diff --git a/TODO.md b/TODO.md
index 3ca7116..8f585d8 100644
--- a/TODO.md
+++ b/TODO.md
@@ -5,10 +5,9 @@ x- Use nid to connect
 X- Get nid for a node
 X- A node must have a function
 X- The function in Broadcast and Funnel nodes can be optional
-- Add Supervisors functionality
-- Use counters for stats
+X- Add Supervisors functionality
+X- Use counters for stats
 x- Improve test
 
 Future
 - Improve API
-- Update to GenStage
diff --git a/lib/exstreme/gnode/behaviour.ex b/lib/exstreme/gnode/behaviour.ex
index 01c4a20..f86c99f 100644
--- a/lib/exstreme/gnode/behaviour.ex
+++ b/lib/exstreme/gnode/behaviour.ex
@@ -20,8 +20,6 @@ defmodule Exstreme.GNode.Behaviour do
 
         @type t :: %Data{next: [atom], nid: atom, func: graph_func, funnel_queue: [term], received_counter: non_neg_integer, sent_counter: non_neg_integer, opts: [key: term]}
         defstruct [next: [], nid: nil, func: nil, funnel_queue: [], received_counter: 0, sent_counter: 0, opts: []]
-
-        #TODO use counters
       end
 
       def start_link(params \\ []) do
@@ -36,18 +34,23 @@ defmodule Exstreme.GNode.Behaviour do
         {:ok, %Data{func: func, nid: nid, opts: opts}}
       end
 
-      def handle_cast({:connect, to_nid}, data) do
+      def handle_cast({:next, from_data, msg}, data) do
+        send self, {:on_next, from_data, msg}
+        {:noreply, %{data | received_counter: data.received_counter + 1}}
+      end
+
+      def handle_call({:connect, to_nid}, _from, data) do
         new_data = update_in(data.next, fn(next) -> [to_nid | next] end)
-        {:noreply, new_data}
+        {:reply, :ok, new_data}
       end
 
       def handle_info({:send_next, next, msg}, data) do
         Enum.each(next, &(GenServer.cast(&1, {:next, data, msg})))
-        {:noreply, data}
+        {:noreply, %{data | sent_counter: data.sent_counter + Enum.count(next)}}
       end
 
-      def send_next(pid, next, msg) do
-        send pid, {:send_next, next, msg}
+      def send_next(next, msg) do
+        send self, {:send_next, next, msg}
       end
     end
   end
diff --git a/lib/exstreme/gnode/broadcast.ex b/lib/exstreme/gnode/broadcast.ex
index 2d0f91e..267ee13 100644
--- a/lib/exstreme/gnode/broadcast.ex
+++ b/lib/exstreme/gnode/broadcast.ex
@@ -2,9 +2,9 @@ defmodule Exstreme.GNode.Broadcast do
   use Exstreme.GNode.Behaviour
 
   # Broadcasts the message to the next nodes
-  def handle_cast({:next, _, msg}, data) do
+  def handle_info({:on_next, _, msg}, data) do
     {:ok, result} = data.func.(msg, data)
-    send_next(self, data.next, result)
+    send_next(data.next, result)
     {:noreply, data}
   end
 end
diff --git a/lib/exstreme/gnode/common.ex b/lib/exstreme/gnode/common.ex
index 964b696..098f80f 100644
--- a/lib/exstreme/gnode/common.ex
+++ b/lib/exstreme/gnode/common.ex
@@ -2,9 +2,9 @@ defmodule Exstreme.GNode.Common do
   use Exstreme.GNode.Behaviour
 
   # Sends the result to the next one
-  def handle_cast({:next, _, msg}, data) do
+  def handle_info({:on_next, _, msg}, data) do
     {:ok, result} = data.func.(msg, data)
-    send_next(self, data.next, result)
+    send_next(data.next, result)
     {:noreply, data}
   end
 end
diff --git a/lib/exstreme/gnode/funnel.ex b/lib/exstreme/gnode/funnel.ex
index 45d240d..6382e44 100644
--- a/lib/exstreme/gnode/funnel.ex
+++ b/lib/exstreme/gnode/funnel.ex
@@ -3,7 +3,7 @@ defmodule Exstreme.GNode.Funnel do
 
   # Receives a message and saves it in a messages map queue,
   # when all the messages are done sends a the map
-  def handle_cast({:next, from_data, msg}, data) do
+  def handle_info({:on_next, from_data, msg}, data) do
     {result, new_queue} =
       data.funnel_queue
       |> add_queue(from_data.nid, msg)
@@ -20,7 +20,7 @@ defmodule Exstreme.GNode.Funnel do
     if result != nil do
       new_msg = Map.values(result)
       {:ok, result} = data.func.(new_msg, data)
-      send_next(self, data.next, result)
+      send_next(data.next, result)
     end
   end
 
diff --git a/lib/exstreme/gnode/graph_supervisor.ex b/lib/exstreme/gnode/graph_supervisor.ex
new file mode 100644
index 0000000..5a123f0
--- /dev/null
+++ b/lib/exstreme/gnode/graph_supervisor.ex
@@ -0,0 +1,23 @@
+defmodule Exstreme.GraphSupervisor do
+  use Supervisor
+
+  def start_link(graph) do
+    pid =
+      graph.name
+      |> String.to_atom
+      |> Process.whereis
+    if pid != nil && Process.alive?(pid) do
+      {:error, "The supervisor alredy exists"}
+    else
+      Supervisor.start_link(__MODULE__, graph, name: String.to_atom(graph.name))
+    end
+  end
+
+  def init(graph) do
+    children =
+      Enum.map(graph.nodes, fn({gnode, params}) ->
+        worker(Keyword.get(params, :module), [params], id: gnode)
+      end)
+    supervise(children, strategy: :one_for_one)
+  end
+end
diff --git a/lib/exstreme/gnode/supervisor.ex b/lib/exstreme/gnode/supervisor.ex
deleted file mode 100644
index 41b931f..0000000
--- a/lib/exstreme/gnode/supervisor.ex
+++ /dev/null
@@ -1,3 +0,0 @@
-defmodule Exstreme.Supervisor do
-
-end
diff --git a/lib/exstreme/graph_builder.ex b/lib/exstreme/graph_builder.ex
index 70be31b..e206bce 100644
--- a/lib/exstreme/graph_builder.ex
+++ b/lib/exstreme/graph_builder.ex
@@ -7,6 +7,7 @@ defmodule Exstreme.GraphBuilder do
   alias Exstreme.GNode.Common
   alias Exstreme.Graph
   alias Exstreme.GraphValidator
+  alias Exstreme.GraphSupervisor
 
   @doc """
   Builds the Supervision tree for the graph
@@ -16,7 +17,7 @@ defmodule Exstreme.GraphBuilder do
     with :ok <- GraphValidator.validate(graph) do
       graph
       |> update_nodes_relations
-      |> start_nodes
+      |> start_graph
       |> connect_nodes
     end
   end
@@ -36,33 +37,37 @@ defmodule Exstreme.GraphBuilder do
         {gnode, new_params}
       end
 
-    update_in(graph.nodes, &(&1 |> Enum.map(update_node_func) |> Map.new))
+    update_in(graph.nodes, &(Map.new(Enum.map(&1, update_node_func))))
   end
 
-  # Starts all the nodes
-  @spec start_nodes(Graph.t) :: Graph.t
-  defp start_nodes(graph) do
-    update_in(graph.nodes, fn(nodes) ->
+  @spec start_graph(Graph.t) :: Graph.t
+  defp start_graph(graph) do
+    graph = update_in(graph.nodes, fn(nodes) ->
       nodes
-      |> Enum.map(&start_node/1)
+      |> Enum.map(&setup_node/1)
       |> Map.new
     end)
+    case GraphSupervisor.start_link(graph) do
+      {:error, msg} ->
+        raise ArgumentError, message: msg
+      _ -> :ok
+    end
+    graph
   end
 
-  # Starts a gnode
-  @spec start_node({atom, [term: any]}) :: {atom, [key: any]}
-  defp start_node({gnode, params}) do
-    type = Keyword.get(params, :type)
+  # setup node's params
+  @spec setup_node({atom, [term: any]}) :: {atom, [key: any]}
+  defp setup_node({gnode, params}) do
+    module = case Keyword.get(params, :type) do
+      :broadcast -> Broadcast
+      :funnel -> Funnel
+      _ -> Common
+    end
     params =
       params
       |> Keyword.put(:nid, gnode)
+      |> Keyword.put(:module, module)
       |> Keyword.put_new(:func, fn(data, _) -> {:ok, data} end)
-    {:ok, _} =
-      case type do
-        :broadcast -> Broadcast.start_link(params)
-        :funnel -> Funnel.start_link(params)
-        _ -> Common.start_link(params)
-      end
     {gnode, params}
   end
 
@@ -87,6 +92,6 @@ defmodule Exstreme.GraphBuilder do
   defp connect_pair({from, to}, nodes) when is_atom(to) do
     nid_from = Keyword.get(nodes[from], :nid)
     nid_to =  Keyword.get(nodes[to], :nid)
-    GenServer.cast(nid_from, {:connect, nid_to})
+    :ok = GenServer.call(nid_from, {:connect, nid_to})
   end
 end
diff --git a/test/exstreme/graph_builder_test.exs b/test/exstreme/graph_builder_test.exs
index 982bdf4..76b9289 100644
--- a/test/exstreme/graph_builder_test.exs
+++ b/test/exstreme/graph_builder_test.exs
@@ -5,31 +5,43 @@ defmodule Exstreme.GraphBuilderTest do
   alias Exstreme.Graph
   doctest Exstreme.GraphBuilder
 
-  test "creates a graph and check built params" do
-    graph_built = GraphBuilder.build(create_graph)
+  setup_all do
+    {:ok,
+      graph_built: GraphBuilder.build(create_graph),
+      graph_many_built: GraphBuilder.build(graph_many_nodes("demo_1"))}
+  end
+
+  test "crashes when tries to create a graph with the same name" do
+    assert_raise ArgumentError, fn ->
+      GraphBuilder.build(create_graph("demo_1"))
+    end
+  end
+
+  test "creates a graph and check built params", %{graph_built: graph_built} do
     assert graph_built != create_graph
     Enum.each(graph_built.nodes, fn({nid, params}) ->
+      assert nid != nil
       assert Keyword.has_key?(params, :after_nodes)
       assert Keyword.has_key?(params, :before_nodes)
       assert Keyword.get(params, :nid) != nil
-      assert nid |> Process.whereis |> Process.alive? == true
+      pid = Process.whereis(nid)
+      assert pid != nil
+      assert Process.alive?(pid) == true
     end)
   end
 
-  test "sends a message to the graph with common nodes" do
-    graph_built = GraphBuilder.build(create_graph)
+  test "sends a message to the graph with common nodes", %{graph_built: graph_built} do
     [start_node] = Graph.find_start_node(graph_built)
     [last_node] = Graph.find_last_node(graph_built)
-    GenServer.cast(last_node, {:connect, self})
+    :ok = GenServer.call(last_node, {:connect, self})
     GenServer.cast(start_node, {:next, self, {:sum, 0}})
     assert_receive {_, {:next, _, {:sum, 2}}}
   end
 
-  test "sends a message to the graph with many nodes" do
-    graph_built = GraphBuilder.build(graph_many_nodes)
-    [start_node] = Graph.find_start_node(graph_built)
-    [last_node] = Graph.find_last_node(graph_built)
-    GenServer.cast(last_node, {:connect, self})
+  test "sends a message to the graph with many nodes", %{graph_many_built: graph_many_built} do
+    [start_node] = Graph.find_start_node(graph_many_built)
+    [last_node] = Graph.find_last_node(graph_many_built)
+    :ok = GenServer.call(last_node, {:connect, self})
     GenServer.cast(start_node, {:next, self, {:sum, 0}})
     assert_receive {_, {:next, _, {:sum, 7}}}
   end
diff --git a/test/support/common.ex b/test/support/common.ex
index e263648..a025ab8 100644
--- a/test/support/common.ex
+++ b/test/support/common.ex
@@ -6,8 +6,8 @@ defmodule Exstreme.Common do
     quote do
       def graph_name, do: "demo"
 
-      def graph_many_nodes do
-        graph = GraphCreator.create_graph(graph_name, [])
+      def graph_many_nodes(name \\ nil) do
+        graph = GraphCreator.create_graph(name || graph_name, [])
         {graph, n1} = GraphCreator.create_node(graph, params)
         {graph, n2} = GraphCreator.create_node(graph, params)
         {graph, b1} = GraphCreator.create_broadcast(graph, params_broadcast)
@@ -58,8 +58,8 @@ defmodule Exstreme.Common do
         GraphCreator.add_connection(graph, n1, n2)
       end
 
-      defp create_graph do
-        graph = GraphCreator.create_graph(graph_name, [])
+      defp create_graph(name \\ nil) do
+        graph = GraphCreator.create_graph(name || graph_name, [])
         {graph, n1} = GraphCreator.create_node(graph, params)
         {graph, n2} = GraphCreator.create_node(graph, params)
         GraphCreator.add_connection(graph, n1, n2)