diff --git a/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/IRecipeSender.cs b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/IRecipeSender.cs
new file mode 100644
index 00000000..40dae6fc
--- /dev/null
+++ b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/IRecipeSender.cs
@@ -0,0 +1,21 @@
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+/// Whether a single POST attempt reached the server () or never did ().
+internal enum AttemptKind
+{
+ Connected,
+ ConnectFailed,
+}
+
+/// Result of one POST attempt against a single base URL.
+/// Did the attempt reach the server?
+/// HTTP status when ; 0 otherwise.
+/// Parsed response body on a 2xx; null otherwise.
+/// Connection/exception detail when ; null otherwise.
+internal sealed record AttemptOutcome(AttemptKind Kind, int StatusCode, RecipeDownloadResult? Body, string? Error);
+
+/// Seam over a single recipe-download POST attempt, so the failover loop is testable without real HTTP.
+internal interface IRecipeSender
+{
+ Task SendAsync(string baseUrl, RecipeDownload payload, CancellationToken ct);
+}
diff --git a/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/Notifier.cs b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/Notifier.cs
new file mode 100644
index 00000000..93eb1fce
--- /dev/null
+++ b/src/ZB.MOM.WW.ScadaBridge.DelmiaNotifier/Notifier.cs
@@ -0,0 +1,47 @@
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+/// Final outcome of the notify operation, mapped 1:1 to the YES/NO + exit-code contract.
+internal sealed record NotifyResult(bool Ok, string Reason);
+
+///
+/// Connect-failure-only failover loop: tries each base URL in order. A node that responds at all is
+/// authoritative — its answer is final (success, business rejection, or HTTP error alike). Only a
+/// failure to connect rolls over to the next URL; if every URL fails to connect the last error is reported.
+///
+internal static class Notifier
+{
+ public static async Task RunAsync(
+ string[] baseUrls, RecipeDownload payload, IRecipeSender sender, CancellationToken ct)
+ {
+ var lastError = "no base URLs configured";
+
+ foreach (var baseUrl in baseUrls)
+ {
+ var outcome = await sender.SendAsync(baseUrl, payload, ct);
+
+ if (outcome.Kind == AttemptKind.ConnectFailed)
+ {
+ lastError = outcome.Error ?? "connection failed";
+ continue; // unreachable node → try the next
+ }
+
+ // Connected — this node's answer is authoritative; never fail over past it.
+ if (IsSuccessStatus(outcome.StatusCode))
+ {
+ if (outcome.Body is { Result: true })
+ {
+ return new NotifyResult(true, outcome.Body.ResultText ?? string.Empty);
+ }
+
+ var reason = outcome.Body?.ResultText;
+ return new NotifyResult(false, string.IsNullOrEmpty(reason) ? "request rejected" : reason);
+ }
+
+ return new NotifyResult(false, $"HTTP {outcome.StatusCode}");
+ }
+
+ return new NotifyResult(false, $"all URLs unreachable: {lastError}");
+ }
+
+ private static bool IsSuccessStatus(int status) => status is >= 200 and < 300;
+}
diff --git a/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/NotifierTests.cs b/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/NotifierTests.cs
new file mode 100644
index 00000000..95bc488e
--- /dev/null
+++ b/tests/ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests/NotifierTests.cs
@@ -0,0 +1,70 @@
+using ZB.MOM.WW.ScadaBridge.DelmiaNotifier;
+
+namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests;
+
+public class NotifierTests
+{
+ private sealed class FakeSender(params AttemptOutcome[] outcomes) : IRecipeSender
+ {
+ private readonly Queue _outcomes = new(outcomes);
+ public int Calls { get; private set; }
+
+ public Task SendAsync(string baseUrl, RecipeDownload payload, CancellationToken ct)
+ {
+ Calls++;
+ return Task.FromResult(_outcomes.Dequeue());
+ }
+ }
+
+ private static readonly string[] TwoUrls = ["http://a", "http://b"];
+ private static readonly RecipeDownload Payload =
+ new() { MachineCode = "Z", DownloadPath = "x", WorkOrderNumber = "W", PartNumber = "P" };
+
+ [Fact]
+ public async Task ConnectFailure_advances_to_next_url()
+ {
+ var sender = new FakeSender(
+ new AttemptOutcome(AttemptKind.ConnectFailed, 0, null, "refused"),
+ new AttemptOutcome(AttemptKind.Connected, 200, new RecipeDownloadResult { Result = true }, null));
+ var result = await Notifier.RunAsync(TwoUrls, Payload, sender, CancellationToken.None);
+ Assert.True(result.Ok);
+ Assert.Equal(2, sender.Calls);
+ }
+
+ [Fact]
+ public async Task Connected_result_false_is_final_no_failover()
+ {
+ var sender = new FakeSender(
+ new AttemptOutcome(AttemptKind.Connected, 200, new RecipeDownloadResult { Result = false, ResultText = "bad machine" }, null),
+ new AttemptOutcome(AttemptKind.Connected, 200, new RecipeDownloadResult { Result = true }, null));
+ var result = await Notifier.RunAsync(TwoUrls, Payload, sender, CancellationToken.None);
+ Assert.False(result.Ok);
+ Assert.Contains("bad machine", result.Reason);
+ Assert.Equal(1, sender.Calls);
+ }
+
+ [Fact]
+ public async Task Connected_5xx_is_final_no_failover()
+ {
+ var sender = new FakeSender(
+ new AttemptOutcome(AttemptKind.Connected, 500, null, null),
+ new AttemptOutcome(AttemptKind.Connected, 200, new RecipeDownloadResult { Result = true }, null));
+ var result = await Notifier.RunAsync(TwoUrls, Payload, sender, CancellationToken.None);
+ Assert.False(result.Ok);
+ Assert.Contains("500", result.Reason);
+ Assert.Equal(1, sender.Calls);
+ }
+
+ [Fact]
+ public async Task All_connect_failures_report_unreachable_with_last_error()
+ {
+ var sender = new FakeSender(
+ new AttemptOutcome(AttemptKind.ConnectFailed, 0, null, "refused-a"),
+ new AttemptOutcome(AttemptKind.ConnectFailed, 0, null, "refused-b"));
+ var result = await Notifier.RunAsync(TwoUrls, Payload, sender, CancellationToken.None);
+ Assert.False(result.Ok);
+ Assert.Contains("unreachable", result.Reason);
+ Assert.Contains("refused-b", result.Reason);
+ Assert.Equal(2, sender.Calls);
+ }
+}