[BUG] AskUserQuestion preview panel truncates content with 'N lines hidden' — no way to scroll or expand

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When AskUserQuestion uses the preview option (side-by-side layout with options on the left and a preview panel on the right), the preview panel hard-truncates long content and displays a ✂ N lines hidden indicator. There is no way to scroll, expand, or read the hidden content.

This makes it impossible to make an informed choice when Claude presents options with detailed previews — the user literally cannot see what they're choosing between.

Screenshot

<img width="2091" height="825" alt="Image" src="https://github.com/user-attachments/assets/2d14f4b7-e9f8-4d0a-b66f-40fb90091867" />

<img width="876" height="1221" alt="Image" src="https://github.com/user-attachments/assets/3fce6e9b-0306-40d2-bab5-37901300afaf" />

What Should Happen?

The preview panel should be scrollable (e.g., with arrow keys, j/k, or Page Up/Down) so users can read the full preview content before making a selection.

Error Messages/Logs

N/A — this is a UI/UX issue, not an error

Steps to Reproduce

1. Start a Claude Code CLI session
2. Trigger AskUserQuestion with options that have long preview content (e.g., code architecture diagrams + file trees, ~50+ lines)
3. Observe the preview panel shows ✂ N lines hidden
4. Try every keybinding (arrow keys, j/k, Page Up/Down, scroll wheel, Tab, Enter, etc.) — none of them reveal the hidden content

Note on Duplicate History

This issue has been reported multiple times but was incorrectly chain-closed by the auto-duplicate bot:

• #33062 → closed as dup of #29125
• #34508 → closed as dup of #33062
• #30206 → closed as dup of #29125

The chain ultimately leads to #28991, which is an iOS Remote Control specific issue (now stale), and #23862, which is about AskUserQuestion overlapping preceding text output — a completely different problem.

Neither #28991 nor #23862 tracks the CLI TUI preview panel truncation issue described here. There is currently no properly tracked open issue for this bug.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.77

Platform

Anthropic API

Operating System

Windows 10

Terminal/Shell

Windows Terminal / PowerShell 7 (pwsh)

Additional Information

The preview panel height appears to be calculated based on terminal rows. Maximizing the terminal window or reducing font size increases the visible lines, but does not fully resolve the issue for longer previews. There should be a scroll mechanism regardless of terminal size.

Also reported on macOS and Linux by other users in the duplicate chain above.