Tesla.Builder.adapter

You're seeing just the macro adapter, go back to Tesla.Builder module for more information.
Link to this macro

adapter(name, opts)

View Source (macro)

Choose adapter for your API client.

defmodule ExampleApi do
  use Tesla

  # set adapter as module
  adapter Tesla.Adapter.Hackney

  # set adapter as anonymous function
  adapter fn env ->
    ...
    env
  end
end