services/event-subscriber/EventSubscriber.Api/Program.cs

@@ -54,9 +54,9 @@ await app.RunAsync();
 
 /// <summary>The NRC notification body, as Open Notificaties POSTs it. Only the fields the
 /// projection needs are bound; <c>aanmaakdatum</c>/<c>kenmerken</c> are ignored for the minimal slice.</summary>
-public sealed record NotificationDto(string Kanaal, string Resource, string Actie, Uri ResourceUrl)
+public sealed record NotificationDto(string Kanaal, string Resource, string Actie, Uri ResourceUrl, Uri? HoofdObject = null)
 {
-    public Notification ToNotification() => new(Kanaal, Resource, Actie, ResourceUrl);
+    public Notification ToNotification() => new(Kanaal, Resource, Actie, ResourceUrl, HoofdObject);
 }
 
 public partial class Program

services/event-subscriber/EventSubscriber.Application/Notification.cs

@@ -11,14 +11,23 @@ public sealed record Notification(
     string Kanaal,
     string Resource,
     string Actie,
-    Uri ResourceUrl)
+    Uri ResourceUrl,
+    Uri? HoofdObject = null)
 {
-    /// <summary>The only event the walking-skeleton projection reacts to: a zaak being created.</summary>
+    /// <summary>A zaak being created — projected as INGEDIEND.</summary>
     public bool IsZaakCreated =>
         Kanaal == "zaken" && Resource == "zaak" && Actie == "create";
 
-    /// <summary>The zaak UUID — the trailing path segment of the resource URL — used as the projection key.</summary>
-    public string ZaakId => ResourceUrl.Segments[^1].Trim('/');
+    /// <summary>A status being set on a zaak — the approval, projected as INGESCHREVEN (S-09b). In the
+    /// walking skeleton the only status ever set after creation is the approval, and the subscriber may
+    /// not read OpenZaak (§8.1), so any status-create is taken as the approval.</summary>
+    public bool IsZaakStatusSet =>
+        Kanaal == "zaken" && Resource == "status" && Actie == "create";
+
+    /// <summary>The zaak UUID used as the projection key. For a status notification the resource URL is
+    /// the status, so the zaak comes from <c>hoofdObject</c> (which, for a zaak-create, equals the
+    /// resource URL) — see the NRC payload note.</summary>
+    public string ZaakId => (HoofdObject ?? ResourceUrl).Segments[^1].Trim('/');
 
     /// <summary>
     /// A deterministic dedup key. Open Notificaties carries no notification id and may

services/event-subscriber/EventSubscriber.Application/NotificationProjector.cs

@@ -7,13 +7,15 @@ namespace EventSubscriber.Application;
 /// </summary>
 public sealed class NotificationProjector(INotificationLog log, IProjectionStore store)
 {
-    /// <summary>Handle one inbound notification. Ignores anything that is not a zaak-created event.</summary>
+    /// <summary>Handle one inbound notification. Reacts to a zaak being created (INGEDIEND) and a
+    /// status being set (INGESCHREVEN); ignores everything else.</summary>
     public async Task HandleAsync(Notification notification, CancellationToken ct = default)
     {
-        if (!notification.IsZaakCreated)
+        if (!notification.IsZaakCreated && !notification.IsZaakStatusSet)
             return;
 
-        var recorded = new RecordedNotification(notification.IdempotencyKey, notification.Actie, notification.ZaakId);
+        var recorded = new RecordedNotification(
+            notification.IdempotencyKey, notification.Actie, notification.ZaakId, notification.Resource);
 
         // Atomic record-or-skip: a duplicate (or concurrent) delivery is recognised and dropped
         // before it touches the projection, so the projection stays a faithful derived artefact.
@@ -31,8 +33,10 @@ public sealed class NotificationProjector(INotificationLog log, IProjectionStore
             await store.UpsertAsync(ToEntry(recorded), ct);
     }
 
-    /// <summary>The minimal projection row for an accepted notification. A zaak-create maps to
-    /// INGEDIEND; bsn/naam are deferred (ADR-0008).</summary>
+    /// <summary>The projection row for an accepted notification: a status-set maps to INGESCHREVEN,
+    /// a zaak-create to INGEDIEND. bsn/naam are deferred (ADR-0008).</summary>
     private static RegisterEntry ToEntry(RecordedNotification recorded)
-        => new(recorded.ZaakId, RegistrationStatus.Ingediend);
+        => new(recorded.ZaakId, recorded.Resource == "status"
+            ? RegistrationStatus.Ingeschreven
+            : RegistrationStatus.Ingediend);
 }

services/event-subscriber/EventSubscriber.Application/Ports.cs

@@ -19,8 +19,10 @@ public interface INotificationLog
     Task<IReadOnlyList<RecordedNotification>> AllAsync(CancellationToken ct = default);
 }
 
-/// <summary>A notification that has been accepted, retaining what a rebuild needs to recompute its projection row.</summary>
-public sealed record RecordedNotification(string Key, string Actie, string ZaakId);
+/// <summary>A notification that has been accepted, retaining what a rebuild needs to recompute its
+/// projection row — including the ZGW <c>resource</c>, which distinguishes a zaak-create (INGEDIEND)
+/// from a status-set (INGESCHREVEN) so a rebuild reproduces the right status.</summary>
+public sealed record RecordedNotification(string Key, string Actie, string ZaakId, string Resource);
 
 /// <summary>The read projection store. Owned by the projection bounded context (ADR-0008); the
 /// subscriber writes to it and the projection-api reads it.</summary>

services/event-subscriber/EventSubscriber.Application/RegisterEntry.cs

@@ -17,4 +17,7 @@ public static class RegistrationStatus
 {
     /// <summary>A zaak has been created; the registration is submitted.</summary>
     public const string Ingediend = "INGEDIEND";
+
+    /// <summary>The registration has been approved and entered in the register (S-09b).</summary>
+    public const string Ingeschreven = "INGESCHREVEN";
 }

services/projection-api/Projection.ReadModel/EfNotificationLog.cs

@@ -15,6 +15,7 @@ public sealed class EfNotificationLog(ProjectionDbContext db) : INotificationLog
             Key = notification.Key,
             Actie = notification.Actie,
             ZaakId = notification.ZaakId,
+            Resource = notification.Resource,
             ReceivedAt = DateTimeOffset.UtcNow,
         });
 
@@ -34,6 +35,6 @@ public sealed class EfNotificationLog(ProjectionDbContext db) : INotificationLog
     public async Task<IReadOnlyList<RecordedNotification>> AllAsync(CancellationToken ct = default)
         => await db.ProcessedNotifications
             .OrderBy(r => r.ReceivedAt)
-            .Select(r => new RecordedNotification(r.Key, r.Actie, r.ZaakId))
+            .Select(r => new RecordedNotification(r.Key, r.Actie, r.ZaakId, r.Resource))
             .ToListAsync(ct);
 }

services/projection-api/Projection.ReadModel/Migrations/20260713145944_AddNotificationResource.Designer.cs

@@ -0,0 +1,84 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using Projection.ReadModel;
+
+#nullable disable
+
+namespace Projection.ReadModel.Migrations
+{
+    [DbContext(typeof(ProjectionDbContext))]
+    [Migration("20260713145944_AddNotificationResource")]
+    partial class AddNotificationResource
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.0")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("Projection.ReadModel.ProcessedNotificationRow", b =>
+                {
+                    b.Property<string>("Key")
+                        .HasColumnType("text")
+                        .HasColumnName("key");
+
+                    b.Property<string>("Actie")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("actie");
+
+                    b.Property<DateTimeOffset>("ReceivedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("received_at");
+
+                    b.Property<string>("Resource")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("resource");
+
+                    b.Property<string>("ZaakId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("zaak_id");
+
+                    b.HasKey("Key");
+
+                    b.ToTable("processed_notifications", (string)null);
+                });
+
+            modelBuilder.Entity("Projection.ReadModel.RegisterEntryRow", b =>
+                {
+                    b.Property<string>("Id")
+                        .HasColumnType("text")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Bsn")
+                        .HasColumnType("text")
+                        .HasColumnName("bsn");
+
+                    b.Property<string>("NaamPlaceholder")
+                        .HasColumnType("text")
+                        .HasColumnName("naam_placeholder");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("status");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("register_projection", (string)null);
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

services/projection-api/Projection.ReadModel/Migrations/20260713145944_AddNotificationResource.cs

@@ -0,0 +1,31 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Projection.ReadModel.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddNotificationResource : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            // Pre-existing rows are all zaak-creates (the only notification the projector recorded
+            // before S-09b), so default the backfill to "zaak" rather than "".
+            migrationBuilder.AddColumn<string>(
+                name: "resource",
+                table: "processed_notifications",
+                type: "text",
+                nullable: false,
+                defaultValue: "zaak");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "resource",
+                table: "processed_notifications");
+        }
+    }
+}

services/projection-api/Projection.ReadModel/Migrations/ProjectionDbContextModelSnapshot.cs

@@ -37,6 +37,11 @@ namespace Projection.ReadModel.Migrations
                         .HasColumnType("timestamp with time zone")
                         .HasColumnName("received_at");
 
+                    b.Property<string>("Resource")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("resource");
+
                     b.Property<string>("ZaakId")
                         .IsRequired()
                         .HasColumnType("text")

services/projection-api/Projection.ReadModel/ProjectionDbContext.cs

@@ -35,6 +35,7 @@ public sealed class ProjectionDbContext(DbContextOptions<ProjectionDbContext> op
             e.Property(r => r.Key).HasColumnName("key");
             e.Property(r => r.Actie).HasColumnName("actie").IsRequired();
             e.Property(r => r.ZaakId).HasColumnName("zaak_id").IsRequired();
+            e.Property(r => r.Resource).HasColumnName("resource").IsRequired();
             e.Property(r => r.ReceivedAt).HasColumnName("received_at");
         });
     }
@@ -55,5 +56,10 @@ public sealed class ProcessedNotificationRow
     public required string Key { get; set; }
     public required string Actie { get; set; }
     public required string ZaakId { get; set; }
+
+    /// <summary>The ZGW resource (e.g. <c>zaak</c> or <c>status</c>) — retained so a rebuild reprojects
+    /// the right status without reading OpenZaak (S-09b).</summary>
+    public required string Resource { get; set; }
+
     public DateTimeOffset ReceivedAt { get; set; }
 }

tests/acceptance/Support/InMemoryDomainPorts.cs

@@ -26,12 +26,19 @@ public sealed class InMemoryAclClient : IAclClient
     public static readonly Uri OpenedZaakUrl = new("http://openzaak/zaken/api/v1/zaken/acc-zaak");
 
     public string? OpenedForBsn { get; private set; }
+    public Uri? ApprovedZaakUrl { get; private set; }
 
     public Task<Uri> OpenZaakAsync(string bsn, CancellationToken ct = default)
     {
         OpenedForBsn = bsn;
         return Task.FromResult(OpenedZaakUrl);
     }
+
+    public Task ApproveZaakAsync(Uri zaakUrl, CancellationToken ct = default)
+    {
+        ApprovedZaakUrl = zaakUrl;
+        return Task.CompletedTask;
+    }
 }
 
 /// <summary>An in-memory registration store for the domain acceptance scenario.</summary>

tests/acceptance/Support/InMemoryZaakGateway.cs

@@ -11,10 +11,17 @@ public sealed class InMemoryZaakGateway : IZaakGateway
     public static readonly Uri CreatedZaakUrl = new("http://openzaak/zaken/api/v1/zaken/created-123");
 
     public ZaakRequest? Captured { get; private set; }
+    public (Uri Zaak, Uri Zaaktype, DateOnly Datum)? Approved { get; private set; }
 
     public Task<Uri> OpenZaakAsync(ZaakRequest request, CancellationToken ct = default)
     {
         Captured = request;
         return Task.FromResult(CreatedZaakUrl);
     }
+
+    public Task SetZaakToEindstatusAsync(Uri zaakUrl, Uri zaaktypeUrl, DateOnly datumStatusGezet, CancellationToken ct = default)
+    {
+        Approved = (zaakUrl, zaaktypeUrl, datumStatusGezet);
+        return Task.CompletedTask;
+    }
 }