Disabling Grunt

To disable Grunt integration in Sails, simply delete your Gruntfile (and/or tasks/ folder). You can also disable the Grunt hook. Just set the grunt property to false in .sailsrc hooks like this:

{
    "hooks": {
        "grunt": false
    }
}

Can I customize this for SASS, Angular, client-side Jade templates, etc?

Yep! Just replace the relevant grunt task in your tasks/ directory, or add a new one. Like SASS for example.

If you still want to use Grunt for other purposes, but don't want any of the default web front-end stuff, just delete your project's assets folder and remove the front-end oriented tasks from the grunt/register/ and grunt/config/ folders. You can also run sails new myCoolApi --no-frontend to omit the assets folder and front-end-oriented Grunt tasks for future projects. You can also replace your sails-generate-frontend module with alternative community generators, or create your own. This allows sails new to create the boilerplate for native iOS apps, Android apps, Cordova apps, SteroidsJS apps, etc.

{
    "paths": {
        "public": "assets"
    }
}