diff --git a/scripts/typeclass_stats.lean b/scripts/typeclass_stats.lean
new file mode 100644
index 0000000000000..55e63e25a9cfd
--- /dev/null
+++ b/scripts/typeclass_stats.lean
@@ -0,0 +1,122 @@
+import algebra.group.defs
+
+open tactic declaration environment native
+
+meta def pos_line (p : option pos) : string :=
+match p with
+| some x := to_string x.line
+| _      := "null"
+end
+
+def prepare_filename₁ : string → list string :=
+λ xs, ((xs.split_on '/').drop_while (λ x, x ≠ "library" ∧ x ≠ "src"))
+
+def prepare_filename₂ : list string → list string
+| ("library" :: l) := ("core" :: l)
+| ("src" :: l)     := l
+| _                := []
+
+def filename : string → string :=
+"/".intercalate ∘ prepare_filename₂ ∘ prepare_filename₁
+
+def topic : string → string :=
+list.head ∘ prepare_filename₂ ∘ prepare_filename₁
+
+structure item :=
+(file : string)
+(line : string)
+(name : string)
+(topic : string)
+
+structure node extends item.
+
+namespace node
+
+def jsonify : node → string :=
+λ n,
+"{ \"name\" : \"" ++ n.name ++ "\",\n" ++
+  "\"topic\" : \"" ++ n.topic ++ "\",\n" ++
+  "\"file\" : \"" ++ n.file ++ "\",\n" ++
+  "\"line\" : " ++ n.line ++ " }\n"
+
+instance : has_to_string node := ⟨jsonify⟩
+
+end node
+
+structure edge extends item :=
+(source : string)
+(target : string)
+
+namespace edge
+
+def jsonify : edge → string :=
+λ e,
+"{ \"name\" : \"" ++ e.name ++ "\",\n" ++
+  "\"topic\" : \"" ++ e.topic ++ "\",\n" ++
+  "\"source\" : \"" ++ e.source ++ "\",\n" ++
+  "\"target\" : \"" ++ e.target ++ "\",\n" ++
+  "\"file\" : \"" ++ e.file ++ "\",\n" ++
+  "\"line\" : " ++ e.line ++ " }\n"
+
+instance : has_to_string edge := ⟨jsonify⟩
+
+end edge
+
+/- parses information about `decl` if it is an instance or a class. -/
+meta def parse_decl (env : environment) (decl : declaration) :
+  tactic (option (node ⊕ edge)) :=
+let name := decl.to_name in
+do
+    if (env.decl_olean name).is_some
+    then do
+      olean_file ← env.decl_olean name,
+      let I : item :=
+      { name := to_string name,
+        file := filename olean_file,
+        line := pos_line (env.decl_pos name),
+        topic := topic olean_file },
+      (l, tgt) ← return decl.type.pi_binders,
+      guard (l.tail.all $ λ b, b.info = binder_info.inst_implicit),
+      is_c ← succeeds (tactic.has_attribute `class name),
+      if is_c then do
+        let N : node := { .. I },
+        return (some (sum.inl N))
+      else do
+      is_i ← succeeds (tactic.has_attribute `instance name),
+      if is_i then do
+        guard (tgt.get_app_args.head.is_var && l.ilast.type.get_app_args.head.is_var),
+        let src := to_string l.ilast.type.erase_annotations.get_app_fn.const_name,
+        let tgt := to_string tgt.erase_annotations.get_app_fn.const_name,
+        guard (src ≠ tgt),
+        let E : edge := { source := src, target := tgt, .. I },
+        return (some (sum.inr E))
+      else do return none
+    else do return none
+
+/-- prints information about unary classes and forgetful instances in the environment.
+  It only prints instances and classes that have at most 1 argument
+  that is not a type-class argument (within square brackets),
+  and the instances can only be forgetful instances
+  (where the conclusion is a class applied to a variable) -/
+meta def print_content : tactic unit :=
+do curr_env ← get_env,
+   o ← (curr_env.fold [] list.cons).mmap_filter (λ x, parse_decl curr_env x <|> pure none),
+   let (ns, es) := o.partition_map id,
+   trace "{ \"nodes\" : \n",
+   trace (to_string ns),
+   trace ",\n  \"edges\" :\n",
+   trace (to_string es),
+   trace "}",
+   skip
+
+meta def test : tactic unit :=
+do curr_env ← get_env,
+   d ← get_decl `comm_monoid.to_comm_semigroup,
+   trace (to_string d.to_name),
+   o ← parse_decl curr_env d,
+   trace (to_string o),
+   skip
+
+-- run_cmd test
+
+run_cmd print_content