Expose listserv announcement signals on events

src/client/index.ts

@@ -52,6 +52,8 @@ export type EngineEvent = {
   publishable: boolean;
   extractionVersion: string;
   imageUrl: string | null;
+  /** How many campus listserv emails announced this event, on which lists, and when first. */
+  announcements: { emails: number; listservs: string[]; firstAnnouncedAt: string | null };
   /** Recurring official events share a series (same host + title); `size` counts occurrences in the feed. */
   series: { id: string; size: number } | null;
   duplicateOf: string | null;

src/queries.ts

@@ -175,6 +175,16 @@ function eventPayload(r: Row) {
     publishable: !!r.publishable,
     extractionVersion: String(r.extractionVersion),
     imageUrl: (r.imageUrl as string) ?? null,
+    /**
+     * Listserv promotion: how many campus emails announced this event (its own email, if any, plus
+     * reminder/cross-list emails folded into it) and when it was first announced. Official
+     * MyPrincetonU events that nobody emailed have 0 and null.
+     */
+    announcements: {
+      emails: (r.source === 'listserv' ? 1 : 0) + Number(r.repeatCount ?? 0),
+      listservs: [...new Set([...((r.lists as string[]) ?? []), ...((r.repeatLists as string[]) ?? [])])].sort(),
+      firstAnnouncedAt: r.firstAnnouncedAt ? new Date(r.firstAnnouncedAt as string).toISOString() : null
+    },
     series: r.seriesId ? { id: String(r.seriesId), size: Number(r.seriesSize) } : null,
     duplicateOf: (r.duplicateOf as string) ?? null,
     source:
@@ -206,7 +216,12 @@ function eventPayload(r: Row) {
 
 const EVENT_COLUMNS = (sql: Sql) => sql`
   e.*, m.subject, m.sender_name, m.sent_at, m.source_url,
-  (SELECT array_agg(listserv ORDER BY listserv) FROM message_lists l WHERE l.message_id = e.message_id) AS lists`;
+  (SELECT array_agg(listserv ORDER BY listserv) FROM message_lists l WHERE l.message_id = e.message_id) AS lists,
+  (SELECT count(*)::int FROM events d WHERE d.duplicate_of = e.id) AS repeat_count,
+  (SELECT array_agg(DISTINCT l2.listserv) FROM events d JOIN message_lists l2 ON l2.message_id = d.message_id
+     WHERE d.duplicate_of = e.id) AS repeat_lists,
+  LEAST(m.sent_at, (SELECT min(m2.sent_at) FROM events d JOIN messages m2 ON m2.id = d.message_id
+     WHERE d.duplicate_of = e.id)) AS first_announced_at`;
 
 export async function listEvents(sql: Sql, f: EventFilters) {
   const limit = Math.min(Math.max(f.limit ?? 50, 1), 200);

src/sources/mpu-events.ts

@@ -203,7 +203,7 @@ export async function markDuplicates(sql: Sql): Promise<number> {
         l.host_org_id = o.host_org_id
         OR similarity_words(l.title, o.title) >= 0.5
       )
-    RETURNING l.id`;
+    RETURNING l.id, l.duplicate_of`;
   // Reminder emails ("final call", "tomorrow!") re-announce the same event: keep the earliest
   // extraction and mark later ones as its duplicates.
   const reminders = await sql`
@@ -225,6 +225,10 @@ export async function markDuplicates(sql: Sql): Promise<number> {
           AND abs(extract(epoch FROM p.starts_at - o.starts_at)) <= 1800
           AND similarity_words(p.title, o.title) >= 0.4
       )
-    RETURNING l.id`;
+    RETURNING l.id, l.duplicate_of`;
+  // The surviving event gained an announcement; bump it so consumers re-read its promotion data.
+  const targets = [...new Set([...official, ...reminders].map((r) => String(r.duplicateOf)))];
+  if (targets.length)
+    await sql`UPDATE events SET updated_at = now(), revision = nextval('revision_seq') WHERE id IN ${sql(targets)}`;
   return official.length + reminders.length;
 }

test/pipeline.test.ts

@@ -64,5 +64,9 @@ test('reminder emails for the same event collapse to the first announcement', {
   const dupes = await sql`SELECT duplicate_of FROM events WHERE status = 'duplicate' AND title ILIKE '%MealMates%'`;
   assert.equal(active.length, 1);
   assert.equal(dupes.length, 1);
+  const { listEvents } = await import('../src/queries.ts');
+  const [kept] = (await listEvents(sql, { from: '2026-09-28T00:00:00Z', query: 'MealMates' })).results;
+  assert.equal(kept.announcements.emails, 2, 'the reminder counts as a second announcement');
+  assert.equal(kept.announcements.firstAnnouncedAt, '2026-09-28T13:00:00.000Z');
   await closeDb();
 });