tmux Setup

PiG works inside tmux, but tmux strips modifier information from certain keys by default. Without configuration, Shift+Enter and Ctrl+Enter are usually indistinguishable from plain Enter. The setup is the same as for Pi 1.5.0 (Pi's tmux guide).

Recommended Configuration

Add to ~/.tmux.conf:

set -g extended-keys on
set -g extended-keys-format csi-u

The configuration applies to the tmux server, so start a new server. Save your work first: tmux kill-server ends every session of that server.

tmux kill-server
tmux

PiG requests extended key reporting automatically when Kitty keyboard protocol is not available. With extended-keys-format csi-u, tmux forwards modified keys in CSI-u format, which is the most reliable configuration. The extended-keys-format option requires tmux 3.5 or later.

Verify modified keys

Start PiG inside the new tmux session and check these keys:

1. Shift+Enter inserts a new line in the editor.
2. Enter submits the prompt.
3. Alt+Enter queues a follow-up on macOS and Linux. Windows and WSL use Ctrl+Q.

If these keys still act like plain Enter, check that the terminal outside tmux reports modified keys. See Terminal setup.

Why csi-u Is Recommended

With only:

set -g extended-keys on

tmux defaults to extended-keys-format xterm. When an application requests extended key reporting, modified keys are forwarded in xterm modifyOtherKeys format such as:

• Ctrl+C → \x1b[27;5;99~
• Ctrl+D → \x1b[27;5;100~
• Ctrl+Enter → \x1b[27;5;13~

With extended-keys-format csi-u, the same keys are forwarded as:

• Ctrl+C → \x1b[99;5u
• Ctrl+D → \x1b[100;5u
• Ctrl+Enter → \x1b[13;5u

PiG supports both formats, but csi-u is the recommended tmux setup.

What This Fixes

Without tmux extended keys, modified Enter keys collapse to legacy sequences:

This affects the default keybindings (Enter to submit, Shift+Enter for newline) and any custom keybindings using modified Enter.

Requirements

• tmux 3.5 or later for extended-keys-format csi-u (run tmux -V to check)
• A terminal emulator that supports extended keys (Ghostty, Kitty, iTerm2, WezTerm, Windows Terminal)

With tmux 3.2 through 3.4, omit extended-keys-format csi-u; PiG still supports tmux's default xterm modifyOtherKeys format.

Known issues