diff --git a/lib/polar_web/controllers/publish/testing/assessment_controller.ex b/lib/polar_web/controllers/publish/testing/assessment_controller.ex
index b2eec0d..8067ed6 100644
--- a/lib/polar_web/controllers/publish/testing/assessment_controller.ex
+++ b/lib/polar_web/controllers/publish/testing/assessment_controller.ex
@@ -6,12 +6,18 @@ defmodule PolarWeb.Publish.Testing.AssessmentController do
 
   alias Polar.Streams.Version
 
+  alias PolarWeb.Params.Assessment
+
+  action_fallback PolarWeb.FallbackController
+
   def create(conn, %{
         "version_id" => version_id,
         "assessment" => assessment_params
       }) do
     with %Version{} = check <- Repo.get(Version, version_id),
-         {:ok, assessment} <- Machines.get_or_create_assessment(check, assessment_params) do
+         {:ok, assessment_params} <- Assessment.parse(assessment_params),
+         {:ok, assessment} <-
+           Machines.get_or_create_assessment(check, Map.from_struct(assessment_params)) do
       assessment = Repo.preload(assessment, [:check])
 
       conn
diff --git a/lib/polar_web/controllers/publish/testing/check_controller.ex b/lib/polar_web/controllers/publish/testing/check_controller.ex
index 7707ca8..6218756 100644
--- a/lib/polar_web/controllers/publish/testing/check_controller.ex
+++ b/lib/polar_web/controllers/publish/testing/check_controller.ex
@@ -3,6 +3,8 @@ defmodule PolarWeb.Publish.Testing.CheckController do
 
   alias Polar.Machines
 
+  action_fallback PolarWeb.FallbackController
+
   def index(conn, _params) do
     checks = Machines.list_checks()
 
diff --git a/lib/polar_web/controllers/publish/testing/cluster_controller.ex b/lib/polar_web/controllers/publish/testing/cluster_controller.ex
index c191370..1851fd4 100644
--- a/lib/polar_web/controllers/publish/testing/cluster_controller.ex
+++ b/lib/polar_web/controllers/publish/testing/cluster_controller.ex
@@ -3,6 +3,8 @@ defmodule PolarWeb.Publish.Testing.ClusterController do
 
   alias Polar.Machines
 
+  action_fallback PolarWeb.FallbackController
+
   def index(conn, _params) do
     clusters = Machines.list_clusters(:for_testing)
 
diff --git a/lib/polar_web/params/assessment.ex b/lib/polar_web/params/assessment.ex
new file mode 100644
index 0000000..d5b84e9
--- /dev/null
+++ b/lib/polar_web/params/assessment.ex
@@ -0,0 +1,29 @@
+defmodule PolarWeb.Params.Assessment do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @required_attrs ~w(
+    check_id 
+    cluster_id 
+    instance_type
+  )a
+
+  @primary_key false
+  embedded_schema do
+    field :check_id, :integer
+    field :cluster_id, :integer
+    field :instance_type, :string
+  end
+
+  def parse(params) do
+    %__MODULE__{}
+    |> changeset(params)
+    |> apply_action(:insert)
+  end
+
+  def changeset(assessment, params) do
+    assessment
+    |> cast(params, @required_attrs)
+    |> validate_required(@required_attrs)
+  end
+end
diff --git a/test/polar_web/controllers/publish/testing/assessment_controller_test.exs b/test/polar_web/controllers/publish/testing/assessment_controller_test.exs
index caa11ae..4bdddf0 100644
--- a/test/polar_web/controllers/publish/testing/assessment_controller_test.exs
+++ b/test/polar_web/controllers/publish/testing/assessment_controller_test.exs
@@ -78,5 +78,22 @@ defmodule PolarWeb.Publish.Testing.AssessmentControllerTest do
 
       assert %{"id" => _id, "current_state" => "created", "check" => _check} = data
     end
+
+    test "invalid parameter passed in", %{
+      version: version,
+      conn: conn,
+      check: check,
+      cluster: cluster
+    } do
+      conn =
+        post(conn, ~p"/publish/testing/versions/#{version.id}/assessments", %{
+          "assessment" => %{
+            "check_id" => check.id,
+            "cluster_id" => cluster.id
+          }
+        })
+
+      assert %{"errors" => _errors} = json_response(conn, 422)
+    end
   end
 end