diff --git a/apps/api/src/broker/expand.ts b/apps/api/src/broker/expand.ts
index e052b23..63888b2 100644
--- a/apps/api/src/broker/expand.ts
+++ b/apps/api/src/broker/expand.ts
@@ -64,6 +64,8 @@ export interface CalendarOccurrence {
   allDay: boolean
   location: string | null
   description: string | null
+  /** True when this occurrence belongs to a recurring series (has RRULE). False for single events. */
+  hasRrule: boolean
 }
 
 /**
@@ -219,8 +221,11 @@ export function expandOccurrences(
 
   const occurrences: CalendarOccurrence[] = []
 
+  // Capture once — used in both the non-recurring and recurring branches to populate hasRrule.
+  const isRecurring = event.isRecurring()
+
   // --- 4. Non-recurring event: single occurrence check ---
-  if (!event.isRecurring()) {
+  if (!isRecurring) {
     if (dtstart.compare(rangeStart) >= 0 && dtstart.compare(rangeEnd) < 0) {
       // Use ICAL.Event.endDate which derives end from DTEND, or DTSTART+DURATION, or sensible default.
       // Do NOT use getFirstPropertyValue('dtend') directly — events with only DURATION set return null,
@@ -253,6 +258,7 @@ export function expandOccurrences(
         allDay,
         location: event.location ?? null,
         description: event.description ?? null,
+        hasRrule: isRecurring, // always false in the non-recurring branch
       })
     }
     return occurrences
@@ -299,6 +305,7 @@ export function expandOccurrences(
       allDay,
       location: event.location ?? null,
       description: event.description ?? null,
+      hasRrule: isRecurring, // always true in the recurring branch
     })
   }