Tmux's Config that's very close to i3wm (Setting with an idea of using tmux without x-server)

.tmux.conf

# Config that is very close to a i3 window manager's keybinding.

set -s escape-time 0
setw -g aggressive-resize on

# First remove *all* keybindings
unbind-key -a

# List keys
bind-key ? list-keys

# Copy mode
bind-key [ copy-mode

# Paste buffer
bind-key ] paste-buffer

# Refresh client
bind-key r refresh-client \; display-message "Refresh already"

# Start with index 1
set -g base-index 1
setw -g pane-base-index 1

# Set new prefix
# Note : you can press super key by set M.
# (tested with tty only)
set -g prefix M-Space
bind-key Space send-prefix

# Clock
setw -g clock-mode-style 24

# Config Reloads
bind R source-file ~/.tmux.conf \; display-message "Config reloaded"

# Mouse on/off
set -g mouse off

# Split window
bind-key h split-window -h
bind-key v split-window -v

# Rotate Window
bind-key -n M-o rotate-window

# Swap pane
bind-key -r L swap-pane -U
bind-key -r K swap-pane -D

# Move pane with Control (no prefix)
bind-key -n M-j select-pane -L
bind-key -n M-k select-pane -D
bind-key -n M-l select-pane -U
bind-key -n M-\; select-pane -R

# Resize pane with Alt (prefix with repeat)
bind-key -r j resize-pane -L 5 \; display-message "Resize left"
bind-key -r k resize-pane -D 5 \; display-message "Resize down"
bind-key -r l resize-pane -U 5 \; display-message "Resize up"
bind-key -r \; resize-pane -R 5 \; display-message "Resize right"

# Automatically set window title
set-window-option -g automatic-rename on
set-option -g set-titles on

# Choose Window
bind-key w choose-window

# New Window with number
bind-key 1 new-window -t 1
bind-key 2 new-window -t 2
bind-key 3 new-window -t 3
bind-key 4 new-window -t 4
bind-key 5 new-window -t 5
bind-key 6 new-window -t 6
bind-key 7 new-window -t 7
bind-key 8 new-window -t 8
bind-key 9 new-window -t 9
bind-key 0 new-window -t 10

# Switch windows alt+number
bind-key -n M-1 select-window -t 1
bind-key -n M-2 select-window -t 2
bind-key -n M-3 select-window -t 3
bind-key -n M-4 select-window -t 4
bind-key -n M-5 select-window -t 5
bind-key -n M-6 select-window -t 6
bind-key -n M-7 select-window -t 7
bind-key -n M-8 select-window -t 8
bind-key -n M-9 select-window -t 9
bind-key -n M-0 select-window -t 10

# Change current pane to next window
bind-key ! join-pane -t :1
bind-key @ join-pane -t :2
bind-key '#' join-pane -t :3
bind-key '$' join-pane -t :4
bind-key '%' join-pane -t :5
bind-key '^' join-pane -t :6
bind-key '&' join-pane -t :7
bind-key '*' join-pane -t :8
bind-key '(' join-pane -t :9
bind-key ')' join-pane -t :10

# Kill Selected Pane
bind-key Q kill-pane

I have bound prefix key to the windows key.
This is not actually possible in tmux alone, but using kbd package keymap editing, one can send e.g. f12 keycode upon window key press, and then in tmux use f12 for prefix.

@dkrikun Interesting. However, won't it affect all consoles (ttys) for all users?

It would be nice if you elaborate what you did.

I tried to dumpkeys > backup.kmap but got Couldn't get a file descriptor referring to the console and the backp.kmap was empty.

Thanks to @CSaratakij and @odedlaz for your inputs.

this is very cool! ive been looking for something like this for a while, but never felt like actually making it myself