  The Klein-Gordon equation for a scalar field sourced by a static spherically
symmetric background is an interesting second-order differential equation with
applications in particle physics, astrophysics, and elsewhere. Here we present
static solutions for generic source density profiles in the case where the
scalar field has no interactions or a mass term. For a $\lambda\phi^4$
self-interaction term, we develop the techniques that are necessary numerical
computation. We also provide code to perform the numerical calculations that
can be adapted for arbitrary density profiles.
