diff --git a/lib/client_api/instance_controller.ex b/lib/client_api/instance_controller.ex
new file mode 100644
index 0000000..5291b1d
--- /dev/null
+++ b/lib/client_api/instance_controller.ex
@@ -0,0 +1,50 @@
+defmodule Bonfire.API.MastoCompatible.InstanceController do
+  use Bonfire.UI.Common.Web, :controller
+  alias Bonfire.Common.Config
+
+  def show(conn, _) do
+    app_name = Bonfire.Application.name()
+    instance = Application.get_env(:activity_pub, :instance)
+    base_url = Bonfire.Common.URIs.base_url()
+
+    json(conn, %{
+      "title" => Config.get([:ui, :theme, :instance_name], nil) || "An instance of #{app_name}",
+      "description" => Config.get([:ui, :theme, :instance_description], nil),
+      "email" => "no-reply@no-reply.net",
+      "thumbnail" => Config.get([:ui, :theme, :instance_icon], nil),
+      "background_image" => Config.get([:ui, :theme, :instance_image], nil),
+      "avatar_upload_limit" => 0,
+      "background_upload_limit" => 0,
+      "banner_upload_limit" => 0,
+      "upload_limit" => 0,
+      # TODO
+      "languages" => [
+        "en"
+      ],
+      "max_toot_chars" => 500_000,
+      "poll_limits" => %{
+        "max_expiration" => 31_536_000,
+        "max_option_chars" => 500_000,
+        "max_options" => 100,
+        "min_expiration" => 0
+      },
+      "registrations" => !Bonfire.Me.Accounts.instance_is_invite_only?(),
+      "stats" => %{
+        "domain_count" => 1,
+        # TODO
+        "status_count" => 1,
+        "user_count" => Bonfire.Me.Users.maybe_count()
+      },
+      "uri" => base_url,
+      "urls" => %{
+        # TODO
+        "streaming_api" => "wss://#{base_url}"
+      },
+      "version" => "2.7.2 (compatible; #{app_name} #{Bonfire.Application.version()})",
+      # non-standard
+      "federating" => ActivityPub.Config.federating?(),
+      # non-standard
+      "app_repository" => Bonfire.Application.repository()
+    })
+  end
+end