23-P3D4C2U — Table Module Read-Only Exposure Design Note

Date: 2026-05-08 Status: DESIGN (read-only inventory + design proposal). No implementation. Scope: Expose universal event core (event_outbox + read-state) through the existing Table Module / DirectusTable shelf — without a bespoke notification UI. Result: VIABLE via PG_VIEW_PROJECTION + table_registry row + DOT-driven Directus permission seed. Nuxt path = NO_NUXT_CODE.

1. Anchor: the Assembly path

Canonical pipeline (Điều 7 / Assembly Module SSOT / Table Module SSOT v4.1):

PG schema (or PG view)
  → Directus collection / metadata / permissions
    → table_registry row (id, table_id, collection, fields, sort, filter, page_url, flags)
      → DirectusTable.vue runtime (GET table_registry → GET items)
        → existing Nuxt route /knowledge/registries/{singular}

Hard rule (Table Module SSOT v4.1):

"Mỗi bảng trong UI = 1 record trong table_registry (Directus). Không có record = bảng đó KHÔNG ĐƯỢC PHÉP TỒN TẠI."

This pack must add ONE row, not a new shelf.

2. Live inventory (verified 2026-05-08)

2.1 table_registry — 20 active rows, generic-route convention works

Verified via Directus GET /items/table_registry:

Signal	Evidence
Total rows	20 (ids 1..20)
Generic route convention	`/knowledge/registries/{singular}` — used by 13/20 rows incl. system_issues, agent, dot_tool, module, page, collection, checkpoint_*, table
`tbl_system_issues` precedent	✅ id=20, collection=`system_issues`, page_url=`/knowledge/registries/system_issue`, default_sort=`-detected_at`, status=published, rows_per_page=50, enable_search=true
Field-config shape	`fields: [{key,label,sortable?,filterable?,filterOptions?}...]`; settings: `default_sort`, `default_filter` (Directus filter object), `rows_per_page`, `enable_search`, `enable_pagination`, `enable_insert_marks`, `enable_proposals`, `module`, `status`
Module status (registry SSOT)	`tbl_system_issues` published — proves shelf accepts an event-domain, append-only, timeseries-style table

2.2 Directus collection visibility

directus_list_collections returns event_* tables already auto-discovered as whitelisted Directus collections:

event_outbox
event_pending
event_read
event_subscription
event_type_registry

Read attempt (GET /items/event_outbox) → HTTP 403 for the admin token currently in use. Interpretation: the collections are introspected but no read role/permission is seeded yet. This is the gap P3D4C2U must close via DOT, not by click-config.

2.3 PG event core — live deviations to preserve

From P3D4C1U report (PASS, deviations carried forward):

event_subject_ref      = text          (D1; system_issues.id is integer)
read_status_source IN  ('explicit','implicit_self')   (D2)
event_pending          = empty          (immediate-only PoC, seam preserved)
worker_created         = false
pg_cron_used           = false
fn_event_unread        EXISTS
fn_event_mark_read     EXISTS
fn_event_board         NOT created

Functions are NOT in scope for Table Module rendering (function-backed display = FUNCTION_BACKED_NOT_ALLOWED_NOW). DirectusTable consumes a collection or view, not a function.

2.4 No projection view exists yet

KB search (v_event_outbox*, v_event_*) returned only design sketches (P3D4B v_iu_notification_board non-executable, P3D4C0X 5-layer note). No live v_event_outbox_table in PG today.

3. Display source decision — `PG_VIEW_PROJECTION`

Options evaluated:

Option	Verdict	Rationale
`RAW_EVENT_OUTBOX`	❌ rejected	`event_outbox` carries `payload jsonb` + `payload_classification` + potential body/raw refs. Directus field-allowlist alone is brittle (any future column auto-leaks unless registry is updated). Schema-level masking is safer + simpler.
`PG_VIEW_PROJECTION`	✅ chosen	One read-only view exposes only the metadata allowlist; `payload`/body never reach Directus. Future read-state join (LEFT JOIN `event_read` for `is_read` flag) lives in the view, not in DirectusTable config. Aligns with Điều 43 "consolidated read-only VIEW, 0 duplicate, 0 drift" pattern.
`FUNCTION_BACKED_NOT_ALLOWED_NOW`	n/a	DirectusTable cannot consume `fn_event_unread`. Defer.
`BLOCKED`	n/a	Path is viable.

3.1 Candidate view — non-executable sketch

⚠️ Sketch only; column types, ordering, and Directus introspection compatibility must be verified at the implementation prompt. Do NOT copy-paste-execute.

view name : v_event_outbox_table
purpose   : metadata-only read projection of event_outbox for Table Module
columns   : event_id (uuid)            -- PK proxy
            occurred_at (timestamptz)  -- default sort key
            event_domain (text)
            event_type (text)
            event_stream (text)
            delivery_lane (text)       -- 'immediate' | 'delayed'
            severity (text)
            event_subject_table (text)
            event_subject_ref (text)   -- preserve D1: text not uuid
            canonical_address (text)
            actor_ref (text)
            source_system (text)
            payload_classification (text)
            -- joined later (Phase optional):
            -- is_read (bool) via LEFT JOIN event_read ON event_id+actor
            -- read_status_source (text) — propagate D2 values verbatim
ordering  : occurred_at DESC, event_id DESC (deterministic tie-break)
NOT exposed:
  - payload jsonb / body / raw
  - vector / embedding fields if present
  - secret / token / password
  - any unrestricted JSON

Ownership: PG view owned by Directus PG role (whatever system_issues view-style collections use); read GRANT only.

4. Draft `table_registry` declaration

Modeled on row #20 (tbl_system_issues):

{
  "table_id": "tbl_event_outbox",
  "name": "Sổ sự kiện hệ thống (Event Outbox)",
  "collection": "v_event_outbox_table",
  "page_url": "/knowledge/registries/event_outbox",
  "status": "draft",
  "module": null,
  "default_sort": "-occurred_at",
  "default_filter": null,
  "enable_search": true,
  "enable_pagination": true,
  "enable_insert_marks": false,
  "enable_proposals": false,
  "rows_per_page": 50,
  "fields": [
    {"key": "occurred_at",            "label": "Thời điểm",       "sortable": true,  "filterable": true},
    {"key": "event_domain",           "label": "Miền",             "sortable": true,  "filterable": true},
    {"key": "event_type",             "label": "Loại sự kiện",    "sortable": true,  "filterable": true},
    {"key": "event_stream",           "label": "Luồng",            "sortable": true,  "filterable": true},
    {"key": "delivery_lane",          "label": "Kênh phát",        "sortable": true,  "filterable": true,
       "filterOptions": ["immediate","delayed"]},
    {"key": "severity",               "label": "Mức độ",           "sortable": true,  "filterable": true},
    {"key": "event_subject_table",    "label": "Bảng đối tượng",   "sortable": true,  "filterable": true},
    {"key": "event_subject_ref",      "label": "Khóa đối tượng",   "sortable": false, "filterable": true},
    {"key": "canonical_address",      "label": "Địa chỉ chuẩn",    "sortable": false, "filterable": false},
    {"key": "actor_ref",              "label": "Tác nhân",         "sortable": true,  "filterable": true},
    {"key": "source_system",          "label": "Hệ nguồn",         "sortable": true,  "filterable": true},
    {"key": "payload_classification", "label": "Phân loại payload","sortable": true,  "filterable": true}
  ]
}

Notes:

enable_insert_marks=false, enable_proposals=false: read-only consumption, no write affordance.
mark_read_ui = DEFERRED (out of P3D4C2U; would require write permission + bespoke UI which is forbidden).
Status draft until DOT registration prompt approved; flip to published at execution.

5. Minimal DOT-driven Directus exposure plan

DOT-only, no click-config. Suggested handler split (to be drafted in next pack):

Step	Operation	Object	Idempotent?
1	Create PG view `v_event_outbox_table`	PG	yes (`CREATE OR REPLACE VIEW`)
2	GRANT SELECT on view to Directus PG role	PG	yes
3	Directus collection meta seed (`note`, `display_template`, `archive_field`=null, hidden=false)	`directus_collections`	yes (DOT-managed seed)
4	Directus field meta seed for the 12 visible columns (interface, display)	`directus_fields`	yes
5	Directus permission seed: role=`public_readonly` (or existing `agent_readonly`) → action=`read`, fields=allowlist, no filter	`directus_permissions`	yes
6	Insert `table_registry` row (status=`draft` first, flip to `published` after smoke)	`table_registry`	yes (filter by `table_id=tbl_event_outbox`)
7	Smoke: `GET /items/v_event_outbox_table?limit=1` returns 200; `GET /items/table_registry?filter[table_id][_eq]=tbl_event_outbox` returns 1 row	—	—
8	Rollback path: revoke permission → drop registry row → drop view	—	—

Verify pair (Điều 33 APR / DOT convention): the registration handler must ship with a paired verify handler that reproduces step 7 and asserts schema diffs match expectations.

No raw INSERT into Directus tables that bypass cache invalidation: prefer Directus REST/Items API; if raw INSERT INTO directus_* is necessary (per S178 Fix 20 M3B precedent), restart Directus after.

6. Nuxt path — `NO_NUXT_CODE`

Justification:

tbl_system_issues (id=20) already uses /knowledge/registries/system_issue. The Nuxt repo carries a generic registry route that mounts <DirectusTable tableId="...">; adding a sibling URL /knowledge/registries/event_outbox with the same pattern requires no new component.
DirectusTable is TPL-001 (Điều 28). Adding tbl_event_outbox = a new TPL-001 instance via config declaration. NO new template, NO fork.
Caveat (inventory uncertainty): Table Module SSOT v4.1 still lists TT-020/021/022 as 🔴 (DirectusTable wiring to registry "đang xây"). However, 13 of 20 registry rows are already published and follow the /knowledge/registries/{singular} pattern, indicating the route convention is in production. The implementation prompt should run a smoke check on /knowledge/registries/system_issue rendering before flipping tbl_event_outbox to published. If the generic route is not actually wired, the recommendation flips to NEEDS_GENERIC_TEMPLATE_EXTENSION.

Forbidden (re-stated for the implementer):

bespoke notification page or component
notification-specific business logic in Nuxt
Nuxt direct PG
Directus mark-read write endpoint in this pack
modification of Điều 43 context-pack builder

7. Điều 43 / graphic alignment

Điều 43 is referenced as model + context source, not modified.

Pattern reuse:

Điều 43 context_pack_section_definitions proves "config-driven row + generic dispatcher = zero-code add" — same shape as table_registry.
The proposed view v_event_outbox_table could later become a data source for an Điều 43 section (e.g. an EVENT_RECENT section pointing to the same view). That is out of scope here; no section_definition is added in this pack.
architecture_mmd already represents Gate/Warehouse/Brain relationships. Event-flow visualization, if needed later, must be added as a new Điều 43 section row, not a parallel diagram system.

Hard boundary respected: P3D4C2U does NOT touch context-pack builder, verify, or section_definitions.

8. Risk register

Risk	Likelihood	Mitigation
`event_outbox` schema evolves and adds an unsafe column (e.g. `body`)	medium	View has explicit allowlist of columns; new columns in base table do NOT auto-flow to view. Re-deploy view to expose.
Directus introspection mishandles a PG view (no PK)	low-medium	Set `directus_collections.singleton=false` + use `event_id` as virtual PK in collection meta seed. Verify in smoke.
Generic Nuxt route not actually wired (TT-020/021 🔴)	low	Smoke `system_issue` registry page before publishing `event_outbox`. If broken, downgrade recommendation to `NEEDS_GENERIC_TEMPLATE_EXTENSION`.
`event_subject_ref` rendered as link/lookup confuses users (text not FK)	low	Field config keeps it text-only; no relational interface. Document in field meta `note`.
Permission seed accidentally grants write	medium	Permission row scoped to `action='read'`; verify pair must assert no `create/update/delete` rows exist for this collection.

9. Decision summary

display_source                 = PG_VIEW_PROJECTION
pg_projection_needed           = YES
pg_projection_name             = v_event_outbox_table
table_registry_declaration     = drafted (§4)
directus_dot_plan              = drafted (§5, 8 steps + verify pair + rollback)
nuxt_path                      = NO_NUXT_CODE  (caveat: smoke generic route first)
mark_read_ui                   = DEFERRED
recommendation                 = PROCEED_TO_DOT_TABLE_REGISTRATION_PROMPT
next_required_pack             = P3D4C2U_DOT_TABLE_REGISTRATION_IMPLEMENTATION_PROMPT_REVIEW

Strongest output (per prompt §9): universal events can be exposed by adding one read-only PG view + one table_registry row + DOT-managed Directus permission seed. No new shelf. No bespoke UI.