defmodule MyApp.AddFilteringTypes do
  def run(blueprint, _) do
    {:ok, blueprint}
  end
end

defmodule Schema do
  use Absinthe.Schema
  @pipeline_modifier __MODULE__
  
  object :instance do
    field :name, :string
  end
  
  object :snapshot do
    field :instance, :instance
  end

  query do
    field :health, :string
    field :instances, list_of(:instance) do
      meta :fancy_filter
    end
  end
  
  def pipeline(pipeline) do
    Absinthe.Pipeline.insert_after
      pipeline,
      Absinthe.Phase.Schema.TypeImports,
      MyApp.AddFilteringTypes
    )
  end
end