diff --git a/internal/db/sqlite/store.go b/internal/db/sqlite/store.go
index 1cdc670..08053b2 100644
--- a/internal/db/sqlite/store.go
+++ b/internal/db/sqlite/store.go
@@ -132,3 +132,8 @@ func (s *Store) QueryRowContext(ctx context.Context, query string, args ...inter
 	}
 	return stmt.QueryRowContext(ctx, args...)
 }
+
+// Ping checks if the database connection is alive.
+func (s *Store) Ping() error {
+	return s.db.Ping()
+}
diff --git a/internal/update/update.go b/internal/update/update.go
index 8fcf439..88d660f 100644
--- a/internal/update/update.go
+++ b/internal/update/update.go
@@ -573,21 +573,30 @@ func (u *Updater) Restart() error {
 
 	log.Info().Str("path", workerPath).Msg("Restarting worker with new binary")
 
-	// Start the new process
-	cmd := exec.Command(workerPath) // #nosec G204 -- workerPath is from internal installDir
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	cmd.Env = os.Environ()
+	// Use nohup to start a detached process that survives parent exit
+	// The new worker will retry binding to the port after the old process exits
+	cmd := exec.Command("nohup", workerPath) // #nosec G204 -- workerPath is from internal installDir
+	cmd.Stdout = nil                         // Detach stdout
+	cmd.Stderr = nil                         // Detach stderr
+	cmd.Stdin = nil                          // Detach stdin
+	cmd.Env = append(os.Environ(), "CLAUDE_MNEMONIC_RESTART=1")
 
+	// Start in background - don't wait
 	if err := cmd.Start(); err != nil {
 		return fmt.Errorf("failed to start new worker: %w", err)
 	}
 
-	// Give the new process time to start
-	time.Sleep(RestartDelay)
+	// Release the child process so it's not a zombie
+	go func() {
+		_ = cmd.Wait()
+	}()
 
-	// Exit current process - the new one is now running
 	log.Info().Int("new_pid", cmd.Process.Pid).Msg("New worker started, exiting old process")
+
+	// Give a moment for the log to flush
+	time.Sleep(100 * time.Millisecond)
+
+	// Exit current process - the new one will bind to the port
 	os.Exit(0)
 
 	return nil // Never reached
diff --git a/internal/vector/chroma/client.go b/internal/vector/chroma/client.go
index 35384ca..cc46b4f 100644
--- a/internal/vector/chroma/client.go
+++ b/internal/vector/chroma/client.go
@@ -449,6 +449,13 @@ func (c *Client) nextID() int {
 	return c.requestID
 }
 
+// IsConnected returns whether the client is currently connected to ChromaDB.
+func (c *Client) IsConnected() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.connected
+}
+
 // Close closes the connection to ChromaDB.
 func (c *Client) Close() error {
 	c.mu.Lock()
diff --git a/internal/worker/handlers.go b/internal/worker/handlers.go
index 6a8f7b6..1cbabb2 100644
--- a/internal/worker/handlers.go
+++ b/internal/worker/handlers.go
@@ -751,6 +751,110 @@ func (s *Service) handleUpdateStatus(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, status)
 }
 
+// ComponentHealth represents the health status of a single component.
+type ComponentHealth struct {
+	Name    string `json:"name"`
+	Status  string `json:"status"` // "healthy", "degraded", "unhealthy"
+	Message string `json:"message,omitempty"`
+}
+
+// SelfCheckResponse contains the health status of all components.
+type SelfCheckResponse struct {
+	Overall    string            `json:"overall"` // "healthy", "degraded", "unhealthy"
+	Version    string            `json:"version"`
+	Uptime     string            `json:"uptime"`
+	Components []ComponentHealth `json:"components"`
+}
+
+// handleSelfCheck returns the health status of all components.
+func (s *Service) handleSelfCheck(w http.ResponseWriter, r *http.Request) {
+	components := []ComponentHealth{}
+	overall := "healthy"
+
+	// Check Worker Service
+	workerStatus := ComponentHealth{Name: "Worker Service", Status: "healthy"}
+	if !s.ready.Load() {
+		if err := s.GetInitError(); err != nil {
+			workerStatus.Status = "unhealthy"
+			workerStatus.Message = err.Error()
+			overall = "unhealthy"
+		} else {
+			workerStatus.Status = "degraded"
+			workerStatus.Message = "Initializing"
+			if overall == "healthy" {
+				overall = "degraded"
+			}
+		}
+	}
+	components = append(components, workerStatus)
+
+	// Check SQLite Database
+	dbStatus := ComponentHealth{Name: "SQLite Database", Status: "healthy"}
+	if s.store == nil {
+		dbStatus.Status = "unhealthy"
+		dbStatus.Message = "Not initialized"
+		overall = "unhealthy"
+	} else if err := s.store.Ping(); err != nil {
+		dbStatus.Status = "unhealthy"
+		dbStatus.Message = err.Error()
+		overall = "unhealthy"
+	}
+	components = append(components, dbStatus)
+
+	// Check ChromaDB
+	chromaStatus := ComponentHealth{Name: "ChromaDB", Status: "healthy"}
+	if s.chromaClient == nil {
+		chromaStatus.Status = "degraded"
+		chromaStatus.Message = "Not configured"
+		if overall == "healthy" {
+			overall = "degraded"
+		}
+	} else if !s.chromaClient.IsConnected() {
+		chromaStatus.Status = "degraded"
+		chromaStatus.Message = "Not connected"
+		if overall == "healthy" {
+			overall = "degraded"
+		}
+	}
+	components = append(components, chromaStatus)
+
+	// Check SDK Processor
+	sdkStatus := ComponentHealth{Name: "SDK Processor", Status: "healthy"}
+	if s.processor == nil {
+		sdkStatus.Status = "degraded"
+		sdkStatus.Message = "Not initialized"
+		if overall == "healthy" {
+			overall = "degraded"
+		}
+	} else if !s.processor.IsAvailable() {
+		sdkStatus.Status = "degraded"
+		sdkStatus.Message = "Claude CLI not available"
+		if overall == "healthy" {
+			overall = "degraded"
+		}
+	}
+	components = append(components, sdkStatus)
+
+	// Check SSE Broadcaster
+	sseStatus := ComponentHealth{Name: "SSE Broadcaster", Status: "healthy"}
+	if s.sseBroadcaster == nil {
+		sseStatus.Status = "unhealthy"
+		sseStatus.Message = "Not initialized"
+		overall = "unhealthy"
+	}
+	components = append(components, sseStatus)
+
+	// Calculate uptime
+	uptime := time.Since(s.startTime).Round(time.Second).String()
+
+	writeJSON(w, SelfCheckResponse{
+		Overall:    overall,
+		Version:    s.version,
+		Uptime:     uptime,
+		Components: components,
+	})
+}
+
 // handleUpdateRestart restarts the worker with the new binary.
 func (s *Service) handleUpdateRestart(w http.ResponseWriter, r *http.Request) {
 	status := s.updater.GetStatus()
diff --git a/internal/worker/sdk/processor.go b/internal/worker/sdk/processor.go
index 20943d5..adfcc7f 100644
--- a/internal/worker/sdk/processor.go
+++ b/internal/worker/sdk/processor.go
@@ -92,6 +92,12 @@ func NewProcessor(observationStore *sqlite.ObservationStore, summaryStore *sqlit
 	}, nil
 }
 
+// IsAvailable checks if the Claude CLI is available for processing.
+func (p *Processor) IsAvailable() bool {
+	_, err := os.Stat(p.claudePath)
+	return err == nil
+}
+
 // ProcessObservation processes a single tool observation and extracts insights.
 func (p *Processor) ProcessObservation(ctx context.Context, sdkSessionID, project string, toolName string, toolInput, toolResponse interface{}, promptNumber int, cwd string) error {
 	p.mu.Lock()
diff --git a/internal/worker/service.go b/internal/worker/service.go
index 14d65d2..a99f12a 100644
--- a/internal/worker/service.go
+++ b/internal/worker/service.go
@@ -602,6 +602,9 @@ func (s *Service) setupRoutes() {
 	s.router.Get("/api/update/status", s.handleUpdateStatus)
 	s.router.Post("/api/update/restart", s.handleUpdateRestart)
 
+	// Selfcheck endpoint (works before DB is ready - checks all components)
+	s.router.Get("/api/selfcheck", s.handleSelfCheck)
+
 	// SSE endpoint (works before DB is ready)
 	s.router.Get("/api/events", s.sseBroadcaster.HandleSSE)
 
@@ -668,11 +671,34 @@ func (s *Service) Start() error {
 		ReadHeaderTimeout: 10 * time.Second,
 	}
 
+	// Check if we're in restart mode (after update)
+	isRestart := os.Getenv("CLAUDE_MNEMONIC_RESTART") == "1"
+
 	s.wg.Add(1)
 	go func() {
 		defer s.wg.Done()
-		if err := s.server.ListenAndServe(); err != http.ErrServerClosed {
-			log.Error().Err(err).Msg("HTTP server error")
+
+		var lastErr error
+		maxRetries := 1
+		if isRestart {
+			maxRetries = 10 // Retry up to 10 times during restart
+		}
+
+		for i := 0; i < maxRetries; i++ {
+			lastErr = s.server.ListenAndServe()
+			if lastErr == http.ErrServerClosed {
+				return // Normal shutdown
+			}
+
+			if i < maxRetries-1 && isRestart {
+				log.Warn().Err(lastErr).Int("retry", i+1).Msg("Port not ready, retrying...")
+				time.Sleep(500 * time.Millisecond)
+				continue
+			}
+		}
+
+		if lastErr != nil {
+			log.Error().Err(lastErr).Msg("HTTP server error")
 		}
 	}()
 
@@ -681,6 +707,7 @@ func (s *Service) Start() error {
 	log.Info().
 		Int("port", port).
 		Int("pid", getPID()).
+		Bool("restart_mode", isRestart).
 		Msg("Worker HTTP server started (initialization in progress)")
 
 	return nil
diff --git a/internal/worker/static/placeholder.html b/internal/worker/static/placeholder.html
index 7fda878..e69de29 100644
--- a/internal/worker/static/placeholder.html
+++ b/internal/worker/static/placeholder.html
@@ -1 +0,0 @@
-<!-- Placeholder for go:embed - replaced by UI build -->
diff --git a/ui/src/App.vue b/ui/src/App.vue
index 96e8df3..2b38384 100644
--- a/ui/src/App.vue
+++ b/ui/src/App.vue
@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { watch } from 'vue'
-import { useSSE, useStats, useTimeline, useUpdate } from '@/composables'
+import { useSSE, useStats, useTimeline, useUpdate, useHealth } from '@/composables'
 import Header from '@/components/Header.vue'
 import StatsCards from '@/components/StatsCards.vue'
 import FilterTabs from '@/components/FilterTabs.vue'
@@ -11,6 +11,7 @@ import Sidebar from '@/components/Sidebar.vue'
 const { isConnected, isProcessing, queueDepth, lastEvent } = useSSE()
 const { stats } = useStats()
 const { updateInfo, updateStatus, isUpdating, applyUpdate } = useUpdate()
+const { health } = useHealth()
 const {
   filteredItems,
   loading,
@@ -66,6 +67,7 @@ watch(lastEvent, (event) => {
           :prompt-count="promptCount"
           :summary-count="summaryCount"
           :current-project="currentProject"
+          :health="health"
           @update:project="setProject"
         />
 
diff --git a/ui/src/components/Header.vue b/ui/src/components/Header.vue
index 75aeea7..105b5c3 100644
--- a/ui/src/components/Header.vue
+++ b/ui/src/components/Header.vue
@@ -22,15 +22,35 @@ const restartWorker = async () => {
   isRestarting.value = true
   try {
     await fetch('/api/update/restart', { method: 'POST' })
-    // Wait a moment for the new process to start, then reload
-    setTimeout(() => {
-      globalThis.location.reload()
-    }, 2000)
+    // Poll for new worker to be ready before reloading
+    await waitForWorker()
+    globalThis.location.reload()
   } catch (error) {
     console.error('Failed to restart:', error)
     isRestarting.value = false
   }
 }
+
+// Poll health endpoint until worker is ready
+const waitForWorker = async (maxAttempts = 30, delayMs = 500): Promise<void> => {
+  for (let i = 0; i < maxAttempts; i++) {
+    await new Promise(resolve => setTimeout(resolve, delayMs))
+    try {
+      const response = await fetch('/api/health', {
+        signal: AbortSignal.timeout(2000)
+      })
+      if (response.ok) {
+        const data = await response.json()
+        if (data.status === 'ready') {
+          return // Worker is ready
+        }
+      }
+    } catch {
+      // Worker not ready yet, continue polling
+    }
+  }
+  // Timeout - reload anyway
+}
 </script>
 
 <template>
diff --git a/ui/src/components/Sidebar.vue b/ui/src/components/Sidebar.vue
index 9327a5e..9e8ed96 100644
--- a/ui/src/components/Sidebar.vue
+++ b/ui/src/components/Sidebar.vue
@@ -1,148 +1,264 @@
 <script setup lang="ts">
-import type { Stats } from '@/types'
+import { ref, computed } from 'vue'
+import type { Stats, SelfCheckResponse } from '@/types'
 import ProjectFilter from './ProjectFilter.vue'
 
-defineProps<{
+const props = defineProps<{
   stats: Stats | null
   observationCount: number
   promptCount: number
   summaryCount: number
   currentProject: string | null
+  health: SelfCheckResponse | null
 }>()
 
 defineEmits<{
   'update:project': [project: string | null]
 }>()
 
+// Collapse state - persisted in localStorage
+const isCollapsed = ref(localStorage.getItem('sidebar-collapsed') === 'true')
+
+function toggleCollapse() {
+  isCollapsed.value = !isCollapsed.value
+  localStorage.setItem('sidebar-collapsed', String(isCollapsed.value))
+}
+
 function formatNumber(n: number): string {
   if (n >= 1000000) return (n / 1000000).toFixed(1) + 'M'
   if (n >= 1000) return (n / 1000).toFixed(1) + 'K'
   return n.toString()
 }
+
+// Health status helpers
+const overallHealthIcon = computed(() => {
+  if (!props.health) return 'fa-circle-question'
+  switch (props.health.overall) {
+    case 'healthy': return 'fa-circle-check'
+    case 'degraded': return 'fa-triangle-exclamation'
+    case 'unhealthy': return 'fa-circle-xmark'
+  }
+})
+
+const overallHealthColor = computed(() => {
+  if (!props.health) return 'text-slate-400'
+  switch (props.health.overall) {
+    case 'healthy': return 'text-green-400'
+    case 'degraded': return 'text-amber-400'
+    case 'unhealthy': return 'text-red-400'
+  }
+})
+
+function getStatusColor(status: string): string {
+  switch (status) {
+    case 'healthy': return 'text-green-400'
+    case 'degraded': return 'text-amber-400'
+    case 'unhealthy': return 'text-red-400'
+    default: return 'text-slate-400'
+  }
+}
 </script>
 
 <template>
-  <aside class="w-72 flex-shrink-0 space-y-4">
-    <!-- Project Filter -->
-    <div class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
-      <div class="flex items-center gap-2 mb-3">
-        <i class="fas fa-filter text-claude-400" />
-        <h3 class="text-sm font-semibold text-white">Filter by Project</h3>
-      </div>
-      <ProjectFilter
-        :current-project="currentProject"
-        @update:project="$emit('update:project', $event)"
+  <aside
+    :class="[
+      'flex-shrink-0 transition-all duration-300 ease-in-out',
+      isCollapsed ? 'w-12' : 'w-72'
+    ]"
+  >
+    <!-- Collapse Toggle Button -->
+    <button
+      @click="toggleCollapse"
+      class="w-full flex items-center justify-center py-2 mb-4 bg-slate-800/50 rounded-lg border border-slate-700/50 hover:bg-slate-700/50 transition-colors"
+      :title="isCollapsed ? 'Expand sidebar' : 'Collapse sidebar'"
+    >
+      <i
+        :class="[
+          'fas transition-transform duration-300',
+          isCollapsed ? 'fa-chevron-right' : 'fa-chevron-left'
+        ]"
+        class="text-slate-400"
       />
+    </button>
+
+    <div v-show="!isCollapsed" class="space-y-4">
+      <!-- Project Filter -->
+      <div class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
+        <div class="flex items-center gap-2 mb-3">
+          <i class="fas fa-filter text-claude-400" />
+          <h3 class="text-sm font-semibold text-white">Filter by Project</h3>
+        </div>
+        <ProjectFilter
+          :current-project="currentProject"
+          @update:project="$emit('update:project', $event)"
+        />
+      </div>
+
+      <!-- Component Health -->
+      <div class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
+        <div class="flex items-center gap-2 mb-3">
+          <i :class="['fas', overallHealthIcon, overallHealthColor]" />
+          <h3 class="text-sm font-semibold text-white">System Health</h3>
+        </div>
+
+        <div v-if="health" class="space-y-2">
+          <div
+            v-for="component in health.components"
+            :key="component.name"
+            class="flex items-center justify-between"
+          >
+            <span class="text-slate-400 text-sm truncate" :title="component.message">
+              {{ component.name }}
+            </span>
+            <span
+              :class="['text-xs font-medium capitalize', getStatusColor(component.status)]"
+            >
+              {{ component.status }}
+            </span>
+          </div>
+        </div>
+        <div v-else class="text-slate-500 text-sm">
+          Loading health status...
+        </div>
+      </div>
+
+      <!-- Memory Stats -->
+      <div class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
+        <div class="flex items-center gap-2 mb-3">
+          <i class="fas fa-brain text-purple-400" />
+          <h3 class="text-sm font-semibold text-white">Memory Contents</h3>
+        </div>
+
+        <div class="space-y-3">
+          <!-- Observations -->
+          <div class="flex items-center justify-between">
+            <div class="flex items-center gap-2">
+              <i class="fas fa-lightbulb text-amber-400 w-4" />
+              <span class="text-slate-400 text-sm">Observations</span>
+            </div>
+            <span class="text-white font-medium">{{ formatNumber(observationCount) }}</span>
+          </div>
+
+          <!-- Prompts -->
+          <div class="flex items-center justify-between">
+            <div class="flex items-center gap-2">
+              <i class="fas fa-comment text-blue-400 w-4" />
+              <span class="text-slate-400 text-sm">Prompts</span>
+            </div>
+            <span class="text-white font-medium">{{ formatNumber(promptCount) }}</span>
+          </div>
+
+          <!-- Summaries -->
+          <div class="flex items-center justify-between">
+            <div class="flex items-center gap-2">
+              <i class="fas fa-clipboard-list text-green-400 w-4" />
+              <span class="text-slate-400 text-sm">Summaries</span>
+            </div>
+            <span class="text-white font-medium">{{ formatNumber(summaryCount) }}</span>
+          </div>
+        </div>
+      </div>
+
+      <!-- Retrieval Stats -->
+      <div v-if="stats?.retrieval" class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
+        <div class="flex items-center gap-2 mb-3">
+          <i class="fas fa-search text-cyan-400" />
+          <h3 class="text-sm font-semibold text-white">Retrieval Stats</h3>
+        </div>
+
+        <div class="space-y-3">
+          <!-- Total Requests -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Total Requests</span>
+            <span class="text-white font-medium">{{ formatNumber(stats.retrieval.TotalRequests) }}</span>
+          </div>
+
+          <!-- Observations Served -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Obs Served</span>
+            <span class="text-white font-medium">{{ formatNumber(stats.retrieval.ObservationsServed) }}</span>
+          </div>
+
+          <!-- Search Requests -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Searches</span>
+            <span class="text-white font-medium">{{ formatNumber(stats.retrieval.SearchRequests) }}</span>
+          </div>
+
+          <!-- Context Injections -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Injections</span>
+            <span class="text-white font-medium">{{ formatNumber(stats.retrieval.ContextInjections) }}</span>
+          </div>
+
+          <!-- Verified Stale -->
+          <div v-if="stats.retrieval.VerifiedStale > 0" class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Verified Stale</span>
+            <span class="text-amber-400 font-medium">{{ formatNumber(stats.retrieval.VerifiedStale) }}</span>
+          </div>
+
+          <!-- Deleted Invalid -->
+          <div v-if="stats.retrieval.DeletedInvalid > 0" class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Deleted Invalid</span>
+            <span class="text-red-400 font-medium">{{ formatNumber(stats.retrieval.DeletedInvalid) }}</span>
+          </div>
+        </div>
+      </div>
+
+      <!-- Session Info -->
+      <div v-if="stats" class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
+        <div class="flex items-center gap-2 mb-3">
+          <i class="fas fa-clock text-slate-400" />
+          <h3 class="text-sm font-semibold text-white">Worker Info</h3>
+        </div>
+
+        <div class="space-y-3">
+          <!-- Uptime -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Uptime</span>
+            <span class="text-white font-medium text-xs">{{ stats.uptime }}</span>
+          </div>
+
+          <!-- Sessions Today -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Sessions Today</span>
+            <span class="text-white font-medium">{{ stats.sessionsToday }}</span>
+          </div>
+
+          <!-- Connected Clients -->
+          <div class="flex items-center justify-between">
+            <span class="text-slate-400 text-sm">Connected Clients</span>
+            <span class="text-white font-medium">{{ stats.connectedClients }}</span>
+          </div>
+        </div>
+      </div>
     </div>
 
-    <!-- Memory Stats -->
-    <div class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
-      <div class="flex items-center gap-2 mb-3">
+    <!-- Collapsed State - Show icons only -->
+    <div v-show="isCollapsed" class="space-y-2">
+      <!-- Health indicator -->
+      <div
+        class="bg-slate-800/50 rounded-lg p-3 border border-slate-700/50 flex justify-center"
+        :title="`System: ${health?.overall || 'Unknown'}`"
+      >
+        <i :class="['fas', overallHealthIcon, overallHealthColor]" />
+      </div>
+
+      <!-- Memory indicator -->
+      <div
+        class="bg-slate-800/50 rounded-lg p-3 border border-slate-700/50 flex justify-center"
+        :title="`${observationCount} observations, ${promptCount} prompts`"
+      >
         <i class="fas fa-brain text-purple-400" />
-        <h3 class="text-sm font-semibold text-white">Memory Contents</h3>
       </div>
 
-      <div class="space-y-3">
-        <!-- Observations -->
-        <div class="flex items-center justify-between">
-          <div class="flex items-center gap-2">
-            <i class="fas fa-lightbulb text-amber-400 w-4" />
-            <span class="text-slate-400 text-sm">Observations</span>
-          </div>
-          <span class="text-white font-medium">{{ formatNumber(observationCount) }}</span>
-        </div>
-
-        <!-- Prompts -->
-        <div class="flex items-center justify-between">
-          <div class="flex items-center gap-2">
-            <i class="fas fa-comment text-blue-400 w-4" />
-            <span class="text-slate-400 text-sm">Prompts</span>
-          </div>
-          <span class="text-white font-medium">{{ formatNumber(promptCount) }}</span>
-        </div>
-
-        <!-- Summaries -->
-        <div class="flex items-center justify-between">
-          <div class="flex items-center gap-2">
-            <i class="fas fa-clipboard-list text-green-400 w-4" />
-            <span class="text-slate-400 text-sm">Summaries</span>
-          </div>
-          <span class="text-white font-medium">{{ formatNumber(summaryCount) }}</span>
-        </div>
-      </div>
-    </div>
-
-    <!-- Retrieval Stats -->
-    <div v-if="stats?.retrieval" class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
-      <div class="flex items-center gap-2 mb-3">
+      <!-- Stats indicator -->
+      <div
+        v-if="stats?.retrieval"
+        class="bg-slate-800/50 rounded-lg p-3 border border-slate-700/50 flex justify-center"
+        :title="`${stats.retrieval.TotalRequests} total requests`"
+      >
         <i class="fas fa-search text-cyan-400" />
-        <h3 class="text-sm font-semibold text-white">Retrieval Stats</h3>
-      </div>
-
-      <div class="space-y-3">
-        <!-- Total Requests -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Total Requests</span>
-          <span class="text-white font-medium">{{ formatNumber(stats.retrieval.TotalRequests) }}</span>
-        </div>
-
-        <!-- Observations Served -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Obs Served</span>
-          <span class="text-white font-medium">{{ formatNumber(stats.retrieval.ObservationsServed) }}</span>
-        </div>
-
-        <!-- Search Requests -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Searches</span>
-          <span class="text-white font-medium">{{ formatNumber(stats.retrieval.SearchRequests) }}</span>
-        </div>
-
-        <!-- Context Injections -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Injections</span>
-          <span class="text-white font-medium">{{ formatNumber(stats.retrieval.ContextInjections) }}</span>
-        </div>
-
-        <!-- Verified Stale -->
-        <div v-if="stats.retrieval.VerifiedStale > 0" class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Verified Stale</span>
-          <span class="text-amber-400 font-medium">{{ formatNumber(stats.retrieval.VerifiedStale) }}</span>
-        </div>
-
-        <!-- Deleted Invalid -->
-        <div v-if="stats.retrieval.DeletedInvalid > 0" class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Deleted Invalid</span>
-          <span class="text-red-400 font-medium">{{ formatNumber(stats.retrieval.DeletedInvalid) }}</span>
-        </div>
-      </div>
-    </div>
-
-    <!-- Session Info -->
-    <div v-if="stats" class="bg-slate-800/50 rounded-lg p-4 border border-slate-700/50">
-      <div class="flex items-center gap-2 mb-3">
-        <i class="fas fa-clock text-slate-400" />
-        <h3 class="text-sm font-semibold text-white">Worker Info</h3>
-      </div>
-
-      <div class="space-y-3">
-        <!-- Uptime -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Uptime</span>
-          <span class="text-white font-medium text-xs">{{ stats.uptime }}</span>
-        </div>
-
-        <!-- Sessions Today -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Sessions Today</span>
-          <span class="text-white font-medium">{{ stats.sessionsToday }}</span>
-        </div>
-
-        <!-- Connected Clients -->
-        <div class="flex items-center justify-between">
-          <span class="text-slate-400 text-sm">Connected Clients</span>
-          <span class="text-white font-medium">{{ stats.connectedClients }}</span>
-        </div>
       </div>
     </div>
   </aside>
diff --git a/ui/src/composables/index.ts b/ui/src/composables/index.ts
index 96906d8..39dbd3b 100644
--- a/ui/src/composables/index.ts
+++ b/ui/src/composables/index.ts
@@ -2,3 +2,4 @@ export { useSSE } from './useSSE'
 export { useStats } from './useStats'
 export { useTimeline } from './useTimeline'
 export { useUpdate } from './useUpdate'
+export { useHealth } from './useHealth'
diff --git a/ui/src/composables/useHealth.ts b/ui/src/composables/useHealth.ts
new file mode 100644
index 0000000..edefaaa
--- /dev/null
+++ b/ui/src/composables/useHealth.ts
@@ -0,0 +1,55 @@
+import { ref, onMounted, onUnmounted } from 'vue'
+import type { SelfCheckResponse } from '@/types'
+
+const CHECK_INTERVAL = 30 * 1000 // 30 seconds
+
+export function useHealth() {
+  const health = ref<SelfCheckResponse | null>(null)
+  const loading = ref(false)
+  const error = ref<string | null>(null)
+  let intervalId: ReturnType<typeof setInterval> | null = null
+
+  async function fetchHealth() {
+    loading.value = true
+    error.value = null
+    try {
+      const response = await fetch('/api/selfcheck')
+      if (!response.ok) {
+        throw new Error(`HTTP ${response.status}`)
+      }
+      health.value = await response.json()
+    } catch (e) {
+      error.value = e instanceof Error ? e.message : 'Unknown error'
+      health.value = null
+    } finally {
+      loading.value = false
+    }
+  }
+
+  function startPolling() {
+    fetchHealth()
+    intervalId = setInterval(fetchHealth, CHECK_INTERVAL)
+  }
+
+  function stopPolling() {
+    if (intervalId) {
+      clearInterval(intervalId)
+      intervalId = null
+    }
+  }
+
+  onMounted(() => {
+    startPolling()
+  })
+
+  onUnmounted(() => {
+    stopPolling()
+  })
+
+  return {
+    health,
+    loading,
+    error,
+    refresh: fetchHealth
+  }
+}
diff --git a/ui/src/types/api.ts b/ui/src/types/api.ts
index ec03238..e807f5a 100644
--- a/ui/src/types/api.ts
+++ b/ui/src/types/api.ts
@@ -50,3 +50,16 @@ export interface SSEEvent {
 }
 
 export type FilterType = 'all' | 'observations' | 'summaries' | 'prompts'
+
+export interface ComponentHealth {
+  name: string
+  status: 'healthy' | 'degraded' | 'unhealthy'
+  message?: string
+}
+
+export interface SelfCheckResponse {
+  overall: 'healthy' | 'degraded' | 'unhealthy'
+  version: string
+  uptime: string
+  components: ComponentHealth[]
+}
diff --git a/ui/tsconfig.tsbuildinfo b/ui/tsconfig.tsbuildinfo
index 539068d..ceecad8 100644
--- a/ui/tsconfig.tsbuildinfo
+++ b/ui/tsconfig.tsbuildinfo
@@ -1 +1 @@
-{"root":["./src/main.ts","./src/vite-env.d.ts","./src/components/index.ts","./src/composables/index.ts","./src/composables/usesse.ts","./src/composables/usestats.ts","./src/composables/usetimeline.ts","./src/composables/useupdate.ts","./src/types/api.ts","./src/types/index.ts","./src/types/observation.ts","./src/types/prompt.ts","./src/types/summary.ts","./src/utils/api.ts","./src/utils/formatters.ts","./src/app.vue","./src/components/badge.vue","./src/components/card.vue","./src/components/filtertabs.vue","./src/components/header.vue","./src/components/iconbox.vue","./src/components/observationcard.vue","./src/components/projectfilter.vue","./src/components/promptcard.vue","./src/components/sidebar.vue","./src/components/statscards.vue","./src/components/summarycard.vue","./src/components/timeline.vue"],"version":"5.7.3"}
\ No newline at end of file
+{"root":["./src/main.ts","./src/vite-env.d.ts","./src/components/index.ts","./src/composables/index.ts","./src/composables/usehealth.ts","./src/composables/usesse.ts","./src/composables/usestats.ts","./src/composables/usetimeline.ts","./src/composables/useupdate.ts","./src/types/api.ts","./src/types/index.ts","./src/types/observation.ts","./src/types/prompt.ts","./src/types/summary.ts","./src/utils/api.ts","./src/utils/formatters.ts","./src/app.vue","./src/components/badge.vue","./src/components/card.vue","./src/components/filtertabs.vue","./src/components/header.vue","./src/components/iconbox.vue","./src/components/observationcard.vue","./src/components/projectfilter.vue","./src/components/promptcard.vue","./src/components/sidebar.vue","./src/components/statscards.vue","./src/components/summarycard.vue","./src/components/timeline.vue"],"version":"5.7.3"}
\ No newline at end of file