Is it possible to create realtime outline effect in Eevee, only with shaders? I know It's possible to do this with solidify modifier, or manually duplicating the mesh, fatten and flip normals (which is more or less the same thing as the solidify method). Like this one


And I want it to be rendered realtime in viewport. So no freestyle.
Blender has a rich shading system. So I wonder If the outline effect can be created only with shader nodes.
It would be nice to not have to solidify every object in the scene and add aditional geometry to the objects.
Here's a rough attempt in eevee.

A Shader to RGB and a color ramp in constant mode, with a limited range of colors, then used for color in an other diffuse shader, will take care of the toon look.
Fresnel used as fac to mix a black diffuse shader will create the outline (I added a color ramp to distort the Fresnel info a bit).