Codex App terminal block cursor is not readable
What version of the Codex App are you using (From “About Codex” dialog)?
26.602.40724
What subscription do you have?
Pro
What platform is your computer?
Darwin 25.5.0 arm64 arm
What issue are you seeing?
In the Codex App built-in terminal, a block cursor can make the character under the cursor unreadable. When the cursor shape is a block, the app appears to draw the cursor as a solid block without inverting the cell foreground and background. If the cursor color is close to the text color or the active theme colors, the character under the cursor effectively disappears.
This is especially noticeable in shells/editors that use a block cursor for normal mode or command mode. A block cursor is currently much less usable in the Codex terminal than in most standalone terminals.
More generally, the Codex App terminal does not appear to expose settings to customize terminal appearance details such as terminal colors, font, cursor shape, cursor color, or cursor rendering behavior. That makes it hard to work around readability/accessibility issues like this one from the app settings alone.
What steps can reproduce the bug?
- Open the Codex App terminal.
- Use a shell or terminal application that sets the cursor shape to block, for example:
printf '\e[2 q'- Place the cursor over visible text in the terminal prompt or inside a terminal editor.
- Observe that the character under the block cursor is difficult or impossible to read.
<img width="238" height="122" alt="Image" src="https://github.com/user-attachments/assets/9927257e-0d59-41af-9c74-a116e7920b97" />
What is the expected behavior?
When the terminal cursor shape is block, the Codex App terminal should render it like most terminal emulators: invert the foreground and background colors for the cell under the cursor. The character under the block cursor should remain readable regardless of the theme or configured cursor color.
In other words, block cursor rendering should behave as an inverse-video cell, not as a solid block that obscures the glyph.
The app should also provide terminal appearance settings, or otherwise inherit enough terminal appearance behavior, so users can customize terminal colors, font, cursor shape, and related cursor rendering preferences when needed.
Additional information
Workarounds such as forcing an I-beam cursor with printf '\e[6 q' can avoid the readability issue, but they require shell/editor-specific configuration and do not address the underlying block cursor rendering behavior or the lack of terminal appearance customization in the app.