diff --git a/test/chronoscope/nts_test.exs b/test/chronoscope/nts_test.exs
index 08b3b25..54aeab6 100644
--- a/test/chronoscope/nts_test.exs
+++ b/test/chronoscope/nts_test.exs
@@ -1,6 +1,7 @@
 defmodule Chronoscope.NTSTest do
   use Chronoscope.Case
 
+  alias Chronoscope.NTS
   alias Chronoscope.NTS.DynamicSupervisorMock
   alias Chronoscope.NTS.GenServerMock
   alias Chronoscope.NTS.RegistryMock
@@ -43,5 +44,47 @@ defmodule Chronoscope.NTSTest do
 
       assert remove("localhost", 1111) == {:error, :not_found}
     end
+
+    test "removes a client" do
+      RegistryMock
+      |> expect(:lookup, fn _, _ -> [{1, 2}] end)
+
+      GenServerMock
+      |> expect(:call, fn 1, :terminate -> :terminating end)
+
+      assert remove("localhost", 1111) == {:ok, :terminating}
+    end
+  end
+
+  describe "Chronoscope.NTS.key_establishment()" do
+    test "creates a new client" do
+      RegistryMock
+      |> expect(:lookup, fn _, _ -> [] end)
+
+      DynamicSupervisorMock
+      |> expect(:start_child, fn NTS.DynamicSupervisor,
+                                 {NTS.Client,
+                                  [
+                                    server: %{host: "localhost", port: 1111},
+                                    name: {:via, RegistryMock, {NTS.Registry, "localhost:1111"}}
+                                  ]} ->
+        {:ok, 1}
+      end)
+
+      GenServerMock
+      |> expect(:call, fn 1, :key_establishment -> :result end)
+
+      assert key_establishment("localhost", 1111) == :result
+    end
+
+    test "reuses an existing client" do
+      RegistryMock
+      |> expect(:lookup, fn _, _ -> [{1, 2}] end)
+
+      GenServerMock
+      |> expect(:call, fn 1, :key_establishment -> :result end)
+
+      assert key_establishment("localhost", 1111) == :result
+    end
   end
 end