diff --git a/apps/x/apps/renderer/src/App.tsx b/apps/x/apps/renderer/src/App.tsx
index 3e8634a0..6001f48b 100644
--- a/apps/x/apps/renderer/src/App.tsx
+++ b/apps/x/apps/renderer/src/App.tsx
@@ -54,6 +54,7 @@ import { Button } from "@/components/ui/button"
 import { Toaster } from "@/components/ui/sonner"
 import { stripKnowledgePrefix, toKnowledgePath, wikiLabel } from '@/lib/wiki-links'
 import { splitFrontmatter, joinFrontmatter } from '@/lib/frontmatter'
+import { extractConferenceLink } from '@/lib/calendar-event'
 import { OnboardingModal } from '@/components/onboarding'
 import { CommandPalette, type CommandPaletteContext, type CommandPaletteMention } from '@/components/search-dialog'
 import { TrackModal } from '@/components/track-modal'
@@ -3120,10 +3121,7 @@ function App() {
         conferenceData?: { entryPoints?: Array<{ entryPointType?: string; uri?: string }> }
       }
       if (!e || typeof e !== 'object') return
-      // Order matches extractConferenceLink in calendar-block.tsx:
-      // entryPoints first (covers Zoom/integrated providers), then hangoutLink (Google Meet shortcut).
-      const conferenceLink = e.conferenceData?.entryPoints?.find(p => p.entryPointType === 'video')?.uri
-        || e.hangoutLink
+      const conferenceLink = extractConferenceLink(e as Record<string, unknown>)
       if (openMeeting && conferenceLink) {
         window.open(conferenceLink, '_blank')
       } else if (openMeeting) {
diff --git a/apps/x/apps/renderer/src/extensions/calendar-block.tsx b/apps/x/apps/renderer/src/extensions/calendar-block.tsx
index 9f0eec02..ecc5403d 100644
--- a/apps/x/apps/renderer/src/extensions/calendar-block.tsx
+++ b/apps/x/apps/renderer/src/extensions/calendar-block.tsx
@@ -3,6 +3,7 @@ import { ReactNodeViewRenderer, NodeViewWrapper } from '@tiptap/react'
 import { X, Calendar, Video, ChevronDown, Mic } from 'lucide-react'
 import { blocks } from '@x/shared'
 import { useState, useEffect, useRef } from 'react'
+import { extractConferenceLink } from '../lib/calendar-event'
 
 function formatTime(dateStr: string): string {
   const d = new Date(dateStr)
@@ -40,25 +41,6 @@ function getTimeRange(event: blocks.CalendarEvent): string {
   return `${startTime} \u2013 ${endTime}`
 }
 
-/**
- * Extract a video conference link from raw Google Calendar event JSON.
- * Checks conferenceData.entryPoints (video type), hangoutLink, then falls back
- * to conferenceLink if already set.
- */
-function extractConferenceLink(raw: Record<string, unknown>): string | undefined {
-  // Check conferenceData.entryPoints for video entry
-  const confData = raw.conferenceData as { entryPoints?: { entryPointType?: string; uri?: string }[] } | undefined
-  if (confData?.entryPoints) {
-    const video = confData.entryPoints.find(ep => ep.entryPointType === 'video')
-    if (video?.uri) return video.uri
-  }
-  // Check hangoutLink (Google Meet shortcut)
-  if (typeof raw.hangoutLink === 'string') return raw.hangoutLink
-  // Fall back to conferenceLink if present
-  if (typeof raw.conferenceLink === 'string') return raw.conferenceLink
-  return undefined
-}
-
 interface ResolvedEvent {
   event: blocks.CalendarEvent
   loaded: blocks.CalendarEvent | null
diff --git a/apps/x/apps/renderer/src/lib/calendar-event.ts b/apps/x/apps/renderer/src/lib/calendar-event.ts
new file mode 100644
index 00000000..b7ace75a
--- /dev/null
+++ b/apps/x/apps/renderer/src/lib/calendar-event.ts
@@ -0,0 +1,15 @@
+/**
+ * Extract a video conference link from raw Google Calendar event JSON.
+ * Checks conferenceData.entryPoints (video type), hangoutLink, then falls back
+ * to a top-level conferenceLink if present.
+ */
+export function extractConferenceLink(raw: Record<string, unknown>): string | undefined {
+  const confData = raw.conferenceData as { entryPoints?: { entryPointType?: string; uri?: string }[] } | undefined
+  if (confData?.entryPoints) {
+    const video = confData.entryPoints.find(ep => ep.entryPointType === 'video')
+    if (video?.uri) return video.uri
+  }
+  if (typeof raw.hangoutLink === 'string') return raw.hangoutLink
+  if (typeof raw.conferenceLink === 'string') return raw.conferenceLink
+  return undefined
+}
diff --git a/apps/x/packages/core/src/knowledge/notify_calendar_meetings.ts b/apps/x/packages/core/src/knowledge/notify_calendar_meetings.ts
index 5e3aa68b..cca9d230 100644
--- a/apps/x/packages/core/src/knowledge/notify_calendar_meetings.ts
+++ b/apps/x/packages/core/src/knowledge/notify_calendar_meetings.ts
@@ -48,7 +48,12 @@ async function loadState(): Promise<NotificationState> {
 }
 
 async function saveState(state: NotificationState): Promise<void> {
-    await fs.writeFile(STATE_FILE, JSON.stringify(state, null, 2), "utf-8");
+    // Write to a sibling tmp file then rename so a mid-write crash can't leave
+    // the JSON corrupt — a corrupt state file would make every event in the
+    // 90s notify window re-fire on next start.
+    const tmp = `${STATE_FILE}.tmp`;
+    await fs.writeFile(tmp, JSON.stringify(state, null, 2), "utf-8");
+    await fs.rename(tmp, STATE_FILE);
 }
 
 function gcState(state: NotificationState): NotificationState {