windows: terminal/code font setting is hidden and missing Geist Mono causes unreadable spacing

What version of the Codex App are you using?

Codex Desktop for Windows, observed on app version 26.602.30954.

What platform is your computer?

Windows 11 / Windows build shown by Command Prompt: 10.0.26200.8457.

What issue are you seeing?

The integrated terminal rendered text with extremely wide per-character spacing, making the terminal hard to read. The terminal itself was functioning, but the font metrics/rendering looked broken.

Local investigation showed the configured Codex Desktop dark-theme code font stack was:

[desktop.appearanceDarkChromeTheme.fonts]
code = '"Geist Mono", ui-monospace, "SFMono-Regular"'

However, Geist Mono was not installed on the system. Windows Terminal was configured normally with Consolas, so changing Windows Terminal settings would not address the embedded Codex terminal. Installing Geist Mono for the Windows user fixed local font resolution; after install, the font's internal family name is Geist Mono, matching the Codex config.

The confusing part is that this code/terminal font setting does not appear to be exposed in the Codex Desktop Settings UI. From a user perspective, the terminal looks broken, but there is no visible setting explaining that Codex is trying to use a missing font.

Expected behavior

Codex Desktop should either:

1. Expose the terminal/code font setting in the Settings UI, or
2. Detect when the configured font family is unavailable and show a warning/diagnostic, or
3. Ship/bundle the default font it configures, or
4. Fall back to a known-good installed Windows monospace font without broken spacing.

Actual behavior

The embedded terminal silently fell back to a bad rendering/font path and displayed text with huge character spacing. The user cannot discover or fix this from the Settings UI.

Local workaround

Install Geist Mono manually, then restart/refresh Codex Desktop.

On this Windows machine, installing the current Vercel Geist release and registering the per-user fonts resolved font availability:

• Source: vercel/geist-font release v1.7.2
• Installed under: %LOCALAPPDATA%\Microsoft\Windows\Fonts
• Verified internal font family: Geist Mono

Related issues / duplicate search

I found the closed enhancement:

• #10620 - Codex App: Set font for built-in terminal

I also found a related closed issue where a local Geist Mono fallback finding was mentioned:

• #18311 - included a note that installing Geist Mono fixed local terminal font resolution

This report is narrower: on current Codex Desktop for Windows, the app can be configured to use an unavailable Geist Mono font, the terminal becomes unreadable, and the relevant setting/diagnostic is not visible in the UI.