diff --git a/docs/project/backlog/README.md b/docs/project/backlog/README.md
index e72f6c8..883ff30 100644
--- a/docs/project/backlog/README.md
+++ b/docs/project/backlog/README.md
@@ -73,6 +73,7 @@ for its existing violations, so every WP ends green.
 | [WP-26](WP-26-org-template-editor.md)   | Admin org-template editor                                    | 6 · Brief v2                | done   |
 | [WP-27](WP-27-brief-ux-layer.md)        | Brief UX layer (undo/redo, standaardbrief, diff)             | 6 · Brief v2                | todo   |
 | [WP-28](WP-28-brief-v2-demo-polish.md)  | Brief v2 demo polish (scenarios, e2e, docs)                  | 6 · Brief v2                | todo   |
+| [WP-29](WP-29-stamdata-beheer-editor.md) | Stamdata beheer editor (low-code, PR-emitting)             | follow-on · ADR-0004        | done   |
 
 Sequencing dependencies (stated in the WPs too): 01 before 10–15 (axe covers story churn);
 03/04 before 05–09 (boundaries stop new violations during refactors); 06 before 07 (typed
diff --git a/docs/project/backlog/WP-29-stamdata-beheer-editor.md b/docs/project/backlog/WP-29-stamdata-beheer-editor.md
new file mode 100644
index 0000000..fc204d9
--- /dev/null
+++ b/docs/project/backlog/WP-29-stamdata-beheer-editor.md
@@ -0,0 +1,80 @@
+# WP-29 — Stamdata beheer editor (low-code, PR-emitting)
+
+Status: done (0e77faf)
+Phase: follow-on — ADR-0004 realization (not part of the 2026-07-02 showcase audit)
+
+## Why
+
+ADR-0004 (stamdata-as-code) named a **future low-code editor that commits a PR** as its
+mitigation for "a non-developer may need dev assistance to edit C#", and floated a
+**data-file format** as the alternative to typed-C# constants when hand-editing ergonomics
+outweigh maximal compile-time safety. This WP realizes both: an admin-only maintenance editor
+that reads the stamdata catalog, edits rows in a grid, and produces the edited JSON data-file
+the admin drops into the repo — the existing CI build + `StamdataValidationTests` stay the
+authority. No production database, no runtime write path (ADR-0004 unchanged).
+
+## Read first
+
+- ADR-0004 (`docs/reference/architecture/0004-stamdata-as-code.md`) — the model this obeys.
+- ADR-0001 (BFF-lite + decision DTOs) — the endpoints are screen-shaped, admin-gated reads.
+- `src/app/brief/**` (WP-23/26) — the org-template admin editor is the closest prior art
+  (root store + machine + capability guard + admin role).
+
+## Decisions (pre-made, don't relitigate)
+
+- **Read-only endpoints only.** `GET /stamdata` (catalog) and `GET /stamdata/{table}?peildatum=`
+  (schema + rows). No POST/PUT/DELETE — the edit lands as a reviewed PR, not a write. The
+  `stamdata:edit` capability / `CanEditStamdata` gate the *reads* (naming is the enforce-twin
+  of a future edit capability; deliberate).
+- **Generic, schema-driven.** One endpoint pair + one grid editor serve every table. Columns
+  are reflected from the typed record (`StamdataTable.Of<T>`); the FE renders inputs by column
+  type (`date`/`number`/`enum`/`text`). A new table is one line in `StamdataCatalog` — no new
+  endpoint, UI, or test. (Catalog of one today; this is the shape ADR-0004 prescribed.)
+- **Data-file format for `professions`.** `professions.json` (embedded resource) replaces the
+  hardcoded C# dictionary, deserialized into `ProfessionMapping`. This trades compile-time
+  *value* checking (gate #1) for editor ergonomics — the value gate becomes
+  `StamdataValidationTests` (gate #2), exactly the trade-off ADR-0004's consequences listed.
+- **Valid-time.** `geldigVan`/`geldigTot` (half-open `[van, tot)`); a table is temporal iff it
+  has both columns. `peildatum` previews "which rows applied on date X". `Professions.ByProgram`
+  preserves pre-valid-time behaviour by filtering to rows active today.
+- **Apply path = download → PR.** The editor's `download()` serializes the draft to
+  `{table}.json`; the admin commits it. `mutation-command` is intentionally not used.
+- Admin-only, resource-independent authz — same shape as org-template management (role IS the
+  decision), denials audited (no PII).
+
+## Files
+
+- Backend: `backend/src/BigRegister.Api/Stamdata/{StamdataCatalog,StamdataTable,StamdataFile,ProfessionMapping}.cs` (new), `Professions.cs` (now loads the data-file), `professions.json` (new), `BigRegister.Api.csproj` (embed `Stamdata\*.json`); `Program.cs` (two GET endpoints + `StamdataAdmin` gate), `Contracts/Dtos.cs` (3 DTOs), `Domain/Authorization/Authz.cs` (`stamdata:edit` + `CanEditStamdata`); tests `StamdataEndpointTests.cs` (new), `StamdataValidationTests.cs` (generic `Every_catalog_table_is_valid`).
+- Frontend: `src/app/beheer/**` (contracts / domain + specs / infrastructure + spec / application / ui + organism story); `app.routes.ts` (guarded lazy route), `shared/domain/capability.ts` + `shared/infrastructure/me.adapter.ts` (`stamdata:edit`), `eslint.config.mjs` (`beheer` boundary rules), `tsconfig.json` (`@beheer/*` alias); regenerated `backend/swagger.json` + `src/app/shared/infrastructure/api-client.ts`.
+
+## Acceptance criteria
+
+- [x] `GET /stamdata` and `GET /stamdata/{table}` return admin-only (403 + audit otherwise).
+- [x] `professions` served from `professions.json`; `ProfessionMapping` typed; behaviour of
+      `Professions.ByProgram` unchanged for all-current rows.
+- [x] Generic build gate: `Every_catalog_table_is_valid` covers every catalog table (keys
+      non-blank, no overlapping validity, well-formed windows).
+- [x] `beheer/stamdata` route capability-guarded; page shows denial for non-admin; grid
+      renders from reflected schema; edits update dirty/change-count; `download()` yields a
+      valid `{table}.json`; `peildatum` before 2000-01-01 → zero rows.
+- [x] Full gate GREEN both sides; `npm run gen:api` leaves no drift; new stamdata story passes axe.
+
+## Verification
+
+`cd backend && dotnet test && dotnet format --verify-no-changes`; `npm run lint && npm run
+check:tokens && npm test && npm run build && npm run build-storybook && npm run test-storybook:ci`;
+`npm run gen:api && git diff --exit-code -- backend/swagger.json src/app/shared/infrastructure/api-client.ts`.
+Live: `/beheer/stamdata?role=admin` renders + edits + downloads; without `?role=admin` denies.
+
+## Out of scope
+
+- Runtime persistence of edits (would contradict ADR-0004) — the download-to-PR path is the design.
+- Migrating `PolicyQuestions` / document-categories into the catalog (each is a later one-liner).
+- A write-back "commit a PR on the admin's behalf" integration (the `download()` seam is where it slots in).
+
+## Risks
+
+- Data-file weakens compile-time value safety for `professions` — mitigated by
+  `StamdataValidationTests` running in CI (a bad value fails the build, never prod).
+- Generic reflection assumes the record's first property is the key and camelCase JSON names —
+  documented conventions in `StamdataTable`; covered by the endpoint schema test.
diff --git a/docs/reference/architecture/0004-stamdata-as-code.md b/docs/reference/architecture/0004-stamdata-as-code.md
index 7dde07c..f432799 100644
--- a/docs/reference/architecture/0004-stamdata-as-code.md
+++ b/docs/reference/architecture/0004-stamdata-as-code.md
@@ -35,10 +35,17 @@ production database, never runtime-editable.
 
 1. **One home, typed.** Business-editable reference data lives in the
    `BigRegister.Stamdata` namespace (`backend/src/BigRegister.Api/Stamdata/`), one file per
-   concern, as plain typed C# data (records / dictionaries). Separate the **data** (what the
-   business tunes) from the **rules** (dev-owned logic that consumes it): the profession
-   *table* is `Stamdata.Professions`; the *rule* "an English diploma needs a B2 question"
-   stays in `DiplomaRules`.
+   concern. A table lives **either** as plain typed C# data (records / dictionaries) **or** as
+   a typed JSON data-file deserialized into a record (`professions.json` → `ProfessionMapping`,
+   loaded via `StamdataFile`). Both are checked-in config-as-code, gated the same way; the
+   data-file trades the compiler's *value* check (gate #1 sees only the shape, not a wrong
+   `beroep`) for hand-editing ergonomics and the low-code editor below — the value gate becomes
+   `StamdataValidationTests`. Separate the **data** (what the business tunes) from the **rules**
+   (dev-owned logic that consumes it): the profession *table* is `Stamdata.Professions`; the
+   *rule* "an English diploma needs a B2 question" stays in `DiplomaRules`. Tables may carry
+   **valid-time** (`geldigVan`/`geldigTot`, half-open `[van, tot)`); `StamdataCatalog` +
+   `StamdataTable.Of<T>` describe every table generically (columns reflected from the record)
+   so one endpoint pair and one grid editor serve all of them.
 2. **Served unchanged.** The existing BFF-lite endpoints keep serving this data
    (`/duo/diplomas`, `/intake/policy`, `/uploads/categories`, …). No frontend change — the
    FE still renders decisions.
@@ -54,7 +61,7 @@ production database, never runtime-editable.
 
 | Kind | Home | Gate |
 | --- | --- | --- |
-| Reference tables + tunable numbers (professions↔diplomas, thresholds, policy questions, document categories) | `Stamdata/` typed C# | compiler + `StamdataValidationTests` |
+| Reference tables + tunable numbers (professions↔diplomas, thresholds, policy questions, document categories) | `Stamdata/` typed C# **or** typed JSON data-file (`professions.json`), optionally valid-timed | compiler (shape; + values when C#) + `StamdataValidationTests` (values, references, validity windows) |
 | User-facing UI copy | `$localize` → `src/locale/*.xlf` | build (`i18nMissingTranslation: error`) |
 | Letter / brief passage content | config-as-code in the backend (seed content), **not** the DB | compiler + endpoint tests |
 
@@ -80,3 +87,9 @@ everyone. Stamdata (the rules and reference tables the whole register runs on) s
   which now consumes both (behaviour unchanged), guarded by `StamdataValidationTests`.
   Document-category definitions follow the same pattern as the obvious next step; not moved
   yet.
+- **Shipped as a follow-on (WP-29):** the "future low-code editor" and "data-file format" this
+  ADR floated are now real. `professions` moved to `professions.json` (typed, valid-timed) and
+  the generic `StamdataCatalog`/`StamdataTable`/`StamdataFile` model plus read-only, admin-gated
+  `GET /stamdata` endpoints back an Angular `beheer/stamdata` editor. It is **not** a runtime
+  write path: the admin edits a grid and downloads the edited JSON to commit as a reviewed PR —
+  the compile/validation gate stays the authority, so this ADR's core decision is unchanged.