diff --git a/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/NotifierJsonContext.cs b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/NotifierJsonContext.cs
new file mode 100644
index 00000000..e2684855
--- /dev/null
+++ b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/NotifierJsonContext.cs
@@ -0,0 +1,7 @@
+using System.Text.Json.Serialization;
+
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+[JsonSerializable(typeof(RecipeDownload))]
+[JsonSerializable(typeof(RecipeDownloadResult))]
+internal partial class NotifierJsonContext : JsonSerializerContext;
diff --git a/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownload.cs b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownload.cs
new file mode 100644
index 00000000..7034ec6f
--- /dev/null
+++ b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownload.cs
@@ -0,0 +1,11 @@
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+internal sealed class RecipeDownload
+{
+    public string? MachineCode { get; set; }
+    public string? DownloadPath { get; set; }
+    public string? WorkOrderNumber { get; set; }
+    public string? PartNumber { get; set; }
+    public string? JobStepNumber { get; set; }
+    public string? Username { get; set; }
+}
diff --git a/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownloadResult.cs b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownloadResult.cs
new file mode 100644
index 00000000..5d4e0c42
--- /dev/null
+++ b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/RecipeDownloadResult.cs
@@ -0,0 +1,7 @@
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+internal sealed class RecipeDownloadResult
+{
+    public bool Result { get; set; }
+    public string? ResultText { get; set; }
+}
diff --git a/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/JsonContractTests.cs b/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/JsonContractTests.cs
new file mode 100644
index 00000000..c6074f04
--- /dev/null
+++ b/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/JsonContractTests.cs
@@ -0,0 +1,27 @@
+using System.Text.Json;
+using ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests;
+
+public class JsonContractTests
+{
+    [Fact]
+    public void RecipeDownload_serializes_pascalcase()
+    {
+        var json = JsonSerializer.Serialize(
+            new RecipeDownload { MachineCode = "Z28061", DownloadPath = @"C:\r.nc",
+                WorkOrderNumber = "W1", PartNumber = "P1", JobStepNumber = "0100", Username = "op" },
+            NotifierJsonContext.Default.RecipeDownload);
+        Assert.Contains("\"MachineCode\":\"Z28061\"", json);
+        Assert.Contains("\"DownloadPath\"", json);
+    }
+
+    [Fact]
+    public void RecipeDownloadResult_deserializes_pascalcase()
+    {
+        var r = JsonSerializer.Deserialize("{\"Result\":true,\"ResultText\":\"ok\"}",
+            NotifierJsonContext.Default.RecipeDownloadResult);
+        Assert.True(r!.Result);
+        Assert.Equal("ok", r.ResultText);
+    }
+}