[Critical UX Regression] No way to access conversation history — alternate screen buffer kills all scrollback (v2.1.89+)

[dima0923-wq]

Environment

• Claude Code version: 2.1.90
• Terminal: Apple Terminal (macOS Sonoma 14.5)
• Model: Claude Opus 4.6 (1M context)
• Plan: Max-tier usage

Problem

Since v2.1.89, Claude Code switched to an alternate screen buffer (fullscreen TUI) that completely destroys native terminal scrollback. You cannot scroll up to see messages from even 10 messages ago. This is a severe regression from pre-v2.1.89 where everything was written to normal terminal scrollback and you could freely scroll up, use Cmd+F, etc.

What broke:

1. Native scrollback gone — Terminal's scroll buffer is empty. Mouse wheel / trackpad scroll shows nothing above current view.
2. Transcript mode (Ctrl+O) is insufficient — Only has Ctrl+E (toggle expand) and q (exit). No way to export to scrollback, open in editor, or search. The documented [ and v keys do not exist.
3. No opt-out — There is no environment variable to disable the alternate screen buffer. CLAUDE_CODE_NO_FLICKER controls flicker rendering, not the screen buffer.
4. Cmd+F doesn't work — Because alternate screen buffer content isn't in the terminal's search scope.

What used to work (pre-v2.1.89):

• Full native scrollback — scroll up to see entire conversation
• Cmd+F to search any message
• Copy/paste from any point in the conversation
• tmux copy mode worked normally

Impact

This makes Claude Code significantly harder to use for long sessions (which is the primary use case for power users). When working with agent teams on complex multi-file projects, you need to reference previous tool outputs, error messages, and decisions. Currently you can't.

Related issues (fragmented, none resolved)

• Avoid clearing the terminal scrollback #2479 — Avoid clearing the terminal scrollback (2024, still open)
• Terminal scrollback cleared at random during conversation #42667 — Terminal scrollback cleared at random
• Scrollback content lost mid-conversation in tmux sessions #42180 — Scrollback lost in tmux
• v2.1.89: scrollback history lost in terminal (Ghostty) #42024 — Scrollback lost in Ghostty
• v2.1.89 regression: flicker-free rendering destroys terminal scrollback by default #41965 — v2.1.89 regression: flicker-free destroys scrollback
• Terminal scrollback not working in long sessions (alternate screen buffer) #42002 — Alternate screen buffer blocks scrollback
• Terminal scrollback wiped during session (alternate screen buffer cleared on redraw) #42340 — Scrollback wiped on redraw
• Virtual scroll height underestimation makes older messages unreachable in long/resumed sessions #42076 — Virtual scroll height underestimation
• [Feature Request] Add configurable TUI scrollback buffer size for conversation history #42527 — Feature request for configurable scrollback buffer
• [BUG] No working mechanism to review previous context after compaction, plan-mode clear, or branch navigation — data preserved but UI inaccessible #27242 — No mechanism to review previous context
• Compaction clears screen - can't scroll up to see previous context #18204 — Compaction clears screen

12+ open issues about the same root cause, zero resolution.

Expected Solution

At minimum ONE of:

1. CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 — env var to opt out of fullscreen TUI and use normal terminal output (like pre-v2.1.89)
2. Working transcript export — Ctrl+O → key that actually dumps full conversation to native scrollback (the documented [ key doesn't exist)
3. Ctrl+O → editor — key that opens full conversation in $EDITOR (the documented v key doesn't exist)
4. claude history or claude export — CLI command to dump current session to stdout/file

Suggested Priority

This affects every single user on every terminal emulator. 12+ open issues. Basic usability regression. Should be P0.

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Submitted via Claude Code v2.1.90

[github-actions]

Found 3 possible duplicate issues:

1. v2.1.89 regression: flicker-free rendering destroys terminal scrollback by default #41965
2. v2.1.89: scrollback history lost in terminal (Ghostty) #42024
3. Terminal scrollback wiped during session (alternate screen buffer cleared on redraw) #42340

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

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🤖 Generated with Claude Code

[georgesamuelson]

Cross-posting from my comment on #28077 — these two issues are compounding.

Background

Power user running multi-hour operational sessions (1,500+ sessions, institutional memory across projects). Setup: Ghostty 1.3.2, scrollback-limit = 10000000, macOS, Claude Code 2.1.91, tmux.

My sessions involve transcript digestion, document generation, multi-step task tracking, and cross-referencing earlier outputs. I capture full conversation logs via tmux capture-pane + save-buffer — these feed into session resume protocols, compaction recovery, and searchable archives.

Two Compounding Regressions

Regression 1: Internal Render Buffer Cap (v2.1.76) — see #28077

~300 line hard cap in the Ink TUI renderer. No user-configurable fix. Compiled into the binary.

Regression 2: Alternate Screen Buffer (v2.1.89) — this issue

Completely bypasses native terminal scrollback. tmux capture-pane gets nothing.

Partial fix: CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 restores native scrollback, but you're still capped at ~300 lines from Regression 1.

The Combined Effect

• Before v2.1.76: Full conversation in scrollback. tmux capture works. 2,000+ lines visible.
• After v2.1.76: Capped at ~300 lines, tmux capture still works.
• After v2.1.89: Capped at ~300 lines AND tmux capture gets nothing.
• With env var: Back to ~300 lines with tmux capture working — still a major regression.

The Ask

1. Expose tui.maxScrollbackLines in settings.json or as env var
2. Document CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN — it works but is undocumented
3. Auto-detect tmux/screen ($TMUX/$STY) and default to native scrollback
4. Don't silently break existing workflows — rendering changes that kill scrollback should be opt-in

Full details in my comment on #28077.

[originlabs-app]

Confirming this regression on v2.1.90 (macOS, Terminal.app). With the 1M context window (Opus 4.6), conversations get long fast — and losing scrollback makes it impossible to review what happened earlier in the session. Ctrl+O transcript mode helps but it's not discoverable and not a substitute for native scrollback. Would appreciate an env var opt-out like CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 or a setting in settings.json.