Feature request: Per-session mode isolation for tmux users

[Tarek98]

Hello there, this is a feature I'd love to see implemented for caveman as I really like using it in claude code but would love different tmux panes to use different modes. All of the below is the problem description & proposed solution written by Claude Code:

Problem

When running multiple Claude Code sessions in tmux panes, all
sessions share a
single flag file (~/.claude/.caveman-active). Running /caveman ultra in one
pane silently changes the mode in every other pane.

Root Cause

caveman-mode-tracker.js and caveman-activate.js both resolve
flagPath as:

const flagPath = path.join(claudeDir, '.caveman-active');

Single global file, no per-session discrimination.

Proposed Fix

Key flag file by $TMUX_PANE (e.g. %0, %1) when inside tmux:

// caveman-config.js
function getFlagPath(claudeDir) {
const base = path.join(claudeDir, '.caveman-active');
const pane = process.env.TMUX_PANE;
if (pane) {
const safe = pane.replace(/[^a-zA-Z0-9%]/g, '');
if (safe) return base + '-' + safe;
}
return base;
}

Replace hardcoded flagPath in caveman-mode-tracker.js and
caveman-activate.js
with getFlagPath(claudeDir). Same treatment for
caveman-statusline.sh with
a fallback to the global flag if pane-specific file doesn't
exist.

Behavior After Fix

• Each tmux pane gets its own flag (.caveman-active-%0,
  .caveman-active-%1)
• /caveman ultra in pane 1 does not affect pane 2
• Non-tmux sessions fall back to .caveman-active (unchanged
  behavior)
• $CAVEMAN_DEFAULT_MODE still works as per-pane override at
  launch time

Environment

macOS, tmux, multiple Claude Code sessions per window