v2.1.89 regression: flicker-free rendering destroys terminal scrollback by default

[sstraus]

v2.1.89 regression: flicker-free rendering destroys terminal scrollback

v2.1.89 introduced "flicker-free alt-screen rendering with virtualized scrollback" (CLAUDE_CODE_NO_FLICKER=1), but this behavior appears to be enabled by default, causing terminal scrollback to be destroyed after ~2 pages of output.

Observed behavior

When Claude Code output exceeds the visible terminal height (~24 rows), the terminal is fully re-rendered — the startup banner and conversation are reprinted from scratch. This destroys existing scrollback content. The startup mascot/banner remains visible at the top because it's re-rendered each time, but intermediate content is lost.

Evidence

I ran identical tests across three configurations using PTY sessions (24 rows × 120 cols):

Test: Two consecutive prompts — "print numbers 1-100" then "print alphabet A-Z"

Configuration	Result
v2.1.87	Single banner, linear output: header → 1-100 → A-Z. Scrollback preserved.
v2.1.89 (default)	Banner appears 3 times in output. CC re-renders the entire conversation when content exceeds screen height. Scrollback destroyed on each re-render.
v2.1.89 + CLAUDE_CODE_NO_FLICKER=0	Same as v2.1.87 — single banner, linear output, scrollback preserved.

v2.1.89 default output (truncated for clarity)

▐▛███▜▌   Claude Code v2.1.89        ← 1st render
  11
  ...
  85
▐▛███▜▌   Claude Code v2.1.89        ← 2nd render (re-render, scrollback destroyed)
❯ print the numbers from 1 to 100...
  1
  ...
  83
▐▛███▜▌   Claude Code v2.1.89        ← 3rd render (re-render again)
  1
  ...
  100
❯ now print the alphabet...
  1. A
  ...
  26. Z

Reproduction

1. Install Claude Code v2.1.89
2. Open any terminal (iTerm2, xterm.js, etc.)
3. Start a session and ask for output longer than the terminal height
4. Scroll up — only ~2 pages of content are available

Workaround: Set CLAUDE_CODE_NO_FLICKER=0 in environment or Claude Code settings.

Environment

• macOS (Darwin 25.4.0, arm64)
• Claude Code v2.1.89
• Tested in: iTerm2, xterm.js (via Tauri WebView)
• Both terminals exhibit the same behavior

[seanmartinsmith]

can confirm CLAUDE_CODE_NO_FLICKER=0 does not fix this on windows 11 + windows terminal + bash. set it in ~/.claude/settings.json env block, restarted session, transcript still disappears mid-conversation at low context usage (~11%).

env:

• claude code 2.1.89
• windows 11 home (10.0.26200)
• windows terminal
• bash shell
• opus 4.6 (1M context)

downgrading to 2.1.87 restores normal behavior per other reports

[xbzzoo]

https://t.me/+t_ed3b95DqczNmU1

[MatthewLaw1]

Confirming that CLAUDE_CODE_NO_FLICKER=0 works as a fix for MacOS. Destruction of terminal scrollback is inconsistent, as usually it will preserve the entry prompt banner: "welcome back " but will begin evicting old lines of conversation data only.

Claude Code v2.1.89
Terminal.app zsh
MacOS 26.4 (25E246)

[vicenzomasat]

Workaround working for me, just like in 2.1.87.

My problem:
What Should Happen?
It should show the conversation as normal.

Error Messages/Logs
Steps to Reproduce

1. Start conversation
2. Make a plan
3. All previous context gone, he remembered, but the text wasn't there, just the new plan

Claude Model
Opus

Is this a regression?
Yes, this worked in a previous version

Last Working Version
2.1.87

Claude Code Version
2.1.89

Platform
Anthropic Max Account

Operating System
Ubuntu 24.04/Debian Linux

Terminal/Shell
Ghostty

[ocombe]

Another issue from CLAUDE_CODE_NO_FLICKER is that shift+enter don't work anymore when it's set to 1, setting to 0 resolves the issue (shift + enter doesn't submit and creates a new line)