diff --git a/psf-memo-client/test/property/topics-table.property.test.js b/psf-memo-client/test/property/topics-table.property.test.js
new file mode 100644
index 0000000..0df5923
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+++ b/psf-memo-client/test/property/topics-table.property.test.js
@@ -0,0 +1,116 @@
+/*
+  Property tests for the topics table view model.
+
+  The unit tests probe buildTopicsTable at fixed fixtures. These properties
+  pin down the layout contract over broad random topic lists:
+
+    - Row order: exactly one row per topic, in the input order.
+    - Cell alignment: every row has one cell per header, in the header order,
+      with the topic name, relative-time label, post count, and follower count
+      each in its matching column.
+    - Link round trip: each row link percent-encodes the room and decodes back
+      to it.
+    - Count conservation: the digits in the post/follower cells sum to the
+      input post/follower counts.
+
+  `now` is injected so every property is deterministic.
+*/
+
+'use strict'
+
+const test = require('node:test')
+const { seededRandom, forAll, intGen } = require('./harness')
+const {
+  buildTopicsTable,
+  TOPICS_TABLE_HEADERS,
+  TOPICS_TABLE_WRAPPER_CLASS
+} = require('../../src/services/topics-table')
+const { relativeTime } = require('../../src/services/relative-time')
+
+const rng = seededRandom(20260918)
+
+const DAY = 24 * 60 * 60 * 1000
+const NOW = 1800000000000
+
+// Room names mix plain words, spaces, path separators, unicode, and a leading
+// '#', so the link encoder and the '#room' label are exercised.
+const ROOM_NAMES = ['bitcoin', 'cash', 'space room', 'a/b', 'são paulo', '#tagged', 'emoji-😀', '']
+
+function randomRoom () {
+  return `${ROOM_NAMES[Math.floor(rng() * ROOM_NAMES.length)]}${intGen(rng, 0, 999)()}`
+}
+
+// Fields are sometimes omitted so the default count/last-seen handling is part
+// of the generated input space.
+function topicGen () {
+  const topic = { room: randomRoom() }
+  if (rng() < 0.85) topic.postCount = intGen(rng, 0, 10000)()
+  if (rng() < 0.85) topic.followerCount = intGen(rng, 0, 10000)()
+  if (rng() < 0.85) topic.lastSeen = NOW - intGen(rng, 0, 400 * DAY)()
+  return topic
+}
+
+function topicsGen () {
+  return () => Array.from({ length: intGen(rng, 0, 20)() }, topicGen)
+}
+
+test('buildTopicsTable keeps one row per topic in the same order', async () => {
+  await forAll(
+    topicsGen(),
+    (topics) => {
+      const table = buildTopicsTable(topics, { now: NOW })
+      if (table.rows.length !== topics.length) return false
+      return table.rows.every((row, i) => row.room === topics[i].room)
+    },
+    { label: 'topics table row order' }
+  )
+})
+
+test('buildTopicsTable keeps the four cells aligned with the header order', async () => {
+  await forAll(
+    topicsGen(),
+    (topics) => {
+      const table = buildTopicsTable(topics, { now: NOW })
+      if (JSON.stringify(table.headers) !== JSON.stringify(TOPICS_TABLE_HEADERS)) return false
+      if (table.wrapperClass !== TOPICS_TABLE_WRAPPER_CLASS) return false
+      return table.rows.every((row, i) => {
+        const topic = topics[i]
+        return row.cells.length === TOPICS_TABLE_HEADERS.length &&
+          row.cells[0] === `#${topic.room}` &&
+          row.cells[1] === relativeTime(topic.lastSeen, NOW) &&
+          row.cells[2] === `${topic.postCount ?? 0} posts` &&
+          row.cells[3] === `${topic.followerCount ?? 0} followers`
+      })
+    },
+    { label: 'topics table cell alignment' }
+  )
+})
+
+test('buildTopicsTable percent-encodes row links that round-trip the room', async () => {
+  await forAll(
+    topicsGen(),
+    (topics) => {
+      const table = buildTopicsTable(topics, { now: NOW })
+      return table.rows.every((row) => {
+        if (row.href !== `/topics/${encodeURIComponent(row.room)}`) return false
+        return decodeURIComponent(row.href.slice('/topics/'.length)) === row.room
+      })
+    },
+    { label: 'topics table link round trip' }
+  )
+})
+
+test('buildTopicsTable conserves post and follower counts into the cells', async () => {
+  await forAll(
+    topicsGen(),
+    (topics) => {
+      const table = buildTopicsTable(topics, { now: NOW })
+      const expectedPosts = topics.reduce((sum, topic) => sum + (topic.postCount ?? 0), 0)
+      const expectedFollowers = topics.reduce((sum, topic) => sum + (topic.followerCount ?? 0), 0)
+      const posted = table.rows.reduce((sum, row) => sum + Number.parseInt(row.cells[2], 10), 0)
+      const followers = table.rows.reduce((sum, row) => sum + Number.parseInt(row.cells[3], 10), 0)
+      return posted === expectedPosts && followers === expectedFollowers
+    },
+    { label: 'topics table count conservation' }
+  )
+})