A codesigned binary release can be installed using the yabai installer script; it will always point at the latest release version.

# install yabai binary into /usr/local/bin and man page yabai.1 into /usr/local/man/man1
curl -L https://raw.githubusercontent.com/koekeishiya/yabai/master/scripts/install.sh | sh /dev/stdin

# install yabai binary into ~/.local/bin and man page yabai.1 into ~/.local/man
curl -L https://raw.githubusercontent.com/koekeishiya/yabai/master/scripts/install.sh | sh /dev/stdin ~/.local/bin ~/.local/man

Alternatively, Homebrew can also be used from the tap koekeishiya/formulae.

brew install koekeishiya/formulae/yabai

macOS Big Sur:

Open System Preferences.app and navigate to Security & Privacy, then Privacy, then Accessibility. Click the lock icon at the bottom and enter your password to allow changes to the list.

macOS Ventura and above:

Open System Settings.app and navigate to Privacy & Security, then Accessibility. Click the + button at the bottom left of the list view and enter your password to allow changes to the list.

Starting with yabai --start-service will prompt the user to allow yabai accessibility permissions. Check the box next to yabai to allow accessibility permissions.

If you disabled System Integrity Protection; configure the scripting addition. Afterwards simply start yabai.

# start yabai
yabai --start-service

To update yabai to the latest version, simply upgrade it with the yabai installer script or Homebrew (depending on the original installation method) and reconfigure the scripting addition again:

# stop yabai
yabai --stop-service

# upgrade yabai with installer script -- (with or without directory override)
curl -L https://raw.githubusercontent.com/koekeishiya/yabai/master/scripts/install.sh | sh /dev/stdin

# or

# upgrade yabai with homebrew (remove old service file because homebrew changes binary path)
yabai --uninstall-service
brew upgrade yabai

# start yabai
yabai --start-service

yabai uses the macOS Mach APIs to inject code into Dock.app; this requires elevated (root) privileges. You can configure your user to execute yabai --load-sa as the root user without having to enter a password. To do this, we add a new configuration entry that is loaded by /etc/sudoers.

# create a new file for writing - visudo uses the vim editor by default.
# go read about this if you have no idea what is going on.

sudo visudo -f /private/etc/sudoers.d/yabai

# input the line below into the file you are editing.
#  replace <yabai> with the path to the yabai binary (output of: which yabai).
#  replace <user> with your username (output of: whoami). 
#  replace <hash> with the sha256 hash of the yabai binary (output of: shasum -a 256 $(which yabai)).
#   this hash must be updated manually after upgrading yabai.

<user> ALL=(root) NOPASSWD: sha256:<hash> <yabai> --load-sa

If you know what you are doing, the following one-liner can be used to update the sudoers file correctly:

echo "$(whoami) ALL=(root) NOPASSWD: sha256:$(shasum -a 256 $(which yabai) | cut -d " " -f 1) $(which yabai) --load-sa" | sudo tee /private/etc/sudoers.d/yabai

After the above edit has been made, add the command to load the scripting addition at the top of your yabairc config file

# for this to work you must configure sudo such that
# it will be able to run the command without password

yabai -m signal --add event=dock_did_restart action="sudo yabai --load-sa"
sudo yabai --load-sa

# .. more yabai startup stuff