# External Art
When you need to use a module, overlay, or pass a value from one of your inputs
to the rest of your NixOS configuration, [extern][extern] is where you do it.

Modules and overlays are self explanatory, and the `specialArgs` attribute is
used to extend the arguments passed to all NixOS modules, allowing for
arbitrary values to be passed from flake inputs to the rest of your
configuration.

[extern]: https://github.com/divnix/devos/tree/core/extern/default.nix