diff --git a/src/day8/re_frame/trace/app_state.cljs b/src/day8/re_frame/trace/app_state.cljs
index a63a25b..d6680b4 100644
--- a/src/day8/re_frame/trace/app_state.cljs
+++ b/src/day8/re_frame/trace/app_state.cljs
@@ -48,17 +48,30 @@
     (into (view data) (mapv crawl data))
     (view data)))
 
+(declare jsonml->hiccup)
+
+(defn data-structure
+  [jsonml]
+  (let [expand? (r/atom true)]
+    (fn []
+      [:span.re-frame-trace--object
+        {:on-click #(swap! expand? not)}
+        (jsonml->hiccup (if @expand?
+                          (cljs-devtools/body-api-call
+                            (.-object (get jsonml 1))
+                            (.-config (get jsonml 1)))
+                          (cljs-devtools/header-api-call
+                            (.-object (get jsonml 1))
+                            (.-config (get jsonml 1)))))])))
+
 (defn jsonml->hiccup
   [jsonml]
   (cond
-    (array? jsonml)    (if (= "object" (get jsonml 0))
-                         [:span.re-frame-trace--object
-                           (jsonml->hiccup (cljs-devtools/body-api-call
-                                             (.-object (get jsonml 1))
-                                             (.-config (get jsonml 1))))]
-                         (mapv jsonml->hiccup jsonml))
-    (object? jsonml)   {:style (string->css (js->clj jsonml))}
-    :else              (str->hiccup jsonml)))
+    (and (array? jsonml)
+         (= "object" (get jsonml 0))) [data-structure jsonml]
+    (array? jsonml)                   (mapv jsonml->hiccup jsonml)
+    (object? jsonml)                  {:style (string->css (js->clj jsonml))}
+    :else                             (str->hiccup jsonml)))
 
 (defn tab [data]
   [:div {:style {:flex "1 0 auto" :width "100%" :height "100%" :display "flex" :flex-direction "column"}}