fix(notifications): stop digest and announcement emails to users inactive for 90 days

apps/notifications/src/__tests__/activeUsers.test.ts

@@ -0,0 +1,58 @@
+import { describe, expect, jest, test } from '@jest/globals'
+import type { Knex } from 'knex'
+import {
+  EMAIL_ACTIVE_WITHIN_DAYS,
+  getRecentlyActiveUserIds
+} from '../email/notifications/activeUsers'
+
+// Minimal knex double: records the chain and resolves to `rows`.
+const mockDb = (rows: { user_id: number }[]) => {
+  const calls: { method: string; args: any[] }[] = []
+  const builder: any = {}
+  for (const method of ['select', 'from', 'whereIn', 'andWhere']) {
+    builder[method] = (...args: any[]) => {
+      calls.push({ method, args })
+      return builder
+    }
+  }
+  builder.then = (resolve: (v: any) => any) =>
+    Promise.resolve(rows).then(resolve)
+  const db = { select: builder.select } as unknown as Knex
+  return { db, calls }
+}
+
+describe('getRecentlyActiveUserIds', () => {
+  test('returns the active subset', async () => {
+    const { db } = mockDb([{ user_id: 1 }, { user_id: 3 }])
+    const result = await getRecentlyActiveUserIds(db, [1, 2, 3])
+    expect([...result].sort()).toEqual([1, 3])
+  })
+
+  test('filters on last_active_at within the cutoff', async () => {
+    const now = new Date('2026-10-07T00:00:00Z').getTime()
+    const spy = jest.spyOn(Date, 'now').mockReturnValue(now)
+    const { db, calls } = mockDb([])
+    await getRecentlyActiveUserIds(db, [1, 2])
+    spy.mockRestore()
+
+    expect(calls.find((c) => c.method === 'from')?.args).toEqual(['users'])
+    expect(calls.find((c) => c.method === 'whereIn')?.args).toEqual([
+      'user_id',
+      [1, 2]
+    ])
+    const [column, op, cutoff] = calls.find((c) => c.method === 'andWhere')!
+      .args as [string, string, Date]
+    expect(column).toBe('last_active_at')
+    expect(op).toBe('>=')
+    expect(cutoff.getTime()).toBe(
+      now - EMAIL_ACTIVE_WITHIN_DAYS * 24 * 60 * 60 * 1000
+    )
+  })
+
+  test('skips the query for an empty list', async () => {
+    const { db, calls } = mockDb([])
+    const result = await getRecentlyActiveUserIds(db, [])
+    expect(result.size).toBe(0)
+    expect(calls).toHaveLength(0)
+  })
+})

apps/notifications/src/email/notifications/activeUsers.ts

@@ -0,0 +1,26 @@
+import { Knex } from 'knex'
+
+// Digest and announcement emails only go to users who opened the app within
+// this many days. Transactional emails are not affected.
+export const EMAIL_ACTIVE_WITHIN_DAYS = 90
+
+/**
+ * Returns the subset of userIds whose users.last_active_at (set on app open by
+ * POST /v1/users/me/ping) is within EMAIL_ACTIVE_WITHIN_DAYS. Users with no
+ * last_active_at count as inactive.
+ */
+export async function getRecentlyActiveUserIds(
+  discoveryDb: Knex,
+  userIds: number[]
+): Promise<Set<number>> {
+  if (userIds.length === 0) return new Set()
+  const cutoff = new Date(
+    Date.now() - EMAIL_ACTIVE_WITHIN_DAYS * 24 * 60 * 60 * 1000
+  )
+  const rows = await discoveryDb
+    .select<{ user_id: number }[]>('user_id')
+    .from('users')
+    .whereIn('user_id', userIds)
+    .andWhere('last_active_at', '>=', cutoff)
+  return new Set(rows.map((r) => r.user_id))
+}

apps/notifications/src/email/notifications/index.ts

@@ -10,6 +10,10 @@ import { DMEntityType } from './types'
 
 import { logger } from '../../logger'
 import { sendNotificationEmail } from './sendEmail'
+import {
+  EMAIL_ACTIVE_WITHIN_DAYS,
+  getRecentlyActiveUserIds
+} from './activeUsers'
 import {
   EmailFrequency,
   buildUserNotificationSettings
@@ -513,11 +517,28 @@ export async function processEmailNotifications(
 const processGroupOfEmails = async (
   dnDb: Knex,
   identityDb: Knex,
-  users: EmailUsers,
+  allUsers: EmailUsers,
   frequency: EmailFrequency,
   startOffset: Moment,
   remoteConfig: RemoteConfig
 ) => {
+  const activeUserIds = await getRecentlyActiveUserIds(
+    dnDb,
+    Object.keys(allUsers).map(Number)
+  )
+  const inactiveCount = Object.keys(allUsers).length - activeUserIds.size
+  if (inactiveCount > 0) {
+    logger.info(
+      `processEmailNotifications | skipping ${inactiveCount} users inactive for over ${EMAIL_ACTIVE_WITHIN_DAYS} days`
+    )
+  }
+  const users: EmailUsers = Object.fromEntries(
+    Object.entries(allUsers).filter(([userId]) =>
+      activeUserIds.has(Number(userId))
+    )
+  )
+  if (Object.keys(users).length === 0) return
+
   const userNotificationSettings = await buildUserNotificationSettings(
     identityDb,
     Object.keys(users).map(Number)

apps/notifications/src/processNotifications/mappers/announcement.ts

@@ -8,6 +8,7 @@ import { BaseNotification } from './base'
 import { sendPushNotification } from '../../sns'
 import { ResourceIds, Resources } from '../../email/notifications/renderEmail'
 import { sendNotificationEmail } from '../../email/notifications/sendEmail'
+import { getRecentlyActiveUserIds } from '../../email/notifications/activeUsers'
 import {
   buildUserNotificationSettings,
   Device
@@ -191,6 +192,9 @@ export class Announcement extends BaseNotification<AnnouncementNotificationRow>
         frequency: 'live'
       })
     ) {
+      const activeUserIds = await getRecentlyActiveUserIds(this.dnDB, [userId])
+      if (!activeUserIds.has(userId)) return
+
       const notification: AppEmailNotification = {
         receiver_user_id: userId,
         ...this.notification

apps/notifications/src/processNotifications/mappers/userNotificationSettings.ts

@@ -154,7 +154,7 @@ export class UserNotificationSettings {
   getUserEmailFrequency(userId: number) {
     const emailSettings = this.email?.[userId]
     if (emailSettings === undefined) {
-      return 'daily'
+      return 'weekly'
     }
     return emailSettings.frequency
   }

apps/notifications/src/utils/populateDB.ts

@@ -284,6 +284,7 @@ export const createUsers = async (db: Knex, users: CreateUser[]) => {
         wallet: `0x${user.user_id}`,
         creator_node_endpoint: `https://dn1.io,https://dn2.io,https://dn3.io`,
         is_available: true,
+        last_active_at: new Date(Date.now()),
         ...user
       }))
     )