diff --git a/src/darkleaf/di/core.clj b/src/darkleaf/di/core.clj
index d0c01265..461bd4dd 100644
--- a/src/darkleaf/di/core.clj
+++ b/src/darkleaf/di/core.clj
@@ -826,3 +826,68 @@
             (p/demolish factory obj)
             (after-demolish! {:key key :object obj})
             nil))))))
+
+(defn inspect []
+ (fn [registry]
+   (fn [key]
+     (let [factory (registry key)]
+       (reify p/Factory
+         (dependencies [_]
+           (p/dependencies factory))
+         (build [_ deps]
+           (into [{:key key :deps (keys deps)}]
+                 (comp
+                  (mapcat val)
+                  (distinct))
+                 deps))
+         (demolish [_ obj]))))))
+
+
+(defn- graphviz-id [x]
+  (str "\"" x "\""))
+
+(defn render-graphviz [root middlewares]
+  (let [system     (start root middlewares (inspect))
+        components @system]
+
+    (with-out-str
+      (println "digraph {")
+      (println "rankdir=LR;")
+      #_(println "splines=ortho;")
+      #_(println "concentrate=true;")
+
+      (println "node [shape=box color=gray style=rounded];")
+      (println "edge [color=gray arrowhead=empty];")
+
+      #_
+      (println (graphviz-id (-> components first :key))
+               (str "[color=magenta];"))
+
+      (doseq [{:keys [key deps]} components]
+        (print "{")
+        (doseq [token (interpose "," (map graphviz-id deps))]
+          (print token))
+        (println "}"  "->" (graphviz-id key)))
+
+      #_
+      (doseq [[cluster keys] (->> components
+                                  (map :key)
+                                  (group-by try-namespace))
+              :when          (and (some? cluster)
+                                  (not (str/starts-with? cluster "env"))
+                                  (not (str/starts-with? cluster "darkleaf.di.core")))]
+        (println "subgraph" (graphviz-id cluster) "{")
+        (println " " (str "label=" (graphviz-id cluster) ";"))
+        (println " " "cluster=true;")
+        (println " " "labeljust=l;")
+        (println " " "color=gray;")
+        (println " " "style=dashed;")
+
+        (doseq [key keys]
+          (println " " (graphviz-id key)
+                   (str "["
+                        "label=" (graphviz-id (name key)) ;; keywords must start with :
+                        "];")))
+        (println "}"))
+
+      (println "}"))))
diff --git a/test/darkleaf/di/tutorial/x_inspect_test.clj b/test/darkleaf/di/tutorial/x_inspect_test.clj
new file mode 100644
index 00000000..afb18bef
--- /dev/null
+++ b/test/darkleaf/di/tutorial/x_inspect_test.clj
@@ -0,0 +1,26 @@
+(ns darkleaf.di.tutorial.x-inspect-test
+  (:require
+   [clojure.test :as t]
+   [darkleaf.di.core :as di]))
+
+(defn a []
+  :ok)
+
+(defn b [{a `a}]
+  :ok)
+
+(defn c [{a `a
+          b `b}]
+  :ok)
+
+(t/deftest ok
+  (with-open [info (di/start `c (di/inspect))]
+    (t/is (= [{:key `c :deps [`a `b]}
+              {:key `a :deps nil}
+              {:key `b :deps [`a]}]
+             @info))))
+
+
+(comment
+  (di/render-graphviz `c nil)
+  ,,,)