term = "xterm-256color"

What to set the TERM environment variable to. The default is xterm-256color, which should provide a good level of feature support without requiring the installation of additional terminfo data.

If you want to get the most application support out of wezterm, then you may wish to install a copy of the wezterm TERM definition:

$ tempfile=$(mktemp) \
  && curl -o $tempfile https://raw.githubusercontent.com/wez/wezterm/main/termwiz/data/wezterm.terminfo \
  && tic -x -o ~/.terminfo $tempfile \
  && rm $tempfile

You can then set term = "wezterm" in your .wezterm.lua config file.

Doing this will inform some software of newer, more advanced features such as colored underlines, styled underlines (eg: undercurl). If the system you are using has a relatively outdated ncurses installation, the wezterm terminfo will also enable italics and true color support.

If you are using WSL, wezterm will automatically populate WSLENV to properly set TERM, COLORTERM, TERM_PROGRAM and TERM_PROGRAM_VERSION in the environment when crossing between win32 and WSL environments. See this Microsoft blog post for more information on how WSLENV works.

If your package manager installed the terminfo data in a non-standard location, which will likely be the case if your are using nixpkgs/home-manager/NixOS, then you need to set TERMINFO_DIRS in the environment in order for applications to find it. The following snippet works if you installed wezterm.terminfo with nix into your user profile. Update the path to TERMINFO_DIRS to match the location on your system.

config.set_environment_variables = {
  TERMINFO_DIRS = '/home/user/.nix-profile/share/terminfo',
  WSLENV = 'TERMINFO_DIRS',
}
config.term = 'wezterm'