Sync tmux window name to Claude Code's task summary title

Claude Code writes an auto-generated summary of the current task to the
terminal title, but tmux windows showed only the version number. A
SessionStart hook sets window-local automatic-rename options so the
window name tracks the pane title live (truncated to 22 cells, ~10 CJK
characters), updating in real time as the task summary and busy/idle
spinner change. A SessionEnd hook unsets the window-local options to
restore normal tmux naming.

Author: ngs

rc.d/claude/hooks/tmux-window-title.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Claude Code SessionStart hook: while Claude Code runs inside tmux, keep the
+# window name synced to Claude Code's terminal title — an auto-generated
+# summary of the current task that updates as the conversation evolves —
+# instead of the version-number default. Implemented with window-local tmux
+# options so tmux tracks the title live with no further hook invocations.
+# The SessionEnd hook in settings.json unsets them to restore normal naming.
+
+[ -n "$TMUX" ] && [ -n "$TMUX_PANE" ] || exit 0
+
+# #{=22:...} truncates by cell width: 22 cells is roughly 10 CJK characters.
+tmux set-option -w -t "$TMUX_PANE" automatic-rename-format '#{=22:pane_title}' 2>/dev/null
+tmux set-option -w -t "$TMUX_PANE" automatic-rename on 2>/dev/null
+exit 0

rc.d/claude/settings.json

@@ -48,6 +48,26 @@
         ]
       }
     ],
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "$HOME/dotfiles/rc.d/claude/hooks/tmux-window-title.sh"
+          }
+        ]
+      }
+    ],
+    "SessionEnd": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "[ -n \"$TMUX\" ] && [ -n \"$TMUX_PANE\" ] && { tmux set-option -w -t \"$TMUX_PANE\" -u automatic-rename-format; tmux set-option -w -t \"$TMUX_PANE\" -u automatic-rename; } 2>/dev/null || true"
+          }
+        ]
+      }
+    ],
     "Stop": [
       {
         "hooks": [