diff --git a/src/CLAUDE.md b/src/CLAUDE.md
index f14ba685..5cfcac39 100644
--- a/src/CLAUDE.md
+++ b/src/CLAUDE.md
@@ -69,6 +69,7 @@ export const FlowSessionRepo = { createFlowSession, /* other methods */ }
 - Components → React Query Hooks → API Services → Repository Layer
 - Never skip layers or access repositories directly from hooks
 - Never call Tauri commands directly from hooks
+- **CRITICAL: Never call API services directly from components** - always use React Query hooks
 
 ### State Management Priority
 
@@ -86,8 +87,16 @@ const { data: flowSessions } = useGetFlowSessions()
 // ✅ Good: UI state with Zustand
 const { isMenuOpen, toggleMenu } = useUIStore()
 
+// ✅ Good: Mutations with React Query
+const updateMutation = useUpdatePreferences()
+updateMutation.mutate(data)
+
 // ❌ Bad: Database state with Zustand
 const { flowSessions, fetchFlowSessions } = useFlowSessionStore() // Don't do this
+
+// ❌ Bad: Direct API calls from components
+import { slackApi } from '@/api/ebbApi/slackApi'
+await slackApi.updatePreferences(data) // Don't do this - use React Query hook instead
 ```
 
 ## Tauri Command Patterns
@@ -238,13 +247,25 @@ export default function MyPage() {
 
 ### Data Fetching in Components
 
-Always use React Query hooks:
+Always use React Query hooks - never call API services directly:
 
 ```typescript
-import { useGetFlowSessions } from '../api/hooks/useFlowSession'
+import { useGetFlowSessions, useUpdateFlowSession } from '../api/hooks/useFlowSession'
 
 export default function FlowSessionList() {
   const { data: sessions, isLoading, error } = useGetFlowSessions()
+  const updateMutation = useUpdateFlowSession()
+  
+  const handleUpdate = (id: string, data: UpdateData) => {
+    updateMutation.mutate({ id, data }, {
+      onSuccess: () => {
+        toast.success('Updated successfully')
+      },
+      onError: (error) => {
+        logAndToastError('Update failed', error)
+      }
+    })
+  }
   
   if (isLoading) return <div>Loading...</div>
   if (error) return <div>Error loading sessions</div>
@@ -252,13 +273,31 @@ export default function FlowSessionList() {
   return (
     <div>
       {sessions?.map(session => (
-        <div key={session.id}>{session.objective}</div>
+        <div key={session.id}>
+          {session.objective}
+          <button 
+            onClick={() => handleUpdate(session.id, newData)}
+            disabled={updateMutation.isPending}
+          >
+            {updateMutation.isPending ? 'Updating...' : 'Update'}
+          </button>
+        </div>
       ))}
     </div>
   )
 }
 ```
 
+**❌ Never do this in components:**
+```typescript
+// DON'T import and call API services directly
+import { FlowSessionApi } from '../api/ebbApi/flowSessionApi'
+
+const handleUpdate = async () => {
+  await FlowSessionApi.updateFlowSession(id, data) // Wrong - violates layer pattern
+}
+```
+
 ## File Organization
 
 - `src/api/hooks/`: React Query hooks (Layer 1)
diff --git a/src/api/hooks/useSlack.ts b/src/api/hooks/useSlack.ts
index 8f7074da..f1874c05 100644
--- a/src/api/hooks/useSlack.ts
+++ b/src/api/hooks/useSlack.ts
@@ -1,5 +1,5 @@
-import { useQuery } from '@tanstack/react-query'
-import { slackApi } from '../ebbApi/slackApi'
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
+import { slackApi, SlackPreferences } from '../ebbApi/slackApi'
 
 const slackKeys = {
   all: ['slack'] as const,
@@ -16,3 +16,15 @@ export const useSlackStatus = () => {
     retry: false,
   })
 }
+
+export const useUpdateSlackPreferences = () => {
+  const queryClient = useQueryClient()
+
+  return useMutation({
+    mutationFn: (preferences: SlackPreferences) => slackApi.updatePreferences(preferences),
+    onSuccess: () => {
+      // Invalidate and refetch slack status to get updated preferences
+      queryClient.invalidateQueries({ queryKey: slackKeys.status() })
+    },
+  })
+}
diff --git a/src/components/SlackFocusToggle.tsx b/src/components/SlackFocusToggle.tsx
index 37b26cef..377124b5 100644
--- a/src/components/SlackFocusToggle.tsx
+++ b/src/components/SlackFocusToggle.tsx
@@ -1,7 +1,8 @@
-import { useState } from 'react'
+import { useState, useEffect } from 'react'
 import { SlackIcon } from '@/components/icons/SlackIcon'
 import { Switch } from '@/components/ui/switch'
 import { Button } from '@/components/ui/button'
+import { Input } from '@/components/ui/input'
 import {
   Dialog,
   DialogContent,
@@ -9,7 +10,7 @@ import {
   DialogTitle,
 } from '@/components/ui/dialog'
 import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip'
-import { useSlackStatus } from '@/api/hooks/useSlack'
+import { useSlackStatus, useUpdateSlackPreferences } from '@/api/hooks/useSlack'
 import { logAndToastError } from '@/lib/utils/ebbError.util'
 import { initiateSlackOAuth } from '@/lib/utils/slackAuth.util'
 import { Skeleton } from '@/components/ui/skeleton'
@@ -29,7 +30,18 @@ export function SlackFocusToggle({ slackSettings, onSlackSettingsChange }: Slack
   const navigate = useNavigate()
 
   const [showDialog, setShowDialog] = useState(false)
+  const [customStatusText, setCustomStatusText] = useState('')
+  const [customStatusEmoji, setCustomStatusEmoji] = useState('')
   const { data: slackStatus, isLoading: slackStatusLoading } = useSlackStatus()
+  const updatePreferencesMutation = useUpdateSlackPreferences()
+
+  // Load current preferences when dialog opens
+  useEffect(() => {
+    if (showDialog && slackStatus?.preferences) {
+      setCustomStatusText(slackStatus.preferences.custom_status_text || '')
+      setCustomStatusEmoji(slackStatus.preferences.custom_status_emoji || '')
+    }
+  }, [showDialog, slackStatus?.preferences])
 
   const handleSlackToggle = async () => {
     if (!user) {
@@ -60,6 +72,31 @@ export function SlackFocusToggle({ slackSettings, onSlackSettingsChange }: Slack
     }
   }
 
+  const validateEmoji = (emoji: string): boolean => {
+    if (!emoji) return true // Empty is valid
+    return emoji.startsWith(':') && emoji.endsWith(':') && emoji.length > 2
+  }
+
+  const handleSavePreferences = async () => {
+    if (!validateEmoji(customStatusEmoji)) {
+      toast.error('Emoji must be in format :emoji_name: (e.g., :brain:)')
+      return
+    }
+
+    updatePreferencesMutation.mutate({
+      custom_status_text: customStatusText,
+      custom_status_emoji: customStatusEmoji
+    }, {
+      onSuccess: () => {
+        toast.success('Slack preferences updated')
+        setShowDialog(false)
+      },
+      onError: (error) => {
+        logAndToastError('Failed to update Slack preferences', error)
+      }
+    })
+  }
+
   const navigateToSettings = () => {
     setShowDialog(false)
     // Navigate to settings page - you may need to adjust this based on your routing
@@ -128,6 +165,45 @@ export function SlackFocusToggle({ slackSettings, onSlackSettingsChange }: Slack
               />
             </div>
 
+            <div className="space-y-4">
+              <div className="space-y-2">
+                <label htmlFor="custom-status-text" className="text-sm font-medium">Custom Status Text</label>
+                <Input
+                  id="custom-status-text"
+                  value={customStatusText}
+                  onChange={(e) => setCustomStatusText(e.target.value)}
+                  placeholder="e.g., In a focus session"
+                  maxLength={100}
+                />
+                <div className="text-xs text-muted-foreground">
+                  Status message shown during focus sessions
+                </div>
+              </div>
+
+              <div className="space-y-2">
+                <label htmlFor="custom-status-emoji" className="text-sm font-medium">Custom Status Emoji</label>
+                <Input
+                  id="custom-status-emoji"
+                  value={customStatusEmoji}
+                  onChange={(e) => setCustomStatusEmoji(e.target.value)}
+                  placeholder="e.g., :brain:"
+                  maxLength={50}
+                  className={!validateEmoji(customStatusEmoji) ? 'border-red-500' : ''}
+                />
+                <div className="text-xs text-muted-foreground">
+                  Emoji in format :emoji_name: (e.g., :brain:, :rocket:)
+                </div>
+              </div>
+
+              <Button 
+                onClick={handleSavePreferences} 
+                className="w-full"
+                disabled={updatePreferencesMutation.isPending}
+              >
+                {updatePreferencesMutation.isPending ? 'Saving...' : 'Save Preferences'}
+              </Button>
+            </div>
+
             <div className="pt-4 border-t">
               <Button 
                 variant="outline"