diff --git a/frontend/src/stores/systemActivity.js b/frontend/src/stores/systemActivity.js
new file mode 100644
index 0000000..e152ade
--- /dev/null
+++ b/frontend/src/stores/systemActivity.js
@@ -0,0 +1,103 @@
+import { defineStore } from 'pinia'
+import { ref } from 'vue'
+
+import { useApi } from '../composables/useApi.js'
+
+export const useSystemActivityStore = defineStore('systemActivity', () => {
+  const api = useApi()
+
+  // Live polled state.
+  const queues = ref(null)       // { queues: {name: depth|null}, fetched_at }
+  const workers = ref(null)      // { workers: {hostname: {...}}, fetched_at }
+  const recentMinute = ref([])   // last-60s rows (for Overview summary)
+  const failures = ref(null)     // { recent, count_by_type, since }
+
+  // Paginated runs (Activity tab "All recent activity" pane).
+  const runs = ref([])
+  const runsCursor = ref(null)
+  const runsHasMore = ref(false)
+  const runsFilter = ref({ queue: null, status: null, limit: 50 })
+
+  const loading = ref({ queues: false, workers: false, runs: false, failures: false })
+  const lastError = ref(null)
+
+  async function loadQueues() {
+    loading.value.queues = true
+    lastError.value = null
+    try {
+      queues.value = await api.get('/api/system/activity/queues')
+    } catch (e) {
+      lastError.value = e.message
+    } finally {
+      loading.value.queues = false
+    }
+  }
+
+  async function loadWorkers() {
+    loading.value.workers = true
+    lastError.value = null
+    try {
+      workers.value = await api.get('/api/system/activity/workers')
+    } catch (e) {
+      lastError.value = e.message
+    } finally {
+      loading.value.workers = false
+    }
+  }
+
+  async function loadRecentMinute() {
+    // Used by the Overview summary card: pull last 60s of runs to compute
+    // per-queue ok/err counts. One call covers all queues; UI groups.
+    try {
+      const body = await api.get('/api/system/activity/runs', {
+        params: { limit: 200 },
+      })
+      recentMinute.value = body.runs || []
+    } catch (e) {
+      lastError.value = e.message
+    }
+  }
+
+  async function loadRuns({ reset = false } = {}) {
+    loading.value.runs = true
+    lastError.value = null
+    try {
+      const params = { limit: runsFilter.value.limit }
+      if (runsFilter.value.queue) params.queue = runsFilter.value.queue
+      if (runsFilter.value.status) params.status = runsFilter.value.status
+      if (!reset && runsCursor.value) params.before_id = runsCursor.value
+      const body = await api.get('/api/system/activity/runs', { params })
+      runs.value = reset ? body.runs : [...runs.value, ...body.runs]
+      runsCursor.value = body.next_cursor
+      runsHasMore.value = body.next_cursor !== null
+    } catch (e) {
+      lastError.value = e.message
+    } finally {
+      loading.value.runs = false
+    }
+  }
+
+  async function loadFailures() {
+    loading.value.failures = true
+    lastError.value = null
+    try {
+      failures.value = await api.get('/api/system/activity/failures')
+    } catch (e) {
+      lastError.value = e.message
+    } finally {
+      loading.value.failures = false
+    }
+  }
+
+  function setFilter(filter) {
+    runsFilter.value = { ...runsFilter.value, ...filter }
+  }
+
+  return {
+    queues, workers, recentMinute, failures,
+    runs, runsCursor, runsHasMore, runsFilter,
+    loading, lastError,
+    loadQueues, loadWorkers, loadRecentMinute,
+    loadRuns, loadFailures, setFilter,
+  }
+})