[BUG] Multi-line input causes scrambled rendering in input area

[stephenli-go1]

Preflight Checklist

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

What's Wrong?

Description

When typing or editing multi-line input in the Claude Code input area, the rendering becomes visually scrambled. Dashed border lines bleed into the text area, and ghost/duplicate lines of text appear below the actual input. The actual input content is received correctly — the issue is purely visual.

Actual Behavior

• Dashed border lines bleed into the input text area
• Ghost/duplicate lines of previously typed text appear below the input
• Cursor positioning appears incorrect visually

Screenshot

Environment

• Claude Code version: 2.1.34 (Claude Code)
• Terminal: iTerm2 (xterm-256color)
• Terminal size: 80x25
• OS: macOS 14 (Sonoma), Darwin 23.6.0
• Character encoding: UTF-8

What Should Happen?

Input text should render cleanly without visual artifacts.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code in an 80x25 terminal
2. Type a multi-line message in the input area (e.g., two or more lines)
3. Observe garbled rendering — border lines overlapping text, duplicate text appearing

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

2.1.34

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

No response

[github-actions]

Found 3 possible duplicate issues:

1. Blank lines render above input when typing after Ctrl+Enter newline #18785
2. Prompt bar UI bug in v2.1.23: text disappears, lines compact #21647
3. [BUG] TUI rendering corrupted in neovim's built-in terminal (macOS) #20436

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[ilkerhk]

I have similar issue (both on konsole and on xterm). Almost always happens and when happens it is impossible to see what is selected using arrow keys. See below

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[mconq-asana]

I have the same issue. I've noticed that it happens mostly when I paste or add new lines with Shift+Return. Also, when I resize the terminal window, the visual artifacts disappear. I already tried disabling "Terminal may enable paste bracketing" as previously suggested by Claude Code.

=== Claude Code TUI Diagnostics ===

Claude Code version: 2.1.45 (Claude Code)
TERM: xterm-256color
TERM_PROGRAM: iTerm.app
TERM_PROGRAM_VERSION: 3.6.6
LANG: en_US.UTF-8
LC_ALL:
Terminal size: 140x80
Shell: /bin/zsh

--- macOS ---
ProductName:		macOS
ProductVersion:		26.3
BuildVersion:		25D125

--- Hardware ---
Apple M1 Max

Screenshot: adding multiple lines with shift+return

Screenshot: adding multiple lines with shift+return and then resizing the iterm2 window

[ajrossnz]

I'd like to use claude code in an 80x25 window in raw ansi, and I can't do that either, it's a mess. Any way to support TERM=ansi and 80x25? (or any chance of this in the future?)

[yiminhale]

Same symptom, different trigger — status line text bleeds into input area

Environment:

• Claude Code: v2.1.85 ~ v2.1.88
• macOS (Darwin 25.4.0)
• Terminal: macOS Terminal.app
• Plan: Pro (claude.ai first-party auth)

Symptom:

Starting around v2.1.85, the status line text ([2026-03-31 13:36:27] ~/GitHub/hale_77 | Opus 4.6, token count, permission indicator) visually bleeds into the input area while typing. Characters from the status line intermix with the typed text — not flickering, but overlapping/merging.

Example of what the input area looks like while typing:

───────────────────────────────────────────────── Ops ──
❯                                                                                                                                                                                                           
──1번으로 진행해줘. 지금도 보면  ──────────────────────
  [2026-03-31 13:36:27] ~/GitHub/hale_77 | Opus 4.6                          88710 tokens  
  ⏵⏵ bypass permissions on (shift+tab to cycle)                                                       

The typed text (1번으로 진행해줘. 지금도 보면) renders on the same line as the border, and the status line content appears to overlap with or bleed into the input region. The actual input received by Claude is correct — this is purely a visual rendering issue.

Not present before v2.1.85. This may be related to the status line feature introduced around that version, causing a cursor position / repaint calculation mismatch between the input area and the bottom status bar.