wezterm/docs/config/lua/window-events/user-var-changed.md

user-var-changed

{{since('20220903-194523-3bb1ed61')}}

The user-var-changed event is emitted when a user var escape sequence is used to set a user var.

You can use something like the following from your shell:

printf "\033]1337;SetUserVar=%s=%s\007" foo `echo -n bar | base64`

to set the user var named foo to the value bar.

Then, if you have this in your config:

local wezterm = require 'wezterm'

wezterm.on('user-var-changed', function(window, pane, name, value)
  wezterm.log_info('var', name, value)
end)

return {}

your event handler will be called with name = 'foo' and value = 'bar'.

See also pane:get_user_vars().