Display problems almost always come from the terminal emulator, not
the shell. Please fill the terminal section carefully — bash vs PowerShell
tells us very little; VSCode integrated terminal vs Windows Terminal
tells us everything.

Symptom (tick all that apply)

• Whole screen flickers / flashes during streaming response
• Lines tear or only half-redraw
• Stale output left behind after a frame updates
• Cursor jumps to wrong column or vanishes
• Mojibake / wrong-width characters (e.g. □, half-width emoji)
• Other (describe below)

When it happens

• During assistant streaming (token-by-token output)
• When tool cards expand / collapse
• During scroll-up / scrollback
• On terminal resize
• On launch / on quit
• Other (describe below)

In review mode, diff panel calculates wrong character witdh

Terminal — the important part

Where exactly are you running reasonix?

• VSCode integrated terminal — VSCode version: ?
• Cursor integrated terminal — Cursor version: ?
• Windows Terminal — version: ?
• cmd.exe (legacy console host)
• PowerShell ISE (note: ISE doesn't support ANSI — most things will look broken)
• iTerm2 / Terminal.app / Alacritty / kitty / WezTerm / Hyper
• tmux / screen / mosh — and inside which outer terminal? ?
• Other:

reasonix --version; node --version
uname -a
echo "TERM=$TERM"
echo "TERM_PROGRAM=$TERM_PROGRAM"
echo "TERM_PROGRAM_VERSION=$TERM_PROGRAM_VERSION"
echo "COLORTERM=$COLORTERM"
echo "WT_SESSION=$WT_SESSION"
echo "VSCODE_INJECTION=$VSCODE_INJECTION"
echo "WSL_DISTRO_NAME=$WSL_DISTRO_NAME"

0.49.0
v26.1.0
Linux archlinux-3302 7.0.9-arch1-1 #1 SMP PREEMPT_DYNAMIC Sun, 17 May 2026 17:23:07 +0000 x86_64 GNU/Linux
TERM=alacritty

Reproduction

Steps that reliably trigger it (commands run, files edited, was a tool
streaming a long response, was the window being resized, …):

1. start reasonix
2. switch to review mode
3. ask ai to modify something

Screen recording (strongly preferred)

Wrong border positions exists only when Chinese character occur. So probably issue lies in width calculation?