feat(workflow): document-wait task + 30-day timeout cancellation (S-10a, closes #102) (#105)

## What & why

S-10a, the **workflow/timeout spine** of the (split) document-upload slice: the registratie process
now parks at a **`WachtOpDocumenten`** user task with an **interrupting `P30D` boundary timer**. When
the documents arrive the task completes and the process continues into the diploma routing (S-13) →
Beoordelen; if the 30 days lapse, the timer cancels the wait, runs a `RegistratieVerlopen`
external-worker task, and the domain expires the aggregate to a new terminal status **`Verlopen`**.
Backend only — the real upload trigger (portal → BFF → ACL → Documenten API) is S-10b (#103).

Closes #102

Mechanism recorded in **ADR-0017**; opened as proposal #104. Mirrors the S-14 escalation
(boundary-timer + external-worker) and S-11 withdrawal (interrupting cancel) patterns.

## Definition of Done

- [x] Linked Gitea issue (above).
- [x] Failing test committed before the implementation (red→green pairs per layer).
- [x] Implementation makes the test pass.
- [x] Conventional Commits referencing the issue (`refs #102`).
- [ ] CI green — all Gitea Actions jobs (pending on this PR).
- [x] `docker compose up` health unaffected (no new services; deploy path unchanged).
- [x] Docs updated (ADR-0017, demo-script, BACKLOG split).
- [x] ADR added (`docs/architecture/adr-0017-document-wait-timeout-cancellation.md`).
- [x] Demo note in `docs/demo-script.md`.

## Notes for reviewers

- **Domain** (`Registration.Expire()` + `Verlopen`), **application** (`ExpireRegistrationWorker`),
  **infra** (`RegistratieVerlopenProcessor`/`Pump`, `IRegistratieVerlopenClient`, Flowable
  acquire/complete + `CompleteDocumentWaitAsync`) — the timeout counterpart to the OpenZaak/escalation
  worker trios; idempotent per §8.6.
- **BPMN** verified live against a `flowable-rest` probe: complete `WachtOpDocumenten` → routes to
  Beoordelen; fire the P30D timer → `RegistratieVerlopen` job (carrying `registrationId`) + the wait
  task cancelled. `verify-domain` exercises both branches in-stack (completes the wait in every existing
  block; fires the timer and asserts `Verlopen` in a new block).
- **Scope boundary:** on expiry the aggregate goes `Verlopen` and the process ends, but the ZGW *zaak*
  is not yet set to a cancellation status — that needs a new ACL method + statustype seeding and is
  folded into S-10b (noted in ADR-0017).
- `CompleteDocumentWaitAsync` is built and HTTP-tested here but not yet called from a domain endpoint;
  S-10b wires the upload trigger to it.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: #105

services/bff/Bff.Api/DownstreamClients.cs

@@ -27,6 +27,11 @@ public interface IDomainClient
     /// unknown or not the caller's (404), so the BFF can relay a 404 rather than a 500.</summary>
     Task<bool> WithdrawRegistrationAsync(string registrationId, string bsn, CancellationToken ct = default);
 
+    /// <summary>Provide the documents the caller's own registration is waiting for ("documenten
+    /// aanleveren"). Owner-scoped by <paramref name="bsn"/>. Returns <c>false</c> when the domain
+    /// reports the registration is unknown or not the caller's (404), so the BFF can relay a 404.</summary>
+    Task<bool> ProvideDocumentsAsync(string registrationId, string bsn, CancellationToken ct = default);
+
     /// <summary>The behandelaar's werkbak — registrations awaiting beoordeling.</summary>
     Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default);
 
@@ -63,6 +68,17 @@ public sealed class DomainClient(HttpClient http) : IDomainClient
         return true;
     }
 
+    public async Task<bool> ProvideDocumentsAsync(string registrationId, string bsn, CancellationToken ct = default)
+    {
+        using var response = await http.PostAsJsonAsync(
+            $"registrations/{registrationId}/documents", new { bsn }, ct);
+        // The domain 404s an unknown or not-owned registration; relay that rather than fail hard.
+        if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+            return false;
+        response.EnsureSuccessStatusCode();
+        return true;
+    }
+
     public async Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default)
         => await http.GetFromJsonAsync<List<WerkbakItem>>("behandel/werkbak", ct) ?? [];
 

services/bff/Bff.Api/Program.cs

@@ -104,6 +104,26 @@ app.MapPost("/self-service/registrations/{id}/withdraw", async (string id, Claim
     .Produces(StatusCodes.Status401Unauthorized)
     .Produces(StatusCodes.Status404NotFound);
 
+// Self-service provide-documents (S-10a): the signed-in zorgprofessional supplies the documents their
+// registration is waiting for ("documenten aanleveren"). The bsn comes from the DigiD token and is
+// forwarded to the domain, which owner-scopes the action and completes the WachtOpDocumenten task; a
+// registration that is unknown or not the caller's comes back 404. The real file upload + ZGW storage
+// is S-10b — this is the trigger that unblocks the process.
+app.MapPost("/self-service/registrations/{id}/documents", async (string id, ClaimsPrincipal user, IDomainClient domain, CancellationToken ct) =>
+{
+    var bsn = user.FindFirstValue("bsn");
+    if (string.IsNullOrWhiteSpace(bsn))
+        return Results.BadRequest("The token carries no bsn claim.");
+
+    var provided = await domain.ProvideDocumentsAsync(id, bsn, ct);
+    return provided ? Results.NoContent() : Results.NotFound();
+})
+    .RequireAuthorization()
+    .Produces(StatusCodes.Status204NoContent)
+    .Produces(StatusCodes.Status400BadRequest)
+    .Produces(StatusCodes.Status401Unauthorized)
+    .Produces(StatusCodes.Status404NotFound);
+
 // Openbaar register: an anonymous public lookup that exposes only public-safe fields (S-09).
 app.MapGet("/openbaar/register", async (string? q, IProjectionClient projection, CancellationToken ct) =>
 {

services/bff/Bff.Tests/BffFactory.cs

@@ -94,6 +94,18 @@ internal sealed class FakeDomainClient : IDomainClient
         return Task.FromResult(WithdrawSucceeds);
     }
 
+    public (string RegistrationId, string Bsn)? DocumentsProvidedFor { get; private set; }
+
+    /// <summary>Whether the fake domain reports the provide-documents as done (true → 204) or
+    /// not-found/not-owned (false → 404). Tests set this to exercise the relay.</summary>
+    public bool ProvideDocumentsSucceeds { get; set; } = true;
+
+    public Task<bool> ProvideDocumentsAsync(string registrationId, string bsn, CancellationToken ct = default)
+    {
+        DocumentsProvidedFor = (registrationId, bsn);
+        return Task.FromResult(ProvideDocumentsSucceeds);
+    }
+
     public (string RegistrationId, string Besluit)? Decided { get; private set; }
 
     public Task<IReadOnlyList<WerkbakItem>> GetWerkbakAsync(CancellationToken ct = default)

services/bff/Bff.Tests/SelfServiceEndpointTests.cs

@@ -112,5 +112,46 @@ public class SelfServiceEndpointTests
         Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
     }
 
+    private static HttpRequestMessage ProvideDocuments(string? bearer, string id = "reg-123")
+    {
+        var request = new HttpRequestMessage(HttpMethod.Post, $"/self-service/registrations/{id}/documents");
+        if (bearer is not null)
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", bearer);
+        return request;
+    }
+
+    [Fact]
+    public async Task Rejects_providing_documents_without_a_token()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient().SendAsync(ProvideDocuments(bearer: null));
+
+        Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
+        Assert.Null(factory.Domain.DocumentsProvidedFor);
+    }
+
+    [Fact]
+    public async Task Provides_documents_for_the_callers_registration_forwarding_the_id_and_bsn()
+    {
+        using var factory = new BffFactory();
+
+        var response = await factory.CreateClient().SendAsync(ProvideDocuments(TestTokens.Valid("123456782"), "reg-9"));
+
+        Assert.Equal(HttpStatusCode.NoContent, response.StatusCode);
+        Assert.Equal(("reg-9", "123456782"), factory.Domain.DocumentsProvidedFor);
+    }
+
+    [Fact]
+    public async Task Relays_not_found_providing_documents_for_an_unknown_or_not_owned_registration()
+    {
+        using var factory = new BffFactory();
+        factory.Domain.ProvideDocumentsSucceeds = false;
+
+        var response = await factory.CreateClient().SendAsync(ProvideDocuments(TestTokens.Valid("123456782")));
+
+        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+    }
+
     private sealed record SubmitAcceptedDto(string RegistrationId, string Status);
 }

services/bff/openapi.json

@@ -61,6 +61,37 @@
         }
       }
     },
+    "/self-service/registrations/{id}/documents": {
+      "post": {
+        "tags": [
+          "Bff.Api"
+        ],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "required": true,
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          },
+          "400": {
+            "description": "Bad Request"
+          },
+          "401": {
+            "description": "Unauthorized"
+          },
+          "404": {
+            "description": "Not Found"
+          }
+        }
+      }
+    },
     "/openbaar/register": {
       "get": {
         "tags": [

services/domain/Big.Api/Program.cs

@@ -22,22 +22,29 @@ builder.Services.AddTransient<IWorkflowClient>(sp => sp.GetRequiredService<Flowa
 builder.Services.AddTransient<IExternalWorkerClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
 builder.Services.AddTransient<IUserTaskClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
 builder.Services.AddTransient<IBeoordelingEscalatieClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
+builder.Services.AddTransient<IRegistratieVerlopenClient>(sp => sp.GetRequiredService<FlowableWorkflowClient>());
 builder.Services.AddHttpClient<IAclClient, AclHttpClient>();
 
 builder.Services.AddScoped<SubmitRegistration>();
 builder.Services.AddScoped<ApproveRegistration>();
 builder.Services.AddScoped<BeoordeelRegistratie>();
 builder.Services.AddScoped<WithdrawRegistration>();
+builder.Services.AddScoped<ProvideDocuments>();
 builder.Services.AddScoped<Werkbak>();
 builder.Services.AddScoped<OpenZaakWorker>();
 builder.Services.AddScoped<OpenZaakJobProcessor>();
 builder.Services.AddScoped<BeoordelingEscalatieProcessor>();
+builder.Services.AddScoped<ExpireRegistrationWorker>();
+builder.Services.AddScoped<RegistratieVerlopenProcessor>();
 
 // The hosted external-task job worker polls Flowable and drives OpenZaakAanmaken to completion.
 builder.Services.AddHostedService<OpenZaakJobPump>();
 // The escalation worker polls the BeoordelingEscaleren jobs the 14-day timer parks and reassigns
 // each overdue beoordeling to the teamlead (S-14).
 builder.Services.AddHostedService<BeoordelingEscalatiePump>();
+// The document-timeout worker polls the RegistratieVerlopen jobs the 30-day timer on WachtOpDocumenten
+// parks and expires each lapsed registration to VERLOPEN (S-10a, ADR-0017).
+builder.Services.AddHostedService<RegistratieVerlopenPump>();
 
 var app = builder.Build();
 
@@ -101,6 +108,23 @@ app.MapPost("/registrations/{id}/withdraw", async (string id, WithdrawRequest bo
     return outcome == WithdrawOutcome.Withdrawn ? Results.NoContent() : Results.NotFound();
 });
 
+// Provide documents (S-10a): the zorgprofessional supplies the documents their registration is parked
+// waiting for, completing the WachtOpDocumenten task so the process advances to beoordeling (ADR-0017).
+// Owner-scoped by the caller's bsn (the BFF forwards it from the DigiD token); unknown or not-the-
+// caller's is 404 (indistinguishable). Idempotent — completing an already-left wait is a no-op. The
+// real file upload + ZGW storage is S-10b; this endpoint is the trigger that unblocks the process.
+app.MapPost("/registrations/{id}/documents", async (string id, ProvideDocumentsRequest body, ProvideDocuments provide, CancellationToken ct) =>
+{
+    if (!Guid.TryParse(id, out var guid))
+        return Results.NotFound();
+
+    if (string.IsNullOrWhiteSpace(body?.Bsn))
+        return Results.BadRequest(new { error = "A bsn is required to provide documents." });
+
+    var outcome = await provide.HandleAsync(new ProvideDocumentsCommand(new RegistrationId(guid), body.Bsn), ct);
+    return outcome == ProvideDocumentsOutcome.Accepted ? Results.NoContent() : Results.NotFound();
+});
+
 // The behandelaar's werkbak (S-12): the registrations awaiting beoordeling, read from the open
 // Beoordelen user tasks (§8.2) and enriched with bsn + status. The BFF proxies this behind
 // medewerker-realm + behandelaar-role authorization; the domain trusts its callers (§8.3).
@@ -128,6 +152,8 @@ public sealed record DecideRequest(string Besluit);
 
 public sealed record WithdrawRequest(string Bsn);
 
+public sealed record ProvideDocumentsRequest(string Bsn);
+
 public sealed record RegistrationResponse(string RegistrationId, string Status, string? ZaakUrl);
 
 public partial class Program;

services/domain/Big.Application/ExpireRegistrationWorker.cs

@@ -0,0 +1,37 @@
+using Big.Domain;
+
+namespace Big.Application;
+
+/// <summary>
+/// Handles one acquired <c>RegistratieVerlopen</c> external-worker job (S-10a, ADR-0017): load the
+/// registration the job correlates to and expire it to VERLOPEN — the 30-day document-wait timer fired
+/// before the documents arrived, so the case is cancelled. Pure application logic over ports; it knows
+/// nothing of Flowable. The polling loop that feeds it jobs lives in Infrastructure. Mirrors
+/// <see cref="OpenZaakWorker"/>.
+/// </summary>
+public sealed class ExpireRegistrationWorker(IRegistrationStore store)
+{
+    /// <summary>
+    /// Process the job. Idempotent and tolerant of races (§8.6, at-least-once delivery): a job whose
+    /// registration is already resolved — a redelivered expiry (VERLOPEN), or one withdrawn/decided
+    /// while it waited (INGETROKKEN/INGESCHREVEN/AFGEWEZEN) — is a no-op, so the job still completes
+    /// rather than throwing into a redelivery loop. Only a still-open registration is expired. An
+    /// unknown registration is an error: it throws, leaving the job un-completed for Flowable to redeliver.
+    /// </summary>
+    public async Task HandleAsync(RegistratieVerlopenJob job, CancellationToken ct = default)
+    {
+        ArgumentNullException.ThrowIfNull(job);
+
+        var registration = await store.GetAsync(job.RegistrationId, ct)
+            ?? throw new InvalidOperationException(
+                $"No registration {job.RegistrationId} for RegistratieVerlopen job {job.JobId}.");
+
+        // Only a still-open registration lapses; an already-resolved one (expired, or withdrawn/decided
+        // while it waited) is left untouched so the job can complete without violating the aggregate.
+        if (registration.Status is not (RegistrationStatus.Ingediend or RegistrationStatus.InBehandeling))
+            return;
+
+        registration.Expire();
+        await store.SaveAsync(registration, ct);
+    }
+}

services/domain/Big.Application/Ports.cs

@@ -25,6 +25,14 @@ public interface IWorkflowClient
     /// ended, or not yet parked) it is a no-op; the aggregate is INGETROKKEN regardless.
     /// </summary>
     Task WithdrawProcessAsync(string processInstanceId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Signal that the required documents have arrived (S-10a): complete the <c>WachtOpDocumenten</c>
+    /// user task in the instance so the process leaves the 30-day wait state and continues to
+    /// beoordeling (ADR-0017). Best-effort — if the instance is not parked at that task (already
+    /// continued, or timed out) it is a no-op. The upload trigger that calls this is wired in S-10b.
+    /// </summary>
+    Task CompleteDocumentWaitAsync(string processInstanceId, CancellationToken ct = default);
 }
 
 /// <summary>
@@ -95,3 +103,11 @@ public sealed record OpenZaakJob(string JobId, RegistrationId RegistrationId);
 /// once the 14-day boundary timer fires (ADR-0015).
 /// </summary>
 public sealed record EscalatieJob(string JobId, string ProcessInstanceId);
+
+/// <summary>
+/// An acquired <c>RegistratieVerlopen</c> job (S-10a): the Flowable job id and the registration id it
+/// carries as a process variable. The 30-day boundary timer on <c>WachtOpDocumenten</c> spawns it when
+/// the required documents were not supplied in time; expiring the correlated registration to VERLOPEN
+/// cancels the case (ADR-0017).
+/// </summary>
+public sealed record RegistratieVerlopenJob(string JobId, RegistrationId RegistrationId);

services/domain/Big.Application/ProvideDocuments.cs

@@ -0,0 +1,47 @@
+using Big.Domain;
+
+namespace Big.Application;
+
+/// <summary>A zorgprofessional's signal that they have supplied the documents their registration is
+/// waiting for ("documenten aanleveren"). <paramref name="Bsn"/> is the authenticated caller (from the
+/// DigiD token, forwarded by the BFF): only the registration's own bsn may provide its documents.</summary>
+public sealed record ProvideDocumentsCommand(RegistrationId RegistrationId, string Bsn);
+
+/// <summary>The outcome of a provide-documents request.</summary>
+public enum ProvideDocumentsOutcome
+{
+    /// <summary>The documents were accepted; the process's document wait was completed (if any).</summary>
+    Accepted,
+
+    /// <summary>No registration with that id belongs to the caller — unknown, or owned by someone else
+    /// (the two are deliberately indistinguishable, so the endpoint reveals neither).</summary>
+    NotFound,
+}
+
+/// <summary>
+/// The provide-documents use case (S-10a): a zorgprofessional supplies the documents their registration
+/// is parked waiting for, completing the WachtOpDocumenten task so the registratie process leaves the
+/// 30-day wait and continues to beoordeling (ADR-0017). Owner-scoped by bsn. Completing the wait is
+/// best-effort: if the registration never started a process (or already left the wait), the request
+/// still stands, mirroring how <see cref="WithdrawRegistration"/> cancels best-effort. The actual file
+/// upload and its ZGW storage via the ACL is S-10b; this is the trigger that unblocks the process.
+/// </summary>
+public sealed class ProvideDocuments(IRegistrationStore store, IWorkflowClient workflow)
+{
+    public async Task<ProvideDocumentsOutcome> HandleAsync(ProvideDocumentsCommand command, CancellationToken ct = default)
+    {
+        ArgumentNullException.ThrowIfNull(command);
+
+        var registration = await store.GetAsync(command.RegistrationId, ct);
+
+        // Unknown, or not the caller's registration: report NotFound either way (don't reveal which).
+        if (registration is null || registration.Bsn != command.Bsn)
+            return ProvideDocumentsOutcome.NotFound;
+
+        // Complete the document wait (if a process is running) so beoordeling can proceed.
+        if (registration.ProcessInstanceId is not null)
+            await workflow.CompleteDocumentWaitAsync(registration.ProcessInstanceId, ct);
+
+        return ProvideDocumentsOutcome.Accepted;
+    }
+}

services/domain/Big.Domain/Registration.cs

@@ -133,8 +133,24 @@ public sealed class Registration
         Status = RegistrationStatus.Ingetrokken;
     }
 
-    // A decision (or withdrawal) is only valid while the registration is still open (INGEDIEND or
-    // IN_BEHANDELING).
+    /// <summary>
+    /// Expire the registration — the 30-day document-wait timer fired before the required documents
+    /// were supplied, so the registratie process cancels the case (S-10a). Allowed while it is still
+    /// open (INGEDIEND or IN_BEHANDELING) and needs no zaak; a decided (INGESCHREVEN/AFGEWEZEN) or
+    /// withdrawn (INGETROKKEN) registration can no longer expire. Re-expiring one already
+    /// <see cref="RegistrationStatus.Verlopen"/> is a no-op — the worker job may be redelivered (§8.6).
+    /// </summary>
+    public void Expire()
+    {
+        if (Status == RegistrationStatus.Verlopen)
+            return;
+
+        RequireOpenForDecision(nameof(Expire));
+        Status = RegistrationStatus.Verlopen;
+    }
+
+    // A decision (or withdrawal, or expiry) is only valid while the registration is still open
+    // (INGEDIEND or IN_BEHANDELING).
     private void RequireOpenForDecision(string decision)
     {
         if (Status is not (RegistrationStatus.Ingediend or RegistrationStatus.InBehandeling))

services/domain/Big.Domain/RegistrationStatus.cs

@@ -21,4 +21,8 @@ public enum RegistrationStatus
 
     /// <summary>Withdrawn by the zorgprofessional before a decision (S-11). Terminal.</summary>
     Ingetrokken,
+
+    /// <summary>Lapsed: the required documents were not supplied within the 30-day window, so the
+    /// registratie process cancelled the case (S-10a). Terminal.</summary>
+    Verlopen,
 }

services/domain/Big.Infrastructure/FlowableWorkflowClient.cs

@@ -15,12 +15,14 @@ namespace Big.Infrastructure;
 /// The REST contract here is the one verified against a live flowable-rest engine (ADR-0009).
 /// </summary>
 public sealed class FlowableWorkflowClient(HttpClient http, FlowableOptions options)
-    : IWorkflowClient, IExternalWorkerClient, IUserTaskClient, IBeoordelingEscalatieClient
+    : IWorkflowClient, IExternalWorkerClient, IUserTaskClient, IBeoordelingEscalatieClient, IRegistratieVerlopenClient
 {
     private const string Topic = "OpenZaakAanmaken";
     private const string EscalatieTopic = "BeoordelingEscaleren";
+    private const string VerlopenTopic = "RegistratieVerlopen";
     private const string ProcessDefinitionKey = "registratie";
     private const string BeoordelenTaskKey = "Beoordelen";
+    private const string WachtOpDocumentenTaskKey = "WachtOpDocumenten";
     private const string BehandelaarGroup = "behandelaar";
     private const string TeamleadGroup = "teamlead";
     private const string RegistrationIdVariable = "registrationId";
@@ -114,6 +116,25 @@ public sealed class FlowableWorkflowClient(HttpClient http, FlowableOptions opti
         response.EnsureSuccessStatusCode();
     }
 
+    public async Task CompleteDocumentWaitAsync(string processInstanceId, CancellationToken ct = default)
+    {
+        // Find the still-open WachtOpDocumenten task in this instance and complete it, so the process
+        // leaves the 30-day wait and continues to beoordeling (S-10a, ADR-0017). If the instance is no
+        // longer parked there (already continued, or the timer already cancelled it) this is a
+        // best-effort no-op — mirroring the withdrawal/escalation correlation (§8.6).
+        var query = new TaskByInstanceQueryRequest(processInstanceId, WachtOpDocumentenTaskKey);
+        var page = await PostAsync<TaskByInstanceQueryRequest, TaskQueryResult>(
+            "service/query/tasks", query, ct);
+
+        var task = page?.Data?.FirstOrDefault();
+        if (task is null)
+            return;
+
+        using var response = await SendAsync(
+            $"service/runtime/tasks/{task.Id}", new CompleteTaskRequest("complete", []), ct);
+        response.EnsureSuccessStatusCode();
+    }
+
     public async Task<IReadOnlyList<EscalatieJob>> AcquireBeoordelingEscalatieJobsAsync(int maxJobs, CancellationToken ct = default)
     {
         var request = new AcquireJobsRequest(EscalatieTopic, options.LockDuration, maxJobs, options.WorkerId);
@@ -155,6 +176,23 @@ public sealed class FlowableWorkflowClient(HttpClient http, FlowableOptions opti
         response.EnsureSuccessStatusCode();
     }
 
+    public async Task<IReadOnlyList<RegistratieVerlopenJob>> AcquireRegistratieVerlopenJobsAsync(int maxJobs, CancellationToken ct = default)
+    {
+        var request = new AcquireJobsRequest(VerlopenTopic, options.LockDuration, maxJobs, options.WorkerId);
+
+        var jobs = await PostAsync<AcquireJobsRequest, List<AcquiredJob>>(
+            "external-job-api/acquire/jobs", request, ct) ?? [];
+
+        return [.. jobs.Select(job => new RegistratieVerlopenJob(job.Id, RegistrationId.Parse(job.RegistrationId())))];
+    }
+
+    public async Task CompleteRegistratieVerlopenJobAsync(string jobId, CancellationToken ct = default)
+    {
+        using var response = await SendAsync(
+            $"external-job-api/acquire/jobs/{jobId}/complete", new CompleteJobRequest(options.WorkerId, []), ct);
+        response.EnsureSuccessStatusCode();
+    }
+
     private async Task<TResponse?> GetAsync<TResponse>(string path, CancellationToken ct)
     {
         var message = new HttpRequestMessage(HttpMethod.Get, new Uri(options.BaseUrl, path));

services/domain/Big.Infrastructure/IExternalWorkerClient.cs

@@ -36,3 +36,19 @@ public interface IBeoordelingEscalatieClient
     /// <summary>Complete an acquired escalation job so its token reaches the escalation end event.</summary>
     Task CompleteBeoordelingEscalatieJobAsync(string jobId, CancellationToken ct = default);
 }
+
+/// <summary>
+/// The document-timeout side of the Workflow Client (S-10a): the <c>RegistratieVerlopen</c>
+/// external-worker jobs parked by the 30-day boundary timer on <c>WachtOpDocumenten</c>. Kept separate
+/// from the other worker ports (interface segregation) so neither the OpenZaak nor escalation worker
+/// sees expiry. Implemented by <see cref="FlowableWorkflowClient"/> — the only code that talks to
+/// Flowable (§8.2, ADR-0017).
+/// </summary>
+public interface IRegistratieVerlopenClient
+{
+    /// <summary>Acquire and lock up to <paramref name="maxJobs"/> <c>RegistratieVerlopen</c> jobs.</summary>
+    Task<IReadOnlyList<RegistratieVerlopenJob>> AcquireRegistratieVerlopenJobsAsync(int maxJobs, CancellationToken ct = default);
+
+    /// <summary>Complete an acquired expiry job so its token reaches the <c>endVerlopen</c> end event.</summary>
+    Task CompleteRegistratieVerlopenJobAsync(string jobId, CancellationToken ct = default);
+}

services/domain/Big.Infrastructure/RegistratieVerlopenProcessor.cs

@@ -0,0 +1,41 @@
+using Big.Application;
+using Microsoft.Extensions.Logging;
+
+namespace Big.Infrastructure;
+
+/// <summary>
+/// One poll tick of the document-timeout worker (S-10a, ADR-0017): acquire the parked
+/// <c>RegistratieVerlopen</c> jobs — the tokens the 30-day boundary timer on <c>WachtOpDocumenten</c>
+/// spawns — expire each correlated registration via the <see cref="ExpireRegistrationWorker"/>, and
+/// complete the job so its token reaches <c>endVerlopen</c>. A job that fails is logged and left
+/// un-completed so Flowable redelivers it (§8.6). Split out from the hosted pump so the
+/// acquire→expire→complete logic is unit-testable without a running host. Mirrors
+/// <see cref="OpenZaakJobProcessor"/> and <see cref="BeoordelingEscalatieProcessor"/>.
+/// </summary>
+public sealed class RegistratieVerlopenProcessor(
+    IRegistratieVerlopenClient client,
+    ExpireRegistrationWorker worker,
+    ILogger<RegistratieVerlopenProcessor> logger)
+{
+    /// <summary>Acquire and process up to <paramref name="maxJobs"/> jobs. Returns the number acquired.</summary>
+    public async Task<int> PumpOnceAsync(int maxJobs, CancellationToken ct = default)
+    {
+        var jobs = await client.AcquireRegistratieVerlopenJobsAsync(maxJobs, ct);
+
+        foreach (var job in jobs)
+        {
+            try
+            {
+                await worker.HandleAsync(job, ct);
+                await client.CompleteRegistratieVerlopenJobAsync(job.JobId, ct);
+            }
+            catch (Exception ex)
+            {
+                // Leave the job un-completed: its lock expires and Flowable redelivers it (§8.6).
+                logger.LogError(ex, "RegistratieVerlopen job {JobId} failed; leaving it for redelivery.", job.JobId);
+            }
+        }
+
+        return jobs.Count;
+    }
+}

services/domain/Big.Infrastructure/RegistratieVerlopenPump.cs

@@ -0,0 +1,49 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace Big.Infrastructure;
+
+/// <summary>
+/// The hosted polling loop of the document-timeout worker (S-10a, ADR-0017): on an interval it
+/// resolves a scoped <see cref="RegistratieVerlopenProcessor"/> and asks it to drain the parked
+/// <c>RegistratieVerlopen</c> jobs. A deliberately thin shell — all acquire/expire/complete logic
+/// lives in the processor, which is unit-tested; this class only owns the timer, the per-tick scope,
+/// and loop resilience. Structurally identical to <see cref="BeoordelingEscalatiePump"/>.
+/// </summary>
+public sealed class RegistratieVerlopenPump(
+    IServiceScopeFactory scopeFactory,
+    FlowableOptions options,
+    ILogger<RegistratieVerlopenPump> logger) : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                using var scope = scopeFactory.CreateScope();
+                var processor = scope.ServiceProvider.GetRequiredService<RegistratieVerlopenProcessor>();
+                await processor.PumpOnceAsync(options.MaxJobsPerPoll, stoppingToken);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                // A transient fault (e.g. Flowable briefly unreachable) must not kill the loop.
+                logger.LogError(ex, "RegistratieVerlopen job poll failed; retrying after the poll interval.");
+            }
+
+            try
+            {
+                await Task.Delay(options.PollInterval, stoppingToken);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+        }
+    }
+}

services/domain/Big.Tests/ExpireRegistrationWorkerTests.cs

@@ -0,0 +1,84 @@
+using Big.Application;
+using Big.Domain;
+
+namespace Big.Tests;
+
+// S-10a (#102): the application handler behind the RegistratieVerlopen external-worker job. The 30-day
+// document-wait timer fired, so the correlated registration is expired to VERLOPEN. Mirrors
+// OpenZaakWorker — pure application logic over ports, idempotent under at-least-once delivery (§8.6).
+public class ExpireRegistrationWorkerTests
+{
+    private const string Bsn = "123456782";
+
+    private static Registration Submitted(string processInstanceId = "proc-1")
+    {
+        var registration = Registration.Submit(Bsn);
+        registration.RecordProcessStarted(processInstanceId);
+        return registration;
+    }
+
+    [Fact]
+    public async Task Expires_the_registration_the_job_correlates_to()
+    {
+        var store = new FakeRegistrationStore();
+        var registration = Submitted();
+        store.Seed(registration);
+
+        await new ExpireRegistrationWorker(store).HandleAsync(
+            new RegistratieVerlopenJob("job-7", registration.Id));
+
+        var saved = await store.GetAsync(registration.Id);
+        Assert.Equal(RegistrationStatus.Verlopen, saved!.Status);
+        Assert.Equal(1, store.SaveCount);
+    }
+
+    [Fact]
+    public async Task An_already_verlopen_registration_is_not_persisted_again()
+    {
+        // A redelivered job (§8.6) finds the aggregate already VERLOPEN: a no-op, not saved again.
+        var store = new FakeRegistrationStore();
+        var registration = Submitted();
+        registration.Expire();
+        store.Seed(registration);
+
+        await new ExpireRegistrationWorker(store).HandleAsync(
+            new RegistratieVerlopenJob("job-7", registration.Id));
+
+        Assert.Equal(0, store.SaveCount);
+        Assert.Equal(RegistrationStatus.Verlopen, (await store.GetAsync(registration.Id))!.Status);
+    }
+
+    [Fact]
+    public async Task An_already_resolved_registration_is_left_alone_and_the_job_completes()
+    {
+        // Race with S-11: the citizen withdrew while parked at WachtOpDocumenten, so the aggregate is
+        // already terminal (INGETROKKEN) when the timer's job arrives. Expiring it would violate the
+        // aggregate's invariant; the worker must instead no-op (and let the job complete), not throw
+        // into a redelivery loop.
+        var store = new FakeRegistrationStore();
+        var registration = Submitted();
+        registration.Withdraw();
+        store.Seed(registration);
+
+        await new ExpireRegistrationWorker(store).HandleAsync(
+            new RegistratieVerlopenJob("job-7", registration.Id));
+
+        Assert.Equal(0, store.SaveCount);
+        Assert.Equal(RegistrationStatus.Ingetrokken, (await store.GetAsync(registration.Id))!.Status);
+    }
+
+    [Fact]
+    public async Task An_unknown_registration_throws_so_the_job_is_redelivered()
+    {
+        var store = new FakeRegistrationStore();
+
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            new ExpireRegistrationWorker(store).HandleAsync(
+                new RegistratieVerlopenJob("job-7", RegistrationId.New())));
+    }
+
+    [Fact]
+    public async Task Rejects_a_null_job()
+        => await Assert.ThrowsAsync<ArgumentNullException>(() =>
+            new ExpireRegistrationWorker(new FakeRegistrationStore()).HandleAsync(null!));
+}

services/domain/Big.Tests/Fakes.cs

@@ -34,6 +34,7 @@ internal sealed class FakeWorkflowClient(string processInstanceId = "proc-1", Ac
     public RegistrationId? StartedFor { get; private set; }
     public DiplomaOrigin? StartedWithOrigin { get; private set; }
     public string? WithdrawnProcessInstanceId { get; private set; }
+    public string? CompletedDocumentWaitFor { get; private set; }
 
     public Task<string> StartRegistrationProcessAsync(
         RegistrationId registrationId, DiplomaOrigin diplomaOrigin, CancellationToken ct = default)
@@ -49,6 +50,12 @@ internal sealed class FakeWorkflowClient(string processInstanceId = "proc-1", Ac
         WithdrawnProcessInstanceId = processInstanceId;
         return Task.CompletedTask;
     }
+
+    public Task CompleteDocumentWaitAsync(string processInstanceId, CancellationToken ct = default)
+    {
+        CompletedDocumentWaitFor = processInstanceId;
+        return Task.CompletedTask;
+    }
 }
 
 /// <summary>A fake user-task client for the werkbak/decision use cases: returns a scripted set of

services/domain/Big.Tests/FlowableWorkflowClientTests.cs

@@ -426,4 +426,106 @@ public class FlowableWorkflowClientTests
             capture.Seen.RequestUri!.ToString());
         Assert.Contains("\"workerId\":\"worker-x\"", capture.Body);
     }
+
+    // ── S-10a (#102): document-wait timeout → RegistratieVerlopen (ADR-0017) ──────────────────────
+    // A 30-day interrupting boundary timer on WachtOpDocumenten spawns a RegistratieVerlopen
+    // external-worker job carrying the registration id; the worker expires the registration and
+    // completes the job. Separately, "documents received" completes the WachtOpDocumenten user task.
+
+    [Fact]
+    public async Task Acquire_verlopen_jobs_posts_the_topic_and_parses_jobs_with_their_registration_id()
+    {
+        var rid = RegistrationId.New();
+        var capture = new RequestCapture();
+        var client = Client(capture.Responds(HttpStatusCode.OK,
+            $$"""[{"id":"job-9","variables":[{"name":"registrationId","type":"string","value":"{{rid}}"}]}]"""));
+
+        var jobs = await client.AcquireRegistratieVerlopenJobsAsync(3);
+
+        var job = Assert.Single(jobs);
+        Assert.Equal("job-9", job.JobId);
+        Assert.Equal(rid, job.RegistrationId);
+        Assert.Equal("http://flowable/flowable-rest/external-job-api/acquire/jobs",
+            capture.Seen!.RequestUri!.ToString());
+        Assert.Contains("\"topic\":\"RegistratieVerlopen\"", capture.Body);
+        Assert.Contains("\"numberOfTasks\":3", capture.Body);
+        Assert.Contains("\"workerId\":\"worker-x\"", capture.Body);
+    }
+
+    [Theory]
+    [InlineData("[]")]
+    [InlineData("null")]
+    public async Task Acquire_verlopen_jobs_returns_empty_when_none_are_parked(string body)
+    {
+        var capture = new RequestCapture();
+        var client = Client(capture.Responds(HttpStatusCode.OK, body));
+
+        Assert.Empty(await client.AcquireRegistratieVerlopenJobsAsync(1));
+        Assert.NotNull(capture.Seen);
+    }
+
+    [Fact]
+    public async Task Complete_verlopen_job_posts_to_the_job_complete_endpoint()
+    {
+        var capture = new RequestCapture();
+        var client = Client(capture.Responds(HttpStatusCode.NoContent));
+
+        await client.CompleteRegistratieVerlopenJobAsync("job-9");
+
+        Assert.Equal(HttpMethod.Post, capture.Seen!.Method);
+        Assert.Equal("http://flowable/flowable-rest/external-job-api/acquire/jobs/job-9/complete",
+            capture.Seen.RequestUri!.ToString());
+        Assert.Contains("\"workerId\":\"worker-x\"", capture.Body);
+    }
+
+    [Fact]
+    public async Task Provide_documents_completes_the_wacht_op_documenten_task_in_the_instance()
+    {
+        var requests = new List<(HttpMethod Method, string Url, string? Body)>();
+        var client = Client(new StubHandler(async req =>
+        {
+            requests.Add((req.Method, req.RequestUri!.ToString(),
+                req.Content is null ? null : await req.Content.ReadAsStringAsync()));
+            return req.RequestUri!.AbsoluteUri.EndsWith("service/query/tasks")
+                ? new HttpResponseMessage(HttpStatusCode.OK)
+                {
+                    Content = new StringContent("""{"data":[{"id":"task-3"}],"total":1}""",
+                        Encoding.UTF8, "application/json"),
+                }
+                : new HttpResponseMessage(HttpStatusCode.OK);
+        }));
+
+        await client.CompleteDocumentWaitAsync("pi-1");
+
+        // 1. Find the still-open WachtOpDocumenten task in this process instance.
+        var query = requests.Single(r => r.Url.EndsWith("service/query/tasks"));
+        Assert.Equal(HttpMethod.Post, query.Method);
+        Assert.Contains("\"processInstanceId\":\"pi-1\"", query.Body);
+        Assert.Contains("\"taskDefinitionKey\":\"WachtOpDocumenten\"", query.Body);
+        // 2. Complete that task so the process leaves the wait state.
+        var complete = requests.Single(r => r.Url.EndsWith("service/runtime/tasks/task-3"));
+        Assert.Equal(HttpMethod.Post, complete.Method);
+        Assert.Contains("\"action\":\"complete\"", complete.Body);
+    }
+
+    [Fact]
+    public async Task Provide_documents_is_a_no_op_when_the_wait_task_is_no_longer_open()
+    {
+        // The process already left WachtOpDocumenten (e.g. timed out): nothing to complete, no throw.
+        var methods = new List<HttpMethod>();
+        var client = Client(new StubHandler(req =>
+        {
+            methods.Add(req.Method);
+            return Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent("""{"data":[],"total":0}""", Encoding.UTF8, "application/json"),
+            });
+        }));
+
+        await client.CompleteDocumentWaitAsync("pi-1");
+
+        // Only the query ran; no task-completion POST followed.
+        Assert.DoesNotContain(methods, m => m == HttpMethod.Put || m == HttpMethod.Delete);
+        Assert.Single(methods);
+    }
 }

services/domain/Big.Tests/ProvideDocumentsTests.cs

@@ -0,0 +1,85 @@
+using Big.Application;
+using Big.Domain;
+
+namespace Big.Tests;
+
+// S-10a (#102): the "documents received" use case. A zorgprofessional supplies the documents their
+// registration is waiting for; the handler completes the WachtOpDocumenten task via the Workflow Client
+// so the process leaves the 30-day wait and continues to beoordeling. Owner-scoped by the caller's bsn,
+// like WithdrawRegistration. (The real file upload + ZGW storage is S-10b; this is the trigger path.)
+public class ProvideDocumentsTests
+{
+    private const string Bsn = "123456782";
+
+    private static Registration Submitted(string processInstanceId = "proc-1")
+    {
+        var registration = Registration.Submit(Bsn);
+        registration.RecordProcessStarted(processInstanceId);
+        return registration;
+    }
+
+    private static ProvideDocumentsCommand Command(RegistrationId id, string bsn = Bsn) => new(id, bsn);
+
+    [Fact]
+    public async Task Providing_documents_completes_the_document_wait()
+    {
+        var store = new FakeRegistrationStore();
+        var registration = Submitted("proc-42");
+        store.Seed(registration);
+        var workflow = new FakeWorkflowClient();
+        var handler = new ProvideDocuments(store, workflow);
+
+        var outcome = await handler.HandleAsync(Command(registration.Id));
+
+        Assert.Equal(ProvideDocumentsOutcome.Accepted, outcome);
+        Assert.Equal("proc-42", workflow.CompletedDocumentWaitFor);
+    }
+
+    [Fact]
+    public async Task A_different_bsn_cannot_provide_documents()
+    {
+        // Owner-scoping: only the registration's own bsn may supply its documents. Another bsn is told
+        // NotFound (existence not revealed) and the wait is not completed.
+        var store = new FakeRegistrationStore();
+        var registration = Submitted();
+        store.Seed(registration);
+        var workflow = new FakeWorkflowClient();
+        var handler = new ProvideDocuments(store, workflow);
+
+        var outcome = await handler.HandleAsync(Command(registration.Id, bsn: "999999990"));
+
+        Assert.Equal(ProvideDocumentsOutcome.NotFound, outcome);
+        Assert.Null(workflow.CompletedDocumentWaitFor);
+    }
+
+    [Fact]
+    public async Task Providing_for_an_unknown_registration_is_not_found()
+    {
+        var store = new FakeRegistrationStore();
+        var handler = new ProvideDocuments(store, new FakeWorkflowClient());
+
+        Assert.Equal(ProvideDocumentsOutcome.NotFound, await handler.HandleAsync(Command(RegistrationId.New())));
+    }
+
+    [Fact]
+    public async Task Providing_before_a_process_started_is_accepted_without_calling_the_workflow()
+    {
+        // No process yet → no wait task to complete; the request still stands (best-effort, mirroring
+        // WithdrawRegistration) and the Workflow Client is not called.
+        var store = new FakeRegistrationStore();
+        var registration = Registration.Submit(Bsn); // no RecordProcessStarted
+        store.Seed(registration);
+        var workflow = new FakeWorkflowClient();
+        var handler = new ProvideDocuments(store, workflow);
+
+        var outcome = await handler.HandleAsync(Command(registration.Id));
+
+        Assert.Equal(ProvideDocumentsOutcome.Accepted, outcome);
+        Assert.Null(workflow.CompletedDocumentWaitFor);
+    }
+
+    [Fact]
+    public async Task Rejects_a_null_command()
+        => await Assert.ThrowsAsync<ArgumentNullException>(() =>
+            new ProvideDocuments(new FakeRegistrationStore(), new FakeWorkflowClient()).HandleAsync(null!));
+}

services/domain/Big.Tests/RegistratieVerlopenProcessorTests.cs

@@ -0,0 +1,79 @@
+using Big.Application;
+using Big.Infrastructure;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace Big.Tests;
+
+// S-10a (#102): the document-timeout drain loop. Mirrors BeoordelingEscalatieProcessor — acquire the
+// parked RegistratieVerlopen jobs (the tokens the 30-day boundary timer on WachtOpDocumenten spawns),
+// expire each correlated registration via the ExpireRegistrationWorker, then complete the job. A job
+// whose expiry fails is logged and left un-completed for Flowable to redeliver (§8.6).
+public class RegistratieVerlopenProcessorTests
+{
+    /// <summary>A fake client scripting the jobs to acquire and recording completions.</summary>
+    private sealed class FakeVerlopenClient(params RegistratieVerlopenJob[] jobs) : IRegistratieVerlopenClient
+    {
+        public int AcquireCount { get; private set; }
+        public List<string> Completed { get; } = [];
+
+        public Task<IReadOnlyList<RegistratieVerlopenJob>> AcquireRegistratieVerlopenJobsAsync(int maxJobs, CancellationToken ct = default)
+        {
+            AcquireCount++;
+            return Task.FromResult<IReadOnlyList<RegistratieVerlopenJob>>(jobs.Take(maxJobs).ToList());
+        }
+
+        public Task CompleteRegistratieVerlopenJobAsync(string jobId, CancellationToken ct = default)
+        {
+            Completed.Add(jobId);
+            return Task.CompletedTask;
+        }
+    }
+
+    private static ExpireRegistrationWorker Worker(FakeRegistrationStore store) => new(store);
+
+    [Fact]
+    public async Task Acquires_a_job_expires_the_registration_and_completes_the_job()
+    {
+        var store = new FakeRegistrationStore();
+        var registration = Domain.Registration.Submit("123456782");
+        store.Seed(registration);
+        var client = new FakeVerlopenClient(new RegistratieVerlopenJob("job-9", registration.Id));
+
+        var acquired = await new RegistratieVerlopenProcessor(
+            client, Worker(store), NullLogger<RegistratieVerlopenProcessor>.Instance).PumpOnceAsync(5);
+
+        Assert.Equal(1, acquired);
+        Assert.Equal(Domain.RegistrationStatus.Verlopen, (await store.GetAsync(registration.Id))!.Status);
+        Assert.Equal("job-9", Assert.Single(client.Completed));
+    }
+
+    [Fact]
+    public async Task A_failing_expiry_is_left_uncompleted_for_flowable_to_redeliver()
+    {
+        // Unknown registration → the worker throws → the job is left for redelivery, error logged.
+        var store = new FakeRegistrationStore();
+        var client = new FakeVerlopenClient(new RegistratieVerlopenJob("job-9", Domain.RegistrationId.New()));
+        var logger = new CapturingLogger<RegistratieVerlopenProcessor>();
+
+        var acquired = await new RegistratieVerlopenProcessor(client, Worker(store), logger).PumpOnceAsync(5);
+
+        Assert.Equal(1, acquired);
+        Assert.Empty(client.Completed);
+        var error = Assert.Single(logger.Entries, e => e.Level == LogLevel.Error);
+        Assert.Contains("job-9", error.Message);
+    }
+
+    [Fact]
+    public async Task Does_nothing_but_poll_when_there_are_no_jobs()
+    {
+        var client = new FakeVerlopenClient();
+
+        var acquired = await new RegistratieVerlopenProcessor(
+            client, Worker(new FakeRegistrationStore()), NullLogger<RegistratieVerlopenProcessor>.Instance).PumpOnceAsync(5);
+
+        Assert.Equal(0, acquired);
+        Assert.Equal(1, client.AcquireCount);
+        Assert.Empty(client.Completed);
+    }
+}

services/domain/Big.Tests/RegistrationTests.cs

@@ -294,4 +294,63 @@ public class RegistrationTests
         Assert.Contains("only an INGEDIEND", ex.Message);
         Assert.Equal(RegistrationStatus.Afgewezen, registration.Status);
     }
+
+    [Fact]
+    public void Expiring_an_ingediend_registration_sets_it_verlopen()
+    {
+        // The 30-day document-wait timer fired before the documents arrived (S-10a): the case is
+        // cancelled and the aggregate becomes terminal VERLOPEN.
+        var registration = Registration.Submit("123456782");
+
+        registration.Expire();
+
+        Assert.Equal(RegistrationStatus.Verlopen, registration.Status);
+    }
+
+    [Fact]
+    public void Expiring_needs_no_zaak()
+    {
+        // The timer fires on a purely time-based boundary; expiry does not depend on the zaak.
+        var registration = Registration.Submit("123456782");
+
+        registration.Expire();
+
+        Assert.Equal(RegistrationStatus.Verlopen, registration.Status);
+        Assert.Null(registration.ZaakUrl);
+    }
+
+    [Fact]
+    public void Re_expiring_an_already_verlopen_registration_is_idempotent()
+    {
+        // The RegistratieVerlopen worker job may be redelivered (§8.6); re-expiring is a no-op.
+        var registration = Registration.Submit("123456782");
+        registration.Expire();
+
+        registration.Expire();
+
+        Assert.Equal(RegistrationStatus.Verlopen, registration.Status);
+    }
+
+    [Fact]
+    public void Expiring_an_approved_registration_is_rejected()
+    {
+        var registration = Registration.Submit("123456782");
+        registration.AttachZaak(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
+        registration.Approve();
+
+        var ex = Assert.Throws<InvalidOperationException>(() => registration.Expire());
+        Assert.Contains("only an INGEDIEND", ex.Message);
+        Assert.Equal(RegistrationStatus.Ingeschreven, registration.Status);
+    }
+
+    [Fact]
+    public void Expiring_a_withdrawn_registration_is_rejected()
+    {
+        var registration = Registration.Submit("123456782");
+        registration.Withdraw();
+
+        var ex = Assert.Throws<InvalidOperationException>(() => registration.Expire());
+        Assert.Contains("only an INGEDIEND", ex.Message);
+        Assert.Equal(RegistrationStatus.Ingetrokken, registration.Status);
+    }
 }

services/domain/stryker-config.json

@@ -5,7 +5,8 @@
     "reporters": ["progress", "html"],
     "mutate": [
       "!**/OpenZaakJobPump.cs",
-      "!**/BeoordelingEscalatiePump.cs"
+      "!**/BeoordelingEscalatiePump.cs",
+      "!**/RegistratieVerlopenPump.cs"
     ],
     "thresholds": {
       "high": 95,