Use vi keys in buffer

copy mode

// what it does

`setw` (set-window-option) with `-g` sets mode-keys globally to vi, switching copy mode from its default emacs bindings to vi-style ones. This is what enables g/G for top/bottom, / and ? for search, and Space to begin a selection. Put it in ~/.tmux.conf so every session starts with vi navigation in the scrollback.

// tmux command

: setw -g mode-keys vi

// gotcha

mode-keys only governs copy mode — the command prompt (prefix :) is controlled by the separate `status-keys` option, so setting vi here won't make the prompt vi. The change applies the next time you enter copy mode, not to a session already in it.