{
  nix-shell = {
    wraps = "nix-shell";
    body = ''
      command nix-shell $argv --command "fish"
    '';
  };
  nix = {
    wraps = "nix";
    body = ''
      if status is-interactive
        and test (count $argv) = 1 -a "$argv[1]" = develop
          nix develop --command (status fish-path)
      else
        command nix $argv
      end
    '';
  };
  nix-prefetch-hash = {
    body = ''
      nix-hash --type sha256 --to-base64 (nix-prefetch-url $argv)
    '';
  };
}