diff --git a/shared/src/index.ts b/shared/src/index.ts
index 53a7f346a..3c32aa6bf 100644
--- a/shared/src/index.ts
+++ b/shared/src/index.ts
@@ -47,6 +47,9 @@ export * from './oidc/oidc.schema';
 export * from './oauth/oauth.schema';
 export * from './admin/admin.schema';
 
+// Realtime WS event contract registry (event names + payload schemas)
+export * from './realtime/events.schema';
+
 // Sanitisation helpers — used by the client today, scoped here so the server
 // has them ready if rich-text input ever ships.
 export * from './sanitize/sanitize';
diff --git a/shared/src/realtime/events.schema.spec.ts b/shared/src/realtime/events.schema.spec.ts
new file mode 100644
index 000000000..ce3fa219c
--- /dev/null
+++ b/shared/src/realtime/events.schema.spec.ts
@@ -0,0 +1,176 @@
+import {
+  TREK_WS_EVENTS,
+  TREK_WS_EVENT_NAMES,
+  TREK_WS_TRIP_EVENT_NAMES,
+  TREK_WS_USER_EVENT_NAMES,
+  type TrekWsEventName,
+} from './events.schema';
+
+import { describe, it, expect } from 'vitest';
+
+/**
+ * One representative wire payload per event, transcribed from the emitting
+ * server call sites. The completeness guard below fails the moment a registry
+ * event has no fixture (or a fixture goes stale), i18n-parity style — so the
+ * fixture map cannot silently shrink relative to the registry.
+ */
+const FIXTURES: Record<TrekWsEventName, Record<string, unknown>> = {
+  'place:created': { place: { id: 3, name: 'Louvre' } },
+  'place:updated': { place: { id: 3, name: 'Louvre' } },
+  'place:deleted': { placeId: 3 },
+  'assignment:created': { assignment: { id: 9, day_id: 2 } },
+  'assignment:updated': { assignment: { id: 9, day_id: 2 } },
+  'assignment:deleted': { assignmentId: 9, dayId: 2 },
+  'assignment:moved': { assignment: { id: 9, day_id: 4 }, oldDayId: 2, newDayId: 4 },
+  'assignment:reordered': { dayId: 2, orderedIds: [3, 1, 2] },
+  'assignment:participants': { assignmentId: 9, participants: [{ user_id: 1 }] },
+  'day:created': { day: { id: 2, date: '2026-06-11' } },
+  'day:updated': { day: { id: 2, date: '2026-06-11' } },
+  'day:deleted': { dayId: 2 },
+  'day:reordered': { orderedIds: [2, 1] },
+  'dayNote:created': { dayId: 2, note: { id: 5 } },
+  'dayNote:updated': { dayId: 2, note: { id: 5 } },
+  'dayNote:deleted': { noteId: 5, dayId: 2 },
+  'packing:created': { item: { id: 7 } },
+  'packing:updated': { item: { id: 7 } },
+  'packing:deleted': { itemId: 7 },
+  'packing:reordered': { orderedIds: [7, 8] },
+  'packing:bag-created': { bag: { id: 1 } },
+  'packing:bag-updated': { bag: { id: 1 } },
+  'packing:bag-deleted': { bagId: 1 },
+  'packing:bag-members-updated': { bagId: 1, members: [{ user_id: 1 }] },
+  'packing:assignees': { category: 'clothes', assignees: [1, 2] },
+  'packing:template-applied': { items: [{ id: 7 }] },
+  'todo:created': { item: { id: 4 } },
+  'todo:updated': { item: { id: 4 } },
+  'todo:deleted': { itemId: 4 },
+  'todo:assignees': { category: 'before', assignees: [1] },
+  'budget:created': { item: { id: 11 } },
+  'budget:updated': { item: { id: 11 } },
+  'budget:deleted': { itemId: 11 },
+  'budget:reordered': { orderedIds: [11, 12] },
+  'budget:members-updated': { itemId: 11, members: [{ user_id: 1 }], persons: 2 },
+  'budget:member-paid-updated': { itemId: 11, userId: 1, paid: true },
+  'budget:settlement-created': { settlement: { id: 2 } },
+  'budget:settlement-updated': { settlement: { id: 2 } },
+  'budget:settlement-deleted': { settlementId: 2 },
+  'reservation:created': { reservation: { id: 6 } },
+  'reservation:updated': { reservation: { id: 6 } },
+  'reservation:deleted': { reservationId: 6 },
+  'reservation:positions': { positions: [{ id: 6, position: 0 }], day_id: 2 },
+  'reservation:travelers-updated': { reservationId: 6, travelers: [{ user_id: 1 }] },
+  'accommodation:created': { accommodation: { id: 8 } },
+  'accommodation:updated': { accommodation: { id: 8 } },
+  'accommodation:deleted': { accommodationId: 8 },
+  'trip:updated': { trip: { id: 1, name: 'Paris' } },
+  'trip:deleted': { id: 1 },
+  'member:added': { member: { user_id: 2 } },
+  'member:removed': { userId: 2 },
+  'file:created': { file: { id: 13 } },
+  'file:updated': { file: { id: 13 } },
+  'file:deleted': { fileId: 13 },
+  'collab:note:created': { note: { id: 3 } },
+  'collab:note:updated': { note: { id: 3 } },
+  'collab:note:deleted': { noteId: 3 },
+  'collab:poll:created': { poll: { id: 2 } },
+  'collab:poll:voted': { poll: { id: 2 } },
+  'collab:poll:closed': { poll: { id: 2 } },
+  'collab:poll:deleted': { pollId: 2 },
+  'collab:message:created': { message: { id: 14 } },
+  'collab:message:reacted': { messageId: 14, reactions: { '👍': [1] } },
+  'collab:message:deleted': { messageId: 14, username: 'ana' },
+  'memories:updated': { userId: 1 },
+  'notification:new': { notification: { id: 21, sender_username: 'ana' } },
+  'notification:updated': { notification: { id: 21 } },
+  'collections:updated': { collectionId: 4 },
+  'collections:accepted': { collectionId: 4 },
+  'collections:declined': { collectionId: 4 },
+  'collections:left': { collectionId: 4 },
+  'collections:deleted': { collectionId: 4 },
+  'collections:cancelled': { collectionId: 4 },
+  'collections:removed': { collectionId: 4 },
+  'collections:invite': { from: { id: 1, username: 'ana' }, collectionId: 4 },
+  'vacay:update': {},
+  'vacay:settings': {},
+  'vacay:accepted': {},
+  'vacay:declined': {},
+  'vacay:cancelled': {},
+  'vacay:dissolved': {},
+  'vacay:invite': { from: { id: 1, username: 'ana' }, planId: 2 },
+  'vacay:share': { from: { id: 1 } },
+  'vacay:share-removed': {},
+  'vacay:shared-update': {},
+  'journey:trip:synced': { journeyId: 3, tripId: 1 },
+  'journey:entry:created': { journeyId: 3, entry: { id: 5 } },
+  'journey:entry:updated': { journeyId: 3, entry: { id: 5 } },
+  'journey:entry:deleted': { journeyId: 3, entryId: 5 },
+  'journey:entries:reordered': { journeyId: 3, orderedIds: [5, 4] },
+  'journey:contributor:changed': { journeyId: 3, targetUserId: 2, role: 'editor' },
+  'import:progress': { jobId: 'j1', tripId: 1, status: 'running', done: 1, total: 3, fileName: 'a.pdf' },
+  'import:done': { jobId: 'j1', tripId: 1, result: { items: [] } },
+  'import:error': { jobId: 'j1', tripId: 1, message: 'boom' },
+};
+
+/** Divergent shapes emitted for the same event today (see DRIFT notes in the registry). */
+const DRIFT_VARIANTS: Partial<Record<TrekWsEventName, Record<string, unknown>[]>> = {
+  'assignment:moved': [{ assignment: { id: 9, day_id: 4 }, oldDayId: 2 }],
+  'assignment:reordered': [{ dayId: 2, assignmentIds: [3, 1, 2] }],
+  'day:deleted': [{ id: 2 }],
+  'day:reordered': [{ day: { id: 2 } }],
+  'budget:reordered': [{ orderedCategories: ['food', 'transport'] }],
+  'reservation:created': [{}],
+  'reservation:updated': [{}],
+  'reservation:positions': [{ positions: [], dayId: 2 }],
+  'accommodation:created': [{}],
+  'accommodation:updated': [{}],
+  'accommodation:deleted': [{}, { id: 8, linkedReservationId: 6 }],
+  'journey:entry:updated': [{ journeyId: 3, entryId: 5 }],
+};
+
+describe('@trek/shared realtime event registry', () => {
+  it('WSEVT-REG-001: pins the authoritative inventory counts (65 trip + 29 user = 94)', () => {
+    expect(TREK_WS_TRIP_EVENT_NAMES).toHaveLength(65);
+    expect(TREK_WS_USER_EVENT_NAMES).toHaveLength(29);
+    expect(TREK_WS_EVENT_NAMES).toHaveLength(94);
+  });
+
+  it('WSEVT-REG-002: every name is domain:action shaped and outside the reserved plugin: namespace', () => {
+    for (const name of TREK_WS_EVENT_NAMES) {
+      expect(name).toMatch(/^[a-zA-Z]+(:[a-zA-Z-]+)+$/);
+      expect(name.startsWith('plugin:')).toBe(false);
+    }
+  });
+
+  it('WSEVT-REG-003: trip/user scopes partition the registry', () => {
+    const union = new Set<string>([...TREK_WS_TRIP_EVENT_NAMES, ...TREK_WS_USER_EVENT_NAMES]);
+    expect(union.size).toBe(TREK_WS_EVENT_NAMES.length);
+  });
+
+  it('WSEVT-REG-004: the fixture map covers every registry event (completeness guard)', () => {
+    expect(Object.keys(FIXTURES).sort()).toEqual([...TREK_WS_EVENT_NAMES].sort());
+  });
+
+  it('WSEVT-REG-005: every event schema parses its representative server payload', () => {
+    for (const name of TREK_WS_EVENT_NAMES) {
+      const result = TREK_WS_EVENTS[name].payload.safeParse(FIXTURES[name]);
+      expect(result.success, `${name} rejected its fixture: ${JSON.stringify(FIXTURES[name])}`).toBe(true);
+    }
+  });
+
+  it('WSEVT-REG-006: drift unions accept every shape the server emits today', () => {
+    for (const [name, variants] of Object.entries(DRIFT_VARIANTS)) {
+      for (const variant of variants ?? []) {
+        const result = TREK_WS_EVENTS[name as TrekWsEventName].payload.safeParse(variant);
+        expect(result.success, `${name} rejected drift variant ${JSON.stringify(variant)}`).toBe(true);
+      }
+    }
+  });
+
+  it('WSEVT-REG-007: payload schemas tolerate the MCP _source marker (strip, not reject)', () => {
+    const result = TREK_WS_EVENTS['place:created'].payload.safeParse({
+      place: { id: 3 },
+      _source: 'mcp',
+    });
+    expect(result.success).toBe(true);
+  });
+});
diff --git a/shared/src/realtime/events.schema.ts b/shared/src/realtime/events.schema.ts
new file mode 100644
index 000000000..00c2e1c64
--- /dev/null
+++ b/shared/src/realtime/events.schema.ts
@@ -0,0 +1,346 @@
+import { z } from 'zod';
+
+/**
+ * WS event contract registry — the single source of truth for every realtime
+ * event TREK broadcasts (roadmap: "Tokenization & registries", paired with the
+ * server's injectable RealtimeService facade).
+ *
+ * Wire envelopes (see server/src/websocket.ts):
+ * - Trip-scoped (`scope: 'trip'`, sent via `broadcast`): the transport wraps
+ *   the payload as `{ type: <event name>, tripId, ...payload }` — `tripId` is
+ *   always injected by the transport and is NOT part of the payload schema.
+ * - User-scoped (`scope: 'user'`, sent via `broadcastToUser`): the payload is
+ *   sent verbatim and carries its own `type: <event name>` discriminator; the
+ *   schemas below describe the fields BESIDES `type`.
+ * - MCP-originated broadcasts add a `_source: 'mcp'` marker key to the payload
+ *   (server/src/mcp/tools/_shared.ts). Zod object schemas strip unknown keys,
+ *   so it needs no per-event modeling.
+ *
+ * Deliberately NOT in the registry:
+ * - The dynamic plugin namespace: trip broadcasts force-namespaced to
+ *   `plugin:<pluginId>:<event>` and user messages typed `plugin:<pluginId>`
+ *   (plugin-host-deps.factory.ts). Names and payloads are plugin-chosen; the
+ *   `plugin:` prefix is the reserved escape hatch (see the template-literal
+ *   types below) and registry names must never collide with it.
+ * - Transport control frames sent directly over the socket, not through
+ *   broadcast: `welcome`, `joined`, `left`, `error` (server→client) and
+ *   `join`, `leave` (client→server). They belong to the transport, which is
+ *   deliberately-late roadmap work.
+ *
+ * Payload schemas are transcribed from the actual server call sites (server
+ * shape wins over client expectations — parity). Entity rows are `z.unknown()`
+ * scaffolding on purpose: the key structure and event names are the contract
+ * being pinned here; row shapes belong to their domain schemas and tighten
+ * opportunistically. Where the same event is emitted with divergent shapes
+ * today, the schema is the union of the real shapes and the divergence is
+ * flagged with a DRIFT comment — do not "fix" a drift here without fixing the
+ * emitting call site first.
+ */
+
+/** An entity row whose shape is owned by its domain schema (scaffolding). */
+const entity = z.unknown();
+/** Ids cross the wire as numbers or numeric strings depending on the emitting route. */
+const id = z.union([z.number(), z.string()]);
+const idList = z.array(id);
+/**
+ * A "something changed, refetch" ping — no declared payload fields. Loose on
+ * purpose (zod v4 infers a plain `z.object({})` as `Record<string, never>`,
+ * which would make `{ type } & payload` unsatisfiable for user-scoped events
+ * whose wire payload is exactly `{ type }`).
+ */
+const empty = z.looseObject({});
+
+export interface TrekWsEventContract {
+  scope: 'trip' | 'user';
+  payload: z.ZodType;
+}
+
+export const TREK_WS_EVENTS = {
+  // ── Places ────────────────────────────────────────────────────────────────
+  'place:created': { scope: 'trip', payload: z.object({ place: entity }) },
+  'place:updated': { scope: 'trip', payload: z.object({ place: entity }) },
+  'place:deleted': { scope: 'trip', payload: z.object({ placeId: id }) },
+
+  // ── Assignments ──────────────────────────────────────────────────────────
+  'assignment:created': { scope: 'trip', payload: z.object({ assignment: entity }) },
+  'assignment:updated': { scope: 'trip', payload: z.object({ assignment: entity }) },
+  'assignment:deleted': { scope: 'trip', payload: z.object({ assignmentId: id, dayId: id }) },
+  // DRIFT: REST sends { assignment, oldDayId, newDayId }; the MCP tool omits
+  // newDayId (assignments.mcp.ts) — the client keys a day map on `undefined`.
+  'assignment:moved': {
+    scope: 'trip',
+    payload: z.object({ assignment: entity, oldDayId: id, newDayId: id.optional() }),
+  },
+  // DRIFT: REST sends { dayId, orderedIds }; the MCP tool sends
+  // { dayId, assignmentIds } — the client only reads orderedIds.
+  'assignment:reordered': {
+    scope: 'trip',
+    payload: z.union([z.object({ dayId: id, orderedIds: idList }), z.object({ dayId: id, assignmentIds: idList })]),
+  },
+  'assignment:participants': {
+    scope: 'trip',
+    payload: z.object({ assignmentId: id, participants: z.array(z.unknown()) }),
+  },
+
+  // ── Days ─────────────────────────────────────────────────────────────────
+  'day:created': { scope: 'trip', payload: z.object({ day: entity }) },
+  'day:updated': { scope: 'trip', payload: z.object({ day: entity }) },
+  // DRIFT: REST + plugins send { dayId }; the MCP tool sends { id }.
+  'day:deleted': {
+    scope: 'trip',
+    payload: z.union([z.object({ dayId: id }), z.object({ id })]),
+  },
+  // Two legitimate shapes: a plain reorder sends { orderedIds }; the
+  // insert-at-position create path re-uses the event with { day }.
+  'day:reordered': {
+    scope: 'trip',
+    payload: z.union([z.object({ orderedIds: idList }), z.object({ day: entity })]),
+  },
+
+  // ── Day notes ────────────────────────────────────────────────────────────
+  'dayNote:created': { scope: 'trip', payload: z.object({ dayId: id, note: entity }) },
+  'dayNote:updated': { scope: 'trip', payload: z.object({ dayId: id, note: entity }) },
+  'dayNote:deleted': { scope: 'trip', payload: z.object({ noteId: id, dayId: id }) },
+
+  // ── Packing ──────────────────────────────────────────────────────────────
+  'packing:created': { scope: 'trip', payload: z.object({ item: entity }) },
+  'packing:updated': { scope: 'trip', payload: z.object({ item: entity }) },
+  'packing:deleted': { scope: 'trip', payload: z.object({ itemId: id }) },
+  'packing:reordered': { scope: 'trip', payload: z.object({ orderedIds: idList }) },
+  'packing:bag-created': { scope: 'trip', payload: z.object({ bag: entity }) },
+  'packing:bag-updated': { scope: 'trip', payload: z.object({ bag: entity }) },
+  'packing:bag-deleted': { scope: 'trip', payload: z.object({ bagId: id }) },
+  'packing:bag-members-updated': {
+    scope: 'trip',
+    payload: z.object({ bagId: id, members: z.array(z.unknown()) }),
+  },
+  'packing:assignees': {
+    scope: 'trip',
+    payload: z.object({ category: z.string(), assignees: z.array(z.unknown()) }),
+  },
+  'packing:template-applied': { scope: 'trip', payload: z.object({ items: z.array(z.unknown()) }) },
+
+  // ── Todo ─────────────────────────────────────────────────────────────────
+  'todo:created': { scope: 'trip', payload: z.object({ item: entity }) },
+  'todo:updated': { scope: 'trip', payload: z.object({ item: entity }) },
+  'todo:deleted': { scope: 'trip', payload: z.object({ itemId: id }) },
+  'todo:assignees': {
+    scope: 'trip',
+    payload: z.object({ category: z.string(), assignees: z.array(z.unknown()) }),
+  },
+
+  // ── Budget ───────────────────────────────────────────────────────────────
+  'budget:created': { scope: 'trip', payload: z.object({ item: entity }) },
+  'budget:updated': { scope: 'trip', payload: z.object({ item: entity }) },
+  'budget:deleted': { scope: 'trip', payload: z.object({ itemId: id }) },
+  // Intentional union: item reorder vs category reorder (the client handles both).
+  'budget:reordered': {
+    scope: 'trip',
+    payload: z.union([z.object({ orderedIds: idList }), z.object({ orderedCategories: z.array(z.string()) })]),
+  },
+  'budget:members-updated': {
+    scope: 'trip',
+    payload: z.object({ itemId: id, members: z.array(z.unknown()), persons: z.unknown() }),
+  },
+  'budget:member-paid-updated': {
+    scope: 'trip',
+    payload: z.object({ itemId: id, userId: id, paid: z.unknown() }),
+  },
+  'budget:settlement-created': { scope: 'trip', payload: z.object({ settlement: entity }) },
+  'budget:settlement-updated': { scope: 'trip', payload: z.object({ settlement: entity }) },
+  'budget:settlement-deleted': { scope: 'trip', payload: z.object({ settlementId: id }) },
+
+  // ── Reservations ─────────────────────────────────────────────────────────
+  // DRIFT: the accommodation cascade paths emit an empty refetch ping `{}`;
+  // the client reads payload.reservation.id unguarded on the `{}` variant.
+  'reservation:created': {
+    scope: 'trip',
+    payload: z.union([z.object({ reservation: entity }), empty]),
+  },
+  'reservation:updated': {
+    scope: 'trip',
+    payload: z.union([z.object({ reservation: entity }), empty]),
+  },
+  'reservation:deleted': { scope: 'trip', payload: z.object({ reservationId: id }) },
+  // DRIFT: REST sends { positions, day_id }; the MCP tool sends { positions, dayId }.
+  'reservation:positions': {
+    scope: 'trip',
+    payload: z.union([
+      z.object({ positions: z.array(z.unknown()), day_id: id.nullish() }),
+      z.object({ positions: z.array(z.unknown()), dayId: id.nullish() }),
+    ]),
+  },
+  'reservation:travelers-updated': {
+    scope: 'trip',
+    payload: z.object({ reservationId: id, travelers: z.array(z.unknown()) }),
+  },
+
+  // ── Accommodations ───────────────────────────────────────────────────────
+  // DRIFT: `{ accommodation }` vs empty refetch ping `{}` (reservation cascade
+  // paths); the client handles neither event today (refetches off trip:updated).
+  'accommodation:created': {
+    scope: 'trip',
+    payload: z.union([z.object({ accommodation: entity }), empty]),
+  },
+  'accommodation:updated': {
+    scope: 'trip',
+    payload: z.union([z.object({ accommodation: entity }), empty]),
+  },
+  // DRIFT: { accommodationId } vs `{}` vs the MCP day-clear path's
+  // { id, linkedReservationId } (days.mcp.ts).
+  'accommodation:deleted': {
+    scope: 'trip',
+    payload: z.union([z.object({ accommodationId: id }), z.object({ id, linkedReservationId: id.nullish() }), empty]),
+  },
+
+  // ── Trip / members ───────────────────────────────────────────────────────
+  'trip:updated': { scope: 'trip', payload: z.object({ trip: entity }) },
+  // Note the key is `id`, not `tripId` (the transport injects tripId anyway).
+  'trip:deleted': { scope: 'trip', payload: z.object({ id }) },
+  'member:added': { scope: 'trip', payload: z.object({ member: entity }) },
+  'member:removed': { scope: 'trip', payload: z.object({ userId: id }) },
+
+  // ── Files ────────────────────────────────────────────────────────────────
+  'file:created': { scope: 'trip', payload: z.object({ file: entity }) },
+  'file:updated': { scope: 'trip', payload: z.object({ file: entity }) },
+  'file:deleted': { scope: 'trip', payload: z.object({ fileId: id }) },
+
+  // ── Collab ───────────────────────────────────────────────────────────────
+  'collab:note:created': { scope: 'trip', payload: z.object({ note: entity }) },
+  'collab:note:updated': { scope: 'trip', payload: z.object({ note: entity }) },
+  'collab:note:deleted': { scope: 'trip', payload: z.object({ noteId: id }) },
+  'collab:poll:created': { scope: 'trip', payload: z.object({ poll: entity }) },
+  'collab:poll:voted': { scope: 'trip', payload: z.object({ poll: entity }) },
+  'collab:poll:closed': { scope: 'trip', payload: z.object({ poll: entity }) },
+  'collab:poll:deleted': { scope: 'trip', payload: z.object({ pollId: id }) },
+  'collab:message:created': { scope: 'trip', payload: z.object({ message: entity }) },
+  'collab:message:reacted': {
+    scope: 'trip',
+    payload: z.object({ messageId: id, reactions: z.unknown() }),
+  },
+  'collab:message:deleted': {
+    scope: 'trip',
+    payload: z.object({ messageId: id, username: z.string().nullish() }),
+  },
+
+  // ── Memories ─────────────────────────────────────────────────────────────
+  'memories:updated': { scope: 'trip', payload: z.object({ userId: id }) },
+
+  // ── Notifications (user-scoped) ──────────────────────────────────────────
+  'notification:new': { scope: 'user', payload: z.object({ notification: entity }) },
+  'notification:updated': { scope: 'user', payload: z.object({ notification: entity }) },
+
+  // ── Collections (user-scoped) ────────────────────────────────────────────
+  'collections:updated': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:accepted': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:declined': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:left': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:deleted': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:cancelled': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:removed': { scope: 'user', payload: z.object({ collectionId: id }) },
+  'collections:invite': {
+    scope: 'user',
+    payload: z.object({ from: z.object({ id, username: z.string() }), collectionId: id }),
+  },
+
+  // ── Vacay (user-scoped) ──────────────────────────────────────────────────
+  'vacay:update': { scope: 'user', payload: empty },
+  'vacay:settings': { scope: 'user', payload: empty },
+  'vacay:accepted': { scope: 'user', payload: empty },
+  'vacay:declined': { scope: 'user', payload: empty },
+  'vacay:cancelled': { scope: 'user', payload: empty },
+  'vacay:dissolved': { scope: 'user', payload: empty },
+  'vacay:invite': {
+    scope: 'user',
+    payload: z.object({ from: z.object({ id, username: z.string() }), planId: id }),
+  },
+  'vacay:share': { scope: 'user', payload: z.object({ from: z.object({ id }) }) },
+  'vacay:share-removed': { scope: 'user', payload: empty },
+  'vacay:shared-update': { scope: 'user', payload: empty },
+
+  // ── Journey (user-scoped; broadcastJourneyEvent injects journeyId) ──────
+  'journey:trip:synced': { scope: 'user', payload: z.object({ journeyId: id, tripId: id }) },
+  'journey:entry:created': { scope: 'user', payload: z.object({ journeyId: id, entry: entity }) },
+  // DRIFT: the soft-delete path emits { journeyId, entryId } under :updated
+  // instead of { journeyId, entry } (journeyService.ts).
+  'journey:entry:updated': {
+    scope: 'user',
+    payload: z.union([z.object({ journeyId: id, entry: entity }), z.object({ journeyId: id, entryId: id })]),
+  },
+  'journey:entry:deleted': { scope: 'user', payload: z.object({ journeyId: id, entryId: id }) },
+  'journey:entries:reordered': {
+    scope: 'user',
+    payload: z.object({ journeyId: id, orderedIds: idList }),
+  },
+  'journey:contributor:changed': {
+    scope: 'user',
+    payload: z.object({ journeyId: id, targetUserId: id, role: z.unknown() }),
+  },
+
+  // ── Booking import (user-scoped; push() injects jobId + tripId) ─────────
+  'import:progress': {
+    scope: 'user',
+    payload: z.object({
+      jobId: z.string(),
+      tripId: id.nullish(),
+      status: z.string(),
+      done: z.number(),
+      total: z.number(),
+      fileName: z.string().optional(),
+    }),
+  },
+  'import:done': {
+    scope: 'user',
+    payload: z.object({ jobId: z.string(), tripId: id.nullish(), result: z.unknown() }),
+  },
+  'import:error': {
+    scope: 'user',
+    payload: z.object({ jobId: z.string(), tripId: id.nullish(), message: z.string() }),
+  },
+} as const satisfies Record<string, TrekWsEventContract>;
+
+/** Every registered event name (65 trip-scoped + 29 user-scoped). */
+export type TrekWsEventName = keyof typeof TREK_WS_EVENTS;
+
+/** Names broadcast to a trip room (`{ type, tripId, ...payload }` envelope). */
+export type TrekWsTripEventName = {
+  [K in TrekWsEventName]: (typeof TREK_WS_EVENTS)[K]['scope'] extends 'trip' ? K : never;
+}[TrekWsEventName];
+
+/** Names sent to a single user's sockets (payload carries `type` itself). */
+export type TrekWsUserEventName = {
+  [K in TrekWsEventName]: (typeof TREK_WS_EVENTS)[K]['scope'] extends 'user' ? K : never;
+}[TrekWsEventName];
+
+/** The payload contract for one event (the part beside type/tripId on the wire). */
+export type TrekWsPayload<E extends TrekWsEventName> = z.infer<(typeof TREK_WS_EVENTS)[E]['payload']>;
+
+/**
+ * The reserved plugin escape hatch: trip broadcasts are force-namespaced to
+ * `plugin:<pluginId>:<event>` and user-scoped plugin messages are typed
+ * `plugin:<pluginId>` by the host — names and payloads are plugin-chosen and
+ * deliberately outside the registry.
+ */
+export type TrekWsPluginEventName = `plugin:${string}`;
+
+/** All registered names, for runtime enumeration (client ratchet, audits). */
+export const TREK_WS_EVENT_NAMES = Object.keys(TREK_WS_EVENTS) as TrekWsEventName[];
+
+/** Trip-scoped subset of {@link TREK_WS_EVENT_NAMES}. */
+export const TREK_WS_TRIP_EVENT_NAMES = TREK_WS_EVENT_NAMES.filter(
+  (name) => TREK_WS_EVENTS[name].scope === 'trip',
+) as TrekWsTripEventName[];
+
+/** User-scoped subset of {@link TREK_WS_EVENT_NAMES}. */
+export const TREK_WS_USER_EVENT_NAMES = TREK_WS_EVENT_NAMES.filter(
+  (name) => TREK_WS_EVENTS[name].scope === 'user',
+) as TrekWsUserEventName[];
+
+// Compile-time lockstep: the trip/user unions must partition the full name
+// union exactly — fails `tsc` if a scope literal widens or a name lands in
+// neither bucket (same pattern as the MCP access-group gate).
+type AssertExact<A, B> = [A] extends [B] ? ([B] extends [A] ? true : never) : never;
+export const TREK_WS_SCOPES_PARTITION_EVENT_NAMES: AssertExact<
+  TrekWsTripEventName | TrekWsUserEventName,
+  TrekWsEventName
+> = true;