diff --git a/config/test.exs b/config/test.exs
index 3463a3f5..9d6473e6 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -27,3 +27,5 @@ config :phoenix, :plug_init_mode, :runtime
 # Enable helpful, but potentially expensive runtime checks
 config :phoenix_live_view,
   enable_expensive_runtime_checks: true
+
+config :music_library, :last_fm, nil
diff --git a/lib/last_fm/api_behaviour.ex b/lib/last_fm/api_behaviour.ex
new file mode 100644
index 00000000..fe343b26
--- /dev/null
+++ b/lib/last_fm/api_behaviour.ex
@@ -0,0 +1,7 @@
+defmodule LastFm.APIBehaviour do
+  alias LastFm.Track
+
+  @type user :: String.t()
+  @type api_key :: String.t()
+  @callback get_recent_tracks(user, api_key) :: {:ok, [%Track{}]} | {:error, String.t()}
+end
diff --git a/lib/last_fm/api.ex b/lib/last_fm/api_impl.ex
similarity index 94%
rename from lib/last_fm/api.ex
rename to lib/last_fm/api_impl.ex
index 67294866..4182411e 100644
--- a/lib/last_fm/api.ex
+++ b/lib/last_fm/api_impl.ex
@@ -1,10 +1,13 @@
-defmodule LastFm.API do
+defmodule LastFm.APIImpl do
+  @behaviour LastFm.APIBehaviour
+
   require Logger
 
   alias LastFm.Track
 
   @base_url "http://ws.audioscrobbler.com/2.0/"
 
+  @impl true
   def get_recent_tracks(user, api_key) do
     options = [
       method: "user.getrecenttracks",
diff --git a/lib/last_fm/refresh.ex b/lib/last_fm/refresh.ex
index 44c3ff3b..7c0afd54 100644
--- a/lib/last_fm/refresh.ex
+++ b/lib/last_fm/refresh.ex
@@ -3,7 +3,7 @@ defmodule LastFm.Refresh do
 
   require Logger
 
-  alias LastFm.{API, Feed}
+  alias LastFm.Feed
 
   @refresh_interval System.convert_time_unit(30, :second, :millisecond)
 
@@ -12,7 +12,7 @@ defmodule LastFm.Refresh do
   end
 
   def init(config) do
-    if config.api_key do
+    if enabled?(config) do
       {:ok, config, {:continue, :refresh}}
     else
       :ignore
@@ -20,7 +20,7 @@ defmodule LastFm.Refresh do
   end
 
   def handle_continue(:refresh, config) do
-    case API.get_recent_tracks(config.user, config.api_key) do
+    case config.api.get_recent_tracks(config.user, config.api_key) do
       {:ok, tracks} ->
         Feed.update(tracks)
         Process.send_after(self(), :refresh, @refresh_interval)
@@ -32,4 +32,8 @@ defmodule LastFm.Refresh do
         {:noreply, config}
     end
   end
+
+  defp enabled?(config) do
+    config.api && config.api_key
+  end
 end
diff --git a/lib/last_fm/supervisor.ex b/lib/last_fm/supervisor.ex
index ef157de6..c931def5 100644
--- a/lib/last_fm/supervisor.ex
+++ b/lib/last_fm/supervisor.ex
@@ -6,11 +6,15 @@ defmodule LastFm.Supervisor do
   end
 
   @impl true
-  def init(_init_arg) do
+  def init(opts) do
     :ok = LastFm.Feed.create_table!()
 
+    api =
+      Keyword.fetch!(opts, :api)
+      |> IO.inspect()
+
     children = [
-      {LastFm.Refresh, %{user: "cloud8421", api_key: api_key()}}
+      {LastFm.Refresh, %{api: api, user: "cloud8421", api_key: api_key()}}
     ]
 
     Supervisor.init(children, strategy: :one_for_one)
diff --git a/lib/music_library/application.ex b/lib/music_library/application.ex
index 5cf2a0c6..7d0a9234 100644
--- a/lib/music_library/application.ex
+++ b/lib/music_library/application.ex
@@ -15,7 +15,7 @@ defmodule MusicLibrary.Application do
        repos: Application.fetch_env!(:music_library, :ecto_repos), skip: skip_migrations?()},
       {DNSCluster, query: Application.get_env(:music_library, :dns_cluster_query) || :ignore},
       {Phoenix.PubSub, name: MusicLibrary.PubSub},
-      LastFm.Supervisor,
+      {LastFm.Supervisor, api: last_fm()},
       # Start a worker by calling: MusicLibrary.Worker.start_link(arg)
       # {MusicLibrary.Worker, arg},
       # Start to serve requests, typically the last entry
@@ -40,4 +40,8 @@ defmodule MusicLibrary.Application do
     # By default, sqlite migrations are run when using a release
     System.get_env("RELEASE_NAME") != nil
   end
+
+  defp last_fm do
+    Application.get_env(:music_library, :last_fm, LastFm.APIImpl)
+  end
 end
diff --git a/test/test_helper.exs b/test/test_helper.exs
index f22d9fbf..3bdbd5d3 100644
--- a/test/test_helper.exs
+++ b/test/test_helper.exs
@@ -1,5 +1,8 @@
 Mox.defmock(MusicBrainz.APIBehaviourMock, for: MusicBrainz.APIBehaviour)
 Application.put_env(:music_library, :musicbrainz, MusicBrainz.APIBehaviourMock)
 
+Mox.defmock(LastFm.APIBehaviourMock, for: LastFm.APIBehaviour)
+Application.put_env(:music_library, :last_fm, LastFm.APIBehaviourMock)
+
 ExUnit.start()
 Ecto.Adapters.SQL.Sandbox.mode(MusicLibrary.Repo, :manual)