Add Reach to your project dependencies:

{:reach, "~> 2.0", only: [:dev, :test], runtime: false}

Optional dependencies enable richer output:

{:jason, "~> 1.0"},      # JSON output
{:boxart, "~> 0.3.3"},   # terminal graphs
{:makeup, "~> 1.0"},
{:makeup_elixir, "~> 1.0"},
{:makeup_js, "~> 0.1"}

Then fetch dependencies:

mix deps.get

For local development on Reach itself, run:

mix ci