shift+letter keybindings do not match in WezTerm kitty mode

[farzadmf]

Is this a reproducible bug?

• I confirm this is a reproducible bug, not a feature request, idea, question, contribution proposal, or direction check.
• I reproduced this bug on the version and environment reported below using the exact steps provided.

Current behavior

A prefix+shift+<letter> keybinding does not match. Herdr runs the prefix+<letter> action instead. For example, prefix+shift+r starts resize mode instead of a config reload. Herdr does the same action for prefix+r and prefix+shift+r.

Expected behavior

A prefix+shift+<letter> keybinding matches. Herdr does a different action for prefix+<letter> and prefix+shift+<letter>.

Reproduction

1. Set enable_kitty_keyboard = true in the WezTerm config.
2. Start herdr.
3. Press the prefix key (ctrl+b by default), then r. Resize mode starts.
4. Press the prefix key, then shift+r. Resize mode starts again.

Impact

You cannot use prefix+shift+<letter> keybindings. The default reload_config (prefix+shift+r) does not work. The keybinding does the prefix+<letter> action.

Environment

• Herdr version: 0.8.0
• Update channel (stable or preview): stable
• Operating system: macOS 15 (Darwin 25.6.0)
• Terminal: WezTerm 20260805-104032-4b1c3c15
• Shell, if relevant: zsh
• Relevant config, if any: WezTerm enable_kitty_keyboard = true

[akbash-bot]

Could you capture the exact bytes WezTerm sends for shift+r? This will show which key identity/modifiers Herdr needs to preserve.

In a plain WezTerm shell (outside Herdr), run this command, then press shift+r once when prompted:

python3 - <<'PY'
import os, select, sys, termios, time, tty
fd = sys.stdin.fileno()
saved = termios.tcgetattr(fd)
data = b""
print("Press shift+r once now", flush=True)
try:
    os.write(sys.stdout.fileno(), b"\x1b[>7u")
    tty.setraw(fd)
    deadline = time.monotonic() + 5
    while time.monotonic() < deadline:
        ready, _, _ = select.select([fd], [], [], 0.25)
        if ready:
            data += os.read(fd, 4096)
        elif data:
            break
finally:
    os.write(sys.stdout.fileno(), b"\x1b[<u")
    termios.tcsetattr(fd, termios.TCSADRAIN, saved)
print("bytes:", data.hex(" "))
PY

Please paste only the final bytes: line. It contains only that keypress, not terminal content.

[farzadmf]

bytes: 52 1b 5b 31 31 34 3a 38 32 3b 32 3a 33 75

[akbash-bot]

Thanks. That capture follows the standard encoding and passes Herdr's current raw-input path, so I need the bytes from the exact in-Herdr interaction (prefix mode temporarily changes the keyboard flags).

Please run a disposable named session with debug logging:

HERDR_LOG=herdr=debug herdr --session issue-2435-capture

Press ctrl+b, then shift+r once. Detach with ctrl+b, then q. Back in the shell, run:

grep 'raw input event parsed' ~/.config/herdr/sessions/issue-2435-capture/herdr-server.log | tail -n 8
herdr session stop issue-2435-capture
herdr session delete issue-2435-capture

Please paste the eight log lines. They may show those keypresses, but should not contain pane contents.

[farzadmf]

What are we looking for here, asking for all these bytes?