Run Mac app in the background (#1199)

app_builder/lib/app_builder/macos.ex

@@ -98,7 +98,8 @@ defmodule AppBuilder.MacOS do
         :info_plist,
         :url_schemes,
         :document_types,
-        :additional_paths
+        :additional_paths,
+        :is_agent_app
       ])
 
     app_name = Keyword.fetch!(options, :name)
@@ -301,7 +302,11 @@ defmodule AppBuilder.MacOS do
     </array>
   <% end %>
 
-    </dict>
+  <%= if options[:is_agent_app] do %>
+    <key>LSUIElement</key>
+    <true/>
+  <% end %>
+  </dict>
   </plist>
   """
 

mix.exs

@@ -192,12 +192,18 @@ defmodule Livebook.MixProject do
   ]
 
   defp build_mac_app(release) do
-    AppBuilder.build_mac_app(release, @app_options)
+    options =
+      [
+        is_agent_app: true
+      ] ++ @app_options
+
+    AppBuilder.build_mac_app(release, options)
   end
 
   defp build_mac_app_dmg(release) do
     options =
       [
+        is_agent_app: true,
         codesign: [
           identity: System.fetch_env!("CODESIGN_IDENTITY")
         ],