tmux.conf using the new tmux copy-pipe command

.tmux.conf

# Start tmux shells with right hooks
set-option -g default-command "reattach-to-user-namespace -l zsh"

# vi keys
setw -g mode-keys vi

# Setup 'v' to begin selection as in Vim
bind-key -t vi-copy v begin-selection
bind-key -t vi-copy y copy-pipe "/usr/local/bin/reattach-to-user-namespace pbcopy"

# Update default binding of `Enter` to also use copy-pipe
unbind -t vi-copy Enter
bind-key -t vi-copy Enter copy-pipe "/usr/local/bin/reattach-to-user-namespace pbcopy"

# Unlimited history
set -g history-limit 30000
 
# Mouse support
setw -g mode-mouse on
set-option -g mouse-select-pane on
set-option -g mouse-select-window on
set-window-option -g mode-mouse on

# battery
# set-option -g status-left '[Battery: #(/usr/local/bin/power.sh)] #[default] Windows:'

# Separate scroll buffers from history buffer
set -g terminal-overrides 'xterm*:smcup@:rmcup@'

# first session
new-session -s Basic -n zsh -d

I had to use the full qualified path to reattach command in the copy-pipe tmux statements. Otherwise, this configuration borrows much from the thoughbot's post:
http://robots.thoughtbot.com/post/55885045171/tmux-copy-paste-on-os-x-a-better-future