Fix Claude Code Terminal Enhanced Keyboard Mode (kitty Keyboard Protocol/modifyOtherKeys) Persisting After Exit — Ctrl-C/Ctrl-D Broken in Ghostty, Kitty, WezTerm, and tmux (v2.1.86 Fix)

Symptoms

• Ctrl-C produces '9;5u' or '0;133u' escape sequences instead of sending SIGINT after exiting Claude Code
• Ctrl-D produces '0;133u', '0;5u', or similar CSI u sequences instead of sending EOF after exiting Claude Code
• Ctrl-W, Ctrl-Z, Ctrl-/, and other control key combinations stop functioning in the shell after Claude Code exits
• Pressing Ctrl-D at an empty bash/zsh prompt closes the terminal tab/window instead of exiting the shell normally
• Running 'reset' or opening a new terminal tab restores normal behavior, confirming the issue is terminal state corruption rather than shell misconfiguration
• Issue occurs inconsistently — some Claude Code sessions exit cleanly while others leave the terminal in broken keyboard mode
• Inside tmux, escape sequences differ from outside tmux (e.g., '0;133u' in tmux vs '0;5u' in bare terminal), requiring different escape sequence handling

Error signatures

Ctrl-C produces '9;5u'

Ctrl-D produces '0;133u'

Ctrl-D produces '0;5u'

modifiedOtherKeys not restored on exit

kitty keyboard protocol left enabled

terminal enhanced keyboard mode not disabled

Possible causes

• Claude Code enables the kitty keyboard protocol (CSI > flags u) for rich key event handling in its TUI but does not send the pop command (CSI < u) to restore the terminal's keyboard mode stack on exit. The protocol remains active, causing all subsequent keyboard input to be encoded as CSI u escape sequences instead of raw control characters
• Claude Code enables modifyOtherKeys / XTMODKEYS mode 2 (CSI > 4 ; 2 m) for its own key handling but does not restore the previous mode on exit or when spawning subprocesses (e.g., via $EDITOR). This leaves the terminal mapping Ctrl+key combinations to escape sequences
• Unlike the kitty keyboard protocol which supports progressive enhancement queries (CSI ? u), XTMODKEYS has no standard query mechanism to detect the current state, making it harder for applications to restore the original terminal configuration
• The issue is most visible in terminals that support enhanced keyboard protocols (Ghostty, Kitty, WezTerm, foot) and in tmux sessions where the escape sequence handling differs between the inner and outer terminal
• The bug was introduced when Claude Code added enhanced keyboard support for its TUI and was not present in earlier versions

Solutions

claude --version

npm install -g @anthropic-ai/claude-code@latest

npm install -g @anthropic-ai/claude-code@2.1.86

mkdir -p ~/.claude

cat ~/.claude/settings.json 2>/dev/null || echo '{}'

claude --version

{
  "hooks": {
    "Stop": [{
      "matcher": "",
      "hooks": [{
        "type": "command",
        "command": "printf '\\e[<u\\e[>0m'"
      }]
    }]
  }
}

printf '\e[<u'

printf '\e[=0u'

printf '\e[<u\e[>0m'

printf '\ePtmux;\e\e[<u\e\\'

reset

Agent JSON

Canonical machine-readable representation of this issue:

{
  "issue_id": "e131a20e-740e-40c3-9497-a724d68005de",
  "slug": "fix-claude-code-terminal-enhanced-keyboard-mode-kitty-keyboard-protocol-modifyotherkeys-persisting-after-exit-ctrl-c-ctr-dfkjnf",
  "verification_status": "unverified",
  "canonical_json": "https://codekb.dev/v1/issues/fix-claude-code-terminal-enhanced-keyboard-mode-kitty-keyboard-protocol-modifyotherkeys-persisting-after-exit-ctrl-c-ctr-dfkjnf"
}