S-26/#162 · Werkbak refreshes itself when a registration is ready for beoordeling (#164)

## What & why

The behandel werkbak now **refreshes itself** while it is open, so a registration that reaches
beoordeling after the behandelaar opened the page shows up on its own — no reload.

`interval(WERKBAK_REFRESH_MS)` (5 s) re-reads the existing BFF endpoint, scoped to the page with
`takeUntilDestroyed()`. A *background* read leaves the rows and states on screen alone until it has
an answer, so a tick never flashes the loading state over rows being read and one failed poll never
swaps the list for the error alert; a read that comes back also clears an earlier failure, so the
view recovers on its own rather than needing the very reload this slice removes.

No new endpoint, dependency or server-side state, and no service boundary moves — rxjs and
`GET /behandel/werkbak` are both already here. **ADR-0032** records why polling rather than a pushed
stream: nothing notifies the BFF either, so SSE/WebSockets would poll the domain *inside* the BFF for
the same freshness, plus connection lifecycle, nginx buffering and a stateful BFF. Proposal: #163.

Closes #162

## Definition of Done

- [x] Linked Gitea issue (above).
- [x] Failing test committed before the implementation.
- [x] Implementation makes the test pass; refactor commit if structure improved.
- [x] Conventional Commits referencing the issue (`refs #162`).
- [ ] CI green — all Gitea Actions jobs.
- [x] `docker compose up` from a fresh clone reaches green health checks within 3 minutes (unchanged; only the behandel bundle differs).
- [x] Docs updated if behaviour, contracts, or operations changed.
- [x] ADR added in `docs/architecture/` (ADR-0032).
- [x] Demo note in `docs/demo-script.md` (user-visible).

## Notes for reviewers

**The e2e is the real acceptance test, and it took two goes to make it one.** Simply dropping the
`staff.reload()` from the happy path proved nothing: the werkbak was visited *after* the documents
were supplied, so the row was already there at page load. The spec now logs the behandelaar in
**first**, asserts the row is not there yet, and only then has the citizen supply the documents that
route it to Beoordelen — so the row can only reach that already-open, never-reloaded page via the
refresh. Verified both ways against a live stack: with the interval stubbed out it fails at
`Goedkeuren <ref> … element(s) not found` after 30 s; with it, the behandel nginx logs the poll that
delivers the row. The page is foregrounded before the assertion because Chromium throttles timers in
a hidden tab.

**Ceiling (named in the ADR):** a fixed 5 s interval, per open page, that keeps polling in a
background tab; each tick costs one Flowable task query plus a store read per open task. Upgrade
path: publish task events from the domain, then swap the `interval` for a stream — the endpoint
contract and the rendering stay put. Gate on `document.visibilityState` first if request volume is
the concern.

**Two housekeeping notes, neither blocking:**
- #162 is on **no milestone** (DoD item 1). It is portal UX, so it fits neither *Data Governance*
  nor *Production Posture* cleanly — your call where it lands.
- The issue titles itself **S-26**, which already belongs to the self-service resume slice (#111,
  `BACKLOG.md`). Everything here references **#162**; worth renumbering the title if the S-ids are
  meant to stay unique. `BACKLOG.md` is untouched for the same reason (it mirrors the active
  milestone, and this slice is on none).Reviewed-on: #164

BACKLOG.md

@@ -296,9 +296,9 @@ Split into independently deployable sub-slices (CLAUDE.md §13):
 Split into independently deployable sub-slices (CLAUDE.md §13):
 
 - **S-19a** (#149, ✅) · ACL writes the `RegisterRecord` to Objecten on approval, idempotently, alongside the ZGW eindstatus. Carries the ADR (ADR-0028).
-- **S-19b** (#150) · Read projection sourced from Objecten instead of NRC zaak events. *(split — #150 closed)*
-  - **S-19b-1** (#152) · Objecten publishes to NRC — broker, celery worker, `objecten` kanaal, notifications config. Turns back on what ADR-0028 deliberately disabled.
-  - **S-19b-2** (#153) · Projection derived from `RegisterRecord` objects, rebuildable from the Objecten-derived log. Depends on S-19b-1.
+- **S-19b** (#150, ✅) · Read projection sourced from Objecten instead of NRC zaak events. *(split — #150 closed)*
+  - **S-19b-1** (#152, ✅) · Objecten publishes to NRC — broker, celery worker, `objecten` kanaal, notifications config. Turns back on what ADR-0028 deliberately disabled.
+  - **S-19b-2** (#153, ✅) · Projection derived from `RegisterRecord` objects, rebuildable from the Objecten-derived log. The ACL also writes an INGEDIEND record on submit, so the register holds the whole lifecycle. Carries ADR-0030.
 
 ---
 

apps/behandel/src/app/werkbak/werkbak-page.spec.ts

@@ -4,7 +4,7 @@ import { of, throwError } from 'rxjs';
 import { BffApiV1Service, type WerkbakItem } from 'api-client';
 import { AuthService } from 'auth';
 import { axe } from 'vitest-axe';
-import { WerkbakPage } from './werkbak-page';
+import { WERKBAK_REFRESH_MS, WerkbakPage } from './werkbak-page';
 
 const sample: WerkbakItem[] = [
   { registrationId: 'reg-1', bsn: '123456782', status: 'InBehandeling' },
@@ -81,6 +81,94 @@ describe('WerkbakPage', () => {
     });
   });
 
+  it('picks up a newly submitted registration without a reload', async () => {
+    // S-26 (#162): a registration reaches Beoordelen asynchronously, after the citizen supplies
+    // documents — so the werkbak must refresh itself rather than wait for the behandelaar to reload.
+    vi.useFakeTimers();
+    try {
+      const getBehandelWerkbak = vi
+        .fn()
+        .mockReturnValueOnce(of([sample[0]]))
+        .mockReturnValue(of(sample));
+      const { providers } = setup({ getBehandelWerkbak });
+      const { detectChanges } = await render(WerkbakPage, { providers });
+
+      expect(screen.getByText('reg-1')).toBeTruthy();
+      expect(screen.queryByText('reg-2')).toBeNull();
+
+      vi.advanceTimersByTime(WERKBAK_REFRESH_MS);
+      detectChanges();
+
+      expect(getBehandelWerkbak).toHaveBeenCalledTimes(2);
+      expect(screen.getByText('reg-2')).toBeTruthy();
+      // A background refresh must not flash the loading state over the rows the behandelaar is reading.
+      expect(screen.queryByText(/bezig met laden/i)).toBeNull();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it('keeps the rows on screen when a background refresh fails', async () => {
+    // A blip on a background poll must not replace the list with the load-failure alert; the next
+    // tick recovers. Only the first load speaks for whether the werkbak is readable at all.
+    vi.useFakeTimers();
+    try {
+      const getBehandelWerkbak = vi
+        .fn()
+        .mockReturnValueOnce(of(sample))
+        .mockReturnValue(throwError(() => new Error('503')));
+      const { providers } = setup({ getBehandelWerkbak });
+      const { detectChanges } = await render(WerkbakPage, { providers });
+
+      vi.advanceTimersByTime(WERKBAK_REFRESH_MS);
+      detectChanges();
+
+      expect(screen.getByText('reg-1')).toBeTruthy();
+      expect(screen.queryByText(/kon de werkbak niet laden/i)).toBeNull();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it('stops refreshing once the page is destroyed', async () => {
+    vi.useFakeTimers();
+    try {
+      const { getBehandelWerkbak, providers } = setup();
+      const { fixture } = await render(WerkbakPage, { providers });
+
+      fixture.destroy();
+      vi.advanceTimersByTime(WERKBAK_REFRESH_MS * 3);
+
+      expect(getBehandelWerkbak).toHaveBeenCalledTimes(1);
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it('clears a load failure once a refresh succeeds', async () => {
+    // Without this the werkbak stays stuck on the error until the behandelaar reloads — the very
+    // thing this slice removes. A recovered read must put the rows back.
+    vi.useFakeTimers();
+    try {
+      const getBehandelWerkbak = vi
+        .fn()
+        .mockReturnValueOnce(throwError(() => new Error('503')))
+        .mockReturnValue(of(sample));
+      const { providers } = setup({ getBehandelWerkbak });
+      const { detectChanges } = await render(WerkbakPage, { providers });
+
+      expect(screen.getByText(/kon de werkbak niet laden/i)).toBeTruthy();
+
+      vi.advanceTimersByTime(WERKBAK_REFRESH_MS);
+      detectChanges();
+
+      expect(screen.queryByText(/kon de werkbak niet laden/i)).toBeNull();
+      expect(screen.getByText('reg-1')).toBeTruthy();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   it('shows an empty state when the werkbak has no items', async () => {
     const { providers } = setup({ getBehandelWerkbak: vi.fn().mockReturnValue(of([])) });
     await render(WerkbakPage, { providers });

apps/behandel/src/app/werkbak/werkbak-page.ts

@@ -1,7 +1,15 @@
 import { Component, inject, signal } from '@angular/core';
+import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
+import { interval } from 'rxjs';
 import { BffApiV1Service, type WerkbakItem } from 'api-client';
 import { UtrechtComponentsModule } from 'ui';
 
+/**
+ * How often an open werkbak re-reads itself (S-26/#162, ADR-0032). Exported so the spec advances the
+ * clock by exactly one interval instead of hard-coding the number.
+ */
+export const WERKBAK_REFRESH_MS = 5_000;
+
 /** The two decisions a behandelaar can make; the BFF validates these exact values (ADR-0013). */
 type Besluit = 'goedkeuren' | 'afwijzen';
 
@@ -10,6 +18,11 @@ type Besluit = 'goedkeuren' | 'afwijzen';
  * Flowable `Beoordelen` tasks, read through the domain) and decides each — goedkeuren or afwijzen. A
  * decision posts to the BFF, which applies the domain transition and completes the workflow task
  * (ADR-0013; S-12). After a decision the werkbak refreshes so the handled item drops off the list.
+ *
+ * The page also re-reads itself every {@link WERKBAK_REFRESH_MS} while it is open, so a registration
+ * that reaches beoordeling after the behandelaar opened the werkbak shows up on its own — no reload
+ * (S-26/#162). Polling rather than a pushed stream: nothing notifies the BFF either, so a stream
+ * would poll the domain in the BFF instead and add connection state for the same freshness (ADR-0032).
  */
 @Component({
   selector: 'app-werkbak-page',
@@ -27,19 +40,37 @@ export class WerkbakPage {
 
   constructor() {
     this.load();
+    // ponytail: a fixed interval, polled while the page lives — it keeps refreshing in a background
+    // tab. Gate on `document.visibilityState` if the request volume ever matters.
+    interval(WERKBAK_REFRESH_MS)
+      .pipe(takeUntilDestroyed())
+      .subscribe(() => this.load({ background: true }));
   }
 
-  load(): void {
-    this.loading.set(true);
-    this.failed.set(false);
+  /**
+   * Read the werkbak. A `background` read is the interval refresh: it leaves the rows and the states
+   * the behandelaar is looking at alone until it has an answer — no loading flash on every tick, and
+   * a blip does not swap the list for the failure alert (the next tick recovers). Only a foreground
+   * read — on open, or after a decision — speaks for whether the werkbak is readable at all.
+   */
+  load(options: { background?: boolean } = {}): void {
+    const background = options.background ?? false;
+    if (!background) {
+      this.loading.set(true);
+      this.failed.set(false);
+    }
     this.bff.getBehandelWerkbak().subscribe({
       next: (rows: WerkbakItem[]) => {
         this.items.set(rows);
         this.loading.set(false);
         this.loaded.set(true);
+        // A read that came back is the answer, so a refresh also clears an earlier failure — the
+        // werkbak recovers on its own instead of showing the error until someone reloads.
+        this.failed.set(false);
       },
       // Surface the failure (e.g. 403 for a non-behandelaar) instead of swallowing it.
       error: () => {
+        if (background) return;
         this.items.set([]);
         this.loading.set(false);
         this.loaded.set(true);

docs/architecture/adr-0023-observability-stack.md

@@ -67,6 +67,14 @@ itself, so no in-image healthcheck tool is required.
 - Three more images built each CI run (kept small; not on the health-gate list).
 - Storage is ephemeral container fs — a demo backplane, not a retention target.
   Object storage for Tempo / remote-write for Prometheus is a later concern.
+- Tempo runs **single-binary**, so its distributor and ingester are one process and
+  some of its distributed-mode machinery is not just redundant but harmful. Its
+  ingester-pool health check is disabled (`ingester_client.pool_config`) because with
+  a single in-process ingester the check can never route around a failure — a 1s
+  loopback-gRPC deadline missed under CI load only evicted the one ingester and made
+  Tempo drop spans, which is how `verify-tracing` flaked (#156). Expect the same
+  shape from other distributed-mode knobs if we tune them; the fix is to switch to
+  real multi-ingester Tempo, not to re-enable them here.
 
 ## Coupling rules touched (CLAUDE.md §8)
 

docs/architecture/adr-0028-objecten-holds-the-register.md

@@ -130,8 +130,8 @@ every message was dropped on the floor — a delivery path that looks wired and
   independent of the case that produced it.
 - The disclosure boundary is enforced by Objecten's schema validation (ADR-0027), not by
   discipline in projection code.
-- The read projection can become a cache of Objecten rather than a re-derivation of ZGW
-  (S-19b, #150).
+- The read projection can become a cache of Objecten rather than a re-derivation of ZGW —
+  done in S-19b-2 (#153), ADR-0030.
 
 **Negative / costs**
 
@@ -142,8 +142,9 @@ every message was dropped on the floor — a delivery path that looks wired and
   (`Acl__Objecten__Token`) in compose.
 - Two new hand-kept constants: the pinned objecttype UUID (two files) and the objecttype
   name (compose + `register.py`).
-- Until S-19b lands, the public register is still read from the NRC-derived projection, so
-  the register record is written but not yet read — the two must agree.
+- ~~Until S-19b lands, the public register is still read from the NRC-derived projection, so
+  the register record is written but not yet read — the two must agree.~~ Closed by ADR-0030:
+  the projection is now derived from the register, so there is only one source to agree with.
 
 ## Coupling rules touched (CLAUDE.md §8)
 

docs/architecture/adr-0030-projection-sourced-from-the-register.md

@@ -0,0 +1,141 @@
+# ADR-0030: The read projection is sourced from the register, not from ZGW
+
+- **Status:** Accepted
+- **Date:** 2026-08-28
+- **Deciders:** Respellion engineering
+- **Slice:** S-19b-2 (#153), second of the S-19b (#150) split
+- **Builds on:** ADR-0008 (read projection store), ADR-0028 (Objecten holds the register), ADR-0029 (Objecten publishes to NRC)
+
+## Context
+
+ADR-0028 moved the authoritative register record into the Objecten API, and said what should
+follow: "the read projection can become a cache of Objecten rather than a re-derivation of
+ZGW." Until this slice it was still the latter — the Event Subscriber listened on the `zaken`
+kanaal and inferred register state from case events:
+
+- a `zaak`/`create` meant INGEDIEND;
+- any `status`/`create` was taken to be the approval, so meant INGESCHREVEN — the subscriber
+  may not read OpenZaak (§8.1), so it could not tell one statustype from another;
+- the citizen-facing reference was not in the notification at all, so every projection had a
+  second hop: ask the ACL for the zaak's identificatie (#78).
+
+So the register — a fact about a person — was reconstructed by guessing at the lifecycle of the
+case that happened to produce it. ADR-0029 made the register itself publish. This ADR switches
+the projection over to it.
+
+## Decision
+
+**The Event Subscriber listens on the `objecten` kanaal and projects the `RegisterRecord` the
+notification points at. The projection is a cache of the register; ZGW is no longer a source.**
+
+- The subscriber's abonnement moves from `zaken` to `objecten` (`register-abonnement.py`, and
+  the CI projection check).
+- An Objecten notification carries **no record data** — only the object URL and the objecttype
+  as a kenmerk — so the record is read back through the ACL (`POST /register-records/read`).
+  §8.1 applies to Objecten exactly as ADR-0028 established: the ACL is the only code that talks
+  to it.
+- The accepted acties are `create`, `update` and `partial_update`. The last one is not
+  defensive breadth: the ACL upserts with PATCH, and DRF routes a PATCH through the notifying
+  `update()` while naming the action `partial_update` — which is what Objecten publishes. So
+  every approval arrives as `partial_update`, and accepting only `create`/`update` drops the
+  one state change this slice exists to project. `destroy` is deliberately not accepted:
+  removing a registration from the public register is its own decision.
+- The record already carries `id`, `status` and `reference`, so the row is the record. The
+  zaak-shaped surface goes: `IsZaakCreated`, `IsZaakStatusSet`, `ZaakUrl`, `ZaakId`, and
+  `ToEntry`'s `Resource == "status"` inference are replaced by `IsRegisterRecordWritten` +
+  `ObjectUrl`, and the ACL enrichment hop disappears.
+
+### The ACL writes an INGEDIEND record on submit
+
+Before this slice only approval wrote a record, so re-sourcing alone would have silently
+dropped every INGEDIEND row from the public register. `OpenZaakAsync` therefore upserts a
+record with status INGEDIEND after opening the zaak, keyed on the same zaak id that approval
+later upserts to INGESCHREVEN.
+
+This is the same two-writes-converging posture ADR-0028 already accepted for approval, now on
+the submit path too: both writes are idempotent, so a retried submit updates the record rather
+than adding a second one (§8.6). The reference comes from the registration itself, so unlike
+approval this path needs no ZGW read-back.
+
+The alternative — a register holding only INGESCHREVEN — is arguably the more correct reading
+of "public register", but it narrows what the openbaar portal shows and reads against PRD §68
+("~50 register entries with diverse statuses"). Rejected as a behaviour change this slice was
+not asked to make.
+
+### The dedup key is the projected row, not the notification
+
+NRC carries no notification id and may redeliver, so the idempotency key is derived from
+content (as before). The obvious candidates both break here:
+
+- **the object URL alone** — the ACL upserts *one object per registration*, so submit and
+  approval notify about the same URL, and the approval would be swallowed as a duplicate;
+- **object URL + actie** — a retried approval is a second `update`, so it would be dropped
+  while genuinely being the same state (harmless), but a *third* distinct state would collide
+  with it (not harmless).
+
+The key is therefore the object plus the state that write puts in the projection —
+`objecten:object:{url}:{status}:{reference}`. A redelivery collapses; a genuine state change
+does not. That is exactly the property §8.6 asks for, and it needs no version field from
+Objecten's internals.
+
+### The notification log holds the row, not the event
+
+`processed_notifications` stops describing ZGW events (`actie`, `zaak_id`, `resource`) and
+holds the projected row itself (`register_id`, `status`, `reference`). A rebuild becomes a
+replay with no mapping rules and no upstream reads at all — §8.4 held before via the ACL hop;
+now it holds outright.
+
+The migration **drops** the old columns rather than renaming them. EF scaffolded renames
+(`resource` → `register_id`, `zaak_id` → `status`) that would have carried ZGW values into
+columns meaning something else entirely, and a rebuild would then have projected that garbage.
+
+- ponytail ceiling: the migration empties both tables. A pre-slice row describes a zaak event
+  the new projector cannot reproject, and the registrations behind those rows have no
+  RegisterRecord in Objecten (only approvals wrote one), so they are not re-derivable from the
+  new source either.
+- Upgrade path: fine while stacks are ephemeral. If a long-lived environment ever needs to keep
+  them, backfill by walking Objecten's objects rather than replaying the log.
+
+## Consequences
+
+**Positive**
+
+- The register is read from the register. The projection is a derived cache of a first-class
+  record, not an inference over someone else's lifecycle.
+- The "any status-create is the approval" guess is gone — a real source of wrongness the moment
+  the zaaktype grows a second statustype.
+- One hop fewer per notification: the record carries its own reference, so the ACL enrichment
+  call disappears.
+- A rebuild needs nothing but its own log (§8.4).
+
+**Negative / costs**
+
+- Submission is now two writes across two modules and eventually consistent. A failure between
+  them leaves a zaak with no register record until the submit is retried; nothing repairs that
+  automatically yet — the same gap ADR-0028 recorded for approval, now on a second path.
+- The projection lags the register by a notification round trip, where it used to lag the zaak
+  by one. In practice the same order of magnitude.
+- Projecting now depends on the ACL being reachable, where the reference enrichment used to be
+  the only ACL dependency. A failed read means the notification is not logged and not
+  projected — NRC retries, so it converges, but the failure mode is now on the main path.
+- OpenZaak still publishes to `zaken` and nothing in the product listens. Kept because the
+  `verify-nrc` check asserts that path, and turning off a working publisher to save nothing
+  would be its own risk.
+
+## Coupling rules touched (CLAUDE.md §8)
+
+None bent. §8.1 holds — the subscriber reaches Objecten only through the ACL. §8.4 is
+strengthened: the projection is rebuildable from its own log, with no upstream reads at all.
+§8.6 is what the dedup-key discussion above is about.
+
+## Verification
+
+`make verify-projection` (`infra/run-projection-check.sh`, in CI's `verify-stack`) opens a zaak
+**through the ACL** and asserts projection-api serves a row for it with status INGEDIEND — the
+whole new chain in one assertion: ACL → Objecten → `objecten-celery` → NRC → `nrc-beat` →
+Event Subscriber → projection → projection-api. A zaak created behind the ACL's back produces
+no row, which is the re-source working rather than a gap.
+
+`RegisterProjectieBijwerken.feature` covers the use case in business language, including the
+approval case — the same row moving INGEDIEND → INGESCHREVEN, which is now one registration's
+record being updated rather than two unrelated ZGW events.

docs/architecture/adr-0031-mfa-on-the-medewerker-realm.md

@@ -0,0 +1,49 @@
+# ADR-0031 — MFA on the medewerker realm, with a fixture TOTP secret
+
+- **Status:** Accepted
+- **Date:** 2026-09-03
+- **Slice:** S-15c (Gitea #132)
+
+## Context
+
+Staff (behandelaar, teamlead, beheerder) act on citizens' registrations and on the ACL's
+default-fill: the highest-privilege logins in the platform. The medewerker realm protected
+them with a password alone, while the citizen realms (digid, eherkenning, eidas) mock
+brokers that carry their own assurance levels. A reference application that demonstrates a
+government architecture should show MFA on the staff realm.
+
+Two things had to be decided: **how** to enforce OTP in a realm export, and **how the
+automated checks and a human demo obtain a code** — the e2e drives a real browser login and
+`make keycloak-smoke` drives a real password grant, so neither can scan a QR.
+
+## Decision
+
+**Enforce OTP by giving every seeded medewerker a TOTP credential**, rather than replacing
+Keycloak's browser flow with a copy whose OTP execution is `REQUIRED`.
+
+Keycloak's stock `browser` and `direct grant` flows both contain a *conditional OTP*
+subflow that fires when the user has an OTP credential. Seeding the credential therefore
+turns the challenge on for every seeded user, in both flows, without duplicating ~40 lines
+of flow JSON into the export. `CONFIGURE_TOTP` is additionally set as a **default required
+action**, so a medewerker created later must enrol before their first login.
+
+**The seeded secret is a fixed, committed fixture** (`BIGMEDEWERKEROTPSEED`) shared by all
+medewerkers. Codes are then computable: `infra/keycloak/check_realms.py` (Python, stdlib
+`hmac`) and `tests/e2e/medewerker-login.ts` (Node `crypto`) each implement RFC 6238 in
+about six lines — no OTP dependency on either side, and no enrolment step in the tests.
+
+## Consequences
+
+- A password alone no longer yields a token on the medewerker realm; `check_realms.py`
+  asserts that refusal, so the enforcement cannot silently regress.
+- Every medewerker login in the e2e goes through `loginMedewerker()`, which submits the OTP
+  form. New staff specs must use it.
+- **The secret is public.** It is a demo fixture and worthless outside this synthetic
+  stack, in the same class as the committed `test123` passwords and the mock DigiD broker.
+  A real deployment enrols per-user authenticators (or federates to DigiD Machtigen /
+  eHerkenning at the required assurance level) and seeds no credentials at all.
+- Enforcement is *effectively* realm-wide but *technically* per-user: the conditional
+  subflow is what fires. A medewerker whose OTP credential were removed would fall back to
+  the required action at next login (enrol, then challenge) rather than skipping MFA — an
+  acceptable equivalence for this purpose, and the reason the required action is set.
+- Reversal is a one-file edit: drop the `otp` credentials and the `requiredActions` block.

docs/architecture/adr-0032-werkbak-live-refresh.md

@@ -0,0 +1,79 @@
+# ADR-0032: The werkbak refreshes itself by polling, not by a pushed stream
+
+- **Status:** Accepted
+- **Date:** 2026-09-04
+- **Deciders:** Respellion engineering
+- **Slice:** #162 (proposal #163). The issue titles it S-26; that id already belongs to
+  the self-service resume slice (#111), so #162 is the identifier that counts.
+
+## Context
+
+The werkbak (S-12) is a read of the open Flowable `Beoordelen` tasks: portal → BFF
+`GET /behandel/werkbak` → domain `Werkbak` query → workflow engine, each task enriched
+from its aggregate. A registration reaches `Beoordelen` **asynchronously**, only once the
+citizen supplies its documents and the DMN routes it (S-10a) — so it appears in a werkbak
+that is already open, and until now a behandelaar had to reload the page to see it.
+
+Three forces shape the mechanism:
+
+- **Nothing notifies anyone.** The trigger lives in Flowable. The domain does not publish
+  task events, and there is no bus between the domain and the BFF.
+- **The BFF is stateless** and sits behind each portal's nginx.
+- **This is the repo's first live-updating view**, so the choice sets a precedent.
+
+## Decision
+
+**The werkbak page re-reads the existing BFF endpoint on a fixed interval
+(`WERKBAK_REFRESH_MS`, 5 s) while it is open. No new endpoint, dependency or server-side
+state.**
+
+The refresh is a *background* read: it leaves the rows and the loading/failure states
+untouched until it has an answer, so a tick never flashes a spinner over rows a
+behandelaar is reading and a single failed poll never swaps the list for the error alert.
+A read that comes back also clears an earlier failure, so the view recovers on its own —
+the same reload this slice set out to remove would otherwise be needed to escape a
+transient error. Only a foreground read (on open, after a decision) speaks for whether the
+werkbak is readable at all.
+
+### Why not SSE or WebSockets
+
+Neither buys freshness here, because **nothing notifies the BFF either**:
+
+- **SSE** (`text/event-stream`) would mean a new streaming endpoint whose handler polls the
+  domain and forwards diffs — the same latency, plus connection lifecycle, nginx
+  buffering, and auth on a long-lived connection.
+- **WebSocket/SignalR** adds a dependency (CLAUDE.md §13) and makes the BFF stateful and
+  sticky-session-bound. A genuine push path would *also* need the domain to publish task
+  events. Warranted by high-frequency, bidirectional or fan-out-heavy traffic; the werkbak
+  is none of those.
+
+Polling meets the acceptance ("a registration can be seen in the werkbak once it is ready
+for review") in a handful of lines inside one component.
+
+- ponytail ceiling: a fixed 5 s interval, per open page, that keeps polling in a
+  background tab. Each tick costs one Flowable task query plus a store read per open task.
+- Upgrade path: publish task events from the domain, then swap the component's `interval`
+  for a stream. The endpoint contract and the component's rendering stay as they are;
+  gate on `document.visibilityState` first if request volume is the concern.
+
+## Consequences
+
+**Positive**
+
+- The outcome is delivered with no new endpoint, dependency, or server-side state, and no
+  service boundary moves.
+- Self-healing: a transient read failure no longer strands the view until a manual reload.
+- The e2e got *simpler* — the happy path waits for the werkbak row without reloading the
+  page, which is itself the live-refresh assertion.
+
+**Negative / costs**
+
+- Staleness is bounded by one interval (≤5 s) rather than instant.
+- One `GET /behandel/werkbak` per open werkbak per interval, including in hidden tabs.
+- The precedent is polling; a future view with genuinely high-frequency updates will have
+  to revisit this (see the upgrade path above).
+
+## Coupling rules touched (CLAUDE.md §8)
+
+None. The poll reuses the existing portal → BFF → domain read path: §8.3 (portals talk
+only to the BFF) and §8.2 (only the Workflow Client talks to Flowable) are unchanged.

docs/architecture/fds/README.md

@@ -0,0 +1,50 @@
+# FDS-architectuur — Open Register
+
+Deze map bevat de architectuurbesluiten en de engineer-documentatie voor de FDS-kant van deze
+referentie-applicatie: deelnemen aan het Federatief Datastelsel als **afnemer**.
+
+De strategische inzet, de slices en de portfoliostatus staan in het Innovation Lab-repo,
+`Respellion/innovation-lab`, onder `projects/open-register-fd/`. Daar staan ook de
+architectuurblauwdruk, de FDS gap-analyse en de privacy-views.
+
+## Documenten
+
+| Document | Waarvoor |
+|---|---|
+| [`c4-component-view.md`](c4-component-view.md) | Componentview op niveau 3: ports en adapters, en welke views nog waarde toevoegen |
+| [`slice-1-proposal.md`](slice-1-proposal.md) | Het bouwbare eerste increment; plak dit in een `poc-voorstel`-issue |
+| `adr/` | De geaccepteerde architectuurbesluiten, ADR-0001 tot en met ADR-0006. Zie de tabel hieronder. |
+
+## Architecture Decision Records
+
+Een ADR legt een besluit vast dat **vaststaat**, met de context en de gevolgen, zodat het niet stil
+opnieuw wordt uitgevochten. Statuswaarden: `proposed` → `accepted` → (`vervangen door ADR-NNNN` |
+`deprecated`).
+
+Een geaccepteerde ADR wijzigen betekent een nieuwe ADR schrijven die de oude vervangt. Wij
+herschrijven de historie nooit.
+
+ADRs liggen naast governance. Acceptatie volgt de asynchrone bezwaarronde uit
+`Respellion/innovation-lab`, `operating-model/operating-model.md`, sectie *Besluitvorming*.
+
+| ADR | Besluit | Status |
+|---|---|---|
+| [0001](adr/0001-acl-at-every-register-boundary.md) | Anti-Corruption Layer op elke registergrens | accepted |
+| [0002](adr/0002-fsc-for-connectivity.md) | FSC voor connectiviteit tussen organisaties, geen ruwe REST | accepted |
+| [0003](adr/0003-pbac-via-opa.md) | Policy-based access control via OPA, FTV-klaar | accepted |
+| [0004](adr/0004-bounded-cache.md) | Begrensde cache; registers blijven systeem van registratie | accepted |
+| [0005](adr/0005-ldv-verwerkingenlog.md) | Verwerkingenlog via event-emissie, in lijn met LDV | accepted |
+| [0006](adr/0006-module-boundary-and-reuse.md) | Modulegrens en hergebruikstrategie: in-process → .NET-module → OpenMetadata-feed → gateway op verzoek | accepted |
+
+## Nummering
+
+Deze reeks staat los van de ADR-reeks over de referentie-applicatie zelf, die in
+[`../`](../adr-0001-loose-coupling.md) loopt van `adr-0001-loose-coupling` tot en met
+`adr-0010-bff-oidc`. Vandaar de eigen map `fds/`: beide reeksen beginnen bij 0001, en de nummers
+zouden anders over de volle breedte botsen.
+
+In de MkDocs-navigatie staan deze zes daarom als **FDS ADR-000N**, zodat de zijbalk ze niet met de
+reeks van de applicatie verwart.
+
+Nieuwe FDS-ADR: kopieer [`adr/template.md`](adr/template.md), neem het volgende nummer, en open een
+pull request.

docs/architecture/fds/adr/0001-acl-at-every-register-boundary.md

@@ -0,0 +1,42 @@
+# ADR-0001: Anti-Corruption Layer op elke registergrens
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle (Build, Lead Link)
+- **Vervangt / vervangen door:** —
+
+## Context
+
+De applicatie bevraagt meerdere registers: BRP, NHR/KVK, en ZGW via OpenZaak. Hun vocabulaires en
+schema's verschillen van elkaar en van ons domein. Zij veranderen ook zelf mee met de FDS-standaarden.
+
+Lekt registervocabulaire het domeinmodel in, dan werkt elke wijziging aan de registerzijde door in de
+bedrijfslogica. Het domein wordt dan een lappendeken van vreemde begrippen in plaats van ubiquitous
+language.
+
+## Besluit
+
+Elk register is bereikbaar via een Anti-Corruption Layer: **één adapter per register**, die een
+**port** vervult die het domein definieert.
+
+Adapters doen alleen vertalen en velden versmallen. Zij bevatten geen bedrijfslogica. Het domein
+spreekt `Persoon` en `Organisatie`, en nooit veldnamen uit BRP of NHR.
+
+## Gevolgen
+
+**Positief:** verloop in registers en FDS-standaarden blijft bij de adapter. Het domein blijft stabiel
+en testbaar. Adapters zijn onafhankelijk vervangbaar, en dat is precies wat de FSC-wissel uit
+ADR-0002 goedkoop maakt. Het patroon generaliseert naar een herbruikbare ACL-template per register,
+een Foundations-kandidaat.
+
+**Negatief en kosten:** één vertaalmap per register om te schrijven en te onderhouden, plus een extra
+indirectie die engineers moeten respecteren in plaats van omzeilen.
+
+**Vervolgwerk:** extraheer de ACL-template zodra de tweede adapter bestaat (slice 3).
+
+## Overwogen alternatieven
+
+- **Registers direct aanroepen uit de applicatieservices** — afgewezen: dit koppelt bedrijfscode aan
+  registerschema's en aan versies van FDS-standaarden.
+- **Eén generieke registeradapter** — afgewezen: registers verschillen genoeg dat een generieke
+  abstractie zou gaan lekken of opzwellen. Adapters per register zijn duidelijker.

docs/architecture/fds/adr/0002-fsc-for-connectivity.md

@@ -0,0 +1,44 @@
+# ADR-0002: FSC voor connectiviteit tussen organisaties, geen ruwe REST
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle, Upstream Liaison
+- **Vervangt / vervangen door:** —
+
+## Context
+
+Registerbevragingen kruisen een organisatiegrens naar systemen van bronhouders met
+persoonsgegevens. Het FDS noemt Federatieve Service Connectiviteit (FSC, de opvolger van NLX) als de
+richting voor connectiviteit: wederzijdse authenticatie op organisatieniveau, autorisatie
+gecontroleerd tegen een contract en gehandhaafd bij de bron, en symmetrische transactielogging.
+
+Een ruwe REST-client met mTLS geeft ons geen van de contractadministratie, delegatie of onafhankelijke
+tweezijdige verantwoording die een FG of auditor nodig heeft.
+
+## Besluit
+
+Het FSC Client-component stuurt alle registerbevragingen via een **FSC outway**, de
+EUPL-referentie-implementatie. De ACL-adapter hangt af van de FSC Client, en niet van een HTTP-client.
+
+FSC-zaken — contracten, identiteiten, delegatie — leven in dit component, achter de Register Port.
+
+## Gevolgen
+
+**Positief:** de autorisatie wordt bij de bron gehandhaafd, en niet op gezag van de aanroeper
+vertrouwd. Onweerlegbaar loggen aan beide uiteinden maakt onafhankelijke afstemming tegen ons LDV-log
+mogelijk. Delegatie wordt expliciet meegedragen. Wij lopen in lijn met de FDS-richting, vóór er een
+verplichting is.
+
+**Negatief en kosten:** FSC is operationeel zwaarder dan een REST-aanroep — beheer van certificaten en
+identiteiten, plus een outway die op De Werf moet draaien. De vergelijking FSC tegenover DSP loopt
+binnen het FDS nog, dus sommige details kunnen schuiven.
+
+**Vervolgwerk:** valideer het contract- en logginggedrag van de huidige fsc-nlx-implementatie
+(slice 2). Herzie dit als het FDS voor DSP kiest; ADR-0001 houdt die wissel beperkt tot één component.
+
+## Overwogen alternatieven
+
+- **Ruwe REST met mTLS** — afgewezen: geen contractlaag, geen tweezijdig log, en het wijkt af van het
+  FDS.
+- **Wachten tot het FDS FSC tegenover DSP heeft beslist** — afgewezen: de naad uit ADR-0001 laat ons nu
+  adopteren en later aanpassen. Wachten geeft het voordeel van vroege expertise weg.

docs/architecture/fds/adr/0003-pbac-via-opa.md

@@ -0,0 +1,44 @@
+# ADR-0003: Policy-based access control via OPA, FTV-klaar
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle, FG (geconsulteerd)
+- **Vervangt / vervangen door:** —
+
+## Context
+
+Elke bevraging van persoonsgegevens uit BRP of NHR is een verwerking die een grondslag en een
+begrensde doelbinding nodig heeft. Toegangsregels moeten handhaafbaar en auditeerbaar zijn, en
+wijzigbaar zonder de bedrijfscode opnieuw uit te rollen.
+
+De Federatieve Toegangsverlening (FTV) van het FDS beweegt naar policy-based access control, maar is
+nog geen afgeronde standaard.
+
+## Besluit
+
+Introduceer een Policy Decision Point met Open Policy Agent (OPA). De applicatieservices roepen de
+PDP aan — via een Authorisation Port en een PDP Client — **vóór elke registerbevraging**, en geven
+rol, doel en grondslag mee.
+
+Policies schrijven wij als code, **geversioneerd in Gitea**, en zij gaan via review naar productie. De
+PDP staat zo gepositioneerd dat wij bij de komst van FTV alleen het policy-dialect opnieuw uitdrukken,
+zonder de architectuurgrens te verplaatsen.
+
+## Gevolgen
+
+**Positief:** doelbinding en grondslag worden gehandhaafd, en niet alleen gedocumenteerd. De FG kan de
+werkelijke regels in versiebeheer lezen, waardoor het verwerkingenregister en de gehandhaafde policy
+naar elkaar toe groeien. Toegangswijzigingen zijn reviewbaar en gedateerd.
+
+**Negatief en kosten:** BRP-autorisatiebesluiten correct modelleren is juridisch werk, geen
+engineering. De PDP maakt de handhaving betrouwbaar, niet de policy juist. Daarnaast komt er een
+component bij om te exploiteren.
+
+**Vervolgwerk:** een promotiepijplijn voor policies in Gitea Actions. Policies opnieuw uitdrukken zodra
+FTV stabiliseert. Een FG-review van de policy-set vóórdat er echte persoonsgegevens in komen.
+
+## Overwogen alternatieven
+
+- **Rolcontroles in de applicatiecode** — afgewezen: niet auditeerbaar, niet wijzigbaar zonder deploy,
+  en het verspreidt toegangslogica over de codebase.
+- **Wachten op FTV** — afgewezen: de PBAC-vorm is al duidelijk. Nu OPA, later het FTV-dialect.

docs/architecture/fds/adr/0004-bounded-cache.md

@@ -0,0 +1,48 @@
+# ADR-0004: Begrensde cache; registers blijven systeem van registratie
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle, FG (geconsulteerd)
+- **Vervangt / vervangen door:** —
+
+## Context
+
+*Data bij de bron* verbiedt het behandelen van registerdata als lokale bron van waarheid. Maar BRP of
+NHR bij elke interactie bevragen is onpraktisch en vergroot de blootstelling.
+
+Persoonsgegevens zijn de data die wij het minst willen opbouwen. Een onbegrensde cache wordt stil een
+schaduwregister, met een onbeheerde bewaarverplichting als gevolg.
+
+## Besluit
+
+Een **begrensde cache** staat achter een Cache Port, beheerd door een Cache Manager. Vier grenzen
+gelden.
+
+| Grens | Wat die betekent |
+|---|---|
+| **Tijd** | Een TTL die aan het doel hangt |
+| **Omvang** | Alleen de werkset van een actieve zaak |
+| **Gezag** | Antwoordt nooit wat de bron niet zou antwoorden; geen systeem van registratie |
+| **Adresseerbaarheid** | Gesleuteld op subject, zodat verwijderen op verzoek kan |
+
+Purge-triggers: het verstrijken van de TTL, het sluiten van de zaak, en een verwijderingsverzoek.
+
+## Gevolgen
+
+**Positief:** de prestaties van een lokale kopie, zonder een onbevoegd register te worden. Bewaartermijn
+en het recht op verwijdering zijn echte operaties, geen hoop. Dit is consistent met zowel
+AVG-dataminimalisatie als FDS-data-bij-de-bron.
+
+**Negatief en kosten:** de mapping van doel naar TTL is een beleidsbesluit, samen met de FG en de
+autorisatievoorwaarden, en geen engineeringconstante. Die is dus makkelijk fout te krijgen. Daarnaast
+komt de complexiteit van cache-invalidatie erbij.
+
+**Vervolgwerk:** definieer het beleid voor doel naar TTL met de FG. Maak een toestandsdiagram voor de
+levensloop van een cache-entry. Documenteer de aanvaardbare veroudering per register.
+
+## Overwogen alternatieven
+
+- **Geen cache; altijd de bron bevragen** — afgewezen: onpraktische latency en belasting, en meer
+  blootstelling per aanroep.
+- **Een onbegrensde of algemene cache** — afgewezen: die wordt een schaduwregister, precies de
+  faalvorm waar de AVG en het FDS beide tegen duwen.

docs/architecture/fds/adr/0005-ldv-verwerkingenlog.md

@@ -0,0 +1,42 @@
+# ADR-0005: Verwerkingenlog via event-emissie, in lijn met LDV
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle, FG (geconsulteerd)
+- **Vervangt / vervangen door:** —
+
+## Context
+
+AVG art. 30 vereist een register van verwerkingsactiviteiten. De FDS-bouwsteen Logboek
+Dataverwerkingen (LDV) wijst naar een gestandaardiseerd verwerkingslog dat de burger kan bevragen.
+
+Database-CDC met Debezium legt *datawijzigingen* vast, en niet *verwerkingsgebeurtenissen met
+doelbinding*. Het is dus geen verwerkingenlog.
+
+## Besluit
+
+Elke registeradapter stuurt een **verwerkingsactiviteit-event** naar een eigen Redpanda-topic, via een
+Verwerking Port en een LDV Emitter. Het event bevat: subjectcategorie, register, velden, doel en
+doelbinding, grondslag, bevragende rol, en tijdstempel. **Nooit de opgehaalde waarden.**
+
+Een projectie maakt het log bevraagbaar. De emissie is asynchroon, maar niet over te slaan: de adapter
+die de Register Port vervult, is dezelfde code die het event uitstuurt.
+
+## Gevolgen
+
+**Positief:** het spoor voor art. 30 en LDV ontstaat als neveneffect van de bevraging, dus het kan niet
+uit de pas lopen met de werkelijkheid. Het is af te stemmen tegen de tweezijdige logs van FSC
+(ADR-0002). Het is onderscheidend in een tender.
+
+**Negatief en kosten:** een topic en een projectie om te exploiteren. Het ontsluiten van het log naar
+de burger valt buiten de huidige scope; wij produceren het log. Het eventschema vraagt governance.
+
+**Vervolgwerk:** definieer het schema van het verwerkingsevent. Bouw de bevraagbare projectie. Sluit
+aan op de LDV-standaard zodra die volwassen wordt; dit is een upstream-kandidaat.
+
+## Overwogen alternatieven
+
+- **Debezium-CDC hergebruiken als log** — afgewezen: dat legt datawijzigingen vast, en geen verwerking
+  met doelbinding. Verkeerde semantiek.
+- **Synchroon loggen in het aanroeppad** — afgewezen: dat koppelt de latency van de bevraging aan het
+  log. Asynchroon maar niet over te slaan geeft zowel snelheid als garantie.

docs/architecture/fds/adr/0006-module-boundary-and-reuse.md

@@ -0,0 +1,68 @@
+# ADR-0006: Modulegrens en hergebruikstrategie voor de governed-access spine
+
+- **Status:** accepted
+- **Datum:** 2026-06-13
+- **Deciders:** Lab Circle (Lead Link, Build, Upstream Liaison)
+- **Vervangt / vervangen door:** —
+
+## Context
+
+De compliance-spine uit slice 1 bestaat uit de PDP-controle (ADR-0003), gegoverneerd uitgaand verkeer
+via FSC (ADR-0002), emissie van het verwerkingenlog (ADR-0005), en de begrensde cache (ADR-0004),
+allemaal achter ports (ADR-0001). Die spine is mogelijk breder herbruikbaar dan alleen in de
+referentie-applicatie.
+
+Er spelen twee hergebruikvragen: welke verpakkingsvorm kiezen wij, en hoe verhoudt de spine zich tot
+andere omgevingen zoals het OpenMetadata-datagovernanceproject?
+
+Twee verduidelijkingen bepalen het besluit.
+
+1. **OpenMetadata is geen afnemer.** In het datagovernanceproject is het de catalogus- en
+   lineage-laag over (synthetische) data. Het bevraagt geen BRP of NHR. FSC of de begrensde cache
+   daarin inbouwen zou zinloos zijn. De juiste aansluiting is **integratie van de output van de
+   spine**, en niet het inbouwen van de spine.
+2. **FSC en de begrensde cache zijn zaken die alleen een afnemer aangaan.** "Maak het herbruikbaar"
+   mag deze niet uitsmeren over componenten die geen registerdata bevragen.
+
+Nu al een taalonafhankelijke gateway bouwen — vóórdat er een tweede, niet-.NET afnemer bestaat — zou
+de valkuil van speculatieve architectuur herhalen, die wij voor de capability-laag al hebben
+afgewezen.
+
+## Besluit
+
+Wij nemen een **vraaggestuurde reeks van vier stappen** aan. Elke stap hangt af van echte behoefte, en
+niet van verwachte behoefte.
+
+| Stap | Wat | Wanneer |
+|---|---|---|
+| 1 | **In-process bewijzen.** Bouw de spine als gewone componenten achter ports, binnen de .NET register-applicatie. Nog geen extractie. Doel: de compliance-invarianten één keer echt valideren. | Slice 1 |
+| 2 | **Extraheren als .NET-module.** Zodra een tweede .NET-afnemer in zicht is, haal de spine eruit als een geversioneerde .NET-library of SDK. Dit is de ACL-template-extractie die het charter al plant. Herbruikbaar voor .NET-afnemers, en dat is genoeg voor register-reference en zijn broertjes. | Slice 3 |
+| 3 | **De feed LDV naar OpenMetadata aansluiten.** Route verwerkingsevents uit de LDV-emitter naar OpenMetadata als access- en usage-metadata bij het geclassificeerde asset: wie las welk persoonsgegevensveld, met welk doel, hoe vaak. Optioneel laten classificatietags uit OpenMetadata terugstromen om veldminimalisatie in de ACL aan te sturen. Dit is de concrete brug tussen beide anchor-projecten: integratie, geen inbouw. | Na stap 2 |
+| 4 | **Alleen op verzoek een taalonafhankelijke gateway bouwen.** Heeft een echte niet-.NET afnemer gegoverneerde registertoegang nodig, verpak de spine dan als zelfstandige sidecar of proxy met een dunne lokale API, met PDP, FSC-egress en LDV erachter. Niet eerder. | Op verzoek |
+
+## Gevolgen
+
+**Positief:** eigen software blijft minimaal. Hergebruik volgt op validatie in plaats van eraan vooraf
+te gaan. Beide anchor-projecten krijgen een concreet, benoemd integratiepunt (stap 3). Zaken die
+alleen een afnemer aangaan, blijven ingesloten.
+
+**Negatief en kosten:** de .NET-module uit stap 2 dient geen niet-.NET afnemers. Dat aanvaarden wij,
+omdat stap 4 dat geval dekt zodra het echt is. Stap 3 vraagt een afgesproken schema voor het
+verwerkingsevent, stabiel genoeg voor OpenMetadata om te consumeren.
+
+**Vervolgwerk:**
+
+1. Neem stap 3 als expliciet integratiepunt op in beide projectpagina's in het Innovation Lab-repo:
+   `projects/open-register-fd/README.md` en `projects/openmetadata/README.md`.
+2. Herzie de trigger van stap 4 bij elke portfolio-review. Bouw niet vooruit.
+3. Regel governance op het schema van het verwerkingsevent; dat is een gedeelde afhankelijkheid van
+   stap 1 en stap 3.
+
+## Overwogen alternatieven
+
+- **De taalonafhankelijke gateway vooraf bouwen** — afgewezen: speculatieve architectuur voordat er een
+  tweede afnemer bestaat. De latency en de operationele kosten zijn niet te rechtvaardigen.
+- **De spine in OpenMetadata inbouwen** — afgewezen: OpenMetadata is geen afnemer. Dit is een
+  categoriefout.
+- **De spine permanent in-process houden, zonder extractie** — afgewezen: dat geeft het hergebruik
+  tussen projecten en applicaties weg, en dat is een kerndoel van de Open Register-inzet.

docs/architecture/fds/adr/template.md

@@ -0,0 +1,27 @@
+# ADR-NNNN: <titel>
+
+- **Status:** proposed
+- **Datum:** JJJJ-MM-DD
+- **Deciders:** <rollen>
+- **Vervangt / vervangen door:** —
+
+## Context
+
+<De krachten die spelen: het probleem, de beperkingen, de FDS- en AVG-drijfveren. Waarom er nu een
+besluit nodig is.>
+
+## Besluit
+
+<De keuze, eenvoudig gesteld.>
+
+## Gevolgen
+
+**Positief:** <wat dit oplevert>
+
+**Negatief en kosten:** <wat het kost, en wat wij aanvaarden>
+
+**Vervolgwerk:** <welk werk dit oproept>
+
+## Overwogen alternatieven
+
+<De afgewezen opties, en waarom.>

docs/architecture/fds/c4-component-view.md

@@ -0,0 +1,127 @@
+# C4-componentview — register-applicatie en capability-laag
+
+> Niveau 3, de componentview. Deze view zoomt in op de container van de .NET register-applicatie uit
+> het L2-containerdiagram. Zij verbindt het geheel op componentniveau — domein, ports, adapters en de
+> FDS-capability-componenten — en toont waar elk onderdeel externe tooling raakt.
+>
+> De hexagonale structuur is expliciet: het domein hangt alleen af van **ports** (interfaces). Elke
+> concrete capability is een **adapter** die aan een port is gebonden.
+>
+> De containerview (L2), de blauwdruk en de privacy-datastroomviews staan in het Innovation Lab-repo,
+> `Respellion/innovation-lab`, onder `projects/open-register-fd/`.
+
+```mermaid
+C4Component
+    title Componentview — register-applicatie (.NET) en de FDS-capability-laag
+
+    Person(user, "Behandelaar", "Behandelt zaken")
+    Container(spa, "Frontend", "Angular + NL Design System", "Zaakinterface")
+
+    Container_Boundary(app, "Register-applicatie (.NET, hexagonaal)") {
+        Component(api, "API / application services", ".NET", "Orkestreert use cases; verklaart doelbinding per vraag")
+        Component(domain, "Domeinmodel", ".NET / DDD", "Ubiquitous language; geen registervocabulaire")
+
+        Component(portReg, "Register Port", "interface", "De vraag van het domein: Personen / Organisaties")
+        Component(portPol, "Authorisation Port", "interface", "mag-deze-verwerking-doorgaan?")
+        Component(portLog, "Verwerking Port", "interface", "leg de verwerkingsgebeurtenis vast")
+        Component(portTm, "Terugmelding Port", "interface", "meld een vermoedelijke fout")
+        Component(portCache, "Cache Port", "interface", "doelgebonden lezen, schrijven en verwijderen")
+
+        Component(aclBrp, "BRP-adapter", ".NET", "Vertaalt domein<->BRP; minimale velden")
+        Component(aclKvk, "NHR/KVK-adapter", ".NET", "Vertaalt domein<->NHR; UBO-bewust")
+        Component(pdpClient, "PDP Client", ".NET -> OPA", "Roept de policy engine; geeft doel en grondslag mee")
+        Component(ldvEmit, "LDV Emitter", ".NET", "Bouwt het verwerkingsevent; publiceert naar Redpanda")
+        Component(fscClient, "FSC Client", ".NET", "Stuurt contractuele aanroepen via de outway")
+        Component(cacheMgr, "Cache Manager", ".NET", "TTL en verwijderen op subjectsleutel")
+        Component(tmHandler, "Terugmelding Handler", ".NET -> Flowable", "Start het terugmeldproces")
+        Component(procClient, "Process Client", ".NET -> Flowable", "Uitvoering van BPMN en DMN")
+    }
+
+    System_Ext(opa, "OPA (PDP)", "Policies geversioneerd in Gitea")
+    System_Ext(fsc, "FSC Outway", "EUPL-referentie-implementatie")
+    System_Ext(flowable, "Flowable", "BPMN + DMN")
+    ContainerDb_Ext(cache, "Begrensde cache", "PostgreSQL")
+    System_Ext(redpanda, "Redpanda", "LDV-topic + CDC")
+    System_Ext(brp, "BRP", "via FSC inway")
+    System_Ext(kvk, "NHR / KVK", "via FSC inway")
+    System_Ext(kanidm, "Kanidm", "OIDC")
+
+    Rel(user, spa, "Gebruikt")
+    Rel(spa, api, "REST/JSON")
+    Rel(kanidm, api, "OIDC", "authenticatie")
+    Rel(api, domain, "Roept aan")
+    Rel(api, portPol, "Controleert vóór de bevraging")
+    Rel(api, portReg, "Vraagt data")
+    Rel(api, portTm, "Dient melding in")
+    Rel(api, procClient, "Voert proces uit")
+
+    Rel(portPol, pdpClient, "gebonden aan")
+    Rel(pdpClient, opa, "besluitverzoek")
+
+    Rel(portReg, aclBrp, "gebonden aan")
+    Rel(portReg, aclKvk, "gebonden aan")
+    Rel(aclBrp, fscClient, "via")
+    Rel(aclKvk, fscClient, "via")
+    Rel(aclBrp, portLog, "stuurt event")
+    Rel(aclKvk, portLog, "stuurt event")
+    Rel(aclBrp, portCache, "leest en schrijft")
+    Rel(aclKvk, portCache, "leest en schrijft")
+    Rel(fscClient, fsc, "contractuele aanroep")
+    Rel(fsc, brp, "mTLS + contract")
+    Rel(fsc, kvk, "mTLS + contract")
+
+    Rel(portLog, ldvEmit, "gebonden aan")
+    Rel(ldvEmit, redpanda, "publiceert")
+    Rel(portCache, cacheMgr, "gebonden aan")
+    Rel(cacheMgr, cache, "slaat op")
+    Rel(portTm, tmHandler, "gebonden aan")
+    Rel(tmHandler, flowable, "start proces")
+    Rel(procClient, flowable, "voert uit")
+```
+
+## Hoe je dit leest
+
+1. **De ports zijn de naad.** Het domein en de application services hangen af van de vijf interfaces,
+   en nooit van adapters. FSC wisselen voor DSP, of OPA voor de latere FTV-client, verandert een
+   adapter — geen port, en niet het domein. Dit is de clock-speed boundary, concreet gemaakt.
+2. **De compliance-componenten zijn adapters, geen domeinlogica.** De PDP-client, de LDV-emitter, de
+   FSC-client en de cache manager staan allemaal aan de adapterzijde. Een bevraging kan er fysiek niet
+   langs, omdat de adapter die de Register Port vervult dezelfde code is die het LDV-event uitstuurt
+   en via FSC routeert.
+3. **Slechts twee componenten raken de registers**: de BRP-adapter en de NHR/KVK-adapter. Beide
+   bereiken ze uitsluitend via de FSC-client. Er is geen vierde pad.
+
+## Componenten tegenover verplichtingen
+
+| Component | Omvang eigen bouw | Verplichting die het afdekt |
+|---|---|---|
+| Domeinmodel | het product | correctheid van de bedrijfsregels |
+| BRP- en NHR-adapters | dun | dataminimalisatie: vertalen en velden versmallen |
+| PDP Client | klein | handhaven van grondslag en doelbinding |
+| LDV Emitter | klein | verwerkingenlog (AVG art. 30 en LDV) |
+| FSC Client | klein | geautoriseerde, gelogde connectiviteit |
+| Cache Manager | klein | grenzen aan bewaring, en verwijdering |
+| Terugmelding Handler | klein | de terugmeldplicht van de afnemer |
+
+---
+
+## Aanvullende views die voor engineers waarde hebben
+
+De diagrammen tot hier verklaren *structuur* en *compliance-intentie*. Engineers die dit bouwen,
+hebben er nog een aantal nodig. Wij tekenen geen view voordat er iets echt is om te beschrijven, dus
+elke regel noemt de trigger.
+
+| # | View | Wat het toevoegt | Trigger |
+|---|---|---|---|
+| 1 | **Deploymentview** (C4 deployment, topologie) | Waar elke container op De Werf draait: k3s-namespaces, welke services sidecar zijn en welke een eigen pod (is OPA een sidecar of centraal? waar eindigt de FSC outway?), netwerkpolicies tussen de vlakken van de vertrouwensgrens, en beheer van secrets en mTLS-certificaten voor FSC. Hier worden de privacy*grenzen* echte firewall- en netwerkregels. | Vóór de eerste deploy met meerdere services. **Hoogste waarde als volgende.** |
+| 2 | **Sequences voor de niet-gelukkige paden** | Wij hebben het gelukkige pad. Engineers hebben de lastige nodig: PDP-*deny* midden in een transactie, een verlopen of ingetrokken FSC-contract, een register-timeout terwijl er een verouderde cache-entry ligt, en een gedeeltelijk NHR-antwoord waarbij een UBO-veld is achtergehouden. Dit bepaalt de foutafhandeling, en hier verstoppen de compliance-randgevallen zich. | Direct na slice 1. |
+| 3 | **Domeinmodel en ERD** | De bounded contexts en aggregates in het domein, plus het cacheschema: welke persoonsgegevens blijven staan, op welke sleutel, en met welke purge-kolom. Dit is tegelijk het artefact dat de FG beoordeelt voor bewaartermijnen. | Zodra het domein in slice 1 stabiliseert. |
+| 4 | **Dataclassificatie- en catalogusview** | Elk veld dat een grens kruist, getagd — persoonsgegeven? bijzondere categorie? UBO-beperkt? — en gemapt op zijn classificatie in OpenMetadata. Dit stuurt de GDPR-scrubbingregels en de lineage-tags. | Beter *uit* OpenMetadata gegenereerd zodra die gevuld is, dan met de hand getekend. |
+| 5 | **Toestandsdiagram: levensloop van een cache-entry** | `fetched` → `valid` (binnen TTL) → `stale` → `purged` (TTL verstreken \| zaak gesloten \| verwijderingsverzoek). Klein, maar het pint de bewaarsemantiek vast die "begrensde cache" nu alleen in prose beschrijft. | Samen met ADR-0004-vervolgwerk. |
+| 6 | **BPMN-view: de terugmelding-workflow** | Het Flowable-proces zelf: ingediend → verstuurd naar bronhouder → bevestigd → opgelost of afgewezen. Dit is uitvoerbaar BPMN, dus het diagram en de implementatie zijn hetzelfde artefact. | Wanneer de terugmelding-slice start. |
+| 7 | **Threat model en vertrouwensgrensview** (STRIDE-stijl) | Dreigingen over de vertrouwensgrens leggen: tokendiefstal, cache poisoning, replay tegen FSC, policy bypass, en manipulatie van logs. Past natuurlijk bij de FSC-zoom, en is het anker van het securitygesprek. | Vóór het verwerken van echte persoonsgegevens. |
+| 8 | **CI/CD- en policy-promotieview** | Hoe OPA-policies en BPMN/DMN-modellen van een pull request naar draaiende configuratie gaan. "Toegangsbeheer is configuratie in Gitea" geldt alleen als er een pijplijn is die review en promotie handhaaft. | Samen met het vervolgwerk uit ADR-0003. |
+
+**Voorstel voor de volgende twee.** De **deploymentview**, omdat die de privacygrenzen omzet in
+handhaafbare netwerkpolicy. En de **sequences voor de niet-gelukkige paden**, omdat compliance daar
+werkelijk breekt.

docs/architecture/fds/slice-1-proposal.md

@@ -0,0 +1,103 @@
+# POC-voorstel — slice 1: walking skeleton (één register, gegoverneerde bevraging)
+
+> Klaar om in een `poc-voorstel`-issue te plakken, met de labels `build` en `poc`. Dit is het bouwbare
+> eerste increment dat de architectuurdocumenten beschrijven. Het bewijst met opzet de
+> *compliance-spine* end-to-end op de dunst mogelijke functionaliteit.
+
+## Probleem en strategische vraag
+
+Kunnen wij een registerbevraging demonstreren die *structureel* gegoverneerd is — onmogelijk uit te
+voeren zonder gehandhaafde grondslag en een automatische regel in het verwerkingenlog — op onze
+soevereine stack?
+
+Dit is de geloofwaardigheidstoets achter de hele Open Register-inzet (slice 1 van het charter) en
+achter de FDS gap-analyse.
+
+## Hypothese
+
+Wij verwachten dat het doorverbinden van één registerbevraging door de volledige capability-spine —
+Register Port → ACL-adapter → PDP-controle → FSC-aanroep → LDV-emissie → begrensde cache — de claim
+"compliance is structureel" bewijst.
+
+Wij weten dat wij het goed hebben als een geautomatiseerde test aantoont dat een bevraging **niet** kan
+voltooien als de PDP weigert, en **altijd** een LDV-event oplevert als de PDP toestaat.
+
+## Scope ter grootte van één blok
+
+**Wel in scope**
+
+| Onderdeel | Wat |
+|---|---|
+| Register | **NHR/KVK**, basisgegevens over onderneming en bestuurder. Gekozen boven BRP; zie de slotnotitie. |
+| Use case | Geef bij een KVK-nummer de geregistreerde organisatie terug aan het domein, voor één verklaard doel. |
+| Ports | De vijf ports als interface. Concrete adapters: NHR-ACL, PDP-client (OPA), FSC-client met sandbox- of test-outway, LDV-emitter (Redpanda-topic), en cache manager (PostgreSQL met TTL). |
+| Policy | OPA draait met één handgeschreven voorbeeldpolicy in Gitea: één allow-regel en één deny-geval. |
+| Log | Verwerkingsevent-schema v0 plus een minimale bevraagbare projectie; een tabelweergave is genoeg. |
+| Tests | Tests die de twee compliance-invarianten vastleggen: deny blokkeert, allow logt. |
+
+**Niet in scope** — even belangrijk om op te schrijven.
+
+1. Afgewerkte interface of NL Design System-schermen, verder dan een dev-harness.
+2. BRP en paden met veel persoonsgegevens. Die gaan naar slice 2, met een door de FG beoordeelde
+   policy.
+3. UBO-data. Het regime van beperkte toegankelijkheid valt buiten deze slice.
+4. De terugmelding-workflow (latere slice), DCAT-export, en Superset-dashboards.
+5. Echte register-endpoints. Alleen sandbox en stubs.
+
+## Definition of Done
+
+- [ ] Een bevraging op KVK-nummer geeft een domein-`Organisatie` terug via de NHR-ACL-adapter, zonder
+      registervocabulaire in het domein (ADR-0001).
+- [ ] De aanroep loopt via de FSC-client naar een sandbox-outway, en niet via een ruwe HTTP-client
+      (ADR-0002).
+- [ ] Er vindt geen bevraging plaats tenzij de PDP allow teruggeeft voor de combinatie rol, doel en
+      grondslag (ADR-0003).
+- [ ] Elke toegestane bevraging stuurt precies één verwerkingsevent naar Redpanda, bevraagbaar in de
+      projectie, zonder opgehaalde waarden (ADR-0005).
+- [ ] Cache-entries dragen een TTL en een subjectsleutel; een purge-aanroep verwijdert ze (ADR-0004).
+- [ ] **De tests op de compliance-invarianten slagen in CI:** (a) PDP-deny betekent geen FSC-aanroep;
+      (b) PDP-allow betekent precies één LDV-event; (c) te ruim gevraagde velden bereiken het domein
+      nooit.
+- [ ] Het geheel draait lokaal uit een gedocumenteerd `compose`- of k3s-manifest met stubs, zonder
+      echte registertoegang.
+- [ ] ADR-0001 tot en met ADR-0005 zijn vanuit de code gelinkt. Eén nieuwe ADR als er in slice 1 een
+      besluit ontstaat.
+
+## Acceptatiedemo (bewijs voor de week-3-toets)
+
+Live: een geslaagde bevraging plus de bijbehorende LDV-regel. Zet daarna de policy op deny en toon
+dezelfde bevraging geweigerd, zonder registeraanroep en zonder data.
+
+Dat contrast *is* de demo.
+
+## Ontvangende Delivery Circle (voorlopig)
+
+De register-reference Delivery Circle. De Handoff-ontvanger krijgt bij de kickoff een naam.
+
+Waarschijnlijke adoptie: de capability-spine wordt het herbruikbare substraat voor de
+register-reference-applicatie.
+
+## Upstream-kandidaten
+
+| Project | Wat wij kunnen bijdragen |
+|---|---|
+| fsc-nlx | Ergonomie van de sandbox en testomgeving, plus documentatie |
+| OPA | Policy-patronen voor het modelleren van Nederlandse grondslagen |
+| OpenMetadata | Later een DCAT-AP-NL exporter; dit verbindt het OpenMetadata-project |
+
+## AVG- en soevereiniteitsoverwegingen
+
+Alleen NHR-basisgegevens, over onderneming en bestuurder, en in slice 1 **gestubd**. Er worden geen
+echte persoonsgegevens verwerkt.
+
+Een FG-review is een voorwaarde voor slice 2, met echte data en BRP. Alle componenten draaien
+zelfgehost op De Werf; OPA-policies en BPMN staan in Gitea.
+
+## Slotnotitie: waarom NHR vóór BRP voor het skeleton
+
+Beide registers bevatten persoonsgegevens, dus geen van beide is "gratis". NHR-basisgegevens over
+onderneming en bestuurder zijn echter minder gevoelig dan BRP-gegevens over inwoners, en er is een
+duidelijker verhaal rond een publieke sandbox.
+
+Zo bewijst slice 1 het *mechanisme*, voordat slice 2 BRP oppakt onder een door de FG beoordeelde
+policy. UBO-data blijft buiten scope tot het toegangsregime is gemodelleerd.

docs/demo-script.md

@@ -5,6 +5,40 @@ copy-pasteable walkthrough against a local `make up` stack.
 
 ---
 
+## S-26/#162 — the werkbak refreshes itself (ADR-0032)
+
+**Outcome:** a registration that reaches beoordeling while a behandelaar already has the werkbak open
+**appears on its own** — no reload. The page re-reads `GET /behandel/werkbak` every 5 seconds; a
+background refresh swaps the rows in without flashing the loading state, and a transient failure no
+longer strands the view on its error message until someone reloads.
+
+```bash
+# 1. Two windows. Left: the behandel werkbak, already open and idle.
+python3 infra/keycloak/check_realms.py otp   # a code, valid right now
+open http://localhost:8142                   # merel-behandelaar / test123 + that code
+#
+# 2. Right: submit a registration and supply its documents (this is what routes it to Beoordelen).
+open http://localhost:8140                   # jan-burger / test123 → indienen → upload a PDF
+#
+# 3. Watch the left window. Within ~5 seconds the new reference appears in the werkbak — the page was
+#    never reloaded and never left the werkbak.
+#
+# 4. Automated, end to end: the happy path now waits for the werkbak row WITHOUT reloading, so the
+#    absence of the reload IS the assertion.
+make verify-e2e        # → registration.spec: "… → behandelaar goedkeurt → public INGESCHREVEN"
+#
+# 5. Component level (background refresh, failure recovery, teardown):
+pnpm nx test behandel  # → "picks up a newly submitted registration without a reload" (+3 guards)
+```
+
+**The path:** unchanged — portal → BFF `GET /behandel/werkbak` → domain `Werkbak` → Flowable. Only the
+page's cadence is new: `interval(WERKBAK_REFRESH_MS)` scoped to the page with `takeUntilDestroyed()`.
+
+**Not push:** nothing notifies the BFF either, so SSE/WebSockets would poll the domain inside the BFF
+for the same freshness plus connection state — see ADR-0032 for the trade-off and the upgrade path.
+
+---
+
 ## S-19a — approval writes the register record to Objecten (#149, ADR-0028)
 
 **Outcome:** approving a registration no longer only moves the ZGW zaak to its eindstatus — it also
@@ -140,7 +174,8 @@ zaaktype cache). Store is in-memory: an edit reverts to the configured env on re
 
 ```bash
 make up
-# 1. Log in as bram-beheerder / test123 → "Default-fill" tab → change a value → Opslaan.
+# 1. Log in as bram-beheerder / test123 + OTP (`python3 infra/keycloak/check_realms.py otp`)
+#    → "Default-fill" tab → change a value → Opslaan.
 open http://localhost:8143/default-fill
 #
 # 2. Automated: the ACL uses the current default-fill per zaak (unit) and the endpoints are behind the
@@ -161,7 +196,8 @@ directly (ADR-0025); managing the default-fill config (S-15b) and MFA (S-15c) co
 
 ```bash
 make up
-# 1. Log in as bram-beheerder / test123 → the catalogus lists the published zaaktypen.
+# 1. Log in as bram-beheerder / test123 + OTP (`python3 infra/keycloak/check_realms.py otp`)
+#    → the catalogus lists the published zaaktypen.
 open http://localhost:8143
 #
 # 2. Automated (a CI verify-stack e2e): a beheerder logs in and sees BIG-REGISTRATIE.
@@ -304,7 +340,8 @@ make verify-local     # → "OK — a fresh local stack completed the flow with
 
 # 3. Or by hand in the browser: log in at http://localhost:8140 (jan-burger / test123), submit +
 #    upload a PDF, then approve it in the werkbak at http://localhost:8142 (merel-behandelaar /
-#    test123); it shows as INGESCHREVEN in the openbaar register at http://localhost:8141.
+#    test123 + OTP, see S-15c); it shows as INGESCHREVEN in the openbaar register at
+#    http://localhost:8141.
 ```
 
 > The zaaktype is discovered by the ACL itself since S-27 (below); `local-seed`'s `acl.env` now
@@ -589,7 +626,7 @@ or **afwijzen** — which also completes the Beoordelen task so the process adva
 
 ```text
 # 1. Open the behandel portal and log in as a behandelaar (medewerker realm):
-#    http://localhost:8142/   →  merel-behandelaar / test123
+#    http://localhost:8142/   →  merel-behandelaar / test123 + OTP
 #
 # 2. The werkbak lists the registrations awaiting beoordeling (referentie / bsn / status).
 #    Find the reference from the submit confirmation and click "Goedkeuren" on that row.
@@ -812,3 +849,32 @@ make verify-domain     # → "the timed-out registration's zaak was cancelled to
 `POST /annuleringen` → ZGW `resultaten` + `statussen` (Geannuleerd); the aggregate then moves to
 `Verlopen`. The ACL cancels the zaak **before** the aggregate is expired, so a failed ZGW call leaves the
 job for redelivery rather than diverging the two (ADR-0019).
+
+---
+
+## S-15c — MFA on the medewerker realm (#132, ADR-0031)
+
+**Outcome:** staff logins (behandel + beheer portals) need a **second factor**. The medewerker realm
+seeds every medewerker with a TOTP credential, so Keycloak's conditional-OTP step challenges them in
+both the browser flow and the direct grant; a password alone no longer yields a token. `CONFIGURE_TOTP`
+is a default required action, so a medewerker added later must enrol first. Citizen realms (digid,
+eherkenning, eidas) are unchanged — they mock brokers that carry their own assurance.
+
+```bash
+# 1. Manual: log in to the behandel portal. After username + password Keycloak asks for a code.
+python3 infra/keycloak/check_realms.py otp   # a valid code, right now
+open http://localhost:8142                   # merel-behandelaar / test123 + that code
+#
+# 2. Automated: the realm smoke check asserts the password alone is REFUSED, then that
+#    password + TOTP succeeds and still carries the behandelaar role:
+make keycloak-smoke    # → "medewerker  merel-behandelaar  password-only login refused [OK]"
+#
+# 3. End-to-end: every staff login in the e2e goes through the OTP prompt (loginMedewerker):
+make verify-e2e        # → registration.spec (behandelaar approves), catalogus.spec, default-fill.spec
+```
+
+**The path:** the seeded `otp` credential in `infra/keycloak/realms/medewerker-realm.json` activates
+Keycloak's stock conditional-OTP subflow — no custom browser flow. The fixture secret is shared and
+committed on purpose so the checks can compute codes; a real deployment enrols per-user authenticators
+(ADR-0031).
+

docs/index.md

@@ -9,6 +9,9 @@ should teach.
 - **[Product Requirements](PRD.md)** — what we're building and why.
 - **[ADR-0001: Loose coupling](architecture/adr-0001-loose-coupling.md)** — the
   non-negotiable integration stance; the template for future ADRs.
+- **[FDS architecture](architecture/fds/README.md)** — participating in the Federatief
+  Datastelsel as an afnemer: FDS ADR-0001…0006, the L3 component view, the slice-1 proposal.
+  In Dutch; the strategic framing lives in `Respellion/innovation-lab`.
 - **[Working in Gitea](gitea-workflow.md)** — issues, milestones, branches, PRs.
 - **[CI runbook](runbooks/ci.md)** — the pipeline and the `make ci` local gate.
 

docs/runbooks/keycloak.md

@@ -23,6 +23,9 @@ login per realm and asserts the identifying claim:
 | eidas | pierre-dupont | `eidas_id` |
 | medewerker | merel-behandelaar | role `behandelaar` |
 
+The medewerker row also asserts that the password **alone** is refused — that realm
+enforces MFA (below).
+
 All test users / credentials are in [../synthetic-data.md](../synthetic-data.md).
 
 ## Notes
@@ -35,3 +38,36 @@ All test users / credentials are in [../synthetic-data.md](../synthetic-data.md)
 - **Image** pinned to `quay.io/keycloak/keycloak:26.1`.
 - Claims are injected by OIDC protocol mappers on `big-portal` (user attribute → token
   claim); `medewerker` roles come through `realm_access.roles`.
+
+## MFA on the medewerker realm (S-15c)
+
+Staff logins (behandel + beheer portals) need a second factor; citizen/company realms
+(digid, eherkenning, eidas) do not. Two halves in `medewerker-realm.json`:
+
+- Every seeded medewerker carries a **TOTP credential** with the fixture secret
+  `BIGMEDEWERKEROTPSEED`, so Keycloak's built-in *conditional OTP* step fires on every
+  login — browser flow (an `#otp` prompt after the password) and direct grant (a `totp`
+  form field) alike.
+- `CONFIGURE_TOTP` is a **default required action**, so any medewerker added later must
+  enrol an authenticator before the first login.
+
+See [../architecture/adr-0031-mfa-on-the-medewerker-realm.md](../architecture/adr-0031-mfa-on-the-medewerker-realm.md).
+
+### Getting a code
+
+```bash
+python3 infra/keycloak/check_realms.py otp   # prints a valid 6-digit code right now
+```
+
+Or enrol a phone once: the secret in base32 is `IJEUOTKFIRCVORKSJNCVET2UKBJUKRKE`
+(`otpauth://totp/medewerker?secret=IJEUOTKFIRCVORKSJNCVET2UKBJUKRKE`). The e2e computes its
+own code in `tests/e2e/medewerker-login.ts`.
+
+**A code is single-use.** Keycloak's `otpPolicyCodeReusable` defaults to false, so it refuses a
+code it has already accepted — a second login as the same medewerker inside the same 30-second
+window fails with `invalid_grant` / *Invalid user credentials*, even though the code is current.
+Nothing to fix in the realm: wait for the next window, or spend the following counter, which is
+what `nextUnusedCounter` in `tests/e2e/medewerker-login.ts` does for back-to-back specs.
+
+**Fixture only.** A shared, committed secret is a demo convenience, never a production
+posture — see the ADR's consequences.

docs/synthetic-data.md

@@ -19,6 +19,11 @@ All test users share the password **`test123`**.
 | `eidas` | eIDAS (EU) | `pierre-dupont` | `eidas_id` = `FR/NL/AB-1234-5678` |
 | `medewerker` | Internal staff | `merel-behandelaar` | role `behandelaar` |
 | `medewerker` | Internal staff | `tom-teamlead` | roles `behandelaar`, `teamlead` |
+| `medewerker` | Internal staff | `bram-beheerder` | role `beheerder` |
+
+`medewerker` users additionally need a **second factor**: that realm enforces MFA (S-15c,
+ADR-0031). All three share the fixture TOTP secret `BIGMEDEWERKEROTPSEED`; print a current
+code with `python3 infra/keycloak/check_realms.py otp`.
 
 The identifying claims are injected via OIDC protocol mappers on `big-portal`
 (user-attribute → token claim); `medewerker` roles appear in `realm_access.roles`.
@@ -32,5 +37,8 @@ curl -s -X POST \
   -d username=jan-burger -d password=test123 -d scope=openid | jq -r .access_token
 ```
 
+For a `medewerker` user, add `-d totp=$(python3 infra/keycloak/check_realms.py otp)` —
+without it the grant is refused with `invalid_grant`.
+
 Decode the JWT payload to see the `bsn` claim. `make keycloak-smoke` checks every realm
 automatically.

infra/keycloak/check_realms.py

@@ -1,19 +1,25 @@
 #!/usr/bin/env python3
 """Smoke-check the Keycloak realms: each realm's OIDC login works (password grant)
-and returns its expected identifying claim. Stdlib only. Exits non-zero on failure.
+and returns its expected identifying claim. The medewerker realm additionally enforces
+MFA (S-15c), so its login must be refused without a TOTP code. Stdlib only.
+Exits non-zero on failure.
 """
-import base64, json, sys, urllib.error, urllib.parse, urllib.request
+import base64, hashlib, hmac, json, struct, sys, time, urllib.error, urllib.parse, urllib.request
 
 BASE = "http://localhost:8180"
 CLIENT = "big-portal"
 PWD = "test123"
 
-# realm, user, claim ("__roles__" => check realm_access.roles), expected-contains
+# Fixture TOTP secret seeded into every medewerker in infra/keycloak/realms/medewerker-realm.json.
+# Keycloak HMACs the raw secret bytes, so no base32 decoding is involved.
+OTP_SECRET = b"BIGMEDEWERKEROTPSEED"
+
+# realm, user, claim ("__roles__" => check realm_access.roles), expected-contains, mfa-enforced
 CHECKS = [
-    ("digid", "jan-burger", "bsn", "123456782"),
-    ("eherkenning", "acme-ondernemer", "kvk", "12345678"),
-    ("eidas", "pierre-dupont", "eidas_id", "FR/NL"),
-    ("medewerker", "merel-behandelaar", "__roles__", "behandelaar"),
+    ("digid", "jan-burger", "bsn", "123456782", False),
+    ("eherkenning", "acme-ondernemer", "kvk", "12345678", False),
+    ("eidas", "pierre-dupont", "eidas_id", "FR/NL", False),
+    ("medewerker", "merel-behandelaar", "__roles__", "behandelaar", True),
 ]
 
 
@@ -23,10 +29,17 @@ def decode(jwt):
     return json.loads(base64.urlsafe_b64decode(p))
 
 
-def grant(realm, user):
+def totp(secret=OTP_SECRET, period=30, digits=6):
+    """RFC 6238 code: HMAC-SHA1 over the 30-second counter, dynamically truncated."""
+    mac = hmac.new(secret, struct.pack(">Q", int(time.time()) // period), hashlib.sha1).digest()
+    o = mac[-1] & 0x0F
+    return str((struct.unpack(">I", mac[o:o + 4])[0] & 0x7FFFFFFF) % 10 ** digits).zfill(digits)
+
+
+def grant(realm, user, **extra):
     data = urllib.parse.urlencode({
         "grant_type": "password", "client_id": CLIENT,
-        "username": user, "password": PWD, "scope": "openid",
+        "username": user, "password": PWD, "scope": "openid", **extra,
     }).encode()
     req = urllib.request.Request(
         f"{BASE}/realms/{realm}/protocol/openid-connect/token", data=data,
@@ -35,11 +48,27 @@ def grant(realm, user):
         return json.loads(r.read())
 
 
+def second_factor_refused(realm, user):
+    """The password alone must not yield a token on an MFA-enforced realm."""
+    try:
+        grant(realm, user)
+    except urllib.error.HTTPError as e:
+        return e.code in (400, 401)
+    return False
+
+
 def main():
     ok = True
-    for realm, user, claim, expect in CHECKS:
+    for realm, user, claim, expect, mfa in CHECKS:
+        extra = {}
+        if mfa:
+            refused = second_factor_refused(realm, user)
+            ok = ok and refused
+            print(f"{realm:12} {user:18} password-only login refused "
+                  f"[{'OK' if refused else 'MFA NOT ENFORCED'}]")
+            extra = {"totp": totp()}
         try:
-            at = decode(grant(realm, user)["access_token"])
+            at = decode(grant(realm, user, **extra)["access_token"])
             if claim == "__roles__":
                 val = at.get("realm_access", {}).get("roles", [])
                 good = expect in val
@@ -57,4 +86,9 @@ def main():
 
 
 if __name__ == "__main__":
-    main()
+    # `check_realms.py otp` prints a current code for the fixture secret — what a human demoing
+    # the medewerker portals types at Keycloak's OTP prompt (docs/runbooks/keycloak.md).
+    if len(sys.argv) > 1 and sys.argv[1] == "otp":
+        print(totp())
+    else:
+        main()

infra/keycloak/realms/medewerker-realm.json

@@ -2,6 +2,16 @@
   "realm": "medewerker",
   "enabled": true,
   "displayName": "Medewerkers",
+  "requiredActions": [
+    {
+      "alias": "CONFIGURE_TOTP",
+      "name": "Configure OTP",
+      "providerId": "CONFIGURE_TOTP",
+      "enabled": true,
+      "defaultAction": true,
+      "priority": 10
+    }
+  ],
   "roles": {
     "realm": [
       { "name": "behandelaar", "description": "Behandelt registratieaanvragen" },
@@ -43,7 +53,15 @@
       "lastName": "Behandelaar",
       "email": "merel@big.example.nl",
       "emailVerified": true,
-      "credentials": [{ "type": "password", "value": "test123", "temporary": false }],
+      "credentials": [
+        { "type": "password", "value": "test123", "temporary": false },
+        {
+          "type": "otp",
+          "userLabel": "seeded TOTP (fixture)",
+          "secretData": "{\"value\":\"BIGMEDEWERKEROTPSEED\"}",
+          "credentialData": "{\"subType\":\"totp\",\"digits\":6,\"counter\":0,\"period\":30,\"algorithm\":\"HmacSHA1\"}"
+        }
+      ],
       "realmRoles": ["behandelaar"]
     },
     {
@@ -53,7 +71,15 @@
       "lastName": "Teamlead",
       "email": "tom@big.example.nl",
       "emailVerified": true,
-      "credentials": [{ "type": "password", "value": "test123", "temporary": false }],
+      "credentials": [
+        { "type": "password", "value": "test123", "temporary": false },
+        {
+          "type": "otp",
+          "userLabel": "seeded TOTP (fixture)",
+          "secretData": "{\"value\":\"BIGMEDEWERKEROTPSEED\"}",
+          "credentialData": "{\"subType\":\"totp\",\"digits\":6,\"counter\":0,\"period\":30,\"algorithm\":\"HmacSHA1\"}"
+        }
+      ],
       "realmRoles": ["behandelaar", "teamlead"]
     },
     {
@@ -63,7 +89,15 @@
       "lastName": "Beheerder",
       "email": "bram@big.example.nl",
       "emailVerified": true,
-      "credentials": [{ "type": "password", "value": "test123", "temporary": false }],
+      "credentials": [
+        { "type": "password", "value": "test123", "temporary": false },
+        {
+          "type": "otp",
+          "userLabel": "seeded TOTP (fixture)",
+          "secretData": "{\"value\":\"BIGMEDEWERKEROTPSEED\"}",
+          "credentialData": "{\"subType\":\"totp\",\"digits\":6,\"counter\":0,\"period\":30,\"algorithm\":\"HmacSHA1\"}"
+        }
+      ],
       "realmRoles": ["beheerder"]
     }
   ]

infra/local/register-abonnement.py

@@ -2,10 +2,10 @@
 """Local-stack bootstrap (S-B04, #110, ADR-0020) — register the NRC abonnement.
 
 Runs as the `nrc-subscribe` init container of infra/docker-compose.local.yml. Registers an
-abonnement on the `zaken` kanaal pointing at the event-subscriber's /notifications callback, so
-OpenZaak's notifications (zaak create + status set) reach the projection — without this the openbaar
-(public) register stays empty. This is what infra/verify-notification-driver.py does for CI (minus
-the test zaak it also creates).
+abonnement on the `objecten` kanaal pointing at the event-subscriber's /notifications callback, so
+the register writes the ACL makes (INGEDIEND on submit, INGESCHREVEN on approval) reach the
+projection — without this the openbaar (public) register stays empty. Since S-19b-2 the projection
+is sourced from the register in Objecten, not from ZGW zaak events (ADR-0030).
 
 The callback host is the event-subscriber's resolved **container IP**, not `event-subscriber`, because
 NRC validates callbackUrl with Django's URLValidator (a single-label host is rejected — same reason the
@@ -22,6 +22,8 @@ SINK_PORT = os.environ.get("SINK_PORT", "8080")
 SINK_AUTH = os.environ.get("SINK_AUTH", "Bearer big-reference-notifications")
 CID = os.environ.get("OZ_CLIENT_ID", "big-reference-seed")
 SECRET = os.environ.get("OZ_SECRET", "insecure-dev-secret-change-me")
+# The projection is sourced from the register in Objecten, not from ZGW zaak events (S-19b-2).
+KANAAL = "objecten"
 
 
 def token():
@@ -60,7 +62,10 @@ def main():
     status, body = call("GET", f"{NRC}/api/v1/abonnement")
     for ab in (body or []) if status == 200 else []:
         if str(ab.get("callbackUrl", "")).endswith("/notifications"):
-            if ab.get("callbackUrl") == callback:
+            # The kanaal is part of "current": an abonnement left over from before S-19b-2 points at
+            # the right callback but listens on `zaken`, and would never be replaced on IP alone.
+            kanalen = [k.get("naam") for k in ab.get("kanalen", [])]
+            if ab.get("callbackUrl") == callback and kanalen == [KANAAL]:
                 print(f"abonnement already current: {ab['url']}")
                 return
             call("DELETE", ab["url"])
@@ -68,7 +73,7 @@ def main():
 
     status, ab = call("POST", f"{NRC}/api/v1/abonnement", {
         "callbackUrl": callback, "auth": SINK_AUTH,
-        "kanalen": [{"naam": "zaken", "filters": {}}]})
+        "kanalen": [{"naam": KANAAL, "filters": {}}]})
     if status != 201:
         sys.exit(f"create abonnement -> {status}: {json.dumps(ab)}")
     print(f"abonnement registered: {ab['url']} -> {callback}")

infra/observability/tempo/tempo.yaml

@@ -25,3 +25,15 @@ storage:
       path: /var/tempo/blocks
     wal:
       path: /var/tempo/wal
+
+# #156: don't let the distributor evict its own ingester. Tempo runs single-binary here, so the
+# distributor and the ingester are the same process and the "pool" holds exactly one, in-process,
+# member. dskit still health-checks it over loopback gRPC with a 1s deadline (checkinterval 15s);
+# on the shared CI runner a transient stall blows that deadline, the only ingester is dropped from
+# the pool ("removing distributor_pool failing healthcheck"), and every push then fails ("pusher
+# failed to consume trace data", err="context canceled") until the next check — silently losing
+# spans, which is how verify-tracing flaked. With one in-process ingester the check can never route
+# around a failure, so it can only ever discard data. Turn it off.
+ingester_client:
+  pool_config:
+    healthcheckenabled: false

infra/run-projection-check.sh

@@ -1,18 +1,26 @@
 #!/usr/bin/env bash
 #
-# Verify the end-to-end read-projection path (S-06) against an ALREADY-RUNNING full stack:
-# OpenZaak → NRC → Event Subscriber → projection → projection-api. Seeds a published BIG
-# zaaktype (idempotent), registers an abonnement on the `zaken` kanaal pointing at the real
-# Event Subscriber's /notifications callback (with the bearer it enforces), creates a zaak,
-# and asserts projection-api serves a row for that zaak with status INGEDIEND.
+# Verify the end-to-end read-projection path (S-06, re-sourced by S-19b-2) against an ALREADY-RUNNING
+# full stack: ACL → Objecten → NRC → Event Subscriber → projection → projection-api. Seeds a
+# published BIG zaaktype (idempotent), registers an abonnement on the `objecten` kanaal pointing at
+# the real Event Subscriber's /notifications callback (with the bearer it enforces), opens a zaak
+# *through the ACL*, and asserts projection-api serves a row for it with status INGEDIEND.
+#
+# The zaak is opened through the ACL, not straight against OpenZaak: since ADR-0030 the projection is
+# derived from the RegisterRecord in Objecten, and the ACL is what writes that record (INGEDIEND on
+# submit). A zaak created behind the ACL's back produces no register write and so no projection row —
+# which is the point of the re-source.
 #
 # All in-network, reaching services by container IP — single-label hosts aren't URL-valid and
-# the runner can't reach published ports (gitea-actions-gotchas.md §5/§6). Reuses the
-# notification driver to register the abonnement + create the zaak. Does NOT manage the stack
-# lifecycle (the caller owns bring-up + teardown). Plain docker primitives only. See ADR-0007/0008.
+# the runner can't reach published ports (gitea-actions-gotchas.md §5/§6). Does not own the stack
+# lifecycle (the caller brings it up and tears it down), but does recreate the `acl` service to
+# repoint it — see below, and run-domain-check.sh, which does the same. Plain docker primitives only.
+# See ADR-0007/0008/0030.
 set -euo pipefail
 
 here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+root="$(cd "$here/.." && pwd)"
+compose="$root/infra/docker-compose.yml"
 WEBHOOK_AUTH="${NOTIFICATION_WEBHOOK_TOKEN:-Bearer big-reference-notifications}"
 
 cleanup() { docker rm -f rr-pverify rr-pquery >/dev/null 2>&1 || true; }
@@ -24,11 +32,13 @@ oz="$(docker ps -q --filter 'name=[-_]openzaak[-_]' | head -1)"
 nrc="$(docker ps -q --filter 'name=nrc-web' | head -1)"
 es="$(docker ps -q --filter 'name=event-subscriber' | head -1)"
 proj="$(docker ps -q --filter 'name=projection-api' | head -1)"
+acl="$(docker ps -q --filter 'name=[-_]acl[-_]' | head -1)"
 [ -n "$oz" ] && [ -n "$nrc" ] || { echo "ERROR: OpenZaak and/or NRC not running — bring the stack up first" >&2; exit 1; }
 [ -n "$es" ] && [ -n "$proj" ] || { echo "ERROR: event-subscriber and/or projection-api not running — bring the stack up first" >&2; exit 1; }
+[ -n "$acl" ] || { echo "ERROR: acl not running — bring the stack up first" >&2; exit 1; }
 net="$(docker inspect -f '{{range $k,$_ := .NetworkSettings.Networks}}{{$k}}{{"\n"}}{{end}}' "$oz" | head -1)"
-oz_ip="$(ip "$oz")"; nrc_ip="$(ip "$nrc")"; es_ip="$(ip "$es")"; proj_ip="$(ip "$proj")"
-echo ">> network=$net openzaak=$oz_ip nrc=$nrc_ip event-subscriber=$es_ip projection-api=$proj_ip"
+oz_ip="$(ip "$oz")"; nrc_ip="$(ip "$nrc")"; es_ip="$(ip "$es")"; proj_ip="$(ip "$proj")"; acl_ip="$(ip "$acl")"
+echo ">> network=$net openzaak=$oz_ip nrc=$nrc_ip event-subscriber=$es_ip projection-api=$proj_ip acl=$acl_ip"
 
 echo ">> seeding a published BIG zaaktype (idempotent)"
 sid="$(docker create --network "$net" -e "OZ_BASE=http://$oz_ip:8000" -e OZ_PUBLISH=1 \
@@ -37,19 +47,39 @@ docker cp "$here/openzaak/seed_catalogus.py" "$sid:/seed.py" >/dev/null
 docker start -a "$sid"
 docker rm -f "$sid" >/dev/null
 
-echo ">> registering abonnement at the Event Subscriber + creating a zaak"
+echo ">> registering the event-subscriber abonnement on the objecten kanaal"
 docker rm -f rr-pverify >/dev/null 2>&1 || true
+# The same script the local stack uses (ADR-0020), so both paths register the identical abonnement.
 drv="$(docker create --network "$net" --name rr-pverify \
-  -e "OZ_BASE=http://$oz_ip:8000" -e "NRC_BASE=http://$nrc_ip:8000" \
-  -e "SINK_CALLBACK=http://$es_ip:8080/notifications" -e "SINK_AUTH=$WEBHOOK_AUTH" \
-  python:3-slim python /driver.py)"
-docker cp "$here/verify-notification-driver.py" "$drv:/driver.py" >/dev/null
+  -e "NRC_BASE=http://$nrc_ip:8000" \
+  -e "SINK_HOST=$es_ip" -e "SINK_PORT=8080" -e "SINK_AUTH=$WEBHOOK_AUTH" \
+  python:3-slim python /subscribe.py)"
+docker cp "$here/local/register-abonnement.py" "$drv:/subscribe.py" >/dev/null
 docker start -a "$drv"
-zaak_url="$(docker logs rr-pverify 2>/dev/null | sed -n 's/^ZAAK_CREATED //p' | head -1)"
 docker rm -f rr-pverify >/dev/null
-[ -n "$zaak_url" ] || { echo "ERROR: driver did not create a zaak" >&2; exit 1; }
+
+# OpenZaak reflects the request Host into the zaaktype `url` it returns, and then rejects that same
+# URL on zaak-create when the host is single-label ("Voer een geldige URL in."). The stack's ACL is
+# configured with `http://openzaak:8000/`, so it must be repointed at OpenZaak's container IP before
+# it can open a zaak — exactly what run-domain-check.sh does, and the same class of constraint as the
+# `objecten.local` alias (ADR-0029). The ACL resolves the zaaktype itself (S-27, ADR-0021), so the
+# base URL is the only thing to inject.
+echo ">> recreating the acl service pointed at OpenZaak's IP"
+ACL_OPENZAAK_BASEURL="http://$oz_ip:8000/" docker compose -f "$compose" up -d acl
+WAIT_TIMEOUT="${WAIT_TIMEOUT:-120}" bash "$here/wait-healthy.sh" acl
+# The container is replaced, so its IP may have changed.
+acl="$(docker ps -q --filter 'name=[-_]acl[-_]' | head -1)"
+acl_ip="$(ip "$acl")"
+
+echo ">> opening a zaak through the ACL (which writes the INGEDIEND register record)"
+reference="PROJ-$(date +%s)"
+zaak_url="$(docker run --rm --network "$net" curlimages/curl:latest \
+  -fsS -X POST "http://$acl_ip:8080/zaken" -H 'Content-Type: application/json' \
+  -d "{\"bsn\":\"123456782\",\"reference\":\"$reference\"}" \
+  | sed -n 's/.*"zaakUrl":"\([^"]*\)".*/\1/p')"
+[ -n "$zaak_url" ] || { echo "ERROR: the ACL did not open a zaak" >&2; exit 1; }
 zaak_uuid="${zaak_url##*/}"
-echo ">> zaak created: $zaak_url"
+echo ">> zaak created: $zaak_url (reference $reference)"
 
 echo ">> polling projection-api for the projected row (status INGEDIEND)"
 for _ in $(seq 1 30); do
@@ -63,6 +93,8 @@ for _ in $(seq 1 30); do
   sleep 2
 done
 echo "FAIL — projection-api never served an INGEDIEND row for zaak $zaak_uuid" >&2
+echo "       The chain is ACL → Objecten → NRC → event-subscriber → projection (ADR-0030)." >&2
 echo "--- event-subscriber log ---" >&2; docker logs "$es" 2>&1 | tail -10 >&2
 echo "--- projection-api log ---" >&2; docker logs "$proj" 2>&1 | tail -10 >&2
+echo "--- acl log ---" >&2; docker logs "$acl" 2>&1 | tail -10 >&2
 exit 1

infra/tracing-check.py

@@ -59,6 +59,20 @@ def services_in_trace(trace_id):
     return names
 
 
+def tempo_ingest_state():
+    """#156: distinguish a broken trace chain from Tempo dropping spans. `ingester_clients` is 0
+    when the distributor has evicted its (single, in-process) ingester over a failed loopback
+    health check — pushes fail and spans are lost, which looks identical to missing instrumentation
+    from here. Diagnostics only; never fails the check."""
+    try:
+        for line in _get(f"{TEMPO}/metrics").decode().splitlines():
+            if line.startswith("tempo_distributor_ingester_clients "):
+                return f"tempo {line.strip()} (0 = no ingester in the pool — evicted, so pushes\n       are failing and spans are being dropped; see #156)"
+    except Exception as e:
+        return f"tempo /metrics unreadable: {e}"
+    return "tempo_distributor_ingester_clients not reported"
+
+
 def main():
     deadline = time.time() + TIMEOUT
     generate_traffic()
@@ -74,6 +88,7 @@ def main():
         generate_traffic()
     print(f"FAIL — no single trace spanned {sorted(WANT)}; services seen: {sorted(seen)}",
           file=sys.stderr)
+    print(f"       {tempo_ingest_state()}", file=sys.stderr)
     return 1
 
 

infra/wait-healthy.sh

@@ -15,9 +15,13 @@ set -euo pipefail
 timeout="${WAIT_TIMEOUT:-420}"
 deadline=$(( $(date +%s) + timeout ))
 
-# compose service name -> container id. The name filter matches both docker
-# compose ("infra-openzaak-1") and podman-compose ("infra_openzaak_1") naming.
-cid_for() { docker ps -aq --filter "name=$1" | head -1; }
+# compose service name -> container id. `--filter name=` is a substring match, so it is anchored on
+# the compose replica suffix — otherwise 'objecten' also matches objecten-db / objecten-redis /
+# objecten-celery, and 'objecttypen' matches objecttypen-db. Whichever docker listed first won, so a
+# service with a sibling that has no healthcheck timed out with status=none while it was in fact
+# healthy. The pattern matches both docker compose ("infra-objecten-1") and podman-compose
+# ("infra_objecten_1") naming; the same anchoring the verify check scripts use.
+cid_for() { docker ps -aq --filter "name=$1[-_][0-9]+\$" | head -1; }
 
 for svc in "$@"; do
   echo "waiting for '$svc' to be healthy (timeout ${timeout}s)..."

mkdocs.yml

@@ -32,6 +32,17 @@ nav:
       - "ADR-0008: Read projection store": architecture/adr-0008-read-projection-store.md
       - "ADR-0009: External-task job worker": architecture/adr-0009-external-task-job-worker.md
       - "ADR-0010: BFF OIDC validation": architecture/adr-0010-bff-oidc.md
+  - FDS-architectuur:
+      - Overzicht: architecture/fds/README.md
+      - Componentview (L3): architecture/fds/c4-component-view.md
+      - "Slice 1: walking skeleton": architecture/fds/slice-1-proposal.md
+      - "FDS ADR-0001: ACL op elke registergrens": architecture/fds/adr/0001-acl-at-every-register-boundary.md
+      - "FDS ADR-0002: FSC voor connectiviteit": architecture/fds/adr/0002-fsc-for-connectivity.md
+      - "FDS ADR-0003: PBAC via OPA": architecture/fds/adr/0003-pbac-via-opa.md
+      - "FDS ADR-0004: Begrensde cache": architecture/fds/adr/0004-bounded-cache.md
+      - "FDS ADR-0005: Verwerkingenlog via events": architecture/fds/adr/0005-ldv-verwerkingenlog.md
+      - "FDS ADR-0006: Modulegrens en hergebruik": architecture/fds/adr/0006-module-boundary-and-reuse.md
+      - "FDS ADR-template": architecture/fds/adr/template.md
   - Working in Gitea: gitea-workflow.md
   - Frontend decisions: frontend-decisions.md
   - Demo script: demo-script.md
@@ -42,7 +53,11 @@ markdown_extensions:
   - admonition
   - toc:
       permalink: true
-  - pymdownx.superfences
+  - pymdownx.superfences:
+      custom_fences:
+        - name: mermaid
+          class: mermaid
+          format: !!python/name:pymdownx.superfences.fence_code_format
 
 # Many docs referenced by PRD.md land in later slices; don't fail the build on them.
 validation:

services/acl/Acl.Api/Program.cs

@@ -90,6 +90,16 @@ app.MapPost("/zaken/reference", async (ZaakReferenceRequest body, AclService acl
     return Results.Ok(new { reference });
 });
 
+// Read the register record an object in Objecten holds. The Event Subscriber projects a register
+// write from the notification NRC delivers, which carries only the object URL, and may not talk to
+// Objecten itself (§8.1, ADR-0028/ADR-0030). 404 when the object holds no record — the subscriber
+// treats that as "nothing to project" rather than an error (§8.6).
+app.MapPost("/register-records/read", async (RegisterRecordReadRequest body, AclService acl, CancellationToken ct) =>
+{
+    var record = await acl.GetRegisterRecordAsync(new Uri(body.ObjectUrl), ct);
+    return record is null ? Results.NotFound() : Results.Ok(record);
+});
+
 // Store an uploaded diploma against a zaak (S-10b): the domain sends the file as base64; the ACL
 // creates the ZGW enkelvoudiginformatieobject and relates it to the zaak (§8.1). Returns its URL.
 app.MapPost("/documenten", async (StoreDocumentRequest body, AclService acl, CancellationToken ct) =>
@@ -131,6 +141,9 @@ public sealed record CancelZaakRequest(string ZaakUrl);
 
 public sealed record ZaakReferenceRequest(string ZaakUrl);
 
+/// <summary>The object whose register record the Event Subscriber wants read back (S-19b-2).</summary>
+public sealed record RegisterRecordReadRequest(string ObjectUrl);
+
 public sealed record StoreDocumentRequest(string ZaakUrl, string ContentBase64, string FileName, string ContentType);
 
 public partial class Program;

services/acl/Acl.Application/AclService.cs

@@ -24,7 +24,16 @@ public sealed class AclService(
             clock.Today,
             registration.Reference);
 
-        return await gateway.OpenZaakAsync(request, ct);
+        var zaakUrl = await gateway.OpenZaakAsync(request, ct);
+
+        // The register — not ZGW — is what the read projection is sourced from (ADR-0028/ADR-0030),
+        // so the record exists from submission, not only from approval. Same two-writes-converging
+        // posture as ApproveZaakAsync: the upsert is keyed on the zaak id, so a retried submit
+        // updates the record rather than adding a second one (§8.6).
+        await register.UpsertAsync(
+            new RegisterRecord(ZaakId(zaakUrl), RegisterRecordStatus.Ingediend, registration.Reference), ct);
+
+        return zaakUrl;
     }
 
     /// <summary>
@@ -52,6 +61,18 @@ public sealed class AclService(
             ct);
     }
 
+    /// <summary>
+    /// The register record held by an object in Objecten, for the Event Subscriber (S-19b-2). The
+    /// subscriber gets only an object URL on the notification and may not read Objecten itself
+    /// (§8.1, ADR-0028), so the ACL reads it back.
+    /// </summary>
+    public Task<RegisterRecord?> GetRegisterRecordAsync(Uri objectUrl, CancellationToken ct = default)
+    {
+        ArgumentNullException.ThrowIfNull(objectUrl);
+
+        return register.GetAsync(objectUrl, ct);
+    }
+
     /// <summary>The zaak's UUID — the key the register record and the read projection rows share.</summary>
     private static string ZaakId(Uri zaakUrl) => zaakUrl.Segments[^1].TrimEnd('/');
 

services/acl/Acl.Application/IRegisterRecordGateway.cs

@@ -13,6 +13,14 @@ public interface IRegisterRecordGateway
     /// the existing object instead of creating a second one (§8.6).
     /// </summary>
     Task UpsertAsync(RegisterRecord record, CancellationToken ct = default);
+
+    /// <summary>
+    /// The register record held by the object at <paramref name="objectUrl"/>, or <c>null</c> if that
+    /// object holds none. The Event Subscriber projects a register write from the notification NRC
+    /// delivers, which carries only the object URL — so it reads the record back through the ACL
+    /// rather than talking to Objecten itself (§8.1, S-19b-2).
+    /// </summary>
+    Task<RegisterRecord?> GetAsync(Uri objectUrl, CancellationToken ct = default);
 }
 
 /// <summary>

services/acl/Acl.Infrastructure/ObjectenGateway.cs

@@ -1,3 +1,4 @@
+using System.Net;
 using System.Net.Http.Headers;
 using System.Net.Http.Json;
 using System.Text.Json.Serialization;
@@ -38,6 +39,30 @@ public sealed class ObjectenGateway(HttpClient http, ObjectenOptions options, IC
                 "Updating the register record", ct);
     }
 
+    public async Task<RegisterRecord?> GetAsync(Uri objectUrl, CancellationToken ct = default)
+    {
+        ArgumentNullException.ThrowIfNull(objectUrl);
+
+        // Fetched by the URL the notification carried, so no objecttype resolution and no search —
+        // unlike a write, which has to find the object for a registration id.
+        using var message = new HttpRequestMessage(HttpMethod.Get, objectUrl);
+        message.Headers.Authorization = new AuthenticationHeaderValue("Token", options.Token);
+        message.Headers.Add("Accept-Crs", "EPSG:4326");
+
+        using var response = await http.SendAsync(message, ct);
+        // The object may be gone by the time a (possibly redelivered) notification is handled —
+        // there is simply nothing to project, which is not a failure (§8.6).
+        if (response.StatusCode == HttpStatusCode.NotFound)
+            return null;
+
+        await EnsureSuccessAsync(response, "Reading the register record", ct);
+
+        var body = await response.Content.ReadFromJsonAsync<ReadObjectDto>(ct)
+            ?? throw new InvalidOperationException("Objecten returned an empty object response");
+        var data = body.Record?.Data;
+        return data is null ? null : new RegisterRecord(data.Id, data.Status, data.Reference);
+    }
+
     private RecordDto NewRecord(int typeVersion, RecordDataDto data) =>
         new(typeVersion, data, clock.Today.ToString("yyyy-MM-dd"));
 
@@ -141,6 +166,12 @@ public sealed class ObjectenGateway(HttpClient http, ObjectenOptions options, IC
     private sealed record ObjectDto(
         [property: JsonPropertyName("url")] string Url);
 
+    private sealed record ReadObjectDto(
+        [property: JsonPropertyName("record")] ReadRecordDto? Record);
+
+    private sealed record ReadRecordDto(
+        [property: JsonPropertyName("data")] RecordDataDto? Data);
+
     private sealed record CreateObjectDto(
         [property: JsonPropertyName("type")] string Type,
         [property: JsonPropertyName("record")] RecordDto Record);

services/acl/Acl.Tests/AclServiceTests.cs

@@ -79,11 +79,21 @@ public class AclServiceTests
     {
         public readonly List<RegisterRecord> Upserted = [];
 
+        public RegisterRecord? Stored;
+
+        public Uri? ReadFrom;
+
         public Task UpsertAsync(RegisterRecord record, CancellationToken ct = default)
         {
             Upserted.Add(record);
             return Task.CompletedTask;
         }
+
+        public Task<RegisterRecord?> GetAsync(Uri objectUrl, CancellationToken ct = default)
+        {
+            ReadFrom = objectUrl;
+            return Task.FromResult(Stored);
+        }
     }
 
     private static AclDefaults Defaults() => new()
@@ -130,6 +140,52 @@ public class AclServiceTests
         Assert.Equal("reg-77", req.Identificatie);
     }
 
+    [Fact]
+    public async Task Opening_a_zaak_also_writes_an_ingediend_register_record(/* S-19b-2 */)
+    {
+        var gateway = new FakeGateway();
+        var register = new FakeRegisterRecordGateway();
+        var service = ServiceWith(gateway, register, Defaults(), new DateOnly(2026, 6, 4));
+
+        await service.OpenZaakAsync(new DomainRegistration("123456782", "reg-77"));
+
+        // The register — not ZGW — is what the read projection is sourced from (ADR-0028), so a
+        // submitted registration has to exist there the moment the zaak is opened, not only on
+        // approval. Approval upserts this same record to INGESCHREVEN.
+        var record = Assert.Single(register.Upserted);
+        Assert.Equal("abc", record.Id);
+        Assert.Equal("INGEDIEND", record.Status);
+        // The reference comes from the registration itself — no ZGW read-back needed on this path.
+        Assert.Equal("reg-77", record.Reference);
+    }
+
+    [Fact]
+    public async Task Reading_a_register_record_goes_through_the_objecten_gateway(/* S-19b-2 */)
+    {
+        var gateway = new FakeGateway();
+        var register = new FakeRegisterRecordGateway { Stored = new RegisterRecord("abc", "INGESCHREVEN", "reg-77") };
+        var service = ServiceWith(gateway, register, Defaults(), new DateOnly(2026, 6, 4));
+        var objectUrl = new Uri("http://objecten.local:8000/api/v2/objects/9de4a2ca");
+
+        var record = await service.GetRegisterRecordAsync(objectUrl);
+
+        Assert.Equal(objectUrl, register.ReadFrom);
+        Assert.Equal("abc", record!.Id);
+        Assert.Equal("INGESCHREVEN", record.Status);
+        Assert.Equal("reg-77", record.Reference);
+    }
+
+    [Fact]
+    public async Task Reading_a_register_record_from_a_null_url_is_rejected(/* S-19b-2 */)
+    {
+        var gateway = new FakeGateway();
+        var register = new FakeRegisterRecordGateway();
+        var service = ServiceWith(gateway, register, Defaults(), new DateOnly(2026, 6, 4));
+
+        await Assert.ThrowsAsync<ArgumentNullException>(() => service.GetRegisterRecordAsync(null!));
+        Assert.Null(register.ReadFrom);
+    }
+
     [Fact]
     public async Task Opening_a_zaak_reflects_a_default_fill_update(/* S-15b */)
     {

services/acl/Acl.Tests/ObjectenGatewayTests.cs

@@ -83,6 +83,43 @@ public class ObjectenGatewayTests
 
     private static RegisterRecord Record() => new("zaak-uuid-1", RegisterRecordStatus.Ingeschreven, "REG-2026-0001");
 
+    [Fact]
+    public async Task Reads_a_register_record_back_from_its_object_url(/* S-19b-2 */)
+    {
+        var sent = new List<Sent>();
+        var objectUrl = new Uri("http://objecten:8000/api/v2/objects/obj-9");
+        var gateway = Gateway(sent, _ => Json(new
+        {
+            url = objectUrl.ToString(),
+            record = new { data = new { id = "zaak-uuid-1", status = "INGESCHREVEN", reference = "REG-2026-0001" } },
+        }));
+
+        var record = await gateway.GetAsync(objectUrl);
+
+        // The object is fetched directly by the URL the notification carried — no objecttype
+        // resolution and no search, unlike a write.
+        var read = Assert.Single(sent);
+        Assert.Equal(HttpMethod.Get, read.Method);
+        Assert.Equal(objectUrl, read.Uri);
+        // Objecten is a geo API: the CRS header is required on reads too.
+        Assert.Equal("EPSG:4326", read.AcceptCrs);
+        Assert.Equal("Token objecten-token", read.Auth);
+        Assert.Equal("zaak-uuid-1", record!.Id);
+        Assert.Equal("INGESCHREVEN", record.Status);
+        Assert.Equal("REG-2026-0001", record.Reference);
+    }
+
+    [Fact]
+    public async Task Reading_an_object_that_is_gone_yields_no_record(/* S-19b-2 */)
+    {
+        var sent = new List<Sent>();
+        var gateway = Gateway(sent, _ => new HttpResponseMessage(HttpStatusCode.NotFound));
+
+        // A record deleted between the notification and the read is not an error — there is simply
+        // nothing to project (§8.6: the subscriber tolerates whatever order deliveries arrive in).
+        Assert.Null(await gateway.GetAsync(new Uri("http://objecten:8000/api/v2/objects/gone")));
+    }
+
     [Fact]
     public async Task Creates_the_object_when_none_exists_for_the_registration()
     {

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

@@ -1,3 +1,4 @@
+using System.Net;
 using System.Net.Http.Json;
 using System.Text.Json.Serialization;
 using EventSubscriber.Application;
@@ -5,26 +6,28 @@ using EventSubscriber.Application;
 namespace EventSubscriber.Api;
 
 /// <summary>
-/// HTTP client to the ACL service. The subscriber enriches the projection with the zaak's reference
-/// (identificatie) by asking the ACL — the only code that may read ZGW (§8.1) — rather than reading
-/// OpenZaak itself (adr-proposal #78).
+/// HTTP client to the ACL service. An Objecten notification carries only the object URL, so the
+/// subscriber reads the register record back through the ACL — the only code that may talk to
+/// Objecten (§8.1, ADR-0028/ADR-0030) — rather than reading Objecten itself.
 /// </summary>
 public sealed class AclHttpClient(HttpClient http) : IAclClient
 {
-    public async Task<string> GetZaakReferenceAsync(Uri zaakUrl, CancellationToken ct = default)
+    public async Task<RegisterRecord?> GetRegisterRecordAsync(Uri objectUrl, CancellationToken ct = default)
     {
-        ArgumentNullException.ThrowIfNull(zaakUrl);
+        ArgumentNullException.ThrowIfNull(objectUrl);
 
         using var response = await http.PostAsJsonAsync(
-            new Uri(http.BaseAddress!, "zaken/reference"), new ReferenceRequest(zaakUrl.ToString()), ct);
-        response.EnsureSuccessStatusCode();
+            new Uri(http.BaseAddress!, "register-records/read"),
+            new ReadRequest(objectUrl.ToString()), ct);
 
-        var body = await response.Content.ReadFromJsonAsync<ReferenceResponse>(ct)
-            ?? throw new InvalidOperationException("The ACL returned an empty reference response.");
-        return body.Reference;
+        // The object holds no register record (deleted, or never one) — nothing to project (§8.6).
+        if (response.StatusCode == HttpStatusCode.NotFound)
+            return null;
+
+        response.EnsureSuccessStatusCode();
+        return await response.Content.ReadFromJsonAsync<RegisterRecord>(ct)
+            ?? throw new InvalidOperationException("The ACL returned an empty register record response.");
     }
 
-    private sealed record ReferenceRequest([property: JsonPropertyName("zaakUrl")] string ZaakUrl);
-
-    private sealed record ReferenceResponse([property: JsonPropertyName("reference")] string Reference);
+    private sealed record ReadRequest([property: JsonPropertyName("objectUrl")] string ObjectUrl);
 }

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

@@ -84,11 +84,12 @@ app.MapPost("/admin/rebuild", async (NotificationProjector projector, Cancellati
 
 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, Uri? HoofdObject = null)
+/// <summary>The NRC notification body, as Open Notificaties POSTs it. Only the fields the projector
+/// needs are bound; <c>aanmaakdatum</c>, <c>kenmerken</c> and <c>hoofdObject</c> are ignored — for a
+/// register write hoofdObject is the same object as resourceUrl (ADR-0030).</summary>
+public sealed record NotificationDto(string Kanaal, string Resource, string Actie, Uri ResourceUrl)
 {
-    public Notification ToNotification() => new(Kanaal, Resource, Actie, ResourceUrl, HoofdObject);
+    public Notification ToNotification() => new(Kanaal, Resource, Actie, ResourceUrl);
 }
 
 public partial class Program

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

@@ -2,40 +2,39 @@ namespace EventSubscriber.Application;
 
 /// <summary>
 /// An inbound NRC (Open Notificaties) notification, as Open Notificaties POSTs it to an
-/// abonnement callback. Only the fields the projection needs are modelled; the full ZGW
-/// "Notificatie" resource also carries <c>aanmaakdatum</c> and <c>kenmerken</c> which the
-/// minimal projection ignores (bsn is deferred — see ADR-0008). For a <c>zaken</c>/<c>zaak</c>/<c>create</c>
-/// notification <c>hoofdObject</c> and <c>resourceUrl</c> are both the created zaak's URL.
+/// abonnement callback. Only the fields the projection needs are modelled.
 /// </summary>
+/// <remarks>
+/// Since S-19b-2 the subscriber listens on the <c>objecten</c> kanaal, not <c>zaken</c>: the
+/// register record in Objecten is what the projection is derived from (ADR-0030), so the
+/// projection is a cache of the register rather than a re-derivation of the case system. An
+/// Objecten notification carries <b>no record data</b> — only the object URL (as both
+/// <c>hoofdObject</c> and <c>resourceUrl</c>) and the objecttype as a kenmerk — so the record
+/// itself is read back through the ACL.
+/// </remarks>
 public sealed record Notification(
     string Kanaal,
     string Resource,
     string Actie,
-    Uri ResourceUrl,
-    Uri? HoofdObject = null)
+    Uri ResourceUrl)
 {
-    /// <summary>A zaak being created — projected as INGEDIEND.</summary>
-    public bool IsZaakCreated =>
-        Kanaal == "zaken" && Resource == "zaak" && Actie == "create";
-
-    /// <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 URL this notification concerns — <c>hoofdObject</c> (the zaak) for a status
-    /// notification, else the resource URL (which, for a zaak-create, is the zaak).</summary>
-    public Uri ZaakUrl => HoofdObject ?? ResourceUrl;
-
-    /// <summary>The zaak UUID used as the projection key — the trailing segment of <see cref="ZaakUrl"/>.</summary>
-    public string ZaakId => ZaakUrl.Segments[^1].Trim('/');
-
     /// <summary>
-    /// A deterministic dedup key. Open Notificaties carries no notification id and may
-    /// redeliver, so the key is derived from the immutable notification content: two
-    /// deliveries of the same zaak-create collapse to one. (NRC may also deliver
-    /// out of order; the projector tolerates that — order does not change the outcome.)
+    /// A register record written to Objecten — <c>create</c> on submit and <c>partial_update</c> on
+    /// approval, since the ACL upserts the same object for a registration (§8.6).
     /// </summary>
-    public string IdempotencyKey => $"{Kanaal}:{Resource}:{Actie}:{ResourceUrl}";
+    /// <remarks>
+    /// <c>partial_update</c> is what a PATCH actually reports: DRF routes it through the notifying
+    /// <c>update()</c> but names the action <c>partial_update</c>, and that is what Objecten puts in
+    /// the notification. <c>update</c> is accepted too, so a PUT-shaped write would project the same
+    /// way. <c>destroy</c> is deliberately not: removing a registration from the public register is
+    /// its own decision, not a side effect of this one.
+    /// </remarks>
+    public bool IsRegisterRecordWritten =>
+        Kanaal == "objecten" && Resource == "object"
+        && Actie is "create" or "update" or "partial_update";
+
+    /// <summary>The object holding the register record. For a <c>resource: object</c> notification
+    /// Objecten sends the object as both <c>hoofdObject</c> and <c>resourceUrl</c> — the object is
+    /// the main resource — so the notification's own <c>hoofdObject</c> is not modelled.</summary>
+    public Uri ObjectUrl => ResourceUrl;
 }

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

@@ -3,21 +3,27 @@ namespace EventSubscriber.Application;
 /// <summary>
 /// Projects inbound NRC notifications into the read projection. Tolerates duplicate and
 /// out-of-order deliveries (CLAUDE.md §8.6): the notification log dedups, and the projection
-/// upsert is idempotent on the zaak id. Rebuilds the projection by replaying the log.
+/// upsert is idempotent on the register id. Rebuilds the projection by replaying the log.
 /// </summary>
 public sealed class NotificationProjector(INotificationLog log, IProjectionStore store, IAclClient acl)
 {
-    /// <summary>Handle one inbound notification. Reacts to a zaak being created (INGEDIEND) and a
-    /// status being set (INGESCHREVEN); ignores everything else. Enriches the row with the zaak's
-    /// reference via the ACL (§8.1) and records it so a rebuild needs no ZGW access (#78).</summary>
+    /// <summary>Handle one inbound notification. Reacts to a register record being written to
+    /// Objecten (S-19b-2, ADR-0030) and ignores everything else. The notification carries only the
+    /// object URL, so the record is read back through the ACL (§8.1) and becomes the row verbatim.</summary>
     public async Task HandleAsync(Notification notification, CancellationToken ct = default)
     {
-        if (!notification.IsZaakCreated && !notification.IsZaakStatusSet)
+        ArgumentNullException.ThrowIfNull(notification);
+
+        if (!notification.IsRegisterRecordWritten)
+            return;
+
+        var record = await acl.GetRegisterRecordAsync(notification.ObjectUrl, ct);
+        // The object is gone, or holds no register record — nothing to project (§8.6).
+        if (record is null)
             return;
 
-        var reference = await acl.GetZaakReferenceAsync(notification.ZaakUrl, ct);
         var recorded = new RecordedNotification(
-            notification.IdempotencyKey, notification.Actie, notification.ZaakId, notification.Resource, reference);
+            KeyFor(notification.ObjectUrl, record), record.Id, record.Status, record.Reference);
 
         // 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.
@@ -27,6 +33,20 @@ public sealed class NotificationProjector(INotificationLog log, IProjectionStore
         await store.UpsertAsync(ToEntry(recorded), ct);
     }
 
+    /// <summary>
+    /// A deterministic dedup key: the object, plus the state that write puts in the projection.
+    /// </summary>
+    /// <remarks>
+    /// Open Notificaties carries no notification id and may redeliver, so the key is derived from
+    /// content. It cannot be the object URL alone — the ACL upserts one object per registration, so
+    /// submit and approval both notify about the *same* URL and the approval would be swallowed as a
+    /// duplicate. Nor can it include the actie: a retried approval would be a second `update`. Keying
+    /// on the projected row means a redelivery collapses and a genuine state change does not, which
+    /// is exactly the property §8.6 asks for.
+    /// </remarks>
+    private static string KeyFor(Uri objectUrl, RegisterRecord record)
+        => $"objecten:object:{objectUrl}:{record.Status}:{record.Reference}";
+
     /// <summary>Rebuild the projection from the durable notification log (PRD §8.4).</summary>
     public async Task RebuildAsync(CancellationToken ct = default)
     {
@@ -35,11 +55,9 @@ public sealed class NotificationProjector(INotificationLog log, IProjectionStore
             await store.UpsertAsync(ToEntry(recorded), ct);
     }
 
-    /// <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>
+    /// <summary>The projection row for an accepted notification. The log already holds exactly the
+    /// row's fields, so a rebuild needs no mapping rules and no upstream reads. bsn/naam stay
+    /// deferred — the register record is public-safe by construction (ADR-0027).</summary>
     private static RegisterEntry ToEntry(RecordedNotification recorded)
-        => new(
-            recorded.ZaakId,
-            recorded.Resource == "status" ? RegistrationStatus.Ingeschreven : RegistrationStatus.Ingediend,
-            Reference: recorded.Reference);
+        => new(recorded.RegisterId, recorded.Status, recorded.Reference);
 }

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

@@ -4,7 +4,7 @@ namespace EventSubscriber.Application;
 /// The durable log of notifications the subscriber has accepted. It is both the idempotency
 /// guard (a replayed notification is recognised and dropped) and the rebuild source: the
 /// projection is a derived artefact (PRD §8.4) regenerated by replaying this log, so a rebuild
-/// needs no access to OpenZaak (CLAUDE.md §8.1). Implemented in Infrastructure over Postgres.
+/// needs no access to Objecten or ZGW (CLAUDE.md §8.1). Implemented in Infrastructure over Postgres.
 /// </summary>
 public interface INotificationLog
 {
@@ -19,22 +19,29 @@ 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 — the ZGW <c>resource</c> (zaak-create → INGEDIEND vs status-set → INGESCHREVEN) and
-/// the zaak <c>reference</c> (identificatie), so a rebuild reproduces the row without re-reading ZGW (#78).</summary>
-public sealed record RecordedNotification(string Key, string Actie, string ZaakId, string Resource, string? Reference);
+/// <summary>
+/// An accepted notification, retaining exactly the projection row it produced — so a rebuild
+/// reproduces the row by replaying the log, without re-reading Objecten (S-19b-2, ADR-0030).
+/// </summary>
+public sealed record RecordedNotification(string Key, string RegisterId, string Status, string? Reference);
 
 /// <summary>
-/// Port to the Anti-Corruption Layer. The subscriber enriches the projection with the zaak's
-/// public-safe reference (its identificatie) by asking the ACL — the only code that may read ZGW
-/// (§8.1) — rather than reading OpenZaak itself (adr-proposal #78).
+/// Port to the Anti-Corruption Layer. An Objecten notification carries only the object URL, so the
+/// subscriber reads the register record back through the ACL — the only code that may talk to
+/// Objecten (§8.1, ADR-0028) — rather than reading Objecten itself.
 /// </summary>
 public interface IAclClient
 {
-    /// <summary>The zaak's reference (identificatie) for the read projection.</summary>
-    Task<string> GetZaakReferenceAsync(Uri zaakUrl, CancellationToken ct = default);
+    /// <summary>The register record the object at <paramref name="objectUrl"/> holds, or
+    /// <c>null</c> if it holds none — the object may be gone by the time a redelivered
+    /// notification is handled, which is not an error (§8.6).</summary>
+    Task<RegisterRecord?> GetRegisterRecordAsync(Uri objectUrl, CancellationToken ct = default);
 }
 
+/// <summary>The public-safe register record as the ACL returns it — the RegisterRecord objecttype's
+/// schema (ADR-0027). No bsn, no name: the register is world-readable.</summary>
+public sealed record RegisterRecord(string Id, string Status, string? Reference);
+
 /// <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>
 public interface IProjectionStore

services/event-subscriber/EventSubscriber.Tests/AclHttpClientTests.cs

@@ -5,27 +5,42 @@ using EventSubscriber.Api;
 namespace EventSubscriber.Tests;
 
 /// <summary>
-/// Unit tests for the subscriber's ACL client, which reads a zaak's reference (identificatie) through
-/// the ACL — the only code allowed to talk to ZGW (§8.1, #78). Uses a scripted message handler so no
-/// real ACL is required.
+/// Unit tests for the subscriber's ACL client, which reads a register record through the ACL — the
+/// only code allowed to talk to Objecten (§8.1, ADR-0028/ADR-0030). Uses a scripted message handler
+/// so no real ACL is required.
 /// </summary>
 public class AclHttpClientTests
 {
+    private const string ObjectUrl = "http://objecten.local:8000/api/v2/objects/obj-9";
+
     private static AclHttpClient Client(StubHandler handler) =>
         new(new HttpClient(handler) { BaseAddress = new Uri("http://acl/") });
 
     [Fact]
-    public async Task Reads_a_zaak_reference_by_posting_the_zaak_url_and_returns_it()
+    public async Task Reads_a_register_record_by_posting_the_object_url()
     {
         var capture = new RequestCapture();
-        var client = Client(capture.Responds(HttpStatusCode.OK, """{"reference":"REG-42"}"""));
+        var client = Client(capture.Responds(
+            HttpStatusCode.OK, """{"id":"zaak-1","status":"INGESCHREVEN","reference":"REG-42"}"""));
 
-        var reference = await client.GetZaakReferenceAsync(new Uri("http://openzaak/zaken/api/v1/zaken/abc"));
+        var record = await client.GetRegisterRecordAsync(new Uri(ObjectUrl));
 
-        Assert.Equal("REG-42", reference);
+        Assert.Equal("zaak-1", record!.Id);
+        Assert.Equal("INGESCHREVEN", record.Status);
+        Assert.Equal("REG-42", record.Reference);
         Assert.Equal(HttpMethod.Post, capture.Seen!.Method);
-        Assert.Equal("http://acl/zaken/reference", capture.Seen.RequestUri!.ToString());
-        Assert.Contains("\"zaakUrl\":\"http://openzaak/zaken/api/v1/zaken/abc\"", capture.Body);
+        Assert.Equal("http://acl/register-records/read", capture.Seen.RequestUri!.ToString());
+        Assert.Contains($"\"objectUrl\":\"{ObjectUrl}\"", capture.Body);
+    }
+
+    [Fact]
+    public async Task Reads_a_missing_record_as_nothing_to_project()
+    {
+        var capture = new RequestCapture();
+        var client = Client(capture.Responds(HttpStatusCode.NotFound));
+
+        // The object may be gone by the time a redelivered notification is handled (§8.6).
+        Assert.Null(await client.GetRegisterRecordAsync(new Uri(ObjectUrl)));
     }
 
     [Fact]
@@ -35,7 +50,7 @@ public class AclHttpClientTests
         var client = Client(capture.Responds(HttpStatusCode.BadGateway));
 
         await Assert.ThrowsAsync<HttpRequestException>(
-            () => client.GetZaakReferenceAsync(new Uri("http://openzaak/zaken/api/v1/zaken/abc")));
+            () => client.GetRegisterRecordAsync(new Uri(ObjectUrl)));
     }
 
     [Fact]
@@ -45,17 +60,17 @@ public class AclHttpClientTests
         var client = Client(capture.Responds(HttpStatusCode.OK, "null"));
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(
-            () => client.GetZaakReferenceAsync(new Uri("http://openzaak/zaken/api/v1/zaken/abc")));
+            () => client.GetRegisterRecordAsync(new Uri(ObjectUrl)));
         Assert.Contains("empty", ex.Message, StringComparison.OrdinalIgnoreCase);
     }
 
     [Fact]
-    public async Task Rejects_a_null_zaak_url_without_sending_a_request()
+    public async Task Rejects_a_null_object_url_without_sending_a_request()
     {
         var capture = new RequestCapture();
-        var client = Client(capture.Responds(HttpStatusCode.OK, """{"reference":"REG-1"}"""));
+        var client = Client(capture.Responds(HttpStatusCode.OK, "{}"));
 
-        await Assert.ThrowsAsync<ArgumentNullException>(() => client.GetZaakReferenceAsync(null!));
+        await Assert.ThrowsAsync<ArgumentNullException>(() => client.GetRegisterRecordAsync(null!));
         Assert.Null(capture.Seen);
     }
 }

services/event-subscriber/EventSubscriber.Tests/InMemoryStores.cs

@@ -5,16 +5,18 @@ namespace EventSubscriber.Tests;
 /// <summary>In-memory stand-ins for the projection store and notification log, so the
 /// projector's behaviour is exercised without Postgres (hand-written stubs, the repo's
 /// convention — no mocking library).</summary>
-/// <summary>A fake ACL client that returns a fixed reference derived from the zaak, and records
-/// how many times it was called (to prove a rebuild does not re-read via the ACL).</summary>
+/// <summary>A fake ACL client standing in for the register records Objecten holds: a test seeds a
+/// record per object URL, and the call count proves a rebuild does not re-read through the ACL.</summary>
 internal sealed class FakeAclClient : IAclClient
 {
+    public Dictionary<string, RegisterRecord> Records { get; } = [];
+
     public int CallCount { get; private set; }
 
-    public Task<string> GetZaakReferenceAsync(Uri zaakUrl, CancellationToken ct = default)
+    public Task<RegisterRecord?> GetRegisterRecordAsync(Uri objectUrl, CancellationToken ct = default)
     {
         CallCount++;
-        return Task.FromResult("REG-" + zaakUrl.Segments[^1].Trim('/'));
+        return Task.FromResult(Records.TryGetValue(objectUrl.ToString(), out var record) ? record : null);
     }
 }
 

services/event-subscriber/EventSubscriber.Tests/NotificationProjectorTests.cs

@@ -2,13 +2,14 @@ using EventSubscriber.Application;
 
 namespace EventSubscriber.Tests;
 
-/// <summary>Behaviour of the projector that turns NRC notifications into projection rows.
-/// The walking skeleton reacts only to a zaak being created (status INGEDIEND) and must
-/// tolerate duplicate and out-of-order deliveries (CLAUDE.md §8.6).</summary>
+/// <summary>Behaviour of the projector that turns NRC notifications into projection rows. Since
+/// S-19b-2 the source is the register in Objecten (ADR-0030), not ZGW zaak events: a notification
+/// carries only the object URL, so the record is read back through the ACL. Duplicate and
+/// out-of-order deliveries must be tolerated (CLAUDE.md §8.6).</summary>
 public sealed class NotificationProjectorTests
 {
-    private const string ZaakUrl = "http://openzaak:8000/zaken/api/v1/zaken/11111111-1111-1111-1111-111111111111";
-    private const string StatusUrl = "http://openzaak:8000/zaken/api/v1/statussen/22222222-2222-2222-2222-222222222222";
+    private const string ObjectUrl = "http://objecten.local:8000/api/v2/objects/11111111-1111-1111-1111-111111111111";
+    private const string ZaakId = "99999999-9999-9999-9999-999999999999";
 
     private readonly InMemoryNotificationLog _log = new();
     private readonly InMemoryProjectionStore _store = new();
@@ -16,46 +17,60 @@ public sealed class NotificationProjectorTests
 
     private NotificationProjector Projector() => new(_log, _store, _acl);
 
-    private static Notification ZaakCreated(string url = ZaakUrl)
-        => new("zaken", "zaak", "create", new Uri(url));
-
-    // A status-set notification: resourceUrl is the status resource, hoofdObject is the zaak it belongs to.
-    private static Notification StatusSet(string zaakUrl = ZaakUrl, string statusUrl = StatusUrl)
-        => new("zaken", "status", "create", new Uri(statusUrl), new Uri(zaakUrl));
-
-    [Fact]
-    public async Task creating_a_zaak_writes_one_row_with_status_ingediend()
+    /// <summary>A register write as Objecten publishes it: the object is both hoofdObject and
+    /// resourceUrl, and the record itself is only reachable by reading that object.</summary>
+    private Notification RecordWritten(string actie = "create", string url = ObjectUrl, string status = RegistrationStatus.Ingediend, string zaakId = ZaakId)
     {
-        await Projector().HandleAsync(ZaakCreated());
-
-        var entry = Assert.Single(await _store.AllAsync());
-        Assert.Equal("11111111-1111-1111-1111-111111111111", entry.Id);
-        Assert.Equal(RegistrationStatus.Ingediend, entry.Status);
-        // Enriched with the zaak's reference (identificatie), fetched via the ACL (#78).
-        Assert.Equal("REG-11111111-1111-1111-1111-111111111111", entry.Reference);
+        _acl.Records[url] = new RegisterRecord(zaakId, status, "REG-2026-0001");
+        return new Notification("objecten", "object", actie, new Uri(url));
     }
 
     [Fact]
-    public async Task rebuild_reproduces_the_reference_without_re_reading_via_the_acl()
+    public async Task a_register_record_write_is_projected_as_a_row_keyed_on_the_registration()
     {
-        var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        var callsAfterProjection = _acl.CallCount;
-
-        await projector.RebuildAsync();
+        await Projector().HandleAsync(RecordWritten());
 
         var entry = Assert.Single(await _store.AllAsync());
-        Assert.Equal("REG-11111111-1111-1111-1111-111111111111", entry.Reference);
-        // Rebuild replays the log (which stored the reference) — no extra ACL calls (#78, ADR-0008).
-        Assert.Equal(callsAfterProjection, _acl.CallCount);
+        // Keyed on the record's own id (the zaak id), not on the Objecten object's uuid — the
+        // projection row and the register record are the same registration.
+        Assert.Equal(ZaakId, entry.Id);
+        Assert.Equal(RegistrationStatus.Ingediend, entry.Status);
+        Assert.Equal("REG-2026-0001", entry.Reference);
+    }
+
+    // The ACL PATCHes the same object on approval. DRF routes a PATCH through `update()` but reports
+    // the action as `partial_update`, which is what Objecten puts in the notification — so accepting
+    // only `create`/`update` silently drops every approval.
+    [Theory]
+    [InlineData("partial_update")]
+    [InlineData("update")]
+    public async Task approval_updates_the_same_row_from_ingediend_to_ingeschreven(string actie)
+    {
+        var projector = Projector();
+        await projector.HandleAsync(RecordWritten());
+        await projector.HandleAsync(RecordWritten(actie, status: RegistrationStatus.Ingeschreven));
+
+        var entry = Assert.Single(await _store.AllAsync());
+        Assert.Equal(ZaakId, entry.Id);
+        Assert.Equal(RegistrationStatus.Ingeschreven, entry.Status);
+    }
+
+    [Fact]
+    public async Task an_object_whose_record_is_gone_is_not_projected()
+    {
+        // Nothing seeded in the fake ACL: the object was deleted before this (redelivered)
+        // notification was handled. Not an error — there is simply nothing to project (§8.6).
+        await Projector().HandleAsync(new Notification("objecten", "object", "create", new Uri(ObjectUrl)));
+
+        Assert.Empty(await _store.AllAsync());
     }
 
     [Fact]
     public async Task replaying_the_same_notification_keeps_a_single_row()
     {
         var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        await projector.HandleAsync(ZaakCreated());
+        await projector.HandleAsync(RecordWritten());
+        await projector.HandleAsync(RecordWritten());
 
         Assert.Single(await _store.AllAsync());
     }
@@ -64,8 +79,8 @@ public sealed class NotificationProjectorTests
     public async Task a_replayed_notification_never_reaches_the_projection_store()
     {
         var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        await projector.HandleAsync(ZaakCreated());
+        await projector.HandleAsync(RecordWritten());
+        await projector.HandleAsync(RecordWritten());
 
         // The duplicate is dropped at the log, before the (idempotent) upsert — so the store
         // is written exactly once. Row count alone can't see this; the upsert count can.
@@ -73,77 +88,59 @@ public sealed class NotificationProjectorTests
     }
 
     [Fact]
-    public async Task two_different_zaken_each_get_their_own_row()
+    public async Task two_different_registrations_each_get_their_own_row()
     {
         var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        await projector.HandleAsync(ZaakCreated(ZaakUrl[..^1] + "2")); // a distinct zaak url
+        await projector.HandleAsync(RecordWritten());
+        await projector.HandleAsync(RecordWritten(url: ObjectUrl[..^1] + "2", zaakId: "other-zaak"));
 
         Assert.Equal(2, (await _store.AllAsync()).Count);
     }
 
     [Theory]
-    [InlineData("documenten", "enkelvoudiginformatieobject", "create")] // wrong kanaal + resource
-    [InlineData("documenten", "zaak", "create")]                        // wrong kanaal only
-    [InlineData("zaken", "zaak", "update")]                             // wrong actie
-    [InlineData("zaken", "zaak", "destroy")]                            // wrong actie
-    [InlineData("zaken", "status", "update")]                           // a status change we ignore
-    [InlineData("zaken", "resultaat", "create")]                        // not a status we project
+    [InlineData("zaken", "zaak", "create")]      // the ZGW source S-19b-2 replaced
+    [InlineData("zaken", "status", "create")]    // ditto
+    [InlineData("objecten", "object", "destroy")] // a delete we do not project
+    [InlineData("documenten", "object", "create")] // wrong kanaal
     public async Task an_unrelated_notification_is_not_projected(string kanaal, string resource, string actie)
     {
-        await Projector().HandleAsync(new Notification(kanaal, resource, actie, new Uri(ZaakUrl)));
+        _acl.Records[ObjectUrl] = new RegisterRecord(ZaakId, RegistrationStatus.Ingediend, "REG-2026-0001");
+
+        await Projector().HandleAsync(new Notification(kanaal, resource, actie, new Uri(ObjectUrl)));
 
         Assert.Empty(await _store.AllAsync());
     }
 
     [Fact]
-    public async Task setting_a_status_projects_ingeschreven_keyed_on_the_zaak_not_the_status()
-    {
-        await Projector().HandleAsync(StatusSet());
-
-        var entry = Assert.Single(await _store.AllAsync());
-        // Keyed on the zaak (hoofdObject), not the status resource URL.
-        Assert.Equal("11111111-1111-1111-1111-111111111111", entry.Id);
-        Assert.Equal(RegistrationStatus.Ingeschreven, entry.Status);
-    }
-
-    [Fact]
-    public async Task approving_updates_the_existing_zaak_row_from_ingediend_to_ingeschreven()
+    public async Task rebuild_reproduces_the_row_without_re_reading_through_the_acl()
     {
         var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        await projector.HandleAsync(StatusSet());
-
-        var entry = Assert.Single(await _store.AllAsync());
-        Assert.Equal("11111111-1111-1111-1111-111111111111", entry.Id);
-        Assert.Equal(RegistrationStatus.Ingeschreven, entry.Status);
-    }
-
-    [Fact]
-    public async Task rebuild_reproduces_the_approved_status()
-    {
-        var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
-        await projector.HandleAsync(StatusSet());
+        await projector.HandleAsync(RecordWritten());
+        await projector.HandleAsync(RecordWritten("partial_update", status: RegistrationStatus.Ingeschreven));
+        var callsAfterProjection = _acl.CallCount;
 
         await projector.RebuildAsync();
 
         var entry = Assert.Single(await _store.AllAsync());
         Assert.Equal(RegistrationStatus.Ingeschreven, entry.Status);
+        Assert.Equal("REG-2026-0001", entry.Reference);
+        // The log holds the projected row itself, so a rebuild needs neither the ACL nor
+        // Objecten (§8.4, ADR-0030).
+        Assert.Equal(callsAfterProjection, _acl.CallCount);
     }
 
     [Fact]
     public async Task rebuild_clears_stale_rows_and_repopulates_from_the_notification_log()
     {
         var projector = Projector();
-        await projector.HandleAsync(ZaakCreated());
+        await projector.HandleAsync(RecordWritten());
         // A stale row that is not backed by any logged notification must not survive a rebuild.
         await _store.UpsertAsync(new RegisterEntry("stale-9999", RegistrationStatus.Ingediend));
 
         await projector.RebuildAsync();
 
         var entry = Assert.Single(await _store.AllAsync());
-        Assert.Equal("11111111-1111-1111-1111-111111111111", entry.Id);
+        Assert.Equal(ZaakId, entry.Id);
         Assert.Equal(RegistrationStatus.Ingediend, entry.Status);
     }
 }

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

@@ -13,9 +13,8 @@ public sealed class EfNotificationLog(ProjectionDbContext db) : INotificationLog
         db.ProcessedNotifications.Add(new ProcessedNotificationRow
         {
             Key = notification.Key,
-            Actie = notification.Actie,
-            ZaakId = notification.ZaakId,
-            Resource = notification.Resource,
+            RegisterId = notification.RegisterId,
+            Status = notification.Status,
             Reference = notification.Reference,
             ReceivedAt = DateTimeOffset.UtcNow,
         });
@@ -36,6 +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, r.Resource, r.Reference))
+            .Select(r => new RecordedNotification(r.Key, r.RegisterId, r.Status, r.Reference))
             .ToListAsync(ct);
 }

services/projection-api/Projection.ReadModel/Migrations/20260828103132_ProjectionSourcedFromObjecten.Designer.cs

@@ -0,0 +1,87 @@
+// <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("20260828103132_ProjectionSourcedFromObjecten")]
+    partial class ProjectionSourcedFromObjecten
+    {
+        /// <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<DateTimeOffset>("ReceivedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("received_at");
+
+                    b.Property<string>("Reference")
+                        .HasColumnType("text")
+                        .HasColumnName("reference");
+
+                    b.Property<string>("RegisterId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("register_id");
+
+                    b.Property<string>("Status")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("status");
+
+                    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>("Reference")
+                        .HasColumnType("text")
+                        .HasColumnName("reference");
+
+                    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/20260828103132_ProjectionSourcedFromObjecten.cs

@@ -0,0 +1,69 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Projection.ReadModel.Migrations
+{
+    /// <summary>
+    /// S-19b-2 (ADR-0030): the notification log stops describing ZGW zaak events and starts holding
+    /// the projected register row itself (register id, status, reference).
+    /// </summary>
+    /// <remarks>
+    /// The old columns are dropped and the new ones added rather than renamed. EF scaffolded renames
+    /// (<c>resource</c> → <c>register_id</c>, <c>zaak_id</c> → <c>status</c>), which would carry ZGW
+    /// values into columns that mean something else entirely — "zaak"/"status" as a register id, a
+    /// zaak uuid as a register status — and a rebuild would then project that garbage.
+    ///
+    /// Both tables are emptied instead. A pre-existing row describes a zaak event the new projector
+    /// cannot reproject, and the registrations behind those rows have no RegisterRecord in Objecten
+    /// (only approvals wrote one before this slice), so they are not re-derivable from the new source
+    /// either. The projection is a derived artefact (§8.4) and repopulates as register writes arrive.
+    /// </remarks>
+    public partial class ProjectionSourcedFromObjecten : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            // ponytail: drops the pre-slice register rather than backfilling it. Fine while stacks are
+            // ephemeral (a fresh `docker compose up` is the norm). If a long-lived environment ever
+            // needs to keep them, backfill by walking Objecten's objects instead of replaying the log.
+            migrationBuilder.Sql("DELETE FROM processed_notifications;");
+            migrationBuilder.Sql("DELETE FROM register_projection;");
+
+            migrationBuilder.DropColumn(name: "actie", table: "processed_notifications");
+            migrationBuilder.DropColumn(name: "zaak_id", table: "processed_notifications");
+            migrationBuilder.DropColumn(name: "resource", table: "processed_notifications");
+
+            migrationBuilder.AddColumn<string>(
+                name: "register_id",
+                table: "processed_notifications",
+                type: "text",
+                nullable: false,
+                defaultValue: "");
+
+            migrationBuilder.AddColumn<string>(
+                name: "status",
+                table: "processed_notifications",
+                type: "text",
+                nullable: false,
+                defaultValue: "");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.Sql("DELETE FROM processed_notifications;");
+            migrationBuilder.Sql("DELETE FROM register_projection;");
+
+            migrationBuilder.DropColumn(name: "register_id", table: "processed_notifications");
+            migrationBuilder.DropColumn(name: "status", table: "processed_notifications");
+
+            migrationBuilder.AddColumn<string>(
+                name: "actie", table: "processed_notifications", type: "text", nullable: false, defaultValue: "");
+            migrationBuilder.AddColumn<string>(
+                name: "zaak_id", table: "processed_notifications", type: "text", nullable: false, defaultValue: "");
+            migrationBuilder.AddColumn<string>(
+                name: "resource", table: "processed_notifications", type: "text", nullable: false, defaultValue: "");
+        }
+    }
+}

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

@@ -28,11 +28,6 @@ namespace Projection.ReadModel.Migrations
                         .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");
@@ -41,15 +36,15 @@ namespace Projection.ReadModel.Migrations
                         .HasColumnType("text")
                         .HasColumnName("reference");
 
-                    b.Property<string>("Resource")
+                    b.Property<string>("RegisterId")
                         .IsRequired()
                         .HasColumnType("text")
-                        .HasColumnName("resource");
+                        .HasColumnName("register_id");
 
-                    b.Property<string>("ZaakId")
+                    b.Property<string>("Status")
                         .IsRequired()
                         .HasColumnType("text")
-                        .HasColumnName("zaak_id");
+                        .HasColumnName("status");
 
                     b.HasKey("Key");
 

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

@@ -34,9 +34,8 @@ public sealed class ProjectionDbContext(DbContextOptions<ProjectionDbContext> op
             e.ToTable("processed_notifications");
             e.HasKey(r => r.Key);
             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.RegisterId).HasColumnName("register_id").IsRequired();
+            e.Property(r => r.Status).HasColumnName("status").IsRequired();
             e.Property(r => r.Reference).HasColumnName("reference");
             e.Property(r => r.ReceivedAt).HasColumnName("received_at");
         });
@@ -56,18 +55,20 @@ public sealed class RegisterEntryRow
     public string? NaamPlaceholder { get; set; }
 }
 
-/// <summary>An accepted notification, retained so the projection can be rebuilt without OpenZaak (§8.1).</summary>
+/// <summary>An accepted notification, retained so the projection can be rebuilt without reading
+/// Objecten or ZGW (§8.1, §8.4). Since S-19b-2 it holds the projected row itself — the register
+/// record's id, status and reference — so a rebuild is a replay with no mapping rules (ADR-0030).</summary>
 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; }
+    /// <summary>The registration this record is for (the zaak id) — the projection row's key.</summary>
+    public required string RegisterId { get; set; }
 
-    /// <summary>The zaak reference (identificatie), retained so a rebuild reprojects it without the ACL (#78).</summary>
+    /// <summary>The register status the record carried (INGEDIEND / INGESCHREVEN).</summary>
+    public required string Status { get; set; }
+
+    /// <summary>The citizen-facing reference the record carried — matches the submit confirmation (#78).</summary>
     public string? Reference { get; set; }
 
     public DateTimeOffset ReceivedAt { get; set; }

tests/acceptance/Features/RegisterProjectieBijwerken.feature

@@ -1,19 +1,28 @@
 # language: en
-# Drives S-06 (#7). On a zaak-created notification from NRC the Event Subscriber writes a
-# rebuildable read-projection row (PRD §8.4). This scenario exercises the use case against an
-# in-memory stand-in for the projection store and notification log; real OpenZaak → NRC →
-# subscriber delivery is verified by the live-stack check (verify-projection, ADR-0007/#58).
-Feature: Register-projectie bijwerken op een zaaknotificatie
-  Als openbaar register wil ik dat een aangemaakte zaak in de projectie verschijnt
-  zodat het register de ingediende registratie kan tonen.
+# Drives S-19b-2 (#153), re-sourcing S-06 (#7). The read projection is derived from the
+# RegisterRecord in Objecten (ADR-0030), not from ZGW zaak events: the ACL records a registration
+# in the register, Objecten notifies, and the Event Subscriber projects the record that
+# notification points at. This scenario exercises the use case against in-memory stand-ins for the
+# register, the projection store and the notification log; real Objecten → NRC → subscriber
+# delivery is verified by the live-stack check (verify-projection, ADR-0007/0030).
+Feature: Register-projectie bijwerken op een registerwijziging
+  Als openbaar register wil ik dat een registratie in de projectie verschijnt zodra zij
+  in het register is vastgelegd, zodat het register haar actuele status kan tonen.
 
-  Scenario: Een zaaknotificatie levert een rij met status INGEDIEND
-    Given a zaak is created in OpenZaak with id "11111111-1111-1111-1111-111111111111"
-    When the NRC notification for that zaak is delivered to the event subscriber
+  Scenario: Een ingediende registratie levert een rij met status INGEDIEND
+    Given registration "11111111-1111-1111-1111-111111111111" is recorded in the register with status "INGEDIEND"
+    When the register notification is delivered to the event subscriber
     Then the register projection contains a row for "11111111-1111-1111-1111-111111111111" with status "INGEDIEND"
 
+  Scenario: Een goedgekeurde registratie werkt dezelfde rij bij
+    Given registration "33333333-3333-3333-3333-333333333333" is recorded in the register with status "INGEDIEND"
+    And the register notification is delivered to the event subscriber
+    When registration "33333333-3333-3333-3333-333333333333" is recorded in the register with status "INGESCHREVEN"
+    And the register notification is delivered to the event subscriber
+    Then the register projection contains a row for "33333333-3333-3333-3333-333333333333" with status "INGESCHREVEN"
+
   Scenario: Dezelfde notificatie tweemaal levert geen duplicaat
-    Given a zaak is created in OpenZaak with id "22222222-2222-2222-2222-222222222222"
-    When the NRC notification for that zaak is delivered to the event subscriber
-    And the same NRC notification is delivered again
+    Given registration "22222222-2222-2222-2222-222222222222" is recorded in the register with status "INGEDIEND"
+    When the register notification is delivered to the event subscriber
+    And the same register notification is delivered again
     Then the register projection contains exactly one row for "22222222-2222-2222-2222-222222222222"

tests/acceptance/Steps/RegisterProjectieBijwerkenSteps.cs

@@ -5,31 +5,39 @@ using Xunit;
 
 namespace Acceptance.Steps;
 
-/// <summary>Bindings for <c>RegisterProjectieBijwerken.feature</c> (S-06). Reqnroll creates
-/// one instance per scenario, so instance fields hold scenario-scoped state.</summary>
+/// <summary>Bindings for <c>RegisterProjectieBijwerken.feature</c> (S-06, re-sourced by S-19b-2).
+/// Reqnroll creates one instance per scenario, so instance fields hold scenario-scoped state.</summary>
 [Binding]
 public sealed class RegisterProjectieBijwerkenSteps
 {
-    private const string ZaakBase = "http://openzaak:8000/zaken/api/v1/zaken/";
+    private const string ObjectBase = "http://objecten.local:8000/api/v2/objects/";
 
     private readonly InMemoryNotificationLog _log = new();
     private readonly InMemoryProjectionStore _store = new();
+    private readonly InMemoryRegisterRecordClient _register = new();
     private readonly NotificationProjector _projector;
     private Notification? _notification;
 
     public RegisterProjectieBijwerkenSteps()
-        => _projector = new NotificationProjector(_log, _store, new InMemoryAclReferenceClient());
+        => _projector = new NotificationProjector(_log, _store, _register);
 
-    [Given("a zaak is created in OpenZaak with id \"(.*)\"")]
-    public void GivenAZaakIsCreatedInOpenZaakWithId(string id)
-        => _notification = new Notification("zaken", "zaak", "create", new Uri(ZaakBase + id));
+    [Given("registration \"(.*)\" is recorded in the register with status \"(.*)\"")]
+    [When("registration \"(.*)\" is recorded in the register with status \"(.*)\"")]
+    public void RegistrationIsRecorded(string id, string status)
+    {
+        // The ACL upserts one object per registration, so submit and approval share an object URL.
+        var objectUrl = ObjectBase + id;
+        _register.Records[objectUrl] = new RegisterRecord(id, status, "REG-" + id);
+        _notification = new Notification("objecten", "object", "create", new Uri(objectUrl));
+    }
 
-    [When("the NRC notification for that zaak is delivered to the event subscriber")]
-    public Task WhenTheNotificationIsDelivered()
+    [Given("the register notification is delivered to the event subscriber")]
+    [When("the register notification is delivered to the event subscriber")]
+    public Task TheNotificationIsDelivered()
         => _projector.HandleAsync(_notification!);
 
-    [When("the same NRC notification is delivered again")]
-    public Task WhenTheSameNotificationIsDeliveredAgain()
+    [When("the same register notification is delivered again")]
+    public Task TheSameNotificationIsDeliveredAgain()
         => _projector.HandleAsync(_notification!);
 
     [Then("the register projection contains a row for \"(.*)\" with status \"(.*)\"")]

tests/acceptance/Support/InMemoryProjectionStores.cs

@@ -39,10 +39,12 @@ public sealed class InMemoryProjectionStore : IProjectionStore
         => [.. _byId.Values.Where(e => e.Id == id)];
 }
 
-/// <summary>A fake ACL client for the projection acceptance scenario: returns a reference derived
-/// from the zaak, so the projector can enrich rows without a running ACL (#78).</summary>
-public sealed class InMemoryAclReferenceClient : IAclClient
+/// <summary>An in-memory stand-in for the register the ACL reads back for the projector, so the
+/// scenario runs without a running ACL or Objecten (S-19b-2, ADR-0030).</summary>
+public sealed class InMemoryRegisterRecordClient : IAclClient
 {
-    public Task<string> GetZaakReferenceAsync(Uri zaakUrl, CancellationToken ct = default)
-        => Task.FromResult("REG-" + zaakUrl.Segments[^1].Trim('/'));
+    public Dictionary<string, RegisterRecord> Records { get; } = [];
+
+    public Task<RegisterRecord?> GetRegisterRecordAsync(Uri objectUrl, CancellationToken ct = default)
+        => Task.FromResult(Records.TryGetValue(objectUrl.ToString(), out var record) ? record : null);
 }

tests/acceptance/Support/InMemoryZaakGateway.cs

@@ -65,4 +65,8 @@ public sealed class InMemoryRegisterRecordGateway : IRegisterRecordGateway
         Upserted.Add(record);
         return Task.CompletedTask;
     }
+
+    /// <summary>The most recently written record — scenarios never read one back by object URL.</summary>
+    public Task<RegisterRecord?> GetAsync(Uri objectUrl, CancellationToken ct = default)
+        => Task.FromResult(Upserted.Count == 0 ? null : Upserted[^1]);
 }

tests/e2e/catalogus.spec.ts

@@ -1,4 +1,5 @@
 import { expect, test } from '@playwright/test';
+import { loginMedewerker } from './medewerker-login';
 
 // S-15a walking skeleton: a beheerder logs in to the beheer portal (medewerker realm) and sees the
 // read-only ZTC catalogus. The verify stack seeds and publishes the BIG-REGISTRATIE zaaktype (the
@@ -7,10 +8,9 @@ import { expect, test } from '@playwright/test';
 test('a beheerder sees the published zaaktypen in the catalogus', async ({ page }) => {
   await page.goto('http://beheer/');
 
-  // The beheer portal redirects to the Keycloak medewerker realm login (same realm as behandel).
-  await page.locator('#username').fill('bram-beheerder');
-  await page.locator('#password').fill('test123');
-  await page.locator('#kc-login').click();
+  // The beheer portal redirects to the Keycloak medewerker realm login (same realm as behandel),
+  // which enforces MFA: password, then a TOTP code.
+  await loginMedewerker(page, 'bram-beheerder');
 
   await expect(page.getByRole('heading', { name: /Catalogus/i })).toBeVisible();
 

tests/e2e/default-fill.spec.ts

@@ -1,4 +1,5 @@
 import { expect, test } from '@playwright/test';
+import { loginMedewerker } from './medewerker-login';
 
 // S-15b: a beheerder edits the ACL default-fill in the beheer portal and gets a saved confirmation.
 // Runs against the shared verify stack; it edits + saves (the ACL store is in-memory, ADR-0026) and
@@ -6,10 +7,8 @@ import { expect, test } from '@playwright/test';
 test('a beheerder edits and saves the default-fill', async ({ page }) => {
   await page.goto('http://beheer/');
 
-  // Keycloak medewerker-realm login (same realm as behandel).
-  await page.locator('#username').fill('bram-beheerder');
-  await page.locator('#password').fill('test123');
-  await page.locator('#kc-login').click();
+  // Keycloak medewerker-realm login (same realm as behandel) — password + enforced TOTP.
+  await loginMedewerker(page, 'bram-beheerder');
 
   await expect(page.getByRole('heading', { name: /Catalogus/i })).toBeVisible();
 

tests/e2e/medewerker-login.spec.ts

@@ -0,0 +1,14 @@
+import { expect, test } from '@playwright/test';
+import { OTP_PERIOD_MS, nextUnusedCounter } from './medewerker-login';
+
+// Pure check of the TOTP counter guard in loginMedewerker — no browser, no stack. Keycloak refuses
+// a code it has already accepted (its otpPolicyCodeReusable defaults to false), so two logins as
+// the same medewerker inside one 30-second window must not spend the same counter twice (#132).
+test('a login never spends a TOTP counter this medewerker already used', () => {
+  const now = 3 * OTP_PERIOD_MS + 1_000; // 1 second into counter 3
+
+  expect(nextUnusedCounter(now, -1)).toBe(3); // nothing spent yet → the current counter
+  expect(nextUnusedCounter(now, 3)).toBe(4); // the current counter is spent → the next one
+  expect(nextUnusedCounter(now, 4)).toBe(5); // two logins already in this window → the one after
+  expect(nextUnusedCounter(now + OTP_PERIOD_MS, 3)).toBe(4); // window moved on → current again
+});

tests/e2e/medewerker-login.ts

@@ -0,0 +1,57 @@
+import { createHmac } from 'node:crypto';
+import { readFileSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import type { Page } from '@playwright/test';
+
+// The medewerker realm enforces MFA (S-15c), so a staff login is two steps: password, then a TOTP
+// code. The realm export seeds every medewerker with this fixture secret — Keycloak HMACs the raw
+// secret bytes — so the e2e can compute a valid code instead of enrolling an authenticator.
+const OTP_SECRET = 'BIGMEDEWERKEROTPSEED';
+
+export const OTP_PERIOD_MS = 30_000;
+
+// RFC 6238 TOTP: HMAC-SHA1 over the 30-second counter, dynamically truncated to 6 digits.
+export function totp(secret = OTP_SECRET, at = Date.now()): string {
+  const counter = Buffer.alloc(8);
+  counter.writeBigUInt64BE(BigInt(Math.floor(at / OTP_PERIOD_MS)));
+  const mac = createHmac('sha1', secret).update(counter).digest();
+  const offset = mac[mac.length - 1] & 0x0f;
+  return String((mac.readUInt32BE(offset) & 0x7fffffff) % 1_000_000).padStart(6, '0');
+}
+
+// Keycloak refuses a TOTP code it has already accepted (its otpPolicyCodeReusable defaults to
+// false), so two logins as the same medewerker inside one 30-second window would both submit the
+// same code and the second is rejected. Spend the first counter this medewerker has left.
+export function nextUnusedCounter(now: number, spent: number): number {
+  return Math.max(Math.floor(now / OTP_PERIOD_MS), spent + 1);
+}
+
+// The spent counter lives on disk rather than in module state: Playwright starts a fresh worker
+// process for a retry, which would otherwise forget it and resubmit the rejected code.
+function spendCounter(username: string): number {
+  const file = join(tmpdir(), `otp-counter-${username}`);
+  let spent = -1;
+  try {
+    spent = Number(readFileSync(file, 'utf8')) || -1;
+  } catch {
+    // first login as this medewerker in this run
+  }
+  const counter = nextUnusedCounter(Date.now(), spent);
+  writeFileSync(file, String(counter));
+  return counter;
+}
+
+export async function loginMedewerker(page: Page, username: string): Promise<void> {
+  await page.locator('#username').fill(username);
+  await page.locator('#password').fill('test123');
+  await page.locator('#kc-login').click();
+
+  // Keycloak's conditional-OTP step. Wait out the rest of the window if the counter we may spend is
+  // still in the future; its lookAheadWindow would accept the code a moment early, but only by one
+  // counter — waiting keeps a third login in the same window valid too.
+  const counter = spendCounter(username);
+  await page.waitForTimeout(Math.max(0, counter * OTP_PERIOD_MS - Date.now()));
+  await page.locator('#otp').fill(totp(OTP_SECRET, counter * OTP_PERIOD_MS));
+  await page.locator('#kc-login').click();
+}

tests/e2e/registration.spec.ts

@@ -1,11 +1,17 @@
 import { expect, request, test } from '@playwright/test';
+import { loginMedewerker } from './medewerker-login';
 
-// Walking-skeleton happy path (S-08d + S-09 + S-09b + S-12 + S-10a): a zorgprofessional logs in via
-// mock DigiD and submits through the self-service portal → BFF → domain; the entry appears in the
-// openbaar register as INGEDIEND; the citizen supplies the documents the process is waiting for
-// (S-10a); a behandelaar then logs in to the behandel portal, finds the registration in the werkbak,
-// and approves it (goedkeuren); the decision completes the Flowable Beoordelen task and flows via the
-// ACL → NRC → event-subscriber → projection, and the openbaar register shows INGESCHREVEN.
+// Walking-skeleton happy path (S-08d + S-09 + S-09b + S-12 + S-10a + S-19b-2): a zorgprofessional
+// logs in via mock DigiD and submits through the self-service portal → BFF → domain; the entry
+// appears in the openbaar register as INGEDIEND; the citizen supplies the documents the process is
+// waiting for (S-10a); a behandelaar then logs in to the behandel portal, finds the registration in
+// the werkbak, and approves it (goedkeuren); the decision completes the Flowable Beoordelen task and
+// flows via the ACL → Objecten → NRC → event-subscriber → projection, and the openbaar register
+// shows INGESCHREVEN.
+//
+// Since ADR-0030 both public statuses come from the register in Objecten, not from ZGW zaak events:
+// the ACL writes the record on submit (INGEDIEND) and upserts it on approval (INGESCHREVEN), so the
+// INGEDIEND assertion below is itself proof of the re-sourced path.
 test('DigiD submit → public INGEDIEND → documenten → behandelaar goedkeurt → public INGESCHREVEN', async ({
   page,
   context,
@@ -53,12 +59,32 @@ test('DigiD submit → public INGEDIEND → documenten → behandelaar goedkeurt
   await expect(staff.getByRole('row', { name: reference }).getByRole('cell', { name: 'INGEDIEND' }))
     .toBeVisible();
 
+  // A behandelaar opens the behandel-portal werkbak and approves the registration (goedkeuren) — the
+  // S-12 flow that replaces the temporary admin endpoint. The staff tab switches to the medewerker
+  // realm (a different Keycloak realm than the citizen's digid session).
+  //
+  // The werkbak is opened BEFORE the citizen supplies the documents that route the registration to
+  // Beoordelen, so its row cannot be there at page load: the only thing that can deliver it to this
+  // already-open page is the werkbak refreshing itself (S-26/#162, ADR-0032). This spec used to
+  // `staff.reload()` in a poll loop here; the absence of that reload is the live-refresh assertion.
+  await staff.goto('http://behandel/');
+  // That realm enforces MFA (S-15c), so the behandelaar logs in with password + TOTP.
+  await loginMedewerker(staff, 'merel-behandelaar');
+
+  await expect(staff.getByRole('heading', { name: /Werkbak/i })).toBeVisible();
+
+  // Target the decide button by reference (not a generic "Goedkeuren"): the shared verify stack holds
+  // other open tasks, so a positional match could act on someone else's registration.
+  const goedkeuren = staff.getByRole('button', { name: `Goedkeuren ${reference}` });
+  await expect(goedkeuren, 'the registration is not awaiting beoordeling yet').toBeHidden();
+
   // Provide the documents the registration is waiting for (S-10a), on the still-open self-service tab.
   // The process parks at WachtOpDocumenten only after the zaak is opened; the INGEDIEND row above proves
   // the zaak exists — so the OpenZaak worker has completed and the process is now at the wait — which is
   // why we supply the documents here rather than right after submit, when the trigger would race the
   // wait and no-op. (S-10b turns this into a real file upload; here it is the trigger that unblocks
   // beoordeling.)
+  await page.bringToFront();
   await page.setInputFiles('#diploma', {
     name: 'diploma.pdf',
     mimeType: 'application/pdf',
@@ -67,27 +93,11 @@ test('DigiD submit → public INGEDIEND → documenten → behandelaar goedkeurt
   await page.getByRole('button', { name: /documenten aanleveren/i }).click();
   await expect(page.getByText(/documenten zijn aangeleverd/i)).toBeVisible();
 
-  // A behandelaar picks the registration up in the behandel-portal werkbak and approves it (goedkeuren)
-  // — the S-12 flow that replaces the temporary admin endpoint. The staff tab switches to the
-  // medewerker realm (a different Keycloak realm than the citizen's digid session).
-  await staff.goto('http://behandel/');
-  await staff.locator('#username').fill('merel-behandelaar');
-  await staff.locator('#password').fill('test123');
-  await staff.locator('#kc-login').click();
-
-  await expect(staff.getByRole('heading', { name: /Werkbak/i })).toBeVisible();
-
-  // The registration reaches the Beoordelen user task only after its documents are provided (above), so
-  // it appears in the werkbak asynchronously — reload until this reference's row shows up. Target the
-  // decide button by reference (not a generic "Goedkeuren"): the shared verify stack holds other open
-  // tasks, so a positional match could act on someone else's registration.
-  const goedkeuren = staff.getByRole('button', { name: `Goedkeuren ${reference}` });
-  await expect
-    .poll(async () => {
-      await staff.reload();
-      return goedkeuren.count();
-    }, { timeout: 30_000, intervals: [1_000, 2_000, 3_000, 5_000] })
-    .toBeGreaterThan(0);
+  // Back to the werkbak — untouched since login, never reloaded. The row arrives on its own once the
+  // DMN routes the registration to Beoordelen. (Foregrounded so Chromium doesn't throttle the page's
+  // refresh timer as a hidden tab.)
+  await staff.bringToFront();
+  await expect(goedkeuren).toBeVisible({ timeout: 30_000 });
 
   // Click and wait for the decide POST to finish (204) BEFORE leaving the page. `click()` only
   // dispatches the request; navigating away immediately cancels it in flight (nginx logs a 499) and